Monitoring of total ammoniacal concentration in blood

• US 6,219,567 B1
• Filed: 06/21/1999
• Issued: 04/17/2001
• Est. Priority Date: 06/21/1999
• Status: Expired due to Term

• Current Assignee: Cardiox Corporation
• Original Assignee: Cardiox Corporation
• Inventors: Eggers, Philip E., Eggers, Eric A., Eggers, Andrew R., Huntley, Scott P.
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/337,382
• Time in Patent Office: 666 Days
• Field of Search: 600/309, 600/310, 600/311, 600/312, 600/317, 600/322, 600/329, 600/341, 600/345, 600/347, 600/348, 600/364, 600/353
• US Class Current: 600/322
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G01N 33/84 involving inorganic compounds or pH

Abstract

Total ammoniacal concentration (TAC) in blood is measured and displayed on a repetitive basis by a controller driven sensor arrangement which may be utilized either with a catheter structure or with a bypass system. The catheter based sensors may be employed with a peripheral region of the vascular system of the body. Repetitive measurements are carried out and these measurements are subjected to a moving average filtering procedure, whereupon the filtered TAC values are displayed numerically and graphically. The controller functions to compute the rate-of-rise of TAC and compares that value with a threshold rate-of-rise valuation which is inputted by the practitioner. Threshold values for TAC also may be inputted and the system not only provides alarm warnings for threshold excursions in TAC above threshold or excursions in rate-of-rise of TAC above threshold but also provides a visual cuing as a warning that TAC is elevating from one filtered measurement to the next.

Claims

1. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value and being within a vascular system directing a bloodstream extending to peripheral regions of a body remotely disposed from the heart, comprising:

a blood by-passing assembly including;

a blood transport conduit extending from a proximal end to a distal tip, said distal tip being positionable in blood exchange relationship within said bloodstream at one of said peripheral regions,

a blood sampling chamber coupled in blood exchange communication with said blood transport conduit proximal end, and

a pump coupled with said sampling chamber and actuable to urge the transport of blood from said bloodstream into said sampling chamber;

an ammoniacal component sensor assembly having an ammoniacal component forward assembly located within said sampling chamber and contactable with blood within said sampling chamber, said sensor assembly being controllable to provide an ammoniacal sensor output; and

a controller, controllable to control said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving a sequence of ammoniacal component parameters under said control, responsive to said ammoniacal component parameters to derive total ammoniacal concentration values and display signals corresponding therewith; and

a display assembly responsive to said display signals to provide visibly perceptible information outputs corresponding therewith.

2. The system of claim 1 in which:

said controller includes an inputting assembly manually controllable to provide a total ammoniacal concentration threshold value;

said controller is responsive to said total ammoniacal concentration threshold value to retain it in memory;

said controller is responsive to a given said total ammoniacal concentration value and to said memory retained total ammoniacal concentration threshold value to derive an alarm signal when said given total ammoniacal concentration value is greater than said memory retained total ammoniacal concentration threshold value; and

said display assembly is responsive to said alarm signal to provide a perceptible alarm output.

3. The system of claim 1 in which:

said controller includes an inputting assembly manually controllable to provide a rate of change of total ammoniacal concentration threshold value;

said controller is responsive to a given said total ammoniacal concentration value and to a previous such concentration value to derive a current total ammoniacal concentration rate of change value, and is responsive to said rate of change of total ammoniacal concentration threshold value and to said current total ammoniacal concentration rate of change value to derive an alarm signal when said current total ammoniacal concentration rate of change value is greater than or equal to said rate of change of total ammoniacal concentration threshold value, and

said display assembly is responsive to said alarm signal to provide a perceptible alarm output.

4. The system of claim 1 in which:

said controller is responsive to a first said total ammoniacal concentration value and is responsive to a second said total ammoniacal concentration value derived subsequent to said first total ammoniacal concentration value, and is responsive to derive a warning signal when said second total ammoniacal concentration value is greater than said first total ammoniacal concentration value; and

said display assembly is responsive to said warning signal to provide a perceptible warning output.

5. The system of claim 1 in which:

said controller includes a time clock providing a time output;

said controller is responsive to said real time output with the contemporaneous derived occurrence of a said display signal to derive a time associated display signal; and

said display assembly is responsive to each of a sequence said of said time associated display signals to produce a trend defining graphics display thereof.

6. The system of claim 1 in which:

said controller is responsive to retain each said total ammoniacal concentration value in memory, is responsive to a given said total ammoniacal concentration and n−

1 memory retained previously occurring said values of total ammoniacal concentration to derive a filtered total ammoniacal concentration value representing the moving average filtering of n values of said total ammoniacal concentration value and provided as said display signal.

7. The system of claim 1 in which:

said ammoniacal component forward assembly comprises;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood;

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with said blood within said sampling chamber; and

said ammoniacal component sensor includes;

a transmission assembly for conveying said ammoniacal sensor output as a signal corresponding with said output condition.

8. The system of claim 7 in which:

said ammoniacal component is ammonia (NH₃);

said membrane is permiable to gaseous ammonia;

said reactor is a gaseous ammonia sensitive dye;

said transmission assembly is a fiberoptic colorimetric measurement assembly which quantiates a change in color of the dye and is mounted within said first sensor channel; and

said controller additionally is responsive to said pH value to derive said total ammoniacal concentration value.

9. The system of claim 7 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

10. The system of claim 7 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises an amperometric assembly coupled with said first and second electrodes.

11. The system of claim 7 wherein:

said reactor comprises an ammoniacal component-sensitive fluorescent material having a fluorescence intensity as said output condition; and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying said fluorescence intensity as said ammoniacal sensor output.

12. The system of claim 7 wherein

said reactor comprises an ammoniacal component-sensitive fluorescent material stimulatable into fluorescence, the rate of quenching of said fluorescence being said output condition;

and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying resultant generated light as said ammoniacal sensor output.

13. The system of claim 7 in which said ammoniacal component reactor is configured as a Schottky diode array having a conductive polymer responsive to said ammoniacal component to effect a forward bias alteration as said ammoniacal sensor output.

14. The system of claim 7 in which said ammoniacal component sensor forward assembly is configured as a Schottky diode array having a conductive polymer responsive to said ammoniacal component to effect a forward bias alteration as said ammoniacal sensor output.

15. The system of claim 7 in which:

said ammoniacal component is ammonia (NH₃);

said ammoniacal component sensor comprises a fiberoptic assembly having a forward face as said forward assembly in blood contacting position within said blood sampling chamber, said forward face being adapted for direct light exchange communication with said blood within said sampling chamber, said fiberoptic assembly being extensible to a light source and photoresponsive assembly for deriving said ammoniacal sensor output; and

said controller is additionally responsive to said pH value to derive said total ammoniacal concentration value.

16. The system of claim 1 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from a proximal end to a fiberoptic tip forming a component of said forward assembly of said ammoniacal component sensor assembly;

a membrane coupled with said fiberoptic assembly at said forward assembly, permeable to said ammoniacal component, having an outer surface in blood contacting position within said blood sampling chamber, and an inner surface spaced from said fiberoptic tip to define an equilibriation cavity; and

including a light transmission and reception assembly optically coupled with said fiberoptic assembly at said proximal end and controllable to derive said ammoniacal sensor output with respect to ammoniacal component at said equilibrium cavity.

17. The system of claim 1 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from a proximal end to said forward assembly and having a forward light transmission leg and a return leg spaced from said forward light transmission leg to define a gap situated at said forward assembly; and

a membrane permeable to said ammoniacal component, having an outer surface in blood contacting position within said blood sampling chamber, said membrane sealingly extending about said gap to define an equilibriation cavity.

18. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith;

said controller including an inputting assembly manually controllable to provide a total ammoniacal concentration threshold value, is further responsive to said total ammoniacal concentration threshold value to retain it in memory, and said controller is responsive to a given said total ammoniacal concentration value and to said memory retained total ammoniacal concentration threshold value to derive an alarm signal when said given total ammoniacal concentration value is greater than said memory retained total ammoniacal concentration threshold value; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and is responsive to said alarm signal to provide a perceptible alarm output.

19. The system of claim 18 in which:

said ammoniacal component responsive forward assembly comprises;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood;

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with blood within said bloodstream; and

said ammoniacal component sensor includes;

a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output.

20. The system of claim 19 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

21. The system of claim 19 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises an amperometric assembly coupled with said first and second electrodes.

22. The system of claim 19 wherein:

said reactor comprises an ammoniacal component-sensitive fluorescent material having a fluorescence intensity as said output condition; and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying said fluorescence intensity as said ammoniacal sensor output.

23. The system of claim 19 wherein

said reactor comprises an ammoniacal component-sensitive fluorescent material stimulatable into fluorescence, the rate of quenching of said fluorescence being said output condition;

and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying resultant generated light as said ammoniacal sensor output.

24. The system of claim 18 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending within said first sensor channel from said catheter assembly proximal end region to a fiberoptic tip located at and forming a component of said forward assembly;

a membrane forming a component of said forward assembly, permeable to said ammoniacal component, having an outer surface contactable with said bloodstream and an inner surface spaced from said fiberoptic tip to define an equilibriation cavity; and

including a light transmission and reception assembly optically coupled with said fiberoptic assembly at said proximal end region and controllable to derive said ammoniacal sensor output with respect to ammoniacal component at said equilibriation cavity.

25. The system of claim 24 in which said membrane inner surface is light reflecting.

26. The system of claim 18 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to a fiberoptic tip at said forward assembly, including an outer surface extending inwardly from said fiberoptic tip;

an end plug impervious to blood having an inwardly disposed surface spaced from said fiberoptic tip to define the length of an equilibriation cavity;

a membrane permeable to said ammoniacal component having an outer surface contactable with said bloodstream, said membrane extending sealingly about said outer surface and said end plug to define the sides of said equilibration cavity.

27. The system of claim 26 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to said forward assembly and having a forward light transmission leg and a return transmission leg spaced from said forward light transmission leg to define a gap situated at said forward assembly; and

a membrane permeable to said ammoniacal component, having an outer surface contactable with said bloodstream, said membrane sealingly extending about said gap to define an equilibration cavity.

28. The system of claim 18 in which:

said ammoniacal component is ammonia (NH₃);

said ammoniacal sensor output is provided in correspondence with the concentration of ammonia gas (NH₃) in said bloodstream; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

29. The system of claim 18 in which:

said catheter assembly includes a second sensor channel extending from said proximal region to said measurement region;

including a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃); and

said controller is responsive to control said pH sensor, and is responsive to said pH output to derive aid total ammoniacal concentration value.

30. The system of claim 29 in which:

said pH sensor forward assembly includes a membrane impervious to blood and permeable to hydrogen ions and including a pH indicator located for response to said hydrogen ions; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

31. The system of claim 18 in which:

said catheter assembly has an outer principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

32. The system of claim 31 in which said outer principal cross-sectional dimension is within a range of about 0.010 inch to 0.060 inch.

33. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region of said vascular system;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, said controller including an inputting assembly manually controllable to provide a rate of change of total ammoniacal concentration threshold value, said controller being responsive to a given said total ammoniacal concentration value and to a previous such concentration value to derive a current total ammoniacal concentration rate of change value, and is responsive to said rate of change of total ammoniacal concentration threshold value and to said current total ammoniacal concentration rate of change value to derive an alarm signal when said current total ammoniacal concentration rate of change value is greater than or equal to said rate of change of total ammoniacal concentration threshold value, and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and being responsive to said alarm signal to provide a perceptible alarm output.

34. The system of claim 33 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending within said first sensor channel from said catheter assembly proximal end region to a fiberoptic tip located at and forming a component of said forward assembly;

a membrane forming a component of said forward assembly, permeable to said ammoniacal component, having an outer surface contactable with said bloodstream and an inner surface spaced from said fiberoptic tip to define an equilibriation cavity; and

including a light transmission and reception assembly optically coupled with said fiberoptic assembly at said proximal end region and controllable to derive said ammoniacal sensor output with respect to ammoniacal component at said equilibriation cavity.

35. The system of claim 34 in which said membrane inner surface is light reflecting.

36. The system of claim 33 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to a fiberoptic tip at said forward assembly, including an outer surface extending inwardly from said fiberoptic tip;

an end plug impervious to blood having an inwardly disposed surface spaced from said fiberoptic tip to define the length of an equilibriation cavity;

a membrane permeable to said ammoniacal component having an outer surface contactable with said bloodstream, said membrane extending sealingly about said outer surface and said end plug to define the sides of said equilibration cavity.

37. The system of claim 33 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to said forward assembly and having a forward light transmission leg and a return transmission leg spaced from said forward light transmission leg to define a gap situated at said forward assembly; and

a membrane permeable to said ammoniacal component, having an outer surface contactable with said bloodstream, said membrane sealingly extending about said gap to define an equilibration cavity.

38. The system of claim 33 in which:

said ammoniacal component is ammonia (NH₃);

said ammoniacal sensor output is provided in correspondence with the concentration of ammonia gas (NH₃) in said bloodstream; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

39. The system of claim 33 in which:

said catheter assembly includes a second sensor channel extending from said proximal region to said measurement region;

including a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃); and

said controller is responsive to control said pH sensor, and is responsive to said pH output to derive said total ammoniacal concentration value.

40. The system of claim 39 in which:

said pH sensor forward assembly includes a membrane impervious to blood and permeable to hydrogen ions and including a pH indicator located for response to said hydrogen ions; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

41. The system of claim 33 in which:

said catheter assembly has an outer principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

42. The system of claim 41 in which said outer principal cross-sectional dimension is within a range of about 0.010 inch to 0.060 inch.

43. The system of claim 33 in which:

said ammoniacal component responsive forward assembly comprises;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood;

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with blood within said bloodstream; and

said ammoniacal component sensor includes;

a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output.

44. The system of claim 43 wherein:

said reactor comprises an ammoniacal component-sensitive fluorescent material having a fluorescence intensity as said output condition; and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying said fluorescence intensity as said ammoniacal sensor output.

45. The system of claim 43 wherein

said reactor comprises an ammoniacal component-sensitive fluorescent material stimulatable into fluorescence, the rate of quenching of said fluorescence being said output condition;

and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying resultant generated light as said ammoniacal sensor output.

46. The system of claim 43 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

47. The system of claim 43 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

48. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, said controller being responsive to a first said total ammoniacal concentration value and is responsive to a second said total ammoniacal concentration value derived subsequent to said first ammoniacal concentration value, and is responsive to derive a warning signal when said second total ammoniacal concentration value is greater than said first total ammoniacal concentration value; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and being responsive to said warning signal to provide a perceptible warning output.

49. The system of claim 48 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending within said first sensor channel from said catheter assembly proximal end region to a fiberoptic tip located at and forming a component of said forward assembly;

a membrane forming a component of said forward assembly, permeable to said ammoniacal component, having an outer surface contactable with said bloodstream and an inner surface spaced from said fiberoptic tip to define an equilibriation cavity; and

including a light transmission and reception assembly optically coupled with said fiberoptic assembly at said proximal end region and controllable to derive said ammoniacal sensor output with respect to ammoniacal component at said equilibriation cavity.

50. The system of claim 49 in which said membrane inner surface is light reflecting.

51. The system of claim 48 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to a fiberoptic tip at said forward assembly, including an outer surface extending inwardly from said fiberoptic tip;

an end plug impervious to blood having an inwardly disposed surface spaced from said fiberoptic tip to define the length of an equilibriation cavity;

a membrane permeable to said ammoniacal component having an outer surface contactable with said bloodstream, said membrane extending sealingly about said outer surface and said end plug to define the sides of said equilibration cavity.

52. The system of claim 48 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to said forward assembly and having a forward light transmission leg and a return transmission leg spaced from said forward light transmission leg to define a gap situated at said forward assembly; and

a membrane permeable to said ammoniacal component, having an outer surface contactable with said bloodstream, said membrane sealingly extending about said gap to define an equilibration cavity.

53. The system of claim 48 in which:

said ammoniacal component is ammonia (NH₃);

said ammoniacal sensor output is provided in correspondence with the concentration of ammonia gas (NH₃) in said bloodstream; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

54. The system of claim 48 in which:

said catheter assembly includes a second sensor channel extending from said proximal region to said measurement region;

including a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃); and

said controller is responsive to control said pH sensor, and is responsive to said pH output t o derive said total ammoniacal concentration value.

55. The system of claim 54 in which:

said pH sensor forward assembly includes a membrane impervious to blood and permeable to hydrogen ions and including a pH indicator located for response to said hydrogen ions; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

56. The system of claim 48 in which:

said catheter assembly has an outer principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

57. The system of claim 56 in which said outer principal cross-sectional dimension is within a range of about 0.010 inch to 0.060 inch.

58. The system of claim 48 in which:

said ammoniacal component responsive forward assembly comprises;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood;

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with blood within said bloodstream; and

said ammoniacal component sensor includes;

a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output.

59. The system of claim 58 wherein:

said reactor comprises an ammoniacal component-sensitive fluorescent material having a fluorescence intensity as said output condition; and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying said fluorescence intensity as said ammoniacal sensor output.

60. The system of claim 58 wherein

said reactor comprises an ammoniacal component-sensitive fluorescent material stimulatable into fluorescence, the rate of quenching of said fluorescence being said output condition;

and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying resultant generated light as said ammoniacal sensor output.

61. The system of claim 58 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

62. The system of claim 58 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

63. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region of said vascular system;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, said controller including a real time clock providing a real time output, and being responsive to said real time output with the contemporaneous derived occurrence of said total ammoniacal concentration value to derive a time associated display signal; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and being responsive to each of a sequence of said time associated display signals to produce a trend defining graphics display thereof.

64. The system of claim 63 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending within said first sensor channel from said catheter assembly proximal end region to a fiberoptic tip located at and forming a component of said forward assembly;

a membrane forming a component of said forward assembly, permeable to said ammoniacal component, having an outer surface contactable with said bloodstream and an inner surface spaced from said fiberoptic tip to define an equilibriation cavity; and

including a light transmission and reception assembly optically coupled with said fiberoptic assembly at said proximal end region and controllable to derive said ammoniacal sensor output with respect to ammoniacal component at said equilibriation cavity.

65. The system of claim 64 in which said membrane inner surface is light reflecting.

66. The system of claim 63 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to a fiberoptic tip at said forward assembly, including an outer surface extending inwardly from said fiberoptic tip;

an end plug impervious to blood having an inwardly disposed surface spaced from said fiberoptic tip to define the length of an equilibriation cavity;

a membrane permeable to said ammoniacal component having an outer surface contactable with said bloodstream, said membrane extending sealingly about said outer surface and said end plug to define the sides of said equilibration cavity.

67. The system of claim 63 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to said forward assembly and having a forward light transmission leg and a return transmission leg spaced from said forward light transmission leg to define a gap situated at said forward assembly; and

a membrane permeable to said ammoniacal component, having an outer surface contactable with said bloodstream, said membrane sealingly extending about said gap to define an equilibration cavity.

68. The system of claim 63 in which:

said ammoniacal component is ammonia (NH₃);

said ammoniacal sensor output is provided in correspondence with the concentration of ammonia gas (NH₃) in said bloodstream; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

69. The system of claim 63 in which:

said catheter assembly includes a second sensor channel extending from said proximal region to said measurement region;

including a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃); and

said controller is responsive to control said pH sensor, and is responsive to said pH output to derive said total ammoniacal concentration value.

70. The system of claim 69 in which:

said pH sensor forward assembly includes a membrane impervious to blood and permeable to hydrogen ions and including a pH indicator located for response to said hydrogen ions; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

71. The system of claim 63 in which:

said catheter assembly has an outer principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

72. The system of claim 71 in which said outer principal cross-sectional dimension is within a range of about 0.010 inch to 0.060 inch.

73. The system of claim 63 in which:

said ammoniacal component responsive forward assembly comprises;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood;

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with blood within said bloodstream; and

said ammoniacal component sensor includes;

a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output.

74. The system of claim 73 wherein:

said reactor comprises an ammoniacal component-sensitive fluorescent material having a fluorescence intensity as said output condition; and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying said fluorescence intensity as said ammoniacal sensor output.

75. The system of claim 73 wherein

said reactor comprises an ammoniacal component-sensitive fluorescent material stimulatable into fluorescence, the rate of quenching of said fluorescence being said output condition;

and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying resultant generated light as said ammoniacal sensor output.

76. The system of claim 73 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

77. The system of claim 73 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

78. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, said controller being responsive to retain each said total ammoniacal concentration value in memory, being responsive to a given said total ammoniacal concentration and n−

1 memory retained previously occurring said values of total ammoniacal concentration to derive a filtered total ammoniacal concentration value representing the moving average filtering of n values of said total ammoniacal concentration value and provided as said display signal; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith.

79. The system of claim 78 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending within said first sensor channel from said catheter assembly proximal end region to a fiberoptic tip located at and forming a component of said forward assembly;

a membrane forming a component of said forward assembly, permeable to said ammoniacal component, having an outer surface contactable with said bloodstream and an inner surface spaced from said fiberoptic tip to define an equilibriation cavity; and

including a light transmission and reception assembly optically coupled with said fiberoptic assembly at said proximal end region and controllable to derive said ammoniacal sensor output with respect to ammoniacal component at said equilibriation cavity.

80. The system of claim 79 in which said membrane inner surface is light reflecting.

81. The system of claim 78 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to a fiberoptic tip at said forward assembly, including an outer surface extending inwardly from said fiberoptic tip;

an end plug impervious to blood having an inwardly disposed surface spaced from said fiberoptic tip to define the length of an equilibriation cavity;

a membrane permeable to said ammoniacal component having an outer surface contactable with said bloodstream, said membrane extending sealingly about said outer surface and said end plug to define the sides of said equilibration cavity.

82. The system of claim 78 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to said forward assembly and having a forward light transmission leg and a return transmission leg spaced from said forward light transmission leg to define a gap situated at said forward assembly; and

a membrane permeable to said ammoniacal component, having an outer surface contactable with said bloodstream, said membrane sealingly extending about said gap to define an equilibration cavity.

83. The system of claim 78 in which:

said ammoniacal component is ammonia (NH₃);

said ammoniacal sensor output is provided in correspondence with the concentration of ammonia gas (NH₃) in said bloodstream; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

84. The system of claim 78 in which:

said catheter assembly includes a second sensor channel extending from said proximal region to said measurement region;

including a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃); and

said controller is responsive to control said pH sensor, and is responsive to said pH output to derive said total ammoniacal concentration value.

85. The system of claim 84 in which:

said pH sensor forward assembly includes a membrane impervious to blood and permeable to hydrogen ions and including a pH indicator located for response to said hydrogen ions; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

86. The system of claim 78 in which:

said catheter assembly has an outer principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

87. The system of claim 86 in which said outer principal cross-sectional dimension is within a range of about 0.010 inch to 0.060 inch.

88. The system of claim 78 in which:

said ammoniacal component responsive forward assembly comprises;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood;

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with blood within said bloodstream; and

said ammoniacal component sensor includes;

a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output.

89. The system of claim 88 wherein:

said reactor comprises an ammoniacal component-sensitive fluorescent material having a fluorescence intensity as said output condition; and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying said fluorescence intensity as said ammoniacal sensor output.

90. The system of claim 88 wherein

said reactor comprises an ammoniacal component-sensitive fluorescent material stimulatable into fluorescence, the rate of quenching of said fluorescence being said output condition;

and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying resultant generated light as said ammoniacal sensor output.

91. The system of claim 88 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

92. The system of claim 88 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

93. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, said controller including a time clock providing a time output;

said controller is responsive to said time output with the corresponding occurrence of said display signal to derive a time associated display signal; and

a display assembly responsive to said time associated display signal and a corresponding total ammoniacal concentration derived display signal to provide an associative display of each as a visible perceptible information output.

94. The system of claim 93 in which said catheter assembly measurement region is adapted to be located within said vascular system at said peripheral region.

95. The system of claim 93 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending within said first sensor channel from said catheter assembly proximal end region to a fiberoptic tip located at and forming a component of said forward assembly;

a membrane forming a component of said forward assembly, permeable to said ammoniacal component, having an outer surface contactable with said bloodstream and an inner surface spaced from said fiberoptic tip to define an equilibriation cavity; and

including a light transmission and reception assembly optically coupled with said fiberoptic assembly at said proximal end region and controllable to derive said ammoniacal sensor output with respect to ammoniacal component at said equilibriation cavity.

96. The system of claim 95 in which said membrane inner surface is light reflecting.

97. The system of claim 93 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to a fiberoptic tip at said forward assembly, including an outer surface extending inwardly from said fiberoptic tip;

an end plug impervious to blood having an inwardly disposed surface spaced from said fiberoptic tip to define the length of an equilibriation cavity;

a membrane permeable to said ammoniacal component having an outer surface contactable with said bloodstream, said membrane extending sealingly about said outer surface and said end plug to define the sides of said equilibration cavity.

98. The system of claim 93 in which said ammoniacal component sensor comprises:

a fiberoptic assembly extending from said catheter proximal end region to said forward assembly and having a forward light transmission leg and a return transmission leg spaced from said forward light transmission leg to define a gap situated at said forward assembly; and

a membrane permeable to said ammoniacal component, having an outer surface contactable with said bloodstream, said membrane sealingly extending about said gap to define an equilibration cavity.

99. The system of claim 93 in which:

said ammoniacal component is ammonia (NH₃);

said ammoniacal sensor output is provided in correspondence with the concentration of ammonia gas (NH₃) in said bloodstream; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

100. The system of claim 93 in which:

said catheter assembly includes a second sensor channel extending from said proximal region to said measurement region;

including a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃); and

said controller is responsive to control said pH sensor, and is responsive to said pH output to derive said total ammoniacal concentration value.

101. The system of claim 100 in which:

said pH sensor forward assembly includes a membrane impervious to blood and permeable to hydrogen ions and including a pH indicator located for response to said hydrogen ions; and

said controller derives said total ammoniacal concentration value in correspondence with the expressions;

102. The system of claim 93 in which:

said catheter assembly has an outer principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

103. The system of claim 102 in which said outer principal cross-sectional dimension is within a range of about 0.010 inch to 0.060 inch.

104. The system of claim 93 in which:

said ammoniacal component responsive forward assembly comprises;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood;

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with blood within said bloodstream; and

said ammoniacal component sensor includes;

a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output.

105. The system of claim 104 wherein:

said reactor comprises an ammoniacal component-sensitive fluorescent material having a fluorescence intensity as said output condition; and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying said fluorescence intensity as said ammoniacal sensor output.

106. The system of claim 104 wherein

said reactor comprises an ammoniacal component-sensitive fluorescent material stimulatable into fluorescence, the rate of quenching of said fluorescence being said output condition;

and

said transmission component is a fiberoptic assembly for stimulating said reactor and conveying resultant generated light as said ammoniacal sensor output.

107. The system of claim 104 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

108. The system of claim 104 in which:

said ammoniacal component is ammonium;

said membrane is permeable to ammonium ion (NH₄⁺);

said reactor comprises first and second electrodes immersed within an electrolyte sensitive to said ammonium ion; and

said transmission assembly comprises a potentiometric assembly coupled with said first and second electrodes.

109. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region,

said ammoniacal component responsive forward assembly comprising;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood,

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contactable with blood within said bloodstream,

said ammoniacal component sensor including a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output,

said ammoniacal component is ammonia (NH₃),

said membrane is permeable to gaseous ammonia,

said reactor is a gaseous ammonia sensitive dye, and

said transmission assembly is a fiberoptic colorimetric measurement assembly which quantiates a change in color of the dye and is mounted within said first sensor channel;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, said controller additionally being responsive to said pH value to derive said total ammoniacal concentration value; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith.

110. The system of claim 109 in which:

said fiberoptic extends to a forward face positionable at said catheter tip for immersion within said bloodstream;

said gaseous ammonia sensitive dye is incorporated within said membrane; and

said membrane is formed over said fiberoptic in intimate abutment with said fiberoptic forward face.

111. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region,

said ammoniacal component is ammonia (NH₃);

said ammoniacal component sensor further comprising a fiberoptic assembly within said first sensor channel having a forward face at said forward assembly adapted for direct light exchange communication with said bloodstream, said fiberoptic assembly being extensible to a light source and photoresponsive assembly for measuring the concentration of ammonia gas (NH₃) in the bloodstream and providing said ammoniacal sensor output;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, said controller being additionally responsive to said pH value to derive said total ammoniacal concentration value, and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith.

112. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region,

said ammoniacal component responsive forward assembly comprising;

an ammoniacal component concentration reactor having an output condition responsive to the concentration of said ammoniacal component in blood,

a membrane forming a blood confronting surface of said reactor, permeable to said ammoniacal component, said surface being contractable with blood within said bloodstream,

said ammoniacal component sensor includes a transmission assembly for conveying a signal corresponding with said output condition to said catheter proximal end region as said ammoniacal sensor output,

said ammoniacal component reactor being configured as Schottky diode array having a conductive polymer responsive to said ammoniacal component to effect a forward bias alternation as said ammoniacal sensor output;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith.

113. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region, said ammoniacal component sensor forward assembly being configured as a Schottky diode array having a conductive polymer responsive to said ammoniacal component to effect a forward bias alteration as said ammoniacal sensor output;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith.

114. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region, said ammoniacal component sensor forward assembly comprising an acoustic-wave sensor having an acoustic wave delay line within an oscillator loop to derive said ammoniacal sensor output as a frequency shift;

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter to derive a total ammoniacal concentration value and a display signal corresponding therewith, and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith.

115. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region of said vascular system and including a second sensor channel extending from said proximal region to said measurement region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region,

a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃);

a controller coupled to effect operational control of said ammoniacal component sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to control said pH sensor responsive to said ammoniacal component parameter and to said pH output to derive a total ammoniacal concentration value and a display signal corresponding therewith,

said controller including an inputting assembly manually controllable to provide a total ammoniacal concentration threshold value,

said controller being responsive to said total ammoniacal concentration threshold value to retain it in memory,

said controller being responsive to a given said total ammoniacal concentration value and to said memory retained total ammoniacal concentration threshold value to derive an alarm signal when said given total ammoniacal concentration value is greater than said memory retained total ammoniacal concentration threshold value, and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and responsive to said alarm signal to provide a perceptible alarm output signal.

116. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said blood stream at said peripheral region, and including a second sensor channel extending from said proximal region to said measurement region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region,

a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃);

a controller coupled to effect operational control of said ammoniacal component sensor assembly and said pH sensor, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter and to said pH output to derive a total ammoniacal concentration value and a display signal corresponding therewith,

said controller including an inputting assembly manually controllable to provide a rate of change of ammoniacal concentration threshold value,

said controller being responsive to a given said total ammoniacal concentration value and to a previous such concentration value to derive a current total ammoniacal concentration rate of change value, and responsive to said rate of change of total ammoniacal concentration threshold value and to said current total ammoniacal concentration rate of change value to derive an alarm signal when said current total ammoniacal concentration rate of change value is greater than said rate of change of total ammoniacal concentration threshold value; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and responsive to said alarm signal to provide a perceptible alarm output.

117. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region, and including a second sensor channel extending from said proximal region to said measurement region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region,

a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃);

a controller coupled to effect operational control of said ammoniacal component sensor assembly and said pH sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter and to said pH output to derive a total ammoniacal concentration value and a display signal corresponding therewith, responsive to a first said total ammoniacal concentration value and responsive to a second said total ammoniacal concentration value derived subsequent to said first total ammoniacal concentration value, and responsive to derive a warning signal when said second total ammoniacal concentration value is greater than said first total ammoniacal concentration value; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and responsive to said warning signal to provide a perceptible warning output.

118. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, said measurement region being adapted to be positionable within said bloodstream at said peripheral region, and including a second sensor channel extending from said proximal region to said measurement region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said proximal end region,

a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region;

said ammoniacal component is ammonia (NH₃);

a controller coupled to effect operational control of said ammoniacal component sensor assembly and said pH sensor, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter and to said pH output to derive a total ammoniacal concentration value and a display signal corresponding therewith,

said controller including a time clock providing a time output, and being responsive to said real time output with the contemporaneous derived occurrence of said total ammoniacal concentration value to derive a time associated display signal; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith, and responsive to each of a sequence said of said time associated display signals to publish a trend defining graphics display thereof.

119. A system for monitoring the ammoniacal concentration in blood, such blood exhibiting a pH value, and being within a vascular system directing a bloodstream extending to a peripheral region of the body remotely disposed from the heart, comprising:

catheter assembly comprising;

a first catheter having a first proximal region, a first measurement region spaced therefrom extending to a first tip, having an outer first principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region while avoiding generation of substantial hydraulic impedance to blood flow, said first catheter having a first sensor channel, said first sensor channel extending from said first proximal region to said first measurement region, and

a second catheter having a second proximal region, a second measurement region spaced therefrom extending to a second tip, having an outer second principal cross-sectional dimension effective for insertion within said bloodstream, in spaced relationship from said first catheter at said peripheral region while avoiding generation of substantial hydraulic impedance to blood flow, said second catheter having a second sensor channel, said second sensor channel extending from said second proximal region to a said second measurement region;

an ammoniacal component sensor assembly, supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said first measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide an ammoniacal sensor output at said first proximal end region,

said ammoniacal component is ammonia (NH₃);

said ammoniacal component sensor assembly ammoniacal component forward assembly is an ammonia sensor forward assembly, said sensor assembly being controllable to provide said ammoniacal sensor output as an ammonia sensor output;

a pH sensor assembly supported by said second sensor channel, having a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said second proximal region, said pH sensor assembly being controllable to provide a pH output at said second proximal region; and

a controller coupled to effect operational control of said ammoniacal component sensor assembly and said pH sensor assembly, and responsive to said ammoniacal sensor output for deriving an ammoniacal component parameter at repeating measurement intervals, responsive to said ammoniacal component parameter and to said pH output to derive a total ammoniacal concentration value and deriving a display signal corresponding with said total ammoniacal concentration value; and

a display assembly responsive to said display signal to provide a visibly perceptible information output corresponding therewith.

120. The system of claim 119 in which said first and second outer principal cross-sectional dimensions are within a range of about 0.010 inch to 0.060 inch.

121. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region;

(b) providing a controller actuable to control said ammoniacal component sensor assembly to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values, said controller further being responsive to said total ammoniacal concentration values and to a memory retained total ammoniacal concentration threshold value to derive an alarm signal when one of said total ammoniacal concentration values is greater than or equal to said memory retained total ammoniacal concentration threshold value;

(c) providing a display assembly responsive to said display signals to derive a visibly perceptible information output corresponding therewith, and responsive to said alarm signal to provide a perceptible alarm output;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and effect derivation of said perceptible information output, including the step of;

inputting to said memory of said controller said ammoniacal concentration threshold value.

122. The method of claim 121 in which:

said step (d) positions said catheter assembly measurement region within said blood supply in a manner wherein said tip is in confronting relationship with respect to one of said given path directions of said directed blood.

123. The method of claim 121 in which:

said step (a) provides said catheter assembly ammoniacal component responsive forward assembly as being responsive to an ammonia (NH₃) ammoniacal component; and

said step (b) provides said controller as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values in correspondence with the expressions;

124. The method of claim 121, in which:

said step (a) provides said catheter assembly ammoniacal component sensor as being responsive to an ammonia gas (NH₃) ammoniacal component, said ammoniacal component sensor including a fiberoptic assembly within said first sensor channel having a forward face at said measurement region adapted for direct light exchange communication with said bloodstream, said fiberoptic assembly being extensible to a light source and photoresponsive assembly for deriving said ammoniacal sensor outputs or concentrations of ammonia gas in said bloodstream; and

said step (b) provides said controller as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values.

125. The method of claim 121 in which:

said step (a) provides said catheter assembly as having an outer principal cross-sectional dimension effective for insertion within said bloodstream at one of said peripheral regions of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

126. The method of claim 125 wherein said step (a) provides said catheter assembly as having a said outer principal cross-sectional dimension within a range of about 0.018 inch to 0.060 inch.

127. The method of claim 121 in which:

said step (a) provides said catheter assembly as comprising;

a first catheter, having an outer first principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said first catheter having said first sensor channel and said ammoniacal component sensor is responsive to an ammonia (NH3) ammoniacal component and deriving said ammoniacal sensor outputs as concentrations of ammonia gas in said bloodstream, and

a second catheter, having an outer second principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said second catheter having a second sensor channel extending from a second proximal region to a second measurement region extending to a second tip, said second catheter having a pH sensor assembly supported by said second sensor channel, having a second forward assembly which is pH responsive and said pH sensor assembly being controllable to provide a pH output at said second proximal region;

said step (b) provides said controller as actuable to control said ammoniacal component sensor of said first catheter and said pH sensor assembly of said second catheter to respectively derive said ammoniacal sensor outputs and said pH output and is responsive to said ammoniacal sensor outputs and to said pH output to derive said sequence of total ammoniacal concentration values; and

said step (b) includes the steps of;

(b1) positioning said first catheter measurement region within said bloodstream at one of said peripheral regions, and

(b2) positioning said second catheter second measurement region at one of said peripheral regions in spaced relationship from said first catheter.

128. The method of claim 127 in which said step (a) provides said outer first principal cross-sectional dimension and said outer second principal cross-sectional dimension as being less than about 0.18 inch.

129. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region;

(b) providing a controller actuable to control said ammoniacal component sensor assembly to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values, said controller being responsive to a first one of said total ammoniacal concentration values and being responsive to a second one of said total ammoniacal concentration value derived subsequent to said first one of said total ammoniacal concentration values and being responsive to derive a warning signal when said second one of said ammoniacal concentration values is greater than said first one of said ammoniacal concentration values;

(c) providing a display assembly responsive to said display signals to derive a visibly perceptible information output corresponding therewith, and responsive to said warning signal to provide a perceptible warning output;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and effect derivation of said perceptible information output.

130. The method of claim 129 in which:

said step (d) positions said catheter assembly measurement region within said blood supply in a manner wherein said tip is in confronting relationship with respect to one of said given path directions of said directed blood.

131. The method of claim 129 in which:

said step (a) provides said catheter assembly ammoniacal component responsive forward assembly as being responsive to an ammonia (NH₃) ammoniacal component; and

said step (b) provides said controller as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values in correspondence with the expressions;

132. The method of claim 129 in which:

said step (a) provides said catheter assembly ammoniacal component sensor as being responsive to an ammonia gas (NH₃) ammoniacal component, said ammoniacal component sensor including a fiberoptic assembly within said first sensor channel having a forward face at said measurement region adapted for direct light exchange communication with said bloodstream, said fiberoptic assembly being extensible to a light source and photoresponsive assembly for deriving said ammoniacal sensor outputs or concentrations of ammonia gas in said bloodstream; and

said step (b) providers provides said controller or as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values.

133. The method of claim 129 in which:

said step (a) provides said catheter assembly as having an outer principal cross-sectional dimension effective for insertion within said bloodstream at one of said peripheral regions of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

134. The method of claim 133 wherein said step (a) provides said catheter assembly as having a said outer principal cross-sectional dimension within a range of about 0.018 inch to 0.060 inch.

135. The method of claim 129 in which:

said step (a) provides said catheter assembly as comprising;

a first catheter, having an outer first principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said first catheter having said first sensor channel and said ammoniacal component sensor is responsive to an ammonia (NH3) ammoniacal component and deriving said ammoniacal sensor outputs as concentrations of ammonia gas in said bloodstream, and

a second catheter, having an outer second principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said second catheter having a second sensor channel extending from a second proximal region to a second measurement region extending to a second tip, said second catheter having a pH sensor assembly supported by said second sensor channel, having a second forward assembly which is pH responsive and said pH sensor assembly being controllable to provide a pH output at said second proximal region;

said step (b) provides said controller as actuable to control said ammoniacal component sensor of said first catheter and said pH sensor assembly of said second catheter to respectively derive said ammoniacal sensor outputs and said pH output and is responsive to said ammoniacal sensor outputs and to said pH output to derive said sequence of total ammoniacal concentration values; and

said step (b) includes the steps of;

(b1) positioning said first catheter measurement region within said bloodstream at one of said peripheral regions, and

(b2) positioning said second catheter second measurement region at one of said peripheral regions in spaced relationship from said first catheter.

136. The method of claim 135 in which said step (a) provides said outer first principal cross-sectional dimension and said outer second principal cross-sectional dimension as being less than about 0.18 inch.

137. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region;

(b) providing a controller actuable to control said ammoniacal component sensor assembly to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values,

said controller including a time clock providing a time output, and being responsive to said time output with the contemporaneous derived occurrence of one of said display signals to derive a time associated display signal;

(c) providing a display assembly responsive to said display signals to derive a visibly perceptible information output corresponding therewith, said display assembly being responsive to each of a sequence of said time associated display signals to produce a trend defining graphics display thereof;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and said time associated display signals and effect derivation of said perceptible information output with said trend defining graphics display.

138. The method of claim 137 in which:

said step (d) positions said catheter assembly measurement region within said blood supply in a manner wherein said tip is in confronting relationship with respect to one of said given path directions of said directed blood.

139. The method of claim 137 in which:

said step (a) provides said catheter assembly ammoniacal component responsive forward assembly as being responsive to an ammonia (NH₃) ammoniacal component; and

said step (b) provides said controller as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values in correspondence with the expressions;

140. The method of claim 137 in which:

said step (a) provides said catheter assembly ammoniacal component sensor as being responsive to an ammonia gas (NH₃) ammoniacal component, said ammoniacal component sensor including a fiberoptic assembly within said first sensor channel having a forward face at said measurement region adapted for direct light exchange communication with said bloodstream, said fiberoptic assembly being extensible to a light source and photoresponsive assembly for deriving said ammoniacal sensor outputs or concentrations of ammonia gas in said bloodstream; and

said step (b) providers provides said controller or as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values.

141. The method of claim 137 in which:

said step (a) provides said catheter assembly as having an outer principal cross-sectional dimension effective for insertion within said bloodstream at one of said peripheral regions of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

142. The method of claim 141 wherein said step (a) provides said catheter assembly as having a said outer principal cross-sectional dimension within a range of about 0.018 inch to 0.060 inch.

143. The method of claim 137 in which:

said step (a) provides said catheter assembly as comprising;

a first catheter, having an outer first principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said first catheter having said first sensor channel and said ammoniacal component sensor is responsive to an ammonia (NH3) ammoniacal component and deriving said ammoniacal sensor outputs as concentrations of ammonia gas in said bloodstream, and

a second catheter, having an outer second principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said second catheter having a second sensor channel extending from a second proximal region to a second measurement region extending to a second tip, said second catheter having a pH sensor assembly supported by said second sensor channel, having a second forward assembly which is pH responsive and said pH sensor assembly being controllable to provide a pH output at said second proximal region;

said step (b) provides said controller as actuable to control said ammoniacal component sensor of said first catheter and said pH sensor assembly of said second catheter to respectively derive said ammoniacal sensor outputs and said pH output and is responsive to said ammoniacal sensor outputs and to said pH output to derive said sequence of total ammoniacal concentration values; and

said step (b) includes the steps of;

(b1) positioning said first catheter measurement region within said bloodstream at one of said peripheral regions, and

(b2) positioning said second catheter second measurement region at one of said peripheral regions in spaced relationship from said first catheter.

144. The method of claim 143 in which said step (a) provides said outer first principal cross-sectional dimension and said outer second principal cross-sectional dimension as being less than about 0.18 inch.

145. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region;

(b) providing a controller actuable to control said ammoniacal component sensor assembly to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values, said controller including a time clock providing a time output, and being responsive to said time output and the occurrence of a derived ones of said display signals to derive associated time of occurrence display signals;

(c) providing a display assembly responsive to said display signals and said associated time of occurrence display signals to provide visually perceptible representations of each as a visibly perceptible information output;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and associated time of occurrence display signals and effect derivation of said perceptible information output.

146. The method of claim 145 in which:

said step (d) positions said catheter assembly measurement region within said blood supply in a manner wherein said tip is in confronting relationship with respect to one of said given path directions of said directed blood.

147. The method of claim 145 in which:

said step (a) provides said catheter assembly ammoniacal component responsive forward assembly as being responsive to an ammonia (NH₃) ammoniacal component; and

said step (b) provides said controller as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values in correspondence with the expressions;

148. The method of claim 145 in which:

said step (a) provides said catheter assembly ammoniacal component sensor as being responsive to an ammonia gas (NH₃) ammoniacal component, said ammoniacal component sensor including a fiberoptic assembly within said first sensor channel having a forward face at said measurement region adapted for direct light exchange communication with said bloodstream, said fiberoptic assembly being extensible to a light source and photoresponsive assembly for deriving said ammoniacal sensor outputs or concentrations of ammonia gas in said bloodstream; and

said step (b) providers provides said controller or as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values.

149. The method of claim 145 in which:

said step (a) provides said catheter assembly as having an outer principal cross-sectional dimension effective for insertion within said bloodstream at one of said peripheral regions of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

150. The method of claim 149 wherein said step (a) provides said catheter assembly as having a said outer principal cross-sectional dimension within a range of about 0.018 inch to 0.060 inch.

151. The method of claim 145 in which:

said step (a) provides said catheter assembly as comprising;

a first catheter, having an outer first principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said first catheter having said first sensor channel and said ammoniacal component sensor is responsive to an ammonia (NH3) ammoniacal component and deriving said ammoniacal sensor outputs as concentrations of ammonia gas in said bloodstream, and

a second catheter, having an outer second principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said second catheter having a second sensor channel extending from a second proximal region to a second measurement region extending to a second tip, said second catheter having a pH sensor assembly supported by said second sensor channel, having a second forward assembly which is pH responsive and said pH sensor assembly being controllable to provide a pH output at said second proximal region;

said step (b) provides said controller as actuable to control said ammoniacal component sensor of said first catheter and said pH sensor assembly of said second catheter to respectively derive said ammoniacal sensor outputs and said pH output and is responsive to said ammoniacal sensor outputs and to said pH output to derive said sequence of total ammoniacal concentration values; and

said step (b) includes the steps of;

(b1) positioning said first catheter measurement region within said bloodstream at one of said peripheral regions, and

(b2) positioning said second catheter second measurement region at one of said peripheral regions in spaced relationship from said first catheter.

152. The method of claim 151 in which said step (a) provides said outer first principal cross-sectional dimension and said outer second principal cross-sectional dimension as being less than about 0.18 inch.

153. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region;

(b) providing a controller actuable to control said ammoniacal component sensor assembly to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values, said controller being responsive to a given one of said total ammoniacal concentration values and to a previous such concentration value to derive a current total ammoniacal concentration rate of change value, and being responsive to said rate of change of total ammoniacal concentration threshold value and to said current total ammoniacal concentration rate of change value to derive an alarm signal when said current total ammoniacal concentration rate of change value is greater than said rate of change of total ammoniacal concentration threshold value;

(c) providing a display assembly responsive to said display signals to derive a visibly perceptible information output corresponding therewith, and responsive to said alarm signal to provide a perceptible alarm output;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and effect derivation of said perceptible information output, including the step of inputting to said controller assembly a rate of change of total ammoniacal concentration threshold value.

154. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region;

(b) providing a controller actuable to control said ammoniacal component sensor assembly to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values, said controller being responsive to retain said total ammoniacal concentration values in memory, being responsive to a given one of said total ammoniacal concentration value and n−

1 memory retained previously occurring said total ammoniacal concentration values to derive a filtered total ammoniacal concentration value representing the moving average filtering of n of said total ammoniacal concentration values and provided as one of said display signals;

(c) providing a display assembly responsive to said display signals to derive a visibly perceptible information output corresponding therewith;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and effect derivation of said perceptible information output.

155. The method of claim 154 in which:

said step (d) positions said catheter assembly measurement region within said blood supply in a manner wherein said tip is in confronting relationship with respect to one of said given path directions of said directed blood.

156. The method of claim 154 in which:

said step (a) provides said catheter assembly ammoniacal component responsive forward assembly as being responsive to an ammonia (NH₃) ammoniacal component; and

said step (b) provides said controller as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values in correspondence with the expressions;

157. The method of claim 154 in which:

said step (a) provides said catheter assembly ammoniacal component sensor as being responsive to an ammonia gas (NH₃) ammoniacal component, said ammoniacal component sensor including a fiberoptic assembly within said first sensor channel having a forward face at said measurement region adapted for direct light exchange communication with said bloodstream, said fiberoptic assembly being extensible to a light source and photoresponsive assembly for deriving said ammoniacal sensor outputs or concentrations of ammonia gas in said bloodstream; and

said step (b) providers provides said controller or as being responsive to said ammoniacal sensor outputs and to said given pH value to derive said total ammoniacal concentration values.

158. The method of claim 154 in which:

said step (a) provides said catheter assembly as having an outer principal cross-sectional dimension effective for insertion within said bloodstream at one of said peripheral regions of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow.

159. The method of claim 158 wherein said step (a) provides said catheter assembly as having a said outer principal cross-sectional dimension within a range of about 0.018 inch to 0.060 inch.

160. The method of claim 154 in which:

said step (a) provides said catheter assembly as comprising;

a first catheter, having an outer first principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said first catheter having said first sensor channel and said ammoniacal component sensor is responsive to an ammonia (NH3) ammoniacal component and deriving said ammoniacal sensor outputs as concentrations of ammonia gas in said bloodstream, and

a second catheter, having an outer second principal cross-sectional dimension effective for insertion within said bloodstream at said peripheral region of said vascular system while avoiding generation of substantial hydraulic impedance to bloodflow, said second catheter having a second sensor channel extending from a second proximal region to a second measurement region extending to a second tip, said second catheter having a pH sensor assembly supported by said second sensor channel, having a second forward assembly which is pH responsive and said pH sensor assembly being controllable to provide a pH output at said second proximal region;

said step (b) provides said controller as actuable to control said ammoniacal component sensor of said first catheter and said pH sensor assembly of said second catheter to respectively derive said ammoniacal sensor outputs and said pH output and is responsive to said ammoniacal sensor outputs and to said pH output to derive said sequence of total ammoniacal concentration values; and

said step (b) includes the steps of;

(b1) positioning said first catheter measurement region within said bloodstream at one of said peripheral regions, and

(b2) positioning said second catheter second measurement region at one of said peripheral regions in spaced relationship from said first catheter.

161. The method of claim 160 in which said step (a) provides said outer first principal cross-sectional dimension and said outer second principal cross-sectional dimension as being less than about 0.18 inch.

162. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region, said catheter assembly ammoniacal component sensor being responsive to an ammonia (NH₃) ammoniacal component, said ammoniacal component sensor including a fiberoptic colorimetric measurement assembly which quantiates a change in color and is mounted within said first sensor channel, extending from a face at said forward assembly to a sensor output at said proximal region, said forward assembly comprising a gaseous ammonia sensitive dye and a membrane encompassing said dye, permeable to gaseous ammonia mounted over said fiberoptic face;

(b) providing a controller actuable to control said ammoniacal component sensor assembly to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values;

(c) providing a display assembly responsive to said display signals to derive a visibly perceptible information output corresponding therewith;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and effect derivation of said perceptible information output.

163. The method of claim 162 in which said step (a) provides said forward assembly dye as being incorporated within said membrane.

164. The method for monitoring the ammoniacal concentration in blood within the vascular system contained bloodstream of the body, such system directing blood exhibiting a given pH value along given path directions and extending to peripheral regions of such body without the immediate region of the heart, comprising the steps of:

(a) providing a catheter assembly having a proximal end region, a measurement region spaced therefrom extending to a tip, having a first sensor channel extending from said proximal region to said measurement region, an ammoniacal component sensor supported by said first sensor channel, having an ammoniacal component responsive forward assembly at said measurement region contactable with flowing blood within said bloodstream, said sensor assembly being controllable to provide ammoniacal sensor outputs at said proximal end region,

said catheter assembly having a second sensor channel extending from said proximal region to said measurement region, having a pH sensor including a pH responsive forward assembly and a fiberoptic transmission component extending therefrom to said proximal region, said pH sensor assembly being controllable to provide a pH output at said proximal region, said ammoniacal component sensor is provided as an ammonia (NH₃) sensor and said ammoniacal sensor outputs are provided in correspondence with the concentration of ammonia gas in said bloodstream;

(b) providing a controller actuable to control said ammoniacal component sensor and said pH sensor to derive said ammoniacal sensor outputs over a sequence of measurement intervals, and responsive to said ammoniacal sensor outputs and to said pH output to derive a sequence of total ammoniacal concentration values over a measurement period and deriving display signals corresponding with said sequence of values;

(c) providing a display assembly responsive to said display signals to derive a visibly perceptible information output corresponding therewith;

(d) positioning said catheter assembly measurement region within said bloodstream at one of said peripheral regions; and

(e) actuating said controller to derive said display signals and effect derivation of said perceptible information output.