Remote sensing tonometric catheter apparatus and method

• US 6,334,064 B1
• Filed: 05/26/1995
• Issued: 12/25/2001
• Est. Priority Date: 08/26/1988
• Status: Expired due to Fees

• Current Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Original Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Inventors: Fiddian-Green, Richard Guy
• Primary Examiner(s): Lacyk, John P.
• Application Number:
  US08/452,183
• Time in Patent Office: 2,405 Days
• Field of Search: 128/632, 128/635, 128/691, 128/672, 128/673, 128/736, 128/748, 128/749, 128/774, 128/778, 128/750, 128/752, 128/309, 128/310, 128/311, 128/316, 128/322, 128/323, 128/324, 128/325, 128/345, 128/348, 128/353, 128/361, 128/366
• US Class Current: 600/311
• 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 5/6853 with a balloon
• CPC Class Codes: A61M 2025/1061 having separate inflations tubes, e.g. coaxial tubes or tubes otherwise arranged apart from the catheter tube
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00

Abstract

A tonometric device for use in hollow viscus tonometry and remote sensing of patient fluid parameters is disclosed in combination with a secondary apparatus, such as a urinary catheter, a nasogastric sump apparatus, or a feeding tube, for example. The device is capable of monitoring certain critical fluid properties of interest, such as oxygen gases and carbon dioxide gases in the wall tissue itself of the patient'"'"'s organ, rather than monitoring such properties in a lumen of the organ. A walled sampling chamber, which is preferably an inflated balloon member, is provided on an elongated tube, with provisions for positioning the sampling chamber in direct contact with a wall portion of the patient'"'"'s internal organ.

Claims

1. A method for measuring partial pressure of one or more gases in the gastrointestinal lumen of a patient comprising the steps of:

A. defining an intraluminal region as a region-of-interest within the gut of a patient by inserting a catheter into said patient, said catheter having a distal end and a proximal end, whereby said distal tip is located in a desired intraluminal region in the gut of said patient and said proximal end is external to said patient, and wherein said catheter further includes an open-faced chamber defined near the distal end of said catheter, and a gas permeable membrane spanning said open-faced chamber to define a closed gas-filled gas sensing region therein, said closed gas sensing region having substantially no fluidic communication with said proximal end, and includes a detector, said detector including a CO₂ sensor affixed to said catheter near said distal end and including selectively operative sensor means for generating at said proximal end a signal representative of the concentration of CO₂ in said intraluminal region adjacent to said distal end,

B. sensing in said gut the concentration of said gases in said region-of-interest, and

C. generating a signal representative of said concentration, said signal being representative of the partial pressure of said gases in said region-of-interest, wherein said sensing step and said generating step include the step of operating said sensor means.

2. The method of claim 1 wherein said gases include one or more gases selected from the group consisting of carbon dioxide (CO₂) and oxygen (O₂).

3. The method of claim 2 wherein the number of gases measured is greater than 1, and wherein said method includes the step of sensing in said gut the partial pressure of said gases with separate sensors.

4. The method of claim 1 wherein said detector further includes an O₂ sensor affixed to said catheter near said distal end and including selectively operative sensor means for generating at said proximal end a signal representative of the concentration of O₂ in said intraluminal region adjacent to said distal end, and

wherein said sensing step and said generating step include the step of operating said sensor means.

5. An intraluminal gastrointestinal gas measuring system, comprising:

A. an elongated catheter having a distal end and a proximal end,

B. one or more gas sensors affixed to said catheter near said distal end, wherein at least one of said gas sensors includes a sampling chamber defined near the distal end of said catheter, and a gas permeable membrane spanning said chamber to define a closed fluid filled gas sensing region therein, said closed gas sensing region having substantially no fluidic communication with said proximal end, and wherein at least one of said gas sensors is adjacent to said closed gas sensing region and in optical communication with said proximal end, and

C. sensor means for generating at said proximal end a signal representative of the partial pressure of said gases external to said catheter and adjacent to said gas sensors.

6. A measuring system according to claim 5 wherein at least one of said sensors is a CO₂ sensor.

7. A measuring system according to claim 6 wherein at least one of said sensors is an O₂ sensor.

8. A measuring system according to claim 6 wherein said sensor means is selectively operative and includes:

A. a first optically transmissive optical fiber extending from a first point at the boundary of said gas sensing region to said proximal end,

B. a second optically transmissive optical fiber extending from a second point at the boundary of said gas sensing region to said proximal end, said first optical fiber at said first point being optically coupled to said second optical fiber at said second point,

C. means for directing optical radiation through said first fiber from a point near said proximal end toward said gas sensing region, and

D. means for detecting at a point near said proximal end optical radiation coupled from said first fiber across said gas sensing region to said second fiber and through said second fiber.

9. A system according to claim 8 wherein said sensor means further comprises means coupled to said second fiber near said proximal end for determining gas concentration in said gas sensing region from said detected optical radiation.

10. A measuring system according to claim 9 wherein said catheter further comprises

A. first calibration lumen extending from said proximal end to and in selective communication with said chamber of said sensor,

B. second calibration lumen extending from said proximal end to and, in selective communication with said chamber of said sensor,

C. means for selectively passing a calibration gas through said first calibration lumen and said chamber to said second calibration lumen, and

D. means for operating said sensor means while said calibration means is passing said calibration gas through said sensing region.

11. A measuring system according to claim 9 wherein said catheter further includes at least one open ended lumen extending between said distal end and said proximal end.

12. A measuring system according to claim 5 wherein said catheter further includes at least one open ended lumen extending between said distal end and said proximal end.

13. An intraluminal gastrointestinal gas measuring system, comprising:

A. an elongated catheter having a distal end and a proximal end,

B. one or more gas sensors affixed to said catheter near said distal end, wherein at least one of said gas sensors includes an open-faced chamber defined near the distal end of said catheter, and a gas permeable membrane spanning said open-faced chamber to define a closed gas-filled gas sensing region therein, said closed gas sensing region having substantially no fluidic communication with said proximal end, and wherein at least one of said gas sensors is adjacent to said closed gas sensing region and in optical communication with said proximal end, and

C. sensor means for generating at said proximal end a signal representative of the partial pressure of said gases external to said catheter and adjacent to said gas sensors.

14. A measuring system according to claim 13 wherein at least one of said sensors is a CO₂ sensor.

15. A measuring system according to claim 14 wherein at least one of said sensors is an O₂ sensor.

16. A measuring system according to claim 14 wherein said sensor means is selectively operative and includes:

A. a first optically transmissive optical fiber extending from a first point at the boundary of said gas sensing region to said proximal end,

B. a second optically transmissive optical fiber extending from a second point at the boundary of said gas sensing region to said proximal end, said first optical fiber at said first point being optically coupled to said second optical fiber at said second point,

C. means for directing optical radiation through said first fiber from a point near said proximal end toward said gas sensing region, and

D. means for detecting at a point near said proximal end optical radiation coupled from said first fiber across said gas sensing region to said second fiber and through said second fiber.

17. A system according to claim 16 wherein said sensor means further comprises means coupled to said second fiber near said proximal end for determining gas concentration in said gas sensing region from said detected optical radiation.

18. A measuring system according to claim 17 wherein said catheter further comprises

A. first calibration lumen extending from said proximal end to and in selective communication with said chamber of said sensor,

B. second calibration lumen extending from said proximal end to and, in selective communication with said chamber of said sensor,

C. means for selectively passing a calibration gas through said first calibration lumen and said chamber to said second calibration lumen, and

D. means for operating said sensor means while said calibration means is passing said calibration gas through said sensing region.

19. A measuring system according to claim 17 wherein said catheter further includes at least one open ended lumen extending between said distal end and said proximal end.

20. A measuring system according to claim 13 wherein said catheter further includes at least one open ended lumen extending between said distal end and said proximal end.