Tissue penetrating apparatus and methods

• US 5,460,182 A
• Filed: 09/14/1992
• Issued: 10/24/1995
• Est. Priority Date: 09/14/1992
• Status: Expired due to Fees

• Current Assignee: Sextant Medical Corporation
• Original Assignee: Sextant Medical Corporation
• Inventors: Goldberger, Daniel S., Goodman, David E.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Casler, Brian L.
• Application Number:
  US07/944,516
• Time in Patent Office: 1,135 Days
• Field of Search: 128/664, 128/665, 128/754, 128/633, 128/634, 606/2, 606/14, 606/15, 606/167, 606/172, 606/173, 356/432, 356/433, 356/435, 607/88, 607/89
• US Class Current: 600/342
• CPC Class Codes: A61B 17/068 Surgical staplers , e.g. containing multiple staples or clampsstaplers containing only one staple A61B17/10; magazines or containers for staples A61B17/105; for performing anastomosis A61B17/115; staplers in general B25C5/00
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery
• CPC Class Codes: A61B 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• CPC Class Codes: A61B 17/3474 Insufflating needles, e.g. Veress needles
• CPC Class Codes: A61B 17/3494 with safety means for protection against accidental cutting or pricking, e.g. limiting insertion depth, pressure sensors for the peridural space A61B17/3401
• CPC Class Codes: A61B 18/00 Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body eye surgery A61F9/007; ear surgery A61F11/00
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2017/00057 Light
• CPC Class Codes: A61B 2017/00061 spectrum
• CPC Class Codes: A61B 2017/00119 alarm; indicating an abnormal situation
• CPC Class Codes: A61B 2017/00123 and automatic shutdown
• CPC Class Codes: A61B 2017/00508 using laser
• CPC Class Codes: A61B 2017/00557 inflatable A61B2017/22051 takes precedence
• CPC Class Codes: A61B 2090/3614 using optical fibre
• CPC Class Codes: A61B 2560/0276 Determining malfunction
• CPC Class Codes: A61B 2562/08 Sensors provided with means for identification, e.g. barcodes or memory chips
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/6848 Needles

Abstract

A tissue penetrating apparatus including a surgical appliance having a sharp tip for penetrating tissue, a first optical element for emitting one or more selected monochromatic wavelengths of light, and a second optical element for sensing light corresponding to the one or more selected monochromatic wavelengths of light. The first and second optical elements are optical transmission fibers secured to the appliance proximate to the tip so that one fiber passes one or more monochromatic wavelengths of light into the tissue to be penetrated, and the other fiber passes the light sensed to a light detector. A control circuit is used to illuminate the one or more light sources to emit light out one of the first and second optical fibers, and to provide an electrical signal corresponding to the light sensed at the other of the first and second optical fibers. The electrical signal includes sensed light at each of the monochromatic wavelengths of light emitted, and sensed light in the absence of emitted light. An analysis circuit or a microprocessor based device may be used for processing the electrical signals and determining when the appliance tip has entered a body cavity. An annunciator is actuated to indicate the relative extent of passage through the tissue and when penetration has occurred.

Claims

1. A tissue penetrating appliance comprising:

a sharp tip having a tissue contacting surface configured to penetrate tissue and a longitudinal axis, the tissue contacting surface having a first face lying in a first plane at an angle relative to the longitudinal axis;

a first light transmitting optical element connected to the tip having a first end to emit one or more selected wavelengths of light from a first location on the tissue contacting surface and having a second end; and

a second light transmitting optical element connected to the tip having a first end to receive light corresponding to the one or more selected wavelengths of light at a second location on the tissue contacting surface and having a second end,

wherein the first and second optical elements are secured to the appliance, the first and second locations are spaced apart, the first optical element first end terminates in the first face in the first plane, and the second optical element first end terminates in the tissue contacting surface;

a first fixture receiving the second ends of the first and second optical elements;

a source of light having one or more monochromatic wavelengths;

a light detector responsive to a sensed light intensity having an electrical signal corresponding to the sensed light intensity;

a first coupler having a transmission channel input and output and a reception channel input and output, the transmission channel comprising an optical fiber connected to transmit light emitted by the light source to the transmission channel output, the reception channel comprising an optical fiber connected to transmit light coupled to the reception channel input to the light detector, the first coupler being coupled to the first fixture so that the reception channel input is in optical communication with one of the first and second optical elements and the transmission channel output is in optical communication with the other of the first and second optical elements;

a control circuit connected to the light source having a first state to cause the light source to emit light at the one or more wavelengths and said light received at the first end of the other of the first and second optical elements is coupled to the light detector to provide an electrical signal corresponding to said received light; and

means for processing the provided electrical signals and determining when the appliance tip has entered a body cavity.

2. The apparatus of claim 1 further comprising an annunciator wherein the processing means actuates the annunciator when the tip has entered a body cavity.

3. The apparatus of claim 2 wherein the processing means further actuates the annunciator to produce a variable signal corresponding to the extent that the tip has passed into the tissue.

4. The apparatus of claim 1 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.

5. A tissue penetrating appliance comprising:

a sharp tip having a tissue contacting surface configured to penetrate tissue and a longitudinal axis, the tissue contacting surface having a first face lying in a first plane at an angle relative to the longitudinal axis;

a first light transmitting optical element connected to the tip having a first end to emit one or more selected wavelengths of light from a first location on the tissue contacting surface and having a second end; and

a second light transmitting optical element connected to the tip having a first end to receive light corresponding to the one or more selected wavelengths of light at a second location on the tissue contacting surface and having a second end,

wherein the first and second optical elements are secured to the appliance and the first and second locations are spaced apart, the first optical element first end terminates in the first face in the first plane, and the second optical element first end terminates in the tissue contacting surface;

a first fixture receiving the second ends of the first and second optical elements;

a source of light having one or more monochromatic wavelengths;

a light detector responsive to a sensed light intensity having an electrical signal corresponding to the sensed light intensity;

a first coupler having a transmission channel input and output and a reception channel input and output, the transmission channel comprising an optical fiber connected to transmit light emitted by the light source to the transmission channel output, the reception channel comprising an optical fiber connected to transmit light coupled to the reception channel input to the light detector, the first coupler being coupled to the first fixture so that the reception channel input is in optical communication with one of the first and second optical elements and the transmission channel output is in optical communication with the other of the first and second optical elements;

a control circuit connected to the light source having a first state to cause the light source to emit light at the one or more wavelengths and said light received at the first end of the other of the first and second optical elements is coupled to the light detector to provide an electrical signal corresponding to said received light; and

means for processing the provided electrical signals and determining when the appliance tip is in proximity to venous perfused tissue.

6. The apparatus of claim 5 further comprising an annunciator wherein the processing means actuates the annunciator when the tip is in proximity to venus perfused tissue.

7. The apparatus of claim 6 wherein the processing means further comprises an output signal operable to actuate the annunciator to produce a variable signal corresponding to the extent that the tip has passed in proximity to and into the venus perfused tissue.

8. The apparatus of claim 5 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.

9. A tissue penetrating appliance comprising:

a sharp tip having a tissue contacting surface configured to penetrate tissue and a longitudinal axis, the tissue contacting surface having a first face lying in a first plane at an angle relative to the longitudinal axis;

a first light transmitting optical element connected to the tip having a first end to emit one or more selected wavelengths of light from a first location on the tissue contacting surface and having a second end;

a second light transmitting optical element connected to the tip having a first end to receive light corresponding to the one or more selected wavelengths of light at a second location on the tissue contacting surface and having a second end,

wherein the first and second optical elements are secured to the appliance, the first and second locations are spaced apart, the first optical element first end terminates in the first face in the first plane, and the second optical element first end terminates in the tissue contacting surface;

a first fixture receiving the second ends of the first and second optical elements;

a source of light having one or more monochromatic wavelengths;

a light detector responsive to a sensed light intensity having an electrical signal corresponding to the sensed light intensity;

a first coupler having a transmission channel input and output and a reception channel input and output, the transmission channel comprising an optical fiber connected to transmit light emitted by the light source to the transmission channel output, the reception channel comprising an optical fiber connected to transmit light coupled to the reception channel input to the light detector, the first coupler being coupled to the first fixture so that the reception channel input is in optical communication with one of the first and second optical elements and the transmission channel output is in optical communication with the other of the first and second optical elements;

a control circuit connected to the light source having a first state to cause the light source to emit light at the one or more wavelengths and said light received at the first end of the other of the first and second optical elements is coupled to the light detector to provide an electrical signal corresponding to said received light; and

means for processing the provided electrical signals and determining when the appliance tip is in proximity to arterial perfused tissue.

10. The apparatus of claim 9 further comprising an annunciator wherein the processing means actuates the annunciator when the tip is in proximity to arterial perfused tissue.

11. The apparatus of claim 10 wherein the processing means further comprises an output signal operable to actuate the annunciator to produce a variable signal corresponding to the extent that the tip has passed in proximity to and into the arterial perfused tissue.

12. The apparatus of claim 9 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.

13. A tissue penetrating appliance comprising:

a sharp tip having a tissue contacting surface configured to penetrate tissue and a longitudinal axis, the tissue contacting surface having a first face lying in a first plane at an angle relative to the longitudinal axis;

a first light transmitting optical element connected to the tip having a first end to emit one or more selected wavelengths of light from a first location on the tissue contacting surface and having a second end;

a second light transmitting optical element connected to the tip having a first end to receive light corresponding to the one or more selected wavelengths of light at a second location on the tissue contacting surface and having a second end,

wherein the first and second optical elements are secured to the appliance, and the first and second locations are spaced apart, the first optical element first end terminates in the first face in the first plane, and the second optical element first end terminates in the tissue contacting surface;

a first fixture receiving the second ends of the first and second optical elements;

a first plurality of monochromatic light sources having different discrete wavelengths;

a light detector responsive to a sensed light intensity having an electrical signal corresponding to the sensed light intensity;

a first coupler having a transmission channel input and output and a reception channel input and output, a synchronous optical multiplexer having a plurality of inputs, a plurality of optical fibers respectively connected between the first plurality of monochromatic light sources and the plurality of inputs, and an output to the transmission channel, the reception channel comprising an optical fiber connected to transmit light coupled to the reception channel input to the light detector, the first coupler being coupled to the first fixture so that the reception channel input is in optical communication with one of the first and second optical elements and the transmission channel output is in optical communication with the other of the first and second optical elements;

a control circuit operatively connected to the first plurality of light sources having a first state to cause the first plurality of monochromatic light sources to emit light one at a time in a selected sequence and said light received at the first end of the other of the first and second optical elements is coupled to the light detector to provide an electrical signal corresponding to said received light.

14. The apparatus of claim 13 wherein the first coupler transmission channel further comprises a second light detector optically coupled to the light transmitted to the output of the transmission channel, the second light detector monitoring the intensity of the light emitted at each of the monochromatic wavelengths.

15. The apparatus of claim 13 further comprising a demultiplexer circuit connected to separate the electrical signal provided by the light detector in response to one or more of the monochromatic wavelengths into separate signals corresponding to the one or more monochromatic wavelengths.

16. The apparatus of claim 13 further comprising means for processing the provided electrical signals and determining when the appliance tip has entered a body cavity.

17. The apparatus of claim 13 further comprising means for processing the provided electrical signals and determining when the appliance tip is in proximity to venous perfused tissue.

18. The apparatus of claim 13 further comprising means for processing the provided electrical signals and determining when the appliance tip is in proximity to arterial perfused tissue.

19. The apparatus of claim 13 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.

20. A tissue penetrating appliance comprising:

a sharp tip having a tissue contacting surface configured to penetrate tissue and a longitudinal axis, the tissue contacting surface having a first face lying in a first plane at an angle relative to the longitudinal axis;

a first light transmitting optical element connected to the tip having a first end to emit one or more selected wavelengths of light from a first location on the tissue contacting surface and having a second end;

a second light transmitting optical element connected to the tip having a first end to receive light corresponding to the one or more selected wavelengths of light at a second location on the tissue contacting surface and having a second end,

wherein the first and second optical elements are secured to the appliance and the first and second locations are spaced apart, the first optical element first end terminates in the first face in the first plane, and the second optical element first end terminates in the tissue contacting surface;

a first fixture receiving the second ends of the first and second optical elements;

a source of light having one or more monochromatic wavelengths;

a light detector responsive to a sensed light intensity having an electrical signal corresponding to the sensed light intensity;

a first coupler having a transmission channel input and output and a reception channel input and output, the transmission channel comprising an optical fiber connected to transmit light emitted by the light source to the transmission channel output, the reception channel comprising an optical fiber connected to transmit light coupled to the reception channel input to the light detector, the first coupler being coupled to the first fixture so that the reception channel input is in optical communication with one of the first and second optical elements and the transmission channel output is in optical communication with the other of the first and second optical elements;

a control circuit connected to the light source having a first state to cause the light source to emit light at the one or more wavelengths and said light received at the first end of the other of the first and second optical elements is coupled to the light detector to provide an electrical signal corresponding to said received light;

wherein;

the light source further comprises a first plurality of monochromatic light sources having different discrete wavelengths;

the first coupler further comprises;

a wavelength optical multiplexer having a plurality of inputs,

a plurality of optical fibers respectively connected between the first plurality of monochromatic light sources and the plurality of inputs; and

an output to the transmission channel;

wherein the light detector further comprises;

an optical demultiplexer having an input and a plurality of outputs, the input being optically connected to the reception channel, the plurality of outputs corresponding to each of the plurality of monochromatic light sources,

a plurality of light detectors, and

a plurality of optical fibers coupling the plurality of outputs to the plurality of light detectors;

and wherein the control circuit causes the first plurality of monochromatic light sources to emit light simultaneously and the plurality of light detectors simultaneously provide separate signals corresponding to the received light in response to the discrete wavelengths at the tip.

21. The apparatus of claim 20 further comprising means for processing the provided electrical signals and determining when the appliance tip has entered a body cavity.

22. The apparatus of claim 20 further comprising means for processing the provided electrical signals and determining when the appliance tip is in proximity to venus perfused tissue.

23. The apparatus of claim 20 further comprising means for processing the provided electrical signals and determining when the appliance tip is in proximity to arterial perfused tissue.

24. The apparatus of claim 20 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.

27. The apparatus of claim 20 further comprising:

a source of light having one or more monochromatic wavelengths;

a light detector responsive to a sensed light intensity having an electrical signal corresponding to the sensed light intensity;

a first coupler having a transmission channel input and output and a reception channel input and output, the transmission channel comprising an optical fiber connected to transmit light emitted by the light source to the transmission channel output, the reception channel comprising an optical fiber connected to transmit light coupled to the reception channel input to the light detector, the first coupler coupled to the first fixture so that the reception channel input is in optical communication with one of the first and second optical elements and the transmission channel output is in optical communication with the other of the first and second optical elements; and

a control circuit connected to the light source having a first state to cause the light source to emit light at the one or more wavelengths and said light received at the first end of the other of the first and second optical element is coupled to the light detector to provide an electrical signal corresponding to said received light.

28. The apparatus of claim 27 wherein the control circuit further comprises control means for operating the light source to emit light at an intensity, in response to the control circuit being in the first state, whereby the electrical signal includes received light illumination in response to one or more of the monochromatic wavelengths of light emitted.

29. The apparatus of claim 27 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.

25. A tissue penetrating appliance comprising:

a sharp tip having a longitudinal axis and a tissue contacting surface configured to penetrate tissue including a first face lying in a first plane at an angle relative to the longitudinal axis and a second face in a second plane at an angle relative to the longitudinal axis of the tip, wherein the first and second planes intersect;

a first light transmitting optical element connected to the tip having a first end to emit one or more selected wavelengths of light from a first location on the tissue contacting surface and having a second end, the first optical element first end terminating in the first face in the first plane;

a second light transmitting optical element connected to the tip having a first end to receive light corresponding to the one or more selected wavelengths of light at a second location on the tissue contacting surface and having a second end, the second optical element first end terminating in the second face of the second plane; and

a first fixture receiving the second ends of the first and second optical elements.

26. The apparatus of claim 25 wherein the first fixture further comprises:

a pair of optical fibers each having a first end and a second end and a selected length;

a first connector optically connected between the second ends of first and second optical fibers and the first ends of the pair of optical fibers respectively; and

a second connector optically connected to the second ends of the pair of optical fibers.

30. The apparatus of claim 25 wherein the first end of the second optical element terminates in the first face of the first plane.

31. The apparatus of claim 30 wherein the tissue penetrating appliance is a needle.

32. The apparatus of claim 30 wherein the first face is a conical surface.

33. The apparatus of claim 25 wherein the tip has a longitudinal axis, the tissue contacting surface includes a face lying in a plane inclined relative to the longitudinal axis, and wherein the first optical element first end terminates a first distance below the plane and wherein the second optical element first end terminates a second distance below the tissue contacting surface.

34. The apparatus of claim 25 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.

35. A method for penetrating tissue comprising the steps of:

providing a surgical appliance having a sharp tip having a surface for contacting and penetrating tissue, a first optical element in the tissue contacting surface for emitting one or more selected monochromatic wavelengths of light, and a second optical element in the tissue contacting surface for sensing light corresponding to the one or more selected monochromatic wavelengths of light characterized by securing the first and second optical elements to the tip at locations on the tissue contacting surface spaced a distance apart;

bringing the sharp tip tissue contacting surface into penetrating contact with tissue;

launching light at the one or more selected wavelengths out the first optical element to illuminate tissue;

sensing the light intensity at the second optical element in response to the launched light;

detecting variations in sensed light intensity;

an

determining when the light intensity variations correspond to the sharp tip passing into and through tissue,

wherein the step of detecting variations in light intensity further comprises sensing arterial pulsatile flow in the tissue proximate to the sharp tip.

36. The method of claim 35 wherein the first optical element further comprises a first optical fiber having a first end at the tissue contacting surface and the step of launching light further comprises coupling light from a first light source into the first optical fiber for transmission to the tissue.

37. The method of claim 36 wherein the second optical element further comprises a a second optical fiber having an end at the tissue contacting surface and the step of sensing the light intensity further comprises transmitting the light intensity at the end of the second optical fiber to a light detector.

38. The method of claim 35 further comprising providing an annunciator, detecting when the determined changes in intensity correspond to the tip passing through the tissue approaching a sensed arterial pulsatile flow, and providing a first alarm in response thereto.

39. A method for penetrating tissue comprising the steps of:

providing a surgical appliance having a sharp tip having a surface for contacting and penetrating tissue, a first optical element in the tissue contacting surface for emitting one or more selected monochromatic wavelengths of light, and a second optical element in the tissue contacting surface for sensing light corresponding to the one or more selected monochromatic wavelengths of light characterized by securing the first and second optical elements to the tip at locations on the tissue contacting surface spaced a distance apart;

bringing the sharp tip tissue contacting surface into penetrating contact with tissue;

launching light at the one or more selected wavelengths out the first optical element to illuminate tissue;

sensing the light intensity at the second optical element in response to the launched light;

detecting variations in sensed light intensity; and

determining when the light intensity variations correspond to the sharp tip passing into and through tissue;

wherein the first optical element further comprises a first optical fiber having an end at the tissue contacting surface an the step of launching light further comprises coupling light from a first light source into the first optical fiber for transmission to the tissue and wherein the first light source further comprises more than one monochromatic light source and the step of coupling light from the first light source further comprises multiplexing the more than one wavelengths of light into the first optical fiber.

40. The method of claim 39 wherein the second optical element further comprises a a second optical fiber having an end at the tissue contacting surface, the step of launching the light further comprises launching the one or more wavelengths simultaneously, and the step of sensing the light intensity further comprises transmitting the light intensity at the end of the second optical fiber to a light demultiplexor for separating the more than one sensed wavelengths into a corresponding more than one separate optical signals, and separately sensing the light intensity of the wavelength of each separate optical signal.

41. The method of claim 40 wherein the separate signals are separated by wavelength and the step of separately sensing the separate signals further comprises sensing each of the separate signals by a different light detector.

42. The method of claim 39 wherein the first optical element further comprises a first optical fiber having an end at the tissue contacting surface and the step of launching light further comprises coupling light from a first light source into the first optical fiber for transmission to the tissue.

43. The method of claim 42 wherein the second optical element further comprises a second optical fiber having an end at the tissue contacting surface and the step of sensing the light intensity further comprises transmitting the light intensity at the end of the second optical fiber to a light detector.

44. A method for passing a surgical appliance through tissue and into a body cavity comprising:

providing the surgical appliance with a controlled light source and a light detector;

sensing the light intensity at the appliance in response to the controlled light source illumination of the tissue;

generating an electrical signal representative of the sensed light intensity of light at the appliance;

processing the electrical signal to identify changes in sensed light intensity corresponding to the surgical appliance moving relative to the tissue;

identifying a relative change in sensed light intensity based on comparing a first sensed light intensity of the appliance at a first tissue depth and a second sensed light intensity of the appliance at a second tissue depth, the second tissue depth being closer to the body cavity than the first tissue depth; and

indicating that the appliance is about to pass into the body cavity in response to the identified relative change corresponding to a selected relative change in light intensity.

45. The method of claim 44 wherein the controlled light source provides more than one monochromatic wavelength of light and the processing and indicating steps further comprise providing separate electrical signals for each of the more than one wavelengths of light sensed, processing each of the provided separate signals separately, and indicating that the appliance is about to pass through the tissue into the body cavity when relative change in intensity of at least one of the one or more separate signals corresponds to a selected relative change in light intensity, each wavelength having a selected relative change appropriate for that wavelength.

46. The method of claim 45 wherein the indicating step further comprises indicating that the appliance is about to pass through the tissue into the body cavity when the relative change in intensity of all of the one or more separate signals corresponds to their respective selected relative changes in light intensity.

47. The method of claim 46 wherein the indicating step further comprises providing a first alarm when the relative intensity change of at least one of the separate signals corresponds to the appliance being about to pass through the tissue into the body cavity and providing a second alarm when the relative intensity changes of all of the separate signals corresponds to the appliance being about to pass through the tissue into the body cavity.

48. The method of claim 45 wherein the indicating step further comprises providing a first alarm.

49. The method of claim 44 wherein the indicating step further comprises providing a first alarm.

50. A method for passing a surgical appliance through tissue comprising:

providing the surgical appliance with a controlled light source and a light detector;

sensing the light intensity at the appliance in response to the controlled light source illumination of the tissue;

generating an electrical signal representative of the sensed light intensity of light at the appliance;

processing the electrical signal to identify changes in sensed light intensity corresponding to the surgical appliance moving relative to the tissue, said processing step comprising evaluating the electrical signal for the existence of sensed light variations corresponding to a blood flow in a blood vessel in the illuminated tissue; and

indicating when the appliance is about to pass through a blood vessel in the tissue in response to an identified change of said sensed light variations corresponding to a selected relative change indicative of blood flow.

51. The method of claim 50 wherein the indicating step further comprises indicating when the appliance is about to pass through an venus blood vessel in the tissue.

52. The method of claim 50 wherein the indicating step further comprises indicating when the appliance is about to pass through a venus blood vessel in the tissue.

53. The method of claim 50 wherein the controlled light source provides more than one monochromatic wavelength of light and the processing and indicating steps further comprise providing separate electrical signals for each of the more than one wavelengths of light sensed, processing each of the provided separate signals separately, and indicating that the appliance is about to pass through the blood vessel when the relative change of said sensed light variations of at least one of the one or more separate signals corresponds to a selected relative change indicative of blood flow, each wavelength having a selected relative change appropriate for that wavelength.

54. The method of claim 53 wherein the indicating step further comprises indicating that the appliance has passed into the blood vessel when the relative change in intensity of all of the one or more separate signals corresponds to their respective selected relative changes.

55. The method of claim 50 wherein the indicating step further comprises providing a first alarm.

56. A tissue penetrating appliance comprising:

a sharp tip having a tissue contacting surface configured to penetrate tissue and a longitudinal axis, the tissue contacting surface having a first face lying in a first plane at an angle relative to the longitudinal axis;

a source of light having one or more monochromatic wavelengths;

a light detector responsive to a sensed light intensity having an electrical signal corresponding to the sensed light intensity;

a first light transmitting optical element having a first end and a second end, operatively connected between the light source and the tip to emit from a first location on the tissue contacting surface one or more selected wavelengths of light from the light source;

a second light transmitting optical element having a first end and a second end, operatively connected between the light detector and the tip to receive at a second location on the tissue contacting surface light corresponding to the one or more selected wavelengths of light, the first and second locations being spaced apart, wherein the first optical element first end terminates in the first face in the first plane, and the second optical element first end terminates in the tissue contacting surface;

a control circuit connected to the light source having a first state to cause the light source to emit light at the one or more wavelengths and said light received at the second optical element first end is coupled to the light detector to provide an electrical signal corresponding to said received light; and

means for processing the provided electrical signals and determining when the appliance tip has entered a body cavity.

57. The apparatus of claim 56 further comprising means for processing the provided electrical signals and determining when the appliance tip is about to enter a body cavity.

58. The apparatus of claim 57 further comprising an annunciator having a variable audible signal, wherein the processing means actuates the annunciator when the tip is in proximity to the body cavity to produce a variable signal corresponding to the extent that the tip is about to pass into and has passed into the body cavity.

59. The apparatus of claim 56 further comprising means for processing the provided electrical signals and determining when the appliance tip is in proximity to venous perfused tissue.

60. The apparatus of claim 56 further comprising means for processing the provided electrical signals and determining when the appliance tip is in proximity to arterial perfused tissue.

61. The apparatus of claim 56 wherein each of the first and second optical elements further comprises a length of fiber optic conductor.