Implantable optical pressure sensor for sensing urinary sphincter pressure

• US 20060247724A1
• Filed: 04/28/2005
• Published: 11/02/2006
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gerber, Martin T., Miesel, Keith A., Shumaker, Steven J.
• Granted Patent: US 7,610,093 B2
• Time in Patent Office: Days
• US Class Current: 607/41
• CPC Class Codes: A61B 5/202 Assessing bladder functions, e.g. incontinence assessment
• CPC Class Codes: A61B 5/205 Determining bladder or urethral pressure
• CPC Class Codes: A61N 1/36007 of urogenital or gastrointestinal organs, e.g. for incontinence control

Abstract

The disclosure describes an optical fiber pressure sensor to measure sphincter pressure which may be incorporated into a therapeutic sphincter control system. The system senses sphincter pressure and sends the information to a stimulator that is capable of stimulation therapy to control sphincter contractility, thus reducing unwanted urinary incontinence. Measuring sphincter pressure is accomplished through the use of an optical fiber connected to flexible tube section placed through the sphincter, where properties of the emitted light are changed proportional to the pressure on the tube section. The light is returned to a light detector to measure light properties and create an electrical signal representative of the pressure on the tube section. The signal may then be sent by wireless telemetry to an implanted stimulator or external programmer.

Claims

1. An implantable electrical stimulation system comprising:

an implantable pressure sensor including an optical fiber, an emitter that transmits light via the optical fiber, a detector that detects reflected light via the optical fiber, circuitry that generates pressure information based on the detected light, and a fixation mechanism that positions the optical fiber proximate a sphincter within a patient; and

an implantable stimulator that delivers electrical stimulation to the patient based on the pressure information.

2. The system of claim 1, wherein the implantable pressure sensor further includes a flexible tube section coupled to the optical fiber, and a reflective, flexible diaphragm mounted within the flexible tube section, wherein the diaphragm reflects the light transmitted via the optical fiber, and deflects in response to exertion of pressure against the flexible tube section by the sphincter.

3. The system of claim 2, wherein the circuitry generates the pressure information based on changes in one or more properties of the reflected light in response to deflection of the diaphragm.

4. The system of claim 2 wherein the optical fiber includes a first optical fiber that transmits the light from the emitter and a second optical fiber that receives the light reflected by the diaphragm.

5. The system of claim 2, wherein the optical fiber and the flexible tube section have a combined length of less than approximately 7 cm and the flexible tube section has an outer diameter of approximately 1 to 3 mm.

6. The system of claim 1, wherein the implantable pressure sensor includes a housing, the optical fiber extending from the housing, and the fixation mechanism is positioned to attach the housing to an inner wall of a bladder of the patient.

7. The system of claim 1, wherein the implantable sensor includes a telemetry circuit that transmits the pressure information.

8. The system of claim 7, wherein the telemetry circuit transmits the pressure information to the implantable stimulator, the implantable stimulator adjusting one or more parameters of the electrical stimulation based on the transmitted pressure information.

9. The system of claim 7, further comprising an external programmer to adjust stimulation parameters associated with the electrical stimulation delivered by the implantable stimulator, wherein the telemetry circuit transmits the pressure information to the external programmer.

10. The system of claim 1, wherein the implantable pressure sensor includes a sensor housing, wherein the optical fiber and flexible tube section extend from the sensor housing, the system further comprising a cystoscopic deployment device to deploy the implantable pressure sensor, the deployment device defining a cavity to carry the sensor housing and a channel to accommodate the optical fiber and flexible tube section extending from the housing.

11. A method comprising:

transmitting light via an optical fiber positioned proximate a sphincter within a patient;

detecting reflected light via the optical fiber; and

generating pressure information based on the detected light.

12. The method of claim 11, wherein the optical fiber is coupled to a flexible tube section that contains a reflective, flexible diaphragm mounted within the flexible tube section, and the flexible tube section is mounted within the sphincter, wherein the diaphragm reflects the light transmitted via the optical fiber, and deflects in response to exertion of pressure against the flexible tube section by the sphincter.

13. The method of claim 12, further comprising generating the pressure information based on changes in one or more properties of the reflected light in response to deflection of the diaphragm.

14. The method of claim 11, wherein the optical fiber includes a first optical fiber that transmits the light and a second optical fiber that receives the light reflected by the diaphragm.

15. The method of claim 11, wherein the optical fiber extends from a housing, the method further comprising attaching the housing to a bladder wall of the patient.

16. The method of claim 11, wherein the optical fiber is positioned proximate a urinary sphincter of the patient.

17. The method of claim 11, further comprising adjusting one or more parameters of electrical stimulation delivered to the patient based on the pressure information.

18. The method of claim 11, further comprising cystoscopically deploying the optical fiber within the urethra.

19. An implantable pressure sensor comprising:

an optical fiber;

an emitter that transmits light via the optical fiber;

a detector that detects reflected light via the optical fiber;

circuitry that generates pressure information based on the detected light; and

a fixation mechanism that positions the optical fiber proximate a sphincter within a patient.

20. The sensor of claim 19, wherein the implantable pressure sensor further includes a flexible tube section coupled to the optical fiber, and a reflective, flexible diaphragm mounted within the flexible tube section, wherein the diaphragm reflects the light transmitted via the optical fiber, and deflects in response to exertion of pressure against the flexible tube section by the sphincter.

21. The sensor of claim 20, wherein the circuitry generates the pressure information based on changes in one or more properties of the reflected light in response to deflection of the diaphragm.

22. The sensor of claim 20, wherein the optical fiber includes a first optical fiber that transmits the light from the emitter and a second optical fiber that receives the light reflected by the diaphragm.

23. The sensor of claim 20, wherein the optical fiber and the flexible tube section have a combined length of less than approximately 7 cm and the flexible tube section has an outer diameter of approximately 1 to 3 mm.

24. The sensor of claim 19, wherein the implantable pressure sensor includes a housing, the optical fiber extending from the housing, and the fixation mechanism is positioned to attach the housing to an inner wall of a bladder of the patient.

25. The sensor of claim 19, wherein the implantable sensor includes a telemetry circuit that transmits the pressure information.

26. The sensor of claim 19, further comprising a sensor housing, wherein the optical fiber extends from the sensor housing, and wherein the fixation mechanism includes a vacuum cavity defined by the sensor housing and a pin that extends through tissue captured in the vacuum cavity.

27. An implantable pressure sensor comprising:

a sensor housing;

an optical fiber extending from the sensor housing;

a flexible tube section coupled to the optical fiber;

a reflective, flexible diaphragm within the flexible tube section;

an emitter that transmits light via the optical fiber to the diaphragm;

a detector that detects reflected light from the diaphragm the optical fiber;

circuitry that generates pressure information based on the detected light; and

a fixation mechanism that positions the optical fiber proximate a sphincter within a patient,

wherein the diaphragm deflects in response to exertion of pressure against the flexible tube section by the sphincter.

28. The sensor of claim 27, wherein the optical fiber includes a first optical fiber that transmits the light from the emitter and a second optical fiber that receives the light reflected by the diaphragm.

29. The sensor of claim 27, wherein the optical fiber and the flexible tube section have a combined length of less than approximately 7 cm and the flexible tube section has an outer diameter of approximately 1 to 3 mm.

30. The sensor of claim 27, further comprising a sensor housing, wherein the optical fiber extends from the sensor housing, and wherein the fixation mechanism includes a vacuum cavity defined by the sensor housing and a pin that extends through tissue captured in the vacuum cavity.