Method and apparatus for monitoring disc pressure during heat treatment of an intervertebral disc

• US 20060224223A1
• Filed: 03/30/2006
• Published: 10/05/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Sherwood Services AG
• Inventors: Podhajsky, Ronald J., Johnson, Kristin D.
• Granted Patent: US 7,627,380 B2
• Time in Patent Office: Days
• US Class Current: 607/117
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 2017/00261 Discectomy
• CPC Class Codes: A61B 2018/0044 Spinal cord
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension

Abstract

A probe system and method for treating an intervertebral disc of a patient are disclose. A probe has a cannula having an open end defined at a distal end and adapted to couple to a power source. A stylet fits into the cannula so that a distal end of the stylet occludes the open end at the distal end of the cannula. The probe system also includes a pressure monitoring apparatus coupled to the stylet, with the stylet including a pressure sensor in proximity to the distal end of the stylet. The pressure sensor communicates with the pressure monitoring apparatus to measure the pressure of the intervertebral disc. The power source delivers power to the distal end of the cannula, causing heating of the disc when the distal end of the cannula is disposed within the disc, thereby relieving patient pain associated with the disc.

Claims

1. A probe system for treating an intervertebral disc of a patient, comprising:

a probe, the probe comprising;

a cannula having a proximal end and a distal end and having an open end defined at the distal end thereof, said cannula adapted to couple to a power source;

a stylet having a proximal end and a distal end, said stylet fitting into said cannula so that the distal end of the stylet occludes said open end at said distal end of said cannula; and

a pressure monitoring apparatus adapted to be coupled to said stylet, said stylet including a pressure sensor in proximity to the distal end of said stylet, said pressure sensor adapted to communicate with said pressure monitoring apparatus so as to measure the pressure of the intervertebral disc, wherein the power source delivers power to said distal end of said cannula, causing heating of the disc when said distal end of said cannula is disposed within the disc, to relieve patient pain associated with the disc thereby.

2. The probe system in accordance with claim 1, wherein said pressure sensor is disposed in an aperture defined in proximity to the distal end of said stylet, and said pressure sensor is at least partially exposed through said aperture in said stylet, to sense pressure in the disc thereby.

3. The probe system in accordance with claim 1, wherein said stylet has a tip at the distal end of said stylet, said tip of said stylet having an aperture defined therein, and said pressure sensor is at least partially exposed through said aperture at said tip, to sense pressure in the disc thereby.

4. The probe system in accordance with claim 1, wherein said cannula is substantially insulated on a surface of said cannula in communication with the body of the patient including the intervertebral disc, said cannula having an uninsulated electrically conductive tip at the distal end of said cannula, said uninsulated electrically conductive tip adapted to couple to said power source such that when said distal end of said cannula is within the disc, power can be transmitted to heat the disc.

5. The probe system in accordance with claim 4 further comprising:

an impedance monitoring apparatus adapted to be coupled to said stylet by electrical interface to monitor the tissue impedance of the patient to confirm the proper placement of said distal end of said cannula inside of the disc.

6. The probe system in accordance with claim 1 further comprising:

a temperature monitoring apparatus adapted to be coupled to said stylet, said stylet including a temperature sensor in proximity to the tip of said stylet, said temperature sensor adapted to communicate with said temperature monitoring apparatus so as to measure the temperature of the intervertebral disc when the tip of said stylet is disposed in proximity to the disc.

7. A method of treating back or neck pain of a patient by heating an intervertebral disc, comprising the steps of:

providing a probe having a proximal end and a distal end, said distal end having a tip, said probe operatively coupled to a power source;

providing a pressure sensor in proximity to said tip of said probe and a pressure monitoring apparatus operatively coupled to the pressure sensor via the probe;

delivering power from said power source to said distal end of said probe, causing heating of the disc when the distal end of the probe is disposed within the disc, to relieve patient pain associated with the disc thereby; and

measuring pressure of the disc.

8. The method according to claim 7, wherein the step of delivering power from said power source to said disc via said probe is performed for a period of approximately one minute.

9. The method according to claim 8, wherein immediately following the step of delivering power from said power source to said disc via said probe, the method further comprises the step of turning off the power.

10. The method according to claim 9, wherein following the step of turning off the power, the method further comprises the steps of waiting for a period of approximately one minute and measuring the pressure sensed by the pressure sensor.

11. The method according to claim 10, wherein, if it is determined that further treatment is necessary based upon the measured pressure in that a substantial change in disc pressure to a pressure level below a threshold pressure has not been achieved, the method further comprises the step of re-delivering power from said power source to the disc via said probe causing heating of the disc.

12. The method in accordance with claim 7, wherein said probe is a radiofrequency electrode and said power source is a radiofrequency generator, the method further comprising the steps of:

increasing voltage output of said radiofrequency generator so as to send current through said radiofrequency electrode into the disc and thus heat the disc by ohmic heating; and

decreasing the voltage output of said radiofrequency generator after a change in disc pressure has been measured.

13. The method in accordance with claim 7, wherein said pressure sensor is disposed in proximity to said tip of said distal end of said probe, said probe having an aperture disposed such that said pressure sensor is at least partially exposed through said aperture in said probe, thereby to sense pressure in the disc.

14. The method in accordance with claim 7, wherein said pressure sensor is disposed at said tip of said distal end of said probe, said probe having an aperture disposed such that said pressure sensor is at least partially exposed through said aperture, thereby to sense pressure in the disc.

15. A method of treating back or neck pain of a patient by heating the interior of an intervertebral disc, comprising the steps of:

providing a probe, the probe having a proximal end and a distal end having a tip, said probe coupled to a power source;

providing a pressure sensor at one of at and in proximity to said tip of said probe and a pressure monitoring apparatus operatively coupled to said pressure sensor via said probe;

inserting said probe into said patient so that said tip at said distal end of said probe is positioned inside the intervertebral disc;

delivering power via said probe to said probe tip so as to heat tissue around said probe tip when said probe tip is in the intervertebral disc so that said probe tip causes heating of the interior of the intervertebral disc to a temperature substantially above body temperature by absorption of at least a portion of said power delivered via said probe tip to the tissue of the intervertebral disc, thereby causing heating and resultant changes in the disc material and nearby neurological structures to relieve the patient'"'"'s pain; and

monitoring pressure of the intervertebral disc by reading output of said pressure monitoring apparatus operatively coupled to said pressure sensor, and thereby quantitatively monitoring said heating process of the intervertebral disc.

16. The method in accordance with claim 15, wherein said pressure sensor is disposed in proximity to said tip of said distal end of said probe, said probe having an aperture disposed such that said pressure sensor is at least partially exposed through said aperture in said probe, thereby to sense pressure in the disc.

17. The method in accordance with claim 15, wherein said pressure sensor is disposed at said tip of said distal end of said probe, said probe having an aperture disposed such that said pressure sensor is at least partially exposed through said aperture in said probe, thereby to sense pressure in the disc.

18. The method according to claim 17, wherein the step of delivering power is performed for a period of approximately one minute.

19. The method according to claim 18, wherein immediately following the step of delivering power, the method further comprises the step of turning off the power.

20. The method according to claim 19, wherein following the step of turning off the power, the method further comprises the steps of waiting for a period of approximately one minute and reading the output of the pressure monitoring apparatus operatively coupled to said pressure sensor.

21. The method according to claim 20, wherein, if it is determined that further treatment is necessary based upon the measured pressure in that a substantial change in disc pressure to a pressure level below a threshold pressure has not been achieved, the method further comprises the step of:

re-delivering power from said power source to the disc via said probe causing heating of the disc.