Electrically sensing and stimulating system for placement of a nerve stimulator or sensor

• US 6,829,508 B2
• Filed: 04/04/2002
• Issued: 12/07/2004
• Est. Priority Date: 10/19/2001
• Status: Active Grant

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Fey, Kate E., Schulman, Joseph H., Byers, Charles L., Canfield, David L., Weisner, Ralph M.
• Primary Examiner(s): Layno, Carl
• Application Number:
  US10/116,619
• Publication Number:
  US 20030078643A1
• Time in Patent Office: 978 Days
• Field of Search: 607/48, 607/115-116, 607/118, 607/150, 600/585, 600/546-548
• US Class Current: 607/116
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes

Abstract

An electrically sensing and stimulating outer sheath for ensuring accurate surgical placement of a microsensor or a microstimulator near a nerve in living tissue is disclosed. The electrically sensing outer sheath may also be used to verify the function of the microstimulator or microsensor during surgical placement but before the outer sheath is removed. In the event that the microstimulator is not optimally placed near the nerve, or if the microstimulator is malfunctioning, this can be determined prior to removal of the outer sheath, thus reducing the possibility of nerve or tissue damage that might be incurred during a separate operation to remove the microstimulator.

Claims

1. An insertion device for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an outer sheath configured for receiving the medical device, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current to the living tissue for stimulating a neuro-muscular pathway for determining the proximity of the outer sheath to the neuro-muscular pathway in order to position said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway.

2. The insertion device according to claim 1 further comprising an electrical stimulator electrically coupled to said electrical conductor.

8. The insertion device according to claim 1 wherein said outer sheath is substantially cylindrically shaped having an outer diameter and an inner diameter defining a wall therebetween and wherein said electrical conductor comprises an electrical conductor located inside said wall of said outer sheath.

3. An insertion device for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an outer sheath configured for receiving said medical device, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for determining the proximity of the outer sheath to the neuro-muscular pathway in order to position said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway; and

wherein said outer sheath has a distal end, said distal end being sharpened.

4. An insertion device for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an outer sheath configured for receiving said medical device, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for determining the proximity of the outer sheath to the neuro-muscular pathway in order to position said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway; and

wherein said outer sheath has a proximal end and a distal end and said outer sheath includes a ring electrode at said distal end that is coupled to said electrical conductor for contacting the living tissue.

5. An insertion device for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an outer sheath configured for receiving said medical device, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for determining the proximity of the outer sheath to the neuro-muscular pathway in order to position said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway;

wherein said outer sheath has a proximal end and a distal end and said outer sheath includes a ring electrode at said distal end that is coupled to said electrical conductor for contacting the living tissue; and

a ring return electrode, located on said outer sheath between said proximal end and said distal end, to form an electrical return path.

6. An insertion device for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an outer sheath configured for receiving said medical device, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for determining the proximity of the outer sheath to the neuro-muscular pathway in order to position said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway; and

wherein said outer sheath has a proximal end and a distal end and said electrical conductor comprises an electrically insulated wire located between said proximal end and said distal end.

7. An insertion device for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an outer sheath configured for receiving said medical device, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for determining the proximity of the outer sheath to the neuro-muscular pathway in order to position said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway; and

wherein said outer sheath is substantially cylindrically shaped having an outer diameter and an inner diameter defining a wall therebetween and wherein said electrical conductor comprises an insulated wire located inside said wall of said outer sheath.

9. An insertion device suitable for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an inner sheath capable of forcing said medical device through an outer sheath, said outer sheath surrounding said inner sheath, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current to the living tissue for stimulating a neuro-muscular pathway for positioning said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway.

10. The insertion device according to claim 9 further comprising an electrical stimulator electrically coupled to said electrical conductor.

11. The insertion device according to claim 9 wherein said inner sheath has a distal end, said distal end being sharpened.

12. An insertion device suitable for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an inner sheath capable of forcing said medical device through an outer sheath, said outer sheath surrounding said inner sheath, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for positioning said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway; and

wherein said outer sheath has a distal end, said distal end being sharpened.

13. An insertion device suitable for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an inner sheath capable of forcing said medical device through an outer sheath, said outer sheath surrounding said inner sheath, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for positioning said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway; and

wherein said outer sheath has a distal end and said outer sheath includes a ring electrode at said distal end that is coupled to said electrical conductor for contacting the living tissue.

14. An insertion device suitable for placement of a medical device proximate to a desired neuro-muscular pathway in living tissue, said insertion device comprising:

an inner sheath capable of forcing said medical device through an outer sheath, said outer sheath surrounding said inner sheath, said outer sheath having an electrical conductor configured for contacting the living tissue and passing an electric current between said medical device and the living tissue for stimulating a neuro-muscular pathway for positioning said outer sheath near a neuro-muscular pathway so as to facilitate implantation of said medical device proximate to the neuro-muscular pathway;

wherein said outer sheath has a distal end and said outer sheath includes a ring electrode at said distal end that is coupled to said electrical conductor for contacting the living tissue; and

wherein said outer sheath has a proximal end, said outer sheath additionally comprising a ring return electrode located on said outer sheath between said proximal end and said distal end to form an electrical return path.

15. A method of placing an implantable medical device proximate to a desired neuro-muscular pathway in living tissue, said method comprising the steps of:

inserting an inner sheath and an outer sheath into a desired location of a patient'"'"'s body, said inner sheath being removably housed within said outer sheath;

stimulating the neuro-muscular pathway by conducting electricity through said outer sheath for determining the position of said outer sheath relative to the neuro-muscular pathway;

removing said inner sheath;

inserting said implantable medical device through said outer sheath until said implantable medical device is positioned proximate to the neuro-muscular pathway; and

removing said outer sheath.

16. An insertion device for placement of a implantable microdevice proximate to a neuro-muscular pathway in living tissue, said implantable microdevice adapted for neuro-muscular stimulation and sensing proximate to a desired neuro-muscular pathway in living tissue said system comprising:

an outer sheath and an inner sheath adapted for penetration into living tissue said inner sheath being a hollow tube having an outside diameter that is approximately equal to an outside diameter of said implantable microdevice and removably insertable into said outer sheath, such that when said inner sheath is inserted into said outer sheath, said inner sheath may be suitable to be removably insertable into the living tissue; and

wherein

said outer sheath comprises an electrical conductor for conducting electric current; and

wherein

said outer sheath comprises an outer sheath electrode coupled to said electrical conductor and adapted for contacting living tissue for stimulating the neuro-muscular pathway for determining the proximity of said outer sheath to the neuro-muscular pathway, so as to facilitate implantation of said microdevice proximate to the neuro-muscular pathway.

17. The insertion device according to claim 16 further comprising:

a rigid electrode probe, having a sharpened end, said probe being removably insertable into said inner sheath; and

said electrode probe being electrically conductive at said sharpened end and adapted for contacting and electrically stimulating desired living tissue.

18. The insertion device according to claim 17 wherein said electrode probe is electrically coupled to and energized by a foot-operated switch.

19. The insertion device according to claim 16 wherein said outer sheath is substantially cylindrically shaped having an outer diameter and an inner diameter defining an inner surface and an outer surface and wherein said electrical conductor is an insulated wire that is located along said inner surface of said outer sheath.

20. The insertion device according to claim 16 wherein said outer sheath is substantially cylindrically shaped having an outer diameter defining an outer surface and an inner diameter defining an inner surface and wherein said electrical conductor is an insulated wire that is located along said outside surface of said outer sheath.

21. The insertion device according to claim 16 wherein said outer sheath is substantially cylindrically shaped having an outer diameter defining an outer surface and an inner diameter defining an inner surface and wherein said electrical conductor is an insulated wire that is located inside said wall of said outer sheath.

22. The insertion device according to claim 16 wherein said electrical conductor is a ring electrode.

23. The insertion device according to claim 16 wherein an outer sheath is substantially cylindrically shaped having an outer diameter defining an outer surface and an inner diameter defining an inner surface and wherein a ring return electrode is located on said outer surface of said outer sheath to form an electrical return path.

24. The insertion device according to claim 16 wherein said outer sheath is substantially cylindrically shaped having an outer diameter and an inner diameter defining a wall therebetween and wherein said electrical conductor is a conductive path of metal that is located in said wall of said outer sheath.

25. The insertion device according to claim 16 additionally comprising a blunt-end push rod, which is removably insertable into said outer sheath and is configured for pushing said microdevice through said outer sheath and into proximity to the neuro-muscular pathway.

26. The insertion device according to claim 16 wherein said implantable microdevice comprises:

a hermetically-sealed housing;

at least two exposed electrodes for passing an electrical signal between said microdevice and the surrounding tissue; and

electronic circuit means within said housing for generating or receiving an electrical signal.

27. A method of placing a microdevice proximate to a neuro-muscular pathway in living tissue when it is located near the neuro-muscular pathway, said method comprising the steps of:

inserting an electrode probe in the living tissue to locate near the neuro-muscular pathway;

electrically stimulating the neuro-muscular pathway with said electrode probe;

monitoring a neuro-muscular response to verify the location of said electrode probe with respect to the neuro-muscular pathway;

placing an outer sheath and an inner sheath around said electrode probe;

positioning said outer sheath and said inner sheath near the neuro-muscular pathway;

removing said electrode probe;

electrically stimulating the neuro-muscular pathway with said outer sheath to verify the location of said outer sheath with respect to the neuro-muscular pathway;

inserting said microdevice through said outer sheath into the living tissue; and

confirming the location of said microdevice with said outer sheath by electrically stimulating the neuro-muscular pathway and detecting a response thereto before removing said outer sheath.

28. The method of claim 27 further comprising confirming the location of said microdevice near the neuro-muscular pathway, prior to ejecting said microdevice from said outer sheath, by electrically stimulating the neuro-muscular pathway by passing an electric current from an electrical stimulator along an outer sheath lead wire to an outer sheath electrode located on said outer sheath and detecting a response thereto.

29. The method of claim 27 further comprising removing said microdevice from the living tissue with said outer sheath if said microdevice has not been ejected from said outer sheath.

30. An insertion device for placement of a microdevice for modifying or affecting a body parameter when said microdevice is located near a desired neuro-muscular pathway in living tissue, said microdevice substantially cylindrically shaped having an outer diameter, said system comprising:

an outer sheath having a distal end, said distal end being sharp and being expandable to allow said microdevice to be ejected therethrough, wherein said outer sheath is a substantially cylindrically shaped hollow tube having an inner diameter approximately equal to said outer diameter of said microdevice, said outer sheath being sized to temporarily house said microdevice, wherein said outer sheath is removably insertable into the living tissue;

an electrical conductor forming a part of said outer sheath; and

wherein

said outer sheath contains an electrode located on said distal end configured for contacting the living tissue and that is electrically connected to said electrical conductor for passing an electrical signal between said insertion device and the living tissue to confirm that said distal end is suitably positioned near the neuro-muscular pathway.

31. The insertion device according to claim 30 wherein said outer sheath has an outer diameter defining an outer surface, said electrode comprising a ring electrode on said outer surface that is coupled to said electrical signal conducting means.

32. The insertion device according to claim 31 wherein a ring return electrode is located on said outer surface of said outer sheath to form an electrical return path.

33. An implantation device for placement of a microdevice for modifying or affecting a body parameter when said microdevice is located near a desired neuro-muscular pathway in living tissue, said microdevice being substantially cylindrically shaped having an outer diameter, said device comprising:

an outer sheath being substantially cylindrically shaped having an inner diameter that defines a hollow center with said internal diameter slightly larger than said outer diameter of said microdevice that is to pass through said hollow center, wherein said outer sheath has a distal end that is sharpened for penetrating living tissue and further has an aperture that passes through said distal end;

an outer sheath connection means for attaching to said implantation device;

a plunger that is removably insertable into said hollow center of said outer sheath;

a ratcheting lever actuateable for causing said plunger to slide in said hollow center toward said distal end; and

means for conducting an electrical signal along said outer sheath to a sheath electrode that is located at said distal end.

34. The implantation device according to claim 33 wherein said sheath electrode comprises a ring electrode coupled to means for conducting an electrical signal.

35. The implantation device according to claim 33 wherein a ring return electrode is located on said outer sheath to form an electrical return path.

36. The implantation device according to claim 33 additionally comprising means for placing sold microdevice into said hollow center of said outer sheath to enable placement of said microdevice at said distal end of said outer sheath.

37. The implantation device according to claim 33 further comprising:

an elongated electrode probe having an outer diameter,

said plunger being substantially cylindrical in cross-section, said plunger having a length and an inner diameter defining a passageway extending longitudinally along said length thereof, said inner diameter of said probe being slightly larger than said outer diameter of said electrode probe; and

wherein

said electrode probe is removably insertable into said plunger.

38. An insertion device for placement of an implantable medical device proximate to a neuro-muscular pathway in living tissue, said insertion device comprising:

an outer sheath, having an expandable sharpened tip for penetrating the living tissue, said tip being expandable to allow said implantable medical device to be removably ejected from said outer sheath; and

an electrical conductor forming a part of said outer sheath, wherein said electrical conductor is configured for contacting the living tissue and passing an electric current to the living tissue in order to facilitate positioning said outer sheath near the neuro-muscular pathway.

39. An insertion device adaptable for placement of an implantable medical device proximate to a neuro-muscular pathway in living tissue, wherein said implantable medical device having an axial dimension of less than 60 mm and a lateral dimension of less than 6 mm, said system comprising an outer sheath configured for at least partially containing said implantable medical device, wherein said outer sheath has an outer diameter and an inner diameter defining a wall, said wall defining at least one through hole in said wall, said hole located to enable electrical contact between said implantable medical device while contained in said outer sheath and the living tissue.

40. The insertion device according to claim 39 wherein said medical device is a microstimulator.

41. The insertion device according to claim 39 wherein said medical device is a microsensor.