CANNULA CONFIGURED TO DELIVER TEST STIMULATION

• US 20080269740A1
• Filed: 04/25/2007
• Published: 10/30/2008
• Est. Priority Date: 04/25/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gerber, Martin T., Bonde, Eric H.
• Granted Patent: US 9,399,130 B2
• Time in Patent Office: Days
• US Class Current: 606/53
• CPC Class Codes: A61B 17/3415 for introducing tubes or catheters, e.g. gastrostomy tubes, drain catheters A61B17/3417 takes precedence; body piercing catheter guide needles A61M25/06
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2090/3937 Visible markers
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0558 Anchoring or fixation means therefor
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/37241 providing test stimulations

Abstract

The disclosure is directed to an implant tool and cannula used to facilitate the implantation of a medical device into a patient. The implant tool includes a housing that is held by a user and a needle attached to the housing. The cannula may be positioned over the needle and delivered to a target tissue within the patient. The cannula includes an electrode at a distal portion to deliver test stimulation to confirm the location of the target site or placement of the implant tool relative to the target site before removing the needle of the implant tool. In this manner, the cannula may be repositioned within the patient until the position of the implant tool and cannula relative to the target site is verified with the test stimulation.

Claims

1. A cannula comprising:

an elongated housing defining a lumen configured to allow passage of a medical device;

an electrode positioned on a distal portion of the elongated housing;

an electrical contact positioned on a proximal portion of the elongated housing; and

a conductive element that resides within the elongated housing and electrically couples the electrode to the electrical contact.

2. The cannula of claim 1, wherein the elongated housing comprises a shape memory material.

3. The cannula of claim 1, wherein the lumen defined by the elongated housing is configured to receive a needle of an implant tool.

4. The cannula of claim 1, wherein the electrode comprises a ring electrode positioned around an outer circumference of the elongated housing.

5. The cannula of claim 1, wherein the electrode comprises a partial ring electrode.

6. The cannula of claim 1, further comprising a plurality of electrodes located at different circumferential positions around the distal end of the elongated housing.

7. The cannula of claim 6, further comprising a plurality of electrical contacts located at the proximal end of the elongated housing, wherein each of the plurality of electrical contacts are electrically coupled to one of the plurality of electrodes via separate conductive elements.

8. The cannula of claim 1, wherein the conductive element substantially defines a helix around the elongated housing between the proximal end and the distal end.

9. A system comprising:

a cannula comprising;

an elongated housing defining a lumen configured to allow passage of a medical device;

an electrode positioned on a distal portion of the elongated housing;

a first electrical contact positioned on a proximal portion of the elongated housing; and

a conductive element that resides within the elongated housing and electrically couples the electrode to the electrical contact; and

an implant tool comprising;

a needle coupled to a housing and configured to be inserted into tissue of a patient and to fit within an inner lumen of the cannula; and

a second electrical contact configured to electrically couple to the first electrical contact.

10. The system of claim 9, wherein the elongated housing comprises a shape memory material.

11. The system of claim 9, wherein the electrode comprises a ring electrode positioned around an outer circumference of the elongated housing.

12. The system of claim 9, further comprising:

a plurality of electrodes located at different circumferential positions around the distal end of the elongated housing; and

a plurality of electrical contacts located at the proximal portion of the elongated housing, wherein each of the plurality of electrical contacts are electrically coupled to one of the plurality of electrodes via separate conductive elements.

13. The system of claim 9, further comprising a signal generator that generates test stimulation delivered to the tissue via the electrode of the elongated housing.

14. The system of claim 9, wherein the implant tool comprises:

a flange that extends near a side of the needle and defines a channel configured to accept the cannula between the needle and the flange; and

a release mechanism configured to move the cannula toward a distal end of the needle.

15. The system of claim 9, further comprising an electrical stimulator configured to couple to the second electrical contact of the implant tool.

16. The system of claim 15, wherein the electrical stimulator is located within a housing of the implant tool.

17. A method comprising:

introducing a cannula and needle assembly into a patient, wherein the needle is at least partially disposed within a lumen of the cannula, and wherein the lumen is configured to allow passage of a medical device;

advancing the cannula to a target site within the patient; and

delivering test stimulation to the patient via an electrode positioned at a distal portion of the cannula.

18. The method of claim 17, wherein advancing the cannula comprises tunneling the cannula through tissue with a piercing tip of the needle.

19. The method of claim 17, wherein delivering test stimulation comprises delivering test stimulation to tissue of the patient located adjacent to a circumferential subsection of the cannula.

20. The method of claim 17, further comprising:

removing the needle from the cannula after delivering test stimulation; and

passing the medical device to the target site through the lumen of the cannula.

21. The method of claim 20, wherein removing the needle from the cannula comprises:

moving the cannula off of the needle in a first direction with a release mechanism coupled to the needle; and

simultaneously retracting the needle from the patient in a second direction opposite the first direction.

22. The method of claim 17, wherein the test stimulation comprises a first test stimulation, the method further comprising rotating the cannula and delivering a second test stimulation to the patient.

23. The method of claim 17, further comprising adjusting a position of the needle within the patient after delivering the test stimulation.