Expandable fixation mechanism

• US 20060095078A1
• Filed: 10/29/2004
• Published: 05/04/2006
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Tronnes, Carole A.
• Granted Patent: US 8,489,189 B2
• Time in Patent Office: Days
• US Class Current: 607/2
• 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 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation

Abstract

In general, the invention is directed to a medical device implantable in a body of a patient. The device includes a housing with a plurality of collapsible fixation structures coupled to the housing, and can be in a collapsed configuration or an expanded configuration. The device assumes a collapsed configuration when in the bore of an insertion device, and assumes the expanded configuration when expelled from the insertion device into the body of the patient. The extended fixation structures engage the tissues in the body and restrict migration. One exemplary application of the invention is in the context of a microstimulator, with a pulse generator housed in the housing and one or more electrodes coupled to the housing. The fixation structures help keep the electrodes proximate to the tissues that are to receive the stimulation.

Claims

1. An implantable medical device comprising:

a housing;

an electrode coupled to the housing;

a pulse generator coupled to the electrode; and

a plurality of collapsible fixation structures coupled to the housing.

2. The device of claim 1, wherein the housing is constructed of at least one of silicone, polyurethane, titanium, stainless steel, fluoropolymer and hydrogel.

3. The device of claim 1, wherein at least one fixation structure is constructed of at least one of silicone, polyurethane, titanium, stainless steel, fluoropolymer and hydrogel.

4. The device of claim 1, wherein the housing is substantially cylindrical and has a diameter from one millimeter to seven millimeters.

5. The device of claim 1, wherein a length of the housing is from ten millimeters to twenty millimeters.

6. The device of claim 1, further comprising a power supply coupled to the pulse generator.

7. The device of claim 1, wherein the fixation structures include flanges.

8. The device of claim 1, wherein the fixation structures include tines.

9. The device of claim 1, wherein the collapsible fixation structures are configured to assume a fully expanded state, wherein the housing defines an axis, and wherein the fixation structures are oriented substantially orthogonally from the axis when in the fully expanded state.

10. The device of claim 1, wherein the collapsible fixation structures are configured to assume a collapsed state, and wherein the device is sized to fit inside a bore of an insertion device.

11. The device of claim 1, wherein the insertion device comprises one of a needle, a hollow trocar, an endoscope, a catheter or a cannula.

12. The device of claim 1, wherein the collapsible fixation structures are configured to assume a fully expanded configuration, and wherein at least a portion of at least one fixation structure projects from one to seven millimeters from the housing when the fixation structure is in the fully expanded configuration.

13. The device of claim 1, wherein the device comprises an implantable neurostimulator.

14. The device of claim 1, wherein the device comprises an implantable physiological sensor.

15. An implantable medical device comprising:

a housing;

a plurality of at least ten collapsible fixation structures coupled to the housing.

16. The device of claim 15, wherein the housing is constructed of at least one of silicone, polyurethane, titanium, stainless steel, fluoropolymer and hydrogel.

17. The device of claim 15, wherein at least one fixation structure is constructed of at least one of silicone, polyurethane, titanium, stainless steel, fluoropolymer and hydrogel.

18. The device of claim 15, wherein the housing comprises a hollow sleeve sized to fit over an implantable medical lead.

19. The device of claim 15, wherein the fixation structures include flanges.

20. The device of claim 15, wherein the fixation structures include tines.

21. The device of claim 15, wherein the collapsible fixation structures are configured to assume a fully expanded state, wherein the housing defines an axis, and wherein the fixation structures are oriented substantially orthogonally from the axis when in the fully expanded state.

22. The device of claim 15, wherein the housing is substantially cylindrical and has a diameter from one millimeter to seven millimeters.

23. The device of claim 15, wherein a length of the housing is from ten millimeters to twenty millimeters.

24. The device of claim 15, wherein the collapsible fixation structures are configured to assume a fully expanded configuration, and wherein at least a portion of at least one fixation structure projects from one to seven millimeters from the housing when the fixation structure is in the fully expanded configuration.

25. The device of claim 15, wherein the device comprises an implantable neurostimulator.

26. The device of claim 15, wherein the device comprises an implantable physiological sensor.

27. A method for implanting a medical device, comprising:

placing a medical device into a bore of an insertion device;

inserting the insertion device into the body of a patient; and

ejecting the medical device from the insertion device proximate to a target tissue,

wherein the medical device includes a plurality of collapsible fixation structures configured to assume one of an expanded state and a collapsed state,

wherein placing the medical device into the bore causes the medical device to assume the collapsed state, and

wherein ejecting the medical device causes the medical device to assume the expanded state.

28. The method of claim 27, wherein the medical device comprises an implantable neurostimulator.

29. The method of claim 27, wherein the medical device comprises an implantable physiological sensor.

30. The method of claim 27, wherein the insertion device comprises one of a needle, a hollow trocar, an endoscope, a catheter or a cannula.

31. An implantable medical device comprising:

a pulse generator means for generating an electrical stimulation;

a housing means for housing the pulse generator means;

an electrode means for delivering the electrical stimulation from the pulse generator means to a target tissue; and

a plurality of collapsible fixation means coupled to the housing means for restricting migration of the housing means when the housing means is implanted proximate to the target tissue.

32. The implantable medical device of claim 31, further comprising a power supply means coupled to the pulse generator means for supplying power to the pulse generator means.