Enhanced stability implantable medical device

• US 20090093765A1
• Filed: 10/08/2008
• Published: 04/09/2009
• Est. Priority Date: 10/09/2007
• Status: Active Grant

• Current Assignee: Stealth Therapeutics, Inc.
• Original Assignee: Stealth Therapeutics, Inc.
• Inventors: Glenn, Bradley J.
• Granted Patent: US 8,209,015 B2
• Time in Patent Office: Days
• US Class Current: 604/151
• CPC Class Codes: A61M 2039/0223 having means for anchoring the subcutaneous access site
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation

Abstract

An implantable medical device is provided which has a housing of an elongate form to minimize a size of an incision required for implantation. A stabilizing element is associated with the elongated form housing for the medical device. The stabilizing element transitions from a low profile initial form to a higher width final form to provide the medical device with a stabilized footprint after implantation. The stabilizing element is in the form of a rotating wing in one embodiment. In another embodiment, the stabilizing element is in the form of an expanding loop that can bend to extend out of side openings of a cavity within the housing, to provide such stabilization at the implantation site. The medical device can be in the form of a pacemaker, infusion pump, vascular access port or other subcutaneously implanted medical device.

Claims

1. A shape variable medical device for implantation subcutaneously, the medical device comprising in combination:

a housing;

said housing having an elongate form between a front end and a rear end;

said housing having a long axis extending from said front end to said rear end;

said housing having a lateral axis non-parallel with said long axis;

said lateral axis having a length less than a length of said long axis;

at least one stabilizing element;

said stabilizing element pivotably attached to said housing;

said stabilizing element having an elongate form extending between ends thereof;

said ends of said stabilizing element joined together by sides extending between said ends and on opposite portions of said stabilizing element;

said sides of said stabilizing element longer than said ends of said stabilizing element; and

said sides of said stabilizing element having a length longer than a length of said lateral axis, such that when said stabilizing element is rotated from a first position more aligned with said long axis to a second position more aligned with said lateral axis, said stabilizing element extends laterally from said housing to stabilize said housing.

2. The medical device of claim 1 wherein an axle extends from a bottom of said housing, said stabilizing element pivotably attached to said axle.

3. The medical device of claim 2 wherein said stabilizing element has a shape similar to that of a perimeter of said housing, such that said stabilizing element remains substantially within a perimeter of said housing when said stabilizing element has said ends of said stabilizing element aligned with said long axis of said housing.

4. The medical device of claim 3 wherein said stabilizing element is adapted to rotate at least about 45°

relative to said housing.

5. The medical device of claim 4 wherein a detent snap assembly is formed into said stabilizing element and said housing to cause said stabilizing element to tend to remain in a deployed position after rotation to said deployed position to maintain stability for said medical device.

6. The medical device of claim 4 wherein said housing and said stabilizing element include holes therein, said holes adapted to receive sutures passing therethrough to secure said stabilizing element in a deployed orientation rotated away from alignment with said perimeter of said housing to maintain stability of said medical device after implantation.

7. The medical device of claim 4 wherein electric leads extend from said housing and said housing contains at least portions of a pacemaker therein, such that said medical device is in the form of a pacemaker.

8. The medical device of claim 4 wherein an outlet tube extends from said housing and an infusion pump apparatus is at least partially contained within said housing, such that said medical device is in the form of an infusion pump.

9. The medical device of claim 4 wherein an outlet tube extends from said housing and a septum is formed in said housing into which a needle can removably pass in a resealing fashion, such that said medical device is in the form of a subcutaneous access port.

10. The medical device of claim 1 wherein a pair of stabilizing elements are each rotatably attached to said housing, each of said stabilizing elements having a first collapsed position generally aligned with an elongate form of said housing and contained substantially within a perimeter of said housing and a second deployed position where each of said stabilizing elements extends laterally outside of a perimeter of said housing.

11. The medical device of claim 10 wherein each of said stabilizing elements is adapted to rotate at least about 45°

in opposite directions from each other.

12. The medical device of claim 11 wherein each of said stabilizing elements has at least one end thereof which is beveled on a side facing the other, such that these beveled surfaces face each other and can receive a spreader rod therebetween to cause simultaneous rotation in opposite directions for the at least two stabilizing elements.

13. A shape changing medical device for implantation into a subcutaneous location, the medical device comprising in combination:

a housing;

said housing having an elongate form between a front end and a rear end;

said housing having a long axis extending from said front end to said rear end;

said housing having a lateral axis non-parallel with said long axis;

said lateral axis having a length less than a length of said long axis;

a cavity formed in said housing, said cavity having a rear opening out of said housing;

said cavity also having at least one side opening out of said housing; and

a stabilizing element adapted to extend at least partially laterally out of said at least one side opening of said cavity to enhance a lateral width of said medical device.

14. The shape changing medical device of claim 13 wherein said stabilizing element is adapted to bend to extend laterally out of said at least one side opening.

15. The shape changing medical device of claim 14 wherein said housing includes two opposite side openings, said stabilizing element adapted to extend out of both of said side openings.

16. The shape changing medical device of claim 15 wherein said stabilizing element is in the form of a continuous loop of bendable material.

17. The shape changing medical device of claim 16 wherein said loop includes four generally linear legs joined together by four joints including a front joint a rear joint and two side joints, said side joints adapted to be initially closer to each other and move away from each other when said loop is bent with said two side joints passing out of said two opposite side openings of said cavity to expand a width of said loop to greater than a width of said housing.

18. The shape changing medical device of claim 17 wherein said loop has a first elongate form narrower than a width of said housing and a second deployed form wider than a width of said housing.

19. A medical device adapted to be implanted subcutaneously and to morph between a lower profile dynamic form and a higher profile static form, the medical device comprising in combination:

a housing;

said housing adapted to contain at least a portion of a medical device therein for treatment of a patient into which the medical device is implanted;

said housing having an elongate form with a lateral cross-section lesser in area than a long axis cross-section;

said long axis non-parallel with said lateral cross-section;

a stabilizing element interfacing with said housing; and

said stabilizing element adapted to be affixed to said housing and adjusted to exhibit a width greater than a width of said lateral cross-section of said housing when said stabilizing element is transitioned from the lower profile dynamic form for the medical device to the higher profile static form for the medical device.

20. The medical device of claim 19 wherein said stabilizing element has a length between ends thereof at least as great as said long axis of said housing.

21. The medical device of claim 19 wherein said stabilizing element is adapted to rotate relative to said housing to transition said stabilizing element from the lower profile dynamic position to the higher profile static position.

22. The medical device of claim 21 wherein said stabilizing element is in the form of a wing having an elongate form extending between ends thereof.

23. The medical device of claim 22 wherein said wing has a contour similar to the contour of said housing with said wing adapted to rotate at least about 45°

from the lower profile dynamic position to the higher profile static position for said wing.

24. The medical device of claim 22 wherein a pair of wings are provided, each of said wings adapted to rotate in opposite directions relative to said housing, said pair of wings having similar lengths extending between ends thereof, with rear most ends having beveled surfaces thereon facing each other, such that a spreader rod can be inserted between said beveled surfaces and cause rotation of said wings in opposite directions away from said spreader rod upon impacting each of said beveled surfaces.

25. The medical device of claim 19 wherein said stabilizing element is adapted to be attached to said housing after implantation of said medical device.

26. The medical device of claim 25 wherein said housing includes a cavity therein, said cavity having a rear opening and a pair of side openings where said cavity can be accessed within an interior of said housing, the stabilizing element in the form of a bendable expandable width structure adapted to be passed through said rear opening and extend laterally out of said side openings of said cavity.

27. The medical device of claim 26 wherein said expandable width structure is in the form of a loop having four legs of similar length joined together by joints including a front joint, a rear joint and a pair of side joints, said side joints adapted to pass out of said side openings.

28. The medical device of claim 27 wherein said cavity includes an abutment wall on a side of said cavity opposite said rear opening, said front joint of said loop adapted to impact said abutment wall and with further advancement of said loop, said side joints are adapted to move away from each other with said rear joint moving towards said front joint until said side joints extend out of said side openings of said cavity.

29. The medical device of claim 19 wherein said housing includes electrical leads extending therefrom and said housing includes at least portions of a pacemaker therein, such that the medical device is in the form of a pacemaker.

30. The medical device of claim 19 wherein an outlet tube extends from said housing and said housing includes at least portions of a fluid reservoir and a fluid pumping apparatus therein, such that the medical device is in the form of an infusion pump.

31. A method for minimally invasive implantation of a subcutaneous medical device, the method including the steps of:

configuring the medical device to be at least partially contained within a housing having an elongate form with a long axis between ends greater than a lateral axis non-parallel with the long axis;

making an incision large enough to pass the housing through the incision along the long axis;

passing the housing through the incision to a subcutaneous implantation site; and

manipulating a stabilizing element coupled to the housing to enhance a lateral width of the housing, such that the stabilizing element resists rotation of the housing about the long axis.

32. The method of claim 31 including the further steps of:

configuring the stabilizing element as a rotating wing pivotably attached to the housing; and

said manipulating step including the step of rotating the stabilizing element from a first position aligned with the long axis to a second position extending laterally a distance greater than a width of the housing.

33. The method of claim 32 including the further step of configuring the rotating wing to have a length greater than a width of the housing so that ends of the rotating wing extend laterally from sides of the housing upon rotation of the rotating wing at least 45°

from initially aligned with the long axis.

34. The method of claim 32 wherein said manipulating step includes the step of manipulating a pair of the stabilizing elements in the form of a pair of rotating wings in opposite directions relative to the housing.

35. The method of claim 34 including the further step of advancing a spreader rod toward the housing and between the two wings to cause rotation of the two wings in opposite directions away from each other and relative to the housing.

36. The method of claim 31 including the further steps of:

configuring the housing to include a cavity therein with a rear opening and at least one side opening; and

configuring the stabilizing element to be in the form of an expandable element which can pass through the rear opening and expand laterally out of said at least one side opening.

37. The method of claim 36 including the further steps of:

configuring the cavity to include at least two side openings opposite each other; and

extending said expandable element laterally out of both side openings simultaneously.

38. The method of claim 37 including the further steps of configuring the expandable element as a loop.

39. The method of claim 38 including the further steps of configuring the expandable element to include four legs joined together by four joints including two side joints which extend away from each other and out of the side openings when a rear joint of the loop is moved toward a front joint of the loop.