RESONANT STRUCTURES FOR IMPLANTABLE DEVICES

• US 20080021510A1
• Filed: 07/20/2007
• Published: 01/24/2008
• Est. Priority Date: 07/21/2006
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Tangren, John, Mi, Bin, Chavan, Abhijeet
• Granted Patent: US 7,912,548 B2
• Time in Patent Office: Days
• US Class Current: 607/36
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile

Abstract

An implantable medical device comprising a housing and a limiting structure defining a resonant region in the housing. An acoustic transducer is connected to the limiting structure and extends into the resonant region so that the resonant region mechanically amplifies the deformation of the acoustic transducer at a resonant frequency. An implantable medical device comprising a housing and a limiting structure defining a resonant region in the housing. An acoustic transducer having the shape of a beam is mechanically coupled to the limiting structure and partially extends into the resonant region so that the resonant region mechanically amplifies the deformation of the acoustic transducer at a resonant frequency. An implantable medical device comprising a housing, an acoustic transducer coupled to the housing, and a means for mechanically amplifying the deformation of the acoustic transducer at a resonant frequency. The means defines a resonant region in the housing.

Claims

1. An implantable medical device comprising:

a housing and a limiting structure defining a resonant region in the housing; and

an acoustic transducer connected to the limiting structure and extending into the resonant region so that the resonant region mechanically amplifies the deformation of the acoustic transducer at a resonant frequency.

2. The implantable medical device of claim 1 wherein the limiting structure further comprises an annular non-active structure coupled to an inner side of the housing and the acoustic transducer is located on a top surface of the limiting structure.

3. The implantable medical device of claim 1 wherein the limiting structure comprises the acoustic transducer and has an annular shape.

4. The implantable medical device of claim 3 wherein the limiting structure comprises a lead zirconate titanate (PZT) material and has an inner diameter of 8.4 millimeters, an outer diameter of approximately 16.8 millimeters, and a thickness of approximately 2 millimeters.

5. The implantable medical device of claim 1 wherein the limiting structure has an approximately semicircular shape and is located in a corner of the housing.

6. The implantable medical device of claim 1 wherein the acoustic transducer has a length of no more than half of the radius of the resonant region.

7. The implantable medical device of claim 1 wherein the limiting structure comprises a header coupled to the housing.

8. The implantable medical device of claim 1 wherein the resonant region has a resonance greater than approximately 20 kiloHertz.

9. The implantable medical device of claim 1 wherein the resonant region has a resonance of approximately 40 kiloHertz.

10. An implantable medical device comprising:

a housing and a limiting structure defining a resonant region in the housing; and

an acoustic transducer having the shape of a beam mechanically coupled to the limiting structure and partially extending into the resonant region so that the resonant region mechanically amplifies the deformation of the acoustic transducer at a resonant frequency.

11. The implantable medical device of claim 10 wherein the limiting structure comprises at least a portion of an edge of the housing, the acoustic transducer is connected to the portion, and the resonant region comprises a portion of a mode shape of the housing at the resonant frequency.

12. The implantable medical device of claim 10 wherein the limiting structure comprises a corner of the housing, the acoustic transducer is connected to the corner, and the resonant region comprises a portion of a mode shape of the housing at the resonant frequency.

13. The implantable medical device of claim 10 wherein the acoustic transducer is located in a region of maximum stress and maximum strain.

14. The implantable medical device of claim 10 wherein the acoustic transducer comprises a piezoelectric material.

15. The implantable medical device of claim 14 wherein the piezoelectric material comprises polyvinylidine diflouride (PVDF) material.

16. The implantable medical device of claim 14 wherein the piezoelectric material comprises lead zirconate titanate (PZT) material.

17. The implantable medical device of claim 14 wherein the piezoelectric material comprises lead magnesium niobate-lead titanate (PMN-PT).

18. An implantable medical device comprising:

a housing;

an acoustic transducer coupled to the housing; and

a means for mechanically amplifying the deformation of the acoustic transducer at a resonant frequency, the means defining a resonant region in the housing.

19. The implantable medical device of claim 18 wherein the means for mechanically amplifying comprises an annular non-active structure coupled to an inner side of the housing and the acoustic transducer is located on a top surface of the limiting structure.

20. The implantable medical device of claim 18 wherein the means for mechanically amplifying comprises the acoustic transducer and has an annular shape.

21. The implantable medical device of claim 18 wherein the means for mechanically amplifying comprises at least a portion of an edge of the housing, the acoustic transducer is connected to the portion, and the resonant region comprises a portion of a mode shape of the housing at the resonant frequency.

22. The implantable medical device of claim 18 wherein the means for mechanically amplifying comprises a header, which defines the resonant region in the housing and is coupled to the housing.