Mechanical defibrillator and method for defibrillating a heart

• US 5,433,731 A
• Filed: 03/21/1994
• Issued: 07/18/1995
• Est. Priority Date: 03/29/1993
• Status: Expired due to Fees

• Current Assignee: Pacesetter AB (Abbott Laboratories)
• Original Assignee: Pacesetter AB (Abbott Laboratories)
• Inventors: Hoegnelid, Kurt, Nilsson, Kenth-Ake-Sune, Ljungstroem, Jan, Wecke, Liliane
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US08/210,467
• Time in Patent Office: 484 Days
• Field of Search: 600/16, 600/17, 601/48, 601/108, 601/148-153, 607/5
• US Class Current: 607/5
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

An implantable heart defibrillator and a method for defibrillating a heart, employ a shock pulse generator for delivering a defibrillation shock to a heart, the delivered energy being mechanical. The shock pulse generator includes an electromechanical energy converter which generates, e.g., pressure, by means of a piezoelement, in a pressure chamber. Pressure is transmitted by a fluid in an electrode devised like a hydraulic line to a balloon-like electrode head in contact with heart tissue. The generated pressure causes the electrode head to expand and deliver a mechanical shock to the heart corresponding to the pressure.

Claims

1. An implantable heart defibrillator comprising:

implantable means for detecting a condition of a heart and for emitting a sensed condition signal;

implantable control means for generating, dependent on said sensed condition signal, a command signal to initiate a selected cardiac therapy regimen including, when warranted by said sensed condition signal, a defibrillation regimen; and

implantable shock generator means, responsive to said command signal, for generating at least one defibrillation shock pulse containing non-electrical energy as at least part of said defibrillation regimen; and

including means adapted for contact with tissue of said heart for delivering said shock pulse containing said non-electrical energy to said heart as a direct mechanical impact to said heart tissue.

2. An implantable heart defibrillator as claimed in claim 1 wherein said means adapted for contact with tissue of said heart include electrode means for delivering said shock pulse containing said nonelectrical energy to said heart tissue.

3. An implantable heart defibrillator as claimed in claim 2 wherein said electrode means comprise a mechanical electrode having a distal end locatable at said heart with an electrode head disposed at said distal end which is mechanically movable in response to said non-electrical energy.

4. An implantable heart defibrillator as claimed in claim 1 wherein said shock pulse has a chronological morphology and wherein said shock generator means includes means for selectively configuring the chronological morphology of said shock pulse.

5. An implantable heart defibrillator as claimed in claim 1 wherein said shock generator means includes an electromechanical energy converter means for converting electrical energy into mechanical energy as said non-electrical energy.

6. An implantable heart defibrillator as claimed in claim 5 wherein said electromechanical energy converter means comprises at least one movable part, and means for producing a stroke motion by said movable part to produce said impact.

7. An implantable heart defibrillator as claimed in claim 6 wherein said shock generator means includes a mechanical electrode having an electrode head locatable at said heart for delivering said mechanical energy to said heart, said mechanical electrode including an outer electrode part and an inner electrode part, said inner electrode part comprising said movable part and being movable relative to said outer electrode part, said inner electrode part having a proximal end attached to said means for producing a stroke motion and a distal end attached to said electrode head, said means for producing a stroke motion causing said inner electrode part to move within said outer electrode part and thereby to impart said mechanical energy to said heart via said electrode head.

8. An implantable heart defibrillator as claimed in claim 7 wherein said outer electrode part comprises a sleeve and said inner electrode part comprises a wire slidable in said sleeve.

9. An implantable heart defibrillator as claimed in claim 7 wherein said electrode head comprises a bellows movable by said inner electrode part, and said bellows carrying a pressure distribution plate which interacts with said heart tissue to produce said impact.

10. An implantable heart defibrillator as claimed in claim 6 wherein said means for producing a stroke motion comprises means for electromagnetically producing a stroke motion to produce said impact.

11. An implantable heart defibrillator as claimed in claim 6 wherein said means for producing a stroke motion comprises means for piezoelectrically producing a stroke motion to produce said impact.

12. An implantable heart defibrillator as claimed in claim 1 wherein said means adapted for contact with tissue of said heart has an enclosure having an exterior adapted for contact with said heart and wherein said shock generator means includes electrochemical means for converting electrical energy into said mechanical energy by electrochemically generating pressure in said enclosure to produce said impact.

13. An implantable heart defibrillator as claimed in claim 12 wherein said shock generator means includes a mechanical electrode having an electrode head locatable at said heart for delivering said mechanical energy to said heart, said mechanical electrode including an outer electrode part and an inner electrode part, said inner electrode part containing a pressure-transfer medium in communication with said enclosure, said pressure-transfer medium transferring pressure from said enclosure to said distal end for delivery to said heart as said impact.

14. An implantable heart defibrillator as claimed in claim 13 wherein said pressure-transfer medium comprises a fluid, and wherein said electrode head comprises at least one elastic, expandable section at said distal end of said electrode.

15. An implantable heart defibrillator as claimed in claim 1 wherein said electrode means adapted for contact with tissue of said heart includes an electrode having an electrode head disposed at a distal end of said electrode locatable at said heart for delivering said mechanical energy to said heart, and electromechanical energy converter means disposed at said electrode head for converting electrical energy into said mechanical energy to produce said impact.

16. An implantable heart defibrillator as claimed in claim 15 wherein said electromechanical energy converter means comprise a piezoelectric element.

17. An implantable heart defibrillator as claimed in claim 15 wherein said electromechanical energy converter means comprises an electrostrictive element.

18. An implantable heart defibrillator as claimed in claim 15 wherein said electromechanical energy converter means comprises a magnetostrictive element.

19. An implantable heart defibrillator as claimed in claim 16 wherein said electromechanical energy converter means comprises a bubble jet generator.

20. An implantable heart defibrillator as claimed in claim 15 wherein said electromechanical energy converter means is disposed on an exterior of said electrode head.

21. An implantable heart defibrillator as claimed in claim 20 wherein said electromechanical energy converter means comprises a piezoelectric element.

22. An implantable heart defibrillator as claimed in claim 1 wherein said means adapted for contact with tissue of said heart comprises an electrode system having a plurality of energy delivery locations locatable at a plurality of respectively different locations at said heart for delivering said non-electrical energy as impacts to said heart at said plurality of different locations.

23. An implantable heart defibrillator as claimed in claim 1 further comprising means for delivering electrical stimulation to said heart, and wherein said control means comprises means for delivering a command signal to each of said shock generator means and said means for delivering electrical stimulation for shocking said heart with a combination of electrical energy from said means for delivering electrical stimulation and said nonelectrical energy from said shock generator means.

24. A method for defibrillating a heart comprising the steps of:

converting electrical energy into a non-electrical energy shock pulse; and

delivering said non-electrical energy shock pulse in vivo to a heart exhibiting fibrillation as a direct mechanical impact to tissue of said heart for defibrillating said heart.

25. A method for defibrillating a heart as claimed in claim 24 wherein the step of converting electrical energy into non-electrical energy is further defined by converting electrical energy into mechanical energy.

26. A method for defibrillating a heart as claimed in claim 25 wherein the step of converting electrical energy into mechanical energy is further defined by electromagnetically converting said electrical energy into said mechanical energy.

27. A method for defibrillating a heart as claimed in claim 25 wherein the step of converting electrical energy into mechanical energy is further defined by electrochemically converting said electrical energy into said mechanical energy.

28. A method for defibrillating a heart as claimed in claim 25 wherein the step of converting electrical energy into mechanical energy is further defined by piezoelectrically converting said electrical energy into said mechanical energy.

29. A method for defibrillating a heart as claimed in claim 25 wherein the step of converting electrical energy into mechanical energy is further defined by electrostrictively converting said electrical energy into said mechanical energy.

30. A method for defibrillating a heart as claimed in claim 25 wherein the step of converting electrical energy into mechanical energy is further defined by magnetostrictively converting said electrical energy into said mechanical energy.

31. A method for defibrillating a heart as claimed in claim 24 wherein the step of delivering said non-electrical energy in vivo to said heart is further defined by delivering said non-electrical energy in vivo to a plurality of locations at said heart.

32. An implantable heart defibrillator comprising:

implantable means for detecting a condition of a heart and for emitting a sensed condition signal;

implantable control means for generating, dependent on said sensed condition signal, a command signal to initiate a selected cardiac therapy regimen including, when warranted by said sensed condition signal, a defibrillation regimen; and

implantable shock generator means, responsive to said command signal, for generating at least one defibrillation shock by piezoelectrically converting electrical energy into mechanical energy, as at least part of said defibrillation regimen, and for delivering said shock containing said mechanical energy to said heart.

33. An implantable heart defibrillator comprising:

implantable means for detecting a condition of a heart and for emitting a sensed condition signal;

implantable control means for generating, dependent on said sensed condition signal, a command signal to initiate a selected cardiac therapy regimen including, when warranted by said sensed condition signal, a defibrillation regimen; and

implantable shock generator means, responsive to said command signal, for generating at least one defibrillation shock by converting electrical energy into chemical energy and converting said chemical energy into mechanical energy, as at least part of said defibrillation regimen, and for delivering said shock containing said mechanical energy to said heart.

34. An implantable heart defibrillator comprising:

implantable means for detecting a condition of a heart and for emitting a sensed condition signal;

implantable control means for generating, dependent on said sensed condition signal, a command signal to initiate a selected cardiac therapy regimen including, when warranted by said sensed condition signal, a defibrillation regimen; and

implantable bubble generator means, responsive to said command signal, for generating at least one defibrillation shock containing mechanical energy as at least part of said defibrillation regimen, and for delivering said shock containing said mechanical energy to said heart.