Cardiac assistance systems having multiple fluid plenums

• US 6,602,182 B1
• Filed: 11/28/2000
• Issued: 08/05/2003
• Est. Priority Date: 11/28/2000
• Status: Expired due to Term

• Current Assignee: Abiomed, Inc. (Johnson & Johnson)
• Original Assignee: Abiomed, Inc. (Johnson & Johnson)
• Inventors: Milbocker, Michael T.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US09/723,805
• Time in Patent Office: 980 Days
• Field of Search: 600/16, 600/17, 600/18
• US Class Current: 600/16
• CPC Class Codes: A61M 2205/33 Controlling, regulating or measuring
• CPC Class Codes: A61M 2205/3303 Using a biosensor
• CPC Class Codes: A61M 2205/8243 by induction
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/191 mechanically acting upon the outside of the patient's native heart, e.g. compressive structures placed around the heart
• CPC Class Codes: A61M 60/468 the force acting on the actuation means being hydraulic or pneumatic
• CPC Class Codes: A61M 60/515 Regulation using real-time patient data
• CPC Class Codes: A61M 60/839 of devices for mechanical circulatory actuation
• CPC Class Codes: A61M 60/876 Implantable batteries
• CPC Class Codes: A61M 60/882 Devices powered by the patient, e.g. skeletal muscle powered devices

Abstract

A unified, non-blood contacting, implantable heart assist system surrounds the natural heart and provides circumferential contraction in synchrony with the heart'"'"'s natural contractions. The pumping unit is composed of adjacent tube pairs arranged along a bias with respect to the axis of the heart and bound in a non-distensible sheath forming a heart wrap. The tube pairs are tapered at both ends such that when they are juxtaposed and deflated they approximately follow the surface of the diastolic myocardium. Inflation of the tube pairs causes the wrap to follow the motion of the myocardial surface during systole. A muscle-driven or electromagnetically powered energy converter inflates the tubes using hydraulic fluid pressure. An implanted electronic controller detects electrical activity in the natural heart, synchronizes pumping activity with this signal, and measures and diagnoses system as well as physiological operating parameters for automated operation. A transcutaneous energy transmission and telemetry subsystem allows the Unified System to be controlled and powered externally.

Claims

1. A control system for activating a cardiac pumping unit comprising:

an electrode for implantation on the heart or a suitable adjacent site, to receive electrical signals capable of indicating reliably the beginning of systole;

an electronic controller for synchronized release of actuating fluid to a pumping unit and for subsequent synchronized evacuation of fluid from the pumping unit;

a plenum for storage of a pressurized volume of fluid of sufficient size to provide a flow at nearly constant pressure during the release interval;

a plenum for storage of evacuated fluid which is maintained at a sufficient state of evacuation so as to provide evacuating flow at a nearly constant pressure during the evacuation interval; and

an energy converter for pumping fluid from the evacuated plenum to the pressurize plenum and maintaining their respective pressurized states.

2. The control system of claim 1 further comprising a housing for containing the plenums and energy converter, the back of which has a convex surface curvature compatible with the internal abdominal cavity.

3. The control system of claim 1 wherein the energy converter further comprises a reciprocating pump.

4. The system of claim 1, wherein the pumping unit further comprises a collapsible, non- distensible, biocompatible sheath.

5. The system of claim 4, wherein said pumping unit comprises:

a plurality of elongate inflatable elements each having a longitudinal axis; and

a sheath defining a set of unit cells, each cell encompassing at least two juxtaposed elongate inflatable members,

wherein said sheath nondistensibly secures said elongate inflatable elements in a substantially parallel position relative to each other.

6. The system of claim 5, wherein said sheath has a length extending between a first and a second end and a width substantially parallel with said longitudinal axis, said sheath having inner and outer surfaces joined periodically along said length at connection points disposed between said inner and outer surfaces to form a contiguous plurality of unit cells.

7. The system of claim 5, wherein said sheath and said inflatable elements are each constructed of thin, collapsible, non-distensible, and biocompatible material.

8. The system of claim 5, wherein said plurality of inflatable elements and said sheath are integrally formed in a single unit.

9. The system of claim 5, wherein said inflation elements have a top end and a bottom end, and wherein one or more of said top and bottom ends is tapered.

10. The system of claim 5, wherein said first end and said second end of said sheath are connected to form a paraboloid of revolution.

11. The system of claim 5, wherein said plurality of elongate elements are filled with a filler medium to a first amount and wherein the contractile force applied by the pumping unit is proportional to said first amount of a filler medium used to fill said plurality of elongate elements.

12. The system of claim 5, further comprising:

at least one pocket interposed between the inner surface of the sheath and the heart, the pocket adapted to be filled with a second filler medium at time of implantation to conform said pumping unit to the heart.

13. The system of claim 5, wherein said second filler medium comprises:

a flexible, deformable substance that substantially maintains its volume when compressed.

14. The system of claim 1, further comprising:

attachment device configured to prevent said pumping unit from unintentionally adjusting during operation.

15. The control system of claim 1 wherein the system further comprises;

an internal electronic controller programmed to generate activating signals to control the release of actuating fluid to the pumping unit and for subsequent synchronized evacuation of fluid from the pumping unit, and

an external controller in radio communication with the internal controller.

16. The implantable cardiac assist system of claim 15 wherein the system further comprises:

an actuator for converting said actuating signal into a periodic movement of at least one valve member.

17. The implantable cardiac assist system of claim 15 wherein the system further comprises:

a volume displacement chamber containing a energy converter and fluid plenums.

18. The implantable cardiac assist system of claim 15 wherein the internal controller further comprises a data transceiver for receiving a data signal from the external controller.

19. The implantable cardiac assist system of claim 15 wherein the internal controller further comprises a data transceiver for transmitting a data signal to the external controller.

20. An implantable control system for activating a cardiac pumping unit comprising:

an electrode for implantation on the heart or a suitable adjacent site, to receive electrical signals capable of indicating reliably the beginning of systole,

an electronic controller for synchronized release of actuating fluid to the pumping unit and for subsequent synchronized evacuation of fluid from the pumping unit,

a plenum for storage of a low pressure volume of fluid of sufficient size to provide a flow at nearly constant pressure during the release interval for initially filling the pumping unit,

a plenum for storage of a high pressure volume of fluid of sufficient size to provide a flow of nearly constant pressure during the release interval for filling to capacity the pumping unit,

a plenum for storage of evacuated fluid which is maintained at a sufficient state of evacuation so as to provide evacuating flow at a nearly constant pressure during the evacuation interval,

a first energy converter for continuously pumping fluid from the evacuated plenum to the low pressurize plenum and maintaining their respective pressurized states, and

a second energy converter for continuously pumping fluid from the evacuated plenum to the high pressure plenum and maintaining their respective states, the two energy converters pumping substantially different flows, the high pressure energy converter pumping a substantially lower flow.