Passive cardiac restraint systems having multiple layers of inflatable elements

• US 6,547,716 B1
• Filed: 11/28/2000
• Issued: 04/15/2003
• 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): Winakur, Eric F.
• Assistant Examiner(s): Veniaminov, Nikita R
• Application Number:
  US09/723,565
• Time in Patent Office: 868 Days
• Field of Search: 600/37, 623/3.1, 623/3.16, 623/3.17, 623/3.21, 607/2, 607/12, 139/383.R, 601/151, 601/148, 601/144, 602/21, 602/13, 571/0, 568/9, 571/3
• US Class Current: 600/37
• CPC Class Codes: A61F 2/2481 Devices outside the heart wall, e.g. bags, strips or bands
• 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 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 60/289 Devices for mechanical circulatory actuation assisting the residual heart function by means mechanically acting upon the patient's native heart or blood vessel structure, e.g. direct cardiac compression [DCC] devices
• CPC Class Codes: A61M 60/435 with diastole or systole switching by valve means located between the blood pump and the hydraulic or pneumatic energy source
• CPC Class Codes: A61M 60/468 the force acting on the actuation means being hydraulic or pneumatic
• CPC Class Codes: A61M 60/508 Electronic control means, e.g. for feedback regulation
• CPC Class Codes: A61M 60/515 Regulation using real-time patient data
• CPC Class Codes: A61M 60/554 of blood pressure
• CPC Class Codes: A61M 60/839 of devices for mechanical circulatory actuation
• CPC Class Codes: A61M 60/861 Connections or anchorings for connecting or anchoring pumps or pumping devices to parts of the patient's body
• CPC Class Codes: A61M 60/869 Compliance chambers containing a gas or liquid other than blood to compensate volume variations of a blood chamber
• 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 non-blood contacting, implantable heart assist system surrounds the natural heart and provides resistance to cardiac hypertrophy. The restraint system 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 compressed they approximately follow the surface of the myocardium. Inflation of the tube pairs with a compressible fluid causes the wrap to exert a restraining force on the heart to prevent overexpansion during diastole.

Claims

1. A cardiac restraint device for applying a restraining force to a selected portion of a natural heart, the device comprising:

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, the sheath being adapted for placement about a natural heart,

wherein said sheath secures said elongate inflatable elements in a substantially parallel position relative to each other such that the inflatable elements form at least one inner and at least one outer layer of inflatable elements that surround a portion of the heart in use to apply a restraining force.

2. The cardiac restraint device of claim 1, 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.

3. The cardiac restraint device of claim 1, wherein said sheath and said inflatable elements are filled with a compressible fluid.

4. The cardiac restraint device of claim 1, wherein said plurality of inflatable elements and said sheath are integrally formed in a single unit.

5. The cardiac restraint device of claim 1, 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.

6. The cardiac restraint device of claim 1, wherein said first end and said second end of said sheath are connected to form a paraboloid of revolution.

7. The cardiac restraint device of claim 1, wherein said plurality of elongate elements are filled with a first medium to a first amount and wherein the resistive force applied by the restraint device is proportional to said first amount of first medium.

8. The cardiac restraint device of claim 7, further comprising:

at least one pocket adapted to be 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.

9. The cardiac restraint device of claim 8, wherein said second filler medium comprises:

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

10. The cardiac restraint device of claim 7 wherein the first medium is a compressible fluid.

11. The system of claim 1, further comprising:

an attachment device configured to prevent said restraint device from unintentionally adjusting during operation.

12. The system of claim 11, wherein said attachment device comprises at least one gripping element adapted to directly attach said restraint device to the heart.

13. The system of claim 11, wherein said attachment device comprises:

means for tethering said restraint device to the heart.