Step-down skeletal muscle energy conversion method

• US 5,653,676 A
• Filed: 06/07/1995
• Issued: 08/05/1997
• Est. Priority Date: 09/30/1991
• Status: Expired due to Term

• Current Assignee: TC1 LLC (Abbott Laboratories Incorporated)
• Original Assignee: Thoratec Laboratories Corp. (Thoratec LLC)
• Inventors: Litwak, Philip, Rueff, John Robert, Harvey, Robert Joseph, Farrar, David John, Buck, Keith Evan
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): GILBERT, SAMUEL G
• Application Number:
  US08/483,420
• Time in Patent Office: 790 Days
• Field of Search: 128/898, 128/899, 600/16-18, 623/3
• US Class Current: 600/16
• CPC Class Codes: A61M 60/139 inside the aorta, e.g. intra-aortic balloon pumps
• 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 60/17 inside a ventricle, e.g. intraventricular balloon pumps
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/183 drawing blood from both ventricles, e.g. bi-ventricular assist devices [BiVAD]
• CPC Class Codes: A61M 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/232 Centrifugal pumps
• CPC Class Codes: A61M 60/274 the inlet and outlet being the same, e.g. para-aortic counter-pulsation blood pumps
• CPC Class Codes: A61M 60/295 Balloon pumps for circulatory assistance
• CPC Class Codes: A61M 60/405 the force acting on the blood contacting member being hydraulic or pneumatic
• CPC Class Codes: A61M 60/427 the force acting on the blood contacting member being hydraulic or pneumatic
• CPC Class Codes: A61M 60/495 Electromagnetic force
• CPC Class Codes: A61M 60/882 Devices powered by the patient, e.g. skeletal muscle powered devices

Abstract

This invention provides a simple skeletal muscle linear pull energy convertor which can harness the maximal amount of muscle power for a wide variety of implantable medical devices, including the full range of circulatory support devices. The muscle powered system provides completely implantable circulatory support as an alternative to cardiac transplantation, with a quality of life relatively free from external batteries, transcutaneous energy transmission and other electromechanical hardware.

Claims

1. A method for improving the flow rate in a cardiovascular circulatory system, said method comprising the steps of:

surgically attaching at least a portion of a skeletal muscle to at least one movable part of hydraulic conversion means;

surgically implanting said conversion means for converting linear contraction of the skeletal muscle attached to said conversion means to hydraulic energy, the conversion means being coupled to a circulatory support device by coupling means including a hydraulic transmission line such that the hydraulic energy is transmitted through the hydraulic transmission line and drives the circulatory support device;

attaching stimulating means to the skeletal muscle whereby the muscle contracts upon adequate stimulation from the stimulating means;

conditioning the skeletal muscle by stimulating the muscle periodically with the stimulating means, thereby generating alternate contraction and relaxation of the muscle for a time sufficient to convert fast-twitch fibers of the muscle to slow-twitch fibers, wherein during said conditioning step the circulatory support device receives hydraulic energy from an extracorporeal power source through an access port disposed within the hydraulic transmission line; and

continuing periodic stimulation of the conditioned skeletal muscle to generate linear contractile energy such that the linear contractile energy is converted into hydraulic energy by said convertor which causes operation of said circulatory support device.

2. A method for improving the flow rate in a cardiovascular circulatory system, said method comprising the steps of:

surgically attaching at least a portion of a skeletal muscle to at least one movable part of hydraulic conversion means;

surgically anchoring directly to the skeleton said conversion means for converting contraction of said skeletal muscle attached to said conversion means to hydraulic energy, the conversion means being coupled to a circulatory support device by coupling means including a hydraulic transmission line such that the hydraulic energy is transmitted through the hydraulic transmission line and drives the circulatory support device;

attaching stimulating means to the skeletal muscle whereby the muscle contracts upon adequate stimulation from the stimulating means and pulls in tension against said conversion means;

conditioning of the skeletal muscle by stimulating the muscle periodically with the stimulating means, thereby generating alternate contraction and relaxation of the muscle for a time sufficient to convert fast-twitch fibers of the muscle to slow-twitch fibers, wherein during said conditioning step the circulatory support device receives hydraulic energy from an extracorporeal power source through an access port disposed within the hydraulic transmission line; and

continuing periodic stimulation of the conditioned skeletal muscle to generate contractile tensile energy such that the contractile tensile energy is converted into hydraulic energy by said conversion means which actuates said circulatory support device.