Implantable microstimulator system for prevention of disorders

• US 6,181,965 B1
• Filed: 01/25/2000
• Issued: 01/30/2001
• Est. Priority Date: 02/20/1996
• Status: Expired due to Term

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Loeb, Gerald E., Richmond, Frances J. R.
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US09/490,920
• Time in Patent Office: 371 Days
• Field of Search: 607/1-3, 607/46, 607/48-52, 607/59-61, 128/899, 600/554, 600/302, 600/377
• US Class Current: 607/3
• CPC Class Codes: A61N 1/326 for promoting growth of cells, e.g. bone cells
• CPC Class Codes: A61N 1/36003 of motor muscles, e.g. for walking assistance
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

Improved implantable microstimulators are covered with a biocompatible polymeric coating in order to provide increased strength to the capsule and to capture fragments of the microstimulator should it become mechanically disrupted. Such coating also makes the microstimulator safer and easier to handle. The coating may include one or more diffusible chemical agents that are released in a controlled manner into the surrounding tissue. The chemical agents, such as trophic factors, antibiotics, hormones, neurotransmitters and other pharmaceutical substances, are selected to produce desired physiological effects, to aid, support or to supplement the effects of the electrical stimulation. Further, microstimulators in accordance with the invention provide systems that prevent and/or treat various disorders associated with prolonged inactivity, confinement or immobilization of one or more muscles. Such disorders include pressure ulcers, venous emboli, autonomic dysreflexia, sensorimotor spasticity and muscle atrophy. The microstimulator systems include external control for controlling the operation of the microstimulators. The control includes memory for programming preferred stimulation patterns for later activation by the patient or caregiver.

Claims

1. A system for the prevention or reversal of one or more disorders associated with inactivity, immobilization or confinement of one or more muscles, the system comprising:

(a) at least one implantable microstimulator comprising a hermetically-sealed housing, at least two exposed electrodes for providing electrical current, and electronic means within said hermetically-sealed housing for generating electrical current applied to said exposed electrodes, wherein each at least one implantable microstimulator is of a size and shape capable of implantation by expulsion through a narrow cannula, and wherein said at least one implantable microstimulator is coated with a polymeric coating over a substantial portion of the surface area of the hermetically-sealed housing, and wherein the polymeric coating includes a chemical agent therein that diffuses from the surface of the coating into the surrounding tissue;

(b) implantation means useful for implanting said at least one implantable microstimulator into muscle tissue so as to be proximate to a motor nerve fiber;

(c) external control means for commanding the at least one implanted microstimulator to produce various stimulation pulses until a desired stimulation sequence and pattern are identified, said external control means having a memory element;

(d) storage means for storing the desired stimulation sequence and pattern in the memory element of the external controller; and

(e) trigger means for triggering the desired stimulation sequence and pattern from the external controller to provide regular electrically-induced contraction of the muscle each time such is desired.

2. A system for reducing the incidence of disorders and medical complications resulting from physical confinement or immobilization of the whole body or parts thereof, comprising:

at least one implantable microstimulator comprising a hermetically-sealed housing, at least two exposed electrodes, electronic means within said hermetically-sealed housing for generating an electrical current and applying said electrical current to said at least two exposed electrodes, and a battery for providing operating power to the at least one implantable microstimulator means for implanting the at least one implantable microstimulator in muscle associated with an affected site; and

means for administering prescribed sequences of electrical stimulation through the at least two exposed electrodes of the at least one implantable microstimulator to nerves or muscle in the vicinity of the at least one implantable microstimulator comprising;

means for preprogramming said at least one implantable microstimulator with a desired sequence and pattern of electrical simulation; and

means for activating said desired sequence and pattern of electrical stimulation at prescribed intervals.