Method of reducing the incidence of medical complications using implantable microstimulators

• US 6,185,455 B1
• Filed: 01/25/2000
• Issued: 02/06/2001
• 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:
  US09/490,919
• Time in Patent Office: 378 Days
• Field of Search: 607/1-3, 607/48-52, 607/59-61, 607/46, 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 include memory for programming preferred stimulation patterns for later activation by the patient or caregiver.

Claims

1. A method for reducing the incidence of medical complications from physical inactivity, confinement or immobilization of the whole body or parts thereof, comprising:

(a) coating a substantial portion of the surface of at least one implantable microstimulator with a coating containing a pharmaceutical agent, wherein each of the at least one implantable microstimulator comprises a hermetically-sealed housing, at least two exposed electrodes, and electronic means within said hermetically-sealed housing for generating an electrical current and applying said electrical current to said at least two exposed electrodes;

(b) implanting the at least one implantable microstimulator in muscle associated with an affected site;

(c) administering prescribed sequences of electrical stimulation through the at least two exposed electrodes of the at least one implantable microstimulator to nerves or muscles in the vicinity of the at least one implantable microstimulator; and

(d) controlling the at least one implantable microstimulator to electrically excite a physiological response from the body tissue near the at least two exposed electrodes simultaneously with elution of a locally high level of the pharmaceutical agent from the coating.

2. The method of claim 1 wherein the step of coating includes applying said coating so that said coating contacts at least one of said at least two exposed electrodes, whereby electrical current/voltage applied to said at least two exposed electrodes affects the rate at which the pharmaceutical agent is eluted from the coating.

3. A method for reducing the incidence of medical complications resulting from physical inactivity, confinement or immobilization of the whole body or parts thereof, comprising:

(a) implanting at least one implantable microstimulator in muscle associated with an affected site, wherein each of the at least one implantable microstimulator comprises a hermetically-sealed housing, a battery for providing operating power to the at least one implantable microstimulator, at least two exposed electrodes, and 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

(b) administering prescribed sequences of electrical stimulation through the at least two exposed electrodes of the at least one implantable microstimulator to nerves or muscles in the vicinity of the at least one implantable microstimulator comprising;

preprogramming the at least one implantable microstimulator with a desired sequence and pattern of electrical stimulation; and

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