Implantable living tissue stimulators
First Claim
1. In an implantable living tissue stimulator of the type comprising a plurality of stimulator circuit means which form the stimulator circuitry and include at least a power source and pulse generating means powered by said power source to provide pulses adapted to be applied to body tissue to be stimulated, with at least some of the stimulator circuit means being exposable to body saline fluid when said stimulator is implanted in a body, the improvement comprising:
- current conductive shield means surrounding at least the stimulator circuit means which is exposable to body saline fluid, and connected to a reference potential in said stimulator circuitry for substantially inhibiting the flow of current via body saline fluid to or from said circuit means which are exposable to the body saline fluid, by conducting said current to said reference potential.
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Accused Products
Abstract
An implantable living tissue stimulator is described with a current conductive protective shield, to prevent the flow of currents to or from the stimulator circuitry via the electrically conductive body fluid. Also disclosed is an implantable living tissue stimulator of the rechargeable type in which the stimulator circuit components are surrounded by a pickup coil, designed to pick up an external magnetic field for recharging the power source, e.g., battery of the stimulator. One embodiment incorporates one or more ferrite slabs extending through the coil wound about the rest of the stimulator components, in order to increase the coil pick up efficiency and to divert the magnetic field from the stimulator metal components, such as a metal container in which the stimulator circuitry is hermetically sealed and thereby minimize the heating of the components and/or metal container. Also disclosed is a stimulator in which the coil, wound about the stimulator circuit components and the ferrite slabs, is sealed within a ceramic or glass hermetic container which is impervious to body saline fluid or gases.
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Citations
25 Claims
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1. In an implantable living tissue stimulator of the type comprising a plurality of stimulator circuit means which form the stimulator circuitry and include at least a power source and pulse generating means powered by said power source to provide pulses adapted to be applied to body tissue to be stimulated, with at least some of the stimulator circuit means being exposable to body saline fluid when said stimulator is implanted in a body, the improvement comprising:
current conductive shield means surrounding at least the stimulator circuit means which is exposable to body saline fluid, and connected to a reference potential in said stimulator circuitry for substantially inhibiting the flow of current via body saline fluid to or from said circuit means which are exposable to the body saline fluid, by conducting said current to said reference potential. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. In an implantable living tissue stimulator of the type comprising a plurality of stimulator circuit means which form the stimulator circuitry and include at least a power source, pulse generating means powered by said power source to provide pulses adapted to be applied to tissue to be stimulated, a coil and a circuit connected to said coil and responsive to a current induced in said coil by an alternating magnetic field external to said body, the improvement comprising:
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said coil being wound about at least some of said stimulator circuit means; and matter means of high magnetic permeability extending through the coil for at least diverting a substantial portion of the magnetic field which passes through said coil from the stimulator circuit means about which the coil is wound, the dimension of said matter means along the longitudinal axis of said coil, being not less than the extent of the stimulator circuit means about which said coil is wound, along said longitudinal axis. - View Dependent Claims (15)
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16. In an implantable living tissue stimulator of the type comprising a plurality of stimulator circuit means which form the stimulator circuitry and include at least a power source, pulse generating means powered by said power source to provide pulses adapted to be applied to tissue to be stimulated, a coil and a circuit connected to said coil and responsive to a current induced in said coil by an alternating magnetic field external to said body, the improvement comprising:
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said coil being wound about at least some of said stimulator circuit means; and matter means of high magnetic permeability extending through the coil for at least diverting a substantial portion of the magnetic field which passes through said coil from the stimulator circuit means about which the coil is wound, said high magnetic permeability matter means being exposed on at least two sides of the stimulator circuit means about which the coil is wound. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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25. In a living tissue stimulator of the implantable type including a power source and rechargeable means for recharging said power source by responding to an external magnetic field and pulse generating means powered by said power source to provide pulses adapted to be applied to body tissue to be stimulated, the improvement comprising:
current conductive shield means surrounding said stimulator for inhibiting the flow of current from said stimulator or thereto via the body fluid when said stimulator is implanted, said shield means defining a plurality of current conductive members each of which is electrically connected to a reference potential of said power source, said current conductive members being spaced apart from one another whereby any current flowing to or from said stimulator via the body fluid is conducted to said reference potential by at least one of said current conductive members, with any substantially square area on the surface of any of said members being less than the total conductive surface area of said members, by a factor n, where n is not less than 100.
Specification