Abstract An implantable electrically operated medical device, such as a pacemaker, having one or more electrochemical cells and operative electric circuitry mounted in an encapsulated covering of epoxy resin which is impermeable to body fluids. The electrochemical cells generate a hydrogen gas and the encapsulated covering, while being relatively impermeable to hydrogen gas is capable of passing the gas through at a relatively low permeation rate. Buildup in pressures within the encapsulant occur under increased hydrogen evolution rates from the electrochemical cells and the improved device modifies the shape of the electrochemical cells and reinforces the epoxy resin encapsulant over the corners of the cells to strengthen the encapsulant covering and increase the burst strength of the device.
An implantable electrically powered medical device comprising: at least one generally cylindrically shaped electrochemical cell of a type which has hydrogen gas emitted during discharge thereof, an electric pulse generator including electrode members extending therefrom, a mounting member having recessed therethrough for positioning said cell and said pulse generator, an encapsulant covering the epoxy resin material positioned over the mounting member with said cell and pulse generator therein, and with the electrode members extending through the mounting member, the encapsulant covering having a thickness over the top and bottom of the cell in the mounting member from 0.040 to 0.140 inches and the radius of curvature of said cells at the top and bottom edges of the same being from greater than 1/8 inch to about 1/4 inch and a mesh material positioned in the encapsulant covering over the top and bottom of the cell at at least the edges of the same.
Claim 2
Dependent Claim
153 words
An implantable electrically powered medical device comprising: at least one generally cylindrically shaped electrochemical cell of a type which has hydrogen gas emitted during discharge thereof, an electric pulse generator including electrode members extending therefrom, a mounting member having recessed therethrough for positioning said cell and said pulse generator, an encapsulant covering the epoxy resin material positioned over the mounting member with said cell and pulse generator therein, and with the electrode members extending through the mounting member, the encapsulant covering having a thickness over the top and bottom of the cell in the mounting member from 0.040 to 0.140 inches and the radius of curvature of said cells at the top and bottom edges of the same being from greater than 1/8 inch to about 1/4 inch and a mesh material positioned in the encapsulant covering over the top and bottom of the cell at at least the edges of the same.
Claim 3
Dependent Claim
19 words
The implantable electrically powered medical device of claim 1 in which the mesh material is a metallic mesh material.
Claim 4
Dependent Claim
19 words
The implantable electrically powered medical device of claim 1 in which the mesh material is a glass mesh material.