End of life increased pulse width and rate change apparatus

Claim 2

In an electromedical pulse generator used to stimulate a selected portion of a living animal body of the type having terminal means adapted for connection to an electrical lead having power source means, and having electrical pulse generating means electrically connected to the power source means for supplying output pulses at a first predetermined rate to the terminal means, each pulse having a first predetermined pulse width sufficient to stimulate the selected portion of the body, the improvement comprising: means electrically connected to the power source means and to the pulse generating means and responsive to a significant decrease in the power source output below a predetermined level for increasing the output pulse width from said first predetermined pulse width to a second, greater predetermined pulse width for continuing to stimulate the selected portion of the body over a predetermined range of power source outputs less than said predetermined level.

Claim 3

A pulse generator according to claim 1 wherein the responsive means comprises means for decreasing the output pulse rate to a second, lower predetermined rate.

Claim 4

A pulse generator according to claim 2 wherein the responsive means includes energy storage means having a discharge time which controls the predetermined output

Claim 5

A pulse generator according to cLaim 3 wherein the energy storage means is connected within the responsive means for preventing the transmission of energy from the pulse generating means to the terminal means while the energy storage means is discharging, thereby controlling the predetermined output pulse rate.

Claim 6

A pulse generator according to claim 3 wherein the energy storage means includes a capacitor.

Claim 7

A pulse generator according to claim 1 wherein the responsive means includes energy storage circuit means having a charging time which determines the output pulse width.

Claim 8

A pulse generator according to claim 6 wherein the energy storage circuit means is connected within the responsive means for allowing the transmission of energy from the pulse generating means to the terminal means, only during the time the energy storage circuit means is charging to a certain predetermined level, thereby determining the output pulse width.

Claim 9

A pulse generator according to claim 6 wherein the energy storage circuit means includes a capacitor.

Claim 10

A pulse generator according to claim 1 wherein the improvement further comprises means for sensing a significant decrease in power source output level including transistor means and means connected to the transistor means for biasing the transistor means for detecting a decrease in the power source output below the predetermined level.

Claim 11

A pulse generator according to claim 9 wherein the biasing means comprises resistive voltage divider means, the divider means being connected to ratio the portion of the power source output that is applied to the transistor means for rendering the transistor means conductive only when the power source output is greater than the predetermined level.

Claim 12

A pulse generator according to claim 1 further comprising implantable circuit means for adjusting the output pulse width, said circuit means including means for magnetic coupling to a non-implantable external adjusting device, thereby permitting extracorporeal adjustment of the circuit means.

Claim 13

A pulse generator according to claim 11 wherein the circuit means is a magnetically coupled potentiometer.

Claim 14

In an electromedical pulse generator used to stimulate a selected portion of the body of the type having terminal means adapted for connection to a body implantable electrical lead, having power source means and having electrical impulse generating means electrically connected to the power source means for supplying output pulses to the terminal means at a first predetermined rate, the improvement comprising: means for sensing a significant decrease in the power source output below a predetermined level, means responsive to the sensing means for fixing the output pulse rate at a second diverse predetermined rate over a predetermined range of power source outputs, means connecting the sensing means to the power source means, and means connecting the responsive means to the sensing means and the impulse generating means.

Claim 15

In an electromedical pulse generator used to stimulate a selected portion of the body of the type having terminal means adapted for connection to a body implantable electrical lead, having power source means and having electrical impulse generating means electrically connected to the power source means for supplying output pulses to the terminal means at a first predetermined rate, the improvement comprising: means for sensing a significant decrease in the power source output below a predetermined level, means responsive to the sensing means for fixing the output pulse rate at a second diverse predetermined rate over a predetermined range of power source outputs, means connecting the sensing means to the power source means, and means connecting the responsive means to the sensing means and the impulse generating means.

Claim 16

In an electromedical pulse generator used to stimulate a selected portion of a living animal body comprising terminal means adapted for connection to an electrical lead, power source means, electrical pulse generating means electrically connected to the power source means for supplying output pulses at predetermined intervals to the terminal means, each pulse having a predetermined pulse width sufficient to stimulate the selected portion of the body, and timing circuit means electrically connected to said power source means and said pulse generating means for establishing the pulse intervals and pulse width, said timing circuit means having a timing capacitor, and charge and discharge circuit means connected to said timing capacitor and said power source means for cyclicly charging said timing capacitor to a maximum charge level over a first time period to establish said pulse width and discharging said timing capacitor over a second time period to establish said pulse rate, the improvement comprising: means connected to the powEr source means and to the timing circuit means and responsive to a decrease in the power source output level for increasing the maximum charge level of said timing capacitor and for increasing the pulse width and the pulse intervals.

Claim 17

In an electromedical pulse generator used to stimulate a selected portion of a living animal body comprising terminal means adapted for connection to an electrical lead, power source means, electrical pulse generating means electrically connected to the power source means for supplying output pulses at predetermined intervals to the terminal means, each pulse having a predetermined pulse width sufficient to stimulate the selected portion of the body, and timing circuit means electrically connected to said power source means and said pulse generating means for establishing the pulse intervals and pulse width, said timing circuit means having a timing capacitor, and charge and discharge circuit means connected to said timing capacitor and said power source means for cyclicly charging said timing capacitor to a maximum charge level over a first time period to establish said pulse width and discharging said timing capacitor over a second time period to establish said pulse rate, the improvement comprising: means connected to the powEr source means and to the timing circuit means and responsive to a decrease in the power source output level for increasing the maximum charge level of said timing capacitor and for increasing the pulse width and the pulse intervals.