Defibrillation pacing circuitry

Patent metadata

Field	Value
Publication number	US-2016166841-A1
Application number	US-201615051805-A
Country	US
Kind code	A1
Filing date	Feb 24, 2016
Priority date	Nov 5, 2001
Publication date	Jun 16, 2016
Grant date	—

Abstract

Electrical circuit componentry is switchable into a defibrillator circuit to deliver a constant pacing current to a patient. The circuitry may include a constant current source inserted in a leg of the defibrillator circuit or a resistor of selected value inserted between a high voltage source and the high side of a defibrillator circuit.

First claim

1 . (canceled)

2 . An implantable defibrillator comprising:
an H-bridge circuit comprising a high side and a low side, wherein the H-bridge circuit comprises first and second legs connected between the high side and the low side thereof, wherein the first leg of the H-bridge circuit comprises first and second current switching elements and the second leg of the H-bridge circuit comprises at least a third current switching element, the H-bridge comprising output nodes for coupling to patient tissue via implantable electrodes, a first output node located on the first leg between the first and second current switching elements and a second output node located on the second leg; wherein one of the first and second current switching elements along with the third current switching element define a pair of current switching elements such that, when a constant current pacing stimulus is desired, the defibrillator is configured to select the pair of current switching elements to generate a pacing stimulus of a first polarity for application via the first and second output nodes; and a constant current source connected to one of the high side or the low side of the H-bridge circuit, wherein the constant current source comprises a voltage source and a controlled current output circuit connected between the voltage source and the H-bridge circuit, and the defibrillator is configured to apply a control signal to the constant current source to generate a substantially constant current output via the output nodes.

3 . The implantable defibrillator of claim 2 wherein the H-bridge circuit further comprises a fourth current switching element, the fourth current switching element disposed in the second leg such that the second output node is between the third and fourth current switching elements.

4 . The implantable defibrillator of claim 3 wherein the constant current source is connected to the high side of the H-bridge circuit to control current flowing into the H-bridge circuit.

5 . The implantable defibrillator of claim 4 wherein the constant current source comprises a switch connected in parallel with a resistor.

6 . The implantable defibrillator of claim 3 wherein the constant current source is connected to the low side of the H-bridge circuit to control current flowing through at least one leg thereof.

7 . The implantable defibrillator of claim 3 wherein:
in the first leg of the H-bridge, the first current switching element links the high side of the H-bridge to the first output node and the second current switching element links the low side of the H-bridge to the first output node;
in the second leg of the H-bridge, the third current switching element links the high side of the H-bridge to the second output node and the fourth current switching element links the low side of the H-bridge to the second output node;
the constant current source includes an amplifier for generating a control signal output; and
the defibrillator is configured to selectively provide the control signal output to the fourth switching element.

8 . The implantable defibrillator of claim 7 wherein the defibrillator is configured to generate a substantially constant current pacing therapy by applying a first voltage to the high side of the H-bridge, closing the first switch, and applying the control signal output to the fourth switch.

9 . The implantable defibrillator of claim 8 wherein the defibrillator comprises a therapy circuit with a high power capacitor for use in delivering either pacing or defibrillator therapy, such that the first voltage is received from the high power capacitor.

10 . The implantable defibrillator of claim 3 wherein:
in the first leg of the H-bridge, the first current switching element links the high side of the H-bridge to the first output node and the second current switching element links the low side of the H-bridge to the first output node;
in the second leg of the H-bridge, the third current switching element links the high side of the H-bridge to the second output node and the fourth current switching element links the low side of the H-bridge to the second output node;
the constant current source includes a voltage source for generating a control signal output; and
the defibrillator is configured to selectively provide the control signal output to the fourth switching element.

11 . The implantable defibrillator of claim 10 wherein the defibrillator is configured to generate a substantially constant current pacing therapy by applying a first voltage to the high side of the H-bridge, closing the first switch, and applying the control signal output to the fourth switch.

12 . The implantable defibrillator of claim 11 wherein the defibrillator comprises a therapy circuit with a high power capacitor for use in delivering either pacing or defibrillator therapy, such that the first voltage is received from the high power capacitor.

13 . The implantable defibrillator of claim 3 wherein:
in the first leg of the H-bridge, the first current switching element links the high side of the H-bridge to the first output node and the second current switching element links the low side of the H-bridge to the first output node, with a first resistor and a first defibrillator switch parallel to one another and between the second current switching element and the low side of the H-bridge;
in the second leg of the H-bridge, the third current switching element links the high side of the H-bridge to the second output node and the fourth current switching element links the low side of the H-bridge to the second output node with a second resistor and a second defibrillator switch parallel to one another and between the second current switching element and the low side of the H-bridge; and
the implantable defibrillator is configured to select between defibrillation output and controlled current output by opening or closing the first and second defibrillator switches.

14 . The implantable defibrillator of claim 13 wherein the defibrillator is configured to selectively close the first and second defibrillator switches to deliver defibrillation output, and to selectively open the first and second defibrillator switches to deliver controlled current output.

15 . The implantable defibrillator of claim 2 wherein the first leg of the H-bridge is configured with the first switch linking the high side of the H-bridge to the first output node, and the second switch linking the low side of the H-bridge to the first output node, with a resistor dispose between the second switch and the low side of the H-bridge and placed in parallel with a defibrillator switch, wherein defibrillator switch is controllable by the defibrillator as follows:
for delivery of a defibrillation therapy, the implantable defibrillator is configured to close the defibrillator switch; and
for delivery of a controlled current output, the implantable defibrillator is configured to open the defibrillator switch to force current through the resistor.

16 . An implantable defibrillator comprising:
a high power capacitor configured for delivery of controlled current output and defibrillation therapy; an H-bridge circuit to selectively couple the high power capacitor to outputs for delivery of therapy to a patient in at least controlled current output and defibrillation therapy modes, the H-bridge circuit having a high side and a low side; a selectable control circuit coupling the high power capacitor to the H-bridge circuit, the selectable control circuit including a resistor for use in providing a controlled current output and a switch f

Assignees

• Cameron Health Inc
• Cameron Health Inc

Inventors

• Ostroff Alan H

Classifications

• A61N1/39622

  Pacing therapy · CPC title

• A61N1/362

  Heart stimulators (heart defibrillators A61N1/39) · CPC title

• A61N1/3912 Primary

  Output circuitry therefor, e.g. switches · CPC title

• A61N1/3962 Primary

  in combination with another heart therapy · CPC title