Wearable cardioverter defibrillator (wcd) system with isolated patient parameter component

Patent metadata

Field	Value
Publication number	US-2017157416-A1
Application number	US-201615365801-A
Country	US
Kind code	A1
Filing date	Nov 30, 2016
Priority date	Dec 4, 2015
Publication date	Jun 8, 2017
Grant date	—

Abstract

Embodiments are directed to wearable cardioverter defibrillator (WCD) systems that include patient parameter electrodes, such as ECG electrodes, that are at least substantially electrically isolated from other circuits of the WCD system. In embodiments, the WCD system includes a power source, an energy storage module, and a processor each connected to a first circuit ground. A patient parameter sense port, such as an ECG port, is coupled to the patient. A measurement circuit may render a physiological input from the sensed patient parameter received at the patient parameter sense port, and the measurement circuit includes an isolating circuit that electrically isolates the patient parameter sense port from the first circuit ground. The sensing of physiological inputs of the patient can be improved, resulting in fewer erroneous readings and false alarms.

First claim

1 . A wearable cardioverter defibrillator (WCD) system, comprising:
a support structure configured to be worn by a patient; a power source connected to a first circuit ground; an energy storage module connected to the first circuit ground and configured to charged from the power source so as to store an electrical charge; a discharge circuit coupled to the energy storage module; a patient parameter sense port configured to be coupled to the patient; a measurement circuit configured to render a physiological input from a sensed patient parameter received at the patient parameter sense port, the measurement circuit including an isolating circuit configured to electrically isolate the patient parameter sense port from the first circuit ground; and a processor connected to the first circuit ground, operatively coupled to the measurement circuit, and configured to: determine from the physiological input whether or not a shock criterion is met, and control the discharge circuit to discharge the stored electrical charge through the patient if the shock criterion is met while the support structure configured to be worn by the patient.

2 . The WCD system of claim 1 , in which
the patient parameter is an electrical patient physiological signal received at the patient parameter sense port from Electrocardiogram (ECG) electrodes, and the physiological input includes an ECG signal detected by the ECG electrodes.

3 . The WCD system of claim 2 , in which
the measurement circuit further includes an ECG acquisition circuit operatively coupled to the patient parameter sense port and the isolating circuit, the ECG acquisition circuit being configured to detect the ECG signal, the measurement circuit having a second circuit ground that is isolated from the first circuit ground.

4 . The WCD system of claim 3 , in which
the isolating circuit includes an isolated digital data coupler configured to couple a first digital signal representative of the sensed patient parameter from the ECG acquisition circuit to the processor.

5 . The WCD system of claim 4 , in which
the isolated digital data coupler is configured to couple a second digital signal from the processor to the ECG acquisition circuit.

6 . The WCD system of claim 4 , in which
the isolating circuit further includes an isolated power supply configured to transfer power from the power source to the ECG acquisition circuit.

7 . The WCD system of claim 3 , in which
the isolating circuit includes an isolating signal coupler configured to couple a first parameter signal representative of the sensed patient parameter from the patient parameter sense port to the ECG acquisition circuit.

8 . The WCD system of claim 2 , in which
the ECG acquisition circuit operatively couples the isolating circuit to the patient parameter sense port, and the ECG acquisition circuit is connected to a second circuit ground isolated from the first circuit ground.

9 . The WCD system of claim 8 , in which
the isolating circuit operatively couples the ECG acquisition circuit to the patient parameter sense port, and the ECG acquisition circuit is connected to the first circuit ground.

10 . The WCD system of claim 1 , in which
the isolating circuit includes an isolation barrier electrically isolating the patient parameter sense port from the first circuit ground with at least 100 volts of protection across the isolation barrier.

11 . The WCD system of claim 1 , in which
the isolating circuit includes an isolated circuit portion connected to a second circuit ground isolated from the first circuit ground and a non-isolated circuit portion connected to the first circuit ground, and the isolating circuit further includes a voltage-difference reducing circuit configured to reduce a voltage difference between the first and second circuit grounds.

12 . The WCD system of claim 11 , in which
the voltage-difference reducing circuit includes a resistor connecting the first circuit ground to the second circuit ground.

13 . The WCD system of claim 1 , in which
the isolating circuit includes an isolating signal coupler configured to couple a signal representative of the sensed patient parameter from an isolated circuit portion of the isolating circuit to a non-isolated circuit portion of the isolating circuit, the isolated circuit portion is isolated from the first circuit ground, and the non-isolated circuit portion is connected to the first circuit ground.

14 . The WCD system of claim 13 , in which
the isolating circuit further includes an isolated power supply configured to transfer power from the power source to the isolated circuit portion of the isolating circuit.

15 . The WCD system of claim 14 , in which
the isolated power supply includes an isolation transformer having a first winding coupled to the first circuit ground and a second winding isolated from the first winding and coupled to the second circuit ground.

Assignees

• West Affum Holdings Corp

Inventors

• Medema Douglas Keith
• Cowan Kenneth Frederick
• Lu Zhong Qun

Classifications

• A61N1/3925

  Monitoring; Protecting · CPC title

• A61N1/046

  Specially adapted for shock therapy, e.g. defibrillation · CPC title

• A61N1/3975

  Power supply (A61N1/378 takes precedence) · CPC title

• A61N1/0484 Primary

  Garment electrodes worn by the patient · CPC title

• A61N1/3987 Primary

  characterised by the timing or triggering of the shock · CPC title