Physio-Control, Inc.

Physio-Control Manufacturing Corporation

David W Tecklenburg

Richard C Nova

James S Neumiller

Gary DeBardi

Richard J Cardin

Paul S Tamura

Tyler R Hart

Zhong Qun Lu

Scott Owen Schweizer

Douglas M Gustavson

Devices, systems, and methods are disclosed that identify a type of cable coupled to a receptacle of a defibrillator and that activate one or both of an ECG monitoring module and an energy storage circuit based at least in part on the identified cable type. The cable-type identification may allow a defibrillator to, for example, operate in either or both of an ECG monitoring mode and/or a therapy mode, based on the type of cable that is coupled to the defibrillator. The disclosed devices, systems, and methods can monitor an ECG of a patient and deliver defibrillation therapy to the patient, depending on the type of cable coupled to the defibrillator and/or the type of detected ECG signal of the patient.

Electrocardiogram monitoring

Techniques for determining whether one or more leads are not adequately connected to a patient, e.g., for ECG monitoring, are described. The techniques involve injection of an integrated signal (which includes a test signal) into one lead, and monitoring the driven lead and the response at the other leads, including the common mode and the difference between the other leads. These 'lead-off' detection techniques may be provided by an external defibrillator that provides three-wire ECG monitoring. Techniques for determining a type of a cable coupled to a defibrillator are also described. The cable-type identification may allow a defibrillator to, for example, operate in either a three-wire ECG monitoring mode or a therapy mode, based on whether a three-wire ECG cable or a defibrillation cable is coupled to the defibrillator.

A control circuit ideally suited for a capacitor charging circuit (100) that uses an apparent measure of current flow through a circuit line to regulate current drawn from a battery through the circuit line is disclosed. A summing circuit (136) produces a difference voltage (138) of the battery voltage (152) subtracted from a threshold reference voltage (151). The difference voltage (138) is subsequently amplified by an amplifier (140), rectified by a diode (142), and added to a voltage measure (130) from a current-sense resistor (117) by a summing circuit (128). The resulting voltage measure (126) is an apparent measure of current flow and is provided to a charge controller (122) which regulates current flow through a transformer (107) by controlling the operation of a switch (108). As the voltage on the battery (102) decreases below the reference voltage set by voltage source (150), the increasing difference voltage (138) adds bias to the actual measure of current flow (130), thus providing the charge controller (122) with an apparent measure of current flow through the transformer (107) that is higher than the actual level of current flow. The charge controller is thereby deceived and reduces the current drawn from the battery through the transformer.

Automatic rate control for defibrillator capacitor charging

Growing community of inventors

Mill Creek, WA, United States of America

David W Tecklenburg