Physio-control, Inc.

Medtronic Physio-control Manufacturing Corporation

Physio-control Manufacturing Corporation

Other

Medtronic Physio-control Corp.

Daniel Yerkovich

Ronald Eugene Stickney

David R Hampton

Cynthia P Jayne

William Edward Crone

James W Taylor

Tae Hong Joo

Patricia O'Hearn

Paula Lank

Carlton B Morgan

Stephen T Vincent

Thomas D Lyster

Eric C Hagen

Donald C Maier

Douglas H Roberts

John Mathew Adams

Gregory T Kavounas

Richard C Nova

Douglas Keith Medema

Neil G McIlvaine

Gary DeBardi

Richard J Cardin

Patrick F Kelly

Paul S Tamura

David Dean Aoyama

Stephen B Johnson

Joseph Bradley Williamson

Randall J Makela

Randal M Schmidt

Appropriate cardiac therapy is determined by data sensed and analyzed by the disclosed defibrillators and other medical devices that one or both of treat and monitor a patient. The disclosed devices sense various patient physiological parameters including patient pulse and breathing data to determine whether the patient has a pulse and to determine if the patient is breathing. Depending on the analysis of the generated patient physiological data, the disclosed devices determine the appropriate therapy for the patient, which can include providing breathing assistance to the patient and providing electrotherapy and other therapies to the patient. Some of the disclosed medical devices can be wearable by the patient. The disclosed devices can include therapy modules like electrotherapy for delivering therapies to the patient while other devices monitor but do not deliver the therapies to the patient.

Pulse detection apparatus, software, and methods using patient physiological signals

A cardiac pulse in a patient is determined by evaluating physiological signals in the patient. A medical device evaluates two or more different physiological signals, such as phonocardiogram (PCG) signals, electrocardiogram (ECG) signals, patient impedance signals, piezoelectric signals, and accelerometer signals for features indicative of the presence of a cardiac pulse. Using these features, the medical device determines whether a cardiac pulse is present in the patient. The medical device may also be configured to report whether the patient is in a VF, VT, asystole, or PEA condition, in addition to being in a pulseless condition, and prompt different therapies, such as chest compressions, rescue breathing, defibrillation, and PEA-specific electrotherapy, depending on the analysis of the physiological signals. Auto-capture of a cardiac pulse using pacing stimuli is further provided. The medical devices, or any portion thereof, can be worn by the patient or may be attached to the patient.

The presence of a cardiac pulse in a patient is determined by evaluating physiological signals in the patient. In one embodiment, a medical device evaluates two or more different physiological signals, such as phonocardiogram (PCG) signals, electrocardiogram (ECG) signals, patient impedance signals, piezoelectric signals, and accelerometer signals for features indicative of the presence of a cardiac pulse. Using these features, the medical device determines whether a cardiac pulse is present in the patient. The medical device may also be configured to report whether the patient is in a VF, VT, asystole, or PEA condition, in addition to being in a pulseless condition, and prompt different therapies, such as chest compressions, rescue breathing, defibrillation, and PEA-specific electrotherapy, depending on the analysis of the physiological signals. Auto-capture of a cardiac pulse using pacing stimuli is further provided.

Defibrillator assemblies and methods to wirelessly transfer energy from an external source to a battery or other rechargeable power source within the defibrillator assembly. The transfer of energy may be through a non-contact interface on a defibrillator cradle or a docking station that mounts the defibrillator. The rate of energy transfer may be equal to the energy drain caused by self-discharge and automated self-testing. Accordingly, since the rate of energy transfer is lower than that required to run the defibrillator system continuously, several wireless methods of energy transfer may be used. In addition, the defibrillator assembly may communicate diagnostic and non-diagnostic data to the external source.

Apparatus and method for maintaining a defibrillator battery charge and optionally communicating

A system is provided for delivering a defibrillation pulse to a patient and a corresponding method of storing such a system is provided in accordance with the present invention. The system includes a defibrillator (e.g., an AED) that is configured to deliver the defibrillation pulse to the patient and a cell that is configured to convert light into electrical power for the defibrillator. The method includes storing an defibrillator of the system for future use and arranging a light receiving system to receive light such that the light receiving system converts light into electrical power for the defibrillator.

Defibrillator power management systems and corresponding defibrillator storage methods

A method and system for monitoring the capacity of a battery pack is provided. The battery pack is capable of delivering current to a load. The battery pack includes a monitor cell and battery cells. The monitor cell has an initial energy level that is lower by a predetermined difference from the initial energy level of at least one of the other battery cells. A monitoring system including an analog-to-digital converter and a microprocessor is connected to the battery pack and monitors the voltage of the battery pack. When the monitoring system detects a voltage change indicating depletion of the monitor cell, the monitoring system provides a signal indicative that the battery pack is nearing depletion. The proportional rate of discharge of the monitor cell relative to the other cells during normal defibrillator operation is matched to the proportional rate of discharge occurring at other times. Thus, the assumptions as to the remaining energy reserves when the monitor cell is depleted remain accurate whether the battery pack is discharged by normal defibrillator operation or by other phenomenon such as energy drain during non-use. In addition, the system will accurately provide a warning of battery pack depletion regardless of the type of batteries used or the initial energy levels, as long as the batteries are initially similar to one another. Thus, batteries from any manufacturer or production lot may be used for the battery pack without requiring advance knowledge of the energy characteristics of the particular set of batteries.

Method and system for providing a warning of a remaining energy level of a battery pack in a defibrillator

A method and apparatus for controlling the common mode impedance misbalance of an isolated single-ended circuit for all common mode paths, thereby allowing the balancing of the common mode impedances which reduces common mode effects while maintaining the advantages of the single-ended amplifier including circuit simplicity and the reference input connected to circuit ground. In one embodiment, two solid shields enclose the circuit as completely as possible with the inner shield connected to circuit ground which is also the reference for all other inputs to the circuit. A discrete capacitor is connected between the outer shield and each of the non-reference inputs. When the shield is complete, i.e., solid, almost solid with minimal holes or a fine mesh, the value of the discrete capacitor is selected to match the parasitic capacitance formed between the outer shield and the inner shield. In another embodiment, the shield may be incomplete, i.e., a grid, coarse mesh or a solid shield only enclosing a portion of the circuit; this shield is connected to the non-reference input of the circuit. In this case, the exposures of the incomplete outer shield and the electronic circuit ground plane (or inner shield) to an external noise source are matched to balance the effect of their parasitic capacitances. Also, in the case of an incomplete shield, a discrete capacitor may be connected between the outer shield and the non-reference input of the circuit to enable balancing the impedances to common mode currents.

Method and apparatus for controlling the common mode impedance

A method and system for monitoring the capacity of a battery pack (6) is provided. The battery pack (6) is capable of delivering current to a load (R.sub.L). The battery pack (6) includes a monitor cell (C4) and battery cells (C1, C2, and C3). The monitor cell (C4) has a predetermined initial energy level that is lower than the predetermined initial energy level of the battery cells. A monitoring system (22) including an analog-to-digital converter (10) and a microprocessor (12) is connected to the battery pack and monitors the voltage of the battery pack. When the monitoring system detects a voltage change indicating depletion of the monitor cell (C4), the monitoring system provides a signal indicative that the battery pack is nearing depletion.

Method and system for monitoring the condition of a battery pack in a

A high energy transfer relay includes a housing, a solenoid, a pivot arm, a stationary contact, a switching contact and a leaf spring. The switching contact is mounted on the leaf spring. The armature of the solenoid is coupled to the pivot arm such that when the solenoid is energized, the pivot arm moves in the direction of the stationary contact. Movement is against the force of the leaf spring which is positioned to bias the pivot arm away from the stationary contact against a stop. The leaf spring also pre-loads the pivot point. In addition, the resilience of the leaf spring cushions the impact of the switching contact on the stationary contact to help prevent contact bounce. The outer end of the pivot arm includes a flat that coacts with a flat wall to form an air cushion. The air cushion also assists in preventing contact bounce by absorbing the momentum of the pivot arm after the contacts mate. Additionally, the moment of inertia of the pivot arm and associated elements located on the switching contact side of the pivot point is counterbalanced by the moment of inertia of the armature and the part of the pivot arm on the solenoid side of the pivot point. Balancing the moments of inertia ensures that an acceleration force applied to the solenoid side of the pivot point will be counterbalanced by an equal and opposite force on the switching contact side of the pivot point.

High energy transfer relay

In an external cardiac defibrillator (8), a method and system for determining when a relay (22) has failed in a conductive state. The defibrillator (8) includes a charge circuit (14) that charges an energy storage capacitor (C) to a predetermined voltage. The relay (22) is closed to direct a defibrillation pulse from the energy storage capacitor to a patient (25) needing ventricular therapy. The relay (22) is then opened following application of the defibrillation pulse. A monitor circuit (18) monitors the voltage on the energy storage capacitor. If the measured voltage across the energy storage capacitor (C) is less than or equal to a threshold value after a predetermined delay, the relay (22) has failed. If the measured voltage exceeds the threshold value, the relay (22) is operating correctly.

Method and system for detecting relay failure

A portable defibrillator (10) with a common therapy/data port (12). A set of electrodes (34) is connected to the therapy/data port to connect the defibrillator to a patient. If connected to a patient, the defibrillator operates in a normal mode of operation where it analyzes a patient's electrocardiogram (ECG), and, if required, applies defibrillation therapy through the port to the patient. A communication cable (42) is connected to the therapy/data port to connect the defibrillator to an auxiliary component (44). If connected to an auxiliary component, the defibrillator operates in a data communication mode of operation where data may be transmitted to and received from the auxiliary component through the therapy/data port. A test cable is connected to the therapy/data port to connect the defibrillator to a test load. If connected to a test load, the defibrillator operates in a user test mode of operation to allow a user to test the operation of the defibrillator. Preferably, the portable defibrillator automatically determines whether it is connected to a patient, an auxiliary component, or a test load.

Common therapy/data port for a portable defibrillator

Circuits for controlling the current flow of an energy pulse as a function of the temperature of a resistive element in the circuit so that the current flow varies over time in accordance with a predetermined waveform. The circuits include at least one negative temperature coefficient thermistor connected between an energy storage device and connectors for delivering energy stored in the storage source to an external load. In one embodiment of the invention the circuit includes a second thermistor for shunting a residual portion of the current delivered by an energy pulse away from the external load. In another embodiment of the circuit, a small inductive device is used for adjusting the shape of the predetermined waveform. In yet another embodiment of the device, a plurality of thermistors arranged in a bridge-like configuration are used to control the current of the energy pulse so that its waveform is biphasic. Heat sinks may be attached to the thermistors for cooling the latter so as to increase the rate at which energy pulses may be delivered by the circuits.

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Seattle, WA, United States of America

Daniel Yerkovich