Abstract: According to the disclosure there is provided an apparatus that assesses chest recoil of a subject during cardio pulmonary resuscitation (CPR) carried out by a rescuer on the subject and provides feedback to the rescuer. This apparatus may include a bio-signal measurement system configured to measure bio-signals of the subject. The apparatus may identify when CPR is required and may provide a CPR start signal to indicate when CPR should be started and this apparatus may identify when CPR is to be ceased. A CPR stop signal may be provided to a rescuer to indicate when CPR should be stopped. The apparatus may include electronic circuits capable of measuring impedance signals of the subject, may include sensors that sense bio-signals, and may include defibrillator shock electronics capable of providing a shock to the subject to restart or reset the heart of the subject.

Abstract: A guide system for indicating an activator of a defibrillator to a user including a motion detection circuit which determines motion of the defibrillator and generates at least one defibrillator motion mode signal, and a guide circuit which receives the defibrillator motion mode signal and causes the activator to be indicated to the user of the defibrillator.

Abstract: A defibrillator is provided comprising an activation mechanism having an activator and a status indicator, wherein the activator is disposable in a first condition in which the defibrillator is deactivated and in a second condition in which the defibrillator is activated and the status indicator is operable in at least a first mode in which a ‘defibrillator ready’ status of the defibrillator is indicated and a second mode in which a ‘defibrillator not ready’ status of the defibrillator is indicated. By having an activation mechanism which includes the activator and the status indicator, users of the defibrillator are not confused between separate activation and status indication devices and are able to use the activator promptly.

Abstract: A defibrillator assesses cardio pulmonary resuscitation carried out on a subject and provides feedback. The defibrillator measures bio signals of the subject, determines when CPR is required and produces a start signal and determines and when CPR is no longer required and produces a stop signal. A measurement system measures compression signals during CPR chest compressions, a CPR assessment system receives the CPR start signal and the CPR stop signal and receives compression signals. The defibrillator uses the compression signals to establish a first CPR performance measurement, set a performance baseline of the person equal to the first CPR performance measurement of the person, compare the further CPR performance measurement of the person with the CPR performance baseline of the person, produce a feedback signal and set the CPR performance baseline of the person equal to the further CPR performance measurement of the person and return to earlier operations.

Abstract: An electrode test system of a defibrillator including electrodes in a face-to-face test arrangement forming a capacitor, an impedance measurement signal generator connected to the electrodes and configured to send an ac signal to the electrodes, an impedance measurement signal processor connected to the electrodes which is placeable in an electrode test state and configured to receive an electrode test ac signal from the electrodes and process the electrode test ac signal to obtain a processed electrode test ac signal, a defibrillator processor connected to the impedance measurement signal generator and the impedance measurement signal processor configured to place the impedance measurement signal processor in the electrode test state and to receive the processed electrode test ac signal, analyze the processed electrode test ac signal to obtain an electrode test impedance signal and analyze the electrode test impedance signal to determine a pass condition or a fail condition of the electrodes.

Abstract: An external defibrillator estimates the phase of ventricular defibrillation (VF) by deriving, from an ECG exhibiting VF, at least one quality marker representing the morphology of the ECG and, therefore, the duration of the VF. The duration of the VF is calculated as a function of the value (s) of the quality marker (s). The quality marker (s) may comprise any one or more of the median slope of the ECG, the average slope of the ECG, the ratio of the power in relatively high and low frequency bands of the ECG, and a measure of the density and amplitude of peaks in the ECG, over a predetermined period.

Abstract: An external defibrillator estimates the phase of ventricular defibrillation (VF) by deriving, from an ECG exhibiting VF, at least one quality marker representing the morphology of the ECG and, therefore, the duration of the VF. The duration of the VF is calculated as a function of the value (s) of the quality marker (s). The quality marker (s) may comprise any one or more of the median slope of the ECG, the average slope of the ECG, the ratio of the power in relatively high and low frequency bands of the ECG, and a measure of the density and amplitude of peaks in the ECG, over a predetermined period.

Abstract: A cardiopulmonary resuscitation (CPR) compression force indicator includes circuitry (20, 26, 28, 30) for monitoring a patient's transthoracic impedance while the patient is being given CPR and generating a corresponding impedance signal, circuitry (32, 34, 36) for processing the impedance signal to provide an ongoing measurement of cardiac hemodynamic output, a microprocessor (24) for determining if the measurement falls outside pre-set limits, and indicator(s) (38) for indicating such determination externally to the person giving the CPR.

Abstract: An electrode identification system (1) for defibrillators, comprising an electrode plug (2) adapted for connection to at least one electrode having a first pair of conducting contacts (6, 8), an identification element (10) connected between the first pair of conducting contacts, a second pair of conducting contacts (12, 14) for connection to the electrode, and a housing (16) providing a cavity (18, 20) which substantially encases the first and second pairs of conducting contacts and the identification element and an aperture through which ends of the first and second pairs of conducting contacts extend, a defibrillator socket (3) adapted for connection to a defibrillator and adapted for connection to an electrode plug having a first pair of conducting contacts (24, 26) for connection to the first pair of conducting contacts of the electrode plug, a second pair of conducting contacts (28, 30) for connection to the second pair of conducting contacts of the electrode plug and for connection to the defibrillator,

Abstract: An external defibrillator estimates the phase of ventricular defibrillation (VF) by deriving, from an ECG exhibiting VF, at least one quality marker representing the morphology of the ECG and, therefore, the duration of the VF. The duration of the VF is calculated as a function of the value (s) of the quality marker (s). The quality marker (s) may comprise any one or more of the median slope of the ECG, the average slope of the ECG, the ratio of the power in relatively high and low frequency bands of the ECG, and a measure of the density and amplitude of peaks in the ECG, over a predetermined period.

Abstract: Systems and methods for testing defibrillator electrode conductivity. Connection for electrically connecting electrodes and defibrillation signal generator connected to the electrodes. Patient impedance measurement system comprising patient signal generator and patient signal receiver. A defibrillator controller connected to defibrillation signal generator and patient impedance measurement system.

Abstract: A defibrillator (1) comprising electrodes (3), a connection (5) for electrically connecting the electrodes together, a defibrillation circuit (9) connected to the electrodes, and an electrode test system (7), comprising a test initiation device operable to generate a test initiating signal, a test signal generator (15) operable to generate a dc voltage test signal, a test signal switch (17) connected to the electrodes and, on receipt of the test initiating signal, operable to connect the electrodes to the test signal generator for passing the dc voltage test signal to the electrodes, and a test processing device (19) connected to the test signal switch to receive a dc voltage electrode return signal and process the electrode return signal to determine a pass test result or a fail test result for the electrodes.

Abstract: An external defibrillator includes patient electrodes (20) for obtaining the patient's electrocardiogram (ECG) and for applying a shock to the patient. A microprocessor (24) analyses the patient's ECU using a diagnostic algorithm to detect if the patient's heart is in a shockable rhythm, and shock delivery circuitry (10) is enabled when a shockable rhythm is detected by the diagnostic algorithm. The patient electrodes also allow obtaining a signal (Z) which is a measure of the patient's transthoracic impedance and the microprocessor is responsive to Z to detect conditions likely to cause the diagnostic algorithm to generate a false detection of a shockable rhythm. If such detection is made, the microprocessor prevents detection of a shockable rhythm by the diagnostic algorithm, at least for a period of time.

Abstract: An apparatus for indicating cardiac output comprises means for monitoring a patient's transthoracic impedance and generating a corresponding impedance signal, and signal processing means for (a) deriving a signal S1 which is a measure of the average amplitude of the impedance signal, (b) filtering the impedance signal at a plurality of different wavelengths within a predetermined frequency band, (c) for each filter deriving a signal S2 which is a measure of the average amplitude of the respective filter output, (d) calculating the ratio of the maximum one of the signals S2 derived from step (c) to the signal S1 derived from step (a), and (e) using the ratio from step (d) in a decision tree to provide a signal indicating cardiac output or not.

Abstract: An external defibrillator includes patient electrodes (20) for obtaining the patient's electrocardiogram (ECG) and for applying a shock to the patient. A microprocessor (24) analyses the patient's ECG using a diagnostic algorithm to detect if the patient's heart is in a shockable rhythm, and shock delivery circuitry (10) is enabled when a shockable rhythm is detected by the diagnostic algorithm. The patient electrodes also allow obtaining a signal (Z) which is a measure of the patient's transthoracic impedance and the microprocessor is responsive to Z to detect conditions likely to cause the diagnostic algorithm to generate a false detection of a shockable rhythm. If such detection is made, the microprocessor prevents detection of a shockable rhythm by the diagnostic algorithm, at least for a period of time.

Abstract: An electrode identification system (1) for defibrillators, comprising an electrode plug (2) adapted for connection to at least one electrode having a first pair of conducting contacts (6, 8), an identification element (10) connected between the first pair of conducting contacts, a second pair of conducting contacts (12, 14) for connection to the electrode, and a housing (16) providing a cavity (18, 20) which substantially encases the first and second pairs of conducting contacts and the identification element and an aperture through which ends of the first and second pairs of conducting contacts extend, a defibrillator socket (3) adapted for connection to a defibrillator and adapted for connection to an electrode plug having a first pair of conducting contacts (24, 26) for connection to the first pair of conducting contacts of the electrode plug, a second pair of conducting contacts (28, 30) for connection to the second pair of conducting contacts of the electrode plug and for connection to the defibrillator,

Abstract: An external defibrillator includes patient electrodes (20) for obtaining the patient's electrocardiogram (ECG) and for applying a shock to the patient. A microprocessor (24) analyses the patient's ECG using a diagnostic algorithm to detect if the patient's heart is in a shockable rhythm, and shock delivery circuitry (10) is enabled when a shockable rhythm is detected by the diagnostic algorithm. The patient electrodes also allow obtaining a signal (Z) which is a measure of the patient's transthoracic impedance and the microprocessor is responsive to Z to detect conditions likely to cause the diagnostic algorithm to generate a false detection of a shockable rhythm. If such detection is made, the microprocessor prevents detection of a shockable rhythm by the diagnostic algorithm, at least for a period of time.

Abstract: A defibrillator (1) comprising electrodes (3), a connection (5) for electrically connecting the electrodes together, a defibrillation circuit (9) connected to the electrodes, and an electrode test system (7), comprising a test initiation device operable to generate a test initiating signal, a test signal generator (15) operable to generate a dc voltage test signal, a test signal switch (17) connected to the electrodes and, on receipt of the test initiating signal, operable to connect the electrodes to the test signal generator for passing the dc voltage test signal to the electrodes, and a test processing device (19) connected to the test signal switch to receive a dc voltage electrode return signal and process the electrode return signal to determine a pass test result or a fail test result for the electrodes.

Abstract: A sealed medical electrode package comprises first and second electrodes each comprising a conductive layer (14) disposed on one major surface of a flexible nonconductive backing sheet (10). The electrodes are disposed with their conductive layers (14) face-to-face and their backing sheets separably sealed together around their peripheral edges so that the backing sheets form a substantially gas-impermeable enclosure containing the conductive layers. In an alternative embodiment (FIG. 6) a respective electrical contact extends through each backing sheet into electrical contact with the respective conductive layer, and a substantially gas-impermeable packaging material encloses the electrodes. The packaging material has a respective aperture exposing each electrical contact, the periphery of each aperture being sealed to the backing sheet around the respective contact.