Abstract: External pacemaker systems and methods deliver pacing waveforms that minimize hydrolysis of the electrode gel. Compensating pulses are interleaved with the pacing pulses, with a polarity and duration that balance the net charge at the electrode locations. The compensating pulses are preferably rectangular for continuous pacing, and decay individually for on-demand pacing.

Abstract: The presence of a cardiac pulse in a patient is determined by evaluating fluctuations in an electrical signal that represents a measurement of the patient's transthoracic impedance. Impedance signal data obtained from the patient is analyzed for a feature indicative of the presence of a cardiac pulse. Whether a cardiac pulse is present in the patient is determined based on the feature in the impedance signal data. Electrocardiogram (ECG) data may also be obtained in time coordination with the impedance signal data. Various applications for the pulse detection of the invention include detection of PEA and prompting PEA-specific therapy, prompting defibrillation therapy and/or CPR, and prompting rescue breathing depending on detection of respiration.

Abstract: The presence of a cardiac pulse in a patient is determined by evaluating fluctuations in an electrical signal that represents a measurement of the patient's transthoracic impedance. Impedance signal data obtained from the patient is analyzed for a feature indicative of the presence of a cardiac pulse. Whether a cardiac pulse is present in the patient is determined based on the feature in the impedance signal data. Electrocardiogram (ECG) data may also be obtained in time coordination with the impedance signal data. Various applications for the pulse detection of the invention include detection of PEA and prompting PEA-specific therapy, prompting defibrillation therapy and/or CPR, and prompting rescue breathing depending on detection of respiration.

Abstract: The presence of a cardiac pulse in a patient is determined by evaluating fluctuations in an electrical signal that represents a measurement of the patient's transthoracic impedance. Impedance signal data obtained from the patient is analyzed for a feature indicative of the presence of a cardiac pulse. Whether a cardiac pulse is present in the patient is determined based on the feature in the impedance signal data. Electrocardiogram (ECG) data may also be obtained in time coordination with the impedance signal data. Various applications for the pulse detection of the invention include detection of PEA and prompting PEA-specific therapy, prompting defibrillation therapy and/or CPR, and prompting rescue breathing depending on detection of respiration.

Abstract: A cardiac therapy pulse delivery system includes a plurality of electrodes, an ECG signal processor circuit, and a pulse generator circuit. Each of the electrodes has at least one therapy element and at least one monitor element that are electrically insulated from one another. The ECG signal processor circuit is electrically coupled to each monitor element on each electrode and is operable to convert ECG signals detected by the monitor elements into ECG data. The cardiac pulse generator circuit is electrically coupled to each therapy element on each electrode and is operable to supply one or more cardiac therapy pulses thereto.

Abstract: Methods and apparatus are provided for minimizing the inherent time delays within external defibrillators and allowing operators to administer CPR therapy as close in time as possible to the delivery of a defibrillation shock to a patient. The methods and apparatuses utilize timing schemes for initiation and completion of charging or maintaining the charge of an energy storage device of an external defibrillator for at least a portion of a predetermined CPR therapy delivery time.

Abstract: Methods and apparatus are provided for minimizing the inherent time delays within external defibrillators. The methods and apparatuses utilize timing schemes for initiation and completion of charging of an energy storage device of an external defibrillator, measuring one or physical parameters of the patient and conducting a physiology analysis of the patient. The initiation and completion of one or more of these activities are arranged so that the energy storage device is charged to a desired level and available for a defibrillation shock to the patient with minimal delay after activation of the external defibrillator.

Abstract: A therapy-delivering, portable medical device (200) capable of triggering and/or communicating with an alarm system (100), as well as a related system and method therefor. The portable medical device (200) is configured to establish a communication link (107) with an alarm system (100) such as a residential or business alarm, upon the occurrence of a triggering event. Triggering events may be related to the use, operation or deployment of the portable medical device (200) in an emergency situation, or they may be for service, status or maintenance purposes, e.g., to report device failures, system checks, etc. The portable medical device (200) is configured to deliver therapy to a patient, wherein the therapy delivered to the patient may be any or combination of medial therapies, e.g., defibrillation, drugs, etc., for any one or combination of medical applications, such as stroke, cardiac arrest, diabetic shock, etc.

Abstract: A method and apparatus for performing self-tests on defibrillation and pacing circuits including a patient isolation switch is disclosed. Tests are provided for the defibrillation and pacing circuitry as well as the isolation switch. For testing the defibrillation circuitry, the impedance drive circuits and preamplifier may be utilized such that the energy storage capacitor is not required to be charged and discharged during the test, thus conserving energy. For testing the pacing circuitry and the isolation switch, the defibrillation circuitry is utilized. For certain of the tests, the test stimulus is the output voltage on the energy storage capacitor, while for other tests the test stimulus may be the pace current as indicated by the voltage across the input to the preamplifier. Alternative tests may be performed depending on whether the impedance at the output of the defibrillator is determined to be an open circuit or a short circuit.

Abstract: A medical device is configured to support two-way communication to remotely monitor and manage medical device parameter status and software. A two-way communication module is incorporated into the medical device. A remote monitoring service is configured to regularly communicate with the medical device to initiate status assessments of medical device parameters and perform software updates. The medical device then sends a return message to the remote monitoring service using the two-way communication network. The return message can include the requested information, parameter values, or information about the software updates. This system can be advantageously used to efficiently monitor a large number of portable or mobile medical devices in a manner that is transparent to the users of the medical devices.

Abstract: A circuit for generating both a biphasic defibrillation waveform and an external pacing waveform in an external defibrillator is provided. The output circuit of the device utilizes one or more SCR switches for applying energy to a patient. In one embodiment, the output circuit is in the form of an H-bridge, with three SCR legs and one IGBT leg. A drive circuit for one of the SCR legs is provided such that the SCR may be continuously driven on for either a high energy biphasic defibrillation pulse or a low energy pacing pulse. In one embodiment, the output circuit conducts the pacing waveform through a combination of one upper leg SCR of the H-bridge and a current source. The current source is configured to bypass a lower leg SCR of the H-bridge. The output circuit is capable of conducting pacing currents of as low as 10 mA.

Abstract: Medical electrode arrangements are provided for electrotherapy and monitoring applications. In one embodiment, each electrode arrangement includes a smaller electrode that is releasably attached to the back of a larger electrode. For adult applications, the larger electrode is applied to the patient. For pediatric applications, the larger electrode is preferably removed, and the smaller electrode is applied to the patient. Face-to-face and back-to-back electrode arrangement configurations are also provided. In a further embodiment, an electrode arrangement is comprised of first and second conductive regions of a common substrate that are separable by a division line in the substrate. For adult applications, stored energy is conducted through both conductive regions. For pediatric applications, the second region of the substrate is removed along the division line. A sensing mechanism is also provided to detect whether the electrode arrangement has been placed in an adult or pediatric configuration.

Abstract: A method and apparatus for performing self-tests on defibrillation and pacing circuits including a patient isolation switch is disclosed. Following a test of the defibrillation and pacing circuitry, the isolation switch is tested by closing certain switches within the defibrillation circuitry so as to create a circuit path, and then opening and closing the isolation switch. Alternative tests may be performed depending on whether the impedance at the output of the defibrillator is determined to be an open circuit or a short circuit. If the output is determined to be an open circuit, then the test monitors the voltage across the output of the defibrillator as indicated by the voltage of a DC offset of a preamplifier coupled to the output of the defibrillator. For the short circuit test, the voltage on the energy storage capacitor is monitored.

Abstract: An external defibrillator with an output circuit having four legs arrayed in the form of an “H” (an “H-bridge”) is disclosed. The output circuit is designed to be able to conduct a range of defibrillation pulse energies, from below 50 joules to above 200 joules. Each leg of the output circuit contains a solid-state switch. By selectively switching on pairs of switches in the H-bridge, a biphasic defibrillation pulse may be applied to a patient. The switches in three of the legs of the H-bridge output circuit are preferably SCR switches, while the fourth leg includes an IGBT switch. In one embodiment, a single power switch is utilized in each of the legs of the H-bridge output circuit, and are included in a single integrated module or package. The use of single semiconductor switches in an integrated surface mountable module or package simplifies the assembly and manufacturing of the defibrillator device.

Abstract: The invention provides a wireless automatic location identification (ALI) capable system (10), including a medical device (12) having a wireless data communicator (14), a wireless communication network (16), and a remote locating service (18) for remotely locating and monitoring one or more medical devices over the wireless communication network. When the medical device is linked to the remote locating service over the communication network, the ALI-capable system identifies the location of the medical device and relays the location information to the remote locating service. The system permits reliable determination of the location of the medical device wherever the medical device is situated. The medical device may further be configured to transmit signals indicative of its status, condition, or self-test results, to the remote locating service. This feature allows the remote locating service to centrally monitor the status or condition of a plurality of medical devices.

Abstract: 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.

Abstract: The present invention is directed to a defibrillator having both a manual and an AED mode with corresponding user commands for both modes. The defibrillator includes a door which conceals manual mode commands, such that opening of the door puts the defibrillator in the manual mode and simultaneously reveals the manual mode command buttons. In one actual embodiment, the door includes apertures which allow access to the AED command buttons. When the door is in the open position, a keypad is revealed having manual commands which preferably take the form of buttons. In another actual embodiment, the door includes a switch which senses when the door is opened and sends the defibrillator into manual mode. The door includes a front side having AED command buttons, and a back side having manual mode command buttons. The door conceals a keypad having further manual mode command buttons.

Abstract: Medical electrode arrangements are provided for electrotherapy and monitoring applications. In one embodiment, each electrode arrangement includes a smaller electrode that is releasably attached to the back of a larger electrode. For adult applications, the larger electrode is applied to the patient. For pediatric applications, the larger electrode is preferably removed, and the smaller electrode is applied to the patient. Face-to-face and back-to-back electrode arrangement configurations are also provided. In another embodiment, an electrode arrangement is comprised of first and second conductive regions that are separable from each other. In yet further embodiments, an electrode arrangement is comprised of two or more electrodes that are not physically or electrically connected to each other. At least one electrode from each electrode arrangement is placed on the patient. A sensor is also provided to sense which electrodes in each electrode arrangement have been placed on the patient.

Abstract: A circuit package with improved heat dissipation properties for high-power circuits. In one embodiment, the circuit package comprises two circuit boards positioned in different planes, at least one brace affixed between the two circuit boards, a molded housing enclosing an area between the circuit boards, and a plurality of electrically conductive leads extending from the sides of the circuit package. The molded housing is configured to expose at least one surface of the circuit boards to the exterior surface of the circuit package. The leads are configured in a J-shape, which allows the circuit package to be mounted in an upright position. The brace functions as a flexible spacer for holding the two circuit boards in position during the application of the molded housing. In one embodiment, a H-bridge circuit is configured on the first and second circuit boards of the circuit package.

Abstract: Methods and apparatus are provided for portable medical devices such as defibrillators having different charging and operating voltages. The apparatus comprises a connection for receiving DC input voltage VIN, an energy storage device (e.g., a capacitor), a battery having at least two cells therein coupled to the connection and the capacitor, and switches to selectively reconfigure the battery cells so as to: (i) charge from VIN, and (ii) discharge to the capacitor at VOUT>VIN. The method comprises charging the battery from VIN while its cells are arranged substantially in parallel, then reconfiguring the switches to arrange some of the charged cells substantially in series to give VOUT>VIN, and then charging the capacitor therefrom. The cells are thereafter reconfigured back to the parallel arrangement ready to be recharged from VIN. Isolation switches are conveniently provided to isolate the battery from VIN while charging the capacitor.