Abstract: An ECG signal detection device that includes a differential amplifier input circuit and a driven reference electrode lead is disclosed. More specifically, the ECG signal detection device includes a differential amplifier input circuit and three-electrode leads, two of which terminate at a common patient coupling device such as an electrode pad or a defibrillator paddle. The third electrode lead terminates at a second, separate patient coupling device. Two electrical cords that include the electrode leads extend between the patient coupling devices and the differential amplifier input circuit. One electrical cord includes the two-electrode leads that terminate at the common patient coupling 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: In one embodiment, a method is characterized by measuring a patient parameter associated with a human body; in response to the patient parameter, retrieving a maximum expected device parameter; and setting a limit on an energy source such that during defibrillation of the patient a defibrillation parameter associated with the maximum expected device parameter is within a defined tolerance. In another embodiment, a method is characterized by specifying at least one device parameter limit of a defibrillation unit; and in response to the at least one specified device parameter, determining a prediction confidence level at which the device parameter limit is exceeded for one or more values of a patient parameter.

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: A system, method and apparatus for obtaining status information from a portable medical device and communicating said status information to a remote system or user. In one embodiment, the system comprises a sensing device that comprises an optical receiver for receiving status information from at least one status indicator of the portable medical device. The optical receiver is positioned in sufficient proximity to the status indicator to allow optical communication between the optical receiver and the status indicator. A circuit couplable to the optical receiver communicates the status information represented by the status indicator to the remote system or user. In another embodiment, the sensing device comprises a microphone to receive audible status signals from the portable medical device. In yet another embodiment, the sensing device is mounted to a housing, which allows sensing device to sense the status information of an enclosed portable medical device.

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: An electrotherapy delivery device includes an upper member having a handle portion and a pediatric electrode mounted to the bottom surface of the upper member. A base member having an adult electrode is selectively attached to the upper member with a coupling mechanism to conceal the pediatric electrode. The upper member attaches to the base member across diametrically opposed corners of the base member to provide the user with a more ergonomic hand position when accessing the paddles from the defibrillator. The device further include a plurality of switches operable to deliver a charge and to select the level of charge to be delivered to the patient. The paddle is provided with a processing circuit that receives an output from separate energy level increase and decrease switches, processes the output from the switches, and outputs a signal to the defibrillator corresponding to the level of energy selected by the switches.

Abstract: An external defibrillator having an output circuit that allows a defibrillation pulse to be discharged to a patient is provided. The output circuit, charging circuit, preamplifier circuit, impedance measurement circuit, energy storage device, battery, and measurement and control circuits of the defibrillator are all referenced to a common ground. The use of a common ground is simpler and less expensive than previous designs which utilized isolation stages and circuits for isolating the high and low voltage circuitry. The output circuit is in the form of an H-bridge which contains three SCR legs and one IGBT leg. Each of the legs contains a single semiconductor switch. The IGBT is placed in the northwest leg of the H-bridge. The two lower legs each contain SCRs, one or both of which may be driven by DC gate drive signals.

Abstract: A pulse detection apparatus, software, and method that uses signal data obtained from an accelerometer placed on a patient's body to detect the presence of a cardiac pulse. The accelerometer is adapted to sense movement due to a cardiac pulse and produce accelerometer signal data in response thereto. Processing circuitry analyzes the accelerometer signal data for a feature indicative of a cardiac pulse and determines whether a cardiac pulse is present in the patient based on the feature. In one aspect, the feature may be a temporal energy feature, such as a relative change in energy. In another aspect, the feature may be a spectral energy feature such as the energy or frequency of a peak in the energy spectrum of the signal. In yet another aspect, the feature may be obtained by comparing the accelerometer signal data with a previously-identified pattern known to predict the presence of a cardiac pulse. Multiple features may also be obtained and classified to determine the presence of a cardiac pulse.

Abstract: An automated external defibrillator (AED) (10) designed for use by a rescuer with minimal or no training during a medical emergency is provided. The AED implements a user interface program (22) which guides the rescuer through operation of the AED and application of CPR and defibrillation therapy to a patient by displaying a series of visual instructions on a graphic display (14) or other visual output device, and by providing additional aural instructions via a speaker (18) or other aural output device. The rescuer merely needs to press a start button (12) to initiate operation of the AED and begin CPR and defibrillation instruction.

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: A medical device constructed according to the invention includes electrodes (12a, 12b), a measuring unit (24) for measuring a patient-dependent electrical parameter (e.g., impedance) of the patient, an electrotherapy generator (26) for delivering electrotherapy to the patient, and a processing unit (20) for controlling the delivery of electrotherapy to the patient. Electrotherapy is preferably delivered to the patient based on the measured patient-dependent electrical parameter and a predetermined response of a reference patient to a nominal electrotherapy. The actual electrotherapy delivered to the patient is controlled so that the electrotherapy has a probability of success for the patient that is equivalent to the probability of success of the nominal electrotherapy for the reference patient. A consistent shock efficacy across different patients is achieved.

Abstract: The present invention provides 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: The invention provides a method for sequentially activating a medical device and exposing at least a portion of the user interface of the medical device to an operator, in a single action to be performed by the operator. The medical device, for example, an automated external defibrillator (AED), includes a housing having a user interface and a lid that is coupled to the housing. The lid, when closed, is covering at least a portion of the user interface. In one embodiment, the medical device further includes an on/off button. The button is configured such that, when an operator depresses the button, it causes a switch to close to thereby activate the medical device, and further causes the lid to open via a latch mechanism.

Abstract: A selectively removable charging pack is provided, which is operable to recharge the power source of a portable external defibrillator when coupled thereto. The charging pack comprises an elongate body of generally triangular shaped cross-section having a front region, a back region, a top region, and left and right sides and that form a bottom region at the convergence of left and right sides. The body houses a charging source in the form of charging cells that are operable to recharge the power source of a portable external defibrillator when inserted in its charging well. The front of the charging pack is formed with a latch, which may be utilized by a user to remove the charging pack from the defibrillator. The latch automatically secures the charging pack in the charging well when the charging pack is inserted into the defibrillator.

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 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: 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.