Abstract: A method for gathering event data using a data gathering instrument having an instrument clock and an instrument data storage medium, the method comprising the steps of: gathering event data using the data gathering instrument; storing the event data in an instrument data storage medium; using an instrument clock to associate time information with the event data; storing the associated time information in the instrument data storage medium; separating the instrument data storage medium from the data gathering instrument; separating the instrument clock from the data gathering instrument; and storing in a main data storage medium the event data and the time information stored in the instrument data storage medium. The invention also includes a data gathering system practicing this method, the data gathering instrument itself, and removable instrument clock and memory modules, preferably disposed together in a housing such as a PCMCIA format card.

Abstract: A defibrillator featuring a treatment mode and a training mode comprises an energy source, an electrode connector, a controller, and training mode circuitry. The controller comprises a feature for connecting the energy source to the electrode connector and a pause actuator for permitting a user to inhibit electrical stimulation when no longer required. The training mode circuitry simulates the operation of the defibrillator in treatment mode.

Abstract: The present invention is an apparatus and method for detecting differential mode signals in an environment where differential mode signals co-exist, and might be corrupted by, common mode signals. The most basic apparatus of the present invention essentially comprises first and second input leads through which both differential mode and common mode signals are input; a first amplifier block having a gain that is substantially one; and at least an inverting node and a non-inverting node connected to the first and second input leads. The output of the amplifier block is fed back to the input of the non-inverting node of the amplifier block in a manner to increase differential mode impedance while maintaining a low common mode impedance. Various embodiments of the basic presently claimed circuitry provides for additional methods of monitoring the level of common-mode signal introduced to the apparatus and other fault detection functions.

Abstract: The present invention is an apparatus and method for detecting differential mode signals in an environment where differential mode signals co-exist, and might be corrupted by, common mode signals. The most basic apparatus of the present invention essentially comprises first and second input leads through which both differential mode and common mode signals are input; a first amplifier block having a gain that is substantially one; and at least an inverting node and a non-inverting node connected to the first and second input leads. The output of the amplifier block is fed back to the input of the non-inverting node of the amplifier block in a manner to increase differential mode impedance while maintaining a low common mode impedance. Various embodiments of the basic presently claimed circuitry provides for additional methods of monitoring the level of common-mode signal introduced to the apparatus and other fault detection functions.

Abstract: This invention provides an external defibrillator and defibrillation method that automatically compensates for patient-to-patient impedance differences in the delivery of electrotherapeutic pulses for defibrillation and cardioversion. In a preferred embodiment, the defibrillator has an energy source that may be discharged through electrodes on the patient to provide a biphasic voltage or current pulse. In one aspect of the invention, the first and second phase duration and initial first phase amplitude are predetermined values. In a second aspect of the invention, the duration of the first phase of the pulse may be extended if the amplitude of the first phase of the pulse fails to fall to a threshold value by the end of the predetermined first phase duration, as might occur with a high impedance patient.

Abstract: A defibrillator and electrode system that gives the user a visible and/or audible indication of the condition of the electrodes and other parts of the defibrillator system prior to deployment of the electrodes and use of the defibrillator. In a preferred embodiment of the method of this invention, a patient simulation and analyze circuit within the defibrillator periodically tests the condition of the system and provides the user with a visual indication of the system's condition.

Abstract: A defibrillator has a treatment mode and a training mode. The defibrillator includes an energy source; an electrode connector; a controller, including a feature for connecting the energy source to the electrode connector; and training mode features for stimulating the operation of the defibrillator in treatment mode. Also included is a method of operating a defibrillator including the steps of providing a defibrillator (with the defibrillator including a defibrillation energy source, a controller and electrode connectors, and with the controller including circuitry for actuating the defibrillator to deliver a defibrillation shock from the defibrillation energy source to the electrode connectors) and operating the defibrillator in a training mode to simulate delivery of a shock from the energy source to the electrode connectors without delivering a defibrillation shock from the energy source to the electrode connectors.

Abstract: An electrotherapy method and apparatus for delivering a multiphasic waveform from an energy source to a patient. The preferred embodiment of the method comprises the steps of charging the energy source to an initial level; discharging the energy source across the electrodes to deliver electrical energy to the patient in a multiphasic waveform; monitoring a patient-dependent electrical parameter during the discharging step; shaping the waveform of the delivered electrical energy based on a value of the monitored electrical parameter, wherein the relative duration of the phases of the multiphasic waveform is dependent on the value of the monitored electrical parameter.

Abstract: This invention provides an external defibrillator and defibrillation method that automatically compensates for patient-to-patient impedance differences in the delivery of electrotherapeutic pulses for defibrillation and cardioversion. In a preferred embodiment, the defibrillator has an energy source that may be discharged through electrodes on the patient to provide a biphasic voltage or current pulse. In one aspect of the invention, the first and second phase duration and initial first phase amplitude are predetermined values. In a second aspect of the invention, the duration of the first phase of the pulse may be extended if the amplitude of the first phase of the pulse fails to fall to a threshold value by the end of the predetermined first phase duration, as might occur with a high impedance patient.

Abstract: This invention provides an external defibrillator and defibrillation method that automatically compensates for patient-to-patient impedance differences in the delivery of electrotherapeutic pulses for defibrillation and cardioversion. In a preferred embodiment, the defibrillator has an energy source that may be discharged through electrodes on the patient to provide a biphasic voltage or current pulse. In one aspect of the invention, the first and second phase duration and initial first phase amplitude are predetermined values. In a second aspect of the invention, the duration of the first phase of the pulse may be extended if the amplitude of the first phase of the pulse fails to fall to a threshold value by the end of the predetermined first phase duration, as might occur with a high impedance patient.

Abstract: A defibrillator system comprising an external defibrillator, a defibrillator communicator and a communication network. In a preferred embodiment, the defibrillator comprises electrodes, an energy source and a controller, with the controller comprising an ECG signal analyzer and local actuator on the defibrillator for delivering an electrical pulse from the energy source to the electrodes. The communication network comprises a communication station, preferably a computer with a modem, and signal carriers, such as telephone lines, so that information can be transmitted from the communicator to the communication station. The defibrillator communicator automatically transmits information to the communication station in response to deployment of the defibrillator. In alternative embodiments, additional information (such as patient ECG data and defibrillator operation data) is sent from the communication station to the communicator. A method of operating such a defibrillator system is included.

Abstract: A defibrillator and electrode system that gives the user a visible and/or audible indication of the condition of the electrodes and other parts of the defibrillator system prior to deployment of the electrodes and use of the defibrillator. In a preferred embodiment of the method of this invention, a patient simulation and analyze circuit within the defibrillator periodically tests the condition of the system and provides the user with a visual indication of the system's condition.

Abstract: A method for gathering event data using a data gathering instrument having an instrument clock and an instrument data storage medium, the method comprising the steps of: gathering event data using the data gathering instrument; storing the event data in an instrument data storage medium; using an instrument clock to associate time information with the event data; storing the associated time information in the instrument data storage medium; separating the instrument data storage medium from the data gathering instrument; separating the instrument clock from the data gathering instrument; and storing in a main data storage medium the event data and the time information stored in the instrument data storage medium. The invention also includes a data gathering system practicing this method, the data gathering instrument itself, and removable instrument clock and memory modules, preferably disposed together in a housing such as a PCMCIA format card.

Abstract: This invention is a battery monitor and battery capacity indicator that uses a sense cell in addition to the main battery to determine main battery remaining capacity and depletion condition. A parameter of the sense cell is related to the main battery capacity so that the main battery will have a minimum capacity remaining when the sense cell parameter reaches a particular value or crosses a particular threshold. In a preferred embodiment, the sense cell is a battery which is identical and of the same manufacturing lot as the battery cell or cells in the main battery pack. A current is drawn from the sense cell that is larger than the current being drawn from the main battery. When the sense cell is fully depleted, the main battery will have a remaining capacity whose magnitude depends on the relationship between the main battery current and the sense cell current.

Abstract: A defibrillator electrode system. In the preferred embodiments, each electrode and the conductor leading to the instrument (such as the defibrillator or ECG monitor) is mounted on the same flexible substrate. In one two-electrode system embodiment, each electrode-conductor pair is mounted on a separate flexible substrate, and the two substrates are mounted in a retainer. In another preferred two-electrode system embodiment, the two electrode-conductor pairs are mounted on the same flexible substrate. In both embodiments, the retainer attaches to the instrument and provides the electrical connection between the conductors and the instrument. Conductive gel covers the electrodes in the preferred embodiments, and an adhesive surrounds the electrodes. The flexible substrate is provided with a release coating in appropriate spots. In their undeployed storage positions, the electrodes' conductive gel portions and adhesive portions lie against the release coating.