Abstract: A method for displaying time-correlated medical event data including the steps of: providing time-correlated event data to a display device; selecting a first event to be displayed; and displaying the first event together with a time-correlated second event on the display device. In another embodiment, the invention is a method for displaying time-correlated medical event data including the steps of: manually entering data comprising a first event into a display device; time-correlating the first event with data comprising a second event collected by a medical device; and displaying the first event together with the second event on the display device.

Abstract: A method and circuit are described for automatically testing various components of a defibrillator at random or otherwise aperiodic time intervals. A random number is generated that falls within a range of numbers corresponding to minimum and maximum acceptable time intervals between successive testing of the defibrillator. Ambient conditions can be measured and the acceptable range of numbers adjusted accordingly. High energy test procedures may be performed less frequently, as appropriate for the measured ambient conditions. The range of numbers can also be adjusted to provide greater frequency testing where desirable, such as following a use of the defibrillator, following a repair of the defibrillator, to detect infant mortality effects, or to detect wear-out effects. The defibrillator includes a testing circuit for testing the various other components. The testing circuit includes a controller coupled with a timer, a random number generator, a memory, and an ambient condition sensor.

Abstract: A method for displaying time-correlated medical event data including the steps of: providing time-correlated event data to a display device; selecting a first event to be displayed; and displaying the first event together with a time-correlated second event on the display device. In another embodiment, the invention is a method for displaying time-correlated medical event data including the steps of: manually entering data comprising a first event into a display device; time-correlating the first event with data comprising a second event collected by a medical device; and displaying the first event together with the second event on the display device.

Abstract: A method for displaying time-correlated medical event data including the steps of: providing time-correlated event data to a display device; selecting a first event to be displayed; and displaying the first event together with a time-correlated second event on the display device. In another embodiment, the invention is a method for displaying time-correlated medical event data including the steps of: manually entering data comprising a first event into a display device; time-correlating the first event with data comprising a second event collected by a medical device; and displaying the first event together with the second event on the display device.

Abstract: A method and apparatus for indicating a low battery condition and for dynamically controlling the load on a battery in order to optimize battery usage. A dynamic load controller for a battery includes detection circuitry for measuring at least one condition related to battery capacity, and power control circuitry for adjusting a power load on the battery based upon the condition. The dynamic load controller may be employed to control the power load on a battery that powers an electrotherapy device, such as a defibrillator. The battery condition may include the slope of a capacity curve, which may be the product of the battery voltage and the power delivered from the battery as a function of the delivered power. Based upon this condition, the power control circuitry adjusts the power load to optimize power delivery from the battery.

Abstract: A defibrillator with an automatic self-test system that includes a test signal generator and a defibrillator status indicator. The test system preferably performs functional tests and calibration verification tests automatically in response to test signals generated periodically and/or in response to predetermined conditions or events and indicates the test results visually and audibly. The invention also relates to a method for automatically determining and indicating a defibrillator's status without human intervention.

Abstract: A method of maintaining an electronic device, the method including the steps of monitoring ambient an environmental condition such as temperature or humidity; monitoring a self-test initialization criterion; performing an automatic device self-test if the self-test criterion is met and if the environmental condition is within a predetermined range; and not performing the automatic device self-test if the self-test criterion is met but the environmental condition is outside the predetermined range. In a preferred embodiment, the device is an external defibrillator.

Abstract: An electrotherapy device control system that improves on prior art electrotherapy device control systems by providing for operation of the electrotherapy device with software code or instructions stored on an attachable memory device. In one embodiment, the invention is a method of controlling the operation characteristics of an electrotherapy device, including the steps of providing an electrotherapy device having a controller and a first memory, the first memory containing instructions for use by the controller to operate the electrotherapy device; attaching a second memory to the electrotherapy device, the second memory containing instructions for use by the controller to operate the electrotherapy device; and operating the electrotherapy device using instructions contained only in the second memory. The invention also includes an apparatus for performing the method and a memory device for use with the apparatus.

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: 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: A defibrillator with an automatic self-test system that includes a test signal generator and a defibrillator status indicator. The test system preferably performs functional tests and calibration verification tests automatically in response to test signals generated periodically and/or in response to predetermined conditions or events and indicates the test results visually and audibly. The invention also relates to a method for automatically determining and indicating a defibrillator's status without human intervention.

Abstract: A method for displaying time-correlated medical event data including the steps of: providing time-correlated event data to a display device; selecting a first event to be displayed; and displaying the first event together with a time-correlated second event on the display device. In another embodiment, the invention is a method for displaying time-correlated medical event data including the steps of: manually entering data comprising a first event into a display device; time-correlating the first event with data comprising a second event collected by a medical device; and displaying the first event together with the second event on the display device.

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 means for local actuation of the defibrillator to deliver 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. Likewise, the defibrillator communicator comprises means for automatically transmitting information to the communication station in response to deployment of the defibrillator.

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 method and apparatus for indicating a low battery condition and for dynamically controlling the load on a battery in order to optimize battery usage. A dynamic load controller for a battery includes detection circuitry for measuring at least one condition related to battery capacity, and power control circuitry for adjusting a power load on the battery based upon the condition. The dynamic load controller may be employed to control the power load on a battery that powers an electrotherapy device, such as a defibrillator. The battery condition may include the slope of a capacity curve, which may be the product of the battery voltage and the power delivered from the battery as a function of the delivered power. Based upon this condition, the power control circuitry adjusts the power load to optimize power delivery from the battery.

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 method of operating an electrotherapy device that provides advantages over prior art approaches. In one embodiment, the electrotherapy device stores collected information in a detachable memory device and uses a clock within the memory device to associate a time information with the electrotherapy information. The time information is useful for producing later reports or displays of the collected information by the electrotherapy device or by another device to which the detachable memory device has been attached. The invention is also an electrotherapy system including: an electrotherapy device, the electrotherapy device including a memory device port; and a memory device, the memory device including a connector adapted to be connected to the electrotherapy device memory port, a clock, and a digital memory.

Abstract: The invention provides a method for delivering electrotherapy to a patient through electrodes connected to a plurality of capacitors, including the steps of discharging at least one of the capacitors across the electrodes to deliver electrical energy to the patient, monitoring a patient-dependent electrical parameter (such as voltage, current or charge) during the discharging step, and adjusting energy delivered to the patient based on a value of the electrical parameter. The adjusting step may include selecting a serial or parallel arrangement for the capacitors based on a value of the 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: 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.