An automatic external defibrillator (AED) includes a device for scaling the stored energy communicated to the patient responsive to a known patient weight. An electrode set, for use with an automatic external defibrillator (AED), the AED includes a plurality of electrodes for making electrical contact with a skin surface of a patient. Each electrode of the plurality of electrodes is electrically connectable to a electrical connector for communicating a stored energy to a patient. The electrodes system further includes a device for scaling the stored energy communicated to the patient responsive to a known patient weight. A method of defibrillating the heart of a human patient using an AED includes the steps of: adherably placing at least two electrodes on the skin surface of the patient, the electrodes being spaced apart to define a desired energy path therebetween; scaling the dischargeable defibrillating energy responsive to a known patient body weight; and discharging defibrillating energy across the energy path, the discharge generating an energy vector, the vector being passable through the heart of the patient.
RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application No. 60/092,076, filed Jul. 8, 1998, incorporated herein by reference.
A defibrillation system for patients of all ages may include an Automated External Defibrillator (AED) coupled to a set of universal electrodes. Universal electrodes may be reduced-size versions of adult electrodes, and may include an opening to lower effective impedance. The AED may include an adult/pediatric mode control or switch. Based upon the setting of the adult/pediatric switch, the AED may perform an adult defibrillation sequence or a pediatric defibrillation sequence. An adult defibrillation sequence may comprise delivery of one or more waveforms or shocks characterized by energies appropriate for adults, for example, 150 Joule biphasic waveforms. A pediatric defibrillation sequence may comprise delivery of one or more waveforms characterized by energies appropriate for children, for example, 50 Joule biphasic waveforms. Another pediatric defibrillation sequence may comprise delivery of an escalating low-energy shock sequence to a patient, such as a 25 to 50 Joule shock, followed by a 65 to 75 Joule shock as necessary, followed by one or more 100 Joule shocks as necessary.
An automated external defibrillator automatically determines the type of patient to which it is attached based on patient-specific information entered by the user. The defibrillator includes electrodes that are adapted for placement on a patient, a pulse generator connected to the electrodes, and processing circuitry that controls the defibrillation pulse delivery from the pulse generator. The automated external defibrillator causes a defibrillation pulse to be delivered to the patient in accordance with the determined patient type. A user interface having a user input connected to the processing circuitry enables the user of the defibrillator to enter patient-specific information. The user may enter the patient-specific information by interacting with the user input during a time period in relation to a prompt from the defibrillator. In another aspect, data pertaining to identification of the type of patient connected to the electrodes may be recorded with event data in a memory.
An energy reduction unit is removably connectable to an external defibrillator to reduce the defibrillation energy delivered by the defibrillator to a patient. Use of the energy reduction unit is particularly suited to defibrillating pediatric patients (infants and children under 8) with an automatic or semi-automatic external defibrillator (AED). In one embodiment, the energy reduction unit includes an attenuator which partially dissipates energy produced by the AED. The attenuator is advantageously designed to present an impedance to the AED which, when connected to the patient, is approximately equal to the patient's impedance. The energy reduction unit may include a presence-detect function which enables the defibrillator to modify analysis of ECG signals to account for differences heart rhythms of pediatric and adult patients. In a second embodiment, the energy reduction unit includes an energy control modifier circuit which affects the charging operations performed internal to the AED. Other than being attached to the defibrillation equipment, the energy reduction unit does not otherwise change how an operator uses the equipment.
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.
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.
