Abstract: Impedance across a load, such as a pair of face-to-face electrodes and/or a patient's transthoracic and transmyocardial impedance, respectively, is modeled as a resistor in series with a capacitor, wherein the reactance component of the impedance equals 2 .pi.*frequency/capacitance. A reference square wave voltage is applied to the load in series with a selected load resistor, and a response voltage is measured across the load. Both the reference voltage and the response voltage are then used to estimate a transfer function between them. Equating this transfer function to a resistor-capacitor circuit model results in estimation of the actual resistance and capacitance components of the true impedance. Alternately, the impedance may be measured with a high current load, such as during a defibrillator discharge.

Abstract: Impedance across a load, such as a pair of face-to-face electrodes, or across electrodes in contact with a patient's chest cavity, respectively, is modeled as a resistor in series with a capacitor, wherein the reactance component of the impedance equals 2.pi.*frequency/capacitance. A reference square wave voltage is applied to the load in series with a selected load resistor, and a response voltage is measured across the load. Both the reference voltage and the response voltage are then used to estimate a transfer function between them. Equating this transfer function to a resistor-capacitor circuit model results in estimation of the actual resistance and capacitance components of the true impedance.

Abstract: A composition providing electrically conductive adhesive hydrogels suitable for use as skin contact adhesives and, particularly, suitable for use as an electrical interface for disposable medical devices. The hydrogels are cationic acrylates and may be, for example, preferably made from acrylic esters of quaternary chlorides and/or sulfates or acrylic amides of quaternary chlorides. The present hydrogels are formed by free radical polymerization in the presence of water, preferably by ultra-violet curing with initiator and multi-functional cross-linking agent. The present hydrogels also preferably include a buffer system to help prevent discoloration of the hydrogels and/or hydrolysis of the hydrogels and/or improve shelf-life. Other additives may be added to the present hydrogels either before or after curing (i.e. conductivity enhancers, pharmaceuticals, humectants, plasticizers, etc.) depending on intended end-use.

Abstract: A non-invasive radiolucent electrode for stimulating the heart is disclosed. The electrode is configured to include at least one pad having a first surface adapted to contact the patient's skin, and a conductive mesh backing substantially covering a second surface of the pad and configured to be radiolucent.

Abstract: A non-invasive radiolucent electrode configured to include at least one skin-contacting pad is provided, characterized in that the pad, in an exemplary embodiment, is configured with an expanded foil backing. In addition, a non-invasive radiolucent electrode suitable for cardiac stimulation and RF grounding applications through the same skin-contacting pad is also provided.

Abstract: An electrode having multiple conductive polymer pads for performing multiple, electrical physiological functions from a single set of electrodes with respect to a patient at or about the same time, such as defibrillating, pacing, and monitoring of that patient's heart, is described. The electrode is advantageously integrated into a cardiac system having stimulating means coupled to the electrode for delivering electrical impulses to the electrode to be used to stimulate the patient's heart, and monitoring means also coupled to the electrode for receiving and displaying electrical impulses produced by the patient's heart. The conductive polymers which comprise the pads are optionally inherently adhesive, so that the pads will adhere to a patient's body over their entire surface area. Moreover, they are rubber-based, will not smear or leave a residue on a patient's skin, have lower impedance, and depolarize faster compared with present saline-based gels, further contributing to the multi-functional capability.

Abstract: An electrode having multiple conductive polymer pads for performing multiple, electrical physiological functions from a single set of electrodes with respect to a patient at or about the same time, such as defibrillating, pacing, and monitoring of that patient's heart, is described. The electrode is advantageously integrated into a cardiac system having stimulating means coupled to the electrode for delivering electrical impulses to the electrode to be used to stimulate the patient's heart, and monitoring means also coupled to the electrode for receiving and displaying electrical impulses produced by the patient's heart.The conductive polymers which comprise the pads are optionally inherently adhesive, so that the pads will adhere to a patient's body over their entire surface area. Moveover, they are rubber-based, will not smear or leave a residue on a patient's skin, have lower impedance, and depolarize faster compared with present saline-based gels, further contributing to the multi-functional capability.