Abstract: An oximeter can include a sensor and a processor. The processor can access signal information corresponding to a test signal. The signal information can correspond to a characteristic. The characteristic can be determined using at least one of an AC component and a DC component. The processor can compare the characteristic and a reference value. The processor can adjust the signal, based on the comparison, to set a relationship between the characteristic and the reference value.

Abstract: A device includes a first sensor coupler that is configured to receive a first input signal from a first sensor. The first input signal corresponds to a first physiological parameter and is based on optical excitation of a tissue. The device includes a processor coupled to the first sensor coupler. The processor is configured to generate an output signal based on the first input signal. The first physiological parameter is encoded in the output signal. The output signal differs from the first input signal. The device includes an output coupler configured to communicate the output signal to a remote device.

Abstract: A device includes a first sensor coupler that is configured to receive a first input signal from a first sensor. The first input signal corresponds to a first physiological parameter and is based on optical excitation of a tissue. The device includes a processor coupled to the first sensor coupler. The processor is configured to generate an output signal based on the first input signal. The first physiological parameter is encoded in the output signal. The output signal differs from the first input signal. The device includes an output coupler configured to communicate the output signal to a remote device.

Abstract: A device includes a first sensor coupler that is configured to receive a first input signal from a first sensor. The first input signal corresponds to a first physiological parameter and is based on optical excitation of a tissue. The device includes a processor coupled to the first sensor coupler. The processor is configured to generate an output signal based on the first input signal. The first physiological parameter is encoded in the output signal. The output signal differs from the first input signal. The device includes an output coupler configured to communicate the output signal to a remote device.

Abstract: A device includes a first sensor coupler that is configured to receive a first input signal from a first sensor. The first input signal corresponds to a first physiological parameter and is based on optical excitation of a tissue. The device includes a processor coupled to the first sensor coupler. The processor is configured to generate an output signal based on the first input signal. The first physiological parameter is encoded in the output signal. The output signal differs from the first input signal. The device includes an output coupler configured to communicate the output signal to a remote device.

Abstract: A capacitor-discharge implantable cardioverter defibrillator (ICD) has a relatively smaller mass of less than about 120 grams. The smaller mass of the ICD is achieved by selecting and arranging the internal components of the ICD to deliver a maximum defibrillation countershock optimized in terms of a minimum physiologically effective current (I.sub.pe), rather than a minimum defibrillation threshold energy (DFT). As a result of the optimization in terms of a minimum effective current I.sub.pe, there is a significant decrease in the maximum electrical charge energy (E.sub.c) that must be stored by the capacitor of the ICD to less than about 30 Joules, even though a higher safety margin is provided for by the device. Due to this decrease in the maximum E.sub.

Abstract: A capacitor-discharge implantable cardioverter defibrillator (ICD) has a relatively smaller energy storage capacity of less than about 1.0 Amp-hours. The smaller energy storage capacity of the ICD is achieved by selecting and arranging the internal components of the ICD to deliver a maximum defibrillation countershock optimized in terms of a minimum physiologically effective current (I.sub.pe) rather than a minimum defibrillation threshold energy (DFT). As a result of the optimization in terms of a minimum effective current I.sub.pe, there is a significant decrease in the maximum electrical charge energy (E.sub.c) that must be stored by the capacitor of the ICD to less than about 30 Joules, even though a higher safety margin is provided for by the device. Due to this decrease in the maximum E.sub.

Abstract: A capacitor-discharge implantable cardioverter defibrillator (ICD) has a relatively longer device life of greater that 5 years. The longer life of the ICD is achieved by selecting and arranging the internal components of the ICD to deliver a maximum defibrillation countershock optimized in terms of a minimum physiologically effective current (I.sub.pe), rather than a minimum defibrillation threshold energy (DFT). As a result of the optimization in terms of a minimum effective current I.sub.pe, there is a significant decrease in the maximum electrical charge energy (E.sub.c) that must be stored by the capacitor of the ICD to less than about 30 Joules, even though a higher safety margin is provided for by the device. Due to this decrease in the maximum E.sub.

Abstract: The model that is developed in the present invention is based upon the pioneering neurophysiological models of Lapicque and Weiss. The present model determines mathematically the optimum pulse duration, d.sub.p, for a truncated capacitor-discharge waveform employed for defibrillation. The model comprehends the system time constant, RC, where R is tissue resistance and C is the value of the capacitor being discharged, and also the chronaxie time, d.sub.c, defined by Lapicque, which is a characteristic time associated with the heart. The present model and analysis find the optimum pulse duration to be d.sub.p =(0.58)(RC+d.sub.c). Taking the best estimate of the chronaxie value from the literature to be 2.7 ms, permits one to rewrite the optimum pulse duration as d.sub.p =(0.58)RC+1.6 ms.

Abstract: The model that is developed in the invention is based upon the pioneering neurophysiological models of Lapicque and Weiss. The present model determines mathematically the optimum pulse duration, d.sub.p, for a truncated capacitor-discharge waveform employed for defibrillation. The model comprehends the system time constant, RC, where R is tissue resistance and C is the value of the capacitor being discharged, and also the chronaxie time, d.sub.c, defined by Lapicque, which is a characteristic time associated with the heart. The present model and analysis find the optimum pulse duration to be d.sub.p =(0.58)(RC+d.sub.c). Taking the best estimate of the chronaxie value from the literature to be 2.7 ms, permits one to rewrite the optimum pulse duration as d.sub.p =(0.58)RC+1.6 ms. The apparatus makes use of the mathematical definition of optimum pulse duration by storing in the control circuitry of the defibrillation system the actual measured value of the particular capacitor incorporated in the system.

Abstract: The model that is developed in the present invention is based upon the pioneering neurophysiological models of Lapicque and Weiss. The present model determines mathematically the optimum pulse duration, d.sub.p, for a truncated capacitor-discharge waveform employed for defibrillation. The model comprehends the system time constant, RC, where R is tissue resistance and C is the value of the capacitor being discharged, and also the chronaxie time, d.sub.c, defined by Lapicque, which is a characteristic time associated with the heart. The present model and analysis find the optimum pulse duration to be d.sub.p =(0.58)(RC+d.sub.c). Taking the best estimate of the chronaxie value from the literature to be 2.7 ms, permits one to rewrite the optimum pulse duration as d.sub.p =(0.58)RC+1.6 ms.

Abstract: A capacitor-discharge implantable cardioverter defibrillator (ICD) has a relatively smaller displacement volume of less than about 90 cc. The smaller volume of the ICD is achieved by selecting and arranging the internal components of the ICD to deliver a maximum defibrillation countershock optimized in terms of a minimum physiologically effective current (I.sub.pe), rather than a minimum defibrillation threshold energy (DFT). As a result of the optimization in terms of a minimum effective current I.sub.pe, there is a significant decrease in the maximum electrical charge energy (E.sub.c) that must be stored by the capacitor of the ICD to less than about 30 Joules, even though a higher safety margin is provided for by the device. Due to this decrease in the maximum E.sub.