Abstract: An ECG signal detection device that includes a differential amplifier input circuit and a driven reference electrode lead is disclosed. More specifically, the ECG signal detection device includes a differential amplifier input circuit and three-electrode leads, two of which terminate at a common patient coupling device such as an electrode pad or a defibrillator paddle. The third electrode lead terminates at a second, separate patient coupling device. Two electrical cords that include the electrode leads extend between the patient coupling devices and the differential amplifier input circuit. One electrical cord includes the two-electrode leads that terminate at the common patient coupling device.

Abstract: An ECG signal detection device that includes a differential amplifier input circuit and a driven reference electrode lead is disclosed. More specifically, the ECG signal detection device includes a differential amplifier input circuit and three-electrode leads, two of which terminate at a common patient coupling device such as an electrode pad or a defibrillator paddle. The third electrode lead terminates at a second, separate patient coupling device. Two electrical cords that include the electrode leads extend between the patient coupling devices and the differential amplifier input circuit. One electrical cord includes the two-electrode leads that terminate at the common patient coupling device.

Abstract: An energy adjusting circuit for use with a defibrillator. The energy adjusting circuit reduces the defibrillation pulse energy that would otherwise be applied to the patient by the defibrillator. The energy adjusting circuit can be part of the defibrillator itself, or part of an adapter coupled to the output ports of a conventional defibrillator. In an adapter designed for pediatric defibrillation, the adapter may include paddles configured for use on babies and small children. The energy adjusting circuit may be formed entirely from passive components and may include a divider circuit with two resistors. The resistance of the two resistors is selected so as to absorb a predetermined percentage of the defibrillation pulse energy that would otherwise be applied to the patient. An isolation circuit may be further included to assist with the measurement of ECG signals through the electrodes.

Abstract: A signal measuring system for use with an Implantable Medical Device (IMD) is provided for measuring physiologic signals having a relatively large effective dynamic range. In one embodiment, the system includes a High-Pass Filter (HPF), an Analog-to-Digital Converter (ADC), a Decimation Filter (DF), and a Compensation Filter (CF). The HPF receives an input signal that includes both the baseline wander imposed on a physiological signal. According to one aspect of the invention, the HPF attenuates low frequency components of the input signal, including a portion of the frequency band within the desired output signal bandwidth. The ADC then oversamples the output signal of the HPF. The DF receives the output samples from the ADC and generates output samples at rate that is at least twice the maximum frequency of the desired output signal. The CF then amplifies the low frequency end of the DF output samples.

Abstract: An ECG signal measuring system uses low frequency compression/enhancement techniques combined with dither techniques to effectively increase the dynamic range while maintaining resolution. This aspect of the present invention is achieved without increasing the number of bits of the ADC. The system includes a HPF, an ADC, a decimation filter (DF), and a compensation filter (CF). The HPF receives an input signal (i.e., the bias current combined with ECG input signal) and attenuates the low frequency components of the input signal, including a portion of the frequency band within the desired ECG frequency band. The ADC oversamples the output signal of the HPF. The DF receives the output samples of the ADC and generates output samples at rate that is at least twice the maximum frequency of the desired ECG output signal. The CF amplifies the low frequency end of the DF output samples.