Defibrillator with electrocardiogram monitor
First Claim
1. In combination, defibrillator for generating a polarization voltage signal and an electrocardiographic monitor, said monitor comprising:
- a first preamplifier for amplifying electrocardiographic signals received at the first preamplifier, the first preamplifier having a dynamic range corresponding to the amplitude of the polarization voltage signal that is generated by the defibrillator;
a first high-pass filter to which the electrocardiographic signals amplified by the preamplifier are supplied, the first high pass filter having a predetermined cut-off frequency;
a second high-pass filter to which the electrocardiographic signals amplified by the first preamplifier are supplied, the second high-pass filter having a cut-off frequency that is higher than the cut-off frequency of the first high-pass filter so that any portion of the polarization voltage signal present within the electrocardiographic signal is attenuated without erasing the electrocardiographic signals;
filter switching means for actuating the second high-pass filter for a time period corresponding to the time period in which the polarization voltage signal is generated by the defibrillator;
an electrocardiographic signal processing circuit for processing electrocardiographic signals transmitted through one of the first high pass filter and the first and second high-pass filters; and
output means for monitoring the electrocardiographic signals processed by the electrocardiographic signal processing circuit.
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Accused Products
Abstract
In a defibrillator with an electrocardiographic monitor which monitors electrocardiographic signals induced at electrodes by means of a preamplifier and supplying the signals to an electrocardiographic signal processing circuit through high-pass filters, the dynamic range of a preamplifier is made wider in accordance with the amplitude of a polarization voltage which is developed when a defibrillator is operated. A high-pass filter is formed of a first high-pass filter which operates in a normal state and a second high-pass filter whose blocking frequency is higher than that of the first high-pass filter so that the polarization voltage is attenuated without erasing the electrocardiographic signals. The second high-pass filter is operated in synchronization with the operation of the defibrillator during a time period corresponding to the time period in which the polarization voltage is generated.
185 Citations
4 Claims
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1. In combination, defibrillator for generating a polarization voltage signal and an electrocardiographic monitor, said monitor comprising:
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a first preamplifier for amplifying electrocardiographic signals received at the first preamplifier, the first preamplifier having a dynamic range corresponding to the amplitude of the polarization voltage signal that is generated by the defibrillator; a first high-pass filter to which the electrocardiographic signals amplified by the preamplifier are supplied, the first high pass filter having a predetermined cut-off frequency; a second high-pass filter to which the electrocardiographic signals amplified by the first preamplifier are supplied, the second high-pass filter having a cut-off frequency that is higher than the cut-off frequency of the first high-pass filter so that any portion of the polarization voltage signal present within the electrocardiographic signal is attenuated without erasing the electrocardiographic signals; filter switching means for actuating the second high-pass filter for a time period corresponding to the time period in which the polarization voltage signal is generated by the defibrillator; an electrocardiographic signal processing circuit for processing electrocardiographic signals transmitted through one of the first high pass filter and the first and second high-pass filters; and output means for monitoring the electrocardiographic signals processed by the electrocardiographic signal processing circuit. - View Dependent Claims (2, 3, 4)
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Specification