METHOD AND ELECTRONIC MEDICAL DEVICE FOR SIMULTANEOUSLY MEASURING AN IMPEDANCE AND A BIOPOTENTIAL SIGNAL
First Claim
1. A method of continuously and simultaneously measuring an impedance signal and a biopotential signal on a biological subject'"'"'s skin, the method comprising:
- attaching input and output electrodes to the biological subject'"'"'s skin;
applying a predetermined alternating current having a first frequency to the output electrodes for creating an alternating voltage signal over the input electrodes, the first frequency being at least a predetermined minimum frequency;
measuring an input signal from the input electrodes, the input signal comprising a biopotential signal and the alternating voltage signal;
extracting from the input signal the biopotential signal;
extracting from the input signal the alternating voltage signal by amplifying and demodulating the input signal using a control signal having a frequency equal to the first frequency; and
determining the impedance signal from the alternating voltage signal.
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Accused Products
Abstract
A method and device is disclosed for continuously and simultaneously measuring an impedance signal and a biopotential signal on a biological subject'"'"'s skin. In one aspect, the method includes attaching input and output electrodes to the biological subject'"'"'s skin and applying a predetermined alternating current having a first frequency to the output electrodes for creating an alternating voltage signal over the input electrodes. The first frequency is above a predetermined minimum frequency. The method also includes measuring an input signal from the input electrodes which includes a biopotential signal and the alternating voltage signal. The method also includes extracting from the input signal the biopotential signal and the alternating voltage signal, and determining the impedance signal from the alternating voltage signal. The alternating voltage signal is extracted by amplifying and demodulating the input signal using a control signal having a frequency equal to the first frequency.
28 Citations
18 Claims
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1. A method of continuously and simultaneously measuring an impedance signal and a biopotential signal on a biological subject'"'"'s skin, the method comprising:
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attaching input and output electrodes to the biological subject'"'"'s skin; applying a predetermined alternating current having a first frequency to the output electrodes for creating an alternating voltage signal over the input electrodes, the first frequency being at least a predetermined minimum frequency; measuring an input signal from the input electrodes, the input signal comprising a biopotential signal and the alternating voltage signal; extracting from the input signal the biopotential signal; extracting from the input signal the alternating voltage signal by amplifying and demodulating the input signal using a control signal having a frequency equal to the first frequency; and determining the impedance signal from the alternating voltage signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An electronic medical device for continuously and simultaneously measuring an impedance signal and a biopotential signal on a biological subject'"'"'s skin, the device comprising:
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input and output electrodes provided for being attached to the biological subject'"'"'s skin and connected to input and output terminals of the device; a current source connected to the output terminals configured to generate a predetermined alternating current having a first frequency above a predetermined minimum frequency, the predetermined alternating current being applied to the output electrodes for creating an alternating voltage signal over the input electrodes; an impedance signal extraction module connected to the input terminals and configured to extract the alternating voltage signal from an input signal which is measured on the input electrodes and to determine the impedance signal from the alternating voltage signal, the impedance signal extraction module comprising a first amplifier connected to the input terminals and configured to amplify the input signal and a demodulation module connected to the first amplifier and configured to demodulate the input signal using a control signal having a frequency equal to the first frequency; and a biopotential signal extraction module connected to the input terminals and configured to extract the biopotential signal from the input signal. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. A device for continuously and simultaneously measuring an impedance signal and a biopotential signal on a biological subject'"'"'s skin, the device comprising:
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means for attaching input and output electrodes to the biological subject'"'"'s skin; means for applying a predetermined alternating current having a first frequency to the output electrodes for creating an alternating voltage signal over the input electrodes, the first frequency being at least a predetermined minimum frequency; means for measuring an input signal from the input electrodes, the input signal comprising a biopotential signal and the alternating voltage signal; means for extracting from the input signal the biopotential signal; means for extracting from the input signal the alternating voltage signal by amplifying and demodulating the input signal using a control signal having a frequency equal to the first frequency; and means for determining the impedance signal from the alternating voltage signal.
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Specification