Device and method for dynamic skin impedance measurement and correction
AssigneeWellness Allied Inc
InventorsWeihui Li, Tao Zhang
Life of this patent
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Abstract
A skin impedance measuring device and method includes: an electrode system having at least two electrodes placed on the skin; an adjustable voltage output unit to generate forward and reverse voltages on the electrodes; a skin impedance measurement unit to measure electrical signals from the electrodes; a central processing unit and a computing memory for calculating forward and reverse skin impedances, determining whether the measurement results are abnormal, and correcting abnormal results by delivering additional DC or AC voltages of adjustable magnitudes and frequencies based on impedances; and a display unit.
Claims17
A skin impedance measuring device, comprising:
- an adjustable voltage output unit, configured to output step-function DC voltages with adjustable magnitudes, which are conducted to a local skin area through electrodes to form forward or reverse voltages;
- or configured to output AC voltages with adjustable magnitudes and frequencies, which are conducted to a local skin area through electrodes to form alternating voltages;
- and
- the adjustable voltage output unit comprises one or more of the following devices —waveform generator, digital signal generator with digital-to-analog converter (DAC);
- and, a current-drive circuit, activated when the magnitude of the driving current is below a predetermined threshold;
- an electrode system, having at least two electrodes placed at measurement points on the skin to conduct the voltages from the adjustable voltage output unit to related measurement points;
- a skin impedance measurement unit, configured to measure electrical signals from the measurement points, thereby obtaining the skin impedance;
- a microcontroller processor;
- and
- a computing memory, which stores instructions executed by the microcontroller processor;
- when the instruction is executed by the microcontroller processor, the following steps are executed:
- calculating the difference between a forward skin impedance measured using a forward DC voltage and a reverse skin impedance measured using a reverse DC voltage;
- determining whether measurement results are abnormal by continuously measuring the forward skin impedances, the reverse skin impedances, and their differences;
- correcting abnormal results by adjusting the magnitudes and time durations of the DC voltages, and/or applying additional AC voltages of adjustable frequencies and magnitudes of AC voltages;
- remeasuring the skin impedances to check if the differences between the forward skin impedance and the reverse skin impedance are reduced to a preset threshold to ensure an accuracy of the measurement data;
- and
- a display unit for displaying measurement results.
A method for measuring skin impedance, comprising:
- applying step-function DC voltages of various magnitudes to the stimulating electrode, to form forward and reverse DC voltages between stimulating and reference electrodes and conducting the voltage to the skin through electrodes;
- measuring the forward skin impedance and reverse skin impedance with forward and reverse DC voltages;
- determining whether the measured results are abnormal based on the differences between the forward and reverse skin impedances;
- correcting abnormal results by adjusting the magnitudes and time duration of the step-function DC voltages, and/or generating additional AC voltages of adjustable magnitude and frequency based on the difference of the forward and reverse skin impedances, applying these voltages to the skin through electrodes;
- remeasuring the skin impedance to check if the forward and reverse skin impedance difference is reduced to a preset small range;
- if the difference between the forward and reverse skin impedance cannot be reduced below a threshold, recording the forward and reverse skin impedances, calculating arithmetic and geometric averages to estimate the true skin impedance and provide as clinical evidence for future diagnosis and therapy.
Dependencies are inferred from the claim text.