US 11,896,358 B2
Device and method for dynamic skin impedance measurement and correction
Weihui Li, Natick, MA (US); and Tao Zhang, Natick, MA (US)
Assigned to Wellness Allied Inc, Dover, MA (US)
Filed by Wellness Allied Inc, Natick, MA (US)
Filed on May 11, 2020, as Appl. No. 16/871,106.
Prior Publication US 2021/0345901 A1, Nov. 11, 2021
Int. Cl. A61B 5/0531 (2021.01); A61B 5/00 (2006.01)
CPC A61B 5/0531 (2013.01) [A61B 5/7221 (2013.01); A61B 5/742 (2013.01); A61B 2562/0215 (2017.08)] 17 Claims
OG exemplary drawing
 
1. 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.