US 12,446,792 B2
Systems and methods of monitoring electrodermal activity (EDA) using an AC signal and discrete fourier transform (DFT) analysis
José Carlos Conchell Añó, Valencia (ES)
Assigned to Analog Devices International Unlimited Company, Limerick (IE)
Filed by Analog Devices International Unlimited Company, Limerick (IE)
Filed on Jan. 17, 2022, as Appl. No. 17/577,210.
Application 17/577,210 is a division of application No. 15/230,637, filed on Aug. 8, 2016, granted, now 11,224,354.
Prior Publication US 2022/0211289 A1, Jul. 7, 2022
Int. Cl. A61B 5/0531 (2021.01); A61B 5/00 (2006.01)
CPC A61B 5/0531 (2013.01) [A61B 5/7257 (2013.01); A61B 2562/0209 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of monitoring electrodermal activity, comprising:
providing an alternating current (AC) excitation signal at a predetermined excitation frequency to cause an AC current to flow between a first dry electrode and a second dry electrode within a stratum corneum of skin, the first dry electrode for making contact with a first area of the skin, and the second dry electrode for making contact with a second area of the skin, wherein the AC excitation signal is a square wave signal;
converting the square wave signal to an AC sinusoidal signal;
converting the AC current to an AC voltage signal;
sampling the AC voltage signal;
converting the sampled AC voltage signal to a digitized voltage level sequence; and
performing a discrete Fourier transform (DFT) to generate a complex frequency domain representation of the digitized voltage level sequence and to separate noise frequencies from the complex frequency domain representation of the digitized voltage level sequence.