# US 12,758,113 B2 · ESC evaluation method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,758,113 B2 - Document ID: US12758113B2 - Status: Granted - Kind: B2 - Application number: 18/523,301 - Filed: 2023-11-29 - Published: 2024-06-06 - Granted: 2026-10-13 - Earliest claimed: 2022-12-05 - Assignees: Withings - Applicants: Withings - Inventors: Roger Yu; Brice Brac De La Perriere; Jérôme Bredin; Antoine Merlot - Web page: https://patentgrep.com/patent/US12758113B2 ## CPC - A61B 5/0531: Measuring skin impedance - A61B 5/0533: Measuring galvanic skin response - A61B 5/0537: Measuring body composition by impedance, e.g. tissue hydration or fat content - A61B 5/6887: {mounted on external non-worn devices, e.g. non-medical devices} - A61B 2560/0223: of calibration, e.g. protocols for calibrating sensors - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A method to evaluate an electrochemical skin conductance (ESC) of a user body using a measurement device, the measurement device including a pair of electrodes including an anode and a cathode, a direct voltage source, a measurement resistor, control circuitry configured to set the electrical resistance value of the measurement resistor and to set the value of the direct voltage, wherein the method includes, by the control circuitry pre-stabilizing during a pre-stabilizing period, measuring during a measurement period following the pre-stabilization period. ## Claims ### Claim 1 A method to evaluate an electrochemical skin conductance, ESC, of a user body using a measurement device, the measurement device including a pair of electrodes comprising an anode and a cathode configured each to be in contact with the user body, a direct voltage source configured to apply a direct voltage to the anode, wherein a value of the direct voltage is variable, a measurement resistor configured to determine a current value flowing through the user body, wherein an electrical resistance value of the measurement resistor is variable amongst a predetermined range, and control circuitry configured to set the electrical resistance value of the measurement resistor and to set the value of the direct voltage, the method comprising, by the control circuitry: pre-stabilizing during a pre-stabilizing period, the pre-stabilizing comprising: setting the electrical resistance value of the measurement resistor at a predetermined pre-stabilization value, which is the same regardless of the user, wherein the control circuitry sets the pre-stabilization value amongst a lower 50% of the predetermined range, applying a pre-stabilization voltage at the anode during the pre-stabilizing period, calibrating the measurement resistor, by the control circuitry during a calibration period following the pre-stabilizing period, the calibrating comprising: varying the electrical resistance value of the measurement resistor, and setting the electrical resistance value at a calibration value based on a comparison between a voltage at the anode and a voltage at the cathode, and measuring during a measurement period following the calibration period, the measuring comprising: applying at least one measurement voltage at the anode, and generating ESC values using at least one voltage measurement at the anode and/or the cathode obtained during the measurement period. ### Claim 2 (depends on 1) The method of claim 1, wherein applying at least one measurement voltage at the anode includes applying at least one voltage step, and wherein the pre-stabilizing period lasts longer than each voltage step. ### Claim 3 (depends on 1) The method of claim 1, wherein the control circuitry sets the pre-stabilization value of the electrical resistance value of the measurement resistor amongst the lower 25% of the predetermined range. ### Claim 4 (depends on 1) The method of claim 1, wherein the pre-stabilization value of the measurement resistor is chosen amongst the lower 10%, or is the lowest value, of the predetermined range. ### Claim 5 (depends on 1) The method of claim 1, wherein the predetermined range is between 3 kOhms and 500 kOhms. ### Claim 6 (depends on 1) The method of claim 1, wherein the electrical resistance value of the measurement resistor for the measuring is the calibration value. ### Claim 7 (depends on 1) The method of claim 1, further comprising, by the control circuitry: measuring at least one voltage difference around the measurement resistor during the pre-stabilization period, and determining a duration of the pre-stabilization period using at least the at least one voltage difference. ### Claim 8 (depends on 1) The method of claim 1, further comprising, by the control circuitry: determining at least one current value flowing through the user body using at least one voltage difference around the measurement resistor and the pre-stabilization value, and determining a duration of the pre-stabilization period using at least the current value. ### Claim 9 (depends on 8) The method of claim 8, further comprising, by the control circuitry: computing an integral of the at least one current value since the beginning of the pre-stabilization period, and determining the duration of the pre-stabilization period using at least the integral. ### Claim 10 (depends on 9) The method of claim 9, wherein the duration of the pre-stabilization period is the shortest between: X seconds, wherein X is comprised between 5s and 15s, a period of time for which the integral reaches a predetermined threshold. ### Claim 11 (depends on 10) The method of claim 10, wherein X is comprised between 7s and 12s. ### Claim 12 (depends on 1) The method of claim 1, wherein the pair of electrodes is made of indium tin oxide. ### Claim 13 (depends on 1) The method of claim 1, wherein the applying the at least one measurement voltage at the anode comprises applying between 3 and 6 voltage steps and each step lasts between 100 ms and 700 ms. ### Claim 14 (depends on 13) The method of claim 13, wherein each step lasts between 200 ms and 500 ms. ### Claim 15 (depends on 1) The method of claim 1, wherein applying the at least one measurement voltage at the anode comprises applying a plurality of voltage steps, each voltage step including a stabilization period, and wherein the pre-stabilization period lasts longer than a sum of the stabilization periods of the plurality of voltage steps. ### Claim 16 (depends on 1) The method of claim 1, wherein the pre-stabilization value is lower than the calibration value. ### Claim 17 (depends on 1) A measurement device to evaluate an electrochemical skin conductance (ESC) of the feet of a user, comprising: a pair of electrodes comprising an anode and a cathode configured each to be in contact with the user's body, a direct voltage source configured to apply a direct voltage to the anode, wherein a value of the direct voltage is variable, a measurement resistor configured to determine a current value flowing through the user's body, wherein an electrical resistance value of the measurement resistor is variable amongst a predetermined range, control circuitry configured to set the electrical resistance value of the measurement resistor and to set the value of the direct voltage, wherein the control circuitry is configured to perform the method of claim 1. ### Claim 18 (depends on 1) A non-transitory computer readable medium storing a computer program comprising instructions that, when performed by a processor of a measurement device, perform the method of claim 1.