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US-12622595-B2 - Electrodermal apparatus

US12622595B2US 12622595 B2US12622595 B2US 12622595B2US-12622595-B2

Abstract

The invention presents an electrodermal apparatus comprising at least two electrodes ( 10 ), each of which is configured to be in contact with a dermal region, and an electronic circuit comprising an analog-to-digital converter and a processor that is configured to execute computer-executable instructions in order to bias the electrodes ( 10 ), to measure the current flowing between pairs of electrodes ( 10 ), to apply digital preprocessing to the measured electrical signals and to determine the conductance of the dermal layer, wherein the sensor further comprises an accelerometer, delivering electrical signals to the processor, the preprocessing taking into account the level of the signals that are delivered by the accelerometer.

Inventors

  • YANN FRACHI

Assignees

  • OVOMIND SA

Dates

Publication Date
20260512
Application Date
20210923
Priority Date
20200923

Claims (5)

  1. 1 . A system comprising a computer and an electrodermal sensor comprising a blood sensor and at least two electrodes, each of which is configured to be in contact with a dermal region, and an electronic circuit comprising an analog-to-digital converter and a processor that is configured to execute computer-executable instructions in order to bias said electrodes, to measure the current flowing between pairs of electrodes, to apply digital preprocessing to the measured electrical signals and to determine the conductance of the dermal layer, said sensor further comprising an accelerometer, delivering electrical signals to said processor, said preprocessing taking into account the level of said signals that are delivered by said accelerometer, characterized in that said computer executes a program controlling: the processing of the digital conductance data provided by said processor over a sliding time window, the result of which provides a value S arousal corresponding to an intensity of the emotion and processing of a series of heart rate signals consisting of bandpass filtering of the frequencies between 0.04 and 0.26 Hz and detecting peaks and measuring the time between the peaks RR, over said sliding time window, the result of which provides a value S valence corresponding to the positivity and negativity of the emotion.
  2. 2 . The system according to claim 1 , wherein said electrodes are formed by studs formed by a stamped steel sheet.
  3. 3 . The system according to claim 1 , wherein the system further comprises a temperature sensor.
  4. 4 . The system according to claim 1 , wherein the system further comprises a heart rate sensor.
  5. 5 . The system according to claim 4 , wherein said heart rate sensor delivers physiological signals by photoplethysmography.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is the U.S. National Stage of International Application Number PCT/IB2021/058697 filed on Sep. 23, 2021, which application claims priority under 35 USC § 119 to French Patent Application No. 2009668 filed on Sep. 23, 2020. Both applications are hereby incorporated by reference in their entirety. FIELD OF THE INVENTION The present invention relates to the field of measuring galvanic skin response and electro-cutaneous activity, and in particular to portable devices and methods for measuring the electrodermal activity of the skin of a user. Background of the Invention Electrodermal activity is a biological electrical activity recorded on the surface of the skin and reflecting the activity of the sweat glands and of the autonomic nervous system, and consequently, inter alia, the individual's perception and subconscious behavior rather than that of a response that the individual wishes to give. The scientific study of the galvanic skin response began in the early 1900s. The psychologist C. G. Jung is among the first to use its recording in psychoanalysis and he discusses this experiment in his publication “Studies in Word Analysis” published in 1962. Wilhelm Reich also studied the electrodermal response in experiments conducted at the Institute of Psychology of the University of Oslo, in 1935 and 1936, with the aim of confirming the existence of a bioelectric charge behind his concept of “vegetative currents of pleasure”. In the 1960s and until the end of the 1970s, the psychogalvanic response was used in all the fields of psychology for a wide variety of research. Psychogalvanic phenomena are linked to the activity of the sympathetic nervous system, and are manifested by the variation in the electrical resistance of the skin, after an emotion. Many studies have focused on the exploitation of GSR (Galvanic Skin Response) or EDR (electrodermal resistance) signals representative of the variation in the electrical resistance of the skin caused by the activity of the sweat glands following a sensory excitation, called psychogalvanic reflex, for various applications such as lie detectors, emotion analysis, or controlling video games using new human-machine interfaces. Prior Art Patent FR3063425 proposes a system for determining an emotion of a user comprising a sensor to sense the electrodermal activity of the user, a first circuit adapted to: a/ detect strong emotional moments felt by the user as a function of an analysis of information from the sensor (of electrodermal activity, b/ if a strong emotional moment is detected in step /a/, ask the user to classify said strong emotional moment. This solution requires learning at the initiative of the user, who must identify a “strong emotional moment” and then classify it. It is quite obvious that this solution leads to erratic or even fanciful behaviors, and is in no way reproducible or reliable since it depends on the user's subjective experience, on their ability to properly complete this learning, and on the nature of the events to which the user is exposed during this learning phase. Patent application WO2017202626 relates to a sensor intended to measure the conductance of the skin. An amplifier is used to convert the conductance of the skin into an analog output voltage which is then converted into the digital domain, so that the increase in the conductance of the tonic skin and the conductance response of the phasic skin are obtained in the digital domain. The amplifier has a nonlinear logarithmic gain, with a decreasing gain in order to increase the conductance values of the skin. The sensor makes it possible to detect both the increase of the tonic and phasic signals over a wide range of conductance of the skin. It allows optimum use of the analog-digital converter so that a lower resolution and therefore a less expensive converter can be used. Patent application US 2013/183646 describes an apparatus for interoperable use of several data from biosensors attached to the user's finger. These sensors may be electrodermal response (EDR) sensors, or photoplethysmograph (PPG) signals, or temperature signals, or three-axis acceleration signals, and combinations thereof. The biometric card saves and processes the signals from the sensors and communicates them to a mobile device that interoperably uses several sensor information to determine aspects of the emotional state of the user. The article “RUI GUO ET AL: “Pervasive and unobtrusive emotion sensing for human mental health”, PERVASIVE COMPUTING TECHNOLOGIES FOR HEALTHCARE (PERVASIVEHEALTH), 2013 7TH INTERNATIONAL CONFERENCE ON, IEEE, May 5, 2013 (2013 May. 5), pages 436-439, XP032439656. DOi: 10.4108/ICST.PERVASIVEHEAL TH.2013.252133, ISBN: 978-1-4 799-0296-5. Another article JORN BAKKER ET AL: “What's Your Current Stress Level? Detection of Stress Patterns from GSR Sensor Data”, DATA MINING WORKSHOPS (ICDMW), 2011 IEEE 11 TH INTERNATIONAL CONFERENCE ON, IEEE