Dry skin conductance electrode

Abstract

The present invention relates to a dry skin conductance electrode ( 12, 13 ) for contacting the skin ( 10 ) of a user. In order to provide a dry skin conductance electrode for long-term measurements which does not cause problems to the user while still providing a good signal level, the electrode ( 12, 13 ) comprises a material made of a noble metal doped with at least one dopant selected from the group consisting of hydrogen, lithium, sodium, potassium, rubidium, caesium and beryllium. The present invention also relates to a skin conductance sensor ( 20 ), a wristband ( 30 ) and an emotional event detection system.

1 . Skin conductance sensor comprising at least two dry electrodes, wherein the sensor ( 20 ) is adapted to sense a user's skin conductance between the at least two dry electrodes, wherein at least one of the electrodes is a dry skin conductance electrode for contacting the skin of a user, the electrode comprising a material made of a noble metal doped with at least one dopant selected from the group consisting of hydrogen, lithium, sodium, potassium, rubidium, caesium and beryllium wherein the material is located at an outer surface of the electrode for interfacing with the skin. 
     
     
         2 . Skin conductance sensor of  claim 1 , wherein the noble metal is an element selected from the group consisting of gold, palladium and platinum. 
     
     
         3 . Skin conductance sensor of  claim 1 , wherein the dopant is lithium, sodium or potassium. 
     
     
         4 . Skin conductance sensor of  claim 1 , wherein the noble metal is gold, palladium or platinum, and the dopant is lithium. 
     
     
         5 . Skin conductance sensor of  claim 1 , wherein the difference in ionization potential between the noble metal and the dopant is at or above a level at which the noble metal is prevented from taking part in the electrochemical reaction with the skin. 
     
     
         6 . Skin conductance sensor of  claim 1 , wherein the concentration of the dopant is between 0.1 and 5%. 
     
     
         7 . (canceled) 
     
     
         8 . Skin conductance sensor of  claim 1 , wherein the electrode comprises an outer layer which is formed of the material. 
     
     
         9 . Skin conductance sensor of  claim 8 , wherein the electrode further comprises at least one inner layer beneath the outer layer. 
     
     
         10 . (canceled) 
     
     
         11 . Skin conductance sensor of  claim 1  further comprising:
 a voltage generator for applying a voltage between the at least two electrodes, 
 a measuring unit for measuring a current between the at least two electrodes and 
 a calculating unit for calculating skin conductance based on the measured current. 
 
     
     
         12 . Wristband comprising the skin conductance sensor of  claim 1 . 
     
     
         13 . Wristband of  claim 12  wherein the at least two electrodes are arranged for contacting the volar side of the wrist of the user. 
     
     
         14 . Emotional event detection system for detecting an emotional event of a user, the system comprising:
 the skin conductance sensor  claim 1 ,   a transmission link for transmitting data indicative of the sensed skin conductance, and   a processing unit adapted to process the transmitted data and detect an emotional event of the user based on the transmitted data.   
     
     
         15 . Emotional event detection system of  claim 14 , wherein the transmission link is a wireless link between the skin conductance sensor and the processing unit.