Electrode connection monitoring

Abstract

The present invention relates to an apparatus and a method for measuring muscular activity, in particular in relation to bruxism, and providing an electrical stimulation in response to the measured muscular activity through electrodes applied to the skin of an individual, wherein the quality of the connectivity of the electrodes to the skin is monitored and the electrical stimulation signal is changed based on said quality measurement.

1 - 35 . (canceled) 
     
     
         36 . Apparatus comprising:
 an electrode assembly comprising three electrodes: a first, a second and a reference electrode, mounted on a common substrate in a fixed spatial relationship one to another wherein said reference electrode lies approximately equidistant from said first and second electrodes, said electrode assembly adapted for being applied to the skin of an individual, wherein the apparatus is operative to receive and monitor electrical signals and provide electrical stimulation to said individual, said apparatus further comprising:   inputs for receiving signals from said electrodes,   means for measuring EMG signals from said electrode(s) when the electrodes are applied to the skin,   a source of a monitoring signal having a frequency and outputs for use in applying said monitoring signal alternately to said first and second electrodes,   means for determining the amplitude of the frequency of the monitoring signal at the input of said reference electrode,   means for providing an electrical stimulation feedback signal to the reference electrode upon the detection of EMG signals indicative of a muscular activity relating to bruxism of the individual,   wherein said apparatus is configured so that said monitoring signal is applied at a voltage sufficient to produce a preset current between the first electrode and the reference electrode and between the second electrode and the reference electrode,   wherein the amplitude of the frequency of the monitoring signal at said reference electrode is measured to determine the quality of the connection via the skin between the first electrode and the reference electrode and the quality of the connection via the skin between the second electrode and the reference electrode, and   wherein the feedback signal is modulated if the quality of the electrical connection between the electrodes is changed.   
     
     
         37 . Apparatus as claimed in  claim 36 , comprising a Fourier transform analyser for extracting frequency content information from said received signals. 
     
     
         38 . Apparatus as claimed in  claim 36 , further comprising means for measuring the amplitude within the received signals of at least one selected frequency other than that of said monitoring signal. 
     
     
         39 . Apparatus as claimed in  claim 37 , wherein said apparatus is for measuring EMG signals from said electrodes when the electrodes are applied to the skin and the amplitude of the said frequency of the monitoring signal in signals received at said inputs as determined by said Fourier transform analyser is measured for monitoring the quality of the electrical connection between the electrodes and the skin. 
     
     
         40 . Apparatus as claimed in  claim 36 , wherein said EMG signals indicative of the muscular activity are identified by measuring therein the amplitude of one or more selected frequencies different from the frequency of the monitoring signal. 
     
     
         41 . Apparatus as claimed in  claim 36 , wherein the feedback signal is reduced when the quality of the electrical connection is reduced. 
     
     
         42 . Apparatus according to  claim 36 , wherein the feedback signal is reduced if the amplitude of the said frequency of the monitoring signal in signals received at said inputs is not below a preset threshold level or wherein the intensity of the feedback signal is reduced if the amplitude of the said frequency of the monitoring signal in signals received at said inputs is not below a preset threshold level. 
     
     
         43 . Apparatus as claimed in  claim 42 , wherein the feedback signal is reduced by half or blocked. 
     
     
         44 . A method for monitoring activity of the temporal muscle and/or the masseter muscle, in particular activity due to teeth and/or jaw clenching, said method comprising the steps of:
 providing an apparatus as defined in claim  1  comprising electrode(s),   measuring EMG signals from said electrode(s) when the electrodes are applied to the skin,   applying a monitoring signal having a frequency to said at least first electrode,   determining the received signal of said frequency of the monitoring signal in signals received, for monitoring the quality of the electrical connection between the electrodes and the skin,   providing an electrical stimulation feedback signal upon the detection of EMG signals indicative of a muscular activity of the individual,   wherein the feedback signal is modulated if the quality of the electrical connection between the electrodes is changed.   
     
     
         45 . The method as claimed in  claim 44 , wherein the receiving signal is determined by determining the amplitude of the said frequency of the monitoring signal in signals received. 
     
     
         46 . The method as claimed in  claim 44 , comprising extracting frequency content information from said received signals and performing a Fourier transform analysis, such as an FFT analysis. 
     
     
         47 . The method as claimed in  claim 44 , comprising for receiving signals from said first electrode, from a second electrode and from said reference electrode. 
     
     
         48 . The method as claimed in  claim 47 , wherein the respective electrodes are connected. 
     
     
         49 . The method as claimed in  claim 44 , wherein said electrodes are provided in an electrode assembly in which said electrode assembly comprises three electrodes mounted on a common substrate in a fixed spatial relationship one to another. 
     
     
         50 . The method as claimed in  claim 44 , wherein said reference electrode lies approximately equidistant from said first and second electrodes. 
     
     
         51 . The method as claimed  claim 44 , further comprising the step of measuring the amplitude within the received signals of at least one selected frequency other than that of said monitoring signal. 
     
     
         52 . The method as claimed in  claim 44 , wherein said activity is an episode of bruxism. 
     
     
         53 . The method as claimed in  claim 44 , wherein said EMG signals indicative of the muscular activity are identified by measuring therein the amplitude of one or more selected frequencies different from the frequency of the monitoring signal. 
     
     
         54 . The method as claimed in  claim 44 , wherein the feedback signal is reduced, when the quality of the electrical connection is reduced. 
     
     
         55 . The method according to  claim 44 , wherein the feedback signal is reduced if the amplitude of the said frequency of the monitoring signal in signals received is not below a preset threshold level or wherein the intensity of the feedback signal is reduced if the amplitude of the said frequency of the monitoring signal in signals received is not below a preset threshold level. 
     
     
         56 . The method as claimed in  claim 44 , wherein the feedback signal is reduced by half or blocked. 
     
     
         57 . The method as claimed in  claim 44 , wherein said monitoring signal is applied at a voltage sufficient to produce a preset current between the first electrode and the reference electrode and between the second electrode and the reference electrode.