Method and Apparatus for Detecting Seizures Including Loose Electrode Monitoring

Abstract

Apparatuses and methods for monitoring a patient for seizure activity and for verifying the contact integrity of electrodes included among an EMG sensor may include generating a test signal of known periodicity and applying the signal to at least one electrode in a sensor system. The test signal may be monitored to verify contact integrity of the electrodes.

1 - 30 . (canceled) 
     
     
         31 . A sensor system for monitoring a patient for seizure activity using electromyography and for checking the contact integrity of electrodes included among the sensor comprising:
 sensor electrodes including a pair of detection electrodes and a common electrode;   a circuit path for generating a time-varying test signal with a controlled period;   wherein the circuit path is configured for applying said test signal to said common electrode;   a clock element configured for sending a trigger signal to said circuit path, the trigger signal used to establish said period;   wherein the sensor electrodes are configured such that when the sensor electrodes are positioned on the patient's skin near a muscle and contact integrity is maintained between the skin and the sensor electrodes said applied test signal may be collected along with electrical signal from muscle activation; and   a detection circuit configured for processing and detection of the collected test signal and said electrical signal from muscle activation;   wherein said detection circuit includes at least one element configured to operate in response to said trigger signal and to establish a time window for analysis of the collected test signal.   
     
     
         32 . The system of  claim 31  wherein said detection circuit includes at least one amplifier used for analysis of both said collected test signal and said electrical signal from muscle activation. 
     
     
         33 . The system of  claim 31  wherein said circuit path for generating the test signal comprises a voltage source connected to a digital-to-analog converter. 
     
     
         34 . The system of  claim 31  wherein said digital-to-analog converter is configured to use a look-up table to build the test signal in segments of varying amplitude. 
     
     
         35 . The system of  claim 34  wherein a time period between said segments is set using said trigger signal. 
     
     
         36 . The system of  claim 35  wherein said time window is also set using said trigger signal. 
     
     
         37 . The system of  claim 31  wherein said detection circuit includes at least one amplifier used for analysis of both said collected test signal and said signal from muscle activation; and
 wherein the sensor system is configured to create an imbalance potential at the inputs of said amplifier when said contact integrity is maintained between the skin and the sensor electrodes; and 
 wherein the imbalance potential enhances the sensitivity of the detection circuit for detection of said test signal. 
 
     
     
         38 . A sensor system for monitoring a patient for seizure activity using electromyography and for checking the contact integrity of electrodes included among the sensor comprising:
 sensor electrodes including a pair of detection electrodes and a common electrode;   a circuit path for generating a time varying test signal with a controlled period;   wherein the circuit path is configured for applying said test signal to said common electrode;   a clock element configured for sending a trigger signal to said circuit path, the trigger signal used to establish said period;   wherein the electrodes are configured such that when properly in contact with the skin near a muscle at least a portion of said applied test signal may be collected along with electrical signal from muscle activation using said pair of detection electrodes; and   a detection circuit configured for processing and detection of collected electrical signal from muscle activation;   a second circuit connected to at least one detection electrode among said pair of detection electrodes configured for processing and detection of collected test signal;   wherein said second circuit includes at least one element configured to operate in response to said trigger signal and to establish a time window for analysis of the collected test signal.   
     
     
         39 . The system of  claim 38  wherein said circuit path for generating the test signal comprises a voltage source connected to a digital-to-analog converter. 
     
     
         40 . The system of  claim 39  wherein said digital-to-analog converter is configured to use a look-up table to build the test signal in segments of varying amplitude. 
     
     
         41 . The system of  claim 40  wherein a time period between said segments is set using said trigger signal. 
     
     
         42 . The system of  claim 40  wherein said time period is also set using said trigger signal. 
     
     
         43 - 45 . (canceled)