Electrode units for sensing physiological electrical activity

Abstract

Systems and apparatus for monitoring physiological electrical activity of an individual include a first electrode unit for receiving a first signal indicative of electrical activity at a first location on a body of the individual and a second electrode unit for receiving a second signal indicative of electrical activity at a second location on the body of the individual. Each of the first and second electrode units may be operated in a field-sensing mode wherein the electrode unit is placed on or in proximity to the individual's skin. The first and second electrode units comprise a capacitive sensor element, and the capacitive sensor element of each of the electrode units comprising an electrodynamic sensor which is sensitive to electromagnetic waves; and an antenna comprising an electrically conductive radiating element for receiving electromagnetic waves. The field-sensing mode can be either non-contact field-sensing mode wherein the electrode unit does not contact the individual's skin, or a contact field-sensing mode wherein the electrode unit is placed directly on the individual's skin.

What is claimed is: 
     
         1 . A system for sensing physiological electrical activity in an individual comprising:
 a first electrode unit for generating a first signal based on a first detected physiological electrical activity at a first location on or in proximity to the individual's skin; and   a second electrode unit for generating a second signal based on a second detected physiological electrical activity at a second location on or in proximity to the individual's skin;   wherein each of the first and second electrode units comprises a capacitive sensor element, the capacitive sensor element of each of the electrode units comprising:   an electrodynamic sensor; and
 an antenna comprising an electrically conductive radiating element, the radiating element in electrical contact with the electrodynamic sensor, the antenna located relatively more proximate than the electrodynamic sensor to the individual's skin. 
   
     
     
         2 . The system according to  claim 1  wherein the physiological electrical activity comprises electrical activity of an organ, the organ comprising at least one of a heart, a brain and an eye. 
     
     
         3 . The system according to  claim 1  wherein the capacitive sensor element of each of the electrode units comprises an electrically non-conductive layer disposed on the radiating element, wherein the non-conductive layer is on an outside face of the electrode unit which is located relatively more proximate than the radiating element to the individual's skin. 
     
     
         4 . The system according to  claim 3  wherein the capacitive sensor element comprises a metallization layer electrically connected to an inner metallization layer in direct electrical contact with the electrodynamic sensor. 
     
     
         5 . The system according to  claim 4  comprising an insulator layer to provide a compressive force for facilitating the direct electrical contact. 
     
     
         6 . The system according to  claim 1  wherein at least one of the electrode units comprises a detector configured to detect a presence of a resistive sensor element electrically connected to the at least one of the electrode units. 
     
     
         7 . The system according to  claim 1  wherein the system is configured to combine the first signal and the second signal to generate one or more waveforms and to use the waveforms to determine a medical state of the individual. 
     
     
         8 . The system according to  claim 1  comprising a base unit connected to the electrode units to receive the first and second signals, the base unit comprising a digital signal processor configured to generate one or more waveforms based on a combination of the first and second signals. 
     
     
         9 . The system according to  claim 8  wherein the system is incorporated into a vehicle and at least one of the electrode units and the base unit is located in the interior of the vehicle. 
     
     
         10 . The system according to  claim 9  wherein the electrode units are embedded into a seat in the vehicle. 
     
     
         11 . The system according to  claim 9  wherein at least one of the electrode units is wirelessly connected to the base unit. 
     
     
         12 . The system according to  claim 9  wherein at least one of the electrode units is incorporated into a steering control of the vehicle. 
     
     
         13 . The system according to  claim 9  wherein the system is configured to use the waveforms to determine a medical state of an operator of the vehicle. 
     
     
         14 . The system according to  claim 13  wherein the medical state is drowsiness, unconsciousness, incapacity, brain injury, stroke, arrhythmias, compensated shock, decompensated shock, sepsis, heart attack, sleep, stress, attentiveness, cognition, respirations, or internal bleeding. 
     
     
         15 . An electrode unit for use in sensing physiological electrical activity in an electrical activity monitoring system, the electrode unit comprising:
 an electrodynamic sensor sensitive to electromagnetic waves; and   an antenna comprising an electrically conductive radiating element, the radiating element in electrical contact with the electrodynamic sensor, the antenna located relatively more proximate than the electrodynamic sensor to an individual's skin;   wherein the electrode unit is incorporated into a vehicle.   
     
     
         16 . The electrode unit according to  claim 15  wherein the electrode unit is incorporated into a seat or a steering control of the vehicle. 
     
     
         17 . The electrode unit according to  claim 15  wherein the electrode unit is in communication with a base unit, the base unit comprising a digital signal processor. 
     
     
         18 . The electrode unit according to  claim 17  wherein the electrode unit is in wireless communication with the base unit. 
     
     
         19 . A system for sensing physiological electrical activity in an individual comprising:
 a first electrode unit for generating a first signal based on a first detected physiological electrical activity at a first location on or in proximity to the individual's skin; and   a second electrode unit for generating a second signal based on a second detected physiological electrical activity at a second location on or in proximity to the individual's skin;   wherein each of the first and second electrode units comprises a capacitive sensor element, each of the first and second electrode units configurable to operate in:
 a contact mode wherein the electrode unit is in contract with the individual's skin; and 
 a non-contact mode wherein the electrode unit is not in contact with the individual's skin, the electrode unit configured to generate its corresponding signal based on a detected electric field at a location in proximity to the individual's skin.