A method and system for monitoring internal electrical impedance of a biological object

Abstract

Method and system for monitoring an internal electrical impedance of a biological object including Internal Thoracic Impedance (ITI) comprising placing two arrays of electrodes on opposite sides of the biological object, wherein each of said two arrays comprise three equally spaced electrodes; imposing an alternating electrical current between pairs of the electrodes and obtaining voltage signals representative of a voltage drop thereon, calculating two values of internal electrical impedance of the biological object corresponding to the uttermost electrodes of said two arrays of electrodes placed on the opposite sides of the biological object.

1 . A method for monitoring an internal electrical impedance of a biological object, comprising the steps of:
 i) placing two arrays of electrodes on opposite sides of the biological object, wherein each of said two arrays comprise three equally spaced electrodes;   ii) imposing an alternating electrical current between pairs of said electrodes and obtaining voltage signals representative of a voltage drop thereon,   iii) calculating two values of internal electrical impedance of the biological object corresponding to the uttermost electrodes of said two arrays of electrodes placed on the opposite sides of the biological object.   
     
     
         2 . The method of  claim 1  wherein said internal electrical impedance of a biological object includes an Internal Thoracic Impedance (ITI). 
     
     
         3 . The method of  claim 2  further comprising comparing said two calculated values of internal electrical impedance therebetween. 
     
     
         4 . The method of  claim 3  further comprising a denying or an acceptance of said two calculated values of internal electrical impedance based on the comparison result. 
     
     
         5 . The method of  claim 4  wherein said denying of acceptance is based on exciding or non-exciding a pre-determined threshold value of the comparison result accordingly. 
     
     
         6 . The method of  claim 5  wherein said pre-determined threshold value is about 3 Ohm. 
     
     
         7 . The method of  claim 4  further comprising repeating the steps ii) and iii) till the acceptance of said two calculated values of internal electrical impedance. 
     
     
         8 . The method of  claim 7  further comprising averaging of said two calculated values of internal electrical impedance. 
     
     
         9 . The method of  claim 1  wherein said alternating electrical current has a value from 0.5 to 5 mA. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 1  wherein said alternating electrical current has a frequency from 50 to 200 KHz. 
     
     
         12 . The method of  claim 11  wherein said alternating electrical current includes alternating current of any periodic waveform. 
     
     
         13 . The method of  claim 1  wherein a number of said imposing is defined by number of combinations by said pairs of electrodes. 
     
     
         14 - 20 . (canceled) 
     
     
         21 . A method of impedance plethysmography comprising the steps of:
 i. placing two arrays of electrodes on opposite sides a patient thorax, wherein each of said two arrays comprise three equally spaced electrodes;   ii. imposing an alternating electrical current between pairs of said electrodes and obtaining voltage signals representative of a voltage drop thereon,   iii. calculating two values of internal electrical impedance of the biological obj ect corresponding to the uttermost electrodes of said two arrays of electrodes placed on the opposite sides of the biological object.   
     
     
         22 . The method of  claim 21  further comprising comparing said two calculated values of Internal Thoracic Impedance (ITI) therebetween. 
     
     
         23 . The method of  claim 22  further comprising a denying or an acceptance of said two calculated values of Internal Thoracic Impedance (ITI) based on the comparison result. 
     
     
         24 . The method of  claim 23  wherein said denying of acceptance is based on exciding or non-exciding a pre-determined threshold value of the comparison result accordingly. 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 24  further comprising repeating the steps ii) and iii) till the acceptance of said two calculated values of internal electrical impedance. 
     
     
         27 . The method of  claim 26  further comprising averaging of said two calculated values of internal electrical impedance. 
     
     
         28 - 31 . (canceled) 
     
     
         32 . The method of  claim 21  whreein a number of said imposing is defined by number of combinations by said pairs of electrodes. 
     
     
         33 . The method of  claim 21  wherein the steps i-iii are performed at least twice during the monitoring. 
     
     
         34 - 40 . (canceled)