Volumetric Induction Phase Shift Detection System for Determining Tissue Water Content Properties

Abstract

A method and apparatus of determining the condition of a bulk tissue sample, by: positioning a bulk tissue sample between a pair of induction coils (or antennae); passing a spectrum of alternating current (or voltage) through a first of the induction coils (or antennae); measuring spectrum of alternating current (or voltage) produced in the second of the induction coils (or antennae); and comparing the phase shift between the spectrum of alternating currents (or voltages) in the first and second induction coils (or antennae), thereby determining the condition of the bulk tissue sample.

1 . A method of determining the condition of a bulk tissue sample, comprising:
 positioning a bulk tissue sample between a pair of induction coils or antennae;   passing a spectrum of alternating current or voltage through a first of the induction coils or antennae;   measuring a spectrum of alternating current or voltage produced in the second of the induction coils or antennae; and   comparing the phase shift between the spectrum of alternating currents or voltages in the first and second induction coils or antennae, thereby determining the condition of the bulk tissue sample.   
     
     
         2 . The method of  claim 1 , wherein the first and second induction coils or antennae do not contact the bulk tissue sample. 
     
     
         3 . The method of  claim 1 , wherein determining the condition of the bulk tissue sample comprises:
 detecting at least one condition from the group consisting of edema, ischemia, bleeding, dehydration, water accumulation in the bulk tissue sample, extravasation, and disease.   
     
     
         4 . The method of  claim 1 , wherein the bulk tissue sample is selected from the group consisting of brain tissue, lung tissue, heart tissue, muscle tissue, skin tissue, kidney tissue, cornea tissue, liver tissue, abdomen tissue, head tissue, leg tissue, arm tissue, pelvis tissue, chest tissue or trunk tissue. 
     
     
         5 . The method of claim I, wherein the frequency of the spectrum of alternating current is between 10 kHz and 10 GHz. 
     
     
         6 . The method of  claim 1 , wherein the frequency of the spectrum of alternating current is between 1 MHz and 10 GHz. 
     
     
         7 . The method of  claim 1 , wherein determining the condition of the bulk tissue sample comprises detecting edema, ischemia, dehydration, extravasation, in the tissue sample, and wherein the spectrum of frequency of the alternating current is between 100 kHz to 10 GHz. 
     
     
         8 . The method of  claim 1 , wherein determining the condition of the bulk tissue sample comprises detecting interperitoneal bleeding in the tissue sample, and wherein the spectrum of frequency of the alternating current is between 100 kHz to 10 GHz 
     
     
         9 . A method of determining changes in the condition of a bulk tissue sample over time, comprising:
 positioning a bulk tissue sample between a pair of induction coils or antennae;   passing a spectrum of alternating current or voltage through a first of the induction coils or antennae;   measuring a spectrum of alternating current or voltage produced in the second of the induction coils or antennae; and   comparing the phase shift between the spectrum of alternating currents or voltages in the first and second induction coils or antennae over time, thereby determining a change in the condition of the bulk tissue sample over time.   
     
     
         10 . The method of  claim 9 , wherein the first and second induction coils or antennae do not contact the bulk tissue sample. 
     
     
         11 . The method of  claim 9 , wherein determining the change in the condition of the bulk tissue sample over time comprises:
 detecting a change over time in at least one condition from the group consisting of edema, ischemia, bleeding, dehydration, water accumulation in the bulk tissue sample, extravasation, and disease.   
     
     
         12 . The method of  claim 9 , wherein the bulk tissue sample is selected from the group consisting of brain tissue, lung tissue, heart tissue, muscle tissue, skin tissue, kidney tissue, cornea tissue, liver tissue, abdomen tissue, head tissue, leg tissue, arm tissue, pelvis tissue, chest tissue or trunk tissue. 
     
     
         13 . An apparatus for determining the condition of a bulk tissue sample, comprising:
 a first induction coil or antenna;   a second induction coil or antenna;   an alternating current power supply connected to the first induction coil or antenna, the alternating current power supply configured to generate a spectrum of currents or voltages in the first induction coil or antenna; and   a measurement system connected to the second induction coil or antenna, wherein the measurement system is configured to measure a phase shift difference in the spectrum of currents or voltages between the first and second induction coils or antennae when the first and second induction coils or antennae are positioned on opposite sides of a tissue sample.   
     
     
         14 . The apparatus of  claim 13 , further comprising:
 a system to compare the phase shift between the alternating currents or voltages in the first and second induction coils or antennae to determine the condition of the bulk tissue sample.   
     
     
         15 . The apparatus of  claim 13 , wherein the alternating current power supply produces a spectrum of alternating currents with a frequency between 10 kHz and 10 GHz. 
     
     
         16 . The apparatus of  claim 13 , wherein the alternating current power supply produces a spectrum of alternating currents with a frequency between 1 MHz and 10 GHz. 
     
     
         17 . The apparatus of  claim 14 , wherein the system to determine the condition of the bulk tissue sample comprises:
 a system configured to detect at least one of edema, ischemia, bleeding, dehydration, water accumulation in the bulk tissue sample, extravasation, and disease by analysis of the phase shift difference in the currents between the pair of induction coils or antennae.   
     
     
         18 . The apparatus of  claim 13 , wherein the alternating current power supply comprises:
 a function generator configured to generate an alternating current in the first induction coil or antenna having a frequency that changes in pre-programmed steps.   
     
     
         19 . The apparatus of  claim 18 , wherein the function generator supplies an excitation signal of approximately 20 mA in the range of 1 to 8.5 MHz at pre-programmed steps. 
     
     
         20 . The apparatus of  claim 13 , further comprising:
 a first differential receiving amplifier connected to the first induction coil or antenna; and   a second differential receiving amplifier connected to the second induction coil or antenna.   
     
     
         21 . The apparatus of  claim 13 , further comprising:
 a dual-channel demodulator connected to the first and second induction coils or antennae; and   an analog-digital converter connected to the dual-channel demodulator.   
     
     
         22 . The apparatus of  claim 21 , wherein the dual-channel demodulator comprises:
 a mixer; and   a narrow band pass filter.