Apparatus for non-invasively determining deep tissue temperature using microwave radiometry

A radiometer system for measuring deep tissue temperature, comprising:

• a sensor assembly including a flexible circuit board having an antenna aperture configured to receive microwave signals from tissue, an inductor electrically connected to the antenna aperture,
• a thermistor electrically connected to the inductor and configured to measure skin temperature, and a capacitor electrically connected between the thermistor and a ground connection;
• a switch module electrically connected to the sensor assembly and configured to alternate between receiving signals from the sensor assembly and signals from a reference source;
• a radiometer electrically connected to the switch module and configured to process the alternating signals to determine a temperature difference between tissue temperature and reference temperature;
• and
• a temperature output calculator configured to calculate deep tissue temperature based on the temperature difference.

A method for non-invasively measuring deep tissue temperature, comprising:

• positioning a sensor assembly on skin, the sensor assembly including an antenna aperture, a thermistor, an inductor electrically connecting the antenna aperture to the thermistor, and a capacitor electrically connected between the thermistor and ground;
• receiving microwave signals from tissue through the antenna aperture;
• measuring skin temperature using the thermistor while the inductor provides electrical isolation between microwave signals and temperature sensing signals;
• alternating between processing signals from the sensor assembly and signals from a reference source using a switch module;
• determining a temperature difference between tissue temperature and reference temperature using a radiometer;
• and
• calculating deep tissue temperature based on the temperature difference.