Systems and methods for detecting physical changes without physical contact

A method comprising:

• establishing, by an electric field generator, an electric field around a desired area of detection that includes a body being monitored, the electric field generator comprising an oscillator oscillating at a frequency;
• and
• detecting, by a demodulator coupled to an output of the electric field generator, a change in a frequency of the generated electric field around the desired area of detection, wherein the detecting comprises multiplying the output of the electric field generator by a phase-shifted version of the output of the electric field generator, the phase-shifted version of the output of the electric field generator being generated by a resonant circuit;
• wherein characteristics of the body being monitored cause the change in the frequency of the generated electric field around the desired area of detection.

A non-transitory computer-readable medium containing instructions which when executed by a processor perform steps of:

• generating, by an electric field generator, an electric field around a desired area of detection that includes a body being monitored, the electric field generator comprising an oscillator oscillating at a frequency;
• and
• detecting, by a demodulator, a change in a frequency of the generated electric field, and wherein the detecting comprises analyzing an output of an analog-to-digital converter (ADC) coupled to a sample-and-hold circuit configured to sample an output of the electric field generator;
• wherein characteristics of the body being monitored cause the change in the frequency of the generated electric field around the desired area of detection.