Patent ID: 8295903

Claim:
A device for detecting and analyzing vital fields, the device comprising: a) control circuitry configured to generate a first control signal at a first sampling frequency and a second control signal at a second sampling frequency different from the first sampling frequency; b) a detector in electrical communication with the control circuitry, the detector comprising: i. an avalanche diode having an active region on which vital waves from the vital field are incident; ii. an avalanche initiator configured to provide energy to the avalanche diode, the energy generating seed electrons for electron avalanches; iii. a capacitor coupled to the avalanche diode's cathode and configured to periodically apply a low voltage to the cathode; and iv. electromagnetic shielding substantially enclosing the avalanche diode and the avalanche initiator such that the electromagnetic shielding prevents unwanted electromagnetic interference with the electron avalanches but allows the vital waves to pass; and c) signal processing circuitry in electrical communication with the detector; wherein: a) the control circuitry sends the first control signal to the detector; b) the first control signal causes the capacitor to modulate high gain operation of the avalanche diode at the first sampling frequency by applying the low voltage to the cathode at the first sampling frequency; c) an input frequency from the vital waves mixes with a harmonic of the first sampling frequency in the active region of the avalanche diode during high gain operation of the avalanche diode, generating a first mixed signal having a first beat frequency; d) the avalanche diode sends the first mixed signal to the signal processing circuitry; e) the control circuitry sends the second control signal to the detector; f) the second control signal causes the capacitor to modulate high gain operation of the avalanche diode at the second sampling frequency by applying the low voltage to the cathode at the second sampling frequency; g) the input frequency from the vital waves mixes with a harmonic of the second sampling frequency in the active region of the avalanche diode during high gain operation of the avalanche diode, generating a second mixed signal having a second beat frequency; h) the avalanche diode sends the second mixed signal to the signal processing circuitry; and i) the signal processing circuitry determines the input frequency from the vital waves using the first and second beat frequencies.