Methods and systems for electromagnetic near-field coherent sensing

Abstract

The present disclosure may be embodied as methods and / or systems for non-contact measuring of an on-body and / or inside-body motion of an individual. A sensing signal is provided within a near-field coupling range of a motion to be measured. In this way, a measurement signal may be generated as the sensing signal modulated by the motion. The sensing signal may be an ID-modulated signal. In some embodiments, the sensing signal is a backscattered RFID link provided a wireless tag. A downlink signal may be provided to power the wireless tag. The sensing signal may be a harmonic of the downlink signal. The measurement signal is detected. The motion is measured based on the measurement signal. The measurement signal may be detected as far-field radiation after transmission through a source of the motion. The measurement signal may be detected as reflected from a source of the motion as antenna reflection.

Description

[0001] Statement Regarding Federally Funded Research [0002] This invention was made with Government support under Contract No. DE-AR0000528 awarded by the Department of Energy. The government has certain rights in this invention. [0003] Cross References to Related Applications [0004] This application claims priority to U.S. Provisional Application No. 62 / 521,163 (pending), filed June 16, 2017, and U.S. Provisional Application No. 62 / 618,352 (pending), filed January 17, 2018, The disclosure thereof is incorporated herein by reference. technical field [0005] The present disclosure relates to the detection of motion, and in particular, to the detection of vital signs that do not require physical contact. Background technique [0006] Monitoring of vital signs, such as heart rate, blood pressure, respiratory rate, and respiratory effort, is a key procedure in patient management and pathology documentation. Current approaches based on body electrodes, light absorpt...

AI Technical Summary

Problems solved by technology

Current approaches based on body electrodes, light absorption, pressure or strain gauges, and ultrasound or radio frequency (RF) backscatter have their own limitations in sensing capability and sampling rate

Measurements may also be uncomfortable due to direct skin contact or restricted movement of the subject, or disruption of the individual's circadian rhythm

This inconvenience creates a significant workload for caregivers and prevents continuous long-term monitoring

[0007] Conventional techniques for far-field vital signal detection based on radio frequency (“RF”) can easily obtain respiratory motion due to strong reflections from the body surface and the geometric mean of the reflected signals, but these techniques have difficulty distinguishing smaller mechanical vibrations Details such as heartbeat and wrist pulse waveforms with low RF frequencies

Although heart rate can be recovered after careful filtering, blood pressure estimation and simultaneous monitoring of multiple freely active individuals is still not possible

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