A circuit model of an ultra wideband impulse radar system for breath‐activity monitoring

Abstract

The aim of this work is to present a circuit model to analyze and design ultra wideband (UWB) radars for the remote monitoring of breath activity. The model includes the impulse signal source, the transceiver antenna, the transmission medium, and the human thorax. First of all, the proposed model has been validated by comparing its responses with those achieved both numerically, with a commercial electromagnetic modeling software, and experimentally, by means of a setup based on an indirect time domain reflectometry system. Then, the model has been used for analyzing the feasibility of a UWB radar operating in the 36-GHz range with an effective isotropic radiated power lower than - 41.3dBm/MHz, i.e. within the limits issued by the United States Federal Communications Commission for unlicensed UWB imaging systems. The model outlined the possibility of the considered UWB radar of monitoring the breath activity of a subject up to distances of about 10m in open air. Copyright (C) 2011 John Wiley & Sons, Ltd

Design and realization of a UWB radar for breath activity monitoring

“…978-1-4673-0717-8/12/$31.00 ©2012 IEEE By using the model described in [5], simulations have been performed by considering a source with a repetition rate of 1 MHz having a time behavior similar to that of Fig. 4b.…”

“…By using the electromagnetic radiation in the microwave region, it is potentially possible to monitor any physiological activity involving movements of parts of the body without contact with the subject under examination and, consequently, to carry out a remote monitoring in a non-invasive way. The systems proposed in literature for the remote monitoring of breath activity are mainly based on Doppler [1,2] or ultra wideband (UWB) [3][4][5] techniques.…”

A Twin Spiral Planar Antenna for UWB Medical Radars

“…Ultrawideband radar systems transmit and receive ultrashort pulses having ultrawide bandwidth and very low power levels [1][2][3][4][5]. ese properties make UWB radars safe for the exposed human being and compliant with other apparatuses in the environment, but at the same time increase the difficulty for the echo signal detection.…”

Radar cross section measurements of the human body for UWB radar applications

“…By using the electromagnetic radiation in the microwave region, on the other hand, it is potentially possible to monitor any physiological activity involving movements of parts of the body, without contact with the subject under observation. In particular, among the possible remote monitoring solutions employing electromagnetic radiation, ultra wideband (UWB) radars are today proposed as valuable substitutes for RIP systems, thanks to their high resolution and to the extremely low energy spectral density of the radiated signals, making them suitable for use in complex environments where interference with other apparatus can represent a problem [2].…”

“…A circuit model suitable to design a UWB radar for breath activity monitoring has been proposed in [2]. The model, in order to be applied, requires knowledge of the radar cross section (RCS) of the human body, together with its changes resulting from respiratory activity.…”