Metrological Characterization for Vital Sign Detection by a Bioradar

Abstract

Abstract:In space missions, during the long isolation at extreme conditions for human health, it is of paramount importance to monitor vital parameters. One such parameter is the breathing rate. Indeed, several factors can induce some breathing anomalies during the sleep, which may cause apnea episodes. In order to act timely with the right therapy, an early diagnosis is required. Conventional devices are usually uncomfortable since they require electrodes or probes in contact with the subject. An alternative way to perform this kind of measurement in a remote sensing modality is provided by a continuous wave bioradar operating in the microwave frequency band. This is an effective contactless tool for monitoring the respiratory activity through the measurement of chest deformation due to inhalation and exhalation. The radar emits a low power electromagnetic wave at a single frequency, which is reflected by the human chest. By measuring of the phase shift between the incident and reflected wave, it is possible to detect and monitor the respiratory rate. The main contribution of this work is concerned with a metrological characterization of the continuous wave bioradar; which is a topic not thoroughly assessed in the relevant literature. In particular, the bioradar measurements are also compared with data recorded by a spirometer, which is a standard medical device that measures the air volume inhaled and exhaled by the subject. The purpose of this study is the characterization of the measurement standard uncertainty to enable the assessment of the bioradar system performance.

CW Doppler Radar as Occupancy Sensor: A Comparison of Different Detection Strategies

“…The spectrograms are determined by plotting the short-time Fourier transforms of the signal over time windows having duration of 3 s and overlap of 2.9 s. As can be observed, the Doppler band is essentially null in the case of empty scene (Figure 8A). When a static target is present at 3 m distance (Figure 8B), it is possible to notice a slight increase in the amplitude of some spectral components around the typical frequencies of respiratory activity (0.2-0.4 Hz) (Cerasuolo et al, 2017). Finally, if the person walks around (Figure 8C), the spectrum has a significant amplitude at different frequencies.…”

“…In addition, there are also situations where it is difficult to apply contact sensors, as in the case of patients suffering from severe burns. A metrological characterization of a bioradar as a tool to measure the breathing rate of a human has been reported in (Cerasuolo et al, 2017). In ambient assisted living and elderly care, CW radars have been proposed to recognize human gait and detect falls (Geisheimer et al, 2001;Otero, 2005;Hornsteiner and Detlefsen, 2008;Dremina and Anishchenko, 2016) while, in security applications, they can be used to get situation awareness in through the wall scenarios (Lubecke et al, 2007;Gennarelli et al, 2016).…”

Evaluation Protocol for Analogue Intelligent Medical Radars: Towards a Systematic Approach Based on Theory and a State of the Art

“…In this section, we analyse more than 50 papers on medical radar experiments in order to extract from them interesting elements about their protocols [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ...…”

“…These walls can also be anechoic [ 39 , 45 , 66 ]. Rarely, the experiment is carried out outside with no proximate walls [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ], or surrounded by ruins [ 24 , 74 ]. Ref.…”

Editorial for Special Issue “Radar Systems for the Societal Challenges”

“…In particular, good examples of the development and adaptation of the CW Doppler radar to the human detection and activity classification in through-wall configuration and for vital signs monitoring are presented in [7,8], respectively. The paper from Yang et al…”