Non-contact Sleep/Wake Monitoring Using Impulse-Radio Ultrawideband Radar in Neonates

Background: The gold standard for sleep monitoring, polysomnography (PSG), is too obtrusive and limited for practical use with tiny infants or in neonatal intensive care unit (NICU) settings. The ability of impulse-radio ultrawideband (IR-UWB) radar, a non-contact sensing technology, to assess vital signs and fine movement asymmetry in neonates was recently demonstrated. The purpose of this study was to investigate the possibility of quantitatively distinguishing and measuring sleep/wake states in neonates using IR-UWB radar and to compare its accuracy with behavioral observation-based sleep/wake analyses using video recordings.Methods: One preterm and three term neonates in the NICU were enrolled, and voluntary movements and vital signs were measured by radar at ages ranging from 2 to 27 days. Data from a video camcorder, amplitude-integrated electroencephalography (aEEG), and actigraphy were simultaneously recorded for reference. Radar signals were processed using a sleep/wake decision algorithm integrated with breathing signals and movement features.Results: The average recording time for the analysis was 13.0 (7.0–20.5) h across neonates. Compared with video analyses, the sleep/wake decision algorithm for neonates correctly classified 72.2% of sleep epochs and 80.6% of wake epochs and achieved a final Cohen's kappa coefficient of 0.49 (0.41–0.59) and an overall accuracy of 75.2%.Conclusions: IR-UWB radar can provide considerable accuracy regarding sleep/wake decisions in neonates, and although current performance is not yet sufficient, this study demonstrated the feasibility of its possible use in the NICU for the first time. This unobtrusive, non-contact radar technology is a promising method for monitoring sleep/wake states with vital signs in neonates.

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An Overview of Signal Processing Techniques for Remote Health Monitoring Using Impulse Radio UWB Transceiver

Sensors ◽

10.3390/s20092479 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2479 ◽

Cited By ~ 11

Author(s):

Faheem Khan ◽

Asim Ghaffar ◽

Naeem Khan ◽

Sung Ho Cho

Keyword(s):

Heart Rate ◽

Signal Processing ◽

Health Monitoring ◽

Vital Signs ◽

Impulse Radio ◽

Non Invasive ◽

Uwb Radar ◽

Processing Techniques ◽

Signal Processing Techniques ◽

Remote Health

Non-invasive remote health monitoring plays a vital role in epidemiological situations such as SARS outbreak (2003), MERS (2015) and the recently ongoing outbreak of COVID-19 because it is extremely risky to get close to the patient due to the spread of contagious infections. Non-invasive monitoring is also extremely necessary in situations where it is difficult to use complicated wired connections, such as ECG monitoring for infants, burn victims or during rescue missions when people are buried during building collapses/earthquakes. Due to the unique characteristics such as higher penetration capabilities, extremely precise ranging, low power requirement, low cost, simple hardware and robustness to multipath interferences, Impulse Radio Ultra Wideband (IR-UWB) technology is appropriate for non-invasive medical applications. IR-UWB sensors detect the macro as well as micro movement inside the human body due to its fine range resolution. The two vital signs, i.e., respiration rate and heart rate, can be measured by IR-UWB radar by measuring the change in the magnitude of signal due to displacement caused by human lungs, heart during respiration and heart beating. This paper reviews recent advances in IR- UWB radar sensor design for healthcare, such as vital signs measurements of a stationary human, vitals of a non-stationary human, vital signs of people in a vehicle, through the wall vitals measurement, neonate’s health monitoring, fall detection, sleep monitoring and medical imaging. Although we have covered many topics related to health monitoring using IR-UWB, this paper is mainly focused on signal processing techniques for measurement of vital signs, i.e., respiration and heart rate monitoring.

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Non-contact respiration monitoring using impulse radio ultrawideband radar in neonates

Royal Society Open Science ◽

10.1098/rsos.190149 ◽

2019 ◽

Vol 6 (6) ◽

pp. 190149 ◽

Cited By ~ 9

Author(s):

Jong Deok Kim ◽

Won Hyuk Lee ◽

Yonggu Lee ◽

Hyun Ju Lee ◽

Teahyen Cha ◽

...

Keyword(s):

Neonatal Intensive Care ◽

Intraclass Correlation ◽

Impulse Radio ◽

Respiration Monitoring ◽

Radar Sensors ◽

Uwb Radar ◽

Impedance Pneumography ◽

Adult Humans ◽

Radar Measurements ◽

Good Agreement

Vital sign monitoring in neonates requires adhesive electrodes, which often damage fragile newborn skin. Because impulse radio ultrawideband (IR-UWB) radar has been reported to recognize chest movement without contact in adult humans, IR-UWB may be used to measure respiratory rates (RRs) in a non-contact fashion. We investigated the feasibility of radar sensors for respiration monitoring in neonates without any respiratory support to compare the accuracy and reliability of radar measurements with those of conventional impedance pneumography measurements. In the neonatal intensive care unit, RRs were measured using radar (RR Rd ) and impedance pneumography (RR IP ) simultaneously. The neonatal voluntary movements were measured using the radar sensor and categorized into three levels (low [M 0 ], intermediate [M 1 ] and high [M 2 ]). RR Rd highly agreed with RR IP ( r = 0.90; intraclass correlation coefficient [ICC] = 0.846 [0.835–0.856]). For the M 0 movement, there was good agreement between RR Rd and RR IP (ICC = 0.893; mean bias −0.15 [limits of agreement (LOA) −9.6 to 10.0]). However, the agreement was slightly lower for the M 1 (ICC = 0.833; mean bias = 0.95 [LOA −11.4 to 13.3]) and M 2 (ICC = 0.749; mean bias = 3.04 [LOA –9.30 to 15.4]) movements than for the M 0 movement. In conclusion, IR-UWB radar can provide accurate and reliable estimates of RR in neonates in a non-contact fashion. The performance of radar measurements could be affected by neonate movement.

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Feasibility of non-contact cardiorespiratory monitoring using impulse-radio ultra-wideband radar in the neonatal intensive care unit

PLoS ONE ◽

10.1371/journal.pone.0243939 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243939

Author(s):

Won Hyuk Lee ◽

Yonggu Lee ◽

Jae Yoon Na ◽

Seung Hyun Kim ◽

Hyun Ju Lee ◽

...

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Neonatal Intensive Care Unit ◽

Neonatal Intensive Care ◽

Correlation Coefficients ◽

Impulse Radio ◽

Ultra Wideband ◽

Uwb Radar ◽

Impedance Pneumography ◽

Wideband Radar

Background Current cardiorespiratory monitoring equipment can cause injuries and infections in neonates with fragile skin. Impulse-radio ultra-wideband (IR-UWB) radar was recently demonstrated to be an effective contactless vital sign monitor in adults. The purpose of this study was to assess heart rates (HRs) and respiratory rates (RRs) in the neonatal intensive care unit (NICU) using IR-UWB radar and to evaluate its accuracy and reliability compared to conventional electrocardiography (ECG)/impedance pneumography (IPG). Methods The HR and RR were recorded in 34 neonates between 3 and 72 days of age during minimal movement (51 measurements in total) using IR-UWB radar (HRRd, RRRd) and ECG/IPG (HRECG, RRIPG) simultaneously. The radar signals were processed in real time using algorithms for neonates. Radar and ECG/IPG measurements were compared using concordance correlation coefficients (CCCs) and Bland-Altman plots. Results From the 34 neonates, 12,530 HR samples and 3,504 RR samples were measured. Both the HR and RR measured using the two methods were highly concordant when the neonates had minimal movements (CCC = 0.95 between the RRRd and RRIPG, CCC = 0.97 between the HRRd and HRECG). In the Bland-Altman plot, the mean biases were 0.17 breaths/min (95% limit of agreement [LOA] -7.0–7.3) between the RRRd and RRIPG and -0.23 bpm (95% LOA -5.3–4.8) between the HRRd and HRECG. Moreover, the agreement for the HR and RR measurements between the two modalities was consistently high regardless of neonate weight. Conclusions A cardiorespiratory monitor using IR-UWB radar may provide accurate non-contact HR and RR estimates without wires and electrodes for neonates in the NICU.

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Appropriate Drone Flight Altitude for Horse Behavioral Observation

Drones ◽

10.3390/drones5030071 ◽

2021 ◽

Vol 5 (3) ◽

pp. 71

Author(s):

Tomoko Saitoh ◽

Moyu Kobayashi

Keyword(s):

Avoidance Behavior ◽

Correlation Coefficients ◽

Behavioral Observation ◽

Animal Research ◽

Behavioral Data ◽

Flight Altitude ◽

Recording Time ◽

Livestock Management ◽

Behavioral Observations ◽

Video Observations

Recently, drone technology advanced, and its safety and operability markedly improved, leading to its increased application in animal research. This study demonstrated drone application in livestock management, using its technology to observe horse behavior and verify the appropriate horse–drone distance for aerial behavioral observations. Recordings were conducted from September to October 2017 on 11 horses using the Phantom 4 Pro drone. Four flight altitudes were tested (60, 50, 40, and 30 m) to investigate the reactions of the horses to the drones and observe their behavior; the recording time at each altitude was 5 min. None of the horses displayed avoidance behavior at any flight altitude, and the observer was able to distinguish between any two horses. Recorded behaviors were foraging, moving, standing, recumbency, avoidance, and others. Foraging was the most common behavior observed both directly and in the drone videos. The correlation coefficients of all behavioral data from direct and drone video observations at all altitudes were significant (p < 0.01). These results indicate that horse behavior can be discerned with equal accuracy by both direct and recorded drone video observations. In conclusion, drones can be useful for recording and analyzing horse behavior.

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Non-contact Detection of Vital Signs via a UWB Radar Sensor

Lecture Notes in Electrical Engineering - Communications, Signal Processing, and Systems ◽

10.1007/978-981-13-6504-1_86 ◽

2019 ◽

pp. 708-716

Author(s):

Zhenzhen Duan ◽

Yang Zhang ◽

Jian Zhang ◽

Jing Liang

Keyword(s):

Vital Signs ◽

Contact Detection ◽

Radar Sensor ◽

Uwb Radar

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A randomized controlled trial of kangaroo mother care versus conventional method on vital signs and arterial oxygen saturation rate in newborns who were hospitalized in neonatal intensive care unit

Journal of Clinical Neonatology ◽

10.4103/2249-4847.151163 ◽

2015 ◽

Vol 4 (1) ◽

pp. 26 ◽

Cited By ~ 4

Author(s):

Khadijeh Nasiriani ◽

Khadijeh Dehghani ◽

ZahraPour Movahed ◽

Hamideh Dehghani

Keyword(s):

Intensive Care Unit ◽

Randomized Controlled Trial ◽

Neonatal Intensive Care ◽

Controlled Trial ◽

Arterial Oxygen Saturation ◽

Vital Signs ◽

Kangaroo Mother Care ◽

Arterial Oxygen ◽

Randomized Controlled ◽

Saturation Rate

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Non-contact physiological monitoring of preterm infants in the Neonatal Intensive Care Unit

npj Digital Medicine ◽

10.1038/s41746-019-0199-5 ◽

2019 ◽

Vol 2 (1) ◽

Cited By ~ 7

Author(s):

Mauricio Villarroel ◽

Sitthichok Chaichulee ◽

João Jorge ◽

Sara Davis ◽

Gabrielle Green ◽

...

Keyword(s):

Intensive Care Unit ◽

Heart Rate ◽

Respiratory Rate ◽

Preterm Infants ◽

Neonatal Intensive Care ◽

Mean Absolute Error ◽

Vital Signs ◽

Absolute Error ◽

Video Camera ◽

The Mean

AbstractThe implementation of video-based non-contact technologies to monitor the vital signs of preterm infants in the hospital presents several challenges, such as the detection of the presence or the absence of a patient in the video frame, robustness to changes in lighting conditions, automated identification of suitable time periods and regions of interest from which vital signs can be estimated. We carried out a clinical study to evaluate the accuracy and the proportion of time that heart rate and respiratory rate can be estimated from preterm infants using only a video camera in a clinical environment, without interfering with regular patient care. A total of 426.6 h of video and reference vital signs were recorded for 90 sessions from 30 preterm infants in the Neonatal Intensive Care Unit (NICU) of the John Radcliffe Hospital in Oxford. Each preterm infant was recorded under regular ambient light during daytime for up to four consecutive days. We developed multi-task deep learning algorithms to automatically segment skin areas and to estimate vital signs only when the infant was present in the field of view of the video camera and no clinical interventions were undertaken. We propose signal quality assessment algorithms for both heart rate and respiratory rate to discriminate between clinically acceptable and noisy signals. The mean absolute error between the reference and camera-derived heart rates was 2.3 beats/min for over 76% of the time for which the reference and camera data were valid. The mean absolute error between the reference and camera-derived respiratory rate was 3.5 breaths/min for over 82% of the time. Accurate estimates of heart rate and respiratory rate could be derived for at least 90% of the time, if gaps of up to 30 seconds with no estimates were allowed.

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