Continuous In-Bed Monitoring of Vital Signs Using a Multi Radar Setup for Freely Moving Patients

In hospitals, continuous monitoring of vital parameters can provide valuable information about the course of a patient’s illness and allows early warning of emergencies. To enable such monitoring without restricting the patient’s freedom of movement and comfort, a radar system is attached under the mattress which consists of four individual radar modules to cover the entire width of the bed. Using radar, heartbeat and respiration can be measured without contact and through clothing. By processing the raw radar data, the presence of a patient can be determined and movements are categorized into the classes “bed exit”, “bed entry”, and “on bed movement”. Using this information, the vital parameters can be assessed in sections where the patient lies calmly in bed. In the first step, the presence and movement classification is demonstrated using recorded training and test data. Next, the radar was modified to perform vital sign measurements synchronized to a gold standard device. The evaluation of the individual radar modules shows that, regardless of the lying position of the test person, at least one of the radar modules delivers accurate results for continuous monitoring.

[1]  S. Lemeshow,et al.  A new Simplified Acute Physiology Score (SAPS II) based on a European/North American multicenter study. , 1993, JAMA.

[2]  M. Singer,et al.  Unexpected Deaths and Referrals to Intensive Care of Patients on General Wards – Are Some Cases Potentially Avoidable? , 1999, Journal of the Royal College of Physicians of London.

[3]  Michael Stinson,et al.  Evidence-Based Physical Diagnosis , 2001, Annals of Internal Medicine.

[4]  J. Zimmerman,et al.  Acute Physiology and Chronic Health Evaluation (APACHE) IV: Hospital mortality assessment for today’s critically ill patients* , 2006, Critical care medicine.

[5]  Rahul Mehra,et al.  Comparison of continuous versus intermittent monitoring of atrial arrhythmias. , 2006, Heart rhythm.

[6]  A. Schwartz,et al.  Adult obstructive sleep apnea: pathophysiology and diagnosis. , 2007, Chest.

[7]  Xiaomeng Gao,et al.  Data-Based Quadrature Imbalance Compensation for a CW Doppler Radar System , 2013, IEEE Transactions on Microwave Theory and Techniques.

[8]  Steven M Bradley,et al.  Early detection of occult atrial fibrillation and stroke prevention , 2015, Heart.

[9]  Simon Cooper,et al.  Attitudes towards vital signs monitoring in the detection of clinical deterioration: scale development and survey of ward nurses. , 2015, International journal for quality in health care : journal of the International Society for Quality in Health Care.

[10]  Andreas H Taenzer,et al.  Surveillance Monitoring Management for General Care Units: Strategy, Design, and Implementation. , 2016, Joint Commission journal on quality and patient safety.

[11]  Alexander Koelpin,et al.  Six-Port Based Interferometry for Precise Radar and Sensing Applications , 2016, Sensors.

[12]  Nan Liu,et al.  A novel cardiovascular risk stratification model incorporating ECG and heart rate variability for patients presenting to the emergency department with chest pain , 2016, Critical Care.

[13]  Sung Ho Cho,et al.  A Detailed Algorithm for Vital Sign Monitoring of a Stationary/Non-Stationary Human through IR-UWB Radar , 2017, Sensors.

[14]  Robert Weigel,et al.  Local Pulse Wave Detection Using Continuous Wave Radar Systems , 2017, IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology.

[15]  Robert Weigel,et al.  Support Vector Machine-Based Instantaneous Presence Detection for Continuous Wave Radar Systems , 2018, 2018 Asia-Pacific Microwave Conference (APMC).

[16]  Robert Weigel,et al.  Radar-Based Heart Sound Detection , 2018, Scientific Reports.

[17]  Robert Weigel,et al.  A contactless system for continuous vital sign monitoring in palliative and intensive care , 2018, 2018 Annual IEEE International Systems Conference (SysCon).

[18]  Lei Chen,et al.  Doppler Vital Signs Detection in the Presence of Large-Scale Random Body Movements , 2018, IEEE Transactions on Microwave Theory and Techniques.

[19]  Xinming Huang,et al.  Respiration and Heartbeat Rates Measurement Based on Autocorrelation Using IR-UWB Radar , 2018, IEEE Transactions on Circuits and Systems II: Express Briefs.

[20]  Jenshan Lin,et al.  Wavelet-Transform-Based Data-Length-Variation Technique for Fast Heart Rate Detection Using 5.8-GHz CW Doppler Radar , 2018, IEEE Transactions on Microwave Theory and Techniques.

[21]  Robert Weigel,et al.  Respiration Extraction from Radar Heart Sound Measurements , 2019, 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC).

[22]  Young-Hyo Lim,et al.  Preclinical Evaluation of a Noncontact Simultaneous Monitoring Method for Respiration and Carotid Pulsation Using Impulse-Radio Ultra-Wideband Radar , 2019, Scientific Reports.

[23]  Xiaohua Zhu,et al.  Microwave Sensing and Sleep: Noncontact Sleep-Monitoring Technology With Microwave Biomedical Radar , 2019, IEEE Microwave Magazine.

[24]  Xiaohua Zhu,et al.  A Noncontact Breathing Disorder Recognition System Using 2.4-GHz Digital-IF Doppler Radar , 2019, IEEE Journal of Biomedical and Health Informatics.

[25]  Robert Weigel,et al.  A Clinically Evaluated Interferometric Continuous-Wave Radar System for the Contactless Measurement of Human Vital Parameters , 2019, Sensors.

[26]  George Shaker,et al.  Remote Monitoring of Human Vital Signs Using mm-Wave FMCW Radar , 2019, IEEE Access.

[27]  Yong Wang,et al.  Remote Monitoring of Human Vital Signs Based on 77-GHz mm-Wave FMCW Radar , 2020, Sensors.

[28]  Robert Weigel,et al.  A dataset of clinically recorded radar vital signs with synchronised reference sensor signals , 2020, Scientific data.

[29]  Robert Weigel,et al.  On the Impact of System Nonlinearities in Continuous-Wave Radar Systems for Vital Parameter Sensing , 2020, 2020 IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNeT).

[30]  Sheng Zhao,et al.  Vital Sign Detection during Large-Scale and Fast Body Movements Based on an Adaptive Noise Cancellation Algorithm Using a Single Doppler Radar Sensor , 2020, Sensors.

[31]  Robert Weigel,et al.  A Radar-Based Vital Sign Sensing System for In-Bed Monitoring in Clinical Applications , 2020, 2020 German Microwave Conference (GeMiC).

[32]  Robert Weigel,et al.  Automatic Signal Quality Index Determination of Radar-Recorded Heart Sound Signals Using Ensemble Classification , 2020, IEEE Transactions on Biomedical Engineering.

[33]  J. I. Godino-Llorente,et al.  Cardiopulmonary Activity Monitoring Using Millimeter Wave Radars , 2020, Remote. Sens..

[34]  Nebojša Malešević,et al.  Contactless Real-Time Heartbeat Detection via 24 GHz Continuous-Wave Doppler Radar Using Artificial Neural Networks , 2020, Sensors.