key: cord-351825-fdog73g2 authors: Tsai, Cheng-Yu; Chang, Nai-Chien; Fang, Hsiu-Chen; Chen, Ying-Che; Lee, Su-Shin title: A Novel Non-contact Self-Injection-Locked Radar for Vital Sign Sensing and Body Movement Monitoring in COVID-19 Isolation Ward date: 2020-08-26 journal: J Med Syst DOI: 10.1007/s10916-020-01637-z sha: doc_id: 351825 cord_uid: fdog73g2 BACKGROUND: The outbreak of Coronavirus disease (COVID-19) pandemic has become the most serious global health issue. Isolation policy in hospitals is one of the most crucial protocols to prevent nosocomial infection of COVID-19. It is important to monitor and assess the physical conditions of the patients in isolation. METHODS: Our institution has installed the novel non-contact wireless sensor for vital sign sensing and body movement monitoring for patients in COVID-19 isolation ward. RESULTS: We have collected and compared data between the radar record with the nurse’s handover record of two patients, one recorded for 13 days and the other recorded for 5 days. The P value by Fisher’s exact test were 0.139 (temperature, P > 0.05) and 0.292 (heart beat rate, P > 0.05) respectively. CONCLUSIONS: This is the first report about the application experience of this equipment. Therefore we attempted to share the experience and try to apply this equipment in COVID-19 patients in future to offer the more reliable and safe policy. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10916-020-01637-z) contains supplementary material, which is available to authorized users. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10916-020-01637-z) contains supplementary material, which is available to authorized users. pneumonia. [1] The healthcare industry is suffering from the surge of COVID-19, and carrying the risks of being overwhelmed by the pandemic. For example, there is a potential risk of nosocomial transmission due to the viable virus remained on personal protective equipment (PPE) used by the healthcare staff. Zamora et al. has reported a substantial risk of self-contamination when doffing PPE. [2] In addition, since there is a higher risk of being infected or in quarantine caused by the exposure to COVID-19 from improper protections, hospital staff's morale is highly affected. Therefore, we shall utilize the new technology to protect the healthcare staff as well as maintaining proper health care service quality to the publics. In this report, we introduce a non-contact self-injectionlocked radar (SIL Radar Technology INC., Kaohsiung, Taiwan). The SIL Oscillator's output signal is received and demodulated by a remote frequency discriminator to obtain the pulse rate information. [3] It can provide the information for vital signs and large body movements of the patient. This instrument has been used on COVID-19 patients as an auxiliary monitor system in the isolation ward. The non-contact wireless sensor has been fixed on the ceiling of the ward. It detects and records the vital signs of the patient every five seconds automatically without physical contacts between the patient and healthcare staff. There have been several engineering research articles of the device presented by the inventors. The technologies of self-injection-locked radar and infrared light are used in non-contact detection of vital signs, included body temperature, heart rate, respiratory rate and body positioning [3] [4] [5] [6] [7] . As more information is collected, the software of this device is able to conduct an autocalibration to extract the displacement information, which enhances the measurement accuracy of body temperature, heart rate and respiratory rate. [5] We have collected and compared data between the radar record with the nurse's handover record of two patients, one recorded for 13 days and the other recorded for 5 days. The P value by Fisher's exact test were 0.139 (temperature, P > 0.05) and 0.292 (heart beat rate, P > 0.05) respectively. In addition, the device can detect the human face and body movement to identify actual positions of the patient, such as lying on the bed or falling down on the floor in the ward. [8] The device has performed aforementioned function via remote wireless controlling system automatically, and 24 h a day uninterruptedly to ensure the comfort and privacy of the patient. During the COVID-19 pandemic, the emotional stress of the healthcare staff in the isolation ward is enormous. Contactless assessment of the important physiological parameters can reduce the risk of transmission of COVID-19 virus, and also boost the morale of the team members. The camera based vital sign sensors have been developed for the past 20 years. The majority of these contactless devices are infrared thermography with a Red-Green-Blue (RGB) digital camera. The applications of these sensors are monitoring of neonates in neonatal intensive care units, monitoring of heart rate during regional anesthesia, during dialysis and in the post-anesthesia care units. [9] Since the RGB camera records the facial features of the patient, there may be violations of privacy. Due to the same issue, the device can't be installed in the toilet or shower room. On the other hand, the selfinjection-locked radar uses the wideband oscillators and extracts accurate vital signs from the received Doppler-shifted signal. There is no high-resolution image captured, and the privacy issue is minimized. (Fig. 1) . In our hospital, we have setup a self-injection-locked radar on the ceiling of the ward and its bathroom to monitor patient's vital signs. (Fig. 2) The device has been used to collect the heart rate and body temperature of the isolated patient from COVID-19. The data is consistent with the nursing handover record. The P value by Fisher's exact test are temperature, P > 0.05 and heart rate, P > 0.05 respectively. There is no statistics difference between these two sets of data. For patients in the isolation ward, the healthcare staff has to care them under PPE. However, in the report of Wang et al., the virus nucleic acid can be tested in multiple surface areas in the patient's room. [10] Therefore, utilizing the contactless radar technology allows the healthcare staff to check the heart rate and temperature of the patient from the nursing station (a clean zone) anytime. The nursing staffs no longer need to rush into the rooms to check the patients' vital signs if patients fall asleep. The continuously heart rate data can help medical staffs to rule out bradycardia situation of the patient. This can decrease the infection and transmission risk for the healthcare staff. Furthermore, the device can detect the actual position of isolated patients via sensing movements of the human face and body. Since cough and shortness of breath are very important symptoms of COVID-19, we also could use the selfinjection-locked radar to detect the real-time movement of cough and any respiratory movement. This function can save time for the healthcare staff since there is no need to physically check on patients frequently. Another benefit is the reduced waste of PPE. The wireless feature will also provide another advantage for long period of isolation; the patient won't be "cabled" with the EKG wires. Patients under long-term isolation normally suffer from uncomfortable mental stress. The wireless device can provide comfort and privacy for them. The device is programmed with Artificial Intelligence (AI) self-learning function. This function can detect the abnormal physical data trend, such as the pause or deceleration of respiratory rate. As aforementioned advantages and features, we are here to share the experiences and extend the usage of this device for COVID-19 patients under isolation. This is the first report about the application experience of this equipment. Therefore we attempted to share the experience and try to apply this equipment in COVID-19 patients in future to offer the more reliable and safe policy. Fig. 1 The thermography without high resolution image of patient can protect the privacy of the patient. The heart rate and respiratory rate are listed on the right side Fig. 2 One self-injection-locked radar locates on the ceiling of the water closet to monitor patient vital sign in this private area Intensive Care Management of Coronavirus Disease 2019 (COVID-19): Challenges and Recommendations Contamination: a comparison of 2 personal protective systems Wrist Pulse Rate Monitor Using Self-Injection-Locked Radar Technology. Biosensors (Basel) An injectionand Frequency-Locked Loop for Reducing phase noise of wideband oscillators Single Self-Injection-Locked Radar With Two Antennas for Monitoring Vital Signs With Large Body Movement Cancellation Monitoring Displacement by a Quadrature Self-Injection-Locked Radar With Measurement-and Differential-Based Offset Calibration Methods Detection of vital signs for multiple subjects by using self-injection-locked radar and mutually injection-locked beam scanning array Displacement monitoring system based on a quadrature self-injection-locked radar technology A Broader Look: Camera-Based Vital Sign Environmental virus surveillance in the isolation ward of COVID-19 Acknowledgements The authors thank Peggy Tsai for English editing. Authors' contributions CYT and SSL are major contributor in writing the manuscript. HCF, NCC and YCC analyzed and interpreted the patient data. All authors read and approved the final manuscript. Ethics approval and consent to participate: not applicable.Consent for publication not applicable. The authors declare that they have no competing interests.