Research on the Application of Novel Wearable Devices for Physiological Monitoring During Manned Centrifuge Training

Objective: The manned centrifuge is currently the most effective means of simulating real loads on the ground. However, due to factors such as centrifuge training and severe physical conditions, real-time monitoring of physiological indicators during manned centrifuge tests remains immature. In recent years, with the innovative development of new wearable physiological monitoring devices, an increasing number of wearable devices have been utilized in scientific research, healthcare, and other fields. Studies have reported their application in physiological indicator detection during manned centrifuge training. The new wearable wireless device, BioHarness 3.0 (manufactured by Zephyr Technology Corporation, USA), is a lightweight device with an internal accelerometer, demonstrating high reliability and effectiveness. Therefore, this study aims to use the new wearable wireless device, BioHarness 3.0, to monitor heart rate and respiration in subjects during manned centrifuge tests, and to explore the stability of the device by comparing and analyzing changes in respiratory frequency and heart rate among flight personnel under different load conditions.Methods: Twelve flight personnel underwent training on the manned centrifuge in both Gradual Onset Rate (GOR) and Rapid Onset Rate (ROR) modes. The new wearable device was used to record relaxation endurance (GOR1), anti-G straining endurance (GOR2), and ear pulse, subjective complaints, and training completion status under 8G, 6G, and 3.5G load conditions in the Gradual Onset Rate mode. Physiological monitoring devices were worn during acceleration exposure to record the flight personnel's respiration and heart rate. Results: All 12 flight personnel completed the manned centrifuge tests. Using wearable physiological monitoring devices, respiratory waveforms and heart rate signals were collected from all 12 subjects in the Gradual Onset Rate mode. In the Rapid Onset Rate mode, respiratory data were lost in 2 cases under medium loads and 1 case under high loads, with 2 cases of heart rate data loss also noted. Analysis of the data results revealed that compared to baseline respiratory frequency and heart rate, both respiratory frequency and heart rate significantly increased during GOR1 and GOR2, but there was no significant difference in respiratory frequency between GOR1 and GOR2. In the Rapid Onset Rate mode, the average heart rates of subjects under low, medium, and high loads were 129.30 ±21.18 beats/min, 139.42±18.70 beats/min, and 157.49±16.25 beats/min, respectively, while the average respiratory frequencies were 20.29 ± 4.20, 26.32 ± 3.99 breaths/min, and 25.04 ± 3.22 breaths/min, respectively. The average heart rate and respiratory frequency of the low-load group were significantly lower than those of the medium- and high-load groups, but there was no significant difference in heart rate between the medium-and high-load groups. Conclusion: The new wearable device technology can be used for physiological indicator detection in manned centrifuge tests. Additionally, it was found that subjects' heart rates increased with increasing load under Gradual Onset Rate conditions, but heart rate levels under medium and high loads in the Rapid Onset Rate mode were related to subjects' experience and condition. Subjects' respiratory frequencies increased with increasing load under Gradual Onset Rate conditions, while anti-G breathing are too fast under medium and high loads in the Rapid Onset Rate mode.