During long-duration space missions,astronauts face health challenges such as bone density loss,muscle atrophy,cardiovascular dysfunction,immune function suppression caused by microgravity,as well as mental health issues in a confined environment.There is an urgent need for real-time,continuous,and multi-dimensional health monitoring technologies to safeguard the health and safety of astronauts.This paper systematically reviews the technical requirements and current development status of astronaut on-orbit health monitoring,with a focus on analyzing breakthroughs in technologies such as dynamic electrocardiography,non-invasive blood pressure assessment,flexible electronic skin,and molecular probe spectroscopy.It also elaborates on how the integration of artificial intelligence and bionics technologies is propelling the monitoring system towards intelligence and autonomy,providing a reference for the medical support of astronauts during long-duration spaceflight missions.

Objective:To explore the effects of immersion hypothermia and body temperature afterdrop during rewarming on animal bodies by establishing animal body temperature afterdrop model.Methods:The mini-swine were submerged in the simulated low temperature seawater (1.0℃) from the chest down. When their body temperatures dropped to 28.0℃, they were immediately removed from the seawater and placed in the warm water of 35.0℃ for rewarming. The body temperature, electrocardiogram, and heart rate were real-time monitored. Blood samples were collected before the mini-swine entering the seawater, when being removed from the seawater, and when the ventricular fibrillation occurred as a result of body temperature afterdrop. The levels of blood glucose, platelets, blood urea nitrogen, creatinine, serum potassium, total bilirubin, lactate dehydrogenase (LDH), aspartate aminotransferase (AST), cold shock protein (CSP), and adrenaline were measured.Results:As the seawater immersion went on, the body temperatures of the mini-swine gradually decreased and their heart rates gradually increased. But the heart rates began to decrease when the body temperature dropped to an average of 35.5℃. During rewarming, the body temperature continued to drop, then began to rise from the lowest average of 25.3℃. The average body temperature afterdrop was 2.7℃. The heart rates began to rise from the lowest average of 50 beats per minute. When the body temperature rose to an average of 37.1℃, the heart rates returned to an average of 112 beats per minute. Compared with the values before seawater immersion, the blood glucose, blood urea nitrogen, creatinine, total bilirubin, serum potassium, AST, and CSP of the mini-swine were significantly increased when they were removed from the seawater, with statistically significant differences ( P<0.05). Compared with the values at the removal from seawater, when the ventricular fibrillation caused by the afterdrop occurred, the blood glucose level was significantly reduced, while the values of blood urea nitrogen, creatinine, total bilirubin, and AST were significantly increased, with statistically significant differences ( P<0.05), but the values of platelet, LDH, and adrenaline had no significant changes. Conclusion:Low temperature seawater immersion and body temperature afterdrop significantly affect heart rate, blood glucose, and liver and kidney functions, which can provide a theoretical basis for preventing and treating temperature afterdrop during rewarming in patients with hypothermia.

Objective:To explore the effects of immersion hypothermia and body temperature afterdrop during rewarming on animal bodies by establishing animal body temperature afterdrop model.Methods:The mini-swine were submerged in the simulated low temperature seawater (1.0℃) from the chest down. When their body temperatures dropped to 28.0℃, they were immediately removed from the seawater and placed in the warm water of 35.0℃ for rewarming. The body temperature, electrocardiogram, and heart rate were real-time monitored. Blood samples were collected before the mini-swine entering the seawater, when being removed from the seawater, and when the ventricular fibrillation occurred as a result of body temperature afterdrop. The levels of blood glucose, platelets, blood urea nitrogen, creatinine, serum potassium, total bilirubin, lactate dehydrogenase (LDH), aspartate aminotransferase (AST), cold shock protein (CSP), and adrenaline were measured.Results:As the seawater immersion went on, the body temperatures of the mini-swine gradually decreased and their heart rates gradually increased. But the heart rates began to decrease when the body temperature dropped to an average of 35.5℃. During rewarming, the body temperature continued to drop, then began to rise from the lowest average of 25.3℃. The average body temperature afterdrop was 2.7℃. The heart rates began to rise from the lowest average of 50 beats per minute. When the body temperature rose to an average of 37.1℃, the heart rates returned to an average of 112 beats per minute. Compared with the values before seawater immersion, the blood glucose, blood urea nitrogen, creatinine, total bilirubin, serum potassium, AST, and CSP of the mini-swine were significantly increased when they were removed from the seawater, with statistically significant differences ( P<0.05). Compared with the values at the removal from seawater, when the ventricular fibrillation caused by the afterdrop occurred, the blood glucose level was significantly reduced, while the values of blood urea nitrogen, creatinine, total bilirubin, and AST were significantly increased, with statistically significant differences ( P<0.05), but the values of platelet, LDH, and adrenaline had no significant changes. Conclusion:Low temperature seawater immersion and body temperature afterdrop significantly affect heart rate, blood glucose, and liver and kidney functions, which can provide a theoretical basis for preventing and treating temperature afterdrop during rewarming in patients with hypothermia.

Objective:To provide a reliable basis for the objective evaluation of the kinetic visual acuity (KVA) of navy pilots through a comprehensive analysis of the KVA test results among 190 navy pilots.Methods:We measured both the monocular and binocular KVA of 190 navy pilots at the Naval Medical Center with a DS-3 dynamic vision apparatus. The vision target velocity was set at 30 km/h. The hole-in-the card was also performed to examine the dominant eyes of the navy pilots.Results:The static visual acuity of all pilots tested was ≥1.0, but 6.05% of the monocular KVA and 4.74% of the binocular KVA were <1.0. There were no statistically significant differences in the binocular KVA ( P=0.07) and monocular KVA ( P=0.16) of the navy pilots of different age groups. The KVA of the left eyes was slightly higher than that those of the right eyes, but without statistical significance ( P=0.168). The KVA of the dominant eyes were slightly lower than the non-dominant eyes, but without statistical significance either ( P=0.284). The monocular KVA was significantly lower than the binocular KVA ( P<0.05). Conclusion:In the health exam for navy pilot recruitment and pilot health assessment, it is advisable for candidates/pilots to take a KVA test in addition to a static visual acuity test. The age of the examined navy pilots has no significant impact on their KVA. The monocular KVA is significantly lower than the binocular KVA. The KVA of the left eyes and the right eyes is relatively balanced, and the advantage of dominant eyes is not reflected in the KVA test.

Objective:To provide a reliable basis for the objective evaluation of the kinetic visual acuity (KVA) of navy pilots through a comprehensive analysis of the KVA test results among 190 navy pilots.Methods:We measured both the monocular and binocular KVA of 190 navy pilots at the Naval Medical Center with a DS-3 dynamic vision apparatus. The vision target velocity was set at 30 km/h. The hole-in-the card was also performed to examine the dominant eyes of the navy pilots.Results:The static visual acuity of all pilots tested was ≥1.0, but 6.05% of the monocular KVA and 4.74% of the binocular KVA were <1.0. There were no statistically significant differences in the binocular KVA ( P=0.07) and monocular KVA ( P=0.16) of the navy pilots of different age groups. The KVA of the left eyes was slightly higher than that those of the right eyes, but without statistical significance ( P=0.168). The KVA of the dominant eyes were slightly lower than the non-dominant eyes, but without statistical significance either ( P=0.284). The monocular KVA was significantly lower than the binocular KVA ( P<0.05). Conclusion:In the health exam for navy pilot recruitment and pilot health assessment, it is advisable for candidates/pilots to take a KVA test in addition to a static visual acuity test. The age of the examined navy pilots has no significant impact on their KVA. The monocular KVA is significantly lower than the binocular KVA. The KVA of the left eyes and the right eyes is relatively balanced, and the advantage of dominant eyes is not reflected in the KVA test.

Objective To study the analgesic effect of repeated hyperbaric oxygen (HBO) exposures and explore the mechanism involving neural nitric oxide synthase ( nNOS), nitric oxide ( NO) and γ-aminobutyric acid (GABA).Methods The animal pain model was established and the animals were randomly divided into the HBO group, the hyperbaric air ( HBA) group, the normobaric air (NBA) group and the normobaric oxygen ( NBO) group, and were exposed repeatedly to either HBO or air .The chamber was ventilated with 100％ O2 for 5 min, then, the chamber was pressurized to 0.35 MPa at a rate of 0.10 MPa/min.At the pressure of 0.35 MPa, the chamber was again ventilated with oxygen /air for 60 minutes, and then, was decompressed at a rate of 0.10 MPa/min.The animals were exposed in the chamber one session a day for a succession of 4 days.Analgesic effect was evaluated by abdominal contraction test , and nitrate reductase assay was used to determine the expression levels of NO and NOS in the brain tissue and the spinal cord.NOS inhibitors were given by i.c.v injection to measure the effect of NOS on the analgesic effect of HBO.The nNOS + neurons and glatamic acid decarboxylase ( GAD) positive ( GAD +) neurons in the periaqueductal gray ( PAG) were labeled by fluorescopy.Results Repeated HBO treatment induced a biphasic analgesic effect, including: (1) early analgesia which was displayed an hour after HBO exposure and lasted for about 8 hours; (2) late analgesia which was displayed one day after HBO exposure , reached peak one week later and lasted for about 3 weeks.Three hours after the termination of last HBO exposure , medication of the non-specific NOS inhibitor N′-Nitro-L-arginine-methyl ester hydrochloride ( L-NAME ) and nNOS inhibitor S-methyl-L-thiocitrulline (SMTC) could obviously inhibit early analgesic effect .L-NAME and SMTC could significantly inhibit late analgesia .One hour after HBO exposure, the levels of NO and nNOS in the brain tissue and spinal cord were considerably elevated .The late analgesic effect of HBO significantly decreased , when CGP35348 was injected in the lateral ventricle 7 days after HBO treatment.Immunofluorescence indicated that there was a co-localization between nNOS + neurons and GAD + neurons in the PAG.Conclusions Repeated 4 HBO exposures induced a double -phased analgesia.Initial analgesic effect displayed one hour after HBO treatment, involving activation of nNOS, while late analgesic effect emerged one day after HBO exposure , with the interaction between nNOS and GABA B receptors.

Objective To explore the entrainment effect of different light regimens on the circadian rhythms of peripheral blood immune cells in mice .Methods One hundred and forty-four male C57BL/6 mice were kept under the 12 h-light and 12 h-dark cycle for 4 weeks.Then, the animals were randomly divided into 3 groups.The 24 animals in group 1 were treated with the former light regimen , the 60 animals in group 2 were kept in the light regimen of phase advance 12 hours, simulating eastward flight, and another 60 animals in group 3 were kept in the light regimen of phase delay 12 hours, simulating westward flight.Peripheral blood samples of the animals in group 1 were collected respectively one day before and 21 days after changes of light regimens, and blood samples of the animals in group 2 and 3 were collected on different days (i.e.day 2, 4, 7, 14 and 21) after changes of light regimens .Peripheral blood samples were taken at 4 different timepoints in 24 hours ( i.e.9 :00, 15:00, 21 :00 and 3 :00).Detections were made in immune cells , including the numbers of leukocytes, the percentage of lymphocytes , the percentage of CD4 +lymphocytes, the percentage of CD8 +lymphocytes, as well as monocyte and granulocyte counts .Finally, the circadian rhythms of differentimmune cells were evaluated in the animals of different groups .Results The immune cells in the C57BL/6 mice displayed different circadian rhythms under the 12 h-light and 12 h-dark cycle for 4 weeks.Under the new light regimens, the circadian rhythms of immune cells were entrained .It took 2 weeks for the animals of the simulated westward flight phase delay group to entrain the circadian rhythm , while the rate of entrainment for the animals of the simulated eastward flight phase delay group was 3 weeks.Conclusions Under the 12 h-light and 12 h-dark cycle, immune cells in the peripheral blood displayed a rise and fall circadian rhythm , which might facilitate the balance of the immune system .However, under the new light regimens, the circadian rhythms of different immune cells in the peripheral blood were entrained , with the entrainment rate of immune cells in the phase delay group being faster than that of the phase advance group .

Objective To discuss the effects of ship cabin color on the identification of instrument board by the ship crew.Methods The crew instrument identification system (HYS-2000) was applied in the study.The identification ability of 10 volunteers working in the environment of 6 different color matches was detected respectively at day 1, 4, 7, 10, 13, 16, 19 and 22.TOPSIS (technique for order preference by similarity to an ideal solution) and clustering analysis were used for comprehensive analysis of the crew ability in the identification of 6 different color matches.Results The selected color environment (CE), the simulated navigation time (SNT) and the interaction between CE and SNT seemed to have no significant effects on the accuracy of instrument identification , and there was no statistical significance when comparisons were made between them.(P >0.05).However, CE, SNT and the interaction between CE and SNT had significant effects on the response time of instrument identification by the subjects , and statistical significance could be noted, when comparisons were made between them (P <0.01).Results indicated that the priority ordering by TOPSIS was CE3, CE2, CE6, CE5, CE4 and CE1, and clustering analysis showed that by superiority CE 3 and CE2 belonged to the first type, CE6 belonged to the second type, CE4 belonged to the third type and CE4, CE1 belonged to the fourth type.Conclusions The ship cabin with cold color and low saturation CE with color brightness decreasing from top to bottom had lower effects on the crew identification of the instrument board . With this reason, the best ship cabin color matching was CE3 and CE2.

Objective To study the dynamic response of the head and neck for the pilots during arrested deck landing for prevention,diagnosis and treatment of head and neck injuries.Methods The multi-rigid-body model of the pilot in driving posture was established by abstracting head and neck physiological anatomy,cervical vertebra stress characteristics and cervical muscle tension characteristics.The passive neck properties were modeled by spring-damper paralleling link.Results A head and neck dynamic response model was established by taking the arrested motion data as the input.Also,the simulation architecture,simulation process and validation methods were demonstrated.The double thread simulation process of dynamics and biomechanics were established,and the related factors that affect the dynamic response were included in the simulation process.The verification method of the simulation model was described and the factors affecting the accuracy of modeling were analyzed.Conclusions The factors affecting the reliability of simulation and the accuracy of the model are varied.Accelerating curve of head is affected not only by physiological structure of neck,initial velocity of aircraft landing,weight of plane and property of arrested device,but also by the position of arrested device and attitude of aircraft during arresting.The mathematical simulation could be a feasible tool of studying the dynamic response mechanism of head and neck in arrested deck landing.

Objective To study the analgesic effect of repeated hyperbaric oxygen (HBO) exposures and explore the mechanism involving neural nitric oxide synthase ( nNOS), nitric oxide ( NO) and γ-aminobutyric acid (GABA).Methods The animal pain model was established and the animals were randomly divided into the HBO group, the hyperbaric air ( HBA) group, the normobaric air (NBA) group and the normobaric oxygen ( NBO) group, and were exposed repeatedly to either HBO or air .The chamber was ventilated with 100％ O2 for 5 min, then, the chamber was pressurized to 0.35 MPa at a rate of 0.10 MPa/min.At the pressure of 0.35 MPa, the chamber was again ventilated with oxygen /air for 60 minutes, and then, was decompressed at a rate of 0.10 MPa/min.The animals were exposed in the chamber one session a day for a succession of 4 days.Analgesic effect was evaluated by abdominal contraction test , and nitrate reductase assay was used to determine the expression levels of NO and NOS in the brain tissue and the spinal cord.NOS inhibitors were given by i.c.v injection to measure the effect of NOS on the analgesic effect of HBO.The nNOS + neurons and glatamic acid decarboxylase ( GAD) positive ( GAD +) neurons in the periaqueductal gray ( PAG) were labeled by fluorescopy.Results Repeated HBO treatment induced a biphasic analgesic effect, including: (1) early analgesia which was displayed an hour after HBO exposure and lasted for about 8 hours; (2) late analgesia which was displayed one day after HBO exposure , reached peak one week later and lasted for about 3 weeks.Three hours after the termination of last HBO exposure , medication of the non-specific NOS inhibitor N′-Nitro-L-arginine-methyl ester hydrochloride ( L-NAME ) and nNOS inhibitor S-methyl-L-thiocitrulline (SMTC) could obviously inhibit early analgesic effect .L-NAME and SMTC could significantly inhibit late analgesia .One hour after HBO exposure, the levels of NO and nNOS in the brain tissue and spinal cord were considerably elevated .The late analgesic effect of HBO significantly decreased , when CGP35348 was injected in the lateral ventricle 7 days after HBO treatment.Immunofluorescence indicated that there was a co-localization between nNOS + neurons and GAD + neurons in the PAG.Conclusions Repeated 4 HBO exposures induced a double -phased analgesia.Initial analgesic effect displayed one hour after HBO treatment, involving activation of nNOS, while late analgesic effect emerged one day after HBO exposure , with the interaction between nNOS and GABA B receptors.