Objective:An isolated wireless electronic stethoscope was developed to solve the problem that doctors cannot auscultate in personal protective equipment（PPE）during the COVID-19 outbreak.Methods:The development adopted low-noise audio amplification，high-frequency sampling，high-precision analog-to-digital conversion，and stainless-steel unibody design to improve the audio quality. In order to solve the problem of difficulty in turning on the Bluetooth headsets after automatic power off when the doctors are wearing PPE，we customized the Bluetooth headsets without the setting of automatically power off.Results:The isolated wireless electronic stethoscope has been clinically applied in Huoshenshan hospital in Wuhan，GuangGu branch of Hubei Maternal and Child Healthcare Hospital，Shanghai Public Health Clinical Center and other hospitals，receiving good feedback from doctors at front line.Conclusion:The isolated wireless electronic stethoscope can meet the needs of auscultation when the doctors are wearing PPE.

Objective:An isolated wireless electronic stethoscope was developed to solve the problem that doctors cannot auscultate in personal protective equipment（PPE）during the COVID-19 outbreak.Methods:The development adopted low-noise audio amplification，high-frequency sampling，high-precision analog-to-digital conversion，and stainless-steel unibody design to improve the audio quality. In order to solve the problem of difficulty in turning on the Bluetooth headsets after automatic power off when the doctors are wearing PPE，we customized the Bluetooth headsets without the setting of automatically power off.Results:The isolated wireless electronic stethoscope has been clinically applied in Huoshenshan hospital in Wuhan，GuangGu branch of Hubei Maternal and Child Healthcare Hospital，Shanghai Public Health Clinical Center and other hospitals，receiving good feedback from doctors at front line.Conclusion:The isolated wireless electronic stethoscope can meet the needs of auscultation when the doctors are wearing PPE.

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 design an electrically-heated dry diving suit with a portable power supply for divers to keep warm in a low temperature underwater environment.Methods:To synthesize the technological solutions of waterproofing, thermal insulation, and electrical heating, to design an electrically-heated dry diving suit with a waterproof layer, a heating and thermal insulation layer, and an underwater lithium battery pack.Results:The results of both unmanned and manned testing showed that the electrically-heated dry diving suit with water tight, thermal protection with CLO value of 3.155, and electrically heating could, ensure that divers maintain their core body temperature above 35.8℃ over 5 h in (10±2)℃ underwater environments.Conclusion:The electrically-heated dry diving suit can electrically generate heat and keep divers warm underwater, prevent hypothermia of divers and maintain their normal body temperature in a high pressure and cold environment, so as to improve their underwater operation capability.

Objective:To design an electrically-heated dry diving suit with a portable power supply for divers to keep warm in a low temperature underwater environment.Methods:To synthesize the technological solutions of waterproofing, thermal insulation, and electrical heating, to design an electrically-heated dry diving suit with a waterproof layer, a heating and thermal insulation layer, and an underwater lithium battery pack.Results:The results of both unmanned and manned testing showed that the electrically-heated dry diving suit with water tight, thermal protection with CLO value of 3.155, and electrically heating could, ensure that divers maintain their core body temperature above 35.8℃ over 5 h in (10±2)℃ underwater environments.Conclusion:The electrically-heated dry diving suit can electrically generate heat and keep divers warm underwater, prevent hypothermia of divers and maintain their normal body temperature in a high pressure and cold environment, so as to improve their underwater operation capability.

Objective To develop a device which could be used for marine search and location of those overboard.Methods The marine search and location device to retrieve men overboard was chiefly based on radio direction finder and satellite positioning technology,which could transmit back data of identification and vital signs over radio.Results Simulated tests indicated that the device could work properly,and all the indices could be met.Conclusions Comprehensive application of radio direction finding,satellite positioning,monitoring of vital signs and other technology could improve the efficiency of marine search and rescue considerably.

Objective To develop a device which could be used for marine search and location of those overboard.Methods The marine search and location device to retrieve men overboard was chiefly based on radio direction finder and satellite positioning technology,which could transmit back data of identification and vital signs over radio.Results Simulated tests indicated that the device could work properly,and all the indices could be met.Conclusions Comprehensive application of radio direction finding,satellite positioning,monitoring of vital signs and other technology could improve the efficiency of marine search and rescue considerably.