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Objective To observe the effect of excess oxygen supply for different time periods on the mitochondrial energy metabolism in alveolar epithelial type Ⅱ cells. Methods Rat RLE-6TN cells were assigned into a control group (21% O2 for 4 h) and excess oxygen supply groups (95% O2 for 1,2,3,and 4 h,res-pectively).The content of adenosine triphosphate (ATP),the activity of mitochondrial respiratory chain complex V,and the mitochondrial membrane potential were determined by luciferase assay,micro-assay,and fluorescent probe JC-1,respectively.Real-time fluorescence quantitative PCR was employed to determine the mRNA levels of NADH dehydrogenase subunit 1 (ND1),cytochrome b (Cytb),cytochrome C oxidase subunit I (COXI),and adenosine triphosphatase 6 (ATPase6) in the core subunits of mitochondrial respiratory chain complexes Ⅰ,Ⅲ,Ⅳ,and Ⅴ,respectively. Results Compared with the control group,excess oxygen supply for 1,2,3,and 4 h down-regulated the mRNA levels of ND1 (q=24.800,P<0.001;q=13.650,P<0.001;q=9.869,P<0.001;q=20.700,P<0.001),COXI (q=16.750,P<0.001;q=10.120,P<0.001;q=8.476,P<0.001;q=14.060,P<0.001),and ATPase6 (q=22.770,P<0.001;q=15.540,P<0.001;q=12.870,P<0.001;q=18.160,P<0.001).Moreover,excess oxygen supply for 1 h and 4 h decreased the ATPase activity (q=9.435,P<0.001;q=11.230,P<0.001) and ATP content (q=5.615,P=0.007;q=5.029,P=0.005).The excess oxygen supply for 2 h and 3 h did not cause significant changes in ATPase activity (q=0.156,P=0.914;q=3.197,P=0.116) and ATP content (q=0.859,P=0.557;q=1.273,P=0.652).There was no significant difference in mitochondrial membrane potential among the groups (F=0.303,P=0.869). Conclusion Short-term excess oxygen supply down-regulates the expression of the core subunits of mitochondrial respiratory chain complexes and reduces the activity of ATPase,leading to the energy metabolism disorder of alveolar epithelial type Ⅱ cells.
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Animals , Rats , Energy Metabolism , Adenosine Triphosphate , Adenosine Triphosphatases , RNA, Messenger , OxygenABSTRACT
Objective:To determine the risk factors of perioperative cerebral oxygen supply and utilization and cerebral activity in newborns with congenital heart disease(CHD).Methods:In this prospective cohort study, NIRS and amplitude integrated EEG(aEEG) performed before and after surgery were used to assess cerebral oxygen supply and utilization and cerebral activity in these newborns. Cerebral tissue oxygenation index(TOI) and fractional tissue oxygen extraction(FTOE) measured from NIRS for each patient were compared to background pattern and SWC of aEEG before and after surgery. Analysis included clinical characteristics and explore the risk factors of TOI, FTOE.Results:90 CHD newborns were obtained. Pre- and postoperative TOI were 0.56±0.05 and 0.59±0.03, both of them were lower than the average for normal newborns( P<0.05). Pre- and postoperative FTOE were 0.36±0.07 and 0.39±0.04. TOI and FTOE were significantly improved after surgery( P<0.05). There was negative correlation between the TOI improvement after surgery and SpO 2 of right upper limb( β: -0.202). Patient with Respiratory support before surgery had lower preoperative TOI levels( β: -0.879). Preoperative SpO 2 was higher, then preoperative TOI was also higher( β: 0.214). The postoperative FTOE of who had lower amplitude showed by aEEG was significantly lower( P<0.05). The postoperative TOI of who had immature SWC was lower than mature SWC( P<0.05). Delayed chest closure was a risk factor for postoperative death. Conclusion:TOI in children with CHD improved significantly after operative, especially in patient with cyanosis CHD. Preoperative TOI is positively related to SpO 2. It’s positive correlation between cerebral activity and cerebral oxygen utilization. The patient who has immature SWC showed lower cerebral oxygen supply. Monitoring cerebral activity and oxygenation may be useful in perioperative management and cerebral protection of newborns with CHD.
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Abstract Objective: To identify risk factors for Oxygen (O2) needs in pregnant and postpartum women with COVID-19. Methods: Prospective cohort involving pregnant women hospitalized with COVID-19 from April to October 2020. The oxygen need was analyzed regarding risk factors: demographic characteristics, clinical and laboratory parameters at hospital admission, and chest Computer Tomography (CT) findings. Poisson univariate analysis was used to estimate the Relative Risk (RR) and 95% Confidence Intervals. Results: 145 patients, 80 who used and 65 who did not use O2, were included. Body mass index ≥ 30, smoking, and chronic hypertension increased the risk of O2 need by 1.86 (95% CI 1.10-3.21), 1.57 (95% CI 1.16‒2.12), and 1.46 (95% CI 1.09‒1.95), respectively. Patients who were hospitalized for COVID-19 and for obstetric reasons had 8.24 (95% CI 2.8‒24.29) and 3.44 (95% CI 1.05‒11.31) times more use of O2 than those admitted for childbirth and abortion. Respiratory rate ≥ 24 breaths/min and O2 saturation < 95% presented RR for O2 requirements of 2.55 (1.82‒3.56) and 1.68 (95% CI 1.27-2.20), respectively. Ground Glass (GG) < 50% and with GG ≥ 50%, the risk of O2 use were respectively 3.41-fold and 5.33-fold higher than in patients who haven't viral pneumonia on CT. The combination of C-reactive protein ≥ 21 mg/L, hemoglobin < 11.0 g/dL, and lymphopenia < 1500 mm3 on hospital admission increased the risk of O2 use by 4.97-times. Conclusions: In obstetric patients, clinical history, laboratory, clinical and radiological parameters at admission were identified as a risk for O2 need, selecting the population with the greatest chance of worsening. HIGHLIGHTS In unvaccinated pregnant and postpartum women, any need for oxygen supply increases the risk of invasive ventilation. Obesity, smoking and chronic arterial hypertension proved to be risk factors for the use of oxygen in pregnant and postpartum women with COVID-19. The combination of C-reactive protein ≥ 21 mg/L, hemoglobin < 11.0 g/dL, and lymphopenia < 1500 mm on hospital admission and the presence of ground glass ≥ 50% in computer tomography increased the risk of O2 use by 4.97 and 5.33 times respectively in pregnant and postpartum women with COVID-19.
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In the COVID-19 outbreak, several general hospitals in Wuhan were transferred to designated hospitals. However, most of the designated hospitals had suffered from insufficient oxygen supply in different degrees. Taking a designated hospital as an example, this paper summarized the emergency management system of oxygen supply from the aspects of engineering transformation, process formulation and safety management through the PDCA cycle theory, discussed the management experience of oxygen supply under the epidemic situation, and explored the management mode of emergency normalization from the perspective of peacetime and wartime integration. The purpose was to provide reference for the management of medical oxygen supply in public health emergencies and normal operation.
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@#Photodynamic therapy, a new type of non-invasive treatment, is based on the principle that the photosensitizer excited by laser can transfer energy to oxygen, which generates cytotoxic singlet oxygen and thus induce tumor cell apoptosis or necrosis. As an oxygen-dependent therapy, the antitumor effect of photodynamic therapy is obviously limited by hypoxia environment of solid tumor tissue. Therefore, reversing and improving the hypoxia of tumor tissue can significantly enhance the efficacy of photodynamic therapy. This review focuses on the progress of tumor oxygenation strategy mediated by nano-delivery system, including direct oxygen delivery strategies, catalytic oxygen production strategies, responsive material in situ oxygen supply strategies and microorganism oxygen supply strategies, aiming to improve the antitumor effect of photodynamic therapy. It provides new ideas and new approaches for further study of oxygen-enchancing nano-delivery system for photodynamic therapy.
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Objective To evaluate the effect of desflurane-remifentanil anesthesia on balance between cerebral oxygen supply and demand during cerebral revascularization in the patients with moyamoya disease.Methods Forty patients of both sexes with moyamoya disease,aged 18-64 yr,with body mass index of 18-25 kg/m2,undergoing superficial temporal artery-middle cerebral artery anastomosis,were allocated into 2 groups using a random number table method:desflurane-remifentanil group (D group) and propofol-remifentanil group (P group),with 20 cases in each group.Anesthesia was induced by intravenously injecting etomidate 0.3 mg/kg,sufentanil 0.4-0.5 μg/kg,and cis-atracurium 0.15-0.2 mg/kg.The patients were mechanically ventilated after tracheal intubation,and the end-tidal pressure of carbon dioxide was maintained at 35-45 mmHg.Anesthesia was maintained with propofol 4-6 mg · kg-1 · h-1 (group P),4％-6％ desflurane (group D),remifentanil 0.1-0.3 μg· kg-1 · min-1,remifentanil 0.1-0.3 μg · kg-1 · min-1 and intermittent intravenous boluses of cis-atracurium,and BIS value was maintained at 40-60.At 15 min after intubation (T1),30 min after skin incision (T2),immediately after opening the dura mater (T3),immediately after vascular bypass and patency (T4),and at the end of surgery (T5),blood samples were obtained from the radial artery and internal jugular bulb for blood gas analysis,jugular venous oxygen saturation (SjvO2) was recorded,and arteriovenous blood O2 content difference (Da-jvO2) and cerebral O2 extraction rate (CERO2) were calculated.Results Compared with group P,Da-jvO2 at T3-6 and CERO2 at T4-6 were significantly decreased,and SjvO2 was increased at T4-6 in group D (P＜0.05).Compared with the value at T1,Da-jvO2 was significantly decreased,and SjvO2 was increased at T5 in group D (P＜0.05).CERO2 was significantly lower,and SjvO2 was higher at T5 than at T3 in group P (P＜0.05).Compared with the values at T4,CERO2 was significantly decreased,and SjvO2 was increased at T5 in P and D groups (P＜ 0.05).Conclusion Compared with propofol-remifentanil anesthesia,desflurane-remifentanil anesthesia can maintain the balance between cerebral oxygen supply and demand better during cerebral revascularization in the patients with moyamoya disease.
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Cardiopulmonary bypass (CPB) is often accompanied by postoperative nerve injury in children. Studies have shown that monitoring of cerebral blood flow and cerebral oxygenation during enhanced operation can help to detect the adverse events of cerebral ischemia and hypoxia in time, guide physicians to adjust perfusion parameters in time, and can significantly reduce the incidence of postoperative nerve injury and improve the prognosis of children. Transcranial doppler (TCD) can directly reflect cerebral perfusion and indirectly reflect cerebral oxygen supply and demand by monitoring cerebral blood flow velocity, and jugular blood oxygen saturation (SjbO2) and cerebral local oxygen saturation (CrSO2) directly reflect cerebral oxygen supply and demand by monitoring cerebral oxygenation in the cerebral hemisphere. Therefore, the combined monitoring of these indexes during the perioperative period of cardiac surgery in children can reflect the cerebral oxygen supply and demand in an all-round way, and prevent the ischemic and hypoxic nerve injury. The research status has been reviewed in present paper of TCD, SjbO2 and CrSO2 in monitoring cerebral oxygen supply and demand during perioperative cardiac surgery in children with CPB in order to provide evidence for the prevention of postoperative nerve injury.
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Objection To improve the central oxygen supply system at field conditions to realize rapid transport of oxygen cylinders and enhanced application of medical oxygen.Methods The modified central oxygen supply system was composed of the 40-L oxygen cylinder,triple ball valve,flowmeter,dichotomantheshos hose,disposable nasal catheter for oxygen inhalation,pressure relief valve,immovable hanger and L-shaped trolley for oxygen cylinder.The trolley was composed of a bearing frame designed according to the size of oxygen cylinder,a fixing band and two wheels,which could be used for efficient fixation and rapid transport of oxygen cylinder.Results The improved system met the requirements for materials storage,loading,deployment and withdrawal during oxygen supply,and saved manpower and space.Conclusion The improved system enhances the efficiency of medical oxygen application and the supportability of field medical unit,and thus is worthy promoting in mobile medical unit.
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The necessity of paratroopers equipped with high altitude parachuting oxygen supply devices was elaborated firstly,the selection of oxygen source,working principle and the physiological requirements of high altitude parachuting oxygen supply device were also expounded in detail.The technical indexes of high altitude parachuting oxygen supply devices produced by COBHAM and Airborne systems were mainly introduced.The present status of high altitude parachuting oxygen supply devices in China was summarized.The advantages of high altitude parachuting oxygen supply devices at abroad were analyzed,the gaps between domestic and foreign high altitude parachuting oxygen supply devices and the future development direction of them in China were proposed.In order to provide life support for paratroopers to perform special tasks such as parachuting,the following points need to be specified:more scientific researches need to be strengthened in China and the superior performance of high altitude parachuting oxygen supply devices than foreign ones should be developed as soon as possible.
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Objective To observe the influence state of asarone injection for the pulmonary surfactant proteins and oxygen supply state of newborns with pneumonia. Methods 72 newborns with pneumonia were selected as the study object, and they were randomly divided into control group (36 cases) and observation group (36 cases), the control group were treated with conventional treatment of pneumonia, the observation group were treated with asarone injection on the treatment method of control group, then the pulmonary surfactant protein indexes, oxygenation function indexes and blood gas analysis of two groups before and after the treatment were respectively detected and compared. Results The pulmonary surfactant protein indexes, oxygenation function indexes and blood gas analysis of two groups before the treatment all had no significant differences, while the pulmonary surfactant protein indexes, oxygenation function indexes and blood gas analysis of observation group at first, second and fifth day after the treatment were all significantly better than those of control group, all P<0.05, there were all significant differences. Conclusion The asarone injection can significantly improve the pulmonary surfactant proteins and oxygen supply of newborns with pneumonia, so its application value in the treatment of newborns with pneumonia is higher.
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Objective To discuss the influence of two recombinant hemoglobin (rHb1.1 and rHb2.0) and human serum albumin (HSA) on oxygen supply and demand balance in rat with coronary heart disease (CHD). Methods Male Wistar rats were randomly divided into normal control group, CHD model group, HSA treatment group, rHb1.1 treatment group and rHb2.0 treatment group, 20 rats in each group. Rat model of CHD was established by high fat diet combined with pituitrin injection. The mean arterial pressure (MAP) decreased to 40 mmHg (1 mmHg = 0.133 kPa) after femoral arterial blood was drawn from the femoral arteries, and the rats were resuscitated with 13.4% HSA, rHb1.1 and rHb2.0, respectively, at the rate of 60 mL·kg-1·h-1 (20 mL/kg). The changes of electrocardiogram (ECG) ST-segment were calculated before model reproduction and at 12 hours after the last time injection of pituitrin. MAP, heart rate (HR), superior mesenteric artery blood flow (QSMA) and arterial blood gas analysis were recorded at 0, 30, 60, 90 and 120 minutes after the administration. The blood was collected after 12-hour fasting, and serum total cholesterol (TC) and triglyceride (TG) were determined by enzymatic method. The pathological changes in cardiac tissue were observed with light microscope. Results Compared with the normal control group, the changes of ECG ST-segment and TC, TG of model group were significantly increased. Compared with the model group, rHb can significantly reduce the value of ST segment changes, and HSA has no such effect; rHb short-term infusion has no significant effect on blood lipids, but can reduce myocardial pathological changes. Compared with the normal control group, the MAP of the model group decreased significantly, the HR was increased, the QSMA was slowed down, the pH value, the residual alkali (BE), the arterial carbon dioxide partial pressure (PaCO2) and HCO3- were decreased significantly. MAP in rHb1.1 group and rHb2.0 group were significantly higher than those in HSA group. Values of MAP were significantly higher in rHb2.0 group than those in rHb1.1 group at 90 minutes and 120 minutes (mmHg: 80.9±3.3 vs. 69.4±4.9, 79.2±4.0 vs. 69.1±3.7, both P < 0.05). The HR of HSA, rHb1.1 and rHb2.0 decreased to normal in 30 minutes after administration, significantly lower than those in the model group (bpm: 534±46, 518±28, 526±37 vs. 609±52, all P < 0.05). In the rHb2.0 group, the QSMA increased significantly at 60, 90 and 120 minutes compared with the model group (qv·mL-1·min-1: 5.6±0.4 vs. 3.9±0.6, 6.2±0.6 vs. 4.1±0.4, 6.9±0.7 vs. 4.0±0.3, all P < 0.05), but there was no significant difference between the HSA group and the rHb1.1 group. The pH, BE, PaCO2 did not return to the normal level after administration of HSA; pH, PaCO2 and HCO3- in the rHb1.1 group returned to normal level at 60 minutes after administration, and BE returned to normal level at 90 minutes after administration. Each index in rHb2.0 group can restore to normal levels 30 minutes ahead of. Conclusion Recombinant hemoglobin can significantly improve the oxygen supply and demand balance of rats with CHD model, can quickly and effectively correct the hypoxic state of blood metabolic acidosis, and rHb2.0 has better effect than rHb1.1.
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This paper is to explore the feasibility of molecular sieve oxygen generator in the supply of oxygen in hospital. By introducing the different principles of oxygenation technology of pressure swing adsorption and oxygenation technology of heavy cooling, this article compared the merits of two ways in national regulations, safety, convenience, and economical efficiency. Oxygenation technology of pressure swing adsorption was more advanced, more automated and life-longer compared with cylinder oxygen supply and central oxygen supply. Molecular sieve oxygen generator is a new generation of oxygen generating equipment with a good application prospect, and can provide a better choice for hospital oxygen supply.
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Objective:Developed two kinds of oxygen conversion adapter in order to make the respirator be used rapidly in all of the hospital without changing the oxygen connecting device of respirator. Methods:Designed one double sleeve type structure with a socket and a plug on each side which was named oxygen conversion adapter. Results: The installation of oxygen conversion adapter only cost a few seconds who made the using of respirator have no obstacle. Conclusion:Oxygen conversion adapter not only solve the oxygen plug and socket mismatch problem but also saved money.
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Objective:To study a set of system for supplying oxygen monitoring and control in networking. Methods: Oxygen monitoring devices, which are laid up the entrance of clinical department, include signal monitoring and control. Electromechanical actuator consists of oxygen valve and oxygen solenoid valve;Sensor group consists of a pressure sensor, an oxygen concentration sensor and a gas flow sensor;The design circuit includes signal acquisition and data processing, communication and the master circuit board, oxygen dedicated solenoid valve control driver circuit board. Results:The center monitoring technology for oxygen supplying in hospital can monitor oxygen pressure, concentration and flow of all clinical departments. Meanwhile, the monitoring center can be timely warned when oxygen pressure and concentration are lower than normal value. If firing appeared in ward, oxygen supplying can be closed by remote automatic or manual oxygen monitoring control device. Conclusion:This monitoring system can ensure quality and security of oxygen supply, and achieve remote monitoring and alarm of oxygen supply, and improve the level of oxygen supply management.
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Objective To discuss the effect of the modified structure of oxygen equipment on oxygen inhalation effect of patients receiving oxygen therapy.Methods The structure of oxygen equipment was modified.and 80 patients who required oxygen therapy were divided into the modified group and the non-modified group according to odd and even number of hospital admission sequence randomly with 40 patients in each group.The modified group used the modified oxygen equipment,the non-modified group used traditional one.The differences of respiration,heart rate and blood oxygen saturation rate between the two groups before oxygen inhalation,30 minutes and 2 hours after oxygen were compared.Results There was no significant difference in the respiration,heart rate and blood oxygen saturation rate between the two groups.Conclusions The modified oxygen equipment doesn't affect the oxygen therapy effect of patients,besides,it avoids the problems of pollution and the complicated disinfection procedure of the structure of the humidifier bottle,fluid and breathing vessel of the traditional equipment.
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Objective As an effective means of liver function support for acute liver failure, bioartificial liver has seen great progress in recent years. However, the development of this type of device is currently hindered by limited oxygen transport to cultured hepatocytes. In this study we try to resolve this problem by supplementing the circulating medium of the bioreactor with red blood cells.Methods Freshly isolated primary porcine hepatocytes were inoculated into our newly designed bioreactor and were divided into two groups: RPMI1640 was circulated in the control group and porcine red blood cells were added into the culture medium in the experimental group. The culture media in both groups were oxygenated through extra-corporeal membrane oxygenation, and the oxygen consumption rate (OCR) in the bioreactor was measured by a blood gas analyzer. Liver-specific functions and glucose consumption were also determined. Results The OCR of the experimental group was 1.5 fold that of the control group, and the glucose consumption rate was twice that of the control group. The liver-specific functions of the experimental group were significantly higher than those of the control group in terrns of albumin secretion and urea synthesis. Conclusion Supplementing the circulating medium of the bioreactor with red blood cells can significantly improve the oxygen supply in the bioreactor, thereby enhancing the glucose consumption and liver-specific functions of hepatocytes. This method is convenient and effective, and is expected to be an effective means to resolve the problems of oxygen supply in the bioreactor.
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BACKGROUND: Near-infrared spectroscopy (NIRS) continuously measures regional cerebral oxygen saturation (rSO2) noninvasively and has been shown to detect even small changes in cerebral oxygen supply-demand balance. Although widely used, only the effect of midazolam on cerebral blood flow has been studied in humans and evidence is lacking about its effect on cerebral metabolic rate. We therefore evaluated the effect of midazolam on cerebral oxygen supply-demand balance with NIRS. METHODS: Sixty patients undergoing elective coronary artery bypass graft surgery were randomly allocated into either midazolam (n = 30) or propofol (n = 30) group. rSO2 was recorded before induction while patients were breathing room air as baseline, after pre-oxygenation with 100% oxygen, after administration of either midazolam or propofol, after completion of administration of sufentanil and after tracheal intubation. Hemodynamic variables including cardiac index and mixed venous oxygen saturation were recorded at the same time points. RESULTS: rSO2 and hemodynamic variables were similar between the groups throughout the study period. After pre-oxygenation, rSO2 significantly increased compared to baseline in each group, and did not show any additional increase after administration of either midazolam or propofol and sufentanil in both groups. CONCLUSIONS: Midazolam preserves cerebral blood flow-metabolism coupling to a similar degree to propofol as assessed by near infrared spectroscopy.
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Humans , Anesthesia , Coronary Artery Bypass , Coronary Vessels , Hemodynamics , Intubation , Midazolam , Oxygen , Propofol , Respiration , Spectroscopy, Near-Infrared , Spectrum Analysis , Sufentanil , TransplantsABSTRACT
Objective To observe the expression of peroxisome proliferator-activated receptor γ (PPARγ) in hippocampus neurons in rats after different time of neuron oxygen deprivation/oxygen supply, and to investigate the role of PPARγ in neuron ischemia reperfusion injury.Methods One day old newborn SD rats were chosen. Primary cultured hippocampus neurons were used to establish neuron ischemic reperfusion model in vitro by oxygen and glucose depriving 15 minutes and supplying again, and then the neuron structure was observed by transmission electron microscope of JEM-200EX.The expression of PPARγ mRNA and protein were detected by RT-PCR and Western blot, respectively.Results Neuron structure was damaged after neuron oxygen deprivation/oxygen supply. There was no significant difference between 0 h oxygen supply group and the control group.The expression of PPARγ was decreased both at mRNA and protein level after 6 h of oxygen supply. The difference between 6 h oxygen supply group and the control group was significant(P<0.01), which decreased with the length of reperfusion and the lowest was at 48 h after the reperfusion. The difference among the different reperfusion groups and the control group was significant(P<0.01). Conclusion PPARγ may participate in the pathological damage course of neuron ischemical reperfusion injury, and may become a new intervention target of treatment for ischemic cerebrovascular disease.
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To investigate a relationship between gender differences in recovery from skeletal muscle fatigue and muscle oxygenation, we examined whether there is a difference in oxygen supply and consumption of the working muscles after intermittent handgrip exercise between young males and females using near-infrared spectroscopy (NIRS). Healthy young subjects (25.8±3.9 years ; males, n=10 ; females, n=10) repeated static maximal voluntary contractions (MVC) with a handgrip for 5 seconds followed by 5 seconds rest for a period of 4 minutes in Study 1. The MVC force was measured before, each minute during the handgrip exercise, and 2, 5, and 10 minutes following the exercise. In Study 2, the selected 10 subjects (males, n=5 ; females, n=5) performed the same exercise and their total- and deoxy- hemoglobin/myoglobin level was measured using the venous occlusion NIRS method; and O<sub>2</sub> supply index (OSI) and O<sub>2</sub> consumption index (OCI) calculated before and after the exercise. In Study 1, females exhibited higher %MVC force at the end of the exercise and during the recovery period than males (p<0.05). In Study 2, the %OSI was significantly lower in females than in males at 5 and 10 minutes in the recovery period (p<0.05), but no significant differences were detected in %OCI. Furthermore, %MVC of the recovery period correlated with %OCI of the recovery period in females (r=0.724, p=0.015), but not in males. These findings suggest that female working muscles can convert consumed oxygen more effectively after an intermittent handgrip exercise, and therefore, be able to recover muscle force faster.
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Objective To provide the oxygen supply apparatus when the civil aviator and airforce pilot are inspected the hypoxia tolerance and altitude tolerance in the hypobaric environment.Methods Demand oxygen and contstant flow oxygen were supplied.Results The portable hypobaric oxygen supply apparatus can supply mixed oxygen below the altitude 8 000 m,and the oxygenous concentration of mixed oxygen was adjusted according to the altitude.The pure oxygen was supplied when the altitude was at 8 000～12 000 m.Conclusion The normal and emergency oxygen supply performance can fulfill the system physiological requirements.The portable hypobaric oxygen supply apparatus may be used by the persons engaging in special task on plateau also.