Automatic Control System of Oxygen Concentration in Medical Hyperbaric Oxygen Chamber Based on ZigBee / 中国医疗器械杂志

In order to effectively prevent the damage to the human body caused by abnormal oxygen concentration in the medical hyperbaric oxygen chamber, a ZigBee-based medical hyperbaric oxygen chamber oxygen concentration automatic control system is designed. The data acquisition module uses the microprocessor STM32F103C8T6 to receive the oxygen concentration data of each acquisition point, and the ZigBee of the data processing module transmits the processing results to the MSP430G2553 single-chip microcomputer at the receiving end of the slave. The MSP430G2553 single-chip microcomputer uses a self-organizing TS fuzzy neural network (SOTSFNN) and adds activation. The intensity concept realizes automatic control of the oxygen concentration in the hyperbaric oxygen chamber, and controls the buzzer to give an alarm when the oxygen concentration is lower than 19 mg/L and higher than 23 mg/L, and displays the current real-time oxygen concentration through LCD12864. The experimental results show that as the communication distance increases, the packet loss rate of the system is always lower than 5%, and the signal strength under the same communication distance is better; the system can effectively control the oxygen concentration value within the set range, and the oxygen concentration. The control accuracy is high and the stability is good.

Characterization and influencing factors of visit-to-visit blood pressure variability of the population in a northern Chinese industrial city / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Blood pressure variability (BPV) is a reliable prognostic factor for cardiovascular events. Currently there is a worldwide lack of large sample size studies in visit-to-visit BPV. Based on the Kailuan Study, we analyzed the visit-to-visit BPV of patients to investigate the range and influencing factors of BPV.</p><p><b>METHODS</b>In 11 hospitals in the Kailuan Company, 4 441 patients received routine health checkups. Physical examination measured blood pressure (BP), body height, body weight, and waist circumference, and body mass index was calculated. Blood samples were analyzed for plasma total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FBG), and high-sensitivity c-reactive protein (hs-CRP).</p><p><b>RESULTS</b>The effect of gender on systolic BPV was investigated. The average systolic BPV was 10.35 mmHg (1 mmHg = 0.133 kPa) overall, 10.54 mmHg in males and 10.06 mmHg in females. Multivariate Logistic regression analysis revealed that the age (RR = 1.022), systolic BP (SBP, RR = 1.007), LDL-C (RR = 1.098), and history of hypertension (RR = 1.273) were significant risk factors for higher systolic BPV. We found that aging (RR = 1.022), increased SBP (RR = 1.007), and a history of hypertension (RR = 1.394) were determinants of systolic BPV in males. The risk factors for systolic BPV of females were aging (RR = 1.017), increased SBP (RR = 1.009), increased LDL (RR = 1.136), and increased TG (RR = 1.157).</p><p><b>CONCLUSION</b>Our findings indicated that the systolic BPV is closely associated with age, SBP and history of hypertension.</p>

Correlation between HDL-C/TG ratio and cardiovascular risk in elderly patients with hypertension / 解放军医学杂志

Objective To investigate the correlation between HDL-C/TG ratio and cardiovascular risk in elderly patients with hypertension, in order to set up an evaluation criterion which may objectively assess the cardiovascular risk in elderly population. Methods A survey was carried out among 2011 subjects aged 60 or over, who received health examination in the General Hospital of PLA in May 2008. Hypertension was diagnosed by using the definition recommended by WHO/ISH. The subjects were divided into 4 groups (male hypertesion group, male control group, female hypertension group and female control group) according to their gender and with or without hypertension. The parameters of hematology (systolic pressure, diastolic pressure, pulse pressure and mean arterial pressure) and the indicators of lipidemia [total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)] were measured, and HDL-C/TG ratio was calculated. Logistic regression analysis was used to analyze the correlation between the indicators of lipidemia and cardiovascular risk. Results In both male and female hypertension groups, systolic pressure, diastolic pressure, pulse pressure and mean arterial pressure showed significant differences compared with those of the control groups gender-wise (P0.05). Other indicators of lipidemia showed no significant differences between hypertension group and control group. Logistic regression analysis showed that HDL-C/TG ratio was significantly correlated to the cardiovascular risk (P