1.Body volume measurement in female college students and selection of optimal regression equations in Zhejiang province
Xiaofeng JIN ; Zhiqiang CHEN ; Gengye WU ; Jun ZHAO
Chinese Journal of Tissue Engineering Research 2006;10(20):167-169
BACKGROUND: Human body is an irregular geometrical one, so it is very diffcult to measure its volume.OBJECTIVE: To establish multiple regression equations by taking body height and body mass as the independent variables and body volume as the dependent variable, calculate the body volume of female college students and select optimal regression equations.DESIGN: A single-sample univariate analysis.SETTING: Department of Physical Education of Lishui College, Department of Physical Education of Zhejiang University and Academy of police in Zhejiang. PARTICIPANTS: Eighteen female students aged 18-22 years were selected from Zhejiang Lishui College.METHODS: Both the body height and body mass indexes of the female students were measured with the nation-ratified constitutional test instrument, and the body volume index was measured with a self-made iron container with a diameter of 0.95 m and height of 1.20 m. There was a scale mark for height in the container, water was poured to a fixed height, then the student slowly immersed herself into the water completely and the height difference was recorded. Body volume (m3)=(0.95÷2)2×3.141 59×height difference. The measured data were statistically calculated. Regression equations were established by taking body height and body mass as the independent variables and body volume as the dependent variable,and the optimal regression equation was selected.MAIN OUTCOME MEASURES: The measured data of body height,body mass and body volume of female students and the calculated results of the regression equations were observed.RESULTS: The measured data of body height, body mass and body volume of 18 female students all entered into the in result analysis ① A regression equation in two unknowns for calculating body volume was established: (y)=-0.031 016+0.000 761×body mass+0.000 267×body height. ②A regression equation in one unknown for body volume and its optimal selection: The linear equation was y=0.001×body mass+0.000 8; the logarithm equation was y=0.005 1Ln (body mass)-0.15; the power equation was (y)=0.001×body mass0.9909; the exponent equation was y =0.0192×e0.0188x.and the multiple correlation coefficient R2=0.9497-0.9591, all were close to 1, indicating that the body volume predicted by models was highly correlated with the actual one (r > r0.001(18-2), P < 0.001), the predicted values of the 4 models were not different from the actual one. ③ Analyzing from the simplicity of calculation and the economic way of index measurement, Logarithm equation is the best in the 5 regression equations. ④ The body volume covered body shape, physical function and Physique.CONCLUSION: The index of body volume is one of the important indexes, which cannot be neglected in the study of Physique. Analyzing from the simplicity of calculation and the economic way of index measurement, Logarithm equation is the best.
2.Early monitoring of PtiO2, PtiCO2, pH and brain temperat ure in patients with brain injuries and the clinical significanc e
Weiping LI ; Xiaodong CAI ; Jianzhong WANG ; Gengye CHEN ; Zhongmin CHAI
Chinese Journal of Traumatology 2001;4(1):20-24
Objective: To explore the regulation of early br ain tissue metabolic changing after brain injuries and the clinical significance . Methods: There were 17 patients with brain injuries. Early dire ct monitoring of PtiO2, PtiCO2, pH and brain temperature, dynami c observation of the relation between various parameters and clinics after brai n injuries were performed. Results: Early changes of PtiO2, PtiCO2 and pH we re closely correlated with outcome. The death rate obviously increased when P tiO2 was continuously lower than 9 mm?Hg within 24 hours after injuries. Secondary brain injury prolonged and aggravated brain tissue metabolic disturban ce. When intracerebral pressure was over 30 mm?Hg PtiO2 began to de crea se. The brain temperature in brain death patients was evidently lower than axill ary temperature. Conclusions: The direct monitoring of PtiO2, PtiC O2, pH and brain temperature is safe and accurate and can find early anoxia da mage to brain tissue and provide reliable basis for clinical therapy. It ha s an instructive significance in selecting and studying a new treatment method i n brain injuries. And it can be taken as a criterion in clinical judging brain d eaths.