The Effect of Geographical Environment Factors on the Right Ventricular Diameter Reference Value Based on the Factor Analysis

Aim: To analysis the relationship between healthy adults right ventricular diameter (RVD) and geographical factors. Location: China’s 22 provinces, municipalities and autonomous regions. Methods: Using correlation analysis the relationship between RVD and nine geographic factors, build predictive models by factor analysis. Results: There is significant correlation between RVD and geographical factors, and the annual average temperature is most relevant geographical factors, a predictive model was built by factor analysis: Ŷ = 19.46 + 0.0007072X1 + 0.001034X2 -0.05412X3 -0.001405X4 -0.0006351X5 + 0.02903X6 + 0.01243X7 -0.01033X8 + 0.03816X9 ± 0.63. Then using Kriging interpolation interpolate the geographical distribution of Chinese healthy adult right ventricular diameter reference value in ArcGIS software. Main Conclusion: If geographic factors can be derived in anywhere of China, RVD can be calculated by the model, you can also get RVD from geographical distribution.


Introduction:
For a long time, the majority of people think ventriculus dexter is attacheded on Ventriculus sinister to function ,and due to the right ventride anatomy is compicated anatomy ,indiastolic fitting in blood flow affected by respiratory cycle ,lead to its functional test is relatively difficult.So far still no any recognized quantitative evaluation method and index about ventriculus dexter, There has been insufficient In addition, geographical environment is a complicated synthesis.China is a vast country, has vagaries of climate , complicated topography.Considering the influence of environmental factors about the right ventricle diminished of the healthy adult objectivity is bigger, and maybe has different influence level ,this paper use factor analysis to studied the relationship about the RVD with geographical environment that the healthy adults in China, found some regularity and analysis in further.

Result 1 correlation analysis
Correlation analysis is to study whether there is some kind of dependence between phenomena , explored the related direction and the related degree through have dependencies on specific phenomenon, is the study of random variables of the relationship between a statistical method.
Use adults of right ventricle diminished reference value as the dependent variable, the geographical indicator on 9 charges as independent, use SPSS 18.0 statistical analysis software for correlation analysis, work out at adults right ventricle diminished reference value and single phase relationship with various geographical indicators r and p values, from this we can judged the relationship about the healthy adult right ventricle diminished reference value with geographical factors of the results in table 1.The RVD reference value increased with the increase of altitude(X1) and annual sunshine duration(X2), were positive correlation.It is decreased with the decrease of annual average temperature(X3)、 annual average relative humidity(X4) and annual precipitation(X5), were negative correlation.Thus we find that the geographical environment effects on the RVD is obvious, with the change of geographical elements, the RVD reference value of adults will also have certain changes in our country.

Factor Analysis
Factor Analysis was first put forward by a British psychologist C.E Spearman .It is a generalization of the principal component analysis, it comes from the matrix related to the study of the internal dependencies ,put some complicated relationship of variables comes a representative and hidden variable dimension reduction method of multivariate statistical analysis.
Geographical environment included climate、land、rivers、lakes、mountains、 minerals、animals and plant resources, a natural complex that is constituted a variety of natural elements, interaction between each geographic elements, connect with each other, but the impact on some physiological indexes of hard to explain with a single statement.Factor analysis can be found in a group of data is relevant and hard to explain, find a few meaningful on concept, independent to each other , and can dimension reduction, by the research within the original variable correlation matrix dependencies, put some complicated relation of the variables expressed as common factor and which only has acted to a variable of special factor linear combination.

Judging the conditions of the variable factor analysis
Premise condition is that correlations between variables about use the factor analysis, before that , judging whether factor analysis is appropriate, there are two main methods to judge the condition:① The relationship between independent variables of the computer, it has practical significance for the factor analysis if most of variables correlation coefficient absolute value is greater than 0.3.②experimentwith the statistical magnitude of KMO and Bartlett's spherical inspection to decide that is generally.believed as the effect is better when KMO﹥0.9, Effect can be more than when KMO﹥0.7, and when KMO≤0.5 then are not suitable for factor analysis.
The article selected 9 singlephase relationship between geographical indicators matrix and the appropriate measurements of KMO and Bartlett's spherical check value as follows, table 2 and table 3.
By the above two tables can be seen that the vast majority of geographical indicators of the correlation coefficient between the absolute value is greater than 0.3; and the 9 charges of geographical environment indicators KMO moderate sampling measurements for 0.633﹥0.5, Bartlett's spherical inspection for 0.000.In conclusion, for this article selected factor analysis of 9 geographical indicators is feasible.

factor extraction
Select geographic environmental indicators X1, X2, X3, X4, X5, X6, X7, X8, X9 , as an original variables ,using SPSS software extracted common factors, shown in (table 4 ,figure 1), This is the main composition analysis.That is statistical method through the dimension reduction process , make a certain correlation between the initial variables in to a set of uncorrelated indicators.With less index was used to instead and reacted more information , the processing method is mathematically linear transformation.
Statistical information table of main component including: characteristic value, the contribution rate of each principal component and accumulation contribution rate, from big to small order, and from table 4 shows that the eigenvalues of the first three factors respectively are 4.664, 2.322, 1.031, the cumulative contribution rate reached 89.067%, meet the cumulative variance contribution rate＞70% or principle of characteristic value≥1.After communality than refers to extract common factor, the proportion of the original variables are extracted respectively in the information, or variance of the original variables is determined by the common factor in proportion ,its value greater(0-1) ,indicate that more the variable can be factor suggests .shown in the table 5 below ,the nine original variable are the generality of the above 0.5, and most of the more than 0.7,It's more about extraction of three common factor is able to reflect objectively the main information of original variables.

comparison of the predicted value and the real value.
Through the above study, the article conclude that the factor analysis prediction

Discuss
According to the single correlation coefficient, the correlation is very significant to annual average temperature and annual average relative humidity with the RVD reference value of healthy adults.The correlation is significant to altitude 、annual precipitation and the annual sunshine hours with the RVD reference value is improved with the altitude and annual sunshine hours increased , it is positively correlated.The RVD reference value is lessen with the annual average temperature, annual average relative humidity and annual rainfall is reduced, it is negative correlations.The figure 4 and figure 5 respectively are Chinese altitude and annual average temperature distribution, first can be seen the trend of RVD change compared with altitude ,through compared it with the elevation of the tend of variation(Figure 4),from west to east are diminishing ,and the roughly direction are same, explanation altitude and RVD reference value is positive correlation ,the RVD increases with the increase of altitude; But comparison with the trend of annual average temperature change image(figure 5), the shape of the both are consistent ,but the colour distribution is adverse, explanation annual average temperature and RVD reference value is negative correlated ,the RVD decrease with the annual average temperature is increase.
According to the result ,it can use factor analysis model equation to calculate the adults RVD reference value in this area if got the altitude, annual sunshine duration ,annual average temperature, annual average relative humidity, annual precipitation, annual range of temperature, average wind speed, longitude and latitude of somewhere.Taking Shanghai as an example ,the altitude is 5.5m, annual sunshine duration is 1986.1 h, annual average temperature is 15.7 ℃ ,annual average relative humidity is 79%,annual precipitation is 1120 mm, annual range of temperature is 24.3 ℃ ,average wind speed is 3.8m/s,the longitude is 21.5,latitude is 31.biology, etc.The human can change the environment ,but also environment can change human body function [55] , people have different functions, cases and causes in different areas, even the body functions is changed, because the transformation of regional environment.
Such as the north are most of tough man , southerners are small and exquisite; and the northerners has cold resistance to adapt to the low temperature, southerners has heat-resisting to adapt to the high temperature.A book about a piece of "the plain question•different theory of France is appropriate" of "The yellow Emperor's internal canon of medicine"."Yellow Emperor asked: doctors to treat disease, the same disease and the treatment is different, the results are recovered, what reason is this?
Qibo answer: this is formed by geographical conditions ".This dialogue tells us ,the heavens and the earth is mutual echo, not only must pay attention to the patients themselves in clinical factors , but also should be taken into account the influence of geographical environment.
The environment have obvious regional different rules, it makes a lot of physiological characteristics also showed obvious regionality , the article explores the adults RVD relationship with geographical environment, spatial trends in income distribution diagram macro estimates in most parts of china adult RVD reference value.Geographical environment is a complex, multiple geographical indicators before and after right ventricular could have more and more deep, complex geographical environment and the RVD comprehensive role mechanism remain are research in the further.

The lack of research and prospects
When collected the RVD reference values, the amount of information is found to be limited , there is no coverage to the comprehensive , such as Hong Kong , Macao and Taiwan as well as no data in the Hainan area, the amount of data in some areas is less .This study mainly is the relationship about geographical elements and RVD reference value preliminary, hope can be collected more and more comprehensive data in the next research , real-time update , and to achieve better effect.
research on cardiac surgery effect on right ventricular function.In recent years, the importance of the function of the right rentriclular in heart disease and cardiac surgery has gradually understood.More and more research has proved the right rentricular function directly affects the function of the entire circulatory system.Right rentriclular function is very important for the prognosis of various types of cardiac surgery.Along with the advance of echocardiogram diagnostic techniques.the right rentriclular function and volume evaluation method of continuous improvement.The evaluation has been more and more attract people's attention..How can fast and accurate evaluation of the right rentriclular volume and functions have vital significance in clinical appitcation of genetic.For lack of unified standard reference index of RVD at home and abroad (The right ventricle Diminished).in the practical application of the medical diagnosis, the right ventricle diminished reference value exist differences.Many people tested the reference value about right ventride diminished in the region, and many scholars also investigated and studied the change of RVD reference value of healthy people from the plains moved to plateau.But the RVD reference value's relationship with the environment research has not been reported.
Methods 1 The RVD (The right Ventricle diminished reference value) Derive RVD by retriving literature databases, such as China National Knowledge Infrastructure ,WAN FANG DATA , Super Star Digital Library.Finally 51 cities (county) of hospital and the relevant research organization in China has been collected.There are 3594 samples of healthy adults, age range from 17 to 84,these organizations altogether are 22 provinces, cities, municipalities distributed in China ,and respecitively are Beijing ,Liaoning,Tianjin,Hebei,Henan,Tibet,Sinkiang,Anhui,Shanxi,Jiangxi,Ningxia, Qinghai,Szechwan,Chongqing,Hunan,Shanghai,Fujian,Zhejiang,Jiangsu,Yunnan,Gua ngdong.The region distribution in the large part of China,the eastern plain areas of the data are more than the western plateau region ones, so can better to reflece the geographical distribution regularity of the normal RVD reference value.RVD reference value all was determined by 2D echocardiography measurements .This article selected exclusion standard of healthy people: congenital heart disease ,clarity of rheumatic heart disease ,secondary hypertension ,patients with chronic lung disease,Heavier patients with peripheral vascular disease and symptons .High blood pressure and left heart systolic dysfunction and unstable condition.kidney failure(plasma creatinine ＞ 2.5g/l).For severe liver disease(Aspertate aminotransferase or Alt＞three times the normal) .strokepatients within 3 months .blood disease.diabetes mellitus ,Hyperthyroidism, tuberculosis and the cavity structure have an impact on disease patients.2 The selection of geographic factors Geographical factors data are derived from China meteorological science data sharing service (http://cdc.cma.gov.cn).All the geographical data of index are average of nearly 30 years.The paper selected 9 relative geographical indicators to closely connect with human body physiology.-Altitude(m),annual sunlight ratio(h)、annual temperatures(℃)、annual average relative humidity(%)、annual precipitation(mm)、 annual range of temperature(℃)、annual average wind speed(m/s)、longitude(°) and latitude(°) are represented by X1, X2, X3, X4, X5, X6, X7, X8, X9.
influence the raw data of common factors, can put the relation indexes by factors analysis divided into a class, correlation between the different classes are reduced.Therefore, this article use factor analysis method to study the relationship about 9 geographical indicators with the healthy adults RVD reference value , use the ideas of Preprints (www.preprints.org)| NOT PEER-REVIEWED | Posted: 9 November 2016 doi:10.20944/preprints201611.0053.v1

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(www.preprints.org)| NOT PEER-REVIEWED | Posted: 9 November 2016 doi:10.20944/preprints201611.0053.v1See Fig 1 again, the scree plot is on the decline, the first 3 characteristic values change quickly.The 4,5,6,7,8,9 leveled off, combing with the characteristic root curve infection point and characteristic root value, thus to extract the first three principal components instead of the original variable principal component analysis.To sum up , choose three common factors(expressed as F1,F2,F3) instead of nine geographical indicators to studies the relationship about right ventricular diameter reference value of adults and geographical environment.
figure, Chinese adults RVD reference value are regularly decrease from east to west, the reference value of southeast is smaller, the RVD reference value is higher where the Qinghai-Tibet plateau ,north part of Xinjiang、west region of Sichuan province, Gansu, Qinghai and other places of china, and the RVD reference value is lower where the east and southeast, north china plain, songnen plain and Sanjiang plain etc.
adults RVD reference value is (20.54±0.63)mm in Shanghai areas.Can found the RVD reference value in somewhere through the RVD reference space trend chart of adults.Geographical environment and human health relationship is very closely ,the factors which influence the weather and climate, hydrology, soil, physiognomy ,

Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 9 November 2016 doi:10.20944/preprints201611.0053.v1
table 6 is component score coefficient matrix, use the regression method to calculate factor score coefficient ,and can be obtained the expression about common

Table . 2 Single correlation matrix between nine geographical indicators
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Table . 3 KMO sampling measurements with moderate Bartlett's test of sphericity value
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