Biomedical subjects

Tianfu Wang

Publications and source records attributed to Tianfu Wang.

15 recordsLinked to original sources

PubMed2006

A cross-national study of subjective sexual well-being among older women and men: findings from the Global Study of Sexual Attitudes and Behaviors.

Subjective sexual well-being refers to the cognitive and emotional evaluation of an individual's sexuality. This study examined subjective sexual well-being, explored its various aspects, examined predictors across different cultures, and investigated its possible associations with overall happiness and selected correlates, including sexual dysfunction. Data were drawn from the Global Study of Sexual Attitudes and Behaviors, a survey of 27,500 men and women aged 40-80 years in 29 countries. The cross-national variation of four aspects of sexual well-being (the emotional and physical satisfaction of sexual relationships, satisfaction with sexual health or function, and the importance of sex in one's life) was explored using cluster analysis, and relationships among sexual well-being, general happiness, and various correlates were examined using ordinary least squares regression and ordered logistic regression. Results from the cluster analysis identified three clusters: a gender-equal regime and two male-centered regimes. Despite this cultural variation, the predictors of subjective sexual well-being were found to be largely consistent across world regions.

Adult↗

PubMed2006

[A method based on image processing and analyzing technology for estimating the activity of mesenchymal stem cells].

Cell culture is one of the usual methods for studying living cell and tissue, the method presented in this paper is based on image processing and analyzing technology for activity estimation of mesenchymal stem cells (MSCs). The existing activity estimation methods are costly, complex and invasive. In this method, thresholding is used to preprocess image and to separate out the growth hallow. Then the area is calculated by counting the pixels of the growth hallow. The changes of the activity estimated by this method are similar to those by corresponding cellular experiments. Compared with the existing methods in biology, medicine or medical cellular science, this method is easier, faster, cost-effective and non-invasive. The proposed method has been proved to be efficient by primary experiments of MSCs.

Animals↗

PubMed2006

[Fast edge extraction for ultrasound image of breast tumor based on fuzzy number].

An accurate edge extraction method for the ultrasound breast tumor image is useful for classifying tumors as benign or malignant. This paper refers to a fast technique to extract edge of breast tumor from ultrasound image. This method uses the triangular fuzzy number to build up a fuzzy number plane whose basic unit is the marching square. It is possible to visualize at once the results obtained using different presumption levels. Experiments of benign and malignant breast tumor in ultrasound images have shown that our method can extract the breast tumor edge faster than many conventional methods can do separately, and the results are reliable and credible. Our experiments demonstrate that it can be efficiently used to extract the edge of breast tumor from the ultrasound image.

Breast Neoplasms↗

PubMed2006

[Computer-aided diagnosis of fatty liver based on ultrasonic images].

This study aims to provide a computer-aided method for the diagnosis of fatty liver by B-scan ultrasonic imaging. Fatty liver is referred to the infiltration of triglycerides and other fats of the liver cells, which affected the texture of liver tissue. In this paper, some features including mean intensity ratio, as well as angular second moment, entropy and inverse differential moment of gray level co-occurrence matrix were extracted from B-scan ultrasonic liver images. Feature vectors which indicated two classes of images were created with the four features. Then we used kappa-means clustering algorithm, self-organized feature mapping (SOFM) artificial neural network and back-propagation (BP) artificial neural network to classify these vectors. The accuracy rate of kappa-means clustering algorithm was 100% for normal liver and 63.6% for fatty liver. The results of SOFM neural network showed that the accuracy rate was 84.8% for normal liver and 90.9% for fatty liver. The accuracy rate of neural network was 100% both for normal liver and fatty liver. This technology could detect the characteristics of B-scan images of normal liver and fatty liver more accurately. It could greatly improve the accuracy of the diagnosis of fatty liver.

Diagnosis, Differential↗

PubMed2006

[Review of nonlinear filters for medical ultrasonic images].

Ultrasound medical imaging has been widely applied in clinic diagnoses because of its real-time, non-invasiveness and convenience. However, it suffers from severe speckle noises. Until now, a lot of filtering algorithms have been proposed, but none of them is satisfactory. In this paper, four nonlinear filter methods, based on median filter, wavelet decomposition and anisotropic diffusion, are systematically reviewed. Finally, the prospect of the nonlinear filtering method is discussed.

Algorithms↗

PubMed2006

[The recognition of breast tumor based on ultrasonic image contour features].

The purpose of this article is to evaluate the role of quantitative margin features in the computer-aided diagnosis of malignant and benign solid breast masses using sonographic imaging. The tumour was seperated by the expert. Three contour features circurity (C), area ratio (A) and length width ratio (LWR) was caculated from the tumour contour. Then back-propagation (BP) neural network with contour features was used to classify tumors into benign and malignant. Results from 119 ultrasonic images have been applied in this experiment. BP neural network yielded the following results: 89.7% and 73.5% respectively. The methods applied in this paper are helpful to raise the correctance of breast cancer diagnosis.

Breast Neoplasms↗

PubMed2005

[Dynamic three-dimensional reconstruction of tissue Doppler ultrasound heart images].

Traditional 3D ultrasound reconstruction system can just depict 3D anatomical structure, so it is very difficult to give an accurate assessment of the functionality of the heart. In this study, a dynamic 3D reconstruction method of tissue Doppler ultrasound heart images is set up based on the combination of 3D reconstruction and tissue Doppler imaging technique. Dynamic 3D acceleration field of heart movement is reconstructed to supply a new approach of accurate assessment of functionality of the heart. The key problem of vector interpolation and fusion imaging in the process of acceleration vector field reconstruction is solved. The 3D acceleration field of heart movement and anatomical structure is reconstructed separately from the original tissue Doppler acceleration images and showed in the same field. The experimental results testified that the 3D space relationship of acceleration and anatomical structure is correct and this method can supply more information for the assessment of heart functionality.

Echocardiography, Doppler↗

PubMed2005

[Estimation of fetal weight on the basis of neural network].

The ultrasonic estimation of fetal weight at delivery is of important prognostic significance in obstetrical practice. The convertional regression formulas used for estimating fetal weight have the disadvantage of less reliability. In this study, we used the back propagation neural network (BP) to estimate Fetal Weight. Some input variables were adopted in constructing the BP model: biparietal diameter (BPD), cerebellum transverse diameter (TCD), abdominal circumference (AC), liver length (LL), femur length (FL), fetal thigh soft tissue thickness (FSTT), and gestational age (GA). The fetal weights of 109 singleton fetuses were estimated. In the training group and validation group, coincidence rates were 89.77% and 76.19% respectively. The results show that the estimation based on neural network is more accurate than that by regression method. GA, its unit is not week but day in our formulas, is very valuable in combination with other ultrasonic parameters on estimation.

Anthropometry↗

PubMed2005

[Recommendations for mitral regurgtitation with Doppler echocardiography].

Mitral regurgitation is one of the most serious heart diseases. With the development of up-to-date medical techniques, the ratio of successful operations in valvular repair and valvular replacement has been largely improved. Examinations before operation become extremely crucial. Accurate method is required in assessing the degree of mitral regurgitation to set down the corresponding treatment method. This paper reviews the evaluation methods of mitral valvular regurgitation provided in these years and presents comments on the application areas as well as the merits and disadvantages of those methods. Finally, the prospect of the method based on three-dimensional Doppler ultrasonographic imaging on mitral regurgitation is discussed.

Echocardiography, Doppler, Color↗

PubMed2004

Intimate partner violence in China: national prevalence, risk factors and associated health problems.

CONTEXT: Intimate partner violence has been studied in many developed and developing countries. China remains one of the few large societies for which the prevalence and correlates of intimate partner violence are unknown. METHODS: Data from a nationally representative sample of women and men aged 20-64 with a spouse or other steady partner provide estimates of intimate partner violence in China. Binomial and multinomial logistic regression analyses adjusted for sample design examine risk factors and negative outcomes associated with partner violence. RESULTS: Altogether, 34% of women and 18% of men had ever been hit during their current relationship; the prevalence of hitting resulting in bleeding, bruises, swelling, or severe pain and injuries was 12% for women and 5% for men. Significant risk factors for partner violence included sexual jealousy, patriarchal beliefs, low female contribution to household income, low male socioeconomic status, alcohol consumption and residence in regions other than the South and Southeast. Severe hitting was a significant risk factor for self-reported adverse general and sexual health outcomes, including sexual dysfunction, sexual dissatisfaction and unwanted sex. CONCLUSIONS: As in other societies, intimate partner violence in China is common and is correlated with adverse general and sexual health outcomes.

Adult↗

PubMed2004

[Axis registration and image interpolation of rotary scanning echocardiogram].

The object of this study was to work at accurate axis registration and interpolation methods for multi-dimension reconstruction of rotary scanning ultrasonic medical images. At first, time-field curves of the images' axes were analyzed according to their characteristic points and the axial direction registration was realized. Similar matrix was used to find registration pixels line near the axes of two images. Auto-correlation function and Fourier spectrum were used to evaluate the effects of axes registration. Second, an interpolation method was studied for the special space distribution of rotary scanning images. Results of experiments indicate that the axes registration and interpolation methods were suitable to rotary scanning medical images. The quality of reconstruction can be greatly improved by registration-based interpolation methods.

Algorithms↗

PubMed2004

[Fast volume rendering of echocardiogram with shear-warp algorithm].

Shear-warp is a volume rendering technology based on object-order. It has the characteristics of high speed and high image quality by comparison with the conventional visualization technology. The authors introduced the principle of this algorithm and applied it to the visualization of 3-D data obtained by interpolating rotary scanning echocardiogram. The 3-D reconstruction of the echocardiogram was efficiently completed with high image quality. This algorithm has a prospective application in medical image visualization.

Adult↗

PubMed2003

Population-based study of chlamydial infection in China: a hidden epidemic.

CONTEXT: Sexually transmitted diseases are increasing rapidly in China. Surveillance data imperfectly indicate current prevalence and risk factors. OBJECTIVES: To estimate the prevalence of genital chlamydial and gonococcal infections and to describe patterns of infection by subgroup and behavioral patterns. DESIGN, SETTING, AND PARTICIPANTS: A national stratified probability sample of 3426 Chinese individuals (1738 women and 1688 men) aged 20 to 64 years, who were interviewed between August 1999 and August 2000, completed a computer-administered survey, and provided a urine specimen (69% total participation rate). MAIN OUTCOME MEASURE: Positive test result for chlamydial or gonococcal infections. RESULTS: The overall prevalence per 100 population of chlamydial infection was 2.6 (95% confidence interval [CI], 1.6-4.1) for women and 2.1 (95% CI, 1.3-3.3) for men. For gonococcal infection, the overall prevalence per 100 population was 0.08 (95% CI, 0.02-0.4) for women and 0.02 (95% CI, 0.005-0.1) for men. Risk factors for chlamydial infection among men aged 20 to 44 years were unprotected sex with a commercial sex worker (odds ratio [OR], 8.24; 95% CI, 3.51-19.35), less education (OR, 7.20; 95% CI, 2.31-22.37), and recent sex with their spouse or other steady partner (OR, 7.73; 95% CI, 2.70-22.10). Among women aged 20 to 44 years, risk factors for chlamydial infection were having less education (OR, 2.82; 95% CI, 1.01-7.91) and living in a city (OR, 3.46; 95% CI, 1.67-7.18) or along the southern coast (OR, 2.16; 95% CI, 1.29-3.63) and having a spouse or other steady sexual partner who earned a high income (OR, 2.85; 95% CI, 1.11-7.29), who socialized often (OR, 2.79; 95% CI, 1.08-7.19), or who traveled less than 1 week per year (OR, 5.40; 95% CI, 1.44-20.3). CONCLUSIONS: The prevalence of chlamydial infection in China is substantial. The patterns of infection suggest potential avenues for intervention.

Adult↗

PubMed2003

[On the correlation between the texture of contrast agent ultrasonic image and the intracardiac pressure].

Based on the application of box-counting fractal model to the texture analysis of ultrasonic image after intravenous injection of Levovist acoustics contrast agent in a dog, this paper presents a method to calculate the fractal dimension(D) and assistant characteristic (C(L)) of the ultrasonic images of left ventricle. It was found that the D and C(L) changed regularly in the continued cardiac cycles, that is, the maximum value of D appears during diastasis, the minimum value appears during end-systole; as the ventricular systole begins, D changes from maximum to smallness, and as the diastole begins, D changes from smallness to maximum; the maximum value of C(L) appears around end-systole, the minimum value appears around diastasis; from the start of left ventricular systole to end-systole, C(l) shows a tendency to change from smallness to maximum, and from the start of diastole to diastasis, it shows a tendency to change from maximum to smallness. The changes of D and C(L) are very similar to the changes of left ventricular pressure. It is thus evident that there is correlation between the fractal texture characteristics of the contrast agent ultrasonic images and the changes of intracardiac pressure. The results demonstrate that it is possible to measure the intracardiac pressure noninvasively.

Algorithms↗

PubMed2003

[A review of interpolation in multi-dimensional reconstruction of medical images].

Image interpolation techniques were widely applied in medical imaging for image generation and post processing. Firstly, traditional interpolation methods were listed out in the details of shape-based interpolation and dynamic elastic registration interpolation. Secondly, the characteristics, development and problems in interpolation of rotary scanning ultrasonic cardiac images were analyzed. The relation between interpolation and registration was stated. The analysis indicated that excellent methods in rotary scanning interpolation should be registration-based methods. At last, several evaluation methods about images interpolation were discussed.

Algorithms↗