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991.
992.
Jinao Zhang Yongmin Zhong Chengfan Gu 《International Journal on Interactive Design and Manufacturing》2018,12(3):903-918
Real-time modelling of force interaction with soft tissues is of great importance for interactive surgical simulation. This paper presents a new ChainMail algorithm for real-time modelling of soft tissue deformation under force interaction. Unlike traditional ChainMails using a box-shaped bounding region, the proposed method defines an ellipsoid-shaped bounding region according to the concept of principal strains in continuum mechanics to control the movement of chain elements. Based on this ellipsoid-shaped bounding region, new position adjustment rules are developed and further integrated with temporal-domain model dynamics for dynamic simulation of soft tissue deformation. Haptic interaction with soft tissues is achieved via force input, soft tissue deformation, and force feedback. Experimental results demonstrate that the proposed ChainMail can simulate soft tissue mechanical behaviours, accommodate isotropic and homogeneous, anisotropic and heterogeneous materials, and handle large deformation. The proposed ChainMail also requires only small computational time, capable of achieving real-time computational performance. 相似文献
993.
José Negrillo-Cárdenas Antonio J. Rueda-Ruiz Carlos J. Ogayar-Anguita Rafael Lomas-Vega Rafael J. Segura-Sánchez 《Journal of medical systems》2018,42(7):124
The Subjective Visual Vertical (SVV) is a common test for evaluating the perception of verticality. Altered verticality has been connected with disorders in the otolithic, visual or proprioceptive systems, caused by stroke, Parkinson’s disease or multiple sclerosis, among others. Currently, this test is carried out using a variety of specific, mostly homemade apparatuses that include moving planes, buckets, hemispheric domes or a line projected in a screen. Our aim is to develop a flexible, inexpensive, user-friendly and easily extensible system based on virtual reality for the measurement of the SVV and several related visual diagnostic tests, and validate it through an experimental evaluation. Two different hardware configurations were tested with 50 healthy volunteers in a controlled environment; 28 of them were males and 22 females, with ages ranging from 18 to 49 years, being 23 the average age. The Intraclass Correlation Coefficient (ICC) was computed in each device. In addition, a usability survey was conducted. ICC?=?0.85 in the first configuration (CI?=?0.75–0.92), ICC?=?0.76 in the second configuration (CI?=?0.61–0.87), both with 95% of confidence, which means a substantial reliability. Moreover, 92.2% of subjects rated the usability of the system as “very good”. Our evaluation showed that the proposed system is suitable for the measurement of SVV in healthy subjects. The next step is to perform a more elaborated experimentation on patients and compare the results with the measurements obtained from traditional methods. 相似文献
994.
HIV testing is the gateway to biomedical means of prevention and treatment. Identifying predictors of HIV testing is important to inform future preventive interventions. Of 444 men who have sex with men without known HIV infection enrolled in a study in Hong Kong, 64% had ever been HIV-tested. Testers were generally older, better educated, had a higher monthly income, and more likely self-identified as gay. Testers often used Internet and frequented saunas for sex networking, compared with non-testers attending bars, massage centres and public toilets. HIV testing habit also varied with the profile of body image type and preferred type in sex networking. Higher acceptance of pre-exposure prophylaxis (PrEP) was observed among testers. Overall, socioeconomic status played an important role in both HIV testing and access to PrEP. Interventions targeting sex networking venues and alternative means of testing provision are needed to increase coverage of HIV testing. 相似文献
995.
996.
Stefano Omboni Igor N. Posokhov Yulia V. Kotovskaya Athanase D. Protogerou Jacques Blacher 《Current hypertension reports》2016,18(10):72
The predictive value of vascular biomarkers such as pulse wave velocity (PWV), central arterial pressure (CAP), and augmentation index (AIx), obtained through pulse wave analysis (PWA) in resting conditions, has been documented in a variety of patient groups and populations. This allowed to make appropriate recommendations in clinical practice guidelines of several scientific societies. Due to advances in technologies, largely operator-independent methods are currently available for estimating vascular biomarkers also in ambulatory conditions, over the 24 h. According to the acceptable accuracy and reproducibility of 24-h ambulatory PWA, it appears to be a promising tool for evaluating vascular biomarkers in daily life conditions. This approach may provide an opportunity to further improve the early cardiovascular screening in subjects at risk. However, concerning the clinical use of PWA over the 24 h in ambulatory conditions at the moment, there is no sufficient evidence to support its routine clinical use. In particular, long-term outcome studies are needed to show the predictive value of 24-h PWV, CAP, and AIx values, provided by these devices, over and beyond peripheral blood pressure, and to answer the many technical and clinical questions still open. To this regard, the VASOTENS Registry, an international observational prospective study recently started, will help providing answers on a large sample of hypertensive patients recruited worldwide. 相似文献
997.
Esophageal intramural pseudodiverticulosis (EIP) is a rare disorder of unknown etiology. On histopathology, it is characterized by dilation of the submucosal esophageal glands. The main presenting symptom is dysphagia to solid foods. Most patients diagnosed with EIP also have a history of diabetes mellitus, gastroesophageal reflux disease, esophageal candidiasis, or chronic alcohol and nicotine abuse. Yet, the exact pathophysiologic mechanism still remains unclear. The most frequent complication, occurring in 80 % of the patients, is esophageal stricture. The mainstay of therapy is directed towards symptom relief with administration of proton pump inhibitors (PPIs) combined with antifungals and/or endoscopic dilations, if necessary. We report a case of a 69-year-old man who presented with a 9-month history of progressive dysphagia and a 25 kg-weight loss, with typical endoscopic findings of EIP and successful response to medical therapy with oral antifungals alone. 相似文献
998.
999.
1000.
Xinning Wang Yuchun Yan Fengqi Wu Gaixiu Su Shengnan Li Xinyu Yuan Jianming Lai Zhixuan Zhou 《Clinical rheumatology》2018,37(1):145-149
The purpose of this study is to summarize the manifestations, diagnosis, differential diagnosis, and treatment of childhood brucellosis in non-epidemic areas of China. A retrospective review of 16 admitted children patients with brucella’s disease who were diagnosed of brucellosis during the period from 2011 to 2016 was performed. Diagnostic criteria, clinical presentations, and outcomes were recorded. The most common symptom was fever. Osteoarticular involvement was found in 50% of the patients. They were infected by contacting with infected animals or consuming of unpasteurized milk or meat of sheep or goats, also. Standard agglutination test was positive in all patients and blood culture in 10 (62.5%) patients as well as medulloculture in 3 (18.8%) patients were positive. A combination of antibiotic treatment with rifampin plus cotrimoxazole showed good response and all clinical manifestations improved. Brucellosis is misdiagnosed frequently and should be considered in the differential diagnosis when patients do not respond to standard treatment. Blood culture, together with brucella serology test, is important and helpful in the diagnosis. MRI is a good method in differentiating those with symptoms of arthritis. 相似文献