Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 5 Articles
Many preterm infants suffer from neural disorders caused by early birth\ncomplications. The detection of children with neurological risk is an important\nchallenge. The electroencephalogram is an important technique for establishing\nlong-term neurological prognosis. Within this scope, the goal of\nthis study is to propose an automatic detection of abnormal preterm babiesâ??\nelectroencephalograms (EEG). A corpus of 316 neonatal EEG recordings of\n100 infants born after less than 35 weeks of gestation were preprocessed and a\ntime series of standard deviation was computed. This time series was thresholded\nto detect Inter Burst Intervals (IBI). Temporal features were extracted\nfrom bursts and IBI. Feature selection was carried out with classification\nin one step so as to select the best combination of features in terms of\nclassification performance. Two classifiers were tested: Multiple Linear Regressions\nand Support Vector Machines (SVM). Performance was computed\nusing cross validations. Methods were validated on a corpus of 100 infants\nwith no serious brain damage. The Multiple Linear Regression method shows\nthe best results with a sensitivity of...................
Preparation of a uniform angle of walls is essential for making an ideal\nconvergence angle in fixed prosthodontics. We developed a de novo detachable\nangle-correction apparatus for dental handpiece drills that could help the ideal tooth\npreparation.\nMethods: We utilized a gyro sensor to measure the angular velocities to calculate\nthe slope of an object by integrating the values, acceleration sensor to calculate the\nslope of an object by measuring the acceleration relative to gravity, and Kalman filter\nalgorithm. Converting the angulation of the handpiece body to its drill part could be\nperformed by a specific matrix formulation set on two reference points (2° and 6°). A\nflexible printed circuit board was used to minimize the size of the device. For convergence\nangle investigation, 16 volunteers were divided randomly into two groups for\nperforming tooth preparation on a mandibular first molar resin tooth. All abutments\nwere scanned by a 3D scanner (D700®, 3Shape Co., Japan), the convergence angle\nand tooth axis deviation were analyzed by a CAD program (SolidWorks 2013®, Dassault\nSystems Co., USA) with statistical analysis by Wilcoxon signed-rank test............
Background: Sit-to-stand movements are a necessary part of daily life, and excessive\nmechanical stress on the articular cartilage has been reported to encourage the progression\nof osteoarthritis. Although a change in hip joint angle at seat-off may affect\nhip joint contact force during a sit-to-stand movement, the effect is unclear. This study\naimed to examine the effect of the hip joint angle at seat-off on the hip joint contact\nforce during a sit-to-stand movement by using a computer simulation.\nMethods: A musculoskeletal model was created for the computer simulation, and\neight muscles were attached to each lower limb. Various sit-to-stand movements\nwere generated using parameters (e.g., seat height and time from seat-off to standing\nposture) reported by previous studies. The hip joint contact force for each sit-to-stand\nmovement was calculated. Furthermore, the effect of the hip joint angle at seat-off on\nthe hip joint contact force during the sit-to-stand movement was examined. In this\nstudy, as the changes to the musculoskeletal model parameters affect the hip joint\ncontact force, a sensitivity analysis was conducted.\nResults and conclusions: The hip joint contact force during the sit-to-stand movement\nincreased approximately linearly as the hip flexion angle at the seat-off increased.\nMoreover, the normal sit-to-stand movement and the sit-to-stand movement yielding\na minimum hip joint contact force were approximately equivalent. The effect of the\nchanges to the musculoskeletal model parameters on the main findings of this study\nwas minimal. Thus, the main findings are robust and may help prevent the progression\nof hip osteoarthritis by decreasing mechanical stress, which will be explored in future\nstudies....
Soft tissue sticking on electrosurgical scalpels in minimally invasive surgery can increase\nthe difficulty of operation and easily lead to medical malpractice. It is significant to develop new\nmethods for anti-sticking of soft tissue on electrosurgical scalpels. Based on the characteristics of\nbiomimetic ultra-slippery surface, a self-lubricating slippery surface with wettability gradients on\nelectrosurgical scalpel was designed and fabricated. Non-uniformly distributed cylindrical micro\npillars, which constitute the wettability gradients, were prepared by an electrolytic etching process\nand the theoretic of the spontaneous liquid spreading process was analyzed. The silicophilic property\nof wettability gradients surface was modified by octadecyltrichlorosilane (OTS) self-assembling coat\nwith biocompatible liquid lubricant dimethyl silicone oil. The contact angle of gradientâ??s surface\nat different temperatures was measured. The transportation behaviors of both water and dimethyl\nsilicone oil on the wettability gradientâ??s surface were investigated; the results illustrate that the\nwettability gradientâ??s slippery surface can successfully self-lubricate from regions with low pillar\ndensity to regions with high pillar density, ascribed to the unbalanced Youngâ??s force. The anti-sticking\ncapability of the electrosurgical scalpel with self-lubricating slippery surface was tested. Both the\nadhesion force and adhesion mass under different cycles were calculated. The results suggest that\nthe as-prepared slippery surface has excellent anti-sticking ability associated with better durability....
Many congenital heart defects and degenerative valve diseases require replacement\nof heart valves in children and young adults. Transcatheter xenografts degenerate over time.\nTissue engineering might help to overcome this limitation by providing valves with ability for\nself-repair. A transcatheter decellularized tissue-engineered heart valve (dTEHV) was developed\nusing a polyglycolic acid (PGA) scaffold. A first prototype showed progressive regurgitation after\n6 months in-vivo due to a suboptimal design and misguided remodeling process. A new geometry\nwas developed accordingly with computational fluid dynamics (CFD) simulations and implemented\nby adding a polyether-ether-ketone (PEEK) insert to the bioreactor during cultivation. This lead to\nmore belly-shaped leaflets with higher coaptation areas for this second generation dTEHV. Valve\nfunctionality assessed via angiography, intracardiac echocardiography, and MRI proved to be much\nbetter when compared the first generation dTEHV, with preserved functionality up to 52 weeks after\nimplantation. Macroscopic findings showed no thrombi or signs of acute inflammation. For the\nsecond generation dTEHV, belly-shaped leaflets with soft and agile tissue-formation were seen after\nexplantation. No excessive leaflet shortening occurred in the second generation dTEHV. Histological\nanalysis showed complete engraftment of the dTEHV, with endothelialization of the leaflets and\nthe graft wall. Leaflets consisted of collagenous tissue and some elastic fibers. Adaptive leaflet\nremodeling was visible in all implanted second generation dTEHV, and most importantly no fusion\nbetween leaflet and wall was found. Very few remnants of the PGA scaffold were detected even\n52 weeks after implantation, with no influence on functionality. By adding a polyether-ether-ketone\n(PEEK) insert to the bioreactor construct, a new geometry of PGA-scaffold based dTEHV could be\nimplemented. This resulted in very good valve function of the implanted dTEHV over a period of\n52 weeks....
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