The impeller profile, which is one of the most important factors, determines the creation of shear stress which leads to blood hemolysis in the internal flow of centrifugal blood pump. The investigation of the internal flow field in centrifugal blood pump and the estimation of the hemolysis within different impeller profiles will provide information to improve the performance of centrifugal blood pump. The SST κ-ω with low Reynolds correction was used in our laboratory to study the internal flow fields for four kinds of impellers of centrifugal blood pump. The flow fields included distributions of pressure field, velocity field and shear stress field. In addition, a fast numerical hemolysis approximation was adopted to calculate the normalized index of hemolysis (NIH). The results indicated that the pressure field distribution in all kinds of blood pump were reasonable, but for the log spiral impeller pump, the vortex and backflow were much lower than those of the other pumps, and the high shear stress zone was just about 0.004%, and the NIH was 0.0089.
ObjectiveWe report two family and one sporadic case with dyssynergia cerebellaris myoclonica, investigate the clinical and neural electrophysiological features. MethodsThe proband and sporadic patient was examined by clinical, neuroimaging, video-EEG and synchronous electromyography. ResultsThere were 6 patients with dyssynergia cerebellaris myoclonica of the 27 family members in the first family(3 male and 3 female). There were 4 patients with dyssynergia cerebellaris myoclonica of the 20 family members in the second family(2 male and 2 female). All patiens had disproportionately myoclonus, epilepsy and progressive cerebellar ataxia. EEG showed bursts of spike-slow wave, polyspilke-slow wave distributing in the bilateral brain both in ictal and interictal period, sometimes it is especially in central, parietal and frontal area. EEG showed bursts of spike-slow wave, polyspilke-slow wave distributing in the central, parietal and frontal area in interictal period. Pathology of the skin and muscles are normal. ConclusionThe diagnosis of dyssynergia cerebellaris myoclonica was mainly based on typical clinical manifestations, brain MRI and EEG changes.Long time video EEG and synchronous EMG is important for the diagnosis. Skin and muscles pathology can be normal.