Objective The aim of the present study was to investigate the ability to perceive syllables phrases ,mono-syllabic words ,disyllabic words ,when using a CI and an HA in non -implanted ears (bimodal fitting) ,and the relationship be-tween aided thresholds in the HA ear and bimodal effectiveness .Methods Eighteen children who consistently used a bimodal fitting participated in the study .The loudness of speech in the HA ear matched that with implanted ear ,and the aided thresh-olds in the HA ear were obtained .The recognition rate of syllables phrases ,monosyllabic words ,and disyllabic words was tested under the aforementioned two modes in both the quiet and noisy backgrounds .Results The speech performance of children for monosyllabic words were 82 .67% ± 12 .23% ,83 .61% ± 12 .22% ,for disyllabic words 76 .00% ± 16 .13% ,78 .11% ± 14 .84% , for syllables phrases 60 .11% ± 17 .18% ,65 .43% ± 16 .76% ,with a CI alone or with bimodal fitting in a quiet environment ,re-spectively .In a noisy environment ,monosyllabic words were 75 .50% ± 14 .12% ,76 .83% ± 14 .15% ,and disyllabic words were 68 .22% ± 17 .15% ,77 .18% ± 16 .83% ,and syllables phrases were 49 .39% ± 19 .26% ,56 .33% ± 19 .55% .The results sug-gested that speech performance in a quiet or a noisy environment was significantly better with bimodal hearing than with a CI a-lone .All were statistically significant except the recognition rate of monosyllabic words in quiet background (P<0 .05) .Signifi-cant negative correlations were found between aided thresholds at 250 and 500 Hz ,and the bimodal advantages were noticeable for the some speeching perception .Conclusion Bimodal hearing enhances speech performance for deaf patients .The low -fre-quency residual hearing in the HA ear may play a major role in enhancing auditory and speech performance .

Objective To study the generating algorithm of personalized external fixation model based on STL file, so as to realize the fabrication of personalized external fixation through 3D scanning, model generation and 3D printing. Compared with the traditional plaster fixation, the external fixation obtained by the proposed method has the advantages of good adhesion to the external surface of the limb, good gas permeability and light weight. Methods In order to generate a personalized external fixation model, the key generating algorithms of the model were studied. The point cloud file of the residual limb was obtained by a 3D scanner, and then was converted into an STL format file. The triangular patches were processed by cutting, offsetting, triangulating and hollowing to create an external fixation model with good gas permeability and conformable surface that is fully fitted with the body surface. Finally, the external fixation was fabricated by 3D printing. Results Using the improved point offset algorithm, the problem of severe distortion of the point offset at the plane and sharp corners was solved. Using the tangent sort method, the points on the contour ring were sorted clockwise to obtain a triangular profile. The hollowing of the model was achieved by using the typical three-dimensional "cutting tool" mathematical model and the STL file space intersection method. Conclusions The improved model generating algorithm was validated based on a wrist case, and the personalized external fixed fixation model with conformable surface was obtained. It is proved that the proposed model generating algorithm is effective and practical.

3D printing technology has unique advantages and broad application prospect in biomedicine field. In recent years, cell printing, tissue printing, and organ printing technologies h have appeared successively, and drug printing and medical device printing have been realized. For complex surgical cases, surgeons and researchers have explored a surgical program that involves 3D printing technology, and completed many clinical applications including case discussions, surgical simulations and implantation surgeries. These efforts promoted the application and development of 3D printing technology in medical field. The purpose of this paper is to describe the application and research status of 3D printing technology in medical field from the aspects of medical teaching, orthopedic surgery, stomatology, bioprinting, drug printing, medical device manufacturing, etc., and put forward the prospects for future development.

ObjectiveTo systematically evaluate the safety of Tianzhi granules used in the treatment of mild-to-moderate vascular dementia. MethodA randomized， double-blind， double-simulated， positive drug/placebo parallel controlled multi-center phase Ⅳ clinical trial and an open multi-center phase Ⅳ clinical trial of Tianzhi granules in the treatment of mild-to-moderate vascular dementia were conducted. Safety data of 1 492 patients were included and analyzed according to inclusion and exclusion criteria. The main evaluation measures were the incidence rate of adverse events/adverse reactions， laboratory indicators， vital signs， and electrocardiogram （ECG） results. ResultA total of six adverse events possibly related to the test drug occurred in 520 patients of the double-blind trial， and the symptoms were all mild and recovered. The incidence of adverse events was not statistically different among Tianzhi granules， donepezil， and placebo groups. Nine adverse events possibly related to the test drug were observed in 972 patients of the open trial， and the symptoms were mild and recovered. Laboratory tests （blood routine， urine routine， liver function， kidney function， and coagulation） and vital signs were compared before treatment （baseline） and after treatment of 12 and 24 weeks， respectively. There was no statistical significance in the main indicators before and after treatment. In the double-blinded trial， there was no significant difference in safety indicators between different groups before and after treatment. The most frequent adverse reaction was gastrointestinal discomfort， with an incidence rate of 6.64‰. ConclusionAdverse reactions occasionally occur in patients using Tianzhi granules， and it is safe to use Tianzhi granules to treat mild-to-moderate vascular dementia clinically.