Digital modeling and analysis of the applicability of backward rotation method in lumbar kyphoplasty with unilateral puncture / 中国骨伤

OBJECTIVE@#The 3D model of lumbar spine was established by using Mimics software. To observe the applicability and needling parameters of lumbar vertebral kyphoplasty with unilateral puncture by backward rotation method using simulated puncture.@*METHODS@#Twenty-four patients (12 males and 12 females) with osteoporotic thoracic fracture in the first time and no signs of lumbar misalignment and bone destruction were scanned by spiral CT on the lumbar spine. The original DICOM file was modeled in 3D with Mimics software, and the vertebral bodies were separated. After being imported into 3-matic software, the posterior wall of the vertebral body was restrained for standardized measurement. A sketch perpendicular to the mid-section of the pedicle and the posterior wall of the vertebral body was drawn. The simulated puncture was performed on the sketch. The angle and distance parameters of the range of motion of the puncture needle were recorded, and the puncture needle was recorded at the top. The crossing points of the anterior, middle and posterior zones of the tangential line of the vertebral body were located at the high extraversion angle, and the results were compared and analyzed.@*RESULTS@#All the data in the left and right sides had no significantly differences(>0.05). Data of different segments in different gender were significantly differences(<0.05). The maximal extraversion angle in lumbar spine increased gradually from (33.41±1.31) degree to (56.53±4.71) degree in males, as same as in females from(28.58±2.55) to (53.86±2.68) degree. There was no crossing point in area A, 3.3% of males and 26.67% of females in area B, rest in area C. The distribution areas on gender showed statistically significance (<0.05).@*CONCLUSIONS@#Backward rotation method can theoretically meet the requirements of puncture point for vertebral compression fracture, especially for males and lower lumbar spine. The determination of the maximum inclination angle is of guiding significance to the backward rotation method.

Study on the method of microelectrodes implantation of artificial facial nerve prosthesis in closed mouth of orbicularis oris muscle in monkeys with facial nerve paralysis / 中华口腔医学杂志

Objective@#To explore the optimal method of microelectrode implantation that can produce efficient mouth closure with microelectrode for orbicularis oris muscle (OOM) in rhesus monkeys with unilateral peripheral facial paralysis (UPFP) in order to provide basis for the research and development of artificial facial nerve prosthesis (AFNP).@*Methods@#Right lateral peripheral facial paralysis model on four healthy rhesus monkeys (two males and two femles, aged 5-6 years, weighed 2.0-3.0 kg) were prepared. AFNP electric stimulation was used to induce closed-mouth reaction of the affected OOM with a one-way rectangular pulse, 50 Hz frequency and 0.2 ms pulse width in vitro. Around the affected lateral OOM, four stimulus electrodes implantation positions were selected at the upper lip (position A), the lower lip (position B), the connection with the corner of the mouth to the ipsilateral tragus (position C), and the horizontal line of the mouth angle (position D). According to the different implantation positions of three stimulation electrodes on the stimulation side of AFNP and the results of our previous study, six groups of microelectrode implantation methods were designed. In Group A, two microelectrodes were implanted at position A and one microelectrode was implanted at position B; in Group B, one microelectrode was implanted at position A, B and C respectively; in Group C, one microelectrode was implanted at position A and two microelectrodes were implanted at position B; in Group D, one microelectrode was implanted at position A, B and D respectively; in Group E, one microelectrode was implanted at position A, C and D respectively; in Group F, one microelectrode was implanted at position B, C and D respectively. The minimum stimulating current (threshold current) required for effective mouth closure were recorded. The threshold and peak current values were compared using one-way ANOVA and LSD-t multiple comparisons.@*Results@#The microelectrodes of the AFNP stimulating side in Group E and F failed to induce a smooth mouth closure. The microelectrodes in A, B, C and D group induced smooth mouth closure. The threshold current value of OOM contraction on affected side in the Group A, B, C, and D were (1.35±0.05), (1.02±0.04), (1.40±0.04) and (1.10±0.02) mA, respectively (F=295.302, P<0.001), with the lowest value in Group B and there was significant difference between the current value in Group B and those in the other groups (all P<0.05). The peak current value of OOM contraction on affected side in the four groups were (3.95±0.02), (2.95±0.03), (3.99±0.05) and (3.51±0.01) mA, respectively (F=1 014.985, P<0.001). Group B showed the best lip-closure morphology observed with naked eyes.@*Conclusions@#When three output microelectrode of the AFNP stimulated side are separately imbedded into the upper lip, the lower lip and the connection with the corner of the mouth to the ipsilateral tragus, AFNP can sufficiently induce closed-mouth reaction. These positions are suitable as priority options microelectrodes implantation positions for the microelectrodes of the AFNP stimulated side.

Development of medical simulation training in US Armed Forces and its implications / 军事医学

Medical simulation training of US Armed Forces has formed a research , development and organization system, with the DOD as the chief investor and the CSC as the center .The main research fields are Combat Casualty Training Consortium Initiative , Medical Practice Initiative , Patient Focused Initiative and the Developer Tools Initiative . This article analyzes the organizational system ,operation mode ,development of its technology and areas of focus of medical simulation〗training in U.S.Armed Forces using intelligence investigation and intelligence analysis .We can learn from the successful experience of U.S.Armed Forces and combine it with our actual needs in our own development of medical simulation training.

Numerical simulation of hemodynamics in the carotid artery / 中国组织工程研究

BACKGROUND:To establish the real body’s artery model has its own limitations due to the diversity of different individual differences in the carotid artery and blood flow. OBJECTIVE:To study the effect of different inlet velocity profiles of the common carotid artery and three different flow ratios of internal and external carotid artery on hemodynamics of the carotid artery. METHODS:The carotid bifurcation TF-AHCB numerical model was established. Commercial software ANSYS was used to compute the flow field and calculate hematodynamic parameters, including velocity and wal shear stress. Then, their relationship with atherosclerosis was analyzed from different angles. RESULTS AND CONCLUSION:Flow ratio of internal and external carotid artery significantly influences the flow field of the simulated bifurcation of the carotid artery. Changes in the magnitude of inlet velocity cannot only alter the hematodynamic properties, but also change the range of mechanical mechanism.

Study on secure tunnel in the fixation of talar neck fracture based on digital technology / 中华骨科杂志

Objective To investigate the establishment of secure tunnel in fixation for the talar neck fracture when screws were fixed from the medial wall of talus.Methods The age of volunteers was limited from 20 to 60 years old,and the height of male volunteers was from 165 to 185 centimeters,while the female volunteers' height was from 155 to 175 centimeters.The body mass index (BMI) was less than 25.The volunteers who were not heavy manual workers or standing working for long time had no history of ankle or foot fractures,and there were no evidence of degeneration changes in ankle joints according to X-ray.At last there were 33 males in this study with an average age of 43.7 (21-59) years and an average height of 176.0 (168-184) centimeters.There were 22 females with an average age of 43.2 (22-60) years and an average height of 165.4 (158-172) centimeters.After the volunteers' ankle joints and feet were scanned by CT,the reconstructed images were stored in CD and the slice thickness was 0.75 millimeters.The SuperImageTM Orthopedics Edition1.1 software was used to display the images and perform three dimensional reconstruction.The height of talar neck and the height of tarsal canal were measured.The models that screws passing into tarsal canals were built.The maximal length and angle that screws were inserted in the middle 1/3 and in the inferior 1/3 of medial wall of talus and run along to two directions were measured.At last,the data were analyzed with SPSS 13.0 software.Results The height of talar neck and tarsal canal had no significant difference between left side and right side in the same gender.The height of male talar neck was greater than the female' s.The models of screws passing into tarsal canals was gained.The length and angle in different insert points and different directions of screw fixation were also gained.When the screws were inserted from the middle 1/ 3 of the medial wall of talus,the angle of screw fixation was much wider than that when the screws were inserted from the inferior 1/ 3 of the medial wall of talus.At last,the safe range of the length and angel of screw fixation was calculated.Conclusion Damage of the blood of talus during internal fixation should be avoided.The middle 1/3 of the medial wall of talus is the most favourable choice to the fixation.Combining the digital technology with internal fixation for talar neck fracture could promote the operation' s security and feasibility.

Advantages and disadvantages of bidirectional cavopulmonary shunt with additional pulmonary blood flow : a theoretical analysis / 中华胸心血管外科杂志

Objective The bidirectional cavopulmonary shunt (BCPS) is a major step in the staged palliation of functionally univentricular heart defects.Whether to preserve of additional pulmonary blood flow (APBF) has been a highly controversial issue.The purpose is to mathematical model and set out to determine the significa advantages and disadvantages of bidirectional cavopulmonary shunt with additional pulmonary blood flow:a theoretical analysis nce of APBF and the appropriate APBF ratio.Methods We used models of the univentricular circulation after the bidirectional cavopulmonary anastomosis with additional pulmonary blood and to computational analyze the impact of APBF on oxygen delivery,APBF flow on the CVP and SaO2.Results The influence of APBF depends on the ratio of superior vena cava flow to inferior vena cava flow ( QSVC/QIVC ).For QSVC/QIVC ＞ 0.3,APBF may be associated with decreased oxygen delivery.For QSVC/QIVC ＜ 0.3,appropriate APBF may be associated with increased oxygen delivery.A linear relationship exists between the increase of APBF and CVP,and the slope was depended on the value of pulmonary vascular resistance.Estimating APBF from CVP measurements may be a feasible method.A nonlinear relationship between the increase of APBF and oxygen saturation,and estimating APBF from SaO2 measurements may result in errors.BCPS and appropriate APBF may optimal the oxygen delivery with the increase of age and the decrease in QSVC/QIVC.For patients who accepted BCPS without APBF,there is a decreasing tendency of oxygen delivery with the increase of age and the decrease in QSVC/QIVC.For patients who suffered pulmonary arterivenous malformation,there is a more obvious decrease in oxygen delivery.ConclusionFor patients under age who has normal pulmonary vascularbed ( that is,QSVC/QVC ＞ 0.3),elimination of additional pulmonary blood flow can improve the oxygen delivery under a given cardiac output.For patients who with hypoplastic pulmonary vascular or in older patients under age,APBF is necessary to improve oxygen delivery.For patients who have to accept BCPS as the final procedure,preserving of APBF is suggested.

Visualization and analysis of flow patterns of human carotid bifurcation by computational fluid dynamics / 中华放射学杂志

Objective To investigate flow patterns at carotid bifurcation in vivo by combining computational fluid dynamics(CFD)and MR angiography imaging.Methods Seven subjects underwent contrast-enhanced MR angiography of carotid artery in Siemens 3.0 T MR.Flow patterns of the carotid artery bifurcation were calculated and visualized by combining MR vascular imaging post-processing and CFD. Results The flow patterns of the carotid bifurcations in 7 subjects were varied with different phases of a cardiac cycle.The turbulent flow and back flow occurred at bifurcation and proximal of internal carotid artery (ICA)and external carotid artery(ECA),their occurrence and conformation were varied with different phase of a cardiac cycle.The turbulent flow and back flow faded out quickly when the blood flow to the distal of ICA and ECA.Conclusion CFD combined with MR angiography can be utilized to visualize the cyclical change of flow patterns of carotid bifurcation with different phases of a cardiac cycle.