基于神经网络法反求耳结构弹性模量

目的通过耳结构的位移反算耳结构弹性模量。方法基于Patran软件建立耳结构有限元模型,使用Mat-lab建立计算耳结构反问题的BP神经网络。对耳结构有限元模型进行频率响应分析,得到鼓膜凸和镫骨足板的位移响应;把位移作为BP神经网络的输入、相对应的结构弹性模量作为输出,对网络进行训练。结果利用训练成熟的BP网络反算出耳结构的弹性模量,相对误差非常小。结论反算结果表明,所使用的反问题方法求解耳结构弹性模量是可行的,可为临床提供确定生物结构力学参数简捷有效的方法。     

下颌支矢状骨劈开术数字模型的建立及不同固定方式的稳定性分析

目的:建立下颌支矢状骨劈开术数字模型,探讨3种不同固定方式的应力及位移改变.方法:CT扫描数据导入三维重建软件Mimics以及Geomagic中,建立下颌骨三维实体模型,并进行矢状劈开、坚固内固定,ANSYS进行网格划分,建立三维有限元模型.边界约束后,进行双侧下颌第一磨牙咬合力(132 N)加载.结果:建立了双侧下颌支矢状骨劈开术3种不同固定方式三维有限元模型,获得术前下颌骨及矢状骨劈开后咬合力加载的应力及位移生物力学特点.结论:下颌支矢状骨劈开术倒L形固定应力分布最均匀,劈开处位移最小,与其他2种方式相比,其固定稳定性最佳.     

超声二维应变评价正常人左室扭转和径向位移的初步研究

目的应用超声二维应变技术（2DS）探讨正常左室扭转及径向位移运动特征,构建左室-扭转位移环。方法健康成人志愿者58例,取胸骨旁左室心尖和心底短轴观对各水平旋转及径向位移进行定量分析,计算左室扭转及径向位移,构建左室-扭转位移环,并记录心底部与心尖部旋转角度峰值和左室扭转角度峰值及达峰时间,收缩期及等容舒张期左室径向位移。结果正常人扭转运动主要表现为心底部顺时针旋转和心尖部逆时针旋转,心脏整体表现为心动周期内逆时针方向为主的扭转运动。左室扭转-位移环均呈＂8＂字构型。收缩期及等容舒张期左室扭转与径向位移呈线性相关。结论应用2DS技术可无创性评价正常人左室扭转及径向位移运动特征,构建左室-扭转位移环。     

Can rotatory knee laxity be predicted in isolated anterior cruciate ligament surgery?

Purpose

Despite the overall success of the surgical anterior cruciate ligament (ACL) reconstruction, some patients still present with instability symptoms even after the surgery, mainly due to the presence of associated lesions. At present, the pivot shift test has been reported to be the benchmark to assess rotatory knee laxity. The purpose of this study was to quantitatively evaluate rotatory knee laxity at time-zero in order to determine whether detected post-reconstruction laxity was predictable by its value measured before the reconstruction, which was hypothized to be influenced by the presence of associated lesions.

Methods

Rotatory knee laxity was retrospectively analysed in 42 patients, including two different ACL reconstructions. The maximal anterior displacement and the absolute value of the posterior acceleration reached during the reduction of the tibial lateral compartment were intra-operatively acquired by using a navigation system and identified as discriminating parameters. For each parameter, statistical linear regression analysis (line slope and intercept) was performed between pre- and post-reconstruction values.

Results

No statistically significant influence of the initial posterior acceleration on the post-reconstruction outcome was found (line slope, p > 0.05), although a statistically significant line intercept was indeed identified (p < 0.001). A statistically significant influence on the surgery outcome was instead found for the initial value of the anterior tibial displacement (line slope = 0.39, p = 0.004), meaning that, on average, about 40 % of the post-reconstruction lateral compartment displacement could be explained by the corresponding pre-reconstruction value. Both of these findings highlighted the importance of intra-operative quantification of rotatory knee laxity to identify correct indications for the surgery.

Conclusions

This study provided important implications for the future possibility of defining a quantifying tool able to assess rotatory knee laxity during ACL reconstruction. This could allow detection of additional injuries to secondary restraints by easily performing rotatory knee laxity tests, which in turn could reduce post-surgical recurrence of knee instability.     

运用数字体相关方法追踪呼吸过程中肺部肿瘤和胸腔的运动

目的 研究数字体相关（digital volume correlation,DVC）方法测量肺部肿瘤和胸腔随患者呼吸运动的变形及位移情况的可行性。方法 利用DVC跟踪胸腔内组织三维运动的算法,通过四维CT成像技术拍摄肺癌患者一个完整的呼吸过程。以吸气开始为初始状态,确定肿瘤和胸腔位置,运用DVC软件,分析初始状态下肺部4个特征体域在20%、40%、60%、80%和100%呼吸相位下以及胸腔上4个特征体域在100%呼吸相位下的三维位移值。结果 肿瘤的位移和变形的误差在1 mm以内,胸腔的位移和变形的误差在0.5 mm以内;肿瘤在呼吸过程中沿人体竖直方向运动最大,胸腔在吸气结束时刻沿人体前后方向运动最大。结论 DVC测试技术可用于检测呼吸过程中肺部肿瘤和胸腔等胸部组织的位移和变形情况。本研究为基于DVC方法实现肺部肿瘤无创、非射线、实时的图像引导放射治疗提供了依据。     

持续牵引下电针治疗腰椎间盘突出症疗效观察

目的:观察持续俯卧位牵引下电针治疗腰椎间盘突出症的临床疗效,为临床治疗该症寻求一种更好的方法.方法:将患者随机分为A组(42例)、B组(39例)和C组(38例).三组针刺方法相同,均取夹脊穴配委中、承山等穴,针刺后加电针,在此基础上,A组采用俯卧位持续牵引同时配合电针方法治疗,B组则先仰卧牵引再行电针治疗,C组单纯进行电针治疗,观察并比较临床疗效.结果:A组有效率为95.2%,优于B组的79.5%与C组的65.8%(P＜0.05,P＜0.01).结论:持续俯卧位牵引下电针为治疗腰椎间盘突出症的较佳方法.     

三维屈旋加平拉背压法治疗旁中央型腰椎间盘突出症临床研究

目的：观察三维屈旋加平拉背压法治疗旁中央型腰椎间盘突出症的临床疗效。方法：将203例旁中央型腰椎间盘突出症住院病人随机分为实验组（102例）和对照组（101例）,分别采用三维屈旋加平拉背压法和三维屈曲旋转法治疗,于治疗后7d及治疗后1个月对比分析2组的临床疗效。结果：治疗后7d及治疗后1个月两组临床疗效比较,差异均有统计学意义（X2=24．8408,P〈0．0001;X2=18．0177,P〈0．13001）,实验组疗效优于对照组。结论：三维屈旋加平拉背压法可有效地治疗旁中央、型腰椎间盘突出症,值得在临床推广。     

Does Thumb Immobilization Contribute to Scaphoid Fracture Stability?

Immobilization protocols for nondisplaced scaphoid fractures have included the elbow, wrist, and thumb. This study attempts to demonstrate whether or not immobilization of the thumb makes a difference in preventing motion at the scaphoid fracture site. Using six fresh frozen forearm specimens, a transverse waist scaphoid fracture was created through a dorsal approach. Metallic markers were imbedded on either side of the fracture. Sutures were secured to the flexor pollicus longus (FPL) and extensor pollicus longus (EPL). Each specimen was loaded in extension and flexion by attaching 50-g weights to the EPL and FPL, first with no casting, then with a short arm cast, and finally a short arm thumb spica cast. Angulation and displacement at the fracture site were measured in the coronal, sagittal, and axial planes utilizing image reconstructions from computed tomography. One-way ANOVA with repeated measures and Tukey–Kramer multiple comparison test post hoc analysis were used for statistical evaluation. There was no significant difference in fracture angulation or rotation between spica and short arm casts. There was a significant difference in angulation and rotation in all three planes when comparing between casting and no casting, p < 0.05. In our cadaveric model, wrist immobilization is crucial for nondisplaced scaphoid waist fractures, and short arm casting was just as effective as thumb spica casting in preventing fracture displacement.     

Clinical Study of Acupoint Injection in Treating Lumbar Intervertebral Disc Protrusion

目的：观察穴位注射治疗腰椎间盘突出症的临床疗效。方法：将156例腰椎间盘突出症患者随机分为观察组80例（弥可保注射液）和对照组76例（维生素B12注射液），采用穴位注射受压神经根相应节段夹脊穴的方法。结果：观察组有效率为86．3％，对照组有效率为78．9％，两组疗效比较P〈0．01，差异有统计学意义。结论：“弥可保”注射液穴位注射治疗腰椎间盘突出症的临床疗效明显高于维生素B12穴位注射。