超声测量在假肢接受腔设计中的应用

目的 利用超声成像技术提取小腿肢残患者残肢内外轮廓形状,为制作假肢接受腔提供一种残肢端部三维建模方法。 方法 将超声探头与残肢一同放入水中测量后进行图像重建和特征提取。入选患者分别穿戴利用超声、CT测量数据制作的小腿接受腔假肢,并对比患者穿戴不同假肢时其肢体运动功能差异。 结果 通过超声测量、处理获得的小腿残端三维模型可见皮肤、骨骼轮廓光滑清晰,能较真实地呈现患者小腿残肢形状结构。入选患者分别穿戴利用超声、CT扫描数据制作的小腿接受腔假肢时其肢体运动功能无明显差异（P>0.05）。 结论 借助超声测量提取残肢内外轮廓数据具有成本低、易于操作、无辐射损伤等优点,能为计算机辅助设计及制作假肢接受腔提供准确建模数据。     

残肢与接受腔的三维建模及力学分析

目的：对残肢与接受腔进行三维重建及力学分析，寻求残肢与接受腔间生物力学交互作用，为假肢接受腔的设计提供科学依据。方法：利用CT扫描、图像处理和反求技术重构骨骼、皮肤及接受腔三维模型建立残肢与接受腔的有限元模型．进行有限元受力分析。结果：残肢的主要受力部位是膑韧带、后肌群、胫骨内凸、胫骨远端、腓骨头及腓骨远端；骨骼对力的传递作用显著。结论：残肢受力由穿戴受腔引起，通过骨骼从接受腔传递给软组织，通过改变接受腔形状可以改变残肢的受力分布，残肢与接受腔力学分析是假肢接受腔制定的前提和基础。     

植入式骨整合假肢的研究进展

植入式骨整合似肢取消了传统假肢接受腔．借鉴种植牙的技术，一端插入残端骨内腔，另一端经皮肤伸出体外与假肢联接，这种残肢从根本上解决了传统假肢因接受腔-残肢界面透气性差，产生恶臭，因磨擦引起的残肢感染等问题．下面将对国内外植入式骨整合假肢的研究状况、存在的问题，及其发展趋势进行综述。     

膝下残肢界面应力准动态有限元模型研究

目的:为计算小腿截肢患者行走过程中残肢和接受腔之间的界面压力.方法:根据残肢、骨骼和假肢接受腔的真实几何形状建立了准动态有限元模型,采用了自动面面接触模型模拟皮肤和接受腔衬套之间的边界摩擦和滑动,并在考虑行走过程中外力和惯性载荷的同时,考虑了膝关节刚体位移和残肢弹性变形之间的耦合.结果:对一个步态周期内的残肢界面压力进行了仿真计算,结果表明界面压力主要分布在髌韧带区、腘窝区、胫骨内外侧.在站立相,除髌韧带区外,其他区域的压力具有与地面反力相似的变化规律.结论:本文所建立的准动态模型考虑了患者行走过程中膝关节位移,更接近于人体真实运动,能够用于假肢接受腔界面特性的预测和现代假肢的数字化设计.     

小腿假肢接受腔计算机三维模型的构建

背景:假肢接受腔作为截肢患者肢体残端和假肢之间载荷传递的惟一通道,是影响假肢适配性的重要部件.假肢接受腔的三维建模是接受腔实用性的关键,可以在测量时得到更准确的数据.目的:建立假肢接受腔计算机三维模型,为接受腔有限元分析提供数据基础,为加工制造接受腔提供可靠的参数.方法:选择1例32岁右侧小腿截肢的男性患者,髋关节各肌力正常,髋18°屈曲挛缩,其他关节活动度正常.根据患者CT和核磁共振扫描图像,采用Mimics10.0软件处理数据,构建假肢接受腔计算机三维模型,准确模拟残肢和接受腔的结构.结果与结论:建立的小腿残肢和接受腔计算机三维模型比较准确地反映了接受腔和残肢的几何特征和外部轮廓.假肢接受腔三维模型的建立有助于提高制作的成功率,从根本上改变传统依靠手工设计、测量、取型、修型等落后的生产模式.     

下肢截肢后不良残肢的临床评估和处理

目的分析下肢截肢后不良残肢发生的原因，并介绍其临床处理方法。方法对109例下肢截肢者(共计110个残肢)进行评定，评定内容包括：残肢皮肤软组织状况、长度、形状、关节活动度、肌力、幻肢痛、残肢痛等，然后对不良残肢进行相应的理疗、体疗或手术处理。结果本组合格残肢64肢(占58％)，不合格残肢46肢(占42％)。不合格残肢主要表现为：残端形状不规则20肢，短残肢18肢，残端不稳定瘢痕伴感染13肢，残端肿胀及臃肿14肢，关节屈曲挛缩畸形18肢，神经瘤2肢，经理疗、体疗或手术处理后，均达到装配假肢的条件。结论对不良残肢要进行对症处理，使之能装配或穿戴假肢。由于假肢技术的不断改进，现在残肢的长度不再是影响假肢装配的主要原因，而残端皮肤软组织的条件已成为影响假肢装配的主要因素。     

地震后截肢患者残肢的临床评定和康复治疗

目的分析地震致截肢患者残肢的特点和原因、观察康复治疗的效果。 方法从残端皮肤情况、残肢形态、残肢长度、残肢肿胀、残肢关节活动度和残肢肌力等方面对52条残肢进行评定，并进行物理治疗、残肢塑形和运动治疗。 结果52条残肢中，残端有溃疡或窦道、残肢肿胀、圆锥形残肢和短残肢分别占76%、73%、34%和40%，残肢关节活动受限者占42%，所有患者残肢肌力明显减退。经康复治疗后，残肢无肿胀、溃疡或窦道完全愈合，残肢形状、关节活动度和肌力明显改善，已达到假肢装配条件，均装配假肢，并获得良好的功能。 结论地震后截肢不良残肢发生率高，综合康复治疗能明显改善残肢条件,早期康复治疗对促进患者康复，安装假肢具有重要意义。     

小腿假肢接受腔-残肢生物机械系统三维重构

目的：建立小腿假肢接受腔-残肢生物机械系统三维几何模型。方法：以一名25岁男性小腿截肢患者为对象，采用三维坐标测量和核磁共振成像获得原始数据，利用软件MIMICS、SURFACER、SOLIDWORKS等实现了接受腔和残肢的三维重构．并根据接受腔修型模式等完成了系统装配。结果：数字化三维模型较精确的反映了接受腔-残肢系统的几何特征。结论：这种低成本方法可用于假肢数字化设计、有限元分析和计算机辅助制造。     

下肢截肢的非理想残肢及临床处理

对５９例下肢截肢患者理想残肢与非理想残肢进行了复习，其中非理想残肢５０例（８４．７％），分为不良残肢及残肢并发症２种，列举了它的各种表现，说明了非理想残肢对假肢穿戴的主要影响和临床处理方法。从非理想残肢发生率之高，强调了外科医生应重视截肢与假肢的现代理论与技术的必要性。现代假肢为闭合的全面接触全面承重的接受腔，故传统的截肢方法造成的园锥形残肢已不适用于现代假肢接受腔的安装。     

对截肢问题的探讨

近年来 ,随着生物力学基础理论研究和生物工程学的发展 ,新材料、新工艺的应用 ,假肢制作技术水平的提高 ,尤其是假肢新型接受腔的应用 ,传统的末端开放式接受腔改变成为闭合的、全面接触、全面承重式接受腔 ,并具有残肢承重合理、穿戴舒适、假肢悬吊能力强、不影响残肢血液循环等优点。为了适合现代假肢的良好配戴和发挥最佳代偿功能 ,残肢应具备如下条件 :残肢外形为圆柱状 ,有适当的长度 ,良好的皮肤和软组织条件 ,皮肤感觉正常、无畸形 ,关节活动不受限 ,肌肉力量正常 ,无残肢痛或幻肢痛等。这就要求在截肢部位的选择、截肢手术方法、截…     

Improved imaging of the carotid artery in the short-axis plane by a mechanical scanning ultrasonic probe

To image the intima–media complex of the carotid artery in a wider region, a method for measuring cross-sectional images in the arterial short-axis plane is presented. Using the proposed mechanical scanning system for an ultrasonic probe, cross-sectional images of a silicon rubber tube and a human carotid artery are measured in basic experiments and in in vivo experiments, respectively. These experiments show that this method successfully images the short-axis cross sections. Using the method proposed in this article, B-mode images in the short-axis plane can be accurately measured in a wider region than is possible with conventional methods.     

A new scanning approach for limb extremities using a water bag in freehand 3-D ultrasound

3-D ultrasound (US) can significantly improve the visualization of musculoskeletal tissues, such as residual limbs, feet and hands. Traditionally, mechanical scanning is normally required to obtain the entire volume of these limb extremities. In this paper, a new scanning approach using a water bag was described to collect the complete volume of various tissues surrounding bones. The water bag was used to contain the limb extremity and the scanning was conducted on its external surface from different directions. The recorded 2-D US images containing complete anatomic information surrounding the bones from different directions were used to form full 3-D volumes of the limb extremities. A plastic auxiliary apparatus was designed to hold the water bag and support the subject's limb part with an armrest. A corresponding algorithm was proposed to remove invalid image information within each sweep by a separating plane defined semiautomatically. Two phantoms were used to test the repeatability and accuracy of the imaging. The distance between two plastic bands attached to a plastic tube filled with US gel measured by a micrometer and from the four reconstructed volumes were 39.03 +/- 0.36 mm and 39.2 +/- 0.5 mm, respectively. The diameter, height and volume of a silicone cylinder phantom measured for the 10 reconstructed volumes were 40.2 +/- 1.4 mm, 12.9 +/- 1.0 mm and 16400 +/- 1600 mm(3), respectively. They agreed with the corresponding results obtained by the micrometer, which were 41.29 +/- 0.13 mm, 12.98 +/- 0.17 mm and 17370 +/- 140 mm(3), respectively. The reconstructed volumes of the two phantoms, a chicken leg in vitro, and human fingers in vivo were also reported. The preliminary results obtained in this study demonstrated that this new scanning approach should have potential for the 3-D US imaging of musculoskeletal extremities using freehand scanning.     

Bone Fracture Sensing Using Ultrasound Pitch–Catch Measurements: A Proof-of-Principle Study

The most common imaging method used to diagnose and monitor bone fractures and healing is multiple radiographic images performed by highly trained professionals with expensive equipment that can expose patients to high levels of ionizing radiation. Here we introduce and illustrate proof-of-concept of a potential alternative method for measuring bone fractures: ultrasound pitch–catch measurement technique. Measurements are performed with two piezoelectric transducers, housed in standard orthopedic screws and fixed on either side of simulated fractures, with and without an orthopedic plate, in ex vivo pig limb bones. Using this measurement method, we were able to detect significant differences between uncut and 2-, 5- and 10-mm-deep bone cuts using a two-sided t-test with an α level of 5%.     

A quasi-dynamic nonlinear finite element model to investigate prosthetic interface stresses during walking for trans-tibial amputees

BACKGROUND: To predict the interface pressure between residual limb and prosthetic socket for trans-tibial amputees during walking. METHODS: A quasi-dynamic finite element model was built based on the actual geometry of residual limb, internal bones and socket liner. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. Besides variable external loads and material inertia, the coupling between the large rigid displacement of knee joint and small elastic deformation of residual limb and prosthetic components were also considered. RESULTS: Interface pressure distribution was found to have the same profile during walking. The high pressures fall over popliteal depression, middle patella tendon, lateral tibia and medial tibia regions. Interface pressure predicted by static or quasi-dynamic analysis had the similar double-peaked waveform shape in stance phase. INTERPRETATION: The consideration of inertial effects and motion of knee joint cause 210% average variation of the area between the pressure curve and the horizontal line of pressure threshold between two cases, even though there is only a small change in the peak pressure. The findings in this paper show that the coupling dynamic effects of inertial loads and knee flexion must be considered to study interface pressure between residual limb and prosthetic socket during walking.     

基于超声图像处理的HIFU所致组织损伤自动检测方法:实验研究

目的 探讨基于超声图像处理的HIFU所致组织损伤的自动检测方法。方法 针对HIFU辐照后新鲜离体猪肉声像图中的ROI,通过搜索灰度极大区域自动定位图像中的所有亮斑,结合数学形态学、连通域标记和Canny边缘检测算法提取测试对象的边缘轮廓;根据亮斑中心至边缘轮廓的欧式距离去除边缘附近的亮斑噪声,获取HIFU损伤候选区;而后提取候选区特征参数,并结合支持向量机（SVM）识别HIFU损伤。结果 最大灰度值和矩形度两个特征参数的识别率分别为86.25%和93.33%。选用识别率更高的矩形度,可正确识别单处、多处HIFU损伤或无HIFU损伤的图像。结论 采用此法可直接分析HIFU辐照后超声声像图而自动检测HIFU损伤,无需依靠图像配准技术,可减少手动定位带来的误差。     

胎儿四肢畸形超声检查方法与技巧

目的总结胎儿四肢畸形的超声检查方法与技巧。方法对产前超声诊断及引产后证实的29例四肢畸形胎儿的声像图特点及胎儿四肢超声检查方法与技巧进行总结分析。结果超声显示29例胎儿肢体畸形图像清晰,采用逐段有序扫查、把握检查时机,利用胎儿体位变化、多切面观察检出胎儿软骨发育不良7例,左下肢及右手畸形1例,手及足畸形2例,右上肢远端及手缺如1例,桡骨发育不全3例,并指1例,多指2例,右股骨、胫腓骨弯曲1例,左胫腓骨短及足畸形1例,足内翻9例,足外翻1例。其中羊水过多1例;合并其他畸形4例。结论胎儿肌肉骨骼系统畸形及肢体畸形产前超声检查中长骨发育异常较易诊断,四肢远端是检查的难点、重点,易发生漏诊、误诊。超声检查注重方法与技巧的应用有助于提高胎儿肢体畸形的检出率。     

低剂量多排螺旋CT尿路成像技术在尿路非肿瘤病变中的应用研究

目的:探讨将低剂量多排螺旋CT尿路成像技术(multi-detectorcomputed tomography urography,MDCTU,CTU)用于尿路非肿瘤病变的可行性方案。方法:参照228例体质量75 kg以下成人的腹盆部体径的平均值,制作含骨、脂肪、肌肉及肾脏组织的体部模型,将管径3~7 mm的模拟排泄期输尿管植入其中。应用GE lightspeed 16 CT机对模型进行常规剂量和一系列低剂量扫描,对获得的16个序列的影像资料进行数据分析和图像质量评价,筛选出可满足诊断要求的低剂量扫描序列,将其应用于尿路非肿瘤患者的CTU检查。共录入104例尿路非肿瘤患者,其中行低剂量CTU检查者50例(低剂量组),行常规剂量CTU检查者54例(常规剂量组),比较两组患者的CTU图像质量,评价低剂量CTU的临床可行性。结果:辐射剂量≥4.98 mGy的低剂量扫描序列均可满足临床诊断要求,辐射剂量为4.98 mGy的相应扫描参数为:准直(16×1.25)mm,120 kV,扫描时间0.5 s/rot、扫描层厚5 mm、螺距0.938,噪声指数14,电流60~140 mA。CTU图像对低剂量组和常规剂量组患者的诊断结果相似,仅图像质量评分有差异。结论:低剂量CTU检查扫描序列可应用于尿路非肿瘤性病变。     

Multidetector computed tomographic morphology of ovaries in cynomolgus macaques (Macaca fascicularis).

Macaques are important models for menopause and associated diseases in women. A sensitive, noninvasive technique for quantifying changes in ovarian morphology would facilitate longitudinal studies focused on the health-related sequelae of naturally occurring or experimentally induced alterations in ovarian structure and function. Multidetector computed tomography (MDCT) is a fast, non-invasive imaging technique that uses X-rays, multiple rows of detectors, and computers to generate detailed slice images of structures. The purpose of this study was to describe the utility of MDCT for reliably characterizing ovarian morphology in macaques. Five macaques were scanned using contrast-enhanced MDCT. The following characteristics were described: 1) appearance of ovaries and adjacent landmarks, 2) effects of varying technical protocols on ovarian image quality, 3) radiation doses delivered to the pelvic region during scanning, and 4) MDCT estimates of ovarian volume and antral follicle counts versus those measured directly in ovarian tissue. Ovaries were distinguishable in all MDCT scans and exhibited heterogeneous contrast enhancement. Antral follicles appeared as focal areas of nonenhancement. Ovarian image quality with 5 pediatric scanning protocols was sufficient for discriminating ovarian margins. Pelvic region radiation doses ranged from 0.5 to 0.7 rad. Antral follicles counted using MDCT ranged from 3 to 5 compared with 3 to 4 counted using histology. Ovarian volumes measured using MDCT ranged from 0.41 to 0.67 ml compared with 0.40 to 0.65 ml by water displacement. MDCT is a promising technique for measuring longitudinal changes in macaque ovarian morphology reliably and noninvasively.