双X线透视成像系统进行颈椎在体运动研究方法学的探索

目的观察应用双X线透视成像系统在颈椎在体运动学研究中下颌骨对颈椎图像的干扰度,探索颈椎在体运动学最佳位置的透视方法,为颈椎在体运动学研究提供方法学的可行性论证。方法应用双X线透视成像系统分别在两个C型臂夹角呈正交(90°)位、60°位及45°位采集健康志愿者5名(男4名,女1名)颈椎双平面X线图像,包括中立位、前屈后伸位、左右旋转位、左右侧屈位,比较各个不同位置时下颌骨对颈椎椎体图像的遮挡;采用下颌角对颈椎的干扰程度来作为评价的标准,通过对各个不同位置时下颌骨对颈椎图像干扰程度的评分,筛选最佳角度的透视方法。在做颈椎左右旋转运动透视时,比较躯干固定-头颅旋转模式和头颅固定-躯干旋转模式下下颌骨对颈椎图像的干扰程度,分别采集两种模式下的透视图像。结果 90°、60°和45°位时中立位、前屈后伸位、左右侧屈位、左右旋位透视下颌骨对颈椎图像干扰度均存在显著性差异(P<0.05)。45°位在上述位置时干扰度最小。在相同角度60°位,躯干固定-头颅旋转组与头颅固定-躯干旋转组相比有显著性差异(P<0.05)。结论颈椎在体运动学研究中应用双X线透视成像系统在交角45°位时可以最大限度的减少下颌骨的阻挡,坐位同轴躯干旋转代替头颅旋转可以减少下颌骨的干扰度,基本满足双X线成像系统二维-三维图像的匹配条件。     

双平面荧光成像技术在膝关节运动学研究中的应用

膝关节运动学是运动医学的研究热点.双平面荧光成像技术(dual fluoroscopy imaging technique,DFIT)是一种使用X线测量关节运动的精确无创技术,同时不受皮肤和软组织干扰,对运动无干扰.DFIT近年来被广泛应用于研究膝关节前交叉韧带(anterior cruciate ligament,A...     

正常腕关节运动时腕中关节运动学在体研究

目的:确定腕关节在屈伸、桡尺偏运动时腕中关节的运动学.方法:选健康志愿者10名,腕关节CT扫描后,在自行开发的外科手术模拟系统内三维重建,计算出舟骨、月骨的质心、转动惯量轴,在头状骨上人为建立参照坐标系,用有限螺旋轴表达舟月骨相对于头状骨的旋转及平移运动.结果:腕关节尺偏40°时,舟骨绕头状骨背伸(19.2±10.3)°,桡偏(19.3±6.2)°,月骨背伸(27.8±11.6)°,桡偏(14.0±4.8)°;腕关节桡偏20°时,舟骨绕头状骨掌屈(12.2±5.4)°,尺偏(15.0±3.8)°,月骨掌屈(9.9±3.9)°,尺偏(15.3±3.9)°;腕关节掌屈60°时,舟骨绕头状骨背伸(32.6±5.2)°,月骨背伸(41.5±6.9)°;腕关节背伸600时,舟骨绕头状骨掌屈(7.9±3.9)°,月骨掌屈(20.7±5.0)°.结论:腕关节桡-尺偏,舟、月骨相对于头状骨除了尺-桡偏外,还有较大的非平面运动.当腕关节屈-伸运动,舟骨、月骨相对于头状骨的相对运动主要为伸-曲运动,非平面旋转运动较小.舟骨相对头状骨的运动小于月骨,即舟骨跟随远侧列腕骨一起运动,但又不同于远侧列腕骨之间的微动,舟骨起着远近侧列腕骨的桥梁作用.     

正常国人盂肱关节在不同手臂抬高平面的运动学研究

目的 探究正常国人盂肱关节在外展、肩胛平面外展和前屈时的相对位移,为盂肱关节不稳及肩峰下撞击等疾病的诊断、治疗和随访提供参考依据。方法 采用双平面系统结合模型-图像配准技术,测量13名健康志愿者在手臂外展、肩胛平面外展和前屈的整个过程中肱骨相对于肩胛骨的上下、前后的平移数据。结果 志愿者在手臂外展、肩胛平面外展和前屈时肱骨在前后方向上的总平移量分别为(4.0±1.3)、(4.1±1.5)、(4.8±1.9) mm,上下方向的总平移量分别为(3.0±1.0)、(3.1±1.1)、(3.3±1.5) mm。在整个运动过程中,不同手臂抬高角度的上下平移量具有显著性差异,但未发现其他显著性差异。结论 正常国人手臂抬高过程中,肱骨头平均位于肩胛盂的后上方,且前屈时的肱骨在上下、前后的运动范围均最大。在临床的诊断、治疗和随访过程中,患者行前屈位可能会获得更好的评估效果。     

基于Ilizarov技术原理矫正器在矫正肘关节屈伸挛缩畸形中的临床应用

目的 基于Ilizarov技术原理,设计具有主动矫形力、符合生物力学原理的肘关节矫正器,并研究其临床疗效。方法 将44例创伤后肘关节功能障碍的患者随机分为2组,其中对照组22例给予连续被动运动（continuous positive motion,CPM）治疗,治疗组22例给予肘关节矫正器治疗;所有患者均在治疗3个月后评定治疗前、后肘关节的功能恢复程度。 结果 治疗组患者肘关节屈伸范围均明显优于对照组,有效率为90.91%,明显优于对照组的有效率(81.82%)。结论 本文设计的肘关节矫正器在创伤后肘关节功能障碍康复中有较好的治疗作用,值得临床进一步推广应用。     

提高准静态弹性成像运动估计精度的算法及其仿体实验研究

超声弹性成像作为一种新兴的成像技术手段,可以对病理组织和正常组织的结构性弹性差异进行成像。由于各种良恶性肿瘤以及物理治疗形成的损伤会使得局部组织弹性发生明显变化,因此,采用超声弹性成像检测病变组织或者物理治疗形成的损伤具有重要意义。弹性成像的基础建立在对外力作用下组织运动的精确估计上,在准静态弹性成像中,即为检测轴向外力缓慢施压所造成的组织纵向运动。然而由于非纵向运动,边界条件和设备噪声等因素的影响,实际运动估计中需要通过算法消除各种因素的干扰。本研究采用了一系列方法来提高运动估计的精度,即首先采用二维互相关算法,减小组织横向运动对位移估计的干扰;然后采用分段线性拟合的算法剔除了位移估计中的奇异点,并通过二维中值滤波算法平滑了位移数据;最后采用基于小波变换的低通数字差分算法,成功的抑制了位移数据中的高频噪声对应变估计结果的干扰,并比较了该算法相对于数字低通差分滤波器和直接差分算法的应变估计效果。开展了多层仿体实验和包含有柱状硬物的仿体实验验证了这些算法的可行性。研究表明,通过一系列运动估计算法的改进,可以大大提高运动估计的准确性,降低了图像噪声。     

体素内不相干运动弥散加权成像在受压腰骶神经根诊断中的应用

目的 探讨MR体素内不相干运动(IVIM)弥散加权成像(DWI)在受压腰骶神经根诊断中应用的可行性。方法 前瞻性对照研究。纳入2017年4—10月30例腰椎间盘突出致神经根受压患者(观察组)的常规腰椎MR序列及3D-Fiesta序列、IVIM-DWI序列图像;另按性别、年龄匹配纳入30名健康志愿者作为对照组。在GE ADW 4.6工作站,使用MADC软件包测量对照组双侧L₄、L₅、S₁神经节的扩散系数(D)、灌注相关扩散系数(D*)、灌注分数(f)和表观扩散系数(ADC)值,以及观察组患者受压侧及其对侧神经根的D、D*、f、ADC值。比较对照组同节段左右两侧神经节和不同节段神经节各观察项目测量值,以及观察组受压侧神经根与对侧正常神经根各观察项目测量值。绘制受压神经根D值和ADC值的ROC曲线,评价诊断效果。结果 对照组L₄、L₅、S₁神经根的D值分别为(0.603±0.064)×10^-3 mm²/s、(0.624±0.079)×10^-3 mm²/s、(0.628±0.088) ×10^-3 mm²/s, D*值分别为(3.815±0.541) ×10^-3 mm²/s、(3.862±0.414)×10^-3 mm²/s、(3.915±0.611) ×10^-3 mm²/s; f值分别为0.454%±0.076%、0.484%±0.101%、0.445%±0.094%; ADC值分别为(0.934±0.085)×10^-3 mm²/s、(0.945±0.051)×10^-3 mm²/s、(0.953±0.064)×10^-3 mm²/s。观察组神经根受压侧D、D*、f、ADC值分别为(0.669±0.081)×10^-3 mm²/s、(3.852±0.776)×10^-3 mm²/s、0.528%±0.115%、(1.096±0.087)×10^-3 mm²/s,健侧D、D*、f、ADC值分别为(0.617±0.080)×10^-3 mm²/s、(3.961±0.684)×10^-3 mm²/s、0.479%±0.083%、(0.938±0.074)×10^-3 mm²/s。对照组同节段左右两侧神经节和不同节段神经节所测D、D*、f、ADC值,差异均无统计学意义(P值均＞0.05)。观察组受压侧神经根与对侧正常神经根比较:D和ADC值均升高,差异均有统计学意义(P值均＜0.01);D*、f值差异均无统计学意义(P值均＞0.05)。绘制并分析ROC曲线,D值对诊断神经根受压具有较高效能,其次是ADC值,D值的AUC为0.923(95%CI 0.803~0.987),ADC值的 AUC为0.895(95%CI 0.865~0.999)。结论 IVIM模型的MR DWI技术可用于腰骶神经根检查,且与单指数模型的MR DWI相比能更详细、准确地反映神经根受压后的病理改变。     

基于DirectDraw双缓冲的实时动态成像技术

目的 应用程序基于特定的成像算法将硬件电路采集到的电信号计算成一系列二维静态图像,研究如何将静态图像序列转换成实时动态显示视频.方法 采用具有毫秒级精度的多媒体定时器产生时钟信号触发图像序列间的切换,利用多线程优化程序设计节省总的成像时间,基于DirectDraw双缓冲技术实现图像的快速显示.结果 基于以上软件技术将数据传输、图像计算和图像显示环节有效地结合,实现静态图像序列到实时动态成像的转换.结果显示视频帧速率达到预定的每秒25帧,图像序列间的切换显示所需要的时间远小于1 ms.结论 基于多媒体定时器、多线程和DirectDraw双缓冲技术,可将静态图像序列以特定的帧速率显示出来,从而实现静态图像到动态视频的转换.     

双平面投影心血管三维重建技术研究新进展

近年,来双平面X线系统越来越多地应用于心管临床诊断和研究。事实上,现有的双平面X线血管造影仪几乎可以同时得到两幅相互垂直的血管造影照片,所以若能用这两幅照片重构出血管网的三维结构来,则就可以使双平面X线造影仪成为更高一层次的设备,这将对临床起着重要的意义。本文追踪国际上的研究前沿.试图对现有的3D心血管重建技术作一全面而详尽的概述,包括动脉检测、骨架重建和截面重建,并进行必要的分析。在此基础上,给出了未来研究的发展方向和目标。     

颈椎在体运动学研究方法的进展

背景：颈椎在体运动学研究能够通过侵袭性或非侵袭性方法获取生理载荷下活体颈椎的活动特性,可为颈椎疾病的诊断和治疗提供指导和参考。 目的：对目前有关颈椎在体运动学的研究方法和各自特点进行归纳总结。 方法：应用计算机检索Pubmed数据库(http://www.ncbi.nlm.nih.gov/pubmed/)及万方数据库(http://www. wanfangdata.com.cn),英文检索词为“Spine,cervical,in vivo motion”,中文检索词为“脊柱,颈椎,测量,活动度”。检索文献总计238篇,最终选取30篇作为综述文献。 结果与结论：颈椎在体运动学研究可获取活体颈椎各个关节6个自由度(6DOF)的量化数据,对提高生理载荷下颈椎运动状况的认识水平,进一步了解颈椎退变的运动学特点,以及优化临床颈椎疾患的诊疗方案有重要作用,同时可为人工椎间关节及内固定器尤其是非融合内固定物的研制提供不可或缺的参考数据。其主要通过X射线、CT、MRI、超声、电磁等方法实现,但目前仍缺乏颈椎各节段在体运动范围公认的数值,颈椎在体运动学研究仍需不断深入。     

In vivo Detection and Imaging of Intraventricular Hemorrhage in Neonatal Piglets Using Electrical Impedance Tomography

Intraventricular hemorrhage(IVH) is one of the most severe medical emergencies in neurosurgery. Early detection or diagnosis would significantly reduce the rate of disability and mortality, and improve the prognosis of the patients.Although present medical imaging techniques have high sensitivity to identify bleeding, the use of an additional, non-invasive imaging technique capable of continuously monitoring IVH is required to prevent contingent bleeding or re-bleeding. In this study, electrical impedance tomography(EIT) was applied to detect the onset of IVH modeled on 6 piglets in real time, with the subsequent process being monitored continuously. The experimental IVH model was introduced by one-time injection of 2 ml fresh autologous arterial blood into the ventricles of piglets.Results showed that resistivity variations within the brain caused by the added blood could be detected and imaged in vivo using the EIT method, and the magnitude and the size of region of interest on EIT images may be linearly associated with the volume of the blood. In conclusion, EIT has unique potential for use in clinical practice to provide invaluable real-time neuroimaging data for IVH after the improvement of electrode design, anisotropic realistic modeling, and instrumentation.     

In vivo demonstration of the Haldane effect during extracorporeal gas exchange.

During the extracorporeal support (LFPPV-ECCO2R) of 11 patients suffering from severe lung failure (ARDS), we consistently noticed a higher arterial than mixed-venous PCO2 in blood samples drawn at the same time. Two explanations are possible: a) the Haldane effect (HE), b) CO2 from lung tissue metabolism. In order to distinguish changes in PCO2 due to the HE from those due to tissue CO2 production, CO2 content (CCO2) was calculated. The results were compared to animal experiments with hyperoxic apnea, after which arterial and mixed-venous samples were drawn simultaneously. All blood gas samples were analyzed for pH, PCO2, PO2, and O2-saturation, from which CCO2 was calculated. In both groups, PaCO2 was 2.15 mmHg (2.7 mmHg respectively) higher at a lower CaCO2 (-2.87 ml/l, -14.9 ml/l). Oxygen saturation increased by 8.1% in the human group and 17.8% in the animal group. A significant relationship was found between changes in PCO2 and changes in O2-saturation. This is a demonstration of the Haldane effect.     

Dynamic In Vitro Quantification of Bioprosthetic Heart Valve Leaflet Motion Using Structured Light Projection

Quantification of heart valve leaflet deformation during the cardiac cycle is essential in understanding normal and pathological valvular function, as well as in the design of replacement heart valves. Due to the technical complexities involved, little work to date has been performed on dynamic valve leaflet motion. We have developed a novel experimental method utilizing a noncontacting structured laser-light projection technique to investigate dynamic leaflet motion. Using a simulated circulatory loop, a matrix of 150–200 laser light points were projected over the entire leaflet surface. To obtain unobstructed views of the leaflet surface, a stereo system of high-resolution boroscopes was used to track the light points at discrete temporal points during the cardiac cycle. The leaflet surface at each temporal point was reconstructed in three dimensions, and fit using our biquintic hermite finite element approach (Smith et al., Ann. Biomed. Eng. 26:598–611, 2001). To demonstrate our approach, we utilized a bovine pericardial bioprosthetic heart valve, which revealed regions of complex flexural deformation and substantially different shapes during the opening and closing phases. In conclusion, the current method has high spatial and temporal resolution and can reconstruct the entire surface of the cusp simultaneously. Because it is completely noncontacting, this approach is applicable to studies of fatigue and bioreactor technology for tissue engineered heart valves. © 2001 Biomedical Engineering Society.PAC01: 8719Hh, 8780-y, 4262Be, 8719St     

In vivo study of the complement system during infusion of radiographic contrast media

It has been claimed that activation of the complement system may play a role in reaction to radiographic contrast media (RCM) infusion. In order to clarify the effects of RCM on the complement system, three different parameters (CH50, C3a, and C1 inhibitor) were measured in 20 patients undergoing intravenous pyelography for diagnostic purposes. We found no significant changes in C3a levels, but CH50 and C1 inhibitor fell significantly at the different sampling times; however, the decreases lost significance when the data were corrected for hemodilution with the total protein content of each sample as a reference. We conclude that RCM infusion does not activate the complement system.     

双波长光耦合功能成像乳腺诊断系统

双波长光耦合功能成像乳腺诊断技术是一种基于两种特征脉冲波的生物医学光子功能成像的新技术。提出这种具有完全自主知识产权的“双波长光耦合功能成像乳腺诊断系统”,是基于人体乳腺癌变组织中含氧血红蛋白和去氧血红蛋白在两种波长分别为760和850 nm的近红外光上具有相反的吸收特性的原理,且诊断过程对人体零损伤,因此具有无辐射、经济、方便的优点。在设计中,依照脉冲光较连续光透过生物组织可以获取更多有效信息的新思路,结合对透射光电信号的功率谱和互相关功能图的分析方法,能从频谱中不稳定的突变信号定性检测出组织癌变后的血氧浓度变化。同时,借助相关性函数和系数的值,判定出两种波长(760/850 nm)透射信号的波形周期等参数的相似程度。经武汉大学人民医院对547例患者所做的临床诊断,分析结果如下:正常乳腺组织的功率谱曲线的单一性比较好,曲线较平稳;良性病变功率谱曲线波动大,且很不平稳;而恶性病变更加严重。正常乳腺组织在两种波长的近红外光照射下,相关系数在0.9左右;良性病变组织在两种波长照射下吸收特性差异大,相关系数普遍低于0.8,相关性较弱;恶性病变组织相关性低于0.5,趋近于零,相关性小。该结果能有力地支撑理论,表明该系统可以对乳腺疾病做初步诊断。     

Kinematic analysis of the human wrist during pointing tasks

In this work, we tested the hypothesis that intrinsic kinematic constraints such as Donders’ law are adopted by the brain to solve the redundancy in pointing at targets with the wrist. Ten healthy subjects were asked to point at visual targets displayed on a monitor with the three dof of the wrist. Three-dimensional rotation vectors were derived from the orientation of the wrist acquired during the execution of the motor task and numerically fitted to a quadratic surface to test Donders’ law. The thickness of the Donders’ surfaces, i.e., the deviation from the best fitting surface, ranged between 1° and 2°, for angular excursions from ±15° to ±30°. The results support the hypothesis under test, in particular: (a) Two-dimensional thick surfaces may represent a constraint for wrist kinematics, and (b) inter-subject differences in motor strategies can be appreciated in terms of curvature of the Donders’ surfaces.     

In vivo study of the oxygen tension in the brain tissues during prolonged acceleration

Summary By means of the polarographic method a study was made of the dynamics of oxygen tension (pO₂) in the brain tissues of dogs in prolonged overloads occurring during rotation in a centrifuge. As established, the rate of pO₂ reduction is dependent on the magnitude, direction and period of acceleration. With an acceleration force of 2–12 g in the head-pelvis direction, pO₂ dropped to 92–70% of the initial level after one minute of rotation, whereas in transverse overloads (back-chest) — to 98–80%. Overloads of 2–8 g in the pelvis-head direction caused a reduction of pO₂ to 95–84%. The pO₂ level in the brain tissues also depended on the position of the head in respect to the longitudinal axis of the animal body. But a moderate pO₂ reduction in the brain tissue during rotation shows that hypoxia is not the only factor in the mechanism of disturbances caused by accelerations.Presented by Active Member AMN SSSR V. V. Parin Translated from Byulleten Éksperimental noi Biologii i Meditsiny, Vol. 55, No. 1, pp. 43–48, January 1963Delivered at a meeting of the Moscow Society of Physiologists on March 9, 1962.     

In vivo microdialysis measures of extracellular norepinephrine in the rat amygdala during sleep-wakefulness

Norepinephrine (NE)-containing locus ceruleus (LC) has been known to participate in the regulation of the sleep-wake cycle according to the differential firing rate. The aim of this study was to know the change of extracellular NE level in the rat amygdala, which are reciprocally connected with LC, during sleep-wakefulness. Extracellular NE levels in the rat amygdala were investigated during different stages of the sleep-waking cycle using in vivo microdialysis and polygraphic recording. Dialysates were collected every 5 min and correlated with the results of polygraphic recording. The content of NE was measured by high-performance liquid chromatography with electrochemical detection. NE level was the highest in active waking (AW) and, when compared to AW, NE level was progressively lower in quiet waking (QW; 86%), quiet sleep (QS; 72%), and active sleep (AS or REM sleep; 61%). This result suggests that the rat amygdala also participates in the regulation of the sleep-wake cycle according to the differential NE release.     

In vivo role of truncated trkb receptors during sensory ganglion neurogenesis

The mammalian trkB locus undergoes alternative splicing to produce two different types of brain-derived neurotrophic factor receptors. The first type is the full-length receptor tyrosine kinase (TrkB(Tk+); the second type is a truncated receptor lacking the intracellular tyrosine kinase domain (TrkB(Tk-)). To investigate the function of both types of TrkB receptor in vivo, we have generated knockout mice lacking all isoforms of the TrkB receptor (trkB-/-) and compared sensory neuron survival in these mice to that in the previously described TrkB kinase domain knockout mice (trkB(k)-/-). We observed that the presence of truncated TrkB receptors in trkB(k)-/- mice results in more severe sensory neuron losses. Increased neuron losses associated with the presence of truncated TrkB were most severe in regions where neuron survival is most dependent on brain-derived neurotrophic factor and neurotrophin-3. Our data suggest that truncated TrkB receptors negatively influence neuron survival by interfering with the function of catalytic TrkB receptors.     

In vivo acquisition of extended-spectrum beta-lactamase inSalmonella enteritidis during antimicrobial therapy

The recovery of aSalmonella enteritidis strain that acquired resistance to -lactams (including cefotaxime), to aminoglycosides and to chloramphenicol subsequent to cefotaxime therapy is reported. This resistance pattern to -lactams was due to the presence of an extended-spectrum -lactamase. The isoelectric point of this extended-spectrum -lactamase was 6.3. The resistance genes were located on a transferable high-molecular-weight plasmid.