基于光电容积描记法的多路肌肉收缩传感系统

为了更好地研究肌肉的收缩运动,介绍了光电容积描记法（PPG）探测肌肉收缩运动的原理,设计了可以同时检测4路信号的反射式光电肌肉收缩传感系统。利用可编程恒流源驱动红外LED,将红外光照射到肌肉组织中,透射出肌肉的光被另外的红外探测电路检测到,并被转换为电信号。在单片机的控制下,4路检测到的电信号通过模拟多路开关实现分时导通,随后分别进行低通滤波和AD采样,最后将得到的4路数据通过蓝牙模块传送到上位机电脑端进行后继处理。电路实现了4路信号的同步探测功能,系统测量准确,性能可靠,具有一定的实用价值。     

基于电共轭液的人工肌肉及微手指研究

总结了几种传统人工肌肉的工作原理、特点及其在机器人驱动中的应用现状,分析了面向机器人驱动的传统人工肌肉技术的不足。在描述电共轭液的性能特性基础上,指出基于电共轭液的人工肌肉及微手指不仅在电能到机械能的转化过程中表现出显著的能量转换效率和高灵敏度等性能优点,而且与天然肌肉的驱动原理极其相似,在智能化的机器人驱动方面更具发展潜力。在此基础上,回顾了基于电共轭液的人工肌肉和微手指的研究进展,提出材料研究、作用机理和驱动电压低压化是基于电共轭液的仿生器件研究亟需解决的问题,以及未来的发展趋势及应用前景。     

神经肌肉接头的连续切片电镜观察与三维重建

神经肌肉接头是突触研究中的重要模型系统。在新生小鼠的神经肌肉接头,肌纤维被多个紧密并置的神经末梢共同支配。受分辨率的限制,在光镜下无法区分单个的神经末梢进行研究。利用透射电子显微镜的高分辨率对神经肌肉接头的超微结构进行连续切片观察和电镜图像的三维重建,准确、客观、形象地展示了轴突末梢的立体形态、空间位置和毗邻关系,为神经肌肉接头的发育研究提供了重要信息。     

一种用于人脸动画的拟合抽象肌肉模型

三维人脸动画是计算机图形学领域的热点课题。针对目前三维动画模型对人脸的模拟难度高且效果不够逼真地问题,为了简洁且逼真的模拟人脸表情动作,提出了一种拟合抽象肌肉模型。该模型基于人脸动画模型中常用的抽象肌肉模型,对其中宽线性肌的数学模型进行改进,利用形变参数控制宽线性肌的形态,对面部肌肉动作直接进行模拟。仿真实验表明,利用拟合抽象肌肉模型能够更为真实地模拟出复杂的嘴部动作。因此,拟合抽象肌肉模型与传统的抽象肌肉模型相比,实现的计算复杂度不高,并且模拟效果更加逼真,具有广阔的应用前景。     

基于肌电感应的可穿戴运动分析系统设计与实现

表面肌电信号是皮下肌肉活动在皮肤表面处表现出的微弱的电压信号,它反映了人体运动时肌肉动作的时间和空间信息.对于不同的运动动作,人体各个肌肉群产生的肌电信号的强度也各有差异.本文设计了一种基于肌电信号感应的可穿戴运动分析系统.通过提取采集到的多路肌电信号的时域、频域特征值,用加权归一化的方法给信号强度评级,从而确定人体运动时指定肌肉群的运动强度.可以利用这套系统设计目的性较强的运动动作.     

Maya肌肉系统的制作流程

本文是Maya Muscle插件工具的专题论文,关于角色装配,我们可以在骨骼的基础上建立肌肉,这样当骨骼运动时也会带动肌肉拉伸和压缩,从而驱动角色模型产生形变。肌肉的基本功能是一个影响物体,但是它可以模拟真实生物的肌肉与表皮的相互影响关系(如抖动、挤压、拉伸等肌肉运动)。     

用激光研究肌肉收缩

为了对骨胳肌肉进行研艽英国Wellcome托拉斯提供了一笔37381英镑的奖金，以用激光技术研究肌肉收缩。这项研究由圣·安德鲁斯大学生理学家弗列特尼博士(E. Flitney)指导，这将导致更好地了解肌肉是如何工作的，最终可能成功地增加预防和治疗肌肉疾病的可能性。     

用激光观察皮肤内部

日本庆应大学和资生堂共同开发使用激光不伤肌肉就能观察皮肤内部健康状态的新型显微镜装置。研究引起老人斑的黑色素分布等就能知道紫外线的影响及肌肉的老化,使用化妆品的影响等。皮肤由表皮、真皮、皮下组织三层组成。肌肉的损伤以表皮的厚度为标准,黑色素在真皮的附近。若不研究皮肤的深部,则很难判别皮肤的健康状态。新装置仅在皮肤表面照射激光,便能观察皮下组织。利用激光的反射便可读取皮肤内部的断面信息,用计算机处理成立体图像。在约30分钟内再现皮肤表面到深0.25mm左右的断面,就能分析出表皮和真皮界面的凸凹。而在过去,若不切…     

人体浑浊软介质和生物介质对激光和其它辐射透过率的提高

讨论并用实验研究了人体浑浊介质及生物介质一厚度高于特征衰减深度若千倍的人体组织和散射介质层——对激光和其它辐射的透过率。在挤压和刺穿软的散射介质时，观察到透过率急剧提高。发现压迫人体浑浊介质层时，透明度远高于对模拟生物组织局部加压的情况,这与血液消失以及把肌肉从加压处挤开有关。对无线电辐射——带电粒子、X射线及伽马射线等，也同样观察到散射和吸收的降低。指出可能应用本研究结果作深度辐照，以抑制内部病变（如脊髓)，治疗神经性传染病(侧面肌肉萎缩硬化、播散性硬化、脊髓灰白质炎等)，也可用于治疗肿瘤、溃疡等。     

脾主肌肉的超微结构研究

运用电子显微学和超微结构定量计测技术探讨了中医脾主肌肉的超微结构基础。对骨骼肌和心肌单位视野的线粒体数进行了计测和分析。研究结果表明脾气虚证大白鼠结构正常的线粒体数显著减少,而结构异常的线粒体数显著增加。这些改变提示降低了肌肉中的能量供给。四君子汤(健脾中药)治疗后的数据与正常大白鼠无显著差异。认为线粒体的结构改变是脾主肌肉的超微结构基础之一。     

异物对天线性能的影响分析

针对异物的存在将对天线性能产生影响这一问题,设计了一款单臂阿基米德平面螺旋天线。该天线的尺寸相对较小,剖面极低,具有良好的宽频带特性和圆极化特性。通过HFSS软件模拟仿真并分析异物如铁块、木头、肌肉组织等对天线性能的影响。仿真结果表明：磁导率较大的铁块与介电常数较大的肌肉组织对天线性能影响较大,介电常数小的木头对天线性能影响较小;异物尺寸越大对天线性能的影响越明显;异物距天线轴向的横向距离不同对天线性能的影响程度也有所不同。分析结果为天线作为一种异物检测工具的可行性提供了理论依据。     

Patterns of and mechanisms for shock-induced polarization in the heart: a bidomain analysis

This paper examines the combined action of cardiac fiber curvature and transmural fiber rotation in polarizing the myocardium under the conditions of a strong electrical shock. The study utilizes a three-dimensional finite element model and the continuous bidomain representation of cardiac tissue to model steady-state polarization resulting from a defibrillation-strength uniform applied field. Fiber architecture is incorporated in the model via the shape of the heart, an ellipsoid of variable ellipticity index, and via an analytical function, linear or nonlinear, describing the transmural fiber rotation. Analytical estimates and numerical results are provided for the location and shape of the "bulk" polarization (polarization away from the tissue boundaries) as a function of the fiber field, or more specifically, of the conductivity changes in axial and radial direction with respect to the applied electrical field lines. Polarization in the tissue "bulk" is shown to exist only under the condition of unequal anisotropy ratios in the extra- and intracellular spaces. Variations in heart geometry and, thus, fiber curvature, are found to lead to change in location of the zones of significant membrane polarization. The transmural fiber rotation function modulates the transmembrane potential profile in the radial direction. A higher gradient of the transmural transmembrane potential is observed in the presence of fiber rotation as compared to the no rotation case. The analysis presented here is a step forward in understanding the interaction between tissue structure and applied electric field in establishing the pattern of membrane polarization during the initial phase of the defibrillation shock.     

Reconstruction of Muscle Fascicle-Like Tissues by Anisotropic 3D Patterning

Tissue engineering of skeletal muscle has been proposed as a potential regenerative treatment for extensive muscle damage. In this regard, the highly organized structure of skeletal muscles makes the alignment of cells especially indispensable in muscle tissue engineering. However, achieving the desired alignment continues to prove challenging, particularly in 3D engineered tissue constructs. In this study, a biomimetic approach for the generation of functional skeletal muscle fascicle-like tissues by recapitulating 3D muscle-like cellular and extracellular organization, is demonstrated. Anisotropic 3D alignment of muscle extracellular matrix (MEM) nanofibrils capable of providing a pro-myogenic microenvironment by regulating the kinetics of fibrillogenesis in a stretchable elastomeric chip, is achieved. Reprogrammed muscle progenitor cells develop myofibers along the aligned MEM nanofibrils in a 3D configuration, culminating in the structural and functional maturation of skeletal muscle. The resultant 3D muscle fascicle-like constructs support de novo muscle regeneration and induce functional restoration of injured muscles in animal models inflicted with volumetric muscle loss and congenital muscular dystrophy. This study not only highlights the fundamental roles of the muscle–mimetic structural guidance cues for 3D muscle tissue engineering, but also unveils the clinical potential of artificial muscle constructs in regenerative medicine.     

Bi‐Layered Tubular Microfiber Scaffolds as Functional Templates for Engineering Human Intestinal Smooth Muscle Tissue

Designing biomimetic scaffolds with in vivo–like microenvironments using biomaterials is an essential component of successful tissue engineering approaches. The intestinal smooth muscle layers exhibit a complex tubular structure consisting of two concentric muscle layers in which the inner circular layer is orthogonally oriented to the outer longitudinal layer. Here, a 3D bi‐layered tubular scaffold is presented based on flexible, mechanically robust, and well aligned silk protein microfibers to mimic the native human intestinal smooth muscle structure. The scaffolds are seeded with primary human intestinal smooth muscle cells to replicate intestinal muscle tissues in vitro. Characterization of the tissue constructs reveals good biocompatibility and support for cell alignment and elongation in the different scaffold layers to enhance cell differentiation and functions. Furthermore, the engineered smooth muscle constructs support oriented neurite outgrowth, a requisite step to achieve functional innervation. These results suggest these microfiber scaffolds as functional templates for in vitro regeneration of human intestinal smooth muscle systems. The scaffolding provides a crucial step toward engineering functional human intestinal tissue in vitro, as well as engineering other types of smooth muscles in terms of their similar phenotypes. Such utility may lead to a better understanding of smooth muscle associated diseases and treatments.     

不同结构生物组织光透明作用比较

为了了解生物组织不同结构对光透明进程的影响,利用光相干断层成像术(OCT)和近红外光谱(NIR)对肌肉组织(猪骨骼肌)和上皮组织(猪胃黏膜)经丙三醇处理后的光透明效果进行了比较研究。结果表明,这两种组织的光相干断层成像术成像深度和内层次结构的成像对比度均得到改善;肌肉组织和胃黏膜组织的光透射率分别增加了21%和16%,而漫反射率分别降低了33%和21%;这两种结构组织的光透明效果(肌肉组织较好)和进程(肌肉组织较快)与各自的失水率和失水动力学成正相关,肌肉组织失水过程为先快后慢;胃黏膜组织的失水过程为先慢后快;肌肉组织的总失水率大于胃黏膜组织。这表明结构不同的生物组织的光透明效果存在差异,必须考虑其内部结构的影响。     

A new method for noninvasive measurement of multilayer tissue conductivity and structure using divided electrodes

This paper outlines a new method for measuring multilayer tissue conductivity and structure by using divided electrodes, in which current electrodes are divided into several parts. Our purpose is to estimate the multilayer tissue structure and the conductivity distribution in a cross section of the local tissue by using bioresistance data measured noninvasively. The effect of the new method is assessed by computer simulations using a typical two-dimensional (2-D) model. In this paper, the conductivity distribution in the model is analyzed based on a finite difference method (FDM) and a steepest descent method (SDM). Simulation results show that the conductivity values of skin, fat, and muscle layers can be estimated with an error of less than 0.1%. When random noise at various levels is added to the measured resistance values, estimates of the conductivity values for skin, fat, and muscle layers are still reasonably precise: their root mean square errors are about 1.06%, 1.39%, and 1.61% for 10% noise. In a 2-D model, increasing the number of divided electrodes permits simultaneous estimates of tissue structure and conductivity distribution. Optimal configuration for divided electrodes is examined in terms of dividing pattern.     

Discrete versus syncytial tissue behavior in a model of cardiacstimulation. II. Results of simulation

For pt. I see ibid., vol. 43, no. 12, p. 1129-40 (1996). The research presented here combines mathematical modeling and computer simulation in developing a new model of the membrane polarization induced in the myocardium by the applied electric field. Employing this new model termed the “periodic” bidomain model, the steady-state distribution of the transmembrane potential is calculated on a slice of cardiac tissue composed of abutting myocytes and subjected to two point-source extracellular current stimuli. The goal of this study is to examine the relative contribution of cellular discreteness and macroscopic syncytial tissue behavior in the mechanism by which the applied electric field alters the transmembrane potential in cardiac muscle. The results showed the existence of oscillatory changes in the transmembrane potential at cell ends owing to the local resistive inhomogeneities (gap-junctions). This low-magnitude sawtooth component in the transmembrane potential is superimposed over large-scale transmembrane potential excursions associated with the syncytial (collective) fiber behavior. The character of the cardiac response to stimulation is determined primarily by the large-scale syncytial tissue behavior. The sawtooth contributes to the overall tissue response only in regions where the large-scale transmembrane potential component is small     

A Bioprinting Process Supplemented with In Situ Electrical Stimulation Directly Induces Significant Myotube Formation and Myogenesis

Electric field stimulation has supported biophysical and biological cues for tissue regeneration approaches to affect cell morphology, alignment, and even cellular phenotypes types. Here, an innovative bioprinting approach supported by in situ electrical stiumlation (E-printing) is used to fabricate a bioengineered skeletal muscle construct composed of human adipose stem cells and methacrylated decellularized extracellular matrix (dECM-Ma) derived from porcine muscle. To obtain highly ordered myofiber-like structures, various parameters of the printing process are optimized. The E-printed structure exhibits higher cell viability and fully aligned cytoskeleton than the conventionally printed cell-bearing structures, due to activation of voltage-gated ion channels that affect various signaling pathways. When using the E-printed structure, expression of myogenesis-related genes is upregulated by 1.9–2.5-fold higher than when using a dECM-Ma structure produced without electrical stimulation. Furthermore, when implanted into a rat model of volumetric muscle loss, the structure yields outstanding myogenesis relative to the conventionally bioprinted structure.     

用偏振光学相干层析技术分析研究组织偏振特性

胶原质丰富而且结构排列整齐的生物组织受光照射时会显示双折射的特性。通过精确地控制入射光和反射光的偏振状态,偏振光学相干层析技术能够显示出组织的双折射性。我们利用斯托克斯参数和琼斯矢量,着重讨论点光源照射样品后其背景反射光的偏振特性,从而导出组织的偏振特性。     

偏振延迟梳状分波器的研制

梳状分波器由于具有较高的性价比,在窄间隙密集波分复用系统中已大量使用.文章介绍了一种利用偏振延迟结构制作窄信道间隔的梳状分波器的技术,使用该技术制作的梳状分波器具有插入损耗低、偏振相关损耗低、偏振模色散小且组装方便等特点.文章对这种新型的偏振延迟结构的基本理论、设计思想以及用这种结构制作的梳状分波器的结构做了详尽论述.