基于普通摄像机的人体运动信息检测系统

介绍了一种新型基于普通摄像技术的人体运动信息检测系统。探讨了运用图像处理技术快速准确识别与跟踪关节位置标志点的方法,解决了影响系统检测精度和运行速度的关键问题。该系统用普通摄像机取代专用设备,降低了系统成本;使用操作方便,具有较高的精度,不仅适用于人体运动信息的检测,而且可用作其它较低速运动物体的运动图像检测与分析。     

一种视频图像微机分析三维运动检测系统

作者根据“不在一条直线上的三点，可以规定刚体空间位置“这一定间解析几何基本原理，采用微机图像分析处理系统与录摄像设备相结合，建立了一种非接触式三维运动检测系统。该系统采用两台９０度位置的摄像机对同一测试标本进行同步拍摄，图像采用微机数字化处理，测量基其上标志点的三维空间坐标，数据经自编的三维运动计算程序处理，得出村本质心的三维，六自由度运动，经在颈椎生物力学研究中应用，发现该系统具有自动化程度高，     

震颤行为定量检测仪的研制与初步临床应用

震颤行为是巴金森氏病的一种常见的临床表现，目前在临床中对震颤行为的定量描述方法和定量分级标准尚未形成。作者介绍了利用光电位置检测技术构成的计算机化的震颤行为定量检测仪的原理和初步临床应用情况。     

一种光电容积脉搏波的特征点自动识别算法

目的为弥补现有光电容积脉搏波特征点识别算法存在的需要人为设定阈值筛选门限和对复杂波形适应能力较差的缺陷,提出一种基于脉搏波上升支单调增加几何特性的特征点自动识别算法。方法通过两次Hilbert变换后过零点检测在每个脉搏周期内确定一个"基准点",在"基准点"前后搜索距离其最近的凹拐点即为波谷点、凸拐点即为主波峰点。结果利用MIT-BIH标准数据库中18组数据进行检测验证,平均值达到99.94%灵敏度、99.72%查准率和99.68%检测准确率。对比已有的4种算法,在查准率上有明显的提升,应对复杂的波形依然能准确识别特征点。结论提出的算法在搜索确定脉搏波波谷点和主波峰值点位置过程中取得较高的检测准确率,同时展现出对波形变化更强的适应力。研究结果为临床上通过脉搏波特征提取进行生理病理分析提供良好基础。     

不同激振位置对压电式人工中耳听力补偿性能的影响

研究不同激振位置对压电式人工中耳听力补偿性能的影响,确定压电式人工中耳最优激振位置。建立人耳有限元模型,并通过和相关实验数据进行对比验证模型的可靠性。基于该模型,分别在鼓膜脐部、砧骨体、砧骨长突和圆窗施加相同的位移驱动,通过检测镫骨足底板位移及基底膜的最大位移,分析这些位置的激振对人工中耳听力补偿性能的影响。结果表明,以镫骨足底板位移为评估标准会低估圆窗激振的高频听力补偿效果。砧骨长突激振下的基底膜特征位置处的运动位移大于激振鼓膜脐部及激振砧骨体时的位移值,其中激振砧骨体时的基底膜特征位置处运动位移最小;激振圆窗时的基底膜特征位置处运动位移在低频段小于激振其他位置时对应的位移值,但在中、高频段其激振效果最好。在频率低于400 Hz时,砧骨长突激励听力补偿效果最好,圆窗激励听力补偿效果最差。当频率大于1 kHz时,圆窗激励听力补偿效果比其他位置好。以传统的镫骨足底板响应为评估标准,将低估圆窗激振式人工中耳的听力补偿效果。     

心率变化对心电信号各波间期的影响分析

分析了运动心电信号心率变化对其各特征波形的持续时间的影响程度,其中受影响最大的是ＴＰ间期,其次是ＱＴ间期,Ｐ波和ＱＲＳ波群的宽度基本不变,并根据ＱＴ间期的变化特点给出了运动心电关键检测参数ＳＴ段值的自适应调整Ｊ点后取值位置,对于准确地识别运动心电信号的各特征波和判定运动试验的结果具有重要意义。     

颈动脉不同径向位置的流速波形比较

本文分析颈动脉中血液流动的速度波形随径向位置的变化规律，详细讨论径向位置对流速波形中的最大值Ｖｍａｘ和最小值Ｖｍｉｎ的影响情况。以评估临床上超声流速探头偏离颈动脉管轴位置对所检测的流速可能产生的影响。结果表明当探头偏离血管轴的位置为ｙ＝ｒ／Ｒ≤０．２时，流速测量的相对误差能控制在１０％左右，这对指导无创伤检测血流速度的操作和分析有重要价值。     

多尺度MRI断层图像特征提取新技术研究

由于医学图像本身信号噪声大，边缘呈弱信号特征，用传统的图像边缘检测算法提取图像特征常会将图像中的噪声作为边缘提取，不能准确地反映医学图像中有价值的信息(如病灶大小等)。现提出一种改进算法，此法以现有的小波模极大值特征提取算法为基础，利用模糊理论确定隶属函数，提取弱信号边缘并用多尺度融合理论边缘点合成。结果表明，此方法在提取MRI图像特征的同时，可有效地抑制噪声，有助于剔除图像的伪边缘，准确定位图像边缘信息，有利于图像分割重建，便于医生根据图像确定病灶或组织的位置大小等。     

人体下肢关节坐标系的一种简单定义方法

在对人体运动进行运动学或者动力学分析的时候,通常需要对各关节建立局部坐标系,而目前大部分人体关节坐标系定义方法都主要针对临床应用,需要具备专业的解剖学知识且可操作性差。本文首先描述了下肢的主要解剖学特征点,并通过这些特征点构建了髋关节、膝关节及踝关节坐标系,提出了定义人体关节坐标系的基本原则。通过利用运动捕捉系统对自愿者步态过程中的下肢运动轨迹进行采集,分析构建坐标系的特征点在运动过程中空间相对位置的不变性,说明了文章提出的下肢关节坐标系定义方法在一定范围内是合理的。     

基于视频信号的微血管自律运动频率测量

针对目前微血管运动的检测对设备要求较高，检测时间较长的问题，提出一种简便观测微血管自律运动频率的方法。通过手机摄像头拍摄人体舌面视频，预处理后提取每帧图片中的感兴趣区域，根据每个区域中像素灰度值的变化得到血液容积变化的时序曲线；然后通过小波分解对每个感兴趣区域颜色通道的血液容积变化信号进行降噪，对降噪后的信号进行独立成分分析以降低光照和环境因素影响；提取源信号频域中主要峰值点频率进行拟合，实验结果表明本课题所提取信号频率属于微血管自律运动频率范围。     

Psychometric properties of measurement tools for quantifying knee joint position and movement: a systematic review

This systematic review critically evaluates literature on the reliability and validity of measurement tools for quantifying knee joint angles and knee movement. A search was conducted of seven medical databases and one biomedical engineering database, yielding 43 articles that reported reliability or validity. Tools for quantifying knee joint angles included standard handheld goniometers, fluid-based goniometers, gravity-based goniometers, photographs and two dimensional (2-D) motion analysis. Knee movement was measured with electrogoniometers, 2-D and three dimensional (3-D) motion analysis. Intraclass correlation coefficients for testing knee angles ranged from 0.51-1.00 for intratester reliability and 0.43-0.99 for intertester reliability. For quantifying knee position, sequential MRI and 2-D had the least error of measurement, followed by hand held goniometers and photographs. For dynamic measurements, electrogoniometers and 3-D motion analysis were most reliable and had low error of measurement. Strong concurrent validity was found between hand held goniometers and radiographs, as well as between hand held goniometers and 3-D motion analysis.     

Stereophotogrammetric system for kinesiological studies

This paper describes an inexpensive, simple to implement and use photogrammetric system for the measurement of three dimensional live movements. Nonmetric optical devices are used. All external parameters of the system are surveyed. The internal parameters are estimated using known positional information of control points. Both relevant hardware characteristics and mathematical equations are supplied. The accuracy of a particular implementation of the system adequate for human locomotion studies is discussed.     

医学图像三维可视化系统的构建

针对当前PACS的需要，利用可视化工具包VTK，设计和实现了一个能应用于PACS的三维可视化系统。该系统实现了医学图像的三维可视化与剖面显示功能，丰富了PACS的图像处理功能。     

枕颈部三维运动范围的测量

目的：研究枕颈部正常的三维运动范围，为枕颈部不稳分析和治疗提供生物力学基础。方法：运用脊柱三维运动测量分析系统，对１１具成人新鲜枕颈部标本的三维运动范围进行测试。结果：寰枕关节的前屈、后伸、左／右侧屈、左／右轴向旋转运动范围分别是：１１．７°、９．６°、２．８°／２．７°、６．９°／５．４°；寰枢关节分别为：８．９°、５．９°、３．４°／４．２°、３７．５°／３８．７°；寰枢关节中性区为２７．４°，占主运动范围的７１．７％；枕颈部与脊柱其它部位相比，主运动时伴有更明显的藕合运动，屈伸、侧屈时伴有比主运动范围更大的藕合旋转运动，分别为１０．５°、１４．３°。结论：脊柱三维测试分析系统不仅能对枕颈部的三维运动范围进行精确的测量，且能反映枕颈部三维运动的特点。     

New tridimensional approach to the evaluation of the spine through surface measurement: the BACES system

The aim was to test a new instrument, the BACES system, an articulated arm connected to a computer, to improve noninvasive examination of the spine and to reduce X-ray examinations. To this aim, four observers performed three series of eight measurements on a dummy and two healthy volunteers. Data on the projection of the spine, any curve detectable on the frontal and sagittal plane, and any rotation at each thoracolumbar level were collected and analysed. To detect the role of the observer, of the procedure and of the object in measurement variability, a two-factor analysis of variance was performed. The results showed measurement errors for kyphosis and scoliosis generally below 3 degrees, whereas the lordosis showed a major variability, especially in volunteers, because of the attitude role. Rotations showed a limited variability too, generally below 2 degrees. In the clinical setting, > 2 SD may reasonably be considered a clinical change because it has not a great chance of being a measurement error. Thus, the BACES system allowed us to identify with fairly good precision kyphosis, scoliosis and trunk rotations. Even though at the moment no surface measurement method can replace X-rays, the instrument can integrate and limit the use of radiographic evaluations.     

基于Web的医学断层图像远程重建

实现Internet上Web模式的医学图像三维重建及显示.基于Java Appler编程，利用数字签名解决Java安全限制，读取本地图像。采用体绘制法完成二维图像的三维重建与显示。由超高速CT获得人体器官的断层图像，在Web上重建出了、冠状动脉、头颅、颈椎、骨盆的三维解剖结构。重建可在Internet上以Web模式跨平台运行，且在三维图像上可进行切割模拟操作。结论：①用Java Applet实现基于Web的医学图像三维重 建是可行的，并对三维图像的临床应用起重要推动作用；②基于Web重建的三维医学图像，其精度能够满足临床要求，尤其是冠状动脉的解剖 结构在临床上有很大参考价值。     

A new method for measurement of bone deformation by echo tracking

No method has been available to noninvasively detect bone deformation or strain under loading in vivo. We focused on ultrasonic measurement of the displacement at a certain point on a bone using the echo-tracking method (ET). To develop a method that can noninvasively detect bone deformation in vivo, a preliminary investigation was performed. We investigated the accuracy of measuring displacement with our echo tracking system by using a flat metal panel and found that the method could measure displacement with a precision of a few microns. A three-point bending test of a porcine tibia with both ends fully constrained was performed to measure bone surface displacement, and simultaneous measurement of the surface strain was done using two strain gauges. The correlation between the displacement measured by ET and the strain gauge readings was completely linear (r=0.999), showing that the method could precisely detect bone deformation. The loads versus displacement curves obtained with cyclic loading were typical hysteresis loops that showed viscoelastic properties of the measured bone. We also improved a multi-ET system capable of simultaneously tracking multiple points to detect deformation of the bone surface. Measurement by this echo tracking system was also compared with strain gauge readings during a three point bending test with both ends of the tibia supported. The linearity of both methods was very high (r=0.998). Our ET method might have considerable potential for noninvasive measurement of bone viscoelasticity and plasticity.     

环境声信号库的建立

利用微机对１３８种环境声信号进行了采集、数据存储入库、声图分析，绘制了彩色三维声图及频谱图，并对频谱分析参数进行了统计处理。本数据库的建立为进行环境声信号研究分析和聋人的感觉代偿研究，提供了基础资料和手段。     

人体步态分析系统子系统—测力台系统及其临床应用

站立与行走是人体最基本的运动之一，对站立或行走时足底与支承面之间的压力（垂直、左右、前后三个方向的力）进行测量和分析，可以获得反映人体下肢的结构、功能乃至全身的协调性等方面的信息。本文介绍了人体步态分析系统的子系统—三维测力台系统，及其运用它对正常人和骨科病人的一些测量和分析结果，包括足底压力曲线、矢量图、功率谱、拟合曲线分析等