非接触式心率测量研究初步

基于Matlab软件平台,通过图像光电容积脉搏波描记法(iPPG),提取心率波信号。结合人脸检测与跟踪技术,选取脸部三角区域作为感兴趣区域 (ROI),从中分析提取iPPG信号,然后采用快速傅里叶变换计算出心率。通过对20名志愿者的实验,结果显示在不同颜色通道(R、G、B)提取出的心率信号的信噪比不同,其中G通道的心率信号最强。分析数据显示,与医用心电测量仪相比,该方法测量的平均误差为1.73 beat/min。采用光容积成像技术检测方法,可进一步实现血液灌注三维可视化,能检测动脉血氧饱和度、呼吸率、神经系统的生理活动和新生儿监护,甚至能应用于家庭移动医疗、运动检测等大众场合,提高便捷性,降低医疗成本。     

基于IPPG非接触式生理参数测量算法的研究

介绍了基于成像式光电容积描记技术(imaging photoplethysmography,IPPG)的非接触式人体生理参数测量算法的研究工作。在自主研发的IPPG非接触生理参数测量仪中运用IPPG的新原理。运用视频图像处理的新方法,基于视频信号检测经过人体组织和血液吸收后的反射光强不同,从得到的脉搏波中计算出心率、呼吸频率及血氧饱和度。实现了人体生理参数无创连续非接触测量的新技术。经过实验验证与对比分析,本系统取得了较好的测量效果。在未来家庭健康医疗发展的场景下,具有很大的应用价值。     

人体组织成份的模型及检测方法的研究

本文综述了近年来国内外关于人体组织成份的模型和检测技术的研究现状。其中包括基于五个层次的人体组织模型的建立和１１种检测方法。该领域的研究成果为更好地预防，诊断和治疗人体开辟了一条新途径。     

人体组织成份的模型及检测方法的研究

本文综述了近年来国内外关于人体组织成份的模型和检测技术的研究现状。其中包括基于五个层次的人体组织模型的建立和１１种检测方法。该领域的研究成果为更好地预防、诊断和治疗人体疾病开辟了一条新途径     

软组织厚度自动测量器械的设计与实验研究

目的研究自动测量软组织厚度的关键技术,设计一种自动测量组织厚度的器械,通过实验验证其可行性及准确性。方法设计测厚实验系统,采用直流减速编码器电机实现对测量结构的反馈和控制,按照结构内部的传动关系建立主从运动量间的关系式,即电机转轴转动圈数与器械前端所夹组织厚度的关系,从而实现测厚功能。根据实验组与对照组的结果分析测试实验系统的误差与分布情况。结果 9组实验共产生27对厚度数据,其误差平均值为-0.07 mm,方差为0.03 mm2。按实验次数分组,其组内误差波动较小;按厚度值分组,其组内误差波动较大。结论采用该器械测量厚度是可行的,但还存在一定误差;实验批次决定了器械测量的初始位置,对测量结果影响较大;不同厚度值对应器械前端不同的开口角度,对测量结果影响较小。     

非接触式CT工作管电压检测系统的设计

目的设计了一种非接触式CT扫描工作电压检测系统。方法通过在CT系统上分别进行一组空气和金属膜的扫描,系统计算X射线在空气与金属中的强度衰减比,模拟CT系统曝光工作电压。结果经过实际的CT系统测试和验证,测试结果显示最大的精度误差为-1.225%,满足行业标准的误差要求。结论作为一种安全、简易、低成本的方法,本系统可以替代传统的管电压测试。     

基于改进色度模型的非接触式心率检测与估计

成像式光电容积描记技术能够实现低成本、非接触的远程生理参数检测与估计。其中,基于色度模型的视频图像心率估计算法计算简单、效率高,且具有较强的抗运动干扰能力,但并未考虑实验中光照变化产生的信号干扰。针对该问题,提出一种基于改进色度模型的非接触心率估计算法,通过定义感兴趣(ROI)区域和背景区域的反射光模型,利用两种区域颜色通道信息的比值来消除光照干扰,从而得到消除光照干扰的色度模型,并进行脉搏波的提取与心率估计。对10名在校大学生采集到的人脸图像进行分析,发现该算法估计心率的相对误差为3.52%±2.53%,原始色度模型算法的相对误差为7.23%±2.82%,两者对比有显著性差异(P<0.01)。该算法能有效抑制光照变化所引起的干扰,使所提取脉搏波信号的信噪比平均提高1.52 dB,这对更精确地进行非接触式心率估计与脉搏波信号提取具有重要意义。     

非接触生命参数检测系统自抖动干扰的自适应对消研究

非接触生命参数检测系统可以不接触人体、隔一定的距离检测重要的生命参数 ,如呼吸、心跳等。实际检测中 ,由各种因素所引起的系统本身的自抖动干扰 ,使检测信噪比大大降低 ,本文讨论了一种基于时变步长L MS算法的自适应技术来对消系统的自抖动干扰 ,提出了用附加振动传感器来提取自抖动干扰参考信号的方法 ,并研究了算法的最佳参数。研究结果表明这种方法收敛速度快 ,能有效的对消自抖动干扰     

基于Zener模型的生物组织剪切模量测量

目的克服基于Voigt模型的超声振动检测方法的不足,使用Zener模型更加准确地测量生物组织剪切模量,为组织定征提供有效的手段。方法利用基于力学模型本构关系的剪切波传播速度公式,在获得剪切波在多个频率上速度的前提下,通过数学方法估计出介质的剪切模量。实验对象为不同浓度的凝胶模型和不同程度热力学损伤的猪肝脏,通过超声辐射力振动产生剪切波,获取剪切波在不同实验介质中的传播速度。结果分别用Voigt模型和Zener模型对速度值进行拟合,结果均显示Zener模型描述的准确性更高,并且所估计出的剪切模量能够很好地区分不同浓度的凝胶模型或不同损伤程度的猪肝。结论本方法为无创测量生物组织剪切模量提供了潜在的手段,对医学上的组织定征和疾病诊断有着重要的意义。     

用于提高非接触体温测量精度的恒低温环境系统的设计与实现

目前非接触体温测量已成为研究体温测量方向的热点问题.普遍采用的非接触体温测量的方法是红外辐射法,即用热电堆传感器把人体辐射的红外线能量转化成电信号,但热电堆传感器易受到环境温度影响.提出一种适合于红外传感器的恒低温环境系统的设计方案,可以避免环境温度变化对红外传感器输出信号的影响,且可以增加输出信号的信噪比.采用半导体制冷片(TEC)作为控温的执行器件,利用单片机输出的脉冲宽度调制(PWM)信号对半导体制冷片进行控制,采用PID算法控制调节PWM的占空比.当控温基线在0 ℃时,温度波动小于0.05℃.     

一种无创脉搏波检测分析系统的研制

研制了一套无创脉搏信号检测分析系统，系统采用生理压力传感器同时采集两路脉搏波信号，实现了脉搏波信号的实时采集、存储、动态显示、波形波速度分析和诊断报告的打印，能够较全面的评价心血管系统的功能。该系统采用单片机与计算机结合的设计方式，同时具有单片机小型化、便携的特点和计算机强大的数据存储、分析、处理的能力。初步临床实验表明，该系统操作方便，稳定性好，检测的可重复性较好。     

神经电极的水凝胶涂层及楔形角对组织损伤的影响

目的研究水凝胶涂层的厚度以及电极楔形角对植入损伤的影响。方法基于植入损伤评估系统,进行模拟神经电极植入过程的实验,评估电极植入造成的组织损伤。用浸涂次数(分别为0、1、2、3)控制水凝胶涂层的厚度,选用30°、40°、50°、60°为电极楔形角的变量。以最大组织应变和最大植入力为组织损伤的衡量标准。结果水凝胶涂层越厚,电极植入损伤越大。楔形角越小,植入损伤也越小。同时,减小针尖的楔形角可以减小涂层对组织损伤的影响程度。3次浸涂时,楔形角为30°时,最大组织应变与最大植入力分别增加3.4%和3.8%,而楔形角为60°时,两者分别增加11.3%和18.1%。结论神经电极的水凝胶涂层将增大植入电极对生物组织的损伤,然而减小电极尖端楔形角的方法可以降低水凝胶涂层厚度对植入损伤的影响程度。     

人脂肪干细胞与VEGF-PLGA纳米微球缓释系统构建工程化脂肪组织的相关研究

目的 探讨缓释血管内皮生长因子复合支架与脂肪干细胞构建工程化脂肪的可行性。方法 制备VEGF-PLGA纳米微球缓释支架,检测支架释放 VEGF 浓度,体外提取培养 ADSCs,检测复合支架对 ASC 生长增殖的影响。将复合支架和ADSCs植入裸小鼠背部,8 周后切取植入物称重,组织切片HE染色,评估效果。结果 VEGF-PLGA纳米微球缓释复合支架能连续 12 d释放较高浓度的VEGF,对 ADSCs的生长增殖无影响。动物实验结果显示复合支架与ADSCs共移植能显著提高脂肪组织的形成,增加血管的生成（P＜0.01）,减少组织坏死。结论 VEGF-PLGA纳米微球缓释系统具有良好的生物安全性,其与ADSCs共移植构建工程化脂肪组织具有一定的可行性。     

Effects of Motivation and Verbal Response Type on Psychophysiological Detection of Information

Two independent experiments were designed to investigate the effects of motivation to deceive and the type of verbal response on psychophysiological detection using the Guilty Knowledge Technique. The first was a field experiment in which 72 subjects were randomly assigned to 8 experimental conditions. These conditions were created by a 2 x 4 factorial design (two motivational states crossed with four verbal response modes--affirming, denying, repeating, or no verbal response to questions about personal information). The second experiment was a laboratory experiment in which 160 students were assigned to the same 8 conditions. Results of both experiments indicated that highly motivated subjects were detected better than less motivated subjects. The act of lying was associated with enhanced differential responsivity, but no effects were obtained for verbal response versus no response or for variable versus standard verbal response. Differential responsivity tended to decline when questions were repeated. The first experiment revealed a clear advantage of electrodermal measures over respiration and cardiovascular measures. The results were discussed in relation to previous findings, a new theoretical formulation, and practical implications.     

磁微粒化学发光法的肝纤四项检测限与功能灵敏度研究

目的 评价磁微粒化学发光法检测肝纤维化血清学标志物(透明质酸、层粘连蛋白、Ⅲ型前胶原N端肽、Ⅳ型胶原)的空白限、检出限和功能灵敏度.方法 参照美国临床和实验室标准化协会(Clinical and Laboratory Standards Institute, CLSI)文件,利用空白样品及系列梯度稀释样品在AutoLumo A2000全自动化学发光测定系统上进行检测,确定该方法配套试剂的空白限、检出限及功能灵敏度.结果 透明质酸的空白限为7.59ng/mL、检出限为16.17ng/mL、20％变异系数(coefficient of variation,CV)功能灵敏度为18.72ng/mL;层粘连蛋白的空白限为1.38ng/mL、检出限为3.53ng/mL、20％ CV功能灵敏度为4.16ng/mL;Ⅲ型前胶原N端肽的空白限为0.89ng/mL、检出限为2.40ng/mL、20％ CV功能灵敏度为2.48ng/mL;Ⅳ型胶原的空白限为2.42ng/mL、检出限为6.49ng/mL、20％ CV功能灵敏度为9.21ng/mL.结论 全自动化学发光测定肝纤四项的空白限、检出限和功能灵敏度的建立为临床诊断和治疗提供了更有价值的信息.     

激光消融生物软组织热效应的数值模拟和实验研究

针对激光消融中的关键参数(功率、时间、流速)与消融参数(长短轴和体积)之间的关系进行研究,进行离体组织热效应定量分析,为激光消融手术设备及临床应用提供理论依据及方法指导.选取新鲜猪肝,采用激光生成器(980 nm)和水冷设备,在不同输出功率(0.5、3.0、5.0、7.0、10.0、12.0、15.0 W)和不同时间(...     

Coordinate Regulation of Matrix Metalloproteinase-1 and Tissue Inhibitor of Metalloproteinase-1 Expression in Human Vascular Smooth Muscle Cells

The expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) by human vascular smooth muscle cells (SMC) was monitored as a function of the phenotypic modulation in vitro. Cell phenotype was manipulated by varying serum concentration and cell density. Synthetic phenotype was characterized by a minimum expression of the contractile proteins and a maximal proliferation rate. Contractile phenotype was quiescent and expressed a maximal level of contractile proteins. Synthetic cells expressed the highest levels of both MMP-1 and TIMP-1 and displayed maximal collagenolytic activity. No significant change was detected in MMP-2 expression or catalytic activity. Enzyme immunoassays revealed that MMP-1 expression fell by 77 ± 2.4-95 ± 0.5%, and that of TIMP-1 by 34 ± 0.5-59 ± 1.9%, as the cells acquired a contractile phenotype. The level of the MMP-1/TIMP-1 complex was similarly reduced by 78 ± 2.9-85 ± 1.6%. These data demonstrate that the expression of MMP-1 and TIMP-1 are coordinately regulated with SMC phenotype.     

鸵鸟与人股骨近端组织结构对照研究

目的 本研究旨在评价鸵鸟股骨头生物学特征,探讨其作为股骨头缺血坏死模型实验动物的价值。方法 鸵鸟6只,体重（73.28±5.87）kg,雌雄不限。4只麻醉处死后取双侧股骨。对股骨头形态、关节软骨进行大体观察。X线及CT检测骨质形态及骨小梁走行。测量股骨头最大直径 、颈干角 、前倾角。取关节软骨行HE染色、Masson染色及甲苯胺蓝染色检测。2只鸵鸟行股骨内血管造影检查。结果 鸵鸟股骨头大体呈球形,无明显股骨颈,股骨头及转子形成连续的骨性平台,表面覆以软骨;X线显示股骨内存在两组纵行压力骨小梁系统,内侧起自股骨头止于内侧骨皮质,外侧起自转子下止于外侧骨皮质;股骨头最大直径（45.40±4.40）mm、颈干角（122.29±0.84）°、前倾角（11.62±0.40）°;关节软骨HE染色示软骨基质均匀淡染成红色,软骨细胞呈极性排列,形态呈圆形,染色浅,核偏心嗜碱性。软骨基质Masson染色呈亮绿色,甲苯胺蓝染色强阳性;骨内血管造影显示鸵鸟股骨头血供由支持带动脉,骨内滋养动脉及圆韧带动脉供应。结论 尽管鸵鸟股骨头直径、颈干角、前倾角、关节软骨性质与人类相似。鸵鸟股骨上段解剖结构及力学传导方式及供血方式与人类存在差异,此类大型双足动物为基础制备的股骨头坏死模型仍无法完全模拟人类病理过程。     

Analysis of Human Tissue Management Models for Medical Research: Preparation for Implementation of the 2012 Revision of the Bioethics and Safety Act of Korea

Efficient management of human tissue samples is a critical issue; the supply of samples is unable to satisfy the current demands for research. Lack of informed consent is also an ethical problem. One of the goals of the 2012 revision of Korea''s Bioethics and Safety Act was to implement regulations that govern the management of human tissue samples. To remain competitive, medical institutions must prepare for these future changes. In this report, we review two tissue management models that are currently in use; model 1 is the most common system utilized by hospitals in Korea and model 2 is implemented by some of the larger institutions. We also propose three alternative models that offer advantages over the systems currently in use. Model 3 is a multi-bank model that protects the independence of physicians and pathologists. Model 4 utilizes a comprehensive single bioresource bank; although in this case, the pathologists gain control of the samples, which may make it difficult to implement. Model 5, which employs a bioresource utilization steering committee (BUSC), is viable to implement and still maintains the advantages of Model 4. To comply with the upcoming law, we suggest that physicians and pathologists in an institution should collaborate to choose one of the improved models of tissue management system that best fits for their situation.     

Effect of Enamel Prism Decussation and Chemical Composition on the Biomechanical Behavior of Dental Tissue: A Theoretical Approach to Determine the Loading Conditions to Which Modern Human Teeth are Adapted

This theoretical study explored whether the directions of loads to which modern human molars are commonly subjected to are reflected in the biomechanical behavior of the tissue itself. A detailed finite element model of a piece of decussating enamel (M³ paracone) was created, taking into account differences in crystal orientation between the prism head and the interprismatic matrix, and was tested under differently angled mediolateral loads (i.e., mimicking various stages of the chewing cycle). Second, although teeth are highly mineralized, they also contain organic material and water, while in modern humans, there are systematic differences in chemical composition from the outer enamel surface to the dentinoenamel junction. To test the biomechanical effects of this gradient in mineralization a second set of models with gradually changing properties was created and subjected to the same loads. Chemically heterogeneous enamel yielded overall lower stress levels than homogenous enamel, especially at extreme loading angles. However, the general trends regarding the increase in tensile stresses at more oblique angles, and the number of nodes exhibiting tension, were comparable between the different set‐ups. The findings support suggestions that (a) the biomechanical behavior of dental tissue is the combined result of micromorphology and chemical composition and (b) that the range of loading directions, to which teeth are normally subjected to, can be inferred from dental microanatomy. For (palaeo)biological applications, the findings suggest that the absolute strength of teeth (e.g., bite force) cannot be predicted with certainty, whereas kinematic parameters of the masticatory apparatus can. Anat Rec, 2007. © 2008 Wiley‐Liss, Inc.