血液成分无创光学检测中浮动基准理论的适用性

在浮动基准理论（FRT）应用于血糖无创光学检测研究成果的基础上,进一步研究其在其他血液成分（如胆红素）无创光学检测中的适用性．根据径向检测基准位置存在的条件,经蒙特卡洛模拟的结果表明胆红素测量中难以找到浮动基准位置;而通过研究胆红素与水的置换效应,发现在波长524nm处吸光度值与胆红素的浓度无关,将该波长作为基准波长,实际测量中可以用于去除背景噪声和环境干扰．综合FRT在血糖及胆红素两种不同血液成分中应用的研究结果表明：对于不同检测成分,在相应的检测波段,浮动基准位置和浮动基准波长有一定的特异性,从而进一步完善和扩展了FRT的应用领域．     

浮动基准法无创血糖浓度检测技术

介绍了浮动基准法无创伤测量血糖浓度的原理,并模拟研究了其关键因素——径向检测基准位置的存在条件．在径向检测基准位置,漫反射光对葡萄糖浓度变化不敏感,因而可以作为内部基准来消除人体生理背景变化的干扰．通过设计不同背景条件下的Intralipid溶液测量实验,进行了浮动基准法的初步应用实验．实验结果表明,采用浮动基准法进行光谱数据处理后,有效地减小了测量环境变化及Intralipid样品背景变化的影响,极大地增强了葡萄糖浓度的分辨能力．     

径向跳动测量中测量基准对实际基准的误差修正法

本文论述了在径向跳动测量过程中 ,修正测量基准对实际基准不重合误差的原理和方法 ,给出了应用该方法的软件流程图 ,并对这种方法进行了实验分析。     

多参数监护仪无创血压测量特性的检测校准

目前大多数多参数监护仪血压参数的测量都是基于振荡法的无创血压测量.针对无创血压的检测校准,国内还没有相应的国家标准,只有电子血压计检定规程.这个规程只考虑静态血压,而没有考虑动态血压.对动态无创血压监护参数进行的检测校准,可以最大限度地保障临床使用的安全、准确、可靠.     

人体血糖无创测量中净信号的提取方法

提出了基于背景光谱构建噪声子空间提取葡萄糖净信号的方法,该方法不受参考浓度误差以及偶然相关因素的影响．对葡萄糖水溶液,以纯水为背景提取的葡萄糖净信号与传统方法的结果非常接近,相关系数达到0．9,且反映了葡萄糖的特征吸收信息．最后,在严格控制的实验条件下,对正常志愿者进行了活体口服葡萄糖耐量实验,并从生理状态不变的光谱构建的噪声子空间提取了血糖浓度变化导致的净信号．结果表明,口服葡萄糖耐量实验的漫反射光谱中的葡萄糖净信号,反映了葡萄糖分子在其一级倍频区域的特征吸收．这证实了左手掌部位采集的近红外光谱中确实携带了血糖浓度变化的信息．     

基于ARM的无创心血管功能检测系统

研发了一种智能化的无创心血管参数诊断系统．该系统应用动脉弹性腔模型和血液动力学理论,可以对10个重要的心血管参数进行测量．采用了基于ARM的嵌入式系统技术,克服了目前其他同类仪器体积大、测量参数单一等缺点．详细介绍了系统的硬件构成与软件流程．为了验证系统的性能,该系统在30个人中进行了初步实验．结果证明,该仪器具有良好的准确性和稳定性,与参考仪器测量结果的相关系数可达到0．95,重复性误差最大为2．36％,所获得的参数能较好地评价心血管功能状况,系统可运用于临床诊断和家庭健康监护．     

无创自动测量血压计使用及检定中问题的解决

一、使用中有关问题分析和探讨根据JJG692-2010《无创自动测量血压计检定规程》,无创自动测量血压计首次检定时最大允许误差为±0.4k Pa(±3mm Hg),后续检定和使用中检验时最大允许误差为±0.53k Pa(±4mm Hg);而JJG270-2008《血压计和血压表检定规程》规定血压计的示值最大允许误差为±0.5k Pa(±3.75mm Hg).     

Determination of the optical coefficients of biological tissue by neural network

A system that incorporated a laser source and a CCD camera was used to measure spatially-resolved steady-state diffuse reflectance. Monte Carlo simulations and experiments in tissue phantoms were used to train a neural network that characterizes the reflectance data on a turbid medium. The neural network was used to extract the optical properties (scattering and absorption coefficients) of biological tissue. The accuracy of the neural network was investigated and validated. Tests on tissue-simulation phantoms showed the relative errors of this technique to be 3% for the reduced scattering coefficient and 9% for the absorption coefficients. The optical properties of human skin were also measured in vivo at 633 nm. For human skin tissue it was found that our results were in good agreement with their reference values.     

A feature parameter of optical diffuse reflectance on normal and malignant human breast tissue

Light that is delivered to the tissue surface undergoes multiple elastic scattering and absorption; part of it returns to the surface as optical diffuse reflectance, carrying quantitative information on the structure and composition of the measured tissue. In this paper, we utilized a well tested and publicly available Monte Carlo simulation software to simulate optical diffuse reflectance on normal and malignant human breast tissue in the visible wavelength region 450–650 nm. Based on the Monte Carlo simulation results, we discovered a feature parameter of optical diffuse reflectance on the simulated tissue surface. Normal and malignant human breast tissue may be discriminated by the value of the feature parameter. The values of the feature parameter are shown for normal and malignant human breast tissue in the visible wavelength region 450–650 nm. Experiments with tissue phantoms showed that the feature parameter is correlated to the component of the phantom. So the feature parameter is useful for the non-invasive optical diagnosis of biological tissue.     

A new optical coefficient of biological tissue that determines the diffuse reflectance light distribution on the tissue surface

When a light beam is incident normally upon a tissue, the spatial distribution of diffuse reflectance on the tissue surface is affected by the optical properties of the tissue. The purpose of this paper is to find the relationship between the spatial distribution of diffuse reflectance on the tissue surface and optical properties of the tissue. The diffuse reflected light distribution is found to be determined mainly by a new optical coefficient μ_as. A qualitative relationship between μ_as and the diffuse reflected light distribution was developed by Monte Carlo simulations. Measurements of the diffuse reflected light distribution on solutions of Intralipid-10% with added ink confirm the Monte Carlo simulations. The new optical coefficient μ_as was measured from several tissue examples by the qualitative relationship. The value of μ_as was useful for determining the components of the tissue.