非接触磁感应脑阻抗断层成像系统设计

针对脑组织电阻抗的研究，本文设计了工作频率在10MHz的单通道硬件电路和试验台，可以分辨电导率介于0．001s/m到6s/m的四种不同浓度的NaCl盐溶液，并对模拟正常人脑组织（0．375s/m）的0．195％NaCl盐溶液目标，给出了初步成像结果。     

生物组织非接触光声层析成像EI北大核心CSCD

在光声成像中,超声信号通常需要采用接触传感器探测,这使其在很多应用中受到很大的限制,如脑功能成像。为了替代接触探测器实现非接触的光声层析成像(NCPAT),激光干涉技术被用于远程获取超声信号。本文搭建了非接触光声层析成像系统,系统采用波长为532 nm、能量17.5 m J/cm^2的激光作为光声激发源,激光外差干涉仪作为光声信号的远程探测系统,对实际生物组织模型进行了旋转几何的光声信号探测。利用激光外差干涉仪探测到的光声信号,进行反投影算法的图像重建。实验结果表明在具有组织散射特性的模型中,激光外差干涉仪在2.25 MHz带宽(峰值下15 d B强度的信号宽带)下,NCPAT成像系统可以识别500μm直径的黑色微球,并实现了在强散射介质中多层结构的光学对比成像。这将扩展光声和超声在体成像在生物医学领域的应用范围。     

心冲击图的雷达式非接触检测技术研究

本文介绍了一种检测人体心冲击图的全新技术。该技术运用多普勒雷达原理 ,采用低功率 (P <1mW)毫米波 (λ =8mm)为探测信号 ,探测距离S >10m。在检测对象着各类衣服 ,处于不同姿势、不同的天线照射角度等情况下 ,该技术均可较高质量的非接触、无约束检测到人体心冲击图。该研究为临床监护、家庭保健监护、灾害救护提供了诱人的前景。     

非接触式人体心率监测方法的研究进展

接触式人体心率监测方法的研究广泛而深入,但由于临床特殊环境及患者特殊状态的需要,近年来非接触式监测心率的研究越来越受到关注。文章阐述了测量人体心率研究现状,对比分析了生物雷达技术、语音提取技术、生物热成像技术、人体轮廓图像分析技术、容性耦合技术、激光多普勒技术在提取特征参数时抗干扰、准确度、辨识度等方面的优势与不足,最后指出非接触式提取心率越来越受到国内外生物医学工程研究领域的关注。相信随着新的数据分离技术及高灵敏传感器的不断深入研究,该方法在临床医学方面将得到广泛的应用。     

基于生物雷达的人体步态非接触检测技术研究进展

人体步态是一个全身肌肉骨骼协调运行的复杂机制,具有特异性,可作为身份识别或临床疾病诊断的依据,在灾害救援、战场救护、反恐安保及医疗卫生等领域有着广泛的应用价值.传统的步态非接触检测技术主要包括光学图像和超声等,其易受光线、能见度及障碍物等因素影响.近年来,生物雷达技术发展迅猛,基于生物雷达的人体步态信号非接触检测技术更具优势,主要表现在:不受光线影响,可全天候识别;可穿透衣物、伪装甚至墙壁;可在烟、尘、雾等能见度低的天气条件下使用等.论述了生物雷达技术非接触检测人体步态的技术原理和方法,综述其研究现状,并对其发展趋势进行展望.     

心脏运动的非接触检测：原理与应用

心脏运动的非接触检测是心脏泵生理功能检查的一个有效手段。本文综述了进行心脏运动非接触检测的位移心动图或心动描记图的检测原理、方法及其临床应用研究，对各种不同的具体方案的特点进行了比较。     

基于超声成像的眼压非接触测量方法

目的 目前市场上主流眼压测量设备以接触式和刺激性激励为主,使用过程中极易给患者带来不适,更有甚者会导致角膜感染。为了解决这一问题,提出一种超声成像眼压非接触式测量方法。方法 对该方法进行有限元分析与实验验证,得到角膜形变仿真计算结果,制作模拟眼并搭建眼压测量实验系统,建立眼压、角膜形变与压力的数学模型,并对该模型进行准确性和重复性验证。结果 在某一眼压下,角膜的压平直径和顶点位移分别与压力存在幂函数与线性关系;在恒定压力下,压平直径和顶点位移均与眼压存在幂函数关系,可作为眼压测量指标。通过该方法测得的眼压平均相对误差在8%以下,相对平均偏差在9%以下,重测信度均大于0.9。结论 该方法测量结果准确,重复性较好。研究结果为眼压的非接触测量提供一种有效途径,具有较好的应用前景。     

非接触眼压计与修氏眼压计测量结果的比较

青光眼是四大致盲眼病之一,眼内压增高是青光眼诊断的重要依据。眼压测量对筛查青光眼有重要作用[1-2]。随着诊断技术的不断发展,眼压测量技术由Sch iotz眼压计发展到压平眼压计(GAT)和非接触式眼压计(NCT)。笔者就Sch iotz眼压计和非接触眼压计在临床应用的准确性、可行性进行了测量和评价。现报告如下。1资料与方法1.1临床资料本组患者25例,其中男性11例,女性14例;年龄均在50岁以上,其中50~60岁男10例;60~70岁8例;70岁以上7例,所有患者均无确诊青光眼患者,排除高度近视。1.2方法采用日本产CT-80A非接触眼压计和国产Sch iotz眼压计。…     

肺非特异性防御机制的研究进展

本文综述了近年来肺非特异性防御机制的研究进展,主要包括呼吸道抗微生物肽、巨噬细胞和细胞因子应答以及中性粒细胞的募集和吞噬方面的新发现、新观点.     

非接触标测和频谱分析迷走神经介导的心房颤动

目的： 对在体犬迷走神经介导的心房颤动（房颤）进行非接触标测和频谱分析，以探讨其发生和维持机制。方法: 测定8只犬基础情况及双侧迷走神经刺激时心房有效不应期及其离散度，非接触标测和频谱分析房颤时左、右房的电活动。结果: 迷走神经刺激与基础情况相比，左、右心房有效不应期缩短，但有效不应期离散度增大仅见于左房。迷走神经刺激时房颤易诱发和维持，房颤显示反复有序的激动经优先传导路径传播仅见于左房；频谱分析显示左房的主导频谱高于右房［（12.5±1.5)Hz vs (9.3 ±1.2) Hz，P<0.05］。停止迷走神经刺激，左、右房房颤频谱降低［（9.2±0.5)Hz vs (8.5±0.6)Hz， P>0.05］，房颤自发终止。结论: 左、右房电生理特性改变、激动模式差异以及频谱梯度提示迷走神经介导的房颤发生和维持依赖于左房。     

A novel autonomic activation measurement method for stress monitoring: non-contact measurement of heart rate variability using a compact microwave radar

We developed a novel method for non-contact monitoring of stress-induced autonomic activation through the back of a chair, using a compact 24 GHz microwave radar (8 x 5 x 3 cm), without large-scale equipment and placing a heavy burden on the monitored individual. Following a silent period of 120 s, audio stimuli using a composite tone of 2,120 and 2,130 Hz sine-waves at 95 dB were conducted for 120 s. From dorsal, LF/HF of HRV reflecting sympatho-vagal balance was determined by microwave radar with the maximum entropy method using eight volunteers (mean age 23 +/- 1 years). Mean LF/HF measured by non-contact and contact (using electrocardiography for reference) methods during audio stimuli increased 34 and 37%, respectively, as compared with those of the silent period. Maximum cross-correlations between contact and non-contact measurements averaged 0.73 +/- 0.10. Our method appears to be promising for future monitoring of stress-induced autonomic activation of operators and may reduce stress-induced accidents.     

A non-contact vital sign monitoring system for ambulances using dual-frequency microwave radars

We developed a novel non-contact monitoring system to measure the vital signs of casualties inside a moving ambulance. This system was designed to prevent exposure of patients to infectious organisms under biochemical hazard conditions. The system consists of two microwave radars: a 10-GHz respiratory-monitoring radar is positioned 20 cm away from the surface of the isolator. The 24-GHz cardiac-monitoring radar is positioned below the stretcher underneath the isolator. The subject (22.13 ± 0.99 years) was placed inside the isolator on a stretcher in the simulated ambulance. While the ambulance was in motion at a speed of approximately 10 km/h, the heart rates determined by the cardiac-monitoring radar correlated significantly with those measured by ECG (r = 0.69, p < 0.01), and the respiratory rates derived from the respiratory-monitoring radar correlated with those measured by the respiration curves (r = 0.97, p < 0.0001). The proposed system appears promising for future on-ambulance monitoring of the vital sign of casualties exposed to toxins.     

Non-contact respiratory monitoring system using a ceiling-attached microwave antenna

Using a microwave antenna attached to the room ceiling, we conducted non-contact monitoring of respiratory chest wall motions of subjects in bed and covered by a soft comfortable bedding, to measure the vital signs of patients under nursing care in a welfare institution. Long-term vital sign monitoring using electrodes places a heavy burden on monitored individuals. Our non-contact respiratory monitoring system comprises a 1,215 MHz-microwave radar (LDR-1), antenna box attached to the ceiling, and personal computer with analyzing software. The system was tested on eight healthy volunteers (mean age, 25 years; range, 21–44 years) and eight elderly volunteers with some disorders (mean age, 69 years; range, 66–75 years). Respiratory rates of subjects measured using this system correlated with rates measured using respiration sensors (r = 0.97, P < 0.001 for healthy volunteers, r = 0.98, P < 0.0001 for elderly volunteers). The system could monitor subtle changes in respiratory rate, and monitoring respiratory rate increases caused by disorders such as pneumonia will be possible.     

呼吸信号检测技术研究现状

呼吸检测方法主要分为接触式和非接触式2大类.接触式检测方法包括容积式呼吸检测法、速度式呼吸检测法、温度检测法、位移检测法、阻抗检测法、可穿戴技术和睡眠床垫等.这些方法属于无创检测且技术成熟,但都需要电极或传感器直接或间接接触人体,使人体受到一定的约束或限制,不适合用于严重烧伤患者和新生儿的呼吸监测.非接触式检测利用电磁波、光等媒介,使用无需与人体接触的电极或传感器,可在人体自然状态下对呼吸信号进行非接触检测,特别是基于红外线和生物雷达的非接触检测方法,已成为国内外研究的热点,可用于临床、社区医疗及家庭监护.     

Modified FMCW system for non-contact sensing of human respiration

Abstract

Small displacement detection capability becomes an important key for developing non-contact sensor for human respiration based on radar system. Frequency modulated continuous wave (FMCW) radar has been widely studied and applied for many applications. With respect to the conventional perspective, large bandwidth is needed for detecting the small displacement related to the human respiration. Meanwhile, extracting the respiration pattern from Doppler response has a drawback in identifying the small displacement location. In this paper, the modification on FMCW system was proposed for obtaining the capability in detecting the human respiration and its distance from the radar. Detecting the phase value of the low pass filter (LPF), output from conventional FMCW was investigated and applied as a modification concept. The pattern, rate and amplitude of respiration are extracted from phase detector output. Beat frequency detection is still elaborated for synthesising the reference signal for phase detection. The result shows that the modified FMCW system proposed the capability of detecting the rate and amplitude respiration and location of the target.     

生物雷达信号处理方法研究进展

生物雷达是雷达技术与生物医学工程技术相融合、可在较远距离探测生命信号的特殊雷达,是近年来国外提出的一种新概念雷达.该技术可用于生命体征探测以及非接触临床监护领域.生物医学信号处理方法是该技术得以实现的重要条件.生物雷达信号容易受到检测对象及环境的干扰,特别是呼吸运动回波信号较强,对心搏信号产生混合干扰,使其无法独立检出.因此大量信号处理方法运用在该技术的各个方面.介绍了生物雷达技术进展,以及当前主流信号处理方法的应用情况.     

Oesophageal probe for heart and temperature monitoring during anaesthesia

Electrocardiogram, body temperature and heart sounds are important variables to monitor during anaesthesia. An oesophageal probe for combined monitoring of these variables has been designed. Special consideration has been given to the potential hazards of placing devices close to the heart and in direct contact with the delicate oesophageal mucosa. The probe contains segmental silver electrodes for e.c.g. recording and a miniature accelerometer for heart sound detection, located close to the tip of a 5 mm O.D. PVC tubing.     

A biomedical sensor system for real-time monitoring of astronauts’ physiological parameters during extra-vehicular activities

Objective

To design and test an embedded biomedical sensor system that can monitor astronauts’ comprehensive physiological parameters, and provide real-time data display during extra-vehicle activities (EVA) in the space exploration.

Methods

An embedded system was developed with an array of biomedical sensors that can be integrated into the spacesuit. Wired communications were tested for physiological data acquisition and data transmission to a computer mounted on the spacesuit during task performances simulating EVA sessions.

Results

The sensor integration, data collection and communication, and the real-time data monitoring were successfully validated in the NASA field tests.

Conclusions

The developed system may work as an embedded system for monitoring health status during long-term space mission.     

组织工程骨研究背景与进展

【摘要】随着骨缺损治疗方法的改进,组织工程骨的研究日益蓬勃,组织工程方法治疗骨缺损是一种新的模式。本文复习相关文献,综合报道组织工程骨的研究背景及其种子细胞、生物支架材料及组织工程骨构建三大要素的研究进展,探讨指出目前存在的问题和今后研究的方向。     

人发角蛋白在再生医学中的应用研究进展

角蛋白具有可生物降解、生物活性高和相容性好的优势,从人发中提取的角蛋白还具有低免疫排异性.相对于其他本体材料,其来源几乎不受限制,因而在再生医学领域的研究应用受到越来越多的重视.近年来,人发角蛋白以凝胶、海绵支架、涂层、膜以及复合材料的形式应用于神经材料、皮肤敷料、细胞培养、药物载体以及软组织修复等方面,显示出其在再生医学领域的发展潜力.