基于压电薄膜的非接触式人体生理信号监测椅

对人体的心率和呼吸信号进行日常监测有助于人体健康生活管理,该文设计了一种非接触式生理信号监测系统。通过装有聚偏氟乙烯(PVDF)压电薄膜传感器的新型椅子结构感知人体振动产生的微小压力作用,并将振动信号传送给上位机软件;从振动信号中提取心冲击信号与呼吸信号,并通过LabVIEW显示波形变化,可以完成心率和呼吸的实时监测。结果表明,装置监测的心率值与血氧脉搏仪相比,其平均误差为2.013％,平均呼吸率误差为4.88％,具有较好的实用性。     

基于光电脉搏波描记方法的多生理参数测量研究

基于单个反射式光电探头,在桡动脉位置测量了脉搏波。利用ATmega16单片机进行660nm和940nm的双波长LED发光控制和数据采集与分析。通过对脉搏波极值的读取实现血氧饱和度和心率的测量;其次,利用时间抽取基2快速傅里叶变换(FFT)对获取的桡动脉信号进行傅里叶变换,实现呼吸频率的测量。测量了10名志愿者的生理参数,并对利用本文设计的系统的测量结果和临床方法记录的结果进行数据的相关性分析,得到血氧饱和度、心率和呼吸频率的相关系数分别为r=0.985、r=0.982和r=0.933。通过相关性分析可以看出,可以利用本文系统进行无创、长时间和多参数的测量。     

引入曲率与角度校正的柔性机构三维形状多芯光纤重构方法

为提高柔性机构三维位形参数光纤测量精度,提出了基于曲率与角度校正的多芯光纤三维形状重构方法。通过引入方向角和曲率校正系数,改进了柔性三维形变多芯光纤重构算法;利用准分子激光器和相位掩膜法制备了多芯光纤光栅传感阵列,建立了多芯光纤三维形状重构实验系统;实验测量了不同曲率比例因子下的形状重构误差,分析了曲率与角度校正前后形状重构误差;通过对应变进行了三次样条插值,并对方向角和曲率进行了校正,得到了形状重构误差平均值为0.74 mm、最大值为1.64 mm;利用校正后的多芯光纤传感系统进行三维螺旋形变重构实验,得出重构精度提高了10.2%。研究结果表明,基于曲率与角度校正的多芯光纤三维形状重构方法具有更高精度,在柔性机构三维位形实时监测中具有应用前景。     

基于无线射频技术的无人值守病房监护系统

鉴于目前病房人工监护存在可靠性不足和成本过高的问题,研制了基于无线射频技术的无人值守病房监护系统。该系统可实时监测病人的体温、心率和呼吸频率等生理参数,并将采集到的生理参数通过无线收发模块传到上位计算机,由一人对多病房集中监护,实现了病房监护的无人值守,提高了监护效率和可靠性,具有较大的应用价值。     

光纤位移传感技术的建筑物结构参数测量研究

针对常规方法采集建筑物结构传感信号时,接收的反射信号相位差不明显,导致建筑物结构距离位移、角度位移测量精度较差的问题,设计基于光纤位移传感系统的建筑物结构参数测量方法。将系统的光纤位移传感器,放置在建筑物结构固定端和相对变化端,采集传感区域光纤信号。设置系统调制信号最优频率,保证反射信号相位差变化明显。根据解调的光纤信号相位差,测量建筑物结构内部光纤应变,得到结构参数位移变化量。设置对比实验,分别监测建筑物结构沉降、滑动、倾斜,结果表明,设计方法相比常规方法,降低了距离位移和角度位移测量值误差,提高了测量值与实际位移量的相关性和线性度,充分保证了建筑物结构参数测量精度。     

基于分布式光纤传感的合成气管道温度在线监测研究北大核心CSCD

针对现有煤气化工艺中合成气管道温度监测问题,研究基于拉曼散射的分布式光纤测温系统,研制了带不锈钢套管的耐高温传感光纤,模拟合成气管道周围温度分布,在合成气管道现场铺设434.6 m的分布式耐高温光纤进行实验研究。实验结果表明:基于拉曼散射的分布式光纤测温系统测温范围为0~350℃,测温误差为±2℃,空间分辨率0.5 m,系统能够完成对煤气化合成气管道温度的在线监测,同时可以对温度异常点进行空间定位。     

基于PVDF的汽车驾驶员心电呼吸监测系统研究

汽车驾驶员疲劳驾驶是引发交通事故的重要原因之一,根据心电呼吸等生理参数评估驾驶员疲劳程度成为研究热点。基于PVDF压电薄膜的非接触特性和正压电效应,研究并实现了汽车驾驶员心电呼吸监测系统。硬件部分设计了稳定的信号调理和滤波去噪电路,软件部分构建了准确的心跳和呼吸信号分离算法。测试分析表明,系统能稳定可靠地监测心率和呼吸率,有效地预防疲劳驾驶带来的后果,提高汽车行驶安全性。     

分布式光纤传感技术在架空线路中的应用

设计了一种分布式光纤传感器,该传感器基于光时域反射原理,通过测量光纤中的背向散射光强度随时间的变化来进行光纤传输特性的测试。构造了用于实时监测的分布式光纤测试系统,在架空线路中有较好的监测应用。并对该分布式光纤传感器性能进行了监测,结果验证该传感器有较好的稳定性,测温精度误差范围在±0.5℃左右。     

通讯光纤外径测量控制仪

概述随着光纤通信的迅速发展,对光纤的传输性能与耦合性能要求越来越高,而目前国内光纤拉丝过程中影响上述性能的光纤外径变化在±10μM以上,与实际使用要求相差甚大。为此,我们研制了GY-A型光纤外径测量控制仪。该仪器已达到的技术指标为:/测量范围:50μM～250μM;。2测量精度:误差±0.5％以内;3.控制精度:误差±1％以内;(?)分辨力:0.1μM。     

基于虚拟仪器的水声校准系统的研制

为了提高水声换能器校准的自动化程度和精度,研制了一套基于虚拟仪器技术的八通道水声校准与分析系统.该系统运用模块化的设计思路,以工业控制计算机为硬件平台,由2块高速数据采集卡、2块宽带信号调理卡、1块程控信号源卡以及测量软件构成了校准分析系统;并应用了谱分析和扩展Prony方法测量水声信号幅度和相位;测试结果表明,该系统能够完成水声换能器参数的自动校准,一级校准误差小于±1 dB,二级校准误差小于±1.5 dB.     

Noninvasive measurement of heartbeat, respiration, snoring and body movements of a subject in bed via a pneumatic method

We have developed a noninvasive pneumatics-based system by which to measure heartbeat, respiration, snoring, and body movements of a subject in bed. A thin, air-sealed cushion is placed under the bed mattress of the subject and the small movements attributable to human automatic vital functions are measured as changes in pressure using a pressure sensor having an almost flat frequency response from 0.1 to 5 kHz and a sensitivity of 56 mV/Pa. Using the newly developed system, heartbeat, respiration, apnea, snoring and body movements are clearly measured. In addition, the optimal signal-to-noise (S/N) ratio by which to evaluate the reliability of the heart rate measurement is presented. Heart rates were measured for four different body postures, 13 different subjects, four different bed mattresses, and three different sensor positions. For these measurements, the S/N ratios ranged from 15.9 to 23.5 dB, and so were determined to be reliable.     

Filtering noncorrelated noise in impedance cardiography

Impedance cardiography (ICG) may be altered by noises as respiration and movement artifacts, mainly during exercise. In this work, a scaled Fourier linear combiner (SFLC) event-related to the R-R interval of ECG is proposed. It estimates the deterministic component of the impedance cardiographic signal and removes the noises uncorrelated to this interval. The impedance cardiographic signal is modeled as Fourier series with the coefficients estimated by the least mean square (LMS) algorithm. Simulations have been carried out to evaluate the filter performance for different noise conditions. Moreover, the method capability to remove uncorrelated noises was also examined in physiological data obtained in rest and exercise, by synchronizing respiration and pedalling with a metronome. Analyzing the ICG power spectrum, it was concluded that the proposed filter could remove the noises that are not synchronized with heart rate     

自适应滤波在光电技术提取心率方法中的应用

针对利用光电容积脉搏波提取心率时,传统方法光电检测电路复杂,容易受运动干扰等缺陷,设计了一种实时高效的心率提取方案。采用发光二极管产生的单束波长为940 nm的红外光,利用光电容积脉搏波原理,采集手腕处PPG信号,实现对心率信号的实时监测;并针对运动干扰提出一种自适应滤波方法,利用三轴加速度计获取噪声信号消除运动伪差。实验表明,设计与医用监测仪有良好的一致性,且提出的自适应算法比传统快速傅里叶方法具有更高的准确性,在穿戴设备允许的误差范围内,可以利用本文设计进行无创实时的心率监测。     

Nonconstrained Sleep Monitoring System and Algorithms Using Air-Mattress With Balancing Tube Method

We evaluated the performance of a bed-type sensor system using the air-mattress with balancing tube (AMBT) method to noninvasively monitor the signals of heartbeat, respiration, and events of snoring, sleep apnea and body movement of subject on the system. The proposed system consists of multiple cylindrical air cells, two sensor cells and 18 support cells, and the small physiological signals were measured by the changes in pressure difference between the sensor cells, and the dc component was removed by balancing tube that is connecting the sensor cells. Using newly developed AMBT method, heartbeat, respiration, snoring, and body movement signals were clearly measured. For the concept of a home healthcare system, two automatic processing algorithms were developed: one is to estimate the mean heart and respiration rates for every 30 s, and another one is to detect the snoring, sleep apnea, and body movement events from the measured signals. In the beat-to-beat heart rate and breath-by-breath respiration rate analyses, the correlation coefficients of the heart and respiration rates from the proposed AMBT method compared with reference methods, electrocardiogram, and respiration effort signal from piezoelectric belt, were 0.98 ( $p$ ≪ 0.01) and 0.96 ($p$ ≪ 0.01), respectively. Sensitivity and positive predictive value (PPV) of the detection algorithm for snoring event were 93%, 96%, for sleep apnea event were 93%, 88%, and for body movement event were 86%, 100%, respectively. These findings support that ABMT method provides an accurate and reliable means to monitor heartbeat, respiration activities and the sleep events during sleep.      

FBG-based smart bed system for healthcare applications

This paper presents a smart fiber Bragg grating (FBG) sensor system with an unobtrusive and easy-to-use FBG sensor bed, which automatically monitors the behavior of bedridden patients and their vital signs based on indicative spatio-temporal signature for adaptive intervention triggering and activity planning. We present the subtle design, fabrication, calibration, implementation and deployment issues of the FBG pressure sensors to be used in hospitals or nursing homes to prevent bedsore generation, patient falling out of the bed, and life-threatening situations such as patient's heart rate weakening, breathing pattern change, etc. Through trials conducted in the laboratory for respiratory rate monitoring with a sample group of 10 subjects, the system showed maximum error of ± 1 breaths per minute as compared to manual counting.     

Development and Preliminary Validation of Heart Rate and Breathing Rate Detection Using a Passive, Ballistocardiography-Based Sleep Monitoring System

Techniques such as ballistocardiography (BCG) that can provide noninvasive long-term physiological monitoring have gained interest due to a growing recognition of adverse effects from poor sleep and sleep disorders. The noninvasive analysis of physiological signals (NAPS) system is a BCG-based monitoring system developed to measure heart rate, breathing rate, and musculoskeletal movement that shows promise as a general sleep analysis tool. Overnight sleep studies were conducted on 40 healthy subjects during a clinical trial at the University of Virginia. The NAPS system's measures of heart rate and breathing rate were compared to ECG, pulse oximetry, and respiratory inductance plethysmography (RIP). The subjects were split into a training dataset and a validation dataset, maintaining similar demographics in each set. The NAPS system accurately detected heart rate, averaged over the prescribed 30-s epochs, to within less than 2.72 beats per minute of ECG, and accurately detected breathing rate, averaged over the same epochs, to within 2.10 breaths per minute of RIP bands used in polysomnography.     

采矿工人生理状况监测系统设计

采矿工人生理状况监测系统是工人矿井下作业时,进行实时、连续、长时间地采集、监测心电、呼吸、体温、血氧饱和度和体动等参数,并实现数据无线传输的系统。针对传统监控设备对工人状态掌控缺乏、矿难频发等重大问题,设计了一款无线、可穿戴、无创、低心理负荷的多参数采矿工人生理状况监测系统,以便准确地了解井下工人生理状况,及时预防危险状况发生,安全顺利地完成采矿工作。     

Monitoring respiration and cardiac activity using fiber Bragg grating-based sensor

This paper shows the design of a fiber-based sensor for living activities in human body and the results of a laboratory evaluation carried out on it. The authors have developed a device that allows for monitoring the vibrations of human body evoked by living activities--breathing and cardiac rhythm. The device consists of a Bragg grating inscribed into a single mode optical fiber and operating on a wavelength of around 1550?nm. The fiber Bragg grating (FBG) is mounted inside a pneumatic cushion to be placed between the backrest of the seat and the back of the monitored person. Deformations of the cushion, involving deformations of the FBG, are proportional to the vibrations of the body leaning on the cushion. Laboratory studies have shown that the sensor allows for obtaining dynamic strains on the sensing FBG in the range of 50-124 μ strain caused by breathing and approximately 8.3 μstrain induced by heartbeat, which are fully measurable by today's FBG interrogation systems. The maximum relative measurement error of the presented sensor is 12%. The sensor's simple design enables it to be easily implemented in pilot's and driver's seats for monitoring the physiological condition of pilots and drivers.