基于支持向量机的睡眠监测系统设计

睡眠问题逐渐成为当今快节奏社会人们对生命健康的关注重点,由此本文提出了一套基于支持向量机的睡眠监测系统.该系统利用生物传感器,对心率和呼吸信号的实时监测,通过Wi-Fi的方式将数据传送入上位机,由设计好的机器学习算法,对睡眠呼吸暂停低通气综合征等进行判断,并搭配终端APP便于使用者跟踪病情.     

基于压电薄膜传感器的睡眠监测枕研究

针对人体睡眠的健康监测问题,分析睡眠时人体头部对枕头压力状态变化,研究出一种基于聚偏氟乙烯(PVDF)压电薄膜传感器的睡眠监测枕。睡眠时采集人体脉搏、呼吸及鼾声生理信号,硬件电路调理、MSP430F149单片机有机处理后经蓝牙上传至LabVIEW程序,结合打鼾无规则振动特征,依据信号幅值、均值同预设值对比的双阈值分析方法,实现睡眠时呼吸暂停识别报警,鼾声自动监测记录及睡眠呼吸暂停综合症前期检查监测等功能。     

蓝宝石晶体高温传感器的信号解调及标定

为了使用蓝宝石晶体高温传感器对工业烟气温度进行长期在线监测,设计了蓝宝石晶体高温传感器的解调系统,并对其进行了标定。对蓝宝石晶体高温传感器的白光偏振干涉测温原理进行了理论分析,并利用离散腔长变换(DGT)解调算法对光程差信息进行解调。在此基础上建立了一套以热电偶为参照的标定系统,使用S型高温热电偶采集温度数据,得到了光程差-温度样本。分别利用二次多项式拟合法与BP神经网络法对传感器的输出曲线进行了拟合与泛化,并进行了对比。实验结果表明:在800~1 300℃温度范围内,与二次多项式拟合方法相比,BP神经网络的拟合精度较高,拟合残差均值达到0.33℃;泛化能力强,多次泛化结果误差均值为0.56℃,均方误差为0.55℃。最终使用BP神经网络方法对传感器进行标定,使得传感解调系统满足了工业测高温的精度要求。     

一种新型睡眠呼吸暂停检测系统的设计

为了监测睡眠呼吸暂停低通气综合征,基于光栅编码传感器,设计了可穿戴式的呼吸暂停检测仪。光栅编码传感器被嵌入在一条系在患者腰部的腹带内,在呼吸过程中,由于腹部体积的变化引起腹带中光栅的位置发生变化。通过光电二极管传感器阵列对光栅的运动进行检测,采用单片机对信号进行分析处理,从而判断呼气和吸气的过程,计算出呼吸周期,若周期超时则为呼吸暂停。经多次实验,并与呼吸检测设备的检测结果进行比较,本系统的平均精确度高于95%。     

基于虚拟仪器的温度测量系统

基于虚拟仪器技术,利用热电偶设计了一套温度测量系统,包括硬件和软件设计,硬件包括对热电偶输出信号的放大和滤波,以及对冷端温度的补偿电路,冷端温度通过Pt100热电阻进行测量;软件采用Labview进行编写,界面简洁,可通过图形化的界面对温度进行实时监测。     

基于体震信号的睡眠检测系统的设计与实现

设计并实现了一种基于体震信号的睡眠监测系统。肢体动作、胸腔扩张收缩、心脏泵血都会引起人体和与人体接触物体的震动,采集这些震动,经过压电传感器转换为电信号,通过放大模块等信号处理电路,再传输到后台进行预处理,利用一种基于动作幅度、心率、呼吸而建立的睡眠检测算法得到睡眠质量。同步使用专业睡眠监测仪来监测睡眠,并检验系统的准确性。     

基于心电与呼吸信号的睡眠分期算法研究

睡眠是人类的一项重要生理活动,其质量与人体健康状态密切相关,对睡眠情况进行分析有助于许多疾病的预防和监测.传统的睡眠分期黄金标准是多导睡眠图,并包含脑电、眼电、肌电、呼吸、血氧、运动等多种信号,操作复杂且对测试者睡眠有影响.因此,基于可穿戴设备和有限类型数据进行睡眠分即已成为当前研究热点.本文仅采用了心电和呼吸信号进行特征提取,使用前向序列选择方法进行特征选择,分别采用支持向量机、随机森林和AdaBoost等方法进行分类,在睡眠呼吸障碍患者数据库中进行WAKE-REM-NREM分期上获得最高71.9％的准确率(Kappa=0.36).实验表明心电与呼吸信号可在一定程度上代替多导睡眠仪应用于睡眠呼吸障碍患者的分析,有助于睡眠呼吸类疾病的诊断和评价,为相关设备的便携化提供了算法基础.     

试验数据间的关联度分析

通过关联度分析，对测试磨削温度的三套装置（红外仪、光纤－红外仪以及热电偶）的试验数据进行了定量对比分析和计算，结果表明，试验数据间的关联度大小是选择传感器的重要依据。     

传感器测控系统实验仪

采用市场上容易获得的称重传感器、位移传感器、热电偶、霍尔传感器等传感器构成测控实验系统,对重量、位移、温度和转速等物理量进行测试、监控和显示。硬件部分包括各传感器信号调理电路模块以及由AD574A,89C52,8255A等构成的主板模块。由于采用模块化设计,使用灵活,且很容易增加测量传感器的种类。系统稳定,操作简便,能有效地培养学生的实践动手能力和工程应用能力。     

基于物联网的水质监测系统设计

针对传统水质监测方式中存在的测试周期长、数据反馈速度慢等弊端,本文提出一种智慧型水质实时监测系统。本系统以无线传感器网络、网络摄像机以及各类水质污染监测传感器以及后台数据库为核心,开发具有自愈能力的自组网小型水质监测系统,实现对水产养殖用水的水位、溶解氧、PH值、温度、图像等多参数的采集,并通过无线网络实现传感器检测节点和协调器节点之间数据快速、准确的传输,进而对多参数进行实时远程监测,解决水产养殖业水质实时监测和管理问题。     

Dual Mode Strain–Temperature Sensor with High Stimuli Discriminability and Resolution for Smart Wearables

Strain and temperature are important physiological parameters for health monitoring, providing access to the respiration state, movement of joints, and inflammation processes. The challenge for smart wearables is to unambiguously discriminate strain and temperature using a single sensor element assuring a high degree of sensor integration. Here, a dual-mode sensor with two electrodes and tubular mechanically heterogeneous structure enabling simultaneous sensing of strain and temperature without cross-talk is reported. The sensor structure consists of a thermocouple coiled around an elastic strain-to-magnetic induction conversion unit, revealing a giant magnetoelastic effect, and accommodating a magnetic amorphous wire. The thermocouple provides access to temperature and its coil structure allows to measure impedance changes caused by the applied strain. The dual-mode sensor also exhibits interference-free temperature sensing performance with high coefficient of 54.49 µV °C⁻¹, low strain and temperature detection limits of 0.05% and 0.1 °C, respectively. The use of these sensors in smart textiles to monitor continuously breathing, body movement, body temperature, and ambient temperature is demonstrated. The developed multifunctional wearable sensor is needed for applications in early disease prevention, health monitoring, and interactive electronics as well as for smart prosthetics and intelligent soft robotics.     

All-Nanofiber Self-Powered Skin-Interfaced Real-Time Respiratory Monitoring System for Obstructive Sleep Apnea-Hypopnea Syndrome Diagnosing

Human respiration is an indispensable physiological behavior of the body, which is an important indicator to evaluate health status, especially for sleep-related diseases. A real-time respiratory monitoring and sleep breathing detecting system with convenience, high sensitivity, simple fabrication, and wearing comfort still remains a challenge and urgently desirable. Here, a breathable, highly sensitive, and self-powered electronic skin (e-skin) based on a triboelectric nanogenerator (TENG) is reported for real-time respiratory monitoring and obstructive sleep apnea-hypopnea syndrome (OSAHS) diagnosis. By using multilayer polyacrylonitrile and “polyamide 66” nanofibers as the contact pairs, and deposited gold as the electrodes, a contact-separation type of TENG-based all-nanofiber e-skin is developed. The e-skin has a peak power density of 330 mW m⁻², high pressure sensitivity of 0.217 kPa⁻¹, excellent working stability, and good air permeability. Therefore, the e-skin is simultaneously capable of energy autonomy and accurate real-time subtle respiration monitoring. Meanwhile, a self-powered diagnostic system for real-time detection and severity evaluation of obstructive sleep apnea-hypopnea syndrome are further developed to prevent the occurrence of OSAHS, delay its development, and improve sleep quality. This study hopes to pave a new and practical pathway for real-time respiration monitoring and sleep breathing diseases clinical detection.     

应用积分法的发动机内壁瞬态温度测试研究

在传热学基本原理和能量守恒定律的基础上,本文提出了利用积分法求解航空发动机壁面导热的偏微分方程,进而实现对航空发动机内壁瞬态温度的测量。借助螺塞热电偶温度传感器和多路数据采集卡,建立了瞬态温度测量系统,利用氢氧焰模拟航空发动机内部瞬态高温源,分别得出了传感器和红外测温仪测得的发动机内壁表面温度变化曲线。实验结果表明该方...     

Resonant plethysmography for unconstrained monitoring of respiration

A wireless resonant plethysmography for respiration monitoring and obstructive sleep apnea detection is presented. Inductive coupling is utilised between a respiration sensor and measurement module for unconstrained detection of respiratory motion. The results of this system are compared with those of a conventional wired monitor and better performance is reported.     

在稀薄气流中用红外热图测量中低量值热流

在分析高高空热流测量需求基础上,针对高超声速飞行器稀薄气流地面试验热流量值小等特点,从满足模型壁面定常热流假设和一维半无限大假设条件、减小试验模型侧向导热误差和控制试验模型表面温升等方面分析了试验模型加热时间对热流测量的影响。其次选择较低热扩散系数模型绝热材料、采用瞬变平面热源法提高试验模型材料热物性参数标定精度、采用漫反射补偿等提高发射率测量精度等手段,提高中低量值热流测量精度。最后,在利用薄壁量热法获得模型表面热流时,测量MW/m2量级热流是把热电偶焊接在试验模型内壁面,而用红外热图及测量几kW/m2到几百kW/m2量级热流是测量模型外壁面热流,为了对这三者结果进行比较,在马赫数 Ma 为 12、试验总压 P₀ 为4.2 MPa、试验总温 T₀ 为700 K的试验状态下,用热电偶与红外热图同时测量了双锥薄壁模型不同点的热流,结果表明:红外测热结果与热电偶测量外壁面结果更接近,热电偶布置在外壁面位置所获得的热流大于布置在内壁面位置所获得的热流,模型加热时间对不同量值热流测量的影响是不同的。     

热电式MEMS微波功率传感器的优化设计

为了提高热电式微波功率传感器的传热效率,改善传感器的性能,对热电式微波功率传感器的衬底结构进行了优化设计,得到了最优的衬底结构尺寸。首先研究衬底厚度对热电式微波功率传感器的影响,然后根据得到的最优衬底厚度,研究基底膜位置及尺寸对热电式微波功率传感器性能的影响,最后对所得最优衬底结构传感器的微波特性以及电磁场分布进行研究。结果表明,当传感器衬底的结构尺寸最优时,传感器的最高温度达到352.76 K,S参数小于-20.62 dB。该结构不仅减少了热量在衬底的堆积,提高了负载电阻到热电堆的热传输效率,而且具有良好的微波特性。     

亚微米级硅尖端传感器的研制

提出了一种全新的亚微米级温度传感器的构想。作者在借鉴AFM悬臂测头的基础上，采用了微机械加工技术中的各向同性和各向异性腐蚀技术，在硅材料上完成了悬臂梁与硅尖制作。制成的梁的厚度在6μm左右、尖端曲径半径远小于1μm。随后对悬臂梁前端的硅尖进行尖端放电，隧穿其顶端的Si_3N_4层形成温敏器件──一个微型的热电偶。最后进行了这一温敏传感器的引线和封装。由于制作所形成的硅尖曲径半径在0．1μm左右，从而可以在其尖顶上形成亚微米级的温度传感器，在集成电路的探伤与修补以及生物技术领域，有着广阔的应用前景。     

智能型热电偶温度测量仪的研制

本文研究了应用8031微处理器的智能型温度测量仪。在分析热电偶温度传感器特性的基础上,提出二次查表法补偿冷端误差的新观点;依据这种方法,在常温范围内,可以自动补偿由于热电偶冷端温度变化带来的测量误差。     

热电堆型激光功率计设计与仿真

针对紫外、可见、红外等激光器输出功率测试需求,提出一种由传热体、吸收层、绝缘层和热电偶构成的热电堆型激光功率计.结合热效应和塞贝克效应理论,采用Solidworks三维设计软件构建不同关键结构尺寸的模型,通过ANSYS Workbench仿真软件建立了热电耦合仿真分析模型,分析关键结构尺寸参数对输出电压以及温度分布的影...     

Fast-response silicon flow sensor with an on-chip fluid temperature sensing element

A new silicon flow sensor with a robust thermal isolation structure has been developed. The thermal isolation structure is mainly made of a 20-µm-thick oxidized porous silicon membrane. This thermal isolation structure makes it possible for the sensor to have a fast-response characteristic and an on-chip fluid temperature sensing element design. The sensor can be used in liquid flow as well as gas flow. Its operation is based on heat transfer from the heated sensor to a moving fluid. It has two platinum thin-film resistors, a heating element, and a fluid temperature sensing element on the chip. The sensing element is thermally isolated from the heating element. The external circuit of the sensor maintains a constant temperature difference between the heating element and the fluid. The sensor chip characteristics were evaluated theoretically by heat transfer analysis during the chip design. Measurements were made for oil flow velocity of 0-30 cm/s and air flow velocity of 0-14 m/s. Response time was below 100 ms, and a compensated output for fluid temperature change was obtained.