无线体温监测系统的研制

介绍了一种基于无线遥测技术的医院体温监测系统,该系统以美国TI公司的MSP430超低功耗16位微控器和挪威Nordic VLSI公司推出的单片射频收发器nRF905为核心,实现了同时对多个体温信号的高精度监测和传输.     

内置在线监测机器人系统的气道阻力分析

设计了呼吸监测机器人系统，用于在线监测机械通气重症监护中的呼吸力学参数。建立了内置呼吸监测机器人系统的气道呼吸阻力的数学模型，计算了监测机器人系统的气道的阻力，并在猪气管中进行了模拟实验。理论分析和实验结果均表明在机械通气情况下内置该呼吸参数监测机器人系统时气道的阻力是正常的，该系统能用来连续地监测呼吸力学参数。     

三叉神经疼痛小型射频治疗仪的研制

提出了基于嵌入式系统的便携式三叉神经疼痛射频治疗仪的设计方案.实现了预检、脉冲射频治疗以及连续射频治疗的功能,并通过触摸屏以及液晶显示的图形用户界面进行操作.同时根据系统特点采用改进的分段PID温度控制算法,温度精度小于1℃,满足临床应用的要求.     

基于体域网的动态呼吸监测系统设计

为了实现日常生活的动态呼吸监测,本研究设计了一种电子健康腰带。利用"体域网"的穿戴式人体生理参数动态监测技术和呼吸感应体积描记术(RIP),将电感传感器嵌入织物中,设计了动态呼吸监测穿戴式微系统。对22位被测试者进行了不同日常生活活动(坐-走-跑-恢复)和连续6 h的睡眠呼吸监测实验。结果表明:在不同日常生活中,呼吸率的平均测量精度约为95%。所设计的基于体域网和RIP技术的呼吸波监测腰带,可用于日常生活和睡眠呼吸监测。     

磁共振引导下术中开放式多通道射频接收线圈设计

本研究的目的在于为超声聚能热消融术中开放式磁共振系统设计新型多通道射频接收线圈.首先针对低场磁共振引导超声聚能系统的设计要求,提出新型射频线圈结构,通过计算机仿真对该结构所形成的磁场进行分析,从而验证所设计的线圈模型,并基于该结构模型实现原型线圈.水膜成像实验和测温实验表明,所设计线圈达到临床热消融术中测温要求,从而验证了该设计的可行性.本研究为低场磁共振系统设计了一种新型专用多通道射频线圈,使低场磁共振应用于监测及引导热消融手术成为可能.     

穿戴式呼吸感应体积描记用于睡眠呼吸事件检测

可穿戴式呼吸感应体积描记(背心式RIP)系统是我们根据呼吸感应体积描记技术的基本原理研发的一种可穿戴、低负荷的呼吸监测系统.在实现通气量无创测量的基础上,我们将该系统用于睡眠期呼吸事件检测,将该系统与多导睡眠图仪(PSG)对9例疑似睡眠呼吸暂停低通气综合症(SAHS)病人和7名健康男性志愿者进行同步对照检测与分析.通过对比实验,根据背心式RIP系统发生呼吸事件的特征性变化,提出了背心式RIP系统判别呼吸事件的规则.依据该规则,所有经背心式RIP系统诊断为SAHS患者的结果与PSG的诊断结果完全一致,背心式RIP系统检测呼吸事件的敏感性为97.8%,特异性为95.8%,实验结果表明背心式RIP系统能够可靠地检测出睡眠呼吸事件.由于其低生理、心理负荷特性,不需要佩带口鼻气流传感器,可用于家庭环境下、自然睡眠过程的睡眠呼吸紊乱性疾病的诊断.     

基于电阻抗技术的多通道呼吸监测系统

目的为及时检测到早期呼吸系统疾病引起的呼吸功能的改变,本研究开发了一套采用生物电阻抗技术同时监测胸部和腹部的呼吸电阻抗信号的多通道呼吸监测系统。方法本系统主要分为3个单元：电阻抗数据采集单元、多通道开关单元和控制单元。电阻抗数据采集单元完成生物电阻抗数据高精度的检测,多通道开关单元完成不同部位数据采集通道之间的转换,控制单元采用LabVIEW编程实现对电阻抗数据采集单元和多通道开关单元的控制、同步采集、数据的显示及存储。利用本系统采集5名健康人长跑5000m前后胸部和腹部的同步呼吸电阻抗信号,采用一种新的参数定量描述胸部和腹部的呼吸电阻抗信号的同步程度。结果长跑前后胸部和腹部同步呼吸电阻抗信号的同步程度具有显著差异（P〈0．01）。结论基于电阻抗技术的多通道呼吸监测系统能够有效用于多个部位呼吸电阻抗信号的同步监测,为早期呼吸系统疾病的检测提供辅助诊断信息。     

随行生理监护系统设计及性能初步验证

为实现住院患者连续生命体征监测,研制了随行生理参数监护系统SensEcho。该系统由随行生理参数监测终端、无线组网和数据传输单元、中央监护系统三部分组成。其中随行生理参数监测终端为一件柔性背心,内嵌有呼吸感应体积描记传感器和织物心电电极,实现心电、呼吸、体位和体动等基本生理参数的穿戴式低负荷监测;无线生理信号传输单元为基于WiFi技术的组网系统,能够实现病区内多个患者的移动监护,并设计有多重数据续传和数据完整性保障机制;中央监护系统实现所有随行生理参数监测终端数据的显示和患者集中管理,设计有后台数据服务器和算法服务器,支持医疗大数据深度挖掘分析应用。为验证系统性能,我们开展了生理参数检测算法有效性和受试者可靠性测试,以及无线组网和数据传输可靠性测试。测试结果显示,系统无论在基本生理参数监测还是无线数据传输方面都能达到可靠性要求。该系统在医疗领域的应用有望开启个体化连续生命体征监护医疗新模式,为疾病诊断提供基于连续动态生理数据分析的精准信息。     

基于床垫动态压力检测的胸腹呼吸运动无束缚监测方法

目的 开发一种适用于日常居家使用的无束缚睡眠呼吸监测方法,实现睡眠呼吸暂停综合征(sleep apneasyndrome,SAS)及呼吸系统疾病的无束缚筛查.方法 提出一种基于床单式柔性压力传感器的无束缚胸腹呼吸监测方法,通过检测呼吸时胸部和腹部作用于床垫的动态压力获取呼吸信息.对10名健康受试者进行无束缚监测与胸腹呼...     

光学表面成像系统实时运动监测精度研究

目的:探究光学表面成像系统实时运动监测的精度。方法:将30例患者的呼吸曲线输入到模体中模拟呼吸运动， 同时利用Catalyst系统对模体进行实时运动监测，比较系统监测的呼吸曲线与参考曲线，从而得到光学表面成像系统实时 运动监测的精度。结果:光学表面成像系统监测的呼吸曲线与参考曲线具有较高的一致性，相关系数均大于0.99，显著相 关。监测误差的平均值为（0.24±0.04）mm，并且随着呼吸信号频率的增加而减小。结论:光学表面成像系统的实时运动 监测精度较高，可用于对患者呼吸运动的监测。在进行呼吸门控治疗时，应考虑呼吸监测系统引入的误差。     

Electromagnetic assessment of embedded micro antenna for a novel sphincter in the human body

Abstract

This paper presents a wireless, miniaturized, bi-directional telemetric artificial anal sphincter system that can be used for controlling patients' anal incontinence. The artificial anal sphincter system is mainly composed of an executive mechanism, a wireless power supply system and a wireless communication system. The wireless communication system consists of an internal RF transceiver, an internal RF antenna, a data transmission pathway, an external RF antenna and an external RF control transceiver. A micro NMHA (Normal Mode Helical Antenna) has been used for the transceiver of the internal wireless communication system and a quarter wave-length whip antenna of 7.75?cm has been used for the external wireless communication system. The RF carrier frequency of wireless communication is located in a license-free 433.1?MHz ISM (Industry, Science, and Medical) band. The radiation characteristics and SAR (Specific Absorption Rate) are evaluated using the finite difference time-domain method and 3D human body model. Results show that the SAR values of the antenna satisfy the ICNIRP (International Commission on Nonionizing Radiation Protection) limitations.     

血液冷链分布式无线多点温度监测系统设计

背景：由于血液及血液制品与一般药品不同,当血液处于体外环境时,为保存生物活性,其各种成分都需要不同的储存温度。为保证其安全有效和质量可靠,避免因储藏或运输时温度过高或过低而影响了质量,就必须依靠血液冷链。 目的：针对目前国内血液冷链管理存在的问题,提出一种在运送血液及血液制品的冷链过程中引入分布式多点温度监测系统的解决方案。 方法：该系统采用数字温度传感器结合单片机和无线通信技术与PC实现分布式温度监测,智能判断温度值是否异常并进行报警处理,结合利用Visual C# 2008开发的上位机管理程序,可实现同时对多个从机系统的集中监控。 结果与结论：经多次重复实验证明,系统运行稳定,可靠性良好。     

Low-power hybrid wireless network for monitoring infant incubators

We have created a pilot wireless network for the convenient monitoring of temperature and humidity of infant incubators. This system combines infrared and radio frequency (RF) communication in order to minimize the power consumption of slave devices, and we therefore call it a hybrid wireless network. The slave module installed in the infant incubator receives the calling signal from the host with an infrared receiver, and sends temperature and humidity data to the host with an RF transmitter. The power consumption of the host system is not critical, and hence it uses the maximum power of infrared transmission and continuously operating RF receiver. In our test implementation, we included four slave devices. The PC calls each slave device every second and then waits for 6 s, resulting in a total scan period of 10 s. Slave devices receive the calling signals and transmit three data values (temperature, moisture, and skin temperature); their power demand is 1 mW, and can run for about 1000 h on four AA-size nickel-hydride batteries.     

基于MSP430的无线便携式心电采集系统

系统以MSP430FG439超低功耗微处理器为核心,结合低功耗射频收发器CC2500,实现了心电数据的采集、处理以及无线传输,点阵LCD显示操作界面、心电波形和相关结果。此外当处理器检测到异常波形时,可以将数据无线传输到上位机进行进一步的诊断,这种方式使得无线便携成为可能。由于采用了高集成度的微处理器,简化了系统的心电采集前端模拟放大电路。测试结果显示系统采集的心电波形特征波明显,可用作相关疾病的智能诊断。本系统具有功耗低、体积小、精度高、使用方便等特点。     

一种无线无源膀胱压力监测系统的设计

目的：针对南脊髓损伤所致的排尿障碍所采用的植人式治疗方案中，仪器使用寿命受电池电量制约的问题。本文基下电磁耦合原理，提出一种无线无源的膀胱压力监测系统。方法：该系统由体内压力监测器和体外接收器两部分构成。体内压力监测器以MSP430单片机为控制核心，通过压力传感器采集膀胱压力，并将所测的压力通过无线模块传出至体外接收器。体外接收器负责接收数据，并通过线圈耦合能量给体内压力监测器进行供电。结果：经实验测得：体外线圈的最佳驱动频率为558kHz，体内压力监测器可T作的最大线圈距离为10cm，测压范围为0cmH2O～150cmH2O，分辨率为1mmH2O。结论：该无线无源膀胱压力监测器可实现数据和能量的无线传递，压力测量范闭满足临床应用需求。     

Electromagnetic Power Absorption and Temperature Changes due to Brain Machine Interface Operation

To fully understand neural function, chronic neural recordings must be made simultaneously from 10s or 100s of neurons. To accomplish this goal, several groups are developing brain machine interfaces. For these devices to be viable for chronic human use, it is likely that they will need to be operated and powered externally via a radiofrequency (RF) source. However, RF exposure can result in tissue heating and is regulated by the FDA/FCC. This paper provides an initial estimate of the amount of tissue heating and specific absorption rate (SAR) associated with the operation of a brain-machine interface (BMI). The operation of a brain machine interface was evaluated in an 18-tissue anatomically detailed human head mesh using simulations of electromagnetics and bio-heat phenomena. The simulations were conducted with a single chip, as well as with eight chips, placed on the surface of the human brain and each powered at four frequencies (13.6 MHz, 1.0 GHz, 2.4 GHz, and 5.8 GHz). The simulated chips consist of a wire antenna on a silicon chip covered by a Teflon dura patch. SAR values were calculated using the finite-difference time-domain method and used to predict peak temperature changes caused by electromagnetic absorption in the head using two-dimensional bio-heat equation. Results due to SAR alone show increased heating at higher frequencies, with a peak temperature change at 5.8 GHz of approximately 0.018 degrees C in the single-chip configuration and 0.06 degrees C in the eight-chip configuration with 10 mW of power absorption (in the human head) per chip. In addition, temperature elevations due to power dissipation in the chip(s) were studied. Results show that for the neural tissue, maximum temperature rises of 3.34 degrees C in the single-chip configuration and 7.72 degrees C in the eight-chip configuration were observed for 10 mW dissipation in each chip. Finally, the maximum power dissipation allowable in each chip before a 1.0 degrees C temperature increase (most stringent standards as denoted in the FDA guidelines) is exceeded in the head was simulated and found to be 2.92 mW in the single-chip configuration and 1.25 mW in the eight-chip configuration. As thermal heating due to SAR was insignificant, this study suggests that wireless electromagnetics, i.e., RF may be a viable option for powering, and communicating with brain machine interfaces for clinical applications.     

Home monitoring using wearable radio frequency transmitters

BACKGROUND: Location tracking of a wearable radio frequency (RF) transmitter in a wireless network is a potentially useful tool for the home monitoring of patients in clinical applications. However, the problem of converting RF signals into accurate estimates of transmitter location remains a significant challenge. OBJECTIVES: We wish to demonstrate that long-term home monitoring using RF transmitters is feasible. Additionally, we conjecture that human motion within familiar environments is confined to relatively small regions of high occupancy. Hence, human motion can be modelled as movement along a network of such high occupancy regions. METHODS AND MATERIALS: Our methodology uses a signal processing technique developed by one of the authors (Almudevar). The technique converts longitudinal RF data into an estimated trajectory which does not depend on explicit location estimates. This approach eliminates the need for a location-signal calibration procedure. Given a long-term trajectory, Gaussian mixture models are used to identify high occupancy regions. The methodology was evaluated using data collected under a study funded by an Everyday Technologies for Alzheimer Care (ETAC) research grant from the Alzheimer's Association. A home monitoring system provided by Home Free Systems was used. RESULTS: The proposed methodology was able to reliably reconstruct trajectories using study data. Regions of high occupancy were identified, and the observed transitions between these regions were found to be spatially and serially coherent. In addition, the trajectory was compared to output from a parallel home sensor network, and a high degree a conformity was evident. CONCLUSION: Long-term home monitoring of human motion is feasible using readily available and easily installable technology. Furthermore, by using suitable signal processing algorithms, the often difficult location-signal calibration process can be bypassed.     

A flexible super-capacitive solid-state power supply for miniature implantable medical devices

We present a high-energy local power supply based on a flexible and solid-state supercapacitor for miniature wireless implantable medical devices. Wireless radio-frequency (RF) powering recharges the supercapacitor through an antenna with an RF rectifier. A power management circuit for the super-capacitive system includes a boost converter to increase the breakdown voltage required for powering device circuits, and a parallel conventional capacitor as an intermediate power source to deliver current spikes during high current transients (e.g., wireless data transmission). The supercapacitor has an extremely high area capacitance of ~1.3 mF/mm², and is in the novel form of a 100 μm-thick thin film with the merit of mechanical flexibility and a tailorable size down to 1 mm² to meet various clinical dimension requirements. We experimentally demonstrate that after fully recharging the capacitor with an external RF powering source, the supercapacitor-based local power supply runs a full system for electromyogram (EMG) recording that consumes ~670 μW with wireless-data-transmission functionality for a period of ~1 s in the absence of additional RF powering. Since the quality of wireless powering for implantable devices is sensitive to the position of those devices within the RF electromagnetic field, this high-energy local power supply plays a crucial role in providing continuous and reliable power for medical device operations.     

Towards multi-patient leadless and wireless cardiotocography via RF telemetry

During labour the condition of the fetus is monitored by a cardiotocograph which displays fetal heart rate and a measure of uterine contractions. Ultrasound and tocodynamometer transducers are placed on the mother's abdomen and connected to a bedside monitor and display unit via a cable. This paper describes a prototype wireless system aimed at demonstrating the potential elimination of the cable which is undesirable in a number of respects. The radio link utilised operates at a frequency of 418 MHz with data compression and time division multiplexing (TDM) employed to allow up to 10 units to operate simultaneously on the same frequency in the same area. Data compression is achieved by extracting the Doppler ultrasound signal envelope and representing the frequency content of the signal using a zero crossing counting technique. Two Medium Access Control (MAC) protocols were considered, with a synchronised time division multiplexing system shown to offer greater throughput and resistance to interference than Carrier Sense Multiple Access (CSMA). This wireless RF telemetry system could be readily adapted for other multi-patient monitoring applications.