SUTIL: Intelligent ischemia monitoring system

SUTIL is an intelligent monitoring system for intensive and exhaustive follow up of patients in coronary care units. This system processes electrocardiographic and hemodynamic signals in real time, with the main objective of detecting ischemic episodes. In this paper, we describe the tasks included in SUTIL. In addition to basic tasks, those at higher levels will also be presented. Some of these latter tasks attempt to mimic, to some extent, the way in which the human expert operates.     

On the design and assessment of a 2.45 GHz radio telecommand system for remote patient monitoring

This paper discusses the design and operational assessment of a minimum-power, 2.45 GHz portable pulse receiver and associated base transmitter comprising the interrogation link in a duplex, cross-band RF transponder designed for short-range, remote patient monitoring. A tangential receiver sensitivity of −53 dBm was achieved using a 50 Ω microstrip stub-matched zero-bias diode detector and a CMOS baseband amplifier consuming 20 μA from +3 V. The base transmitter generated an on–off keyed peak output of 0.5 W into 50 Ω. Both linear and right-hand circularly-polarised antennas were employed in system evaluations carried out within an operational Coronary Care Unit ward. For transmitting antenna heights of between 0.3 and 2.2 m above floor level, transponder interrogations were 95% reliable within the 82 m² area of the ward, falling to an average of 46% in the surrounding rooms and corridors. Separating the polarisation modes, using the circular antenna set gave the higher overall reliability.     

基于无线技术的远程病人监护系统

基于无线通信的远程病人监护系统是现代通信技术在医疗领域的最新应用,已经引起越来越多人们的关注。根据监护目的、对象及应用领域的不同对远程监护系统进行了分类,并提出了基于无线传感器网络的远程监护体系结构,最后对基于无线个人域网（wireless personal areanetwork,wPAN）标准的无线通信技术进行概述。该系统可以应用于家庭、社区及医院的远程医疗健康监护,并可以根据需求进行扩展和升级。     

Wireless biopotential acquisition system for portable healthcare monitoring

A complete biopotential acquisition system with an analogue front-end (AFE) chip is proposed for portable healthcare monitoring. A graphical user interface (GUI) is also implemented to display the extracted biopotential signals in real-time on a computer for patients or in a hospital via the internet for doctors. The AFE circuit defines the quality of the acquired biosignals. Thus, an AFE chip with low power consumption and a high common-mode rejection ratio (CMRR) was implemented in the TSMC 0.18-μm CMOS process. The measurement results show that the proposed AFE, with a core area of 0.1 mm², has a CMRR of 90 dB, and power consumption of 21.6?μW. Biopotential signals of electroencephalogram (EEG), electrocardiogram (ECG) and electromyogram (EMG) were measured to verify the proposed system. The board size of the proposed system is 6 cm×2.5 cm and the weight is 30 g. The total power consumption of the proposed system is 66 mW.     

Software QRS detection in ambulatory monitoring — a review

The QRS detection algorithm is an essential part of any computer-based system for the analysis of ambulatory ECG recordings. This review asserts that most one-channel QRS detectors described in the literature can be considered as having the same basic structure. A discussion of some of the current detection schemes is presented with regard to this structure. Some additional features of QRS detectors are mentioned. The evaluation of performance and the problem of multichannel detection, which is now gaining importance, are also briefly treated.     

穿戴式随行监护系统心电信号质量评价研究

穿戴式生理参数监测技术是一种新型的生理监护技术,代表未来监护技术的发展方向,但该类技术应用于临床尚有许多问题亟待解决。本文针对自主研发的穿戴式随行监护系统(SensEcho-5B)的心电信号质量评价问题开展了探索性研究。首先基于模板匹配法开发出一种心电信号质量评价算法,用于心电信号的自动、定量评价,在100名受试者(15名健康人和85名心血管疾病患者)随机抽取的100 h心电信号数据集上进行了算法性能测试。在此基础上使用SensEcho-5B与心电Holter同步采集了30名受试者(7名健康人和23名心血管疾病患者)的24 h心电数据,使用心电信号质量评价算法对两个系统同步记录的心电信号质量进行评价。算法性能测试结果:敏感度为100%,特异度为99.51%,准确率为99.99%。30名受试者的对照试验结果:SensEcho-5B所检测到的心电信号,信号质量较差时间的中位数(Q1,Q3)为8.93(0.84,32.53)min,Holter所检测到的心电信号,信号质量较差时间的中位数(Q1,Q3)为14.75(4.39,35.98)min(秩和检验P=0.133)。研究结果表明,本文提出的心电信号质量评价算法能够对穿戴式随行监护系统的心电信号质量进行有效评价;随行监护系统SensEcho-5B与对照Holter相比,心电信号质量相当。后续研究将进一步在真实临床环境中采集大样本量的随行监护生理数据,并对心电信号质量进行分析和评价,从而使监护系统的性能得到持续优化。     

智能实时睡眠监测与干预系统的设计与实现

目的设计可以监测、分析、干预以及反馈人体睡眠状况的智能实时睡眠监测与干预系统,以改善使用者睡眠问题。方法首先设计智能实时睡眠监测与干预系统,其中生命体征信号采集模块实时监测人体肢体动作、心脏泵血等引发的振动;数据处理中心提取体动信号、呼吸信号与心冲击信号(ballistocardiogram,BCG)信号,利用睡眠监测算法进行睡眠状况分析;中药香薰器由数据处理中心控制开关,利用含有中药成分的香薰干预睡眠;同时睡眠监测实时反馈干预情况下的数据。然后选取3名失眠的被试者进行测试,检验系统的有效性。结果所构建的系统可以实时记录被试者睡眠情况并形成睡眠分期图,也可利用中药香薰有效地干预被试者不良睡眠情况。结论该系统能够实现非接触式睡眠情况采集与分析以及对入睡困难或睡眠质量不佳等状况的干预。     

The compensation of perturbing temperature fluctuation in glucose monitoring technologies based on impedance spectroscopy

Non-invasive glucose monitoring techniques based on impedance spectroscopy are affected by a variety of perturbing effects. In order to use the impedance as a glucose measure, these perturbing effects need to be quantified and compensated. Since effects induced by temperature fluctuations certainly rank among the severest perturbations, a clinical study was carried out to establish whether temperature, as a perturbing factor, could be compensated for in impedance spectroscopy. The results as well as a concept allowing for the compensation of perturbing temperature fluctuations are presented here. The compensation technique described is a generic approach that, in principle, can be applied to compensate most perturbation effects provided that there are now multiplicative interactions between the variable of interest (in our case the glucose) and the perturbations. The results allow for the determination of the minimum required sensitivity of an impedance spectrometer to glucose in order to be operational in home-use conditions. Furthermore, the data can be used to estimate if a universal temperature compensation can be applied or if an individual calibration is necessary. For instance, applying a universal temperature compensation and requiring an application range of +/-5 degrees C, the minimum required sensitivity of the minimum impedance and frequency in a sensor-skin RLC circuit to resolve glucose variations equivalent to 10 mg/dl is 0.85 Omega/mg/dl and 0.14 MHz/mg/dl, respectively. The sensitivity requirements reduce by about a factor 1.6, if for each subject an individual calibration is carried out. Depending on the measure and the calibration procedure, the required sensitivities are a factor 3-50 greater than those reported in the literature. Thus, in order to be operational in home-use conditions, the signal-to-noise ratio (S/N) of existing impedance-based monitoring platforms using RLC circuits need to be improved by about one order of magnitude. In order to make non-invasive glucose monitoring possible we, therefore, suggest some measures that may improve the S/N by the required factor.     

Real-time waveform analysis of multichannel nerve impulses with a multimicroprocessor system

A new system for the online real-time waveform separation of the nerve impulses recorded from multichannel extracellular electrodes placed to the peripheral nerve trunk has been developed using two microprocessors and a graphics computer. One microprocessor (Intel 8085) performs nerve impulse detection and the other (Intel 8086) separates nerve impulses by clustering in the two-dimensional histograms representing the distribution of the parameters extracted from their waveforms. System performance was examined with two channel impulses recorded from the nerve trunk innervating the Sartorius muscle of a frog. These data could be classified into 6–8 different groups in real time.     

Smart Vest: wearable multi-parameter remote physiological monitoring system

The wearable physiological monitoring system is a washable shirt, which uses an array of sensors connected to a central processing unit with firmware for continuously monitoring physiological signals. The data collected can be correlated to produce an overall picture of the wearer's health. In this paper, we discuss the wearable physiological monitoring system called ‘Smart Vest’. The Smart Vest consists of a comfortable to wear vest with sensors integrated for monitoring physiological parameters, wearable data acquisition and processing hardware and remote monitoring station. The wearable data acquisition system is designed using microcontroller and interfaced with wireless communication and global positioning system (GPS) modules. The physiological signals monitored are electrocardiogram (ECG), photoplethysmogram (PPG), body temperature, blood pressure, galvanic skin response (GSR) and heart rate. The acquired physiological signals are sampled at 250 samples/s, digitized at 12-bit resolution and transmitted wireless to a remote physiological monitoring station along with the geo-location of the wearer. The paper describes a prototype Smart Vest system used for remote monitoring of physiological parameters and the clinical validation of the data are also presented.     

A computer based wireless system for online acquisition, monitoring and digital processing of ECG waveforms

Various ECG instruments have addressed a wide variety of clinical and technical issues. However, there is still scope for improvement in them particularly in the area of their susceptibility to noise, lack of universal connectivity and off-line processing. A prototype system has been developed that caters to these limitations. It includes an analog system and a FM transceiver pair interfaced through sound port of the computer. The real time acquired data is viewed and filtered using MATLAB software. The ECG system described captures the bio-signal faithfully in real time wireless mode with minimum noise and has universal connectivity.     

Noninvasive heart rate monitoring system for avian embryos based on the ballistocardiogram

A noninvasive heart rate (HR) monitoring system for avian embryos has been developed based on the ballistocardiogram (BCG). The BCG was detected using a phonograph cartridge as a record of the velocity of the minute ballistic movements of the eggshell, which are generated by recoil and impact of heart contraction and blood ejection. The autocorrelation coefficients (ACCs) of the detected signal were computed to confirm whether the detected signal contained ballistic movement. An envelope of ACC was calculated by the monitoring system to measure the intervals between peaks and/or highly correlated parts in the ACC, and then the system obtained HR by measuring these intervals. To demonstrate the valid range of the detecting method, the BCGs of chickens and Japanese quail embryos of different ages were measured. The result of the experiment shows that the BCGs of chickens and quail embryos are detected fully after about two-thirds of the incubation period has passed. The monitoring system will enable us to perform long-term HR measurement for developing avian embryos up to hatching.     

A study on a non-contacting respiration signal monitoring system using Doppler ultrasound

We proposed non-contacting respiration signal monitoring system for sleep apnea syndrome. Experiments were conducted by emitting 40 kHz ultrasound beam, which is set tone burst mode by 1 ms period to a subject chest. Normal respiration condition and a simulated sleep apnea syndrome condition were measured while subjects were holding breath. To obtain the actual respiration signal from the raw signal, ultrasound attenuation characteristics were considered. The Doppler ultrasound signal was detectable once the received signal obtained by demodulation circuits passed through a low pass filter (LPF). The signal’s ripples were eliminated by moving average method and the signal’s peaks were detected by phase portrait reconstruction method to measure the respiration rate. This paper is the WC2006 special issue paper.     

磁声电导率检测系统设计及其线性扫频理论验证

临床研究证实病灶组织的早期诊断能显著降低患癌风险,由于磁声电成像具有高分辨率和高对比度优势,因而有望成为一种新的检测方法。本文采用模块化设计思维,设计并实现了一款低成本、数字化磁声电导率检测系统,并提出线性调频连续波激励洛伦兹力电阻抗检测理论,通过0.5%NaCl均匀仿体实验,清晰获得与实际物理尺寸一致的均匀仿体电导率曲线,验证了线性扫频理论应用在本系统是准确且可行的。同时,1 000μs线性扫频时宽所获得分辨率优于500μs和1 500μs,提示线性扫频时宽是影响电导率分辨率的重要因素。通过对不同浓度NaCl均匀仿体的实验,得到了相同结论,证明了本系统的可重复测量性。     

Stroke patients' perceptions of home blood pressure monitoring: a qualitative study

Background

Stroke is the leading cause of adult disability in the UK. Hypertension is the leading modifiable risk factor for stroke. There is increasing interest n home blood pressure monitors for self-monitoring, but no published research on the experiences of stroke patients who do self-monitor

Aim

To explore stroke patients'' experiences of self-monitoring with nurse-led support

Design and setting

A qualitative study of 26 (66%) patients from the first 39 participants to complete the intervention arm of a community-based randomised controlled trial (RCT) of home blood pressure monitoring in 381 patients recruited from hospital stroke clinics in south London

Method

Semi-structured face-to-face interviews were conducted with 26 patients. Interviews were digitally recorded and transcribed, and a thematic analysis of the data was undertaken

Results

Participants were highly motivated to avoid a further stroke and developed a strong focus on blood pressure control and attaining a ‘good result’. Only aminority reported anxiety about their blood pressure. Participants gained a welcome sense of empowerment and control over managing their health; some felt confident and ‘experimented’ with their medication doses. Eight patients required physical help to self-monitor and there was uncertainty about where responsibility lay for such help. Patients who lived alone and were functionally impaired had the least positive experience. Active engagement with the home blood pressure monitoring process by GPs was variable

Conclusion

Patients in this study generally reported increased knowledge and empowerment about blood pressure control and avoiding further strokes. The technique is overall welcome, acceptable, and successful, even in patients with disabilities. Since home blood pressure monitoring can also lead to improved blood pressure control, this simple, pragmatic interventionmight bemore widely used     

Reliability and efficacy of a monitoring system for an implanted pulse generator

 The Selection 900/900E is a physiological pacing device with a sophisticated monitoring system for detecting and analyzing atrial arrhythmias. We have investigated the reliability and efficacy of the Selection monitoring system. Twelve patients with episodes of atrial tachyarrhythmias were implanted the with Selection device (7 men, 5 women, aged 73 ± 6 years old). Ten patients had sick sinus syndrome and two patients had a high degree of atrioventricular (AV) block. All patients underwent 24-h external Holter monitoring after the operation (136 ± 41 days) to evaluate the accuracy of the data recorded by the internal monitoring system. There was no significant difference in counter data between the 24-h external Holter and the internal monitoring systems. Four patients recorded an episode of atrial fibrillation by both systems. In two patients, the 24-h external Holter monitoring system misread DDI pacing after mode switching as sinus rhythm or pacing failure. In another patient, the featured function of this pacing device for atrial tachyarrhythmia was recognized as a sensing failure by the 24-h external Holter monitoring system. The Selection 900/900E monitoring system is a reliable and informative way to evaluate the relevance of pacing therapy. Received: January 7, 2002 / Accepted: September 10, 2002 Correspondence to:M. Osako     

Rhythm monitoring using a microcomputer system

The design and construction details of a microcomputer system are described which can be applied easily and effectively to chronobiological studies especially when it may be necessary to monitor long-term rhythmic variables. In its present form the system is designed to acquire, store and analyze data from circadian rhythm studies in small mammals. This application is discussed in addition to design of the system, applications, and future modifications.     

Application of a modified two-point backward difference to sequential event detection in surface electromyography

Reliable detection of onset and termination of muscle contraction is an essential task in the analysis of surface electromyographic signals. An event detection method that can be used for sequential detection of both onset and termination of muscle contraction is described. The method builds on the techniques of envelope detection, two-point backward difference and threshold based decision making. Therefore, fast conventional digital signal processing techniques can be used in its implementation. Because the method is computationally efficient, it can be employed in both real-time and non-real-time applications. This text discusses the architecture of the method, considers the practical aspects of its implementation, analyses its computational complexity and evaluates its performance on the grounds of experimental results.