Alexander fractional differential window filter for ECG denoising

The electrocardiogram (ECG) non-invasively monitors the electrical activities of the heart. During the process of recording and transmission, ECG signals are often corrupted by various types of noises. Minimizations of these noises facilitate accurate detection of various anomalies. In the present paper, Alexander fractional differential window (AFDW) filter is proposed for ECG signal denoising. The designed filter is based on the concept of generalized Alexander polynomial and the R–L differential equation of fractional calculus. This concept is utilized to formulate a window that acts as a forward filter. Thereafter, the backward filter is constructed by reversing the coefficients of the forward filter. The proposed AFDW filter is then obtained by averaging of the forward and backward filter coefficients. The performance of the designed AFDW filter is validated by adding the various type of noise to the original ECG signal obtained from MIT-BIH arrhythmia database. The two non-diagnostic measure, i.e., SNR, MSE, and one diagnostic measure, i.e., wavelet energy based diagnostic distortion (WEDD) have been employed for the quantitative evaluation of the designed filter. Extensive experimentations on all the 48-records of MIT-BIH arrhythmia database resulted in average SNR of 22.014?±?3.806365, 14.703?±?3.790275, 13.3183?±?3.748230; average MSE of 0.001458?±?0.00028, 0.0078?±?0.000319, 0.01061?±?0.000472; and average WEDD value of 0.020169?±?0.01306, 0.1207?±?0.061272, 0.1432?±?0.073588, for ECG signal contaminated by the power line, random, and the white Gaussian noise respectively. A new metric named as morphological power preservation measure (MPPM) is also proposed that account for the power preservance (as indicated by PSD plots) and the QRS morphology. The proposed AFDW filter retained much of the original (clean) signal power without any significant morphological distortion as validated by MPPM measure that were 0.0126, 0.08493, and 0.10336 for the ECG signal corrupted by the different type of noises. The versatility of the proposed AFDW filter is also validated by its application on the ECG signal from MIT-BIH database corrupted by the combination of the noises as well as on the real noisy ECG signals are taken from MIT-BIH ID database. Furthermore, the comparative study has also been done between the proposed AFDW filter and existing state of the art denoising algorithms. The results clearly prove the supremacy of our proposed AFDW filter.     

ECG信号预处理的综合实现方法

体表电极检测到的ECG信号常含有不同类型的干扰，因此，检测分析前要进行预处理。文中采用数字滤波处理，在前人工作基础上进行了归纳，全面详细地阐述了对心电信号进行带通滤波、微分、平方非线性放大、移动窗积分等一系列预处理措施；用matlab验证来自MIT—BIH数据库的心电信号的处理效果。由结果可知．用文中方法消噪的同时又有效地恢复和放大了波形特征信息，优化了心电波形，为后继检测和分析提供了更加可靠的依据。由于其简单易行，为临床实现提供了重要的现实依据。     

USB心电信号采集卡的研制

一种心电信号通过USB口传入计算机，用于显示、存储和分析的采集、传输采集卡的研制。从硬件角度介绍三导心电信号的采集、放大、滤波、模数转换和USB传输的电路原理与构成。所选用的单片机为TI公司的MSP430系列。USB传输部分所用芯片为SunPlus公司的SPCP825。     

Feedback channel for transmission of the ECG signal via telephone lines

The elaborated devices produce a feedback channel in the three-channel system for ECG transmission through the telephone line. Crystal-controlled frequencies and medium-scale integrated microcircuits are used in the receiving and transmitting parts of the device. The system trial operation has demonstrated serviceability and interference immunity.     

一种心电信号遥测记忆装置设计

本文介绍了一种无线式心电信号的检测与实时存取的方法，给出了各部结构及工作原理。该装置可应用于普通的心电图机或心电监护仪使之具有遥测和记忆功能，从而可随时记录有用的心电信号供临床分析诊断。     

运动心电信号的时频分析研究

运动心电信号是反映运动时人体心脏负荷状况的重要信息，准确表述运动心电信号特征对于更好评价运动负荷实验是很有意义的，介绍了维格纳时频分析的原理与算法实现，将维格纳分布应用到运动心电信号的分析中，得到一些有益的结论，在时颇平面上研究运动心电信号特征变化是一个较好的途径。     

心电放大器前置放大级及定标电路设计

本文介绍具有差动输入的三运放形式的心电检测前置放大电路及1mV定标电路。定标信号的采集由计算机发出命令控制，通过自动闭锁、复零控制等方式，可获得标准的1mV定标信号。     

基于MSP430微控制器的心电信号采集系统设计

目的:设计一个具有高性能、低功耗特性的心电信号采集系统,以满足长时间监测患者生理状况的需求.方法:采用ADAS1000低功耗心电图模拟前端与MSP430F5529微控制器,利用串行外设接口总线实现模拟前端的配置以及心电数据的回读.结果:该系统可对正常活动状态下的患者做24 h动态心电监测,采集的数据准确可靠.结论:该系统实现了印制电路板的一体化集成,功耗低,可用于由电池供电的便携式应用(如穿戴式设备)中.     

ECG compression method by using multiple polynomial modelling: comparison with wavelet-changing technique

The proposed ECG compression combined two approaches, ECG beat alignment and polynomial modeling. QRS complexes are firstly detected then aligned in order to reduce high frequency changes from beat to beat. These changes are modeled by means a polynomial projection. ECG from MIT-BIH database are used to evaluate the performances of the proposed technique. A comparison with the wavelet approach is performed by means the compression ratio (CR) versus the RRD curve.     

通过PC机串口采集动态实时心电信号

介绍了网上心电实时监护系统，应用ATmega8型8位微处理器芯片实现了10位精度的心电AD转换．通过RS232行接口向PC机传送数据，并介绍这2部分的软、硬件设计思想。     

脉搏氧饱和度监测的新技术--MasiITlo信号萃取技术

Masimo SET是一种新型氧饱和度仪,其采集、处理和报告动脉氧饱和度与心率的方法,与传统的氧饱和度仪根本不同.如下所述,Masimo SET将自调谐滤波器的输出功率加到尘理信息实时监视系统,采用专利技术在检测到的生理信息中精确地建立一个"噪声基准",因而能直接计算动脉氧饱和度与心率.由于不是依赖传统的"红光与红外线之比"的方法,Masimo SET系统从根本上消除了运动伪迹、外周灌注不足以及大部分低信噪比环境中遇到的问题.这就极大地扩展了SPO2在活动大、信号小和噪声强的环境中的实际应用.     

在实时操作系统DSP/BIOS上实现心电信号R波的捡出

介绍了一种心电信号R波快速检测算法在实时操作系统DSP／BIOS中的实现过程和调试评测方法。应用DSP／BIOS 进行心电实时程序研究,降低了程序设计的难度,提高了程序的稳定性,方便程序的调试和测评,可以在相关实时系统开发中应用。     

Video-EEG monitoring and simultaneous ECG for the differential diagnosis of transient consciousness disorders. A case report

We present the case of a 36 year-old woman, with history of transient consciousness disorders with vegetative state, interpreted as epileptic crises and treated with valproate for two years. After nine asymptomatic years, they reappeared associated with migraine, vomiting and some generalized convulsions. Electroencephalogram and cerebral magnetic resonance turned out normal, and treatment with zonisamide was started, without beneficial results. Later cardiological studies objectified a blockage of the left branch that coincided with dizziness. The study was completed with Video-EGG monitoring, where there was an episode that showed temporary right epileptiform activity, with a diagnosis established of focal epilepsy of unknown cause. At present, she remains asymptomatic with oxycarbazepine.     

Perforator flaps--the evolution of a reconstructive surgical technique

Trauma, oncological resections and pressure sores can cause major soft tissue defects. The evolution of cutaneous, myocutaneous, and fasciocutaneous flaps currently makes possible the restoration of contour and, in many cases, function. This evolution was closely related to the increased understanding of the vascular anatomy of the skin and subcutis and has led to the development of perforator flaps. A perforator flap is a large flap of skin that survives on a single vascular stalk that perforates the muscle, referred to in briefas a 'perforator'. This has its origin in a larger vascular stalk that runs beneath the muscle. The vascular stalk of such a perforator flap can be lengthened by dissecting the perforator from the muscle in continuity with the vessels running beneath the muscle. Moreover, the larger diameter of these vessels facilitates the creation of a vascular anastomosis in the receptor area. By the use of such perforator flaps, proper innervation and a good blood supply to the flap can be combined with less morbidity at the donor site. Important possibilities include the filling of a dorsal (decubitus) defect and breast reconstruction.     

基于JAVA手机便携式心电监护分析仪的ECG信号采集模块设计

目的：设计一种基于JAVA手机的便携式心电监护仪的心电信号采集模块。方法：心电采集模块采用低功耗51单片机为控制核心,通过心电信号的采集、放大、滤波、A/D转换以及红外通讯接口5个模块,实现心电信号的采集及与JAVA移动手机之间的通信。结果：设计的采集模块具有高输入阻抗、高共模抑制比、低噪声、增益可控等优点,可实现心电信号无失真采集和与手机间进行红外线通信。结论：该心电信号采集模块成本低、体积小、耗电少,适合患者自身携带和医务工作者使用。     

Location of central venous catheters in children by endocavitary ECG: A new technique

A new technique to establish the position of a central venous catheter (CVC) by endocavitary ECGraphy is described. The principle is based on the fact that the catheter itself may be considered as an electrical conductor by means of its liquid content (saline solution), therefore acting as an exploring electrode. The intrinsic deflection of the P wave shows the proper position of the CVC tip at the sinus node level. The technique has been successfully utilised in 52 children needing antineoplastic chemotherapy and/or total parenteral nutrition, thus avoiding chest X-ray control, which is troublesome and potentially harmful in neonates and infants.     

A differential filtration technique for the measurement of schistosome cercarial densities in standing waters.

The technique of differential filtration allows the detection of schistosome cercariae, with a recovery greater than 80%, in natural waters with a high concentration of microorganisms. This technique makes use of a new type of monofilament polyamide filter Nytrel-TI, with a pore size of 40 μm, allowing filtration of turbid water without clogging of the filter. A three-level prefiltration column (1000, 500 and 200 μm), which retains organisms larger than cercariae, facilitates reading of the filter. The apparatus used weighs less than 3.5 kg; it requires no power supply and can easily be used in the field.