A real-time ECG data compression and transmission algorithm for an e-health device

This paper introduces a real-time data compression and transmission algorithm between e-health terminals for a periodic ECGsignal. The proposed algorithm consists of five compression procedures and four reconstruction procedures. In order to evaluate the performance of the proposed algorithm, the algorithm was applied to all 48 recordings of MIT-BIH arrhythmia database, and the compress ratio (CR), percent root mean square difference (PRD), percent root mean square difference normalized (PRDN), rms, SNR, and quality score (QS) values were obtained. The result showed that the CR was 27.9:1 and the PRD was 2.93 on average for all 48 data instances with a 15% window size. In addition, the performance of the algorithm was compared to those of similar algorithms introduced recently by others. It was found that the proposed algorithm showed clearly superior performance in all 48 data instances at a compression ratio lower than 15:1, whereas it showed similar or slightly inferior PRD performance for a data compression ratio higher than 20:1. In light of the fact that the similarity with the original data becomes meaningless when the PRD is higher than 2, the proposed algorithm shows significantly better performance compared to the performance levels of other algorithms. Moreover, because the algorithm can compress and transmit data in real time, it can be served as an optimal biosignal data transmission method for limited bandwidth communication between e-health devices.     

Integrated e-Health approach based on vascular ultrasound and pulse wave analysis for asymptomatic atherosclerosis detection and cardiovascular risk stratification in the community

New strategies are urgently needed to identify subjects at increased risk of atherosclerotic cardiovascular disease (ACVD) development or complications. A National Public University Center (CUiiDARTE) was created in Uruguay, based on six main pillars: 1) integration of experts in different disciplines and creation of multidisciplinary teams, 2) incidence in public and professional education programs to give training in the use of new technologies and to shift the focus from ACVD treatment to disease prevention, 3) implementation of free vascular studies in the community (distributed rather than centralized healthcare), 4) innovation and application of e-Health and noninvasive technology and approaches, 5) design and development of a biomedical approach to determine the target population and patient workflow, and 6) improvement in individual risk estimation and differentiation between aging and ACVD-related arterial changes using population-based epidemiological and statistical patient-specific models. This work describes main features of CUiiDARTE project implementation, the scientific and technological steps and innovations done for individual risk stratification, and sub-clinical ACVD diagnosis.     

ECG与PPG多通道信号采集系统滤波延迟补偿研究

ECG和PPG信号的多通道同步采集是无损心血管健康风险评估研究的基础。针对ECG和PPG信号采集过程中滤波对同步采集系统延时的问题,提出一种ECG和PPG信号采集补偿的方案,使采集系统可以实现真正意义上的同步。首先,通过仿真对ECG和PPG信号采集过程中各个电路单元产生的延时进行估算;然后,通过函数发生器产生的信号对两种信号采集过程的延时进行实际测量,并且与仿真结果进行比较。在此基础上,通过ECG和PPG信号的相位进行调整,补偿了信号的延迟,最终实现了信号的绝对同步。ECG和PPG多通道采集系统的硬件延时主要集中在滤波过程。经测试,现有设计方案中两组信号通道间的延时实际值为2.012 ms,通过延时补偿后,可以将延时降低为0.01 ms,降低到了99.95%,为后续心血管健康监测算法研究奠定了硬件基础,具有较高的实用价值。     

Analysis and characterization of device variations in an LSI chip using an integrated device matrix array

For future large-scale integration design technology, the device matrix array (DMA), which precisely evaluates within-die variation in device parameters, has been developed. The DMA consists of a 14-by-14 array of common units. The unit size is 240 by 240 /spl mu/m, and each unit contains 148 measurement elements (52 transistors, 30 capacitors, 51 resistors, and 15 ring oscillators). The element selection and precise measurement are achieved with low parasitic resistance measurement buses and leakage-controlled switching circuits, which allow the measurement accuracy for a transistor, resistor, or capacitor of 90 pA, 11 m/spl Omega/, and 23 aF, respectively, in the 3/spl sigma/ range. The ability to obtain 29 008 samples from a chip enables statistical analysis of the variation in 148 elements of each chip with 240-/spl mu/m spatial resolution. This high resolution and large sample number allows us to precisely decompose the data into systematic and random variation parts with newly developed fourth-order polynomial fitting. Our methodology has been verified using a test chip fabricated by a 130-nm CMOS process with a 100-nm physical gate length and five Cu interconnect layers. In MOSFETs, the random part was dominant and indicated a certain /spl sigma/ value in every chip. In the case of the interconnect layers, the random and systematic parts of the resistance and the capacitance indicated variance fluctuations. By chip, by item, by size, by structure, random or systematic, the /spl sigma/ values of each variation show inconsistency which we believe is attributable to the Cu process. The correlation coefficients of systematic part between device element and ring oscillator frequency shown very high value (0.87-0.98), and those of a random part were low enough (-0.10-0.22) to prove the accuracy of decomposition.     

Monolithically integrated photonic switching device using an MSMPD, MESFETs, and a VCSEL

We have fabricated a photonic switching device that monolithically integrates a metal-semiconductor-metal photodetector, metal-semiconductor field-effect transistors, and a vertical-cavity surface-emitting laser. This device can perform both NOR- and OR-types of operation with thresholding input-output characteristics. The contrast ratio is more than 30 dB with optical gain. The device also shows a 3-dB bandwidth of 220 MHz and switching energy of 700 fJ at a 100-MHz frequency     

Digital analysis of the electroencephalogram, the blood pressure wave, and the electrocardiogram

The electroencephalogram (EEG), the blood pressure wave, and the electrocardiogram (ECG), produce patterns that the eye of the physician has empirically correlated with important aspects of health. Digital computer techniques for the recognition of these patterns are made particularly difficult by the realities of pattern context sensitivity, frequent signal artifact, real-time operation, finite storage limitations, and reasonable cost. Evaluations of these techniques are handicapped by the absence of absolute standards, the wide signal variability associated with pathologic states, and the sheer mechanics of comparison with human analysis. Computer analysis of the EEG has been directed toward monitoring sleep and certain pathologic states, leaving the more difficult problem of diagnosis to the trained neurologist. Automatic pattern recognition of the blood pressure wave has been implemented with straightforward techniques for diagnostic use in the cardiac catheterization laboratory and for monitoring in the intensive care unit. Computer analysis of the ECG has been directed toward morphological and rhythm diagnosis, having great potential utility in clinical heart stations, and toward rhythm monitoring, a most practical application arising in coronary intensive care units. Promising systems are emerging, but years of evaluation and adjustment will be necessary to meet the need for both accuracy and economy.     

Note on the fields of an upward-traveling current wave pulse

The so-called transmission-line model for an upward-traveling lightning stroke is often employed by the atmospheric and electromagnetic compatibility community. Simple expressions are obtained for the radiation fields of an idealized lightning channel. The model is an attenuated traveling current, which is perpendicular to a perfectly conducting ground plane. The enhancement of the radiation field at higher elevation angles is confirmed following Krider's (1992) prediction     

Multiscale entropy analysis of pulse wave velocity for assessing atherosclerosis in the aged and diabetic

This study proposed a dynamic pulse wave velocity (PWV)-based biomedical parameter in assessing the degree of atherosclerosis for the aged and diabetic populations. Totally, 91 subjects were recruited from a single medical institution between July 2009 and October 2010. The subjects were divided into four groups: young healthy adults (Group 1, n = 22), healthy upper middle-aged adults (Group 2, n = 28), type 2 diabetics with satisfactory blood sugar control (Group 3, n = 21), and unsatisfactory blood sugar control (Group 4, n = 20). A self-developed six-channel electrocardiography (ECG)-PWV-based equipment was used to acquire 1000 successive recordings of PWV(foot) values within 30 min. The data, thus, obtained were analyzed with multiscale entropy (MSE). Large-scale MSE index (MEI(LS)) was chosen as the assessment parameter. Not only did MEI(LS) successfully differentiate between subjects in Groups 1 and 2, but it also showed a significant difference between Groups 3 and 4. Compared with the conventional parameter of PWV(foot) and MEI on R-R interval [i.e., MEI(RRI)] in evaluating the degree of atherosclerotic change, the dynamic parameter, MEI(LS) (PWV), could better reflect the impact of age and blood sugar control on the progression of atherosclerosis.     

Monolithically integrated Bragg deflector for an optical guided wave made of zinc-oxide film

A new film Bragg deflector has been fabricated on a non-piezoelectric substrate. The deflector is made of ZnO film, so that both an optical waveguide and acoustic-surface-wave transducers are monolithically integrated. High diffraction efficiencies (more than 90%) are obtained with this device.     

Nonlinear analysis of a CMOS integrated silicon pressure sensor

This paper reports theoretical and experimental results of analysis on the nonlinear characteristics of a CMOS integrated pressure sensor with a square silicon diaphragm. It is shown that nonlinearity is caused by both the large diaphragm deflection and the nonlinear piezoresistance of the resistors. The optimum layout for the piezoresistors to minimize their nonlinearity is also shown. The measured nonlinearity for the fabricated device agrees well quantitatively with the numerically analyzed nonlinearity.     

机载电子设备可靠性与结构一体化设计方法

开展了可靠性与结构一体化设计方法的研究.通过对机载电子设备数字样机进行应力分析发现设计薄弱环节,并根据薄弱环节对设备进行了设计优化,从而满足设备的环境适应性要求.在此基础上,进行设备的潜在故障分析与可靠性优化,提升设备的可靠性指标.某机载电子设备的应用实践与试验验证表明了这种一体化设计方法在电子设备设计中的适用性.     

Test device structures for integrated circuit design,process technology development and evaluation

In the present paper, mask contours of npn transistors, pnp lateral transistors, diffused and pinch resistors, bridge and Greek cross sheet resistors, metal to doped silicon region contact resistors, parasitic pnp transistors, test diodes and alignment marks have been drawn (500 ×) for the development and testing of integrated circuit design and technology.The layout design of devices is based on 10 μm design rules with defined minimum dimensions and clearances in order to avoid the failure of the circuit due to technological inaccuracies. Devices could be easily designed, fabricated and performance evaluated in a fairly good R & D set-up having semiconductor device fabrication facilities.     

Performance analysis and stability testing of a new structure of optoelectronic integrated device

This paper is devoted to the evaluation of the transient performance as well as testing the stability of a new version of optoelectronic integrated devices. This version is composed of a resonant cavity enhanced heterojunction phototransistor and a light-emitting diode. It will be called as a resonant cavity enhanced optoelectronic integrated device. The evaluation of its transient response is based on the frequency response of the constituent elements and the optical feedback inside the device. Analytical expressions describing the transient behavior are derived. The numerical results show that the transient performance of the version under consideration strongly depends on the optical feedback inside the device and it has a very high optical gain in comparison with the conventional types. In addition, the possibility of operating the new device in two distinct modes is also available as similar to conventional types. Moreover, testing the stability of the new version demonstrates that its optical gain is stable as long as the value of the optical feedback is maintained below threshold value, while exhibits instability for values of optical feedback, which is greater or equal to this threshold value.     

一种全光纤脉冲压缩器的理论分析

文章对由色散补偿光纤(DCF)、分布式拉曼放大的色散位移光纤(DSF)以及非线性光纤环镜(NOLM)构成的全光纤脉冲压缩器进行了理论分析和数值模拟.结果表明,光脉冲经DCF后可消除啁啾,为压缩提供有利条件;而经分布式拉曼放大的DSF后,脉冲得到了较大的压缩;最后再通过NOLM消基座.利用此压缩器可获得压缩率高且压缩效果好的光脉冲.     

Thermal response of integrated circuit input devices to an electrostatic energy pulse

The thermal response to an electro static discharge (ESD) pulse in silicon is presented and discussed using the three-dimensional heat equation and a set of boundary conditions that physically simulate the behavior of input protection mechanisms commonly used in integrated circuits. Waveforms that vary exponentially and linearly in time are quantitatively analyzed for a spatially localized hot spot and for an even distribution of heat along a circular periphery. The results confirm recent observations that deviation from the smooth and slow exponential waveform due to parasitic oscillations and coupling is a major cause of ESD related damage.     

Thermal analysis and an improved heat-dissipation structure design for an AlGaInP-LED micro-array device

This paper describes a novel finite element thermal analysis model for an AlGaInP-LED micro-array device. We also conduct a transient analysis for the internal temperature field distribution of a 5×5 array device when a 3×3 unit is driven by pulse current. In addition, for broader applications, a simplified thermal analysis model is introduced and its accuracy is verified. The internal temperature field distribution of 100×100 units is calculated using the simplified model. The temperature at the device center reaches 360.6 °C after 1.5 s. In order to solve the heat dissipation problem of the device, an optimized heat dissipation structure is designed, and the effects of the number and size of the heat dissipation fins on the thermal characteristics of the device are analyzed. This work has been supported by the Young Scientists Fund of the National Natural Science Foundation of China (No.61204055). E-mail:gaofl@jlu.edu.cn       

无载波单脉冲天线阵近场波束扫描的时域模拟

运用时域电场积分方程(TD-EFIE)方法得出了在耦合条件下无载波单脉冲激励线天线阵列的瞬态电流分布,通过对阵列天线辐射近、远场的模拟,论证了阵列天线近场主波束形成及实施主波束扫描的可行性;并给出了在一定距离上实现近场主波束扫描时,天线阵各单元所需要的延时量.对于设计无载波单脉冲体制相控阵探地雷达系统具有意义.     

Experimental demonstration of pulse shaping and shortening byspatial filtering of an induced-phase-modulated probe wave

An asymmetrically induced phase modulation resulting in an intensity-dependent spatial beam deflection and a subsequent spatial filtering have been used for all-optical pulse shaping and shortening. A compression factor of eight and controllable symmetrical super-Gaussian pulses and pulse trains have been observed in a good agreement with previous analyses in a pump-probe beam configuration     

Polarization-modulation diagnostics of thermal stresses in an integrated pressure transducer

A semiconductor pressure transducer consisting of a sensing resistor implanted into a silicon membrane as an elastic mechanical element is studied by the modulation polarimetry technique. Internal mechanical stresses are detected. The coordinate distributions of uniaxial stresses are measured in two cases: stresses remaining from local crystal doping inhomogeneities and stresses caused by heating by flowing current. The coordinate distribution of the temperature caused by the heat flux released by the resistor current is determined by double integration of the stress function, taking into account corresponding boundary conditions.