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代写论文一般多少钱 Virtual Instrumentation For Acquisition Computer Science Essay

眼动检测已经吸引了大量的研究人员从许多领域。从早在1950年代开始,许多研究人员就开始研究眼球运动。眼球运动检测的几种方法已在文献[1-5]解释。这些方法要么是昂贵的或笨重的,或造成大量的不适的主题。眼电图(EOG)是广泛应用于眼科眼科诊断和临床实验室的研究,因为它记录眼球运动的全方位提供一种非侵入性的方法。除了临床研究和实验室使用,EOG也广泛用于开发辅助设备[ 1 ]。已经有很多努力开发基于EOG的辅助装置,受这一事实的物理能量耗尽在移动的眼睛是较小的相比其他的手势如点头(哑人),说话或写作等electrooculograms(给予受教育机会)所产生的眼球运动,是最有利的方便[1-3]。它至少会导致病人的不适和记录是以最小的干扰与主题活动和最小的不适。基于EOG的方法简便易行,可用于长期监测。所有这些优势的眼电图作为记录眼球运动的一个合适的方法,进行这方面的研究工作主要集中在眼球运动信号的采集与分析。EOG信号的记录一直是相关的几个问题。该信号是很少确定的,即使在不同的实验中的同一人。它是一个多因素的结果,包括眼球旋转和运动,眼睑运动。肌电图的眼、肌肉产生眼睑运动、眨眼、电极位置、头部运动,影响亮度,重复性和灵活性等从EOG测量设备两大要求。考虑到成本和专用的EOG采集仪器的可用性,这是决定开发为生物信号采集虚拟仪器。这种虚拟仪器应该是经济的,便携的,易于使用。开发的虚拟仪器有所有这些功能可在它。

医院需要几个测量系统,可以测量病人的生理参数。测量系统能够准确测量病人的心脏状况的命脉,心脏的电活动的身体温度,大脑的电活动等信息应可用于诊断和治疗的医生。基于PC的信号采集,分析是一种有效的和成本有效的生物医学信号采集和监控的方法。由于生物信号电平是非常低的,放大的信号是重要的。因此,一个基于PC的系统由额外的电路的信号的隔离和放大。用于信号处理的数据采集卡和软件是很重要的。获取的信号包含有用的信息。但是从原始形式的信号中提取有用的信息是一项艰巨的任务。这激发了生物信号分析,从生物信号中提取有用的信息。在许多情况下,它是观察到的波形的频率内容比时域表示提供了更多有用的信息。许多生物信号显示诊断非常有用的特性,在频域上看时。在这项工作中,我们已经获得了虚拟仪器,在水平和垂直通道EOG信号的处理与分析。基于PC的仪器可以很容易地绕过需要独立的仪器,通过使用目前可用的和一些廉价的收购设备。有几个软件包,可用于目的。在这项工作中国家仪器LabVIEW已经因为强大的工具。LabVIEW是用户友好的,它的高度互动的用户界面开发工具和处理数据采集内置程序使它成为一个方便的选择。

The Electrooculography is a noninvasive technique for measuring the resting potential of the retina. The resting potential is changed when the eye is moved and the movement of the eye is translated into electrical change of potential. Besides the clinical research and laboratory usage, EOG is also extensively used in developing assistive technologies based on the eye movement. EOG is traditionally acquired and measured using dedicated bio-signal measuring equipment developed by some manufacturers. However, the increased performance of personal computers and their reduced cost has made it possible for development of PC based signal processing systems. This research work exploits the benefits of PC based signal acquisition, and analysis. PC based data acquisition and analysis is an efficient and cost effective method for EOG signal acquisition and monitoring. The system developed utilizing virtual instrumentation largely decreased the cost and increased the flexibility of the instrument. The proposed EOG virtual instrument is built by LabVIEW software, DAQ card and additional hardware circuits designed on PCB.

INTRODUCTION

Eye movement detection has attracted a large number of researchers from many fields. From as early as the 1950’s, many researchers began to investigate eye movements. Several methods of eye movement detection have been explained in the literature [1-5]. These methods are either expensive or bulky or cause lot of discomfort to the subject. Electrooculography (EOG) is widely used in ophthalmic research, ophthalmological diagnosis and clinical laboratories because it provides a noninvasive method for recording full range of eye movements. Besides the clinical research and laboratories usage, EOG is also broadly used in developing assistive devices [1]. There have been much efforts to develop EOG based assistive devices, inspired by the fact that the physical energy drained in moving eyes is much lesser when compared to other gestures such as nodding head (dumb people), speaking or writing etc. Electrooculograms (EOGs) occurring as a result of eye movements, are found to be most advantageous and convenient [1-3]. It causes least discomfort to the patient and recording is done with minimal interference with subject activities and minimal discomfort. EOG based method is easy to apply and can be used for long term monitoring. With all these advantages the Electrooculogram is chosen as a suitable method for recording eye movement, for conducting this research work which focused at acquisition and analysis of eye movement signals. The recording of the EOG signal has traditionally been associated with several problems. The signal is seldom deterministic, even for the same person in different experiments. It is a result of a number of factors, including eyeball rotation and movements, eyelid movement. The EMG produced by the muscle of the eye, eyelid movement, the eye blinks, electrode placement, head movements, influence of luminance, etc. The repeatability and flexibility are the two major requirements from EOG measuring equipment. Considering the cost and availability of the dedicated EOG acquisition instrument, it was decided to develop a virtual instrument for the bio signal acquisition. This virtual instrument should be economical, portable and easy to use. The virtual instrument developed had all these features available in it.

Hospitals need several measurement systems that can measure physiological parameters of the patient. Measurement systems should be able to measure accurately the vitals of patient like heart conditions, body temperature electrical activity of the heart, electrical activity of the brain etc. This information should be readily available to the doctors for diagnosis and proper treatment. PC based signal acquisition, and analysis is an efficient and cost effective method for biomedical signal acquisition and monitoring. Since the bio signal level is very low, amplification of signals is important. Hence, a PC based system consists of additional circuits for isolation and amplification of the signals. A data acquisition card and software for signal processing is important. The signals acquired contain useful information. But extracting useful information from signals in their raw form is a difficult task. This has inspired biological signal analysis in extracting useful information from the biological signals. In many cases, it is observed that the frequency content of the waveform provides more useful information than the time domain representation. Many biological signals show diagnostically extremely useful properties when viewed in the frequency domain. In this work we have developed a virtual instrument for acquiring, processing and analysis of EOG signal in horizontal and vertical channels. PC based instrumentation can easily bypass the need for standalone instruments by using the PCs currently available and some inexpensive acquisition equipment. There are several software packages that can be used for the purpose. In this work National Instruments, LabVIEW has been used because of the powerful tools available. LabVIEW is user friendly, its highly interactive user interface developing tools and built in procedures for handling data acquisition have made it a convenient choice.

The paper is organized as follows: Section II explains the experimental components including the challenges, electrode configuration and EOG signal acquisition, Section III explains the significance of the proposed work and section VI briefs the conclusion and future considerations.

EXPERIMENTAL COMPONENTS-MATERIAL AND METHODS

The proposed work is conducted in the following steps:

Design and Simulation of Electrooculogram amplifier.

Building of the hardware circuit board including amplifier and filters.

Design of LabVIEW front panel and block diagram.

Data acquisition using NI- USB 6221, the data acquisition card .

Observing the EOG on the virtual instrument designed, processing of the acquired EOG.

代写论文一般多少钱 Virtual Instrumentation For Acquisition Computer Science Essay

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