Signal conditioning using logarithmic amplifier for biomedical applications of electrical impedance tomography

Author:

Saxena M,Gharpure D C,Wagh V G

Abstract

Abstract Objective: The aim of this study was to explore the use of a logarithmic amplifier to improve the spatial resolution (RES) of a low-cost electrical impedance tomography (EIT) system. In an EIT system, the measured signal has a large dynamic range from µV to mV, which requires high-RES (analog to digital conversion) cards. The logarithmic amplifier reduces the dynamic range by expanding lower values and compressing higher values, thereby improving the sensitivity and at the same time preventing the signal from saturation. In addition, a low-RES analog to digital conversion (ADC) cards can be used, making the system cost effective. This work evaluates the performance of a logarithmic amplifier and a linear amplifier used for signal conditioning in a low-cost EIT system. Approach: Two EIT systems based on a linear amplifier and logarithmic amplifier were designed. Phantom experiments were carried out with very small amounts of current injection. The signal-to-noise ratio (SNR), image quality, minimum detectable size and minimum detectable conductivity change were obtained. Main results: The logarithmic amplifier-based EIT system increased the average SNR by 4 dB. It also showed improvement in the RES and contrast-to-noise ratio of the images. The minimum size detectable by the logarithmic amplifier-based system was of radius 0.25 cm in a tank of radius 11 cm and the minimum change in conductivity detectable was 11%. Significance: Logarithmic amplifier-based signal conditioning is a promising technique for improving the spatial RES of a low-cost EIT system that has a low-RES ADC.

Funder

University Grants Commission

Publisher

IOP Publishing

Subject

Physiology (medical),Biomedical Engineering,Physiology,Biophysics

Cited by 2 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3