Browsing by Author "Luk, Hsiang-Ning"

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Active 433 MHz-W UHF RF-powered chip integrated with a nanocomposite m-MWCNT/polypyrrole sensor for wireless monitoring of volatile anesthetic agent sevoflurane
(2008-01-15)
Chavali, Murthy
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Lin, Tzu-Hsuan
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Wu, Ren-Jang
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Luk, Hsiang-Ning
;
Hung, Shih-Lin
Tiny remote sensors capable of monitoring gases and vapors are having greatest demand due to their potential applications in diverse research fields. In the present work, design and fabrication of an active wireless UHF (433 MHz) RF-powered sensing system for monitoring volatile organic compounds is presented. The developed sensor chip consists of a thin film of gas-responsive composite material, based on modified multiwalled carbon nanotubes (m-MWCNTs) and polypyrrole (Ppy), coated over two comb-like interdigitated gold electrodes. Wireless modules have been integrated with the chemical sensor chip (composite m-MWCNTs/Ppy) and RF components to detect volatile anesthetic agent, fluoromethyl 2,2,2,-trifluoro-1-(trifluoromethyl) ethyl ether (sevoflurane) is demonstrated. (c) 2007 Elsevier B.V. All rights reserved.
New sensing technology for detection of the common inhalational anesthetic agent sevoflurane using conducting polypyrrole films
(2007-10-01)
Wu, Ren-Jang
;
Huang, Yu-Ching
;
Chavali, Murthy
;
Lin, Tzu Hsuan
;
Hung, Shih-Lin
A new type of gas sensor to measure resistance was developed to detect sevoflurane concentrations at room temperature. The measured FTIR spectrum of sevoflurane vapor was given. The sensing material polypyrrole was synthesized in situ by UV-photopolymerization. The relative resistance variation was 3.9 for a sevoflurane concentration of 1.2%. The sensor response time (60 s) and recovery time (20 s) were very short. Molecular dynamic calculations made for sevoflurane adsorption on polypyrrole revealed formation of a new bond, N-H-F. The bond length was predicted to be in the range of 0.2-0.4 nm. The bond energy was about 7.2 kcal/mol. Sensor responses to the concentrations 0. 1-10% were 1.57-5.9, respectively. (C) 2007 Elsevier B.V. All rights reserved.
Towards Development of Wireless Sensor System for Monitoring Anesthetic Agents
(2010-12-01)
Lin, Tzu-Hsuan
;
Hung, Shih-Lin
;
Chavali, Murthy
;
Wu, Ren-Jang
;
Luk, Hsiang-Ning
In this paper, the design and development of sensing system for volatile anesthetic agent based on wireless sensor network is proposed. The proposed system include smart sensor chip fabricated by dip coating conducting polymer for sensing sevoflurane, the most commonly used inhalational anesthetic agent. This paper also discusses the total sensor system design including hardware design, software design and sensor integration. Present sensor system consists of both wireless sensing unit and a wireless receiving unit. The wireless sensing unit includes, sensing module, data acquisition module and wireless microprocessor module. The design of the wireless receiving unit includes two functional modules, a wireless microprocessor module and gateway. The experimental study was conducted to investigate the proposed prototype wireless sensor system. Results indicate the response of the sensor is rapid, and while returning to the initial level immediately after removal of the analyte. The response time T(90) (represents the time to 90% signal with the equilibrium signal) of 5.77% sevoflurane sensing curve is less than 60 s, and recovery time is also less than 60 S. This system has good potential application in monitoring indoor environments in hospitals and being anesthetic agent it is a challenge subject to study as well.