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http://dx.doi.org/10.21288/resko.2016.10.3.237

A Study on Signal Analysis of the Data Aquisition System for Photosensor  

Hwang, InHo (연세대학교 의과대학 의학공학교실)
Yoo, Sun Kook (연세대학교 의과대학 의학공학교실)
Publication Information
Journal of rehabilitation welfare engineering & assistive technology / v.10, no.3, 2016 , pp. 237-242 More about this Journal
Abstract
The major advantage of slip-ring technology in Spiral CT is that it facilitates continuous rotation of the x-ray tube, so that volume data can be acquired from a patient quickly. Not only for such a fast scan, but also for the dose reduction purpose, high signal-to-noise ratio and fast data acquisition system is required. In this study, we have built a multi-channel photodetector and multi-channel data acquisition system for CT application. The detector module consisted of CdWO4 crystal and Si photodiode in 16 channels. For the performance test of the preamplifier stage, both the transimpedance and switched integrator types are optimized for the photodetector modules. Switched integrator showed better noise performance in the limited bandwidth which is suitable for the current CT application. The control sequence for data acquisition and 20 bit ADC is designed with VHDL(Very High Speed Integrated Circuit Hardware Description Language) and implemented on FPGA(Field Programmable Gate Array) chip. Our Si photodiode detector module coupled to CdWO4 crystal showed comparable signal with other commercially available photodiode for CT. Switched integrator type showed higher SNR but narrower bandwidth compared to transimpedance preamplifier. Digital hardware is designed by FPGA, so that the control signal could be redesigned without hardware alteration.
Keywords
Signal Analysis; Photo detector; Switched integrator; ADC; SNR;
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  • Reference
1 Jerald G. Graeme, "Photodiode Amplifers", McGrow Hill, 1996.
2 Davide. Johsnon, "Basic Electric Circuit Analysis", Prentice Hall, 1995.
3 ACF2101, OPA124, OPA2107, INA106, ADS1250 Product Data Sheet, Burr-Brown Co.
4 ACF2101, OPA124 Application Bulletin, Burr-Brown Co.
5 Henry W. Ott, "Noise Reduction Techniques in Electronic System", A Wiley-interscience publication, 1998.
6 McCluskey, E. J., "Logic Design Principles with Emphasis on Testable Semicustom Circuits, Prentice-Hall, Engle wood Cliffs, N.J., 1986.
7 Wakerly, J. F., "Digital Design Principles and Practices, Prentice-Hall, Engle wood Cliffs, N.J., 1990.