隨著近年來放射線治療的進步，國內外在放射線治療癌症的應用逐漸增加，因此也有越來越多致力於放射線治療的相關研究。然而由於放射線如果施打的劑量不當對人體也會造成不良影響，因此目前許多醫院都配有輻射劑量監測儀器。其中劑量的監控方式主要是藉由偵測輻射打在游離腔上時，空氣中的粒子游離化，再量測集電板上的帶電粒子所形成的電流大小，最後藉由游離腔的相關計算公式反向推得輻射劑量之多寡。
由於計劃合作對象核能研究所目前所用的輻射劑量量測儀器是以電流積分器為主要架構，在價格上比較昂貴，而且由於積分器本身的運算原理，因此量測時間也較長。因此本論文主要目的就是開發一套以ADC搭配轉阻放大器(TIA IC)為基本核心的即時量測系統。由於現有的市售開發板價格普遍不高，而IC等電路相關零件也相對便宜，因此在成本的節省上也會比原先的量測儀器高。
本系統以德州儀器的開發板MSP430F5438A為基本核心架構，除了配有12BITS解析度的ADC，再搭配上20M與1G的高精密電阻，使得本儀器的電流量測範圍可以達到50nA至4pA。另外藉由訊號的分析與處理，本儀器量測的準確度也符合核能研究所的預期標準(50nA到0.1nA之間誤差率<2%、0.1nA到4pA之間誤差率<5%)。同時也利用開發板上的其他腳位，實作了一台操作儀器所需擁有的使用者介面，並且擁有多種功能，像是參數設定、溫度量測、訊號校正、資料傳輸與按鍵測試等功能。除此之外，再經過PCB電路板與開發板的封裝測試後，我們的整體製作成本相較於核能研究所購買的德國儀器PTW DIAMENTOR M4-KDK低許多。而且我們同時擁有體積小、重量輕、操作性簡單、量測速度快等優勢。相信此原型機在未來經過EMC與EMI等相關醫療儀器檢測，並且達到IEC60580的標準之後，一定可以取代目前較低效率的儀器，成為未來醫學及核能相關的檢測主流儀器之一。

With recent advances in the technology of radiation therapy, the application of radiation therapy for cancer treatment increases gradually. However, if the dose of radiation doesn’t meet the standard, it will be harmful. Many hospitals are equipped with instruments monitoring the dose of radiation. Wherein the dose monitoring method is mainly by detecting the current formed by the radiation induced charged particles which are collected the ionization chamber’s electrode plates, and then calculating the dose by the relevant formulas of the ionization chamber.
Since the measuring instrument of the Institute of Nuclear Energy Research (INER) is currently a current integrator for the main structure, and the price and efficiency of the instrument are more expensive and poorer; therefore, the main purpose of this thesis is to develop a pico-ampere order measuring prototype for radiation dose monitoring application which is based on ADC and TIA in order to reduce the development cost of the instrument and measurement time.
The basic core structure of this system is the development board MSP430F5438 produced by Texas Instruments (TI). The resolution of its ADC is 12 bits, and we use 20MΩ and 1GΩ high-precision resistors to go with the TIA IC. With the above architecture, our system is able to measure the current from 50nA to 4pA with the error rate less than 2% between 50nA and 0.1nA and less than 5% between 0.1nA and 4pA. We also use the other ports and functions of the development board to realize other functions which are important and helpful to a measurement instrument, including the screen display, key operation and self-test, etc. In addition to the above features, our cost is much lower than the PTW DIAMENTOR M4-KDK produced by Germany after we package and test our development board and circuit. Simultaneously, our prototype is also easier to operate, has smaller size, lighter weight and spends less measure time than the DIAMENTOR M4-KDK. It is believed that our prototype will be able to replace the more expensive instruments and become the mainstream instrument on the market once passing the test of the Electromagnetic Compatibility (EMC) and Electromagnetic Interference (EMI), and complying with the IEC60580 standards.

摘要 (I)
ABSTRACT (III)
ACKNOWLEDGEMENTS (V)
TABLE OF CONTENTS (VI)
LIST OF FIGURES (VIII)
LIST OF TABLES (XI)
LIST OF SYMBOLS (XII)
CHAPTER 1 INTRODUCTION (1)
1.1 Foreword (1)
1.2 Research Motivation and Objective (4)
1.3 Thesis Organization (7)
CHAPTER 2 HARDWARE ARCHITECTURE (8)
2.1 Introduction (8)
2.2 Development Board (9)
2.2.1. Development Board(MSP430F5438A) (9)
2.2.2. Analog to Digital Converter(ADC) (10)
2.2.3. Liquid Crystal Display(LCD) (12)
2.2.4. Push Button (13)
2.2.5. Connecting Ports (15)
2.3 Circuit Board (16)
2.4 External Structure of Prototype (17)
CHAPTER 3 SOFTWARE SYSTEM (21)
3.1 System Construction (21)
3.2 Main System (22)
3.2.1. User Interface and Parameter Setting Systems (22)
3.2.2. Temperature Measurement System (26)
3.2.3. Current Measurement System (29)
3.2.4. Test and Calibration Systems (33)
3.2.5. Data Transmission System (35)
3.3 Sub System (36)
3.3.1. Backend User Interface(UI) (36)
3.3.2. Signal Analysis and Algorithm Design Systems (39)
CHAPTER 4 SPECIFICATIONS OF MEASUREMENT SYSTEM (46)
4.1 Introduction (46)
4.2 Basic Calculations of the Resolution (47)
4.3 Multiple Channels Switching of Measurement (49)
CHAPTER 5 EXPERIMENTAL RESULTS OF THE CURRENT SOURCE AND THE ION CHAMBER (52)
5.1 Introduction (52)
5.2 Experiment Result of the Current Source (53)
5.2.1. Initial Results (53)
5.2.2. Results of Background Calibration Comparison (56)
5.2.3. Results of Different Resistances in Larger Current Interval (62)
5.2.4. Final Results in Larger Current Interval (64)
5.2.5. Results in Smaller Current Interval (66)
5.3 Experiment Result of the Ionization Chamber (72)
5.4 Summary (75)
CHAPTER 6 CONCLUSIONS AND FUTURE DIRECTIONS (78)
REFERENCES (81)

[1] Bentzen, Søren M. "Preventing or reducing late side effects of radiation therapy: radiobiology meets molecular pathology." Nature Reviews Cancer6.9 (2006): 702-713.
[2] Chang, Y. C. "A Study on the Fatigue Levels and Related Factors of Lung Cancer Patients During Radiotherapy." CHANG GUNG MEDICAL JOURNAL20 (1997): 209-209.
[3] Dearnaley, David P., et al. "Comparison of radiation side-effects of conformal and conventional radiotherapy in prostate cancer: a randomised trial." The Lancet 353.9149 (1999): 267-272.
[4] Ministry of Health and Welfare. "Taiwanese death causes statistics." Retrieved May 24, 2016, from http://www.mohw.gov.tw/news/531349778. (2015, June 17).
[5] Wikipedia. "Bragg peak." Retrieved May 26, 2016, from https://en.wikipedia.org/wiki/Bragg_peak.
[6] Adapted from "Proton beam therapy" W P Levin, H Kooy, J S Loeffler and T F DeLaney British Journal of Cancer (2005) 93, 849–854.
[7] International Commission on Radiation Units & Measurements. "Current Activities of ICRU." Retrieved May 28, 2016, from http://www.icru.org/content/uncategorised/current-program-of-the-icru#therapy.
[8] International Organization for Standardization. "General requirements for the competence of testing and calibration laboratories." Retrieved May 28, 2016, from http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=39883. (2005).
[9] Hong, Rong-Hong. "Implementation of a Real-Time Current Measuring System for Ionizing Chamber Use." July, 2014.
[10] National Instruments. "LabVIEW System Design Software." Retrieved May 30, 2016, from http://www.ni.com/labview/zht/#.
[11] Matlab. "The Language of Technical Computing." Retrieved May 30, 2016, from http://www.mathworks.com/products/matlab/.
[12] Instruments, Texas. "Code Composer Studio User’s Guide." Texas Instruments Literature Number SPRU328B (2000).
[13] Instruments, Texas. "MSP430F5438 Datasheet." Reference SLAS612, September (2008).
[14] Nagarajan, Chandrasekhar, et al. "Design of a cubesat computer architecture using COTS hardware for terrestrial thermal imaging." Aerospace Electronics and Remote Sensing Technology (ICARES), 2014 IEEE International Conference on. IEEE, 2014.
[15] Shenzhen Yajingda Electronics. "YJD1602A-1 Datasheet." (Sep 08, 2007).
[16] Maunder, C. "JTAG, the joint test action group." IEE Colloquium on New Ideas in Testing. 1986.
[17] Electronic Industries Association. Engineering Dept. Interface between data terminal equipment and data communication equipment employing serial binary data interchange. Electronic Industries Association, Engineering Dept., 1969.
[18] Chen, Yi-Chen, Fu-Long Hong, and Jade Lin. "Universal serial bus." U.S. Patent No. D488, 158. Apr 6, 2004.
[19] MSP430, U. S. B. "Debugging Interface-MSP-FET430UIF." (2009).
[20] Henrion, W. S., Phillip J. Kruczkowski, and Subhajit Sen. "Trans-impedance amplifier." U.S. Patent No. 6,323,734. Nov 27, 2001.
[21] Instruments, Texas. "TLC27L4CN Datasheet." (August, 1994). Reference SLOS053C, October, 1987.
[22] Kerekes, Tamas, et al. "Evaluation of three-phase transformerless photovoltaic inverter topologies." Power Electronics, IEEE Transactions on24.9 (2009): 2202-2211.
[23] Pratt, Terrence W., Marvin V. Zelkowitz, and Tadepalli V. Gopal.Programming languages: design and implementation. No. 04; QA76. 7, P8 1984. Englewood Cliffs: Prentice-Hall, 1984.
[24] Instruments, Texas. "MSP430x5xx and MSP430x6xx Family."
[25] Falholt, K., B. Lund, and W. Falholt. "An easy colorimetric micromethod for routine determination of free fatty acids in plasma." Clinica Chimica Acta 46.2 (1973): 105-111.
[26] Novak, Istvan. "Reducing simultaneous switching noise and EMI on ground/power planes by dissipative edge termination." Advanced Packaging, IEEE Transactions on 22.3 (1999): 274-283.
[27] Baselli, G., et al. "Spectral and cross-spectral analysis of heart rate and arterial blood pressure variability signals." Computers and Biomedical Research 19.6 (1986): 520-534.
[28] Carlson, A. Bruce, and Paul B. Crilly. "Communication Systems, 5e." (2010).
[29] Dambrine, Gilles, et al. "A new method for determining the FET small-signal equivalent circuit." IEEE Transactions on Microwave Theory and Techniques36.7 (1988): 1151-1159.
[30] Childers, Richard K., and John H. Bunch. "Surface mount device with overvoltage protection feature." U.S. Patent No. 5,142,263. 25 Aug. 1992.
[31] Stimson, H. F. "9. PRECISION RESISTANCE THERMOMETRY AND FIXED POINTS." Precision Measurement and Calibration: Selected NBS Papers on Temperature 2 (1968): 121.
[32] Hirai, Hisayuki, et al. "Enameled wire." U.S. Patent No. 6,906,258. 14 Jun. 2005.
[33] Benesty, Jacob, et al. "Pearson correlation coefficient." Noise reduction in speech processing. Springer Berlin Heidelberg, 2009. 1-4.
[34] Wang, Kuo-Wei, et al. "The Study of Beam Quality of Low Monitor Unit Delivery for Intensity Modulated Radiation Therapy." 台灣應用輻射與同位素雜誌 7.2 (2011): 51-58.
[35] Almond, Peter R., et al. "AAPM’s TG-51 protocol for clinical reference dosimetry of high-energy photon and electron beams." Medical physics 26.9 (1999): 1847-1870.
[36] Almond, P. R., and H. Svensson. "Ionization chamber dosimetry for photon and electron beams." Acta radiologica: therapy, physics, biology (2009).
[37] PTW. "Dosimetry Solutions for Diagnostic Radiology." Retrieved May 31, 2016, from http://www.ptw.de/diamentor_m4-kdk_dap_dose_meter.html.
[38] Toroi, P., et al. "Effects of radiation quality on the calibration of kerma-area product meters in x-ray beams." Physics in medicine and biology 53.18 (2008): 5207.
[39] Sidebottom, Charles, et al. "IEC 60601-1–the third edition." Journal of Medical Device Regulation-May (2006): 9.
[40] IEC61000, Standard. "4-21 Electromagnetic compability (EMC), part 4-21: testing and measurement techniques-reverberation chamber test methods."
[41] Bozec, D., et al. "A good practice guide for the use of GTEM cells in EMC measurements according to IEC61000-4-20." Electromagnetic Compatibility, 2004. EMC 2004. 2004 InternationalSymposium on. Vol. 2. IEEE, 2004.