섬광체에 보정 알고리즘을 적용한 디지털 휴대용 방사선 검출 시스템 구현
Implementation of Digital Portable Radiation Detecting System with the Algorithm of Compensation in scintillator
- 주제(키워드) 방사선 , 임베디드 , 의료기기
- 발행기관 아주대학교
- 지도교수 김영길
- 발행년도 2016
- 학위수여년월 2016. 2
- 학위명 박사
- 학과 및 전공 일반대학원 의용공학과정
- 실제URI http://www.dcollection.net/handler/ajou/000000021558
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
There are various examples of the radiations used in the medical field, such as a CT scan, nuclear medicine test, x-ray, etc. The CT scan and x-ray can be familiar to the public, but the nuclear medicine test can sound new. This test is to use a small amount of radio-pharmacy, which is stored in each organ or tissue with different amounts and releases the gamma ray. The camera which can detect the gamma ray converts this information into electronic signals so that different organs can be checked. Exposure that is experienced by patients who need these kinds of diagnosis and treatment is defined as ‘medical exposure.’ Even though you add all the amounts of the radiations that about 500,000 radiation workers at industrial sites are exposed to and end up with the exposure issue, it is still 20 to 30% of the radiation amounts for the exposure of the patients in one university hospital. People take risks of the radiation exposure for the diagnosis and treatment of life-threatening diseases, but there is still a chance to significantly reduce the exposure of the patients without hindering the achievement of medical goals. It is extremely important to use the right amount of the radiation in the medical field; therefore, the detailed measurement and constant monitoring are required to see how much radiation is used. Also, the development and application in accordance with the change of the detection efficiency by the temperature are certainly necessary for the performance improvement of the radiation detecting systems. The study designed the system applied with the algorithm correcting the issue that the measured pulse values change in the environment of the changing temperature by improving the performance of the digital portable radiation detecting system and executed the experiments. There are the correction methods for the temperature already existing in the current analog portable radiation detecting system, but the temperature sensor method is only used. The digital portable radiation detecting system applied with the measured pulse value correction based on the temperatures can use both the specific sample method and the temperature sensor method. But the digital portable radiation detecting system does not construct any additional circuit, so it is more suitable to set up the correction value by using the specific samples. After the measured pulse values are corrected with the correction value, they are turned into the energy spectrums. Through this study, the performance improvement from the algorithm of the measured pulse value correction for the temperature by using the specific samples was proven. And if the improvement of the specifications of the hardware is accompanied, then the more detailed and stable detection would be possible compared to the existing radiation detecting system.
more목차
Chapter 1 Introduction 1
Chapter 2 Related Works 6
2.1 Radiation Sensor 6
2.2 Radiation Sources 10
2.3 OS 14
2.3.1 Android Operating System 14
2.3.2 Android Structure 16
2.4 Analog Portable Radiation Detecting System 19
2.4.1 Analog Portable Radiation Detecting System Structure 19
2.4.2 Pulse Shaping Board 20
2.4.3 Signal Processing of Embedded Platform 25
2.4.4 Temperature Compensation of Analog Portable Radiation Detecting System 27
2.5 Detecting Methods of Measured Pulse Values 30
2.5.1 Gaussian Pulse Shaper 30
2.5.2 Trapezoidal Filter 33
2.5.3 Measured Pulse Value Detecting Algorithm Applied to Digital Portable Radiation Detecting System 35
2.6 Digital Portable Radiation Detecting System : DP5G 37
Chapter 3 Implementation of Digital Portable Radiation Detecting System with the Application of Measured Value Correction in Accordance with the Temperature 39
3.1 Digital Portable Radiation Detecting System 39
3.1.1 Digital Portable Radiation Detecting System Structure 39
3.1.2 Signal Processing of Embedded Platform 40
3.2 Proposed Algorithms of Measured Pulse Value Correction in Accordance with the Temperature 42
3.2.1 Algorithm of Measured Pulse Value Correction in Accordance with Specific Samples 43
3.2.2 Algorithm of Measured Pulse Value Correction in Accordance with the Temperature Using the Temperature Sensor 45
Chapter 4 Study Result and Analysis 47
4.1 Study Environment and System 47
4.2 Results and Analysis 48
4.2.1 Results of Radionuclide Measurement Prior to the Application of the Correction 48
4.2.2 Results of the Correction Using Specific Samples 51
4.2.3 Results of the Correction Using the Temperature Sensor 58
chapter 5 Conclusion 65
References 67
Summary (in Korean) 72
