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Feng CJ, Wu CH, Lin CH, Yuan MC, Lee SH, Huang DY, Lin JY, Chen YF, Hsu SM. The evaluation of an on-site monitoring program for activity meter quality assurance with exemption-level sources. J Radiol Prot 2023; 43. [PMID: 37054698 DOI: 10.1088/1361-6498/accc96] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/13/2023] [Indexed: 05/13/2023]
Abstract
This paper discusses the feasibility of a monitoring program for the quality assurance status of activity meters. We sent a questionnaire to clinical nuclear medicine departments of medical institutions, requesting information on their activity meters and quality assurance practices. On-site visits were conducted with exemption-level standard sources (Co-57, Cs-137 and Ba-133) for dose calibrators in nuclear medicine departments including physical inspection, accuracy and reproducibility. A method offering a quick check on the detection efficiency of the space dimension inside the activity meters was also introduced. For dose calibrator quality assurance, the daily checks had the highest implementation. However, annual checks and upon acceptance/after a repair check were reduced to 50% and 44%, respectively. The accuracy results of dose calibrators showed that all models exceeded the ±10% criteria with Co-57 and Cs-137 sources. The reproducibility results showed that some models exceeded the ±5% criteria with Co-57 and Cs-137 sources. The appropriate application of exemption-level standard sources considering the uncertainty that affects the measurement is discussed.
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Affiliation(s)
- Chen-Ju Feng
- Medical Physics and Radiation Measurements Laboratory, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
| | - Chin-Hui Wu
- Department of Medical Imaging and Radiological Sciences, Tzu-Chi University of Science and Technology, Hualien, Taiwan, Republic of China
| | - Chin-Hsiung Lin
- Medical Physics and Radiation Measurements Laboratory, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Department of Medical Physics, Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan, Republic of China
| | - Ming-Chen Yuan
- Health Physics Division, Institute of Nuclear Energy Research, Taoyuan City, Taiwan, Republic of China
| | - Shen-Hao Lee
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Taoyuan City, Taiwan, Republic of China
- Chinese Society of Medical Physics, Taipei, Taiwan, Republic of China
| | - David Yc Huang
- Medical Physics Graduate Program at Duke Kunshan University, Kunshan, Jiangsu, People's Republic of China
| | - Jo-Yu Lin
- Medical Physics and Radiation Measurements Laboratory, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
| | - Ying-Fang Chen
- Medical Physics and Radiation Measurements Laboratory, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
| | - Shih-Ming Hsu
- Medical Physics and Radiation Measurements Laboratory, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
- Chinese Society of Medical Physics, Taipei, Taiwan, Republic of China
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Pfeiffer J, Gandorfer M, Ettema JF. Evaluation of activity meters for estrus detection: A stochastic bioeconomic modeling approach. J Dairy Sci 2019; 103:492-506. [PMID: 31733873 DOI: 10.3168/jds.2019-17063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/27/2019] [Indexed: 11/19/2022]
Abstract
Although estrus detection makes a relevant contribution to the reproductive performance of dairy cattle, studies on the economic evaluation of automatic estrus detection systems are rare. The objective of the present study is to provide an economic evaluation of activity meters used for estrus detection. The effect of different estrus detection rates on gross margins was modeled with SimHerd (SimHerd A/S, Viborg, Denmark). The analysis considers all costs associated with the investment in activity meters. The economic evaluation was carried out through simulation of Simmental herds with yearly milk yields of 7,000 or 9,000 kg and Holstein Friesian herds with yearly milk yields of 9,000 or 11,000 kg, each with herd sizes of 70 or 210 cows. Furthermore, we distinguished between 2 investment scenarios. In scenario 1, only cows are equipped with activity meters for estrus detection, whereas scenario 2 assumes that cows and heifers are equipped with activity meters. Because existing empirical information for some variables shows significant variability (estrus detection rates, time for estrus detection), they were modeled with distributions using the Monte Carlo method in @RISK (Palisade Corporation, Ithaca, NY), allowing us to model a probability distribution of net returns (NR) of investment in activity meters for estrus detection. The simulation results show that the average NR of investment in activity meters for estrus detection over all scenarios ranges from +€7 to +€40 per cow per year for the Simmental breed, and from +€19 to +€46 per cow per year for the Holstein Friesian breed. Generally, the NR depends on the milk production level assumed. For the Simmental breed, depending on the scenario, the simulation results show a 54 to 200% larger average NR of investment in activity meters for estrus detection with a milk yield of 9,000 kg/yr compared with 7,000 kg/yr. For the Holstein Friesian breed, the effect of the modeled milk yield on the NR is much less pronounced. Average NR of investment in activity meters are greater for larger herd sizes because of cost degression effects. An additional equipping of heifers has, on average, a positive effect on the economics of activity meters for estrus detection because of the resulting reduction in the age at first calving. Considering all scenarios, the probability of a positive NR of investment in activity meters ranges between 74 and 98% for the Simmental breed and between 85 and 99% for the Holstein Friesian breed.
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Affiliation(s)
- J Pfeiffer
- Institute for Agricultural Engineering and Animal Husbandry, Bavarian State Research Center for Agriculture, Freising 85354, Germany.
| | - M Gandorfer
- Institute for Agricultural Engineering and Animal Husbandry, Bavarian State Research Center for Agriculture, Freising 85354, Germany
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