PubMed · 5200906
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R L Bohannon. 1970. What does the space program do for hospitals?. https://pubmed.ncbi.nlm.nih.gov/5200906/
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PURPOSE: The goals of this study were to evaluate the use of electronic portal imaging device (EPID) paper images as off-line verification tools and to assess the feasibility of replacing portal films by EPID printed images. MATERIALS AND METHODS: Electronic portal images were acquired using a video-based imaging system. After contrast enhancement, these images were printed and compared to portal films when prescribed, and judged about their usefulness for off-line verification. A total of 2025 images were acquired from 322 fields on 137 patients. The images were shown to eight radiation oncologists and two senior residents in radiation oncology, each one of them judging fields relevant to his (her) daily practice. The questions asked were related to the choice of important anatomical structures and the visibility of such structures, the usefulness of the printed images, the comparison with portal films and the possible replacement of such films by paper images. RESULTS: Answers to the different questions were treated as quantitative scores. For the visibility question, means and standard deviations were calculated for each individual structure, then a global score was obtained for a given treatment site. Means and standard deviations were also computed for the comparison question. Proportions and confidence intervals were used for the other questions. The results show that EPID paper images are useful for some treatment sites such as breast, thorax, prostate, abdomen, pelvis (other than rectum) and axilla. The image quality remains insufficient for some other sites such as head and neck and spine. CONCLUSION: Although global anatomical landmarks scores are good, the usefulness score is not always as high because some essential anatomical structures scores must be taken into account. There is also a strong habit factor related to acceptance of EPID printed images as verification tools. As long as they see more and more images, radiation oncologists can more easily visualize anatomical structures and are less stringent when evaluating the efficiency of EPID paper images as off-line verification tools.
BACKGROUND: The Hunter TPS Vivacare periodontal probe was invented to perform consistent, accurate and reliable periodontal examinations "with controlled pressures". AIMS: The aims of the present investigation are 3: (1) what is the accuracy of the probing force when various probe heads are used in a correct operation position; (2) what is the effect of over- and under-reading of the operation position on the probing force; (3) what is the accuracy of the probing force when different probe handles are used. The Hunter TPS probe consists of a tip connected to a special spring mechanism, which controls the pressure extended to the probe tip. According to the manufacturer, the force indicator lines coincide at approximately 20 g force. METHOD: The test apparatus consisted of an electronic balance, and an electronic caliper. 12 TPS probes tips and 3 handles were selected to test whether there were differences in force between probes. Each probe tip was adapted to the same handle and tested 10 times. In a 2nd test, the TPS handles and over-, accurate-, and under-readings were analyzed as to how they affect the probing force. The 12 TPS probe tips were connected to each of the 3 handles and tested 10x for each of 3 handles and levels. RESULTS: The range in force between TPS probe tips was 8.4 g (p<0.001). For the handles as well as for each of the readings of the operating positions, the differences were small and non-significant. However, between over- and under-readings, there were statistical significant differences. CONCLUSION: The conclusion is that the variation in force between probe tips is high and always above the manufacturer's "approximately" 20 g. As long as the same handle and the same probe tip are used together, and the examiner is reading the markings correct, the TPS probe is adequate.