2D Slice-driven Physics-based 3D Motion Estimation Framework for Pancreatic Radiotherapy

Pancreatic diseases are difficult to treat with high doses of radiation, as they often present both periodic and aperiodic deformations. Nevertheless, we expect that these difficulties can be overcome, and treatment results may be improved with the practical use of a device that can capture 2D slices of organs during irradiation. However, since only a few 2D slices can be taken, the 3D motion needs to be estimated from partially observed information. In this study, we propose a physics-based framework for estimating the 3D motion of organs, regardless of periodicity, from motion information obtained by 2D slices in one or more directions and a regression model that estimates the accuracy of the proposed framework to select the optimal slice. Using information obtained by slice-to-slice registration and setting the surrounding organs as boundaries, the framework drives the physical models for estimating 3D motion. The R2 score of the proposed regression model was greater than 0.9, and the RMSE was 0.357 mm. The mean errors were 5.11 $\pm$ 1.09 mm using an axial slice and 2.13 $\pm$ 0.598 mm using concurrent axial, sagittal, and coronal slices. Our results suggest that the proposed framework is comparable to volume-to-volume registration, and is feasible

Spatially Continuous Non-Contact Cold Sensation Presentation Based on Low-Temperature Airflows

Our perception of cold enriches our understanding of the world and allows us to interact with it. Therefore, the presentation of cold sensations will be beneficial in improving the sense of immersion and presence in virtual reality and the metaverse. This study proposed a novel method for spatially continuous cold sensation presentation based on low-temperature airflows. We defined the shortest distance between two airflows perceived as different cold stimuli as a local cold stimulus group discrimination threshold (LCSGDT). By setting the distance between airflows within the LCSGDT, spatially continuous cold sensations can be achieved with an optimal number of cold airflows. We hypothesized that the LCSGDTs are related to the heat-transfer capability of airflows and developed a model to relate them. We investigated the LCSGDTs at a flow rate of 25 L/min and presentation distances ranging from 10 to 50 mm. The results showed that under these conditions, the LCSGDTs are 131.4 $\pm$ 1.9 mm, and the heat-transfer capacity of the airflow corresponding to these LCSGDTs is an almost constant value, that is, 0.92.Comment: 7 page

Villous Tumor of the Urinary Bladder Resembling Low-grade Mucinous Neoplasm of the Appendix

AbstractMucinous neoplasms of the urinary tract are very rare. We present a 63-year-old-women who had a sessile papillary villous tumor in urinary bladder. Although transurethral resection of the bladder tumor (TURBT) was performed, the villous tumor repetitively recurred and gradually spread to the entire surface of bladder lumen. Histopathologic and immunohistochemical examination showed that the lesion was very similar to low-grade mucinous neoplasm arising in appendix vermiformis. There are no reports on appendiceal metaplasia of urinary bladder mucosa. In this case, we describe this unprecedented neoplasm as “villous tumor of the urinary bladder resembling low-grade mucinous neoplasm of the appendix.

Integration of Independent Heat Transfer Mechanisms for Non-Contact Cold Sensation Presentation With Low Residual Heat

Thermal sensation is crucial to enhancing our comprehension of the world and enhancing our ability to interact with it. Therefore, the development of thermal sensation presentation technologies holds significant potential, providing a novel method of interaction. Traditional technologies often leave residual heat in the system or the skin, affecting subsequent presentations. Our study focuses on presenting thermal sensations with low residual heat, especially cold sensations. To mitigate the impact of residual heat in the presentation system, we opted for a non-contact method, and to address the influence of residual heat on the skin, we present thermal sensations without significantly altering skin temperature. Specifically, we integrated two highly responsive and independent heat transfer mechanisms: convection via cold air and radiation via visible light, providing non-contact thermal stimuli. By rapidly alternating between perceptible decreases and imperceptible increases in temperature on the same skin area, we maintained near-constant skin temperature while presenting continuous cold sensations. In our experiments involving 15 participants, we observed that when the cooling rate was -0.2 to -0.24 degree celsius per second and the cooling time ratio was 30 to 50 %, more than 86.67 % of the participants perceived only persistent cold without any warmth

Development of a system for the assessment of a dual-task performance based on a motion-capture device

The authors produced a dual task (DT) that provided a dynamic balance task and a cognitive task in a game system using motion sensors and virtual images. There had been no DT where a cognitive task needs a dynamic balance task that requires full-body motions. We developed and evaluated a game system to assess the performance of the DT. The DT was to solve a Sudoku puzzle using full-body motions like Tái Chi. An ability to perform a DT is intimately related to risk of falls. To evaluate the developed system, we compared the performance of elderly people and young people. Generally, elderly people are at a higher risk of falls. Twenty elderly community-dwelling adults (mean age, 73.0±6.2 years) and 16 young adults (mean age, 21.8±1.0 years) participated in this study. To compare the two groups, we applied an independent-samples t-test. The time taken for the elderly people was 60.6±43.2 s, whereas the time taken for the young people was 16.0±4.8 s. The difference is statistically significant (p<0.05). This result suggests that the developed game system is useful for the evaluation of the DT performance

Evaluation of Seismic Safety of a Large Caisson Structure

Some centrifugal shaking tests were carried out to clarify the mechanism of seismic interaction between a large caisson foundation and soil layers. Based on the test data, two-dimensional seismic effective stress FE analysis was applied, followed by verifying its applicability. Also, to clarify the flexural and shear behavior of the caisson structure members to the ultimate state and to evaluate the flexural and shear resistance, some large-scale model failure tests of poorly reinforced concrete in caisson foundation were carried out. Based on these test results above-mentioned, seismic analyses of an existing large caisson foundation to ground motion in level 2 earthquakes were carried out, adopting the above-mentioned analysis. As the results, it was concluded that the seismic safety on the caisson foundation was confirmed

2002年以前日本人胃のHIP

Gastric hamartomatous inverted polyp （g-HIP） is rare gastric elevated lesion forming endophytic growth pattern which etiology remains unknown. G-HIP is said to be associated with gastric cancer and gastritis. We systematically reviewed Japanese g-HIP’s clinicopathological features reported before２００２. Japanese g-HIP amount to２０lesions,１８patients ; ７（３８．９％）were males and １１（６１．１％）were females. The mean age of patients was ６０．２ years old. The mean size of the lesions was２１．７millimeter. No of the polyp shape was Yamada type IV７, Yamada type I/flat elevation ６, Yamada type III ４ and Yamada II ３, respectively. The site of the lesions was Body１１, Cardia３, Fornix３and Antrum１, respectively. In１２described cases, accompanied lesion was Gastritis, Carcinoma, GCP, Hyperplastic polyp, GIST and remnant stomach due to ulcer. Of the submucosal shaped（Yamada type I/flat elevation）g-HIP,５０％ has GCP and６２．５％ has gastric cancer. The common feature of g-HIP was pyloric gland-like mucous gland proliferation and cystic dilatation in the H. pylori era of Japan