Sketch-based Solid Prototype Modeling System with Dual Data Structure of Point-set Surfaces and Voxels

Takeuchi, Ryota,Watanabe, Taichi,Yamakawa, Soji Society for Computational Design and Engineering 2011 International Journal of CAD/CAM Vol.11 No.1

This paper proposes a new solid-shape modeling system based on a lusterware-image illustration. The proposed method reconstructs a three dimensional solid shape from a set of rough sketches that are typically drawn in the early stages of the design process. The sketches do not have to be strictly accurate, and this tolerance to the roughness of the input sketches is one of the major advantages of the proposed method. The proposed system creates an initial shape based on the silhouette of the input lusterware-images. Then the user can edit the initial shape with intuitive cutting and dishing-up operations, which are based on sketching user interface. To achieve the goal, the system retains the geometric model with two representations: a point-set data and a volume data. This dual data structure allows the program to create an initial shape from the input images with little computational cost, and the user can apply cutting and dishing-up operations without substantially increasing computational and memory requirements. In this research, we have tested the proposed system by reconstructing solid models of some mechanical parts from rough sketches. The experimental results indicate that the proposed method is useful for the prototyping of a solid shape.

EFFICIENT IMAGE ANALYSIS METHOD FOR RIVER FLOW MEASUREMENT USING SPACE-TIME IMAGES

FUJITA ICHIRO,WATANABE HIDEKI,TSUBAKI RYOTA 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Impact of Sarcopenia on Erectile Function after Nerve-Sparing Robot-Assisted Radical Prostatectomy

Mitsui Yosuke,Sadahira Takuya,Maruyama Yuki,Sato Ryota,Rodrigo Acosta Gonzalez Herik,Wada Koichiro,Araki Motoo,Watanabe Masami,Watanabe Toyohiko,Nasu Yasutomo 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.4

Purpose: To determine the impact of sarcopenia on erectile functional outcomes after a nerve-sparing (NS) robot-assisted radical prostatectomy (RARP) using patient-reported validated questionnaires. Materials and Methods: In this retrospective study, RARP was performed on 841 patients at Okayama University Hospital, of which 132 underwent NS RARP. Erectile functional outcomes were assessed using the 5-item version of the International Index of Erectile Function (IIEF-5) and the Expanded Prostate Cancer Index Composite before and 1, 3, 6, and 12 months after surgery. Automated measurement of skeletal muscle at L3 was achieved using volume analyzer software and normalizing for height (cm2/m2) to calculate skeletal muscle index (SMI). Patients who had an IIEF-5≤4 comprised the group with erectile dysfunction (ED), and those with an IIEF-5≤5 made up the non-ED group. Results: This study enrolled 95 patients of median age 65 years with a preoperative IIEF‑5 of 16. There were no significant differences between patients with and without sarcopenia among those with preoperative IIEF‑5. Postoperatively, in the ED group, SMI and preoperative IIEF‑5 were significantly lower than in the non-ED group. Multiple linear regression analysis revealed that (1) both SMI and preoperative IIEF-5 were independent predictors of ED, and (2) sarcopenia and preoperative IIEF-5 were predictors of ED at 12 months after NS RARP. Conclusions: Patients with sarcopenia can have worse erectile functional outcomes after NS RARP. Sarcopenia and a lower preoperative IIEF-5 score may be predictive of postoperative ED.

Development of Water Assisted Solid State Reaction for the Ceramic Materials

Toda, Kenji,Kim, Sun Woog,Hasegawa, Takuya,Watanabe, Mizuki,Kaneko, Tatsuro,Toda, Ayano,Yamanashi, Ryota,Kumagai, Shota,Muto, Masaru,Itadani, Atsushi,Sato, Mineo,Uematsu, Kazuyoshi,Ishigaki, Tadashi,K Trans Tech Publications, Ltd. 2017 Key Engineering Materials Vol.751 No.-

<P>We report a novel soft chemical synthesis method, water assisted solid state reaction (WASSR) method. This method is very simple and can synthesize many ceramic materials just by storing or mixing raw materials added a small amount of water in a reactor at low temperature below 373 K. For example, well-crystalline SrMoO4 was obtained using the WASSR method.</P>

Poor Prognostic Factors for Surgical Treatment of Spinal Intramedullary Ependymoma (World Health Organization Grade II)

Tsuji Osahiko,Nagoshi Narihito,Ishii Ryota,Nori Satoshi,Suzuki Satoshi,Okada Eijiro,Fujita Nobuyuki,Yagi Mitsuru,Matsumoto Morio,Nakamura Masaya,Watanabe Kota 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.6

Study Design: Single-center retrospective study.Purpose: We aimed to explore the postoperative prognostic factors for spinal intramedullary ependymoma.Overview of Literature: Ependymoma (World Health Organization grade II) is the most frequent intramedullary spinal tumor and is treated by total resection. However, postoperative deterioration of motor function occasionally occurs.Methods: Eighty patients who underwent surgical resection at Keio University and Fujita Health University in Tokyo, Japan between 2003 and 2015 with more than 2 years of follow-up were enrolled. A good surgical result was defined as an improvement in the modified McCormick Scale score by one grade or more or having the same clinical grade as was observed preoperatively. Meanwhile, a poor result was defined as a reduction in the McCormick Scale score of one grade or more or remaining in grade IV or V at final follow-up. Univariate and multivariate logistic regression analyses of the following factors were performed in the two groups: sex, age, preoperative Visual Analog Scale (VAS), tumor location, the extent of tumor resection, hemosiderin caps, cavity length, and tumor length on magnetic resonance imaging.Results: At final follow-up, 15 patients were included in the poor results group and 65 in the good results group. In the univariate analysis, the factors related to poor results were as follows: higher age, preoperative McCormick Scale score severity, higher preoperative VAS, thoracic location, hemosiderin capped, and non-gross total resection (GTR). A multiple logistic regression analysis was conducted and showed that age, worse preoperative McCormick Scale score, and non-GTR were significant factors for poor prognosis.Conclusions: The independent risk factors for motor deterioration after ependymoma resection were age, worse preoperative McCormick Scale score, and non-GTR. Early surgery for patients with even mild neurological disorders could facilitate functional outcomes. These results may contribute to determining the optimal timing of surgery for spinal intramedullary ependymoma.

Early Phase Functional Recovery after Spinal Intramedullary Tumor Resection Could Predict Ambulatory Capacity at 1 Year after Surgery

Suzuki Tetsuya,Tsuji Osahiko,Ichikawa Masahiko,Ishii Ryota,Nagoshi Narihito,Kawakami Michiyuki,Watanabe Kota,Matsumoto Morio,Tsuji Tetsuya,Fujiwara Toshiyuki,Nakamura Masaya 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.2

Study Design: This is a single-center retrospective cohort study with a university hospital setting.Purpose: This study aims to evaluate the short-term course of physical function and walking ability after intramedullary spinal cord tumor (ISCT) resection and predict walking independence 1 year after surgery.Overview of Literature: Although several reports have shown the postoperative functional prognosis of spinal intramedullary tumors with long-term follow-up, no reports have identified the predictors associated with the functional outcome at an early stage. Methods: A total of 79 individuals who underwent ISCT resection at our institute between 2014 and 2019 were enrolled in the study, whose preoperative walking state was independent ambulator regardless of cane support with the Functional Independence Measure Locomotor Scale (FIM-L) score of ≥6. The FIM-L, the American Spinal Injury Association (ASIA) motor and sensory scores in the lower extremities, and the Walking Index for Spinal Cord Injury II (WISCI II) were assessed for walking independence, lower-limb function, and walking ability, respectively. These evaluations were performed at 4 time points: preoperatively, 1 week (1W), 2 weeks (2W), and 1 year after surgery.Results: In the early phase after surgery, 71% and 43% of the participants were nonindependent ambulators at 1W and 2W, respectively. Histopathology indicated that patients with solid tumors (ependymoma, astrocytoma, or lipoma) showed significantly lower indices at 1W and 2W than those with vascular tumors (hemangioblastoma or cavernous hemangioma). Regarding tumor location, thoracic cases exhibited poorer lower-limb function at 1W and 2W and poorer walking ability at 2W than cervical cases. According to the receiver operating characteristic (ROC) analysis, 2 WISCI II points at 2W had the highest sensitivity (100%) and specificity (92.2%) in predicting the level of walking independence at 1 year postoperatively (the area under the ROC curve was 0.99 (95% confidence interval, 0.93–1.00).Conclusions: The higher the lower-limb function scores in the early phase, the better the improvement in walking ability is predicted 1 year after ISCT resection.

Longitudinal Changes in Physical and Cognitive Functions among Participants with and without Rheumatoid Arthritis in Community-Dwelling Middle-Aged and Older Adults

Mikako Yasuoka,Chikako Tange,Yukiko Nishita,Makiko Tomida,Ryota Watanabe,Hiroshi Shimokata,Rei Otsuka,Masayo Kojima 대한노인병학회 2023 Annals of geriatric medicine and research Vol.27 No.1

Background: This study evaluated the chronological changes in physical and cognitive functions in middle-aged and older adults with and without rheumatoid arthritis (RA). Methods: This population-based case-control longitudinal study included individuals aged 40–79 years at baseline who agreed to participate. We identified 42 participants with RA and randomly selected 84 ageand sex-matched controls. Physical function was assessed according to gait speed, grip strength, and skeletal muscle mass. Cognitive function was assessed based on the information, similarities, picture completion, and digit symbol substitution test scores of the Wechsler Adult Intelligence Scale-Revised Short Form. The general linear mixed models comprised the fixed effects of the intercept, case, age, time in years since baseline, and case×time interaction, which were used to examine longitudinal changes in physical and cognitive functions. Results: Regardless of RA status, grip strength decreased and the picture completion score increased in the group aged <65 years, while skeletal muscle mass index and gait speed decreased in the group aged ≥65 years. The interaction of case×follow-up years for grip strength in the group aged ≥65 years was significant (p=0.03). The decline in grip strength in the control group (slope=-0.45) was greater than that in the RA group (slope=-0.19). Conclusion: Chronological changes in physical and cognitive functions were comparable between participants with and without RA; however, the decline in grip strength in the control group was greater among older adults with RA.