Material Cost Minimization Problem for Aluminum Alloy Beam using Beam String Structure

Aluminum alloy is a light-weight material with excellent corrosion resistance but low rigidity. When the aluminum alloy is used to a girder bridge, it takes high costs owing to the increment of its stiffness. Therefore in order to reduce a material cost, the cost minimization problem was performed on beam string structure (BSS) made of the aluminum alloy material based on the results of the topology optimization. We focused on the layout of the BSS and diameter of the cable. The conducted simulation made clear the effectivity of the BSS to the aluminum alloy material for a reduction of material cost and increment of the beam span

Vitreoretinal Surgical Robotic System with Autonomous Orbital Manipulation using Vector-Field Inequalities

Vitreoretinal surgery pertains to the treatment of delicate tissues on the fundus of the eye using thin instruments. Surgeons frequently rotate the eye during surgery, which is called orbital manipulation, to observe regions around the fundus without moving the patient. In this paper, we propose the autonomous orbital manipulation of the eye in robot-assisted vitreoretinal surgery with our tele-operated surgical system. In a simulation study, we preliminarily investigated the increase in the manipulability of our system using orbital manipulation. Furthermore, we demonstrated the feasibility of our method in experiments with a physical robot and a realistic eye model, showing an increase in the view-able area of the fundus when compared to a conventional technique. Source code and minimal example available at https://github.com/mmmarinho/icra2023_orbitalmanipulation.Comment: 7 pages, 7 figures, accepted on ICRA202

Head-Related Transfer Function Interpolation from Spatially Sparse Measurements Using Autoencoder with Source Position Conditioning

We propose a method of head-related transfer function (HRTF) interpolation from sparsely measured HRTFs using an autoencoder with source position conditioning. The proposed method is drawn from an analogy between an HRTF interpolation method based on regularized linear regression (RLR) and an autoencoder. Through this analogy, we found the key feature of the RLR-based method that HRTFs are decomposed into source-position-dependent and source-position-independent factors. On the basis of this finding, we design the encoder and decoder so that their weights and biases are generated from source positions. Furthermore, we introduce an aggregation module that reduces the dependence of latent variables on source position for obtaining a source-position-independent representation of each subject. Numerical experiments show that the proposed method can work well for unseen subjects and achieve an interpolation performance with only one-eighth measurements comparable to that of the RLR-based method.Comment: Accepted to International Workshop on Acoustic Signal Enhancement (IWAENC) 202

Autonomous Coordinated Control of the Light Guide for Positioning in Vitreoretinal Surgery

Vitreoretinal surgery is challenging even for expert surgeons owing to the delicate target tissues and the diminutive workspace in the retina. In addition to improved dexterity and accuracy, robot assistance allows for (partial) task automation. In this work, we propose a strategy to automate the motion of the light guide with respect to the surgical instrument. This automation allows the instrument's shadow to always be inside the microscopic view, which is an important cue for the accurate positioning of the instrument in the retina. We show simulations and experiments demonstrating that the proposed strategy is effective in a 700-point grid in the retina of a surgical phantom. Furthermore, we integrated the proposed strategy with image processing and succeeded in positioning the surgical instrument's tip in the retina, relying on only the robot's geometric information and microscopic images.Comment: Accepted on T-MRB 2022, 16 page

Trends in the incidence and mortality of legionellosis in Japan: a nationwide observational study, 1999-2017

This study examined temporal trend, seasonality, and geographical variations of legionellosis incidence and mortality in Japan. This nationwide observational study used the Japanese Vital Statistics and Infectious Diseases Weekly Report (1999-2017) data to calculate legionellosis crude and age-adjusted incidence and mortality rates per 100,000 population by age and sex. Incidence was compared among the 4 seasons and regional incidence among 47 prefectures. Of 13,613 (11,194 men) people with legionellosis in Japan, 725 (569 men) were fatal. Increasing incidence trend occurred from 0.0004 (1999) to 1.37 (2017) per 100,000 population. People aged >= 70 years accounted for 43.1% overall; men's age-adjusted incidence rate was consistently approximately five times higher than for women. Significantly higher incidence occurred in summer than in winter (p=0.013). Geographically, highest incidence (>= 2.0 per 100,000 population) occurred in Hokuriku District, with increasing trends in Hokkaido and middle-part of Japan. Estimated fatality rates decreased consistently at 5.9% (95% confidence interval: - 8.1, - 3.5) annually, from 1999 to 2017, with no trend change point. Increasing legionellosis incidence occurred in Japan during 1999-2017, with declining estimated fatality rates. In this aging society and warming world, disease clinical burden may further deteriorate in future due to increasing incidence trends