An Estimation Method for Environmental Friction Based on Body Dynamic Model of Caenorhabditis elegans

Caenorhabditis elegans is a small worm which is approximately 1 mm in length. The present study proposes an estimation method for frictional force using locomotion information obtained from video analysis of actual worms. The results indicate that the body model driven by the estimated frictional force can trace the locomotion of the worm within a low error level of 4% of the body length. The proposed method can be applied to analyze the relationship between friction and gait control.This work was supported by JSPS KAKENHI Grant Numbers 15H03950 and 20115010

Development of a Training-Assist Robotic System Adapting to Individual Motor Abilities in Virtual Tennis Task

The present paper develops a training-assist robotic system that can adapt a reference hand motion for a virtual tennis task to individual motor abilities. The system first measures maximum hand force and velocity in reaching arm movements prior to the training, and designs a suitable reference trajectory for teaching motion smoothness and timing in the virtual tennis task based on the measured results. A quantitative index for evaluating task performance and motor functions are then defined with consideration of task dynamics. Finally, the effectiveness of the developed training system is validated through a set of preliminary training experiments with health subjects

Force and Motion Analysis of larval zebrafish (Danio rerio) using a body dynamics model

This study proposes a method of body dynamics analysis for larval zebrafish incorporating a viscoelastic body model and a fluidic environment model to support the study of development mechanisms in motion generation. The results showed that the estimated fluid drag coefficients enabled the body dynamics model to approximate the paths of actual larvae with an error level of 0.76±0.74 [%] to the total body length

Obstacle Avoidance Method for Electric Wheelchairs Based on a Multi-Layered Non-Contact Impedance Model

This paper proposes an obstacle avoidance method based on a multi-layered non-contact impedance model for control of the biosignal-based electric wheelchair. The proposed system can calculate a virtual repulsive force before the collision by multi-layered impedance fields covered around it. This system therefore regulates desired path to avoid obstacles in a variety of situations. In the experiments, the mobile robot passed through obstacles smoothly, and could stop emergently to avoid the obstacle in front of the robot owing to virtual forces calculated by the proposed model.This work was supported by JSPS KAKENHI Grant Number JP26330226

Efficient retroviral transduction of human B-lymphoid and myeloid progenitors: marked inhibition of their growth by the Pax5 transgene

We applied a coculture system for the genetic manipulation of human B-lymphoid and myeloid progenitor cells using murine bone marrow stromal cell support, and investigated the effects of forced Pax5 expression in both cell types. Cytokine-stimulated cord blood CD34+ cells could be transduced at 85% efficiency and 95% cell viability by a single 24-h infection with RD114-pseudotyped retroviral vectors, produced by the packaging cell line Plat-F and bicistronic vector plasmids pMXs-Ig, pMYs-Ig, or pMCs-Ig, encoding EGFP. Infected CD34+ cells were seeded onto HESS-5 cells in the presence of stem cell factor and granulocyte colony-stimulating factor, allowing the extensive production of B progenitors and granulocytic cells. We examined the cell number and CD34, CD33, CD19, and CD20 lambda and kappa expressions by flow cytometry. Ectopic expression of Pax5 in CD34+ cells resulted in small myeloid progenitors coexpressing CD33 and CD19 and inhibited myeloid differentiation. After 6 weeks, the number of Pax5-transduced CD19+ cells was 40-fold lower than that of control cells. However, the expression of CD20 and the κ/λ chain on Pax5-transduced CD19+ cells suggests that the Pax5 transgene may not interfere with their differentiation. This report is the first to describe the effects of forced Pax5 expression in human hematopoietic progenitors

A Voice Signal-Based Manipulation Method for the Bio-Remote Environment Control System Based on Candidate Word Discriminations

This paper proposes a voice signal-based manipulation method for the Bio-Remote environment control system. The proposed system learns relationships between multiple candidate words’ phonemes extracted by a largevocabulary speaker-independent model and control commands based on a self-learning look-up table. This allows the user to control various devices even if false recognition words are extracted. Experimental results showed that the method accurately discriminate slurred words (average discrimination rate: 93.9±2.40 [%]), and that participants were able to voluntarily control domestic appliances.This work was supported by JSPS KAKENHI Grant Number JP26330226