Cell migration is believed to be a cyclic process of protrusion of the leading edge, adhesion to the substrate, and generation of traction to move the cell body forward. Actin stress fiber is one of the cytoskeletal structures inside the cell and it is known to be an important protein complex involved in this process. In this study, long-term observation of cell migration was performed by phase contrast microscopy, and we observed veering migration of the cell, i.e., change in direction during cell migration. Based on the time sequence of the cell outline and the trajectory of the centroid of the cell obtained from the time-lapse phase contrast images, mechanism of veering migration could be schematized into 4 steps in which expansion of the cell membrane perpendicular to the direction of migration was included. Such expansion step was not observed during directional migration. In order to understand the underlying molecular mechanism of veering migration, actin stress fibers were observed by laser confocal microscopy and alignment of stress fibers inside the cell in each schematized step of veering migration was discussed.

Wheelchair fittings are principally made on the basis of users' measurements and on the basis of the experience and knowledge of persons such as rehabilitation engineers at local rehabilitation centers. However, to choose a proper wheelchair among the diversity of options available, a quantitative evaluation of the propelling force of each particular wheelchair would be useful. Such evaluation systems have been developed, but for laboratory use only. Our study aims to establish a prototype of ambulatory propelling force measurement system which is built directly in the hub of one of the wheelchair wheels. In our previous research, measurement systems using magnetostrictive torque sensors had been described, but the excessive width and weight of such devices affected the results. To overcome this problem, a measurement system using a giant magnetostrictive material was developed. The excess width of the wheel is merely 25 mm and excess weight of the wheel is merely 1.7 kg. This system enabled us to measure the propelling force and speed of each wheelchair accurately. We also developed a mechanism to attach the measurement unit to the wheels of different diameters. Experiments were performed with units attached to 20- or 24-inch-diameter dedicated wheels. The results show that such a system is able to assess the propelling force, speed and left-right coordination both for adults and children.

The purpose of this study is to develop a wheelchair which can be operated by a physically disabled person on his/her own in a barrier-free construction as smoothly as in the movement of a non-disabled person. While barrier-free environment can be easily obtained by renovating the building, expansion of the room or corridor width is more difficult because of the fixed arrangement of pillars and walls. When viewed from above, a disabled person's body is broadest at his/her shoulder and is narrower at his/her knees. Because of this, by building a wheelchair that fits in a Reuleaux triangle, it is possible to hold the body outline of the disabled person within the wheelchair, and that allows it to turn around inside a narrow corridor. The following results were obtained by experimenting on the prototype. Omni-wheels on the three corners of the wheelchair's frame, each driven by an independently controllable motor, enabled the wheelchair to move omni-directionally. By using three types of operation modes, the wheelchair became more capable of lateral movement in a narrow room, route change for avoiding an obstacle, and sudden course correction. The minimal width of the corridor where it can turn around was 800mm in turning operation, and 750mm in compound operation.

A proper seating posture on a wheelchair is important in order to avoid swallowing and respiratory problems. In addition, an improper seating posture may cause a pressure sore and affect motor performance. Although systems that can measure angles of the seating posture that are defined by the international standard ISO16840-1 have been introduced, there are many improvements that can be made in this regard. The system developed in this study aims to measure the seating posture in three dimensions by recognizing numeric markers pasted on the subject from the images captured by stereo video cameras. A system that can recognize the markers and measure the three-dimensional co-ordinates of the markers and angles of nodal lines composed by the markers was developed using MATLAB (MathWorks). By defining the relation between the up, down, left, and right numeric markers, and utilizing this information, the recognition ratio was improved. The measured co-ordinates and angles were compared with the data obtained by MAC3D (Motion Analysis Corporation). The maximum average co-ordinate errors reduced when a large 500 × 750 mm calibration board was used. When a skeletal model was used, the maximum average error in the X direction was 4.8 mm and the angle error was 0.5°. When five human subjects were used, the maximum average error in the X direction was 10.4 mm and the angle error was 1.6°. The errors increased because there was an interval of around 30 s from the measurement made by the developed system to the measurement by the MAC3D system, during which the subjects' body moved.

Measuring and recording urine flow is essential for patients suffering from urologic problems in hospitals and homes. Therefore, to do so conveniently, a system for uroflowmetry tests by using a Bluetooth weight-scale for standing male subjects has been experimentally developed. By using this system, the voided volume and mean flow rate can be calculated from realtime recorded weight data by considering the frequency distribution and delay of the moving average value.

The experiments to evaluate the system were also conducted. The result shows that the estimated output volume has an error range of approximately 10ml which is higher than the original resolution of a weight-scale, and the estimated average flow rate has an error range of approximately 1.3ml/s. The system has some limitations such as the error range is larger than that of commercially available uroflowmeter, and that only the mean flow rate can be calculated from a continuous output. Thus, although it is currently difficult to use this system in for medical purposes, which require high accuracy, the system can be used for home care patients, because it is inexpensive and portable.