Scrub nurses who assist surgeons during operations are exposed to considerable physical demands. We introduced Archelis^®, a futuristic wearable chair designed for healthcare providers. It allows them to sit during operations（the device supports a half-sitting posture） and reduces fatigue during prolonged and physically demanding procedures. We performed a postoperative questionnaire survey comprising 10 items, among scrub nurses who used Archelis^® during laparoscopic （n＝6） or open colorectal （n＝6） surgery. The original items with a visual analog scale for evaluating the acceptability of Archelis^® under each surgical condition included the overall experience associated with the use of this device, the desire to use the wearable chair, the ease of removing the appliance, and the sensation of stability. We used the Borg scale to evaluate physical discomfort experienced with/without the use of Archelis^®. Overall, Archelis^® was fairly well accepted by scrub nurses who assisted with laparoscopic colorectal surgery, particularly with regard to the sensation of stability provided by the device. However, further improvements are warranted to reduce its weight and the subjective discomfort accompanying its use.

Grasping an object with the human hand is important in accomplishing activities of daily living （ADL）, and the thumbnail has a role in this action. The purpose of this study was to investigate the role of the thumbnail and its pulp when manipulating an object by measuring strain on the thumbnail when grasping a cylinder. The influence of change in the cylinder diameter on thumbnail strain and thumb pressing force was evaluated. Biaxial strain gauges were attached at three points on the surface of the thumbnail （distal central, proximal radial, and proximal ulnar）. The axes of the biaxial strain gauges were aligned in the axial and transverse directions. An asymmetric strain in the radioulnar direction was found on the thumbnail surface when first peak of the striking force occurred with the striking movement. A significant difference in axial strain between the proximal ulnar and distal center locations was observed. These results suggest that the main contact surface with the cylinder is the ulnar surface of the pulp on the thumbnail. With minimum strain in the axial and transverse directions on the ulnar part of the thumbnail surface during the striking movement, compressive strain increased with increasing cylinder diameter and the thumb pressing force also increased in the same manner. The supporting force on the cylinder is from the distal part of the pulp which supports an unstable grip with decrease in a flexion angle of thumb interphalangeal （IP） joint.

Generally, non-contact gaze input devices require calibration before using. However, it is difficult for people with severe multiple disabilities who is mentally challenged and have difficulty in moving their bodies as they wish, to move their eyes according to the instructions. It takes time and effort to use a dedicated device, which makes them difficult to express intentions by looking. In this study, we constructed a real-time gaze area estimation system that does not require calibration while maintaining the resolution required for challenged people. Using a usual web camera, gaze area estimation was realized by learning eye and facial appearance with Convolutional Neural Network （CNN）. Next, 36 gazing points were set on the screen, and the evaluation experiments were performed by changing the relative distance between the camera and the face, and the posture angle of the face. In conclusion, it was confirmed that practical accuracy of the basic posture was maintained up to 1,200 mm for the distance, 100 mm downward in terms of position. The results for the posture angle were obtained for one subject only, but it was shown that the accuracy was maintained up to 10 degrees for the yaw, 15 degrees for the pitch, and 15 degrees for the roll angle, respectively.

This study examined the effects of shapes of daytime running lamps （DRL） on perceived width between the lamps. The width illusion due to the DRL shapes was measured using the paired comparison method （Experiment 1） and the psychophysical staircase method （Experiment 2）. DRL stimuli consisted of two symmetrically arranged white line patterns with a black background. In Experiment 1, 35 young adults were presented with all possible pairs of the 17 DRL stimuli whose maximum width was kept constant and asked to choose one that appeared broader. In Experiment 2, 28 young adults were shown 9 DRL stimuli （standard stimuli） paired with two short white vertical lines separated by varying distances （compared stimuli） and asked to judge which appeared broader. Both experiments yielded similar results and demonstrated that the DRL width illusion is mainly caused by 1） the inner or outer position of bent or angular parts and 2） degree of the resemblance to the Müller-Lyer illusion. The visual illusion of the DRL can change its perceived width by about 5％.

Handy-light sources used in regular train inspections changed from incandescent lamps to LED, which caused reduced visibility in workers over 50 years of age, leading to complaints such as “objects look flat” or “feeling strange.” This study examined the effects of local lighting conditions on fine depth discrimination ability through an experiment that compared performance and psychological rating between age groups. The study aimed to develop working environment in which people could work safely regardless of age, and improve the accuracy of inspections. The results indicated that workers in 50～60 years of age tended to demonstrate a high-level of performance at illumination levels under 1000 lx and display high visibility under warm colors and white light. On the other hand, workers in 20～30 years of age tended to have high visibility under lighting conditions using cold colors.

The aim of this study is to discuss the characteristics of the painting motion of skilled painters in order to hand the excellent skill of painting on to the next generation. The vertical reciprocation painting motion using the roller brush which is one of the basic motions of the painting was analyzed. The painting motions of 11 skilled and inexperienced painters were measured by an optical motion capture system. The relationship between the velocity of the hand holding the roller brush and the painting direction / hand position. The characteristics of the hand velocity of the skilled are as follows: 1） The average velocity between frames is not significantly different from the inexperienced, 2） The velocity when painting the central part is almost constant, and 3） The velocity control varies depending on the painting direction.

Pseudo-haptics, a tactile sense or force sense created by visual stimulation alone, is expected to be useful in the virtual reality （VR） environment. When an unexpected increase or decrease in the display/control （D/C） ratio occurs with cursor movement with a mouse, the illusion of a decrease or increase in resistance is felt in the operating hand. This study aimed to quantify pseudo-haptics caused by changes in the D/C ratio during cursor manipulation in VR environments. A force-feedback device was used as a mouse to deliver resisting force to the operating hand at all times during the trial. The D/C ratio and resisting force were changed during cursor movement, and the subjects indicated whether they felt more resistance before or after the change. Pseudo-haptic feedback was quantified by probit analysis to obtain a point of subjective equality （PSE）. Pseudo-haptic values corresponding to －0.02 N occurred per ＋10％ change in the D/C ratio. These results indicate that it is possible to quantify pseudo-haptics induced by increasing or decreasing the D/C ratio during cursor operation.