To provide a safer sitting environment for wheelchair users, it is important to quantitatively measure the forces acting on the contact surface between the seat and the person in the wheelchair. In addition to the pressure acting on the buttocks, shear forces have received particular attention in recent years; however, measuring shear force is more difficult than measuring pressure. To obtain this measurement, a thin and flexible sensor that can be used in a natural state on a wheelchair is needed. Therefore, we constructed a measurement system using our previously developed wearable sheet-type sensor (0.9 mm thick). In this study, preliminary tests were conducted using human dummies before testing on humans. Sensors were placed in four locations on the humanoid dummy’s back and buttocks, and the electric wheelchair was tilted and reclined five times each. The results showed that the sensor output pattern was reproducible and valid enough to proceed to the next step. However, the shear force in the internal and external directions was greater than expected, which indicates that the equipment and testing methods must be reviewed. On the basis of the results obtained in this preliminary study, preparations will be made for testing on human subjects.

Today, the number of elderly people in Japan is increasing, and the number of families who have members in need of nursing care is also increasing. A home care is promoted by Japanese government, but there is a big problem of a pressure ulcer. Accordingly, many types of antidecubitus aids have been developed. However, these aids are not enough for controlling the body pressure. To address this problem, we developed novel active air mattress, which has soft pressure sensor sheet and can control its air cells independently. In this paper, we analyze the characteristics of the air cell and the relationship between value of the sensors and states of the mattress. As a result, we demonstrate that the condition of the mattress can be estimated from sensor values.

Exercise is widely recognized as effective for various diseases and physical disorders, including those related to brain dysfunction. However, molecular mechanisms behind the beneficial effects of exercise are poorly understood. Many physical workouts, particularly those classified as aerobic exercises such as jogging and walking, produce impulsive forces at the time of foot contact with the ground. Therefore, it was speculated that mechanical impact might be implicated in how exercise contributes to organismal homeostasis. For testing this hypothesis on the brain, a custom-designed ''passive head motion'' (hereafter referred to as PHM) system was developed that can generate vertical accelerations with controlled and defined magnitudes and modes and reproduce mechanical stimulation that might be applied to the heads of rodents during treadmill running at moderate velocities, a typical intervention to test the effects of exercise in animals. By using this system, it was demonstrated that PHM recapitulates the serotonin (5-hydroxytryptamine, hereafter referred to as 5-HT) receptor subtype 2A (5-HT2A) signaling in the prefrontal cortex (PFC) neurons of mice. This work provides detailed protocols for applying PHM and measuring its resultant mechanical accelerations at rodents' heads.

During the rendering of the .pdf version of this article, the °C units were replaced with question marks in Table 1. Please find the proper Table 1 published in the online version of this erratum.

This paper introduces a trial for the testing mechanical properties of an assistive product which is made by three dimensional printer, that is fused deposition modeling(FDM). This three dimensional printing technology is suitable for making personalized assistive product for persons with disabilities. However, objects of FDM have direction dependency on their mechanical properties. Therefore, we explained characteristics of objects which are printed by three dimensional printers and discussed possibility of the technology.