Movement/walking assistance devices have the great advantage of supporting quality of life for the elderly in an aging society. To strike a balance between efficiency of movement and employment of the elderly user's own body, we developed a smart mobility system called Tread-walk, which is controlled by the user walking on a treadmill and amplifies the user's walking speed. Since the user's walking speed is different from the speed at which the Tread-walk moves, users experience a mismatch between their visual optical flow and somatic sense. In this article, we validate the feasibility of an amplifying gain decision method that analyzes user brain activity. To control Tread-walk, the visual sense is integrated with somatosensation in the parietal area of the brain and controlled in the medial prefrontal cortex. Therefore, first, we measure the parietal area when the participants walk while looking at their virtual optical flow. Second, we measure the medical prefrontal cortex when the participants control Tread-walk 2. These experiments are carried out for a variety of speed amplifying gains. We find that the brain activates significantly at amplification gain K = 1.1-1.7 in the virtual optical flow experiment and K = 1.5-2.0 in the Tread-walk experiment; this brain activation represents the amplification gain at which the visual and somatosensory senses seem to receive similar input. In conclusion, the brain would activate the most significantly at the most appropriate amplification gain.

Mechanical performance of a surgical robot can be evaluated and improved based on a working score; however, intuitive operability cannot be evaluated in this way. We propose a method that measures the user's brain activity for evaluating intuitive operability from the perspective of cognitive science. We hypothesized that hand-eye coordination, such as the slave configuration for the endoscope, has the greatest effect on intuitive operability, because it is the cause of physical differences between a human and a robot. The objective of this paper is to clarify the appropriate slave configuration for the endoscope to study hand-eye coordination using brain activity measurements. In the experiment, we used a brain imaging device, optical topography, to measure the users' brain activity while they controlled the hand-controller to position the tip of the virtual arm on the target. The experiment was carried out a number of times with the virtual arm position configured in a variety of ways. According to the results, some subjects showed peak performance with a specific slave configuration. We conclude that the slave configuration with the highest brain activity depends on the body image, which is a spatial symbol in the human brain from the perspective of cognitive science.

Recently, a large amount of stroke survivors are suffering from motor impairment. However, existed therapy interventions have limited effects to restore normal motor function. Thus, we proposed a novel control strategy for gait rehabilitation of hemiplegic patients. The whole system consists of a Functional Electrical Stimulation (FES) device and Treadmill-Walk system. FES contributes to improve the quality of the gait based on real-time adjustment of gait pattern. During gait, the electrical stimuli from separate output channels of an FES device are launched to stimulate two lower extremity muscles (Tibialis Anterior (TA) and Hamstrings). Stimulus launching procedure is based on identifying subject's gait state (stance and swing phases). According to the current variation of treadmill motor, gait phase and muscle activation of lower limbs can be determined during walking on Treadmill-Walk. Three able-bodied subjects simulated hemiplegic patients in the experiment. The results indicated that the proposed method is a safe, feasible and promising intervention.

Surgical robots have undergone considerable improvement in recent years, but the intuitive operability, representing user inter-operability, has not been quantitatively evaluated. Thus, we propose a method for measuring brain activity to determine intuitive operability in order to design a robot with intuitive operability. The objective of this paper is to clarify the angle between the endoscope and the manipulator that facilitates users perceiving the manipulator as part of their body. In the experiments, while subjects controlled the hand controller to position the tip of the virtual slave manipulator on the target in the surgical simulator, we measured the brain activity through brain imaging devices. We carried out the experiment a number of times with the virtual slave manipulator configured in a variety of ways. The results show that activation of the brain is significant with the slave manipulator configured such that the angles are slanted with respect to the horizontal. We conclude that the body image affects hand-eye coordination, which is related to visual and somatic sense feedback.