ABSTRACT
There are patients who cannot produce bioelectric signals such as patients with advanced stages of amyotrophic lateral sclerosis or those who have suffered severe spinal cord injury. These patients are unable to use bioelectrical signal-based assistive devices such as the robot suit HAL. This chapter proposes a noninvasive brain activity scanning method for collecting the patient’s movement intentions by developing 190a hybrid sensor that can measure both optical and bioelectrical signals of the same spot simultaneously and evaluate it. The developed sensor consists of holography laser modules and electrodes. The holography laser modules contain an emitter and receiver. In order to evaluate the hybrid sensor, three kinds of experiments were carried out: (1) operation verification of the hybrid sensor probe in which the pulse waves and the alpha wave were measured with the hybrid sensor probe; (2) an optical data collection experiment in which the optical output was found to be high when the participant was in relaxation state; on the other hand, while the participant was executing mental tasks such as algebraic calculations the optical output lowered; and (3) an assistive device control experiment in which the participant tried to move the upper limb assistive device 10 times. The upper limb movement was recorded 24 times during this period. However, 7 times (out of 24) upper limb movement corresponded to the participant’s intention was recorded 5 s before or after the switch was pressed. We developed and evaluated a hybrid sensor that can collect both kinds of optical and bioelectrical signals from the same spot on the scalp in order to measure brain activity by using optical and bioelectrical data.
