Measurement of brain activity using optical and electrical method

There are patients that cannot produce bioelectric signals such as patients with advanced stages of Amyotrophic Lateral Sclerosis or that have suffered severe spinal cord injury, are unable to use assistive devices such as the exoskeleton HAL. This paper proposes a non-invasive brain activity scanning method for collecting the patient´s movement intentions by developing a hybrid sensor that can measure both optical and bioelectrical signal of a same spot simultaneously and to evaluate it. The developed sensor consists of holography lasers and electrodes. Holography laser contains emitter and receiver inside it. In order to evaluate the hybrid sensor two kinds of experiments were carried out: 1) Data Collection Experiment in which the optical density 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 density lowered. 2) Proof of concept 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 out of this 24 times, the upper limb movement corresponded to the participant´s intention 7 times that was recorder 5sec before or after subject started calculation. We developed a hybrid sensor that can collect both kinds of optical and bioelectrical signal from the same spot on the scalp was developed and evaluated in order to measure brain activity by using optical and bioelectrical data.