Measuring electrooculograms of a simulated underwater diver by utilizing conductivity of seawater

Aiming to develop an advanced monitoring system for divers acting underwater, which is an uncommon environment, we experimentally investigated whether blinking and gaze-point movement can be detected by using our previously proposed simple method of non-invasive bioelectric measurement utilizing the conductivity of seawater for electrocardiography and electromyography. In this experiment, bioelectrodes (target electrodes) were placed on the skin near one eye in the airspace inside a diving mask, and another electrode (common electrode) was placed outside the diving mask in contact with seawater. The bioelectric potentials induced between the target and common electrodes were measured when the participants in the experiment blinked and moved their gaze point within the diving mask in seawater. The results of the measurements revealed that changes in the bioelectric potentials can be observed when the participant was performing these actions; in other words, electrooculograms (EOGs) can be obtained by using our previously proposed method. A model of the proposed measurement method, namely, a simple electric circuit consisting of resistors and a battery, was then used to demonstrate that it is theoretically possible to measure the EOG potentials by the proposed method.