Crosstalk analysis, its effects and reduction techniques among photovoltaic devices used as transparent optical sensors for a wearable line-of-sight detection system

Abstract

Our group has developed a wearable eye-tracking system that comprises transparent optical sensors on eyeglasses to detect the reflection from the eye and thus, the position of the eye, where photovoltaic cells are used as the sensors. In this paper, crosstalk, or electric interference, among the photovoltaic cells is discussed. The crosstalk makes the neighboring sensors dependent on each other, which leads to large errors in eye-tracking. We experimentally investigated the source of crosstalk by testing different designs of photovoltaic cells and their interconnection. It was revealed that sharing of the electrolyte by the photovoltaic devices was dominant. In addition, overlapping circuits were found to contribute to the crosstalk. We revised the design of the sensors and successfully reduced the crosstalk and improved the accuracy.

Mental Fatigue Monitoring Using a Wearable Transparent Eye Detection System

“…In order to use the eye movement to assess the user’s states, detection of the eye movement needs to be conducted without disturbing the subjects, where light weight is essential and low-power-consumption is preferable for long term monitoring and unnecessity of batteries. We have developed a see-through-type eye-tracking system using photovoltaic cells as transparent optical sensors on eyeglasses [ 18 , 19 , 20 ]. Dye-sensitized photovoltaic cells, which have been studied as transparent solar cells [ 21 ], are microfabricated on the eyeglasses, as shown in Figure 1 .…”

Fatigue Assessment by Blink Detected with Attachable Optical Sensors of Dye-Sensitized Photovoltaic Cells

“…In order to obtain the information with minimal physical and mental stress, we used a wearable, see-through eyeglass-type eye-tracking system [ 14 , 15 ]. The system had an array of transparent optical sensors, which were dye-sensitized photovoltaic devices [ 16 , 17 , 18 ]. While dye-sensitized photovoltaic devices have been studied as next generation solar cells, we utilized them as optical sensors.…”