# Experimental Demonstration of Single-Channel EEG Signal Using 32 x 32 Pixel OLED Screen and Camera
## 1 Introduction
The popularity of smart devices and the camera installed in every smart device has resulted in the use of a camera as a receiver for communication purposes in VLC systems. In conventional VLC systems, PD is the receiver which requires hardware modification due to filters and amplifiers; however, with the receiver being the camera the cost of implementation is considerably reduced due to inbuilt filters and focusing properties, reducing the unwanted noise [12; 13]. Bit Error Rate (BER) is calculated by comparing the transmitted and received data bits through images such as The QR code obtained at receiver section through image capture can be easily compared to the transmitted image in 2D to calculate BER and to analyse the system performance. The several modulation and demodulation techniques of VLC are used for OCC, as OCC is an extension of VLC, hence the modulation techniques of VLC can be easily incorporated on visible light optical camera communication (VL-OCC). The VL-OCC aims to use commercial LED- or OLED-based infrastructure lighting as the transmitter, and the receiver being the camera. The VL-OCC technology employing the OLED screen as transmitter and the camera as receiver is believed to play an important role in the provision of internet of thing (IoT) and the 5G wireless network [13; 14]. Furthermore, the camera focussing ability mitigates the blurring and the inbuilt filters automatically filter the unwanted noise, without any infrastructure modifications unlike conventional VLC systems that have a PD as the receiver. The concept of transmitting a 1D signal in the digitized form using the On-Off Keying Non-Return to Zero (OOK-NRZ) modulation scheme in a 2D image, with an OLED screen as transmitter and a camera as receiver makes VLC an good alternative to RF communications for data transmission. The adverse impacts of RF signals on human wellbeing and interferences to other medical electronic devices have been in particularly in hospitals. Moreover, it has been stated by the World Health Organization that RF has the possibility of causing cancer in humans [10; 11; 12; 13]. The fact that VLC is more friendly to human and medical electronics is one of the main advantages of using VLC in medicinal services or healthcare. Therefore, this research work proposes a novel VL-OCC-based wireless healthcare system for EEG, using the screen of an OLED as the transmitter and a camera as the receiver. Experiments were carried out in line of sight (LOS) using on-off keying non return to zero (OOK_NRZ) modulation in a realistic medical scenario, with the patient being in the vicinity of the field of view (FOV) of the camera. The camera, having a wider FOV than conventional photodiodes, can scan a larger area, hence the patient can be anywhere within the room. Furthermore, rotating the camera to maintain the LOS is easily feasible, unlike conventional VLC systems deploying photodiodes. The proposed system's experimental results of transmitting the EEG signal in 1D to a 2D image shows that that the system can communicate up to distance of 5.5 m at a camera frame rate of 30 fps, achieving a bit rate of 2.8 kbps. Our contribution: There are three main contributions in this research paper. * The link distance of 5.5 m is achieved, in comparison to the results of available literature of EEG and VLC. * The proposed system will be beneficial in the healthcare environment, such as hospitals, where the RF technology is expensive and suffers from Electromagnetic Interference (EMI). * Due to bit rate being limited by camera frame rate, the achievable rate in the proposed research work in this paper is 2.8 kbps. The bit rate of 2.8 kbps is enough to transmit single-channel EEG transmission using VL-OCC. The remaining paper is divided into different sections: Section 2 lists the related works; Section 3 narrates the system architecture and applications of VL-OCC; Section 4 illustrates the proposed system model for EEG using VL-OCC; Section 5 the experimental work with results; and the conclusion is listed in Section 6.