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[ABSTRACT]World Health Organization (WHO) reported that heart disease, stroke, lower respiratory infections and chronic obstructive lung disease have remained the top major killers in the world during the past decade. In Indonesia, it covers 37% or about 1.8 millions mortality cases. Hence, human vital sign monitoring such as electrocardiograph (ECG) monitoring system is very essential for mitigating and preventing people fail to be handled a proper assistance from healthcare physicians. In this paper, we propose a real time ECG monitoring system, which the ECG data is able to be checked wirelessly at specified device directlly without any server for data pooling (centralized database). ECG QRS wave and arrhythmia detection are important features for ECG monitoring system. Up to now, there are several studies ECG wave detection, however, they are mainly focus on internet of things-based telemedicine system for data transfer. In this case, real time monitoring system could be disrupted by a pooling time and packet loss due to its IP-based connection. Hence, in this study, we propose a wireless ECG monitoring system with direct point to point communication at 2.4 GHz by using 3-lead acquistion system on single channel wireless ECG device. The system is developed based on AD8232 chip for acquisition, NRF24101 wireless link platform for data transfer and Arduino microcontroller for ECG data processing. In order to evaluate the performance of wireless ECG system, we use wearable textile antennas (as Tx and Rx antenna), on which are attached the human body and experimentally tested in indoor environment, representing an off‐body communication. The results show that the developed system is able to transfer and display real time ECG signals up to approximately 15m of obstruction environment, which the measurement is conducted in a sitting position of volunteers. We have also validated the obtained ECG data, comparing to the data taken from the healthcare clinic equipment. Moreover, according to QRS wave analysis, our ECG signals have reasonable RR, PR, QRS and ST wave interval comparing to the standard ECG signals.

[ABSTRACT]Wireless technology is developing nowadays and one of the most important elements in wireless technology is the antenna. For the user, antenna usually has compact size and considers having high gain. By using High Impedance Surface structure as the substrate, it can enhance gain performance without increase dimension of antenna. In this research, planar rectangular HIS structure has been implemented as substrate of microstrip antenna with dual feeding line. The resonant frequency is 2,445 GHz with 85 MHz bandwidth. HIS unit cell is designed and simulated to obtain the resonant frequency as shown in its reflection phase diagram. The unit cell consists of 1x2 planar array configuration is implemented in circular patch microstrip antenna using electromagnetic coupled feeding method. The antenna consists of two substrate layers. The first layer consists of circular patch and the second substrate consists of two feed lines with HIS unit cell. Based on simulation results, in port 1 shows bandwidth of 150 MHz and 7,85 dB gain. For port 2, the bandwidth is 160 MHz with 7,98 dB gain. To validate the simulation result, measurement has been conducted. Measurement results show 160 MHz bandwidth and 7,92 dB gain in port 1, meanwhile, in port 2, shows 170 MHz bandwidth and 7,12 dB gain.