Nurhayati Nurhayati, Mohammad As’ad Rosyadi, Ahmed J.A. Al-Gburi, Ismaini Zain, Rina Rifqie Mariana, Annis Catur Adi, Nurul Muslihah, Amalia Ruhana
Stunting is a significant health issue affecting the growth of children under five, particularly in developing countries. This study aims to develop a portable stunting detection system integrated with a wearable Coplanar Vivaldi Antenna (CVA) using the Internet of Things (IoT) and an ESP32 microcontroller. The system comprises two components: a hat embedded with ultrasonic and flex sensors for measuring height and head circumference, and a platform equipped with a load cell sensor to measure body weight. The ESP-NOW communication protocol is implemented to enable real-time data synchronization. The CVA is integrated into the hat to enable wireless data transmission via IoT to the receiver unit. A parametric study of the CVA was conducted to investigate the effects of cavity width and corrugation. Simulation results show that a CVA with a cavity radius of 3.5 mm achieves an S11 below –10 dB across 1.98–3.76 GHz and 5.27–10.84 GHz, (133.17% bandwidth). Variations in the corrugated structure lead to differences in directivity, with the highest gain observed in CVA type C at 7.858 dBi. CVA type J demonstrates resonances at 2.39 GHz (–35.05 dB) and 5.87 GHz (–28.99 dB). The Specific Absorption Rate (SAR) was measured using a child voxel with a value of 0.279 W/kg. Testing shows high accuracy, with error rates of 0.16% for height, 0.13% for head circumference, and 0.08% for body weight, with a data transmission success rate of 93% up to 20 m. The system also calculates Z-scores based on World Health Organization (WHO) standards. Copyright © by the author.
Department of Electrical Engineering, Faculty of Engineering, Universitas Negeri Surabaya, Surabaya, Indonesia; Department of Informatics, Faculty of Information and Creative Technology, Universitas Internasional Semen Indonesia, Gresik, Indonesia; Center for Telecommunication Research & Innovation (CeTRI), Fakulti Teknologi Dan Kejuruteraan Elektronik Dan Komputer (FTKEK), Universiti Teknikal Malaysia Melaka (UTeM), Jalan Hang Tuah Jaya, Durian Tunggal, Melaka, Malaysia; Department of Statistics, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, East Java, Surabaya, Indonesia; Department of Culinary Education Study, Faculty of Engineering, Universitas Negeri Malang, Jalan Semarang, Malang, East Java, Indonesia; Department of Nutrition, Faculty of Public Health, Universitas Airlangga, Surabaya, Indonesia; Department of Nutrition Science, Faculty of Health Science, Universitas Brawijaya, East Java, Malang, Indonesia; Nutrition Study Program, Faculty of Sports and Health Sciences, Universitas Negeri Surabaya, Surabaya, Indonesia
