[01] Israel Esan Owolabi, Department of Electrical and Electronic Engineering, Afe Babalola University, Ado-Ekiti, Nigeria. [02] Vincent Andrew Akpan, Department of Biomedical Technology, The Federal University of Technology, Akure, Nigeria. [03] Olajide Patrick Oludola, Department of Physics, Afe Babalola University, Ado-Ekiti, Nigeria.

Body Mass Index (BMI) is a non-invasive method employed to measure the body fat using the individual’s weight and height which has a directly relationship with obesity. Obesity is therefore the major public health risk in the world which is associated with a lot of disease such as hypertension, type-2 diabetes mellitus, kidney disease, respiratory problems, degenerative joint disease, and cardiovascular disease. Thus, this paper present the design and development of a low-cost automatic BMI machine for indoor and out-door use. The proposed low-cost automatic BMI machine consists of 7 main sections, namely: 1). four load-cells connected in Wheatstone bridge configuration with four SR-120 foil-type strain gauges incorporated; 2). load-cell HX711 amplifier module; 3). HC-SR04 ultrasonic sensor module; 4). Internet-ready Arduino Mega 2560 real-time embedded system development board; 5). an intelligent YJD1602A-1 liquid crystal display (LCD) module; 6). an automatic two-way backup power supply module; and 7). a mechanical assembly for enclosing the automatic BMI components. The BMI is computed as the body weight per height squared. The weight measurement is accomplished using the load-cell assembly via the load-cell amplifier module while the height measurement is achieved using the HC-SR04 ultrasonic sensor module. The weight and height measurement modules are interface to the Arduino Mega 2560 development board where the BMI is computed automatically via a computer program embedded in the Arduino Mega 2560 development board and the BMI for an individual is readily displayed on the LCD. The automatic two-way backup power supply module allows the proposed automatic BMI machine to be used for indoor and out-door BMI measurements in the absence and/or presence of public power supply. The proposed automatic BMI machine have been designed, constructed and deployed for automatic BMI measurements and the results have been compared with manual measurements where mean errors of the height, weight, and BMI measurements of 0.0133, 1.8125, and 1.0733 respectively were recorded. The performance of the proposed low-cost automatic BMI machine indicates that it can be used in homes, hospitals, companies as well as in any environments where routine BMI monitoring may be desired.

Body Mass Index (BMI), Classification, Electronic Instrumentation, Embedded Systems, Internet-of-Things, Obesity, Risk of Co-Morbidity

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