Design of Analog Front End for Measuring Bioimpedance

This paper presents a novel approach to measuring body impedance using readily available components while maintaining low complexity and cost. The core of the design is the AD5933 integrated circuit, a widely used impedance measurement IC. To enhance its capabilities and ensure safe bioimpedance measurement, a custom analog frontend is introduced in this work. This front-end improves measurement precision, extends frequency range, and adheres to IEC 60601-1 safety standards. The system is designed to operate with minimal hardware requirements while providing reliable impedance measurements across various frequencies. The first section of this paper discusses the technical aspects of the hardware design, detailing the implementation of voltage-controlled current sources, signal conditioning, and calibration methods. The second section presents experimental results obtained from testing the system with resistive loads, RC phantoms, and commercial electrodes. These results validate the system’s accuracy and show its potential for biomedical applications. The proposed design provides a cost-effective and practical solution for bioimpedance measurements, making it suitable for research use.