Wave-Weighted Modulation in Electrical Impedance Tomography

Abstract

This study proposes a wave-weighted modulation method to improve the distinction between areas with small conductivity differences in Electrical Impedance Tomography. The modulated signal is generated by modulating the probe and carrier signals, which are adjusted through modulation indexes, including the amplitude, frequency, and phase. The proposed method was compared with commonly applied methods in Electrical Impedance Tomography and validated through simulations and experimental results. The simulation results showed significant improvements over commonly applied methods, including an increase in the current flow density and a tendency for the current to pass through the different conductivity layers, thereby enhancing the ability to distinguish between layers with small conductivity differences within the object. This study demonstrates the feasibility of the wave-weighted modulation method for enhancing the visualization of biological tissue regions with small conductivity differences in heterogeneous environments, such as hemorrhage, swelling, cancerous and normal tissue layers, or changes in physiological function.

Keywords

• Amplitude modulation
• biomedical imaging
• contrast resolution
• demodulation
• electrical impedance tomography
• frequency modulation