Eight-channel high-speed electrical impedance tomography device implemented on a programmable system on a chip

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Medical Imaging

Background:

• Electrical Impedance Tomography (EIT) is a non-invasive imaging technique.
• Monitoring biological fluid volume and conductivity is crucial for diagnostics.
• Existing EIT systems may have limitations in portability and cost.

Purpose of the Study:

• To develop and evaluate a novel EIT device utilizing a Programmable System on a Chip (PSoC).
• To assess the performance of the EIT-PSoC system in terms of frame frequency, accuracy, and signal-to-noise ratio.
• To validate the system's capability in detecting impedance variations in biological fluid phantoms.

Main Methods:

• Implementation of an EIT system using two PSoC 5LP platforms.
• Characterization using a resistive phantom to measure frame frequency (fps), accuracy (Ac), and signal-to-noise ratio (SNR).
• Evaluation with saline and agar phantoms to assess impedance distribution changes and biological fluid emulation.

Main Results:

• Achieved a frame frequency of 100 fps, median SNR of 63.59 dB, and 95.39% accuracy with a 50 kHz sinusoidal current.
• Successfully distinguished impedance changes in saline phantoms through EIT image reconstruction.
• Demonstrated detection of volume and conductivity variations using agar phantoms and the global impedance (GI) index.

Conclusions:

• The EIT-PSoC system offers a promising, high-performance solution for impedance imaging.
• The developed system accurately detects changes in fluid volume and conductivity.
• This PSoC-based EIT device presents a viable alternative for biological fluid monitoring applications.