A prototype system and reconstruction algorithms for electrical impedance technique in medical body imaging

Area of Science:

• Electrical Impedance Tomography (EIT)
• Medical Imaging
• Biomedical Engineering

Background:

• Static tissue impedance provides insights into electrical characteristics.
• Existing imaging modalities may have limitations in visualizing certain tissue properties.
• Developing novel imaging systems is crucial for advancing diagnostic capabilities.

Purpose of the Study:

• To develop and validate an impedance imaging system for reconstructing cross-sectional images of the body's electrical characteristics.
• To assess the system's ability to differentiate between tissues with varying electrical resistivity.
• To explore the flexibility and performance of different electrode configurations and reconstruction algorithms.

Main Methods:

• Hardware development including a data collection subsystem and microcomputer system (Intel 380).
• Utilization of an electrode array for current sensing and voltage application.
• Development and testing of various impedance reconstruction algorithms.
• Creation and validation of 2D and 3D finite element method (FEM) based computer body models.

Main Results:

• The prototype system demonstrated capability in discriminating high resistivity regions against a low resistivity background in physical phantom models.
• System flexibility allows individual programming of electrode functions for diverse configurations.
• FEM modeling was verified by comparing simulation results with experimental phantom data.
• Image sensitivity was found to be dependent on position, pixel size (resolution), and background resistivity.

Conclusions:

• The developed impedance imaging system shows promise for visualizing electrical characteristics of biological tissues.
• The system's flexibility and validated modeling approach support further optimization for clinical applications.
• Further research is needed to enhance sensitivity, particularly in central regions of the body.