Sensitivity study of a locally developed six electrode focused impedance method

Area of Science:

• Biomedical Engineering
• Electrical Bioimpedance Measurement

Background:

• The Focused Impedance Method (FIM) is a novel electrical bioimpedance technique for localized measurements.
• It builds upon the Tetra-Polar Impedance Measurement (TPIM) but offers significant improvements.
• Indigenous technology development is crucial, especially for Low and Medium Income Countries (LMICs).

Purpose of the Study:

• To conduct an experimental sensitivity study of the six-electrode Focused Impedance Method (FIM-6).
• To compare the performance of FIM-6 with TPIM using indigenously designed circuits and phantoms.
• To evaluate the focused region and sensitivity characteristics of FIM-6.

Main Methods:

• Developed indigenous circuits and a 2D phantom in Nepal.
• Performed experimental sensitivity studies on both FIM-6 and TPIM.
• Utilized different electrode arrangements and placed a cylindrical object at various positions within the phantom.

Main Results:

• FIM-6 demonstrated high and stable sensitivity within a defined central 'focused region'.
• TPIM showed sharply decreasing sensitivity away from the center and exhibited larger areas of negative sensitivity.
• FIM-6 exhibited superior sensitivity characteristics compared to TPIM.

Conclusions:

• The Focused Impedance Method (FIM-6) offers significant advantages over TPIM for localized bioimpedance measurements.
• FIM's focused sensitivity is suitable for targeted organ studies and disease diagnosis.
• This study validates the indigenous development of FIM technology for potential LMIC applications.