Optimization of Peripheral Vascular Sizing with Conductance Guidewire: Theory and Experiment

Area of Science:

• Biomedical Engineering
• Medical Devices
• Vascular Imaging

Background:

• Clinical interventions for coronary arteries typically involve diameters of 2-5 mm.
• Peripheral vasculature, such as the human iliac artery, has significantly larger diameters, ranging up to 10 mm.
• Existing conductance sizing devices face challenges with larger vessel diameters due to increased electrode spacing, leading to parallel conductance or current losses outside the artery lumen.

Purpose of the Study:

• To address measurement inaccuracies in peripheral artery lumen sizing caused by increased electrode spacing in conductance guidewires.
• To propose and validate a novel solution involving adjusted detection electrode distances to compensate for parallel conductance losses.
• To improve the accuracy of conductance-based techniques for measuring peripheral reference vessel diameter.

Main Methods:

• Construction of computational models to simulate conductance guidewire performance with varying electrode spacing combinations.
• Simulation of a range of peripheral artery lumen diameters and surrounding tissue electrical conductivities.
• Validation of computational findings through ex-vivo and in-vivo measurements of peripheral arteries.

Main Results:

• Increased detection electrode spacing significantly improves measurement accuracy for peripheral artery lumen sizing.
• An optimal detection/excitation spacing ratio (0.3) or equidistant electrode interval (5-5-5) accurately predicts lumen diameter within a -10% to 10% error margin.
• Accurate diameter prediction was achieved across a broad range of peripheral artery dimensions (4 mm to 10 mm).

Conclusions:

• The proposed adjustment of detection electrode spacing offers a simple yet effective solution to enhance conductance guidewire accuracy in larger peripheral vessels.
• The findings support the reliability and accuracy of the conductance technique for measuring peripheral reference vessel diameters.
• Optimized electrode configurations can overcome previous limitations, enabling precise lumen sizing in diverse vascular anatomies.