Choi Hyo Won, Berwick Zachary C, Sulkin Matthew S, Owens Christopher D, Kassab Ghassan S
The California Medical Innovations Institute, Inc., San Diego, California, United States of America.
3DT Holdings LLC, San Diego, California, United States of America.
PLoS One. 2017 Jan 3;12(1):e0168886. doi: 10.1371/journal.pone.0168886. eCollection 2017.
Although the clinical range of interventions for coronary arteries is about 2 to 5 mm, the range of diameters of peripheral vasculature is significantly larger (about 10 mm for human iliac artery). When the vessel diameter is increased, the spacing between excitation electrodes on a conductance sizing device must also increase to accommodate the greater range of vessel diameters. The increase in the excitation electrodes distance, however, causes higher parallel conductance or current losses outside of artery lumen. We have previously shown that the conductance catheter/guidewire excitation electrode distances affects the measurement accuracy for the peripheral artery lumen sizing. Here, we propose a simple solution that varies the detection electrode distances to compensate for parallel conductance losses. Computational models were constructed to simulate the conductance guidewire with various electrodes spacing combinations over a range of peripheral artery lumen diameters and surrounding tissue electrical conductivities. The results demonstrate that the measurement accuracy may be significantly improved by increased detection spacing. Specifically, an optimally configured detection/excitation spacing (i.e., 5-5-5 or an equidistant electrode interval with a detection-to-excitation spacing ratio of 0.3) was shown to accurately predict the lumen diameter (i.e., -10% < error < 10%) over a broad range of peripheral artery dimensions (4 mm < diameter < 10 mm). The computational results were substantiated with both ex-vivo and in-vivo measurements of peripheral arteries. The present results support the accuracy of the conductance technique for measurement of peripheral reference vessel diameter.
尽管冠状动脉介入治疗的临床范围约为2至5毫米，但外周血管系统的直径范围要大得多（人类髂动脉约为10毫米）。当血管直径增加时，电导测量装置上激励电极之间的间距也必须增加，以适应更大的血管直径范围。然而，激励电极距离的增加会导致动脉管腔外更高的并联电导或电流损失。我们之前已经表明，电导导管/导丝激励电极的距离会影响外周动脉管腔尺寸测量的准确性。在此，我们提出一种简单的解决方案，即改变检测电极的距离以补偿并联电导损失。构建了计算模型，以模拟在一系列外周动脉管腔直径和周围组织电导率范围内具有各种电极间距组合的电导导丝。结果表明，通过增加检测间距可以显著提高测量准确性。具体而言，一种优化配置的检测/激励间距（即5-5-5或检测与激励间距比为0.3的等距电极间隔）在广泛的外周动脉尺寸范围（4毫米<直径<10毫米）内能够准确预测管腔直径（即-10%<误差<10%）。计算结果通过外周动脉的体外和体内测量得到了证实。目前的结果支持了电导技术测量外周参考血管直径的准确性。
