Podhajsky Ronald J, Yi Ming, Mahajan Roop L
Covidien Energy-Based Devices, Boulder, CO 80301, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:4295-8. doi: 10.1109/IEMBS.2009.5334299.
Two different measurement probes--an electrical probe and a thermal conductivity probe--were designed, fabricated, calibrated, and used in experimental studies on a pig liver model that was designed to control perfusion rates. These probes were fabricated by photolithography and mounted in 1.5-mm diameter catheters. We measured the local impedance and thermal conductivity, respectively, of the artificially perfused liver at different flow rates and, by rotating the probes, in different directions. The results show that both the local electrical conductivity and the thermal conductivity varied location to location, that thermal conductivity increased with decreased distance to large blood vessels, and that significant directional differences exist in both electrical and thermal conductivities. Measurements at different perfusion rates demonstrated that both the local electrical and local thermal conductivities increased linearly with the square root of perfusion rate. These correlations may be of great value to many energy-based biomedical applications.
设计、制造、校准了两种不同的测量探头——电探头和热导率探头，并将其用于对旨在控制灌注速率的猪肝模型进行的实验研究中。这些探头通过光刻法制造，并安装在直径为1.5毫米的导管中。我们分别测量了在不同流速下人工灌注肝脏的局部阻抗和热导率，并通过旋转探头测量了不同方向上的局部阻抗和热导率。结果表明，局部电导率和热导率均随位置不同而变化，热导率随着与大血管距离的减小而增加，并且电导率和热导率在方向上均存在显著差异。在不同灌注速率下的测量表明，局部电导率和局部热导率均随灌注速率的平方根呈线性增加。这些相关性可能对许多基于能量的生物医学应用具有重要价值。
