基于电阻抗法无拘束心排量检测的最佳电极配置

Optimal Electrode Array for Ambulatory Measuring of Cardiac Output Based on the Electrical Impedance Method

介绍了基于电阻抗法的无拘束心排量(CO)检测技术与原理。利用开发的多通道电阻抗分布检测装置,对通电电极配置在不同位置时的胸部电流分布做了大量的实验研究,分析了各种条件下胸部电阻抗Z及其脉动成分△Z的变化规律,探讨了用点状电极替代带状电极进行无拘束CO检测时胸部圆筒模型的适用性,以及用点状电极检测时的最佳电极配置。基于实验研究的结果并考虑日常生活中无拘束CO检测的实际应用,提出了满足胸部圆筒模型条件的电极最佳配置为通电用点状电极为两耳朵的后边--下腹部(腰骨附近),检测用电极为锁骨中央—剑状凸起。

Principle of ambulatory cardiac output（CO） measuring technique is introduced in this paper.A lot of experimental studies of the current distribution on the thorax under the condition that the current injection electrodes were adhered to different positions were carried out by using a developed multichannel impedance mapping system.The static impedance contour maps（Zo-map） and its pulsatile component contour maps（△Z-map） under different measuring conditions were analyzed,and the applicability of a two-compartment coaxial cylindrical model using a spot-electrode array instead of the conventional band-electrode array for ambulatory CO measurement,as well as the optimal spot-electrode array,were discussed.Based on the experimental results and the daily use of the ambulatory CO measuring technique,the optimal spot-electrode array meeting the condition of the two-compartment coaxial cylindrical model was determined as that a pair of spot-electrodes for current injection was located on the positions behind the ears and on the right lower abdomen,and a pair of spot-electrodes for voltage pick-up places on the medial portion at the level of clavicle and on the portion above the xiphisternum.