Accuracy of the conductance catheter for measurement of ventricular volumes seen clinically: effects of electric field homogeneity and parallel conductance.
Accuracy of the conductance catheter for measurement of ventricular volumes seen clinically: effects of electric field homogeneity and parallel conductance.
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临床上测量心室容积的电导导管的准确性：电场均匀性和平行电导的影响。
DOI：
10.1109/10.563296
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Feldman,MD
中科院分区：
文献类型：
--
作者：
Wu,CC;Skalak,TC;Schwenk,TR;Mahler,CM;Anne,A;Finnerty,PW;Haber,HL;Weikle2nd,RM;Feldman,MD
电导容积法是一种重要的临床工具，可以在体内评估左心室功能。然而，该方法的准确性受到电导导管产生的电场的均匀性和周围结构的平行电导的限制。本文探讨了这些来源的误差，在量临床上看到的，在一个房间内的电场特性进行了检查，使用计算机模拟。非导电和导电模型的构建和实验测量获得使用单场（SF）和双场（DF）激励。将计算机模拟结果与体外测量结果进行了比较，验证了电导体积法的理论模型。然后确定场均匀性的影响和平行电导在体积测量中的意义。这项研究的结果表明，DF提供了一个更准确的测量脑室容量比SF，特别是在较大的体积。然而，这两个显着低估了真正的体积在更大的体积。此外，由于腔室壁的平行传导在小体积下是显著的，但在较大体积下减小。此外，室壁之外的平行传导的影响可以忽略不计。这项研究表明，在扩张的心脏患者中应用电流电导技术的局限性。
The conductance-volume method is an important clinical tool which allows the assessment of left ventricular function in vivo. However, the accuracy of this method is limited by the homogeneity of electric field the conductance catheter produces and the parallel conductance of surrounding structures. This paper examines these sources of error in volumes seen clinically, The characteristics of electric field within a chamber were examined using computer simulation. Nonconductive and conductive models were constructed and experimental measurements obtained using both single-field (SF) and dual-field (DF) excitation. Results from computer simulations and in vitro measurements were compared to validate the proposed theoretical model of conductance-volume method. The effects of field homogeneity and significance of parallel conductance in volume measurement were then determined. The results of this study show that DF provide a more accurate measure of intraventricular volume than SF, especially at larger volumes. However, both significantly underestimate true volume at larger volumes. In addition, the parallel conductance due to the chamber wall is significant at small volumes, but diminishes at larger volumes. Furthermore, the effect of parallel conductance beyond the chamber wall may be negligible. This study demonstrates the limitations in applying current conductance technology to patients with dilated hearts.