CRDM Division, Medtronic Adriatic, Zagreb, Croatia.
Med Biol Eng Comput. 2012 Aug;50(8):827-37. doi: 10.1007/s11517-012-0935-3. Epub 2012 Jun 24.
The purpose of our study was to investigate variety of cardiac lead conductor designs as high-frequency (HF) transmission lines. Special attention was given on evaluation of chronic HF applications in cardiac electrotherapy. We measured the characteristic impedance and the attenuation coefficient of six pacing leads between 1 and 21 MHz. They were subsequently immersed into the saline solution simulating the body fluid and the measurements were repeated 10 years later. Identical measurements were performed on 15 new pacing and defibrillation leads. The results revealed that lead geometry is the main factor affecting the HF parameters. Attenuation coefficients of old and contemporary leads do not differ significantly. Penetration of saline within the leads during a decade did not influence much their HF characteristics. Thus, a chronic cardiac contraction sensor based on lead's HF impedance variation is feasible. The signal losses of ultrasonic transducers mounted on the lead might be stable for years at acceptable levels without significant variation. Due to mutually similar values of HF parameters in different leads, design of tensiometric or ultrasonic applications could be universal for majority of commercially available leads. Automatic system calibration could be developed for each and every lead after determination of its HF parameters.
我们的研究目的是研究各种心脏导联导体设计作为高频（HF）传输线。特别关注评估心脏电疗中的慢性 HF 应用。我们在 1 到 21 MHz 之间测量了六种起搏引线的特征阻抗和衰减系数。随后将它们浸入模拟体液的盐溶液中，并在 10 年后重复测量。对 15 个新的起搏和除颤引线进行了相同的测量。结果表明，引线几何形状是影响 HF 参数的主要因素。旧和现代引线的衰减系数没有显著差异。引线在十年间内被盐水渗透并没有对其 HF 特性产生太大影响。因此，基于引线 HF 阻抗变化的慢性心脏收缩传感器是可行的。安装在引线上的超声波传感器的信号损耗可能在可接受的水平上稳定多年，而没有明显变化。由于不同引线上的 HF 参数值相互相似，张力或超声应用的设计可以对大多数市售的引线通用。在确定 HF 参数后，可以为每个引线开发自动系统校准。
