Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA.
IEEE Trans Biomed Eng. 2011 Apr;58(4):845-52. doi: 10.1109/TBME.2010.2098874. Epub 2010 Dec 10.
We have designed, synthesized, and tested an improved version of our original subxiphoid access system intended to facilitate epicardial electrophysiology. The new version of the system incorporates a precision fiber-optic pressure sensor and a novel signal analysis algorithm for identifying pressure-frequency signatures which, in the clinical setting, may allow for safer access to the pericardial space. Following in vivo studies on ten adult canine models, we analyzed 215 pressure-frequency measurements made at the distal tip of the access needle, of which 98 were from nonpericardial, 112 were from pericardial, and five were from ventricular locations. The needle locations as identified by the algorithm were significantly different from each other (p < 0.01), and the algorithm had improved performance when compared to a standard fast Fourier transform (FFT) analysis of the same data. Moreover, the structure of the algorithm can potentially overcome the time lags intrinsic to FFT analysis such that the needle's location can be determined in near-real time. Hydrodynamic pressure-frequency measurements made during traversal of the pericardial membrane revealed a distinct change in signal structure between the pericardial and nonpericardial anatomy. We present and discuss the design principles, details of construction, and performance characteristics of this system.
我们设计、合成并测试了我们最初的经剑突下心包入路系统的改进版本，旨在促进心外膜电生理学。该系统的新版本包含一个精密光纤压力传感器和一种新颖的信号分析算法，用于识别压力-频率特征，在临床环境中，这可能允许更安全地进入心包腔。在对十个成年犬模型进行体内研究后，我们分析了在进入针的远端尖端进行的 215 次压力-频率测量，其中 98 次来自非心包，112 次来自心包，5 次来自心室位置。算法识别的针位置彼此显著不同（p < 0.01），并且与对相同数据进行的标准快速傅里叶变换（FFT）分析相比，算法的性能有所提高。此外，算法的结构有可能克服 FFT 分析固有的时间滞后，从而可以近乎实时地确定针的位置。在心包膜穿行过程中进行的流体动力压力-频率测量揭示了信号结构在心包和非心包解剖之间的明显变化。我们介绍并讨论了该系统的设计原则、构建细节和性能特点。
