Catheter Guidance System for RF Ablation of Arrhythmias

描述(由申请人提供)：射频(RF)导管消融术是心律失常患者的既定治疗方法。房室结折返性心律失常的射频消融已经非常成功，因为已知的房室结解剖能够准确地识别心律失常的起源位置，从而传递消融能量。室性心动过速(VT)的消融是一个更大的挑战，因为心律失常的起始点可能在脑室的任何地方，而现有的定位技术通常需要患者在相当长的一段时间内保持心律失常。这些因素加在一起，主要限制了心律失常期间血流动力学稳定的患者的慢性室性心动过速的治疗。 在这个快速通道项目的第一阶段，将展示一种新的导管引导系统的概念可行性，该系统将消融导管的尖端引导到心律失常的起始处，并减少定位该部位所需的时间，从而使患者只需要在心律失常中维持几次。该系统将采用创新的“反向算法”分析代码，它使用一个等效的移动偶极子(SEMD)来模拟来自体表电极的心电(EGG)电位和从消融导管尖端传递的电流脉冲。通过处理几次室速期间的体表电位，当生物电源最局部化时，系统将识别与心律失常来源相对应的SEMD位置。使用相同的算法，它将通过分析传送到位于导管尖端的电极的低能量偶极电流脉冲产生的电位来实时识别导管尖端的位置。该系统还将包括实时图形显示，使临床医生能够快速将导管尖端引导到心律失常的源头，以精确传递射频能量。 即使在心电信号中存在真实水平的噪声，初步工作也表明，根据体表电位估计SEMD位置是一项突破性创新，将允许精确、快速地将消融导管引导到心律失常灶。第一阶段将在面包板系统中证明可行性，该系统旨在展示引导消融导管到幻影躯干内电源位置的能力。这项工作将为第二阶段全原型制导系统的开发和体内测试奠定基础。

DESCRIPTION (provided by applicant): Radio frequency (RF) catheter ablation is an established treatment for patients with cardiac arrhythmias. RF ablation of atrio-ventricular nodal reentrant arrhythmias has been highly successful, since the known anatomy of the atrio-ventricular node enables precise identification of the site of origin of the arrhythmia and thus delivery of the ablative energy. Ablation of ventricular tachycardia (VT) presents a greater challenge, since the origin of the arrhythmia could be anywhere in the ventricles, and existing techniques used to locate the site usually require that patients be maintained in arrhythmia for a significant period of time. These factors combine to limit the procedure primarily to treatment of slow VTs in patients who are hemodynamically stable during arrhythmia. In Phase I of this Fast-Track project, concept feasibility will be demonstrated for a new catheter guidance system that will direct the tip of an ablation catheter to the site of origin of an arrhythmia and reduce the time needed to locate the site such that a patient need only be maintained in the arrhythmia for a few beats. The system will feature an innovative "inverse algorithm" analysis code that uses a single equivalent moving dipole (SEMD) to model both electrocardiograph (EGG) potentials from body-surface electrodes and the current pulses delivered from the tip of an ablation catheter. By processing body surface potentials during a few beats of VT, the system will identify the SEMD location that corresponds to the source of the arrhythmia when the bioelectrical source is most localized. Using the same algorithm, it will then identify, in real time, the location of the catheter tip from analysis of potentials resulting from low-energy dipolar current pulses delivered to electrodes located at the tip. The system will also include a real-time graphical display that will allow a clinician to quickly guide the catheter tip to the source of the arrhythmia for precise delivery of RF energy. Even in the presence of realistic levels of noise in the ECG signals, preliminary work has shown that estimation of the SEMD location from body surface potentials is a breakthrough innovation that will allow for precise, rapid guidance of ablation catheters to arrhythmic foci. Phase I will prove feasibility in a breadboard system developed to demonstrate the ability to guide an ablation catheter to the location of an electrical source within a phantom torso. This work will serve as the foundation for development and in-vivo test of a full prototype guidance system in Phase II.