Dynamic force control of cardiac ablation catheters

描述(由申请人提供)：微创程序在筛查、诊断和手术中越来越受欢迎。最常见的手术之一是导管消融术治疗心律失常。心律失常是一组心脏节律异常，心脏的电活动不规律或比正常快或慢的情况。通过插管消融程序，可以破坏导致心律不齐的异常心脏组织。众所周知，消融尖端的接触力是决定消融过程中病变大小和消融时间的关键因素之一。如果接触力太小，消融时间会太长，无法烧毁目标组织。如果作用力太大，就会有穿孔的风险。为了解决这一问题，已经提出了各种尖端力传感技术，并于最近实现了商业化。然而，这些技术只提供消融过程中的接触力测量，但不允许任何自动的力控制能力，导致操作员手动控制程序。因此，发展自动力控制和精确的尖端力传感将是一项可以适用于所有人的创新 在未来的导管消融手术中。本项目的目标是开发一种用于心脏消融导管的自动力控制系统。该系统的创新之处在于采用了一种新颖的设计，包括位于消融导管顶端的用于控制接触力的微执行器，以及多个嵌入式光纤应变传感器，这些传感器可以实时检测多轴尖端的力。具体目标包括：i)设计和制造具有嵌入式力控制单元的消融导管原型，通过精确测量尖端力来将线性位移和力施加到目标组织；ii)设计和制作锚定机构以机械地将力控制单元保持到目标位置以提高控制性能；iii)开发接触力控制算法并进行建模和系统识别；以及iv)使用模拟动态心脏功能的体模心脏模型进行导管原型的验证实验，以及体外动物心脏测试。在整个项目期间，设计和原型制作过程以及验证实验将由心脏病学专家进行监测和指导。这项研究的成功完成将证明这项研究的可行性，并支持R01的后续应用，以开发具有更多临床测试的进一步改进的系统。

DESCRIPTION (provided by applicant): Minimally-invasive procedures have become increasingly popular for screening, diagnosis and surgery. One of the most commonly performed procedures is catheter ablation for cardiac arrhythmia. Cardiac arrhythmia is a group of conditions abnormal heart rhythm in which the electrical activity of the heart is irregular or i faster or slower than normal. Through catheterized ablation procedures, abnormal cardiac tissues that cause irregular heartbeats can be destroyed. It is well known that contact force of the ablation tip is one of the critical factors of energy delivery that determine the lesion size ad ablation time during the procedure. If the contact force is too low, the ablation will take too lon to burn the target tissue. If the force is too high, a risk of perforation is introduced. To addres this issue, various tip force-sensing technologies have been proposed and have recently become commercially available. However, these technologies provide only contact force measurement during ablation but do not allow any automatic capability of force control, resulting in manually controlled procedure by the operator. Therefore, development of automatic force control along with accurate tip force sensing will be an innovation that could be applicable to all catheter ablation procedures in the future. The goal of this project is to develop an automatic force control system for cardiac ablation catheters. The innovation in the proposed system consists of a novel design incorporating a micro-actuator located at the tip of an ablation catheter for contact force control, combined with multiple embedded fiber-optic strain sensors that detect a multi-axis tip force in real-time. Specific aims include i) design and fabrication ofa ablation catheter prototype with an embedded force control unit that applies linear displacement and force to the target tissue with an accurate measurement of tip force, ii) design and prototyping of an anchor mechanism that mechanically holds the force control unit to the target site for increased control performance, iii) development of contact force control algorithms with modeling and system identification, and iv) validation experiments of the catheter prototype using phantom heart models that simulate dynamic heart function, and ex-vivo animal heart tests. The design and prototyping process as well as validation experiments will be monitored and guided by a cardiology expert through the entire project period. Successful completion of this research will demonstrate the feasibility of this research and support follow-on R01 application for developing a further improved system with more clinical tests.