Dynamic force control of cardiac ablation catheters

描述（由申请人提供）：微创手术在筛查、诊断和手术中越来越受欢迎。最常进行的手术之一是用于心律失常的导管消融术。心律失常是一组心律异常的情况，其中心脏的电活动不规则或比正常快或慢。通过导管消融手术，可以破坏导致不规则心跳的异常心脏组织。众所周知，消融头端的贴靠力是能量输送的关键因素之一，决定了手术过程中的损伤尺寸和消融时间。如果贴靠力太低，则消融将花费太长时间来烧伤靶组织。如果力太高，则引入穿孔的风险。为了解决这个问题，已经提出了各种尖端力感测技术，并且这些技术最近已经商业化。然而，这些技术在消融期间仅提供贴靠力测量，但不允许任何力控制的自动能力，导致操作者手动控制手术。因此，自动力控制沿着精确的头端力传感的开发将是一项创新，可适用于所有 导管消融术在未来。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。所提出的系统中的创新包括一种新颖的设计，该设计结合了位于消融导管尖端的用于接触力控制的微致动器，以及多个嵌入式光纤应变传感器，这些传感器实时检测多轴尖端力。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，该力控制单元通过尖端力的精确测量向目标组织施加线性位移和力，ii）设计和原型制作锚机构，该锚机构将力控制单元机械地保持到目标部位以提高控制性能，iii）开发具有建模和系统识别的接触力控制算法，以及iv）使用模拟动态心脏功能的体模心脏模型的导管原型的验证实验，以及离体动物心脏测试。设计和原型制作过程以及验证实验将在整个项目期间由心脏病学专家进行监测和指导。本研究的成功完成将证明本研究的可行性，并支持后续的R01申请，以开发进一步改进的系统，进行更多的临床试验。

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.