基于心跳补偿和热损伤区在线估计的心脏导管适形消融技术研究

Since the operation is affected by the heart beating and the surgeons lack of the instant knowledge of lesion morphology, the cardiac radio frequency catheter ablation toward atrial fibrillation has various kinds of disadvantages, such as the inaccurate ablation target tracking and difficult decision making on energy used and so on. It can cause complications like the cardiac muscle perforation and postoperative recurrence as well. Current researches focus on specific techniques like special catheter configuration, image fusion and force feedback, which are not yet able to radically fix problems above. This project proposes a novel concept named 'Shape Adaptive Ablation'(SAA). Firstly, SAA utilizes the properative 4D CT image to obtain the accurate ablation trajectory planning, combines 2D TEE images and electromagnetic tracking signals to achieve information fusion, and realizes the heart beating compensation by means of dynamically adjusting the ablation trajectory under electrocardiograph (ECG) gating information. Secondly, SAA describes the flexible catheter with serially connected discrete micro rigid bodies and build an efficient dynamic model. Thirdly, based on the thermomechanical coupling analysis with the pose and force information, SAA estimates the temperature distribution online and evaluates the morphology of thermal lesion. Finally, SAA uses both the hybrid force/position control and optimal energy control strategy, to perform ablation by accurately following the trajectory shape planned and actively controlling the morphology of lesion. This project provides a theoretical exploration to the precise ablation mode for atrial fibriallation treatment, and has important clinical application value for the improvement of both effectiveness and safety of the surgery.

由于受到心脏跳动影响和缺少对心肌损伤情况的了解，经导管心脏射频消融技术存在消融点定位不准和能量施加难以确定等缺点，导致心肌穿孔等并发症以及术后复发。现有研究关注特殊构型导管、图像融合和力反馈等单项技术，尚无法根本性地解决上述瓶颈。本项目提出适形消融的全新理念：首先，利用术前4D-CT影像精确规划消融轨迹，结合2D经食管超声影像与空间电磁定位完成信息融合，根据心电门控在线调整消融轨迹以实现心跳补偿；其次，在对柔性导管进行微刚体离散化的基础上建立高效的动力学模型；第三，基于导管远端位姿和力信息开展热力耦合分析，在线估计消融区的温度分布并对热损伤区域的形态进行评估；最后，基于力位混合控制和消融能量的优化控制策略，实现精确跟踪消融轨迹形状、主动控制消融区域形态的适形消融。本项目是对房颤消融精准操作模式的理论性探索，对提高房颤治疗的有效性和安全性具有重要的临床应用价值。

由于受到心脏跳动影响和缺少对心肌损伤情况的了解，经导管心脏射频消融技术存在消融点定位不准和能量施加难以确定等缺点，导致心肌穿孔等并发症以及术后复发。为了改善这种状况，本项目综合图像融合以及导管的力位混合控制实现心脏的适形消融。首先利用术前影像实现消融轨迹规划，并利用多模图像配准技术实现消融轨迹的在线调整；其次基于Cosserat梁理论和摩擦的历史效应构建导管的精确动力学模型；然后基于并联柔性铰链和布拉格光栅实现末端的三维力感知，结合热力耦模型实现损伤区域的估计；最终基于逆运动学和逆力学实现导管在图像引导下对给定轨迹的精确跟踪。本研究是对房颤消融适形消融的理论探索，具有较高的理论意义与应用价值。