Cardiac interventional procedures are often performed under fluoroscopic guidance, exposing both the patient and operators to ionizing radiation. To reduce this risk of radiation exposure, we are exploring the use of photoacoustic imaging paired with robotic visual servoing for cardiac catheter visualization and surgical guidance. A cardiac catheterization procedure was performed on two in vivo swine after inserting an optical fiber into the cardiac catheter to produce photoacoustic signals from the tip of the fiber-catheter pair. A combination of photoacoustic imaging and robotic visual servoing was employed to visualize and maintain constant sight of the catheter tip in order to guide the catheter through the femoral or jugular vein, toward the heart. Fluoroscopy provided initial ground truth estimates for 1D validation of the catheter tip positions, and these estimates were refined using a 3D electromagnetic-based cardiac mapping system as the ground truth. The 1D and 3D root mean square errors ranged 0.25-2.28 mm and 1.24-1.54 mm, respectively. The catheter tip was additionally visualized at three locations within the heart: (1) inside the right atrium, (2) in contact with the right ventricular outflow tract, and (3) inside the right ventricle. Lasered regions of cardiac tissue were resected for histopathological analysis, which revealed no laserrelated tissue damage, despite the use of 2.98 mJ per pulse at the fiber tip (379.2 mJ/cm2 fluence). In addition, there was a 19 dB difference in photoacoustic signal contrast when visualizing the catheter tip pre-and post-endocardial tissue contact, which is promising for contact confirmation during cardiac interventional procedures (e.g., cardiac radiofrequency ablation). These results are additionally promising for the use of photoacoustic imaging to guide cardiac interventions by providing depth information and enhanced visualization of catheter tip locations within blood vessels and within the beating heart.

中文翻译：

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基于心脏导管的介入的光声图像指导和机器人视觉伺服的体内演示。

心脏介入手术通常在荧光检查的指导下进行，使患者和操作人员都受到电离辐射的影响。为了减少这种辐射暴露的风险，我们正在探索将光声成像与机器人视觉伺服配合使用以进行心脏导管可视化和手术指导。将光纤插入心脏导管以从纤维导管对尖端产生光声信号后，对两只体内的猪进行心脏导管插入手术。采用光声成像和机器人视觉伺服的组合来可视化并保持对导管尖端的恒定观察，以便将导管通过股静脉或颈静脉朝向心脏引导。荧光检查为导管尖端位置的一维验证提供了最初的地面真实估计，并且使用基于电磁场的3D心脏测绘系统作为地面真实对这些估计进行了完善。1D和3D均方根误差分别为0.25-2.28 mm和1.24-1.54 mm。另外，还可以在心脏的三个位置看到导管尖端：（1）右心房内部；（2）与右心室流出道接触；（3）右心室内。切除心脏组织的激光区域以进行组织病理学分析，尽管在纤维尖端每脉冲使用2.98 mJ（379.2 mJ / cm2的通量），但未发现与激光相关的组织损伤。此外，在观察导管尖端与心内膜组织接触之前和之后，光声信号对比度存在19 dB的差异，这有望在心脏介入手术（例如心脏射频消融）期间进行接触确认。这些结果还有望用于通过光声成像通过提供深度信息和增强血管内和搏动的心脏内导管尖端位置的可视化来指导心脏干预。