Results from the Study of Lesions Created by Robot-Assisted Radiofrequency Ablation

Abstract

he integration of robotic systems in radiofrequency (RF) catheter ablation, has the potential to enhance both the efficiency and safety of the procedure. The objective of our research was to develop and implement a proprietary measurement platform, designed to optimize a robot-assisted ablation process through in vitro experimentation, with the goal of achieving fully stable catheter positioning. In our experiments, we focused on maintaining two key parameters: Constant contact force and Stable catheter positioning. To achieve this, we designed and manufactured a specialized contact force limiting device. The stability of catheter positioning was ensured through the utilization of a robotic arm. In addition to maintaining constant contact force, we examined the parameters influencing the volume of lesions formed at varying temperatures and ablation durations. Our experiments were conducted using custom-developed equipment, designed for this study. The study investigated lesion sizes generated by RF ablation at 30 Watts, examining the effects of varying temperatures (60°C, 65°C, 70°C) and ablation durations (10, 20, 30 seconds). Porcine heart tissue samples were subjected to ablation, resulting in the creation of a total of 186 lesions. Following the ablation procedures, the depth, width, and volume of the lesions were systematically measured. A multivariate linear regression model was employed to analyze the impact of temperature and ablation duration on the volume of the lesions. To ensure stability in catheter positioning, a robotic arm was utilized in conjunction with a custom-developed and manufactured contact force limiter. Subsequently, we employed the assembled in vitro equipment to facilitate the preparation of the lesions. Our experiments successfully produced accurate and reproducible ablation patterns, yielding consistent and reliable results. Increasing the temperature from 60°C to 65°C and 70°C resulted in a significant increase in lesion volume, with measurements of 23.57±12.81 mm³, 38.42±16.86 mm³ and 46.88±15.62 mm³, respectively (p<0.001). Similarly, extending the ablation time from 10 seconds to 20 seconds and 30 seconds also led to a significant increase in lesion volume, with volumes of 23.57±12.81 mm³, 28.52±12.50 mm³ and 33.09±18.88 mm³, respectively (p=0.0035). Our research enhances the understanding of how lesion geometry evolves, over different ablation parameters.