機器人輔助的呼吸運動下超聲波探頭力控制

Abstract

在肝臟射頻消融手術中，外科醫生面臨著同時操作針頭和超聲探頭的挑戰。本作提出了一機器人輔助的超音波探頭力控制系統，為超音波導引的腹部介入性治療提供穩定的超音波成像。 該系統包含六自由度機械手臂、六自由度力與力矩感測器和一個超音波探頭模型，其具有實時補償呼吸擾動的特點。按照既有的手術流程，提出了兩種運行模式。初始註冊模式基於導納控制，透過人機互動的方式迅速定位機器手臂末端的超音波探頭模型，以實現高效的註冊。呼吸擾動消除模式採用自適應控制(Adaptive control)和內部模型原理(Internal model principle)控制，確保在呼吸運動下保持穩定的接觸，從而增強手術的適應性和有效性。自適應控制器通過擾動的頻率成分遞迴最小化其影響，而內部模型控制器則消除擾動的主要頻率成分。 本系統透過一海綿腹部模型的模擬和實驗驗證了該控制結構的有效性，結果顯示相比於基礎導納控制結構，系統性能有了顯著的改善。

In liver radiofrequency ablation, the surgeon faces the challenge of manipulating the needle and the ultrasound probe simultaneously.To address this, a robot-assisted force control system for stable ultrasound imaging has been developed for ultrasound-guided abdominal intervention.This system integrates a 6-DoF robot arm, a 6-DoF force/torque sensor, and an ultrasound probe model, featuring real-time compensation for respiratory disturbances. Following the procedural workflow, the system operates in two modes.The initial registration mode, rooted in admittance control, swiftly positions the robot-held ultrasound for efficient registration by physical human-robot interaction.The respiratory disturbance rejection mode employs adaptive control and internal model principle control, ensuring stable contact despite respiratory motion, thereby enhancing procedural resilience and effectiveness.The adaptive controller recursively minimizes disturbance effects by their frequency components, while the internal model controller eliminates the primary frequency component of the disturbance. The efficacy of this control structure has been verified through simulations and experiments with a sponge abdomen phantom, demonstrating significant improvements compared to the baseline admittance control structure.