Robot-Assisted Trans-Esophageal Ultrasound and the Virtual Admittance-Based Master-Slave Control Method Thereof

The robotic transesophageal ultrasound system has the potential to improve the conventional practice of diagnosis and procedure guidance that are currently performed manually. However, the existing system has obvious shortcomings in both mechanism design and safety control under remote teleoperation. This article proposed a new compact mechanism design and achieved remote teleoperation through system integration. Furthermore, this article introduced a virtual admittance-based master-slave control method that meets the needs of ultrasound operation, making the robot autonomous in regulating both force and speed. Through a series of experiments, the accuracy of the robot in operation and the effectiveness of the control method were verified. The proposed control method can regulate the contact force, slowing the increase of the interaction force to ensure safety. It can also adjust the scale of the motion automatically, allowing the user to fine tune the ultrasound plane efficiently. In addition, the controller can increase the backdrivability, avoiding injuries to the tissue due to mishandling. It is therefore concluded that work has significantly improved the usability of a transesophageal ultrasound robot and made this technology further conform to the control habits of ultrasound scanning.