Compliance Control of a Robotic Breast Ultrasound System Based on Variable Admittance Control

Area of Science:

• Robotics
• Medical Imaging
• Control Systems

Background:

• Patient safety, comfort, and system compliance are crucial in robotic breast ultrasound (RBUS) systems.
• Low system compliance can hinder the effectiveness of automated breast ultrasound examinations.

Purpose of the Study:

• To enhance system compliance and force control accuracy in RBUS.
• To introduce adaptive control strategies for improved probe alignment and scanning reliability.

Main Methods:

• Variable Admittance Control based on the Critical Damping Ratio (VAC-CDR) algorithm was developed to adjust damping and stiffness coefficients.
• A Breast Surface Adaptive Control Strategy (BrS-ACS) was implemented to align the ultrasound probe with the breast surface normal.
• Experimental analysis evaluated the influence of admittance parameters on system compliance.

Main Results:

• The VAC-CDR algorithm demonstrated excellent compliance and robustness with a force control precision of 0.4 N.
• The BrS-ACS strategy ensured accurate and reliable scanning by the ultrasound probe.
• Both simulation and experimental validations confirmed the effectiveness of the proposed control methods.

Conclusions:

• The developed control strategies significantly advance automated ultrasound image scanning.
• This research contributes to safer and more effective robotic breast imaging procedures.