A Constant-Force End-Effector With Online Force Adjustment for Robotic Ultrasonography

Area of Science:

• Robotics
• Medical Imaging
• Biomedical Engineering

Background:

• Current robotic ultrasonography systems face limitations in maintaining consistent probe force.
• Autonomous adaptation of ultrasound probes to patient anatomy is challenging.

Purpose of the Study:

• To propose and evaluate a novel constant-force end-effector (CFEE) for robotic ultrasonography.
• To enable precise force control and autonomous probe adaptation to abdominal contours.

Main Methods:

• Development of a parallel, motor-spring-based constant-force end-effector (CFEE).
• Integration of a displacement measurement unit for probe position acquisition and force control.
• Online adjustment of operating force for safety and operational continuity.
• Simulations and experimental validation of the CFEE performance.

Main Results:

• The CFEE achieved constant forces ranging from 4-12 N with displacements of 0-8 mm.
• Maximum relative error in force generation was 8.28%.
• Displacement measurement accuracy and precision were 0.29 mm and ±0.16 mm, respectively.
• Ultrasound image quality was comparable to manual scans.

Conclusions:

• The proposed CFEE effectively provides precise and adjustable constant forces for robotic ultrasonography.
• The system demonstrates autonomous adaptation capabilities and maintains high-quality imaging.
• The CFEE shows significant potential for various medical applications in ultrasound imaging.