A Tension Sensor Array for Cable-Driven Surgical Robots

Area of Science:

• Robotics
• Surgical Technology
• Sensor Technology

Background:

• Tendon-sheath structures are vital for surgical robots due to their compact design and controllability.
• Accurate estimation of cable tension in long, flexible instruments is challenging due to complex frictional effects.

Purpose of the Study:

• To develop and integrate a miniature tension sensor array into the distal end of endoscopic cable-driven parallel robots.
• To mitigate friction between the tendon and sheath and improve cable tension sensing.

Main Methods:

• A novel miniature tension sensor array (16 mm outer diameter) was designed and mounted at the robot's distal end.
• A force compensation strategy was developed and validated on a single-cable platform before implementation on the robot.
• Performance was evaluated through palpation tests and blind trials with human participants.

Main Results:

• The developed sensor array demonstrated reduced frictional impact and enabled precise tension estimation.
• The robot achieved an average force estimation error of 0.173 N and a root-mean-square error of 0.213 N.
• Participants successfully differentiated silicone pads of varying hardness using the robot's haptic force feedback.

Conclusions:

• The miniature tension sensor array effectively addresses challenges in long-distance cable tension estimation for endoscopic robots.
• The integrated system enhances surgical instrument control and provides valuable force feedback for tactile sensing during procedures.
• This technology has the potential to improve the dexterity and safety of minimally invasive robotic surgery.