New robotic system enables surgeons to perform ‘four-arm’ operations

Four-armed robotic surgical system is controlled by haptic interface pedals.


Robotic surgery, also called robot-assisted surgery, is a promising direction to improve surgeons’ and assistants’ daily life with respect to conventional surgery.

Researchers at Switzerland’s EPFL research institute have developed the first system that enables four-arm laparoscopic surgery by controlling two additional robotic arms via haptic foot interfaces.

The system allows surgeons, in addition to their two natural arms, to control two additional robotic arms using haptic foot interfaces with five degrees of freedom. Each hand controls a manipulative instrument, while one foot controls a smaller secondary arm that is holding an endoscopic camera, and another foot controls such arm, which is holding an actuated gripper.

“Actuators in the foot pedals give haptic feedback to the user, guiding the foot towards the target as if following an invisible field-of-forces, and also limit force and movement to ensure that erroneous feet movements do not endanger the patient,” said Mohamed Bouri, head of the group REHAssist.

In this scenario, the surgeon and robots need to work collaboratively within a concurrent workspace while meeting the precision and safety demands of laparoscopic surgery. To this end, researchers propose a control framework for the robotic arms that deal with all the task- and safety-related constraints.

However, controlling four arms simultaneously, moreover with one’s feet, is far from routine and can be quite tiring and confusing. To reduce the complexity of the control, the system is capable of predicting some of the surgeon’s basic actions and guiding their movements accordingly. When tying a knot, for example, the endoscope can automatically adjust into the proper position, and the gripper could move out of the way.

“Our system opens up new possibilities for surgeons to perform 4-handed laparoscopic procedures, allowing a single person to do a task that is usually performed by two, sometimes three people,” Bouri said.

Researchers have successfully trained on the four-armed robotic surgical system, and clinical trials are currently underway in Geneva.

While the system continues to be tested and improved, the results published in this study confirm the feasibility of four-arm surgical-like tasks without extensive training in tasks. In addition, the study characterizes and motivates the use of robotic assistance for reducing task load, improving performance, increasing fluency, and eliciting higher coordination during four-arm laparoscopic tasks.

Journal reference:

  1. Jacob Hernandez Sanchez, Walid Amanhoud, Aude Billard, Mohamed Bouri. Enabling four-arm laparoscopic surgery by controlling two robotic assistants via haptic foot interfaces. The International Journal of Robotics Research, 2023; DOI: 10.1177/02783649231180366
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