Possibility of Getting an Additional Hand Through Robotics

Ever encountered a task that required more than your two arms could handle? If so, a new device offering a literal helping hand might interest you. This robotic arm, worn on the body, is controlled by the muscle used for breathing.

Currently, the robotic arm is positioned on the chest, but it has the flexibility to be placed above the shoulders or at the side based on the user’s preference. Engineer Giulia Dominijanni, part of the team from the Swiss Federal Institute of Technology in Lausanne (EPFL) that developed the device, emphasizes the customizable nature of the arm.

In the past, robotic components were primarily aimed at replacing missing limbs, allowing direct signals from the brain to operate the device. The challenge with this new robotic arm was to create an additional limb that users could control alongside their natural arms, leading to the innovative breath-controlled design.

Beneath the lungs lies a crucial muscle called the diaphragm responsible for breathing. The new robotic limb is fastened to a user’s chest using an elastic belt that senses diaphragm movements, enabling the arm to extend or retract based on inhaling and exhaling.

The control mechanism is straightforward – deep inhales extend the arm, deep exhales retract it, while regular breathing maintains the current position of the arm.

A virtual assisting tool

Prior to constructing the physical arm, the EPFL team developed a virtual reality (VR) model where users interacted with an avatar sporting the bonus robotic arm alongside their two natural arms.

After engaging in multiple test sessions over three days with the VR arm and breath sensor, 10 to 20 volunteers learned to control the virtual third arm. The eye movement sensors integrated into their headsets validated their ability to manage the bonus arm while performing other activities.

Controlling the virtual arm through breathing felt intuitive to participants, requiring minimal time to master, as noted by Dominijanni. Even after a year, all individuals retained their proficiency in using the VR arm.

Transitioning from the virtual arm to a physical prototype posed no challenge for participants due to the simplicity of the design. The EPFL team shared their preliminary findings in December 2023, focusing on refining the robotic hand’s grasping capabilities.

Future enhancements

Although initial tests demonstrated users’ ability to multitask while controlling a bonus arm, the extent to which individuals can effectively manage two natural arms and a robotic one remains a key inquiry.

Jacob George from the University of Utah’s robotics center highlights the uncertainty surrounding the brain’s adaptation to controlling an additional limb post-amputation. This area of study aims to explore the brain’s capacity for integrating bionic devices into its control systems.

Soheil Gholami underlines the interdisciplinary effort required to understand the complexities of operating multiple limbs simultaneously, emphasizing the potential insights into neuroplasticity and skill acquisition. While not directly involved in this project, Gholami’s work on wearable robotic devices aligns with the research goals.

Robotic limbs offer promising applications in prosthetics for individuals with disabilities or those recovering from injuries. Gholami’s lab investigates the feasibility of surgeons using foot controls to manage supplementary arms, potentially enhancing precision in critical scenarios.

Despite the cognitive challenges of controlling three arms simultaneously, expert training for specific tasks could mitigate coordination issues in complex surgeries or high-risk situations, notes Dominijanni. This approach may streamline procedures involving multiple participants, reducing potential complications.