Burt Upper Limb Rehabilitation Robot

Burt (Barrett Upper-extremity Robotic Trainer) stands as China’s first domestically produced end-effector three-dimensional upper limb rehabilitation robot. Developed through Estun Medical’s joint venture with Barrett Technology, the system employs cable-driven transmission derived from MIT’s Artificial Intelligence Laboratory, providing backdrivable manipulation without the rigid motion characteristics of conventional gear-based systems.

Product Overview

The Burt system emerged from Barrett Technology’s collaboration with the Rehabilitation Institute of Chicago, Spaulding Rehabilitation Hospital, Harvard Medical School, and Northwestern University Medical School. The design philosophy prioritizes inherent mechanical compliance, allowing patients to actively participate in movement while the robot provides precisely calibrated assistance or resistance based on individual capability.

Unlike exoskeleton rehabilitation systems that align robot joints with human anatomical joints, Burt uses an end-effector approach that guides the patient’s hand through three-dimensional space. This architecture eliminates the need for precise limb measurement, simplifies clinical setup procedures, and avoids potential injury from measurement errors causing joint misalignment.

The system received NMPA Class II medical device registration in 2021 and has been deployed across over 1,000 medical institutions in China through the Estun Medical network.

Key Features

The three-degree-of-freedom robotic arm enables compound shoulder-elbow movements in three-dimensional space. Supported motion includes shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension, forearm pronation/supination, and hand grasping functions depending on system configuration.

Cable-driven transmission using flexible steel cables provides inherent backdrivability, meaning patients can move the robot arm freely when motors are not actively driving. This safety feature prevents the robot from forcing movement against patient resistance and eliminates jerky or stuck motion common in rigid gearbox systems.

Force feedback algorithms integrated with servo motor multi-point control enable the system to detect patient effort and adjust assistance levels accordingly. Training modes combine motor control exercises with cognitive training through interactive games, enhancing patient engagement during repetitive therapy sessions.

Technical Specifications

Approved by NMPA in 2021, Burt from Estun Medical uses cable-driven 3-DOF transmission for three-dimensional shoulder-elbow compound motion, accommodating patients from grade 0 to grade 5 muscle strength.

Clinical Applications

The Burt system addresses both neurological and musculoskeletal conditions affecting upper limb function.

Neurological indications include stroke, traumatic brain injury, spinal cord injury, brachial plexus injury, Parkinson’s disease, and multiple sclerosis. The system supports patients from the flaccid paralysis stage through progressive recovery to normal function restoration.

Musculoskeletal applications include post-joint replacement rehabilitation, frozen shoulder therapy, and osteoarthritis management. The ability to provide controlled passive movement makes the system applicable even when patients cannot generate voluntary movement.

Post-surgical burn rehabilitation benefits from the robot’s smooth, controlled movement delivery without the jerky acceleration that might stress healing tissue.

Regulatory Status

The Barrett Technology version of the Burt system has been commercially deployed in United States rehabilitation facilities including Encompass Health and Sunnyview networks prior to the Chinese joint venture formation.

Frequently Asked Questions

What surgeries or procedures can Burt assist with?

Burt is not a surgical robot. It is a rehabilitation robot designed for post-stroke, post-injury, and post-surgical therapy to restore upper limb motor function. The system helps patients relearn movement patterns through repetitive, precisely controlled training exercises.

How does Burt compare to exoskeleton rehabilitation robots?

End-effector systems like Burt guide the patient’s hand through space without strapping onto the arm. Advantages include simpler setup, no limb measurement requirements, reduced equipment weight on the affected arm, and generally lower cost. Exoskeletons provide more direct joint-by-joint control but require precise fitting and are typically heavier and more complex.

What patient muscle strength levels can use Burt?

The system accommodates patients across the full muscle strength spectrum from grade 0 (no detectable muscle contraction) through grade 5 (normal strength). For completely paralyzed patients, the robot provides full passive movement. As patients recover, the system progressively reduces assistance to encourage active participation.