• Gravity Balancing Leg Orthosis (GBO)
• Active Leg EXoskeleton (ALEX)
• Swing Assist Unmotorized Exoskeleton(SUE)
• Upper Arm Orthosis
• Publications
• Current Researchers

Gravity Balancing Leg Orthosis (GBO)

Gravity balancing leg orthosis is designed to assist persons with hemiparesis to walk through elimination of the effects of gravity. The proposed device is designed to be passive. We intend to use this device as a rehabilitation device helping the patients in training their muscles and regaining their former control and strength. This device has the following features: (i) it can fully or partially gravity balance the human leg over the range of its motion; (ii) it is tunable to the geometry and inertia of a specific human subject to achieve the desired level of gravity balancing.

Movie showing a stroke patient with and without leg balanced in GBO


Gravity Balancing Leg Orthosis And Its Performance Evaluation
Presented in CBER day 2006

Gravity Balancing Leg Orthosis for Robotic Rehabilitation
Presented in ICRA 2004

Active Leg EXoskeleton (ALEX)

Active Leg EXoskeleton (ALEX) has been designed for gait rehabilitation of patients with walking disabilities. We propose force-field controller which can apply suitable forces on the leg to help it move on a desired trajectory. The interaction forces between the subject and the orthosis were designed to be ‘assist-as-needed’ for safe and effective gait training. The controller was first tested in simulations and later experiments were conducted. Experiments were performed with healthy subjects walking on a treadmill. It was shown that a healthy subject could be retrained in about 45 minutes with ALEX to walk on a treadmill with a significantly altered gait. In the coming months, this powered orthosis will be used for gait training of stroke patients.

Movies showing before and after effects of training a healthy subject to a new foot trajectory using active leg orthosis.


Gait Rehabilitation With An Active Leg Orthosis
Presented in DETC 2005

Swing Assist Unmotorized Exoskeleton(SUE)

We present a passive device for swing assistance of motor-incomplete spinal cord injury patients. This device is aimed at reducing the physical demands on the therapists during treadmill training. We model the human leg as two links and a point foot mass, with a moving trunk. We employ passive elements in the design which get charged by the treadmill. Using the system dynamics, we optimize the design parameters to obtain a feasible swing motion of the leg. An exoskeleton was constructed based on these design parameters and tests were performed on a healthy subject at different treadmill speeds.

Healthy subject experiment with SUE.

Upper Arm Orthosis

Design of an Orthotic Device for Full or Partial Gravity-Balancing of a Human Upper Arm During Motion