About The Project

The vi-RABT is a 2012 Northeastern University Senior Capstone Design Project:



  • Each year, 795,000 Americans suffer a new or recurrent stroke. Projections show significant increase in stroke population by 2030 [1].
  • Ankle sprains represent 2.15 per 1000 person-years in US [2].
  • There is no cost-effective robotic ankle trainer in the market.


  • Ankle impairment and weak control over balance are prevalent symptoms for individuals with neuro-muscular disorders.
  • Due to the wide range of neurological impairments and orthopedic ankle injuries, there is a need for versatile robotic device to provide controlled ankle and balance rehabilitation exercise.
  • The Virtually-Interfaced Robotic Ankle and Balance Trainer (vi-RABT) is the proposed low-cost robotic system that will improve overall ankle/balance strength and mobility.
  • The system is equipped with 2-degrees of freedom actuation system in addition to complete mean of kinetic/kinematic measurements.
  • vi-RABT provides assistive/resistive ankle rehabilitation and static/dynamic balance  training.
  • vi-RABT is patent-pending, the system shows promising potential for commercialization after patient studies. IP is assigned to Northeastern University


  • Developing a robotic system for rehabilitation of ankle and balance disorders, i.e. mobility and strength
  • The system characteristics address:
  1. Controlled actuation along 2-degrees of freedom of ankle joint,
  2. Real-time force and motion monitoring, providing objective feedback and subsequent evaluations,
  3. Virtual reality interface to maximize patient’s immersion in practice,
  4. Low-cost and portability.
  • The frame was constructed out of T-slotted 80/20 aluminum.
  • Gear-motors were selected so as to train a 300 lb patient:
  1. Plantarflexion/Dorsiflexion: 720 Watts
  2. Inversion/Eversion: 135 Watts
  • Timing belts were recruited to transmit the torque from gear-motors to robotic footplates.
  • Compressive/tensile force measurement was realized by using four compression load cells between acrylic plate and steel bars.
  • Relative encoders were fabricated to the plate for kinematic measurements.

[1] V. L. Roger, et. al., “Executive summary: heart disease and stroke statistics–2012 update: a report from the American Heart Association,” Circulation, vol. 125, no. 1, pp. 188–197, Jan. 2012.

[2] B. R. Waterman, B. D. Owens, S. Davey, M. A. Zacchilli, and P. J. Belmont Jr, “The epidemiology of ankle sprains in the United States,” J Bone Joint Surg Am, vol. 92, no. 13, pp. 2279–2284, Oct. 2010.