Sujay Kestur

BioE M.S. Defense
April 21st, 2023
9:00 AM
Location: GTMI Auditorium (Room 101) 

Zoom link

Committee:
Aaron Young, Ph.D. (Advisor) (School of Mechanical Engineering, Georgia Institute of Technology)
Kinsey Herrin, M.S., CPO (School of Mechanical Engineering, Georgia Institute of Technology)
Young-Hui Chang, Ph.D.  (School of Biological Sciences, Georgia Institute of Technology)

  

Comparing the Biomechanics of Powered and Passive Microprocessor Knees during Community Ambulation Tasks

              Many individuals undergo lower limb amputations as a result of various conditions such as diabetes, vascular diseases, cancer and trauma. The use of a lower limb prostheses is one of the most common solutions to return the ability to complete locomotion tasks of daily living to this population. As the number of amputees is predicted to grow, advances in prosthetic technology have been made to improve patient mobility and quality of life. One of the most significant of these developments has been the introduction of the Microprocessor Prosthetic Knee (MPK). This type of prosthesis is designed to better mimic the natural movement of the knee joint and improve stability, mobility and safety during locomotion. 

              However, there is still a debate over which type of MPK results in better performance: a passive or a powered device. In addition, it remains unclear to what degree one type of MPK has an advantage over the other and specifically during which locomotion modes is this advantage present. Few studies have been done comparing the use of commercial powered and passive MPKs and how these devices affect different aspects of the user's biomechanics. The aim of this study is to address this research gap.  

              In this thesis, an experiment was conducted in which individuals with transfemoral amputation performed various community ambulation tasks while wearing one of three commercial MPKs: the Össur Power Knee, the Össur Rheo Knee and the Ottobock C-Leg 4. The Power Knee is a powered device while the Rheo and C-Leg are passive devices. Several biomechanics variables were analyzed and the evaluation of the prosthesis' performance was determined based on the amount of biological joint energy used. Additionally, an evaluation of the modeling of powered devices was performed in order to validate the inverse dynamics being obtained from them. This thesis covers the experimental procedures performed, an analysis of the results and the further efforts made to improve the modeling of powered prosthetic devices.