NATURAL GAIT INDUCING TRANSTIBIAL PROSTHETIC LUCIA MELARA ROBERT SCOTT ALEXIS GARO EML 4551 ETHICS AND DESIGN PROJECT ORGANIZATION FIU DEPARTMENT OF MECHANICAL ENGINEERING MIAMI, FL

PROBLEM STATEMENT  Current prosthetics produce secondary disabilities  Back complications  Metabolic problems  Passive prosthetics cannot dynamically adjust “push off” force  “Active” prosthetics exist however are impractical  High cost prevents access to most patients  Majority of transtibial amputees are impoverished  3-6 month adaptation period

EXISTING POWERED PROSTHETICS AMP Foot 2BIOM T2 System

PROJECT OBJECTIVES  Design an ankle prosthesis able to actively adjust “push off” force  Reduce cost to achieve higher cost efficiency than industry average  Increase walking range on single charge to 4 kilometers  Design actuation system to allow quick changes of drive motor(s) and springs  5 pound maximum system weight

ENGINEERING STANDARDS  FDA: Center for Devices and Radiological Health  Class I device per Code of Federal Regulations  Title 21 Section  FDA ensures patient safety with device  Device not subject to specific restrictions  ASTM standards for used material values  Aluminum Association referenced for material selection

HILL TYPE MUSCLE MODEL  Mathematical model which views a muscle as spring like structure  Consists of contractile, series, and parallel elements  Produces torque values in reference to angle  Compared to values for natural ankle

HILL TYPE MUSCLE MODEL

ACTUATOR DESIGN ANALYSIS

PROPOSED SOLUTION  Use data from sensors to determine the appropriate torque curve  Compensate for walking speed, slope, terrain changes  Predict user’s next step using predictive algorithms and sensors  “Echo Location” control approach to learn from opposite leg  Higher efficiency actuator system  Lighter, higher efficiency batteries  More efficient actuator system implementing an SEA+UPS system

SOLIDWORKS MODEL

GLOBAL DESIGN INTEGRATION  Modularity  Prosthesis can be combined with different knee prosthetics  Replaceable batteries  Interchangeable motor unit  Simple design that can be manufactured without a CNC machine  3D printed enclosure  Research paper to be published

PROJECT TIMELINE

CONCLUSION AND FUTURE WORK  Completed:  Motion analysis of human gait cycle  Proposed designs  To be done  Complete actuator design analysis on proposed designs  Perform simulation studies  Manufacture first prototype  Perform metabolic and range tests at secured testing facility

QUESTIONS?