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 2
BIOM 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 890.3420
 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
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?