ACTIVE ANKLE FOOT ORTHOTIC (AFO) VOICE OF CUSTOMER Design Project Management

Table of Contents Objective Tree Needs Prioritization Constraints Functional Decomposition Flow Diagram Summary/Conclusions Questions

Objective Tree

Needs Prioritization Customers ranked categories of objective tree for importance directly, group members ranked every objective and category rankings were calculated: Customer Rank  Safe 26%  Perform on Flat Terrain 21%  Portable 19%  Comfortable 12%  Durable 10%  Perform on Special Terrain 7%  Convenient 5% Group rank  Perform on Flat Terrain 18.6%  Perform on Special Terrain 17.3%  Portable 16.4%  Safe 16.2%  Convenient 11.9%  Comfortable 10.3%  Durable 9.3%

Constraints  Low Weight (of AFO)  High Comfort  Easy patient interface with sensing system  Waterproof  Fits into normal shoe size  Safe  Method of Actuation?

Functional Decomposition The active ankle foot orthotic must mitigate the effects of foot drop. Allows adequate motion Modifies Foot Behavoir Interprets sensor data Allows plantar flexion and dorsiifle- xion Identifies phase of gait Utilizes terrain sensing system Compares current and ideal states Determin es foot position Senses Terrain Utilizes terrain sensing system Identifies phase of gait Controls Foot Position Applys force to foot Support Portability Safely store Energy Safely Receive Energy Safely Regulate Energy Accomodates Range of Users Easily Adjustable Reduce/ eliminate custom fitting process Removable Determine Current State Determine Ideal State

Flow Diagram The active ankle foot orthotic must mitigate the effects of foot drop. ON/OFF Terrain Type Phase of Gait Power Store Energy Regulate Power Actuate Device Micro-Controller Determine Actual State Determine Ideal State Compare Real and Ideal States Monitor Energy Level Monitor System Status Check for Errors Record Data Apply Force or Allow Movement Health of System Waste Energy (Noise, Heat, Vibration, etc) Identify Action Receive Power

Summary/Conclusions  Stakeholders need a convenient active ankle foot orthotic to mitigate the effect of foot drop while not constraining user’s motion in ways that force unnatural gait.  Moving forward it is likely that the scope will be limited to:  An untethered active AFO using an actuation source other than air muscles  A tethered rehabilitation active AFO using air muscles

Questions?