P13002: Ankle-Foot Orthotic Un-Tethered, Mechanical

Build, Test, Document

Table of Contents

Website should document your journey through MSD, so include work-in-progress as well as latest results. Use pdf's for display whenever possible so that information is easily viewable without the need to download files and open applications. (Your EDGE file repository should still contain original files).

Sample categories are listed below, but feel free to change or add nodes to better correspond to your project and your Guide’s expectations.

Build, Test, and Integrate

Iterative activities to validate functionality and performance at the sub-system and system level.

Test Plans & Test Results

Below are the active test plans and results documents for each of the system components. These tests were performed on each sub-system before it was attached to the orthotic in order to verify performance.

Formal Test Plan: Formal Test Plan

Valve Test Plan: Valve Test Plan

Sensor Test Plan: Sensor Test Plan

Reservoir Test Plan: Reservoir Test Plan

Power System Test Plan: Power System Test Plan

Micro-controller Test Plan: Microcontoller Test Plan

Cylinder Test Plan: Cylinder Test Plan

Specification testing was performed on the orthotic after all components were installed. All target specification values and test results can be seen in the Test Matrix

Specific specification test procedures and results can be found in individual documents relating to the function.

Mechanical Specs

Electrical and Computer Specs

Miscellaneous Specs

Assembly Instructions

The team was given an existing AFO featuring two rigid components connected by a tamarack joint and an anti-plantar flexion hard stop located posterior to the heal courtesy of Nazareth Community College’s PT Clinic. This device was modified to include a hydraulic locking mechanism, terrain sensing system, and processing and control systems.

In order to allow a greater range of plantar-flexion, the superior heal stop was removed using a band saw. A small plate was machined out of 304 stainless steel. This plate was attached to the inferior heal stop using a bolt. The piston was connected to the plate using a pin joint.

The cylinder was attached to a the AFO posterior to the calf via another pin joint. Four holes were drilled into the AFO in order to bolt the connecting plate of the cylinder to the AFO. The valve and fluid reservoir were connected to the cylinder using 1/8" plumbing fitting. The orientation of the reservoir was chosen to reduce the likelihood of getting air inside the cylinder.

The sensors were fixed to the AFO via 2 "L" brackets and bolts. The "L" brackets were glued to the AFO. The micro-processor and control circuit were printed to a PCB and placed inside a project box along with the battery. The box was then secured to the AFO via Velcro.

User or Operator Instructions/Manual

1. Ensure that the battery is fully charged.
2. Ensure that the cylinder and reservoir are filled with fluid.
3. Switch the circuit to the "on" position.
4. Insert the user's foot into the AFO.
5. Secure all Velcro constraints.
6. Allow user to walk as desired; device will dis-allow plantar flexion on flat ground an up stairs and ramps; device will allow plantar flexion when going down stairs and ramps.
7. Switch the circuit to the "off" position when not in use.

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