Build Preparation Shared VisionOur vision for week two is to finalize the design and begin building of the following components:
- Upper Plug
- Lower Plug
- Upper Base
- Component Housing
- McKibben Muscle
The completion of these components will lead to assembly
and integration of our subsystems from MSDI in phase
Our team also plans to validate received components as well as the printed circuit board design.
End State Shared VisionRequired Deliverables
- The best case scenario is that we have a prototype of an untethered system with the gait monitoring system. If this is not completed with full functionality, then we will present a system with partial functionality. In this situation, explanations and proposed design changes will be provided. The worst case scenario will be presenting a final prototype with functioning pieces but not have a fully integrated system.
- Bill of Materials
- We will deliver a Bill of Materials (BOM) which lists all of the materials included in the final prototype.
- Detailed documentation of design
- We will have the current design along with changes made during the building and testing of MSD II. In addition to this, we will have recommended design changes for future models as well as tips to help with the build process.
- Supporting test data and documentation
- We will have test documentation supporting all of the engineering requirements. If we are unable to achieve full functionality, then we will test what is possible and provide documentation about the procedures that will be used to test the rest of the functionality.
- User’s guide for operation
- We will have a user’s guide for operation. This will include the following:
- Application of the Active Ankle Foot Orthotic (AAFO)
- Recharge and refill information
- Washing information
- How to retrieve data from the gait monitoring system
- Basic trouble shooting
- Showcase at Imagine RIT
- Best Case Scenario: We will demonstrate our working prototype to the public using a team member as the volunteer. Specifically, we will have the volunteer walk on flat ground as well as on the stairs. This variation in terrain will help show the full functionality of our device. Throughout the day, two team members will present at the booth at all times and we will rotate between volunteers every two hours. Alongside the demo, we will display our team poster on our table which further explains the background of the project, design features, and testing and simulation results. Next to our poster, we will have a monitor that plays a video to further display prototype functionality as well as two air muscles for the public to see and touch. Lastly, our team will hand out project overview sheets which include a QR code to direct visitors to our EDGE site.
- User Input
- We will look for user feedback in, ideally, two ways. The first way will be to get input from students and faculty on the RIT campus. During this initial subject testing, our team will gain feedback on our qualitative engineering requirements, such as comfort, ease of application, and aesthetics. Following this testing, we plan to revisit the Physical Therapy Clinic at Nazareth College and speak to clients with Foot Drop. At the very least, we would like to have them try on the orthotic and get their feedback on overall design and wearibility.
Imagine RIT Shared VisionThe following document displays the team's vision for Imagine RIT. Overall, it summarizes our team’s vision for Imagine RIT and presents different scenarios of readiness as well as our elevator speech.
- Best Case Scenario:
We will demonstrate our working prototype to the public
using a team member as the volunteer. Specifically, we
will have the volunteer walk on flat ground as well as
on the stairs. This variation in terrain will help show
the full functionality of our device. Throughout the
day, two team members will present at the booth at all
times and we will rotate between volunteers every two
hours. Alongside the demo, we will display our team
poster on our table which further explains the
background of the project, design features, and testing
and simulation results. Next to our poster, we will
have a computer that plays a video to further display
prototype functionality as well as two air muscles for
the public to see and touch. Lastly, our team will hand
out project overview sheets which include a QR code to
direct visitors to our Edge site.
- Moderate Case Scenario:
In this scenario, our team will demonstrate a working
prototype to the public with a team member as the
volunteer; however, we will only be able to demonstrate
the prototype on flat ground because our booth is not
near stairs. Alongside our demonstration, we will still
include our team poster as well as project overview
sheets and two air muscles. Additionally, we will not
include a video in our presentation in this scenario
due to lack of table space for a computer or because of
- Worst Case Scenario:
The worst case scenario would be that we are unable to
get our prototype to work properly. In this case, we
would display our prototype on the table as well as our
poster that summarizes our progress and our predicted
theoretical analysis, simulations and feasibility test
results, and CAD models. The main focus in this
situation will be on what was learned and how our group
plans to address the remaining address.
- Elevator Speech
Our senior design project is an active ankle foot
orthotic. This is an assistive walking device that is
utilized by individuals with Foot Drop condition. Foot
Drop is a neurological disorder which impairs the
ability of an individual to dorsiflex the foot (i.e.
point the toes upward) and is often a side effect of a
stroke, ALS, Multiple Sclerosis, or a peroneal nerve
injury. Current AFO’s are bulky, rigid, and
disrupt the user’s natural gait by providing
assistance at all times, regardless of need. An active
AFO will provide users with assistance only during
appropriate times in the gait cycle through the use of
an air muscle. This timing will be determined using a
Heelstrike sensor to measure gait and a distance sensor
to distinguish terrain. The air muscle will be filled
with compressed air from an air tank; this will make
the AFO untethered, a feature that has not been
completed by a senior design team at RIT. This device
is not a replacement for medical treatment- it is
simply a device to assist someone with walking.
MSDI BusinessMSD I Action Items
MSD I Postmortem
MSD I Improvement Plan
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MSDII Project PlanMSD II Working Timeline
MSDII Test PlanWorking MSDII Test Plan
|Test Number||Test Plans|
|1||Ankle-foot Force Analysis|
|3||Ease of Application Test|
|4||Survey of Orthotic Aesthetics|
|10||Recording Gait Test|
|12||Slow Motion Deflection|
|14||Extended Use Test|
|16||Air Leak Test|
Problem TrackingWorking Problem Tracking
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Failure ModesWorking Failure Modes
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Engineering Fruition PlanEngineering Fruition Plan
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Updated Bill of Materials
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- Power Input: Power connection and 5V regulator
- Power LED
- System Clock: 16 MHz microcontroller clock
- TO_AFO Connection
- TO_SOLENOID: Two drive circuits for the Solenoid control as well as a ground connection
- SD Card: Level shifter and MicroSD card shield as well as the 3.3V regulator
- TO_FLOW_SENSOR: Power and ground connections as well as an ADC input to read the flow control as needed.
- SERIAL_I2C: Debug connections to the I2C communication as well as the Serial line.
- Hardware Low-battery system
Component Housing Redesign
MotivationThere were multiple changes that needed to be made to the component housing that houses the sensors.
- O-Ring groove needed redesigned to properly contain selected O-Ring to ensure complete sealing of PCB board chamber
- Angle of chamber housing the IR sensor was corrected
- Bosses added to base of PCB board chamber to elevate board off the bottom surface
- Future changes- consider addition of threaded inserts to prevent stripping of threaded holes in the plastic part; additional lid customized to fit around the sensor if additional protection is necessary; main lid will be thicker to allow holes to be counter-bored to fit the necessary screws.
Associated DocumentsO-Ring Gland Size Calculations
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Muscle Attachment Redesign
MotivationBecause of machining capabilities and materials available, some slight changes were made to the plugs that attach the McKibbon muscle to the AFO. However, none of these changes had a significant impact on the functionality of the McKibbon muscle or the AFO.
- Overall height of the part decreased
- Overall width of attachment section of the upper plug decreased
- Thickness of the base plate decreased
- Chamfers and slight insertion groove added for easy assembly and to keep the plug in place better
- Opening cut into the bottom lip of the base plate to provide more room for muscle and allow for better McKibbon muscle function.
- Back side of the lower plug flattened and sanded to prevent discomfort
- Pin hole not yet drilled due to lack of necessity and to allow for quick design modifications A/R
Associated DocumentsBase Drawing
Upper Plug Drawing
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Lower Attachment Redesign
MotivationAfter completing initial lower attachment force lift tests, our team decided that it would be best to incorperate a lift mechanism that would better allow users to apply and remove the AFO easily. In the original design, the fishing line was at a fixed location right above the adjustable strap, making it hard to users to access the strap. Additionally, our team was concerned with the fishing line stretching over time. The new design incorperates an A-shaped thin strap. This strap is more durable than the fishing line and its design allows users to easily access the velcro strap ontop of the foot. <b>
The reason for this test is to find:
- How much force does it take to lift the foot using
the newly added A-shaped strap?
- Does the lift remain comfortable when a force is
- Does the A-shaped strap allow users to apply and
remove the device easier?
- Force was not distributed evenly at the base of the pull
- User experienced slight pain near base of toe when force was applied
- Strap sewing came undone and strap detached from brace at the end of the experiment
- The new strap allows the user to apply/remove the AFO easily because the Velcro strap is more accessible
- An additional 2lbs was required to lift the foot due to an uneven distribution of force at lift base. This will be addressed through brace modifications.
- Sew the A-shaped strap onto the brace at an angle
(see design below).
- Complete same test with modified design to determine
whether or not the device is comfortable during lift and
the amount of force to lift the foot is less than
Build Preparation ReviewThe review was conducted in week 2 based on this agenda
Phase 2 Meeting notes
|Home||Planning & Execution||Problem Definition||Systems Design||Subsystems Design||Detailed Design||Gate Review|
|Build Preparation||Build & Test||Integrate & Assemble||System Validation||System Verification||Final Review|