New Method for Rapid AFO Production

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New Method for Rapid AFO Production

• Group 9
• Team Members
• Ian Pearson
• Corinne Pascale
• Jeffrey Bayers
• Mentor
• Carl Sullivan C.O. ABC Certified Orthotist
• Website http//userfs.cec.wustl.edu/cnp1/bme401/
  

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Background

• Recall
• Orthotics are external braces fitted to a patient
  to correct for deformities and assist in mobility
• Orthotics fabrication is the time, labor, and
  material-intensive process used to create
  orthotics
• Current method requires the technician to create
  a plaster cast of the patients anatomy to
  thermoform high-temperature thermoplastic
  material to

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Need

• Practitioners would like a new procedure to
  create orthotics, specifically ankle-foot
  orthotics (AFOs), without these limitations
• There has been little low-tech exploration of
  this problem solutions are mainly in the form of
  CAD/CAM technologies
• Most literature and patents cover the composition
  of orthotics, not the procedure used to create
  them

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Design Requirements

• From the start, our goal has been to develop a
  new procedure that meets the following
  specifications
• Produces an equal-quality orthotic to current
  methods
• Shortens time necessary to fabricate (goal is lt1
  day)
• Reduces necessary material, specifically
  eliminating plaster
• Is low-tech
• Is inexpensive
• Uses disposable patient-contacting materials
• Minimizes patient t comfort
• Is not too-far removed from current methods

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Design Alternatives Overview

• Through weeks of brainstorming, we found that our
  potential methods fell within two main
  categories
• Mold-to-Patient, in which the thermoplastic is
  molded directly on the patient
• Mold-to-Mold, in which the thermoplastic is
  molded on a mold of the patient
• Ian and I researched the details of our potential
  procedures and summarized our findings and
  recommendations in white papers
• Jeff researched potential materials for these two
  categories of methods

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Design Analysis Overview

• After breaking the methods into categories, we
  rated each option using a weighted Pugh chart.
• The two most viable options from each category
  were then compared.

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Design Alternatives Mold-to-Patient
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Mold-to-Patient Vacuum Tubes
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Mold-to-Patient Vacuum Sleeve/Insert
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Design Analysis Mold-to-Patient
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Design Alternatives Mold-to-Mold
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Design Alternatives Mold-to-Mold

• Plaster Bandages
• Low-Temperature Thermoplastic
• STS Socks

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STS Socks The Process
Photos courtesy of STS (http//www.stssox.com/)
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Design Analysis Mold-to-Mold
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Final Design Analysis
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Our Chosen Design STS Socks

• Why do STS Socks Win?
• They are quick way to produce casts
• In comparison to alternatives, they are
  relatively inexpensive
• They can be applied in two layers to increase
  cast stability (1/16th of an inch thick)
• They will not require a thermal layer (boosting
  patient safety)
• Vacuum can be applied directly in the center of
  the cast
• They produce little mess and require a short
  setting time
• Their surface is rough, but not uneven, allowing
  for application of sculpting putty to cast
• They wont require hot water bath in fact, the
  product comes with all necessary materials

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Details of Our Chosen Design STS Socks

• Our standard procedure will incorporate the
  Mold-to-Mold method. Specifically, the molds
  will be composed of STS Socks.
• The patients anatomy will be cast with the aid
  of STS Socks. Afterwards, a sculptural or
  theatrical putty will be applied to bony
  prominences to build them out
• The dry molds will be covered in two layers of
  thermal stocking and placed on the end of a
  vacuum pump
• High-temperature thermoplastic will be
  thermoformed to the molds
• Additional treatment (hinges, buffing, cutting)
  will proceed as usual

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Details of Our Chosen Design STS Socks

• Advantages
• minimal wrinkling and excellent anatomical
  conformity
• strong resin allows for immediate shipping (no
  delay)
• no plaster necessary!
• no specialized casting rooms required
• strong
• lightweight
• Disadvantages
• easily susceptible to hardening prior to desired
  use if its storage pouch is punctured
• adheres firmly to unprotected skin if addressed
  immediately, lightly swabbing adherence with
  alcohol can help in removing the resin from the
  unprotected skin

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Design Schedule
Corinne Cyan, IanRed, JeffYellow, AllBlue
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New Goals

• Develop a standardized method for creating
  ankle-foot orthotics using STS Socks
• Attempt to fabricate AFOs using the method and
  iron our any details
• Potentially publish our new procedure

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New Responsibilities
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Questions?