Appropriate Prosthetic and Orthotic Technologies in Low Income
Low-Cost Prosthetic Hand Fabrication Processweb.mit.edu/course/3/3.042/team2_06/Technical... ·...
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Implementation We propose to transfer to and sustain our prosthetic hand technology in developing countries. In each regional community, an individual would be trained to serve as the prosthetic “expert” and create prosthetic hands for individuals who need them. Manotech Associates or aide workers from a collaborating international relief agency would need to travel abroad to train the first community experts; but later, the current experts could train future professionals. Unless the prosthetic materials can be obtained within the country, experts would rely on foreign companies for materials. The community system would provide a higher rate of success than shipping do-it-yourself prosthetic-making kits since the process requires some level of experience and ease with using the materials. The prosthetic- making clinic could be part of a larger hospital or a free-standing agency. This method of implementation would allow for the technology to spread to rural areas since patients can seek out a local expert instead of relying on overseas personnel. . . . .. . .. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manotech Associates | Jina Kim, Forrest Liau, David Lin, Teresa Wang | 3.042 Materials Project Laboratory | Spring 2006 | Massachusetts Institute of Technology Wax Mold Paraffin Wax Properties Good shape and detail retention Fast cooling Method Melt wax to 100 °F Dip hand in wax, then cool water for approximately 8 cycles Slide hand out of wax mold Low-Cost Prosthetic Hand Fabrication Process Many individuals in remote, low-income areas of the world are afflicted by hand amputation. However, current custom prosthetic hands are prohibitively expensive and unavailable for those individuals. To meet this need, we devel- oped a prosthesis fabrication process that uses inexpensive tools and materials in a series of simple steps to create a mirror-image prosthetic hand from the individual's intact opposite hand. We found that this fabrication method re- quires minimal training and leads to an inexpensive product with reasonably correct size and shape. With this custom production process, prosthetic hands can be easily created and re-created for individuals of all ages and gender who cannot afford commercial custom prostheses. Plaster Replica Hand Plaster of Paris Properties High detail Little/no shrinkage Method Mix 1:1 weight ratio plaster and water Pour into wax mold and allow to dry Break open and peel away wax mold Reversible Mold Rubber Latex Chemistry Polymerized monomers (isoprene) Properties Elastic; retains shape High surface adherence Method Brush 6-8 layers onto plaster hand Allow 20 min to dry between coats Allow 24 hrs to dry Mold Reversal Peel off and reverse latex mold Prosthetic Hand Tin-based Silicone Rubber Chemistry Base = organosiloxanes + silica Catalyst = organotin Properties – Durable (~5 yrs) Elastic Method Mix base:catalyst in 10:1 weight ratio Pour into suspended glove Allow 24 hrs at room tempera- ture for curing Prosthesis Removal Peel off latex mold + $32.82 $37.70 = + 20% of Total Material Cost lost from Material and Process Inefficiency + 1% of Total Cost for Labor and Equipment Material Company Cost Amount Cost/Hand Amount/Hand Paraffin Wax Polygon $1,480 2000 lbs $7.40 10 lbs Plaster In 2 Art $974.80 4000 lbs $0.37 1.5 lbs Rubber Latex TAP Plastics $3,350.00 160 lbs $0.76 .25 lbs Foam Brush TAP Plastics $100.00 1000 item $0.10 1 brush Silicone Rubber Specialty Silicone P $15.00 1 lb $15.00 1 lb TOTAL $23.63
Transcript of Low-Cost Prosthetic Hand Fabrication Processweb.mit.edu/course/3/3.042/team2_06/Technical... ·...
Implementation
We propose to transfer to and sustain our prosthetic hand technology in developing countries. In each regional community, an individual would be trained to serve as the prosthetic “expert” and create prosthetic hands for individuals who need them. Manotech Associates or aide workers from a collaborating international relief agency would need to travel abroad to train the first community experts; but later, the current experts could train future professionals. Unless the prosthetic materials can be obtained within the country, experts would rely on foreign companies for materials.
The community system would provide a higher rate of success than shipping do-it-yourself prosthetic-making kits since the process requires some level of experience and ease with using the materials. The prosthetic-making clinic could be part of a larger hospital or a free-standing agency. This method of implementation would allow for the technology to spread to rural areas since patients can seek out a local expert instead of relying on overseas personnel.
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Manotech Associates | Jina Kim, Forrest Liau, David Lin, Teresa Wang | 3.042 Materials Project Laboratory | Spring 2006 | Massachusetts Institute of Technology
Wax MoldParaffin Wax
Properties Good shape and detail retentionFast cooling
MethodMelt wax to 100 °FDip hand in wax, then cool water for approximately 8 cyclesSlide hand out of wax mold
Low-Cost Prosthetic Hand Fabrication ProcessMany individuals in remote, low-income areas of the world are afflicted by hand amputation. However, current custom prosthetic hands are prohibitively expensive and unavailable for those individuals. To meet this need, we devel-oped a prosthesis fabrication process that uses inexpensive tools and materials in a series of simple steps to create a mirror-image prosthetic hand from the individual's intact opposite hand. We found that this fabrication method re-quires minimal training and leads to an inexpensive product with reasonably correct size and shape. With this custom production process, prosthetic hands can be easily created and re-created for individuals of all ages and gender who cannot afford commercial custom prostheses.
Plaster Replica HandPlaster of Paris
Properties High detailLittle/no shrinkage
MethodMix 1:1 weight ratio plaster and waterPour into wax mold and allow to dryBreak open and peel away wax mold
Reversible MoldRubber Latex
ChemistryPolymerized monomers (isoprene)
PropertiesElastic; retains shapeHigh surface adherence
MethodBrush 6-8 layers onto plaster handAllow 20 min to dry between coatsAllow 24 hrs to dry
Mold Reversal
Peel off and reverse latex mold
Prosthetic HandTin-based Silicone Rubber
ChemistryBase = organosiloxanes + silicaCatalyst = organotin
Properties –Durable (~5 yrs) Elastic
Method Mix base:catalyst in 10:1 weight ratioPour into suspended gloveAllow 24 hrs at room tempera-ture for curing
Prosthesis Removal
Peel off latex mold
+$32.82
$37.70=+
20% of Total Material Cost lost from Material and Process Inefficiency +1% of Total Cost for
Labor and Equipment
Material Company Cost Amount Cost/Hand Amount/HandParaffin Wax Polygon $1,480 2000 lbs $7.40 10 lbsPlaster In 2 Art $974.80 4000 lbs $0.37 1.5 lbsRubber Latex TAP Plastics $3,350.00 160 lbs $0.76 .25 lbsFoam Brush TAP Plastics $100.00 1000 item $0.10 1 brushSilicone Rubber Specialty Silicone Products$15.00 1 lb $15.00 1 lb
TOTAL $23.63
