Introduction: Thumb Prosthesis

This is a high durability, high functionality low cost prosthesis for those missing the distal phalange of the thumb. This creative method can be extended to replace the distal or distal and middle phalange of any finger. The process detailed below is the greatest technological advance in prosthetics since the introduction of modern plastics, and will spark a revolution in the prosthetics industry.

Step 1: Models

I have included two models (free of restriction, share with all of humanity). You can use either model, the claw model is of more utility and can apply greater force than than a natural nail. You can also generate your own models from scratch OR (the most realistic and best fitting) generate a 3D scanned model from a whole digit scan and applying a mirror function to the model.

Step 2: Measurements

Compare digits to find the specific metrics for scaling your model.

Step 3: Measurements

Measure the residual digit (Residuum). Accurate multiple measurements will allow for a greater custom fit.

Step 4: Measurements

Accuracy in measurement is paramount as this prosthesis relies on mechanical fit rather than flexible suction (restricts blood flow and thus wear time) fit.

Step 5: Scale Model

Adjust model to fit residuum metrics acquired above. This is accomplished with modeling software and scaling for length and diameter. Also one should scale areas radially along the vertical axis.

Step 6: Print

PRINT. This prosthesis is most durable when printed in nylon. I suggest that one always use a human friendly plastic for anything contacting the skin. Taulman Nylon 645 is the best material that I found as it has superior strength and quality as well as meeting the EU's REACH standards for non toxicity. Currently there are no suitable FDA approved printing plastics, however that will soon change.

Step 7: Comparison

Compare the printed prosthesis with existing whole digit.

Step 8: Fitted Prosthesis

Check for fit and comfort of wear. You may want to print a model or two at 2-3% larger and smaller due to the mechanical fit and the tendency of the hand to change size during the course of the day. Fortunately this prosthesis is very inexpensive (approximately $1.00 usd in materials) and one can easily have multiple models of varying size and design which will accommodate any person who has fluctuations in the size of their residuum or dexterity/functional requirements.

Step 9: Fitted Prosthesis

Printed Nylon can be dyed with "RIT" brand dye (or any other organic nontoxic dye) to match ones skin color.

Step 10: Fitted Prosthesis

Due to the 3D printing revolution and some advanced materials this prosthesis is the next technological step forward in Prosthetics. It can be fitted to nearly anyone and is ideal for anyone who works with their hands.

Step 11: Price Comparison

This method for creating prosthetic provides significant cost reduction (typically less than 1% ) over traditionally produced prostheses. These Prostheses are ideal for children, the loss prone, the wear prone and those who use their hands for more than clapping. The total cost of creating 3 of these prostheses including materials, modeling time, measuring time and printing time will in general be in the range of $100.00 usd which is less than the average copay/deductible for a standard PVC/Silicone cosmetic prosthesis.

Step 12: Two Thumbs Up

Create and enjoy a new thumb prosthesis using the above methods. This Design and Creative process is provided free of charge and restriction to all of humanity as an act of compassion by the "Laird of Xibalba".

3D Printing Contest

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