See last chapter in this document for a log/history.

Overview

This page collects information and ideas about a 3d printed hand prosthesis for a kid from iraq.

NOTE:This is work in progress.

This work is done as part of the e-nable project http://enablingthefuture.org with the help of two other volunteers: Holly and Marko (todo: mention their email adress here?).

The receipient (Bashar) is a 9 year old kid from iraq (mosul?). He has lost four fingers of his left hand in an accident. Here is a picture of his left hand:

Possible devices, requirements

First of all, we have to select a 3d design of the hand prosthesis, the requirements for such a design are:

  1. The receipient has a working thumb, so we need a thumbless design.
  2. The receipient has four working finger-stumbs, so the prosthesis has to have enough room for them.
  3. Even better would be a design that uses his finger-stumbs, so it is not just wrist-powered, but also "finger-powered".
  4. Because there is no medical help on site (todo: ask firas) and the receipient is far away, i think we should prefer a simple device.

Todo/question: should we left-out the little finger because of skin-bulge, finger joint not in-row with other fingers.

Raptor Reloaded, Thumbless & Extra length https://www.thingiverse.com/thing:2840414

Pros:

  • Thumbless design (requirement 1).
  • Wrist- and finger-powered.
  • Should have enough room for finger-stumbs, could be scaled for better match.

Cons:

  • A bit complicated, many parts.

I'm calling this the raptor-extra version, for simplicity.

A custom design, Knick-finger based http://enablingthefuture.org/the-knick-finger/

Pros:

  • Thumbless design, of course.
  • Receipient can use his existing fingerstumbs.
  • Simple design.

Cons:

  • Are fingerstumbs are long enough for this type of device?

A three-finger version with glove:

I think we should left out the little finger because of the skin-bulge - so just a three finger version.

Also i would like to connect the three finger-sockets for better grip and to avoid a slip of of the device.

Todo:make a drawing or simple design to better show this idea.

I'm calling this the multi-knickfinger version, for simplicity.

Conclusion, so far

I would like to do the following:

  1. Scale and print the raptor-extra version to get started and to get things going.
  2. Desing and create the multi-knickfinger version, but this will take longer...

Devices that will (likely) not work good

Some existing designs that we looked into, but are probably not working good enough. All existing devices with a thumb will not work, of course.

e-NABLE Phoenix Hand v2 - Thumbless https://www.thingiverse.com/thing:2838726

Pros:

  • Thumbless design (requirement 1).

Cons:

  • Wrist-powered only.
  • Not enough room for finger-stumbs?
  • Right hand version, must be mirrored.

Second Degree Hand https://www.thingiverse.com/thing:300499

Pros:

  • Thumbless design (requirement 1).

Cons:

  • Wrist-powered only.
  • Not enough room for finger-stumbs?
  • Extra degree of freedom not neccessary (requirement 4).

Flexy-Hand 2, thumbless https://www.thingiverse.com/thing:380665

Pros:

  • Thumbless design (requirement 1).

Cons:

  • Wrist-powered only.
  • Not enough room for finger-stumbs?

Note to myself: found another similar device with extra degree of movement.

Testmodel of hand

For better scaling and testing of the 3d-design or the printed hand a 3d-model or mold-cast of bashar's hand would be great. But i think this is out of reach.

Maybe we can create a model of bashar's hand from its pictures, another idea is to create a model of the left hand from my 9 year old son sven and merge it with data from bashar, here is a photo of it:

Some possibly usable 3d handmodels:

Questions

  • How hard is it for firas to do email-/e-nable communication, for example to answer questions or to make additional photos?
  • Is medical staff available on site (for proper fit and usage)?

Log

Wed Jun 16 23:54:29 CEST 2021

Experimenting with gimp, overlayed receipients hand with sven's hand, see *Testmodel of hand* chapter.

Fri Jun 11 12:54:48 CEST 2021

Marko suggested a *thumbless raptor hand*.