Suitability of the Openly Accessible 3D Printed Prosthetic Hands for War-Wounded Children.

John-John Cabibihan,Elsadig Mahdi,Khaled Diab,Mohammed Mudassir,Farah Alkhatib,Laurent A Lambert,Osama S Al-Kwifi

doi:10.3389/frobt.2020.594196

Abstract

The field of rehabilitation and assistive devices is being disrupted by innovations in desktop 3D printers and open-source designs. For upper limb prosthetics, those technologies have demonstrated a strong potential to aid those with missing hands. However, there are basic interfacing issues that need to be addressed for long term usage. The functionality, durability, and the price need to be considered especially for those in difficult living conditions. We evaluated the most popular designs of body-powered, 3D printed prosthetic hands. We selected a representative sample and evaluated its suitability for its grasping postures, durability, and cost. The prosthetic hand can perform three grasping postures out of the 33 grasps that a human hand can do. This corresponds to grasping objects similar to a coin, a golf ball, and a credit card. Results showed that the material used in the hand and the cables can withstand a 22 N normal grasping force, which is acceptable based on standards for accessibility design. The cost model showed that a 3D printed hand could be produced for as low as $19. For the benefit of children with congenital missing limbs and for the war-wounded, the results can serve as a baseline study to advance the development of prosthetic hands that are functional yet low-cost.

Highlights

The loss of upper limbs has significant impact on the functional activities and social interactions of a person
We investigated the probable design aspects where failure can occur: the cables could break and the grasp could become compromised, the material in the fingers could break due to the high stresses from the cables that were under tensile forces, or the fingers’ joints could fail due to the cyclic loads during the grasping and carrying of objects
From the 33 total grasps that a human hand can do, there were only three grasping postures that can be achieved using the 3D printed hand that was considered in this study

Summary

Introduction

The loss of upper limbs has significant impact on the functional activities and social interactions of a person. The loss of upper limbs can be classified according to congenital limb loss or acquired limb loss. There is a 2:1 incidence ratio of congenital limb loss to acquired limb loss (Masada et al, 1986; Vannah et al, 1999; Vasluian et al, 2013). Congenital limb loss is attributed to malformations that have structural abnormalities of prenatal origin (Czeizel, 2005). The prevalence of upper limb loss is twice that of the lower limbs (Hirons et al, 1991). Acquired limb loss can be due to various reasons, including diseases or traumatic amputations from machinery, vehicular accidents, electrical injuries, or weaponry (Krebs et al, 1991)

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Conclusion