Mechanical aspects of robot hands, active hand orthoses and prostheses: A comparative review

The large interest in robot hands and active hand prostheses has in recent years been joined by that in active hand orthoses. Despite the differences in intended uses, these three categories of artificial hand devices share key characteristics. Examination of the commonalities could stimulate future design. Thus, in this article, we undertook...

Assessment of Body-Powered Upper Limb Prostheses by Able-Bodied Subjects, using the Box and Blocks Test and the Nine Hole Peg Test

Study Design: Experimental trial. Background: The functional performance of currently available body-powered prostheses is unknown. Objective: The goal of this study was to objectively assess and compare the functional performance of three commonly used body-powered upper limb terminal devices. Methods: Twenty-one able-bodied subjects (n=21, age...

The Lightweight Delft Cylinder Hand, the First Multi-Articulating Hand That Meets the Basic User Requirements

Rejection rates of upper limb prostheses are high (23-45%). Amputees indicate that the highest design priority should be reduction of the mass of the prosthetic device. Despite all efforts, the mass of the new prosthetic hands is 35-73% higher than that of older hands. Furthermore current hands are thicker than a human hand, they operate slower...

A mechanism to compensate undesired stiffness in joints of prosthetic hands

Background: Cosmetic gloves that cover a prosthetic hand have a parasitic positive stiffness that counteracts the flexion of a finger joint. Objectives: Reducing the required input torque to move a finger of a prosthetic hand by compensating the parasitic stiffness of the cosmetic glove. Study design: Experimental, test bench. Methods: The...

Design and evaluation of two different finger concepts for body-powered prosthetic hand

The goal of this study was to find an efficient method of energy transmission for application in an anthropomorphic underactuated body-powered (BP) prosthetic hand. A pulley-cable finger and a hydraulic cylinder finger were designed and tested to compare the pulley-cable transmission principle with the hydraulic cylinder transmission principle....

Natural grasping, design and evaluation of a voluntary closing adaptive hand prosthesis

Replacement of a missing hand by an artificial alternative remains one of the biggest challenges in rehabilitation. Although many different terminal devices are available, around 27% of the amputees does not actively use their device and 20% totally refrains from wearing it. There are various reasons for prosthesis abandonment, e.g. wearing...

Efficiency of voluntary opening hand and hook prosthetic devices, 24 years of development?

Quantitative data on the mechanical performance of upper-limb prostheses are very important in prostheses development and selection. The primary goal of this study was to objectively evaluate the mechanical performance of adult-size voluntary opening (VO) prosthetic terminal devices and select the best tested device. A second goal was to see...

Efficiency of voluntary closing hand and hook prostheses

The Delft Institute of Prosthetics and Orthotics has started a research program to develop an improved voluntary closing, body-powered hand prosthesis. Five commercially available voluntary closing terminal devices were mechanically tested: three hands [Hosmer APRL VC hand, Hosmer Soft VC Male hand, Otto Bock 8K24] and two hooks [Hosmer APRL VC...