Chapter 2. Prehension

Appendix D - Prosthetic and Robotic Hands 411
way to assist VF2. The active fingers, the index and middle fingers,
can be used as a VF3 to carry some object in a hook grasp.
Table D.3 Commercially available electrical hands. Myoelectric
control, switches, or servos are used to power the one degree of
freedom. They consist of a thumb and two fingers (two more
fingers are created by a glove). The thumb is a virtual finger 1,
and the fingers are virtual finger 2. The two active fingers can act
as a VF3. (T=thumb; kindex, M=middle, R=ring, L=little) (from
Iberall, Beattie, & Bekey, in press; reprinted by permission).
Manufacturer and Control Opp VF1 VFZ3 VF3
Name
Hugh Steeper, Ltd.
Electric (MHlOl- myo. or switch pad T I-M(R-L)
MHllO)
I-M
Electric servocontrol pad T I-M(R-L)
(MH15 1-MH160)
I-M
Otto Bock
Electrohand 2000 m yoelectric pad T I-M(R-L)
I-M
System Electric myoelecaic pad T I-M(R-L)
Hands
Systemteknik AB
2” Electric Hand myo. or switch pad T I-M(R-L)
Variety Ability Sys, Inc.
VASI Hands myo. or switch pad T I-M(R-L)
Hugh Steeper Ltd. manufacturers the Steepe r Electric Hang in
four different sized hands for children and adults. They can be
controlled either by switch, myoelectric control or servo-controlled.
In contrast to a normal human hand, the thumb moves in same plane
as two opposing fingers. In the human hand, the thumb travels in a
plane at almost right angles to fingers. The thumb and first two fingers
3Fingers in parentheses are not part of the hand itself, but are provided by the
glove.
I-M
I-M