Page 198 - Handbook of Biomechatronics

Upper-Limb Prosthetic Devices 195

Fig. 12 Bi-directional EPP control using cineplastized forearm flexor and extensor mus-
cles as an agonist/antagonist pair to control opening and closing of an electric hand.
During closing, the length of the agonist flexor muscle, L ag , is directly proportional to
the angle of closing, F ag . Likewise, during opening, the length of the antagonist extensor
muscle, L ant , is directly proportional to the angle of opening, F ant . This control arrange-
ment is analogous to the physiological arrangement for control of natural joint move-
ments. (From Northwestern University Prosthetics Research Laboratory (NUPRL).)

engineer, physical therapist, and physician work together as a team in order
to have the optimal result.
Fig. 12 shows a schematic of the Classic EPP topology.
A microprocessor-based EPP controller for upper-limb prostheses to be
used either for transradial or for transhumeral amputees was developed
(Bertos et al., 1997, 1998), eliminating analog electronic problems of the
controller developed by Childress et al. (1993).

1.4.4 Many-DoFs
Sequential many-DoF upper-limb prostheses have been used in the 1980s
and 1990s especially for high-level amputations since many-DoF arms were
needed for those cases. They have been controlling different DoF of the
prosthesis sequentially from one control site.
Simultaneous many-DoF upper-limb prostheses were not possible in the
past due to the lack of control sites. TMR enabled the creation and mini-
aturization of sensors and actuators enabled the creation of additional control
sites and practical simultaneous many-DoF upper-limb prostheses.

1.5 Technologies That Affect Upper-Limb Prostheses
1.5.1 Materials
The materials for prosthetic devices obviously follow their time. The first
materials used were wood and leather. During the Renaissance, materials
for prosthetics included iron, steel, copper, and wood (Marshall, 2015).
Modern upper-limb prostheses require a large number of different mate-
rials, especially when the prosthesis is active. These may be divided materials