Abstract
Pneumatic active ankle foot orthosis (AFO) for drop foot correction has
the advantages of inherent compliance and remote force control. However,
pneumatic AFOs that use heavy stationary air compressors as the energy
source have limitations for outdoor use. Although a portable
air-compressor-powered pneumatic AFO has been developed recently, it is
difficult to operate in practical applications owing to the bulky design
of the AFO and excessive power sources with overheating issues. In this
study, the AFO system was optimized to improve wearability. The weight
of the AFO was decreased from 720 to 600 g. A Bluetooth module was
installed instead of a 1.2-m cable between the master and slave boards.
The efficiency of the portable pneumatic actuator increased 12.4%,
whereas its volume decreased 11%. The internal temperature was reduced
from 100°C to 40°C using two cooling fans. Throughout the optimization
process, the wearability of the AFO system was improved for real-life
use.