Page 263 - Handbook of Biomechatronics

Lower-Limb Prosthetics 257

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Fig. 9 The Ossur RHEO KNEE. (From www.ossur.com.)

the prosthesis. With measurements of foot contact time, the controller also
estimates forward speed and modulates swing-phase flexion and extension
damping profiles to achieve dynamic cosmesis throughout each walking
swing phase. The adaptation scheme successfully controls early stance resis-
tance, swing-phase peak flexion angle and extension damping, suggesting
that local sensing and computation are all that is required for an amputee
to walk in a safe, comfortable, and smooth manner.
The C-Leg 4 (Fig. 10) represents an evolution of the first
microprocessor-controlled hydraulic knee with swing and stance-phase
control. This innovative knee joint features onboard sensor technology that
reads and adapts to the individual’s every move. Angles and moments are
measured in real-time 50 times per second. Amputees can move on flat ter-
rain at different gait speeds with confidence. Moreover, thanks to the
hydraulic stance control feature, which is basically a prevention of buckling,
it is easier to tackle slopes, stairs, and other uneven surfaces. The C-leg 4 has
also some stance-phase knee flexion.
A prosthetic leg named high intelligence prosthesis (HIP) developed for
above-knee amputees by Biedermann Motech (Schwennigen, Germany)
uses an array of sensors in the artificial knee component to detect force