This new knee joint has a stance-flexion feature that, while allowing a slight amount of flexion, instantly locks to prevent sudden buckling of the knee, it also has a hydraulic system that eases the initiating swing. This knee is named Symphony. The knee joint seamlessly orchestrates theharmonizes stability of the stance phase and smoothness of the swing phase.
The capability operates even when stepping on a frozen surface that cannot be firmly contacted by the heel. The instant the heel touches the slippery surface, the knee is geometrically locked and knee buckling is prevented.
Moreover, because the knee joint is slightly flexed at the time of contact, the shock of impact with the ground is absorbed, and it is easy to walk comfortably (max. stance-flexion:10бы).
The p-MRS system is a mechanical sensing system that monitors the underfoot location of the ground reaction force. The virtual pivotal point in the polycentric link sensing system is situated at around the toe-break point. When the reaction force is detected on the heel side of the sensing point, the stance phase control is activated.
Then, when the reaction force is detected on the toe side, the stance phase control geometrical lock is released to allow the swing phase. Unlike a load-monitoring system, this more sensitive system works by detecting where the force is being received. Even a small amount of force can accurately trigger activation and this enables smooth transitions between the stance and swing phases.
Selective lock mechanism
At any time, the user can switch between free knee and locked knee modes. If the user feels unsafe with the knee being free, for example on settled snow, in high winds, or on uneven ground, to prevent buckling, the knee can be locked. At other times, such as when standing on a ladder working or when making a golf swing, locking the knee is also convenient.