A new robotic exoskeleton could allow individuals who have lost the ability to move their legs to stand up and even walk again. It can also help them walk independently, guiding their movements and keeping them upright as they participate in rehabilitation therapy.
Named Twin, the exoskeleton designed in Italy for the lower body was presented at the Museum of Science and Technology in Milan. It is still in the prototype stage and is being developed by scientists from the Istituto Italiano di Tecnologia (Italian Institute of Technology) and the Istituto Nazionale Assicurazione Infortuni sul Lavoro (National Institute for Insurance against Accidents at Work).
Designed for use by patients with reduced or absent mobility in the lower body, it moves their legs through motors located at the knee and hip joints. These motors are powered by an integrated battery, which is said to last for about four hours of use per one hour of charging. The Twin can be used in three different operating modes. In Walk mode, intended for individuals who cannot use their legs at all, the exoskeleton moves the user’s legs on their behalf and assists them in sitting and standing up. The person still needs to use crutches for balance, as with other assistive exoskeletons.
Retrain mode is for patients who still have some mobility in their lower limbs. It allows them to walk on their own to the extent they can, but provides adjustable assistance when needed. Throughout the process, the exoskeleton guides them towards a predetermined optimal trajectory of leg movement.
Finally, there is TwinCare mode, intended for individuals who have full use of one leg but not the other. In this case, the exoskeleton enhances the movement of the affected leg to match that of the healthy leg. In all three modes, a physiotherapist or the user themselves can adjust walking parameters, such as step length/type and walking speed, using a wirelessly connected Android tablet.
According to its designers, two things that make Twin stand out from similar exoskeletons are the fact that it is made from lightweight materials – aluminum alloy instead of steel, for example – and that it features an articulated design allowing for the removal of components for transport or upgrade.
