handlebar device for E-NABLE arm

maker for E-Nable France,i designed this handlebar device because since some week i have built an arm for a 12 years old girl ,who had a dream ,drive a bicycle.
Dream exhause!
i design it to have something very safe ,she can take out his new arm very quickly
And there is a 360 degree rotation,like this ,no effort on the arm or his shoulder.
i had some news ,she can drive very easily his bicycle ,and she can go to school alone now .
i design it for a wrist handlebar of 3.2cm of diameter,
The width is adapted to his hand
i design it with rhinoceros 3D ,it's not a parametric CAD file.
you can show on the pictures how we fixed it ,in a good position for drive