Ali has cerebral palsy and so can't support his own bodyweight while going down a playground slide. So Goren Harari and his colleagues at the Holon Institute of Technology in Israel designed this seat that lets him safely use a slide.
You can find complete plans for it at Instructables. The body is made of polycarbonate sheets which is heated into shape. The backrest is angled at 70º. The seat is padded and comes with restraints to keep Ali in place. There's a handle on the back so that a caregiver can move Ali up and down the slide.
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