Here're few things I've been thinking about since the past week. I'm not even sure if it is possible. Please see:
1. If a person has met with an accident and has lost his legs, in usual cases, a knee-replacement or an artificial leg surgery is done. But is it possible that in a few patients due to heavy damage, neural control over the limb, artificial or not becomes impossible? In such a case, is it possible to put robotic limbs in the place of the damage and because neural control over that part is null, maybe the robotic limbs could be controlled by the patient with a remote or something? Hope this isn't sounding like sci-fi!
2. A bat happened to come into our balcony a few weeks ago. After some time, my mum slowly placed it on a tree-branch with a stick. And then while I was over-hearing my mum talk about bats in general with someone, an idea stuck to me: Can a prototype be built that can, imitating bats, help the visually-impaired to travel or do their daily works by sending an ultra-sonic sound that would lead them to the right destination (like bats)? Is it even possible?
Please reply. It would answer many questions of mine!

