How come every time i open a post its about some part requirement or other...anyways...<a href="https://www.ensemble-tech.com" target="_blank" rel="nofollow noopener noreferrer">Your own blog?</a> used to sell servos, they buy it in...

Ultrasonics is the way to go about this...you might want to look at SRF02 or similar transducers. Problem is they arent available in India. However I saw these at Ensemble...

I had a similar biomed project which i was able to sell off to a project center...#-Link-Snipped-#they were more intrested in the project concept more than the physical hardware...u might...