The Northpaw is based on the Feelspace, a project organized by the Cognitive Psychology department of Universität Osnabrück in Germany. The principle is simple and elegant. The buzzers signal north to the wearer. The wearer gets used to it, often forgetting it’s there. They just start getting a better idea of where they are through a kind of subconscious dead reckoning.
Quinn has written about similar direction-sensing enabling technologies before.
I recall something like this in Lords and Ladies by Terry Pratchett. PTerry gifts his elves with “poise” – the ability always to know where they are.