Okay – so when treating wounds, a good way to follow the wounds progress is by simply documenting the area of the wound. When I worked in the primary care sector, we had no real good way of doing this. Classically, wound sizes are described as coins. So a wound could be the size of a 2-krone or the size of a 5-krone or maybe a couple of coins.

But using this method, you can’t really keep track of the size. Using a ruler is possible, but not quite as easy as it seems. First off, you can’t touch the wound making it hard to measure. Second – wounds have weird shapes, making it hard to describe using one dimensional measuring techniques. This article has some more background information about why measuring wounds makes sense and why the current approaches are not so good.

So I thought about ways to measure area without touching it, and came up with what is basically a flashlight with a small lidar (distance measurer) on top. The cone of the flashlight has a different area, depending on how close it is to the surface, and the lidar is able to sense the distance from the flashlight to the surface. A little Pythagorean magic, and voila: you have the area of the circle of light on the surface. The whole thing would be dirt simple and cheap to make, and should be pretty easy to operate and fast to use. Here’s a proof of concept and a run-through of how it works: