Usually with medical innovations, the idea is patented and the product is sold well above cost of production. e.g. this $5 device could be sold for $100 each...

Usually with medical innovations, the idea is patented and the product is sold well above cost of production. e.g. this $5 device could be sold for $100 each... large profit margin. If there is no patent, and no in-place infrastructure already producing the device, then yes, it's unlikely to see rapid scale up by manufacturers. Though if it's really that cheap to produce, I'm sure it will come onto market in some form (whether through charitable foundations or otherwise). All assuming that the device is actually as efficacious as the study implies (with a small sample size).