Another source within the federal government is the NIH Office of Rare Disease Research. If your device is for a rare disease, this site can link you to detailed descriptions, advocacy groups, clinical trials, research resources etc.
You can get statistics on many birth defects which may be applicable to device intervention from The March of Dimes.
Oftentimes medical centers list incidence statistics within a particular disease description or treatment option. Some of the best examples can be found at:
In a few instances device companies that treat the same disease list the incidence rates on their physician portals. Some of the primary companies include:
You can also go to the Healthcare Sales & Marketing Network for a listing of the major device companies in the world and their areas of specialization.