You can search for companies by the product produced, e.g. pulse oximeters. Often you can also link to the company's catalog and sometimes CAD drawings of their products.
Search 14 million U.S. businesses and 135 million U.S. residents for up to date information. The U.S. Business database may be searched by business type, size and geographic location. This source is available through the Columbia Public Library/Daniel Boone Regional Library. You must have a library card from them to access.