Richard, I would recommend using one leg of an off-the-shelf pressure sensor, such as the type sold by NovaSensor or IC Sensors. (I believe that NovaSensor has a product approved for medical use.) The piezoresistors are temperature sensitive as well as pressure sensitive. Perhaps you can adapt one of these for development purposes. If you need a custom device I can help you with that, however, the first approach would be more cost effective for now. Regards, Mike Mattes MicroMechatronics