When medical devices need to determine when to cease or continue a function, or to perhaps to move on to another function, sensors step up to the task. Pressure sensors measure the pressure of gasses or fluids, responding with a signal that can adjust the administration of medication in a drug-delivery device or adjust the concentration of oxygen in an oxygen concentrator. Temperature sensors employed in medical diagnostics ensure that a specimen or sample is at the right temperature before it moves on to the next step in the cycle.