To date, AC motors have proven reliable in many successful designs for driving pumps. They are well-established and comparatively inexpensive. But new medical products require the pump size to be smaller with the option of speed regulation and brushless DC motors (BLDC) are ideally suited for these pump requirements.
As the name suggests, the BLDC motor relies on direct current, so the alternating current must be converted. This conversion leads to higher production costs if compared with AC motors, but the BLDC motor makes up for that with an almost wear-free drive and long service life. They operate quietly with minimal vibration, and because of the reduced heat produced, they require less space and energy. This means they fall perfectly in line with the trend of medical device miniaturization with portability and battery-powered operation.