Portescap application engineer, Matthieu Bouat, explores why brushless DC miniature motors are the correct selection for turbine-driven ventilator designs.
Increasingly popular with medical device manufacturers, turbine-driven ventilators utilise a high-speed turbine to produce pressurized airflow. Regarding their benefits, firstly, pneumatic performance either equals or exceeds that of compressor-based ventilators used in intensive care units. Secondly, their compact packaging and reduced footprint allow battery downsizing and power reduction. Finally, the smaller size aids portability.
Brushless DC (BLDC) miniature motor technology is optimal for powering turbine-driven ventilators. BLDC motors are high performance, reaching speeds up to 60,000rpm while delivering exceptional torque and efficiency. The slotless design ensures low inertia for rapid step response to precisely meet the dynamic airflow needs of patients, promoting comfort and acceptance. Long-term reliability over more than 15,000h operation is possible with electronic commutation and durable ball bearings. The low noise characteristics benefit quiet medical environments.
Portescap offers a range of 16 to 22mm Ultra EC BLDC motors to meet varied power requirements for turbine-driven ventilators. Consequently, support is available for devices used in ICU, transport, home care and neonatal applications. Longevity of its motors will often set or exceed the overall service life of the ventilator.
Despite the additional complexity of anesthesia ventilators, specialized BLDC motors are an ideal selection for this application too. As well as requiring similar motor characteristics to turbine-driven ventilators, those used in anesthesia also need motors that can reliably withstand harsh environmental conditions. For example, during normal operation, the blower unit containing the motor can encounter pathogens, so ventilators undergo regular sterilization cycles with an autoclave or hydrogen peroxide. Furthermore, long term operation in a high oxygen environment can oxidize lubricant in the ball bearings and cause failure, a phenomenon that can be accelerated by high operating temperatures.
A proven solution is Portescap’s 22ECA60 slotless BLDC motor. Able to withstand more than 200 autoclave cycles, this motor is highly reliable even when regularly sterilized. To prevent oxidization of ball bearing lubricant, the motor has low iron losses even at speeds up to 60,000rpm, which reduces heat generation. Additional protection is provided by an integrated thermistor, which allows temperatures to be monitored and controlled.