Disposable medical hand tools are seeing increased use due to their cost and hygiene benefits. Engineers who design these tools usually specify brush DC or brushless DC motors. Here we compare these two options.
An early step of surgical power tool engineering is to determine whether the design will be disposable or reusable. Recent component design and manufacturing advances have rendered many single-use power tool designs for complex surgery a cost-effective option. Nowhere is this more apparent (or significant) than with today’s brush DC and brushless DC (BLDC) motors both of which have lower price points and higher performance than in the past.
Once performance requirements are met, cost is often the next-most critical design consideration. We’ve covered how motors with a BLDC construction are relatively expensive … and in fact, the controllers they require (for commutation) and embedded electronics (for tracking rotor position) further increase overall system cost. The additional cost for these subcomponents (along with premium bearings, dynamic shaft seals, or high-grade magnets) can be justified where the application demands top performance … but not usually for disposable tools.
In contrast, DC motors with their brush-based commutation only need a cost-effective PWM circuit for speed control … and motor-construction advances have made for unprecedented performance increases with only negligible cost increases. That’s made today’s more advanced brush DC motors particularly suitable for short-life surgical tools.
For example,the increasing popularity of disposable surgical power tools (such as surgical staplers) has prompted more demand for higher-performance brush DC motors. These are more suitable than BLDC motors where cost effectiveness is the top design objective.
Still not sure which motor is right for you? Contact Twirl Motor now. Our engineers will gladly help you figure out the right motor or even design a custom products to meet your needs!
