Out of all industries changing motion design, medical technology is driving electric motor innovation hardest. FDA requirements on medical-device makers and their suppliers continue to include motor manufacturers in regulatory scrutiny, so controls on design processes continue to tighten — usually as reverification of production lines and test equipment. Overseas competition, medical-device taxes, and withering Medicare reimbursements are also forcing lower costs for devices and the motors for these applications.
“We see this industry as the most demanding because all medical devices — from medical robots to handpieces to implantables — are getting smaller and more compact,” said Patel of maxon.
So medical continues to adopt technologies from consumer electronics — and the small motor-driven designs they enable. Consider micromechatronic (M3) modules from New Scale Technologies based on SQUIGGLE piezomotors running off closed-loop control. These 12 x 30 mm (or smaller) actuators are best known for lens-focusing functions within consumer and smartphone-grade cameras and UAVs. But now the core electric motor technology runs in sophisticated devices for biometric identification, in-vitro diagnostics, and handheld surgical tools. In addition, some dc motors with diameters of just a few millimeters now have enough power density and reliability to satisfy technical and regulatory requirements for implantable pumps to treat an array of conditions.
Consider a medical application that’s automating a process that surgeons still usually do manually. In the traditional setup, the doctor physically turns a knob to locate and move a device that’s inserted into the human body.
“One manufacturer came to us wanting to automate the process,” said Phil Faluotico, V.P. of HaydonKerk Pittman Engineering. “The system must be extremely small and sterile and as a single use device, it must be inexpensive. We coupled a motor and gearbox to perform the operation … and once we spoke with the customer and saw the application, realized that we could integrate their leadscrew and nut into an extension of our gearbox,” Faluotico added. This changed the product from just a motor and gearbox to a complete solution that includes motor, gearbox, leadscrew, and nut.
Another example is brushless dc cannulated gearmotors, those with gearbox-motor combinations that (among other things) allow for inline driving of Kirschner wires and pins in orthopedic surgery. Demand for cannulated gearmotors is rising as orthopedic-drill designers are looking to decrease their designs’ overall size.
“Increased power density and miniaturization are focus areas for us, which is why we’ve been developing and producing gearboxes, encoders, and brakes in addition to our motors,” agrees Greene. “Modularity and its efficiencies extend to integrated drive electronics, as total drive packages let customers customize products to specific needs and keep footprint to a minimum.”
Others point out that miniaturization brings other benefits. “Shrinking semiconductor sizes have let us put them into smaller and smaller motors,” said Faluotico. “The ability to integrate drives in the backs of motors is beneficial from reliability and cost standpoints.”
While the machines and devices get smaller, in many cases they must also be increasingly precise. Consider the interest in making more inpatient procedures into outpatient procedures. To this end, surgeons are now using robots or motor-assist tools to boost accuracy. Even risky forms of eye and brain surgery now rely on motor-driven automation to let doctors target places in the body while leaving sensitive areas.
Elsewhere, the medical industry is prompting electric-motor innovation for smaller and less costly designs. Case in point: Motor-driven tools in operating rooms must draw low voltage and be quiet. Here, traditional peristaltic pumps can be noisy, especially when they’re in a bank or driven by brush motors. Some manufacturers have addressed the problem with alternative dc-motor designs paired with quiet planetary gearing. Another example is portable oxygen concentrators that demand long life because they run off batteries. Motors in these are increasingly efficient and (because they’re portable) power dense as well.
Online configuration and Internet of Things (IoT) functionality for electric motor design
Online configuration tools and software are changing how design engineers specify and buy motors; visit linearmotiontips.com and search “online configuration tools” for more on what’s on the horizon here. But such tools aren’t the only way in which online connectivity is changing the application of electric motors.
“Designers will optimize future factories with more accessible automation to meet end-user price and productivity needs,” predicted Greene of Dunkermotoren. “We expect integrated servomotors with Ethernet interfaces to fit into this new IoT development. That’s because connectivity, cloud-based platforms, and decentralization of control electronics are enabling new possibilities for controlling and troubleshooting motors.”
The manufacturer maintains that it’s poised to support the IoT trend as a pioneer of intelligent motors with fieldbus interfaces and OEMs embracing its Industry 4.0 approaches. “Many designers already use our integrated drives and custom software and fieldbus capabilities to run critical motion profiles,” Greene added. • Part one of this series can be found here.