Digitized and automated manufacturing is making strides in the world of medical manufacturing, evidenced by recent systems put into production lines during the COVID-19 pandemic.
Given the rigorous standards regulating medical device manufacture, the data-centric Industry 4.0 environment is tailor made for contract manufacturers trying to stay in spec while also coping with the dramatic lack of skilled operators.
As ever, materials are growing more sophisticated and parts are getting smaller, with more complex geometries and tighter tolerance requirements.
In a broad sense, health care trends—aging populations, the drive to more remote diagnostics and therapies outside the expensive hospital environment, more personalized therapies—are driving medical device development. And with continuing pandemic uncertainties and resultant battered supply chains, establishing more visibility into the workings of suppliers and vendors is priority No. 1.
Along with the digitization of health care comes the need to secure all that data being collected. To that end are initiatives like the University of Minnesota’s new Center for Medical Device Cybersecurity, announced Sept. 9. Five heavy hitters in the health industry have teamed to work together in the new center: Boston Scientific, Smiths Medical, Optum, Medtronic and Abbot Laboratories. Their goal is eliminating software vulnerabilities in medical devices that could potentially be used to harm patients or disrupt health-care facilities.
The high-tech future of health care also means more robotic diagnostics and procedures, hence the need for more medical tooling and parts dedicated to use with those systems. For instance, XACT Robotics in Hingham, Mass., the developer of the XACT ACE Robotic System, announced on Aug. 30 that it successfully completed patient enrollment in the first U.S. study evaluating XACT ACE for use in percutaneous lung procedures. This includes biopsies to confirm the presence of cancer. The hands-free robotic system could detect cancer earlier and less invasively.
Meanwhile, iData Research projects 3 million robotic surgical procedures will be performed annually by 2025. Robotic arms on equipment like the da Vinci Surgical System will require plenty of the miniaturized instruments that doctors control to perform these minimally invasive operations. Robotic surgeries use smaller incisions, resulting in less blood loss and scarring, shorter hospital stays and faster recoveries.
Data-fueled AI will also come to the fore in improving patient outcomes. A clear indicator of that path is Stryker’s acquisition of Gauss Surgical of Menlo Park, Calif. Gauss developed Triton, an artificial intelligence-enabled platform for monitoring blood loss during surgery.
Additive manufacturing will also continue to expand its critical role in producing patient-specific implants, tooling and surgical training models. For instance, Italy’s Tsunami Medical is wowing the industry with its use of GE Additive laser and electron beam 3D printing systems to produce a range of highly complex spinal implants.
Small Parts, Sorting Challenges
As medical device materials evolve and parts get smaller, the L series Swiss-style machines of Marubeni Citizen-Cincom (MCC), Allendale, N.J., are answering the call.
“Medical has materials you haven’t heard of before,” joked President and COO Brian Such. Tough materials can be used for simple parts or more complex components requiring the use of many tools to create the different features.
“Our L series machines are a gang machine with subspindle,” and their significant advantage for medical production is that they are modular, Such explained. “With a number of tools available at any moment, we can just slide one out and put three in the same place.”
To handle the smaller diameters typical of current medical drills and mills, MCC offers speeders up to 4x acceleration. “Our live tools reach speeds up to 6,000 or 9,000 rpm depending on the models, but we can slide in a different toolholder, and now we’re 36,000 rpm. When that’s not enough, we can retrofit in our electric spindles, which can get up to 80,000 rpm.”
As an example, Such noted, a customer might be drilling an eight-thousandths hole, “so you need some speed for that–or utilize a 16-thousandths end mill or maybe even an eight-thousandths end mill to lean up a corner somewhere. With our 80,000 rpm electric spindles, we can slide into these pockets. And this same tool can be used as a face tool, a cross tool or a backward-facing tool, so it’s very modular.” MCC has partnered with high-speed spindle seller NSK to create these proprietary spindles.
About two years ago, MCC expanded the functionality of the B axis of its machines by introducing the ATC (automatic tool changer) version of its L20 machine. “Now we have the ability of 13 tools on the B axis,” Such said, whereas typically a B axis has only four tools–and that “is pretty hot stuff for the medical market” given the tight angles of today’s parts.
Another MCC innovation, introduced around 2016, is low-frequency vibration (LFV) cutting. In this process, the machine tool “oscillates the cutting path of the Z or X axis, moving in and out at a very high rate of speed to make little air cuts and break the chips as you’re machining,” Such said. “The medical field loves LFV technology, and most customers who use it for the first time say, ‘I’ll never buy a machine again without it.’ ” With LFV “you 100 percent will break the chips; there’s no in-between. Once you get the process running, it is guaranteed. You still have to know your cutting tools, and cutting tools can still fail, but the problem of chip wrap goes away.”
MCC’s customers range from OEMs with 300 or 400 machines to smaller manufacturers with 10 machines. And those customers “are making all different parts,” from common bone screws and spinal surgery cages to various surgical tools like bone reamers necessary for hip and knee surgeries. There are tiny bone screws of roughly 4 mm diameter with holes for sutures. “Nine different tools come in to cut the different shapes,” Such said. “There are lots of features in this little bone screw–it’s not just a screw with a head.”
After those tiny parts are made, sorting becomes the main issue, Such continued. MCC makes automation equipment tailored to the task.
“These parts are so small that when they drop into the bucket, there could be 300 there. If you’re going to try to pick the last one to try to measure it, which one was that? We can have a device that has different trays for counting,” Such said.
The customer can put 100 parts in one tray, then when the tray moves, put one in the next tray, 100 in the next tray, one in the next tray, and so on. If there are 10 trays, it can run for eight hours or overnight unattended. By measuring parts at intervals, customers can isolate whether previous parts are good or bad thanks to the collection trays.
The Six-Axis Advantage
Steady demand for the cutting tool grinding machines of Rollomatic USA Inc., Mundelein, Illinois, are a clear indicator of the resiliency of medical device manufacturing, asserted President Eric Schwarzenbach.
Among the many instruments Rollomatic machines are called upon by OEMs and contract manufacturers to craft are various orthopedic cutting tools like rasps, bone drills, skull perforators and arthroscopic burrs. Throughout the pandemic, “our customers invested as before–no more, no less” despite the postponement of orthopedic or elective surgeries. “There was enough business around to keep these companies going and to keep their need up for reinvestment.”
Over the past couple of years, he noted, various instruments for robotic surgeries are growing in demand. But those devices pose a particular challenge.
“A drill that a surgeon uses with a handpiece to drill into bone is different than what a robot issues,” he explained. “Robots use longer drills than surgeons do. The nature of making a long drill is harder than a shorter drill. First of all, surgical tool blanks are being machined in a soft state on a Swiss-type lathe and subsequently hardened. These processes inherently cause warping in these blanks, and the longer they are, the more bent they are. And when they are bent, we have trouble reliably loading, grinding and unloading. When we teach customers our machine and setup, we have to be very careful to teach them in some depth and make sure they understand the features to circumvent a bent blank. Bent blanks are often straightened by the manufacturer, but even then they are never perfect—although they don’t have to be perfect. The machine is capable of handling a small distortion.”
The more robotic the industry becomes, “the more focus there has to be on the drill point. While a surgeon can always drill into bone because he can look, see, adjust his hand and pressure so the point doesn’t walk away, the robot doesn’t. So, those points have to be designed to be more self-centering. We help medical device manufacturers to teach them what a self-centering point looks like.”
Schwarzenbach also noted more variants in 17-4 stainless for orthopedic cutters. “The material has become softer and less hardened, which is a challenge for us in terms of finding the right grinding wheels to grind them. As you know, the softer the material, the harder it is to grind.” To answer that need, Rollomatic has partnered with wheel manufacturers in Switzerland and the U.S. to procure wheels suitable for softer materials.
“The softer the material, the more burr it throws off,” Schwarzenbach explained, “so burr removal is an issue. Our customers generally use nylon brushes to remove burrs after grinding, especially with softer materials. But no wheel or process is ever perfect; there will always be a little bit of a loose burr that needs to be removed by some method. We use either nylon or sometimes impregnated brushes with ceramic or abrasives on it to remove those burrs.”
Quick-disconnect grips for medical tools are another growth area, he continued. These tools can be clicked into a handpiece by a surgeon or secured to a robotic arm. Such grips “have become far more complex than we’ve ever seen. We use a peel grinder for most of them.”
Rollomatic’s six-axis capability is the game-changer for medical manufacturers who need more flexibility for programming and easier wheel setup, Schwarzenbach said.
“You don’t need to use complex wheels; you can use more straightforward-shaped wheels, particularly on the drill points,” he said. “You can produce a drill point easier than on a five-axis machine. And don’t forget: Drill points now are becoming as low as 50 to 60 degrees inclusive. They are very steep, as opposed to a carbide drill into metal at 120 or 130 degrees. Our six-axis machines really help grind those drill points far more easily than struggling with setting up a five-axis machine.”
And, Rollomatic’s quick wheel changer offers even more advantages, he added. “We have been selling a lot more wheel-changer machines. The basic wheel changer has six stations, so you can put six wheel packs in to increase flexibility, which serves for shorter batches. Shorter batches need more flexibility with the frequent changeover. Wheel changer machines are very good for that.” While about 80 percent of machines Rollomatic sells into the medical industry retain the standard spindles that house a pair of wheels front and back, some manufacturers “are beginning to embrace our new technology.”
The Role of Force Testing
From the preparation for manufacturing to after the part is made, force testing equipment and its integrated software performs important functions for medical products–often with the goal of patient comfort.
For instance, the contours and coating of a needle can be tested for how easily they enter the skin, while adhesives can be evaluated for how well they adhere to skin, or how easily they are removed.
Prior to manufacturing, “you can build tests to make sure your equipment functions the way it should before you use it in manufacturing,” explained Jacob Morales, technical support engineer for The L.S. Starrett Co., Athol, Mass. And for bandages, “you can test the adhesive before you use it in your manufacturing line,” in batches ranging, for example, from one in 100 to one in 10,000 samples. “Post-process, you can run those tests again to ensure consistency.”
Such tests are particularly important when manufacturing in line with ASTM and ISO standards as well as for producing documentation critical for traceability, added Eric Perkins, Starrett technology manager for force and material testing. Starrett software enables both force and material properties tests, and simply by clicking the right icon, the software can engage the appropriate test. Force measurement covers go/no-go scenarios include testing for peak load, average load, compression testing and more. Syringes, a prime example requiring uniaxial force application, can be tested with sample substances to determine injection force for controlled injection rates.
While these tests provide sample information, they don’t always return data specific to the material composing the sample. Material testing goes further, using material properties to test for elongation and stress-strain, for example.
Starrett software can be integrated into the manufacturing process, Morales explained.
“If you have a force system testing a sample, you can have it programmed with an input-output system so the test is running constantly. The manufacturing equipment moves a sample to the machine and sends a signal; the machine responds by running the test and provides a signal output based on the test results. The rest of your manufacturing equipment can respond appropriately. If you get a result that falls out of tolerance, the signal can alert an operator.”
That flexibility means “you can hook the force system up to a PLC and put it in-line with the production environment, so you’ve taken potential human data entry error out of the picture,” Perkins said. “Users can automatically have a product tested every time it’s queued.”
From Starrett’s basic L1 force software to its more advanced L2, L2Plus and L3 options, “we give customers the ability to test exactly as any manufacturing standard states,” Perkins said. And since Starrett software is compatible across platforms, adding optical and vision systems creates an extremely broad metrology solution.
That level of customization doesn’t stop at software, however. Starrett has been working with manufacturers to create completely automated systems.
“We’re using robots to insert parts into our force test system,” Perkins said. “We’re using pneumatic grippers to grab the parts.” With a constantly running test platform married to this level of automation, “our system will tell if you have a good or bad part, then the robot executes whatever program is required and puts those parts in the designated bin.”
GE’s Big-Picture View
Improving hospital workflows and maintaining supply-chain resiliency have been top of mind for GE Healthcare during the pandemic.
“We’re seeing increased requests for more automation–not just from a typical productivity standpoint but in terms of leveraging automation so we can maintain production at different locations,” said Jimmie Beacham, executive chief engineer for advanced manufacturing at GE Healthcare in Milwaukee. “That’s easier than having to train a new or revolving workforce. It’s not necessarily about the labor but the supply chain security of it where automation makes sense. If I have to switch production from one region to another, it’s a lot easier if the process is automated already.”
A major part of that philosophy is mistake-proofing, he added. “We would train operators and have written procedures,” Beacham explained. “Now we’re looking at employing other technologies that digitize what the operators need to do and that interacts with them. Say you have torque station, where you’re torqueing bolts, followed by a complex assembly and then a cobot. We’re looking at technologies that digitally connect all that–that work in lockstep with the operator so it interacts with that person and doesn’t require the operator to remember it all. That gives us a lot of flexibility when we’re making the same product in three regions around the world. We now have one control process. We’re not relying on operators memorizing paper procedures when they have to cycle through several complex parts of the operation.”
That’s vital for GE Healthcare, which produces an array of smart diagnostic equipment. Additive manufacturing is a big part of the equation, and GE Healthcare has refined its processes in that regard, as well.
“When we first started, probably 80 percent to 90 percent of our time was invested in R&D, trying to figure out how additive works, how you develop materials and parameters to meet our engineering requirements,” he said. “Now we’re at about 80 percent execution, where we’re moving things in to production, and the other 20 percent of our time is devoted to developing new materials for the new funnels coming in. We have a production facility in Monterrey, Mexico, and we have a pretty active funnel of things going there. Then we have some other additive applications we run at the point of use.”
Ultimately, while the pandemic has proved challenging, GE Healthcare has weathered the storm.
“Our big challenge was supply, getting people safely in the plant,” Beacham said. “In some cases, like with ventilators, we relied a lot on automation to enable us to meet unprecedented demand. We brought a lot of people in to do the work, but we still had to find creative ways to manufacture the volume of products our customers desperately needed. And we learned we can manufacture things differently; that has inspired even more ideas.”