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Charles DeBoer will, if things go his way, have unusual credentials for the metal-manufacturing business. The mechanical engineer is going for a Ph.D. M.D. Why? A look at his employer explains.

He works in the Eye Concepts Laboratory at the Doheny Eye Institute, at the University of Southern California's Keck School of Medicine in Los Angeles. The shop has a Haas OM2 (Office Mill) four-axis milling machine with an NSK 50,000-rpm subspindle added to it capable of handling 0.004-inch end mills. Near it sits a Haas HPCL tool-room lathe, a Mitsui grinder, a manual Hardinge Bridgeport lathe, a Morgan moldmaking press, a Miller gas-tungsten-arc welding machine and several small Levin instrument lathes equipped with microscopes.

Why the microscopes? The prototype shop sits directly across the hall from where some of the most progressive eye surgeries in the country take place, performed by surgeons who continually have ideas on how to make their job easier for them and, most importantly, better for the patient.

DeBoer, mechanical engineer, Matthew McCormick, instrument maker, and others from the lab meet every Tuesday to discuss ideas for tools—small tools—to advance the science of ophthalmic surgery.

"In our lab, the surgeons have their skill sets; they understand their patients' needs, and they understand what they want to do" for a surgical procedure, DeBoer explains. "But they don't necessarily understand how to build the device."

This is where McCormick and DeBoer contribute in a big way.

A RARITY IN THE FIELD

DeBoer chose to pursue a medical degree for good reason. Although he says he will stay focused on the engineering side of medical devices, a degree in medical science will help immensely when analyzing which devices are possible and which aren't—particularly handy during those Tuesday-morning meetings.

These weekly discussions represent a rarity in the field. The engineers come prepared with imaginative thinking and manufacturing knowledge. The doctors come with ideas based on their experience behind the mechanics of surgery.

When an idea comes to fruition, McCormick explains, "We develop some preliminary concepts, but don't start to design anything yet."

First, McCormick and DeBoer don the scrubs and walk across the hall—literally—to observe a surgery. Doctors show them how they use their current instruments and explain how a certain procedure could be improved with the right tools.

Then the two return to the lab and start the designs. Often, McCormick works with modeling clay to get the initial ideas.

Then the two work to prove the concept through micro-machining, turning, welding and some innovative workholding (which requires some unusual thinking in the "micro" world). Products are produced in stages and tested for ergonomics on egg whites and plastic eyes. Once proven, the lab starts the FDA-clearing process. Through it all, manufacturability remains a chief consideration.

"I know that some poor guy in a shop is gong to have to make maybe 50 million or so of these things," McCormick says, "so we try to have our first prototype as close to being able to be manufactured as possible."

THE MICRO-COIL

Glaucoma affects millions, yet the oral medication available is remarkably inefficient. Patients may swallow a hundred times the amount required just so the tiny bit they need reaches their eyes. But what if glaucoma medication could be applied directly to the eye?

That question cropped up at a Tuesday meeting. Applying the drug to the eye's surface wouldn't work because the eye would naturally tear up and flush the drug out. But what if a tiny tack, coated with the drug, could be inserted into the eye during surgery; once in the eye, the drug would leach off, or dissolve, and go to work.

Next question: What if you could coat the tack with enough drugs for an entire year? A straight tack wouldn't have enough surface area—but how about a coil?

BINGO.

With the idea, McCormick and engineers from the lab (DeBoer didn’t help with this project) headed back to see what was possible. McCormick designed a tiny fixture on a lathe that would, basically, coil a tiny stainless-steel coil at the required dimensions, so it wouldn't interfere with vision. Then surgeons and machinists worked back and forth until they developed a good length and sharpness for the coil that would, in effect, cleanly pierce and "screw" into the eye (the patient is obviously under anesthesia). The final product was a coil about 0.140 inch long, a material width of about 0.023 inch and a coil ID diameter of 0.080 inch.

Alongside this development came ideas for the instrumentation used to insert the device. The team came up with a combination screw-driver-tweezers-type device that would connect to the micro-notches in the coil head, which had to be both milled and turned with micro-sized tooling.

During product development, McCormick researched manufacturability. It turned out that one company made a CNC coiler that could handle the small diameter. He contacted material suppliers to ensure the grade of stainless was available in the size and shape needed. All this information was integrated into the intellectual property (IP) paperwork, "so that whoever bid on this IP had a much better chance of getting it made and to market," McCormick says.

As it turned out, one company in Minnesota received the IP and now produces thousands of these a year.

BETWEEN TUESDAYS

Between meetings with surgeons, McCormick and DeBoer come back with design ideas and apply micro-machining techniques to make them reality.

Micro-machining can open up significant markets for manufacturers, says McCormick, though he adds that many still hold some misconceptions about the technology. "I think a lot of people don't realize it can be done with a standard-type CNC or manual machine," he says. "People see a four- or five-thousandths end mill, and they don't see how it can possibly last. But with some education and a few broken end mills, you learn the proper speeds, feeds and chip loads."