Medical device innovations - fabricating the future

Jan 9 2005

Two large pieces of metal lie on the floor of what looks like a mini-factory in the Cleveland Clinic’s Lerner Research Institute. The whirring machinery here stamps out prototypes of medical devices imagined by clinicians and researchers to help with diagnostic testing or surgical procedures. But it’s tough to imagine how these huge metal blocks could be used in an operating room or diagnostic testing center.

And, in fact, they won’t be. The shiny silver platforms will be foot rests for an ingenious new virtual treadmill that may one day be used on the International Space Station. As the astronaut watches a video of different environments – uneven ground, running the Boston Marathon or climbing stairs – the footholds move as a leg would move on that terrain.

Elsewhere in the building, a group of engineers is putting together an electronic battery pack that they hope will reach the moon some day. This one is designed to monitor the muscle movements of astronauts, who can suffer from bone loss and muscle atrophy in space.

And, down the hall, there’s a room with a human-size artificial heart made out of metal that researchers hope will extend life someday for those waiting for a transplant, or maybe even replace transplants all together.

From space devices to out-of-this-world concepts like an implantable total artificial heart, these are some of the projects advanced by the Clinic’s Medical Device Innovations (MDI) program. MDI is a part of Biomedical Engineering and most of the people who work here are engineers or technicians, not physicians.

Within MDI are four subgroups: Mechanical Prototype Core, Polymer Laboratory, Engineering Design and Electronics. The Clinic is one of only a handful of health centers worldwide to offer those disciplines on the same campus as its clinicians and researchers.

The initial ideas come from physicians or researchers who at some point – maybe during surgery or assessing a patient or reviewing research data – think, "If only I had…"

Tony Shawan, manager of MDI’s Mechanical Prototype Core, says his group often makes trips to the operating room to see firsthand what the physician has in mind. They’ve worked off everything from a design roughly sketched out on a napkin to formal computer drawings.

"While it takes a long time to get a new medical device to market, it takes the MDI group just a few months, on average, to develop a prototype to demonstrate the new technology," says Peter Cavanagh, Ph.D., chairman of Biomedical Engineering. The four labs in the MDI group work with all clinical disciplines, including cardiothoracic, orthopaedics, neurology and urology.

"First we talk with the inventor to really understand the idea, to understand its technical complexity," Mark Goodin, manager of MDI, says. "Then we ask, ‘What is needed to convey the idea?’

Sometimes it’s just a three-dimensional CAD [Computer-Aided Design] model. We can also take it to another level and demonstrate how the invention works by building a physical prototype." The MDI labs that make those prototypes are packed with unique computer programs and machinery. One computer technique – called Computational Fluid Dynamics – can demonstrate flow patterns through or around a device, ideal for the design of catheters used to deliver drugs.

Another approach – called Stereo-lithography – builds solid models out of liquid polymer, curing one thin layer at a time. That machine can even import a patient’s CT scan and MR image and within a day will replicate the image in plastic. That is ideal in dentistry. The machine simply converts the CT data and makes a plastic model of the patient’s jaw, allowing the doctor to know the exact jaw depth for implants.

MDI’s motto is "Every Good Idea Deserves A Chance." But Ji-Feng Chen, a principal research engineer in the Polymer Lab who has helped to develop the artificial heart, sums it up best when he says, "We make dreams come true." And if that means reaching for the moon, the MDI engineers won’t hesitate to do it.