By Kathryn Doyle
Science journalist and freelance writer covering technology and medicine.
The technology redefines the phrase “broadly applicable”: it’s been used for architecture, industrial design, automotive and aerospace engineering, the military, civil engineering, fashion, and food.
In medicine, it has had most success with prosthetics, dental work, and hearing aids, which can all be made from plastic or pliable materials and often need to be tailored to a specific patient. But scientists have also worked out, at least in theory, how to print blood vessels, skin, even embryonic stem cells.
“The biggest advantage is that everything is customizable,” said Markus Fromherz, Xerox’s chief innovation officer in healthcare.
There are three categories of healthcare where 3-D printing could be applied, or is already, Fromherz said: for body parts or prosthetics (sometimes called “scaffolding”), medical devices, and human tissues.
Printing technology has already revolutionized joint replacements, Fromherz said. “Knee replacement is a very common procedure, there are six or so different types of knees that doctors use,” he said, adding, “with each one you need to cut the bone differently.”
But with 3-D printing, doctors aren’t limited to those six knees. They can design one specific to each patient.
Patients with custom knees don’t have to lose extra inches of bone, instead the surgeon can cut at the optimal point, which could lead to faster recovery times and better functionality.
Strong, flexible new knee joints mimicking bone and cartilage can now be printed with nylon. These surgeries are available at top-tier medical facilities like the Mayo Clinic.
2. Medical devices
Most hearing aids are already 3-D printed, since these have always been customized to the user, and scanning, modeling, and printing saves time over casting a handmade mold of the inner ear. What used to take a week now takes less than a day.
Similarly, making crowns and dental implants–once a two week process–can happen while the patient reads a magazine in the waiting room.
“Printing medical devices is maybe of lesser value as far as a hospital is concerned,” Fromherz said.
Hospitals buy medical devices in bulk and 3-D printing their own devices, which don’t often need customization, doesn’t offer much advantage.
Printing may be best for when doctors need to create a new device on demand for rare, unpredictable conditions. In May 2013, doctors at University of Michigan Health System printed a customized splint for a newborn with a collapsing trachea, which saved the boy’s life.
3. Human tissues
Scientists have printed artificial meat tissue suitable for eating, but making tissues and organs that maintain life has been much harder. So far, printed bits of functional liver tissue in Petri dishes could be viable for testing drugs, and larger models have been useful for surgeons to practice technique.
“Printing functional human tissue will be a game changer, but it’s far out,” Fromherz said.
What the future holds
Fromherz thinks the next step is to build in electronics. Artificial knees could include sensors to measure the pressure and health of the knee, connected wirelessly to an app or provider software.
If you’re printing a device, body part, or tissue from scratch, it won’t be much more difficult to build electronics into the design, Fromherz said. Every printed device or tissue could double as a source of data.
But 3-D printing isn’t foolproof, and there are regulatory and use-case questions yet to be answered, he said.
“With a regular printer, everyone can create a document,” he said. “Not everybody will be skilled or knowledgeable enough to create a knee.”
Not a useful one, anyway. And it still takes at least 30 minutes to print anything. The technology may one day be most useful at military field hospitals or at the scene of an accident, where immediately creating splints, body parts or devices could save lives, but it’s not quick enough yet to be implemented.
“There will be 3-D printers, I’m sure, in every home and hospital in the future,” Fromherz said. “But right now the tech isn’t fast enough.”