Few glassblowers literally do their work under a microscope, a technique necessary for the level of detail required in medical glassblowing.
"A lot of the glassblowing skills that go into scientific apparatus are applied in the medical industry," says Gary T. Farlow of Farlow's Scientific Glassblowing, a small company in Grass Valley, Calif., that makes glass molds for medical devices such as angioplasty balloons. The company also has a booming business making anatomically correct models of organs such as the heart.
Researchers and doctors at universities and hospitals as well as catheter sales teams buy the glass hearts. "It's a sales tool as well as a teaching tool," Farlow says. "We have hearts that they can take into the hospitals to show how their catheters work." His company has also made glass hearts for court cases so that large medical companies being sued, for example, can show a jury how angioplasty works.
Over the past decade, "we changed from not knowing what a heart looked like to crafting anatomically correct arteries and veins," says Wade Martindale, a senior glassblower at Farlow's. Whereas scientific glassblowers work from apparatus drawings and consult with chemists and physicists, medical glassblowers work from cadaver castings and medical drawings and confer with cardiologists and neurologists.
Martindale estimates that he and his experienced apprentice make four full hearts and a few hundred sections of hearts per year. In addition, Farlow says, the company has fashioned "almost every part of the human body," from lungs and the inner ear to the gastrointestinal and reproductive systems to "a path going from the femoral artery in the leg, all the way up to the carotid artery in the neck, and to the arteries and veins of the brain."
The anatomic models are made from borosilicate glass tubing. Martindale tapers it to the proper size on a lathe. "Then I take all that and go to the bench and form everything by hand." He uses torches and other tools to coax the glass into the desired shape.
A few other shops make organs, too, Farlow adds, so his glassblowers are always striving to be more complete than the competition.