ORLANDO, FLA. — Richard Wallin, the chief executive officer at a testing company, Namsa, painted an exotic vision of tomorrow's medical implants during a speech at Antec 2000. But Wallin also detailed rigorous testing procedures that go into new "biocompatible" products, from simple tongue depressors and artificial joints to futuristic devices like an implanted camera to restore sight to a blind person.
Although medical items perform very special functions, many use industrial grades of plastic.
"They're materials that have not been made, for the most part, for the medical device industry, but they've been borrowed from the automotive industry, from commercial products of all kind," Wallin said in his May 8 speech.
Namsa is based in Northwood, Ohio. The company is a nonclinical testing laboratory that specializes in checking medical devices.
Wallin detailed how Namsa tests for substances that leach out of a device when it comes into contact with the body, known as "extractables."
Wallin gave the example of a clamp for a newborn's umbilical cord. First, laboratory technicians break the clamp into small pieces. The parts are put into a container with extraction fluid and held under carefully controlled conditions. The technicians study the fluid to measure the extractables.
The extracted material can be grown in cells in an incubator, or injected into mice.
Wallin said popular concern over biocompatibility was launched in the 1960s when a stabilizer, organic tin, leached out of PVC endotracheal catheters, which are used to administer anesthetic gases. Some patients developed painful lesions in the trachea, or windpipe.
"It turns out that organic tins are very corrosive when placed into contact with body tissue," he said.