Many people who would have died from common ailments a few decades back are alive today thanks to advances in medical technology, including devices created by researchers in laboratories. But getting from a design sketch to an actual approved product can take years.
His coworkers are lathes and drills rather than doctors, nurses and medical technicians, but Juan Fernandez is a highly regarded collaborator at Houston Methodist Hospital.
He made this valve for operating room technicians who wanted a better way to monitor oxygen flow.
"The oxygen goes in and out this way and the sensor will tell how much oxygen is going to the patient," said Fernandez.
These kind of innovations are sometimes so successful, the companies manufacturing the equipment sometimes incorporate them into new designs.
Biomedical engineer Matthew Jackson worked with Fernandez to develop parts for this cardiovascular simulator.
"The payoff of having the machine shop here is that you can create unique solutions to problems in a simple way, where you are just removing and adding material to create something," said Jackson.
Juan Fernandez, who has worked worked more than 25 years here in Houston's Texas Medical Center, says that experience pays off when someone shows him a sketch for a part they want made.
"On paper you can make anything, but once you try to make it into a part, it is hard," he said.
Fernandez produced many of the parts for this cardiovascular simulator.
It uses a plastic reproduction of a patient's aorta to test blood flow.
Matthew Jackson says he needed a device made of plastic, rather than metal, because it has to be inserted into the highly magnetic ring of an MRI machine.
"This is something Juan created for us and it helped with a lot of the initial work we were doing on this project. You sandwich that valve between the two, the left side acts as the ventricle and this side acts as the atrium and you can put this in the MRI magnet because it is all made out of plastic," he said.
Some of the earliest advances in treating heart disease were made here in Houston by Dr. Michael DeBakey, who, in 1991, called on Juan Fernandez to make the prototype for a ventricular assist device.
For Fernandez this was personal. He was just 10-years-old when his father died in front of him.
"He started snoring and I thought he was playing with me and I called my mom and they called the paramedics, but he was gone. The doctor said it was a heart attack," said Fernandez.
The researchers who design new devices gain prestige and money from patents, and the doctors who use them gain status in the medical community.
Juan Fernandez shuns attention and prefers to work alone.
"I know deep down that I helped mankind and that is all that matters to me," he said.
Juan Fernandez is now 65 and could retire. But he continues to work and and do his part for medical science.