Hud Staffield had brutally crippling asthma.
"Felt like I had an anvil on my chest," said Staffield.
Eight-year-old Gillian Coan's symptoms were harder to spot, according to her mom.
"We noticed she was slowing down in daily activities," said Gillian Coan's mom.
But both were diagnosed with a new technology that allowed doctors to give them the precise dosage of steroids to control their attacks.
The machine, developed by a Menlo Park company called Apieron, measures minute particles of gas in the patients breath, known as ENO -- or exhaled nitric oxide.
"It gives us a window into the bronchial tubes without having to stick a bronchoscope into the lungs," said Asthma specialist Dr. James Wolfe.
Dr. Wolfe says nitric oxide passes from the blood supply into the bronchial tubes, when the tissue is inflamed. And being able to measure its concentration gives doctors a far more accurate reading on the severity of the inflammation than older methods that simply calculated the volume of a patient's breath.
"It's a marker of how many cells and how much inflammation is in the lungs" said Dr. Wolfe. "This test tells us about the degree of inflammation. It tells us does the patient have asthma, if they have asthma is controlled, do they more medication, less medication, more steroid more steroids."
The technology was the brainchild of Bhairavi Parikh, who came up with the concept as a graduate student at Harvard and whose husband and son have both suffered from asthma.
She says the key is a small cartridge, imbedded with protein molecules that change color when they come in contact with the gas.
"You can't see it by the eye, but our machine actually measures the color change and correlates it to a concentration of nitric oxide," said Parikh.
From there, there is the severity of inflammation. In the case of Hud Staffield, the more precise readings allowed doctors to trim back the dosage of the powerful steroids that were giving him nausea.
But for Gillian, it told doctors that while her symptoms were mild, the problem wasn't.
"Measure the ENO levels and they're sky high. And even though she has minimally reduced symptoms she has tremendous inflammation in the airways, so we treated her fairly aggressively," said Dr. Wolfe.
And with the early intervention, Gillian and her family say her symptoms are now completely under control.
"I feel a lot better," said Gillian Coan.
Nitric oxide technology may also have an application as an early warning device. Dr. Wolfe says ENO levels often rise in the days preceding a bad asthma attack. Eventually, patients may be able to monitor their own levels at home, and adjust their medications accordingly.