Faculty Profile: Cristina Davis

Associate Professor, Mechanical and Aerospace Engineering

By Derrick Bang/Photo by Kevin Tong

Cristina Davis doesn't think small. An associate professor in the UC Davis Department of Mechanical and Aerospace Engineering, Davis hopes her current research will completely revolutionize the monitoring and treatment options for those who suffer from a malady quite common to Northern California residents: asthma.

"I like working on cutting-edge projects that have large impacts," she admitted.

Her ambition has been noticed and rewarded. The prestigious The Hartwell Foundation recently honored Davis with an Individual Biomedical Research Award, to help her develop — to quote from her research prospectus — a "safe and effective, non-invasive diagnostic health monitoring sensor for children with asthma, to improve their daily quality of life."

And while UC Davis is favorably located within this geographical "hot spot" for adult and pediatric asthma, Davis was also drawn to the university for other reasons. "UC Davis is a perfect match for me," she said. "It has a vibrant bio-medical and biological sciences community. Being an engineer on this campus gives you a lot of great investigators to work with, thanks to the breadth of available talent."

Although this specific project is new, Davis brings a wealth of experience to her efforts. "I've always worked on sensors and instrumentation," she acknowledged.

After graduating with degrees in mathematics and biology from Duke University, she obtained a Ph.D. in biomedical engineering at the University of Virginia, in 1999. She then did a postdoctoral fellowship in electrical engineering and physiology at The John Hopkins University, after which she was involved with several start-up companies and worked in industry for slightly more than half a decade. She then returned to academics and came to UC Davis.

The Hartwell Foundation Award is furthering her goal to design new instrumentation for chemical diagnostic systems, with the desired outcome of improved medical care. "We're doing two things simultaneously," Davis explained. "First, we're building an instrumentation and sensor platform. Second, we're confirming and pursuing breath biomarker validation studies in pediatric asthma patients, which hasn't been done before."

This technical description obscures the simplicity of the anticipated end product: a hand-held sensor, no more intimidating than the inhalers becoming more ubiquitous among young asthma patients, which they'll use in a similar fashion. "Children will be able to self-monitor their own asthma during the course of, say, a school day, and accumulate data that, in turn, will help their doctors fine-tune their inhaler regimens," Davis explained. "This will help determine whether their current drugs are doing an efficient job on a day-to-day basis."

And it'll be as simple as breathing into this sensor.

"We'll look at two fractions of exhaled breath," Davis continued, "the condensate that can be formed by condensing the aerosolized, liquid-containing fraction of breath; and the volatile compounds that are exhaled in the gas phase. We'll have dual-analysis pathways in our device that will examine both fractions, and identify bio-markers of significance, to determine whether someone has poorly controlled asthma."

Asthma is an excellent target, and not just because of a pressing desire to help children suffering from shortness of breath. "Asthma is one of the most common starting points for looking at breath diagnostics," Davis explained, "because it is an extremely common pulmonary disorder."

And while this particular project couldn't be more cutting-edge — Davis envisions such sensor/monitors being part of, for example, a cell phone, and therefore theoretically able to instantly transmit the recorded data to a doctor's office — a comparable, if simpler, device already is in widespread use. We hear about it all the time, and hope never to face one: the breathalyzers used to detect alcohol consumption during roadside traffic stops.

"An alcohol breathalyzer looks at a single compound, and whether it exceeds a specific threshold," Davis clarified. "In our case, we'll look at multiple markers simultaneously. Conceptually, though, a breathalyzer is quite similar."

Davis acknowledges that her proposal is aggressive, and that the time frame seems short. But she's not worried.

"In the three months since this started, we've already made terrific progress. We've begun designing the micro-scale sampling and analysis device, and have an excellent first-generation prototype for pieces of it."

Davis anticipates completing clinical trials of the new device within three to five years. "I expect we'll then have a functioning prototype that will have been designed, from the outset, to be transitioned into industry for potential commercialization."

Nor will that necessarily conclude her involvement. "I like to see things to fruition," she admitted, "so once we get to that point, I hope to continue working closely with industry collaborators."

Many researchers would be content with one such project, but Davis is equally involved with a different sort of crisis: the disastrous threat to the world citrus crop, brought to these shores with the "citrus greening" catastrophe that threatens to demolish Florida's fruit industry. This funded project is sponsored by the California Citrus Research Board and the Florida Research Council.

"We've been building mobile chemical sensors that can be taken out into the field, to monitor off-gas metabolites from citrus trees," Davis explained. "The goal is to determine whether they're infected with specific pathogens such as HLB (huanglongbing, "citrus greening") or CTV (citrus tristeza virus). We're now in year three of a project to define the biomarkers of significance related to those diseases, and to tailor our mobile chemical sensor instrumentation to monitor for those biomarkers." The next step: working with industry to make the commercial development of such sensors financially practical.

As with her asthma project, Davis is well positioned to make a positive impact on a contemporary real-world problem.

When meeting folks at a dinner party, Davis will introduce herself as a professor in the UC Davis Department of Mechanical and Aerospace Engineering. If pressed, she might explain that her job involves "measuring small amounts of stuff in complex environments ... which is hard, but achievable if you have good sensors and good informatics."

And then, after a well-timed comedian's beat, she'll add, "It's not as glamorous as it sounds."

Perhaps not. But the potential implications of her work cannot be overstated to parents who've been awakened, late at night, by the ghastly sound of their child struggling for air.