Lab Rat: Undergrad Aids Research on Lung Function
- By Amanda Kenyon Waite
When Katie Accomando fires up the hair dryer, it's not a sign that she's readying herself for a new day or even a night out. The scene isn't the bathroom or a hair salon; it's a laboratory, where Accomando, an undergraduate student, is the expert operator of a complex piece of equipment designed to help measure the volume of the air in a mouse's lungs.
The device, a plethysmograph, is a prototype, so the blow dryer stands in as a heat source that warms the inside of the "body box" to approximate the conditions inside the lungs. Moisture is also a key component of lung climate, so plastic tubing carries water to add humidity within the chamber where the mouse is placed. Once inside, the mouse turns, sniffs, sits up and investigates while a camera takes pictures of its body as it breathes, sending the images for display on a monitor nearby. A program counts the changes in pixels in the black silhouette of the mouse's body as it expands and contracts, and the tidal volume -- the volume of air inhaled and exhaled at each breath -- is calculated.
Why does Accomando care about the air volume of a mouse's lungs?
She's assisting Jason Bates, research professor of medicine and molecular physiology and biophysics, who researches lung function and the quantitative evaluation of lung mechanics. "Mice are the main species that are used in biomedical research in all disease areas," Bates says, "including lung disease, which is our specialty here."
The plethysmograph in question was a joint creation by Bates and biomedical engineer John Thompson-Figueroa, begun nearly 10 years ago. "What we were trying to do here was to develop a method for studying lung function in mice under natural conditions, which means when they're awake and conscious and moving around," Bates says, pointing out that other methods require mice to be anesthetized and placed on their backs. While the latter scenario may provide more precise measurements, having a way to gauge breathing patterns under normal conditions is important to the research.
After Thompson-Figueroa had moved on from UVM, Bates was in need of an engineer to operate the prototype they had created. Enter Accomando, then a sophomore mechanical engineering major who wanted experience in a bio-engineering lab.
"I saw in Katie a bright, young student with engineering quantitative experience, which is exactly what I wanted," Bates says. He asked Accomando to familiarize herself with the equipment, which he admits as a medical researcher is beyond his own engineering abilities. "I put her onto that, and she became the local expert," Bates says, adding that Accomando has since helped other researchers in the Vermont Lung Center use the unrestrained video-assistent plethysmography system (UVAP) for their own research.
"There are certain things done in the lab that only someone with Katie's background can do," Bates explains. "This UVAP system was a classic example. It was built originally by a trained biomedical engineer, designed by me, and it takes an engineer to run it. So she's fit in very well."
Now a senior, Accomando has begun work on a new project, her thesis on ventilator-induced lung injury, for which Bates serves as adviser.
Three feet to the left of the plethysmograph is another piece of lab equipment Accomando is mastering: a micro-CT scanner. Using the scanner, Accomando takes a series of 2-D images around a mouse's body, which allow her to construct a high-resolution, 3-D image of the entire airway tree of its lungs.
"From this, we can sum up the amount of air trapped in the lungs and calculate the total lung volume more accurately than we can with the plethysmograph," she says. These calculations will help Accomando learn more about what happens to lungs when placed on mechanical ventilators, which can damage lungs with their artificial breathing patterns and lead to mortality in intensive care units.
"We need to have a better idea of how the resolutions of those images depend on scan time and mouse movement and so forth," Bates says. "Again, because Katie's an engineer and has a good understanding of quantitative methods, she's the perfect person to examine things like image resolution as a function of scan time, which is one thing we're interested in."
Though Accomando admits the work has been challenging, she has no regrets showing up in Bates' doorway over a year ago. She credits her engineering coursework for giving her the perseverance she needs when something goes wrong in the lab and she has to troubleshoot a problem with the plethysmograph, for example. On the other hand, the lab work has provided her with the hands-on opportunity to put equations and theories to work, a crucial step for any engineer, she says. "I've learned just about as much working in the lab," she says, "as I have in my classes."