NMU senior Jessica Compton, a speech pathology major, remembers trips to the grocery store with her mother, Virginia. After walking systematically through the aisles of produce and packaged goods, they would push their laden cart to the checkout lane. Then, out came the checkbook.

Phil Watts leaned forward, adjusting the mask over the child's face. He ran one last check over the straps and stood back, examining his handiwork. "Oh yeah, Darth Vader, very cool," he said, laughing. But this isn't a costume: it's a metabolic analyzer, a mask which collects the air breathed out.