On a Thursday afternoon in November, a pea-sized lymph node from a mastectomy patient is brought into the crowded office of Dr. Gerald Smith, laboratory medical director at Aurora Sinai Medical Center. While the patient remains in the operating room, Smith freezes, slices, stains and microscopically examines the tissue for cancer. His conclusion will help determine if more of the woman's breast tissue or lymph nodes are removed. The process takes about 20 minutes. Smtih's possible replacement for this procedure rests atop a table near his microscope—the FastPath Residual Cancer Probe. It's a cancer-detection device that inventor and physicist Bill Gregory, the chief science officer of NovaScan LLC, compares to a metal detector.