Current cell monitoring methods use something called flow cytometry, which passes cells through a laser processing system to study their properties. It's pretty fast, studying thousands of individual cells a second, but it doesn't provide an image of the particles. Instead, their voltages and other properties are analyzed. This new system can be used to pick out individual anomalies, allowing doctors or software to detect rare cell types or possible metastatic cancer cells. In lab tests, the system detected budding yeast and rare breast cancer cells in blood with a record-low false positive rate of one in a million.