Says Gourley, "People didn't believe we could pump cells through a microlaser, make the cells part of the lasing process, and produce meaningful results. As it's turned out, we can do all these things."
The device works by incorporating blood cells into the lasing process, rather than shining a laser light like a spotlight upon the cell. A vertical microlaser beam enters individual cells as they are pushed by a micropump through tiny channels cut into the glass surface of the device. Because cancerous cells contain more protein than normal cells, their additional density changes (by refraction) the speed of the laser light passing through them. This change is registered as a difference in output frequency by a receiver and transmitted by optical fiber to a laptop computer a few feet from the instrument. An algorithm translates the data into a graph that, changing moment by moment, provides surgeons with easily read peaks and valleys that clearly depict when blood pumped from the incision has been cleared of cancerous cells.
In a surgical scalpel, an aspirator would vacuum fluid from the incision to the microcavity laser enclosed in the scalpel's handle. Information would be transmitted from the scalpel to the computer by optical fiber.
Far quicker results
The microcavity laser is far quicker to produce results than flow cell cytometers - the standard instrument used to determine the presence of cancer cells obtained from an incision. Flow cell cytometers require cells to be stained with a dye in order to examine them. This lengthy process may take hours to alter the cells, and is of little immediate help to the patient, who has already been sewn back together.