Handheld microscope diagnoses skin cancer

David L. Shenkenberg, david.shenkenberg@laurin.com

Tissue changes in appearance before full-blown cancer develops. If doctors notice odd-looking tissue, they will remove it so that pathologists can examine it under the microscope. What if researchers could use an optical tool instead of removing tissue from patients’ bodies?

That’s the idea behind a skin cancer detecting microscope developed at Montana State University by Chris Arrasmith, who began the project as an undergraduate and now has a master’s degree in electrical engineering from the university. Along with his adviser, David Dickensheets, Arrasmith has been working with doctors at Vanderbilt University in Nashville, Tenn., to make this microscope a reality.

Chris Arrasmith developed this handheld laser at Montana State University.

The microscope can be held in a doctor’s hands. It contains a tiny silicon mirror based on microelectromechanical systems (MEMS) technology. The laser is an 830-nm external cavity diode, and the sensor is an avalanche photodiode.

The mirror directs the laser beam such that it scans across the skin. The light reflected back into the handheld confocal microscope is analyzed by Raman spectroscopy. The confocal Raman image is built point by point.

Although confocal Raman has been done before, it has been carried out using much larger desktop-size instruments that require tissue to be removed from patients. “The uniqueness of our probe is the combination of confocal microscopy and Raman spectroscopy into a handheld,” Arrasmith said. “This allows Raman spectra to be obtained with resolution on the cellular level.” He expects that the second-generation device will be even smaller, perhaps the size of a chalkboard eraser.

Now that he has graduated, Arrasmith is looking for a job. “I am hoping to find employment by the end of June or so,” he said.