Holographic microscope diagnoses disease


Rebecca Pool

Thursday, November 2, 2017 - 14:15
Image: Prototype device examines blood samples for diseases [Peter Morenus/UConn Photo]
A portable holographic field microscope developed by US-based optical engineers can quickly identify diseased cells and other biological specimens.
The device uses the latest in digital camera sensor technology, advanced optical engineering, computational algorithms, and statistical analysis to provide rapid automated identification of diseased cells.
What's more, the algorithms used with the instrument can quickly compare a sample against the known features of healthy cells and diseased cells to make an accurate identification. 
"Our optical instrument cuts down the time it takes to process [data] from days to minutes," says Professor Bahram Javidi, from the Department of Electrical and Computer Engineering at the University of Connecticut. "And people running the tests don't have to be experts, because the algorithms will determine if a result is positive or negative."
During blood smear analysis, the sample is exposed to a monochromatic light beam generated by a laser diode or other light source.
The light beam is split into two beams in order to generate a digital hologram of the red blood cells in the sample.
An image sensor connected to the 3D microscope records the hologram.
Quantitative phase profiles of healthy red blood cells (top row) and malaria infected cells (bottom row). [Bahram Javidi]
As Javidi highlights, the holograms capture unique micro and nanoscale structural features of individual cells with great detail and clarity.
Algorithms then reconstruct a 3D profile of the cell and measure the interaction of light with the cell under inspection, with diseased cells being identified using computer pattern recognition software and statistical analysis.
According to the researchers, a key potential field application for the microscope is helping medical workers identify patients with malaria in remote areas of Africa and Asia where the disease is endemic.
However, the detailed holograms generated by the instrument could also be used in hospitals and other clinical settings for rapid analysis of cell morphology and cell physiology associated with cancer, hepatitis, HIV, sickle cell disease, heart disease, and other illnesses.
"Light behaves differently when it passes through a healthy cell compared to when it passes through a diseased cell," highlights Javidi. "Today's advanced sensors can detect those subtle differences, and it is those nanoscale variations that we are able to measure with this microscope."
Research is published in Applied Optics.
Website developed by S8080 Digital Media