New Optical Microscope Could Replace Blood Tests
Posted on May 21, 2012
A new device developed by a team of researchers in Israel can reveal similar information as a traditional blood test in real-time, simply by shining a light through the skin. The device provides high-resolution images of blood coursing through our veins.
The developers say the new microscope might help spotlight warning signs, like high white blood cell count, before a patient develops severe medical problems. They also say it could enable doctors in rural areas without easy access to medical labs to screen large populations for common blood disorders.
Lior Golan, a graduate student in the biomedical engineering department at the Israel Institute of Technology (Technion) and one of the authors of the paper, says, "We have invented a new optical microscope that can see individual blood cells as they flow inside our body."
Using the new microscope, the researchers imaged the blood flowing through a vessel in the lower lip of a volunteer. They successfully measured the average diameter of the red and white blood cells and also calculated the percent volume of the different cell types. The device relies on a technique called spectrally encoded confocal microscopy (SECM), which creates images by splitting a light beam into its constituent colors. The colors are spread out in a line from red to violet. To scan blood cells in motion, a probe is pressed against the skin of a patient and the rainbow-like line of light is directed across a blood vessel near the surface of the skin. As blood cells cross the line they scatter light, which is collected and analyzed. The color of the scattered light carries spatial information, and computer programs interpret the signal over time to create 2-D images of the blood cells.
Golan says, "An important feature of the technique is its reliance on reflected light from the flowing cells to form their images, thus avoiding the use of fluorescent dyes that could be toxic. Since the blood cells are in constant motion, their appearance is distinctively different from the static tissue surrounding them."
The device is currently the size of a small shoebox, but the researchers hope to have a thumb-size prototype ready within the next year. The device was reported in a research paper published here in the Optical Society's (OSA) open-access journal Biomedical Optics Express.