Lens-free microscope enables full-colour pathology at low cost

Researchers in Canada have developed a new kind of microscope that can produce large, full-colour images of tissue and fluid samples, but which costs in the range of hundreds of dollars, potentially making it accessible to a very wide range of facilities. Known as a spectral light-fusion microscope, the device has no lens but uses artificial intelligence and mathematical models of light to construct an image.

The discipline of pathology requires accurate coloured images so that clinicians can observe interactions between organisms and tissues. Currently, the best way to produce large 3D images is to electronically "stitch" together multiple images from conventional microscopes, which used lens-based optics to obtain their images. This is a job for skilled technicians, and requires machines that cost in the hundreds of thousands of dollars range.

The spectral fusion microscope, developed by two researchers at the University of Waterloo in Ontario, Canada uses a completely different method to capture its images. Alexander Wong, who holds the Canada Research Chair in Medical Imaging at Waterloo and who led the research alongside systems design engineer Farnoud Kazemzadeh, said: “In medicine, we know that pathology is the gold standard in helping to analyse and diagnose patients, but that standard is difficult to come by in areas that can’t afford it. This technology has the potential to make pathology labs more affordable for communities who currently don’t have access to conventional equipment.”

Wong and Kazemzadeh developed the first-generation version of the microscope last year, using a technique similar to holography where the sample is illuminated by laser light at different wavelengths and the way that the light interacts with the sample is recorded, as they described in a paper in Nature Scientific Reports.

In the second generation of the technology, which they claim has five times the resolution of the earlier version the microscope captures "light fields" that can be analysed using mathematical models of light and AI to construct 3D images that are around 100 times larger than the 2D images captured by traditional microscopes.

"Currently, the technology required to operate a pathology lab is quite expensive and is largely restricted to places such as Europe and North America, which can afford them,’ said Kazemzadeh. “It would be interesting to see what a more affordable, mobile pathology lab could achieve.”