Automated whole slide imaging for conventional optical microscopes

Abstract

Optical microscopes are used to observe magnified views of specimens that are infinitesimal to be directly observed by the human eye. They are commonly used in histopathology, where urgent reports are often crucial in decision-making. However, dependance on microscope technicians has several identified drawbacks, such as, the field of view being only available to the technician and continuous observation of slides inducing human errors. Furthermore, prolonged use of microscopes can lead to severe eye injuries. To address these issues, Whole Slide Imaging (WSI) microscopes, capable of automatically digitizing slides, are available in the market with a high price tag. However, these systems do not provide the user with the ability to change lenses and it is well known that some users have specific brand preferences in microscope lenses and systems. As a solution, this paper presents a method to enhance the functionality of a conventional optical microscope into a WSI microscope by motorizing the navigator and the fine-tune knob. An eyepiece camera is used to obtain photographs synchronously at predefined positions. The obtained images are then registered and stitched to generate a WSI, directly comparable with the output from the microscope. These images have various applications, such as, teaching, collaborative decision making and computer-aided-diagnostics.