Microscopic augmented-reality indicators for long-term live cell time-lapsed imaging

Abstract

Microscopic observations of cultured cells in many lab-on-a-chip applications mostly utilize digital image acquisition using CCD sensors connected to a personal computer. The functionalities of this digital imaging can be enhanced by implementing computer-vision based augmented reality technologies. In this study, we present a new method for precisely relocating biological specimens under microscopic inspections by using augmented reality patterns, called microscopic augmented reality indicators (μ-ARIs). Since the method only requires sticky films attached under sample containers of any shape, long-term live cell observations can be conducted at much less extra cost than with conventional methods. On these sticky films, multiple arrays of position-indicating patterns were imprinted to provide a reference coordinate system for recording and relocating the accurate position and rotation of the specimen under inspection. This approach can be useful for obtaining the exact locations of individual cells inside biological samples using μ-ARI imprinted transparent films in a rapid and controlled manner.

Time‐lapse microscopy using smartphone with augmented reality markers

“…Five subjects—both of whom were skilled in operating an optical microscope and had knowledge of time‐lapse imaging—were chosen to participate in the test. Specifically, they were requested to perform the tasks as rapidly as possible, as the accuracy of restoring an ROI using the μ‐AR film had been verified in our previous work (Yun et al, ). For each of two different ROIs, 10 trials were performed, repeatedly.…”

“…It consists of a smartphone, an optical microscope, an adaptor for mounting the smartphone on a microscope, and a film printed with a μ‐AR marker array providing the position coordinates of ROIs. As described above, the method developed in our previous work (Yun et al, ) to position the ROI was adopted in order to maintain its advantages. A prototype was implemented as follows.…”

“…For saving and restoring ROIs, the method developed in our previous work (Yun et al, ) was used. The specific method is illustrated in Figure .…”

“…Method of positioning ROI using film printed with μ‐AR marker arrays (Yun et al, ). [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.…”

“…On the other hand, others have suggested engraving the roof of a microfluidic chamber so that the relative position of the stage to the chamber could be indexed (Hanson et al, ), which, unfortunately, had a rather low level of accuracy. Meanwhile, our previous research (Yun et al, ) was inspired by the effect of out‐focusing, and it involved the design of a solution in which a film printed with a microscopic augmented reality (μ‐AR) marker array was attached to the bottom of the specimen. By controlling the focal length at different levels, the specimen or an information indicator, the μ‐AR marker, emerged accordingly.…”