In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The method may include placing the sample on the sample-holder of a phase-contrast microscope, establishing a connection between the processor of the mobile terminal and a controller of the microscope, disposing a mobile terminal on a support so that its digital image sensor is positioned in front of an ocular, launching a counting program so that the processor performs successive counting sequences on distinct analysis areas of the sample, wherein between two counting sequences the processor controls a two-axis motorized system to displace the sample, and wherein for each counting sequence the processor implements the following steps of: setting the focus, capturing a main image, and analyzing the main image in order to count the number of fibers.