Application of image analysis method to detection and counting of glass fibers from filter samples

Abstract

Man-made vitreous fibers (MMVFs) are noncrystalline substances made of glass, rock or slag and are widely used as thermal or acoustic insulation materials. There is continued concern about their potential health impacts and thus, their dosimetry and behavior in the environment still require study using filters to collect fiber samples. After deposition or exposure measurements of MMVFs it is often necessary to analyze the filters with deposited fibers. This task is tedious, time-consuming, and requires skill. Therefore, many researchers have tried to simplify or automatize fiber detection and quantification. This article describes features of our in-house software, which automatically detects and counts fibers in images of filter samples. The image analysis is based on the use of a histogram equalization and an adaptive radial convolution filter that enhances fiber contrast and thus, improves the fiber identification. The accuracy of the software analysis was verified by comparison with manual counting using ordinary phase-contrast microscopy method. The correlation between the methods was very high (coefficient of determination was 0.977). However, there were some discrepancies caused by false identifications, which led to implementation of manual corrective functions.

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“…The employed airway geometry see Fig. 2 b was provided by Koullapsis et al [ 29 ] and is originally used in [ 5 , 6 , 24 , 35 ]. Koullapsis et al [ 29 ] adopted this model to conduct in vitro and in silico measurement of the regional deposition ratios of di-2-ethyl hexyl sebacate (DEHS) particles.…”

Can CFD establish a connection to a milder COVID-19 disease in younger people? Aerosol deposition in lungs of different age groups based on Lagrangian particle tracking in turbulent flow

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Experimental methods for flow and aerosol measurements in human airways and their replicas

“…The rest of the fibres are then collected on output filters. The fibres deposited in the model are consequently either counted directly in situ using the microscope (Myojo, 1987(Myojo, , 1990, or washed out, filtrated, and counted on the filter (Belka et al, 2016).…”