Abstract: A system and method for automated analysis of a filter obtained from an air quality monitoring apparatus used for sampling airborne respirable particles such as asbestos fibres, synthetic mineral fibres, pollen or mould particles is described. The system comprises capturing images at a plurality of sample locations. At least one magnified phase contrast image is obtained at each sample location. An automated quality assessment is then performed using a computer vision method to assess one or more quality criteria. Failure may lead to the sample location being ignored for subsequent analysis, or the whole filter slide may be rejected if the overall quality is poor. The quality assessment may performed be in two stages comprising an overall filter quality assessment performed on a series of low power/magnification images captured over the filter and a field of view or graticule level quality assessment performed on high power/magnification images captured at individual sample locations on the filter.

Abstract: A system and method for automated analysis of a membrane filter obtained from an air quality monitoring apparatus used for sampling airborne respirable fibres such as asbestos and synthetic mineral fibres is described. The system comprises capturing a macroscale image a membrane filter and analysing macroscale image using a computer vision method to determine a countable area of the membrane filter and one or more excluded regions within the countable area of the membrane filter. These excluded regions comprise membrane filter grid lines, air bubbles and large particulate matter. The slide is then placed on a robotic XY stage of a digital phase contrast microscope which is used to capture at least one magnified phase contrast image at each of 20 or more sample locations located across the filter member. The sample locations are selected such that a field of view at each sample location does not contain an excluded region.

Abstract: A system and method for automated analysis of a filter obtained from an air quality monitoring apparatus used for sampling airborne respirable particles such as asbestos fibres, synthetic mineral fibres, pollen or mould particles is described. The system comprises capturing images at a plurality of sample locations. At least one magnified phase contrast image is obtained at each sample location. An automated quality assessment is then performed using a computer vision method to assess one or more quality criteria. Failure may lead to the sample location being ignored for subsequent analysis, or the whole filter slide may be rejected if the overall quality is poor. The quality assessment may performed be in two stages comprising an overall filter quality assessment performed on a series of low power/magnification images captured over the filter and a field of view or graticule level quality assessment performed on high power/magnification images captured at individual sample locations on the filter.

Abstract: A system and method for automated analysis of a membrane filter obtained from an air quality monitoring apparatus used for sampling airborne respirable fibres such as asbestos and synthetic mineral fibres is described. The system comprises capturing a macroscale image a membrane filter and analysing macroscale image using a computer vision method to determine a countable area of the membrane filter and one or more excluded regions within the countable area of the membrane filter. These excluded regions comprise membrane filter grid lines, air bubbles and large particulate matter. The slide is then placed on a robotic XY stage of a digital phase contrast microscope which is used to capture at least one magnified phase contrast image at each of 20 or more sample locations located across the filter member. The sample locations are selected such that a field of view at each sample location does not contain an excluded region.