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Particle Imaging In High Resolution

An interesting new paper produced by Lew Brown of Fluid Imaging Technology has shed some light on information about particle imaging. The paper discusses how the quality of the image can affect the ability of imaging particle analysers to produce accurate results in measuring particles, deciphering particles in a heterogenous mixture and also to recognise the particles in good time.

Based on the findings of two studies which were performed on the FlowCAM particle imaging and analysis system, interesting findings has shed new light on the effects of quality imaging. The studies focused on two sample groups, with the first holding images of lesser quality or in other words 'blurry'. The second group consisted of sharper images that were of better quality. Results showed that the ability to measure accurately on all three grounds were significantly less successful in time and accuracy with the first sample group.

The first study consisted of NIST traceable calibrated size beads (10µm ± .08µm) were used for images by two different flow cells to establish the differing quality of the two separate sample groups. Sharper images were measured to be at an average of  9.81 µm by mean Equivalent Spherical Diameter (ESD) .

This measurement puts the first sample group in a significantly better quality range than the second group which was measured to be on an average of 15.64 µm  to achieve a more blurry image. Where as, in the second experiment, Cosmarium algae samples were used to create an extensive range of images that were both of high and low quality. When put under analysis by the FlowCAM's automated pattern recognition feature, there were highly significant differences in the system's ability to recognise particles during a time length.

Findings shows that the better quality images were measured to have a concentration of 1,029 particles/ml where as only 197 particles/ml were recorded for the second sample group. Based on these findings, the paper suggests that relying on blurry images will lead to inaccurate measurements of particles while also resulting in false negatives and false positives.

Edited by: Terry Newman
Last Updated: 15th May 2011