Browsing by Author "Majors, Catherine E."
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Item Clinical training and validation of the LeukoScope: a low-cost, point-of-care device to perform white blood cell and neutrophil counts(Royal Society of Chemistry, 2019) Majors, Catherine E.; Pawlowski, Michal E.; Burke, Daniel C.; Tkaczyk, Tomasz S.; Rieber, Alyssa; Richards-Kortum, RebeccaA white blood cell (WBC) count with partial differential is an important clinical laboratory test. However, current methods to perform a WBC count and differential are difficult to use at the point of care or too expensive for use in low-resource settings. To meet this need, we developed the LeukoScope: a low-cost system to measure a WBC and neutrophil count from a single drop of blood at the point of care. The LeukoScope is battery powered and has a sample-to-answer time of <5 minutes. A drop of blood from a finger stick is added to a LeukoScope sample cartridge where pre-dried acridine orange fluorescently stains WBCs. The cartridge is then inserted into the LeukoScope reader where a portable fluorescence microscope captures a color image of the sample, which is analyzed to report results to the user. The LeukoScope system was tested at the point of care using fingerprick samples collected from 105 general oncology patients in Houston, TX. Performance of the LeukoScope was compared to that of a HemoCue WBC DIFF performed using the same fingerprick sample; clinical laboratory analysis of a venous blood draw was used as the gold standard in all cases. Bland–Altman analysis showed that the LeukoScope and HemoCue WBC DIFF had similar accuracy for measurement of WBC and neutrophil counts as compared to the gold standard. Seven out of eight patients with abnormal WBC count values were correctly identified using the LeukoScope, while six out of eight were correctly identified using the HemoCue WBC DIFF. Five out of six patients with abnormal neutrophil counts were correctly identified using the LeukoScope, while six of six were correctly identified using the HemoCue WBC DIFF.Item Development of a universal, tunable, miniature fluorescence microscope for use at the point of care(The Optical Society, 2018) Wong, Cynthia; Pawlowski, Michal E.; Forcucci, Alessandra; Majors, Catherine E.; Richards-Kortum, Rebecca; Tkaczyk, Tomasz S.Fluorescence microscopy can be a powerful tool for cell-based diagnostic assays; however, imaging can be time consuming and labor intensive to perform. Tunable systems give the ability to electronically focus at user selected depths inside an object volume and may simplify the opto-mechanical design of the imaging system. We present a prototype of a universal, tunable, miniature fluorescence microscope built from poly(methyl methacrylate) singlets that incorporates miniature, electrowetted lenses for electronic focusing. We demonstrate the ability of this system to perform clinically relevant differential white blood cell counts using single use custom cartridges pre-loaded with the fluorescent dye acridine orange.