First Laboratory Evaluation of FUS-3000 Plus: A New-Generation Urine Analyzer.

Background: Urine sediment analysis is a cornerstone of diagnostic testing. This study evaluates FUS-3000 Plus, an automated urine sediment analyzer using advanced imaging and artificial intelligence, to assess its technical performance and diagnostic accuracy for routine clinical use.

Methods: The study analyzed 98 urine samples for chemical parameters (pH, protein, blood, leukocyte esterase, and nitrite) and 76 samples for particle analysis (red blood cells [RBCs], white blood cells, epithelial cells, crystals, bacteria) by both FUS-3000 Plus and sediMAX™, the current laboratory analyzer in use. Additionally, 139 samples were tested for glucosuria and proteinuria, with results compared to the Cobas C702. Carry-over, precision, and linearity were assessed by internal quality controls in accordance with Clinical and Laboratory Standards Institute protocols. Accuracy was further evaluated using external quality controls.

Results: FUS-3000 Plus demonstrated strong agreement with sediMAX for nitrites, protein, and leukocyte esterase (kappa values >0.5) and correlated well with the Cobas C702 for glucosuria and proteinuria. However, discrepancies were observed in glucosuria detection, with some samples yielding inaccurate results even during external quality control assessments. A carry-over effect for RBCs required a rinse step after highly concentrated samples.Precision was acceptable (CV: 3%-11%), and Bland-Altman plots showed strong agreement for formed elements (correlation >0.95). However, the analyzer had reduced accuracy in bacteriuria detection.

Conclusion: FUS-3000 Plus is a reliable tool for routine urinalysis, excelling in particle classification. However, improvements are needed in bacteriuria detection and minimizing carry-over effects. Future research should explore its ability to identify additional cellular elements and its diagnostic utility in diverse clinical populations.