A pilot cohort study of a microfluidic-based point-of-care bilirubin measurement system
Objective The concentration of bilirubin in blood or serum is useful for assessing liver function as well as monitoring treatment. This study evaluates the clinical performance of a novel point-of-care (PoC) device for the detection of bilirubin in serum. The PoC device incorporates an integrated miniature optoelectronic sensing module and a microfluidic test cartridge. Methods Patients' serum total bilirubin concentrations, ranging from 2 {\mu}mol/L to 480 {\mu}mol/L, were measured using the PoC device and the standard laboratory method (n=20). Bland-Altman analysis and regression analysis using Passing-Bablok method were used to benchmark the PoC device against the standard laboratory measurements. The diagnostic capability of the PoC device in categorising the serum samples within clinically relevant bilirubin concentration thresholds of 200, 300, and 450 {\mu}mol/L was assessed using receiver operating characteristic (ROC) analysis. Results The mean difference between the PoC device and the standard laboratory method was -5.6 {\mu}mol/L, with a 95% confidence interval (CI) of -45.1 {\mu}mol/L to 33.9 {\mu}mol/L. The coefficient of determination (R2) was 0.986. The PoC device achieved a detection sensitivity of 90% and specificity of 97% in categorising bilirubin concentrations within bands used in clinical decision-making. Conclusions This study demonstrates that the proposed PoC device is capable of measuring bilirubin levels in patient samples with clinically acceptable accuracy.