Laser-Assisted Self-Monitoring of Blood Glucose: Analytical Performance, Clinical Accuracy, and Usability of the HandyRay-Glu System

Background/Objectives: Diabetes mellitus is a major global health burden, and inadequate glycemic control increases the risk of microvascular and macrovascular complications. Self-monitoring of blood glucose (SMBG) is essential for diabetes management, but conventional finger-prick sampling may reduce adherence due to pain and repeated skin injury. This study evaluated the analytical performance, clinical accuracy, and usability of a novel laser-assisted blood glucose monitoring system, HandyRay-Glu. Methods: A prospective clinical evaluation study was conducted in accordance with ISO 15197:2013. Capillary blood glucose values obtained using the HandyRay-Glu system were compared with reference measurements generated by the cobas c111 analyzer. Analytical performance was assessed by evaluating repeatability, linearity, hematocrit effect, and interference. Clinical performance was assessed according to ISO 15197:2013 system accuracy criteria, and method comparison was performed using Passing–Bablok regression and Bland–Altman analyses. Usability was evaluated using a structured participant questionnaire. Results: A total of 100 adult participants with diabetes mellitus were included. Overall, 97.8% of results met the ISO 15197:2013 accuracy criteria. Passing–Bablok regression showed strong agreement between HandyRay-Glu and the reference method (y = 1.694 + 0.9859x, r = 0.992). Bland–Altman analysis demonstrated a mean bias of −1.763 mg/dL, with 95% limits of agreement ranging from −29.333 to 25.808 mg/dL. Analytical evaluations showed acceptable repeatability, linearity across the tested measurement range, and no clinically significant interference. More than 97% of participants reported satisfaction with device usability. Conclusions: The HandyRay-Glu system met the performance requirements of ISO 15197:2013 and demonstrated high analytical accuracy, acceptable agreement with the reference method, and favorable usability. Laser-assisted blood sampling combined with electrochemical glucose measurement may offer a potential alternative to conventional SMBG systems, and its possible role in improving patient acceptance of regular monitoring warrants further investigation.