VIVARIA: a desktop hand-tracked virtual laboratory for 3Rs-aligned animal procedure simulation

Abstract This study investigated the feasibility and usability of a desktop-based virtual environment using markerless hand tracking to support early-stage procedural familiarization with laboratory animal facility procedures. The simulator, developed in Unity, utilized Ultraleap markerless hand-tracking sensor. The system implemented a modular task/step/condition architecture and automatically logged objective interaction metrics, including completion time, errors, rewinds, and grasp attempts. Twenty-six participants performed three simulated procedures (mouse cage transfer, jaw blood collection, and intraperitoneal injection). Performance logs were analyzed together with post-session questionnaire responses assessing usability and perceived educational value. Completion times differed substantially across procedures. The mouse cage transfer task was completed rapidly (27.99±15.05 s), whereas the jaw blood collection task required significantly longer execution times (124.72±76.09 s) than the intraperitoneal injection task (86.16±40.35 s; $$W=52.0$$ , $$p=0.001$$ ). Critical errors were concentrated in the precision-demanding procedures, with 19 errors recorded in the jaw blood collection task and 10 in the intraperitoneal injection task, while no errors occurred during cage transfer. Step-level analysis further highlighted the difficulty of the jaw blood sampling phase, which showed a success rate of 46.15%, compared with 76.92% for the injection step and near-perfect success for preparatory steps. The results suggest that desktop-based virtual laboratories using markerless hand tracking can provide a viable preparatory environment for laboratory animal science training. Precision-sensitive interactions remained challenging, but the system highlighted differences in interaction difficulty within the desktop markerless hand-tracked environment and enabled detailed analysis of interaction behavior. Educational efficacy, transfer to live-animal procedures, and direct 3Rs reduction outcomes remain to be verified through controlled learning trials, although such platforms may offer a viable preparatory environment for workflow orientation before users interact with live animals