Using mixed-fidelity to create effective environments

Abstract User testing is crucial for ensuring that systems meet user expectations, involving both low- and high-fidelity prototypes. Recently, mixed-fidelity prototypes, which blend various levels of detail, have gained popularity but are mainly used for evaluating single digital prototypes. Typically, medical devices are tested only after engineering is complete, using high-fidelity prototypes in realistic environments. This paper explores when different fidelity levels can be applied and which levels are suitable for creating realistic use environments in medical technology evaluations. We used the PRETAR framework to determine the appropriate fidelity for each artefact based on study constraints, resources, ethical considerations, and data analysis methods. Using a case study of a sensorised glove for vaginal examinations, we developed artefacts with varying levels of fidelity to replicate the fetal head and birth canal to test whether mixed-fidelity prototypes can replicate clinical environments effectively while being cost- and time-efficient and critically examine each design suggestion, discussing the benefits and limitations of our decisions.