Prototyping and usability assessment of additively manufactured hands-free stethoscope holders for manual blood pressure measurement

Abstract This study aimed to design, develop, and evaluate prototype hands-free stethoscope chest piece holders to facilitate manual blood pressure (BP) measurement by freeing one of the operator’s hands. The objective was to assess whether these prototypes could maintain measurement accuracy while improving usability and ergonomics. An iterative design process was employed, guided by Quality Function Deployment (QFD) to identify user requirements. Two prototype devices were fabricated using Material Extrusion (MEX) Additive Manufacturing (AM) with polylactic acid (PLA) material. The prototypes were tested with 19 examinees and 11 operators. BP measurements obtained using the prototypes were compared to the standard auscultatory method. Statistical analysis (ANOVA) was performed to assess accuracy, and user feedback was collected through questionnaires and qualitative analysis. Both prototypes demonstrated comparable accuracy to the standard auscultatory method, with ANOVA showing no statistically significant differences in systolic or diastolic BP measurements. User feedback indicated positive perceptions of comfort and usability, though improvements in adjustability, cushioning, and ease of use were recommended. Almost all participants recognised the potential advantages of the devices for clinical and educational applications.