Structural behaviour of the dilation mechanism in a novel speculum-free cervical cancer screening device: A finite element analysis-based study

Cervical cancer prevention relies on vaccination, screening and treatment. While cytology and human papillomavirus (HPV) DNA testing are widely used in high-income settings, low-resource contexts commonly rely on visual inspection with acetic acid. However, high cost, subjective interpretation, and patient discomfort associated with speculum-based inspection limit uptake. This study investigates the structural behaviour of a dilation mechanism within a novel speculum-free cervical cancer screening device designed for improved accessibility and comfort. From a mechanical perspective, characterising stress, deformation, and failure is essential to optimise the material, geometry, and actuation of the cup to withstand contact and manipulation while meeting safety standards. Using finite-element analysis and iterative prototype design, we quantify stress, deformation, actuation force and collapse behaviour under simplified loading conditions to identify key geometric and material features that improve structural stability and reduce actuation effort. Iterative design enhancements introduced a staged collapse sequence, radial reinforcement rings, and optimised pull pin placement to streamline the cup’s collapsed shape and improve insertion ease while maintaining structural stability. The results demonstrated significant advancements in key performance metrics. Actuation forces were reduced to below 6 N to ensure usability, while the collapsing factor was increased, resulting in a more compact insertion profile. Radial strength was optimised through reinforcement rings and geometric adjustments, enabling the dilation cup to resist deformation at higher pressures without compromising its collapse functionality. Experimental validation demonstrated the effectiveness of incremental design modifications, such as tuning pull-pin angles and reinforcement placement, in balancing structural rigidity. Despite limitations such as boundary condition assumptions and lack of cadaveric studies, the study provides an engineering basis for subsequent bench, tissue-phantom and clinical validation.