How to optimise the use of innovative invasive devices: considerations for feasibility studies.

Innovation in medical devices is essential for advancing patient care but has been undermined by inadequate evaluation and regulation. The UK vaginal mesh scandal exposed systemic flaws in medical device evaluation, where insufficient pre-market testing and ineffective post-market surveillance caused harm to countless women. Unlike pharmaceutical products, medical devices often enter clinical practice without robust evidence or long-term safety data. However, evaluation of devices can present methodological challenges, particularly when they are used during invasive procedures, given their multifaceted nature and contextual variables. Using the ASSIST study and the OdonAssist™ inflatable device for assisted vaginal birth as a case study, we wish to highlight these challenges and present a model for conducting feasibility studies of complex interventions. Early feasibility studies of the OdonAssist device demonstrated that although women accepted the innovation, the success rate of assisted vaginal birth was lower than anticipated. An embedded qualitative evaluation provided critical insights, revealing key factors influencing device use, design, and operator technique. The use of qualitative case study methodology allowed for systematic observation, stakeholder feedback, and iterative device refinement. For example, issues such as accidental activation of the deflation button were identified, leading to real-time design modifications in conjunction with industry partners. Stakeholder engagement-including patients, clinicians (doctors and midwives), ethics committees, and industry partners-was integral to optimising study design, device functionality, and training programmes. This collaborative, data-driven approach expedited the identification of modifications to device use, necessitating design changes and thereby ensuring device safety and usability. The evaluation of innovative devices like the OdonAssist requires a holistic approach that incorporates qualitative methodologies, stakeholder collaboration, and iterative feedback. Embedding case study research within feasibility trials ensures rapid identification of challenges, supports timely modifications, and fosters safer device implementation. Future research should explore video-recorded observations and enhanced patient feedback to refine device technique and training further.