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Introduction: Interventional radiology is a medical specialty used to diagnose and treat diseases. Computed tomography (CT) is often used for image-guided interventions, but it exposes practitioners to ionizing radiation and has limited image contrast. Interventional magnetic resonance imaging (iMRI) offers a radiation-free alternative with excellent soft tissue contrast and real-time needle guidance. Hence, safe patient access during IMRI procedures and comfortable positioning for the physician is paramount to provide care. This study evaluates the feasibility of digital human modelling (DHM) simulations to prospectively assess reach-in bore capabilities and the physical demands in iMRI-guided needle procedures.

Methods: Simulations were completed using Santos Pro (DHM) with 5^th, 50^th, and 95^th percentile stature avatars. A commercially available, 70 cm bore MRI system’s geometry was imported into the simulation and its volume was filled with obstacle avoidance constraints to reflect the spatial constraints that interventionalists consider when performing iMRI techniques. To simulate needle-based iMRI, a reach to the iso-centre of the MRI bore was required; therefore, avatars were directed to reach to three iso-centre horizontal distances (near, middle, far) while their feet were constrained to the floor plane. Reach capabilities and balance stability metrics were extracted for comparison and to assess feasibility to obtain meaningful insights from the DHM approach.

Results: In under a day, iMRI tasks reaches were effectively simulated for three uniquely statured avatars. Each avatar (by stature percentile) behaved uniquely based on their stature-based constraints resulting in simulated iMRI performance that reflects real-world behaviours. All avatars except the 5th percentile female could achieve the required postures. The balance stability outcome metrics also showed lower stability for the far side reaches for all avatars when compared to middle and near reach locations, an expected biological phenomenon that supports the feasibility of using DHM to generate meaningful insights.

Discussion: DHMs proved effective in rapidly understanding and informing design to optimize iMRI task performance. The results highlighted ergonomic challenges associated with reaching into the imaging volume of an MRI for real-time needle guidance, particularly for smaller-stature practitioners. Given the balance instability observed at far reaches, repositioning to the opposite side of the MRI may be a more ergonomic approach for interventions on the far side of the patient. Now that DHM feasibility has been established, it can inform how design parameters like bore diameter and length can be optimized for both patient care and practitioner ergonomics. Further validation against ground truth data is needed, but this study highlights the prospective benefits of DHM to rapidly inform innovations in iMRI procedures.

Conclusion: The DHM enabled us to quickly simulate how three different statured avatars would behave to perform iMRI needle ablation activities. Building on these base models, we can now rapidly iterate through different design variables to optimize the ergonomics associated with iMRI procedures.