Seismic Vulnerability of Transportable Medical Equipment in Hospitals and the Need for Automated Safety Controls: A PRISMA-Based Systematic Review

Earthquakes can disrupt hospital functionality through damage to nonstructural components, yet the seismic behavior of transportable, caster-supported medical equipment has received little dedicated attention. This systematic review, reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement, synthesized evidence on the seismic response of wheeled, non-anchored medical equipment and on related mitigation strategies. PubMed, Scopus, Web of Science, EBSCO, PsycINFO and Google Scholar were searched for English-language studies published from January 1990 to December 2025, supplemented by backward and forward citation searching. Eligible studies were peer-reviewed experimental or numerical investigations reporting the seismic response of wheeled medical or hospital equipment. Methodological quality was appraised with a nine-item checklist adapted for experimental and numerical earthquake-engineering studies, and the findings were synthesized narratively and in structured tables following the Synthesis Without Meta-analysis (SWiM) guideline, because study designs and outcome metrics were too heterogeneous for meta-analysis. Of 789 records, six studies conducted in Japan, China, Canada, New Zealand and Chile were included. Fully locked casters consistently suppressed translational motion but increased acceleration amplification, rocking and overturning, whereas controlled sliding dissipated energy at the cost of larger displacements. A base-width-to-center-of-gravity-height ratio of at least 0.4 markedly reduced overturning, and diagonal partial-lock or switching-lock configurations offered the most favorable balance between displacement and stability. The evidence is limited by the small number of studies and heterogeneous seismic inputs. Static wheel locking alone is therefore an incomplete safeguard, and equipment-specific, adaptive stabilization strategies should be incorporated into hospital seismic preparedness.