A variety of wearable magnetic assemblies are provided that are configured to produce magnetic fields having high field magnitudes and/or high field gradients. Such magnetic assemblies include a plurality of magnetic segments arranged in a linear array. Individual magnetic segments of the magnetic array can each include multiple magnetic elements. An individual magnetic segment can include elements that have similar shape, size, composition, and relative location to elements of neighboring magnetic segments while having magnetic moments that are antiparallel to the magnetic moments of corresponding elements of the neighboring magnetic segments. These wearable magnetic assemblies are configured to exert forces on magnetic particles disposed in a portion of subsurface vasculature to attract, slow, speed, separate, or otherwise influence the magnetic particles in various applications. The magnetic particles can be configured to bind to an analyte of interest.