The present invention relates to a system for the physical manipulation of free magnetic rotors in a circulatory system using a remotely placed magnetic field-generating stator. In one aspect, the invention relates to the control of magnetic particles in a fluid medium using permanent magnet-based or electromagnetic field-generating stator sources. Such a system can be useful for increasing the diffusion of therapeutic agents in a fluid medium, such as a human circulatory system, which can result in substantial clearance of fluid obstructions, such as vascular occlusions, in a circulatory system resulting in increased blood flow. Examples of vascular occlusions targeted by the system include, but are not limited to, atherosclerotic plaques, including fibrous caps, fatty buildup, coronary occlusions, arterial stenosis, restenosis, vein thrombi, arterial thrombi, cerebral thrombi, embolisms, hemorrhages, other blood clots, and very small vessels.