Systems and methods are described for obtaining and acting upon information indicative of circulatory health and related phenomena in human beings or other subjects. Some involve implementing or deploying therapeutic administration systems, for example, for obtaining a priori implant information and signaling a decision whether to initiate implant-site-targeting treatment; or obtaining a flow-change-indicative measurement and signaling a decision whether to administer a clot-reducing agent; or obtaining an indication of a lytic material in a vicinity of a body lumen and accelerating a decrease in a local concentration of the lytic material to extract at least a portion of the lytic material in response to the indication; or a capture component configured to accelerate a decrease in a local concentration of a therapeutic structure along a downstream portion of a vasculature and a dispensation component configured to release the therapeutic structure into an upstream portion of the vasculature.