Described embodiments include a system, method, and computer program product. A receiver circuit receives ultrasound echoes from ultrasound-differentiable micro-objects implanted in a vertebrate subject in accordance with an implantable media format (hereafter “implanted micro-objects”). A format decoding circuit identifies the respective implantation region of the implantable media format occupied by each implanted micro-object based on their respective echoes. A micro-object recognition circuit recognizes each implanted micro-object based upon a machine recognizable feature in the respective echoes. A micro-object decoder circuit respectively decodes each recognized micro-object of the two implanted micro-objects into a unit of information pursuant to the identified implantation region of the recognized micro-object and a conversion table. An aggregator circuit collects the decoded units of information into a decoded information set. A computer storage media saves the decoded information set.
