A fractionated photoacoustic flow cytometry (PAFC) system and methods for the in vivo detection of target objects in biofluidic systems (e.g., blood, lymph, urine, or cerebrospinal fluid) of a living organism is described. The fractionated system includes a fractionated laser system, a fractionated optical system, a fractionated acoustic system, and combinations thereof. The fractionated laser system includes at least one laser or laser array for pulsing a target object within the circulatory vessel with fractionated focused laser beams. The fractionated optical system separates one or several laser beams into multiple beams in a spatial configuration on the skin above the circulatory vessel of the living organism. The fractionated acoustic system includes multiple focused ultrasound transducers for receiving photoacoustic signals emitted by the target object in response to the fractionated laser beams.
1. A fractionated photoacoustic flow cytometry and theranostics system for in vivo detection, therapy, and monitoring of responses to the therapy for at least one target object in a biofluid system of a living organism, comprising: a laser system comprising more than one picosecond pulsed laser operable to provide more than one time-color encoded pulse of laser energy; a fractionated optical system configured to separate each laser beam into a plurality of laser beam fragments having a spatial configuration on the skin above the biofluid system of the living organism; at least one focused ultrasound transducer; a recording system operable for recording a combination of photoacoustic signals received by the at least one focused ultrasound transducer and emitted by the at least one target object in response to the more than one pulse of laser energy; and a triggering system operable to control the more than one pulsed lasers, synchronization of laser pulses from the more than one pulsed lasers with at least one time delay, and the recording system.