Devices and methods for fractionated photoacoustic flow cytometry

A fractionated photoacoustic flow cytometry system for the in vivo detection of at least one target object in a biofluid system of a living organism, comprising:

• a fractionated laser system comprising an array of more than one laser for providing more than one focused dash and/or dot laser beam, each comprising a plurality of beam fragments separated by gaps;
• an optical system configured to deliver the more than one focused dash and/or dot laser beams in a spatial configuration on the skin above a cross-section of the biofluid system of the living organism;
• and
• an acoustic system comprising an array of focused ultrasound transducers forming non-overlapped acoustic focal volumes together covering the whole cross-section of the biofluid system, the focused ultrasound transducers being operable for receiving a photoacoustic signal emitted by the at least one target object in response to the beam fragments.

A fractionated photoacoustic flow cytometry method for detecting circulating target objects in a biofluid system of a living organism in vivo, the method comprising:

• providing a laser beam from a laser in a laser system at a first wavelength;
• separating the laser beam into a fractionated dashed and/or dot laser beam in a fractionated optical system to form a plurality of beam fragments separated by gaps having a spatial configuration on the skin above a cross-section of the biofluid system of the living organism;
• obtaining, in a fractionated acoustic system comprising an array of focused ultrasound transducers forming non-overlapped acoustic focal volumes together covering the whole cross-section of the biofluid system, more than one photoacoustic signal emitted by the circulating target objects induced by the fractionated dashed and/or dot laser beam;
• and
• analyzing the photoacoustic signals to calculate a combination of photoacoustic signals emitted by the circulating target objects, wherein the combination of photoacoustic signals is characteristic of each circulating target object.