Particle imaging systems and methods using acoustic radiation pressure

A method of acoustically focusing particles in a plane, comprising:

• transiting a fluid containing particles therein through a channel at a flow rate;
• adjusting the flow rate for a desired transit time through an interrogation zone through which a light from an excitation source passes;
• optically exciting the particles with the excitation source;
• detecting an optical signal from the particles;
• and
• analyzing the optical signal.

An acoustic flow cytometer capable of measuring axial light loss, comprising:

• a channel having an inlet for accepting a fluid sample stream of analytes;
• an acoustic signal producing transducer coupled to the channel wherein the acoustic signal producing transducer produces an acoustic signal to the channel to induce within the channel acoustic radiation pressure to concentrate the analytes within the fluid sample stream;
• optical equipment for analyzing the analytes wherein the optical equipment comprises a light source or sources with one or more wavelengths for analyzing the analytes when the analytes pass through the one or more wavelengths;
• and
• at least one linear array detector configured to increase signal by spatial isolation of axial light loss to detect absorbance from the analytes to determine characteristics of the analytes.