Micro particle analyzer and micro particle analysis method

A microparticle analysis device comprising:

• a microchip defining a flow path in which a fluid includes a sample flow containing microparticles and a sheath flow to contain the sample flow;
• a vibration element configured to form a droplet in the fluid by imparting vibration to the fluid;
• an electrode configured to apply electric charge to a droplet containing the microparticles;
• an imaging unit configured to acquire a plurality of sequential images of the sample flow during a predetermined period;
• and
• a control unit configured to control a timing at which the droplet breaks off the sample flow on a basis of the plurality of sequential images of the sample flow, the control unit including a processor and a memory containing instructions that, when executed by the processor, are configured to:
• determine a phase of the predetermined period at which the droplet breaks off the sample flow based on the plurality of sequential images;
• determine a break-off position of the droplet in an image of the plurality of sequential images at the determined phase of the predetermined period at which the droplet breaks off the sample flow;
• and
• adjust a voltage of the vibration element based on the determined break-off position of the droplet.