Cell culture device, cell culture method, and recording medium

A cell culture device, comprising:

• an irradiator to emit ultrasonic waves toward a culture solution stored with cells in a culture vessel;
• and
• processing circuitry to
• detect the cells in the culture solution,
• acquire information indicating a settling state of the detected cells, and
• cause the irradiator to emit the ultrasonic waves when the cells are in the settling state based on the information indicating the settling state of the cells,
• wherein the information indicating the settling state of the cells includes a settling velocity calculated by dividing a settling distance determined from coordinates of a cell in two images captured at different times by an elapsed time between capture of the two images, and
• the processing circuitry compares the settling velocity to a threshold velocity and, when the settling velocity is higher than or equal to the threshold velocity, causes the irradiator to emit the ultrasonic waves.