Patent ID: 9097244
Filing Date: 2015-08-04
Classification: A61B,F04B

Abstract:
1. A fluid feeding pump which varies a volume of a pump chamber and thus feeds a fluid out of the pump chamber, the fluid feeding pump comprising: a piezoelectric element which accumulates electric charges inside when a voltage is applied, and which deforms according to an amount of accumulated electric charges and thus increases or decreases the volume of the pump chamber; a drive unit which applies a drive signal with a waveform increasing to a predetermined maximum voltage and then decreasing, and thus drives the piezoelectric element; and an air bubble determining unit which detects a current flowing through the piezoelectric element within a predetermined period after the drive signal is applied to the piezoelectric element, and thus determines whether there is an air bubble in the pump chamber or not, wherein the air bubble determining unit determines that there is an air bubble in the pump chamber when the detected current is smaller than a threshold.