| 摘要 |
PROBLEM TO BE SOLVED: To make miniaturizable a measuring device while making the most of a characteristic of a pump by measuring pressure in a chamber by introducing a pressurized fluid into the chamber in a piezoelectric diaphragm pump on the basis of displacement of a diaphragm. SOLUTION: The piezoelectric diaphragm pump 1 used for a blood pressure measuring device is formed of, for example, a piezoelectric material, and has a diaphragm having electrodes on both surfaces. When driving the pump 1, a driving power source 2 is connected to the diaphragm being a piezoelectric element by a relay r1, and valves SV1 to SV4 are put in a prescribed opening/ closing state so that air is sent into a tank 4. When measuring pressure, for example, relays r1, r2 are switched, the pump 1 is stopped, the diaphragm is connected to a signal processing circuit 3, and the vales SV1 to SV4 are actuated so that the air in the tank 4 is sent into a chamber in the pump 1 to thereby measure pressure, for example, by voltage generated by a piezoelectric effect of the diaphragm. |
