公开(公告)号：JPS6420469A

公开(公告)日：1989-01-24

申请号：JP10984588

申请日：1988-05-02

Applicant: ABBOTT LAB

Inventor： JIYON PASUTOROONE ,  MAIKERU ROORESU ,  JIYOOJI EICHI FUERINGAMU

IPC: A61B8/06 ,  A61M5/36 ,  G01N29/032 ,  G01N29/036 ,  G01N29/22 ,  G01N29/24 ,  G01N29/28 ,  G01N29/34 ,  G01N29/46 ,  G01S15/88

Abstract: PURPOSE: To detect if the air is mixed in an intravenous injection feeding tube by providing an ultrasonic transmitter and an ultrasonic receiver on both sides of a flow passage. CONSTITUTION: A cassette pump 10 forms a flow passage 40 by interposing an elastic member 16 between a front plate 12 and a rear plate 14. An injection is supplied to a patient from an injection source through a flowing-in port 18, the flow passage 40, and a flowing-out port. The passage 40 is bent in semicircular states in air detecting means 22 and 24 which are held in ultrasonic detectors 26 and 28 respectively having ultrasonic transmitters 54 and receivers 56 provided with piezoelectric chips 72 on substrates 58. The quantities of ultrasonic waves propagated to the receivers 56 from the transmitters 54 decrease when air exists in the flow passage 40. When the signal from the receiver 56 drops, an alarm device is actuated to stop the supply of the injection.

公开(公告)号：JPS6428526A

公开(公告)日：1989-01-31

申请号：JP10984688

申请日：1988-05-02

Applicant: ABBOTT LAB

Inventor： JIYOOJI EICHI FUERINGAMU ,  MAIKERU ROORESU

IPC: A61B5/0215 ,  A61M5/168 ,  G01L7/00

Abstract: PURPOSE: To accurately measure the pressure in a disposable pump cassette by monitoring the bending operation of a flexible supporting member supporting a shaft member which moves in accordance with the pressure. CONSTITUTION: The diaphragm 32 of a pump cassette 22 expands or contracts in accordance with the pressure fluctuation of a fluid 20 and two separated flexible guide pieces 14 and a shaft 12 supported by a beam 16 move in the axial direction. The beam 16 is bent and a strain gauge 18 fitted to the beam 16 generates the output signal corresponding to the pressure in the cassette 22. When the output of the gauge 18 is measured through a Wheatstone bridge and a differential amplifier, the pressure in the cassette 22 can be measured accurately.