| 摘要 |
PURPOSE:To eliminate the misjudgment of the presence or absence of a transfusion liquid so that the reliability of the a transfusion liquid detection device is enhanced by detecting the variation of a propagation ratio of an ultrasonic wave with an ultrasonic wave detection means and detecting the variation of an inner pressure of a transfusion tube with an inner pressure change detecting means, thereby detecting the presence or absence of the transfusion liquid. CONSTITUTION:The transfusion liquid detection device 1 is fitted and loaded to the outer section of an arbitrary position of a transfusion tube A in a pressure-contact condition via a insertion hole 3 and a penetration hole 11. An ultrasonic wave transmitted from a transmission section 7 is propagated via the tube A itself and a liquid flowing in the tube A to be received by a receiving section 8. A pressure conversion element 9 is in contact with the circumferential portion of the tube A and the inner pressure of the tube A is measured by means of the pressure conversion element 9. When the liquid does not flow adequately in the tube A and bubbles are generated therein, the propagated ultrasonic wave is attenuated so that the receiving magnitude of the ultrasonic wave at the receiving section 8 is lowered. The receiving section 8 detects whether or not the receiving magnitude dropps more than a prescribed value so that it judges the presence or absence of the transfusion liquid and it confirms the detection inner pressure value of the tube A detected by the pressure conversion element 9 so that it judges again the presence or absence of the transfusion liquid. |
