| 摘要 |
PURPOSE:To arbitrarily set the lower limit value of the size of bubble to be detected by providing the blood circuit of an artificial dialyser for the side of feedback to a patient and correcting a sensitivity error to occur by the change of the flow rate of a fluid to be measured. CONSTITUTION:The transmission frequency of a clock pulse generator 509 is changed by a control signal to be given from a signal processing part 508 based on the setting by a flow rate sensitivity setting device 506. The foam detector is adjusted so that detection sensitivity can be flat regardless of the change of a blood flow rate by heightening the frequency and increasing the detection sensitivity when the flow rate is large and lowering the frequency and decreasing the detection sensitivity when the flow rate is small. The lower limit value of the bubble to be detected is set by a bubble detection sensitivity setting device 507. Delay time t2 of a delay circuit 510 is changed by the control signal to be given from the signal processor 508 based on the setting by bubble detection sensitivity setting device 507. While the lower limit value of the bubble to be detected becomes larger when the delay time is set longer, the lower limit value becomes smaller when the delay time is set shorter, and up to a small bubble can be detected. |
