| 摘要 |
<p>PURPOSE:To accurately measure a flow rate with good reproducibility by providing thermometric parts for measuring the temp. of a fluid at least at two places and calculating the flow rate of the fluid on the basis of the low measured temp. among the measured temps. by the thermometric parts. CONSTITUTION:Two sensors 8a, 8b for measuring a blood flow rate are provided to a catheter 22 in an axially symmetric state in the cross-section of the catheter main body 13. The measured temp. data of the thermometric parts 21a, 21b by the respective sensors 8a, 8b are converted to electric signals by a bridge circuit 23 to be compared with each other by a comparator 28. At this time, since the value of the low measured temp. among the measured temps. by the sensors 8a, 8b corresponds to the temp. of blood, the measured temps. are compared with each other by the comparator 28 and only the signal corresponding to the lower temp. is inputted to an amplifying circuit 24 to be used in the calculation of a blood flow rate. Since the blood flow rate can be measured by a heat dilution method always using lower temp. data even when the catheter 22 is present in a blood vessel 6 in any state, the flow rate can be measured without generating a measuring error and the reproducibility of measurement is good.</p> |
