Closed channel flowmeter esp for blood in arteries

摘要

A hollow needle containing a catheter is inserted into the channel and an auxiliary fluid is injected through the catheter, whilst a sample of the resulting mixture is extracted through the needle. Measuring points are provided for the aux. fluid temp. the mixture temp. and the channel fluid femp-. The end of the catheter (5) is sealed and one or more openings (7) are provided in its wall. This opening is downstream of the end of the needle (3). The first meas. point is in the catheter, the second (11) is downstream of the end of the catheter, and the third (13) is on the outside of the catheter between the end of the needle and the end of the catheter.