[An impedance measuring technique for blood flow qualitative recording]

An impedance measuring technique was developed for blood flow qualitative recordings in laboratory animals. Basically, it consists in the administration of an indicator solution (0,1 ml, NaCl 20%) which, mixing with the blood, provokes a decrease in its electrical resistance, in such way that the passage of this mixture (concentrated saline/blood) through a bipolar receptor electrode, resistively balanced by the electrical impedance of blood alone, will be detected as a sudden resistance fall. The results so far show that it is an adequate technique for blood flow qualitative studies, since, despite its simplicity, provides consistent and unequivocal recordings which, performed simultaneously with those of other circulatory events, may become a helpful tool for their understanding.