Flow-through resistivity cell

Abstract

A resistivity cell formed integrally with or attached to the proximal end of a diagnostic catheter, allowing blood resistivity to be more easily and accurately measured. The cell comprises generally cylindrical body having an internal longitudinal bore of a known cross-sectional area and extending through the wall of the body are first and second pairs of longitudinally aligned electrodes. By joining a syringe to the proximal end of the assembly, a known volume of blood can be drawn into the cell. By applying an alternating current driving signal across the two outer electrodes and measuring the resistance between the two center electrodes, the blood's resistivity can be measured using the equation .rho.=AR/1. By connecting the cell directly to the vascular catheter, the need to maintain the blood sample at body temperature is alleviated.

Dependencies are inferred from the claim text.