PROBLEM TO BE SOLVED: To quickly and accurately detect a change in the aggregation state of erythrocyte.SOLUTION: The erythrocyte monitor includes: an impedance measuring section 3 for measuring an impedance Z between two electrodes 2and 2when an AC voltage V(f) having a frequency fis applied between the electrodes 2and 2provided in the periphery of an artery blood transmission vessel 1 of an artificial heart a contact resistance specifying section 4 for specifying contact resistance Ron the interface of erythrocyte from the impedance Z between the electrodes 2and 2measured by the impedance measuring section 3 and an electric double layer capacity specifying section 5 for specifying electric double layer capacity Con the interface of the erythrocyte by the use of the contact resistance Rspecified by the contact resistance specifying section 4.
