Patent ID: 8480869

Claim:
A measuring device for measuring a Hct value of a blood sample, comprising: a sensor; a holder accepting the sensor; a voltage source supplying a voltage to an electrode system of the sensor; and a detector for detecting an oxidation current or a reduction current flowing through the electrode system of the sensor, the sensor being a sensor for electrochemically measuring a hematocrit (Hct) value of blood, comprising: an insulating substrate; a cover disposed on the insulating substrate; a spacer between the insulating substrate and the cover, defining a channel for leading a blood sample; an electrode system having a working electrode and a counter electrode, both the working electrode and the counter electrode being partially exposed to the channel; and a redox substance layer provided on the counter electrode but not on the working electrode, wherein the part of the counter electrode exposed to the channel is entirely covered by the redox substance layer and no part of a working electrode is covered by the redox substance layer, the device further comprising a calculator that calculates the Hct value based on the value of the current detected by the detector, and a controller configured to direct the voltage source to supply the voltage to the electrode system of the sensor, and to communicate with the detector, wherein the controller and the electrode system are configured so that, to measure the Hct value, a voltage is applied to the electrode system with blood present at the electrode system to cause an oxidation current that does not depend on the redox substance or a reduction current that does not depend on the redox substance to flow between the electrodes, and a value of the oxidation current or the reduction current is detected.