Abstract: Disclosed is an instrument for measuring living body components, which has (i) a fine tube having at one end thereof a connection portion to be connected to an indwelling needle or indwelling catheter and an infusion portion, from which at least a blood anticoagulant solution can be infused, (ii) a fine linear sensor for measuring living body components, extended from the inferior of the fine tube to the outside through the connection portion, and (iii) a mechanism for introducing blood at least into the interior of a fine tube portion of the indwelling needle or catheter intermittently or periodically when the indwelling needle or catheter is connected to the fine tube and kept in the blood vessel and then discharging blood into the blood vessel. A sensing portion of the sensor is located within the fine tube portion of the indwelling needle or catheter when the indwelling needle or catheter is connected to the connection portion of the fine tube.

Abstract: A method and apparatus for measuring a gas partial pressure in a living body on the basis of the principle of polarography. A gas partial pressure sensor includes a biomedical electrode inserted in the living body. A temperature sensor is further provided to measure a temperature of the living body. A polarographic current value measured by the gas partial pressure sensor is corrected to a current value at a reference temperature depending on the temperature measured by the temperature sensor. Then the gas partial pressure at the reference temperature is determined based on a working curve which represents a relationship between the corrected polarographic current value and the gas partial pressure at the reference temperature.

Abstract: Disclosed is a metal electrode for a living body, which comprises a noble metal wire an an insulating covering layer formed around the periphery of the noble metal wire. At least a part of the portion of the insulating covering layer falling in contact with the noble metal wire is composed of a crosslinked epoxy resin. The outermost layer of the insulating covering layer is composed of a polyurethane. Either or both of a part of the tip end and side face of the metal electrode is directly covered with a polyurethane porous membrane instead of the insulating covering layer.

Abstract: An electrode for living bodies consisting of a fine metal wire at least part of the surface of which is directly coated with a porous membrane having fine pores of an average pore diameter of greater than 0.01 .mu.m. The electrode makes it possible to measure the oxygen concentration in the blood vessels and in the living tissues with increased stability and improved response characteristics. Particularly good results are obtained when the porous membrane is a non-homogeneous structure using a cellulose acetate.