invasive, e.g. introduced into the body by a catheter

Measuring for diagnostic purposes; Identification of persons > Measuring characteristics of blood , e.g. gas concentration or pH-value > using chemical or electrochemical methods, e.g. by polarographic means > invasive, e.g. introduced into the body by a catheter

Measuring for diagnostic purposes (radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00); Identification of persons > Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value (non-radiation detecting or locating of foreign bodies in blood A61B5/06) > using chemical or electrochemical methods, e.g. by polarographic means > invasive, e.g. introduced into the body by a catheter