Device and procedure for measuring the concentration of a substance in a complex liquid medium, for example blood.

摘要

The subject of the invention is a procedure and a device for measuring the concentration of a substance in a complex liquid medium flowing through a body, in particular blood flowing through the human body. This procedure, which consists in placing at least a fraction of the said complex liquid medium in the presence of a reference fluid, so as to obtain transfer by diffusion of a quantity of the said substance to the said reference fluid, and in analysing the said reference fluid in order to determine the concentration of the said substance in the said fluid, is characterised in that the said complex liquid medium is circulated through an extracorporeal flow pipe in which the said fraction of the said complex liquid medium is placed in the presence of the said reference fluid. The device comprises an extracorporeal pipe 1 for flow of the blood, a container 3 for containing at least a fraction of the blood, mounted on a branch pipe 2 looped onto the said flow pipe 1, optionally a pipe 4a for supplying a reference fluid to the said container 3, a means 5 for transfer by diffusion of the said substance to the said reference fluid, the said transfer means being contained in the said container 3, a means 6 for analysing the said reference fluid in order to determine the concentration of the said substance, and optionally a pipe 4b for draining the said reference fluid in which the substance has been concentrated.