Abstract: The invention relates to a device for measuring the concentration of an analyte in the blood or tissue of a an animal or a human, particularly a premature infant, wherein for measuring said concentration the device comprises a means (30) comprising at least a first and a second permeability with respect to said analyte, wherein the first permeability for said analyte differs from the second permeability for the analyte. Further, the invention relates to a corresponding method.

Abstract: The present invention relates to an apparatus (10) apparatus for the detection of carbon dioxide. It is described to place (210) a part of a housing in contact with a skin area of a patient. the part of the housing and a gas measuring chamber within the housing are configured such that gases diffusing through the skin area of the patient enter the gas measuring chamber. radiation is emitted (220) from a radiation source within the housing, wherein at least some of the radiation emitted by the radiation source enters the gas measuring chamber. The radiation entering the gas measuring chamber has wavelengths that extend over an absorption band of carbon dioxide and has wavelengths that extend over a region other than the absorption band of carbon dioxide. A radiation filter is positioned (230) relative to the gas measuring chamber such that an interaction radiation path is defined between the radiation source through the gas measuring chamber to the radiation filter.

Abstract: The invention relates to a device for measuring the concentration of an analyte in the blood or tissue of a an animal or a human, particularly a premature infant, wherein for measuring said concentration the device comprises a means (30) comprising at least a first and a second permeability with respect to said analyte, wherein the first permeability for said analyte differs from the second permeability for the analyte. Further, the invention relates to a corresponding method.