Non-invasive measurement of physiological parameters or substance concentrations in human tissue

An apparatus for determining a concentration of an analyte in a sample, the apparatus comprising:

• at least three emitters having a first wavelength characteristic, each emitter being an optical emitter;
• at least three emitters having a second wavelength characteristic, each emitter being an optical emitter;
• and
• at least three detectors,
• wherein the at least three emitters of the first wavelength characteristic, the at least three emitters of the second wavelength characteristic, and the at least three detectors are distributed on a two-dimensional surface,
• wherein next to each of the at least three emitters of the first wavelength characteristic, one of the at least three emitters of the second wavelength characteristic is arranged so that the respective emitters are not separated by non-transparent material,
• wherein the at least three emitters of the first wavelength characteristic, the at least three emitters of the second wavelength characteristic, and the at least three detectors form a plurality of emitter-detector pairs in such a way that groups of similar emitter-detector pairs are formed, wherein similar emitter-detector pairs are defined as having approximately the same emitter-detector distance and approximately the same wavelength characteristic,
• wherein an emitter-detector distance of an emitter-detector pair is defined as a distance between the emitter and the detector in the emitter-detector pair.

An apparatus for determining a concentration of an analyte in a sample, the apparatus comprising:

• at least three emitters having at least three different wavelength characteristics, each emitter being an optical emitter;
• and
• at least three detectors,
• wherein the at least three emitters and the at least three detectors are distributed on a two-dimensional surface.

A method for determining a concentration of a substance in tissue of a living human or a parameter which is derived from concentrations of substances in a living human, the method comprising:

• sequentially emitting, by at least three emitters, light into a sample that is part of the living human;
• detecting, by at least three semiconductor light detectors, a portion of the emitted light after the emitted light has passed through the sample in such a way that the emitted light interacts with the sample and changes direction within the sample so that the emitted light exits the sample on the same side of the sample but in a different location;
• measuring light intensities by the at least three semiconductor light detectors during activation of a first of the at least three emitters;
• measuring light intensities by the at least three semiconductor light detectors during activation of a second of the at least three emitters;
• measuring light intensities by the at least three semiconductor light detectors during activation of a third of the at least three emitters;
• and
• deriving information from the measured light intensities,
• wherein similar emitter-detector pairs are defined as having approximately the same emitter-detector distance and approximately the same wavelength characteristics,
• wherein there is a plurality of groups of similar emitter-detector pairs such that different groups of similar emitter-detector pairs have different wavelength characteristics or different emitter-detector distances,
• wherein there are at least three groups with different wavelength characteristics from one another,
• wherein for each of the at least three wavelength characteristics there is at least a first group of similar emitter-detector pairs and a second group of similar emitter-detector pairs such that the emitter-detector distance of the first group is different from the emitter-detector distance of the second group,
• wherein an emitter-detector distance of an emitter-detector pair is defined as a distance between the emitter and the detector in the emitter-detector pair.