Device and method for determining a concentration in a sample

A device for noninvasively measuring a physiological parameter of a living human or a parameter of the blood of a living human, the device comprising:

• a plurality of transparent surface areas configured to be brought into contact with human skin, the plurality of transparent surface areas made of material that is at least partially transparent to photons;
• a plurality of less transparent surface areas made of material that is less transparent to photons than the material of the plurality of transparent surface areas, the plurality of transparent surface areas separated from each other by the plurality of less transparent surface areas;
• at least a first emitter, a second emitter, and a third emitter that are each configured to emit light towards the human skin, the emitted light including a first wavelength,
• at least a first light detector, a second light detector, and a third light detector that are each configured to detect a portion of the light that is emitted by at least one of the first emitter, the second emitter, or the third emitter and that has interacted with and travelled through a portion of the human skin;
• and
• at least one light barrier element configured to hinder the majority of the photons emitted by the first, second and third emitters from arriving at the first, second, and third light detectors unless the photons have travelled through the human skin;
• and
• an element for photon direction control comprising the at least one light barrier element or a separate element, the element for photon direction control configured to influence a direction of photons emitted from the device for at least one of the first, second, or third emitters;
• and
• a flat printed circuit board, each of the first, second, and third emitters and each of the first, second, and third light detectors being mounted on a surface of the flat printed circuit board,
• wherein there is a first emitter-detector pair including one of the first, second, or third emitters and one of the first, second, or third light detectors and a second emitter-detector pair including one of the first, second, or third emitters and one of the first, second, or third light detectors,
• wherein for each emitter-detector pair there is a center plane perpendicular to the surface of the printed circuit board that passes through the center of the respective emitter and the center of the respective light detector, and each emitted photon traveling approximately in the center plane exits the device with a photon emission direction having an emission angle such that an emission angle of 0 indicates that the photon emission direction is parallel to the printed circuit board and points from the respective emitter toward the respective light detector and an emission angle of 90 indicates that the photon emission direction is perpendicular to the surface of the printed circuit board, and
• wherein the smallest emission angle for the first emitter-detector pair is different from the smallest emission angle for the second emitter-detector pair.

A device for measuring a physiological parameter of a sample or a concentration of a substance in the sample, the device comprising:

• at least one transparent material that allows photons to at least partially pass through the material;
• at least one non-transparent material that is at least less transparent than the at least one transparent material;
• a single contact surface configured to be brought into at least partial contact with an outer surface of the sample, the contact surface comprising at least one of the transparent materials and at least one of the non-transparent materials;
• a light barrier material comprising the at least one non-transparent material, the light barrier material forming one or more cavities and being arranged such that there exists a plane through the device with the intersection of the plane and the one or more cavities forming at least four areas that are at least partially transparent to photons with each of the at least four areas being surrounded by the at least one non-transparent material, the cavities being arranged in a planar, non-linear arrangement;
• a plurality of emitters each comprising a semiconductor element that is configured to emit light through the contact surface into the sample;
• and
• a plurality of light detectors each comprising a semiconductor element that is configured to detect light that has been emitted by one of the plurality of emitters after the light has passed through a portion of the sample and re-entered the device through the contact surface;
• wherein the one or more cavities includes a first emitter cavity, a second emitter cavity, a first detector cavity, and a second detector cavity,
• wherein a first group of emitters of the plurality of emitters is positioned within the first emitter cavity, the first group of emitters including a first emitter that emits light with a first wavelength characteristic and a second emitter that emits light with a second wavelength characteristic different from the first wavelength characteristic,
• wherein a second group of emitters of the plurality of emitters is positioned within the second emitter cavity, the second group of emitters including a first emitter that emits light with the first wavelength characteristic and a second emitter that emits light with the second wavelength characteristic,
• wherein a first light detector of the plurality of light detectors is positioned within the first detector cavity, and
• wherein a second light detector of the plurality of light detectors is positioned within the second detector cavity.