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

A sensor for non-invasively measuring physiological parameters or substance concentrations in human tissue including human skin, the sensor comprising:

• a circuit board comprising a first side;
• a plurality of emitters each comprising a semiconductor component that is configured to emit light, at least three of the plurality of emitters arranged in a planar arrangement on the first side of the circuit board;
• a plurality of detectors each comprising a semiconductor component configured to determine a quantity of light arriving at the plurality of detectors, at least three of the plurality of detectors arranged in a planar arrangement on the first side of the circuit board;
• one or more non-transparent materials;
• and
• a contact element comprising a transparent material and at least one of the one or more non-transparent materials, the contact element forming a contact surface configured to be brought into contact with human tissue to position the sensor to perform non-invasive measurements of physiological parameters or substance concentrations in the human tissue,
• wherein:
• there is a plurality of emitter-detector pairs, each emitter-detector pair including an emitter of the plurality of emitters and a detector of the plurality of detectors, each emitter-detector pair being characterized by an emitter-detector wavelength characteristic corresponding to a wavelength characteristic of the light emitted by the emitter and detected by the detector in the emitter-detector pair and an emitter-detector distance corresponding to a distance between the emitter and the detector in the emitter-detector pair,
• there are at least three emitter-detector pairs with emitter-detector wavelength characteristics that differ from one another,
• there are at least two emitter-detector pairs with emitter-detector distances that differ from one another,
• there is a first emitter-detector pair and a second emitter-detector pair with the same emitter-detector distance and the same emitter-detector wavelength characteristic and a first straight line passing through the emitter and the detector of the first emitter-detector pair and a second straight line passing through the emitter and the detector of the second emitter-detector pair form an angle that is greater than 45 degrees and less than or equal to 90 degrees, and
• at least one of the one or more non-transparent materials is arranged in such a way that, when the contact surface is completely covered by the human tissue, light emitted by the at least three emitters reaches one of the at least three detectors only by passing through the human tissue covering the contact surface.

A method for non-invasively measuring physiological parameters or substance concentrations in human tissue including human skin using a sensor, the method comprising:

• emitting light from each of at least three emitters with a portion of the emitted light penetrating into the human tissue to be non-invasively measured;
• detecting light with each of at least three detectors, the light arriving at the at least three detectors after penetrating into the human tissue and interacting with the human tissue, being partly scattered and partly absorbed by the human tissue, the detected light being light that has been scattered in the human tissue in such a way that it leaves the human tissue and arrives at the at least three detectors;
• blocking a portion of the light emitted from each of the at least three emitters using a non-transparent material, the non-transparent material arranged such that a majority of the light emitted by the at least three emitters and detected by the at least three detectors passed through a portion of the human tissue;
• performing a measurement sequence that includes activating emitters of the at least three emitters in successive steps and detectors of the at least three detectors measure brightness values of detected light in each step of the successive steps;
• recording a set of measurement values that includes values measured by the at least three detectors in the measurement sequence;
• determining one or more physiological parameters or substance concentrations using the set of measurement values;
• and
• measuring coupling of contact between the human tissue and the sensor,
• wherein:
• the at least three emitters and the at least three detectors are located in a single plane in a planar arrangement,
• the at least three emitters are configured to emit a majority of photons in a direction forming an angle of at least 5 degrees to the single plane in which the at least three emitters and the at least three detectors are located, and
• the at least three light emitters are configured to emit at least three different wavelength characteristics.