Spectroscopic device

Abstract

The invention is in the field of spectroscopic devices. The invention relates to a spectroscopic device for determining a concentration of a body substance of a person comprising: a) a spectroscopy module configured to acquire spectroscopic data of the person, b) a heat source to cause the skin of the person to sweat, c) a processor configured to determine whether a trigger condition is fulfilled comprising determining a water concentration, to trigger a measurement of the spectroscopy module to acquire spectroscopic data of the sweat when a trigger condition is fulfilled, and to determine the concentration of the body substance of the person using the spectroscopic data, and d) an output configured to output the concentration of the body substance of the person.

Description

[0001] Spectroscopic Device

[0002] The invention is in the field of spectroscopic devices. The invention relates to a spectroscopic device for determining a concentration of a body substance of a person, a vehicle comprising the spectroscopic device, a method for determining a concentration of a body substance of a person, a use of the concentration of the body substance of the person for controlling a functionality of a vehicle, and a non-transient computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to perform a method for determining a concentration of a body substance of a person.

[0003] Background

[0004] The measurement of body substances of a person plays a role in many different areas. Examples are the medical sector, for example diabetes patients need to regularly measure their blood glucose level. Another example is the vehicle security sector in which intoxicants like alcohol or drug blood concentrations of the driver need to be measured. Spectroscopy is an attractive method for determining body substances as it is non-invasive and is hence well accepted by users. However, many body substances have a low concentration, hence they are difficult to measure accurately due to occlusion.

[0005] US 6 072 180 discloses a spectrometer for measuring substances which are present in the tissue, such as glucose, by means of thermal gradient spectra by inducing a transient thermal gradient in human tissue. However, such measurement requires quite some time equilibrate. In addition, the occlusion problem is not overcome due the low concentration of body substances in the uppermost skin layers.

[0006] US 2023 / 0309868 discloses a fluorescence sensor comprising a heating module for stimulating the release of sweat. However, the release of sweat depends on many factors such as person tendencies or environmental factors.

[0007] It was hence the object of the present invention to provide a reliable, robust, quick and comfortable solution to determining a concentration of a body substance of a person.

[0008] Summary

[0009] In one aspect the invention relates to a spectroscopic device for determining a concentration of a body substance of a person comprising: a) a spectroscopy module configured to acquire spectroscopic data of the person, b) a heat source to cause the skin of the person to sweat, c) a processor configured to trigger a measurement of the spectroscopy module to acquire spectroscopic data of the sweat when a trigger condition is fulfilled, wherein the trigger condition indicates that the skin sweats, and to determine the concentration of the body substance of the person using the spectroscopic data, and d) an output configured to output the concentration of the body substance of the person.

[0010] In another aspect the invention relates to a spectroscopic device for determining a concentration of a body substance of a person comprising: a) a spectroscopy module configured to acquire spectroscopic data of the person, b) a heat source to cause the skin of the person to sweat, c) a processor configured to determine whether a trigger condition is fulfilled comprising determining a water concentration, to trigger a measurement of the spectroscopy module to acquire spectroscopic data of the sweat when the trigger condition is fulfilled, , and to determine the concentration of the body substance of the person using the spectroscopic data, and d) an output configured to output the concentration of the body substance of the person.

[0011] In another aspect the invention relates to a vehicle comprising the spectroscopic device according to the invention.

[0012] In another aspect the invention relates to a method for determining a concentration of a body substance of a person comprising: a) heating the skin of the person to cause the skin of the person to sweat, b) triggering a spectroscopy module to acquire spectroscopic data from the sweat when a trigger condition is fulfilled, wherein the trigger condition indicates that the skin sweats, c) determining the concentration of the body substance of the person using the spectroscopic data, and d) outputting the concentration of the body substance of the person.

[0013] In another aspect the invention relates to a method for determining a concentration of a body substance of a person comprising: a) heating the skin of the person to cause the skin of the person to sweat, b) determining whether a trigger condition is fulfilled comprising determining a water concentration, c) triggering a spectroscopy module to acquire spectroscopic data from the sweat when a trigger condition is fulfilled, d) determining the concentration of the body substance of the person using the spectroscopic data, and e) outputting the concentration of the body substance of the person.

[0014] In another aspect the invention relates to a use of the concentration of the body substance of the person obtained from the method of the present invention for determining the person's fitness to drive a vehicle. In another aspect the invention relates to a non-transient computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to perform a method comprising: a) heating the skin of the person at a measurement location to cause the skin to sweat, b) triggering a spectroscopy module to acquire spectroscopic data from the person when the skin at the measurement location sweats, c) determining the concentration of the body substance of the person using the spectroscopic data, and d) outputting the concentration of the body substance of the person.

[0015] In another aspect the invention relates to a non-transient computer-readable medium including instructions that, when executed by one or more processors of a spectroscopic device according to the disclosure, cause the spectroscopic device to perform a method comprising: a) heating the skin of the person at a measurement location to cause the skin to sweat, b) determining whether a trigger condition is fulfilled comprising determining a water concentration, c) triggering a spectroscopy module to acquire spectroscopic data from the person when the skin at the measurement location sweats, d) determining the concentration of the body substance of the person using the spectroscopic data, and e) outputting the concentration of the body substance of the person.

[0016] The advantage of the present invention is that the concentration of a body substance of a person may be determined more accurately, in particular for those body substances of low concentration. The application of heat causes the skin at the measurement location to sweat. The sweat contains body substances of interest in most cases in a higher concentration compared to the upper skin layers. Optical radiation, in particular infrared radiation, has a low penetration depth into skin, so mostly the stratum corneum and the upper epidermis can be measured. By causing the skin to sweat, the sweat on the surface of the skin can be easily measured which thus leads to decreased occlusion by substances in the stratum corneum. By ensuring, for example from a water signal, that there is sufficient sweat, personal and environmental differences can be taken into account rendering the measurement even more reliable and reproduceable. The occlusion may be further reduced by taking into account the difference of spectra before and after applying heat. Hence, the method enables the reliable detection of body substances of low concentration which are otherwise hardly measurable due to occlusion.

[0017] The spectroscopic device may be integrated into a vehicle including cars, motorcycles, buses, trucks, trams, trains or even airplanes, hence a vehicle may comprise a spectroscopic device. The spectroscopic device may be suitable for integration into a vehicle. The spectroscopic device may be attached to the vehicle, or it may be integrated as component or as part of a component of a vehicle, for example as part of a display in the dashboard, an entertainment control system, or loudspeakers. The spectroscopic device can be placed at various places, for example in the steering wheel and its periphery, such as the steering wheel rim, the steering wheel column, or the steering wheel center behind or besides the emblem; in the dashboard, such as in the instrument cluster bezel or its surrounding, the dashboard button panel or in or around frequently used buttons like the infotainment control button or engine start button, the touchscreen display in the center display of the infotainment system; the overhead and A-pillars, such as in the overhead console behind the light sensor, nestled behind the light sensor housing in the overhead console, the A-pillar trim on the driver side placed behind the A-pillar trim panel; the center console, such as the cup holder insert incorporated within a removable cup holder insert, the gear shift knob positioned on top or on the side of the gear shift knob, the arm rest, the parking break button.

[0018] The spectroscopic device may be integrated into consumer electronics products, in particular in consumer electronic products which are worn on the body, for example a smartwatch, head phones, hearing aids, continuous glucose monitoring (CGM) systems, wearable medical devices, such as blood pressure, temperature, and oxygen levels, virtual reality headsets, smart glasses, skin patches, sleep trackers. The spectroscopic device may be integrated into apparel, for example in a hat, a helmet, a shirt, a scarf, a belt, underwear, shoes, or socks.

[0019] The term "spectroscopic device” may refer to an apparatus which is capable of recording spectroscopic data of a person. The spectroscopic device may be a spectrometer or a device into which a spectrometer is integrated. The spectroscopic device may be portable or stationary, for example a laboratory device. A portable spectroscopic device may be a hand-held spectrometer or a module which is integrated into a portable device like a smartphone, a tablet or a wearable like a smartwatch. A portable spectroscopic device may be communicatively coupled to a computer device, for example a cloud computer or a smartphone. Such computer device may be configured to execute a chemometric model. The computer device may further be configured to receive spectroscopic data from the spectroscopic device. The computer device may store such spectroscopic data, or send it to a system for determining concentration of a body substance.

[0020] A spectroscopic device may comprise a spectroscopy module comprising:

[0021] - an optical element configured for separating incident optical radiation provided by the measurement into a spectrum of constituent wavelength components;

[0022] - a photosensor comprising at least one photosensitive region configured for receiving the optical radiation from the optical element, wherein the photosensor is configured for generating at least one photosensor signal dependent on an illumination of the photosensitive region by the optical radiation.

[0023] The term "optical element” may refer to an arbitrary element configured for influencing optical radiation. The optical element may be configured for at least one of at least partially dispersing the optical radiation, at least partially filtering the optical radiation, at least partially reflecting the optical radiation, e.g. diffusely or directly, at least partially deflecting the optical radiation, at least partially transmitting the optical radiation and at least partially absorbing the optical radiation. The optical element may comprise at least one of a prism, a grating, a beam splitter, or an interferometer, for example a Michelson interferometer. The optical element may be configured for being used in mobile applications, for example for being used in handheld spectrometer devices and / or in spectrometer devices comprised by electronic communication devices, such as a smartphone or a tablet. As another example, the optical element may comprise at least one optical filter element. The optical filter element may be configured for filtering the optical radiation or more specifically at least one selected spectral range of the optical radiation. The optical filter element may specifically be positioned in a light path before the photosensor. As an example, the portable spectrometer may comprise a plurality of a photosensors, for example 5 to 20, such as 8 to 12. The photosensors may be arranged as pixels in an array or in a matrix. The portable spectrometer may comprise a plurality of optical filter elements. An optical filter element may be positioned in a beam path before a photosensor. The optical filter elements may be transmissive at different wavelengths of different wavelength regions. For example, each photosensor may be positioned behind an optical filter with regard to the beam path, wherein each optical filter is transmissive at different wavelength or different wavelength region to the other optical filters.

[0024] The spectroscopy module may comprise one or more than one photosensor. The photosensor may comprise at least one photosensitive region. The photosensitive region may be configured for receiving the optical radiation from the optical element. The photosensor may be configured for generating at least one photosensor signal dependent on an illumination of the photosensitive region by the optical radiation. The term "sensor” may refer to a device configured for detecting at least one condition or for measuring at least one measurement variable. The sensor may be capable of generating at least one signal, such as a measurement signal, which is a qualitative or quantitative indication of the measurement variable and / or measurement property, e.g. of an illumination of the sensor or a part of the sensor. The signal may be or comprise an electrical signal, such as a current, specifically a photocurrent. The term "photosensor” may refer to a sensor or a detector configured for detecting or measuring optical radiation, such as for detecting an illumination and / or a light spot generated by at least one light beam, e.g. by using the photoelectric effect. The photodetector may comprise at least one substrate. As an example, a single photosensor may be a substrate with at least one single photosensitive region, which generates a physical response, e.g. an electronic response, to the illumination for a given wavelength range.

[0025] The term "photosensitive region” may refer to a unit of the photosensor, specifically to a spatial area or volume being part of the photosensor, configured for being illuminated, or in other words for receiving optical radiation, and for generating at least one signal, such as an electronic signal, in response to the illumination. The photosensitive region may be located on a surface of the photosensor. The photosensitive region may specifically be a single, closed, uniform photosensitive region. However, other options may also be feasible.

[0026] The spectroscopic device may comprise at least one light emitting element configured for emitting illumination light for illuminating the person in order to generate detection light from the person. The light emitting element may be an incandescent lamp, for example a tungsten filament lamp or a tungsten halogen lamp, a light-emitting diode (LED), a laser diode, a gas-discharge lamp, for example a xenon lamp, a mercury vapor lamp, or a deuterium lamp. The term "light” may refer to electromagnetic radiation in one or more of the infrared, the visible and the ultraviolet spectral range. The term "ultraviolet spectral range” may refer to electromagnetic radiation having a wavelength of 1 nm to 380 nm, preferably of 100 nm to 380 nm, for example 280 nm to 315 nm (UV-B) or 315 nm to 380 nm (UV-A). Further, in partial accordance with standard ISO-21348 in a valid version at the date of this document, the term "visible spectral range” may refer to a spectral range of 380 nm to 760 nm. The term "infrared spectral range” (IR) may refer to electromagnetic radiation of 760 nm to 1000 m, wherein the range of 760 nm to 1.5 pm is usually denominated as "near infrared spectral range” (NIR) while the range from 1.5 p to 15 pm is denoted as "mid infrared spectral range” (MIR) and the range from 15 pm to 1000 pm as "far infrared spectral range” (FIR). Preferably, light used for the typical purposes of the present invention is light in the infrared (IR) spectral range, more preferred, in the near infrared (NIR) and / or the mid infrared spectral range (MIR), especially the light having a wavelength of 750 nm to 2.5 pm, for example 780 nm to 1.4 pm or 1.4 pm to 2.5 pm. These wavelength regions are particularly suitable for obtaining material properties of a person.

[0027] The spectroscopic device may comprise a processor to process the photosensor signals into spectroscopic data, for example an infrared spectrum. The processor may output the spectroscopic data, for example to an interface for further processing or to a user interface. The processor may further be configured to apply a chemometric model and output the concentration of a body substance obtained by the chemometric model. The spectroscopic device may further comprise a memory. The memory may be configured to store the chemometric model. The memory may be configured to store spectroscopic data.

[0028] The spectroscopic device may contain or be placed behind a transparent display. The term "display” may refer to an arbitrary shaped device configured for displaying an item of information. The item of information may be arbitrary information such as at least one image, at least one diagram, at least one histogram, at least one graphic, text, numbers, at least one sign, or an operating menu. The display may be or may comprise at least one screen. The display may have an arbitrary shape, e.g. a rectangular shape. The display may be a front display of a device.

[0029] The display may be or may comprise at least one organic light-emitting diode (OLED) display. The term "organic light emitting diode” may refer to a light-emitting diode (LED) in which an emissive electroluminescent layer is a film of organic compound configured for emitting light in response to an electric current. The OLED display may be configured for emitting visible light. The display, particularly a display area, may be covered by glass. In particular, the display may comprise at least one glass cover.

[0030] The transparent display may be at least partially transparent. The term "at least partially transparent” may refer to a property of the display to allow light, in particular of a certain wavelength range, e.g. in the infrared spectral region, in particular in the near infrared spectral region, to pass at least partially through. For example, the display may be semitransparent in the near infrared region. For example, the display may have a transparency of 20 % to 50 % in the near infrared region. The display may have a different transparency for other wavelength ranges. For example, the display may have a transparency of > 80 % for the visible spectral range, preferably > 90 % for the visible spectral range. The transparent display may be at least partially transparent over the entire display area or only parts thereof. Typically, it is sufficient if only those parts of the display area are at least partially transparent trough which light needs to pass from the projector or to the camera.

[0031] The display may comprise a display area. The term "display area” may refer to an active area of the display, in particular an area which is activatable. The display may have additional areas such as recesses or cutouts. The display may have a first area associated with a first pixel per inch (PPI) value and a second area associated with a second PPI value. The first PPI value may be lower than the second PPI value, preferably first PPI value is equal to or below 400 PPI, more preferably the second PPI value may be equal to or higher than 300 PPI. The first PPI value may be associated with the at least one continuous area being at least partially transparent.

[0032] The spectroscopy module may be positioned such that it can illuminate the person with light through the transparent display. The spectroscopy module may be positioned such that it can receive light from the person through the transparent display. Light reflected or refracted from the person firstly crosses the transparent display before it impinges on the sensor of the spectroscopy module. From the person's view, the spectroscopy module may be placed behind the transparent display.

[0033] The term "body substance” may refer to any chemical substance which can be found in a human body, in particular in the skin, blood or interstitial fluid of a human body. The body substance may be indicative of the person's fitness to drive a vehicle, the body substance may, for example, reduce the concentration of a person or may be a metabolite of such substance. The body substance may be indicative for a health or fitness condition which compromises the person's fitness, for example a low hydration level or an irregular blood glucose concentration. Body substance may comprise proteins, such as enzymes, antibodies, or hormones; carbohydrates, such as glucose, glycogen, or fructose; lipids, such as triglycerides, cholesterol, and phospholipids; water; nucleic acids, such as DNA or RNA; amino acids, such as alanine, glutamic acid, cysteine; neurotransmitters, such as dopamine, serotonin, and acetylcholine; hormones, such as insulin, estrogen, or testosterone; electrolytes, such as sodium, potassium, or calcium ions; vitamins, such as ascorbic acid, calciferol, cobalamin; metabolites, such as lactate, urea, and creatinine.

[0034] Body substance may be an intoxicant or its metabolite including ethanol, opioids, such as heroin, morphine, fentanyl; stimulants, such as amphetamine, methylphenidate, cocaine; benzodiazepines, such as diazepam, or alprazolam; cannabinoids, such as tetrahydrocannabinol (THC); barbiturates, such as phenobarbital; hallucinogens, such as lysergic acid diethylamide (LSD) or psilocybin; antihistamines, such as diphenhydramine; antipsychotics and antidepressants, such as fluoxetine or amitriptyline; muscle relaxants, such as carisoprodol or cyclobenzaprine; pain killers, such as tramadol, codeine, ibuprofen, naproxen, cyclobenzaprine, or methocarbamol. The term "spectroscopic data” may refer to data associated with a spectroscopic measurement of a person, in particular with optical spectroscopic measurement of the person. The spectroscopic data may be received from the spectroscopic device of the present invention. The spectroscopic data may be received directly from a spectroscopic device or indirectly, i.e. from a storage device to which the spectroscopic data have been stored after the measurement. A spectroscopic measurement may be triggered by a predefined event, for example when the vehicle is switched on, before the engine is started, or after a certain period of time. A spectroscopic measurement may be triggered when a measurement trigger event occurs. A measurement trigger event may be a situation in which an indicator indicates the necessity for a spectroscopic measurement necessary. A measurement trigger event may occur when an indicator indicates that the person's fitness to drive is potentially compromised, for example due to intoxicants such as alcohol or drugs, due to a health problem, for example low sugar concentration of a diabetes patient, or due to fitness problems like dehydration. The measurement trigger event may be determined using person data and / or environmental data. For example, the person data and / or environmental data may indicate an increased likelihood that the person's fitness to drive the vehicle are compromised, such as slow pupil reflex recorded by an optical camera, unusual movement patterns recorded by a pressure sensor, or certain voice characteristics recorded by a microphone. Triggering a spectroscopic measurement in such cases may be particularly useful if the body substance is used for access control of the vehicle, for example to keep drunk persons from driving without burdening obviously sober persons with a measurement.

[0035] The spectroscopic measurement may be made on the skin of the person. The spectroscopic measurement may be made at various body parts of the person, for example the face, the arm, the hand. The spectroscopic measurement may be made at parts of the hand, for example the palm, the back of the hand, one or multiple fingers, such as the thumb, the forefinger, the long finger, the ring finger or auricular finger. The spectroscopic measurement may be made in direct contact with the person or in close proximity, for example with a distance of less than 10 cm or less than 5 cm between person and spectrometer device.

[0036] Spectroscopic data may be or may comprise one or more than one spectrum. The term "spectrum” may refer to a data structure in which several intensity values or values derived thereof such as absorbance of radiation are associated with wavelengths or wavelength ranges of the radiation. The wavelength or wavelength ranges may be those described above. The data structure may be a vector, wherein each element represents an intensity and the position in the vector represents a certain wavelength or wavelength range, so the value at a certain position represents the intensity of that wavelength or wavelength range. The data structure may be a vector or matrix containing value pairs, wherein one value represents the wavelength or wavelength range and the other value the intensity at this wavelength or wavelength range. The spectrum recorded by the spectrometer may be corrected by calibration coefficients to compensate for sensor imperfections or drifts. The spectrum may represent the absorbance or transmittance of radiation after having penetrated the skin of the person. The spectroscopic device comprises a heat source to cause the skin of the person to sweat. The heat source may be positioned in the spectroscopic device such that it can be brought in contact to the skin of the person. The term "heat source” may refer to a device or a component of a device which generates heat or causes a surface to heat up, for example via radiation, for example infrared radiation. A heat source may be a heating element, such as a Nichrome wire, i.e. a resistance wire made from an alloy of nickel and chromium, a Kanthal wire, i.e. a resistance wire made of an alloy of iron, chromium, and aluminum, a silicon carbide heating element, a Calrod elements, i.e. a resistance wire encased in a ceramic insulator, a positive temperature coefficient (PTC) element, a carbon fiber heating element, a mica heating element, i.e. a resistance wire sandwiched between layers of mica, a tubular heating element, i.e. a metal sheath, such as stainless steel, with a heating wire or coil inside. A heat source may be a Peltier element, a transistor or an LED, in particular an LED emissive in the infrared range. The heat source may be the light emitting element of the spectroscopic module. In this case, the skin may be heated by a conductive element transporting the heat generated by the light emitting element to the skin, or the skin may be heated by the radiation of the light emitting element, in particular in case the light emitting element emits light in the infrared range. Normally, the skin needs to be illuminated longer with light than in a spectroscopic measurement in order to cause the skin to sweat.

[0037] The heat source is configured to cause the skin of a person to sweat. The heat source may heat the skin surface to a temperature of 30 °C to 60 °C, for example 35 °C to 50 °C. The heat source may be in contact with the skin of the person. In this case, the temperature may refer to the interface of the heat source with the skin of the person, for example the surface of the heat source which is configured to be in contact with the skin of the person. The heat source may not be in contact with the skin. In this case, the heat source may be hotter than the surface temperature. The skin surface may be heated for 1 s to 1 min, for example 2 s to 45 s, such as 3 s to 20 s or 5 s to 30 s.

[0038] The spectroscopy module is triggered to acquire spectroscopic data of the sweat when a trigger condition is fulfilled. It may be determined whether the trigger condition is fulfilled, for example to verify that the skin sweats. The spectroscopy module may be triggered to acquire spectroscopic data of the sweat only if a trigger condition is fulfilled. Otherwise, an error message may be displayed to the user. Additionally or alternatively, a determination whether the trigger conditions is fulfilled may be repeated, for example directly or with a time delay such as 1 to 5 seconds. The spectroscopy module may be triggered to acquire spectroscopic data of the sweat when the skin sweats.

[0039] The term "trigger condition” may refer to a condition or a set of conditions at which a spectroscopic measurement shall be triggered. If the trigger condition comprises more than one condition, the trigger condition may be fulfilled if all conditions are fulfilled. The trigger condition indicates that the skin sweats, for example the trigger condition may be fulfilled if the conditions make sweat production very likely. The trigger condition may include a temperature of the heating source and a time period. For example, the heating source may be at a temperature of 35 to 50 °C for at least 3 s, or at least 5 s or at least 10 s. The trigger condition may comprise a pressure, for example a pressure exerted by the spectroscopy module against the skin, for example at least 1 kPa, at least 5 kPa, 10 kPa, at least 30 kPa, at least 50 kPa, at least 75 kPa, at least 100 kPa, or at least 150 kPa. This may ensure, that the heating source heats up the skin sufficiently. The pressure may be measured by a pressure sensor. Hence, the spectroscopic device may comprise a pressure sensor for measuring the pressure exerted by the spectroscopy module against the skin of the person, in particular for measuring the pressure exerted by the spectroscopy module against the skin of the person. The term "pressure sensor” may refer to sensor which is capable of recording the pressure exerted by the spectroscopy module against the person and convert the pressure into pressure data comprising the value of the pressure. Examples for pressure sensors include piezoresistive pressure sensors, capacitive pressure sensors, strain gauge pressure sensors, optical pressure sensors, resonant pressure sensors, thermal pressure sensors, piezoelectric pressure sensors, potentiometric pressure sensors. The pressure sensor may be placed in close proximity to the heating source such that the pressure against the body location can be measured which is heated by the heating source. The term "close proximity” may refer to a distance within which negligible pressure variations can be expected, for example less than 5 cm or less than 1 cm or less than 5 mm.

[0040] The trigger condition may comprise a direct sweat measurement, i.e. a measurement which ensures that the skin has actually secreted sweat. The determination whether the trigger condition is fulfilled may be based on a measurement or on data received from a sensor. The presence of sweat may be determined based on a determination of a water concentration. Therefore, determining whether the trigger condition is fulfilled may comprise determining a water concentration. Determining a water concentration may include measuring a value which correlates with the water concentration, for example the impedance of skin or the absorption of infrared light at a wavelength at a water absorption band. The water concentration may be determined from spectroscopic data, for example obtained from the spectroscopy module, or from a different sensor, such as an impedance sensor.

[0041] The trigger condition may comprise a capacitive or conductive impedance, for example an absolute threshold, for example less than 50 kQ at 1 kHz or less than 10 kQ at 100 kHz, or a relative decrease of the impedance, for example by at least 20 % or at least 35 % or at least 50 %. The impedance may be measured by an impedance sensor. Hence, the spectroscopic device may comprise an impedance sensor to measure the impedance of the skin of the person, i.e. the impedance sensor may be placed in the spectroscopic device such that it can be brought into contact with the skin of the person. The term "impedance sensor” may refer to sensor which is capable of measuring the capacitive or conductive impedance of a surface such as the skin of a person and convert the impedance into impedance data comprising the value of the impedance. Examples for impedance sensors are impedance analyzers, in particular bioimpedance analyzers, electrodes or conductivity meters.

[0042] The direct measurement of sweat may be achieved with the spectroscopic device itself. The trigger condition may comprise a water concentration, for example a minimum water concentration indicating the presence of sweat. The minimum water concentration may be absolute, for example at least 20 % or at least 25 % or at least 30 %, or it may be relative, for example an increase of at least 10 % or least 15 % or at least 20 %, wherein this percentage may relate to the water content after sweat has been excreted compared to the water content before. For example, the water content before sweating may be 20 % and after sweating 24 % may mean an increase by 20 %. The water concentration may be measured by the spectroscopic device, i.e. a spectroscopic measurement is performed, wherein the spectroscopic data is used to determine the water concentration. For this purpose, a dedicated spectroscopic model may be employed which may be different to the spectroscopic model for determining the body substance of the person. Hence, spectroscopic data may be acquired to determine the water content of the skin until a trigger condition is reached. The spectroscopy module may then be triggered to acquire spectroscopic data which is used to determine the body substance of the person. The direct measurement of sweat may be achieved by a spectroscopic measurement with the spectroscopic device, wherein the determination of the water concentration is performed with spectroscopic data in a first wavelength range and the determination of the body substance is performed with spectroscopic data in a second wavelength, wherein the first wavelength range and the second wavelength range are different to each other. Different in this context may mean that the first wavelength range and the second wavelength range partially overlap or that they do not overlap. For example, the first wavelength range may be in the NIR region, for example 750 nm to 2500 nm, and the second wavelength range may be in the MIR region, for example 2.5 m to 15 m.

[0043] The determination if a trigger condition is fulfilled may be performed by a processor, for example the processor comprised in the spectroscopic device. The processor may receive sensor data, for example from an impedance sensor or a pressure sensor, determine if a trigger condition is fulfilled, and when the condition is fulfilled trigger the spectroscopy module to acquire spectroscopic data, for example by sending a signal to the spectroscopy module which causes the spectroscopy module to measure.

[0044] The spectroscopic measurement may be performed while the spectroscopy module is in contact with the skin. In this case, the sweat and the upper skin layer may be measured by the spectroscopy module. Alternatively, the spectroscopic measurement may be performed while the spectroscopy module is not in contact with the skin. In this case, the sweat which still sticks to the spectroscopic module, for example its sample interface, may be measured. In the latter case, the trigger condition may comprise a pressure profile, for example a minimum pressure for a period of time when the skin is heated followed by a pressure indicating that the spectroscopic device is no longer in contact with the skin.

[0045] Determining the concentration of a body substance may involve a reference spectrum. The reference spectrum may be a spectrum measured when the skin of the person does not sweat. The reference spectrum may be measured with the spectroscopic device. The spectroscopic device may be triggered to measure a reference spectrum if a reference condition is fulfilled. The term "reference condition” may refer to a condition or a set of conditions at which a spectroscopic measurement shall be triggered in order to obtain a reference spectrum. The reference condition may involve a temperature threshold, for example a skin temperature for which no sweating can be expected, for example less than 35 °C or less than 33 °C or less than 31 °C. The reference condition may involve an impedance threshold, for example an impedance value for which no sweating can be expected, for example more than 50 kQ at 1 kHz or less than 10 kQ at 100 kHz. The reference condition may involve a water concentration threshold, for example less than 30 % or less than 25 % or less than 20 %. The reference condition may involve confirmation of cleaning of the spectroscopic module, for example its sample interface, its interface to the skin of the person. For example, the spectroscopic module may have been cleaned with water, soap, or an organic solvent like ethanol. The cleaning process may be entered to the spectroscopic device, for example to a user interface, for example in an app on a smartphone.

[0046] Alternatively, the reference spectrum may be obtained from a database. The reference spectrum may have been recorded under controlled conditions, for example in the course of enrollment, and stored to the database. The database may be stored in a memory comprised in the spectroscopic device or it may be stored in a cloud service. The combined spectrum may be compared to the reference spectrum. For example, a difference spectrum may be determined by subtracting the reference spectrum from the combined spectrum. Alternatively, the spectra are subject to principle component analysis and the principle components are used for comparison and / or combination. In this way, the influence of background can be reduced. Also, outliers can be identified.

[0047] The concentration of a body substance of the person is determined using the spectroscopic data. The concentration of a body substance of the person may be determined using the spectroscopic data and person data. The concentration of a body substance of the person may be determined using the spectroscopic data and environmental data. The concentration of a body substance of the person may be determined using the spectroscopic data, person data and environmental data. The concentration may be a numeric value, such as mass ratio or a volume ratio. The ratio may relate to the whole body or parts thereof, for example the skin or the blood. For example, in case of alcohol the blood alcohol concentration may be determined. The concentration may be a categoric value, for example indicating the presence of the body substance or certain value ranges, for example none, low, medium, high.

[0048] The term "person data” may refer to data associated with a characteristic of the person such as a physical or chemical characteristic of the person. Person data may refer to any data associated with a characteristic of the person which has been obtained with a method other than spectroscopy. Person data may correlate with the alcohol level of the person. Person data may be personalized data, i.e. specific for a particular person, or it may be data associated with a certain group of people, for example female persons of age 25 to 30. Physical characteristics may comprise thermal characteristics, for example the body temperature, the thermal conductivity or the specific heat capacity of the skin; mechanical characteristics, for example pressure exerted on the spectrometer, compressibility or mechanical elasticity of the skin; optical characteristics, for example the color, refractive index, optical conductivity or absorption coefficients of the skin; electro-magnetic characteristics, for example electrical conductivity, dielectric constant, radio frequency-based permittivity, microwave complex permittivity, millimeter wave complex permittivity, magnetic permittivity or susceptibility of the skin. Chemical characteristics of a person typically refer to the chemical composition of some body tissue like skin, blood or sweat, for example the type and the concentration of certain chemical compounds such as the water content.

[0049] The person data may contain or may be a biomarker. The term "biomarker” may refer to a measurable substance, process or characteristic that is indicative of a biological state or condition. A biomarker may refer to a specific molecule, protein, genetic sequence, or other measurable feature that is associated with a particular disease, condition or treatment response. Examples for biomarkers are body dimensions such as size, head circumference, chest girth, abdominal girth, crotch length, arm length; body weight or body mass index; body topology such as face topology, iris structure, finger print, palm topology; muscle measures like muscular strength, muscular endurance, muscular agility and speed, balance, coordination; cardio-vascular measures such as heart rate, heart rate variability, electrocardiogram, blood pressure, blood oxygen; skin measures such as skin conductance, skin impedance, skin moisture level, skin sebum level, skin roughness, skin elasticity, skin pH, skin blood flow, skin sweat rate; blood metabolites such as blood glucose, blood cholesterol, blood triglycerides, blood urea, blood creatinine, blood lactate, blood bilirubin, blood pH; urine metabolites such as urine glucose, urine urea, urine creatinine, urine ketones, urine pH, urine protein content; hormone levels such as thyroid hormone level, insulin level, growth hormone level, cortisol level, estrogen level, progesterone level, testosterone level, prolactin level; drug levels or levels of drug metabolites such as alcohol, amphetamines, opioids, cocaine, marijuana, benzodiazepines, barbiturates.

[0050] Person data may be received from sensors other than a spectrometer, for example a thermometer, a scale, a balance, an optical camera, an optical 3D scanner system, conductance or impedance gauge such as a corneometer, a sweat rate monitor or sweat patch, a liquid or gas chromatograph, a mass spectrograph, a nuclear magnetic spectrometer or imager, an electrochemical sensor, an immunoassay, a polymerase chain reaction apparatus. The spectroscopic device may be integrated into a portable device which further comprises sensors from which at least parts of the person data is received. Person data may be the temperature measured by the temperature sensor of the spectroscopic device.

[0051] Person data may also be received from a storage device or it can be obtained from a user interface, for example a graphical user interface, to which a user can enter person data, for example from observations. Person data may comprise human characteristics like age, sex, origin, ethnicity; medical history including current and former medications; nutrition such as vegetarian or vegan diet; consumption of stimulants such as caffeine, alcohol, tobacco products, drug; physical activity level such as type of profession, i.e. office job or physically demanding job, kind of sports, average duration of sports, average sleeping hours.

[0052] The term "environmental data” may refer to data associated with a characteristic of the surrounding of the person, for example a physical or chemical characteristic of the surrounding of the person. The characteristic of the surrounding of the person may have an influence on the spectroscopic measurement of the person or on the characteristic of the person such as the physical or chemical characteristic of the person. However, environmental data may not comprise an intrinsic characteristic of the person.

[0053] Environmental data may comprise sensor data from sensors other than a spectrometer. Environmental data may comprise the location of the person, for example the geolocation such as the GPC coordinates, the height above see level, distance to a reference point such as the spectrometer, acceleration, orientation with regard to gravity; weather conditions such air temperature, air pressure, air humidity, wind speed, wind direction, ambient light intensity; time or date; air pollutant levels like CO2 concentration, CO concentration, ozone concentration, nitrogen oxide concentration, sulfur dioxide concentration, fine dust concentration, volatile organic compounds level.

[0054] Sensor data may have been recorded by a sensor capable of determining the sensor data. The sensor may be integrated into the spectrometer. The spectroscopic device may be integrated into a portable device which further comprises sensors from which at least parts of the environmental data is received. The sensor may be communicatively coupled to the spectrometer, for example via a wireless communication or via internet. Examples for sensors may be a GPC receiver, an accelerometer, a gyroscope, an altimeter, a goniometer, a distance sensor like a time-of-flight sensor, a radar or a LiDaR, a pressure sensor such as a MEMS sensor, a piezo sensor or a capacitive sensor, a magnetometer, a barometer, a light sensor, a thermometer, a gas sensor.

[0055] Environmental data may comprise data associated with the spectrometer, for example a spectrometer ID, a version number of the spectrometer, the spectrometer settings, the temperature of the spectrometer, the age of the spectrometer, time since the last calibration was performed, age of the illumination source, number of measurements the spectrometer has already performed in its lifetime or within a certain time such as the last week or the last month. Environmental data may further comprise data associated with the spectroscopic measurement of the person, for example the sampling time, the illumination strength with which the spectrometer illuminates the person, or the distance of the person to the spectrometer.

[0056] Environmental data may be received from a data storage medium. The data storage medium may be part of the spectroscopic device, or it may be a remote storage device, for example a computer system or a cloud system. Environmental data may be received from a database, for example from a database on a remote storage system, in response to a request containing time and / or geographic location. A remote storage system may refer to a system which is far from the person of the measurement, for example a cloud server or a database server. For example, a request containing the GPS coordinates of the person and the time of the spectroscopic measurement may be sent to a cloud server having a weather database. The cloud server may in response to the request send weather data corresponding to the time and location of the request.

[0057] The concentration of a body substance of the person may be determined by employing a chemometric model. The term "chemometric model” may refer to a model which is parameterized to receive spectroscopic data as input and output the concentration of a body substance. The chemometric model may be parameterized to receive spectroscopic data and output the concentration of a body substance. The chemometric model may be parameterized to receive spectroscopic data and environmental data as input and output the concentration of a body substance. The chemometric model may be parameterized to receive spectroscopic data, person data and environmental data as input and output the concentration of a body substance. The chemometric model may be parameterized to receive spectroscopic data as input and output an intermediate concentration of a body substance. The intermediate concentration of a body substance may be adjusted or corrected using the person data and / or the environmental data, for example by employing a refining model. The refining model may be a data-driven model which may be trained with historic data for adjusting or correcting the intermediate concentration of a body substance. A refining model may be a multivariate linear or polynomial regression model, or it may be an artificial neural network.

[0058] A chemometric model may comprise a pre-processing method and a machine learning model to obtain the concentration of a body substance. A chemometric model may comprise a pre-processing method, a feature selection filter and a machine learning model. If the chemometric model comprises two or more partial chemometric models, each partial chemometric model may comprise a separate pre-processing method, a feature selection filter and a machine learning model. Alternatively, the partial models may use the same pre-processing method or feature selection filter.

[0059] The term "pre-processing” may refer to a method to reduce or eliminate interferences from a spectrum such as stray light, noise or baseline drift to enhance the subsequent machine learning. Hence, the pre-processing method may be applied before the machine learning method. Pre-processing may include one or more of baseline correction, scatter correction, smoothing, scaling, aggregation.

[0060] The term "machine learning method” may refer to a model which translates spectra into corresponding person data. The machine learning method hence may use a spectrum as input and derive person data therefrom. The machine learning method may be considered as an integral part of the chemometric model. Machine learning methods may be supervised, semi-supervised or unsupervised. Machine learning methods may include multivariate calibration, classification, pattern recognition, clustering, ensemble methods, neural nets and deep learning, or multivariate curve resolution.

[0061] The term "feature selection filter” may refer to a method to select those parts of the spectrum with a correlation to the person data. A feature selection filter may facilitate the machine learning method of the chemometric model and thus avoid overfitting and reduce the number of required training datasets. A feature selection filter may use a spectrum as input, remove all unselected parts and output a spectrum with only the selected parts left. Hence, the output of the feature selection filter may be a spectrum in form of a vector of lower dimensionality than the input vector. The output of the feature selection filter can be used as input for the machine learning method. Hence, the feature selection filter may be applied before the machine learning method. The input of the feature selection filter may be the received spectrum or it may be the pre-processed spectrum, preferably the pre-processed spectrum. Hence, the feature selection filter may be applied after the pre-processing method.

[0062] A chemometric model may be or may contain a data-driven model. The chemometric model may be a trained data- driven model. Training may comprise adjusting parameters of the chemometric model such that the output of the chemometric model most closely fits to the provided training data. Often, training comprises minimizing a loss or cost function, for example a least mean square value of chemometric model output to provided training data. The complete set of training data may be used for training or parts thereof. Parts of the received training data may be used for training and the remainder may be used for determining the prediction accuracy of the trained chemometric model. Alternatively, cross-validation can be applied, for example K-fold cross-validation, leave-one-out cross- validation, stratified cross-validation.

[0063] The spectroscopic device may be operatively coupled to a person identification system. The person identification system may provide the identity of the person. The person identification system may be a biometric recognition system, for example a fingerprint recognition system, a hand geometry recognition system, an iris recognition system, a retina recognition system, a face recognition system, a vein recognition system, a voice recognition system. The person identification system may be integrated into the same part of the vehicle as the spectroscopic device or into a different part. For example, the spectroscopic device may be placed behind a display with an integrated fingerprint scanner or a behind-display face recognition system. The person identification system may be used to make sure the person using the spectroscopic device is in fact the person and not a different vehicle passenger. This may be efficiently achieved if the spectroscopic device and the person identification system are in close proximity, for example by integrating both in the same part of the vehicle. Alternatively, or additionally, the personalized person data may be obtained using the identity of the person obtained from a person identification system. In particular, a personalized reference spectrum, i.e. a reference spectrum which is specific for the identified person, may be obtained from a database using the identity of the person. The personalized reference spectrum may be used to determine the concentration of the body substance.

[0064] The face recognition system may be a 2D face recognition system, for example a feature extraction analysis from an image, for example from a RGB or an IR camera. The analysis may yield various features like size and position of eyes, nose, mouth ears and their relative distance and orientation. By comparing such features to a reference database, the identify of the person may be identified.

[0065] The face recognition system may be a 3D face recognition system determining a depth map of the person, for example by a stereo camera system, a structured light system, or a time-of-flight camera system. The depth map may be used to identify the person by comparing it to a reference database. The face recognition system may further comprise material recognition or classification by analyzing characteristic reflection of light from the surface, for example as described in WO 2023 / 156315 A1 .

[0066] The concentration of a body substance determined by the chemometric model may be output. The term "outputting” may refer to writing the concentration of a body substance to a non-transitory data storage medium, for example into a file or database, display it on a user interface, for example a screen, or both. Outputting may further mean to forward the concentration of a body substance to a computer system for further processing, for example an electronic control unit (ECU) or the on-board computer system. It is also possible to output the concentration of a body substance through an interface to a cloud system for storage and / or further processing.

[0067] The concentration of the body substance may be used to determine the person's fitness to drive a vehicle. The processor of the spectroscopic device may be configured to determine the person's fitness to drive a vehicle. The board computer of the vehicle or an ECU may be configured to receive the concentration of the body substance and to determine the person's fitness to drive a vehicle using the concentration of the body substance. The determination may involve determining if the concentration of the body substance exceeds or falls below a threshold. The threshold may be given by law, for example for the blood alcohol concentration or the THC concentration. The threshold may also be specific for a certain group of persons, for example a glucose level for patients suffering from type 1 diabetes. The threshold may be specific for a specific person, i.e. a personal threshold, for example for medial conditions like dehydration which may depend on the specific skin type of a person. Person-specific thresholds may be determined using the person identification described above.

[0068] The concentration of a body substance of the person may be used for controlling a functionality of the vehicle. A control signal may be generated using the concentration of the body substance. The control signal may be usable to control a vehicle access control system, for example to fully exclude a person from using a vehicle with an ignition interlock if the concentration of a body substance is above a threshold or to partially exclude the person if the concentration of a body substance is within a certain range, for example by restricting certain functionalities of a vehicle like the engine power, the maximum achievable speed or the entertainment system.

[0069] The control signal may be a Boolean value indicating whether the access can be granted or not. The control signal may be a numeric value, for example classifier indicating the extent of access which can be granted to the person. The control signal may be generated by determining if the concentration of a body substance is above or below a preset threshold. The determination of the control signal may involve region-specific settings, for example a country or state-specific concentration of a body substance threshold. The region-specific settings may be obtained from a storage medium taking into account the geographic location of the vehicle, for example obtained from a GPS system. The determination of the control signal may involve person data, for example the person's age to determine an agespecific threshold of blood alcohol concentration. The determination of the control signal may involve personalized person data, for example a personalized threshold of blood alcohol concentration which may be lower than the general threshold, for example due to a court order as a consequence of a prior driving under the influence. Personalized person data may be selected from a database using the person identity obtained from person identification as described above.

[0070] The control signal may be used for geofence lockout, for example prevent the vehicle from leaving a designated area, for example a home or highways, if a preset concentration of a body substance is exceeded; for passive alert, for example discreetly notify emergency contacts or roadside assistance if a preset concentration of a body substance is exceeded; for adapting autonomous driving functionality, for example, increase distance kept to vehicles driving in front and increase break system pressure to allow for more effective breaking and avoid accidents due to reduced reaction time if the concentration of a body substance is within a preset range; for data logging, for example maintain a discreet log of concentration of a body substance readings for personal health tracking or potential use by law enforcement; for determining eligibility, for example restrict driving privileges based on concentration of a body substance for individuals with prior driving under the influence convictions or for novice persons; for insurance premium adjustments, for example to adjust insurance premiums based on concentration of a body substance measurement history to encourage responsible driving behavior; for emergency response decisions, for example to improve decision making of law enforcement and medical personnel, taking into account concentration of a body substance levels of individuals involved in accidents or medical emergencies; for real-time fleet monitoring, for example an alert fleet managers to elevated concentration of a body substance readings, allowing for immediate intervention such as contacting the person, dispatching a replacement, in particular for commercial vehicles; for route restriction, for example automatically reroute vehicles driven by someone with a detected concentration of a body substance to avoid high-risk areas or congested roads; for remote engine disable, for example in extreme cases such as very high concentration of a body substance to allow fleet managers to remotely disable the vehicle to prevent accidents; for person rewards or penalties, for example to implement incentive programs for maintaining clear person records and penalties for violations.

[0071] The present invention further relates to a non-transient computer-readable medium including instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to the present invention. The term "computer-readable data medium” may refer to any suitable data storage device or computer readable memory on which is stored one or more sets of instructions (for example software) embodying any one or more of the methodologies or functions described herein. The instructions may also reside, completely or at least partially, within the main memory and / or within the processor during execution thereof by the computer, main memory, and processing device, which may constitute computer-readable storage media. The instructions may further be transmitted or received over a network via a network interface device. Computer-readable data medium include hard drives, for example on a server, USB storage device, CD, DVD or Blue-ray discs. The computer program may contain all functionalities and data required for execution of the method according to the present invention or it may provide interfaces to have parts of the method processed on remote systems, for example on a cloud system. Brief Description of the Figures

[0072] Figure 1 illustrates an example for a spectroscopic device.

[0073] Figure 2 illustrates an example for a spectroscopic device of the present invention.

[0074] Figure 3 illustrates another example for a spectroscopic device of the present invention.

[0075] Figure 4 illustrates an example of the method for determining a concentration of a body substance of a person.

[0076] Figure 5 illustrates another example of the method for determining a concentration of a body substance of a person.

[0077] Description of Embodiments

[0078] Figure 1 illustrates an example for a spectroscopic device. The spectroscopic device may be suitable to acquire spectroscopic data of the person from its finger 120. Between the spectroscopic module 100 and the finger 120, there may be a cover 110 which is at least partially transparent to the light emitted by the light emitting element 102. The cover 110 may be a sheet of glass or a polymer like polycarbonate or polymethyl methacrylate (PMMA). The cover 110 may also be a transparent display, for example the display of a control panel or a multimedia system. The spectroscopic device may comprise a heat source 111, for example a Kanthal wire. The heat source 111 may be placed between the cover 110 and the finger 120, so the finger is in contact with the heat source. Alternatively, the heat source 111 may be placed behind the cover 110, for example in case the cover 110 has a high thermal conductivity. The heat source 111 may be communicatively coupled with a processor, for example the processor 107 of the spectrometer module, so the heat source 111 can be controlled by the processor 107 and its operational state can be determined.

[0079] The spectroscopic device may comprise a spectroscopic module 100. The spectroscopic module 100 may comprise a substrate 101, for example a printed circuit board (PCB). The spectroscopic module 100 may comprise a light emitting element 102, for example an LED. The LED may emit light of a desired wavelength, for example infrared light in the range of 750 nm to 2.5 pm. The light emitting element 102 may emit a light ray 103 directed towards the finger 120 of the person.

[0080] The spectroscopic module 100 may comprise a set of photosensors 104 which may be mounted on the substrate 101 . The set of photosensors 104 may comprise an array of photosensors, for example a 3 times 3 array. Each photosensor 105 may be sensitive to light at the wavelength range emitted by the light emitting element 102. The light ray 103 may impinge on the set of photosensors 104 after having penetrated into the finger 120. Each photosensor 105 may be covered with an optical filter 106. The optical filters 106 may be chosen to let pass light at different wavelengths, so each photosensor 105 receives a different wavelength range of light. The photosensor 105 may comprise a photosensitive material, for example a photoconductor like lead sulfide (PbS). The photosensor may generate an electric signal depending on the light intensity of the light impinging on the photosensor 105.

[0081] The spectroscopic module 100 may comprise a processor 107 which may be mounted on the substrate 101. The processor 107 may be operatively coupled to the light source 102 and the photodetectors 105, for example via electric conductors on the PCB. The processor 107 may be a microcontroller configured to control the light emitting element 102, for example to switch it on during the measurement and switch it off afterwards. The processor 107 may be a microcontroller configured to receive the electric signal from the photosensors 105 and convert them into digital signals by analog-to-digital conversion. The processor may thus generate spectroscopic data which may either be further processed to determine the concentration of a body substance of the person or it may forward the spectroscopic data to an electronic control unit (ECU) of the vehicle or the on-board computer of the vehicle for determining the concentration of a body substance of the person.

[0082] Figure 2 illustrates an example for a spectroscopic device of the present invention. The spectroscopic device 200 may be a smartphone, a tablet or a wearable such as a smartwatch. The spectroscopic device 200 may comprise a spectrometer module 210. The spectrometer module 210 may comprise an illumination 211. The illumination 211 may be a light source, for example an incandescent lamp or an LED. The light source may produce electromagnetic radiation in the desired range, for example in the near infrared range. The illumination 211 may further contain optics to direct the electromagnetic radiation from the light source to the object, for example lenses, mirrors and / or apertures. The spectrometer module 210 may further comprise a controller 213, for example an ASIC. The illumination 211 may be operatively coupled to the controller 213. The controller 213 may supply electric power, e.g. from the battery of the portable device 200, and switch the light source of the illumination 211 on and off when required.

[0083] The spectrometer module may further comprise a detector 212. The detector 212 may generate electric signals in response to electromagnetic irradiation impinging on the detector 212. The detector 212 may contain an array of photosensitive regions. Each photosensitive region may be covered by a filter such that electromagnetic radiation of a dedicated wavelength or wavelength range impinges on a photosensitive region. The photosensitive region may be sensitive in the wavelength region of interest, for example in the near infrared region. The photosensitive region may contain a photoconductor, for example PbS or PbSe. The photosensitive region may generate an electric current which is indicative of the intensity of the electromagnetic radiation impinging on the photosensitive region. The detector 212 may contain optics to collect a maximum of incoming electromagnetic radiation. The optics may include mirrors, lenses and / or apertures. The detector 212 may be operatively coupled to the controller 213. The controller 213 may collect the signal or the signals from the detector 212 and forward them to the processor 230. The spectrometer module may further comprise a heat source 214. The heat source 214 may cause the skin of the person to sweat. The heat source 214 may be operatively coupled to the controller 213. The controller 213 may switch the heat source 214 on an off and collect a signal, for example the temperature or the operational state of the heat source 214, from the heat source 214 and forward them to the processor 230.

[0084] The illumination 211, the detector 212 and the heat source 214 may be placed behind a transparent cover, for example a glass cover. The transparent cover may be in contact with the skin of the person.

[0085] The controller 213 may convert the signal or signals from analog to digital. This may, for example, be accomplished by integrating the electric current obtained from each photosensitive region and providing a value of the result in a digital form. By combining these values with the origin of the photosensitive region each of which measures the electromagnetic radiation at a particular wavelength or wavelength region, the controller 213 may gather spectroscopic data and forward these to the processor 230.

[0086] The spectroscopic device 200 may further comprise memory 220, for example RAM or flash memory. The memory 220 may store spectroscopic data, for example obtained from the spectrometer module 210. The memory may store object data, for example obtained from a different sensor of the spectroscopic device 200 or from a user interface to which a user has entered object data. The memory 220 may store environmental data, for example obtained from a different sensor of the spectroscopic device 200 or from a user interface to which a user has entered environmental data. The memory 220 may be operatively coupled to the processor 230, so the processor 230 may receive spectroscopic data, object data and / or environmental data from the memory 220.

[0087] The spectroscopic device 200 may further comprise a communication interface 240, for example a Wi-Fi connection to a network or a connection to a telecommunication network. The communication interface 240 may be operatively coupled to the processor 230, so the processor 230 may receive spectroscopic data, object data and / or environmental data from the communication interface 240, for example from a cloud computer system.

[0088] The spectroscopic device 200 may further comprise a camera 250, for example an RGB camera or an infrared camera. The camera 250 may be used for capturing an image of the object or its environment in order to obtain object data or environmental data. The camera 250 may be operatively coupled to the processor 230, so the processor 230 can receive image data from the camera 250. The processor 230 may execute code which is configured to extract object data or environmental data from the image received from the camera 250.

[0089] The processor 230 may execute the code for the method described above. The processor 230 may obtain the code from memory 220. The processor 230 may in this example execute both code of the spectrometer, in particular the determination of chemometric data using spectroscopic data, object data and environmental data, for example by executing a chemometric model. The portable device 200 may further contain a display (260) for collecting user input and display measurement results, for example via a graphical user interface (GUI).

[0090] Figure 3 illustrates another example for a spectroscopic device of the present invention. The spectroscopic device 320 may be a hand-held spectrometer. The spectroscopic device 320 may comprise an illumination 321, a detector 322, a controller 323 and a communication interface 324. The illumination 321 may be a light source, for example an incandescent lamp or an LED. The light source may produce electromagnetic radiation in the desired range, for example in the near infrared range. The illumination 321 may further contain optics to direct the electromagnetic radiation from the light source to the object, for example lenses, mirrors and / or apertures. The controller 323 may be an ASIC or a microcontroller. The illumination 321 may be operatively coupled to the controller 323. The controller 323 may supply electric power, e.g. from the battery of the spectroscopic device 320, and switch the light source of the illumination 321 on and off when required.

[0091] The detector 322 may generate electric signals in response to electromagnetic irradiation impinging on the detector 322. The detector 322 may contain an array of photosensitive regions. Each photosensitive region may be covered by a filter such that electromagnetic radiation of a dedicated wavelength or wavelength range impinges on a photosensitive region. The photosensitive region may be sensitive in the wavelength region of interest, for example in the near infrared region. The photosensitive region may contain a photoconductor, for example PbS or PbSe. The photosensitive region may generate an electric current which is indicative of the intensity of the electromagnetic radiation impinging on the photosensitive region. The detector 322 may contain optics to collect a maximum of incoming electromagnetic radiation. The optics may include mirrors, lenses and / or apertures.

[0092] The detector 322 may be operatively coupled to the controller 323. The controller 323 may convert the signal or signals from analog to digital. This may, for example, be accomplished by integrating the electric current obtained from each photosensitive region and providing a value of the result in a digital form. By combining these values with the origin of the photosensitive region each of which measures the electromagnetic radiation at a particular wavelength or wavelength region, the controller 323 may gather spectroscopic data.

[0093] The spectrometer device may further comprise a heat source 325. The heat source 325 may cause the skin of the person to sweat. The heat source 325 may be operatively coupled to the controller 323. The controller 323 may switch the heat source 325 on and off and collect a signal from the heat source 325, for example its temperature or its operational state.

[0094] The communication interface 324 may be a wireless connection to a portable device 310. The communication interface 324 may be operatively coupled to the controller 323 so the communication interface 324 may transfer the spectroscopic data from the controller 323 to the portable device 310. The portable device 310 may be a smartphone or a tablet. The portable device 310 may comprise a communication interface 313 to receive the spectroscopic data from the spectroscopic device 320. The portable device 310 may comprise a processor 311, for example a CPU. The processor 311 may be operationally coupled to the communication interface 313. The processor 311 may receive the spectroscopic data form the communication interface 313. The processor 311 may be operationally coupled to memory 312. Memory 312 may store a chemometric model, object data and environmental data. The processor 311 may apply the chemometric model retrieved from memory 312 using the spectroscopic data, the object data and the environmental data and thereby determine chemometric data. The portable device 310 may further comprise a camera 314, for example an RGB camera, which operationally coupled to the processor 311. The processor 311 may receive an image of the object from the camera 314 and extract object data from the image which may be used to determine chemometric data. The determined chemometric data may be stored in memory 312 or it may be displayed on display 314, for example on a user interface.

[0095] Figure 4 illustrates an example of the method for determining a concentration of a body substance of a person. Heat may be applied 401, for example by a Nichrome wire heating element. The heat may be applied to the skin of the person, for example to heat the surface of the skin to a temperature of 35 to 40 °C for 10 s to 20 s. A trigger condition may be determined 402, for example by the processor of the spectroscopic device. The trigger condition may be fulfilled if the heat has been applied for a predefined period of time. The controller of the heat source may send a signal indicating how long the heat has been applied. Determination if the trigger condition is fulfilled 402 may involve impedance data 403, for example received from a bioimpedance sensor integrated into the spectroscopic device. The impedance data 403 may indicate the presence of sweat, for example if the impedance of the skin has decreased by a certain amount, for example by 20 %. If the trigger condition is not fulfilled, further heat may be applied 401 . If the trigger condition is fulfilled, a spectroscopic measurement may be triggered 404, for example by sending a signal to the spectroscopic module causing the spectroscopic module to execute a measurement. Spectroscopic data may be received from the spectroscopy module in response to the trigger. The spectroscopic data may be used to determine the concentration of a body substance 406, for example the blood alcohol concentration or the blood glucose concentration. The determination may be achieved by using a chemometric model which has been trained for determining the concentration of the body substance of interest. Determination may include a reference spectrum obtained from a database 407. The reference spectrum may be a spectrum measured on a person for which the concentration of the body substance is known, for example in case of blood alcohol concentration, the person may have a concentration of 0. The reference spectrum may be from the same person as the spectroscopic data or from a different person. The reference spectrum may also be an average of reference spectra from multiple persons. The determination of the concentration of the body substance 406 may comprise subtracting the reference spectrum from the spectrum of the spectroscopic data.

[0096] Figure 5 illustrates another example of the method for determining a concentration of a body substance of a person. Heat may be applied 501 by a heat source, such as a Peltier element. The heat source may be integrated into a spectroscopic device which is held against the skin of the person. Spectroscopic data may be received 502, for example from the spectroscopic device. The spectroscopic data may be used to determine the water concentration 503, for example by inputting the spectroscopic data to a chemometric model which is trained to determine the water content from spectroscopic data. The trigger condition may be fulfilled 504 if the water concentration exceeds a threshold, for example 25 %. If this is not the case, further heat may be applied 501.

[0097] If the trigger condition is fulfilled 504, a spectroscopic measurement may be triggered 505, for example by sending a signal to the spectroscopic module causing the spectroscopic module to execute a measurement. Spectroscopic data may be received 506 in response to the trigger from the spectroscopic module. The spectroscopic data may be used to determine the concentration of the body substance 507, for example by using a chemometric model which is trained for determining the concentration of the body substance from spectroscopic data. A reference spectrum may be obtained from a database 508, for example a reference spectrum measured on skin without sweat. This reference spectrum may be used to determine the concentration of the body substance, for example by subtracting it from the spectrum of the received spectroscopic data 506.

[0098] The present disclosure has been described in conjunction with preferred embodiments and examples as well. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed invention, from the studies of the drawings, this disclosure and the claims.

[0099] Any steps presented herein can be performed in any order. The methods disclosed herein are not limited to a specific order of these steps. It is also not required that the different steps are per-formed at a certain place or in a certain computing node of a distributed system, i.e. each of the steps may be performed at different computing nodes using different equipment / data processing.

[0100] As used herein ..determining" also includes ..initiating or causing to determine", "generating" also includes ..initiating and / or causing to generate" and "providing” also includes "initiating or causing to determine, generate, select, send and / or receive”. "Initiating or causing to perform an action” includes any processing signal that triggers a computing node or device to perform the respective action.

[0101] In the claims as well as in the description the word "comprising” does not exclude other elements or steps and the indefinite article "a” or "an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation. In the claims as well as in the description the word "comprising” or "including” or similar wording does not exclude other elements or steps and shall not be construed limiting to the elements or steps lined out. The indefinite article "a” or "an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation or further elements may be included. Providing in the scope of this disclosure may include any interface configured to provide data. This may include an application programming interface, a human-machine interface such as a display and / or a software module interface. Providing may include communication of data or sub-mission of data to the interface, in particular display to a user or use of the data by the receiving node, entity or interface.

[0102] Various units, circuits, entities, nodes or other computing components may be described as "configured to” perform a task or tasks. Configured to shall recite structure meaning "having circuitry that” performs the task or tasks on operation. The units, circuits, entities, nodes or other computing components can be configured to perform the task even when the unit / circuit / component is not operating. The units, circuits, entities, nodes or other computing components that form the structure corresponding to "configured to” may include hardware circuits and / or memory storing program instructions executable to implement the operation. The units, circuits, entities, nodes or other computing components may be described as performing a task or tasks, for convenience in the description. Such descriptions shall be interpreted as including the phrase "configured to.” Any recitation of "configured to” is expressly intended not to invoke 35 U.S.C. § 112(f) interpretation.

[0103] In general, the methods, apparatuses, systems, computer elements, nodes or other computing components described herein may include memory, software components and hardware components. The memory can include volatile memory such as static or dynamic random-access memory and / or nonvolatile memory such as optical or magnetic disk storage, flash memory, programmable read-only memories, etc. The hardware components may include any combination of combinatorial logic circuitry, clocked storage devices such as flops, registers, latches, etc., finite state machines, memory such as static random-access memory or embedded dynamic random-access memory, custom designed circuitry, programmable logic arrays, etc.

[0104] Any disclosure and embodiments described herein relate to the methods, the systems, apparatuses, devices, chemicals, materials, computer program elements lined out above and vice versa. Advantageously, the benefits provided by any of the embodiments and examples equally apply to all other embodiments and examples and vice versa. All terms and definitions used herein are understood broadly and have their general meaning.

Claims

Claims1 . A spectroscopic device for determining a concentration of a body substance of a person comprising: a) a spectroscopy module configured to acquire spectroscopic data of the person, b) a heat source to cause the skin of the person to sweat, c) a processor configured to determine whether a trigger condition is fulfilled comprising determining a water concentration, to trigger a measurement of the spectroscopy module to acquire spectroscopic data of the sweat when the trigger condition is fulfilled, , and to determine the concentration of the body substance of the person using the spectroscopic data, and d) an output configured to output the concentration of the body substance of the person.

2. The spectroscopic device according to claim 1 , wherein the spectroscopic device comprises an impedance sensor to measure the impedance of the skin of the person and wherein the trigger condition comprises the impedance.

3. The spectroscopic device according to claim 1 or 2, wherein the spectroscopic device comprises a pressure sensor to measure the pressure exerted by the spectroscopy module against the skin of the person and wherein the trigger condition comprises the pressure.

4. The spectroscopic device according to any of the claims 1 to 3, wherein the trigger condition comprises a water concentration determined from spectroscopic data of the skin.

5. The spectroscopic device according to any of the claims 1 to 4, wherein the processor is configured to use a reference spectrum for determining the concentration of the body substance, wherein the reference spectrum is measured when the skin of the person does not sweat.

6. The spectroscopic device according to any of the claims 1 to 5, wherein the body substance is an intoxicant or its metabolite, in particular alcohol.

7. The spectroscopic device according any of the claims 1 to 6, wherein the spectroscopic device comprises a person identification system to provide the identity of the person and wherein the processor is configured to determine the concentration of the body substance using a personalized reference spectrum obtained from a database using the identity of the person.

8. The spectroscopic device according to any of the claims 1 to 7, wherein the spectroscopy module comprises a photosensor configured to measuring optical radiation with a wavelength of 750 nm to 2.5 pm.

9. A vehicle comprising the spectroscopic device according to any of the claims 1 to 8.

10. A method for determining a concentration of a body substance of a person comprising: a) heating the skin of the person to cause the skin of the person to sweat, b) determining whether a trigger condition is fulfilled comprising determining a water concentration, c) triggering a spectroscopy module to acquire spectroscopic data from the sweat when a trigger condition is fulfilled, d) determining the concentration of the body substance of the person using the spectroscopic data, and e) outputting the concentration of the body substance of the person.11 . The method according to claim 10, wherein the trigger condition comprises an impedance of the skin of less than 50 kQ at 1 kHz.

12. The method according to claim 10 or 11, wherein the trigger condition comprises a water concentration determined from spectroscopic data of above 25 %.

13. The method according to any of the claims 10 to 12, wherein determining the concentration of the body substance of the person further comprises using a reference spectrum, wherein the reference spectrum is measured while the heat source is at a temperature below body temperature.

14. Use of the concentration of the body substance of the person obtained from the method of any of the claims 10 to 13 for determining the person's fitness to drive a vehicle.

15. A non-transient computer-readable medium including instructions that, when executed by one or more processors of a spectroscopic device according to any of the claims 1-9, cause the spectroscopic device to perform a method comprising: a) heating the skin of the person at a measurement location to cause the skin to sweat, b) determining whether a trigger condition is fulfilled comprising determining a water concentration, c) triggering a spectroscopy module to acquire spectroscopic data from the person when the skin at the measurement location sweats, d) determining the concentration of the body substance of the person using the spectroscopic data, and e) outputting the concentration of the body substance of the person.

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