Bioimpedance device

Abstract

The invention is in the field of bioimpedance devices. The invention relates to a bioimpedance device for determining a concentration of a body substance of a person comprising: a) an impedance sensor for acquiring impedance data measured from the person, b) a spectroscopy module for acquiring spectroscopic data measured from the person, c) a processor for determining the concentration of the body substance of the person using the impedance data and the spectroscopic data, and d) an output for outputting the concentration of the body substance of the person.

Description

[0001] Bioimpedance Device

[0002] Description

[0003] The invention is in the field of bioimpedance devices. The invention relates to a bioimpedance device for determining a concentration of a body substance of a person, a vehicle comprising the bioimpedance 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.

[0004] Background

[0005] 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. Impedance measurement 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.

[0006] US 20051 0 203 435 A1 discloses an impedance sensor to measure a skin condition of a person. Two different frequencies are used to enable the sensor to measure more than just water in the skin. However, the method still remains limited to body substances of high content.

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

[0008] Summary

[0009] In one aspect the invention relates to a bioimpedance device for determining a concentration of a body substance of a person comprising: a) an impedance sensor for acquiring impedance data measured from the person, b) a spectroscopy module for acquiring spectroscopic data measured from the person, c) a processor for determining the concentration of the body substance of the person using the impedance data and the spectroscopic data, and d) an output for outputting the concentration of the body substance of the person.

[0010] In another aspect the invention relates to a vehicle comprising the bioimpedance device according to the invention.

[0011] In another aspect the invention relates to a method for determining a concentration of a body substance of a person comprising: a) receiving impedance data measured from the person, b) receiving spectroscopic data measured from the person, c) determining the concentration of the body substance of the person using the impedance data and the spectroscopic data, and d) outputting the concentration of the body substance of the person.

[0012] In another aspect the invention relates to a use of the concentration of the body substance of the person obtained from the method of any of the previous claims for determining the person's fitness to drive a vehicle.

[0013] 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) receiving impedance data measured from the person, b) receiving spectroscopic data measured from the person, c) determining the concentration of the body substance of the person using the impedance data and the spectroscopic data, and d) outputting the concentration of the body substance of the person.

[0014] 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. Skin moisture largely influences the impedance measurement result and occludes the effect of other body substances. By using spectroscopy to determine those body substances of higher concentration, such as water, the impedance measurement can be reliably refined to enable accurate detection of body substances of lower concentration. In addition, the combination of the two methods allows to eliminate other disturbing influence factors, such as the surrounding conditions like temperature or air humidity or imperfections of the measurement. This is because the two measurements are so different that most disturbances have different effects on the two measurements so they can be more easily eliminated by data processing. This enables the usage of the device in difficult environments, such as in a vehicle, and does not require any particularly skilled operators such as medical personal.

[0015] The term "bioimpedance” may refer to the electrical impedance exhibited by biological materials, such as biological tissue like skin. Bioimpedance may comprise information about the physiological or pathological characteristics of biological materials.

[0016] The bioimpedance device may be integrated into a vehicle including cars, motorcycles, buses, trucks, trams, trains or even airplanes, hence a vehicle may comprise a bioimpedance device. The bioimpedance device may be suitable for integration into a vehicle. The bioimpedance 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 bioimpedance 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. The bioimpedance device may be integrated into consumer electronics products, in particular in consumer electronic products which are worn on the body, for example a smartwatch, a headphone, 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 bioimpedance device may be integrated into apparel, for example in a hat, a helmet, a shirt, a scarf, a belt, underwear, shoes, or socks.

[0017] The term "bioimpedance device” may refer to an apparatus which is capable of recording impedance data of a person. The bioimpedance device may be portable or stationary, for example a laboratory device. A portable bioimpedance device may be a hand-held device or a module which is integrated into a portable device like a smartphone, a tablet or a wearable like a smartwatch. A portable bioimpedance 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 impedance data and spectroscopic data from the bioimpedance device. The computer device may store such impedance data and spectroscopic data, or send it to a system for determining concentration of a body substance.

[0018] The bioimpedance device comprises an impedance sensor for acquiring impedance data measured from the person. The impedance sensor may be configured to measure impedance of a person and provide the measured impedance data. The term "impedance sensor” may refer to a device capable of measuring the impedance of an object, in particular the impedance of the skin of a person. An impedance sensor may apply an alternating electric field to the object and measure its ability to resist the movement of charge in response to the alternating electric field. An impedance sensor may be a contact impedance sensor, i.e. an impedance sensor which is in electric contact with the object and measures the electric current flow through the object when an alternating electric field is applied. An impedance sensor may be a contact-less impedance sensor, i.e. an impedance sensor which is electrically insulated against the body, for example by an air gap or a layer of an insulating material. A contact-less impedance sensor may measure the capacitive or inductive impedance of the object from the dielectric loss and / or a phase shift of the electric field caused by the object.

[0019] A contact impedance sensor may comprise two electrodes or more than two, for example four, six, eight or ten. The contact impedance sensor may comprise an array of electrode pairs, for example an 8 by 8 array of electrode pairs. An electrode may have different shapes, for example a circular shape, a rectangular shape or a comb shape. The electrodes may all have the same shape or different shapes, for example one electrode may have a circular shape and the other electrode an arc-shape around the other electrode to form an arc-shaped gap between the electrodes. The electrodes may be made of an electrically conductive material such as a metal, for example stainless steel, silver, or gold, or of carbonaceous materials, for example carbon nanotubes, or combinations of different materials, for example copper covered with a thin layer of gold. The electrodes may be of different size, for example 100 pm to 5 mm such as 200 to 500 pm or 300 pm to 1 mm. The gap between two electrodes for measuring the impedance may have a length of 1 pm to 1 mm, such as 5 to 100 pm or 50 to 500 pm. The contact impedance sensor may comprise reference electrodes. Reference electrodes may refer to electrodes which are not in electric contact with the measurement object, for example due to an insulating layer. The reference electrodes may have the same geometry and the same material as the electrodes. The reference electrodes may be used to determine the internal impedance of the device and subtract it from the impedance measured on the measurement object. A contact impedance sensor may comprise a circuitry to apply a voltage between the electrodes. The voltage may be an alternating voltage. The voltage may be 1 mV to 5 V, for example 10 mV to 1 V or 100 mV to 2 V. The voltage may have a frequency of 1 kHz to 100 kHz, for example 5 kHz to 20 kHz or 30 kHz to 60 kHz. The contact impedance sensor may apply one voltage frequency or more than one, for example two or three. Different frequencies can be applied simultaneously or consecutively. By applying different frequencies, more information about the body substance can be extracted from the measurement object.

[0020] A contact-less impedance sensor may comprise an antenna or a resonator circuit, for example a complementary split ring resonator. A contact-less impedance sensor may generate microwaves, for example 500 MHz to 20 GHz, for example 1 GHz to 10 GHz or 2 GHz to 6 GHz, such as 2.45 GHz. A contact-less impedance sensor may generate microwaves of one wavelength or more than one wavelength, for example two, five, or ten. An antenna or a resonator circuit may be made of a highly conductive material, for example metals like copper, nickel or tin. An antenna or a resonator circuit may be coated with an insulating material, for example a polyurethane. Such coating may have a thickness of 0.1 to 1 mm, for example 0.2 to 0.5 mm. An antenna or a resonator circuit may generate microwaves with a power of 100 piW to 1 W, for example 1 mW to 200 mW. The contact-less impedance sensor may measure the amplitude and / or the phase shift of the applied microwaves. The contact-less impedance sensor may operate in reflection, transmission, or resonator mode.

[0021] The impedance sensor may comprise a readout circuitry for reading out the measured impedance value. The readout circuitry may comprise electrical components mounted on a printed circuit board, or the readout circuitry may be part of an application specific integrated circuit (ASIC). The readout circuitry may measure the current flowing between the electrodes. The readout circuitry may amplify the current flowing between the electrodes. The readout circuitry may comprise an analog-to-digital converter (ADC) to convert the measurement signals into a computer-readable format. The readout circuitry may calculate the impedance from the measured current and the applied voltage. The readout circuitry may correct the impedance, for example by applying calibration coefficient or by subtracting device- intrinsic impedance measured on reference electrodes.

[0022] The impedance measurement may be made on the skin of the person. The impedance measurement may be made at various body parts of the person, for example the face, the arm, the hand. The impedance 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 impedance measurement may be made in direct contact with the person.

[0023] The impedance sensor may output impedance data, for example to a processor. The term "impedance data” may refer to data indicative for impedance measurement results. Impedance data may comprise an electric resistance for an applied alternating voltage. Impedance data may comprise a capacitive or inductive impedance for an applied microwave, i.e. the amplitude and phase shift of the reflected or permitted microwaves. Impedance data may comprise one or more than one impedance values, for example an impedance value for each measured frequency, or values from which the impedance can be calculated, for example the applied voltage and frequency and the measured electric current. Impedance data may comprise further data related to the impedance measurement, for example the internal impedance of the impedance sensor either measured or stored, an identifier identifying the impedance sensor, a timestamp, a confidence value indicating the precision of the measurement, or a sampling time. The bioimpedance device may comprise a spectroscopy module for acquiring spectroscopic data measured from the person. The spectroscopy module may be configured to perform a spectroscopic measurement on a person and provide the measured spectroscopic data. The bioimpedance device may comprise a spectroscopy module comprising:

[0024] - an optical element configured for separating incident optical radiation provided by the measurement into a spectrum of constituent wavelength components;

[0025] - 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.

[0026] 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.

[0027] 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. 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.

[0028] The spectroscopy module 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) for example an LED covered with a fluorescent coating, a superluminescent diode, a laser diode, a gasdischarge lamp, for example a xenon lamp, a mercury vapor lamp, or a deuterium lamp.

[0029] 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” (MidlR) 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 (MidlR), 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.

[0030] The spectroscopy module 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 bioimpedance 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.

[0031] The spectroscopy module 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.

[0032] 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. 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.

[0033] 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.

[0034] 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. The spectroscopic module may be placed in close proximity to the impedance sensor such that the same or essentially the same part of the body of the person is measured by both the impedance sensor and the spectroscopic module. The term "close proximity” may refer to a distance within which negligible variations of the concentration of the body substance can be expected, for example less than 5 cm or less than 1 cm or less than 5 mm.

[0035] 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.

[0036] 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.

[0037] Body substances may be body fat, muscle mass, total free water, extracellular water, intracellular water, bioimpedance cardiography measures such as stroke volume or cardiac output of blood.

[0038] 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 bioimpedance device of the present invention. The spectroscopic data may be received directly from a bioimpedance 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 indicate 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.

[0039] 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.

[0040] 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 bioimpedance device may comprise a pressure sensor for measuring the pressure exerted by the bioimpedance device against the person, in particular for measuring the pressure exerted by the impedance sensor 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 impedance sensor and / or the spectroscopic module such that the pressure against the body location can be measured for which the impedance sensor and / or the spectroscopic data is measured. 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.

[0041] Determining the concentration of a body substance may involve a reference spectrum. The reference spectrum may be a spectrum measured under controlled conditions, i.e. under conditions in which the concentration of the body substance is known, for example from other analytic methods. 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 bioimpedance 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.

[0042] The concentration of a body substance of the person is determined using the impedance data the spectroscopic data. The concentration of a body substance of the person may be determined using the impedance data, the spectroscopic data and person data. The concentration of a body substance of the person may be determined using the impedance data, the spectroscopic data and environmental data. The concentration of a body substance of the person may be determined using the impedance data, 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.

[0043] 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.

[0044] 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.

[0045] 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, 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 bioimpedance 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 bioimpedance device.

[0046] 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 including a physical body measure like height, waist circumference, leg length, arm length, head circumference, foot size, hand size, body shape, for example a category like ectomorph, mesomorph, endomorph, body weight, body mass index, body composition, skin color, hair color, hair type; a demographic characteristic like age, sex, origin, ethnicity; medical history including current and former medications; nutrition habits 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.

[0047] 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. 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.

[0048] Sensor data may have been recorded by a sensor capable of determining the sensor data. The sensor may be integrated into the spectrometer. The bioimpedance 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.

[0049] 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.

[0050] Environmental data may be received from a data storage medium. The data storage medium may be part of the bioimpedance 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.

[0051] The concentration of a body substance of the person may be determined by employing a model. The model may be parameterized to receive impedance data and spectroscopic data as input and output the concentration of a body substance. The model may comprise an impedance model and a chemometric model. The impedance model may determine a concentration of a body substance using the impedance model and the chemometric model may determine a concentration of a body substance from the spectroscopic data. The impedance model and the chemometric model may determine the concentration of the same body substance. In this case, the model may comprise an aggregation model which aggregates both concentrations, for example by averaging. The aggregation model may average the two concentrations of the body substance, for example by weight-averaging. The weights may depend on the body substance, for example the weights may be chosen for each body substance according to the sensitivity of the impedance measurement and spectroscopy with regard to this body substance. The impedance model and the chemometric model may determine the concentration of different body substances, for example the impedance model determines the concentration of a first body substance and the chemometric model determines the concentration of a second body substance. The model may output both concentrations or adjust the concentration of the first body substance using the concentration of the second body substance.

[0052] The term "impedance model” may refer to a model which is parameterized to receive impedance data as input and output the concentration of a body substance. The impedance model may be a deterministic model, i.e. a model using laws of nature to translate the impedance data into the concentration of a body substance. The impedance model may be a data-driven model, i.e. a model which extracts the correlation between impedance data and the concentration of a body substance from historic data by training. The impedance model may be a multivariate linear or polynomial regression model, or it may be an artificial neural network. The impedance model may be parameterized to receive impedance data and environmental data as input and output the concentration of a body substance. The impedance model may be parameterized to receive impedance data, person data and environmental data as input and output the concentration of a body substance. The impedance model may be parameterized to receive impedance data as input and output an intermediate impedance 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.

[0053] 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.

[0054] 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.

[0055] 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. 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.

[0056] 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.

[0057] 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.

[0058] The concentration of the body substance of the person may be determined by: d) determining the concentration of an occlusion body substance using the spectroscopic data, and c2) determining the concentration of the body substance from the impedance data and the concentration of an occlusion body substance.

[0059] The term "occlusion body substance” may refer to a body substance of a concentration higher than the concentration of the body substance to be determined, for example a body substance of a concentration of more than 1 % or more then 5 % or more then 10 %. Examples for occlusion body substances are water, lipids, and proteins. The concentration of the occlusion body substance may be determined by a chemometric model receiving spectroscopic data as input. The concentration of the occlusion body substance may be input to an impedance model with further receives the impedance data as input and outputs the concentration of the body substance. In this way, the impedance model may remove occlusion by the occlusion body substances, for example by correcting the impedance data according to the concentration of the occlusion body substances. A more accurate concentration of the body substances can thus be obtained from the impedance data. The bioimpedance 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 bioimpedance device or into a different part. For example, the bioimpedance 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 bioimpedance device is in fact the person and not a different vehicle passenger. This may be efficiently achieved if the bioimpedance 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.

[0060] 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.

[0061] 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 .

[0062] 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.

[0063] Outputting may be effected through an output or an output interface for outputting the chemometric data of the object. An output or output interface may be a hardware or software component that facilitates the transmission of data from the computer system to external devices or systems. It may include ports, connectors, network cards, and wireless modules supporting various data transfer protocols like USB, HDMI, Ethernet, Bluetooth, and Wi-Fi. The output interface manages the encoding, formatting, and transmission of data, ensuring compatibility with the receiving device. It may comprise a USB port for peripherals, an HDMI port for video and audio signals, or network interface cards for LAN or internet communication. Software components, such as drivers and communication protocols, may also be included to ensure proper data transmission. In cloud-based environments, the output interface may include virtual interfaces like APIs and web services for data exchange between local systems and cloud platforms. The bioimpedance device may comprise a processor for determining the concentration of the body substance. The processor may be configured to determining the concentration of the body substance. The term "processor” may refer to a device configured to processing, manipulating, or transforming data according to a set of instructions. The processor may be capable of executing software, algorithms, or computational tasks to achieve a desired output. Examples of a processor may include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a microcontroller, a field-programmable gate array (FPGA), or an application-specific integrated circuit (ASIC). The processor may be a component of a larger system, such as an embedded system, a computer, or a mobile device, and may interact with other components such as memory, input / output devices, and sensors.

[0064] The concentration of the body substance may be used to determine the person's fitness to drive a vehicle. The processor of the bioimpedance 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 medical 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Brief Description of the Figures

[0070] Figure 1 illustrates an example for a bioimpedance device.

[0071] Figure 2 illustrates possible placements of the bioimpedance device in the interior of a car.

[0072] Figure 3 illustrates an example for a bioimpedance device of the present invention.

[0073] Figure 4 illustrates an example for the method determining a concentration of a body substance of a person.

[0074] Figure 5 illustrates another example for the method determining a concentration of a body substance of a person. Description of Embodiments

[0075] Figure 1 illustrates an example for a bioimpedance device. The bioimpedance device may be suitable to acquire impedance data and 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 bioimpedance device may comprise an impedance sensor comprising a first electrode 111 a, a second electrode 111 b and a controller 112. The electrodes 111 a and 111 b may be placed between the cover 110 and the finger 120, so the finger is in contact with the electrodes. The controller 112 may be communicatively connected to the electrodes 111 a and 111 b. The controller 112 may apply a voltage between the electrodes 111 a and 111 b, for example an alternating voltage of 2 V at a frequency of 10 kHz. The controller 112 may measure the current flow between the electrodes 111 a and 111 b and determine the impedance of the finger 120 therefrom. The controller 112 may adjust the impedance by subtracting the intrinsic impedance, for example by a stored value or an impedance measured between reference electrodes. The controller 112 may convert the impedance into a digital signal and thereby generating impedance data. The impedance data may be send to a processor, for example processor 107.

[0076] The bioimpedance 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 m. The light emitting element 102 may emit a light ray 103 directed towards the finger 120 of the person.

[0077] 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.

[0078] 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.

[0079] The spectroscopic data may be used to determine the concentration of body substances of higher concentration, for example water and lipids. The impedance data may be used to determine the concentration of a body substance of lower concentration, for example the blood alcohol concentration. This determination may take into account the concentration of body substances of higher concentration determined from the spectroscopic data. Such determination may be executed by 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.

[0080] Figure 2 illustrates possible placements of the bioimpedance device in the interior of a car. The figure shows the dashboard, the middle console, the steering wheel and the windshield of a car as seen from the inside of the car. The bioimpedance device may be integrated into various places, for example behind a transparent display or as a separate device in parts of the car accessible to the driver. The bioimpedance device may be integrated in the center above the windscreen (201). Another option is to integrate the bioimpedance device into the interior mirror (202). This may be particularly useful if the mirror functionality is only mimicked by a display which displays the rear view recorded by a camera. The bioimpedance device may be integrated into the A column on the driver's side (203). Another possibility is space behind the steering wheel (204) where the gauges such as the speed gauge are typically placed. The bioimpedance device may further be integrated into the steering wheel rim in a position where the driver puts his palm or fingers (205). Another possibility is to place the bioimpedance device into an engine start-stop button (206), a display in the center of the dashboard (207), the side door, for example just beneath the side window (208), the door handle (209), or the arm rest in the side door (210). Furthermore, the bioimpedance device may also be integrated into the center of the steering wheel (211), for example as part of a control system for the board computer or the entertainment system. The gearshift lever (212) or the center console, such as a display in the center console (213) or a button (214) such as the board computer control button or the park break button are further options. The latter may replace traditional controls with a display. The space behind the steering wheel (204), the center of the dashboard (207) and the center console (213) may be combined in a continuous display behind which the bioimpedance device may be placed.

[0081] Figure 3 illustrates an example for a bioimpedance device of the present invention. The bioimpedance device 300 may be a smartphone, a tablet or a wearable such as a smartwatch. The bioimpedance device 300 may comprise a spectrometer module 310. The spectrometer module 310 may comprise an illumination 311. The illumination 311 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 311 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 310 may further comprise a controller 313, for example an ASIC. The illumination 311 may be operatively coupled to the controller 313. The controller 313 may supply electric power, e.g. from the battery of the portable device 300, and switch the light source of the illumination 311 on and off when required.

[0082] The spectrometer module may further comprise a detector 312. The detector 312 may generate electric signals in response to electromagnetic irradiation impinging on the detector 312. The detector 312 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 312 may contain optics to collect a maximum of incoming electromagnetic radiation. The optics may include mirrors, lenses and / or apertures. The detector 312 may be operatively coupled to the controller 313. The controller 313 may collect the signal or the signals from the detector 312 and forward them to the processor 330.

[0083] The illumination 311, the detector 312 and the pressure sensor 314 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.

[0084] The controller 313 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 313 may gather spectroscopic data and forward these to the processor 330.

[0085] The bioimpedance device 300 may comprise an impedance sensor 320. The impedance sensor 320 may comprise an antenna 321. The antenna may be made of copper, have a size of 5 x 5 mm. The antenna may generate microwaves, for example microwaves with a frequency of 2 to 6 GHz, for example 2.45 GHz. The impedance sensor

[0086] 320 may comprise readout circuitry 322. The readout circuitry may be electrically coupled with the antenna 321. The readout circuitry 322 may read out the amplitude and / or the phase shift of the microwaves and thereby determine the complex impedance. The impedance sensor 320 may comprise a controller 323. The controller 323 may be communicatively coupled with the antenna 321 and the readout circuitry. The controller 323 may switch the antenna

[0087] 321 on and off. The controller 323 may be communicatively coupled with the readout circuitry 322 to receive the impedance values measured by the readout circuitry 322. The controller 323 may convert the impedance values into a digital signal which may become part of impedance data. The controller 323 may forward the impedance data to the processor 330.

[0088] The bioimpedance device 300 may further comprise memory 340, for example RAM or flash memory. The memory 340 may store spectroscopic data, for example obtained from the spectrometer module 310 and impedance data, for example obtained from the impedance sensor 320. The memory 340 may store object data, for example obtained from a different sensor of the bioimpedance device 300 or from a user interface to which a user has entered object data. The memory 340 may store environmental data, for example obtained from a different sensor of the bioimpedance device 300 or from a user interface to which a user has entered environmental data. The memory 340 may be operatively coupled to the processor 330, so the processor 330 may receive spectroscopic data, impedance data, object data and / or environmental data from the memory 340.

[0089] The bioimpedance device 300 may further comprise a communication interface 350, for example a Wi-Fi connection to a network or a connection to a telecommunication network. The communication interface 350 may be operatively coupled to the processor 330, so the processor 330 may receive spectroscopic data, object data and / or environmental data from the communication interface 350, for example from a cloud computer system.

[0090] The processor 330 may execute the code for the method described above. The processor 330 may obtain the code from memory 340. The processor 330 may in this example execute both code of the bioimpedance device 300, in particular the determination of the concentration of the body substance from impedance data, spectroscopic data, object data and environmental data, for example by executing a chemometric model. The portable device 300 may further contain a display (360) for collecting user input and display measurement results, for example via a graphical user interface (GUI).

[0091] Figure 4 illustrates an example for the method determining a concentration of a body substance of a person. An impedance sensor 401 may determine impedance data 402 and forward them to processor 420. A spectroscopy module 411 may determine spectroscopic data 412 and forward them to processor 420. Processor 420 may execute a model which is configured to receive impedance data 402 and spectroscopic data 412 as input and output the concentration of a body substance 430. For example, the model may comprise an impedance model which receives impedance data 402 data as input and outputs a concentration of a body substance, for example the concentration of blood glucose level. The model may further comprise a chemometric model which receives spectroscopic data 412 as input and output the concentration of a body substance. The model may further comprise an aggregation model which receives both concentrations of the body substance as input and outputs an aggregated concentration of the body substance. The aggregation model may average the two concentrations of the body substance, for example by weight-averaging. The weights may depend on the body substance, for example the weights may be chosen for each body substance according to the sensitivity of the impedance measurement and spectroscopy with regard to this body substance.

[0092] Figure 5 illustrates another example for the method determining a concentration of a body substance of a person. As an example, the blood alcohol concentration is desired, for example to determine the fitness to drive of a driver intending to start a car. An impedance sensor 501 may determine impedance data 502. The impedance data 502 may comprise impedance values for different frequencies, for example 1.2 MQ for a frequency of 10 kHz and 0.8 MQ for a frequency of 35 kHz. The impedance data 502 may be input to an impedance model. A spectroscopy module 511 may determine spectroscopic data 512, for example the absorption values at different wavelengths of the infrared spectral range. The spectroscopic data 512 may be input to a chemometric model which determines an occlusion body substance 514, for example water. The water concentration may be 45 %. This value may be input to the impedance model 503. The impedance model 503 may determine the concentration of the body substance 530 using both impedance data 502 and the concentration of the occlusion body substance 514. The impedance model may be a multivariate regression model which has been trained with reference data comprising datasets for the impedance at different frequencies given a certain water content and a certain blood alcohol concentration. The impedance model 503 may output the concentration of the body substance 530, for example to an onboard computer of a car which may grant or deny access to the car depending on the determined concentration of the body substance 530, namely in this example the blood alcohol concentration.

[0093] 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.

[0094] 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. 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.

[0095] 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 or further elements may be included.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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 bioimpedance device for determining a concentration of a body substance of a person comprising: a) an impedance sensor for acquiring impedance data measured from the person, b) a spectroscopy module for acquiring spectroscopic data measured from the person, c) a processor for determining the concentration of the body substance of the person using the impedance data and the spectroscopic data, and d) an output for outputting the concentration of the body substance of the person.

2. The bioimpedance device according to claim 1, wherein the spectroscopy module comprises a light emitting diode for illuminating the person, a plurality of a photosensors and optical filter elements positioned in a light beam path before the photosensors.

3. The bioimpedance device according to claim 1 or 2, wherein the bioimpedance device further comprises a pressure sensor for measuring the pressure exerted by the bioimpedance device against the person.

4. The bioimpedance device according to any of the claims 1 to 3, wherein the impedance sensor and the spectroscopic module are placed less than 5 cm apart from each other.

5. The bioimpedance device according to any of the claims 1 to 4, wherein the body substance is body fat, muscle mass, total free water, extracellular water, intracellular water, bioimpedance cardiography measures.

6. The bioimpedance device according any of the claims 1 to 5, 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.

7. The bioimpedance device according to any of the claims 1 to 6, wherein the spectroscopy module comprises a photosensor configured for measuring optical radiation with a wavelength of 750 nm to 2.5 pm.

8. A vehicle comprising the bioimpedance device according to any of the claims 1 to 7.

9. A method for determining a concentration of a body substance of a person comprising: a) receiving impedance data measured from the person, b) receiving spectroscopic data measured from the person, c) determining the concentration of the body substance of the person using the impedance data and the spectroscopic data, and d) outputting the concentration of the body substance of the person.

10. The method according to claim 9, wherein the concentration of the body substance of the person is determined by: d) determining the concentration of an occlusion body substance using the spectroscopic data, wherein an occlusion body substance is a body substance of a concentration higher than the concentration of the body substance to be determined, andc2) determining the concentration of the body substance from the impedance data and the concentration of an occlusion body substance.

11. The method according to claim 10, wherein the occlusion body substance is at least one of water, lipids, and proteins.

12. The method according to claim 9, wherein the concentration of the body substance is determined from the impedance data to yield a first concentration and from the spectroscopic data to yield a second concentration, wherein the concentration of the body substance is obtained by weight averaging the first and the second concentration.

13. The method according to any of the claims 9 to 12, wherein determining the concentration of the body substance of the person further comprises using person data associated with a characteristic of the person or environmental data associated with a characteristic of the surrounding of the person.

14. Use of the concentration of the body substance of the person obtained from the method of any of the previous claims 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, cause the one or more processors to perform a method comprising: a) receiving impedance data measured from the person, b) receiving spectroscopic data measured from the person, c) determining the concentration of the body substance of the person using the impedance data and the spectroscopic data, and d) outputting the concentration of the body substance of the person.