Non-invasive substance analysis

A method for analyzing a substance, comprising the following steps:

• arranging an optical medium on a substance surface so that at least a portion of the surface of the optical medium is in contact with the substance surface;
• emitting an excitation light beam with an excitation wavelength through the region of the surface of the optical medium in contact with the substance surface onto the substance surface;
• emitting a probe light beam through the optical medium onto the region of the surface of the optical medium which is in direct contact with the substance surface, in such a way that the probe light beam and the excitation light beam overlap at an interface of the optical medium and the substance surface at which the probe light beam is reflected;
• directly or indirectly detecting a deflection of the reflected probe light beam as a function of the wavelength of the excitation light beam;
• and
• analysing the substance on the basis of the detected deflection of the probe light beam as a function of the wavelength of the excitation light beam,
• wherein the substance:
• is a flowing or stationary fluid or emulsion and the analysis of the substance comprises determining a sugar content, alcohol content, fat and/or protein content of the fluid;
• is a fuel and the analysis of the substance comprises determining an alcohol content, rapeseed oil methyl ester content, lead or benzene content of the fuel;
• is fresh or salt water and the analysis of the substance comprises determining a contamination of the water;
• or
• is a body fluid.

A method for analyzing a substance, comprising the following steps:

• arranging an optical medium on a substance surface so that at least a portion of the surface of the optical medium is in contact with the substance surface;
• emitting an excitation light beam with an excitation wavelength through the region of the surface of the optical medium in contact with the substance surface onto the substance surface;
• emitting a probe light beam through the optical medium onto the region of the surface of the optical medium which is in direct contact with the substance surface, in such a way that the probe light beam and the excitation light beam overlap at an interface of the optical medium and the substance surface at which the probe light beam is reflected;
• directly or indirectly detecting a deflection of the reflected probe light beam as a function of the wavelength of the excitation light beam;
• and
• analysing the substance on the basis of the detected deflection of the probe light beam as a function of the wavelength of the excitation light beam, in which, based on the detected deflection of the probe light beam, an absorption intensity value is associated with the wavelength of the excitation light beam, and
• wherein the analysis of the substance comprises determining the blood sugar level of a patient and wherein the absorption intensity value is compared with a calibration absorption intensity value, which represents the absorption intensity value of the skin of the patient at a known blood sugar level and at this exact wavelength of the excitation light beam.

An apparatus for determining blood sugar level of a patient, which comprises the following:

• a system for analysing a substance, comprising:
• an optical medium;
• a device for emitting an excitation light beam with an excitation wavelength,
• wherein the device for emitting the excitation light beam is arranged such that the emitted excitation light beam enters the optical medium and exits the same again at a predetermined point on the surface of the optical medium;
• and
• a measurement device, wherein the measurement device comprises a device for emitting a probe light beam, which is arranged such that an emitted probe light beam enters the optical medium, and during operation the probe light beam and the excitation light beam overlap at an interface of the optical medium and a substance surface at which the probe light beam is reflected,
• and wherein the measurement device comprises a device for receiving the reflected probe light beam and for directly or indirectly detecting a deflection of the reflected probe light beam,
• a controller for setting different wavelengths of the excitation light beam, and
• a logic unit or calculating unit, which is configured to determine blood sugar levels in the skin of a patient from detected deflections of the probe light beam as a function of the excitation wavelength, when the optical medium is brought into contact with the skin of the patient in such away that the excitation light beam emerging from the optical medium at the said predetermined point enters into the skin.

An apparatus for analyzing constituents of a liquid or emulsion, comprising the following:

• a system for analysing a substance, comprising:
• an optical medium;
• a device for emitting an excitation light beam with an excitation wavelength,
• wherein the device for emitting the excitation light beam is arranged such that the emitted excitation light beam enters the optical medium and exits the same again at a predetermined point on the surface of the optical medium;
• and
• a measurement device, wherein the measurement device comprises a device for emitting a probe light beam, which is arranged such that an emitted probe light beam enters the optical medium, and during operation the probe light beam and the excitation light beam overlap at an interface of the optical medium and a substance surface at which the probe light beam is reflected,
• and wherein the measurement device comprises a device for receiving the reflected probe light beam and for directly or indirectly detecting a deflection of the reflected probe light beam,
• a controller for setting different wavelengths of the excitation light beam, and
• a logic unit or calculating unit, which is configured to determine constituents of the liquid or emulsion from detected deflections of the probe light beam as a function of the excitation wavelength, when the optical medium is brought into contact with the liquid or emulsion in such a way that the excitation light beam emerging from the optical medium at the said predetermined point enters into the liquid or emulsion.

A method for analyzing a substance, comprising the following steps:

• arranging an optical medium on a substance surface so that at least a portion of the surface of the optical medium is in contact with the substance surface;
• emitting an excitation light beam with an excitation wavelength through the region of the surface of the optical medium in contact with the substance surface onto the substance surface;
• emitting a probe light beam through the optical medium onto the region of the surface of the optical medium which is in direct contact with the substance surface, in such a way that the probe light beam and the excitation light beam overlap at an interface of the optical medium and the substance surface at which the probe light beam is reflected;
• directly or indirectly detecting a deflection of the reflected probe light beam as a function of the wavelength of the excitation light beam;
• and
• analysing the substance on the basis of the detected deflection of the probe light beam as a function of the wavelength of the excitation light beam, wherein the excitation light beam is an intensity-modulated pulsed excitation light beam, wherein the step of emitting the excitation light beam is repeated for different modulation frequencies and the step of analyzing the substance comprises the analysis of the substance on the basis of the detected deflections of the probe beam as a function of the wavelength and the modulation frequency of the excitation light beam, wherein the step of analyzing the substance comprises either (1) a subtraction of a value which is based on a deflection of the probe light beam that was detected at a first modulation frequency, from a value which is based on a deflection of the probe light beam that was detected at a second modulation frequency;
• or
• (2) a division of a value which is based on a deflection of the probe light beam that was detected at a first modulation frequency, by a value which is based on a deflection of the probe light beam that was detected at a second modulation frequency.