Method and device for determining a degree of thermal damage to hair

Abstract

A method and a device for determining a degree of thermal hair damage are provided. A method for determining a degree of thermal hair damage includes, during exposure of a hair sample of hair to UV or UV/VIS light, recording a spectrum of at least a portion of the UV or UV/VIS light that has interacted with the hair sample. Further, the method includes comparing at least a portion of the spectrum with a spectroscopic calibration model obtained using UV or UV/VIS spectra and degrees of thermal damage of a plurality of calibration hair samples. Also, the method includes determining the degree of thermal hair damage by using the comparison.

Claims

1. A method for determining a degree of thermal hair damage, comprising: during exposure of a hair sample of hair to UV or UV/VIS light, recording a spectrum of at least a portion of the UV or UV/VIS light that has interacted with the hair sample; comparing at least a portion of the spectrum with a spectroscopic calibration model obtained using UV or UV/VIS spectra and degrees of thermal damage of a plurality of calibration hair samples; and determining the degree of thermal hair damage by using the comparison, wherein the spectroscopic calibration model is obtained by: for the plurality of calibration hair samples: exposing the calibration hair samples to a heat of a predetermined temperature for a predetermined time period; during exposure of the calibration to the heat for the predetermined time period, exposing the calibration hair samples to UV or UV/VIS light at a plurality of time intervals; during exposure of the calibration hair samples to the UV or UV/VIS light at each of the plurality of time intervals, acquiring a spectrum of at least a portion of the UV or UV/VIS light that interacted with the calibration hair sample; at each of the plurality of time intervals, determining an intensity ratio of the intensity of UV or UV/VIS light to which the calibration hair samples were exposed to the intensity of UV or UV/VIS light detected in the spectrum for each detected wavelength; determining a degree of thermal hair damage of the calibration hair samples by an independent method; assigning the degree of thermal hair damage to the calibration spectrum; and determining a correlation between the plurality of calibration ratios and the plurality of degrees of thermal hair damage.

2. The method according to claim 1, wherein the exposure of the hair sample and/or the calibration hair sample is carried out with UV or UV/VIS light with a wavelength range of from about 270 to about 290 nm.

3. The method according to claim 1, wherein the independent method comprises determining a notional hair damage period.

4. The method according to claim 3, wherein the at least one part of the UV or UV/VIS light has a wavelength range of from about 300 to about 350 nm.

5. The method according to claim 1, wherein the exposure of the hair sample and/or the calibration hair sample is performed with UV or UV/VIS light of a wavelength of from about 250 to about 300 nm.

6. A method for determining individual treatment instructions, comprising: determining a degree of thermal hair damage of an individual according to claim 1; and determining, via a computer-aided determination, individual treatment instructions depending on the degree of thermal hair damage.

7. The method according to claim 6, wherein the individual treatment instructions comprise the recommendation of bleaching products and/or hair dyes and/or hair care products and/or hair styling products.

8. A device for determining a degree of thermal hair damage, comprising: a UV light source or a UV/VIS light source for exposing a hair sample of the hair to UV or UV/VIS light; a spectrometer for recording a spectrum of at least a portion of the UV or UV/VIS light that has interacted with the hair sample; and a data processing device having a data memory in which a spectroscopic calibration model obtained by means of UV or UV/VIS spectra and degrees of thermal hair damage of a plurality of calibration hair samples is stored, and having a processor for comparing at least a part of the spectrum with the spectroscopic calibration model and for determining the degree of thermal hair damage by using the comparison, wherein the spectroscopic calibration model is obtained by: for the plurality of calibration hair samples: exposing the calibration hair samples to a heat of a predetermined temperature for a predetermined time period; during exposure of the calibration to the heat for the predetermined time period, exposing the calibration hair samples to UV or UV/VIS light at a plurality of time intervals; during exposure of the calibration hair samples to the UV or UV/VIS light at each of the plurality of time intervals, acquiring a spectrum of at least a portion of the UV or UV/VIS light that interacted with the calibration hair sample; at each of the plurality of time intervals, determining an intensity ratio of the intensity of UV or UV/VIS light to which the calibration hair samples were exposed to the intensity of UV or UV/VIS light detected in the spectrum for each detected wavelength; determining a degree of thermal hair damage of the calibration hair samples by an independent method; assigning the degree of thermal hair damage to the calibration spectrum; and determining a correlation between the plurality of calibration ratios and the plurality of degrees of thermal hair damage.

9. The device according to claim 8, wherein the UV or UV/VIS light source and the spectrometer form an integrated unit.

10. The device according to claim 8, wherein the integrated unit and/or the data processing device are mobile devices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) It is understood that other embodiments may be used and structural or logical modifications may be made without deviating from the scope of protection of the present disclosure. It is understood that the features of the various exemplary embodiments described herein may be combined with each other unless specifically stated otherwise. The following detailed description is therefore not to be understood in a restrictive sense and the scope of protection of the present disclosure is defined by the appended claims.

(2) FIG. 1 shows in view 100 a schematic representation of a method for determining a degree of thermal hair damage according to different exemplary embodiments.

DETAILED DESCRIPTION

(3) The following detailed description is merely exemplary in nature and is not intended to limit the disclosure or the application and uses of the subject matter as described herein. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

(4) According to different exemplary embodiments, a hair sample 102P may be examined to determine the degree of thermal damage of a user's hair 102. The hair sample 102P may remain on the head or be removed. Hair sample 102P may be located at a distance 102PL from a user's scalp or may be removed from the user's scalp. The hair sample 102P may have a minimum amount of hair, which may be expressed as a minimum area that may be covered by the (e.g. flatly spread) hair sample 102P, for example at least about 1 cm.sup.2, or as a minimum weight, for example at least about 0.5 g.

(5) In various exemplary embodiments, a device may be used to determine the degree of thermal hair damage of the hair 102, as shown in FIG. 1, exemplarily schematically in view 100.

(6) In various exemplary embodiments, the hair sample 102P may be spread out so that it covers at least one interaction area which is illuminated by a light source 106 with UV or UV/VIS light 110 and from which the light 110, after interaction with the hair sample 102 designated as light 112 to be analyzed, enters a spectrometer 108.

(7) In various exemplary embodiments, the hair sample 102P may be illuminated with UV light 110 or UV/VIS light 110. UV light 110 may cover a wavelength range from about 200 to about 380 nm, or at least a suitable sub-range thereof, for example from about 250 to about 300 nm. UV/VIS light 110 may cover a wavelength range from about 200 to about 500 nm, or at least a suitable sub-range thereof, for example from about 250 to about 400 nm.

(8) In various exemplary embodiments, a light source 106 of UV or UV/VIS light 110 may be, for example, a UV lamp or a UV/VIS lamp, or any other conventional light source providing a suitable light spectrum.

(9) Thanks to progressive improvement of UV or UV/VIS spectroscopy devices, they may be provided in a miniaturized, e.g. mobile, form, for example as a unit which may have the light source 106 and the spectrometer 108 as integrated components.

(10) In various exemplary embodiments, the spectrum may be transmitted to a data processing device 116. Data transmission is marked with the reference character 114. Transmission may be carried out in a known way, for example by employing a data cable (e.g. USB), wireless data transmission (e.g. Bluetooth, WLAN (Wi-Fi), Thread, ZigBee or Near Field Communication (NFC)), or a transmission may be carried out within a device if the spectrometer (and possibly the light source) is part of a data processing device (e.g. smartphone, tablet, laptop or smart mirror) or is removably attached to the data processing device (e.g. by employing a suitable connector) or, vice versa, the spectrometer 108 is designed with an integrated data processing device 116.

(11) For receiving and processing the data and for modeling, the data processing device in various exemplary embodiments may be equipped with appropriate software, for example an app.

(12) In various exemplary embodiments, the recorded UV or UV/VIS spectrum may be used in conjunction with the calibration model to determine the tryptophan content of the hair sample as described above.

(13) In various exemplary embodiments, a fictitious damage period of the hair sample may be determined as described above using the recorded UV or UV/VIS spectrum in conjunction with the calibration model.

(14) In various exemplary embodiments, the degree of thermal hair damage may be determined on a categorical scale (e.g. low, moderate, strong, very strong).

(15) In various exemplary embodiments, the degree of thermal hair damage may be determined in a metric scale (e.g. a numerical value with arbitrary units, as a percentage of the tryptophan content or as a percentage of damage).

(16) In various exemplary embodiments, the described method for determining a degree of thermal hair damage may be performed using a data processing device 116.

(17) The data processing device may, as described above in connection with FIG. 1, include, for example, a mobile data processing device, such as a smartphone, tablet or laptop, but also any other computer, such as a smart mirror, or any other data processing device capable of storing and providing the data, performing the comparison and applying the model, and, if necessary, also creating the model, such as any data processing device with a sufficiently large data memory and a sufficiently powerful processor.

(18) In various exemplary embodiments, the data processing device may have at least one input device for inputting information into the data processing device, for example for inputting tryptophan content measured values for calibration and, if necessary, for inputting instructions, parameters, user data, etc. for executing the method.

(19) In various exemplary embodiments, the at least one input device may include a touch-sensitive screen, microphone and/or keyboard.

(20) In various exemplary embodiments, the data processing device may include at least one output device for outputting information, for example for outputting results of the method.

(21) In various exemplary embodiments, the at least one output device may include a (touch-sensitive) screen, loudspeaker and/or a printer.

(22) In particular in a case where the degree of thermal hair damage is determined for a plurality of hair areas (for example at the base, middle and/or tips), the provision of the degree of thermal hair damage to the user may include a graphical representation, e.g. a display, e.g. using a display device as an output device (e.g. a (touch-sensitive) screen of a smartphone, tablet or smart mirror). In the graphical representation, the determined degree of thermal hair damage of the plurality of areas with a coding based on the degree of thermal hair damage may be displayed in a representation of the user (e.g. a schematic representation or on a photo of the user). For example, in a schematic representation of the user's hairstyle, areas of different degrees of thermal hair damage may be displayed with different colors and/or patterns, e.g. areas with a low degree of thermal hair damage green and areas with a high degree of thermal hair damage red, or similar. In another example, a photo of the user, e.g. a digital photo showing the user's hair or hairstyle, may be overlaid with different patterns, e.g. a dot pattern for areas of a high degree of thermal hair damage and a line pattern for areas of a low degree of thermal hair damage, or similar. Alternatively, the real-time display of the hair on/in a smart mirror may be used to show the determined thermal hair damage levels.

(23) When graphically displaying the degree of thermal hair damage of at least one hair area, e.g. the majority of hair areas, the degree of thermal hair damage may be displayed in various exemplary embodiments only for the area(s) for which the degree(s) of thermal hair damage was/were determined. In various exemplary embodiments, an area for which a degree of thermal hair damage is displayed may be extrapolated beyond the hair area for which the degree of thermal hair damage has been determined, for example by taking into account typical damage distribution patterns.

(24) In addition or alternatively, a display device may be used as an output device to present concrete treatment instructions to the user as images and/or text messages. For example, images of specific products may be displayed that are tailored to the user's degree of thermal damage.

(25) In various exemplary embodiments, the at least one output device may include a loudspeaker and/or the at least one input device may include a loudspeaker. The input of information and/or voice commands is affected via the voice of the user. In this case the device has a module for voice recognition, preferably an intelligent personal assistant (voice assistant), such as Alexa by Amazon, Google Assistant by Google, Cortana by Microsoft or Siri by Apple.

(26) In various exemplary embodiments, any program (e.g. an app) that provides such functionality may be used for modeling.

Exemplary Embodiment 1

(27) 1. Spectroscopic Calibration Model (“Fictitious Hair Damage Period”)

(28) To determine a spectroscopic calibration model, strands of hair of a certain width, for example about 5 mm, are first exposed to heat of about 200° C. for 0 to about 120 minutes in a time series experiment. At intervals of about 10 minutes, each strand of hair is irradiated with UV light with a wavelength of from about 250 to about 300 nm. The light that has interacted with the hair strands is detected in a wavelength range from about 300 to about 350 nm. Then the ratio of irradiated to detected UV light is determined for the range of from about 300 to about 350 nm. This results in a ratio of irradiated UV light to reflected and/or emitted and/or transmitted and/or scattered UV light that is characteristic of the respective degree of thermal damage. For each period of damage about 10 hair strands are measured and the values obtained are averaged using the Wilcoxon Signed-Rank Test.

(29) 2. Determination of the Degree of Thermal Hair Damage

(30) To determine individual hair damage, at least one strand of hair, comprising about 100 hairs, of an individual is irradiated with UV light having a wavelength of from about 250 to about 300 nm, the light which has interacted with the hair strands is detected in a wavelength range of from about 300 to about 350 nm and the ratio of irradiated UV light to reflected and/or emitted and/or transmitted and/or scattered UV light is determined. Using the spectroscopic calibration model, a fictitious damage period at a temperature of about 200° C. is assigned to the obtained ratio. This may be carried out with an app/software on a tablet, laptop or smartphone, for example.

(31) The fictitious hair damage periods are classified by the app/software into the following degrees of thermal hair damage:

(32) TABLE-US-00001 Fictitious hair damage Degree of periods at 200° C. thermal hair damage up to 10 minutes low 10 to 30 minutes moderate 30 to 60 minutes strong greater than 60 minutes very strong

(33) According to the degree of thermal hair damage, the app/software determines a bleaching product recommendation and/or hair dye recommendation and/or hair care product recommendation and/or hair styling product recommendation.

(34) Depending on the degree of thermal hair damage, the recommended bleaching products and/or hair dyes and/or hair care products and/or hair styling products should contain the following ingredients:

(35) TABLE-US-00002 Degree of thermal hair damage Product recommendation low Product contains up to 0.5% by weight of polysiloxane, especially PEG-14 dimethicone (INCI) moderate Product contains up to 0.5% by weight of polysiloxane, especially PEG-14 dimethicone, and up to 0.5% by weight of film-forming polymer, especially octyl acrylamides/acrylates/butyl amino ethyl methacrylate copolymer (INCI) strong Product contains up to 1% by weight of polysiloxane, especially PEG-14 dimethicone, and up to 0.5% by weight of film-forming polymer, especially octyl acrylamide/acrylates/butyl amino ethyl methacrylate copolymer (INCI) very strong Product contains up to 2% by weight of polysiloxane, especially PEG-14 dimethicone, and up to 1% by weight of film-forming polymer, especially octyl acrylamide/acrylates/butyl amino ethyl methacrylate copolymer (INCI)

Exemplary Embodiment 2

(36) 1. Spectroscopic Calibration Model (“Tryptophan Content”)

(37) To determine a spectroscopic calibration model, hair strands with different degrees of thermal hair damage (low, moderate, strong and very strong) are first irradiated with UV light with a wavelength of from about 270 to about 290 nm. The light that has interacted with the hair strands is detected in a wavelength range of from about 270 to about 290 nm. The ratio of irradiated to detected UV light is then determined for this range. In this way, a characteristic UV absorption spectrum for the respective degree of thermal hair damage is obtained. The spectra obtained for each degree of thermal hair damage are averaged.

(38) Ten hair strands of each degree of thermal damage are then examined after basic chemical digestion by High-Performance Liquid Chromatography (HPLC) and the content of tryptophan is determined. The values obtained for each degree of thermal hair damage are averaged.

(39) The tryptophan content averaged for each degree of thermal hair damage is assigned the corresponding averaged absorption spectrum.

(40) 2. Determination of the Degree of Thermal Hair Damage

(41) To determine individual thermal hair damage, at least one strand of hair, comprising about 100 hairs, of an individual is irradiated with UV light with a wavelength of from about 270 to about 290 nm and the light which has interacted with the hair strands is detected in a wavelength range of from about 270 to about 290 nm. Using the spectroscopic calibration model, tryptophan content is assigned to the absorption spectrum obtained. This may be carried out with an app/software on a tablet, laptop or smartphone, for example.

(42) According to the tryptophan content the app/software determines a bleaching product recommendation and/or hair dye recommendation and/or hair care product recommendation and/or hair styling product recommendation.

(43) While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the various embodiments in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment as contemplated herein. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the various embodiments as set forth in the appended claims.