Method for determining a customized hair treatment that improves the condition of hair structure

Abstract

The present invention provides a method for determining a customized hair treatment that improves the condition of a user's hair structure. A first condition of the hair is determined before applying the hair treatment. Based on the first condition, a first hair treatment is selected from a database. The database includes observed effects of hair treatments on changing the condition of the hair. The first hair treatment corresponds to an expected hair condition. A second condition of the user's hair is determined after applying the first hair treatment. The second hair treatment is determined based on the difference between the expected hair condition and the second hair condition. The hair condition can be either hair damage or hair moisture.

Description

[Technical Field]

[0001] The present invention relates to the field of hair care, and in particular to the field of maintaining or improving hair condition by applying appropriate hair treatments, in particular hair care products such as shampoos, conditioners, dyes, hair bleaches, etc. to the hair. The present invention also relates to the field of determining hair properties, in particular the effect of hair treatments on hair condition, and to adjusting hair care treatments based on the observed effect of the hair care treatment on hair condition. The present invention provides a method capable of detecting the effect of previous treatments applied to hair, thereby enhancing personalized hair care counseling, and in particular making it possible to advise which hair care products should be applied to the hair. [Background technology]

[0002] Hair is a biological multicomponent fiber with a high protein content of up to 95% by weight. Structurally, the cross section of hair can be divided into two or three distinct morphological regions (from the outside to the inside): the cuticle, the cortex, and the medulla (the medulla is present in some, but not all, hairs). The protein portion of the cortex is made up of α-keratin helices embedded in a proteinaceous matrix.

[0003] Cosmetic products such as shampoos, conditioners, treatment masks, and colorants are used to improve or change hair properties, typically to improve combability, smooth hair texture, increase hair gloss, reduce hair damage, or impart a new color to hair.

[0004] Due to many factors that affect the internal (cortex and medulla) and external (cuticle) structure of the hair, hair structure varies from person to person. Often, two different people's hair will respond differently to the same hair treatment. Hair care professionals need years of experience to evaluate the potential of different hair care treatments to improve a person's hair condition and / or achieve desired hair properties (hair color, hair gloss, hair volume, hair smoothness, hair damage, which is generally an indicator of how "healthy" the hair fiber is or how close the hair condition is to untreated, undamaged hair).

[0005] Salon hair care professionals can also benefit from tools that help them obtain information about the condition of their clients' hair in order to select the most appropriate hair treatment. To determine products that improve hair condition (reduce damage) or minimize the effects of hair damage, Henkel® developed the SalonLab®-Analyzer, which measures the cysteic acid content of hair using infrared and near-infrared sensing, providing valuable information that allows users (professionals and non-professionals) to determine the level of hair damage. The infrared and / or near-infrared spectrum is compared to a calibration model to more accurately assess the level of damage to the user's hair. Further information on this approach can be found in WO2018 / 007353.

[0006] Despite the great potential of such non-intrusive optical sensing approaches, calibration models are inefficient in providing useful information about the effect of hair care products on the condition of the internal structure of the hair, particularly the condition of the medulla and cortex. As a result, without a more complete picture of the condition of the external and internal structure of the user's hair, it is difficult to make accurate predictions about the effect of hair treatments on improving the condition of the user's hair.

[0007] This is particularly true when attempting to objectively evaluate the effect of a hair treatment on the entire hair structure, including its effect on the internal structure. Some hair treatments replace broken bonds not only on the exterior (cuticle) but also on the interior of the hair, but only their effect on the cuticle can be easily investigated. Without information on the condition of the cortex and medulla, it is difficult to estimate the exact efficiency of this improvement process based solely on the effect of the treatment on the cuticle.

[0008] A further challenge in understanding the full effect of hair treatments on hair is the impact of the hair cuticle, which tends to remove traces of previous treatments applied to the hair. Water tends to adsorb to the cuticle and remove traces of previous treatments, affecting the ability of existing methods to accurately detect the effect of previous hair treatments without losing information about the overall effect of the hair treatment on the cortex and medulla of the hair fiber.

[0009] For the above reasons, there is a need for a method for improving the condition of a user's hair, and more particularly, a method for determining a customized hair treatment that improves the condition of a user's hair. Summary of the Invention

[0010] To address the above needs, the present invention provides a method for determining a customized hair treatment that will improve the condition of a user's hair structure, the method comprising: - determining the first condition of the user's hair structure before applying the hair treatment; - determining a first hair treatment based on the determined first condition, the first hair treatment being selected from a database of hair treatments associated with observed effects of said hair treatments on modifying the condition of the hair structure from a different starting condition of the hair structure, and the determined first hair treatment being associated in the database with an expected condition of the user's hair structure after application of the first hair treatment to the hair; - determining a second condition of the user's hair structure after application of the first hair treatment; - determining the difference between the expected condition of the user's hair structure and a second condition; determining a second hair treatment based on the determined second condition and the determined difference; The first condition, the expected condition, and the second condition are at least one of the degree of hair damage, the moisture content of the hair, the presence of external compounds present on or in the hair, the presence and type of compounds present on or in the hair, and the bulk properties of the hair components.

[0011] This method may be considered as part of a process in which the effectiveness of hair treatments (particularly application of hair care products) is quantitatively evaluated in a user experience that allows evaluation of the efficiency of the hair treatment in achieving improved hair condition. This method is typically implemented using a processor. The method may be further assisted by using a device that acquires data related to the condition of the hair. One such device is, for example, the Salonlab®-Analyzer developed by Henkel®. Similarly, other devices, such as mobile phones, may be used to acquire a reconstructed hyperspectral spectrum of the hair or an image of the hair that allows analysis of defects present in the user's hair. The method of the present invention proceeds iteratively by first predicting the expected changes in hair condition from the application of a hair treatment to the hair. This prediction, based on information from the database, allows for the determination / selection of a hair treatment product that is expected to improve the condition of the hair structure, for example, by alleviating, reducing, or minimizing hair damage and supporting the external and internal structure of the user's hair. The actual effect of applying the hair treatment to the hair structure is then determined, and a second hair treatment is determined based on the discrepancy between the expected change and the determined change. The second hair treatment is selected not only based on the information available in the database, but also, for example, if the observed second condition of the user's hair structure is not improved with respect to the first determined / measured condition than expected and predicted from the database, the second hair treatment compensates for the discrepancy observed after the application of the first hair treatment by selecting a product with a stronger effect for alleviating hair damage. The determination of the first and second hair treatments is made possible by information stored in a database regarding the effect of different hair treatments on the condition of the hair structure, which database may typically result from previous experiments carried out by applying wave treatments to different hair types having different initial conditions of the hair structure and measuring the resulting values ​​of the condition of the hair structure. Because hair has a complex structure, it is difficult to fully assess the complete condition of a user's hair. Two different users with very similar estimated hair conditions are likely to respond differently to the same hair treatment. The method of the present invention provides a means to assess such differences and take corrective measures in determining a second hair treatment. The term "hair treatment" may typically relate to the application of hair products to the hair, such as hair dyes, bleaches, shampoos, conditioners, volume-enhancing products, shine-enhancing products, waviness-enhancing products, etc. The term may also relate to other types of hair treatments, such as hair perming treatments, hair ironing treatments, cutting hair, adding hair extensions to hair, etc. The condition may typically be the degree of hair damage, which can be detected in the form of the cysteic acid content of the user's hair. It may also be the moisture content of the hair. The first and second conditions may typically be determined by measurements that rely on sensing technology, for example, recording signals from light interacting with the hair in the infrared or near-infrared spectral range and comparing the recorded signals with a calibration model. Further details regarding this technology are provided, for example, in WO2018 / 007353.

[0012] According to one embodiment, the present invention further comprises: -Get the user's desired hair condition; - Further, based on the obtained target hair condition, determining a first hair treatment such that the first hair treatment is associated in the database with expected conditions of the user's hair structure that differ from the target hair condition by less than a predetermined amount.

[0013] The selection of suitable hair treatments can be further restricted to achieve the target value provided by the user by obtaining a target hair condition from the user, which can be, for example, a number indicating the hair condition (indicating the degree of damage to the user's hair) on any scale ranging from 0 (very damaged hair condition) to 100 (excellent hair, no hair damage).

[0014] According to one embodiment, the method comprises: - determining a second hair treatment based on a correction applied in the database to the observed effect of the hair treatment on changing the condition of the hair structure from a different starting condition of the hair structure, this correction being estimated based on the determined difference;

[0015] The correction to be applied can advantageously be based on the hair score determined in the first and second determination / measurement of the condition of the hair structure, which is compared with the score of the expected change to the condition of the hair structure found in a database. Based on the difference in the scores, it is possible to determine from the information contained in the database the change in the effect of the hair treatment on the user's specific hair, and simply select the hair treatment that will result in an expected hair score offset by an amount corresponding to the determined score difference. In this way, the user is more likely to achieve the desired target condition of the hair structure.

[0016] According to one embodiment, the first condition, the expected condition, and the second condition are: - exposing a hair sample of the user's hair to at least one of light, stress, elongation or heat while recording a signal from at least a portion of the light interacting with the hair sample or a signal from the response of the hair sample to the stress, elongation or heat; comparing the recorded signal with a first calibration model and determining the condition of the hair structure based on the comparison; is determined using the method.

[0017] More specifically, the first calibration model is - determining the structural condition of a plurality of calibration hair samples using a method for measuring the bulk properties of hair components; - exposing each of the plurality of calibration hair samples to at least one of light, stress, elongation, or heat, and recording a signal from at least a portion of the light interacted with each calibration hair sample or a signal from the hair sample's response to the stress, elongation, or heat; - establishing a first calibration model by determining a correlation between the recorded signals and the determined condition of the structure of the plurality of calibration hair samples; It can be obtained by

[0018] Such methods are an improvement over previous methods of determining the condition of a user's hair by not only providing access to the condition of the outer portion of the hair (the cuticle), but alternatively and / or additionally providing more accurate insight into the internal structure of the hair (typically the cortex and medulla, in addition to the information accessible to the condition of the cuticle). Thus, the above methods can provide a more complete picture of the condition of the structure of a user's hair fiber. The calibration methods used typically measure the bulk properties of hair components. The term "bulk properties of hair components" is understood to refer to the internal components or structure of the hair fiber, as well as the molecular vibrational modes of the outer layer (cuticle) of the hair fiber. Such methods rely on analytical or biophysical methods, which are different from the well-known chromatographic and / or high-performance liquid chromatography (HPLC) methods of the prior art. Bulk properties also provide insight into components located below the cuticle. A non-limiting list of techniques that can sense the interior of the hair fiber includes stress-strain measurements, fatigue measurements, elongation measurements, hair hydrophobicity or swelling behavior, and measurements of non-linear optical effects occurring in hair, such as wave birefringence, attenuated total reflectance, Fourier transform interferometry, and differential scanning calorimetry, to name just a few. A calibration model is established by accurately measuring the condition of the internal structure of hair using one of these techniques on a "calibration" hair sample. The same calibration hair sample is then investigated using a less sophisticated measurement technique, which may include one of the techniques described above, or, particularly advantageously, non-invasive optical measurements using either infrared (IR), near-infrared (NIR), high frequency spectral analysis, or image analysis. The method of the present invention arises from the observation that such a simple and non-invasive method constitutes a signature of information about the condition of the internal structure of the hair fiber. Such signatures cannot be seen in the form of specific absorption at specific wavelengths in the spectrum, as described in the literature. Without intending to be bound by theory, the applicant hypothesizes that these signals consist of indirect influences of the internal structure of the hair, which may also be reflected in unexpected ways in the cuticle. Therefore, the existing IR and NIR sensing technology used in the SalonLab®-Analyzer developed by Henkel® can also determine the condition of the internal structure of hair using a different calibration model established based on techniques that measure the bulk properties of hair components. The term "condition of the internal structure of the hair" is understood to mean "the condition of at least the internal structure of the hair" as the method of the present invention can sense both the internal structure of the hair and the external structure of the hair, thereby providing more complete information regarding the overall condition of the user's hair structure.

[0019] According to one embodiment, the method for measuring the bulk properties of hair components comprises at least one of differential scanning calorimetry applied to hair, electron microscopy of hair, stress-strain measurements, fatigue measurements, elongation measurements, detection of hair hydrophobicity or swelling, and measurement of nonlinear optical effects occurring in hair such as wave birefringence, attenuated total reflectance, Fourier transform interferometry.

[0020] The techniques listed above provide access to the internal structure of the hair fiber, thereby contributing to the establishment of more sophisticated calibration models than prior art methods.

[0021] According to one embodiment, the method further comprises: - obtaining a second calibration model that establishes a correlation between the determined degree of hair damage of the calibration hair sample and a signal recorded from at least a portion of the light that has interacted with the calibration hair sample or a signal corresponding to the response of the hair to stress, elongation or heat during exposure of the calibration hair sample to said light, stress, elongation or heat;

[0022] The second calibration model relies on information already used in the prior art, typically in the Salonlab®-Analyzer device developed by Henkel®, which was designed to detect the degree of hair damage by determining the cysteic acid content of hair, particularly the hair cuticle.

[0023] According to one embodiment, signals recorded while exposing a hair sample to at least one of light, stress, elongation or heat are compared to a second calibration model to determine the degree of hair damage of the hair sample.

[0024] Such a comparison offers the possibility of distinguishing between the contribution of the cuticle to the condition of the hair fiber and the contribution of the cortex and medulla to the condition of the hair fiber. Subtraction of signals recorded using both calibration models provides insight into the specific contribution of the inner portion of the hair fiber structure to the condition of the hair. This inner portion typically comprises a stronger marker of previous hair treatments applied to the hair, providing a means of determining how effective a hair treatment is in improving the overall condition of a user's hair. This provides a valuable tool for salon professionals and individuals alike in understanding the effect of hair treatments on a user's hair and adapting these treatments to the actual, quantitatively assessed condition of the hair.

[0025] According to one embodiment, the method further comprises: - determining a first value of the condition of the hair structure before applying the hair treatment to the hair; - determining a second value of the condition of the hair structure after applying the hair treatment; comparing the difference between the second value of the condition of the hair structure and the first value of the condition of the hair structure; - Based on said comparison, determining the specific contribution of the application of a hair treatment to the condition of the hair structure.

[0026] Such an approach is one way of determining the specific contribution of a hair treatment application to the condition of a user's hair.

[0027] According to another embodiment, the method further comprises: - determining a relationship between the value of the condition of the hair structure obtained using the first calibration model and the value of the degree of hair damage obtained using the second calibration model; - determining the value of the condition of the hair structure and the value of the degree of hair damage after the application of hair treatments; - using the determined relationship, converting the value of the degree of hair damage into a corresponding equivalent value of the condition of the hair structure; - subtracting the corresponding equivalent value from the determined value of the condition of the hair structure to estimate the additional contribution of the application of a hair treatment to the value of the condition of the hair structure.

[0028] Such an approach is a substitute for determining the specific contribution of the application of a hair treatment to the condition of the user's hair structure.

[0029] According to one embodiment, the method further comprises: -Getting user input regarding previous hair treatments applied to the hair; - Adjusting the first hair treatment and the second hair treatment based on the obtained user input.

[0030] By collecting input from the user, a correction step can be applied to the determined hair score by offsetting the determined hair score from the first condition of the user's hair structure by an amount corresponding to the contribution of these past hair treatments. The contribution of the hair treatment to the condition of the hair structure and the hair score can typically be stored in a database. In this way, the first hair treatment recommendation can be more accurate and better predict the effect of its application on the condition of the user's hair structure.

[0031] According to one embodiment, the method further comprises: - obtaining user input regarding a desired target hair condition; - adjusting the first hair treatment and the second hair treatment further based on the obtained user input.

[0032] According to one embodiment, the method further comprises: - determining a customized first hair treatment comprising a mixture of hair treatment products based on the determined first condition, wherein the database includes information relating to each hair treatment product of the mixture; - determining a customized second treatment comprising a mixture of hair treatment products based on the determined second condition and the determined difference, wherein the database comprises information associated with each hair treatment product of the mixture.

[0033] The method of the present invention can be used to create a combination or mixture of chemical compositions tailored for the user, thereby providing effects that cannot be achieved by using commercially available products alone. The determination of the ratio of such a mixture can be based on the contribution of each individual product to the expected condition of the hair structure, the determined / measured value of the condition of the user's hair structure, and the target condition.

[0034] The present invention also relates to a computer program product comprising program instructions configured to implement a method for determining a customized hair treatment for improving the condition of a user's hair structure, the method comprising: - determining the first condition of the user's hair structure before applying the hair treatment; - determining a first hair treatment based on the determined first condition, the first hair treatment being selected from a database of hair treatments associated with observed effects of said hair treatments on modifying the condition of the hair structure from a different starting condition of the hair structure, and the determined first hair treatment being associated in the database with an expected condition of the user's hair structure after application of the first hair treatment to the hair; - determining a second condition of the previous user's hair after application of the first hair treatment; - determining the difference between the expected hair condition and a second condition of the user's hair structure; determining a second hair treatment based on the determined second condition and the determined difference; The first condition, the expected condition, and the second condition are at least one of the degree of hair damage, the moisture content of the hair, the presence of external compounds present on or in the hair, the presence and type of compounds present on or in the hair, and the bulk properties of the hair components.

[0035] The computer program typically carries out the methods of the invention with the aid of a processor.

[0036] In other words, the present invention also relates to a non-transitory computer-readable storage medium having stored thereon program instructions configured to perform the steps of a method for determining a customized hair treatment for improving the condition of a user's hair structure, the method comprising: - determining the first condition of the user's hair structure before applying the hair treatment; - determining a first hair treatment based on the determined first condition, the first hair treatment being selected from a database of hair treatments associated with observed effects of said hair treatments on modifying the condition of the hair structure from a different starting condition of the hair structure, and the determined first hair treatment being associated in the database with an expected condition of the user's hair structure after application of the first hair treatment to the hair; - determining a second condition of the previous user's hair after application of the first hair treatment; - determining the difference between the expected hair condition and a second condition of the user's hair structure; determining a second hair treatment based on the determined second condition and the determined difference; The first condition, the expected condition, and the second condition are at least one of the degree of hair damage, the moisture content of the hair, the presence of external compounds present on or in the hair, the presence and type of compounds present on or in the hair, and the bulk properties of the hair components. [Brief explanation of the drawings]

[0037] The present disclosure will now be described in conjunction with the following drawings, in which like numerals refer to like elements and in which: [Figure 1] FIG. 1 is a flow chart illustrating the steps of a method according to one embodiment; [Figure 2] FIG. 2 is a flow chart illustrating one aspect of one embodiment; [Figure 3] FIG. 3 is a flow chart illustrating further aspects of one embodiment; [Figure 4] 4, 5 and 6 are schematic diagrams of user interfaces implementing aspects of one embodiment; [Figure 5] 4, 5 and 6 are schematic diagrams of user interfaces implementing aspects of one embodiment; [Figure 6] 4, 5 and 6 are schematic diagrams of user interfaces implementing aspects of one embodiment; [Figure 7] FIG. 7 is a schematic illustration of the implementation of a method according to one embodiment on the hair of a user using a device. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention provides a method for determining a hair treatment that is specific to a user and that can improve the condition of the user's hair structure, which method relies on an approach that evaluates the effect of a hair treatment on the user's hair, and is further supported by techniques that allow the condition of the user's hair structure to be determined with sufficient accuracy.

[0039] FIG. 1 is a flow chart illustrating the steps of one embodiment of a method 100 of the present invention.

[0040] A first condition 1 of the user's hair structure is determined 101. This determination can be made by measuring a signal that is typically recorded using optical means. The SalonLab®-Analyzer developed by Henkel® is one such device that allows the recording of such a signal.

[0041] Typically, measurements can be performed such that a user's hair, or more specifically a hair sample, is exposed to a stimulus and the hair's response to the stimulus is measured with a detector. A handheld device can be used for this purpose that uses an optical signal to determine the condition of the user's hair structure. FIG. 7, described in more detail below, provides an example of such a device. The device comprises a light emitter that emits light, for example, in the infrared and / or near-infrared spectral range. The infrared spectral range typically includes wavelengths between 700 nm and 1 mm. The near-infrared spectral range typically includes wavelengths between 700 nm and 2500 nm. Infrared and near-infrared are particularly advantageous spectral ranges for observing physical objects because they can be analyzed in a non-invasive, non-destructive manner and can provide insight into the vibrational modes of the molecules that make up the object being investigated.

[0042] The vibrational modes of the molecule can be used to measure the degree of hair damage, particularly through the amount of cysteic acid present in the hair. In fact, cysteic acid is a marker of broken disulfide bonds (SS) in hair and is an accurate indicator of the damaged state of hair.

[0043] Apart from infrared or near-infrared sensing, devices may rely on other optical sensing techniques such as FTIR (Fourier Transform Interferometry), ATR (Attenuated Total Reflection), or hyperspectral imaging (e.g., using a hyperspectral camera or by reconstructing a hyperspectral signal from multiple narrowband images of hair taken under different illumination intensities, such as may be generated by a mobile phone, as described, for example, in WO 2018 / 228859). It is also possible to obtain information about the condition of a user's hair using imaging devices in the visible spectral range. Such image analysis tools can detect hair defects, provided the images are of high enough resolution. The detection of defects in the images can be determined based on a detection algorithm trained using multiple images of hair in known damaged states using a calibration model.

[0044] The method 100 further accesses information contained in the database 3 and determines 102 a first hair treatment 10 that, according to the database 3, is expected to improve the condition of the user's hair structure from a first condition 1 to an expected condition 11. This information is evaluated from the database 3 based on the determined value of the first condition 1. The determination 102 can further select the first hair treatment 10 based on additional input provided by the user, such as previous hair treatments that the user has applied to their hair in the past days or weeks, or based on a target value for the condition of the user's hair structure entered by the user.

[0045] The term "condition of the hair structure" typically refers to the degree of hair damage, the presence of external compounds present on or in the hair, the presence and type of compounds present on or in the hair, the degree of moisture of the hair, and may also include other parameters such as hair glossiness value, a value indicating hair volume, a value indicating hair waviness, etc.

[0046] After application of the first hair treatment 10, a second condition 2 of the user's hair structure is determined 103. Typically, the same techniques as described above may be used.

[0047] The determined second condition 2 is compared with the expected condition 11, thereby leading to an estimation of the difference 4 between both values.

[0048] Using the information stored in the database 3 and the differences 4 determined as explained above, the method finally determines 105 a second hair treatment 20 that takes into account the discrepancies between the information contained in the database and the determined / measured condition of the user's hair structure.

[0049] 2 and 3 provide a flow chart illustrating how the condition of a user's hair structure may be determined.

[0050] A method 200, as illustrated schematically in the flowchart of FIG. 2, can be used to determine the condition value of a user's hair structure. More specifically, the method 200 can access not only the condition of the cuticle, but also the condition of the hair cortex and / or medulla. The method 200 typically comprises a step 201 of exposing the hair 5 to light 21 while recording a signal 610 from at least a portion of the light 21 that has interacted with the hair 5. As can be seen in FIG. 2, other means of recording a signal can be implemented, such as exposing the hair 5 to one of stresses 24 (mechanical stress, shear stress, compressive stress, torsional stress, etc.), elongation 23, or heat 22. The response of the hair 5 to such inputs is recorded in the form of a signal 600. The thermal response of the hair 5 can be recorded by differential scanning calorimetry. In such an experimental setup, a hair sample is exposed to heat to determine the amount of heat required to raise the temperature of the hair sample, which gives access to the heat capacity of the hair sample and provides insight into the condition of the internal structure of the hair sample.

[0051] The most preferred embodiment consists in recording a signal 610 corresponding to light that has interacted with the hair 5, in particular infrared and / or near infrared light.

[0052] The recorded signals 600, 610 are then compared 202 with a first calibration model 70. This calibration model 70 is, for example, a chart or a mathematical function that provides a correspondence between the values ​​of the recorded signals 600, 610 and values ​​of the condition of the internal structure 80 of the hair 5.

[0053] Based on this comparison, the condition of the internal structure 80 of the hair 5 is determined 203 by identifying the value in the calibration model 70 that shows the closest match to the values ​​of the recorded signals 600, 610.

[0054] One strength of the method of the present invention lies in its ability to determine this value of the internal structure 80 of the hair 5 even with sensing techniques that, in principle, cannot directly assess such internal structure (i.e., the structure of the hair 5 below the cuticle). One aspect of the present invention relies on the establishment of a first calibration model 70 for use in the method 200 of the present invention.

[0055] The first calibration model 70 is established by measuring the condition of the internal structure 80 of calibration hair samples. The value of the condition of the internal structure 80 of these calibration hair samples is known either by exposing the hair to an event that caused the condition of the internal structure 80 to reach a predetermined value, or by measuring this value using a method that measures the bulk properties of the components of the hair 5. Such methods are typically sensitive to the internal structure of the hair 5 below the cuticle and can include one of the following: differential scanning calorimetry applied to hair, electron microscopy of hair, stress-strain measurements, fatigue measurements, elongation measurements, detection of hair hydrophobicity or swelling, or measurement of nonlinear optical effects occurring in hair, such as wave birefringence, attenuated total reflectance, Fourier transform interferometry, etc.

[0056] The same calibration hair sample is then interrogated by another method. Advantageously, this other method is non-invasive, non-destructive, and relies on optical detection means. Preferably, the other method is an infrared and / or near-infrared sensing technique that measures the infrared and / or near-infrared spectrum of light interacting with the hair while exposing the hair to such light. The types of recorded signals described above (exposing a hair sample of hair 5 to one of the following stresses 24, such as mechanical stress, shear stress, compressive stress, torsional stress, elongation 23, or heat 22, and recording the hair's response to such stimuli) may also be used in this other method.

[0057] Since a calibration hair sample will necessarily have the same value for the condition of its internal structure 80 when measured using these two different methods, both values ​​determined using the two different measurement techniques can be compared to establish a calibration curve.

[0058] According to a preferred embodiment, the condition value of the internal structure 80 of the calibration hair sample is determined using differential scanning calorimetry. The condition of the internal structure 80 of the calibration hair sample is then measured using infrared and / or near-infrared sensing technology, such as is already known in connection with the SalonLab®-Analyzer developed by Henkel®.

[0059] The correspondence established between values ​​obtained using optical detection means and values ​​obtained using differential scanning calorimetry provides a way to determine the condition of the internal structure 80 of any hair sample from any user using a simple, non-invasive and non-destructive method. Another advantage of using optical detection methods is that they are faster to perform than other mechanical methods or methods that rely on differential scanning calorimetry.

[0060] The method 200 of the present invention allows for a more complete, more objective, accurate and quantitative determination of the condition of a user's hair 5. This can be used, inter alia, to determine the effect of a hair treatment on the user's hair 5, and further to recommend a more customized and more appropriate hair treatment that takes into account the measured effect of the treatment on the user's particular hair 5.

[0061] From the above method 200, several approaches may be implemented to extract the specific contribution of the hair treatment to the condition of the user's hair 5.

[0062] One approach consists in taking a first measurement of the condition value of the internal structure 80 of the user's hair 5 before a hair treatment is applied to the hair 5. Then, another measurement of the condition value of the internal structure 80 of the user's hair 5 is taken after the application of the hair treatment to said hair 5. As both measurement techniques are sensitive to the internal structure of the user's hair 5, the value of the first measurement can be subtracted from the value of the second measurement to extract the contribution to the condition value of the internal structure 80 of the user's hair 5 that is due only to the hair treatment itself.

[0063] The term "hair treatment" typically refers to at least one of the application of a hair product such as a hair dye, a hair bleach, a shampoo, a conditioner, a hair volume enhancer, a hair gloss enhancer, a hair perm treatment, a hair iron treatment, cutting the hair, or adding hair extensions to the user's hair 5.

[0064] Another approach consists in using two different calibration models when processing the same measurement of the condition value of the internal structure 80 of the user's hair 5 .

[0065] Figure 3 provides another schematic flow chart illustrating method steps used in determining the degree of hair damage 81 using the second calibration model 71. The process depicted in Figure 3 is already known and corresponds to the state of the art as described, for example, in WO 2018 / 007353. The process of Figure 3 also comprises a step 301 of recording a signal corresponding to light 21 that has interacted with the user's hair 5. The recorded signal 610 is compared 302 with the second calibration model 71. Based on this comparison, the degree of hair damage 81 is determined 303.

[0066] The second calibration model 71 is established using, for example, the approach described in WO2018 / 007353. The calibration hair sample is investigated using chromatography or HPLC (high performance liquid chromatography) to determine the degree of hair damage, which is also proportional to the cysteic acid content of the calibration hair sample. The same content of cysteic acid is determined using infrared and / or near-infrared sensing of the calibration hair sample. A correlation is established between the optical signal obtained using infrared and / or near-infrared sensing and the signal determined using HPLC or chromatography to construct the second calibration model.

[0067] In contrast to the first calibration model 70, the second calibration model 71 is intrinsically sensitive to the degree of damage 81 of the cuticle of the hair 5. This provides a way to extract the contribution of the hair treatment to the value of the condition of the internal structure 80 of the hair 5 from a single optical measurement of the signal 610 recorded from the light 21 interacting with the hair 5 or from any other measurement obtaining the signal 600 as described above. It has been observed that there is a substantially linear dependency between the evolution of the degree of damage of the hair 5 detectable using the second calibration model 71 and the evolution of the condition of the internal structure 80 of the hair 5 detectable using the first calibration model 70. By establishing this correlation, it becomes possible to identify the specific contribution of the hair treatment to the value of the condition of the internal structure 80 of the hair 5 by using the first calibration model 70 to determine a value of the condition of the internal structure 80 of the hair 5, using the second calibration model 71 to determine a value of the degree of hair damage, converting the value of the degree of hair damage using the correlation to a corresponding equivalent value of the condition of the internal structure of the hair, and subtracting the corresponding equivalent value from the determined value of the condition of the internal structure 80 of the hair 5.

[0068] The method 100 may be implemented by a computer program that may be executed on any terminal in the form of an application (app) or any other user interface, as represented diagrammatically in Figures 4, 5 and 6. Figures 4-6 further illustrate how the method 100 of the present invention may display measurements in a user-understandable format.

[0069] As seen in FIG. 4, the user interface 500 shows information such as the user's hair color 501 and can provide a scale 510 along which hair condition values ​​range from very poor (at the lower end of the scale 510) to very good (at the upper end of the scale 510). In FIG. 4, the scale 510 is subdivided into five different qualitative ranges. Each hair condition value is associated with a score, which is provided as a number between 0 (very poor condition) and 100 (very good condition). In FIG. 4, a base score 511 is provided. The base score 511 indicates that the measurement corresponds to the initial condition of the internal structure of the user's hair 5, before the application of any hair treatments.

[0070] Of course, the user has already subjected their hair to some hair treatments due to exposure to UV rays from sun exposure, temperature changes, air pollution, previous application of hair care products, etc. Although the base score 511 is an approximation of untreated, non-product treated hair condition, in reality the past history of the user's hair 5 already includes hair product use which is detectable in the score 542 obtained by the method 100 of the present invention.

[0071] The base score numeric value 512 is provided as a base score position 520 on a scale 510, specifically within one of five category types. The scale 510 is an arbitrary unit scale that represents the degree of hair damage to the user's hair 5 (which may be considered an indication of how "healthy" the hair is). This hair damage may reflect only damage measured at the cuticle of the hair 5 using the second calibration model 71, or may reflect more complete hair damage measured using the first calibration model 70.

[0072] The user interface 500 may further include a questionnaire to collect information from the user, particularly information regarding past hair treatments, in order to adjust the value of the base score 511 .

[0073] As shown in Figure 5, the user interface 500 may further comprise hair treatment recommendations based on a prediction 521 of a hair score 522 achievable when applying a hair treatment 530, such as a shampoo and / or conditioner, to the user's hair 5. Such a prediction may typically be possible based on a database relating hair treatments to a quantified effect of the hair treatment on improving the condition of hair after application of the hair treatment with a particular initial condition of the internal structure of the hair 5.

[0074] The prediction 521 may not fully reflect the actual hair score that the user will achieve when applying the hair treatment 530, as the base score 511 may already include the effects of previous known or unknown hair treatments to which the user's hair 5 has been exposed. Furthermore, because a user's hair 5 varies depending on many different factors, two different users with similar base scores 511 may actually react differently when the same hair treatment 530 is applied to their hair.

[0075] The method 100 of the present invention can assist in determining such differences and apply corrective measures to iteratively make better recommendations regarding future hair treatments 530 based on the evolution of the measured hair score.

[0076] Figure 6 shows schematically the achieved score 541 measured on a user's hair 5 after application of the hair treatment 530 recommended in Figure 5. It can be seen that the achieved hair score 542 has a slightly lower value than that predicted in Figure 5. This difference can be used to determine facts regarding the effect of previous treatments on the base score 511. Figure 6 is further evidence that the method 100 of the present invention can quantify the effect 540 of the application of a hair treatment 530 on the value of the internal structure condition 80 of the hair 5.

[0077] Based on the information available from the application of the method 100 of the present invention, the hair treatment 530 recommendations made to the user can be tailored to determine which product or hair treatment 530 will have the strongest and most desirable effect on the condition 80 of the internal structure of the user's hair 5.

[0078] Figure 7 shows a schematic diagram of a device 700 that can be used to carry out the method 100 according to the invention and parts of the methods 200, 300 described above. A user's hair, and more particularly a hair sample 30, is subjected to a stimulus and the response of the hair to the stimulus is measured by a detector 702. In the example shown in Figure 7, the device 700 is a handheld device that uses an optical signal to determine the condition of the internal structure of the user's hair 5. The device 700 comprises a light emitting element 701 that emits light, for example in the infrared and / or near-infrared spectral range.

[0079] The device 700 may be substituted for a mobile phone and may have a different shape not shown in the figures. Some shapes of the device 700 may be better suited to accessing the root length and tip of hair, for example, and may differ from the V- or U-shaped device shown in FIG.

[0080] 7 further shows that the device 700 can communicate wirelessly or wired 703 with remote data processing devices such as a computer 704, cloud service or server. The device 700 can also comprise computing means on the device itself.

[0081] While the foregoing detailed description presents at least one exemplary embodiment, it should be understood that numerous variations exist. It should also be understood that the exemplary embodiment or exemplary embodiments are merely examples and are not intended to limit in any way the scope, applicability, or configuration of the various embodiments. Rather, the foregoing detailed description provides those skilled in the art with a convenient road map for implementing the exemplary embodiments contemplated herein. It will be understood that various changes may be made in the function and arrangement of elements described in the exemplary embodiments without departing from the scope of the various embodiments as set forth in the appended claims.

Claims

1. 1. A method for determining a customized hair treatment that improves the condition of a user's hair structure, the method comprising: determining a first condition of the user's hair structure prior to applying a hair treatment; determining a first hair treatment based on the determined first condition, wherein the first hair treatment is selected from a database of hair treatments associated with observed effects of the hair treatments on changing the condition of the hair structure from a different starting condition of the hair structure, and the determined first hair treatment is associated in the database with an expected condition of the user's hair structure after application of the first hair treatment to the hair; determining a second condition of the user's hair structure after application of the first hair treatment; determining a difference between the expected condition and the second condition of the user's hair structure; determining a second hair treatment based on the determined second condition and the determined difference; The first condition, the expected condition, and the second condition are at least one of the following: degree of hair damage, moisture content of hair, presence of external compounds present on or in hair, presence and type of compounds present on or in hair, and bulk properties of hair components. method.

2. Obtaining a target hair condition of the user; determining the first hair treatment based on the obtained target hair condition such that the first hair treatment is associated in the database with expected conditions of the user's hair structure that differ from the target hair condition by less than a predetermined amount; Further provided with The method of claim 1.

3. determining the second hair treatment based on a correction applied in the database to an observed effect of the hair treatment on changing the condition of the hair structure from a different starting condition of the hair structure, the correction being estimated based on the determined difference; Further provided with The method according to claim 1 or 2.

4. The first condition, the expected condition, and the second condition are: exposing a hair sample of the user's hair to at least one of light, stress, elongation, or heat while recording a signal from at least a portion of the light interacting with the hair sample or a signal from the response of the hair sample to the stress, elongation, or heat; comparing the recorded signal with a first calibration model and determining the condition of the hair structure based on the comparison; determined using the method, The method according to any one of claims 1 to 3.

5. The first calibration model is determining the structural condition of the plurality of calibration hair samples using a method for measuring bulk properties of hair components; exposing each of the plurality of calibration hair samples to at least one of light, stress, elongation, or heat, and recording a signal from at least a portion of the light interacting with each calibration hair sample or a signal from the hair sample's response to the stress, elongation, or heat; establishing the first calibration model by determining a correlation between the recorded signals and the determined structural condition of the plurality of calibration hair samples; obtained by The method of claim 5.

6. The method for measuring the bulk properties of the components of hair comprises at least one of differential scanning calorimetry applied to hair, electron microscopy of hair, stress-strain measurement, fatigue measurement, elongation measurement, detection of hair hydrophobicity or swelling, and measurement of nonlinear optical effects occurring in hair such as wave birefringence, attenuated total reflectance, Fourier transform interferometry, The method of claim 5.

7. obtaining a second calibration model that establishes a correlation between the determined degree of hair damage of the calibration hair sample and a signal recorded from at least a portion of the light that interacted with the calibration hair sample or a signal corresponding to the response of the hair to stress, elongation, or heat during exposure of the calibration hair sample to said light, stress, elongation, or heat; Further provided with The method according to any one of claims 4 to 6.

8. signals recorded while exposing the hair sample to at least one of light, stress, elongation or heat are compared with the second calibration model to determine the degree of hair damage of the hair sample; The method of claim 7.

9. determining a first value of the condition of the structure of the hair before applying a hair treatment to the hair; determining a second value of the condition of the hair structure after applying the hair treatment; comparing the difference between the second value of the hair structure condition and the first value of the hair structure condition; determining the specific contribution of the application of the hair treatment to the condition of the hair structure based on the comparison; and Further provided with 9. The method according to claim 7 or 8.

10. determining a relationship between the hair structure condition value obtained using the first calibration model and the hair damage degree value obtained using the second calibration model; determining a condition value of the hair structure and a value of the degree of hair damage after application of the hair treatment; converting the hair damage degree value into a corresponding equivalent value of the hair structure condition using the determined relationship; subtracting a corresponding equivalent value from the determined value of the condition of the hair structure to estimate the additional contribution of the application of the hair treatment to the value of the condition of the hair structure; Further provided with The method of claim 7.

11. obtaining user input regarding previous hair treatments applied to the hair; adjusting the first hair treatment and the second hair treatment based on the obtained user input; Further provided with The method according to any one of claims 1 to 10.

12. obtaining user input regarding a desired target hair condition; adjusting the first hair treatment and the second hair treatment further based on the obtained user input; Further provided with The method according to any one of claims 1 to 11.

13. determining a customized first hair treatment comprising a mixture of hair treatment products based on the determined first condition, wherein the database includes information associated with each hair treatment product in the mixture; determining a customized second treatment comprising a mixture of hair treatment products based on the determined second condition and the determined difference, wherein the database includes information associated with each hair treatment product in the mixture. The method according to any one of claims 1 to 12.

14. 1. A computer program product comprising program instructions configured to perform a method for determining a customized hair treatment that improves the condition of a user's hair structure, the method comprising: determining a first condition of the user's hair structure prior to applying a hair treatment; determining a first hair treatment based on the determined first condition, wherein the first hair treatment is selected from a database of hair treatments associated with observed effects of the hair treatments on changing the condition of the hair structure from a different starting condition of the hair structure, and the determined first hair treatment is associated in the database with an expected condition of the user's hair structure after application of the first hair treatment to the hair; determining a second condition of the user's hair structure after application of the first hair treatment; determining a difference between the expected condition and the second condition of the user's hair structure; determining a second hair treatment based on the determined second condition and the determined difference; The first condition, the expected condition, and the second condition are at least one of the following: degree of hair damage, moisture content of hair, presence of external compounds present on or in hair, presence and type of compounds present on or in hair, and bulk properties of hair components. Computer program products.

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