PROVIDING AN INDICATION OF A PERSON'S GUM HEALTH

Abstract

An optical analysis of saliva or a fluid-saliva mixture is performed in order to check whether the saliva or fluid-saliva mixture contains blood, which allows for determining whether or not a person may suffer from gingivitis or another condition affecting gum health. Light received from a representative volume of fluid (23) containing saliva is detected and analyzed. The analysis involves determination of at least one measurement value of light received by a light-receiving unit (25) for only a single wavelength of the light, particularly a wavelength that is associated with high absorption by a constituent of blood. It this respect, it is practical if the light-receiving unit (25) is configured to receive reflected light back from the volume of fluid (23). The optical analysis may be performed real-time during an action in a person's mouth involving a gum agitation effect, or after such action has taken place, for example.

Claims

1. A system configured to provide an indication of a person's gum health on the basis of an evaluation of the presence of blood traces in a volume of fluid containing the person's saliva, the system comprising: a light-emitting unit configured to emit light to a volume of fluid containing the person's saliva obtained during brushing or flossing using an oral care appliance, wherein the volume of fluid is at an area at which saliva accumulates on the oral care appliance, a light-receiving unit configured to receive light back from the volume of fluid, and an analysis unit configured to perform an analysis of light received by the light-receiving unit and to provide output representative of the person's gum health, and configured to execute at least one algorithm that is designed to determine at least one measurement value of light received by the light-receiving unit for no more than a single wavelength of the light related to relatively high light absorption by a constituent of blood.

2. A system according to claim 1, wherein the light-receiving unit is configured to receive reflected light back from the volume of fluid.

3. A system according to claim 1, wherein the at least one algorithm is designed to determine measurement values real-time during an action in the person's mouth involving a gum agitation effect, and to monitor a development of the measurement values over time and assess whether a deviation from a gradual course of the development of the measurement values occurs in the development.

4. A system according to claim 3, wherein the at least one algorithm is designed to determine the measurement values at successive discrete moments in time, and to involve determining differences between successive measurement values in assessing whether a deviation from a gradual course of the development of the measurement values occurs in the development.

5. A system according to claim 3, wherein the at least one algorithm is designed to determine that the measurement values are indicative of the presence of blood in a volume of fluid containing saliva when a deviation from a gradual course of the development of the measurement values is found in the development.

6. A system according to claim 1, wherein the light-emitting unit is configured to emit light at only the single wavelength and/or the light-receiving unit comprises a bandpass filter/light detector combination including a bandpass filter that is configured to only allow light at the single wavelength or a narrow wavelength band to pass.

7. A system according to claim 1, comprising a remote device having a processor, wherein the analysis unit comprises the processor of the remote device, and wherein the at least one algorithm to be executed by the analysis unit is defined by an app installed on the remote device.

8. (canceled)

9. A system according to claim 1, comprising the oral care appliance configured to perform the brushing or flossing, wherein at least the light-emitting unit and the light-receiving unit are incorporated in the oral care appliance.

10. An oral care appliance configured to perform an oral care action that involves brushing or flossing, the oral care appliance comprising a handle portion and a head portion, wherein the oral care appliance comprises the system according to claim 1, wherein the handle portion accommodates at least the analysis unit of the system and the area at which saliva accumulates is at the head portion.

11. A method of providing an indication of a person's gum health on the basis of an evaluation of the presence of blood traces in a volume of fluid containing the person's saliva, the method comprising: receiving a volume of fluid containing the person's saliva during brushing or flossing using an oral care appliance, wherein the volume of fluid is at an area at which saliva accumulates on the oral care appliance. emitting light to the volume of fluid containing the person's saliva, receiving the light back from the volume of fluid and analyzing the received light, and determining at least one measurement value of the light received back from the volume of fluid for no more than a single wavelength of the light related to relatively high light absorption by a constituent of blood.

12. A method according to claim 11, comprising monitoring a development of measurement values over time and assessing whether a deviation from a gradual course of the development of the measurement values occurs in the development.

13. A method according to claim 12, comprising determining that the measurement values are indicative of the presence of blood in a volume of fluid containing saliva when a deviation from a gradual course of the development of the measurement values is found in the development.

14. A computer program product comprising code to cause a processor, when the code is executed on the processor, to execute the method according to claim 11.

15. A remote device having a processor, comprising the computer program product according to claim 14.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which:

[0039] FIG. 1 shows absorption spectra of hemoglobin;

[0040] FIG. 2 illustrates the basic setup of a test arrangement for detecting a presence of blood in a toothpaste-saliva mixture;

[0041] FIG. 3 is a graph of measurement values of reflected light plotted against concentration of blood in a toothpaste-saliva mixture;

[0042] FIG. 4 is graph of normalized measurement values of reflected light plotted against concentration of blood in a toothpaste-saliva mixture, for three different concentrations of toothpaste;

[0043] FIG. 5 how the invention may be realized in a diffuse reflective probe;

[0044] FIG. 6 illustrates how the invention may be realized in a drinking glass; and

[0045] FIGS. 7 and 8 illustrate how the invention may be realized in an oral care appliance.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The invention provides a practical way of providing an indication of a person's gum health. According to the invention, the presence of blood traces in a volume of fluid containing a person's saliva is evaluated by performing optical measurements and analyzing the results of the measurements, wherein an appropriate choice is made when it comes to a single wavelength at which the results are considered in the process.

[0047] The invention is particularly aimed at providing a way of detecting blood traces in saliva or a toothpaste-saliva mixture for the purpose of obtaining an indication that the person whose saliva is under investigation may suffer from (early stage) gingivitis or from another condition affecting gum health. In view thereof, the invention provides a reliable method for detecting low hemoglobin concentrations, by using optical detection based on the known absorption peaks in the hemoglobin absorption spectrum. As is generally known, hemoglobin is an important constituent of blood.

[0048] FIG. 1 shows two absorption spectra of hemoglobin, wherein the spectrum that is indicated by reference numeral 11 is related to oxyhemoglobin, i.e. hemoglobin with bound oxygen, and wherein the spectrum that is indicated by reference numeral 12 is related to deoxygenated hemoglobin, i.e. hemoglobin without bound oxygen. The wavelength of light expressed in nm is at the x axis of the spectra, and the absorption coefficient expressed in cm.sup.−1 is at the y axis of the spectra. It appears from the figure that there are some specific, highly absorbing wavelength ranges. Especially the blue wavelength range of 410 to 420 nm involves relatively high values of the absorption coefficient of the hemoglobin. The broader range of high absorption is 400 to 440 nm.

[0049] In the context of the invention, it is sufficient to check whether or not blood is present in a volume of fluid containing saliva, wherein there is no need for determining the exact value of the concentration of the blood in the volume of fluid. The invention involves a method of assessing optical behavior of a volume of fluid containing saliva, which volume of fluid may be obtained during or after an action in a person's mouth involving a gum agitation effect, an oral care action such as brushing or flossing being a practical example of such action. It is known that in the wavelength range of 400 to 440 nm as mentioned, the absorption coefficient of water is relatively low. As water is the main constituent of saliva, there is no need to take the saliva factor into account. The absorption and reflection characteristics of toothpaste may be assumed to be a more or less constant factor, at least in relation to a possible presence of blood in the saliva. In the context of the invention, a notable insight is that measurements can be performed in such a way as to justify regarding the volume of fluid as a semi-infinite layer, so that transmission of light may be assumed to be zero. On the basis of the fact that the presence of blood in the saliva causes absorption of light to be high at a wavelength chosen from the above-mentioned range, wherein the absorption increases as the concentration of the blood increases, this leads to the conclusion that an indication about an extent to which blood is present can be obtained by considering reflection of light at such a wavelength.

[0050] The insight that the volume of fluid may be regarded as a semi-infinite layer has been verified by means of a test. In the test, a brush head provided with a light source and a light detector arranged between the bristle tufts, a container for containing a volume of fluid, and a mirror were used. The container was filled with a volume of toothpaste-saliva mixtures of different concentrations, and for each of those toothpaste-saliva mixtures, it was assessed whether or not the light intensity measured at the light detector would vary as a result of varying a distance between the brush head and the mirror. It was found that the light intensity remained constant regardless the distance, so that it is concluded that transmission is zero, indeed, because if such would not be the case, this would inevitably cause a variation of the light intensity. In respect of a volume of only saliva, it is to be noted that in a practical situation in which the saliva is put to motion under the influence of a moving brush head or the like, infinite layer behavior of the saliva is also applicable due to the formation of air bubbles in the saliva, as the presence of air bubbles causes light scattering effects due to the difference of refractive index between saliva and air.

[0051] To investigate the feasibility of performing an analysis of optical measurement results at only one wavelength for the purpose of determining whether or not blood may be assumed to be present in a volume of fluid under investigation, tests were performed, using a test arrangement of which the basic setup is illustrated in FIG. 2. FIG. 2 diagrammatically shows a light source 21, a collimator 22, a volume of fluid 23 to be investigated as present on a support 24, and a light detector 25 coupled to an analysis unit 26, wherein the light detector 25 is arranged so as to be in a position for receiving light from the light source 21 through reflection. Toothpaste and water were mixed in a 1:5 ratio after which small amounts of sheep blood were added to the mixture. A series of up to more than 10,000 times more toothpaste and water than blood was made to test whether the presence of blood could be found even in extremely small concentrations, comparable to the presence of a tiny drop of blood of about 1 μl in 10 ml of toothpaste-saliva mixture. The 1:10,000 ratio can be regarded as being representative of a worst case scenario as 1μl is an extremely small drop and a person will normally lose more blood from bleeding gums, wherein it is to be noted that a drop of normal size has a volume of about 50 μl.

[0052] FIG. 3 provides an illustration of the results of light reflection measurements for a mixture of toothpaste and saliva in the 1:5 ratio mentioned in the foregoing. The figure shows reflection values measured at a wavelength of 420 nm, plotted against blood concentration values, wherein the latter are expressed as the x value in a 1:x ratio of the blood and the mixture of toothpaste and saliva, so that an increasing x value indicates a decreasing amount of blood. The reflection values are expressed in arbitrary units. It follows from the figure that there is a relation between the reflection values and the blood concentration values, such that higher reflection values are found for lower blood concentration values, indeed, and that this relation is applicable even when 10,000 times more toothpaste and water than blood is present in a volume of fluid.

[0053] FIG. 4 provides an illustration of the results of light reflection measurements for a mixture of toothpaste and saliva in various ratios. Measurement results indicated by means of a square relate to a 1:7 ratio, measurement results indicated by means of a triangle relate to a 1:5 ratio, and measurement results indicated by means of a circle relate to a 1:3 ratio. Reflection values measured at a wavelength of 420 nm are normalized to a maximum reflection of 1, which maximum reflection is associated with the absence of blood in the toothpaste-saliva mixture. In the figure, the normalized reflection values are plotted against blood concentration values. Also this figure demonstrates that there is a relation between the reflection values and the blood concentration values, such that higher reflection values are found for lower blood concentration values, indeed.

[0054] It follows from the tests that were performed that it is possible to detect the presence of blood (hemoglobin) in a mixture of saliva and toothpaste when the optical measurement values follow from detecting and analyzing reflected light for only a single wavelength of the light. Thus, it follows from the tests that even a simple setup is sufficient for enabling detection of small amount of blood in a solution containing toothpaste. The invention provides a way of detecting much lower blood concentrations in a toothpaste-saliva mixture than can be done by the human eye, and therefore enables detection of gingivitis or other conditions affecting gum health in an early, reversible stage. The detection can be done with as little influence on normal oral care routines as possible. For example, when the invention is realized in an oral care appliance as will be explained later, it is even possible that a volume of fluid containing saliva is collected automatically and is subjected automatically to optical analysis.

[0055] In the following, a number of preferred ways in which the invention may be put to practice are explained. A first option relates to a diffuse reflective setup of the arrangement for obtaining measurement results suitable for use in assessing a person's gum health, which, as follows from the foregoing, involves the advantage of not requiring a separate container for receiving the volume of fluid containing saliva. This does not alter the fact that within the framework of the invention, it is possible to use one, as will become apparent from an explanation of a second option.

[0056] According to a first option existing within the framework of the invention, a diffuse reflective probe 50 as illustrated in FIG. 5 is provided, including an illumination spot coupled to a light source 21, for illumination of a volume of fluid 23 to be analyzed. Preferably, the light source 21 is modulated to reject ambient light. The diffuse reflective probe 50 further includes a light detector 25 coupled to an analysis unit 26 configured to determine whether or not blood is present in the volume of fluid 23 and to provide an indication that it is likely that a person suffers from reduced or poor gum health, or not. In the figure, paths of the emitted light and the reflected light are indicated by means of arrows. As explained in the foregoing, according to the invention, reflected light is detected and analyzed for only a single wavelength in order to obtain a measurement value that can be evaluated in order to see whether the measurement supports a presence of blood in the volume of fluid 23. The probe 50 may be equipped with a suitable warning mechanism for issuing a warning signal in case blood appears to be detected.

[0057] The light detector 25 can be realized in various suitable ways. For example, the light detector 25 may comprise a photodiode or a bandpass filter/detector combination. Further, the light source 21 can comprise an incandescent lamp or an LED, capable of emitting light at the single wavelength or being provided with a narrowband bandpass filter.

[0058] According to a second option existing within the framework of the invention, a simple drinking glass 60 is equipped with a light source 21 and a light detector 25 near a transparent bottom of the glass 60, as illustrated in FIG. 6. For the purpose of having a volume of toothpaste-saliva mixture 23 analyzed, a person spits toothpaste-saliva foam in the glass 60. Light that enters through the glass 60 from the light source 21 is reflected from the foam towards the light detector 25, as indicated by arrows in the figure. In a variation, a separate cradle for receiving and supporting a drinking glass 60 of which at least the bottom is transparent to light is used, wherein a light source 21 and a light detector 25 are integrated in the cradle.

[0059] According to a third option existing within the framework of the invention, an oral care appliance is configured to perform one or more functions in a process of detecting blood traces in a volume of fluid containing saliva. An example of this option is illustrated in FIGS. 7 and 8. In FIG. 7, a brush head portion 70 of a power toothbrush is shown. In the context of a power toothbrush, toothpaste-saliva foam will collect automatically on the brush head 71 between the bristle tufts 72 during operation of the power toothbrush. In view thereof, it may be advantageous to have an optical window at the position of the bristle tufts 72 in the brush head 71, and also to have a light source and a light detector arranged in the brush head 71, so that a light reflection measurement can be performed. The toothpaste-saliva foam will also collect automatically on the backside of the brush head 71. It may therefore also be practical if an optical window is provided in the backside of the brush head 71.

[0060] According to yet another possibility, the neck portion 73 of the brush head part 70 may be provided with a recess 74 for the purpose of collecting toothpaste-saliva foam during a brushing action. Such a recess 74 may be used for detecting a presence of blood traces through light reflection measurement, as illustrated in FIG. 8, which is the case when the light detector 25 is arranged outside of a light path from the light source 21 and is at a position for receiving light reflected by the toothpaste-saliva foam 23. As explained earlier, there are no light transmission phenomena that need to be taken into account when investigating and analyzing toothpaste-saliva foam in the shown configuration.

[0061] In general, the invention covers the possibility that an oral care appliance has an optical window at an appropriate position on the device, such as on a functional head of the device or on a neck portion or body portion, and a light-emitting unit and a light-receiving unit associated with the optical window. It is practical for the optical window to be arranged at a position of an area where saliva accumulates during use of the oral care appliance, which may be the position of a recess, as explained.

[0062] In the case of an oral care appliance, it is possible to keep track of a position of (a part of) the oral care appliance with respect to the mouth. For example, if a toothbrush is used, information about the actual position of the brush head 71 may continually be available on the basis of suitable control and/or detection measures. In the context of the invention, such information may be used for obtaining gum health indications at a local level, so that areas of reduced/poor gum health in the mouth may be distinguished from areas of acceptable/good gum health. In this respect, it is noted that it may be advantageous to monitor time dependence of the light reflection during an oral care action, assuming that when a notable decrease of the reflection signal is found, this is caused by (additional) optical absorption following from release of blood. Thus, by monitoring time dependence of the signal that is obtained from the oral care appliance, it is possible to keep track of moments at which a release of blood is invoked. In combination with positioning information, this may help in finding “hot spots” in the mouth, i.e. areas which are made to bleed easily and which may be assumed to have poor gum health.

[0063] In the context of toothbrushes and other oral care appliances, it is possible that a cradle of the device is provided, and that an analysis unit 26 and an associated output interface are incorporated in the cradle. An oral care appliance does not necessarily need to have an optical window and an associated light source 21 and light detector 25 arranged in a part of the device that is destined to be put into a person's mouth during use of the device. The fact is that it is also possible that an oral care appliance is equipped with components as mentioned at a bottom of a handle portion thereof, in which case the device is suitable to be used for detecting light reflection characteristics of a volume of saliva that has been spit on a surface.

[0064] Designing an oral care appliance for putting the invention to practice involves the advantage that the detection of blood traces for the purpose of assessing a person's gum health can be performed automatically during an oral care action, or requires only minimum additional effort without the need for additional tools.

[0065] It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims or the equivalents thereof. While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The invention is not limited to the disclosed embodiments. The drawings are schematic, wherein details which are not required for understanding the invention may have been omitted, and not necessarily to scale.

[0066] Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word “comprising” does not exclude other steps or elements, and the indefinite article “a” or “an” does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope of the invention.

[0067] Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0068] The term “comprise” as used in this text will be understood by a person skilled in the art as covering the term “consist of”. Hence, the term “comprise” may in respect of an embodiment mean “consist of”, but may in another embodiment mean “contain/include at least the defined species and optionally one or more other species”.

[0069] In the present text, denoting light absorption as higher or relatively high on the one hand and as lower or relatively low on the other hand implies that the one light absorption is notably higher than the other light absorption. With reference to an absorption spectrum, higher or relatively high light absorption is related to peaks of the spectrum, whereas lower or relatively low light absorption is not and is rather related to valleys of the spectrum.

[0070] A summary of the invention may read as follows. An optical analysis of saliva or a fluid-saliva mixture is performed in order to check whether the saliva or fluid-saliva mixture contains blood, which allows for determining whether or not a person may suffer from gingivitis or another condition affecting gum health. In particular, light received from a representative volume of fluid 23 containing saliva is detected and analyzed. The analysis involves determination of at least one measurement value of light received by a light-receiving unit 25 for only single wavelength of the light, particularly a wavelength that is associated with high absorption by a constituent of blood. It this respect, it is practical if the light-receiving unit 25 is configured to receive reflected light back from the volume of fluid 23. The optical analysis may be performed real-time during an action in a person's mouth involving a gum agitation effect, or after such action has taken place, for example.