Oral care device with sensing function

Abstract

An oral care system is provided that senses blood in the oral cavity and periodontal tissues. Sensing is performed magnetically using a magnetic field source and a magnetic sensing unit integrated into the cleaning or treatment portion of the oral care device (e.g., the brush head of a toothbrush or the mouthpiece portion of a brushing mouthpiece device). The magnetic field source 16 generates a reference magnetic field, and the sensing unit 18 is configured to sense the magnetic field strength of the reference magnetic field at one or more spatial points. Because blood is a magnetic material, when it is brought into the reference magnetic field, it magnetically interacts with the magnetic field, which can change the magnetic field strength, magnetic field shape, or magnetic flux distribution. This allows the presence of blood to be detected. It also allows the detection of specific oral characteristics or pathologies associated with the presence of blood or an abnormal amount or concentration of blood. For example, this can be based on the application of detection criteria related to one or more characteristics of the sensed magnetic field.

Description

[Technical Field]

[0001] The present invention relates to an oral care device for performing oral cleaning and / or treatment functions. [Background technology]

[0002] WO2018065373A1 discloses a tracking system for recording the position of a toothbrush while brushing teeth, the system comprising: a toothbrush including a head portion, a handle portion, an orientation sensor, a sensor for detecting contact between the toothbrush and the user's jaw, and a magnetic sensor; and a magnetic field generator, the magnetic sensor detecting the absolute position of the toothbrush in a magnetic field generated by the magnetic field generator.

[0003] Regular monitoring of oral health is important to prevent the occurrence of diseases or abnormalities in the gums or teeth. To prevent deterioration of oral health due to caries, periodontal disease, etc., it is known to incorporate a function into oral care devices such as toothbrushes to monitor brushing technique and provide feedback to the user to improve technique. Summary of the Invention [Problem to be solved by the invention]

[0004] However, such functions alone do not necessarily prevent oral problems from occurring, and regular monitoring is important for early detection and treatment. For example, gingivitis is a gum disease that cannot always be avoided with brushing techniques. Other conditions can also lead to inflammation of the gums, accumulation of blood (e.g., at the gum line between the teeth and gums or irrigated in inflamed tissue), and bleeding into the mouth.

[0005] It would be valuable to provide an oral care device that can detect such abnormal conditions or characteristics within the oral cavity during use of the oral care device, so that the user can be alerted to potential problems. [Means for solving the problem]

[0006] The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

[0007] According to one aspect of the present invention, there is provided an oral care system comprising a cleaning and / or treatment portion for an oral care device, at least a portion of which is received within a user's oral cavity during use for a cleaning or treatment function.

[0008] The cleaning or treatment portion has a magnetic field source that generates a reference magnetic field in the oral cavity when received in the oral cavity, and a magnetic field sensing portion configured to detect the magnetic field strength or changes therein of the reference magnetic field at one or more spatial positions.

[0009] The system further includes a processing unit configured to receive the sensor output from the magnetic field sensing unit, which is configured to perform sensing of gum tissue or blood in the oral cavity based on analysis of the sensor output.

[0010] Preferably, the magnetic field source and magnetic field sensing portion are comprised by said at least a portion of the cleaning and / or treatment portion for receipt in the oral cavity of a user during use.

[0011] Preferably, the magnetic field sensing portion is different from the magnetic field source.

[0012] Preferably, the magnetic field sensing portion is configured to detect magnetic field strength at one or more spatial locations within the oral cavity.

[0013] The processing unit may be configured to detect one or more predetermined features. Detection of each feature is based on application of one or more predetermined detection criteria related to the sensor output. For example, the detection criteria may relate to characteristics or properties of the sensor output, such as the magnitude of the detected magnetic field strength, the spatial distribution or pattern of the magnetic field strength, and / or a time variation of the magnetic field strength that matches a defined temporal pattern. These are merely illustrative examples. The features may be anatomical or physiological features.

[0014] The general concept of embodiments of the present invention is the use of magnetic fields for sensing blood in the oral cavity or gum tissue, and detecting characteristics (eg, characteristics related to oral health) based on this sensing.

[0015] Blood is magnetic due to the iron content of hemoglobin. It is the only magnetic fluid in the body, allowing for magnetic sensing and detection of blood. Many lesions or abnormalities in the oral cavity are characterized by the abnormal presence or concentration of blood. For example, gingivitis or other periodontal diseases can lead to periodontitis, which is characterized by abnormal accumulation of blood in the periodontal tissues, resulting in swelling and redness. Inflamed areas of the gums have a higher concentration of blood (blood volume per unit volume of gum) than healthy gums. Furthermore, many defects in the oral cavity, such as gum or tongue lesions, periodontal disease, and dental problems, can result in bleeding. In this case, oral fluids that would otherwise be blood-free contain blood. Additionally or alternatively, blood droplets can accumulate on oral surfaces, such as the gum line between the teeth and gums or in pockets or blisters within the mouth.

[0016] When blood is present in the reference magnetic field, its magnetic properties cause it to interact with the magnetic field, resulting in a distortion of the magnetic field shape or a change in the distribution of magnetic field strength. This change in the reference magnetic field is detected by the magnetic sensor, and based on the characteristics of the detected signal, various features associated with the blood can be detected and identified.

[0017] In general, the reference magnetic field may be a static or a time-varying / alternating magnetic field. The magnetic field source may be passive (permanent magnet) or active (electromagnetic source).

[0018] According to one or more embodiments, the processing unit may be configured to detect one or more abnormalities (health or medical) in the gum tissue or oral cavity based on an analysis of the sensor output and, for example, based on one or more detection criteria related to the sensor output. For example, it may be configured to detect an abnormal presence or concentration of blood in the gum tissue or oral cavity, which detection is based on an analysis of the sensor output.

[0019] According to one or more embodiments, the processor may be configured to detect at least one of inflammation (i.e., excessive blood perfusion) or conditions indicative thereof, static blood on the surface of the gums, static blood at the gum line between the tooth and gum, or bleeding. It may also be possible to detect accumulations or pooling of blood below the tissue surface, such as blisters. The processor may be operable to detect multiple different types or classes of abnormalities based on blood sensing, e.g., each associated with a distinct set of detection criteria related to (characteristics of) the sensor output signal.

[0020] According to one or more embodiments, the processing unit may be configured to detect spatial and / or temporal changes in the magnetic field detected by the magnetic sensing unit. One or more features may be detected based on the spatial and / or temporal changes in the magnetic field strength. If the magnetic field is an alternating magnetic field, the detection of the features may be based on spatial or temporal changes in the baseline, envelope, or amplitude of the magnetic signal.

[0021] For example, detection of a feature or anomaly can be based on detection criteria related to the spatial pattern or distribution (e.g., asymmetry) of magnetic field strength across multiple sensing locations. Alternatively, it can be based on sensing temporal variations in magnetic field strength at a single (or multiple) locations that indicate the sensor has passed a particular location containing the associated blood feature or anomaly.

[0022] With regard to the spatial variation option, in one set of embodiments, the magnetic field sensing portion comprises a plurality of magnetic field sensing elements spaced apart from one another, and spatial variations in magnetic field strength may be detected based on variations in magnetic field strength detected by different sensing elements.

[0023] Based on the asymmetry or disparity between the magnetic field strengths detected at different spatial locations, the presence or local accumulation of blood in a region can be detected. In some examples, the processing unit is configured to estimate the location of a feature or anomaly based on the detected spatial variation of the sensed magnetic field between spatial locations.

[0024] With respect to the time-varying option, in one set of embodiments, the processing unit is configured to receive sensor signals of magnetic field strength over time for one or more locations and detect features based on detected temporal variations in the signals.

[0025] In this detection mode, signals are monitored while the user moves the cleaning and / or treatment portion of the oral care device around the mouth, with fluctuations indicating blood accumulation (or other abnormalities) at the location of the magnetic field sensing portion at the time the fluctuation is detected.

[0026] In some embodiments, detection of a feature or abnormality can be based on a combination of spatial and temporal variations in magnetic field strength. For example, detection of a feature such as an abnormal presence or concentration of blood can be based on detection of temporal variations or changes in the spatial magnetic field distribution across different sensing spatial locations.

[0027] According to one or more embodiments, the oral care system may further include an electromagnetic cleaning and / or treatment unit having a conductor portion including one or more conductive elements (e.g., a single or multi-loop coil or an electrode). It may further include a signal generator configured to generate a radio frequency (RF) and / or microwave frequency alternating electromagnetic field when the generator is operably coupled to the conductor portion including the one or more conductive elements. It may further include a controller, preferably operably coupled to the generator. The controller may be operable at least in a cleaning or treatment mode, in which the controller is configured to control the signal generator to generate an alternating electromagnetic field using the conductor portion to perform an oral cleaning or treatment function when the conductor portion is received in the oral cavity.

[0028] Electromagnetic fields, particularly radio frequency (RF), are known to be effective for use in cleaning or treating tooth surfaces or periodontal tissues, for example, they can loosen biofilm coatings on tooth surfaces.

[0029] In different embodiments, the EM cleaning and / or treatment unit (abbreviated herein as EMCTA), and the magnetic field source and magnetic field sensing unit may cooperate or interact functionally or structurally to provide synergistic effects or to reduce factors. They may share certain elements or may interact electromagnetically. An overview of the different options is given below.

[0030] In one set of embodiments, the EMCTA may be provided functionally and structurally separate from the sensing element.

[0031] Alternatively, in at least one set of embodiments, the signal generator and conductor portion of the EMCTA may provide the magnetic field source that generates the reference magnetic field. In other words, the magnetic field generating elements of the EMCTA serve the dual function of generating the reference magnetic field in this option.

[0032] In this embodiment, and optionally in a subset of embodiments, the magnetic component of the alternating EM field generated in the cleaning or treatment mode provides a reference magnetic field, in other words, the same magnetic field used for cleaning or treatment is simultaneously utilized as a reference magnetic field for sensing.

[0033] Alternatively, in a different subset of embodiments, the EMCTA is used to generate a reference magnetic field, but it does so in a different mode or phase, such that the reference magnetic field is different from the cleaning or treatment magnetic field. For example, the controller can be selectively configured to be in a blood sensing mode in which the signal generator is controlled to generate a different magnetic or electromagnetic field using the conductors for use as the reference magnetic field. The different magnetic field may, in some examples, be a DC magnetic field. This can be achieved by including a rectifier in the generation circuit and driving the coil with a DC current. Additionally or alternatively, the different magnetic field may be an alternating magnetic field at a lower frequency than the cleaning and / or treatment magnetic fields.

[0034] Compatible with any of the above-mentioned options, according to one or more embodiments, the magnetic field sensing portion may be arranged to be powered via inductive or capacitive coupling of energy from the EM field generated by the signal generator and conductor portion.

[0035] Based on the particular feature or anomaly detected, the processing of the sensor signal and / or the detection criteria applied may vary.

[0036] In some embodiments, the analysis of the sensor output is based on filtering or other spectral processing or analysis. For example, according to one or more embodiments, the processing unit may receive a sensor signal of magnetic field strength over time for the one or more locations from the sensing unit and is configured to process the signal to remove frequency components within a predetermined frequency component range.

[0037] In one set of examples, the predetermined range of frequency components may be a range of frequency components associated with a defined heartbeat frequency. This embodiment is effective in distinguishing between static and moving blood. This is useful for detecting blood droplets accumulating on surfaces within the oral cavity, such as the gum line between the teeth and gums, or in pockets or blisters within the oral cavity.

[0038] According to one or more embodiments, the processing unit may be configured to receive a sensor signal of magnetic field strength over time for the one or more locations from the sensing unit, and to detect the presence of blood in the fluid within the oral cavity based on processing the magnetic field signal to extract frequency components above 10 Hz.

[0039] Some oral care devices, such as electric toothbrushes, activate the vibration of the cleaning and / or treatment part (abbreviated as CTP in this document). When the CTP is vibrating, the fluid in the oral cavity exhibits turbulent motion at high frequencies. Blood in the fluid also moves at these high frequencies. By selecting a high frequency, for example 10 Hz or higher, signal components related to the movement of (magnetic) blood in the fluid can be isolated.

[0040] According to one or more embodiments, the processing unit can be configured to receive sensor signals of magnetic field strength over time for one or more locations from the sensing unit and detect the presence of (or a condition indicative of) inflamed periodontal tissue based on the amplitude of the signal and / or based on the baseline level of the signal.

[0041] This is useful for detecting inflamed tissue (or conditions indicative of it). For example, gingivitis has been shown to be associated with at least a 50% increase in blood flow in the area of the affected tissue. This can result in an increase in the amplitude of the vibration. However, it can sometimes result in a decrease in the amplitude of the vibration because more blood is trapped at the site of inflammation between blood pulses, reducing the vibration amplitude.

[0042] Gingivitis is associated with a greater-than-normal accumulation of blood in areas of inflamed periodontium, which results in a detectable increase in the baseline signal.

[0043] According to one or more embodiments, the oral care system may include an oral care device. The oral care device includes a cleaning and / or treatment portion and a treatment portion. Non-limiting examples of oral care devices include electric toothbrushes, brushing mouthpiece devices, oral irrigators, and electric flossing devices. Optionally, the cleaning and / or treatment portion may be releasably coupleable to a further portion of the oral care device, the further portion including the treatment portion.

[0044] An example according to a further aspect of the present invention provides a method for sensing in a user's oral cavity, the method comprising generating a reference magnetic field in the oral cavity, sensing the magnetic field strength of the reference magnetic field at one or more spatial locations in the oral cavity and generating a sensing output signal, performing sensing of periodontal tissue or blood in the oral cavity based on analysis of the sensing output signal, and generating a data output based on the results of the sensing.

[0045] An example according to a further aspect of the present invention provides a computer program comprising computer program code executable on a processor, the computer program code, when operatively coupled to a magnetic field sensing unit configured to sense magnetic field strength or changes therein at one or more spatial locations within the oral cavity based on generation of a reference magnetic field in the oral cavity by a magnetic field source, causing the processor to receive a sensor output from the magnetic field sensing unit indicative of the magnetic field strength or changes therein of the reference magnetic field at the one or more spatial locations within the oral cavity, and based on analysis of the sensor output, perform sensing of periodontal tissue or blood in the oral cavity, and generate a data output indicative of the sensing.

[0046] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief explanation of the drawings]

[0047] [Figure 1] FIG. 1 illustrates a block diagram of an exemplary oral care system. [Figure 2] FIG. 1 illustrates an exemplary system in use, showing the reference magnetic field exposed to a normal fluid. [Figure 3] FIG. 1 illustrates an exemplary system in use, showing a reference magnetic field exposed to blood. [Figure 4] FIG. 1 illustrates an exemplary cleaning and / or treatment portion of a system including multiple magnetic sensing elements. [Figure 5] FIG. 1 illustrates the use of an exemplary system with multiple magnetic sensing elements. [Figure 6] FIG. 1 illustrates an exemplary electromagnetic cleaning and / or treatment unit (EMCTA). [Figure 7] FIG. 1 illustrates a portion of an exemplary system having an EMCTA. [Figure 8] FIG. 1 illustrates a portion of a further exemplary system having an EMCTA. [Figure 9] FIG. 10 illustrates a portion of a further exemplary system including an EMCTA, where the magnetic sensing portion is inductively powered by the EMCTA. [Figure 10] 1 illustrates an exemplary oral care system in which a treatment unit is integrated into the oral care device. [Figure 11] 10A-10C illustrate further exemplary oral care systems that include a processing unit separate from the oral care device. DETAILED DESCRIPTION OF THE INVENTION

[0048] For a better understanding of the present invention, and in order to show more clearly how it may be carried into effect, reference will now be made to the accompanying drawings, which are given by way of example only, in which:

[0049] The present invention will now be described with reference to the figures.

[0050] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems, and methods, are for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the devices, systems, and methods of the present invention will be better understood from the following description, the appended claims, and the accompanying drawings. It should be understood that the figures are schematic only and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

[0051] The present invention provides an oral care system for sensing blood in the oral cavity and periodontal tissues. Sensing is performed magnetically using a magnetic field source and a magnetic sensing unit integrated into the cleaning or treatment portion of the oral care device (e.g., the brush head of a toothbrush or the mouthpiece portion of a brushing mouthpiece device). The magnetic field source generates a reference magnetic field, and the sensing unit is configured to sense the magnetic field strength of the reference magnetic field at one or more spatial points. Because blood is a magnetic material, when it is brought into the reference magnetic field, it magnetically interacts with the magnetic field, which can change the magnetic field strength, magnetic field shape, or magnetic flux distribution. This allows the presence of blood to be detected. Because the magnetic field sensor provides a quantitative output, it also enables more specific sensing. In particular, it allows the detection of specific characteristics associated with blood in the oral cavity, such as an abnormal presence of blood or an abnormality or pathology associated with an abnormal amount or concentration of blood. For example, this can be based on the application of detection criteria related to one or more characteristics of the sensed magnetic field (e.g., magnitude, frequency composition, temporal variation, or spatial variation over an area). These criteria can be predetermined, for example, known to be associated with particular intra-oral features, and can be applied at the time of use.

[0052] FIG. 1 shows a schematic block diagram of elements of an exemplary oral-care system according to one or more embodiments.

[0053] The system 10 includes a cleaning and / or treatment portion 14 (abbreviated herein as CTP) of the oral care device, at least a portion of which is received during use within the user's oral cavity for cleaning or treatment functions.

[0054] The CTP 14 has a support structure 22 carrying a magnetic field source 16 that generates a reference magnetic field within the oral cavity when received therein, and a magnetic field sensing portion 18 configured to detect the magnetic field strength of the reference magnetic field, or changes therein, at one or more spatial locations.

[0055] The system further includes a processing unit 20 configured to receive the sensor output from the magnetic field sensing unit 18 and configured to perform blood sensing based on the sensor output.

[0056] More particularly, it is preferably configured to detect intraoral characteristics based on sensing blood in or on gum tissue or within the oral cavity, the detection being based on sensor output. For example, it can be configured to detect an abnormal presence or concentration of blood in or on gum tissue or within the oral cavity, the detection being based on analysis of sensor output.

[0057] Embodiments are based on detecting characteristics of blood in the oral cavity or tissues within the oral cavity, which may include, for example, one or more of an abnormal presence of blood (indicative of bleeding), such as in the oral cavity (e.g., where blood would not normally be present), or an abnormal concentration or amount of blood, e.g., as droplets, in or on the gums (indicative of inflammation).

[0058] The cleaning and / or treatment portion (abbreviated herein as CTP) 14 refers to the portion of the oral care device designed to be received in the oral cavity for cleaning and / or treatment functions. For example, it may comprise a toothbrush head. It may comprise the head of a flossing or oral irrigation device. In other examples, it may form the mouthpiece portion of a brushing mouthpiece device. In some cases, the entire oral care device is received in the oral cavity (e.g., in the case of a cleaning mouthpiece unit). In this case, the entire device forms the CTP. In use, the CTP 14 may be physically separable from the oral care device 12, e.g., it may be a removable toothbrush head. In other examples, it may be integrally included in the oral care device.

[0059] The support structure may, for example, comprise the platen of a toothbrush, the mating surface of a mouthpiece unit, or any other body or structure that can act as a carrier or housing for the magnetic source and magnetic sensing portion.

[0060] There are various options for the architecture of the system, which will be explained in more detail later.

[0061] With regard to the magnetic field source, this can be a passive magnetic field source (such as a permanent magnet) or an active magnetic field source, for example, a coil, a solenoid, or an electrode pair. For example, a permanent magnet can have a ferrite magnet or a rare earth metal-based magnet such as an alloy of NdFeB or SmCo. In the opposite example, a solenoid or loop coil can be driven with a DC current to generate a static magnetic field, or with an AC current to generate an alternating magnetic field.

[0062] In general, the reference magnetic field may be a static magnetic field or a time-varying magnetic field, for example, an AC magnetic field. A static magnetic field is preferably used. When a time-varying magnetic field source, for example, an AC magnetic field, is used, the detection criteria may need to be adjusted compared to that of the static magnetic field. For example, when the detection criteria includes detecting a change or fluctuation in the detected magnetic field strength (in the case of a static magnetic field), this may need to be defined as a change or fluctuation in the baseline of the detected magnetic field strength, or the envelope of the magnetic field strength (in the case of an AC magnetic field).

[0063] Regarding the magnetic field sensing portion 18, it can have a single magnetic field sensing element of multiple sensing elements. It can sense the magnetic field strength at one location or at multiple locations. By way of non-limiting example, suitable options for sensing the magnetic field include one or more (giant) magnetoresistive sensors or one or more Hall effect sensors. For example, commercially available giant magnetoresistive (GMR) sensors can be provided in very small dimensions (e.g., on the order of 1×1×0.5 mm) and can operate at very low power levels (e.g., nanowatts at 0.9 V).

[0064] The magnetic sensing elements of the magnetic sensing portion 18 can be disposed on an exposed surface of the support structure 22 of the CTP 14, such as on the platen of a brush. Alternatively, they may be at least partially embedded in the support structure. The same applies to the magnetic field sources. For example, in the case of a brush head, they can be disposed at the base of the bristle field, on the support structure, or within the support structure. In a further example, the magnetic sensing elements and / or magnetic field sources can be embedded or carried by protruding elements that rise or extend from the top surface of the support structure 22, holding the sensing elements and / or magnetic field sources at an elevated level relative to the support structure. For example, they can be held at or near the level of the bristle tips (if bristles are included).

[0065] Preferably, the magnetic field source and sensing portion are positioned as close as possible to the gum area during use of the CTP 14 for its cleaning or treatment function, making it more sensitive to detecting abnormal concentrations of blood in the gums, or bleeding from the gums, which may be indicative of gingivitis.

[0066] An exemplary workflow of the system's operation can be understood as follows.

[0067] The cleaning or treatment portion 14 is received within the oral cavity. The magnetic field source 16 is active (as opposed to a passive magnetic field source).

[0068] Due to its magnetic properties, blood (e.g., blood accumulation) within the region covered by the reference magnetic field will magnetically interact with the magnetic field, resulting in changes or disturbances in the shape or strength distribution of the magnetic field compared to the absence of external matter in the magnetic field, which can be detected by the magnetic field sensing unit 18. Depending on the size, shape, and nature of the blood features, they will interact differently with the reference magnetic field and thus be associated with different detectable signatures or fingerprints in the detection signal.

[0069] This is shown schematically in FIGS. 2 and 3, which show an exemplary support structure 22 of the CTP 14, carrying the magnetic field source 16 and magnetic field sensing portion 18, held over a region 34 within the oral cavity. This region may be, for example, the base of the mouth or a cavity at the gum line, or any other region. The magnetic field source 16 is shown generating a static reference magnetic field 32, the field lines of which are shown schematically. FIG. 2 schematically shows a region of fluid 36, e.g., saliva, being brought into the region of the reference magnetic field. FIG. 3 schematically shows a region of blood 38 being brought into the region of the magnetic field. The region of blood represents an increase or accumulation of perfused blood in inflamed tissue, such as caused by gingivitis. Due to its magnetic properties (diamagnetic in this example), blood acts as a distortion of the magnetic field shape, particularly by stretching the magnetic field lines along its length. In the illustrated example, this acts to increase the area covered by the magnetic field, thus reducing the magnetic flux density in the area of the magnetic field sensor 18. As a result, the magnetic field sensor detects a lower magnetic field strength reading. This represents one example of how the characteristics of blood can distort or affect the magnetic field. In contrast, the (non-magnetic) fluid 36 has no or only a negligible distorting effect on the magnetic field 32.

[0070] The magnetic field sensing unit 32 senses the magnetic field strength at one or more locations. Fig. 3 shows one location for the sake of explanation. The sensing data is transmitted to the processing unit 20 (not shown in Fig. 2 or 3).

[0071] The processor 20 applies at least one detection assessment, which may comprise a set of algorithms or rules encoded in the processor's programming. The processor may be operable to selectively apply one of a plurality of different detection assessments, each for detecting a different intra-oral abnormality or feature, such as a blood feature, characteristic, or pathology. Based on the detected feature, the blood distribution characteristic associated with that feature may be expected to interact differently with the reference magnetic field and, therefore, be associated with a different observable sensing signal characteristic or change in the sensing signal characteristic.

[0072] A given detection evaluation is associated with one or more evaluation criteria related to the magnetic field sensing data from the magnetic field sensing unit 18. This may relate to temporal changes in the magnetic field, spatial distribution of the magnetic field across different locations, threshold magnitudes for the magnetic field, threshold changes in the magnetic field compared to a reference value or distribution, and / or other criteria desired or required to detect a particular abnormal condition. The processing unit 20 may be configured to communicate with a local or remote data store that stores the detection criteria. The data store may, in some examples, be included as part of the processing unit, or it may be remotely communicable via a communications interface. Optionally, the processing unit may be switchable between different detection modes, each for detecting a different blood abnormality or characteristic, with a different detection evaluation for detection being applied in each mode. Alternatively, processing unit 20 may be operable to detect any of multiple types of anomalies in a single mode.

[0073] A successful or positive result of a detection evaluation can correspond to satisfying all, or a defined subset, of the detection criteria for that evaluation. Optionally, if a relevant feature or anomaly is detected positively, a notification signal can be generated. This can result in the generation of a sensory output via a user output element, such as an auditory alert, the illumination of one or more lights, or tactile feedback via the handle of the oral care device. Alternatively, the signal can be coupled to a further data store or analysis module configured to compile the detection results for later retrieval and presentation to the user.

[0074] In some examples, the data store may store a record of one or more reference sensing signals associated with normal conditions of the oral cavity and associated with clinically abnormal conditions of the oral cavity, and determining the abnormality may include comparing the detected signal to the reference signal.

[0075] There are different options for the structural configuration of the sensing element in the oral cleaning or treatment portion 14. Based on the blood characteristics or abnormalities detected, there are also different options for the detection evaluation and associated criteria that can be performed.

[0076] According to at least a first set of embodiments, the magnetic sensing portion 18 comprises a single magnetic sensing element, for example in the form of a (giant) magnetoresistive sensor or a Hall effect sensor, examples of which are shown schematically in Figures 2 and 3.

[0077] In operation, the CTP 14 is moved by the user over the region of interest in the oral cavity, and the output of the magnetic sensor 18 is monitored by the processing unit 20. When the CTP 14 passes through a body region (e.g., a tooth) that does not have a significant concentration of blood, there is little change in the magnetic sensor output (see FIG. 2). However, diamagnetic (or paramagnetic) blood disrupts the magnetic field, causing the sensor output to be altered. In general, the presence of blood causes the magnetic field lines to broaden further, and a decrease in the signal (of the magnetic field strength) is expected (FIG. 3). However, for some other shapes, an increase in the magnetic field strength signal is also possible (e.g., when the sensor 18 is placed near the gums and is partially surrounded by an inflamed, blood-rich area).

[0078] Thus, detection is based on sensing changes in the sensed magnetic field. In other words, in this embodiment, detection is based on sensing temporal changes in the sensor output signal, indicative of the reference magnetic field passing over an area containing relevant blood characteristics, such as blood accumulation, either below the tissue surface or within the oral cavity. In the received signal of magnetic field strength over time from the magnetic field sensing unit 18, this can be detected as a variation in the magnetic field signal. Because the magnetic field characteristics are changing, this indicates the presence of a localized area with a higher blood concentration than other areas. Based on the assumption that other areas are normal, this means that the localized area has a blood concentration or accumulation that deviates from normal levels. Thus, abnormalities can be detected based on detecting temporal variations in the magnetic field signal. Note that in the case of an alternating magnetic field, detection can be based on temporal variations in the baseline of the magnetic field signal, or the amplitude or envelope of the magnetic field signal.

[0079] The fluctuation indicates the presence of blood at the location of the magnetic field sensing portion at the time the fluctuation is detected. This also allows for localization of blood characteristics. For example, sensory feedback may be provided when a fluctuation is sensed, thereby alerting the user that the current location of the CTP 14 is the location of a characteristic such as an abnormality. "Fluctuation" herein may refer, for example, to a signal increase or decrease by a predetermined threshold within a predetermined time window. This may be set to a level to eliminate simple background fluctuations due to noise.

[0080] According to one or more embodiments, the processing unit may further comprise a position determination function for determining an indication of the position of at least the magnetic sensing unit within the oral cavity at any given time. By way of example, US 2020 / 069042 and US 2020 / 022488 each disclose suitable exemplary systems for determining the position of a CTP 14 (e.g., a toothbrush head) within the oral cavity.

[0081] The processing unit 20 may be configured to determine the location of the blood presence site based on identifying the detected location of the magnetic sensing unit upon detection of variations in the magnetic signal. This is used to confirm that the presence or accumulation of higher than normal blood is indeed abnormal at that particular location of interest. If the presence or high blood concentration is detected in an unusual location (e.g., while brushing the occlusal surface or buccal side of the teeth), this indicates that the blood is abnormal. Additionally or alternatively, it may simply allow for a precise recording of the location of each detected abnormality, which recording may be saved, for example, in a data store and retrieved at the end of a usage session.

[0082] A configuration with a single magnetic sensor may be susceptible to noise from magnetic fields due to external factors (e.g., magnetic shielding materials or the Earth's magnetic field). Generally, if the magnetic field source and sensor unit are stationary in the mouth, an anomaly may not be detected. This may occur, for example, with certain types of mouthpiece devices. Therefore, according to one or more further sets of embodiments, the magnetic field sensing unit 18 may have multiple magnetic field sensing elements.

[0083] An example is shown in FIGS. 4A and 4B. In this example, the cleaning and / or treatment unit 14 is a brush head for a toothbrush, but the type of cleaning and / or treatment unit is not essential to the technical effect of this embodiment. The magnetic sensing unit 18 has a set of four magnetic sensing elements 18a, 18b, 18c, and 18d, which are spaced apart from each other and from the magnetic field source 16. FIG. 4A schematically shows an exemplary location of the sensing elements 18a-18c and the magnetic field source 16. The sensing elements are arranged in a 2×2 array. The sensing elements have a vertical spacing ΔY and a horizontal spacing Δ, both of which can be adjusted. As a non-limiting example, the horizontal spacing may be configured to be approximately half the width of a typical tooth (e.g., approximately 5-10 mm), and the vertical spacing can be on the order of 10 mm. More or less than four sensors can be provided. 4B shows a schematic side elevation view of the arrangement, where the sensor elements (only two 18a, 18b are visible) are arranged on the surface of the support structure 22 of the cleaning and / or treatment portion 14 and / or at the base of the bristle field 42. In another example, the sensor elements and optionally the magnetic field generators may be incorporated into the tip of a protruding member that extends down to the level of the bristles 46, so that the sensor is close to the gums during use.

[0084] In this set of embodiments, detection of blood-related characteristics can be based on spatial variations in the magnetic field strength detected by different ones of the sensing elements 18a, 18b, 18c, and 18d. For example, a simple asymmetry in the detected magnetic field strength between one set of one or more sensing elements located in one region of the support structure 22 and another set of one or more sensing elements spaced apart from the first set in another region indicates different amounts of blood being detected in the two regions. Based on the assumption that the region with higher or lower detected magnetic field strength represents a healthy individual (the healthy individual side will have higher or lower readings depending on the structural configuration; see above), this means that the other region with higher or lower detected magnetic field strength should be located in a region of abnormal blood concentration, thereby enabling detection of the abnormality.

[0085] Optionally, the detection criteria for the detection evaluation may include a threshold for difference asymmetry, e.g., a minimum percentage difference in sensor readings between two sensing locations, for an abnormality to be detected. Optionally, additionally or alternatively, the detection criteria may include a threshold for the level of sensed magnetic field strength at the higher or lower sensing location, for detection to occur. This may be set, for example, at a level that excludes detection due to one region of the sensing portion 18 simply overlapping a normally zero blood presence region, e.g., the tip of a tooth.

[0086] In the simplest case, this set of embodiments can be realized with a sensing portion 18 having two sensing elements spaced apart in or on a support structure, e.g., on different sides of the support structure. An example of this is shown in Figure 5. As shown, on the side where there is blood accumulation 38, e.g., due to gingivitis, the blood distorts the magnetic field, resulting in a higher or lower sensor reading (low in this example) based on the sensor's location. On the opposite side, a relatively higher reading is detected.

[0087] Optionally, in this set of embodiments, the location of the abnormality relative to the region of the sensing portion may be determined based on where the changed magnetic field strength is detected. If there are only two sensors, this can only be done if it is known in advance whether blood will increase or decrease the detected magnetic field strength in the relevant region (which is usually known). If there are more than two sensors, this may be done by identifying which sensing element has a magnetic field reading that differs from all other sensing elements by a certain threshold, and assuming that the abnormal blood signature is located below or adjacent to the location of this sensing element.

[0088] In some examples, an array of sensing elements may be provided across the sensing area of the sensing unit. In this case, identifying a particular localized region of the sensing area where the sensing elements detect a different magnetic field strength (compared to other areas) allows for more precise location of the anomaly. The location of this region provides the location of the anomaly relative to the sensing area of the sensing unit. In the case of a cleaning or treatment unit that covers a large area of the oral cavity, such as a mouthpiece unit, this may allow for precise location of the anomaly over a large area of the oral cavity. In other cases, it may allow for location over a smaller area of the oral cavity where the sensing area spans.

[0089] The size of the detected regions of different magnetic field strength can also be used to estimate the size or extent of the region of abnormal blood presence or concentration, for example, only areas at the gum line that have bleeding or inflammation and other areas that do not (by way of example only). Thus, embodiments having multiple sensing elements can sense the spatial shape, pattern, or distribution of blood.

[0090] The latter feature may also be used as part of the detection criteria for detecting anomalies. In some examples, the detection criteria may include detection of a certain spatial distribution of magnetic field strength across the sensing region (across different sensing locations) of the sensing portion 18. For example, a set of one or more reference magnetic field distributions or patterns may be stored in a data store, and detection of one or more types or classes of anomalies may depend on detection of the associated reference magnetic field distributions.

[0091] In certain examples, this embodiment may also incorporate the features described above regarding the detection of features or anomalies based on the detection of temporal variations or changes in magnetic field strength. For example, in some embodiments, the detection of anomalies may be based on the detection of temporal changes or variations in the spatial magnetic field distribution across different sensing spatial locations. Detection may be triggered if the magnetic field distribution changes by a defined threshold or in a defined manner. Thus, optionally, the detection of anomalies may be based on a combination of spatial and temporal variations in magnetic field strength.

[0092] A magnetic field distribution in the context of the present disclosure may correspond to the relative magnetic field levels (with respect to each other) detected at each of the sensing locations of the sensing elements 18a, 18b, 18c, 18d, or may correspond to the distribution of absolute values across the locations.

[0093] The magnetic field sensing elements 18a, 18b, 18c, 18d are preferably in a fixed spatial arrangement.

[0094] Based on either the single sensor or multiple sensor options, the lateral distance between the magnetic sensing element and the magnetic field source can be adjusted to adjust sensitivity. For example, the system can be made sensitive to blood closer to the (gingival) surface by moving the sensor 18 laterally closer to the magnetic field source 16, and sensitive to blood further from the surface by moving the sensor away from the magnetic field source.

[0095] Based on either the single sensor element or the multiple sensor element option, detection of inflamed periodontal tissue (or a condition indicative of inflammation), e.g., gingivitis, may be performed based on the detection of specific criteria changes in a certain threshold magnetic field magnitude or magnetic field shape. This is particularly due to the fact that oxygenated blood is diamagnetic, while deoxygenated blood is paramagnetic. They distort the magnetic field in which they exist differently. Thus, the system can be configured to detect blood oxygenation levels based on one or more criteria related to the changes in the different magnetic field magnitudes or patterns of diamagnetic and paramagnetic blood. This increases the specificity in detecting gingivitis, since in gingivitis, the blood is more deoxygenated than in healthy periodontal tissue.

[0096] According to one or more embodiments, the oral care device may additionally include electromagnetic cleaning or treatment functionality.

[0097] Electromagnetic fields, particularly radio frequency (RF), are known to be effective for use in cleaning or treating tooth surfaces or periodontal tissues. For example, they can loosen biofilm coatings on tooth surfaces, actively assisting tooth cleaning with the cleaning or treatment unit 14. Radio frequencies stimulate periodontal tissues, which can exert a localized therapeutic effect. A suitable frequency range for the cleaning or treatment mode can be, for example, between 1 MHz and 10 MHz.

[0098] Thus, according to one or more embodiments, the oral care system may further include an electromagnetic (EM) cleaning and / or treatment unit 60. The EM cleaning or treatment unit 60 may be abbreviated herein as EMCTA.

[0099] Components of an exemplary EM cleaning and / or treatment section 60 are shown in Figure 6. The section 60 has a conductor section 24 that includes one or more conductive elements 52. It further comprises a signal generator 62 configured to generate an alternating electromagnetic field 56 at radio frequency (RF) and / or microwave frequencies when the signal generator 62 is operably coupled to the conductor section 24.

[0100] Optionally, the configuration 60 may include a controller 66 operably coupled to the signal generator 62 during use to selectively activate the generator in a cleaning or treatment mode. The controller can control operation of the signal generator when the cleaning or treatment mode is selectively activated, thereby achieving the cleaning or treatment mode. In some examples, activation of the cleaning or treatment mode can be user-activated, for example, by a physical button on or off the device, or by operably coupled software (e.g., a smartphone app). The controller can be included in the oral care device, or external thereto, but operably connected to the signal generator. In other examples, the signal generator itself can have a processor or IC chip that allows for local activation and realization of the cleaning or treatment mode.

[0101] Generator 62 is an oscillating signal generator, e.g., an oscillator, that generates an AC drive signal that is coupled to conductor 24, resulting in the emission of EM radiation or generation of an EM field. The oral care device may include a local power storage, e.g., a battery, to power generator 62.

[0102] The conductor portion 24 may, for example, have a pair of electrodes 52 driven with cyclically opposite polarities by a generator 62 to cause the generation of an alternating magnetic field between the electrodes. This option is shown in Figure 6, where the conductor portion 24 has a pair of electrodes 52a, 52b, which in some examples have a layered shape. An alternative possibility is the use of one or more inductive coils or wire loops, driven with an alternating current to induce the generation of an alternating magnetic field along the axial direction of the loop or coil.

[0103] The conductor portion may be configured or carried by the oral cleaning or treatment portion (CTP) 14, for example, by the support structure 22. Optionally, the signal generator 62 may be included in the body portion of the oral cleaning device. The conductor portion 24 and the signal generator 62 may be permanently electrically coupled, or may be removably electrically coupleable, for example, such that a connection is established when the CTP is mechanically coupled to the body portion of the oral cleaning device.

[0104] According to one set of embodiments, the signal generator 62 and the conductor portion 24 can provide the magnetic field source 16. In other words, the EMCTA 60 is used to generate the reference magnetic field 32.

[0105] In some examples, the magnetic component of the EM AC field 56 generated in the cleaning or treatment mode provides the reference magnetic field 32 for use in sensing blood. Thus, the reference magnetic field is formed by the EM cleaning or treatment field. In this way, EM cleaning and blood detection can occur simultaneously. In this case, the reference magnetic field is an AC magnetic field.

[0106] According to a further set of embodiments, blood sensing and EM cleaning and / or treatment functions are performed in separate modes. For example, controller 66 can be further selectively configured for a blood sensing mode in which signal generator 62 is controlled to generate a different magnetic or electromagnetic field using conductor portion 24 for use as reference field 32. In this case, cleaning and sensing cannot occur simultaneously. However, cleaning and sensing fields can (optionally) be generated in an alternating manner, e.g., in alternating duty cycle phases of a duty cycle control, so that they can operate quasi-simultaneously.

[0107] The different magnetic field may in some instances be a DC field. This may be achieved by placing a rectifier between generator 62 and the conductor (preferably the coil) when switching to the blood sensing mode, thereby driving the coil with a DC current. Additionally or alternatively, the different magnetic field may be an alternating magnetic field at a lower frequency than the cleaning and / or treatment magnetic fields.

[0108] It is also possible to generate the cleaning and / or treatment magnetic field 56 and a different sensing reference magnetic field 32 precisely simultaneously in the hybrid cleaning / treatment and sensing mode, using the same generator 62 but separate conductor sections 24 to generate the individual magnetic fields. This can be done by providing a rectifier between the generator 62 and the conductor section (e.g., a loop coil) used to generate the reference magnetic field 32. Alternatively, the generator 62 can be connected to the conductor section 24 of the EM cleaning and / or treatment section 60 without a rectifying element. This allows the DC reference magnetic field 32 to be created simultaneously with the AC cleaning / treatment magnetic field 56. However, in this case, there is a possibility that one magnetic field may interfere with another, and therefore, the detection criteria used to detect abnormal blood characteristics must be configured to account for potential changes in the sensing magnetic field characteristics, e.g., a different set of detection criteria for when the hybrid cleaning and sensing mode is active.

[0109] 7 and 8 schematically illustrate two examples in which elements of an EMCTA 60 are used to generate the reference magnetic field 32. In the example of FIG. 7, the conductor portion 24 includes a pair of electrodes 52a, 52b, which may be covered with a protective coating in some examples. In some examples, they are embedded in a resilient protruding member. The electrodes protrude from the surface of the support structure 22 of the oral cleaning or treatment unit 14. An AC field is generated between the electrodes 52 by applying an AC voltage or current between the electrodes by a generator 62 (not shown in FIG. 7). The magnetic component of this ACEM field forms the reference magnetic field 32. Two exemplary sensor elements 18a, 18b of the magnetic sensing portion 18 are shown positioned on the surface of the support structure 22 within the reference magnetic field 32. They may alternatively be provided at the level of the tips of the electrodes 52 and / or hair field (if included).

[0110] In the example of Figure 8, the conductor portion 24 comprises a loop coil 54. In blood sensing mode, this is driven with a DC current to generate the static reference magnetic field 32. In cleaning and / or treatment mode, it is driven with an AC current to generate the alternating EM field. Alternatively, the alternating AC magnetic field for cleaning and / or treatment may also be used for the reference magnetic field. For purposes of illustration, a single sensing element 18 is shown in the reference magnetic field, although more sensing elements may be provided in other embodiments.

[0111] Optionally, a second conductor portion (e.g., a coil instead of an electrode) and optionally a second signal generator may be provided to generate a magnetic field for use in blood detection. The generation of the reference magnetic field may in some instances be completely separate from the EMCTA elements, i.e., there is a separate magnetic field source for the reference magnetic field.

[0112] Compatible with any of the above-described options, according to one or more embodiments, the magnetic field sensing portion 18 may be configured to be powered via inductive or capacitive coupling of energy from the EM field 56 generated by the EMCTA signal generator 62 and the conductor portion 24.

[0113] This can be done within the cleaning and / or treatment mode or the dedicated sensing mode described above. Thus, here, the magnetic field used to transfer power to the sensor is the same as the magnetic field used to perform the cleaning and / or treatment function and / or to perform the sensing function. Alternatively, it can be done within a further dedicated power transfer mode, in which the controller 66 controls the generation of the EM field using the conductor portion 24 primarily for the purpose of powering the magnetic sensing portion 18. Here, EM cleaning and / or treatment is not active during the power transfer mode. A separate magnetic field may be generated for the reference magnetic field 32.

[0114] This set of embodiments has the advantage that no additional active or powered elements need to be integrated into the oral care device or system to power the sensors (they are inherently powered by the power source for the EMCTA 60). Furthermore, no separate power lines need to be run to the active magnetic field sensing portion. This provides a significant simplification in manufacturing if the main power source for the oral care device is in the handle, for example, while the CTP 14 is in the head region.

[0115] Inductive or capacitive coupling can be achieved by providing a transmit pair of transmit inductive coils or capacitor plates connected across the generator 62 and a receive pair of receive inductive coils or capacitor plates (respectively) connected across the magnetic sensing portion (or across a single magnetic sensing element in some examples), with a rectifier provided between the receive coils or plates and the sensor. An example is shown schematically in FIG. 9 , which shows a transmit inductive coil 54 connected across the generator 62 and a receive inductive coil 72 connected across an exemplary magnetic sensing portion or element 18, with a rectifier 74 provided between the receive coil 72 and the magnetic sensing element 18. The transmit and receive inductive coils may be axially aligned (not shown in FIG. 9 ) and axially spaced apart from one another in the electromagnetically coupled configuration. If capacitive coupling is used, the transmit and receive capacitive plates may be positioned in a face-to-face relationship and spaced apart from one another in the electromagnetically coupled configuration.

[0116] Additionally or alternatively, if the reference magnetic field 32 is not generated by the EMCTA 60, it may be possible to provide the magnetic field source 16 (if an active magnetic field source) configured to be powered by inductive or capacitive coupling of energy from the EM field generated by the signal generator and conductor portion.

[0117] For example, an active magnetic field source 16 may be provided, e.g., a DC or AC driven coil or solenoid, the drive of which is powered by an RF generator, which may be powered by inductive or capacitive coupling of electrical energy from, for example, an RF conductor section (capacitive if the conductor section comprises an electrode, inductive if the conductor section comprises one or more coils).

[0118] Depending on the particular anomaly being detected, the way the sensor signals are processed and / or the detection criteria applied may differ.

[0119] According to one or more embodiments, the processing unit 20 is configured to receive a sensor signal of magnetic field strength over time for one or more sensing locations of the sensing unit 18 and is configured to process the signal to remove frequency components within a predetermined range of frequency components associated with a predetermined heartbeat frequency.

[0120] This embodiment is useful for distinguishing between static blood (such as droplets on the surface of periodontal tissue) and flowing blood, which is useful for detecting pockets or blisters of blood from inflamed tissue, such as those associated with gingivitis, because the former is characterized by the accumulation of static blood in inflamed tissue.

[0121] For example, in other technical fields unrelated to oral care, it is known that magnetic fields can be used as part of a heartbeat sensing device. Even in places where there are no major veins or arteries (e.g., the surface of the lungs), blood perfuses the skin, which can generate a signal in a magnetic sensor. Therefore, inflamed tissue due to gingivitis is also expected to exhibit signal components related to blood flow. To remove these signal components and isolate components related to static blood, such as droplets on the gum surface or in pockets or blisters, the sensor output can be analyzed as a function of frequency, and frequency components that approximately correspond to the heartbeat frequency (e.g., 0.5-5 Hz, e.g., 1-3 Hz) can be removed or filtered. For example, one or more band-pass filters can be used. By removing these components, the remaining signal represents static blood, which makes the sensor output specific to unwanted blood in the oral cavity or gums, rather than arterial blood in the gums.

[0122] In some examples, the oral care device may include a heart rate sensing element embodied, for example, in a handle portion of the device, and a predetermined range of frequencies for filtering the magnetic sensing signal may be set based on the detected heart rate.

[0123] It should be noted that if the reference magnetic field 32 is an alternating magnetic field, blood flow may cause oscillations in the baseline or envelope of the (alternating) sensor signal. Therefore, spectral analysis and filtering can be applied here to the baseline or envelope of the signal. For example, the baseline or envelope signal can be first extracted from the raw sensing signal.

[0124] According to one or more embodiments, the processing unit 20 is configured to receive sensor signals of magnetic field strength over time for one or more sensing locations of the sensing unit 18, and is configured to detect the presence of (or a condition indicative of) inflamed periodontal tissue based on the amplitude of oscillations in the signal (or in the signal's envelope or baseline in the case of an alternating reference magnetic field) or based on the magnitude of the signal's baseline.

[0125] This is useful for detecting inflamed tissue (or conditions indicative thereof). For example, studies have shown that gingivitis is associated with increased blood flow in the area of the affected tissue. For example, one study found that blood flow in gums with moderate gingivitis and periodontal disease increased by at least 50%. This results in a change in the baseline of the sensor signal because the concentration or volume of blood in a given area is greater, resulting in a greater distortion in the reference magnetic field. Therefore, the change in baseline can be used to detect inflamed tissue. Additionally, the presence of inflamed tissue can result in a change in the amplitude of oscillations in the signal. For example, the oscillation amplitude may decrease because more blood is retained in the inflamed tissue between blood pulses, resulting in less cyclic fluctuations in blood volume in a given area. In other cases, increased blood flow in the inflamed area may result in an increase in amplitude. Based on the specific characteristics of tissue inflammation to be detected, the configuration and intended operation of the device, pre-stored detection criteria can be applied that define threshold changes in the baseline and / or oscillation amplitude.

[0126] According to one or more embodiments, the processing unit may be configured to receive a sensor signal of magnetic field strength over time for the one or more locations from the sensing unit, and to detect the presence of blood in the oral fluid based on processing the magnetic field signal to extract frequency components above 10 Hz.

[0127] This is useful when sensing is performed during normal use of the oral care device, which is configured to activate the oscillation or vibration of at least a portion of the CTP (e.g., an electric toothbrush with a vibrating head). In the presence of vibrations from the cleaning or treatment unit, the contact fluid in the oral cavity exhibits turbulent motion at high frequencies. This can be used to isolate signal components associated with (magnetic) blood in the oral fluid, but not with normal blood flow in the tissue (e.g., at much lower frequencies, on the order of 0.5-5 Hz, corresponding to heart rate).

[0128] For example, free blood in toothpaste may be disturbed by high-frequency sonic or rotational vibration motion (e.g., on the order of 80-250 Hz). Under normal physiological conditions, blood flow in capillaries has a pulsation frequency of approximately 0.5-3 Hz. On the other hand, under sonic motion, for example, turbulence is expected, with a motion frequency of 80-100 Hz, which is two to three orders of magnitude higher. Therefore, the processing unit 20 can be configured to apply a high-pass filter or otherwise select a high frequency band of the sensing signal to be analyzed in order to distinguish between blood in toothpaste and blood flow through the gum tissue during brushing.

[0129] According to one or more embodiments, detection results collected over multiple different sensing sessions (e.g., multiple different use sessions of an oral care system) may be stored in a local or remote data store to enable longitudinal monitoring of oral health. For example, gingivitis is known to periodically recur following periods of poor dental hygiene. Thus, longitudinal measurements of blood distribution within the oral cavity may be valuable in identifying gingivitis recurrences. Any of the above approaches may be tracked over a series of oral care (e.g., brushing) sessions, and the (re)appearance of unexpected presence or concentration of blood in the mouth or gums may be flagged and a warning message may be generated to alert the user or dentist.

[0130] The architecture of the system 10 provided by the present invention offers different options. The system includes a cleaning and / or treatment portion (CTP) 14 for the oral care device, at least a portion of which is received in the user's oral cavity for cleaning or treatment functions. The magnetic field source 16 and the magnetic field sensing portion are carried by or included in the support structure of the CTP 14. The CTP thus provided may be a separable cleaning or treatment unit designed to be releasably coupled to a further body portion of the oral care device 12 during use of the system. For example, the CTP 14 may be a detachable toothbrush head attachment for an electric toothbrush. An example is shown schematically in FIGS. 10A and 10B. In this embodiment, the treatment portion is integrally provided in (the body portion 15 of) the oral care device 12. The CTP 14 is a toothbrush head in this example, and the support structure is the platen 22 of the toothbrush head. The head is releasably coupleable to the body portion 15, which forms a handle.

[0131] A signal connection is provided between the processing unit 20 integrated into the body portion 15 of the oral care device 12 and the sensing unit 18 integrated into the CTP 14. If the magnetic field source 16 is an active magnetic field source, a power supply line may be provided between a drive or power unit in the body portion 15 and the electric field source 16 in the CTP. The signal or electrical connection is established when the brush head 14 is connected or mated to the body portion 15. The device may further include an actuation mechanism for imparting vibration or oscillation to the brush head during use. A toothbrush is just one example of a suitable oral care appliance. Other examples include a brushing mouthpiece unit, an oral irrigator, or an electric flossing device.

[0132] In some embodiments of the system, the entire oral care device 12 may be provided. However, at a minimum, a cleaning and / or treatment portion (CTP) 14 and a processing portion 20 must be provided, where the CTP is configured to releasably couple to a main body portion 15 of the oral care device during use. For example, in some embodiments, the processing portion 20 can be included in a device or unit separate from the oral care device. An example of this arrangement is shown schematically in FIG. 11. By way of example, the processing portion 20 may be provided by a native processing element of a mobile computing device, such as a smartphone, a wearable computing device (e.g., a smartwatch), or a tablet computer. The system 10 may, in this case, include a communication interface 92 to which a sensor output signal of the sensing portion 16 is coupled and configured to communicate the sensor output signal to the processing portion 20 in the separate unit (e.g., the mobile computing device). This may be a wireless communication interface 92 employing, for example, Bluetooth, W-Fi, or wireless LAN, or in other examples, a wired (or other physical) connection.

[0133] In some instances, the CTP 14 may form an integral part of the oral care device 12, such as in the case of a brushing mouthpiece device, in which case providing the CTP requires providing the entire oral care device.

[0134] An example according to a further aspect of the present invention provides a method for sensing in a user's oral cavity, the method comprising generating a reference magnetic field in the oral cavity, sensing the magnetic field strength of the reference magnetic field at one or more spatial locations in the oral cavity to generate a sensing output signal, and sensing periodontal tissue or blood in the oral cavity based on analysis of the sensing output signal, the method further comprising generating a data output based on the sensing.

[0135] The method may further include detecting one or more blood-related characteristics in the oral cavity or gums based on analysis of the sensing output signal.

[0136] The one or more features may correspond to an abnormality (health or medical) in the gums or oral cavity based on analysis of the sensing output signal, such as, for example, an abnormal presence or concentration of blood in the gum tissue or oral cavity, The detection may be based on application of one or more detection criteria related to a characteristic or property of the sensing output signal.

[0137] An example according to a further aspect of the present invention provides a computer program including computer program code executable on a processor. When the processor is operably coupled to a magnetic field sensing unit configured to sense magnetic field strength or changes therein at one or more spatial locations within the oral cavity based on generation of a reference magnetic field in the oral cavity by a magnetic field source, the code causes the processor to receive from the magnetic field sensing unit a sensor output indicative of the magnetic field strength or changes therein of the reference magnetic field at the one or more spatial locations within the oral cavity, and to perform sensing of gum tissue or blood in the oral cavity based on analysis of the sensor output. The code can further cause the processor to generate a data output indicative of the sensing.

[0138] The code can further cause the processor to detect one or more blood-related characteristics in the oral cavity or gums based on analysis of the sensing output signal.

[0139] The one or more features may correspond to an abnormality (health or medical) in the gums or oral cavity based on analysis of the sensing output signal, such as, for example, an abnormal presence or concentration of blood in the gum tissue or oral cavity, The detection may be based on application of one or more detection criteria related to a characteristic or property of the sensing output signal.

[0140] The above-described embodiments of the present invention employ a processing unit. A processing unit can generally have a single processor or multiple processors. It may be located in a single containing device, structure, or unit, or may be distributed among several different devices, structures, or units. Thus, references to a processing unit being adapted or configured to perform a particular step or task may correspond to that step or task being performed by any one or more of several processing elements, alone or in combination. Those skilled in the art will understand how such distributed processing units may be implemented.

[0141] The one or more processors of the processing unit can be implemented in several ways using software and / or hardware to perform the various functions required. A processor typically uses one or more microprocessors, which can be programmed using software (e.g., microcode) to perform the required functions. A processor can also be implemented as a combination of dedicated hardware to perform some functions and one or more programmed microprocessors and associated circuitry to perform other functions.

[0142] Examples of circuitry that may be employed in various embodiments of the present application include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

[0143] In various implementations, a processor may be associated with one or more storage media, such as volatile and non-volatile computer memory, including RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that, when executed by the one or more processors and / or controllers, perform the required functions. The various storage media may be fixed within the processor or controller, or may be transportable such that one or more programs stored thereon can be loaded into the processor.

[0144] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the figures, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0145] A single processor or other unit may fulfill the functions of several items recited in the claims.

[0146] 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.

[0147] The computer program may be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

[0148] It should be noted that when the term "adapted to" is used in the claims or specification, the term "adapted to" is intended to be equivalent to the term "configured to."

[0149] Any reference signs in the claims should not be construed as limiting the scope of the invention.

Claims

1. An oral care system comprising:

1. An oral care device comprising a cleaning and / or treatment portion, at least a portion of which is adapted to be received within a user's oral cavity for a cleaning or treatment function, the cleaning and / or treatment portion comprising: a magnetic field source that generates a reference magnetic field within the oral cavity when received within the oral cavity; a magnetic field sensing unit that detects the magnetic field strength or changes therein of the reference magnetic field at one or more spatial locations; a processing unit that receives a sensor output from the magnetic field sensing unit and performs sensing of blood in gum tissue or the oral cavity based on an analysis of the sensor output.

2. The oral care system of claim 1 , wherein the processing unit detects one or more predetermined features, and the detection of each feature is based on application of one or more predetermined detection criteria associated with the sensor output characteristics.

3. The oral care system of claim 2 , wherein the processing unit detects at least one of gingival inflammation or a condition indicative thereof, static blood on the surface of the gingiva, static blood at the gum line between the teeth and the gingiva, or bleeding.

4. The oral care system according to claim 1 , wherein the processing unit detects spatial and / or temporal variations in the reference magnetic field detected by the magnetic field sensing unit.

5. The oral care system of claim 4, wherein the magnetic field sensing unit has a plurality of magnetic field sensing elements spaced apart from one another, and the spatial variation in magnetic field strength is based on variations in magnetic field strength detected by different of the magnetic field sensing elements.

6. 6. The oral care system of claim 4 or 5, wherein the processing unit receives a sensor signal of magnetic field strength over time for the one or more locations and detects one or more characteristics based on detected temporal variations in the signal.

7. The system comprises: An electromagnetic cleaning and / or treatment unit, the electromagnetic cleaning and / or treatment unit comprising: a conductor portion including one or more conductive elements; an electromagnetic cleaning and / or treatment portion including a signal generator that generates an alternating electromagnetic field at radio frequency and / or microwave frequency when the signal generator is operably coupled to the conductor portion; 7. The oral care system of claim 1, further comprising: a controller operable in at least a cleaning and / or treatment mode, wherein in the cleaning and / or treatment mode, the controller controls the signal generator to generate an alternating electromagnetic field using the conductor portion to perform an oral cleaning or treatment function when the conductor portion is received in the oral cavity.

8. The oral care system of claim 7 , wherein the signal generator and conductor portion provide a magnetic field source for generating the reference magnetic field.

9. a magnetic component of the AC EM field generated in the cleaning and / or treatment mode provides a reference magnetic field; or 9. The oral care system of claim 8, wherein the controller is further selectively configurable in a blood sensing mode, in which the signal generator is controlled to generate a different magnetic or electromagnetic field using the conductor portion for use as the reference magnetic field.

10. 10. The oral care system of claim 8 or 9, wherein the magnetic field sensing unit is powered by inductive or capacitive coupling of energy from the EM field generated by the signal generator and conductor unit of the electromagnetic cleaning and / or treatment unit.

11. An oral care system as described in any one of claims 1 to 10, wherein the processing unit receives a sensor signal of magnetic field strength over time for one or more positions from the sensing unit and processes the signal to remove frequency components within a predetermined frequency range.

12. 12. The oral care system of claim 1, wherein the processing unit detects the presence of blood in the oral fluid by receiving a sensor signal of magnetic field strength over time for one or more positions from the sensing unit and processing the sensor signal to extract frequency components above 10 Hz.

13. An oral care system as described in any one of claims 1 to 12, wherein the processing unit receives a sensor signal of magnetic field strength over time for one or more positions from the sensing unit and detects the presence of inflamed periodontal tissue or a condition indicative thereof based on the amplitude of oscillation of the signal and / or based on the baseline level of the signal.

14. an oral care device, the oral care device having the cleaning and / or treatment unit and the treatment unit; 14. An oral care system according to any preceding claim, wherein the cleaning and / or treatment portion is releasably connectable to a further portion of the oral care device, the further portion comprising the treatment portion.

15. A method for operating a processor, comprising: receiving a magnetic field strength signal indicative of a magnetic field strength or a change therein of a reference magnetic field at one or more spatial locations within a user's oral cavity; sensing periodontal tissue or blood in the oral cavity based on analysis of the magnetic field strength signal; and generating a data output based on said sensing.

16. A computer program comprising computer program code executable by a processor, the processor is operably coupled to a magnetic field sensing unit configured to sense magnetic field strength or changes therein at one or more spatial locations within the oral cavity based on generation of a reference magnetic field within the oral cavity by a magnetic field source, and the code further comprises: receiving a magnetic field intensity signal from the magnetic field sensing unit indicative of a magnetic field intensity or a change therein of the reference magnetic field at one or more spatial locations within the oral cavity; sensing periodontal tissue or blood in the oral cavity based on analysis of the magnetic field strength signal; a computer program causing generating a data output indicative of said sensing.

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