Electrolysis apparatus and method of operating same

Abstract

An oral care device (100) for tooth tartar removal is provided. The oral care apparatus comprises a control device (102) configured to provide an electrical signal, such as a time-varying electrical signal. The oral care device also includes a pair of electrodes (104A, 104B) for contacting the aqueous solution. And a pair of electrodes each connected to the control device and configured to generate hydrogen ions from the water in the aqueous solution for delivery within the oral cavity of the subject, in particular to the teeth of the subject, in response to the electrical signal. A change in the electrical signal controls the generation of hydrogen ions. The hydrogen ions thus generated can reduce the pH of a portion of the teeth of the subject, thereby facilitating dissolution of tartar on the teeth. Changes in electrical signals (e.g., temporal changes) may provide control of the generation of hydrogen ions in contrast to, for example, uncontrolled generation of hydrogen ions via an invariant voltage between a pair of electrodes provided by a direct current power source. Methods of operating such oral care devices are also provided.

Description

Technical Field

[0001] The present invention relates to an apparatus, in particular an oral care apparatus, comprising a pair of electrodes for electrolyzing water to generate hydrogen ions. The invention also relates to a method of operating the apparatus. Background Art

[0002] The accumulation of calcified deposits in the body can be a problem. An example of calcified deposits is dental tartar.

[0003] Dental tartar, or early dental plaque, is a risk factor for gingivitis and periodontitis. Dental tartar has different calcium phosphate crystal phases with different solubility. The poor water solubility of some calcium phosphate crystal phases can make tartar difficult to remove.

[0004] Currently, dental tartar tends to be treated / removed only by dentists and dental hygienists using mechanical or ultrasonic scalers.

[0005] It would be desirable to provide additional dental tartar treatment / removal options, particularly options that could be used in the patient's own home.

[0006] US2021 / 307500A1 discloses an electric toothbrush, which includes a head and a handle, the handle can be connected to the head and is configured to provide a driving voltage to the head according to user control. The head includes a toothbrush head, in which bristles and a first electrode and a second electrode spaced apart from each other are arranged.

[0007] US 2021 / 330068 A1 discloses an oral cleaning device comprising a head portion, RF electrodes located on the head portion, and a non-conductive barrier located on the head portion to separate the electrodes from each other.

[0008] WO 2014 / 099064 A1 discloses an electrical discharge irrigator device for irrigating a root canal during root canal surgery.

[0009] WO 2007 / 047568 A1 discloses an oral care device for generating a chemical agent in situ on demand via application of an electrical potential across a pair of conductors in communication with an electrolyte. Summary of the invention

[0010] The invention is defined by the independent claim. The dependent claims define advantageous embodiments.

[0011] According to an example of one aspect of the present invention, there is provided an oral care device, comprising: a control device configured to provide an electrical signal; and a pair of electrodes for contacting an aqueous solution, the pair of electrodes being connected to the control device, the electrical signal and the pair of electrodes being configured such that at least one of the electrodes generates hydrogen ions from water in the aqueous solution in response to the electrical signal for delivery in the oral cavity of a subject, and changes in the electrical signal controlling the generation of hydrogen ions.

[0012] The hydrogen ions can help lower the local pH near the subject's teeth, thereby helping dissolve dental plaque. Changes in the electrical signal (e.g., temporal changes) can provide control over the generation of hydrogen ions, as opposed to uncontrolled generation of hydrogen ions, such as via a constant voltage between a pair of electrodes provided by a continuously applied DC power source. This can allow for tighter control of the local pH to which the subject's teeth are exposed, thereby facilitating home use of the oral care device.

[0013] It should be noted that the term "electrical signal" used herein may refer to a voltage or current signal.

[0014] In some embodiments, changes in the electrical signal limit the rate of change of hydrogen ion generation, for example relative to a constant voltage, provided between a pair of electrodes by a DC power source, having an amplitude equal to the peak amplitude of the electrical signal.

[0015] Alternatively or additionally, changes in the electrical signal may promote hydrogen ion neutralization, such as by the electrical signal comprising or being defined by a bidirectional waveform supplied to the electrode. Neutralization promotion provided by such a bidirectional waveform will be explained in more detail below.

[0016] In some embodiments, the oral care device includes an actuator. Such an actuator can, for example, move a cleaning element for cleaning inside a subject's oral cavity.

[0017] Thus, movement of an actuator, such as a pump that causes movement of a toothbrush head and / or controls an irrigator included in an oral care device, can be provided along with hydrogen ion generation, along with enhanced plaque removal.

[0018] In embodiments where the oral care device comprises an actuator, the actuator may be configured to move in response to an electrical signal.

[0019] The term "moving according to an electrical signal" in this document may mean that the actuator control signal and the electrical signal provided by the control device to control the movement of the actuator are identical to each other, or one of the actuator control signal and the electrical signal is based on the other of the actuator control signal and the electrical signal.

[0020] In certain embodiments, movement of the actuator in accordance with an electrical signal provided to the electrodes may facilitate a specific cleaning motion, such as a reciprocating motion, provided by the actuator, in addition to the electrical signal helping to control hydrogen ion generation at a pair of electrodes.

[0021] In some embodiments, the actuator control signal is in phase with the electrical signal. Thus, the movement of the actuator can be synchronized with the electrical signal provided to the electrode.

[0022] Alternatively, a phase difference may be intentionally defined between the actuator control signal and the electrical signal. Thus, the electrical signal may be out of sync with the actuator control signal and thus out of sync with the movement of the actuator, such as the brush head movement / reciprocation.

[0023] In some embodiments, one or both of the electrodes are mechanically coupled to an actuator such that movement of the actuator causes movement of the electrode(s).

[0024] In such embodiments, movement of the actuator may result in an increase in the effective area, in other words, footprint, in which the electrochemical process provided by the electrodes is implemented.

[0025] Alternatively or additionally, the oral care device may include at least one cleaning element for mechanically cleaning the interior of the oral cavity of a subject.

[0026] In some embodiments, at least one cleaning element is mechanically coupled to the actuator such that movement of the actuator causes movement of the at least one cleaning element. The resulting combination of mechanical disruption of dental plaque and pH-assisted dissolution of dental plaque can be particularly effective and may also be implemented, for example, with benefit by subjects in their own homes using an oral care device.

[0027] At least one cleaning element may include bristles for brushing teeth inside the subject's oral cavity. Alternatively or additionally, at least one cleaning element may include a cup formed of an elastic material for rubbing the surface inside the subject's oral cavity. Such a cup may be, for example, a so-called polishing cup.

[0028] Alternatively or additionally, the oral care device may include at least one cleaning element for fluidly cleaning the interior of the oral cavity of a subject.

[0029] In such embodiments, the at least one cleaning element may be arranged such that movement of the actuator causes fluid delivery from the at least one cleaning element.

[0030] In such embodiments, the actuator control signal may be, for example, an electrical switching signal of a pump of an oral irrigator.

[0031] In some embodiments, the electrical signal includes periodic changes in at least one of amplitude, polarity, and frequency. This can help control the accumulation of hydrogen ions, thereby helping to control the local pH.

[0032] Alternatively or additionally, the electrical signal comprises a bidirectional waveform. Changing the polarity of the electrodes via such a bidirectional waveform can help limit the development of a low pH "front" emanating from the electrodes and stabilize the pH. This is because, after the polarity change, hydrogen ions previously generated at one of the electrodes can be neutralized by hydroxide ions currently generated at the same electrode.

[0033] In some embodiments, the positive peak amplitude of the bidirectional waveform is different from the negative peak amplitude of the bidirectional waveform. This can cause a continuous but controlled increase or decrease in pH at a specific location.

[0034] In some embodiments, one of the positive peak amplitude and the negative peak amplitude is at least 1.1 times, such as about 1.5 times, the other of the positive peak amplitude and the negative peak amplitude.

[0035] In one set of embodiments, the electrical signal is a continuous waveform, such as a sine wave or a square wave. Such a continuous waveform can be considered as providing a continuously varying electrical signal.

[0036] In another set of embodiments, the electrical signal is a pulsed electrical signal, which can cause a more gentle and controlled pH change than, for example, a constant voltage across a pair of electrodes.

[0037] In some embodiments, the duty cycle of the pulsed electrical signal is less than or equal to 90%, preferably less than or equal to 75%, and most preferably less than or equal to 50%.

[0038] The duty cycle is the pulse duration or pulse width as a percentage of the total period of the waveform. The small total current "on" time associated with the pulsed electrical signal relative to the constant voltage across a pair of electrodes helps limit the progression of the low pH "front" described above.

[0039] In some embodiments, the electrical (current or voltage) signal is pulsed and bipolar. In such embodiments, the duty cycle associated with the positive component of the bipolar electrical signal may be the same or different than the duty cycle associated with the negative component of the bipolar electrical signal.

[0040] In at least some embodiments, the control device is configured to provide the electrical signal to the pair of electrodes for a predetermined period of time before terminating the provision of the electrical signal to the pair of electrodes. Such a predetermined period of time combined with changes in the electrical signal can help control the accumulation of hydrogen ions generated by the electrodes.

[0041] The predetermined time period may be the same as or different from a (further) predetermined time period during which the actuator moves in response to the electrical signal.

[0042] For example, the additional predetermined period during which the actuator moves according to the electrical signal may be longer than the predetermined period during which the electrical signal is supplied to the pair of electrodes.

[0043] For example, mechanical cleaning via the movement of the actuator may be continued accordingly after the hydrogen ion generation stops due to the expiration of the predetermined time period.

[0044] In some embodiments, the pair of electrodes can be inserted into the oral cavity of the subject, and the aqueous solution includes the subject's saliva and / or one or more oral care agents. This can provide a relatively physically simple way to provide a lower pH near the teeth of the subject.

[0045] Such oral care agent(s) may be at least one selected from toothpaste, mouthwash and whitening agent.

[0046] It should be noted that aqueous solutions, as well as water more generally, may include one or more types of ions.

[0047] In some embodiments, the oral care device includes a cleaning unit, such as a cup, for insertion into the oral cavity of a subject. The cleaning unit may have a groove in which one or both electrodes of the pair of electrodes are mounted. In this way, the cleaning unit may help protect the pair of electrodes and minimize the risk of the pair of electrodes accidentally contacting tissue in the oral cavity of the subject.

[0048] In some embodiments, the pair of electrodes are arranged wherein one of the electrodes defining an outer electrode at least partially surrounds another of the electrodes defining an inner electrode.

[0049] As an alternative or in addition to one of the electrodes defining an outer electrode, the pair of electrodes may be interdigitated. The outer electrode at least partially surrounds the inner electrode.

[0050] Herein, the term “interdigitated” may mean that each of the electrodes has a plurality of electrode members spaced apart from each other, wherein the electrode members of one electrode of a pair of electrodes are arranged in spaces between the electrode members of the other electrode of the pair of electrodes.

[0051] This may provide a particularly space efficient arrangement of a pair of electrodes, particularly when the pair of electrodes are to be included in a brush head and / or mounted within a cleaning unit (e.g. a cup) where space may be limited. Thus, interdigitated electrodes may help to simplify the structure of the oral care device and limit the electrical contacts required to drive the electrodes.

[0052] Furthermore, in combination with the electrical signals described above, such interdigitation of electrodes can help define the electrolysis footprint provided by the device.

[0053] In some embodiments, the cleaning unit, such as a cup, is formed of an elastic material for rubbing the surface of the interior of the oral cavity of the subject. Such a cup can be, for example, a so-called polishing cup.

[0054] In embodiments where the oral care device comprises at least one cleaning element that is mechanically coupled to an actuator such that movement of the actuator causes movement of the at least one cleaning element, the at least one cleaning element may comprise a cup.

[0055] For example, at least one cleaning element may include a cup in addition to bristles.

[0056] More generally, an oral care device may include or be a toothbrush, a mouthpiece, an irrigator, or a professional dental appliance operated by a dentist or dental hygienist. Particular mention is made of an oral care device in the form of a toothbrush.

[0057] According to another aspect, there is provided a method of operating an oral care device comprising a pair of electrodes for contacting an aqueous solution, the method comprising providing an electrical signal to the pair of electrodes to cause water in the aqueous solution to generate hydrogen ions for delivery within an oral cavity of a subject, wherein changes in the electrical signal control the generation of the hydrogen ions.

[0058] The device used in the method may be according to any embodiment described herein. In particular, the electrical signal may be provided by a control device included in the device.

[0059] More generally, embodiments described herein in relation to the method may be applicable to the device, and embodiments described herein in relation to the device may be applicable to the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Examples of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0061] Figure 1 A schematic depiction of dental tartar layered over a thin film layer on a tooth is provided;

[0062] Figure 2 A graph showing the solubility of a calcium phosphate crystalline phase as a function of pH is provided;

[0063] Figure 3 schematically depicts a device according to one example;

[0064] Figure 4 schematically depicts a device according to another example;

[0065] Figure 5 schematically depicts a device according to yet another example;

[0066] Fig. 6A A circuit for providing a unipolar pulsed electrical signal is shown;

[0067] Figure 6B Shown by Fig. 6A The circuit shown provides a bipolar signal (upper pane) and a unipolar pulsed electrical signal (lower pane);

[0068] Figure 7 schematically depicts actuator-driven movement of an electrolysis electrode according to one example;

[0069] Figure 8 schematically depicts an oral care device according to one embodiment;

[0070] Fig. 9 shows a portion of an oral care device according to another example;

[0071] Fig.10 Provides a graph of the depth of plaque and enamel dissolution versus the voltage between the electrolysis electrodes over a 30-second period;

[0072] Fig.11 Schematic depiction of a 2D simulation setup including two electrolysis electrodes;

[0073] Fig. 12A A graph of constant voltage is provided;

[0074] Fig. 12B Provided when Fig. 12A When the electrical signal shown is supplied to the electrode, Fig.11 A graph of pH versus time at various points near the electrode shown;

[0075] Fig.13A A graph of an electrical signal according to a first example is provided;

[0076] Fig. 13B Provided when Fig.13A When the electrical signal shown is supplied to the electrode, Fig.11 A graph of pH versus time at various points near the electrode shown;

[0077] Fig.14A providing a graph of an electrical signal according to a second example;

[0078] Fig. 14B Provided when Fig.14A When the electrical signal shown is supplied to the electrode, Fig.11 A graph of pH versus time at various points near the electrode shown;

[0079] Fig.15 providing a graph of an electrical signal according to a third example; and

[0080] Fig.16 A graph of an electrical signal according to a fourth example is provided. DETAILED DESCRIPTION

[0081] The present invention will be described with reference to the accompanying drawings.

[0082] It should be understood that the detailed description and specific examples, although indicating exemplary embodiments of the apparatus, system and method, are for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects and advantages of the apparatus, system and method of the present invention will become better understood based on the following description, the appended claims and the accompanying drawings. It should be understood that the drawings are merely schematic and are not drawn to scale. It should also be understood that in all drawings, the same reference numerals are used to indicate the same or similar parts.

[0083] An oral care device for removing dental plaque is provided. The oral care device includes a control device configured to provide an electrical signal, such as a time-varying electrical signal. The oral care device also includes a pair of electrodes for contacting an aqueous solution. The pair of electrodes are each connected to the control device and are configured to generate hydrogen ions from water in the aqueous solution in response to the electrical signal for delivery in the oral cavity of a subject, in particular to the teeth of the subject. Changes in the electrical signal control the generation of hydrogen ions. The hydrogen ions thus generated can reduce the local pH of the subject's teeth, thereby helping to dissolve dental plaque on the teeth. Changes in the electrical signal (e.g., time variations) can provide control over the generation of hydrogen ions, which contrasts with the uncontrolled generation of hydrogen ions, for example, via a constant voltage between a pair of electrodes, which is provided by a DC power supply. A method for operating such an oral care device is also provided.

[0084] Figure 1 The enamel layer 10 of a tooth and a thin film layer 12 on the enamel layer 10 are schematically depicted. Figure 1 Dental plaques 14A, 14B, 14C, 14D laminated on the film layer 12 are also shown.

[0085] Figure 1 The dental plaque 14A-D shown includes several different calcium phosphate crystal phases, which have different water solubility. The dental plaque layer 14A farthest from the film layer 12 includes dicalcium phosphate dihydrate (DCPD), the layer 14B adjacent to the dental plaque layer 14A includes octacalcium phosphate (OCP), and the layer 14D closest to the film layer 12 and the layer 14C between the layers 14B and 14D can include a relatively small amount of hydroxyapatite (HAp). HAp is a key component of the enamel layer 10.

[0086] HAp has a lower water solubility than OCP, and OCP has a lower water solubility than DCPD, such that the relative and / or absolute water solubility decreases in the direction of arrow 16. However, the absolute solubility of OCP and DCPD in water is very low, and their proximity to the enamel layer 10 can therefore hinder the removal of dental plaque, especially for subjects in their own homes.

[0087] It has been found that the water solubility of the above crystalline phase is pH-dependent. In particular, dissolution in aqueous solution can be facilitated by lowering the pH. Figure 2 Graphs 18 and 20 are provided showing the solubility of the tartar-containing crystalline phase of calcium phosphate as a function of pH. Figure 2 It is generally shown that for both OCP (Graph 18) and HAp (Graph 20), the concentration of calcium ions dissolved in the solution increases with decreasing pH; at pH 5.5, the solubility of OCP is almost 2 orders of magnitude higher than that of HAp.

[0088] The pH at which enamel 10 begins to dissolve is also determined by Figure 2 The pH is represented by the dashed line 22 in FIG. The pH may be about pH 5.5, which is clinically considered to be the critical oral pH for enamel dissolution (accepted as the threshold).

[0089] The present disclosure is based in part on the recognition that by controlling the local pH of the tooth to less than 7 but equal to or greater than 5.5, OCP and DCPD in dental plaque 14 (particularly early dental plaque) can be dissolved with minimal or no damage to the enamel 10. This is because such a pH range can minimize the dissolution of HAp in the enamel 10, such as Figure 2 shown.

[0090] Figure 3 A device 100 according to an example is schematically depicted. The device 100 includes a control device 102 configured to provide an electrical signal. The device 100 also includes a pair of electrodes 104A, 104B for contacting the aqueous solution. The pair of electrodes 104A, 104B are each connected to the control device 102 and are configured to generate hydrogen ions from water in the aqueous solution in response to the electrical signal.

[0091] Generating hydrogen ions (in other words, H+ ions) from water in an aqueous solution means that the potential difference between the electrodes 104A, 104B generated by the electrical signal is sufficient to cause electrolysis of water to occur.

[0092] The electrodes 104A, 104B may be made of any suitable conductive material capable of electrochemically generating hydrogen ions by water electrolysis. For example, the electrodes 104A, 104B may be selected from platinum electrodes, platinum-coated electrodes, such as platinum-coated titanium electrodes, gold electrodes, gold-coated electrodes, carbon electrodes, such as graphite electrodes, and polymer-based electrodes, wherein the polymer is embedded with a conductive material, such as a conductive material selected from platinum, gold or carbon, such as graphite.

[0093] In some embodiments, each electrode in the pair of electrodes 104A, 104B is a non-sacrificial electrode.

[0094] The term “non-sacrificial electrode” may mean that the electrodes 104A, 104B are each formed of a conductive material that does not or only negligibly dissociates into ions in response to an electrical signal.

[0095] In at least some embodiments, a pair of electrodes 104A, 104B can be inserted into the oral cavity of a subject, wherein the aqueous solution includes the subject's saliva and / or one or more oral care agents, such as toothpaste, mouthwash, and / or whitening agents. This can provide a relatively physically simple way to provide a lower pH near the teeth of the subject.

[0096] Reference again Figure 3 , when electrode 104A operates as a cathode, the following reaction may occur at electrode 104a: (or, )

[0097] The production of hydroxide ions (or consumption of hydrogen ions) can increase the pH near electrode 104A. When electrode 106B is operated as an anode: (or, ),exist Figure 3 Such a local increase in pH, represented by region 106A around electrode 104A, may have less effect on the solubility of plaque 14 than a local decrease in pH near electrode 104B, represented by region 106B around electrode 106B. This is because plaque dissolution, such as Figure 3 Plaque dissolution, as shown at point 108 near middle electrode 104B, may be assisted by lowering the pH, in other words, increasing the hydrogen ion concentration, as previously described.

[0098] The pair of electrodes 104A, 104B may be separated from one another by any suitable distance 110, such as a distance 110 greater than 50 μm, for example between 50 μm and 1 mm.

[0099] A distance 110 greater than 50 μm may help suppress the hydrogen ions generated at the anode from being immediately neutralized by the hydroxide ions generated at the cathode.

[0100] For example, a half distance (L / 2) of 25 μm can be covered by the pH front in ∼0.07 s (L 2 / 4D, where D = 9*10 - 9 m 2 / s,H + The lower limit of 50 μm may mean a total processing time > 0.07 s. The total processing time is a time period, such as a predetermined time period, for providing an electrical signal to a pair of electrodes 104A, 104B (thus, not the current on / off time in a pulse in an embodiment where the electrical signal is a pulse).

[0101] More generally, it has been found that using a constant voltage between a pair of electrodes provided by a DC power source can provide relatively uncontrolled generation of hydrogen ions. In contrast, an electrical signal, such as a time-varying electrical signal, helps to increase control over the generation of hydrogen ions, thereby increasing the local pH to which the subject's teeth are exposed. This will be explained in more detail below.

[0102] The device 100 may include or be a toothbrush, a mouthpiece, an irrigator or a professional dental instrument operated by a dentist or dental hygienist. Particular mention is made of the oral care device 100 in the form of a toothbrush.

[0103] It should be noted that a toothbrush, a mouthpiece, and an irrigator may be considered as examples of a personal care oral device 100. Such a personal care oral device 100 may be used by the subject himself at home.

[0104] In some embodiments, such as Figure 4 As shown, the device 100 includes an actuator 112 connected to the control device 102. In such embodiments, the actuator 112 may be configured to move according to an electrical signal generated by the control device 102.

[0105] The term "moving according to an electrical signal" may mean in this document that the actuator control signal and the electrical signal provided by the control device 102 for controlling the movement of the actuator 112 are identical to each other, or one of the actuator control signal and the electrical signal is based on the other of the actuator control signal and the electrical signal.

[0106] The actuator control signal may, for example, be in phase with the electrical signal, or a phase difference may be defined between the actuator control signal and the electrical signal.

[0107] Thus, movement of the actuator 112, for example causing movement of a brush head of the device 100 in the form of an oral care device 100, can provide for generation of hydrogen ions along with enhanced plaque removal.

[0108] In certain embodiments, movement of the actuator 112 in accordance with electrical signals provided to the electrodes 104A, 104B may facilitate a specific cleaning movement, such as a reciprocating movement, provided by the actuator 112, in addition to the electrical signals helping to control the generation of hydrogen ions at the pair of electrodes 104A, 104B.

[0109] Any suitable type of actuator 112 is contemplated, for example a motor, such as a reciprocating motor (not visible in the figures).

[0110] In some embodiments, such as Figure 4 As shown, the device 100 includes at least one cleaning element 114 for mechanically cleaning the interior of the oral cavity, the at least one cleaning element 114 being mechanically coupled to an actuator 112 such that movement of the actuator 112 causes movement of the at least one cleaning element 114 .

[0111] Any suitable type of cleaning element is contemplated. Figure 4 In the non-limiting example shown, at least one cleaning element 114 includes bristles for brushing teeth within the oral cavity of a subject. In such embodiments, dental plaque removal facilitated by the generation of hydrogen ions can be enhanced by the movement of the bristles caused by movement of the actuator 114 in accordance with the electrical signal.

[0112] The reciprocating movement of the actuator 112 (eg, the reciprocating motor described above) may be provided in accordance with a periodically varying electrical signal.

[0113] In such embodiments, reciprocating movement of the actuator 112 may cause the cleaning element(s) 114 (eg, bristles) to correspondingly move in a reciprocating manner.

[0114] Such periodic electrical signals may also help control the local pH, and in particular help reduce the risk of the local pH at one or both of electrodes 104A, 104B dropping below a particular pH level, as will be explained in more detail below.

[0115] This combination of mechanical disruption of dental plaque and low local pH assisted dissolution of dental plaque may be particularly effective and may also be implemented, for example, to advantage by subjects using the apparatus 100 in their own homes.

[0116] In some non-limiting examples, as an alternative to or in addition to bristles, at least one cleaning element 114 comprises a cup formed of an elastic material for rubbing the surface of the interior of the subject's oral cavity. Such a cup may be, for example, a so-called polishing cup.

[0117] In embodiments where the oral treatment device 100 includes a cup formed of an elastic material, whether or not such a cup is arranged to be moved by the actuator 114, one or both electrodes of the pair of electrodes 104A, 104B may be mounted inside the cup. Fig. 9 An example explaining this situation.

[0118] In some embodiments, such as Figure 4 In the illustrated embodiment, the control device 102 includes a power train circuit device 116 that is configured to provide an actuator control signal to control the actuator 112 and to provide an electrical signal to the pair of electrodes 104A, 104B.

[0119] In such embodiments, the actuator control signal may be the same as the electrical signal to provide an advantageously simple and cost effective electrical design.

[0120] In an alternative embodiment, such as Figure 5 In the illustrated embodiment, in addition to the powertrain circuitry 116 configured to provide actuator control signals, the control device 102 also includes an electrode control circuitry 118 configured to convert the powertrain control signals into electrical signals to provide to the pair of electrodes 104A, 104B.

[0121] The electrode control circuit device 118 may, for example, specifically include only passive electronic components, such as diode(s), resistor(s) and / or capacitor(s), which are arranged to convert the transmission control signal into an electrical signal.

[0122] Examples of such electrode control circuitry 118 are Fig. 6A In this example, the diode will Figure 6B The AC signal shown in the upper pane of the figure is converted into a rectified output waveform in which there is no negative half cycle, as shown in Figure 6B is shown in the lower pane.

[0123] The power train circuitry 116 may be implemented in any suitable manner, such as by the power train circuitry 116 including a microcontroller, such as a motor microcontroller, configured to generate actuator control signals.

[0124] It should also be noted that Fig. 6A and Figure 6B The AC signal of the example shown in does not need to be provided via the power train circuitry 116 and in other examples may be provided by a power source, such as a mains power supply (not visible in the figure) arranged to power the apparatus 100 .

[0125] In such examples, the control device 102 may include an electrode control circuit device 118 to provide a unipolar pulse signal (eg, Figure 6B The lower middle pane shows that the transmission control circuit device 116 is omitted.

[0126] In some embodiments, such as Figure 7 As shown, one or both of the electrodes 104A, 104B are mechanically coupled to the actuator 112 such that movement of the actuator 112 causes movement of the electrode(s) 104A, 104B.

[0127] exist Figure 7 In the non-limiting example shown, the electrical signal 120 is a periodic bipolar electrical signal that varies with time t.

[0128] exist Figure 7 In the positive polarity half cycle 120A of the electrical signal 120 shown, the actuator 112 and the electrodes 104A, 104B exhibit a first movement. In the negative polarity half cycle 120B of the electrical signal 120, the actuator 112 and the electrodes 104A, 104B exhibit a second movement that is a mirror image of the first movement. The gradient / slope of the electrical signal 120 is Figure 7 Indicated by dashed line 122.

[0129] This may be implemented by the control device 102 controlling the actuator 112 by providing an actuator control signal that is in phase with the electrical signal provided to the electrodes 104A, 104B.

[0130] The movement of the actuator can result in an increase in the effective area, in other words, footprint, in which the electrochemical treatment provided by the electrodes 104A, 104B is implemented. In addition, the alternating polarity can mean that the generation of hydrogen ions is implemented on both electrodes 104A, 104B, but is implemented sequentially, thereby further helping to increase the effective area for providing the electrochemical treatment. In addition, the periodic electrical signal can also help control the local pH, particularly to reduce the risk of the local pH at the electrodes 104A, 104B dropping below a specific pH level, which will be explained in more detail below.

[0131] In an alternative embodiment, the control device 102 may be configured to provide an actuator control signal to control the actuator 112 , wherein a phase difference is defined between the actuator control signal and the electrical signal provided to the electrodes 104A, 104B.

[0132] Thus, the electrical signal may be asynchronous with the actuator control signal and, thereby, asynchronous with movement of the actuator 112, for example, brush head motion, such as brush head reciprocation.

[0133] Such a phase difference may be introduced in any suitable manner, such as via one or more capacitor(s), inductor(s), etc. Thus, a relatively small number of electrical components (other than those used to provide the actuator control signals) may be required to provide the phase difference.

[0134] In some embodiments, in addition to a powertrain circuit device 116 configured to provide an actuator control signal, the control device 102 also includes an electrode control circuit device 118 configured to convert the actuator control signal into an electrical signal provided to electrodes 104A, 104B, so that a phase difference is intentionally limited between the actuator control signal and the electrical signal.

[0135] In some embodiments, such as Figure 8 As shown, the device 100 in the form of an oral care device 100 comprises a plurality of pairs of electrodes 104A, 104B; 104C, 104D. In such embodiments, the control device 102 may be configured to provide an electrical signal to each of the plurality of pairs of electrodes 104A, 104B; 104C, 104D.

[0136] The oral care device 100 can be powered in any suitable manner, such as via a mains power source and / or by one or more batteries 124. In embodiments where the oral care device 100 is powered by one or more batteries 124, the control device 102 can be configured to generate an electrical signal, such as a current or voltage signal, from the direct current generated by the one or more batteries 124.

[0137] A first electrical connection 126A may connect the control device 102 to one of the electrodes 104A in the pair of electrodes 104A, 104B, wherein a second electrical connection 126B connects the control device 102 to the other of the electrodes 104B in the pair of electrodes 104A, 104B.

[0138] exist Figure 8 In the non-limiting example shown, two pairs of electrodes 104A, 104B; 104C, 104D are included in the oral care device 100, a first electrical connection 126A connects the control device 102 to electrodes 104A and 104C, and a second electrical connection 126B connects the control device 102 to electrodes 104B and 104D.

[0139] In some embodiments, such as Fig. 9 In the illustrated embodiment, the oral care device 100 comprises a toothbrush including a brush head 128 attached to a handle 130. In such embodiments, a pair of electrodes 104A, 104B are preferably included in the brush head 128, wherein the control device 102 is included in the handle 130.

[0140] exist Figure 8 In the non-limiting example shown, one or more batteries 124 are housed within the handle 130 along with the control device 102 .

[0141] In some embodiments, the brush head 128 including the pair of electrodes 104A, 104B is detachably coupled to the handle 130 to enable replacement of the brush head 128 without having to replace the control device 102 included in the handle 130. In such embodiments, the first electrical connection 126A and the second electrical connection 126B between the control device 102 included in the handle 130 and the pair of electrodes 104A, 104B included in the (replacement) brush head 128 can be established while the brush head 128 is attached (e.g., snap-fit ​​or push-fit) to the handle 130.

[0142] exist Figure 8 In the non-limiting example shown, multiple pairs of electrodes 104A, 104B; 104C, 104D are included in the brush head 128 .

[0143] In embodiments where oral care device 100 is or includes a toothbrush, brush head 128 can include at least one cleaning element 114, such as bristles as described above and / or a cup formed of a resilient material, for abrading surfaces inside the oral cavity of a subject.

[0144] In some embodiments, such as Figure 8 In the illustrated embodiment, the at least one cleaning element 114 includes bristles, and the bristles extend further from the brush head 128 than each of the pair of electrodes 104A, 104B such that the pair of electrodes 104A, 104B are recessed relative to the bristles.

[0145] As previously described, at least one cleaning element 114 and, in some cases, the brush head 128 as a whole may be moved by the actuator 112 .

[0146] In embodiments where the at least one cleaning element 114 comprises a cup formed from an elastomeric material, one or both electrodes of the pair of electrodes 104A, 104B may be mounted within the cup.

[0147] In an embodiment, such as Figure 8 In the illustrated embodiment, multiple pairs of electrodes 104A, 104B; 104C, 104D are included in the oral care device 100, but the oral care device 100 may include multiple cups. In such embodiments, one or two electrodes 104A, 104B; 104C, 104D in each pair of electrodes may be mounted inside a corresponding cup of the multiple cups.

[0148] The electrodes 104A, 104B may be arranged relative to each other in any suitable manner. In some embodiments, the electrodes 104A, 104B are arranged such that one of the electrodes 104B defines an outer electrode 104B that at least partially surrounds another of the electrodes 104A that defines an inner electrode 104A. An example of this is Figure 8 shown.

[0149] Figure 8 Also shown is a region 106A around electrode 104A and a region 106B around electrode 104B. In one of these regions 106A, 106B, depending on the electrical signal, the local pH may increase due to the generation of hydroxide ions, while in the other of these regions 106B, 106A, the local pH may decrease due to the generation of hydrogen ions, as previously described with respect to Figure 3 described.

[0150] As an alternative or in addition to one of the electrodes 104B defining an outer electrode 104B at least partially surrounding the inner electrode 104A, a pair of electrodes 104A, 104B may be interdigitated.

[0151] The term “interdigitated” herein may mean that each of the electrodes 104A, 104B has a plurality of electrode members spaced apart from one another, wherein the electrode members of one electrode of a pair of electrodes 104A, 104B are arranged in spaces between the electrode members of the other electrode of the pair of electrodes 104B, 104A.

[0152] This may provide a particularly space efficient arrangement of the pair of electrodes 104A, 104B, particularly when the pair of electrodes 104A, 104B are to be included in a brush head 128 and / or mounted within a cup where space may be limited.

[0153] Fig. 9 A non-limiting example of such an interdigitated arrangement of a pair of electrodes 104A, 104B is depicted in FIG.

[0154] Similar to Figure 8 In the non-limiting example shown, cleaning elements 114 including bristles are included Fig. 9 In the illustrated oral care device 100. In the latter non-limiting example, a plurality of peripheral bristle tufts are arranged around a centrally located pair of interdigitated electrodes 104A, 104B.

[0155] In some embodiments, such as Figure 8As shown, the oral care device 100 includes a cup 132 for insertion into the oral cavity of a subject, the cup 132 having a groove 134, wherein one or both electrodes of the pair of electrodes 104A, 104B are mounted in the groove 134. In this way, the cup 132 can help protect the pair of electrodes 104A, 104B and minimize the risk of the pair of electrodes 104A, 104B inadvertently contacting tissue within the oral cavity of the subject.

[0156] The cup 132 can be formed of any suitable material, such as an electrically insulating material. In some embodiments, the cup 132 is formed of an elastic material for rubbing the surface of the interior of the subject's oral cavity, as previously described.

[0157] The cup 132 formed of a resilient material can be expanded and bent to the contours of the subject's teeth to facilitate selective stain removal and cleaning between teeth.

[0158] Any suitable resilient material is contemplated for use with the cup 132 , such as silicone rubber.

[0159] In some embodiments, such as in Figure 8 and Fig. 9 In the embodiment shown in , where the handle 130 is in the form of a toothbrush, the brush head 128 is attached to the handle 130 of the oral care device 100 via a neck 136, for example, detachably coupled to the handle 130. Such a neck 136 can extend between an upper end of the handle 130 and a lower end of the brush head 128.

[0160] Fig.10 A graph 138 of the depth of plaque dissolution versus the continuous DC voltage between a pair of electrodes 104A, 104B over a period of 30 seconds is provided. As the voltage increases, the associated local decrease in pH caused by the generation of hydrogen ions causes plaque to dissolve to a greater depth. However, Fig.10 A graph 140 of enamel dissolution depth versus continuous DC voltage between a pair of electrodes 104A, 104B over a 30 second period is also provided, illustrating that relatively low pH conditions caused by relatively high voltages can cause enamel dissolution.

[0161] Fig.11 A 2D simulation setup is schematically depicted, which includes two electrolysis electrodes 104A, 104B (corresponding to Fig.10 Experimental measurements shown in . The saliva-toothpaste mixture also has a conductivity of similar order of magnitude), where d = 145 μm, and w = 500 μm. L1 and L2 represent domain boundaries. In an exemplary embodiment, this 2D simulation setup is used to evaluate various electrical signals.

[0162] Fig. 12AA graph of a constant voltage (step signal) between a pair of electrodes provided by a DC power supply is provided, and Fig. 12B Provided when Fig. 12A When the electrical signal shown in FIG. 1 is supplied to electrodes 104A and 104B, Fig.11 Graphs 142B, 144B, 146B of pH versus time at respective points 142A, 144A, 146A near electrodes 104A, 104B are shown in FIG.

[0163] Although the application of the DC signal causes a relatively large change and strong drift in pH, in the graph 146B (corresponding to Fig.11 A relatively rapid / uncontrolled drop in pH to less than pH 5.5 can be observed at point 146A in FIG. Fig. 12B area 148).

[0164] Fig.13A A graph of an electrical signal according to a first example is provided, wherein the electrical signal is periodic and bipolar, and Fig. 13B Provided when Fig.13A When the electrical signal shown is supplied to electrodes 104A, 104B, Fig.11 Graphs 142C, 144C, 146C of pH versus time at respective points 142A, 144A, 146A near electrodes 104A, 104B are shown.

[0165] In order to be able to Fig.13A and Fig. 13B For comparison, it should be noted that Fig. 12A The intensities of the constant voltages shown in are normalized.

[0166] It can be seen that Fig.13A and Fig. 13B The electrical signal shown in induced a relatively rapid stabilization of pH and a small overall change in pH, which was stabilized at about pH 5. Therefore, changes in the electrical signal can enhance the control of hydrogen ion generation, thereby enhancing the local pH of the subject's tooth exposure.

[0167] In some embodiments, such as Fig.13A and Fig. 13B As shown, the electrical signal includes periodic changes in amplitude. This can help control the accumulation of hydrogen ions and thus help control the local pH.

[0168] Alternatively or additionally, the electrical signal comprises or is a bidirectional waveform. An example of this is Fig.13A. Changing the polarity of electrodes 104A, 104B by such a bidirectional waveform can help limit the development of a low pH "front" emanating from electrodes 104A, 104B and stabilize the pH. This is because, after the polarity change, hydrogen ions previously generated at one of electrodes 104A, 104B can be neutralized by hydroxide ions currently generated at the same electrode 104A, 104B.

[0169] In some embodiments, such as Fig.13A and Fig. 13B As shown, the electrical signal includes a continuous waveform or a continuous waveform. In particular, Fig.13A A continuous waveform in the form of a sine wave is shown.

[0170] In an alternative embodiment, the electrical signal comprises a pulse electrical signal or a pulse electrical signal. Such a pulse electrical signal can be, for example, Fig. 6A and Figure 6B The described manner is generated.

[0171] Fig.14A A graph of an electrical signal according to a second example is provided, wherein the electrical signal is periodic, pulsed (10 Hz, 10% duty cycle) and unipolar, and Fig. 14B Provided when Fig.14A When the electrical signal shown is supplied to electrodes 104A, 104B, Fig.11 Graphs 142D, 144D, 146D of pH versus time at corresponding points 142A, 144A, 146A near electrodes 104A, 104B are shown.

[0172] and Fig. 12A and Fig. 12B The pH reaches the unsafe value of pH 4 relatively quickly compared to the constant voltage. Fig.14A and Fig. 14B The pulse signal in causes a more gentle and controlled change in pH reaching pH 4.8 after about 0.5 seconds.

[0173] In some embodiments, reference Fig.15 , the duty cycle of the pulsed electrical signal is less than or equal to 90%, preferably less than or equal to 75%, and most preferably less than or equal to 50%. The duty cycle is the ratio of the pulse duration or pulse width to the total period 150 of the waveform. Fig. 12A and Fig. 12B The constant voltage, smaller total current "on" time associated with the pulsed electrical signal can help limit the progression of the low pH "frontal".

[0174] In some embodiments, such as Fig.15In the embodiment shown, the electrical (current or voltage) signal is both pulsed and bipolar. The signal in each half cycle can be applied with a given duty cycle. Fig.15 In the non-limiting example shown, the duty cycle is 50%.

[0175] The duty cycle associated with the positive component of the bipolar electrical signal may be the same as or different than the duty cycle associated with the negative component of the bipolar electrical signal.

[0176] It should be noted that in some embodiments, a duty cycle may not be employed.

[0177] In some embodiments, the electrical signal can be defined by an asymmetric pulse. Such an asymmetric electrical signal can help induce a preferential pH change at a specific location.

[0178] In some embodiments, such as Fig.16 As shown, the electrical signal is a bidirectional waveform, and the positive peak amplitude 152 of the bidirectional waveform is different from the negative peak amplitude 154 of the bidirectional waveform. This can cause the pH at a specific location to increase or decrease continuously but in a controlled manner. Therefore, relative to applying a constant voltage, the better control provided by the pulses of the electrical signal can be combined with the generation of "extreme" pH regions confined to the vicinity of the electrode(s) 104A, 104B due to the periodic neutralization provided by changing polarity.

[0179] In some embodiments, one of positive peak amplitude 152 and negative peak amplitude 154 is at least 1.1 times greater than the other of positive peak amplitude 154 and negative peak amplitude 152 .

[0180] exist Fig.16 In the non-limiting example shown, the negative peak amplitude 154 is 1.5 times the positive peak amplitude 152. The average signal is Fig.16 Indicated by dashed line 156.

[0181] In at least some embodiments, the control device 102 is configured to provide an electrical signal to the pair of electrodes 104A, 104B for a predetermined period of time before terminating the provision of the electrical signal to the pair of electrodes 104A, 104B. Such a predetermined period of time combined with changes in the electrical signal can help control the accumulation of hydrogen ions generated by the electrodes 104A, 104B.

[0182] The predetermined time period may be the same as or different from the (other) predetermined time period during which the actuator 112 moves according to the electrical signal. For example, the other predetermined time period during which the actuator 112 moves according to the electrical signal may be longer than the predetermined time period during which the electrical signal is provided to the pair of electrodes 104A, 104B.

[0183] A method of operating a device comprising a pair of electrodes 104A, 104B for contacting an aqueous solution is also provided. The device can be according to any embodiment described herein. The method comprises providing an electrical signal to a pair of electrodes 104A, 104B to cause water in the aqueous solution to generate hydrogen ions. Changes in the electrical signal control the generation of hydrogen ions.

[0184] The electrical signal may be provided by a control device 102 comprised in the apparatus 100 described herein.

[0185] The control device 102 (and / or the powertrain circuit device 116) described above may be implemented in a variety of ways using software and / or hardware to perform various desired functions. A processor is one example of a control device 102 / powertrain circuit device 116 that employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform functions. However, the control device 102 / powertrain circuit device 116 may be implemented with or without a processor, and may also be implemented as a combination of dedicated hardware that performs some functions and a processor that performs other functions, such as one or more programmed microprocessors and associated circuit devices.

[0186] Examples of controller components that may be used in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

[0187] In some examples, the control device 102 / power train circuit device 116 is associated with one or more storage media, such as volatile and non-volatile computer memory, such as RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform the desired functions. The various storage media may be fixed within the control device 102 / power train circuit device 116, or may be transportable so that one or more programs stored thereon can be loaded into the control device 102 / power train circuit device 116.

[0188] Other variations of the disclosed embodiments may be understood and effected by those skilled in the art in practicing the claimed invention by studying the drawings, 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. 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. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A personal oral care device (100) for use by a subject in their own home, the oral care device comprising: A control device (102) configured to provide an electrical signal; as well as A pair of electrodes (104A, 104B), the pair of electrodes are used to contact the aqueous solution, the pair of electrodes are connected to the control device, the electrical signal and the pair of electrodes are configured so that at least one of the electrodes generates hydrogen ions from water in the aqueous solution in response to the electrical signal to deliver changes in the electrical signal that control the generation of hydrogen ions in the oral cavity of the subject, wherein the electrical signal is a pulsed electrical signal.

2. The oral care device (100) of claim 1, wherein the change in the electrical signal limits the rate of change of generation of the hydrogen ions and / or promotes hydrogen ion neutralization.

3. The oral care device (100) according to claim 1 or 2, comprising an actuator (112) configured to move according to the electrical signal.

4. An oral care device (100) according to claim 3, wherein the control device (102) is configured to generate an actuator control signal to control the movement of the actuator (112), the actuator control signal being in phase with the electrical signal, or a phase difference being defined between the actuator control signal and the electrical signal.

5. The oral care device (100) according to claim 3 or 4 comprises at least one cleaning element (114), wherein the at least one cleaning element is used to mechanically or fluidically clean the inside of the subject's oral cavity, and the at least one cleaning element is arranged so that the movement of the actuator causes the movement of the at least one cleaning element or the delivery of fluid from the at least one cleaning element, respectively; optionally, wherein the at least one cleaning element (114) comprises bristles or a fluid delivery nozzle for cleaning the surface inside the subject's oral cavity.

6. The oral care device (100) according to any one of claims 1 to 5, wherein the electrical signal comprises a periodic variation in at least one of amplitude, polarity and frequency.

7. The oral care device (100) according to any one of claims 1 to 6, wherein a duty cycle of the pulse electric signal is less than or equal to 90%, preferably less than or equal to 50%.

8. The oral care device (100) according to any one of claims 1 to 7, wherein the electrical signal comprises a bidirectional waveform supplied to the electrode.

9. The oral care device (100) of claim 8, wherein the positive peak amplitude (152) of the bidirectional waveform is different from the negative peak amplitude (154) of the bidirectional waveform.

10. The oral care device (100) of claim 9, wherein one of the positive peak amplitude and the negative peak amplitude is at least 1.1 times the other of the positive peak amplitude and the negative peak amplitude.

11. The oral care device (100) according to any one of claims 1 to 10, wherein the control device (102) is configured to provide the electrical signal to the pair of electrodes (104A, 104B) within a predetermined time period before terminating the provision of the electrical signal to the pair of electrodes (104A, 104B).

12. The oral care device (100) according to any one of claims 1 to 11, wherein the pair of electrodes (104A, 104B) is insertable into the oral cavity of the subject, and the aqueous solution includes saliva of the subject and / or one or more oral care agents.

13. The oral care device (10) according to any one of claims 1 to 12, comprising a cleaning unit (132) for insertion into the oral cavity of the subject, the cleaning unit having a groove, and one or both electrodes of the pair of electrodes (104A, 104B) are mounted in the groove.

14. An oral care device (10) according to any one of claims 1 to 13, wherein the pair of electrodes are arranged such that: one of the electrodes defining an external electrode at least partially surrounds another of the electrodes defining an internal electrode, and / or wherein the pair of electrodes cross each other.

15. The oral care device (10) according to any one of claims 1 to 14, wherein the personal oral care device is a toothbrush, a mouthpiece or an irrigator.

Images