US20130071806A1 - Iontophoretic oral care devices and methods - Google Patents

Abstract

Embodiments of the present disclosure are directed to oral care devices, system and methods for advanced ionic micro-current control. In some embodiments, an oral care device is actuated upon completion of an electric circuit by a users hand and oral cavity. The electrode on an oral care implement may be configured to lose conductivity over time to indicate a replacement oral care implement is need. In some embodiments, a controller of the oral care device may detect the type of oral care implement and control the ionic micro-current accordingly. Additionally, embodiments may detect a region within the oral cavity that the oral care device is in contact with and apply the ionic micro-current accordingly. Further, in some embodiments, the health status of various regions of a user's oral cavity may be detected and monitored over time.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application claims the benefit of U.S. Provisional Application Ser. No. 61/536,678 filed on Sep. 20, 2011.
TECHNICAL FIELD
• The present application relates generally to oral care devices and, more specifically, oral care devices capable of providing ionic micro-currents to the oral cavity of a user for iontophoresis applications.
SUMMARY
• Iontophoresis is a medical technique that utilizes a small current (or charge) to deliver medicine or chemicals through the skin of a patient. Iontophoresis applications are numerous and may be used to treat many afflictions such as arthritis, warts, herpes and many others. Recently, iontophoresis is being used in oral care devices such as tooth brushes to aid in removing plaque from the teeth of users, as well as increase the delivery of fluorine negative ions to the teeth.
• In one embodiment, an oral care device includes a handle portion and an oral care implement coupled to the handle portion. The oral care implement includes a brush head portion having brush filaments, and the oral care device further includes a first electrode located in the brush head portion and operable to be in electrical contact with an oral cavity of the user, a second electrode located in the handle portion and operable to be in electrical contact with a hand of a user, a power source providing a voltage potential between the first electrode and the second electrode, and a controller circuit electrically coupled to the first electrode, the second electrode, and the power source. Electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode. The first electrode is configured to be electrically decoupled from the controller circuit and the power source after a predetermined operational duration of the oral care device. The controller circuit detects a completion or an opening of the electrical circuit by measuring an impedance through the user between the hand of the user and the oral cavity of the user, such that a measured impedance above a threshold indicates the opening of the electrical circuit and a measured impedance below the threshold indicates the completion of the electrical circuit. Upon detection of the completion of the electrical circuit, the controller circuit controls the oral care device to operate at a first operational mode, and, upon detection of the opening of the electrical circuit, the controller circuit controls the oral care device to operate at a second operational mode.
• In another embodiment, an oral care device includes a handle portion and an oral care implement coupled to the handle portion, wherein the oral care implement includes a brush head portion having brush filaments. The oral care device further includes a first electrode located in the brush head portion and operable to be in electrical contact with an oral cavity of the user, a second electrode located in the handle portion and operable to be in electrical contact with a hand of a user, a power source providing a voltage potential between the first electrode and the second electrode, a vibrating actuator operable to vibrate at a vibration amplitude and frequency to translate the brush head portion at the vibration amplitude and frequency, and a controller circuit in electrical communication with the vibrating actuator, the first electrode, the second electrode, and the power source. Electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode. The controller circuit detects a completion or an opening of the electrical circuit by measuring an impedance through the user between the hand of the user and the oral cavity of the user, such that a measured impedance above a threshold indicates the opening of the electrical circuit and a measured impedance below the threshold indicates the completion of the electrical circuit. Upon detection of the completion of the electrical circuit, the controller circuit controls the oral care device to operate in the first operational mode by generating a micro-current I through the user between the first electrode and the second electrode, and controlling the vibrating actuator to vibrate at the operational vibration amplitude and frequency. Upon detection of the opening of the electrical circuit, the controller circuit controls the oral care device to operate in the second operational mode by stopping the micro-current I through the user between the first electrode and the second electrode, and controlling the vibrating actuator to stop vibrating at the operational vibration amplitude and frequency.
• In yet another embodiment, an oral care device includes a handle portion, and an oral care implement coupled to the handle portion, wherein the oral care implement includes a brush head portion having brush filaments. The oral care device further includes a first electrode located in the brush head portion and operable to be in electrical contact with an oral cavity of a user, a second electrode located in the handle portion and operable to be in electrical contact with a hand of the user, a power source providing a voltage potential between the first electrode and the second electrode, and a controller circuit in electrical communication with the first electrode, the second electrode, and the power source. Electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode. The controller circuit controls a micro-current I that passes through the user between the first electrode and the second electrode, and determines an impedance of the electrical circuit based on the micro-current I. The controller circuit controls the oral care device to operate in a first operational mode when the impedance is within a first impedance range, and controls the oral care device to operate in a second operational mode when the impedance is within a second impedance range.
• In yet another embodiment, an oral care device includes a handle portion, and an oral care implement coupled to the handle portion, wherein the oral care implement includes a brush head portion having brush filaments. The oral care device further includes a first electrode located in the brush head portion and operable to be in electrical contact with a location within an oral cavity of a user, a second electrode located in the handle portion and operable to be in electrical contact with a hand of the user, a power source providing a voltage potential between the first electrode and the second electrode, and a controller circuit in electrical communication with the first electrode, the second electrode, and the power source. Electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the location within the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode. Upon a completion of the electrical circuit, the controller circuit generates a micro-current I through the user between the first electrode and the second electrode such that the micro-current I enhances delivery of chemical actives to the location within the oral cavity of the user, the chemical actives present in an oral care substance located within the oral cavity of the user. The controller circuit calculates an amount of chemical actives delivered to the location within the oral cavity of the user at a time t based at least in part on a value of the micro-current I through the user, the oral care substance, and a polarity of the second electrode with respect to the first electrode.
• In yet another embodiment, an oral care device includes a handle portion, and an oral care implement coupled to the handle portion, wherein the oral care implement includes a brush head portion having brush filaments. The oral care device further includes a first electrode located in the brush head portion and operable to be in electrical contact with a hard tissue within an oral cavity of a user, a second electrode located in the handle portion and operable to be in electrical contact with a hand of the user, a power source providing a voltage potential between the first electrode and the second electrode, and a controller circuit in electrical communication with the first electrode, the second electrode, and the power source. Electrical contact of the second electrode with the hand of the user and electrical contact of the first electrode with the hard tissue within the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode. Upon a completion of the electrical circuit, the controller circuit generates a substantially sinusoidal micro-current I through the user between the hand of the user and the hard tissue within the oral cavity of the user at a frequency that varies across a frequency range. The controller circuit measures a fundamental-harmonic component of a response of the substantially sinusoidal micro-current I through the electric circuit, and calculates a system impedance based at least in part on the fundamental-harmonic component. The controller circuit compares the system impedance with a plurality of impedance values corresponding to a plurality of health statuses corresponding to one or more teeth, selects a closest impedance value to the system impedance, and stores a selected health status corresponding to the closest impedance value.
• In yet another embodiment, a method of hard tissue diagnosis using an electric toothbrush having an oral cavity electrode and a gripping electrode includes generating a substantially sinusoidal micro-current I through an electric circuit closed by a user of the electric toothbrush by contact of the oral cavity electrode with a hard tissue within an oral cavity of the user and by contact of the gripping electrode with a hand of the user, wherein the substantially sinusoidal micro-current I passes through at least the hard tissue within the oral cavity of the user at a frequency that varies across a frequency range. The method further includes detecting a response of the substantially sinusoidal micro-current I through the electric circuit at the gripping electrode, measuring a fundamental-harmonic component of the response, and calculating a system impedance based at least in part on the fundamental-harmonic component. The method further includes comparing the system impedance with a plurality of impedance values corresponding to a plurality of health statuses, selecting a closest impedance value to the system impedance, and storing a selected health status corresponding to the closest impedance value.
• In yet another embodiment, an oral care device includes a handle portion, and an oral care implement coupled to the handle portion, wherein the oral care implement includes a brush head portion having brush filaments. The oral care device further includes a first electrode located in the brush head portion and operable to be in electrical contact with an oral cavity of a user, a second electrode located in the handle portion and operable to be in electrical contact with a hand of the user, an impedance element having an impedance characteristic within the oral care implement and electrically coupled to the first electrode, a power source providing a voltage potential between the first electrode and the second electrode, and a controller circuit in electrical communication with the first electrode, the second electrode, the impedance element, and the power source. Electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode. The controller circuit determines an impedance of the oral care implement, wherein the impedance element of the oral care implement affects the determined impedance. Additionally, the controller circuit generates a micro-current I through the user between the first electrode and the second electrode at a first micro-current amplitude when the impedance is within a first impedance range, and generates the micro-current I through the user between the first electrode and the second electrode at a second micro-current amplitude when the impedance is within a second impedance range.
• In yet another embodiment, an oral care device includes a handle portion, and an oral care implement coupled to the handle portion, wherein the oral care implement includes a brush head portion having brush filaments. the oral care device further includes a first electrode located in the brush head portion and operable to be in electrical contact with an oral cavity of the user, and a second electrode located in the handle portion and operable to be in electrical contact with a hand of a user, wherein electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode. The oral care device further includes a power source providing a voltage potential between the first electrode and the second electrode, and a controller circuit in electrical communication with the first electrode, the second electrode, and the power source. The controller circuit generates an evaluation micro-current I_evalthrough the electrical circuit, wherein the evaluation micro-current I_evalsweeps across an evaluation frequency range, and detects a resonant electrical frequency of the oral care implement based on a frequency response of the oral care implement in response to the evaluation micro-current across the evaluation frequency range. The controller circuit further generates a micro-current I through the user between the first electrode and the second electrode at a first micro-current amplitude when the detected resonant electrical frequency is within a first frequency range, and generates the micro-current I through the user between the first electrode and the second electrode at a second micro-current amplitude when the detected resonant electrical frequency is within a second frequency range.
BRIEF DESCRIPTION OF THE DRAWINGS
• It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.
• FIG. 1 schematically depicts electrical components of an oral care device according to one or more embodiments illustrated and described herein;
• FIG. 2 schematically depicts an oral care device according to one or more embodiments illustrated and described herein;
• FIG. 3 schematically depicts a power source circuit and a controller circuit according to one or more embodiments illustrated and described herein;
• FIGS. 4A-4D schematically depict oral care implements of an oral care device according to various embodiments illustrated and described herein;
• FIGS. 4E-4G schematically depict electrically conductive filaments according to various embodiments illustrated and described herein;
• FIG. 5 graphically depicts an alternating current ramping micro-current method according to one or more embodiments illustrated and described herein;
• FIG. 6 schematically depicts an electrical circuit between an oral care device and a user's body according to one or more embodiments illustrated and described herein;
• FIG. 7 graphically depicts electrical resistance of a plurality of regions within an oral cavity of a user;
• FIG. 8 schematically depicts an oral care device in wireless communication with a user interface device according to one or more embodiments illustrated and described herein;
• FIG. 9 schematically depicts an oral care implement according to one or more embodiments illustrated and described herein;
• FIGS. 10 and 10A schematically depicts an oral care implement comprising an electro-active polymer according to one or more embodiments illustrated and described herein; and
• FIG. 11 graphically depicts an impedance response as a function of frequency for two oral care implement refills according to one or more embodiments illustrated and described herein.
DETAILED DESCRIPTION OF THE INVENTION
• Embodiments disclosed herein are generally related to oral care devices, such as electric toothbrushes, that provide ionic micro-currents to an oral cavity of a user to deliver chemical actives by iontophoresis. More specifically, embodiments are directed to oral care devices capable of detecting when the oral care device is grasped by a user and positioned within the user's mouth, detecting a region of an oral cavity of the user and changing a brushing mode accordingly, detecting a type of oral care implement coupled to the oral care device and changing a brushing mode accordingly, and diagnosing the health status of teeth.
• Embodiments may be implemented in a device having a first electrode that is held by the user or is otherwise in electrical contact with some region of the user's body, and a second electrode that is to be applied at the region of iontophoretic interest (e.g., the oral cavity of a user). Micro-current flows through the user's body between the regions of the body that are in contact with the first and second electrodes because the user's body completes an electric circuit between the first and second electrodes.
• Referring now toFIG. 1, a general schematic of some of the components of one embodiment of anoral care device100 is illustrated. Theoral care device100 generally comprises apower source102, acontroller circuit104, afirst electrode106 and asecond electrode108. Thepower source102 may be any power source capable of producing micro-currents (ionic) according to the particular application in which theoral care device100 is implemented. As an example and not a limitation, thepower source102 may comprise a battery capable of providing micro-currents in the range of 50 to 1000 nA. Thepower source102 may also be an AC-DC converter circuit, DC-DC voltage regulator circuit, or any appropriate circuit to obtain the voltage levels and micro-current levels particular to the iontophoresis application. As an example and not a limitation, thepower source102 may produce a voltage potential of about 30 volts to increase the iontophoresis effect and overcome the high electrical resistance of the human body portion of the electrical (ionic) circuit.
• The first andsecond electrodes106,108 are electrodes that are configured to be in electrical contact with a user's body. Accordingly, the first andsecond electrodes106,108 should be electrically conductive. In one embodiment, the first andsecond electrodes106,108 are made of a metallic material. In another embodiment, the first and/orsecond electrode106,108 may be a touch electrode comprising a non-metal material filled with carbon filling as described in U.S. patent application Ser. No. 12/014,487 entitled “Oral Care Device” (e.g., carbon fibers that are dispersed in a non-electrically conductive resin). It is noted that although the first electrode is illustrated as being associated with a negative polarity (−) and the second electrode is illustrated as being associated with a positive polarity (+), embodiments are not limited thereto. The first electrode may be associated with a positive polarity and the second electrode may be associated with a negative polarity.
• Thecontroller circuit104 is a circuit that is capable of providing ionic current upon completion of an electrical circuit through the body of a user at the desired micro-current levels. Further, thecontroller circuit104 effectuates the ramping control of micro-current that is applied to the user to limit the sensation that is experienced by the user. As an example and not a limitation,FIG. 5 depicts an exemplary micro-current control waveform that may be produced by thecurrent control circuit104. These micro-current control methods, as well as thecurrent control circuit104, will be described in greater detail below.
• FIG. 2 depicts a graphical illustration of anoral care device120 according to one or more embodiments. It should be understood that the arrangement of the components of theoral care device120 is for illustrative purposes only and embodiments are not limited to such arrangement of components or configurations of the illustratedoral care device120. The illustratedoral care device120 comprises a body housing and an oral care implement126. The body housing defines ahandle portion121 on a first end of theoral care device120. The oral care implement126 is coupled to thehandle portion121 defining a second end of theoral care device120. In one embodiment, the oral care implement126 is removably coupled to thehandle portion121 such that oral care implements of differing configurations may be attached to the handle portion121 (e.g., a tongue cleanser or a flossing implement). In an alternative embodiment, the oral care implement126 is not removable from thehandle portion121 such that thehandle portion121 and the oral care implement126 are one integral component. Thehandle portion121 may be made of non-electrically conductive material, such as molded plastic, for example.
• The illustrated oral care implement126 generally comprises astem portion128 and abrush head portion129 that is configured as an electric toothbrush head having toothbrush bristles127 associated therewith. Both thestem portion128 and thebrush head portion129 may be made of a non-electrically conductive material, such as a plastic material. The oral care implement126 has afirst electrode106 that may comprise one or more electrically conductive regions. In the illustrated embodiment, thefirst electrode106 comprises an electrically conductive pad that is located within an opening of thebrush head portion129 such that the electrically conductive pad of thefirst electrode106 is exposed to the oral cavity of a user during operation of theoral care device120.
• As illustrated inFIG. 2, thesecond electrode108 is provided in thehandle portion121 such that it may be in electrical contact with the hand of a user when the user grips thehandle portion121 to operate theoral care device120. As described above, thesecond electrode108 may be made of metallic material, a non-conductive resin with conductive carbon fibers dispersed therein, or any other electrically conductive material. It should be understood that embodiments are not limited to the configuration of the second electrode illustrated inFIG. 2. In one embodiment, an optional vibratingactuator122 is provided and coupled to thepower source102. The vibratingactuator122 may be configured to oscillate at a high frequency to provide vibration to theoral care device120. Thehandle portion121 may also comprise other components, such as ON/OFF buttons or switches162 (seeFIG. 8), mode selection buttons or switches, etc.
• Maintained within thehandle portion121 are various electrical components that produce the therapeutic ionic micro-currents. The power source102 (i.e., a battery) is positioned within the housing with a first polarity (e.g., a positive polarity) of thepower source102 electrically coupled to thesecond electrode108. The opposite polarity (e.g., a negative polarity) of thepower source102 is electrically associated with thefirst electrode106 in the oral care implement126 through thecontroller circuit104. The polarity associated with the first andsecond electrodes106,108 may be reversed depending on the particular application.
• Thecontroller circuit104 may be mounted on a printed circuit board or other structure within thehandle portion121. As shown inFIG. 2, thecontroller circuit104 may comprise apulse generation circuit123 and apulse drive circuit124. Thepulse generation circuit123 andpulse drive circuit124 are illustrated at two physically separate circuits but it should be understood that the two circuits may be implemented in a single circuit (or integrated circuit) in some embodiments. Thepulse generation circuit123 may generate the waveforms that are desired to be applied to the user, and thepulse drive circuit124 may amplify the waveforms to have the appropriate current values for the particular iontophoresis application. An exemplary waveform is depicted inFIG. 5.
• An electric (ionic) circuit is provided by the electrical connection between the negative polarity of thepower source102 and thecontroller circuit104, thecontroller circuit104 and first electrode106 (depicted by dashedline125a), the positive polarity of thepower source102 and the second electrode108 (depicted by dashedline125b), and the conductive path between a hand and the oral cavity of the user (depicted by dashed line131). The circuit is made when the user grips thefirst electrode106 of theoral care device120 and places thebrush head portion129 andfirst electrode106 in his or her mouth. The circuit is opened when the user removes thebrush head portion129 and thefirst electrode106 from his or her mouth. More generally, the circuit is made when a user grips asecond electrode108 of anoral care device100 and applies thefirst electrode106 of theoral care device100 to his or her oral cavity.
• In some embodiments, theoral care device100 may also comprise awireless communications module140 for transmitting data both to and from theoral care device100. Thewireless communications module140 may be configured to wirelessly communicate to external components, such as a mobile device, a computer, an external user interface (seeFIG. 7), and the like. Data may include, but is not limited to, tooth diagnosis information, brushing force, brushing duration, and chemical active delivery.
• Referring now toFIG. 3, a schematic of thecontroller circuit104 and thepower source102 according to one embodiment is depicted. It should be understood that other circuits or modifications to the circuits illustrated inFIG. 3 may be used, and embodiments are not limited to the schematics ofFIG. 3. Thepower source102 of the illustrated embodiment comprises abattery101 and avoltage regulator103. In another embodiment, a voltage regulator is not provided. Thevoltage regulator103 receives the voltage of thebattery101 and provides aground reference potential109, a positive power rail potential105 (V+) with respect to the ground reference potential (e.g., +30V), and a negative power rail107 (V−) with respect to the ground reference potential (e.g., −30V). It should be understood that other voltage potentials may be utilized. The positivepower rail potential105 and the negativepower rail potential107 are provided to apply anodic or cathodic polarities. The voltages provided by thevoltage regulator103 may vary depending on the particular application.
• Thecontroller circuit104 generally comprises apulse generation circuit123 and apulse drive circuit124. Thecontroller circuit104 may be any circuit that is capable of producing the desired ionic current waveform (e.g., the waveform illustrated inFIG. 5) at the particular frequencies, duty cycles, current levels, etc. It should be understood that one or more of the components of thecontroller circuit104 may be provided in one or more integrated circuits (e.g., an application-specific integrated circuit).
• In one embodiment, thepulse generation circuit123 comprises a microcontroller112 and a digital-to-analog converter circuit or chip113 (DAC) that cooperate to create a waveform that corresponds to the micro-current that is to be applied to the user. In some embodiments, the pulser generation circuit does not include a DAC. The waveforms produced by thepulse generation circuit123 are amplified by thepulse drive circuit124 and therefore may have voltages that are less than that necessary to produce the desired micro-currents. For example, the voltages of the waveform pulses may be in a range between zero and a logic voltage level of the microcontroller. The microcontroller112 may provide instructions to the digital-to-analog converter113 to produce the pulses that make up the waveforms. The waveforms may be produced in a manner other than the illustratedpulse generation circuit123.
• As stated above, thepulse drive circuit124 is configured to amplify the waveforms provided by thepulse generation circuit123 such that the desired micro-current levels (as well as desired frequencies and duty cycles) are applied to the user. The exemplarypulse drive circuit124 comprises anoperational amplifier116 that receives the pulse train of the waveforms provided by thepulse generation circuit123 as input and produces the micro-currents as output. Accordingly, theoperational amplifier116 is used as a current source that amplifies the pulse trains of the waveforms. Theoperational amplifier116 is electrically connected to the positive and negative power rails of thepower source102, and is electrically coupled to a current-sensingresistor111 that is further coupled to the ground reference potential. The output of theoperational amplifier116 is electrically coupled to thefirst electrode106, which, in the context of an oral care device, is to be positioned within the oral cavity of a user. Thesecond electrode108 is electrically coupled to the ground reference potential through the current-sensing resistor.
• The current-sensingresistor111 is provided to provide feedback of the ionic micro-current that is passed through the user to the microcontroller112 to monitor and make adjustments to the micro-current levels provided to the user. In one embodiment, the current-sensingresistor111 is a 1 kΩ resistor such that 1 mV across the current-sensingresistor111 corresponds to 1 μA.
• In the embodiment illustrated inFIG. 3, thepulse generation circuit123 andpulse drive circuit124 may be protected by over-voltage protection devices.Zener diodes117 and118 clamp the voltage across the user to less than a user over-voltage value, such as 30V, for example.Zener diodes114 and115 protect the digital-to-analog converter113 and microcontroller112 by clamping the voltage to less than a pulse generation circuit over-voltage, such as 10V, for example.
• In the oral care context, it is predicted that the administration of ionic current may be used to aid in the removal of plaque, as well as preventing plaque regrowth from the teeth and gums as well as administer fluorine ions to the teeth via iontophoresis. The ionic micro-current provided by theoral care device100 may flow from thebrush head portion129, across the saliva by the user to the mouth mucosa and/or teeth, across the body into the hand of the user, and back into the handle of theoral care device100.
• FIGS. 4A-4F illustrate various embodiments of oral care implements andfirst electrodes106. The oral care implements and first electrode may take on a wide variety of configurations. It should be understood that embodiments are not limited to those configurations depicted inFIGS. 4A-4F. Referring toFIG. 4A, abrush head126′ is depicted having a first electrode that comprises a firstconductive pad106athat is positioned adjacent to the toothbrush bristles127, and a secondconductive pad106bthat is positioned under the toothbrush bristles127. Thebrush head126′ depicted inFIG. 4A therefore provides two locations through which ionic current may flow. Thebrush head portion129 depicted inFIG. 4B has a singleconductive pad106 positioned under the toothbrush bristles127, while thebrush head126″ depicted inFIG. 4C has a singleconductive pad106apositioned adjacent to the toothbrush bristles127. It is also contemplated that the toothbrush bristles127 themselves may be electrically conductive and act as the first electrode.
• FIGS. 4D and 4E illustrate an embodiment in which the first electrode is in the form of one or moreinsulated conductor wires106cpositioned amongst the toothbrush bristles127.FIG. 4E illustrates a close-up view of one embodiment of aninsulated conductor wire106cshown inFIG. 4D. Theinsulated conductor wire106ccomprises an electricallyconductive wire core130 that is made out of any electrically conductive material, such as a pliable metallic material, and anouter insulator jacket132 that surrounds the electricallyconductive wire core130. Theouter insulator jacket132 is made of a non-conductive material that is sufficiently pliable to be used in a tooth brush application. An exposedportion130′ of the electricallyconductive wire core130 extends beyond theouter insulator jacket132 such that it is exposed to the oral cavity of the user and may act as the first electrode as described above.
• FIG. 4F illustrates an electricallyconductive brush filament106dconfigured as an electrically conductive material within a polymer. As an example and not a limitation, the electricallyconductive brush filament106dmay comprise a polymer having electrically conductive particles (e.g., electrically conductive carbon particles, nano-particles, conductive soot) embedded therein. In another embodiment, brush filament may be coated with a conductive film or material that loses conductivity over time. For example, the colored film that is applied by a ringdye process to provide a visual indication to the users as to the wear of the bristles may be made electrically conductive.
• The oral care implement may include one or more electricallyconductive brush filaments106das the first electrode. As described in more detail below, the electricallyconductive brush filament106ddepicted inFIG. 4F may be designed to lose conductivity over a period of use. For example, the electrically conductive particles may separate from the brush filament(s) over time, thereby increasing the resistivity of the electricallyconductive brush filament106d.
Ramping of Ionic Micro-Current
• In one embodiment, the oral cavity of the user (teeth) is under positive voltage due to the positivefirst electrode106, and thesecond electrode108 of thebrush head portion129 is under negative voltage to direct flow of fluorine negative ions toward the positively charged teeth. Laboratory experiments suggest that the flow of fluorine ions directly depends on the level of micro-current that is delivered, and that higher current would be beneficial for greater delivery of fluorine ions and potentially for biofilm disruption. Experiments also indicate that pulsed ionic current of 80 μA (amplitude) or less provides little oral care benefit. However, higher current levels may cause unpleasant sensations for the user, such as an electrical feeling, pain, and/or a sour taste. The embodiments described herein enable the use of higher ionic current without the associated unpleasant sensations, and may therefore provide enhanced oral care efficacy.
• In some embodiments, the micro-current (I) may be ramped from a low value to a higher value each time contact is made between the brush head portion and the oral cavity of a user. In other embodiments, the amplitude of the micro-current I may remain constant. Surprisingly, the present inventors have found that higher ionic current values may be applied to the oral cavity of users without unpleasant sensations by ramping the ionic micro-current from a start current I_startto an end current I_endover a rise time I_rise. Generally, when the circuit is made by the application of thefirst electrode106 to the oral cavity of the user, thecontroller circuit104 produces a micro-current I_rampedthat starts at I_startand increments to I_endover t where it then is maintained at I_enduntil the electrical circuit is opened by the removal of thefirst electrode106 from the oral cavity of the user. Current ramping is repeated every single time the electric circuit is opened and closed. As described in more detail below, the end micro-current I_endshould be greater than about 100 μA, which is predicted to be the value of micro-current that increases brushing efficacy. In one embodiment, the end micro-current I_endis between about 100 μA and about 800 μA. In another embodiment, the end micro-current L_adis between about 400 μA and about 800 μA. The micro-current I_rampedmay be alternating current (AC) or direct current (DC) depending on the application. In AC applications, the micro-current ranges described above are amplitude micro-current values. It should be understood that the aforementioned micro-current ranges are intended for oral care applications, and other non-oral care applications may use different current ranges.
• The time t_riseshould be long enough to minimize the sensation of the micro-current experienced by the user, but short enough such that the end micro-current I_endis reached quickly so that the maximum current of the end micro-current I_endis experienced by the user during the brushing session. As an example and not a limitation, the rise time may be between 1 second and 20 seconds. Generally, the shorter the rise time t_rise, the greater the likelihood that a user will experience a sensation resulting from the micro-current. It is noted that it may be desirable for theoral care device100 to provide some sensation to the user so that the user may be aware that a micro-current is present and theoral care device100 is operating correctly. However, micro-currents and rise times that produce unpleasant sensations should be avoided. In one embodiment, theoral care device100 may be programmable by the user such that the user may select variables such as rise time t_rise, start current t_start, end current I_end, a step current I_step(the amount of increased micro-current between increments), frequency, duty cycle, etc.
• FIG. 5 illustrates one exemplary AC embodiment of a micro-current ramping method. Other micro-current ramping methods may include those described and illustrated in U.S. Pat. Appl. No. 61/536,678 filed on Sep. 20, 2011, which is hereby incorporated by reference in its entirety. The operational duty cycle illustrated inFIG. 5 is 50%. Embodiments may have an operational duty cycle other than 50%, and the frequency of the pulsed ramped micro-current I_rampedmay depend on the particular application. In one embodiment, the frequency of the pulsed ramped micro-current I_rampedis about 9 kHz.
• One fullmicro-current pulse train210 and one partialmicro-current pulse train220 are illustrated inFIG. 5. The micro-current starts at start micro-current I_startwhen electrical contact is made between the first electrode and the oral cavity of the user (e.g., atpoint211 and point221). At first contact, the micro-current alternates between I_startand 0 μA. The ramped micro-current I_rampedis shifted by an offset amount I_stepsuch that it alternates between 0 nA and I_startplus I_step. The micro-current shifts further by I_stepuntil the end micro-current I_endis reached. The values of the ramped micro-current I_rampedover time may be expressed as alternating between 0 and (I_start(m−1)I_step) at an operational duty cycle (e.g., 50%), where m=1 upon a completion of the electrical circuit and increments by one at a step frequency until (I_start+(m−1)I_step). After rise time t_rise, the ramped micro-current I_rampedthen alternates between I_endand 0 at the operational frequency until the electrical circuit is opened.
Automatic On-Off Control
• In some embodiments, the opening and closing of the electrical circuit that is completed by a user of an oral care device, such as an electric toothbrush, may automatically control the functionality of the oral care device. For example and referring once again toFIG. 2, theelectric toothbrush120 may be automatically operated in one operational mode, such as an OFF state or a standby state, when: 1) the user physically contacts neither thefirst electrode106 in thebrush head portion129 nor thesecond electrode108 on thehandle portion121, and 2) the user physically contacts only one of thefirst electrode106 or the second electrode. When the user physically contacts both the first and second electrodes by gripping thesecond electrode108 and placing thebrush portion129 into his or her mouth such that thefirst electrode106 contacts the oral cavity, theelectric toothbrush120 may operate in another operational mode, such as one or more ON states. When the user disconnects either thefirst electrode106 or thesecond electrode108, or both from his or her body, theelectric toothbrush120 may switch back to the original mode (e.g., an OFF state or a standby state, as described below).
• In this manner, theelectric toothbrush120 may switch between a plurality of modes based on whether or not the user has gripped thehandle portion121 and placed thebrush head portion129 into his or her mouth. In one embodiment, theelectric toothbrush120 comprises an ON-OFF switch (not shown inFIG. 2) such that when the user places the ON-OFF switch in the ON position, theelectric toothbrush120 operates in a standby state prior to the user placing thebrush head portion129 into his or her mouth (e.g., a second operational mode). During the standby state, the vibratingactuator122 may vibrate at a low vibration amplitude and/or frequency (e.g., a non-operational vibration amplitude and/or frequency) to provide feedback to the user that theelectric toothbrush120 is working properly, without causing water and/or toothpaste to splatter from thebrush head portion129. Theelectric toothbrush120 may also not produce the voltage potentials and/or waveforms associated with the micro-current delivery modes during the standby state.
• When the user contacts thefirst electrode106 and thesecond electrode108, thecontroller circuit104 may detect an impedance characteristic (e.g., resistance and/or reactance) of the electrical circuit that is completed by the user's body. In one embodiment, thecontroller circuit104 compares the detected impedance characteristic with a threshold. When the detected impedance is below a threshold, or within a range associated with the impedance characteristics of the human body, thecontroller circuit104 may switch to operate in one or more ON states (e.g., a first operational mode). The ON state may be any combination of operational vibration frequency, operational vibration amplitude, and micro-current delivery. The operational vibration and/or micro-current delivery may be continuously provided by theelectric toothbrush120 until a high impedance characteristic is detected by thecontroller circuit104, thereby indicating disconnection of thefirst electrode106 and/or thesecond electrode108 from the user's body. Thecontroller circuit104 may then switch the electric toothbrush to the second operational mode (e.g., OFF state, standby state, or other).
• In other embodiments, theelectric toothbrush120 does not include an ON-OFF switch such that theelectric toothbrush120 does not vibrate and does not produce a voltage potential at thefirst electrode106 and thesecond electrode108 when operating in the second operational mode (e.g., an OFF state).
• In some embodiments, thecontroller circuit104 further comprises a timer141 (seeFIG. 1B) that may record the operational duration of theelectric toothbrush120. Thetimer141 may be configured as a distinct circuit, or be integrated into the microcontroller112. Thetimer141 may start recording time once thecontroller circuit104 detects the completion of the electrical circuit via the user's body, and stop recording time once the controller detects the opening of the electrical circuit. Thecontroller circuit104 may record and separately store brushing duration data for individual brushing sessions in a memory component143. The memory component may be any type of computer-readable medium, such as, but not limited to, flash memory and magnetic disk memory. Using the brushing duration data for the individual brushing sessions, the controller circuit (e.g. via the microcontroller112) may calculate a total brushing duration for a particular oral care implement126 that is coupled to thehandle portion121 by summing the brushing duration data for the individual brushing sessions. A user interface may be associated with theelectric toothbrush120, such as on thehandle portion121 or a separate user interface device150 (seeFIG. 7) to display brushing duration data for the individual brushing sessions and/or the total brushing duration for the particular oral care implement126. In one embodiment, theelectric toothbrush120 may comprise an indicator, such as a light emitting diode (LED) and/or an auditory device that announces to the user when he or she has brushed long enough to meet proper brushing techniques, or that the oral care implement126 should be replaced because the calculated total brushing duration exceeds a predetermined threshold.
• The oral care implement126 may also be designed to have a use-life that expires after a pre-determined period of use. For example, thefirst electrode106 at thebrush head portion129 of an oral care implement126 configured as a removable toothbrush head may be configured to lose electrical conductivity as a function of use. Once thefirst electrode106 is no longer electrically conductive, or presents a very high impedance, the overall impedance of the electrical circuit closed by the user's body may be above the impedance threshold such that theelectric toothbrush120 will not operate in an ON state despite a user gripping thehandle portion121 and placing thebrush head portion129 in his or her mouth. Failure of theelectric toothbrush120 to turn on may indicate to the user that it is time to replace the old oral care implement with a new one.
• The first electrode106 (e.g., thefirst electrodes106a-106dillustrated inFIGS. 4A-4F) may be designed to lose electrical conductivity after a predetermined period of time of predetermined brushing mode. A brushing mode may correspond to a force on which a user applies thebrush head portion129 to his or her teeth, the frequency of the brushing motion, and other factors. As an example and not a limitation, the predetermined brushing mode may correspond to a typical brushing force and brushing frequency. Thefirst electrode106 may be designed to wear out or otherwise lose its electrical conductivity after a predetermined period of time of average brushing, wherein the predetermined period of time corresponds with a period of time that a user should replace the oral care implement126 due to bristle wear, for example.
• Thefirst electrode106 may be designed to lose electrical conductivity in a variety of ways, some of which are described below. Referring once again toFIG. 4E, the first electrode is configured as aninsulated conductor wire106c. Theinsulated conductor wire106ccomprises an electricallyconductive wire core130 that is made out of any electrically conductive material, such as a pliable metallic material, and anouter insulator jacket132 that surrounds the electricallyconductive wire core130. Thefirst electrode106 may be defined by a singleinsulated conductor wire106cor a plurality ofinsulated conductor wires106c. An exposedportion130′ of the electricallyconductive wire core130 may be configured to wear down or break off after a predetermined period of time of use such that the electricallyconductive wire core130 is no longer exposed to the oral cavity of the user and thefirst electrode106 ceases to be electrically conductive. After the exposedportion130′ breaks off or is worn down (and as a consequence, changes its conductivity), theelectronic toothbrush120 may no longer turn on until the user replaces the oral care implement126.
• In another embodiment, the electricallyconductive wire core130 may be designed to break or otherwise fail at apredetermined breaking location133 after the predetermined brushing duration (at a predetermined brushing mode/force) such that the portion of the electrically conductive wire core that is exposed at the end of the insulated conductor wire is not electrically coupled to the controller circuit. Thepredetermined breaking location133 is covered by theouter insulator jacket132. A break at thepredetermined breaking location133 may increase the impedance and/or prohibit the closure of the electrical circuit, thereby preventing theelectric toothbrush120 from operating in an ON state.
• Referring once again toFIG. 4F, thefirst electrode106 may be configured as one or more electricallyconductive brush filaments106dcomprised of an electrically conductive material within a polymer (e.g., a polymer having embedded electrically conductive particles). The electricallyconductive brush filaments106dmay be designed to lose conductivity over a predetermined period of time at a predetermined mode, such as a predetermined brushing force and frequency. In one embodiment, the electrically conductive particles (or film) are configured to separate from the brush filament at a loss-rate corresponding to the predetermined brushing mode. For example, the loss-rate may be such that the electrically conductive brush filament(s)106dlose electrical conductivity after a period of time at an average brushing force and brushing frequency that corresponds with when the bristles are sufficiently worn down and the oral care implement should be replaced.
• Alternatively, referring toFIG. 4G, one or moreconductive filaments106emay be provided, wherein the one or moreconductive filaments106eare configured to become conductive over time. Rather than loss of electrical conductivity or contact with the oral cavity as described above, positive electrical contact between the one or moreconductive filaments106emay indicate that the oral care implement should be replaced. Theconductive filament106edepicted inFIG. 4G has anouter insulator jacket132′ that fully surrounds an electricallyconductive wire core130′. Theouter insulator jacket132′ isolates the electricallyconductive wire core130′ from making electrical contact with the oral cavity of a user. However, theouter insulator jacket132′ is designed to break down over time due to brushing activity such that the electricallyconductive wire core130′ is exposed. Positive electrical contact between the electricallyconductive wire core130′ and the oral cavity of a user may be sensed by one or more circuits and/or controllers within the oral care device. Such electrical contact may indicate that the oral care implement should be replaced. As an example and not a limitation, sensed positive electrical contact between the electricallyconductive wire core130′ and the oral cavity of the user may prevent the oral care device from operating in one or more brushing modes.
Automatic Mode Switching
• In some embodiments, the oral care device, such as anelectric toothbrush120, may be configured to automatically detect which region of the oral cavity the user is brushing, and automatically switch its selected operational mode accordingly, wherein the selected operational mode is one of a plurality of operational modes. As an example and not a limitation, it may be desirable that theelectric toothbrush120 operate at a greater vibration amplitude and a greater micro-current amplitude when the user is brushing hard tissue, such as teeth, than when the user is brushing soft tissue (e.g., tongue, gums, cheeks, gingival area, etc.). Further, it may be desirable to change the vibratory motion and the micro-current amplitude/waveform depending on which tooth the user is brushing, or which particular soft tissue region the user is brushing.
• Theelectric toothbrush120 may be configured to measure the impedance of the electric circuit and switch the operational mode depending on the measured impedance. Referring now toFIG. 6, embodiments of the present disclosure may be operable to detect the impedance of the oral cavity tissue that is in contact with thefirst electrode106. The resistances of different areas within the oral cavity have characteristic value ranges.FIG. 6 depicts anelectric circuit10 defined by a power source, such as a battery andvoltage regulator101/103, a conductive path between thefirst electrode106 and the power source, and a conductive path within the body of the user between thefirst electrode106 and thesecond electrode108 having a skin and body resistance R_Sand a tooth resistance R_Tor a soft tissue resistance R_ST. Generally, the tooth resistance is greatest: R_T>R_ST>R_S. Thecontroller circuit104 may calculate the overall resistance of theelectric circuit10 by measuring the ionic current I_Band the voltage across the body V by R=V/I.
• In one embodiment, if the measured resistance (or impedance) is more likely the resistance of a tooth, thecontroller circuit104 may control the electronic toothbrush120 (or other oral care device) to operate in a first operational mode, such as a standard mode with greater vibratory motion and greater micro-current amplitude. If the measured resistance (or impedance) is more likely the resistance of soft tissue, such as the gums or tongue, thecontroller circuit104 may control the electronic tooth brush120 (or other oral care device) in a second operational mode, such as a massage mode that has less vibratory motion and lower micro-current amplitude than the first operational mode associated with the teeth, for example. The measured resistance or impedance may be compared against stored resistance or impedance ranges to determine if thebrush head portion129 is positioned on hard or soft tissue.
• Embodiments may also be configured to apply more than two different operational modes based on type of teeth and/or type of soft tissue that thefirst electrode106 is in contact with. Referring now toFIG. 7, a graph depicts experimental resistance measurements of regions within the oral cavity, including a gum region G, a tongue region T, an upper jaw soft tissue region UST, a gum-tooth interface or gingival line GL, a buccal molar tooth MTB, and an occlusal molar tooth MTO. The values of the graph depicted inFIG. 7 were obtained by applying a 400 μA microcurrent I to the various regions using an electric toothbrush on a single individual. The microcurrent I was ramped at 80 μA/sec to 400 μA, and had a duty cycle of 80% and a frequency of 9 kHz. The voltage V was measured across the toothbrush head (toothbrush shaft-refill-mouth-body-toothbrush handle) using a Fluke 287 Hand Multimeter. The resistance of the various regions was calculated by R=V/I. The resistivity of the toothbrush head (shortcut measurement) was then subtracted from the measured values. Also, the 80% current duty was respected in the calculations.
• As shown in the graph, the resistance of the different regions may vary such that the operational mode of the oral care device may switch depending on the type of region that is detected. The different operational modes may differ in vibratory motion (frequency and amplitude) and micro-current delivery (frequency, duty cycle, waveform shape, amplitude, etc.) to provide the greatest efficacy relating to the type of oral cavity region being brushed or massaged. In some embodiments, the type of motion may also vary between the different operational modes. As an example and not a limitation, the brush head portion may translate in three dimensions when hard tissue is detected, and only two dimensions when soft tissue is detected.
Feedback of Chemical Actives Delivery
• Referring once again toFIG. 6, iontophoresis may increase the delivered amount of chemical actives that are present in an oral care substance, such as sodium fluoride toothpastes, stannous fluoride toothpastes and mouth washes, and the like. Chemical actives that may be present in the oral care substance may include, but are not limited to, Ca²⁺, F⁻, and Sn²⁺. When theoral care device120 is operated in a cathodic state such that thefirst electrode106 in thebrush head portion129 has a negative polarity, anions such as F⁻ are delivered to the teeth. When theoral care device120 is operated in an anodic state such that thefirst electrode106 in the brush head portion has a positive polarity, cations such as Ca²⁺ and Sn²⁺ may be delivered to the teeth.
• An amount of chemical actives delivered to the teeth or soft tissue may be determined based on the amount of micro-current I that is passing through the electric circuit through the body over time t. An increase in micro-current I may lead to an increase in chemical actives delivery. Accordingly, embodiments of the present disclosure may provide feedback to the user as to the amount of chemical actives that have been delivered to the user's teeth during a brushing session via an actives delivery indicator. As an example and not a limitation, the delivered amount may be shown usingLEDs160 on thehandle portion121 of theelectric toothbrush120 starts red, then turns yellow and then green over time t as the user brushes his or her teeth. Any number of LEDs may be provided. Each LED may be associated with a particular actives delivery range. As another example and not a limitation, the electric toothbrush may have a gauge-like display that graphically depicts the amount of chemical actives that have been delivered over time t. The amount of chemical actives that is delivered may be recorded by thecontroller circuit104 and stored in a memory component143 for later use, such as statistical analysis.
• Referring now toFIG. 8, anelectric toothbrush120 is schematically depicted in wireless communication with an actives delivery indicator configured as a separateuser interface device150 comprising ahousing152 and agraphical display154. Theelectric toothbrush120 may transmit a wireless signal from thewireless communications module140 to the actives delivery indicator for a graphical representation of the amount of chemical actives delivered to the oral cavity on thegraphical display154. The user interface may include an alphabetic display, a numeric display, an alpha-numeric display, or combinations thereof. Theuser interface device150 may also comprise one or more inputhard keys156a,156b. In one embodiment, the amount of chemical actives delivered during past brushing sessions may be stored in theuser interface device150 for later retrieval and display on thegraphical display154.
• In some embodiments, the controller circuit104 (e.g., the microcontroller112 of the controller circuit104) may be configured to receive a code associated with the particular oral care substance being used for the particular brushing session. For example, the packaging of the oral care substance, such as a tube of toothpaste, may have a code that may be entered into theelectric toothbrush120 or theuser interface device150 by the user (e.g., manually or automatically by a scanner or another input device that is a component of theelectric toothbrush120 or theuser interface device150 or a separate input device). As another example, the code may be configured as a bar code or an image that may be recognized by a camera within a computing device such as a smartphone, anelectric toothbrush120, or auser interface device150 by image recognition techniques. The code may then be interpreted by the microcontroller112 such that the microcontroller is aware of the type oral care substance and the percentage of chemical actives that are present in such a type of oral care substance. Using this information, thecontroller circuit104 may calculate the amount and type of chemical actives that are delivered based on the amount of micro-current I and the time t.
Hard Tissue Diagnosis
• In some embodiments, the oral care device, such as anelectric toothbrush120, may be configured to diagnose the health status of a user's teeth over using electrical impedance spectroscopy. Embodiments of the present disclosure may measure the system impedance of the user's tooth or teeth over a range of frequencies. It has been shown that caries lesions in teeth affect the electrical impedance of the teeth, which may be due to loss of enamel. Teeth containing a cavity may have a lower electrical resistance than healthy teeth.
• Referring again toFIG. 3, thecontroller circuit104 may produce a substantially sinusoidal micro-current I across a range of frequencies after completion of the electrical circuit between thefirst electrode106 and thesecond electrode108 to diagnose the health status of a tooth. The user may place thebrush head portion129 of the oral care implement126 on a single tooth that he or she desires to diagnose. The substantially sinusoidal micro-current I may pass through the tooth across the range frequencies. Thecontroller circuit104 comprises afrequency analyzer circuit142 that is configured to detect a system impedance of the tooth across using the substantially sinusoidal micro-current I. In one embodiment, thefrequency analyzer circuit142 is a distinct circuit (or integrated circuit) within thecontroller circuit104. In another embodiment, the functionality of the frequency analyzer circuit is provided by the microcontroller112. Any frequency analyzer circuit capable of determining the spectral content of a response of the tooth may be utilized.
• Thecontroller circuit104, via the microcontroller112 or a separatefrequency analyzer circuit142, may measure a fundamental-harmonic component of a response of the substantially sinusoidal micro-current I through the electric circuit, including the tooth being diagnosed. Thecontroller circuit104 may then calculate or otherwise determine the system impedance from the fundamental-harmonic component of the response, which may include the real and/or imaginary parts of the system impedance.
• In one embodiment, the system impedance of the tooth under diagnosis is compared with a plurality of impedance values that correspond to health statuses (e.g., healthy tooth, some decay, significant decay, etc.). The microcontroller112 may select the impedance value that is closest to the system impedance and store it and/or the health status associated with the selected impedance value in the memory component143 for later use and retrieval. The above-described process may be performed for each tooth such that each tooth may be diagnosed.
• Additionally, embodiments may track the health status of individual teeth over time. In one embodiment the user may record the health status of his or her teeth by diagnosing each tooth according to a sequence. During each diagnosis session, the user will diagnosis his or her teeth in a particular sequence such that the health status and/or system impedance value for each tooth are stored in a table or other format for comparison over time. The health status data of the table may be graphically presented to the user so that the user may track the health status of his or her teeth. The current and past health status data may be compared against future system impedance values and health statuses.
• The data may be transmitted and stored in the user interface device150 (seeFIG. 8) for graphical presentation. Further, the health status data may be transmitted to the user's dentist or other health care provider for teeth diagnosis monitoring over time. As an example and not a limitation, the health status of the right maxillary canine may be recorded and tracked over time for evaluation by the user and/or the user's dentist.
Automatic Oral Care Implement Detection and Mode Switching
• Referring generally toFIG. 2, some embodiments of the oral care device, such as anelectric toothbrush120, may be configured to detect the type of oral care implement126 that is coupled to thehandle portion121. Thecontroller circuit104 may then control the operation of theelectric toothbrush120 depending on the detected type of oral care implement126. For example, if thecontroller circuit104 cannot determine the type of oral care implement because the oral care implement does not possess particular characteristics, thecontroller circuit104 may not allow vibratingactuator122 to vibrate and/or the micro-current I to be provided. In this manner, thecontroller circuit104 may be able to detect the type of oral care implement and control theelectric toothbrush120 accordingly. In one embodiment, the electric toothbrush or a separate user interface device (e.g., theuser interface device150 depicted inFIG. 8) may provide an indication that the oral care implement is not compatible with the electric toothbrush when the impedance is not within any predetermined impedance range. In one embodiment, a visual indication may be provided by one or more LEDs associated with the electric toothbrush.
• Referring now toFIG. 9, an oral care implement226 according to one embodiment is schematically illustrated. In the illustrated embodiment, animpedance element260 is provided within the oral care implement226 such thatimpedance element260 is within an electrically conductive path (indicated by dashedlines225a,225b) and electrically coupled to thefirst electrode206 and a handle portion (not shown inFIG. 9) when the oral care implement226 is physically coupled to the handle portion of an electric toothbrush. The illustratedimpedance element260 is depicted as a capacitive element. Theimpedance element260 may also be configured as a resistive element or an inductive element. In another embodiment, theimpedance element260 may comprise a circuit made up of a combination of one or more capacitive elements, resistive elements, and inductive elements. The impedance characteristic of theimpedance element260 may correspond to the type of oral care implement that may affect the mode of toothbrush operation. For example, animpedance element260 having an impedance characteristic within a first impedance range may correspond to a “regular” toothbrush head, while animpedance element260 having an impedance characteristic within a second impedance range may correspond to a “sensitive” toothbrush head. A “regular” toothbrush head may have a greater vibratory motion (e.g., vibration frequency and/or vibration amplitude) and/or increased micro-current amplitude than the “sensitive” toothbrush head.
• Referring toFIGS. 2,3 and9, thecontroller circuit104 may be configured to detect the impedance of the oral care implement226 that is coupled to thehandle portion121. The impedance of the oral care implement226 is affected by theimpedance element260, which in the illustrated example is capacitance. In one embodiment, the controller circuit generates a micro-current I through the user between the first electrode and the second electrode at a first micro-current amplitude (or frequency, duty cycle, waveform shape, etc.) when the impedance characteristic is within a first impedance range, and at a second micro-current amplitude (or frequency, duty cycle, waveform shape, etc.) when the predetermined impedance characteristic is within a second impedance range. In this manner, the amplitude of the micro-current I may be adjusted depending on the type of oral care implement226 that is detected. It should be understood that thecontroller circuit104 may generate the micro-current I through the user at additional micro-current amplitudes when the impedance is within one or more additional impedance ranges.
• The type of oral care implement may also affect the vibratory motion of the oral care implement as controlled by thecontrol circuit104. Thecontroller circuit104 may provide a first signal to the vibratingactuator122 when the impedance is within the first impedance range such that the vibratingactuator122 vibrates at a first vibration frequency and/or a first vibration amplitude. Similarly, thecontroller circuit104 may provide a second signal to the vibrating actuator when the impedance is within the second impedance range such that the vibratingactuator122 vibrates at a second vibration frequency and/or second vibration amplitude. Additional vibration modes corresponding to additional impedance ranges may be provided.
• It should be understood that some operational modes may provide for application of micro-current I only, while other operational modes may provide for vibratory motion of the oral care implement226 only. Yet other operational modes may provide for various combinations of micro-current I application and vibratory motion of the oral care implement226.
• Referring now toFIGS. 10 and 10A, anelectric toothbrush320 capable of automatically detecting a type of oral care implement326 by electric resonant frequency detection (or electric anti-resonant frequency, in alternative embodiments) is schematically illustrated. In this embodiment, each type of oral care implement326 (e.g., “regular” toothbrush head, “sensitive” toothbrush head, tongue massager, and the like) has a predefined electric resonant frequency. Thecontroller circuit104 may be configured to probe the oral care implement326 to determine if it is an authorized oral care implement and, if so, the type of oral care implement. Thecontroller circuit104 may control theelectric toothbrush320 according to an operational mode corresponding to the type of oral care implement326 that is detected.
• Different oral care implements326 may be designed with different electric resonance frequencies. The different oral care implements326 may be recognized and the appropriate maximum micro-current amplitudes (and/or vibratory motion of the brush head portion) can be applied to achieve an optimal cleaning result. In one embodiment, the electric resonant frequency of the oral care implement326 is established by an electro-active polymer within the oral care implement326. For example, an electro-active polymer370, such as a piezoelectric active polymer, may be provided within at least a portion of astem328 of the oral care implement326. The electro-active polymer370 within the oral care implement326 is designed such that the oral care implement326 has an electric resonant frequency (or an electric anti-resonant frequency) within a predetermined frequency range.
• FIG. 10A depicts anequivalent analog circuit380 of the electro-active polymer370, which has resistive, inductive and capacitive properties. To determine the electric resonant or anti-resonant frequency of the oral care implement326, the controller circuit104 (seeFIG. 3) generates an evaluation micro-current I_evalthrough the electrical circuit closed by the user's body B. The evaluation micro-current I_evalis swept across an evaluation frequency range. As an example and not a limitation, the electro-active polymer is chosen such that its impact on the impedance of the oral care implement326 is above 10 MHz. Accordingly, the evaluation frequency range should be proximate 10 MHz in this example. It is noted that the tooth/body impact on impedance is in the range below 1 MHz. Accordingly, the resonant peaks of the electro-active polymer circuit should be in a frequency range that is not influenced by human body impedance.
• Thecontroller circuit104 detects the impedance Z of the electrical circuit as the evaluation micro-current I_evalis swept across the evaluation frequency range.FIG. 11 depicts exemplary impedance response of two exemplary piezoelectric polymer oral care implements326 as a function of frequency f. Curve Ref₁corresponds to a first oral care implement refill, and curve Ref₂corresponds to a second oral care implement refill. “Refill” means a replacement oral care implement. As shown inFIG. 11, the first oral care implement refill has an electric resonant frequency f_R1and an electric anti-resonant frequency f_AR1. The second oral care implement refill has an electric resonant frequency f_R2and an electric anti-resonant frequency f_AR2. The electric resonant and anti-resonant frequencies of the first oral care implement refill are less than the electric resonant and anti-resonant frequencies of the second oral care implement refill. Because the electric resonant and anti-resonant frequencies are different, the type of oral care implement may be detected.
• Thecontroller circuit104 may compare the electric resonant frequency or the anti-resonant frequency with a plurality of frequency ranges. If the electric resonant frequency or the anti-resonant frequency is within one of the plurality of frequency ranges, thecontroller circuit104 may generate a micro-current I (and/or provide a particular vibratory motion) through the user in accordance with the type of oral care implement326 associated with that particular frequency range. For example, thecontroller circuit104 may generate a micro-current I through the user between the first electrode and the second electrode at a first micro-current amplitude when the detected resonant electrical frequency is within a first frequency range, and at a second micro-current amplitude when the detected resonant electrical frequency is within a second frequency range. Additional micro-current amplitude ranges (as well as other micro-current properties, such as duty cycle, frequency, etc.) corresponding to additional operational modes may also be provided.
• It should now be understood that embodiments described herein enable increased ionic micro-current levels in iontophoresis applications without imparting unpleasant sensations in the user or patient by ramping the micro-current from a start current to an end current over a rise time. In oral care applications, the ramped micro-current reduces the voltage drop in the oral cavity, and allows for current levels of greater than 100 μA. The ramping of micro-current techniques described herein may be implemented in any number of iontophoresis applications.
• The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
• Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
• While particular embodiments of the present invention have been illustrated and described, it would be understood to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims (20)

1. An oral care device comprising:

a handle portion;

an oral care implement coupled to the handle portion, the oral care implement comprising a brush head portion comprising brush filaments;

a first electrode located in the brush head portion and operable to be in electrical contact with an oral cavity of a user;

a second electrode located in the handle portion and operable to be in electrical contact with a hand of the user;

a power source providing a voltage potential between the first electrode and the second electrode;

a controller circuit in electrical communication with the first electrode, the second electrode, and the power source, wherein:

electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode;

the controller circuit controls a micro-current I that passes through the user between the first electrode and the second electrode, and determines an impedance of the electrical circuit based on the micro-current I;

the controller circuit controls the oral care device to operate in a first operational mode when the impedance is within a first impedance range; and

the controller circuit controls the oral care device to operate in a second operational mode when the impedance is within a second impedance range.

2. The oral care device as claimed inclaim 1, wherein the first impedance range is indicative of a tooth of the user, the second impedance range is indicative of a soft tissue region of the user, one or more of the additional impedance ranges is indicative of a tongue of the user, and one or more of the additional impedance ranges is indicative of a gingival margin of the user.

3. The oral care device as claimed inclaim 2, wherein the one or more additional impedance ranges are indicative of a position of the brush head portion on the tooth of the user, or indicative of the brush head portion positioned on the tongue of the user.

4. The oral care device as claimed inclaim 1, wherein the first impedance range is indicative of a hard tissue of the user and the second impedance range is indicative of a soft tissue region of the user.

5. The oral care device as claimed inclaim 1, wherein upon a completion of the electrical circuit, the controller circuit generates a ramped micro-current I_rampedthrough the user between the first electrode and the second electrode that increases from a start current I_startto an end current I_endover a rise time I_rise.

6. The oral care device as claimed inclaim 1, further comprising a vibrating actuator operable to vibrate at a vibration amplitude at a first vibration amplitude when the oral care device operates in the first operational mode, and at a second vibration amplitude when the oral care device operates in the second operational mode.

7. The oral care device as claimed inclaim 1, wherein the first operational mode further comprises applying the micro-current I through the user a first micro-current amplitude, and the second operational mode further comprises applying the micro-current I through the user at a second micro-current amplitude.

8. The oral care device as claimed inclaim 1, wherein the first electrode comprises one or more conductive brush filaments positioned proximate to the brush filaments.

9. An oral care device comprising:

a handle portion;

an oral care implement coupled to the handle portion, the oral care implement comprising a brush head portion comprising brush filaments;

a first electrode located in the brush head portion and operable to be in electrical contact with a location within an oral cavity of a user;

a second electrode located in the handle portion and operable to be in electrical contact with a hand of the user;

a power source providing a voltage potential between the first electrode and the second electrode; and

a controller circuit in electrical communication with the first electrode, the second electrode, and the power source, wherein:

electrical contact of the second electrode at the hand of the user and electrical contact of the first electrode at the location within the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode;

upon a completion of the electrical circuit, the controller circuit generates a micro-current I through the user between the first electrode and the second electrode such that the micro-current I enhances delivery of chemical actives to the location within the oral cavity of the user, the chemical actives present in an oral care substance located within the oral cavity of the user; and

the controller circuit calculates an amount of chemical actives delivered to the location within the oral cavity of the user at a time t based at least in part on a value of the micro-current I through the user, the oral care substance, and a polarity of the second electrode with respect to the first electrode.

10. The oral care device as claimed inclaim 9, further comprising an active delivery indicator communicatively coupled to the controller circuit, wherein:

the controller circuit provides a signal to the active delivery indicator corresponding to the amount of chemical actives delivered to the location within the oral cavity of the user at the time t; and

the active delivery indicator provides an indication of the amount of chemical actives delivered to the location within the oral cavity at the time t.

11. The oral care device as claimed inclaim 10, wherein:

the active delivery indicator comprises a housing and a graphical display that is separate from the handle portion and the oral care implement; and

the signal provided by the controller circuit to the active delivery indicator comprises a wireless signal.

12. The oral care device as claimed inclaim 9, wherein the controller circuit is configured to receive a code corresponding to an amount of one or more types of chemical actives that is present in the oral care substance.

13. The oral care device as claimed inclaim 9, further comprising a memory component electrically coupled to the controller circuit, wherein the controller circuit sends a signal to the memory component such that the amount of chemical actives delivered to the location within the oral cavity of the user at time t is stored within the memory component.

14. The oral care device as claimed inclaim 9, wherein the chemical actives are anions when the polarity of the first electrode and the second electrode are such that the oral care device operates in a cathodic state, and the chemical actives are cations when the polarity of the first electrode and the second electrode are such that the oral care device operates in an anodic state.

15. An oral care device comprising:

a handle portion;

an oral care implement coupled to the handle portion, the oral care implement comprising a brush head portion comprising brush filaments;

a first electrode located in the brush head portion and operable to be in electrical contact with a hard tissue within an oral cavity of a user;

a second electrode located in the handle portion and operable to be in electrical contact with a hand of the user;

a power source providing a voltage potential between the first electrode and the second electrode;

a controller circuit in electrical communication with the first electrode, the second electrode, and the power source, wherein:

electrical contact of the second electrode with the hand of the user and electrical contact of the first electrode with the hard tissue within the oral cavity of the user completes an electrical circuit between the first electrode and the second electrode;

upon a completion of the electrical circuit, the controller circuit generates a substantially sinusoidal micro-current I through the user between the hand of the user and the hard tissue within the oral cavity of the user at a frequency that varies across a frequency range;

the controller circuit measures a fundamental-harmonic component of a response of the substantially sinusoidal micro-current I through the electric circuit, and calculates a system impedance based at least in part on the fundamental-harmonic component and

the controller circuit compares the system impedance with a plurality of impedance values corresponding to a plurality of health statuses corresponding to one or more teeth, selects a closest impedance value to the system impedance, and stores a selected health status corresponding to the closest impedance value.

16. The oral care device as claimed inclaim 15, wherein individual health statuses of the plurality of health statuses indicate a level of tooth decay.

17. The oral care device as claimed inclaim 15, wherein the controller circuit compares the selected health status or the system impedance with one or more previously selected health statuses or previously measured system impedances, respectively, to monitor a health of the hard tissue within the oral cavity of the user over time.

18. The oral care device as claimed inclaim 15, wherein the first electrode comprises one or more conductive brush filaments positioned proximate to the brush filaments.

19. The oral care device as claimed inclaim 18, wherein the one or more conductive brush filaments comprise an electrically conductive material within a polymer.

20. The oral care device as claimed inclaim 15, further comprising a user interface, wherein the user interface displays a representation of the selected health status stored by the controller circuit.

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