Patent Publication Number: US-2013239346-A1

Title: Self-powered manual toothbrush with sensors

Description:
TECHNICAL FIELD 
     The disclosed technology relates to the field of toothbrush devices, and more particularly to self-powered manual toothbrushes having at least one sensing mechanism and an indicator such as a display device. 
     BACKGROUND 
     Despite many notable advances in toothbrush technologies over the years, current toothbrushes continue to have a number of shortcomings. For example, while certain electric-powered toothbrushes, e.g., the Oral-B 1000 Professional Care 1000 Electric Toothbrush, may sense pressure being applied thereto during brushing, such devices merely determine whether the pressure is excessive and, if so, shut off the electric drive to the bristles to prevent tooth damage. 
     Other electric toothbrushes, e.g., the Oral-B Triumph with SmartGuide Professional Care 9910 Electric Toothbrush, may provide a visual indication of the time spent brushing but such brushes require powered rotating bristles and thus tend to be rather expensive, e.g., upwards of $100.00 to $200.00. 
     Further, current manual toothbrushes do not provide users with any type of feedback as to how long brushing has occurred or how well the brushing has been done by the user. 
     Accordingly, there remains a need for improved toothbrushes and toothbrush assemblies. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example of a toothbrush assembly in accordance with certain embodiments of the disclosed technology. 
         FIG. 2  is a functional block diagram illustrating an example of a toothbrush assembly in accordance with certain embodiments of the disclosed technology. 
         FIG. 3  is a schematic diagram illustrating a first example of toothbrush assembly circuitry in accordance with certain embodiments of the disclosed technology. 
         FIG. 4  is a schematic diagram illustrating a second example of toothbrush assembly circuitry in accordance with certain embodiments of the disclosed technology. 
         FIG. 5  is a schematic diagram illustrating a third example of toothbrush assembly circuitry in accordance with certain embodiments of the disclosed technology. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the disclosed technology generally include an indicator that is capable of resetting its state with time combined with the use of pressure-sensing and/or motion-sensing mechanisms and an energy scavenging mechanism to enable a manual toothbrush to provide a user with certain information such as a visual and/or audible indication that “correct” toothbrushing is either occurring or has been completed, for example. The information may be based on electric signals that, during a teeth cleaning session, may be generated by any of a number of mechanisms such as an energy scavenging mechanism that relies on the motion or flexing of the toothbrush itself. 
     In certain embodiments, the electrical signals may be generated from piezoelectric sensors attached to or embedded in the toothbrush body itself, e.g., in the neck region, where the most flexing typically occurs during a teeth cleaning session. Alternatively, the sensors may be fabricated into the bristles themselves as the bristles tend to flex more than any other part of the toothbrush during a teeth cleaning session. 
     The pressure of the toothbrush bristles against the user&#39;s teeth generally causes the neck of the toothbrush body to flex slightly, creating a transient voltage on the piezoelectric element or elements. Such a voltage transient may be fed to a circuit comprising a variety of active and passive components. This circuit may transform the transient voltages into a useful measure of toothbrush use by way of a simple counting of the voltage transients or an integration of counts and/or total current generated over the time taken to complete the brushing exercise, for example. 
     In other embodiments, the electrical signals may be generated from a kinetic energy source such as a coil in which a magnet is free to move. In such embodiments, the coil/magnet combination may be embedded within the toothbrush itself and may be aligned to only generate sufficient electrical current when the brush movement is in a certain direction, e.g., perpendicular to the toothbrush axis. The signals indicating correct brushing motions would be fed to a circuit similar to that described above and used to indicate progress in and/or completion of the brushing activity. 
     The indicator may progressively provide a visual and/or audible indication of either a certain threshold or endpoint, e.g., the number and/or direction of brush strokes, being met or exceeded or a series of intermediate criteria being met, e.g. by way of a multi-element electrophoretic display such as a segmented bar that can be activated segment-by-segment as the number of brush strokes passes certain predetermined values. For example, a ten-element linear bar may be implemented such that the cumulative transient count increments each segment of the linear bar as the number of counts exceeds multiples of ten. 
     In certain embodiments, the circuit and/or indicator may be reset to their prior, e.g., original, state by way of a delay circuit or by a manual reset switch fabricated as part of the circuit, for example. This may be advantageous in embodiments where the indicator only needs to display for a short time, for example. 
     Direct printing of circuit elements and/or other pertinent components into or onto certain portions or parts of a toothbrush assembly may facilitate low manufacturing costs and, thus, low retail prices of the toothbrush assembly. This may essentially result in the establishment of a new product category that fits well between manual toothbrushes and electric toothbrushes, in terms of both price and functionality. This is particularly desirable for manual toothbrushes, which are typically used by a user for only a month or so and then discarded. 
     Direct printing of components may also facilitate low-to-very low power consumption by the toothbrush assembly as a whole or any of the individual components. Alternatively, fabrication of conventional silicon circuits and subsequent embedding in or attachment to the toothbrush body may be used. 
       FIG. 1  illustrates an example of a toothbrush assembly  100  in accordance with certain embodiments of the disclosed technology. In the example, the toothbrush assembly  100  includes a plurality of bristles  102  and a toothbrush body  104 . The plurality of bristles  102  may include any of a number of types and arrangements of standard toothbrush bristles. The toothbrush body  104  is coupled with the plurality of bristles  102 . 
     The toothbrush assembly  100  also includes a sensing mechanism  106  that is configured to provide an electric signal responsive to a user using the toothbrush assembly  100  during a teeth cleaning session. While the example shows the sensing mechanism  106  as being part of or incorporated with the toothbrush body  104  and fully separate from the plurality of bristles  102 , it should be noted that the sensing mechanism  106  may be located at other locations or positions with respect to the toothbrush body  104 , the plurality of bristles  102 , or both in other embodiments. 
     In the illustrated example, the toothbrush assembly  100  also includes circuitry  108  that is formed in connection with the toothbrush body  104 . While the circuitry  108  may be visible to a user of the toothbrush assembly  100  in certain embodiments, it may be fully encased in or enclosed by the toothbrush body  104  in other embodiments. Standard printing techniques and materials may be used to create the circuitry  108  on or within a certain portion, area, or component of the toothbrush assembly  100  that is more flexible than other portions, areas or components, for example. The circuitry  108  may include multiple sub-circuits that may be generated or formed separately from each other and subsequently combined with each other to form the circuitry  108 . 
     In certain embodiments, the circuitry  108  may include a small circuit fabricated by conventional lithographic techniques onto a flexible printed circuit board (PCB) that could be subsequently laminated or otherwise connected to charge generators, for example. Certain implementations of the circuitry  108  are described below with regard to  FIGS. 3-5 . 
     The toothbrush assembly  100  of  FIG. 1  also includes an indicator  110  configured to provide information to a user using the toothbrush assembly  100  during a teeth cleaning session. This information may be based at least in part on the electric signal provided by the sensing mechanism  106  to the indicator  110 . In certain embodiments, the indicator  110  may provide the information to the user dynamically. 
     The information provided to the user may include visual information, audible information, or both. For example, visual information may correspond to how many strokes the user has made with the toothbrush assembly  100  during the teeth cleaning session, how many additional strokes the user should make with the toothbrush assembly  100  during the teeth cleaning session, or both. Such visual information may include a number, a bar chart, a line, or any combination thereof In certain embodiments, the indicator  110  may include a line of 4-10 individual electrophoretic, e.g. e-ink, display elements that total 1-2 inches in length. 
     In certain embodiments, the information provided to the user may include information pertaining to how long the user has been using the toothbrush assembly  100  during the teeth cleaning session. Alternatively or in addition thereto, the information provided to the user may include information pertaining to how much longer the user should use the toothbrush assembly  100  during the teeth cleaning session. Alternatively or in addition thereto, the information provided to the user may include information pertaining to how many strokes the user has made with the toothbrush assembly  100  during the teeth cleaning session. Alternatively or in addition thereto, the information provided to the user may include information pertaining to how many additional strokes the user should make with the toothbrush assembly  100  during the teeth cleaning session. Alternatively or in addition thereto, the information provided to the user may include information pertaining to whether the user is using the toothbrush assembly  100  properly during the particular teeth session. 
     The indicator  110  may include a transient display device or a persistent display device. For example, the indicator  110  may include an electrophoretic display device, an electrochromic display device, or both. In embodiments where the indicator  110  includes an electrophoretic display device, the electrophoretic display device may include a plurality of bars corresponding to a number of brush strokes the user has made or has yet to make with the toothbrush assembly  100 , for example. 
     In certain embodiments, the sensing mechanism  106  includes at least one piezoelectric charge generator. Alternatively or in addition thereto, the sensing mechanism  106  includes a kinetic energy assembly. Such a kinetic energy assembly may include a coil and a magnet configured to move within the coil, for example. In these embodiments, the information presented to the user by the indicator  110  may include information pertaining to whether the user is using the toothbrush assembly  100  properly during the teeth cleaning session based at least in part on movement of the magnet within the coil. 
     In certain embodiments, the sensing mechanism  106  may be coupled with the plurality of bristles  102 . In such embodiments, the sensing mechanism  106  may be configured to provide the electric signal to the indicator  110  responsive to an application of pressure to the sensing mechanism  106 . 
     In alternative embodiments, the plurality of bristles  102  may include the sensing mechanism  106 . In such embodiments, the sensing mechanism  106  may be configured to provide the electric signal to the indicator  110  responsive to an application of pressure to the plurality of bristles  102  such as would occur when the user brushes his or her teeth, thus causing his or her teeth to exert said pressure on the plurality of bristles  102 . 
       FIG. 2  is a functional block diagram illustrating an example of a toothbrush assembly  200  in accordance with certain embodiments of the disclosed technology. In the example, the toothbrush assembly  200  includes a sensing mechanism  202 , such as the sensing mechanism  106  of  FIG. 1 . 
     The toothbrush assembly  200  of  FIG. 2  also includes an indicator  204 , such as the indicator  110  of  FIG. 1 . In certain embodiments, the indicator  204  may be configured to operate independent of any power supply external to the toothbrush assembly  200 . In such embodiments, an energy scavenging mechanism  206  may be used to provide operating power to the indicator  204  responsive to the user using the toothbrush assembly  200  during a teeth cleaning session. 
     The energy scavenging mechanism  206  may be attached to or embedded in a portion or area of the toothbrush assembly  200  that is responsive to the movement and/or pressure generated during a teeth cleaning session. In certain embodiments, the sensing mechanism  202  may include the energy scavenging mechanism  206 . The energy scavenging mechanism may be embedded within the toothbrush body of the toothbrush assembly  200 . 
     In certain embodiments, the energy scavenging mechanism  206  may include at least one strip of polyvinylidene fluoride (PVDF) or polymer alternative, e.g., polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), configured to generate an electric charge responsive to movement of the toothbrush assembly  200 . The one or more strips of PVDF may be printed on, embedded in, or laminated to a portion, area, or component of the toothbrush assembly  200  that flexes during a teeth cleaning session, for example. Alternatively or in addition thereto, the energy scavenging mechanism  206  may include a photovoltaic (PV) component. In certain embodiments including a piezoelectric charge generator, for example, a PV component may be used to provide switching current if the piezoelectric element is unable to provide enough operating power for the indicator  204 . In such embodiments, the piezoelectric may be used solely as a sensing device. 
     In certain embodiments, a signal conditioning mechanism  208  may be used to condition the electric signal provided to the indicator  204  by the sensing mechanism  202 . In such embodiments, the energy scavenging mechanism  206  may be used to provide operating power to the signal conditioning mechanism  208 . 
     In certain embodiments, an indicator reset mechanism  210  may be used to reset the indicator  204  responsive to a termination of the teeth cleaning session. For example, the indicator reset mechanism  210  may be used to reset the state of the indicator  204  to its original value using a delay circuit, a mechanical reset mechanism, or a combination thereof. The indicator reset mechanism  210  may include a circuit formed in connection with the toothbrush body of the toothbrush assembly  200 . In these embodiments, the energy scavenging mechanism  206  may be used to provide operating power to the indicator reset mechanism  210 . 
     It should be noted that virtually any of the individually illustrated components of the toothbrush assembly  200  may be combined in a single physical element or combination of elements. For example, the sensing mechanism  202  and the energy scavenging mechanism  206  may be implemented as a single component or combination of components. Alternatively or in addition thereto, the indicator  204  and the indicator reset mechanism  210  may be implemented as a single component or combination of components. 
     It should also be noted that the illustrated connections between the energy scavenging mechanism  206  and the other components do not necessarily reflect physical connections. For example, operating power may be routed from the signal conditioning mechanism  208  to the indicator  204 , the indicator reset mechanism  210 , or both rather than via separate and direct power supplying connections between the energy scavenging mechanism  206  and either or both of the indicator  204  and indicator reset mechanism  210 . 
     In certain embodiments, the starting state and/or resting state calls for all elements of the indicator, e.g., display device, to be in their “off” state, e.g., as denoted by the color white or the number zero. As the user begins to brush his or her teeth, each flexing of the toothbrush, e.g., the bristles, generates an electrical charge, e.g., in piezoelectric charge generators or in a coil/magnet assembly, which may flow through one or more diodes and onto the top electrode of a display element, for example, see, e.g.,  FIG. 3 , which is described below. 
       FIG. 3  is a schematic diagram illustrating a first example of toothbrush assembly circuitry  300  in accordance with certain embodiments of the disclosed technology. In the example, the circuitry  300  includes a ground  302 , a positive charge generator  304  in series with a first diode  312 , a negative charge generator  306  in series with a second diode  314 , two resistors  308  and  310 , a capacitor  316 , and a display element  320  such as either of the indicators  110  and  204  of  FIGS. 1 and 2 , respectively, for example. 
     In the example, the diodes  312  and  314  only allow charge movement in one direction, so the circuitry  300  essentially functions as a charge pump. Charge from the positive charge generator  304  may be fed via the first diode  312  to the display element  320 , e.g., indicator, that then changes from white to another color. For example, the first segment of the display element  320  may be green. Charge of the opposite sign from the negative charge generator  306  may be fed through the second diode  314 , stored on the capacitor  316 , and then bled through the resistor  310  to the same side of the display element. The other resistor  308  is connected directly across the display element  320  to the ground  302 . 
     The characteristics of the display element  320  may be such that there is hysteresis in the response to applied voltage. For example, the display element  320  may include an electrophoretic medium such as materials produced by E-ink Holdings. The values of the resistors  308  and  310  and the capacitor  316  relative to the capacitor formed by the display element  320  may determine the rate of change of the voltage across the display element  320 . As the voltage across the display element  320  slowly decays, changes sign, and then crosses a threshold for the display element  320  to change color in the opposite direction, the display element  320  may revert to its uncolored state, for example. The values of the resistors  308  and  310  and the capacitor  316  may be adjusted during the design process to create a certain reset time. In certain embodiments, this reset time may be on the order of  30  minutes to one hour. 
       FIG. 4  is a schematic diagram illustrating a second example of toothbrush assembly circuitry  400  in accordance with certain embodiments of the disclosed technology. The circuitry  400  may be used, for example, in certain implementations where a display medium requires a faster rate of change in order to switch state than would be possible with a simple resistor/capacitor (R/C) combination. In the illustrated example, the circuitry  400  includes a ground  402 , a first charge source  404  such as a piezoelectric element or battery with mechanical switch in series with a diode  416 , and a second charge source  406  coupled with two diodes  412  and  414  and a first capacitor  408 . 
     The circuitry  400  also includes a switching component  410  such as a thin film transistor (TFT) or other switching mechanism coupled with each of the three diodes  412 ,  414 , and  416 , the first capacitor  408  and a second capacitor  420 , a resistor  418  and a display element  422  such as either of the indicators  110  and  204  of  FIGS. 1 and 2 , respectively, for example. The circuitry  400  of  FIG. 4  may facilitate switching capability such that transitions to opposite color states are more sudden. The timing of the switching may be controlled by the combination of the second capacitor  420  and the resistor  418 , for example. 
       FIG. 5  is a schematic diagram illustrating a third example of toothbrush assembly circuitry  500  in accordance with certain embodiments of the disclosed technology. Such embodiments may allow for independent tailoring of the size of each of a number of multiple charge sources. In the illustrated example, the circuitry  500  includes a ground  502 , a first charge source  504  such as a piezoelectric element or battery with mechanical switch in series with a diode  512 , a second charge source  506  coupled with a diode  510  and a first capacitor  516 , and a resistor  508 . The circuitry  500  also includes a second capacitor  514  and a display element  518  such as either of the indicators  110  and  204  of  FIGS. 1 and 2 , respectively, for example. 
     In embodiments where the values of the first and second capacitors  516  and  514  are at least substantially identical, the initial value of the display element voltage V x  will be the voltage of the first charge source  504  and the final value of the display element voltage V x  will be the difference between the voltage of the first charge source  504  and the voltage of the second charge source  506 . Eventually, when all charge has leaked away, the value of the display element voltage V x  will be zero. In these embodiments, the first and second charge sources  504  and  506  generally provide different voltage levels, e.g., different voltage amplitudes. 
     In embodiments where the value of the second capacitor  514  is less than the value of the first capacitor  516 , the initial value of the display element voltage V x  will be the voltage of the first charge source  504  and the final value of the display element voltage V x  will be the difference between the voltage of the first charge source  504  and the product of the voltage of the second charge source  506  and (C 1 /C 2 ) where C 1  is the value of the first capacitor  516  and C 2  is the value of the second capacitor  514 . Eventually, when all charge has leaked away, the value of the display element voltage V x  will be zero. In these embodiments, the first and second charge sources  504  and  506  may provide voltage levels that are at least substantially similar to each other. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.