FORCE TRIGGER LEVEL

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to power toothbrushes, and, in particular, to a power toothbrush having force sensing capability and automated setting of force trigger level based on brushing mode.

2. Description of the Related Art

In general, power toothbrushes for cleaning teeth, including removal of plaque, are well known. Typically, power toothbrushes rely on a set of bristles which are attached to a bristle mounting plate, which in turn is moved by a driver mechanism to scrub the surfaces of teeth. Such toothbrushes, which rely on scrubbing action of the bristles for actual cleaning, typically require some amount of pressure to be exerted by the user against the teeth to accommodate differences in the various shapes and spacing of the teeth and to effectively clean the teeth. Such pressure, however, if too hard, may result in an abrasion effect, including damage to both the soft and hard tissues in the mouth. This is, of course, undesirable.

Some power toothbrushes contain timers and force sensors to help people achieve better brushing time and force levels. Currently, the force sensor in such power toothbrushes is set to trigger an alarm at a fixed level that will correct particularly heavy brushers (>300g force, i.e. >3N). However, once a user learns to stay below that trigger level, they are not coached to improve further. Thus, the user could be continuing brushing at 2.9N force, whereas the optimal typical brushing force is in the region of 1- 1.5N. Further, if the user has some dental issues, such as sensitive teeth caused by gum recession, which is widely prevalent especially amongst older users, the optimum brushing force may be even lower to prevent erosion of the exposed dentine roots, which are far softer than the crown enamel.

Moreover, some power toothbrushes have multiple modes of operation which typically may be selected by a user via control buttons on the body of the toothbrush. Each mode will typically have a different brushing action and/or amplitude. For instance, a normal mode might have a medium level brushing action and/or amplitude particularly adapted for normal brushing/cleansing of the teeth, while a sensitive mode might have an action which has less brush movement and/or moves at a slower rate. Other modes of operation could be a massage mode in which the brush has a pulsing action or a whitening mode that has a higher level brushing action and/or amplitude and/or rate suited for tooth polishing.

SUMMARY OF THE INVENTION

In one embodiment, a power toothbrush is provided that includes a brushhead, a sensor for measuring a force parameter indicative of a force exerted by the brushhead, and a handle portion having a motor for driving the brushhead and a processing unit structured to control operation of the power toothbrush. The processing unit is further structured to: (i) receive information identifying a brushing mode for the toothbrush, (ii) establish a force trigger level for the power toothbrush, wherein the force trigger level corresponds to the brushing mode, (iii) cause the motor to drive the brushhead in accordance with one or more parameters associated with the brushing mode, (iv) receive the force parameter, and (v) determine whether to cause an alarm to be triggered based upon the force trigger level and the force parameter.

In another embodiment, a method of operating a power toothbrush having a brushhead coupled to a handle portion of the power toothbrush is provided. The method includes receiving information identifying a brushing mode for the power toothbrush, establishing a force trigger level for the power toothbrush, wherein the force trigger level corresponds to the brushing mode, causing a motor provided in the handle portion to drive the brushhead in accordance with one or more parameters associated with the brushing mode, receiving a force parameter measured by a sensor included with the power toothbrush, and determining whether to cause an alarm to be triggered based upon the force trigger level and the force parameter.

In another embodiment, a power toothbrush is provided that includes a brushhead, a sensor for measuring a force parameter indicative of a force exerted by the brushhead, and a handle portion having a motor for driving the brushhead and a processing unit structured to control operation of the power toothbrush. The processing unit is structured to: (i) receive information establishing a force trigger level for the power toothbrush, wherein the force trigger level corresponds to a number of brushing modes for the toothbrush, (ii) cause the motor to drive the brushhead in accordance with one or more parameters associated with the brushing mode, (iii) receive the force parameter, and (iv) determine whether to cause an alarm to be triggered based upon the force trigger level and the force parameter.

In yet another embodiment, a power toothbrush is provided that includes a brushhead, a sensor for measuring a force parameter indicative of a force exerted by the brushhead, and a handle portion having a motor for driving the brushhead and a processing unit structured to control operation of the power toothbrush. The processing unit is structured to: (i) receive information identifying a current position in a mouth of a user where the brushhead is being used, (ii) establish a force trigger level and a brushing mode for the power toothbrush based on the current position, (iii) cause the motor to drive the brushhead in accordance with one or more parameters associated with the brushing mode, (iv) receive the force parameter, and (v) determine whether to cause an alarm to be triggered based upon the force trigger level and the force parameter.

These and other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded schematic view of a toothbrush according to an exemplary embodiment of the present invention;

FIG. 2 is a schematic diagram of the toothbrush of FIG. 1; FIG. 3 is a flowchart illustrating operation of the toothbrush of FIGS. 1 and 2 according to one exemplary embodiment; and

FIG. 4 is a flowchart illustrating operation of the toothbrush of FIGS. 1 and 2 according to another, alternative exemplary embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

As used herein, the singular form of "a", "an", and "the" include plural references unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are "coupled" shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. As used herein, "directly coupled" means that two elements are directly in contact with each other. As used herein, "fixedly coupled" or "fixed" means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other.

As used herein, the word "unitary" means a component is created as a single piece or unit. That is, a component that includes pieces that are created separately and then coupled together as a unit is not a "unitary" component or body. As employed herein, the statement that two or more parts or components "engage" one another shall mean that the parts exert a force against one another either directly or through one or more intermediate parts or components. As employed herein, the term "number" shall mean one or an integer greater than one (i.e., a plurality).

As used herein, the term "force parameter" shall mean a measurement parameter that is indicative of an applied force, such as, without limitation, directly measured force, directly measured pressure, and a force value derived from a directly measured pressure.

As used herein, the term "brushing mode" shall refer to a specific mode of operation of a power toothbrush that has associated with it at least one of: (i) in amplitude of operation the power toothbrush, (ii) a frequency of operation of the power toothbrush, and (iii) a time of operation of the power toothbrush. Directional phrases used herein, such as, for example and without limitation, top, bottom, left, right, upper, lower, front, back, and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.

FIG. 1 is an exploded view of and FIG. 2 is a schematic diagram of a power toothbrush 10 according to an exemplary embodiment of the present invention. Toothbrush 10 includes a handle portion 12 and a DC motor 14 which is powered by a battery 16. Motor 14 provides the driving action for a brushhead 18A, which in turn is removably mounted on a motor driveshaft 22. It should be understood, however, that various alternative driving action arrangements may be used in a power toothbrush which incorporates the concept disclosed herein. The illustration of a DC motor in the exemplary embodiment is only one of several possible motor systems.

Brushhead 18A includes a set of bristles 24A mounted on a bristle back member 25 which together define the bristle portion of brushhead 18 A. Bristles 24A accomplish cleaning through an oscillatory action provided to brushhead 18A by motor 14. The operation of motor 14 is controlled by a processing unit 26, which is a common component of power toothbrushes. Processing unit 26 may be, for example and without limitation, a microprocessor, a microcontroller, or any other suitable processing device and may include a suitable memory for storing routines executed by processing unit 26. As seen in FIGS. 1 and 2, toothbrush 10 may further include a number of similarly structured alternative brushheads 18, labeled 18B and 18C, each of which may be coupled to driveshaft 22 as desired. For example, and without limitation, brushheads 18A, 18B and 18C may be used by the same user, each one for a different purpose. For instance, brushhead 18 A may be structured for normal brushing, brushhead 18B may be structured for gentle brushing, and brushhead 18C may be structured for tooth whitening, with the user selecting the appropriate brushhead 18A, 18B, 18C and connecting it to driveshaft 22 as appropriate. Alternatively, brushheads 18 A, 18B and 18C may be used by different users that share handle portion 12. In addition, while two such alternative brushheads 18 are shown in the illustrated embodiment, it will be appreciated that more or less alternative brushheads may also be employed within the scope of the disclosed concept.

As seen in FIGS. 1 and 2, handle portion 12 includes a sensor element 28 structured to measure the force being applied by a user to his or her teeth by brushhead 18A, 18B, 18C in a direction that is generally perpendicular to the longitudinal axis of toothbrush 10. In the exemplary embodiment, sensor element 28 is located adjacent to motor 14 and is structured to measure the force on driveshaft 22. Alternatively, each brushhead 18A, 18B, 18C may include a sensor element 28 structured to be operatively coupled to processing unit 26 provided in handle portion 12 when the brushhead 18 A, 18B, 18C is coupled to handle portion 12 to measure the force being applied by a user to his or her teeth by brushhead 18 A, 18B, 18C in a direction that is generally perpendicular to the longitudinal axis of toothbrush 10. As will be appreciated, the former configuration wherein sensor element 28 is located within handle portion 12 will help to keep the cost of brushheads 18A, 18B, 18C down and will avoid interconnection issues across the pluggable interface between brushheads 18A, 18B, 18C and handle portion 12. In either configuration, sensor element 28 may be any of a number of known or hereafter developed suitable sensing devices for sensing the force exerted by brushhead 18A, 18B, 18C. Various pressure and force sensors (i.e., force parameter sensors) are known which measure brushing force parameters in different ways, including both mechanical and electrical sensors. Some sensors measure pressure while others measure actual force. Force sensors are generally desirable over pressure sensors because pressure sensors are sensitive to the size of the loaded member (the brushhead) pushing against the sensor and/or the relative positions of the loaded member and the sensor. Pressure sensors can, however, be converted to force sensors by including a shaped protrusion (bump) of a selected area on the sensor to significantly reduce, if not eliminate, the sensitivity of the sensing system to size, shape and/or position of the loaded member (which can in fact be flat). Some sensors use a piezoelectric device to measure the rate of deflection of the sensor and provide velocity information concerning movement of the member, rather than force or pressure information. Still other sensors use strain gauges, some of which incorporate temperature compensation elements. In addition, there are sensors which make use of particular materials which include a characteristic, such as electrical resistance, which changes upon application of pressure or force over a given range.

The measured force value generated by sensor element 28 is provided to processing unit 26. Furthermore, as seen in FIGS. 1 and 2, handle portion 12 further includes an alarm mechanism 34 that is coupled to processing unit 26. Alarm mechanism 34 may be an audible alarm mechanism, such as a speaker, that is structured to generate an audible alarm under the control of processing unit 26. Alternatively, alarm mechanism 34 may be a visual alarm mechanism, such as one or more LEDs, that is/are structured to generate a visual alarm under the control of processing unit 26. In still another alternative embodiment, the alarm may be implemented by processing unit 26 modifying the motor drive mode of motor 14 to give a different sensation in the user's mouth, such as a lowered amplitude and/or a pulsing of the motor 14. Such an alarm mechanism may be more easily perceived by the user. According to an aspect of the disclosed concept, processing unit 26 is programmed to receive the measured force value generated by sensor element 28 and compare that value to a force trigger level that is stored by processing unit 26. If the measured force exceeds the stored force trigger level, processing unit 26 will cause an alarm to be generated, such as by alarm mechanism 34 or by modifying the motor drive as described herein. Thus, toothbrush 10 as just described is structured to provide feedback to the user when the brushing force being employed exceeds the stored force trigger level, which may be a level determined to be safe and appropriate for the user to use. Furthermore, processing unit 26 may store multiple force trigger levels for different applications, and according to an aspect of the disclosed concept, described in greater detail herein, the particular stored force trigger level that is employed at any particular time may be automatically selected by toothbrush 10.

In addition, as seen in FIG. 2, in the non-limiting exemplary embodiment, each brushhead 18A, 18B, 18C includes a recognition element 36 structured to enable the particular brushhead 18A, 18B, 18C to be recognized/identified by processing unit 26. In one non-limiting, particular exemplary embodiment, recognition element 36 is a readonly memory device which is programmed with a unique identification number for identifying the particular brushhead 18A, 18B, 18C in which it is provided. Moreover, in the illustrated exemplary embodiment, brushheads 18A, 18B, 18C and handle portion 12 both include electrically conductive elements 38 which provide a signal communications capability between memory element 36 and processing unit 26. This signal

communications capability enables the stored unique identification number of each brushhead 18A, 18B, 18C to be communicated to processing unit 26 when the brushhead 18A, 18B, 18C is attached to handle portion 12. In this manner, processing unit 26 is able to automatically identify which particular brushhead 18A, 18B, 18C is attached to it at any time. It will be appreciated, however, that the identification and signal

communications configuration shown in FIG. 2 is exemplary only and that alternative recognition elements 36 and mechanisms for transmitting identification information to processing unit 26, such as, without limitation, optical, mechanical, or FID

technologies, may also be employed within the scope of the disclosed concept.

According to one embodiment the disclosed concept, processing unit 26 stores certain information for each brushhead 18A, 18B, 18C in, for example, a lookup table format. In particular, in the exemplary embodiment, processing unit 26 stores the following information for each brushhead 18A, 18B, 18C: (i) a brushing mode to be used with the brushhead, and (ii) a force trigger level to be used with the brushhead. In addition, processing unit 26 is structured to cause toothbrush 10 to operate in a particular manner in connection with a selected brushing mode. For example, each brushing mode may have one or more of an amplitude of movement, a frequency of operation, and/or a timer value (i.e., the time after which an alarm will be sounded) associated with it, with toothbrush 10 being controlled to operate in accordance with the parameters of the selected brushing mode by processing unit 26. For example, and without limitation, the lookup table implemented in processing unit 26 may be as set forth in table 1 below.

18C Whitening (whitening 3N

amplitude)

Table 1

According to a particular embodiment of the disclosed concept, the parameters that are stored in connection with each brushhead 18A, 18B, 18C may be selectively determined by a user by inputting the information into processing unit 26. In the illustrated embodiment, a computing device 40, such as, without limitation, a smart phone or a tablet computer, may be provided with an application that enables wireless communication with processing unit 26 through a wireless communications module 42 provided within handle portion 12. For example, wireless communications module 42 may be a Bluetooth® module that enables Bluetooth® pairing between computing device 40 and handle portion 12. In this manner, a user may selectively input and or change any of the stored parameters that are associated with any of the brushheads 18A, 18B, 18C. In an alternative embodiment, computing device 40 may be a base station associated with toothbrush 10 (e.g. a charging station) that is provided with a suitable user interface and communications connection for inputting such information into processing unit 26.

FIG. 3 is a flowchart illustrating a method of operation of toothbrush 10 according to one exemplary embodiment wherein the brushing mode and force trigger level for toothbrush 10 are automatically selected based upon the particular brushhead 18A, 18B, 18C that is coupled to handle portion 12. The method begins at step 50, after a particular brushhead 18A, 18B, 18C has been attached to handle portion 12. At step 50, processing unit 26 identifies the particular brushhead 18A, 18B, 18C based upon the unique identification information that is received by processing unit 26 as described elsewhere herein. Next, at step 52, processing unit 26 consults the information stored therein (e.g. in the lookup table) to determine the brushing mode and the force trigger level that are to be used with the identified brushhead 18A, 18B, 18C. Then, at step 54, processing unit 26 sets the current brushing mode and force trigger level of toothbrush 10 based upon the identified brushhead determined at step 52. Thereafter, processing unit 26 will control operation of toothbrush 10 in accordance with the parameters of the set brushing mode and force trigger level. For example, using the sample lookup table provided in Table 1 above, if brushhead 18A is attached to handle portion 12, the brushing mode will be set to "normal" and the force trigger level will be set to 2N. As a result, when toothbrush 10 is activated, motor 14 will cause a moderate amplitude motion to be applied to brushhead 18, and will cause the force trigger level to be set to 2N. Thereafter, the force detected by sensor element 28 will be continuously monitored by processing unit 26, if the detected force exceeds the set force trigger level, processing unit 26 will cause an alarm to be generated by alarm mechanism 34 as described herein.

Thus, toothbrush 10 shown in FIGS. 1 and 2 and the method of operation shown in FIG. 3 provide a system wherein brushing mode and force trigger level for a power toothbrush are automatically adjusted and established based upon the particular brushhead that is attached to handle portion 12.

FIG. 4 is a flowchart illustrating a method of operation of toothbrush 10 according to another, alternative exemplary embodiment wherein the force trigger level for toothbrush 10 is automatically set based upon the brushing mode that is selected by a user. In this embodiment, the brushing mode for toothbrush 10 may be selected in any of a number of different ways. For example, a user may select the current brushing mode from a number of possible brushing modes using a user interface provided as part of handle portion 12. As another example, a user may select the current brushing mode using computing device 40 as described herein to communicate the selected current brushing mode to processing unit 26. As will be appreciated, this option may be implemented using an application designed for that purpose that is run on computing device 40. As will also be appreciated, in this particular embodiment, the automatic identification of the particular brushhead 18A, 18B, 18C that is coupled to handle portion 12 as described elsewhere herein is not required, and thus the brushheads 18 A, 18B, 18C in this embodiment need not be provided with a recognition element 36. In this embodiment, processing unit 26 stores a corresponding force trigger level for each possible brushing mode. As described elsewhere herein, this information may be stored by processing unit 26 using a suitable lookup table and may be selectively modified using, for example and without limitation, computing device 40.

Referring to FIG. 4, the method begins at step 60 wherein processing unit 26 determines the brushing mode that is selected by a user. As noted above, the brushing mode may be selected by a user using a user interface provided as part of handle portion 12 or by using computing device 40 to wirelessly communicate the brushing mode selection to processing unit 26. Next, at step 62, processing unit 26 determines the force trigger level that corresponds to the selected brushing mode. As described herein, in the exemplary embodiment, processing unit 26 makes this determination based upon a lookup table stored thereby. Then, at step 64, processing unit 26 sets the current brushing mode and force trigger level for toothbrush 10 based on the selected brushing mode and the determined force trigger level.

Thus, toothbrush 10 shown in FIGS. 1 and 2 and the method of operation shown in FIG. 4 provide a system wherein force trigger level for a power toothbrush is automatically adjusted and established based upon a user selected brushing mode.

In one particular implementation, toothbrush 10 may have only one mode (such as a low end model), or may have several modes, and the force trigger level for each of the modes may be set using a user interface provided as part of toothbrush 10 or an application designed for that purpose that is run on computing device 40. The particular force trigger level for each of the modes may be the same (common among all of the modes) or may be different for different modes.

In another particular implementation, toothbrush 10 may be provided with a number of sensing elements for determining and tracking the position in the user's mouth at which toothbrush 10 is being used at any particular time (e.g. front teeth, rear teeth, etc.). In this implementation, processing unit 26 may store for each of a number of particular positions in the user's mouth (as sensed by toothbrush 10) a particular force trigger level that is to be used when brushing at that position and/or a particular brushing mode that is to be used when brushing at that position. The particular force trigger level and/or brushing mode for each stored mouth position may be set using a user interface provided as part of toothbrush 10 or an application designed for that purpose that is run on computing device 40. Thus, in this implementation, the brushing mode and force trigger level used to trigger an alarm could be customized by detected brushing position in the mouth. One example would be high trigger level & whitening mode when on the front teeth, but sensitive mode & low force trigger level when brushing the molars are sensitive due to gum recession.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" or "including" does not exclude the presence of elements or steps other than those listed in a claim. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In any device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain elements are recited in mutually different dependent claims does not indicate that these elements cannot be used in combination.

Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.