Patent Publication Number: US-2021169622-A1

Title: Simultaneous cleaning of multiple teeth

Description:
CROSS-REFERENCE(S) TO RELATED APPLICATION(S) 
     This application is continuation of U.S. patent application Ser. No. 15/881,636, filed on Jan. 26, 2018, and entitled “Simultaneous Cleaning of Multiple Teeth”, which is hereby incorporated by reference in its entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     This application relates generally to dental care. More specifically, this application relates to a method and apparatus for cleaning multiple teeth or all teeth simultaneously. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings, when considered in connection with the following description, are presented for the purpose of facilitating an understanding of the subject matter sought to be protected. 
         FIG. 1  is an example diagram of a human jaw and teeth; 
         FIG. 2A  shows an example apparatus for simultaneously cleaning multiple teeth; 
         FIG. 2B  shows an example electronic controller for executing software to control the operation of the apparatus of  FIG. 2A ; 
         FIG. 3  shows an example diagram of a fluid circuit of the apparatus of  FIG. 2A ; 
         FIG. 4  shows an example mouthpiece with fluid ports usable as a component of the apparatus of  FIG. 2A ; 
         FIG. 5A  shows the example mouthpiece of  FIG. 4  in a relaxed non-contracted state; 
         FIG. 5B  shows the example mouthpiece of  FIG. 5A  in a contracted state; 
         FIG. 6  shows the example mouthpiece of  FIG. 4  as applied to an upper dental arch; 
         FIG. 7A  shows an example of the mouthpiece of  FIG. 4  enclosing a tooth in a relaxation state; 
         FIG. 7B  shows an example of the mouthpiece of  FIG. 4  enclosing a tooth in a contraction state; 
         FIG. 8A  shows an example mouthpiece pressure waveform without feedback control; and 
         FIG. 8B  shows an example mouthpiece pressure waveform with feedback control. 
     
    
    
     DETAILED DESCRIPTION 
     While the present disclosure is described with reference to several illustrative embodiments described herein, it should be clear that the present disclosure should not be limited to such embodiments. Therefore, the description of the embodiments provided herein is illustrative of the present disclosure and should not limit the scope of the disclosure as claimed. In addition, while the following description references using a mouthpiece in the human oral cavity, it will be appreciated that the disclosure may support use of a similar apparatus adapted to be used on dentures outside the mouth and in animal mouths. 
     Briefly described, a method and an apparatus are disclosed for simultaneously cleaning multiple teeth, such as one or both dental arches in the mouth. The Dental Cleaning Apparatus (DCA) includes a cleaning engine enclosed in a main housing, a fluid tube, a handle, and a mouthpiece. The cleaning engine includes a fluid circuit having a number of pumps and solenoid valves, a programmable controller to control the solenoid valves and other operations, a tooth cleaning fluid, a waste container, and a user interface panel to provide user control and status information. The fluid tube includes a number of separate tubes for injection and evacuation of cleaning fluid from the interior of the mouthpiece. The fluid tube couples with a handle having channels corresponding to the fluid tube to guide the fluid to the mouthpiece. The mouthpiece is generally made from a flexible and supple material, such as silicone, suitable for medical use. In some embodiments, the mouthpiece may have bristles of various shapes, such as conical, cylindrical, or irregular, to better clean the surface of the teeth. The cleaning engine alternates the mouthpiece between a relaxation state and a contraction state to effectively scrub the surface of all enclosed teeth simultaneously. It may automatically learn and adjust the vacuum pressure needed for each user to optimize cleaning. It may also automatically adjust the cleaning cycles according to various algorithms to increase cleaning effectiveness. 
     Unlike sharks, humans only have one set of adult teeth for all their lives. Hence, good dental and oral hygiene is of utmost importance. Besides the obvious reasons for this, such as eating and esthetics, poor oral health provides a breeding ground for bacteria and weakens overall health. 
     Oral hygiene tools and methods have advanced significantly in recent years, including introduction of vibrating or rotating toothbrushes. Even though these tools are a big improvement over manual brushes, they still have significant shortcomings. They take a relatively long time (most vibrating toothbrushes have a cycle of two minutes) for what they do. They can also be less than effective, especially if not used properly. For example, children, infirm elderly, and the handicap may find it difficult to use these tools properly. They also do not effectively clean between the teeth. 
     Hence, there is a need for a teeth cleaning system to improve upon or eliminate these shortcomings. 
       FIG. 1  is an example diagram of a human jaw and teeth. The human oral cavity  100  is formed chiefly by the lower maxilla  102  (mandible) and the upper maxilla  104 . The lower and upper teeth have crowns  106  and  108 , respectively and roots  110  arranged in two upper and lower oral arches, approximate semi-circles starting from one side of the jaw and extending in a curve to the other side, as is common knowledge. 
       FIG. 2A  shows an example apparatus for simultaneously cleaning multiple teeth. In some embodiments, the Dental Cleaning Apparatus (DCA)  200  includes a main housing  202  enclosing a cleaning engine composed of various components, described below with respect to  FIGS. 2B-4 . In various embodiments, the DCA may further include a user interface with various status lights and control buttons  222 , and display  224  for displaying messages  226  to the user. One or more removable compartments  204  may be used to add cleaning fluids and collect waste water. In some embodiments, the cleaning liquid or fluid may be supplied in a cartridge inserted into a special port or receptacle deployed within housing  202 . A power cord  216  may be used to power the DCA. An electronic programmable controller  218  may be accessed via an external port  220  to update software programs or extract data. In some embodiments, the DCA may further include a fluid transport tube  206  having multiple tubes within to deliver or extract fluid via coupling head  208  and interface  210   a  to a corresponding interface  210   b  on a handle  212  coupled with interface  230  of mouthpiece  214  via channels  228 . 
     In various embodiments, the cleaning engine enclosed by main housing  202  may be powered by AC (Alternating Current) power or DC (Direct Current) power, such as batteries. The electrical power so supplied may be used to drive pumps and open or close solenoid valves to pressurize and direct cleaning fluid to the mouthpiece  214  to scrub the teeth and collect waste fluid back from the mouthpiece. The cleaning engine may further include one or more pressure sensors deployed at various points in the fluid circuit, further described with respect to  FIG. 3  below, to measure real-time pressure during cleaning cycle and adjust the pressure and cleaning cycle timing in real-time accordingly. In various embodiments, the DCA may be used by more than one person by changing the handle at the fluid coupling head  208 , as further described below. In some embodiments, the complete cleaning cycle is on the order of a few seconds, such as 10-30 seconds. In other embodiments, the length of the cycle may be longer or shorter and may also be user-settable or selectable, in case of pre-defined cycle durations. 
     In various embodiments, one or more removable containers  204  may be used to supply cleaning fluid, such as liquid or soft gel toothpaste. For example, each user may favor or need a different type of toothpaste. The removable compartment may address this need. Another removable container may be included in the housing  202  to collect waste fluid after cleaning to be disposed, as further described with respect to  FIG. 3  below. 
     With continued reference to  FIG. 2A , in various embodiments, the user interface includes indicator lights and buttons  222 , and display  224  to obtain status information from the DCA and also set various configurations. For example, the indicator lights may be used to indicate “Power ON”, “Active Cycle”, “Finishing”, or other such status information. The control buttons may be used to issue user commands to the DCA to use different configurations or routines. For example, one button can select between gentle cleaning and vigorous cleaning. 
     Another button may indicate Reset to restart the cycle, and the like. Those skilled in the art will appreciate that the status lights and command buttons may be used in many different ways for many different status information and commands without departing from the spirit of the present disclosures. For example, lights may indicate a Short Cycle or a Long Cycle, and buttons, dials, or sliders may be used to command the same or set the cycle time to a custom duration. In some embodiments, all lights, buttons and dials may be replaced with a more comprehensive touch-sensitive display panel  224  to take user input and also display status, configuration, and operational information. 
     In various embodiments, the controller  218  may be a programmable controller, further described below with respect to  FIG. 2B , that directs the operation of the DCA. In other embodiments, the controller may be hardwired with simple and fixed functions, not configurable by the user. In still other embodiments, the controller may be locked to prevent configuration. 
     Such embodiments may be useful to avoid user confusion or misconfiguration, for example, when the users are small children or infirm adults. 
     In various embodiments, the fluid transport tube  206  may be made of flexible material, such as various medical grade plastics or silicone, to couple the cleaning engine with the handle  212  and mouthpiece  214  to deliver cleaning services to the teeth. The coupling head  208  may be pressure-fit over or within the handle  212  to line up the fluid interface  210   a  with handle interface  210   b.  In some embodiments, the fluid interface may include at least one output from the cleaning engine to the mouthpiece to deliver cleaning fluid and at least one input from the mouthpiece back to the cleaning engine to collect waste fluid. In other embodiments in which the mouthpiece covers a single arch of teeth, two output fluid ports (from cleaning engine to mouthpiece) and one input fluid port (from mouthpiece to cleaning engine) may be deployed. Each of the two output ports goes to one branch of the mouthpiece to deliver cleaning fluid, and one common input for collecting waste fluid from both branches, as further described below with respect to  FIGS. 3 and 4 . 
     With continued reference to  FIG. 2A , in various embodiments, the handle  212  may be color-coded so different individual users can easily identify and couple their personal handle attached to their personal mouthpiece with the cleaning engine. In various embodiments, the handle has two ends, each with a fluid interface. One end of the handle couples and interfaces with the fluid transport tube  206  coupling head  208 , and the other end has a similar fluid interface  230  that couples with the mouthpiece  214  via internal handle channels  228 , as further described below with respect to  FIGS. 3 and 4 . In some embodiments, the mouthpiece side of the fluid interface of the handle may have a different geometric arrangement than the side on the coupling head  208 . For example, the mouthpiece side may have more or fewer fluid ports to receive cleaning fluid than provided by the coupling head  208 . The internal configuration of the handle determines how the fluid is delivered to or extracted from the mouthpiece. For example, if the mouthpiece has four ports to receive cleaning fluid while the coupling head  208  has two ports, then the handle internally splits the channels (pathways leading from fluid entry to exit of ports within the body of the handle) leading from the two ports of the coupling head into four ports for delivery to the mouthpiece. In other embodiments, the fluid transport tube may be connected directly to the mouthpiece  214  without a handle. 
     In various embodiments, the mouthpiece  214  is made of medical-grade flexible and supple material like silicone and covers or encloses one oral arch or two (upper and lower arches), as further described with respect to  FIGS. 6-7B . For each type of mouthpiece, the delivery ports and channels (pathways leading from fluid entry to exit ports within the body of the mouthpiece) are split to distribute the cleaning fluid. This way, the handle interface on the mouthpiece side can be used with multiple types of mouthpieces, so the same handle can be used with different types of mouthpieces. In various embodiments, the mouthpiece  214  for use with one oral arch is covered with a large number of bristles, measured in hundreds or thousands, such as 2000 to 4000, to increase cleaning surface and angles for more effective scrubbing and cleaning of teeth surfaces and between the teeth. The bristles may have various profile shapes such as conical, tapered bars, cylindrical, or irregular, or a combination of some or all of these shapes. The teeth-facing and/or the bristles of the mouthpiece may further be dip-coated with additional fine abrasive material to increase cleaning and scrubbing effectiveness of the teeth surfaces. The fine abrasive material so coating the mouthpiece may be of a hardness that is greater than tartar or other sediments and deposits on teeth surfaces, but less than enamel hardness to clean but avoid harming the teeth. 
       FIG. 2B  shows an example electronic controller for executing software to control the operation of the apparatus of  FIG. 2A . In various embodiments, the controller  250  includes baseboard  252  having a CPU (Central Processing Unit)  254 , computer memory  256 , data storage  258 , Input/Output (I/O) ports  260 , Network Interface Card (NIC)  262 , wireless communication interface  264 , all connected with computer data and control bus  268 . Power supply  266  supplies electrical power to the controller. 
     In various embodiment, the controller  250  is a simple programmable computer that can load and execute software, receive sensed data, control display and output other control signals. 
     In various embodiments, the CPU  254  is connected to the computer bus  268  via which it has access to and control over other components of the controller. The memory unit  256  may store both executable program and data during various computations, such as determining pressure values or which valves to open and close. The storage  258  may be a non-volatile memory, such as ROM (Read Only Memory) or solid-state disk drive used to permanently store programs or configuration data. I/O ports  260  may be used by the CPU to receive and transmit electronic signals to other devices. For example, the CPU may read pressure data from pressure sensors or user input and it may also send out signals to open or close a valve or to start or stop a pump. The NIC and wireless interfaces may be used to download or upload new software programs and data by wire, such as using USB (Universal Serial Bus) or Ethernet, or wirelessly, such as using Bluetooth or WiFi protocols. Using this feature, new functions, improved performance, and higher quality may be achieved. A dentist may also be able to use data from the DCA as part of his patients&#39; treatment and maintenance programs. 
       FIG. 3  shows an example diagram of a fluid circuit of the apparatus of  FIG. 2A . In various embodiments, the fluid circuit  300  includes pumps  302  and  304  coupled with solenoid valves  306 ,  308 ,  310 ,  312 , and  314 , cleaning fluid cartridge or container  334 , mouthpiece  316  having ports  318   a,    318   b,  and  320 , sensor  322  with output signal  324 , waste fluid container  326  with separator  328  for holding waste fluid  330  disposed through drain opening  332 . 
     In various embodiments, the fluid circuit  300  performs repeated cleaning cycles to clean the teeth at the rate of about 10-20 cycles per second. In some embodiments, the frequency of the cleaning cycles may be more or less than this range. Each cleaning cycle includes four distinct and successive phases: cleaning fluid or liquid injection, creation of vacuum, air injection, and draining, as further described below. In various embodiments, the pumps and the solenoid valves are computer-controlled devices and are operated by the controller  218  ( FIG. 2A ) via electronic signals transmitted to control interfaces of these devices. In various embodiments, the mouthpiece encloses at least one dental arch and creates a substantially sealed enclosure around the teeth suitable to create a low-pressure vacuum, on the order of 4-8 PSI (Pounds per Square Inch), inside the sealed enclosure. The sealed enclosure boundaries include the walls of the mouthpiece. In various embodiments, stronger or weaker vacuum pressures may be created. 
     In various embodiments, the pumps  302  and  304 , as well as solenoid valves  306 - 314  are controlled by controller  250  ( FIG. 2B ) to move and direct the cleaning fluid and waste fluid through different paths in the fluid circuit, under software control. In the first phase, the fluid injection phase of the cleaning cycle, pump  304  is turned ON, valves  308 ,  312 , and  314  are opened and valves  306  and  310  are closed. This circuit configuration causes the cleaning fluid from container  334  to be pulled or sucked into the mouthpiece  316  via mouthpiece input ports  318   a  and  318   b.  Solenoid valve  314  only pulls air out, not waste fluid, to pull the cleaning liquid into the mouth piece. 
     In various embodiments, in the second phase of the cleaning cycle, vacuum is created within the interior of the mouthpiece. This action causes the mouthpiece to be contracted and entered into a contraction state to exert pressure against the teeth and commence a micro-scrubbing action by the mouthpiece and its bristles, without overt movement as observed in manual or motorized brushing. By virtue of contraction, the bristles contact the teeth surface and start bending under vacuum pressure. The bending or other deformation of the bristles and/or mouthpiece body creates a small motion that rubs the mouthpiece against the teeth, hence creating micro-scrubbing. The length of scrubbing stroke is on the order of the length of the bristles and/or reduction in dimensions of the mouthpiece body under vacuum pressure in a contraction state. This phase is performed by turning OFF pump  302 , turning ON pump  304 , closing valves  306 ,  312 , and  310  and opening valves  308  and  314  to create a path from mouthpiece output port  320  to pump  304 . The suction creates vacuum in the interior of the mouthpiece because the interior of the mouthpiece is now air-tight and the only way out is through the path created which evacuates air and compresses the mouthpiece and its bristles. 
     In various embodiments, in the third phase of the cleaning cycle, air is injected to transition the mouthpiece to a relaxation state, removing pressure from teeth surfaces. More micro-scrubbing takes place as the bristles and mouthpiece body recover their unstressed shapes and move back. During this phase, the controller turns ON pump  302  and  304 , open valves  306 ,  308 , and  314 , and close valves  310  and  312  to break the vacuum and fill the interior of the mouthpiece with normal amounts of air and causing the mouthpiece to regain its unstressed shape. 
     In various embodiments, in the fourth phase of the cleaning cycle, the collected waste fluid is disposed. In this phase, first, pump  302  is turned ON in addition to opening solenoid valves  306  and  310 , while other valves are closed to push waste water out of the drain  332 . Next, pump  302  is turned OFF and valves  306  and  310  are closed and pump  304  is turned ON and valves  308  and  314  are opened to clean out the mouthpiece from any waste fluid. Pump  304  always pulls only air and no fluid goes through it because all waste fluid is precipitated in the waste container  326 . 
     In various embodiments, one or more pressure sensors may be deployed within the fluid circuit and/or within the mouthpiece to collect and transmit pressure data to the controller  250 . For example, sensor  322  may be placed at the output port  320  of the mouthpiece to measure vacuum pressure within the mouthpiece and transmit the pressure data to the CPU to calculate optimal vacuum pressure exerted via pump  304  for best cleaning results. 
     In various embodiments, in operation, the cleaning engine repeatedly goes through the above successive cleaning phases at a rate of approximately 10-20 cycles per second. The amount of scrubbing the teeth experience in a few seconds exceeds the amount of brushing performed in several minutes by existing brushing methods. 
     Those skilled in the art will appreciate that the pumps and solenoid valves may be turned ON and OFF (or opened and closed) in various combinations to direct fluid motion and exert different pressure levels and for different time durations, under software control, to effect different operations of the DCA for creating different cleaning cycles and/or performing various functions. For example, the pressure sensors  322  may provide data used by the DCA software to detect the positioning of the mouthpiece in the mouth and start the cleaning cycles automatically without user input. Another example is the optimization of cleaning cycle, as further described below with respect to  FIGS. 8A and 8B . 
       FIG. 4  shows an example mouthpiece with fluid ports usable as a component of the apparatus of  FIG. 2A . In various embodiments, mouthpiece  400  includes a body  402 , a base  404 , fluid interface with input ports  406   a  and  406   b,  and output port  408  extending into internal mouthpiece channels  416 ,  418 , and  420 , respectively, and leading to internal mouthpiece ports  410   a,    410   b,  and  412 , respectively. In some embodiments, the inner side of the mouthpiece  400  enclosing and facing the teeth, may be covered with bristles to provide extra scrubbing function. 
     In various embodiments, the mouthpiece body  402  may be constructed from flexible and supple material like silicone that is usable for medical applications. A double-arch mouthpiece may be used with DCA that may be configured as two back to back single-arch mouthpieces to cover both the upper and the lower dental arches. Various types and sizes of mouthpieces with various colors, firmness, and abrasive characteristics may be used by different or same users. For each type of mouthpiece, the mouthpiece fluid ports  406   a,    406   b,  and  408  may be standardized in terms of size, location, dimensions, coupling method and other coupling characteristics to fit the corresponding mouthpiece end of the handle  212  ( FIG. 2 ). This way, the handle interface on the mouthpiece side can be used with multiple types of mouthpieces, so the same handle can be used with different types of mouthpieces. In various embodiments, the mouthpiece  400  may be covered with a large number of bristles, on the order of many hundreds or thousands, such as 2000 to 4000 (or more or less depending on the size of the bristles and the mouthpiece), to increase cleaning surface and angles for better cleaning of teeth surfaces and between the teeth. The bristles may have various profile shapes such as conical, tapered bars, cylindrical, or irregular, or a combination of some or all of these shapes. The inner surface and/or the bristles of the mouthpiece may further be coated with fine abrasive materials, such as abrasive powders, to increase cleaning and scrubbing effectiveness of the teeth surfaces. The fine abrasive coating of the mouthpiece and/or bristles may be harder than tartar or other deposits on teeth surfaces to be cleaned, but softer than enamel to avoid harming the teeth. 
     In some embodiments, the mouthpiece body  402  may include more exit ports like  410   a  and  410   b,  and their corresponding channels, deployed at various points on the mouthpiece surface facing the teeth. In such configurations, the cleaning fluid may be distributed more uniformly and completely. 
       FIG. 5A  shows the example mouthpiece of  FIG. 4  in a relaxed non-contracted state. In various embodiments, mouthpiece  500  includes a body  502 , inner sidewalls  504   a  and outer sidewalls  504   b.    
     In various embodiments, the mouthpiece starts out in a relaxation or non-contracted state in the operation of the DCA. In the relaxation state, the mouthpiece inner and outer sidewalls are not stressed under pressure and have their free-standing dimensions. The mouthpiece may also transition to the relaxation state from the contraction state during the cleaning cycles. 
       FIG. 5B  shows the example mouthpiece of  FIG. 5A  in a contracted state. In various embodiments, mouthpiece  550  includes a body  552 , inner sidewalls  554   a  and outer sidewalls  554   b , similar to the mouthpiece of  FIG. 5A . 
     In various embodiments, the mouthpiece encloses at least one dental arch and creates a substantially sealed enclosure around the teeth suitable to create a low-pressure vacuum inside the sealed enclosure. In various embodiments, when vacuum is created within the sealed enclosure, the mouthpiece enters the contracted state in the operation of the DCA. Under these conditions, the mouthpiece inner and outer sidewalls are compressed under vacuum pressure and are contracted and pressed against and squeeze the teeth with compressed dimensions. The mouthpiece may also transition to the contracted state from the relaxation state during the cleaning cycles. 
       FIG. 6  shows the example mouthpiece of  FIG. 4  as applied to an upper dental arch. In various embodiments, configuration  600  includes mouthpiece  602 , enclosing and covering teeth  604 , having a cross section  608 , and having input ports  606 . 
     In various embodiments, the mouthpiece  602  encloses all teeth on the upper dental arch between the mouthpiece walls and the palate (roof of mouth), creating an air-tight and water-tight space within the interior of the mouthpiece that may be vacuumed and evacuated from air under pump pressure. The sealing of the interior of the mouthpiece against air leaks is needed in the operation of the DCA to enable the vacuum creation and air injection phases. 
       FIG. 7A  shows an example of the mouthpiece of  FIG. 4  enclosing a tooth in a relaxation state. In various embodiments, mouthpiece application  700  to a tooth includes mouthpiece  702  with inner sidewall  704  (towards interior of the oral cavity), bottom wall  706 , outer sidewall  708 , bristles  722 , outer rim  710  in contact with and conforming to shape of upper lip&#39;s interior space (gingival-jugal sulcus  714 ), inner rim  712  in contact with and conforming to shape of palate  718 , surrounding tooth  716  with air pockets  720  between bristles and teeth. 
     In various embodiments, the inner rim  712  and outer rim  710  of mouthpiece  702  may have a bulged, enlarged, or thickened cross section, with a circular or oval shape as shown, to better seal the inner space of the mouthpiece enclosing the teeth against the palate  718  and gingival-jugal sulcus  714 , respectively. In the relaxation state of the mouthpiece as shown, the bristles do not firmly touch the teeth and pockets of air remain between the teeth and the bristles or inner surface of the mouthpiece. 
       FIG. 7B  shows an example of the mouthpiece of  FIG. 4  enclosing a tooth in a contraction state. In various embodiments, mouthpiece application  750  to a tooth includes mouthpiece  752  with inner sidewall  754  (towards interior of the oral cavity), bottom wall  756 , outer sidewall  758 , bristles  772  surrounding and firmly pressed against tooth  766 . 
     In various embodiments, the inner rim and outer rim of mouthpiece  752  may have a bulged, enlarged, or thickened cross section, as shown, to better seal the inner space of the mouthpiece enclosing the teeth against the palate and gingival-jugal sulcus, respectively. In the contraction state of the mouthpiece as shown, the bristles firmly touch and press against the teeth and no pockets of air remain between the teeth and the bristles or inner surface of the mouthpiece. The contraction state of the mouthpiece is when most of the cleaning and scrubbing of the teeth surfaces takes place. 
       FIG. 8A  shows an example mouthpiece pressure waveform without feedback control. In various embodiments, the data representation includes a measure of vacuum pressure  802  on the vertical axis, a measure of time  804  on the horizontal axis, and a time-based pressure curve  806  showing the behavior of the DCA with respect to pressure in absence of feedback. 
     In various embodiments, in the absence of a feedback signal, such as a pressure value obtained from a pressure sensor, the DCA operates as an open-loop system. Those skilled in the art will appreciate that an open-loop system operates based on its designed behavior in which the input of the system is de-coupled and unrelated directly to the output of the system. In contrast, in a feed-back system, the input is adjusted based on a feed-back signal taken from the output of the system. As an example, a tricycle is a mechanically stable and balanced system and can operate in an open loop configuration or mode without depending on a feedback signal from its output, which is the balance of the tricycle. A bicycle, in contrast, is not a stable and balanced system and unless the rider adjusts his position and weight balance based on sensing the balance of the bicycle (falling to one side or the other), the system crashes. Feedback systems are generally more precise because any deviation in output can be corrected via the feedback loop. 
     The pressure curve  806  operating in open-loop mode is generated DCA&#39;s cleaning cycle operation and represents the vacuum pressure within the interior of the mouthpiece. Because the shape and surface contours of the oral cavity and the teeth of every person are different, the vacuum created within the interior of the mouthpiece via the mouthpiece needs different levels of exertion by the pumps to maintain the vacuum. For example, if the rims of the mouthpiece do not fully conform to the shape of the palate to create a good seal, the pumps need to work harder to maintain the vacuum. But, in absence of pressure feedback the pumps have no way of knowing if they need to work harder. As such, the pressure within the mouthpiece may fall prematurely or faster before the vacuum phase of the cleaning cycle is complete. This is depicted in the diagram of  FIG. 8A . The pressure curves rise to a peak and then almost immediately fall, creating sub-optimal pressure curves and cleaning cycles. 
       FIG. 8B  shows an example mouthpiece pressure waveform with feedback control. In various embodiments, the data representation includes a time-based pressure curve  856  showing the behavior of the DCA with respect to pressure with feedback. 
     With reference to  FIGS. 3 and 8B , in various embodiments, the feedback signal or signals  324  from pressure sensor  322  may be used by the programmable controller of the DCA to adjust vacuum pressure and air injection in the sealed mouthpiece. Because the operating principle of the DCA is alternating and sustained relaxation (no vacuum in the interior of mouthpiece) and contraction (vacuum in the interior of mouthpiece), an optimal cleaning cycle depends on the ability to sustain vacuum for the duration of the appropriate phases in the cleaning cycle. So, if the seal inside the interior of the mouthpiece is broken prematurely before the appropriate phase is terminated, as indicated by a pressure drop, the controller causes the pumps to continue to work or work harder to maintain the vacuum. This process results in more regular, predictable, and sustained pressure curves, as shown in  FIG. 8B  compared with the pressure curve shown in  FIG. 8A . The more regular and better controlled pressure curves enable the DCA to perform better, since it depends on the pressure cycles to perform cleaning functions. 
     The feedback process enables the DCA to perform near-optimally due to well-controlled pressure cycles. 
     In various embodiments, by detecting a good seal via the pressure signal feedback, the DCA may be able to detect when the mouthpiece is positioned properly in the user&#39;s mouth with proper seal to hold vacuum, and then start the cleaning cycle automatically without user input. 
     Those skilled in the art will appreciate that the pressure feedback signals may be used by the DCA to perform other auxiliary functions to improve the main function of cleaning teeth. For example, the DCA can automatically experiment with different pressure cycle durations and phase durations to find optimal cleaning cycles. The pressure signal informs the DCA about pressure conditions within the interior of the mouthpiece, which largely defines the phase of the cleaning cycle. As long as the pressure is maintained at a particular level, the phase duration of the cleaning cycle can be maintained, thus altering the overall cleaning cycle. 
     Changes can be made to the claimed invention in light of the above Detailed Description. While the above description details certain embodiments of the invention and describes the best mode contemplated, no matter how detailed the above appears in text, the claimed invention can be practiced in many ways. Details of the system may vary considerably in its implementation details, while still being encompassed by the claimed invention disclosed herein. 
     Particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the claimed invention to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the claimed invention encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the claimed invention. 
     The above specification, examples, and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. It is further understood that this disclosure is not limited to the disclosed embodiments, but it is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 
     It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. 
     However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). 
     Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     While the present disclosure has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.