Cleaning unit for surface cleaning device

Abstract

A surface cleaning means is proposed that is based on the combined use of ultrasound and radio frequency (RF) electromagnetic radiation transmitted onto a surface to be cleaned to provide a synergistic cleaning action. One aspect provides a cleaning unit with a body including an ultrasound transducer device and an RF emitter device, the two of which are arranged such that when driven by respective drive signals, they generate overlapping ultrasound and RF radiation (for providing the cleaning action) in a common spatial region, thereby providing a combined cleaning action in the common spatial region. One exemplary application is for use in oral cavity cleaning.

Description

Technical Field

[0001] The present invention relates to a cleaning unit for a surface cleaning device.

Background Art

[0002] Surface cleaning is an operation used in various application fields including household, industrial, institutional, and healthcare fields.

[0003] In the healthcare field, a surface cleaning device can be used to clean the surface of teeth as part of an oral healthcare function.

[0004] Tooth cleaning and prevention of periodontal disease are important parts of oral hygiene. This includes the removal of dental surface coatings, dental plaque, and tartar from teeth to prevent tooth decay, gingivitis, and periodontal disease. Current over-the-counter, manual, and electric toothbrushes are the most common tooth cleaning tools. These generally consist of a head (brush head) with densely packed brush bristles (hairs) attached to a handle that facilitates cleaning of hard-to-reach areas of the oral cavity, and a dentifrice (toothpaste) can be applied to the head. Other exemplary oral cleaning devices include electric brushing mouthpiece devices. In operation, an electric toothbrush performs a high-speed vibrating bristle movement such as back-and-forth vibration, rotational vibration, or vibration to clean teeth. When the movement is controlled at the speed of sound, this is called a sonic toothbrush movement. A sonic toothbrush generates a movement or vibration in the audible frequency range from 20 Hz to 20,000 Hz.

[0005] Currently available, all toothbrushes have brush bristles on the brush head. The brush bristles are usually formed from non-biodegradable nylon and have become a major cause of environmental pollution after disposal. From the perspective of the undesirable wear of tooth enamel and the possibility of trauma to the gingival tissue when hard brush bristles are used, soft brush bristles are generally recommended for toothbrushing.

[0006] In dental cleaning, brushing cleans or removes two types of undesirable deposits from the tooth surface: plaque and extrinsic stains. In dentistry, calculus or tartar is a form of hardened plaque. Once formed, calculus adheres firmly and is too hard to remove with ordinary electric or manual toothbrushes. Tartar hardens into calculus if not removed every 24 hours. Calculus cannot be removed with currently available electric toothbrushes and dental floss. Instead, calculus buildup must be removed by a dental professional using specialized ultrasonic tools or dental hand tools (e.g., periodontal scalers).

[0007] Recent developments have seen the integration of radio frequency (RF) generating elements into toothbrush devices, combined with the sonic vibrations of toothbrush bristles. Radio frequency radiation has a dielectric heating effect on certain materials, which leads to the softening or "melting" of plaque on the tooth surface. This can assist in plaque removal by electric toothbrushes. However, this effect is limited, and this technology remains ineffective in removing tartar. This technology provides no cleaning effect in areas that the brush bristles cannot mechanically access. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Improvements in the field of surface cleaning equipment are widely needed. [Means for solving the problem]

[0009] The present invention is defined by the claims.

[0010] According to an example of one aspect of the present invention, a cleaning unit for a surface cleaning apparatus is provided, the cleaning unit comprising: a body; an ultrasonic transducer apparatus supported by the body, comprising one or more ultrasonic transducers configured to generate ultrasonic radiation in response to one or more drive signals; and an electromagnetic radiator apparatus supported by the body, configured to generate radio frequency electromagnetic (EM) radiation in response to the supply of a radio frequency drive signal; wherein the ultrasonic transducer apparatus and the electromagnetic radiator apparatus are arranged to generate spatially overlapping ultrasonic radiation and EM radiation to enable simultaneous ultrasonic and RF stimulation of the surface to be cleaned.

[0011] The transducer device and / or radiator device described above may be housed within the main body described above.

[0012] Embodiments of the present invention are based on the concept of using a combination of ultrasonic stimulation and RF electromagnetic stimulation to achieve improved surface cleaning. The supply of RF waves to the surface can cause dielectric heating of deposits on the surface. This can lead to softening or melting of the deposits, which can facilitate their removal. Ultrasonic stimulation of the surface can induce cavitation in the presence of a liquid layer between the surface and the ultrasonic transducer, in contact with the surface to be cleaned. Cavitation is known to have an abrasive effect on surfaces, and this effect can be used to remove contaminants from the surface. The cavitation cleaning effect is improved by using RF in combination with ultrasound, because the contaminants are electromagnetically softened simultaneously with the application of ultrasound. This leads to an improved cleaning effect.

[0013] The cleaning unit can be entirely passive, without any active electronic components, and the ultrasonic and RF radiation are excited only in response to the application of an externally generated drive signal. However, this is not essential in all embodiments.

[0014] In some embodiments, the cleaning unit includes an array of protrusions or cleaning elements on the (outer) surface of the main body. These may be for performing a cleaning function during use.

[0015] The above-mentioned protrusion or cleaning element can be supported on the surface of the main body.

[0016] The projection or cleaning element may be designed to make operational contact with the surface to be cleaned during use in order to enable a mechanical cleaning action.

[0017] One advantageous application of the embodiments of the present invention is for oral cleaning. In this case, the cleaning unit may be a cleaning unit for an oral cleaning device such as a toothbrush-type device or a mouthpiece device. However, the embodiments may also be used for a wide range of other surface cleaning applications.

[0018] In some embodiments, the cleaning unit may be an attachment for removably coupling to a base unit of the cleaning device (e.g., a handle), in which case the base unit houses a source for supplying RF drive signals and ultrasonic drive signals. In other embodiments, the cleaning unit may form a larger, integrated part of the cleaning device.

[0019] In some examples, the cleaning unit may be configured such that, when driven by a corresponding drive signal, ultrasonic and RF radiation propagates from the cleaning unit body in a common direction and / or toward a common spatial region, such as a common focusing region, plane, or point. This enables simultaneous ultrasonic and RF stimulation of the surface to be cleaned.

[0020] According to one or more embodiments, the body may have a first outer surface forming a first surface of the body for placement adjacent to a surface to be cleaned during use, and the transducer device and electromagnetic radiator device are each configured to generate radiation that propagates outward from at least a portion of the first surface.

[0021] The first surface described above forms the radiating output surface of the cleaning unit. The transducer device and / or radiator device can be housed within the main body. RF and ultrasonic radiation can propagate outward from the main body by transmission through the first surface.

[0022] RF radiation and ultrasonic radiation can propagate from the main unit along a common propagation path.

[0023] In one or more embodiments, the body may be structurally configured to allow positioning adjacent to the surface to be cleaned on the first surface of the body at a distance of 5 mm or less from the surface. For example, the first surface may have a flat surface or may carry an array of protruding elements, the maximum height of the array of protruding elements from the first surface being 5 mm or less.

[0024] According to one or more embodiments, the main body may have an acoustic wave directing element that receives ultrasonic radiation from an ultrasonic transducer device and redirects (redirects) the radiation along one or more predetermined propagation paths outward from the main body and / or away from the main body.

[0025] The above-described acoustic wave directing element allows for greater control over the output direction of ultrasonic radiation, which enables, for example, the radiation to be directed towards a desired plane, point, or area. By positioning the body such that the surface to be cleaned is located within the spatial region to which the waves are redirected, the surface is ultrasonically stimulated by the waves.

[0026] The ultrasonic transducer device and the wave directing element can be housed within the body. The one or more paths can exit the body so as to be captured by the surface to be cleaned. The one or more paths can exit the body through the first surface.

[0027] The radiator device is configured to generate radiation during use, and these radiations are directed along the same one or more propagation paths as achieved by the (re)directing element. In some examples, the radiator device can also be configured such that its radiation is received and redirected by the wave directing element.

[0028] The acoustic wave directing element can be configured to focus the received ultrasonic radiation into one or more ultrasonic beams directed along the one or more propagation paths. Here, the wave directing element additionally performs a beam focusing function.

[0029] In some examples, the acoustic wave directing element can include one or more parabolic acoustic reflectors. Thereby, a structurally simple configuration for focusing and directing ultrasonic radiation is provided.

[0030] According to one or more embodiments, the body can include an ultrasonic shielding component configured to prevent the propagation of ultrasonic waves in one or more directions from the body.

[0031] For example, the body can further include a second outer surface forming the second surface of the body, and the shielding component is configured to block the propagation of ultrasonic waves from the second outer surface. The second outer surface can be, for example, on the side opposite to the first outer surface of the body. By way of illustration, this configuration can be useful for preventing the propagation of ultrasonic waves from the surface of the cleaning unit body (e.g., the back of the toothbrush head) facing the oral surfaces and tissues that are not targeted during use in oral cleaning applications.

[0032] The shielding component can block ultrasonic radiation.

[0033] The shielding component may be an object formed from an ultrasonic attenuating material, such as a foamed material. The shielding component is positioned to block ultrasonic propagation from the inside of the cleaning unit body toward one or more specific outer boundaries of the body.

[0034] In some embodiments, the shielding component may have a multilayer foam element containing materials having different relative acoustic impedance levels (relative to each other).

[0035] According to one or more embodiments, the cleaning unit may further have an impedance matching layer disposed between the first outer surface and the output surface of the ultrasonic transducer device. The impedance matching layer improves the efficiency of ultrasonic transmission between the ultrasonic transducer and the first surface of the main body.

[0036] According to one or more embodiments, the body may have an outer first surface, the transducer device is configured to generate ultrasonic radiation that propagates outward from at least a portion of the first surface when in operation, the first surface carries an array of projections extending outward from the first surface, these projections are to be operationally brought into contact with a surface to be cleaned during use to enable a mechanical cleaning action, and these projections extend from the first surface to a maximum height of 5 mm or less.

[0037] The aforementioned protrusions are supported by at least a portion of a first surface positioned to transmit ultrasonic radiation from the ultrasonic transducer device. Thus, when the first surface is in contact with the surface to be cleaned, these protrusions spatially coincide with the area of ​​the surface to be cleaned that is stimulated by ultrasound. This allows for simultaneous mechanical and ultrasonic (and RF) cleaning of a common area on the surface to be cleaned during operation.

[0038] The maximum height of 5 mm ensures maximum separation between the output surface of the cleaning unit body and the surface to be cleaned. This is important to minimize the attenuation of ultrasonic waves traveling between the surface of the cleaning unit and the surface to be cleaned when the protrusions come into contact with the surface to be cleaned. This improves the cleaning effect. Attenuation is reduced with respect to both waves traveling in the space between adjacent protrusions and waves passing through the protrusions themselves.

[0039] As an example, in the field of oral cleaning applications, this represents a change from the standard structural design of oral cleaning units, in which the body of the cleaning unit is generally equipped with long brush bristles that stand upright from the surface of the body, forcing a separation of well over 5 mm between the surface and the tooth surface. This will lead to increased attenuation of ultrasonic radiation due to the long distance that the ultrasound must travel to reach the surface. This will also reduce the cavitation effect because the ultrasonic power of the radiation is reduced when the acoustic waves reach the surface to be cleaned. By using shorter protrusions, the cavitation effect is improved, leading to an improved cleaning effect.

[0040] The projections may all be the same height or may have different heights. For example, the distal end of a projection may define an upper profile or envelope whose height may vary, and the maximum height of the upper profile or envelope from the first surface may be 5 mm or less.

[0041] According to one or more embodiments, each projection may be an integrally formed structure, i.e., monolithic.

[0042] According to one or more embodiments, the projection may include a ridge or a boss (embossed projection). The projection may be a dot (e.g., a microdot). The projection may include a ridge. The projection may include brush bristles or a bundle of brush bristles.

[0043] According to one or more embodiments, the protrusions may be formed from a material having a Shore A scale hardness of 5 to 120, preferably 10 to 100, and more preferably 20 to 70.

[0044] The attenuation of ultrasound decreases in relation to the bulk modulus of the medium through which the ultrasound is transmitted. For example, soft nylon brush bristles are a relatively poor transmission medium for ultrasound due to their relative softness. The harder the medium, the less the sound waves pass through it are attenuated.

[0045] According to one or more embodiments, the body has at least a first part and a second part, the first surface is included in the first part, the first part is detachable from the second part, and the second part has the transducer device and the electromagnetic radiator device. This makes it possible to replace the part of the body that carries the protruding element (projection). This makes it possible to replace these mechanical cleaning elements periodically without having to replace the transducer or radiator at the same time.

[0046] The first part can, in some examples, be a monolithic structure formed as a single unit. This means that the arrangement of protrusions is formed integrally with the surface from which these protrusions project.

[0047] According to one or more embodiments, the cleaning unit may be for an oral cleaning device, and the main body is received in the user's mouth.

[0048] In this case, the surface to be cleaned could be the tooth surface.

[0049] When used in the oral cavity, the combined ultrasonic and RF radiation advantageously allows for cleaning in areas that are mechanically inaccessible, such as the gums and subgingival regions. In this way, oral cleaning and, consequently, oral health can be improved.

[0050] In addition to performing cleaning functions, when used in the oral cavity, the combined use of ultrasound and radiofrequency radiation enables various beneficial therapeutic effects. For example, RF radiation promotes irrigation of gingival tissue, which leads to a healing effect on inflamed gums. For instance, RF waves replenish fibroblasts, while ultrasound promotes collagen type conversion. Although these provide complementary parts of the same overall healing response, the two energies of tissue repair synergistically enhance or promote each other.

[0051] The cleaning unit can form a head portion for an oral cleaning device, for example, a head portion for a probe-type cleaning device inserted into the mouth. This can take a structural form similar to a toothbrush, with a handle portion to which the head portion is attached (fixed or detachable).

[0052] According to one or more embodiments, the ultrasonic transducer device and / or radiator device may each be configured such that the corresponding radiation propagates from the main body in two or more directions.

[0053] For example, according to one or more embodiments, at least a portion of the main body is tubular (cylindrical), and the main body has a tubular (cylindrical) outer surface, which forms an RF and ultrasonic radiation output surface. The ultrasonic transducer device is arranged such that ultrasonic radiation propagates from the output surface in multiple directions.

[0054] The radiation can be emitted in a 360-degree direction around the main body.

[0055] In another aspect of the present invention, a surface cleaning apparatus is provided, which has a cleaning unit according to any of the examples or embodiments described above or described later, or according to any claim of this application, or is configured to be electrically and mechanically coupled to such cleaning unit when in use.

[0056] The cleaning device comprises: an ultrasonic driver module operable to generate one or more drive signals that generate ultrasonic radiation when coupled to an ultrasonic transducer device; and a signal generator configured to generate AC drive signals that generate radio frequency radiation when coupled to an electromagnetic radiator device.

[0057] In some embodiments, the surface cleaning device comprises a base unit. For example, the base unit may have a housing that accommodates an ultrasonic driver module and an RF signal generator. In some embodiments, the cleaning unit may be detachably coupled to the base unit of the cleaning device. For example, the cleaning unit may be configured to be detachably electrically and mechanically coupled to the base unit. In other embodiments, the base unit may be fixedly attached to the cleaning unit.

[0058] The cleaning device may further include a controller that is operationally coupled to an ultrasonic driver module and a signal generator, and is configured to simultaneously drive these ultrasonic driver modules and signal generators to generate an ultrasonic drive signal and an AC RF drive signal simultaneously. This enables the simultaneous generation of RF radiation and ultrasonic radiation during operation.

[0059] The cleaning device in question may be an oral cleaning device.

[0060] The cleaning device may further include a mechanical drive mechanism capable of operating to provide a source of sonic vibration motion, and a mechanical coupling arm for coupling the sonic vibration motion to the cleaning unit.

[0061] A controller may be further provided that is configured to control and simultaneously operate the ultrasonic driver module, signal generator, and mechanical drive mechanism while the device is in operation.

[0062] In a preferred example, the signal generator may be configured (or controlled) to generate a drive signal within the frequency range of 1 MHz to 300 MHz in order to cause the EM emitting device to emit EM radiation in the frequency range of 1 MHz to 300 MHz.

[0063] The ultrasonic driver module may be configured (or controlled) to generate a drive signal for generating ultrasonic radiation in the frequency range of 20 kHz to 300 MHz. According to one group of embodiments, the device is for human use, and the ultrasonic driver module is configured (or controlled) to generate a drive signal for generating ultrasonic radiation below 10 MHz.

[0064] According to one embodiment, the device is intended for use by non-humans, and the ultrasonic driver module is configured to generate a drive signal for generating ultrasonic radiation at a frequency of 10 MHz or higher.

[0065] Another example of the present invention provides a surface cleaning method that includes the step of simultaneously supplying ultrasonic radiation and RF frequency electromagnetic radiation to a surface to be cleaned.

[0066] The method may further include the step of bringing a cleaning element or arrangement of protrusions into operational contact with the surface to be cleaned. This may be for the purpose of enabling a mechanical cleaning action. This may be performed simultaneously with the supply of ultrasonic radiation and RF frequency electromagnetic radiation.

[0067] The cleaning element or projection described above may be supported on the (outer) surface of the main body.

[0068] The supply of ultrasonic and electromagnetic radiation can be achieved through the operation of the ultrasonic transducer device and the electromagnetic radiator device, respectively, preferably, in which case the ultrasonic transducer device and the electromagnetic radiator device are housed, supported, or otherwise included by a common body that forms at least part of the cleaning unit for the cleaning device. For example, the ultrasonic transducer device and the radiator device are arranged to generate spatially overlapping ultrasonic and EM radiation to enable simultaneous ultrasonic and EM stimulation of the surface to be cleaned.

[0069] The supply of ultrasonic radiation and electromagnetic radiation can be achieved through the control of: an ultrasonic driver module that can be operated to generate one or more drive signals that generate ultrasonic radiation when coupled to the aforementioned ultrasonic transducer device; and a signal generator configured to generate AC drive signals that generate radio frequency radiation when coupled to the aforementioned electromagnetic radiator device.

[0070] In some embodiments, the method can be carried out by a computer, for example by a controller, or by a processing unit having one or more processors or controllers operably coupled with, for example, the ultrasonic driver module and the signal generator.

[0071] Another aspect of the present invention can provide a computer program product including coding means, which, when executed on a processor or controller, causes the processor or controller to carry out the methods outlined above or any of the embodiments or examples described herein.

[0072] These and other aspects of the present invention will become apparent from the embodiments described below and will be explained by reference to such embodiments.

[0073] The accompanying drawings are provided for illustrative purposes only, in order to better understand the present invention and to more clearly illustrate how it may be carried out. [Brief explanation of the drawing]

[0074] [Figure 1] Figure 1 shows the basic components of an exemplary cleaning unit according to one or more embodiments. [Figure 2] Figure 2 shows the basic components of an exemplary cleaning unit according to one or more embodiments. [Figure 3] Figure 3 shows the emission of ultrasonic and RF radiation from the transducer and radiator devices of the cleaning unit. [Figure 4] Figure 4 shows the emission of ultrasonic and RF radiation from the transducer and radiator devices of the cleaning unit. [Figure 5] Figure 5 shows a cross-section of another exemplary cleaning unit according to one or more embodiments. [Figure 6] Figure 6 shows acoustic directional elements included in an exemplary cleaning unit according to one or more embodiments. [Figure 7A] Figure 7A shows another exemplary cleaning unit having protrusions on exposed surfaces for mechanical cleaning and / or acoustic transmission functions. [Figure 7B] Figure 7B shows another exemplary cleaning unit having protrusions on exposed surfaces for mechanical cleaning and / or acoustic transmission functions. [Figure 8] Figure 8 shows another exemplary cleaning unit with protrusions on its exposed surface. [Figure 9] Figure 9 shows another exemplary cleaning unit having two separable parts, one of which carries a cleaning projection and the other which includes a transducer device and a radiator device. [Figure 10] Figure 10 shows another exemplary cleaning unit having a tubular shape for radiating ultrasonic and / or RF waves in multiple directions. [Figure 11] Figure 11 shows an exemplary cleaning apparatus comprising a cleaning unit according to one or more embodiments. [Figure 12] Figure 12 shows another exemplary cleaning apparatus comprising a cleaning unit according to one or more embodiments. [Figure 13] Figure 13 shows yet another exemplary cleaning apparatus comprising a cleaning unit according to one or more embodiments. [Modes for carrying out the invention]

[0075] The present invention will be described with reference to the drawings.

[0076] The detailed description and specific examples illustrate exemplary embodiments of the apparatus, system, and method, but are for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, system, and method of the invention will be better understood from the following description, appended claims, and accompanying drawings. Please understand that the figures are schematic and not drawn to dimensions. Also understand that the same reference numerals are used throughout the figures to indicate the same or similar parts.

[0077] The present invention provides a surface cleaning means based on the combined use of ultrasonic and radio frequency electromagnetic radiation propagated over a surface to be cleaned in order to provide a synergistic cleaning action. One embodiment provides a cleaning unit comprising a main body including an ultrasonic transducer device and an RF radiator device, the two of which are arranged such that when driven by corresponding drive signals, overlapping ultrasonic and RF electromagnetic radiation (for the purpose of cleaning) are generated in a common spatial region, thereby providing a combined cleaning action in the common spatial region.

[0078] Optionally, in some embodiments, this configuration can be combined with an additional mechanical drive mechanism configured to induce sonic frequency reciprocating motion or vibration of the cleaning unit body, which further enhances the cleaning effect. The mechanical vibration further synergistically improves ultrasonic cavitation. This provides a comprehensive cleaning effect.

[0079] One advantageous application area of ​​embodiments of the present invention includes oral cleaning devices, particularly tooth cleaning devices. One area of ​​tooth cleaning devices is electric toothbrushes.

[0080] Currently, the vast majority of electric toothbrushes utilize sonic technology, where the brush bristles are driven by vibrational motion at sonic frequencies. Motor-driven sonic brushes typically produce 24,000 to 72,000 vibrations per minute at speeds of approximately 1.5 m / s or higher, generating reciprocating acoustic pressure and shear stress to remove plaque from the enamel surface of teeth.

[0081] A small number of electric toothbrushes using ultrasonic technology have been proposed. In ultrasonic toothbrushes, a piezoelectric crystal emits sound waves at a minimum frequency of 20,000 Hz or 1,200,000 pulses per minute to generate ultrasonic motion. Ultrasound can be used to induce a cleaning effect via cavitation. In particular, when a liquid is present between the ultrasonic source and the surface to be cleaned, the cavitation induced by the ultrasound generates numerous nano-sized or microscopic cleaning bubbles on the surface, which have the effect of loosening and removing debris and impurities. Thus, cavitation has a surface polishing effect. In addition, bacterial chains that make up plaque can also be broken down by high-frequency, low-amplitude ultrasonic vibrations. Such an ultrasonic effect works even in areas that brush bristles cannot mechanically access, up to 5 mm below the gingival margin. Thus, sonic toothbrushes require the physical movement of the brush bristles to clean the tooth surface and gingival margin, whereas ultrasonic toothbrushes do not.

[0082] Regarding radio frequency (RF) radiation, as mentioned above, RF radiation in certain MHz ranges can cause dielectric heating. In particular, RF radiation is strongly absorbed by tartar, and especially by bound water composed of hydroxyl groups of polysaccharides and glycoproteins, which are the main components of pellicle (bacterial film), plaque, and tartar deposits. Due to the very low specific heat of polysaccharides and glycoproteins, the absorption of RF radiation can result in rapid heating and a rapid rise in temperature. As a result, softening or "melting" of polysaccharides and glycoproteins occurs. With respect to the tooth deposits of pellicle, plaque, and tartar, polysaccharides, glycoproteins, and bound water act effectively as "cement / binders," while inorganic minerals (mainly calcium phosphate crystals) act effectively as "aggregates." Thus, the melting or softening of the "cement" binder has the effect of loosening or softening pellicle, plaque, and tartar particles from the tooth surface, making them easily removable mechanically, for example, by vibrating brush bristles.

[0083] During operation, RF heating induces osmotic and instantaneous heating of water, polysaccharides, and glycoproteins. When exposed to RF radiation, dipole oscillations in water molecules (or hydroxyl groups in polysaccharides and glycoproteins) lag behind field oscillations in time. The resulting interaction between the dipole and the field leads to energy loss due to heating. The degree of heating depends on the phase difference between the dipole oscillation and the field. In water, this phase difference depends on the strength and extent of the hydrogen bond network. In free liquid water, the motion of water dipoles occurs at GHz frequencies (microwaves), while in more restricted "bound" water it occurs at MHz frequencies (short radio waves), and in ice it occurs at kHz frequencies (long radio waves). Thus, electromagnetic radiation in the MHz radio frequency spectrum is most suitable for stimulating the heating of bound water in dental bacterial films, plaque, and calculus deposits. In particular, in embodiments of the present invention, RF radiation in the range of 1 MHz to 300 MHz is preferred.

[0084] Embodiments of the present invention are based on the combined use of radiofrequency electromagnetic radiation and ultrasonic acoustic radiation for a surface cleaning function. These have a synergistic interaction because radiofrequency radiation softens or dissolves surface deposits (e.g., plaque on the surface of teeth), which leads to more effective removal of these deposits using the cavitation effect induced by ultrasonic radiation. Thus, radiofrequency radiation enhances the cleaning effect that would otherwise be achieved by ultrasonic radiation. As a result, cleaning time can also be reduced.

[0085] Another advantage of using a combination of radio frequency radiation and ultrasonic radiation is that the resulting cleaning device can be used with or without mechanical cleaning elements such as brush bristles. This is because the improvement in the ultrasonic cleaning effect brought about by radio frequency radiation is sufficient to provide a highly effective surface cleaning function without necessarily requiring the mechanical abrasion of the surface that was previously required in the current technology. However, the addition of mechanical cleaning can further enhance the cleaning effect in embodiments of the present invention.

[0086] Furthermore, by applying the RF softening effect, the required amplitude and intensity of ultrasonic radiation and any mechanically driven cleaning element can be reduced without compromising the cleaning effect.

[0087] In certain applications of oral cleaning devices, the combination of ultrasound and radio frequency also has additional synergistic effects related to the stimulation of oral tissues. For example, RF radiation promotes irrigation of gingival tissue, which can lead to a healing effect on inflamed gums.

[0088] Figures 1 and 2 show the basic components of an exemplary cleaning unit 12 for a surface cleaning apparatus according to one or more embodiments.

[0089] The cleaning unit 12 comprises a body 14. The body may function as a housing for one or more components of the cleaning unit. In some examples, the body may form the head portion of the cleaning unit, which is located at the distal end of the cleaning unit and coupled to a handle portion 13 that extends away from the body. This is shown in Figure 2.

[0090] The cleaning unit 12 further comprises an ultrasonic transducer device 20 supported by the main body. In the example shown in Figures 1 and 2, the ultrasonic transducer device is housed within the main body 14. The ultrasonic transducer device comprises one or more ultrasonic transducers adapted to generate ultrasonic radiation 22 in response to one or more drive signals. An electrical supply line (not shown) to the ultrasonic transducer device for supplying drive signals is further provided.

[0091] The cleaning unit 12 further comprises an electromagnetic (EM) radiator device 24 supported by a main body 14. In this example, the radiator device is housed within the main body 14. The electromagnetic radiator device is adapted to generate radio frequency electromagnetic radiation 26 in response to the supply of a radio frequency drive signal. Exemplarily, the radiator device comprises one or more conductive elements that can be operated to be driven by an alternating current or voltage, thereby inducing radiation from the elements of electromagnetic radiation. However, other examples, such as the use of metamaterials, are also possible.

[0092] The ultrasonic transducer device 20 and the radiator device 24 are arranged to generate spatially overlapping ultrasonic and EM radiation to enable simultaneous ultrasonic and RF stimulation of the surface 30 to be cleaned. During operation, these radiations may be generated simultaneously, or drive signals may be supplied alternately to the two devices, but these radiations are propagated in a common spatial region between the two devices, thereby enabling combined or cooperative stimulation of a common region of the surface to be cleaned.

[0093] The main body 14 has a first outer surface (outer surface) that forms a first surface 16 of the main body, and the first surface is positioned adjacent to a surface that is to be cleaned during use. The transducer device 20 and the electromagnetic radiator device 24 are each positioned to generate radiation that propagates outward from at least a portion of the first surface 16.

[0094] This is schematically illustrated in Figures 3 and 4. For ease of explanation, Figure 3 schematically shows the electromagnetic radiator device 24 separated from the other components of the cleaning unit. Figure 3 shows that the radiator device 24 generates radio frequency electromagnetic radiation 26 in response to the supply of a radio frequency drive signal (not shown). Figure 3 also shows a transducer device 20, which includes one or more ultrasonic transducers and is adapted to generate ultrasonic radiation 22 in response to one or more drive signals. Figure 4 schematically shows the cleaning unit in operation, with the radiator device 24 and the ultrasonic transducer device 20 each supplied with corresponding drive signals to generate EM and ultrasonic radiation, respectively. As illustrated, the radiator device and transducer device are arranged so that the ultrasonic radiation 22 and RF radiation 26 propagate away from the cleaning unit body 14 into a common spatial region, so that the surface 30 to be cleaned entering this region can be stimulated by the two radiations. These ultrasonic and RF radiations can be generated simultaneously or alternately, for example, periodically.

[0095] In Figures 1 to 4, the ultrasonic transducer device 20 and the EM radiator device 24 are housed or embedded within the main body 14, but this is not essential. In other embodiments, one or both of these elements may be supported, for example, on the surface of the main body.

[0096] The cleaning unit is entirely passive and may consist only of passive electronic components, with active drive electronic circuits located in a separate unit or in another part of the cleaning apparatus in which the cleaning unit forms part. One aspect of the present invention provides the cleaning unit alone without drive electronic circuits or any other parts of the cleaning apparatus in which the cleaning unit forms part.

[0097] The ultrasonic transducer device 20 and the radio frequency radiator device 24 may each be equipped with an electrical supply line configured to receive a corresponding drive signal during operation.

[0098] With respect to the ultrasonic transducer device 20, in different examples, the device may have a single transducer element or may include an array of transducer elements. Any type of ultrasonic transducer can be used. The most commonly used examples include transducers that operate using the piezoelectric effect or the magnetostrictive effect.

[0099] For example, ultrasound can be generated by applying the output of an electron oscillator to a thin wafer of a piezoelectric material such as lead zirconate titanate (PdZrTi or PZT). This provides a simple and relatively low-cost means of generating ultrasound.

[0100] The use of magnetostrictive transducers can be beneficial because they can generate high-intensity ultrasound in the 20–40 kHz range.

[0101] A wide variety of piezoelectric PZT ceramic mixtures can be used to manufacture ultrasonic transducers suitable for use in the present invention. Any other transducer material can be used, such as piezopolymers like single-layer or multi-layer polyvinylidene fluoride (PVDF), or crystalline piezoelectric materials such as lithium niobate (LiNbO3), quartz, and barium titanate (BaTiO3). Those skilled in the art will notice the wide variety of options for implementing ultrasonic transducers.

[0102] The ultrasonic transducer device may have an array of transducer elements, the array occupying a flat surface or a curved or contoured surface. By providing a curved array, for example, focusing of ultrasonic waves becomes possible.

[0103] Generally, an ultrasonic transducer can be driven based on the supply of a drive signal in the form of an alternating current or voltage to the transducer. This causes the transducer to expand and contract, primarily along one axis, in resonance or near-resonance with the frequency of the supplied drive signal. This converts electrical energy into ultrasonic energy.

[0104] With respect to EM emitting devices, the device may have an array of one or more conductive elements, which are adapted to emit electromagnetic radiation or an alternating electromagnetic field (i.e., electromagnetic radiation) when an AC drive signal is supplied. The frequency of the EM radiation may coincide with the frequency of the alternating drive signal. In other cases, the EM emitting device may form part of a resonant circuit including a resonant capacitor, and the frequency of the EM radiation can be adjusted by adjusting the resonant frequency of the resonant circuit.

[0105] The one or more conductive elements described above may comprise one or more electrodes or one or more conductive coils.

[0106] In some embodiments, as an alternative to the use of conductive elements, the radiator device may include elements formed from metamaterials, electroactive materials, or any other material capable of generating electromagnetic radiation in response to the application of an electrically driven signal.

[0107] During operation (and as further described below), the radiator device may be driven by a drive signal having a frequency between 1 and 300 MHz, according to one or more embodiments.

[0108] The various examples described above (and in more detail below) include only EM emitting devices, but according to any of the embodiments described, the cleaning unit may also include means for sensing electromagnetic radiation. This can be facilitated by providing one or more EM sensing elements. In other examples, the same EM emitting device may also be used for sensing, for example, by monitoring changes in the electrical characteristics of a drive signal applied to the emitting device.

[0109] According to one or more embodiments, the sensing can be used to detect the presence of a surface or object within the electromagnetic field emitted by the radiator device. This alters the characteristics of the EM field, which can be detected in changes in the electrical characteristics of the drive signal to the radiator device. The sensing can also be used, or alternatively, to detect the level of cleanliness of a surface during cleaning, again based on changes in the electrical characteristics of the drive signal.

[0110] However, including a sensing function is not mandatory and may be included or omitted in any of the embodiments described herein.

[0111] The frequency of the RF emission is different from the frequency of the ultrasonic emission (and any possible sound wave vibrations of the cleaning element), and therefore, no wave interference occurs between them.

[0112] Figure 5 schematically shows another exemplary cleaning unit 12 according to one or more embodiments. All of the features and options described above in relation to the cleaning units of Figures 1 to 4 are also applicable to the cleaning unit of Figure 5.

[0113] In the example shown in Figure 5, the cleaning unit body 14 includes an acoustic wave directing element 34 configured to receive at least a portion of the ultrasonic radiation 22 generated by the ultrasonic transducer device 20 and to redirect (redirect) the radiation along one or more predetermined propagation paths directed outward and / or away from the body 14. The acoustic wave directing element may be an acoustic reflector element.

[0114] The acoustic wave directing element 34 has a concave redirecting surface structure, and the ultrasonic transducer device is positioned so that the generated ultrasonic waves are received on the concave surface. The concave surface is adapted to reflect the received acoustic waves (at least within the ultrasonic frequency range). The concave surface is oriented so that the reflected waves are directed along one or more propagation paths that lead these waves to a common spatial area outside the main body 14, which is adapted so that the RF waves also propagate during operation.

[0115] The acoustic wave directing element 34 can take the form of, for example, a parabolic acoustic reflector 34.

[0116] In some examples, the acoustic wave directing element 4 can be adapted to focus the received ultrasonic radiation into an ultrasonic beam or a focused ultrasonic path, and to deliver the focused ultrasonic energy onto a localized spot or area of ​​the surface to be cleaned. Figure 5 shows a single acoustic wave directing element 34, but in other examples, multiple elements may be provided.

[0117] The acoustic wave directing element 34 has the effect of reducing the loss of ultrasonic energy through one or more boundaries of the cleaning unit body 14 located behind the reflective surface of the directing element. In the example of Figure 5, the ultrasound is prevented from escaping through the opposite side 17 of the cleaning unit body 14. This is the side opposite to the front 16 of the body from which RF and ultrasonic radiation is intended to be emitted during operation. The directing element further provides collection of ultrasonic energy and direction of said energy to a controlled and predictable spatial region outside the cleaning unit body 14.

[0118] In some examples, the cleaning unit 12 may be used in conjunction with a cleaning device configured to induce mechanical vibrations at the sonic frequency of the cleaning unit. The acoustic wave directing element 34 may be adapted to further provide the function of redirecting the sonic vibration waves. This is possible because sound waves and ultrasound follow the same acoustic reflection laws. Thus, the vibration waves applied to the body may be directed toward the front surface 16 of the cleaning unit body 14 along the same direction as the ultrasound. This further enhances the loosening and removal of plaque and foreign debris. In this way, the reflector can enhance the synergistic dual cleaning effect of ultrasound and sonic vibrations in these examples.

[0119] In a preferred example, the acoustic wave directing element 34 may be configured to reflect at least 95% of the received acoustic waves in one or more output path directions.

[0120] The space between the acoustic wave directing element 34 and the ultrasonic transducer device 20 can be filled with an acoustically conductive material to facilitate the efficient propagation of ultrasound between the transducer device 20 and the acoustic wave directing element 34.

[0121] Materials, methods, and configurations of acoustic wave directing elements, particularly acoustic reflectors, are well known to those skilled in the art. For illustrative purposes, suitable acoustic reflectors usable in embodiments of the present invention are outlined in U.S. Patent Nos. 4,146,869, 3,881,056, 6,417,602, and U.S. Patent Application Publication No. 20020197182.

[0122] Figure 6 shows an exemplary acoustic wave directing element 34 in operation. The acoustic wave directing element is in the form of a concave acoustic reflector. The ultrasonic transducer device 20 is positioned to direct the ultrasonic radiation 22 onto the concave surface of the reflector element 34. The ultrasonic radiation 22 is reflected from the concave surface. Due to its concave shape, the waves are collected or focused into an ultrasonic beam, which propagates away from the concave surface of the reflector element. The focused ultrasonic waves can then be emitted from the body 14 of the cleaning unit 12 and received in localized areas of the surface 30 to be cleaned.

[0123] In a favorable example, the cleaning unit body 14 may further have an ultrasonic shielding component 42 positioned to prevent ultrasonic waves from propagating outward from the body in one or more directions. The ultrasonic shielding component is formed from an acoustically attenuating material to prevent ultrasonic waves from escaping or leaking out of the body in one or more unintended directions during operation. For example, this may be useful in oral cleaning applications to prevent ultrasonic wave propagation from the surface of the cleaning unit body (e.g., the back of the toothbrush head) that faces unintended oral surfaces and tissues during use.

[0124] For example, in the embodiment shown in Figure 5, the shielding component 42 is positioned to prevent ultrasonic leakage from the rear surface 17 of the main body 14. The rear surface is on the opposite side of the main body from the front surface 16 of the main body, which is positioned to emit ultrasonic and RF waves.

[0125] As an example, the ultrasonic shielding component 42 may be composed of a foamed material. The foamed material naturally contains multiple bubbles of air or other gases. Ultrasound penetrates very little through the gaseous medium. Thus, the foamed material provides an excellent attenuation material. In some embodiments, the shielding component may include multiple layers of different materials such that each material has a different acoustic impedance. In some embodiments, the shielding component may further comprise one or more active components such as an energy conversion device or heating, cooling, monitoring and / or sensing elements.

[0126] In the example shown in Figure 5, the ultrasonic shielding component 42 is positioned behind the reflective surface of the acoustic wave directing element 34.

[0127] In one or more embodiments, the acoustic wave directing element 34 and the shielding component 42 may be formed integrally as a single component. In some examples, the ultrasonic transducer device 20, the acoustic wave directing element 34, and the ultrasonic shielding component 42 may all be formed as a single, integrated component. This simplifies manufacturing and improves robustness against damage or deterioration over time.

[0128] According to one or more embodiments, the cleaning unit 12 may further include an impedance matching layer 44 disposed between the first outer surface 16 of the cleaning unit body 14 and the output surface of the ultrasonic transducer device 20. This is shown in the example in Figure 5.

[0129] The impedance matching layer assists in optimally acoustically coupling the ultrasonic energy from the ultrasonic transducer device 20 to the front or surface 16 of the cleaning unit body 14. Optimal impedance matching can be achieved at least in part by selecting the thickness of the impedance matching layer 44 to be approximately one-quarter of the intended wavelength of the ultrasonic radiation to be generated by the ultrasonic transducer device 20 during use.

[0130] The selected material and structure of the impedance matching layer 44 should minimize interference with the radio frequency electromagnetic radiation of the EM radiator device 24. The layer is preferably formed from a durable material that can withstand repeated impacts of the front surface 16 of the body against a surface 30 to be cleaned, for example, during operation.

[0131] One or more impedance matching layers 44 may be provided. Multilayer impedance matching components can improve the efficiency of acoustic transmission, particularly when transmitting from a generally high-impedance material forming the ultrasonic transducer to a typically much lower-impedance material forming the body of the cleaning unit 14. Suitable materials for the impedance matching layers 44 or components may include epoxy, graphite, or others known to those skilled in the art.

[0132] As mentioned earlier, most commonly, cleaning units are equipped with protruding cleaning elements to perform a mechanical cleaning function. For example, many cleaning units are equipped with brush bristles or other protruding cleaning fibers to rub and abrade the tooth surface, thereby removing deposits from the surface.

[0133] Due to the synergistic interaction between ultrasonic radiation and radio frequency radiation, a group of embodiments of the present invention can be provided without such mechanical cleaning elements. For example, a surface cleaning unit without brush bristles can be provided.

[0134] According to another group of embodiments, an apparatus may be provided with a very short cleaning element that protrudes from the radiating output surface 16 of the cleaning unit. The height of such a cleaning element is preferably small in order to minimize the attenuation of ultrasonic waves acoustically transmitted between the front surface 16 of the cleaning unit and the surface 30 to be cleaned during operation.

[0135] Various options for the mechanical cleaning element of a cleaning unit according to one or more embodiments will be described in more detail, starting with a brief background of the problems addressed by various advantageous embodiments.

[0136] As mentioned above, typical cleaning units in this technology are equipped with relatively long cleaning elements or fibers, such as brush bristles, that enable surface scrubbing. The presence of such long cleaning elements causes many detrimental effects in relation to the ultrasonic radiation device and to the acoustic vibrations. In particular, long brush bristles mean that there is a large spatial distance between the output surface of the cleaning unit at the base of the brush bristles and the distal end of the brush bristles that operatively contacts the surface to be cleaned. As a result, a large gap is created between the ultrasonic output surface of the unit and the surface to be cleaned, which causes significant ultrasonic attenuation of waves passing through this gap. Furthermore, the typically soft materials of cleaning brush bristles are poor acoustic conductors, leading to excessive acoustic attenuation.

[0137] More specifically, in acoustics, sound waves and ultrasonic sounds typically propagate as pressure vibration waves through a medium of gas, liquid, or solid.

[0138] All acoustic waves obey a common set of physical properties, including the laws of reflection, refraction, diffusion, absorption, and attenuation. In a fluid environment, ultrasound is limited to longitudinal propagation, while in solid materials, these waves can be longitudinal, transverse, or a combination of both. Longitudinal ultrasound is transmitted linearly and can be focused. Ultrasound gradually attenuates as it travels spatial distance through the medium in which it propagates.

[0139] According to the Newton-Laplace equation c = √(K / p), the speed of sound c is proportional to the square root of the ratio of the bulk modulus K of a medium to its density ρ.

[0140] Therefore, sound travels faster in less elastic media such as steel and iron. Sound travels even slower in more elastic media such as rubber, plastic and fiberglass. These media deform easily when force is applied. Sound waves are attenuated and / or absorbed as they pass through solids that deform easily when force is applied. Generally, the harder the medium, the faster the sound travels.

[0141] However, most commercially available surface cleaning devices, especially most toothbrush devices, use brush heads with soft bristles. In the field of oral cleaning, the soft bristles used in most devices have the following typical characteristics:

[0142] Firstly, the brush bristles are typically made of durable nylon (~1.15 g / cm²) with a relatively low bulk modulus and a typical length of 5-12 mm. 3 It is formed from a density ρ). This soft material means that the bristles relatively attenuate any propagating ultrasound. Furthermore, the relatively long length of the bristles results in greater attenuation, both when propagating along the solid material of the bristles themselves and when propagating through the space between the bristles, due to the longer path length to which the wave is propagated.

[0143] Secondly, due to the relatively long length of the bristles, during use, most of the space between the bristle bundles and between individual bristles is filled with air rather than liquid. This air gap also increases the attenuation of ultrasound. In particular, the adiabatic bulk modulus of air (~142 kPa) is very low compared to materials such as steel (solid, ~160 GPa), water (liquid, ~2.2 GPa), and rubber (plastic, ~1.5~2.0 GPa), which has a significant negative impact on sound wave propagation. This air gap between the bristle bundles and between the bristles prevents ultrasound-induced cavitation from occurring in the target area of ​​the tooth.

[0144] The two characteristics mentioned above result in rapid attenuation of ultrasonic propagation, which in turn weakens ultrasonic vibrations and cavitation, as well as sound wave vibration transmission (if provided). This affects the cleaning effect on surfaces (e.g., teeth).

[0145] According to at least one embodiment of the present invention, the above problem can be at least partially overcome by using a cleaning unit 12 that has no brush bristles or only short mechanical cleaning elements (e.g., short brush bristles or dots). These preferably have a height of 5 mm or less from the surface they support.

[0146] Figure 7 schematically shows an example according to one or more embodiments. Figure 7 shows only the main body 14 of the exemplary cleaning unit 12. Figure 8 shows another example according to one or more embodiments. The exemplary embodiment in Figure 8 has the same components and features as the example in Figure 5 described above, but an array 50 of protrusions 52 is added.

[0147] In both examples in Figures 7 and 8, the body 14 has a first outer surface 16. The ultrasonic transducer device 20 is positioned so that the ultrasonic radiation 22 generated during operation propagates outward from at least a portion of the first surface. The first surface 16 carries an array 50 of projections 52 extending outward from the first surface. These projections are for operational contact with the surface 30 to be cleaned during use. This is for example to enable a mechanical cleaning action. These projections may also provide an ultrasonic coupling function. These projections extend from the first surface to a maximum height h of 5 mm or less.

[0148] By providing the projection 52 at a height of 5 mm or less, the distance that ultrasonic radiation must travel between the output surface 16 of the cleaning unit body 14 and the surface to be cleaned during operation is minimized. When the cleaning unit is positioned during use so that the distal tip of the projection is in contact with the surface to be cleaned, this distance is kept to less than 5 mm. This reduces ultrasonic attenuation.

[0149] The protrusions may take the form of bumps, bosses, dots (e.g., microdots), ridges, blunt spikes, brush bristles, fibers, or any other form or shape of protrusion. These protrusions are intended to contact the surface to be cleaned. They may be used to provide a mechanical cleaning function based on the friction of the protrusions on the surface to be cleaned. In other examples, they may simply provide an acoustic transmission function, enabling an operational acoustic coupling with the surface to be cleaned.

[0150] By replacing the bristle area, which contains long bristles, with only short protrusions, less waste is generated at landfills. Furthermore, because the short protrusions wear down and abrasion less than the long bristles, their lifespan may be extended.

[0151] Furthermore, areas with long brush bristles can be a significant cause of growth and exponential spread of pathogenic microorganisms, especially when the cleaning unit is stored in a relatively humid room-temperature environment. Thus, shorter cleaning elements help reduce the space available for microorganisms to grow and multiply.

[0152] The projections may all be the same height, or they may be of different heights. For example, the distal ends of these projections may define an upper contour or envelope whose height may vary, and the maximum height of the upper contour or envelope from the first surface may be 5 mm or less.

[0153] The shorter the protrusion, the shorter the distance the ultrasonic radiation must travel between the output surface 16 and the surface 30 to be cleaned. This reduces the attenuation of the ultrasonic radiation. However, in many applications, it is beneficial to include protrusions with some height. These protrusions provide an abrasive effect when rubbed against the surface, aiding in surface cleaning. A height of ≤5 mm is preferred as it optimizes the height to provide an abrasive effect while minimizing ultrasonic attenuation. Furthermore, in cleaning applications where a fluid cleaning agent (e.g., toothpaste for oral cleaning) is applied between the output surface 16 and the surface 30 to be cleaned, a gap of ≤5 mm is typically small enough that the fluid cleaning agent completely fills the space between the protrusions during use, thereby improving acoustic conduction by eliminating the gap between the output surface 16 and the surface to be cleaned. For example, in oral cleaning applications, the height of a pea-sized amount of toothpaste is usually ≤5 mm.

[0154] The projections 52, as shown in one or more examples, may have a diameter of, for example, 0.1 to 2.0 mm, preferably 0.5 to 1.0 mm. The height may be 5 mm or less, preferably 0.3 to 4.0 mm, more preferably 2.5 to 3.5 mm.

[0155] In some cases, each projection can be a monolithic structure formed integrally.

[0156] These protrusions may have a curved or rounded shape. However, this is not mandatory, and in other examples, these protrusions may have different shapes, for example, straight side edges. For example, these protrusions may define a polygon in a cross-section parallel to the output surface 16.

[0157] These protrusions can take the form of bumps, and each bump is a integrally formed structure. In some examples, the protrusions can take the form of dots (microdots).

[0158] These multiple protrusions can be formed from the same or different materials and can have the same or different textures, sizes, and shapes. The array 50 of protrusions 52 can, for example, include >100 protrusions. The array 50 can form a regular array or an irregular arrangement.

[0159] In some cases, the projection can take the form of a ridge with a height of 5 mm or less, for example, a height of 0.5 mm to 4.0 mm.

[0160] In some cases, the arrangement 50 of the protrusions 52 and the outer surface portion 16 supporting them can be formed integrally as a single part. This can be achieved, for example, by techniques such as molding or by 3D printing. This provides a simpler manufacturing process compared to brush bristles.

[0161] For oral cleaning applications, the protrusions are short enough so that the space between the protrusions 52 or short brush bristles is almost completely filled with fluid (e.g., saliva, water) and toothpaste during brushing. Thus, the short length not only shortens the acoustic path length to the surface to be cleaned, but also ensures that the remaining path length is optimally filled with fluid, thereby improving acoustic transmission (compared to air).

[0162] According to one or more embodiments, the protrusions may be formed from a material having a Shore A scale hardness of 5 to 120, preferably 10 to 100, and more preferably 20 to 70. As previously mentioned, materials that are too soft lead to excessive attenuation of ultrasound. Forming the protrusions from a relatively hard material improves the transmission of ultrasound to the surface to be cleaned through the protrusions. The hardness range described above has been found to provide an optimal balance between minimizing acoustic attenuation and not compromising the overall flexibility of the protrusions against cracking or breakage due to excessive brittleness.

[0163] Furthermore, as mentioned earlier, the bristles on more typical cleaning units (e.g., those found in electric toothbrushes) are usually made from durable, non-biodegradable nylon. The typical lifespan of a brush head is about 3-6 months, and billions of worn-out electric toothbrush heads end up in landfills every year. Shorter, more durable protrusions or shorter bristles would reduce the amount of waste generated.

[0164] According to one or more embodiments, the projection 52 is formed from a biodegradable polymer such as cellulose plastic in order to reduce the long-term environmental impact.

[0165] In the example shown in Figure 7, the cleaning unit body 14 has a protrusion on only one surface, but in other examples, the protrusion can be provided on multiple sides.

[0166] According to one or more embodiments, the surface portion supporting the array 50 of projections 52 may be the surface of a removable portion of the cleaning unit body. This allows for the replacement of the projection device 52 without replacing the rest of the cleaning unit body 14 (including the transducer device 20 and the EM emitter device 24).

[0167] An example is schematically shown in Figure 9. In this example, the cleaning unit body 14 has at least a first portion 14a and a second portion 14b, and the first surface 16 (radiation output surface) of the cleaning unit is included in the first portion. The first portion is configured to be removably attached and detachable from the second portion. The second portion 14b includes a transducer device 20 and a radiator device 22.

[0168] By using a detachable design, the array of protrusions can be easily attached to or secured to the body 14 of the cleaning unit 12 and can be easily removed for replacement if worn. Physical attachment means between the two parts may include, for example, a slide lock device, a press fit, a snap fit, a zipper, or any other suitable physical retention mechanism. In this way, if the array of protrusions 50 is worn, it can be easily discarded, reducing the volume it occupies in the landfill and eliminating the need to replace the transducer and EM emitter.

[0169] The first part 14a may be a monolithic structure formed integrally in some examples. This means that the arrangement 50 of the protrusions 52 is formed integrally with the surface 16 from which these protrusions project.

[0170] The examples shown in Figures 1 to 9 illustrate a cleaning unit configured such that ultrasonic and RF radiation propagates from the cleaning unit body 14 from a single surface of the body in a generally single propagation direction. According to one or more embodiments, the ultrasonic transducer device 20, the radiator device 24 and / or body 14 may be configured such that ultrasonic and / or RF radiation propagates from the body in two or more directions. In some examples, the radiation may be emitted in directions covering 360 degrees around the body.

[0171] An example is shown in Figure 10.

[0172] In this example, at least a portion of the body 14 of the cleaning unit 12 is tubular (cylindrical). The body has a tubular outer surface, which forms the RF and ultrasonic radiation output surface. An ultrasonic transducer device 20 (not shown) is arranged so that ultrasonic radiation propagates in multiple directions from the output surface. An EM radiator device (not shown) may also be arranged so that RF radiation propagates in multiple directions from the output surface.

[0173] As an example, the main body 14 may include an inner tubular support structure 62 configured to carry, support, or house one or both of the ultrasonic transducer device 20 and the EM radiator device 24.

[0174] As an example, the ultrasonic transducer device (not shown) may include a plurality of transducer elements mounted at a certain range of angular positions around the tubular support structure 62 so that ultrasonic radiation propagates from the main body 14 in a certain range of directions. The same applies to the EM radiator device. That is, a plurality of EM radiator elements can be provided at different angular positions within a certain range around the tubular support structure 62 so that RF radiation can be emitted from the main body 14 in multiple different directions during operation.

[0175] The ultrasonic transducer elements described above may be arranged, for example, in an annular or tubular array.

[0176] As an option, additional acoustic wave directing elements can be provided. For example, cylindrical or tubular acoustic wave reflecting elements can be inserted coaxially with respect to the (e.g., annular) array of ultrasonic transducers, i.e., inserted radially behind the ultrasonic transducer device. In other words, the tubular acoustic reflecting elements may be positioned to surround the axial center of the cleaning unit body 14 and to be positioned between the array of ultrasonic transducer elements and the axial center of the body 14 in the radial direction. This configuration provides ultrasonic reflection around the body in a 360° radius.

[0177] Although Figure 10 shows that a tubular support structure 62 is provided, this is not mandatory, and the ultrasonic transducer device and EM radiator device can also be supported or mounted within the tubular body in a different way, for example, by a frame structure or using supports.

[0178] In the example shown in Figure 10, the cleaning unit body 14 includes an arrangement 50 of protrusions 52 supported on the tubular outer surface of the device. Thus, the arrangement of the protrusions forms a tubular or annular arrangement of protrusions. Any of the options or features described above regarding the arrangement of the protrusions can be equally applied to the example of this embodiment.

[0179] The tubular cleaning unit body may have applications that are particularly advantageous for non-human use, such as cleaning the inner surface of pipes or tubes.

[0180] During operation, a mechanical motion generator may be optionally used to generate vibrations in the cleaning unit body. This may be intended to induce reciprocating motion or vibration at the distal tip of the projection, enabling these tips to perform a mechanical cleaning action when they come into contact with the surface to be cleaned. For example, sonic vibrations of the cleaning unit body 14 can be applied.

[0181] In contexts other than human use, the radio frequency radiation generated by supplying a drive signal to the EM emitting device can cause dielectric heating of surface deposits such as bound water and / or organic contaminants containing hydroxyl groups.

[0182] According to one or more embodiments, for non-human applications, the cleaning unit may include additional functional components or features to support the cleaning function, such as a vacuum, a chemical spray, or one or more sensors for guiding the positioning of the cleaning unit on a surface or for sensing the progress of cleaning.

[0183] Another example according to the present invention is a surface cleaning device 70.

[0184] The surface cleaning apparatus provided may comprise a cleaning unit 12 according to any of the examples or embodiments described above or below, or according to any claim of this application. In other examples, the surface cleaning apparatus provided may be configured to be electrically and mechanically coupled to the cleaning unit 12 when in use.

[0185] An example is shown in Figure 11. The cleaning device includes an ultrasonic driver module 72 that is operable to generate one or more drive signals that generate ultrasonic radiation when coupled to an ultrasonic transducer device 20. The cleaning device further includes a signal generator 74 configured to generate AC drive signals that generate radio frequency radiation when coupled to an electromagnetic radiator device 24.

[0186] Preferably, the cleaning apparatus further comprises a controller 86 operably coupled to an ultrasonic driver module 72 and a signal generator 74, and configured to control the ultrasonic driver module and the signal generator to activate them simultaneously, thereby simultaneously generating an ultrasonic drive signal and an AC RF drive signal. This enables the simultaneous generation of RF radiation and ultrasonic radiation during operation. Alternatively, the controller may be configured to control the ultrasonic driver module 72 and the signal generator 74 to generate them.

[0187] Furthermore, a signal interconnect can be provided that is configured to provide a fixed or detachable electrical interconnect between the ultrasonic driver module 72 and the cleaning unit 12, which includes the ultrasonic transducer device 20. The signal interconnect may include one or more wire interconnects.

[0188] If the cleaning device is configured to be releasably coupled to the cleaning unit 12, the cleaning device may include an electrical connector 78 configured to electrically couple with the mating electrical connector of the cleaning unit when the cleaning unit is coupled to the device, and these coupled connectors establish an electrical interconnection between the driver and generator in the device and the transducer and radiator in the cleaning unit.

[0189] Figure 11 shows an example in which the cleaning unit 12 can be detachably coupled to the base unit 76 of the cleaning device, which has a housing containing the ultrasonic driver module 72 and RF signal generator 74 of the cleaning device described above.

[0190] Figure 12 shows an example in which the cleaning unit 12 is fixedly attached (for example, integrally attached) to the base unit 76 of the cleaning device 70.

[0191] Figure 13 shows another example of the cleaning device 70, which further includes a mechanical drive mechanism 82 that can be operated to provide a source of sonic vibration motion, and a mechanical coupling arm 84 for coupling the sonic vibration motion to the cleaning unit 12.

[0192] The mechanical connecting arm 84 extends from the top of the base unit 76 and is configured to extend through or be received into the internal cavity of the handle portion 13 of the cleaning unit 12 in the cleaning device. The handle portion is coupled at its distal end to the body 14 (e.g., the head) of the cleaning unit.

[0193] The mechanical connecting arm described above couples the sonic motion to the main body 14 of the cleaning unit. This enables a synergistic combination during operation of RF softening of surface contaminants, ultrasonic-induced cavitation on the surface to be cleaned, and mechanical agitation (for example, scraping or polishing using the arrangement of protrusions 52 on the surface of the cleaning unit body).

[0194] A controller 86 can be further provided, configured to operate the ultrasonic driver module 72, the signal generator 74, and the mechanical drive mechanism 82 simultaneously or alternately during the operation of the device.

[0195] The handle portion 13 of the cleaning unit 12 may further have interconnection wiring to provide electrical interconnection between the ultrasonic driver module 72 and RF signal generator 74 in the base unit 76 and the ultrasonic transducer device 20 and EM radiator device 24 in the cleaning unit body 14.

[0196] According to one of the exemplary cleaning devices 70, the base unit 76 of the cleaning device may further have a rechargeable power source, such as a battery, to provide a power source for the ultrasonic driver module 72 and the RF signal generator 74.

[0197] The cleaning device 70 may be an oral cleaning device for cleaning the oral surface.

[0198] When used in the oral cavity, the combined ultrasonic and RF radiation advantageously allows for cleaning of areas that are mechanically inaccessible, such as the gums and subgingival regions. In this way, oral cleaning and consequently oral health can be improved.

[0199] In addition to performing cleaning functions, when used in the oral cavity, the combined use of ultrasound and radiofrequency radiation enables a range of beneficial therapeutic effects. For example, RF radiation promotes irrigation of gingival tissue, which has a healing effect on inflamed gums. For instance, RF waves lead to fibroblast replenishment, while ultrasound leads to collagen type conversion. These contribute to complementary parts of the same overall healing response, but these two energies synergistically enhance or elevate each other's tissue repair.

[0200] Furthermore, RF radiation removes minerals from the tooth surface and returns them to the solution, allowing bone cells to recycle them for remineralization. Remineralization has the advantage of reducing hypersensitivity in teeth undergoing erosion repair. This effect can be achieved even in areas that are mechanically inaccessible, such as below and near the gingival line.

[0201] In a preferred example, the signal generator 74 may be configured (or controlled) to generate a drive signal within the frequency range of 1 MHz to 300 MHz in order to cause the EM radiator device 24 to produce EM radiation in the frequency range of 1 MHz to 300 MHz.

[0202] The ultrasonic driver module 72 may be configured (or controlled) to generate a drive signal for generating ultrasonic radiation in the frequency range of 20 kHz to 300 MHz. According to one group of embodiments, the device is for human use, and the ultrasonic driver module is configured (or controlled) to generate a drive signal for generating ultrasonic radiation of less than 10 MHz.

[0203] According to one embodiment, the device is for non-human use, and the ultrasonic driver module is configured to generate a drive signal for generating ultrasonic radiation at frequencies of 10 MHz or higher. While these frequencies may not be safe for human use, they can produce stronger cavitation and therefore a stronger cleaning effect for non-human use.

[0204] Another example of the present invention provides a surface cleaning method that includes the step of simultaneously supplying ultrasonic radiation and RF electromagnetic radiation to a surface to be cleaned.

[0205] The method may further include a step of mechanically rubbing the surface to be cleaned, simultaneously with the application of ultrasonic radiation and RF electromagnetic radiation.

[0206] The method is preferably carried out with water or another liquid located between the surface to be cleaned and at least the acoustic output surface of the ultrasonic transducer device.

[0207] In a more specific embodiment, the method may include, in the case of a surface cleaning apparatus, the step of controlling the emission of ultrasonic radiation and radio frequency electromagnetic radiation from the cleaning unit.

[0208] In this group of embodiments, the method may include the step of supplying one or more drive signals to a transducer device included in the body of a cleaning unit, the transducer device having one or more ultrasonic transducers. These drive signals are adapted to cause the transducer device to generate ultrasonic radiation.

[0209] The method may further include the step of supplying one or more radio frequency drive signals to an electromagnetic radiator device included in the body of a cleaning unit. The drive signals are adapted to cause the radiator device to produce radio frequency electromagnetic radiation.

[0210] The ultrasonic transducer and radiator are arranged to generate spatially overlapping ultrasonic and EM radiation, enabling simultaneous ultrasonic and RF stimulation of the surface 30 to be cleaned.

[0211] As described above, the embodiments utilize a controller. This controller can be implemented in various ways using software and / or hardware to perform various necessary functions. A processor is an example of a controller using one or more microprocessors that can be programmed using software (e.g., microcode) to perform the necessary functions. However, the controller can be implemented with or without a processor, and can also be implemented as a combination of dedicated hardware for performing some functions and a processor (e.g., one or more programmed microprocessors and associated circuits) for performing other functions.

[0212] Examples of controller components that can be used in various embodiments of this disclosure include, but are not limited to, common microprocessors, application-specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0213] In various implementations, a processor or controller may be combined with one or more storage media, such as volatile and non-volatile computer memory, including RAM, PROM, EPROM, and EEPROM. These storage media may be encoded with one or more programs that perform the necessary functions when executed on one or more processors and / or controllers. These storage media may be fixed within the processor or controller, or they may be portable so that the stored programs can be loaded into the processor or controller.

[0214] Variations of the disclosed embodiments can be understood and implemented by those skilled in the art who practice the claimed inventions by examining the drawings, this disclosure, and the appended claims. In the claims, the word "including" does not exclude other elements or steps, and the singular form does not exclude the plural.

[0215] Furthermore, a single processor or other unit can perform some of the functions described in the claims.

[0216] Furthermore, the mere fact that certain means are described in different dependent claims does not indicate that combinations of these means cannot be used advantageously.

[0217] Note that when the term “conformed” is used in a claim or description, it is intended to be equivalent to the term “constituted.”

[0218] No reference symbol in a claim should be construed as limiting the scope.

Claims

1. A cleaning unit for a surface cleaning device, The main unit and An arrangement of protrusions or cleaning elements on the surface of the main body to be operatively contacted with the surface to be cleaned during use in order to enable a mechanical cleaning action, An ultrasonic transducer device supported by the aforementioned main body, comprising one or more ultrasonic transducers that generate ultrasonic radiation in response to one or more drive signals, An electromagnetic radiator device supported by the aforementioned body, wherein the electromagnetic radiator device generates radio frequency (RF) electromagnetic (EM) radiation in response to the supply of a radio frequency (RF) drive signal. It has, The ultrasonic transducer device and the electromagnetic radiator device generate spatially overlapping ultrasonic and EM radiation to enable simultaneous ultrasonic and RF stimulation of the surface to be cleaned. Cleaning unit.

2. The main body has a first outer surface which forms a first surface of the main body for placement adjacent to a surface to be cleaned during use, The ultrasonic transducer device and the electromagnetic radiator device each generate radiation that propagates outward from at least a portion of the first surface. The cleaning unit according to claim 1.

3. The cleaning unit according to claim 1 or 2, wherein the main body receives the ultrasonic radiation from the ultrasonic transducer device and redirects the ultrasonic radiation along one or more predetermined propagation paths outward from the main body and / or away from the main body.

4. The cleaning unit according to claim 3, wherein the acoustic wave directing element focuses the received ultrasonic radiation into one or more ultrasonic beams directed along one or more propagation paths.

5. The cleaning unit according to claim 4, wherein the acoustic wave directing element comprises one or more parabolic acoustic reflectors.

6. The cleaning unit according to any one of claims 1 to 5, wherein the main body comprises an ultrasonic shielding component that prevents the propagation of ultrasonic waves in one or more directions from the main body.

7. The main body has an outer first surface, and the ultrasonic transducer device generates ultrasonic radiation that propagates outward from at least a portion of the first surface. The cleaning unit according to any one of claims 1 to 6, wherein the first surface carries the arrangement of projections extending outward from the first surface, and these projections are to be operationally brought into contact with the surface to be cleaned during use to enable a mechanical cleaning action, and these projections extend from the first surface to a maximum height of 5 mm or less.

8. The cleaning unit according to claim 7, wherein the protrusion is formed from a material having a Shore A scale hardness of 5 to 120, preferably 10 to 100, and more preferably 20 to 70.

9. The cleaning unit according to claim 7 or 8, wherein the main body has at least a first part and a second part, the first surface is included in the first part, the first part is detachable from the second part, and the second part has the ultrasonic transducer device and the electromagnetic radiator device.

10. The cleaning unit according to any one of claims 1 to 9, wherein the cleaning unit is for an oral cleaning device and the main body is received in the mouth of a user.

11. The cleaning unit according to any one of claims 1 to 10, wherein at least a portion of the main body is tubular, the main body has a tubular outer surface which forms an output surface for RF and ultrasonic radiation, and the ultrasonic transducer device is arranged such that the ultrasonic radiation propagates in multiple directions from the output surface.

12. A cleaning unit according to any one of claims 1 to 11, An ultrasonic driver module that is operable to generate one or more drive signals that generate ultrasonic radiation when coupled to the ultrasonic transducer, A signal generator that generates an AC drive signal that generates radio frequency radiation when coupled to the electromagnetic radiator device, and A surface cleaning device having the following features.

13. The surface cleaning device according to claim 12, wherein the surface cleaning device comprises a base unit, and the cleaning unit is detachably coupled to the base unit of the surface cleaning device.

14. The surface cleaning device according to claim 12 or 13, wherein the surface cleaning device is an oral cleaning device.

15. A surface cleaning apparatus according to any one of claims 12 to 14, further comprising a mechanical drive mechanism operable to provide a source of sonic vibration motion, and a mechanical coupling arm for coupling the sonic vibration motion to the cleaning unit.

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