Wearable devices for transdermal product delivery

Abstract

The present invention comprises a head (3) having an outer cavity (6) which resonantly accommodates two ultrasonic resonators (resonator 1, resonator 2). The first resonator (1) located at the more distal side emits towards the skin at a first frequency, and the second resonator (2) located at the more proximal side surrounds the outer cavity (6) and emits parallel to the skin at a second frequency. One of the frequencies is high frequency sonication (HFS) and the other is low frequency sonication (LFS). The second resonator (2) comprises an inner through hole (7) to enable the waves from the first resonator (1) to pass through. The waves from the second resonator (2) pass through the head (3), the inner through hole (7) and the outer cavity (6), bounce off and interfere with the waves from the first resonator (1) at the opposite area of ​​the head (3). The interference between the waves creates a static field that increases skin permeability, enabling a device with reduced size to be incorporated into a wearable device.

Description

Technical Field

[0001] The invention may be included in the health and personal care field, more particularly for the delivery of products containing active substances, such as pharmaceuticals and cosmetics. More specifically, the object of the invention is a wearable device for the transdermal and non-invasive delivery of products. Background Art

[0002] There are different techniques and devices for the transdermal and non-invasive delivery of drugs whose molecules are of considerable size, such as insulin.

[0003] To do this, the drug must pass through the stratum corneum of the patient's skin, which has a low absorption capacity, especially for high molecular weight molecules such as insulin.

[0004] The structure of human skin has a stratum corneum consisting of an outer layer of dead cells (keratinocytes) embedded in a lipid matrix, which makes it difficult for substances to diffuse through it, especially substances such as insulin whose molecular size is larger than that of the skin pores.

[0005] In this sense, several techniques were initially developed, such as electrophoresis (voltages up to 150 V) or iontophoresis at lower voltages.

[0006] The benefits of sonophoresis, which involves applying ultrasound waves to a liquid in contact with the skin containing the substance to be applied to the inside of the skin, were discovered starting in 1950. Initially, corticosteroids were transferred using frequencies between 700kHz and 10,000kHz (high-frequency sonophoresis, HFS), and the transfer was 10 times more effective than without ultrasound, thanks to a stable cavitation effect, which forms bubbles oscillating within the stratum corneum in a lipid matrix, disrupting the layers of the stratum corneum to allow better penetration of small molecules.

[0007] Since the 1990s, the study of medium and low frequency sonoporous effects has been started due to the understanding that the application of ultrasound cavitation effect can improve the transmission of certain substances through the skin, and the effect related to liquid cavitation increases inversely with the frequency. The effects of low frequencies of 20-100kHz (low frequency sonophoresis, LFS) began to be studied, and it was found that in LFS, the lower the frequency, the greater the permeability, which indicates that transient cavitation is the most important mechanism for improving skin permeability using LFS.

[0008] Since 1996, several studies have been published on multi-frequency sonophoresis—one frequency in the HFS range and another in the LFS range—with promising results in the application of HFS and LFS, respectively. However, there is a drawback in that for the application of LFS frequencies, the size of the transducer used to deliver LFS frequency waves increases as the frequency decreases and the intensity increases, so the size of the device that delivers a high enough intensity is too large to be part of a wearable device. In other words, the low-frequency ultrasound transducer used to achieve the required intensity is too large to be added to a wearable device. Summary of the invention

[0009] The present invention describes a device for the transdermal delivery of a product in a non-invasive manner, which device is wearable thanks to the combination of two ultrasonic resonators, for example of the piezoelectric type, housed in the same head, one located in a distal position and the other located in a proximal position, so that each resonator, in combination with the configuration of the head, defines a transducer, wherein one of the two resonators operates in resonance at the LFS frequency and the other resonates at the HFS frequency, and similarly, the resonator located in the proximal position has an internal through hole through which the emissions from the other more distal resonator can pass, so that the emissions from the two resonators interact to produce a static field, which increases the permeability effect for a given resonator size, thereby enabling the size of the device to be reduced to obtain a predetermined performance.

[0010] By means of the device of the invention, the product penetrates the stratum corneum by cavitation and opening of the pores, in a reversible manner without causing damage to the skin.

[0011] The device of the invention may optionally have medical uses as will be explained later, but not in an exclusive manner.

[0012] Generally speaking, according to the prior art, the thickness and size of the resonator are determined by the frequency and intensity at which it operates. However, the device of the present invention manages to amplify the generated waves, obtaining resonance peaks at the desired frequencies, especially in the LFS frequency range, because its design emits the wave front in different ways throughout the structure of its head, thus providing the generated waves of the desired frequency and intensity, as described above, in both the LFS and HFS cases, a static field is generated that amplifies the permeability effect. All this allows the device to be made in a size suitable for forming part of a wearable device.

[0013] The configuration of the device enables it to be applied to the delivery of various products. The products can be liquids with higher or lower density or viscosity, and likewise they can have a non-liquid texture such as a gel, ointment or cream. The device can be a device for medical use, as both liquid products and products with non-liquid textures can contain drugs such as insulin. Alternatively, the device can be configured to deliver other types of products such as cosmetics, which can be liquid or have a non-liquid texture, for example, a cream, gel, ointment, etc. as described above.

[0014] The present invention has a preferred exemplary embodiment in which the resonator at the proximal position operates at a resonant frequency of the LFS, while the resonator at the distal position operates at a resonant frequency of the HFS, and another preferred exemplary embodiment in which the opposite occurs, i.e., the resonator at the proximal position operates at a resonant frequency of the HFS, while the resonator at the distal position operates at a resonant frequency of the LFS. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The aforementioned and other advantages and features will be better understood on the basis of the following detailed description of several embodiments with reference to the accompanying drawings, which must be interpreted in an illustrative and non-limiting manner, in which:

[0016] Figure 1 A schematic side view of the head of the device is shown.

[0017] Figure 2A and Figure 2B , Figure 2A a schematic cross-sectional side view showing the construction of a first exemplary embodiment of the device according to the invention, Figure 2B A cross-sectional side view of the head is shown.

[0018] Figure 3A and Figure 3B , Figure 3A a schematic cross-sectional side view showing the construction of a second exemplary embodiment of the device according to the invention, Figure 3B A cross-sectional side view of the head is shown. DETAILED DESCRIPTION

[0019] Next, with the help of the above Figure 1-Figure 3B , provides a detailed description of a preferred exemplary embodiment of a wearable medical device for universal transdermal delivery of an article, and is particularly, but not exclusively, intended for delivery of drugs, more specifically, for delivery of insulin, and which enables the article to penetrate the stratum corneum of the user's skin by cavitation and opening the pores in a reversible and non-damaging manner.

[0020] like Figure 1As shown, the device of the invention comprises two ultrasonic resonators (1, 2), for example of the piezoelectric type, mounted in a same head 3. The head 3 has a proximal region 4 intended to come into contact with the user's skin, and a distal region 5 opposite the proximal region 4 and therefore remote from the user's skin.

[0021] In the proximal region 4, the head 3 has an outer cavity 6, which is intended to contain an ultrasonic conductive substance when in use, which can be a liquid or can also have a non-liquid texture such as an ointment, cream or gel to prevent the presence of gas and thus enable the transmission of ultrasound from the head 3 to the skin. Generally speaking, the ultrasonic conductive substance is consistent with the product to be applied, although it does not necessarily have to be this way. In particular, the product can be deposited in the cavity 6 of the head 3, and then the head 3 is applied to the skin to contact the skin with the product. Alternatively, the device can be applied to a reservoir (not shown) of the product, such as a patch, which is arranged to be fixed (for example, by an adhesive) or simply superimposed on the user's skin. By way of illustration, another possibility is that the device additionally includes a supply element (not shown) that is detachably or non-detachably connected to the head 3 near the cavity 6 to supply the product, in particular to supply the product according to a predetermined dose. The head 3 is preferably made of one or more biocompatible materials.

[0022] The resonators (1, 2) include a first resonator 1 located in a distal region 5 and thus not affected by the cavity 6, and a second resonator 2 located in a proximal region 4, as described below, which surrounds at least a portion of the cavity 6. The resonators (1, 2) are intended to emit narrowband ultrasound waves and operate in resonance, each resonator operating at a predetermined frequency.

[0023] The first resonator 1 is shaped, for example, as a disk, and when in use, the first resonator 1 emits ultrasonic radiation at a first frequency towards the skin of the user, the ultrasonic radiation being approximately in a direction perpendicular to the skin towards the cavity 6. In addition, the second resonator 2 is hollow and when in use, the second resonator 2 emits waves at a second frequency, i.e. the inner through hole 7 of the second resonator 2 enables the waves of the first frequency to pass through without hitting the second resonator 2. Preferably, the inner through hole 7 is larger than the first resonator 1, so that all the waves emitted by the first resonator 1 pass through the inner through hole 7 of the second resonator 2. The second resonator 2 can have an annular shape, whether it has a generatrix that is circular, square, etc. and a directrix that is circular or of other type. Preferably, it has the shape of a circular ring, i.e. an annular ring or a ring with a rectangular cross section.

[0024] The first resonator 1 is superimposed on the second resonator 2, but is not contained by the second resonator 2, that is, the first resonator 1 is at a different height. The superposition makes the wave emitted by the first resonator 1 not collide with the second resonator 2, but pass through the inner through hole 7, as described above.

[0025] The cavity 6 of the head 3 corresponds to the portion at the height of the second resonator 2 and is surrounded by the second resonator 2. Therefore, the waves emitted by the second resonator 2 are substantially parallel to the skin and can amplify the penetration effect of the first resonator 1.

[0026] The head 3 has a triple function: supporting the resonators (1, 2), providing physical continuity for the path of the waves, and causing resonance at a first frequency and a second frequency, as described below. The head 3 is preferably made of a metal such as aluminum, or alternatively, made of a biocompatible polymer material such as polypropylene. Preferably, the head 3 is a unitary structure. The resonators (1, 2) are assembled to the head 3, and the head 3 is configured so that once the resonators (1, 2) have been assembled, the waves emitted by the resonators (1, 2) circulate through the head 3 without encountering gaseous matter before leaving the head 3 to prevent malfunction of the resonators (1, 2). For example, if Figure 2A , Figure 2B , Figure 3A and Figure 3B As shown, the head 3 comprises a receiving portion 13 received in the inner through hole 7 of the second resonator 2, and the receiving portion 13 preferably occupies a peripheral portion of the inner through hole 7. Preferably, the receiving portion 13 constitutes an integral part of the head 3.

[0027] As mentioned before, the second resonator 2 has an internal through hole 7, for example, because it is equipped with the above-mentioned ring shape, and is installed in the head 3 corresponding to the cavity 6, so that the cavity 6 also occupies the internal through hole 7 together with the housing 13 of the head 3. Therefore, firstly, the radiation emitted by the first resonator 1 to the user's skin passes through the internal through hole 7 and the cavity 6 and reaches the skin. Secondly, in the horizontal direction, the waves generated by the second resonator 2 do not escape from the head 3 to "infinity", but are emitted through the internal through hole 7, thus passing through the head 3 and the cavity 6, so they collide, bounce off the relative area of ​​the head 3 itself, and since they are all generated in the horizontal direction, a static field is generated in the cavity 6 for the waves from the second resonator 2, which interacts with the waves of the first resonator 1, which increases the impact of the skin acting in the area surrounded by the head 3 and the second resonator 2 under resonance conditions, further increasing the permeability of the affected skin area and, therefore, increasing the effectiveness of the supply. It is therefore possible to obtain the desired resonance and intensity conditions in a device of such small size, so as to be incorporated into a wearable device.

[0028] The frequency emitted by one of the two resonators (1, 2), the first resonator 1 or the second resonator 2, is significantly lower than the frequency emitted by the other resonator, which has a higher frequency. The low frequency is in the typical LFS domain, i.e. the lowest ultrasonic domain, between about 20 kHz and 100 kHz. Values ​​close to 20 kHz, at the upper limit of human hearing, produce satisfactory results, although at the expense of auditory discomfort for the user. Frequencies in the 55 kHz environment, between 50 kHz and 60 kHz, have been chosen as preferred low frequencies. Furthermore, the high frequency is in the typical HFS domain, for example, between about 1 MHz, 800 kHz and 1200 kHz. The invention works satisfactorily if the first frequency is a high frequency and the second frequency is a low frequency, or vice versa.

[0029] In addition to the configuration of the resonators (1, 2) and their assembly in the head 3 as described above, another feature of the device of the present invention is the resonance process as described below.

[0030] As mentioned above, one of the resonators (1, 2) is intended to be supplied with an HFS frequency so as to transmit ultrasonic waves at the HFS frequency and resonate at the HFS frequency, while the other resonator (1, 2) is intended to be supplied with an LFS frequency so as to transmit ultrasonic waves at the LFS frequency and resonate at the LFS frequency. Each of the resonators (1, 2) has a fundamental vibration frequency according to certain vibration modes, for example, in a thickness mode or in a radial mode, due to its construction.

[0031] For example, a solid resonator (1, 2) in the shape of a cylinder (disk) has a fundamental frequency in the thickness mode, which decreases as the size of the resonator increases, and vice versa. For example, a ceramic with a fundamental frequency of 4 MHz may have a thickness of 0.5 mm and a diameter of 6 mm, while a ceramic with a fundamental frequency of 2 MHz may have a thickness of 1 mm and a diameter of 6 mm, and a ceramic with a fundamental frequency of 1 MHz may have a thickness of 2 mm and a diameter of 10 mm. In other words, a resonator (1, 2) shaped like a disk with a reduced size like the first resonator 1 is suitable for obtaining resonance at the HFS frequency in the thickness mode without adaptation.

[0032] In order to operate resonantly at the LFS frequency in thickness mode, the hollow resonators (1, 2) shaped like a ring, such as the second resonator 2, must have a large size, which is unacceptable in wearable devices.

[0033] In order to solve the above disadvantages, the present invention proposes two types of solutions as shown below, which will be described in detail in the following embodiments.

[0034] A first solution consists in using a first resonator 1 which is solid, for example in the shape of a disk, provided with a fundamental frequency in the thickness mode in the HFS range, provided with a fundamental frequency in the thickness mode in the HFS range, as described below, so as to resonantly operate at the LFS frequency, comprising in the head 3 some parts (8, 9, 10) intended to be in contact with the first resonator 1, thus forming an assembly of first resonator 1 + head 3 which has physical continuity and constitutes a transducer which resonates in the flexion mode at the LFS frequency when supplied with the LFS frequency, even if this LFS frequency is not the fundamental frequency of the first resonator 1 in the thickness mode. A second resonator 2 which has a hollow shape, such as a ring, may have a fundamental frequency in the thickness mode in the HFS range, so that it will resonate at the HFS frequency when supplied with the HFS frequency. According to Figure 2A and Figure 2B , a first example which will be described in detail below indicates dimensions and features which support the explanations made in the first solution.

[0035] In addition, the second solution consists in taking advantage of the fact that the second resonator 2, which has a hollow shape such as a ring, due to its size and structure, has a fundamental frequency in the LFS range in the radial mode, and not in the thickness mode. Therefore, when supplied with the LFS frequency, the second resonator 2 will resonate in the radial mode at the LFS frequency. Furthermore, the first resonator 1, which has a disk shape, due to its size, will have a fundamental frequency in the HFS range in the thickness mode, and when supplied with the HFS frequency, it will resonate at the HFS frequency. According to Figure 3A and Figure 3B , the second example described in detail below indicates dimensions and features that support the explanations made in the second solution.

[0036] Example Description

[0037] The device of the invention has the possibility of operating in different types of operation based on the resonators (1, 2), such as the bending-transmission type (see Figure 2A and Figure 2B ) and transport-transfer type (see Figure 3A and Figure 3B ).according to Figure 2A and Figure 2B For the resonators (resonator 1, resonator 2) operating in the bending-transmission type, the membrane 8 in contact with the first resonator 1 is arranged substantially as an integral part of the head 3, the membrane 8 is preferably made of metal and vibrates by bending. In addition, the head 3 may also include two protrusions (9, 10), one of which is a proximal protrusion 9 and the other is a distal protrusion 10, wherein the protrusions (9, 10) cooperate with the membrane 8 to work in resonance with the first resonator 1 in the flexion-tension mode at a predetermined LFS frequency. In the case of the transmission-transmission type, according to Figure 3A and Figure 3B , the membrane 8 is not required, although similarly the head 3 may comprise a transmission disc 14 for transmitting vibrations.

[0038] The height of the cavity 6 is related to the height of the second resonator 2 and is selected based on the content of the desired product that can be accommodated in the cavity 6, because a reduced height amount will require the user to frequently replace the product in the cavity 6 and a high amount will lead to greater risks in managing a larger amount. According to a preferred exemplary embodiment, the height of the cavity 6 is about 1-2 mm. When in use, the cavity 6 contains an ultrasonic conductive substance to prevent the presence of gas and thus enable the transmission of ultrasound from the head 3 to the skin. The ultrasonic conductive substance can be liquid, or can have a non-liquid texture such as cream, gel, ointment, etc., as long as it is ultrasonic conductive. In particular, when the product to be applied happens to be ultrasonic conductive, the ultrasonic conductive substance can be the product to be applied. The device of the present invention can also be used to supply products with non-liquid textures such as the above-mentioned creams, gels, ointments, etc. To this end, first, the device of the present invention is used with an ultrasonic conductive substance to produce the effects of cavitation and opening the pores of the skin, and these effects are utilized to apply and absorb active products with non-liquid textures such as creams, gels, ointments, etc. without using the device, and the ultrasonic conductive substance can be harmless.

[0039] By way of illustrative, non-limiting example, the head 3 has a cylindrical shape with an inverted "U" shaped cross section with a diameter of about 25 mm, a height of about 2-10 mm, preferably 5-10 mm, and a cavity 6 with a height of about 2-3 mm, 3 mm.

[0040] In order to achieve a sufficiently high acoustic pressure to facilitate the above-mentioned combined effect, i.e. the combined effect caused by the generation of a sufficient number of cavitation bubbles and the opening of the pores in the skin by the implosion of the cavitation bubbles, it is more convenient to emit waves capable of generating high ultrasound intensities, which are greater than 0.5 W / cm 2 , preferably greater than 1W / cm 2 In this sense, above 1W / cm 2 In order to meet the limits set by several laws, and in particular to prevent the eventual risk of skin damage, it is preferred to keep the intensity value at 1 W / cm 2 and 2W / cm 2 between.

[0041] Two examples of features of a head 3 with two resonators (1, 2) are shown below. Figure 2A , Figure 2B , Figure 3A and Figure 3B shown.

[0042] In both examples, the head 3 is a monolithic structure made of aluminium. Alternatively, the head 3 may be a monolithic structure made of polypropylene.

[0043] See Figure 2A , Figure 2B , according to a first example called bend-transmission, comprising the following components:

[0044] The first resonator 1, which is configured as a ceramic disk and used for power application, has a variable thickness between 0.5 mm and 1 mm and a diameter of 6 mm, and has a vibration fundamental frequency of 2 MHz or 4 MHz in a thickness mode.

[0045] The second resonator 2, which is configured as a ring made of ceramic with a rectangular cross section and a circular directrix and is used for power application, has a thickness of 2 mm, an outer diameter of 20 mm and an inner diameter of 14 mm, and has a vibration fundamental frequency of 1 MHz in a thickness mode.

[0046] The diaphragm 8 , which has a diameter of 11 mm and a variable thickness and which is inserted between the first resonator 1 and the second resonator 2 and contacts the first resonator 1 in order to vibrate together with the first resonator 1 in the flexion mode supplied by the first resonator 1 .

[0047] A cavity 6 , which has a variable height and a diameter of 11 mm, is located on the membrane 8 .

[0048] Two protrusions (9, 10), one of which is a proximal protrusion 9 and the other is a distal protrusion 10, between which the membrane 8 is supported, wherein the distal protrusion 10 has an outer diameter of 14 mm and an inner diameter of 8 mm, and the proximal protrusion 9 has an outer diameter of 11 mm and an inner diameter of 8 mm. The protrusions (9, 10) cooperate with the membrane 8 to work in resonance with the first resonator 1 at a predetermined LFS frequency of 55 kHz.

[0049] The head 3 is used to fix the resonators (1, 2) and is supplied with vibrations transmitted from the first resonator 1, and the head 3 is partially composed of a membrane 8 and a proximal protrusion 9 and a distal protrusion 10.

[0050] The receiving portion 13 , which constitutes part of the head portion 3 , is received in a more peripheral area of ​​the inner through hole 7 .

[0051] An adhesive layer 12 , which has a variable thickness, is located between the second resonator 2 and the head 3 .

[0052] In the first example, the coupled "thickness" mode of the second resonator 2 is used to transfer the resonant vibration to the head 3 to which it is attached by direct transmission, wherein the resonant frequency of the second resonator 2, although slightly varied due to the wall thickness of the head 3, is essentially dependent on the shape and material of the second resonator 2. Similarly, the first resonator 1 is used as a supplier of the main frequency, which is a function of the characteristics of the first resonator 1, as well as the configuration of the diaphragm 8 and the protrusions (9, 10), in particular, the overall bending of the first resonator 1, the bending mode of the first resonator 1 being at 55kHz.

[0053] In addition, see Figure 3A , Figure 3B , according to a second example called a transport-transport type, comprising the following components:

[0054] The first resonator 1, which is configured as a ceramic disk and used for power application, has a thickness of 2 mm and a diameter of 10 mm and has a vibration main frequency of 1 MHz in a thickness mode.

[0055] The second resonator 2, which is made of ceramic and used for power application, is configured as a ring with a rectangular cross section and a circular directrix, the ring has a thickness of 2 mm, an outer diameter of 20 mm and an inner diameter of 14 mm, and has a radial vibration main frequency of 55 kHz.

[0056] A transmission disk 14 , which has a diameter of 11 mm and a variable thickness, is arranged on the first resonator 1 in order to receive the vibration of the first resonator 1 and transmit the vibration from the first resonator 1 to the cavity 6 by transmission.

[0057] The cavity 6 , which has a variable height of approximately 3.5 mm and a diameter of 11 mm, is located above the transmission disc 14 .

[0058] The head 3 is used to fasten the resonators (1, 2) and is partially composed of a transmission plate 14, and the transmission plate 14 receives the vibration from the first resonator 1 through transmission.

[0059] The receiving portion 13 constitutes a part of the head portion 3 and is intended to be received in the inner through hole 7 .

[0060] In the second example, the first radial mode of the second resonator 2 is used to excite the flexion mode of the head 3, in particular the flexion mode of the housing 13, at a low frequency, by radial transmission of the second resonator 2 towards the wall of the head 3 to which the second resonator 2 is attached. The final frequency of the second resonator 2 together with the head 3 is a function of the overall curvature of the second resonator 2, which in this case is 55 kHz. Moreover, the first resonator 1 works by direct transmission of the thickness mode at the HFS frequency.

[0061] In the second example, the vibrating membrane 8 is not included, and there is a direct transmission of the excitation wave from the resonator (1, 2) to the cavity 6, which is different from the case of the first example. The first example combines the membrane 8 vibrating by bending to obtain resonance in the first resonator 1 and the membrane 8 together in the LFS frequency, such as at 55kHz, when the second resonator 2 emits in the HFS, such as 1-3MHz. In the second example, on the contrary, as far as the first resonator 1 is concerned, the emission and resonance frequencies of the first resonator 1 are similar and close to 1MHz, so that there is only transmission instead of bending. Therefore, this model is called transmission-transmission because there is a transmission for these two frequencies that is directly realized. In both examples, the first and second frequencies have been interchanged: in the first example, the first frequency is LFS and the second frequency is HFS, while in the second example, it is the other way around.

[0062] For each of the two examples, and generally for any embodiment of the invention, it is envisaged that the head 3 may be made of a metal such as aluminium or alternatively of a biocompatible material such as a polymer, for example polypropylene.

Claims

1. A wearable device for transdermal product delivery, comprising: A head (3), wherein the head (3) comprises: a proximal region (4), which is close to the user's skin during use, a distal region (5) which is away from the skin of the user, and a cavity (6) defined in the proximal region (4) and oriented towards the skin of the user in use; A first resonator (1) housed in the distal region (5) of the head (3) and configured to resonate at a first frequency and transmit ultrasound at the first frequency to the skin of the user; A second resonator (2) housed in the proximal region (4) of the head (3) and configured to resonate at a second frequency and emit ultrasound at the second frequency in a direction parallel to the skin; wherein one of the first frequency and the second frequency is a high frequency sonophoresis frequency and the other is a low frequency sonophoresis frequency, wherein the head (3) is configured such that waves emitted by the first resonator (1) and the second resonator (2) circulate through the head (3) without encountering gaseous matter before exiting the head (3); Characterized in that the second resonator (2) comprises an inner through hole (7) so that waves from the first resonator (1) can pass through without hitting the second resonator (2); A portion of the cavity (6) of the head (3) corresponding to the height of the second resonator (2) is surrounded by the second resonator (2), and The wave from the second resonator (2) is guided through the head (3), the inner through hole (7) and the cavity (6) to bounce off the head (3) at a relative position and interfere with the wave from the first resonator (1).

2. The device according to claim 1, wherein: The low-frequency ultrasound introduction frequency is within the range of 50 Hz-60 Hz.

3. The device according to claim 1, wherein: The high-frequency ultrasound introduction frequency is within the range of 800-1200 Hz.

4. The device according to claim 1, wherein: The first resonator (1) has a disk shape.

5. The device according to claim 1, wherein: The second resonator (2) has a ring shape.

6. The device according to claim 1, wherein: Together with the head (3), the first resonator (1) resonates at the low-frequency ultrasound introduction frequency and the second resonator (2) resonates at the high-frequency ultrasound introduction frequency.

7. The device according to claim 6, wherein: The second resonator (2) has a ring shape and the ring shape has a fundamental vibration frequency in the thickness mode within the high-frequency ultrasonic introduction range, so that when supplied with the high-frequency ultrasonic introduction frequency, it resonates at the high-frequency ultrasonic introduction frequency in the thickness mode. The first resonator (1) has a disk shape and the disk shape has a fundamental vibration frequency in the thickness mode within the high-frequency ultrasonic introduction range. The head also includes at least one component in contact with the first resonator (1) to form a physically continuous component composed of the first resonator (1) and the head (3), which constitutes a transducer with a fundamental frequency in the low-frequency ultrasonic introduction range in the flexion mode.

8. The device according to claim 7, wherein: The component includes a membrane (8) that vibrates by bending, the membrane (8) being inserted between the first resonator (1) and the second resonator (2) and in contact with the first resonator (1).

9. The device according to claim 8, wherein: The component also comprises two protrusions, one of which is a proximal protrusion (9) and the other of which is a distal protrusion (10), the membrane (8) being supported between the proximal protrusion (9) and the distal protrusion (10).

10. The device according to claim 1, wherein: The first resonator (1) resonates and works at the high-frequency ultrasonic introduction frequency, and the second resonator (2) resonates and works at the low-frequency ultrasonic introduction frequency.

11. The device according to claim 10, wherein: The first resonator (1) has a disk shape and the disk shape has a fundamental frequency in the high-frequency ultrasonic introduction range in the thickness mode, so that when the high-frequency ultrasonic introduction frequency is supplied, the resonator resonates at the high-frequency ultrasonic introduction frequency in the thickness mode; and the second resonator (2) has a ring shape and the ring shape has a fundamental frequency in the low-frequency ultrasonic introduction range in the radial mode, so that when the low-frequency ultrasonic introduction frequency is supplied, the resonator resonates at the low-frequency ultrasonic introduction frequency in the radial mode.

12. The device according to claim 11, wherein The head (3) also includes a transmission plate (14) arranged on the first resonator (1) to transfer the vibration from the first resonator (1) to the cavity (6) through transmission.

13. The device according to claim 1, wherein: The head (3) consists of a single monolithic structure.

14. The device according to claim 1, wherein: The head (3) is made of a metal material or a biocompatible polymer material.

15. The device according to claim 14, wherein: The metal material is aluminum.

16. The device according to claim 14, wherein: The biocompatible polymer material is polypropylene.

17. The device according to any one of claims 1 to 16, wherein: The head (3) comprises a receiving portion (13), and the receiving portion (13) occupies at least a portion of the inner through hole (7) of the second resonator (2).

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