Aerosol inhalation device for therapeutic delivery

Abstract

A mist inhalation device (400) for delivering mist to a user, the mist inhalation device (400) being used in conjunction with a drive device (202). The aerosol inhalation device (400) comprises: a housing (204) comprising a liquid chamber (218) for containing a liquid to be aerosolized, the liquid comprising a therapeutic agent; an ultrasound assembly (425) is coupled to the housing (204), the ultrasound assembly (425) including an ultrasound transducer (215), a first assembly portion (426), and a second assembly portion (428) coupled to the first assembly portion (426). At least one of the first assembly portion (426) and the second assembly portion (428) includes an elastically deformable portion that forms a seal between the first assembly portion (426) and the second assembly portion (428) to minimize or prevent fluid leakage therebetween.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority of U.S. Provisional Patent Application No. 63 / 430,309, filed on December 5, 2022. This application is also a partial continuation application of co - pending U.S. Application No. 17 / 678,513, filed on February 23, 2022, which is a continuation application of U.S. Application No. 17 / 552,284 (the "284 application", now Patent No. 11,589,610), filed on December 15, 2021, and the "284 application" is a partial continuation application of U.S. Application No. 17 / 220,189, filed on April 1, 2021, which claims the priority of European Patent Application No. 20168231.7, filed on April 6, 2020; and the "284 application" is also a partial continuation application of U.S. Application No. 17 / 122,025 (now Patent No. 11,672,928), filed on December 15, 2020, which claims the priority of International Patent Application No. PCT / IB2019 / 060808, filed on December 15, 2019, International Patent Application No. PCT / IB2019 / 060810, filed on December 15, 2019, International Patent Application No. PCT / IB2019 / 060811, filed on December 15, 2019, and International Patent Application No. PCT / IB2019 / 060812, filed on December 15, 2019. This application also claims the priority of European Patent Application No. 20168245.7, filed on April 6, 2020, European Patent Application No. 20168231.7, filed on April 6, 2020, and European Patent Application No. 20168938.7, filed on April 9, 2020. All of the above applications are incorporated herein by reference in their entirety. Technical field

[0003] The present invention relates to a mist inhalation device. More particularly, the present invention relates to an inhalation device for atomizing a liquid ultrasonic mist containing a therapeutic agent for inhalation by a user. Background art

[0004] Atomizing inhalation devices are used to generate droplets or vapors for inhalation by a user. The droplets may contain therapeutic agents, drugs, or medications, which are absorbed into the user's bloodstream after inhalation.

[0005] Therapeutic aerosol delivery is a core treatment for asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. This technology can also be applied to the treatment of influenza, osteoporosis, and vaccination.

[0006] Due to the high vascularization of the lungs, thin blood-alveolar barrier, large surface area, and the ability to circumvent gastric enzyme degradation and first-pass metabolism in the liver, it is very attractive to deliver therapeutic agents through the lungs to intervene in non-respiratory systemic diseases. In addition, this approach can also improve patient comfort and treatment compliance. The pulmonary system can be used to deliver substances such as antibodies, proteins, analgesics, and nucleic acids. For example, the efficient delivery of nicotine to the systemic circulation through the lungs can significantly enhance the therapeutic effect of central nervous system diseases such as tobacco dependence.

[0007] The efficacy of therapeutic aerosols is directly related to the amount of drug deposited outside the oropharynx, which is determined by the size of the inhaled particles.

[0008] At present, the commonly used inhaled drug delivery devices in clinical practice are divided into three categories: nebulizers, metered dose inhalers and dry powder inhalers. Among them, there are two main types of nebulizers: jet type and ultrasonic type, but both types of traditional devices have inherent defects.

[0009] The jet nebulizer works based on the Bernoulli principle, and the droplets produced are larger in size, usually deposited in the oropharynx, resulting in low lung deposition efficiency. The ultrasonic nebulizer generates a vibration frequency of 1-1.7 MHz through a piezoelectric crystal, transferring kinetic energy to the liquid to generate an aerosol. However, this technology has poor atomization effect on viscous suspensions or solutions, and is prone to destroying the molecular structure of the drug due to heat generation, thereby weakening the advantages of inhalation therapy.

[0010] Electronic vaporizer inhalers are similar in design to other steam inhalers. Most of these devices have a liquid reservoir with a cotton-like capillary diaphragm inside to hold the liquid and prevent it from leaking. Even so, these devices are still prone to leaks because there is nothing to stop the liquid from flowing from the diaphragm into the mouthpiece. Leakage from electronic vaporizer inhalers can cause a number of problems: first, liquid can seep into the electronic components, potentially causing serious damage to the device; second, liquid can flow into the mouthpiece, and the user may accidentally inhale unvaporized liquid.

[0011] Additionally, the nicotine dose delivered by electronic vaporizers is often inconsistent. Leakage is one reason for uneven dosing, as the diaphragm near the vaporizer can become oversaturated or undersaturated. When the diaphragm is oversaturated, the user inhales a higher dose of vapor than expected; when the diaphragm is undersaturated, the user inhales a lower dose of vapor. Also, the dose inhaled changes with the slightest change in the user's puff force. Unstable dosing, combined with leakage, can also speed up the consumption of the atomizer liquid.

[0012] Traditional electronic vaporizers usually rely on metal heating elements to heat the liquid to vaporize it for inhalation. This method has some drawbacks: the metal elements may be burned, and users may inhale metal particles along with the burned liquid; moreover, some people may not like the burnt smell produced after the liquid is heated.

[0013] Nowadays, people have gradually realized that electronic vaporizers can allow users to ingest nicotine in a relatively safe way and play an important role in the process of quitting smoking. Compared with products such as nicotine patches and chewing gums, smokers using electronic vaporizers are more likely to adhere to the smoking cessation plan. However, traditional electronic vaporizers cannot ensure consistent nicotine dosage for each puff and it is also difficult to simulate the real experience of "inhaling from mouth to lungs".

[0014] Therefore, there is an urgent need in the market for improved mist inhalation devices to solve the above problems. Summary of the Invention

[0015] The present invention provides a mist inhalation device as described in claim 1 and a mist inhaler as described in claim 19, and multiple preferred embodiments of the present invention are also described in the dependent claims.

[0016] Compared with traditional atomizers, multiple embodiments of the present disclosure have many advantages, which are as follows:

[0017] The mist inhalation device in the embodiments of the present disclosure has a higher operating efficiency than traditional mist inhalation devices and has environmental benefits due to reduced power requirements.

[0018] It should be noted that the term "mist" used in the following disclosure means that the liquid is not usually heated as in traditional inhalers known in the prior art. In fact, traditional inhalers use heating elements to heat the liquid above its boiling point to produce steam, which is different from mist.

[0019] In fact, when high-intensity ultrasonic treatment is applied to a liquid, the sound waves propagating into the liquid medium will generate alternating high-pressure (compression) and low-pressure (rarefaction) cycles, the rate of which depends on the frequency. During the low-pressure cycle, high-intensity ultrasonic waves will generate small vacuum bubbles or voids in the liquid. When the bubbles reach a volume where they can no longer absorb energy, they will violently collapse during the high-pressure cycle. This phenomenon is called cavitation. During the implosion process, a very high pressure will be reached locally. When cavitation occurs, broken capillary waves will be generated, and tiny liquid droplets break the surface tension of the liquid and are quickly released into the air to form mist.

[0020] The cavitation phenomenon will be explained more precisely below.

[0021] When the liquid is atomized by ultrasonic vibration, tiny bubbles will be generated in the liquid.

[0022] The generation of cavitation bubbles is a process in which the negative pressure generated by strong ultrasonic waves produced by ultrasonic vibration forms cavitation bubbles. High-intensity ultrasonic waves cause the cavitation bubbles to grow rapidly, while the reduction in the size of the cavitation bubbles during the positive pressure cycle is relatively low and negligible.

[0023] Like all sound waves, ultrasonic waves consist of compression and expansion cycles. When in contact with a liquid, the compression cycle exerts a positive pressure on the liquid, pushing the molecules together. The expansion cycle exerts a negative pressure, pulling the molecules apart from each other.

[0024] Strong ultrasonic waves generate regions of positive and negative pressure. During the negative pressure phase, cavitation bubbles can form and grow. When the cavitation bubbles reach a critical size, they will implode.

[0025] The amount of negative pressure required depends on the type and purity of the liquid. For a truly pure liquid, its tensile strength is so great that existing ultrasonic generators cannot produce enough negative pressure to form cavitation bubbles. For example, in pure water, a negative pressure of more than 1000 atmospheres is required, while the most powerful ultrasonic generators only produce a negative pressure of about 50 atmospheres. The gas trapped in the liquid in the gaps between the liquid particles will reduce the tensile strength of the liquid. This effect is similar to the reduction in strength caused by cracks in solid materials. When the gas-filled gaps are exposed to the negative pressure cycle of the sound wave, the pressure reduction causes the gas in the gaps to expand until a small bubble is released into the solution.

[0026] However, the bubbles irradiated by ultrasonic waves continuously absorb energy from the alternating compression and expansion cycles of the sound wave. These cause the bubbles to grow and contract, reaching a dynamic balance between the void inside the bubble and the liquid outside. In some cases, the ultrasonic waves maintain a bubble with a simple oscillating size. In other cases, the average size of the bubble will increase.

[0027] The growth of cavitation bubbles depends on the intensity of the sound. High-intensity ultrasonic waves can cause the cavitation bubbles to expand rapidly during the negative pressure cycle, so that the cavitation bubbles have no chance to contract during the positive pressure cycle. In this process, the cavitation bubbles can grow rapidly during a single sound cycle.

[0028] For low-intensity ultrasonic waves, the size of the cavitation bubbles oscillates in phase with the expansion and compression cycles. The surface of the cavitation bubbles generated by low-intensity ultrasonic waves is slightly larger during the expansion cycle than during the compression cycle. Since the amount of gas diffusing into or out of the cavitation bubbles depends on the surface area, slightly more gas diffuses into the cavitation bubbles during the expansion cycle than diffuses out during the compression cycle. Therefore, for each sound cycle, the amplitude of the cavitation bubble expansion is slightly larger than the amplitude of the contraction. After many cycles, the cavitation bubbles will grow slowly.

[0029] It has been noted that growing bubbles will eventually reach a critical size at which they will most effectively absorb energy from ultrasonic waves. The critical size depends on the frequency of the ultrasonic waves. Once a bubble has undergone very rapid growth caused by high-intensity ultrasonic waves, it can no longer effectively absorb energy from the sound waves. Without this energy input, the bubble cannot sustain itself. Liquid rushes in and the bubble implodes due to the non-linear response.

[0030] The energy released by the implosion breaks the liquid into tiny particles that disperse into the air as a mist.

[0031] The equation that describes the above non-linear response phenomenon can be described by the "Rayleigh-Plesset" equation. This equation can be derived from the "Navier-Stokes" equation used in fluid mechanics.

[0032] The inventor's approach is to rewrite the "Rayleigh-Plesset" equation where the bubble volume V is used as the dynamic parameter and the physical processes describing dissipation are the same as those used in the more classical form using the radius as the dynamic parameter.

[0033] The derived equation is as follows:

[0034]

[0035] Where:

[0036] V is the bubble volume

[0037] V0 is the equilibrium bubble volume

[0038] ρ0 is the liquid density (assumed to be constant)

[0039] σ is the surface tension

[0040] p V is the vapor pressure

[0041] p0 is the static pressure in the liquid outside the bubble wall

[0042] κ is the polytropic exponent of the gas

[0043] t is the time

[0044] R(t) is the bubble radius

[0045] P(t) is the applied pressure

[0046] c is the speed of sound in the liquid

[0047] φ is the velocity potential

[0048] λ is the wavelength of the sound field

[0049] In an ultrasonic nebulizer, the kinematic viscosity of the liquid is between 1.05 Pa·sec and 1.412 Pa·sec.

[0050] By solving the above equation using the correct viscosity and density parameters and setting the target bubble volume for spraying the liquid into the air, it is found that for the liquid viscosity range of 1.05 Pa·s and 1.412 Pa·s, a frequency range of 2.8 MHz to 3.2 MHz produces bubbles with a size of approximately 0.25 to 0.5 microns.

[0051] The ultrasonic cavitation process has a significant impact on the nicotine concentration in the generated mist.

[0052] Since there is no heating element involved, there is no generation of burnt elements, and the second-hand smoke effect is reduced.

[0053] In an ultrasonic nebulizer, a capillary element can extend between the ultrasonic cavity and the liquid chamber.

[0054] In an ultrasonic nebulizer, the capillary element is a material made at least partially of bamboo fibers.

[0055] The capillary element has a high absorption capacity, a high absorption rate, and a high liquid retention rate.

[0056] It is found that the inherent properties of the proposed materials for capillary action have a significant impact on the effective operation of the ultrasonic nebulizer.

[0057] In addition, the inherent properties of the proposed materials include good hygroscopicity while maintaining good permeability. This allows the inhaled liquid to effectively penetrate the capillary, and the observed high absorption capacity allows for the retention of a considerable amount of liquid. Therefore, compared with other products on the market, the ultrasonic nebulizer can be used for a longer time.

[0058] Another significant advantage of using bamboo fibers is the naturally occurring antibacterial agent in bamboo fibers, namely "bamboo kun", which gives it antibacterial, antifungal, and odor-proof properties, making it suitable for medical applications.

[0059] Regarding the benefits of bamboo fibers for ultrasonic treatment, its inherent properties have been verified by numerical analysis.

[0060] The following formula has been tested with bamboo fiber materials and other materials used as capillary elements (such as cotton, paper, or other fiber bundles), and the results show that the application of bamboo fibers in ultrasonic treatment has better performance:

[0061]

[0062] Where:

[0063] C (cc / gm flow / gm) is the volume of liquid absorbed per mass divided by the dry mass of the capillary element.

[0064] A (cm 2 ) is the total surface area of the capillary element.

[0065] T (cm) is the thickness of the capillary element.

[0066] W f (gm) is the mass of the dry capillary element.

[0067] P f (cc / (g·sec)) is the density of the dry capillary element.

[0068] α is the ratio of the increase in volume after wetting of the capillary element to the volume of liquid diffused into the capillary element.

[0069] V d (cc) is the amount of liquid diffused into the capillary element, the absorption rate.

[0070]

[0071] Q (cc / sec) is the amount of liquid absorbed per unit time.

[0072] r (cm) is the radius of the pores inside the capillary element.

[0073] γ (N / m) is the surface tension of the liquid.

[0074] θ (degrees) is the contact angle of the fiber.

[0075] η (m 2 / sec) is the viscosity of the fluid.

[0076] In an ultrasonic nebulizer, the capillary element can be a material made at least in part of bamboo fiber.

[0077] In an ultrasonic nebulizer, the capillary element material can be 100% bamboo fiber.

[0078] Extensive testing has concluded that 100% pure bamboo fiber is the best choice for ultrasonic treatment.

[0079] In an ultrasonic nebulizer, the capillary element material can be at least 75% bamboo fiber and optionally contain 25% cotton.

[0080] Capillary elements made of 100% pure bamboo fiber or a high proportion of bamboo fiber exhibit high absorption capacity and improved fluid transport performance, making them the best choice for ultrasonic nebulizer applications. Description of the Drawings

[0081] For a better understanding of the present disclosure, preferred embodiments thereof will now be described by way of example only with reference to the accompanying drawings, in which:

[0082] Figure 1 It is a schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0083] Figure 2 It is a schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0084] Figure 3 It is a schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0085] Figure 4 It is a schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0086] Figure 5 It is a schematic exploded perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0087] Figure 6 It is a schematic perspective view of the transducer bracket according to an embodiment of the present disclosure.

[0088] Figure 7 It is a schematic perspective view of the transducer bracket according to an embodiment of the present disclosure.

[0089] Figure 8 It is a schematic perspective view of the capillary element according to an embodiment of the present disclosure.

[0090] Figure 9 It is a schematic perspective view of the capillary element according to an embodiment of the present disclosure.

[0091] Figure 10 It is a schematic perspective view of the transducer bracket according to an embodiment of the present disclosure.

[0092] Figure 11 It is a schematic perspective view of the transducer bracket according to an embodiment of the present disclosure.

[0093] Figure 12 It is a schematic perspective view of the housing component according to an embodiment of the present disclosure.

[0094] Figure 13 It is a schematic perspective view of the absorption element according to an embodiment of the present disclosure.

[0095] Figure 14 It is a schematic perspective view of the housing component according to an embodiment of the present disclosure.

[0096] Figure 15 It is a schematic perspective view of the housing component according to an embodiment of the present disclosure.

[0097] Figure 16Schematic perspective view of the absorption element according to an embodiment of the present disclosure.

[0098] Figure 17 Schematic perspective view of the housing component according to an embodiment of the present disclosure.

[0099] Figure 18 Schematic perspective view of the housing component according to an embodiment of the present disclosure.

[0100] Figure 19 Schematic perspective view of the housing component according to an embodiment of the present disclosure.

[0101] Figure 20 Schematic perspective view of the circuit board according to an embodiment of the present disclosure.

[0102] Figure 21 Schematic perspective view of the circuit board according to an embodiment of the present disclosure.

[0103] Figure 22 Schematic exploded perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0104] Figure 23 Schematic exploded perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0105] Figure 24 Cross-sectional view of the mist inhalation device according to an embodiment of the present disclosure.

[0106] Figure 25 Cross-sectional view of the mist inhalation device according to an embodiment of the present disclosure.

[0107] Figure 26 Cross-sectional view of the mist inhalation device according to an embodiment of the present disclosure.

[0108] Figure 27 Schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0109] Figure 28 Schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0110] Figure 29 Schematic exploded perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0111] Figure 30 Schematic perspective view of the transducer support assembly according to an embodiment of the present disclosure.

[0112] Figure 31 Schematic perspective view of the transducer support assembly according to an embodiment of the present disclosure.

[0113] Figure 32 Schematic exploded perspective view of the transducer support assembly according to an embodiment of the present disclosure.

[0114] Figure 33 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0115] Figure 34 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0116] Figure 35 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0117] Figure 36 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0118] Figure 37 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0119] Figure 38 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0120] Figure 39 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0121] Figure 40 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0122] Figure 41 A schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0123] Figure 42 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0124] Figure 43 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0125] Figure 44 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0126] Figure 45 A schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0127] Figure 46 A schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0128] Figure 47 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0129] Figure 48 A schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0130] Figure 49 Schematic perspective view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0131] Figure 50 Schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0132] Figure 51 Schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0133] Figure 52 Schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0134] Figure 53 Schematic exploded perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0135] Figure 54 Schematic sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0136] Figure 55 Schematic perspective view of the mist inhalation device according to an embodiment of the present disclosure.

[0137] Figure 56 Schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure.

[0138] Figure 57 Schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure, showing the air flow path.

[0139] Figure 58 Schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure, showing the air flow path.

[0140] Figure 59 Schematic perspective sectional view of a part of the mist inhalation device according to an embodiment of the present disclosure, showing the air flow path.

[0141] Figure 60 Schematic exploded perspective view of the driving device according to the present disclosure.

[0142] Figure 61 Schematic perspective view of a part of the driving device according to the present disclosure.

[0143] Figure 62 Schematic perspective view of a part of the driving device according to the present disclosure.

[0144] Figure 63 Schematic perspective view of a part of the driving device according to the present disclosure.

[0145] Figure 64 Schematic perspective view of a part of the driving device according to the present disclosure.

[0146] Figure 65 This is a schematic perspective view of a part of the driving device of the present disclosure.

[0147] Figure 66 This is a schematic perspective view of a part of the driving device of the present disclosure.

[0148] Figure 67 This is a schematic perspective view of a part of the driving device of the present disclosure.

[0149] Figure 68 This is a schematic diagram of the integrated circuit layout of the present disclosure.

[0150] Figure 69 This is a schematic diagram of the integrated circuit of the present disclosure.

[0151] Figure 70 This is a schematic diagram of the pulse width modulation generator of the present disclosure.

[0152] Figure 71 This is a timing diagram of an embodiment of the present disclosure.

[0153] Figure 72 This is a timing diagram of an embodiment of the present disclosure.

[0154] Figure 73 This is a port function table of an embodiment of the present disclosure.

[0155] Figure 74 This is a schematic diagram of the integrated circuit of the present disclosure.

[0156] Figure 75 This is a circuit diagram of the H-bridge of an embodiment of the present disclosure.

[0157] Figure 76 This is a circuit diagram of the current detection device of an embodiment of the present disclosure.

[0158] Figure 77 This is a circuit diagram of the H-bridge of an embodiment of the present disclosure.

[0159] Figure 78 is Figure 75 a graph of the voltage during the H-bridge working stage in

[0160] Figure 79 is Figure 75 a graph of the voltage during the H-bridge working stage in

[0161] Figure 80 is a graph of the voltage and current at the terminals of the ultrasonic transducer when driven by the H-bridge in Figure 75

[0162] Figure 81 This is a schematic diagram of the connection relationship between the integrated circuits of the present disclosure.

[0163] ​Figure 82 Schematic diagram of the integrated circuit of the present disclosure.

[0164] Figure 83 Schematic diagram of the steps of the authentication method according to an embodiment of the present disclosure.

[0165] Figure 84 Schematic perspective view of the end cap of the drive device of the present disclosure.

[0166] Figure 85 Schematic perspective view of the housing of the drive device of the present disclosure.

[0167] Figure 86 Graph of the electromagnetic compatibility (EMC) test results of the mist inhalation device of the present disclosure. Detailed implementation manners

[0168] Reading the following detailed description in conjunction with the accompanying drawings can best understand various aspects of the present disclosure. It should be noted that, according to industry standard practices, the features of each component are not drawn to scale. In fact, for the sake of clear discussion, the dimensions of each feature may be arbitrarily enlarged or reduced.

[0169] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components, concentrations, applications, and arrangements will be described below to simplify the present disclosure. Of course, these are only examples and are not intended to be limiting. For example, in the following description, the connection of the first feature to the second feature may include embodiments where the first feature and the second feature are in direct contact, and may also include embodiments where additional features are provided between the first feature and the second feature such that the two are not in direct contact. In addition, the present disclosure may reuse reference numerals and / or letters in multiple examples, and this repetition is for the sake of simplicity and clarity and does not itself indicate the relationship between the various embodiments and / or configurations discussed.

[0170] The following disclosure describes representative examples. Each example can be regarded as an embodiment, and any reference to "example" in the present disclosure can be replaced with "embodiment".

[0171] Some parts of the present disclosure relate to electronic vapor inhalers. The specific examples described below relate to nicotine. However, other examples are also contemplated, such as inhalers for therapeutic, pharmaceutical, and herbal supplements. In addition, the device can be packaged in the form of a medical device rather than a cigarette.

[0172] Ultrasonic mist inhalers are divided into disposable or reusable types. The term "reusable" as used herein means that the energy storage device can be recharged or replaced, or the liquid can be supplemented by refilling or replacing the liquid storage structure. In some examples, the reusable electronic device supports both charging and liquid supplementation.

[0173] Traditional electronic vaporizers typically rely on high-temperature heating of metal components that are used to heat the liquid in the vaporizer, thereby vaporizing the liquid for inhalation. The liquid usually contains nicotine and flavorings, mixed in a propylene glycol (PG) and vegetable glycerin (VG) solution, and is vaporized at high temperature by a heating element. Problems with traditional inhalers can include the risk of the metal components being burned, and the subsequent inhalation of burned liquid and metal particles. In addition, some users may dislike the burnt taste or mouthfeel produced by heating the liquid.

[0174] For each different application of the mist generation system, there is an optimal frequency or frequency range for driving the ultrasonic vibration device 5 to optimize mist generation. In the example where the ultrasonic vibration device 5 is a piezoelectric transducer, the optimal frequency or frequency range depends at least on the following four parameters:

[0175] 1. Transducer manufacturing process

[0176] In some examples, the ultrasonic vibration device 5 includes a piezoelectric ceramic. The piezoelectric ceramic is made into a ceramic slurry by mixing compounds, and this mixing process may not be consistent throughout the production process. This inconsistency results in the cured piezoelectric ceramic having different resonance frequency ranges.

[0177] If the resonance frequency of the piezoelectric ceramic does not match the operating frequency of the device, no mist will be generated when the device is running. In the case of a medical mist inhaler, a slight shift in the resonance frequency of the piezoelectric ceramic is sufficient to affect mist generation, meaning that the device cannot provide the user with an adequate therapeutic dose.

[0178] 2. Transducer load

[0179] During operation, any change in the piezoelectric transducer load will suppress the overall displacement of its oscillation. To achieve the optimal displacement of the piezoelectric transducer oscillation, the driving frequency must be adjusted so that the circuit can provide sufficient power for the maximum displacement.

[0180] The types of load that may affect the oscillator efficiency include the amount of liquid on the transducer (humidity of the liquid-conducting material), the spring force applied to the liquid-conducting material to maintain permanent contact with the transducer, and may also include the electrical connection method.

[0181] 3. Temperature

[0182] The ultrasonic oscillation of the piezoelectric transducer is partially damped due to the way it is assembled in the device. This may include the transducer being placed in a silicone / rubber ring, and the spring applying pressure to the liquid-conducting material above the transducer. This oscillation damping causes a local temperature rise in the transducer and its surroundings.

[0183] An increase in temperature affects the oscillation due to changes in the behavior of the transducer molecules. An increase in temperature means that the ceramic molecules gain more energy, which temporarily affects their crystal structure. Although this effect is reversed as the temperature decreases, it is still necessary to adjust the power supply frequency to maintain optimal oscillation, which cannot be achieved by traditional fixed-frequency devices.

[0184] An increase in temperature also reduces the viscosity of the vaporized solution (e-liquid), which may require changing the driving frequency to initiate cavitation and maintain continuous mist generation. In the case of traditional fixed-frequency devices, a decrease in liquid viscosity while the driving frequency remains unchanged will reduce or even completely stop mist generation, causing the device to malfunction.

[0185] 4. Distance from the power supply

[0186] The oscillation frequency of the electronic circuit varies with the wire length between the transducer and the driver of the oscillator. The frequency of the electronic circuit is inversely proportional to the distance between the transducer and the rest of the circuit.

[0187] Although the distance parameter is basically fixed in the device, it may vary during the device manufacturing process, thus reducing the overall efficiency of the device. Therefore, it is necessary to modify the driving frequency of the device to compensate for these changes and optimize the device efficiency.

[0188] The piezoelectric transducer can be modeled as an RLC circuit in the electronic circuit, as Figure 5 shown. The above four parameters can be modeled as changes in the total inductance, capacitance, and / or resistance of the RLC circuit, thereby changing the resonant frequency range provided to the transducer. When the circuit frequency increases to approach the resonant point of the transducer, the logarithmic impedance of the entire circuit first drops to a minimum value, then rises to a maximum value, and finally stabilizes in the intermediate range.

[0189] Figure 6 Is a general curve graph showing the change of the total impedance in the RLC circuit with the increase of frequency. Figure 7 Shows how the piezoelectric transducer acts as a capacitor in the first capacitive region below the first predetermined frequency fs and the second capacitive region above the second predetermined frequency fp, and acts as an inductor in the inductive region between the first and second predetermined frequencies fs and fp. To maintain the optimal oscillation of the transducer and thus achieve the highest efficiency, the current flowing through the transducer must be maintained at a frequency within the inductive region.

[0190] In some examples, the frequency controller of the device is configured to maintain the oscillation frequency of the piezoelectric transducer (ultrasonic vibration device 5) within the inductive region to maximize the device efficiency.

[0191] The frequency controller is configured to perform a frequency sweep operation, that is, gradually track the frequency within a predetermined frequency sweep range to drive the transducer. When the frequency controller performs a frequency sweep, it monitors the analog-to-digital conversion value of the analog-to-digital converter (ADC) connected to the transducer. In some examples, the ADC value is a parameter proportional to the voltage across the transducer; in other examples, the ADC value is a parameter proportional to the current flowing through the transducer.

[0192] As will be described in more detail below, in some examples, the frequency controller determines the active power of the ultrasonic transducer by monitoring the current flowing through the transducer.

[0193] During the frequency sweep operation, the frequency controller locates the frequency inductive region of the transducer. Once the frequency controller identifies the inductive region, it records the ADC value and locks the drive frequency of the transducer at a certain frequency within the inductive region (i.e., between the first and second predetermined frequencies fs and fp) to optimize the ultrasonic cavitation effect of the transducer. When the drive frequency is locked within the inductive region, the electromechanical coupling coefficient of the transducer is maximized, thereby maximizing the device efficiency.

[0194] In some examples, the frequency controller is configured to perform a frequency sweep operation to locate the inductive region each time the oscillation starts or restarts. In these examples, the frequency controller is configured to lock the drive frequency at a new frequency within the inductive region each time the oscillation starts, thereby compensating for parameter changes that affect the operating efficiency of the device.

[0195] In some examples, the frequency controller can ensure optimal atomization and maximize the delivery efficiency of the therapeutic agent to the user. In other examples, the frequency controller can optimize the device, improve the working efficiency, and enhance the delivery effect of the therapeutic agent to the user as much as possible.

[0196] In other examples, the frequency controller can optimize the device and improve the efficiency of any other device using ultrasonic technology. In some examples, the frequency controller is configured to be used in combination with therapeutic ultrasound technology to further enhance the drug release effect of the ultrasound-responsive drug delivery system. Having an accurate and optimal frequency during operation can ensure the efficient operation of microbubbles, nanobubbles, nanodroplets, liposomes, emulsions, micelles, or any other delivery system.

[0197] In some examples, to ensure optimal fog generation and optimal delivery of the compound as described above, the frequency controller is configured to operate in a recursive mode. When the frequency controller operates in a recursive mode, it performs a frequency sweep regularly during the operation of the device and monitors the ADC value to determine whether it is higher than a predetermined threshold indicating the optimal oscillation of the transducer.

[0198] In some examples, the frequency controller performs a frequency sweep operation during the atomization of the liquid by the device to prevent a potentially better frequency from being identified for the transducer. If the frequency controller identifies a better frequency, the drive frequency is locked to the newly identified better frequency to maintain optimal operation of the device.

[0199] In some examples, the frequency controller periodically performs a frequency sweep for a predetermined duration during the operation of the device. In the device of the above example, the predetermined duration of the frequency sweep and the time interval between frequency sweeps are selected to optimize the device function. When implemented in an ultrasonic nebulizer device, this will ensure that the user obtains an optimal delivery effect throughout the inhalation process.

[0200] To ensure sufficient aerosol generation, in this example, the nebulizer device includes an ultrasonic / piezoelectric transducer with a diameter of precisely or approximately 16 mm. The transducer is manufactured with specific capacitance and impedance values to control the frequency and power required to generate the desired amount of aerosol.

[0201] A horizontally placed disk-shaped ultrasonic transducer with a diameter of 16 mm would result in a relatively large device volume and may not be ergonomic as a handheld device. To address this issue, in this example, the ultrasonic transducer is vertically fixed in the ultrasonic cavity (the planar surface of the ultrasonic transducer is generally parallel to the aerosol mist flow leading to the mouthpiece and / or generally parallel to the longitudinal length of the nebulizer device). In other words, the ultrasonic transducer is generally perpendicular to the bottom of the nebulizer device.

[0202] Now referring to FIGS. Figure 1 and Figure 2 , a nebulizer device 200 of some examples includes a mist generating device 201 and a driving device 202. In this example, the driving device 202 is provided with a groove 203 for receiving and fixing a part of the mist generating device 201. Thus, the mist generating device 201 can be connected to the driving device 202 to form a compact and portable nebulizer device 200, as shown in Figure 1 .

[0203] Now referring to FIGS. Figures 3 to 5 , the mist generating device 201 includes an elongated mist generator housing 204, which is optionally formed by two interconnected housing parts 205, 206. The mist generator housing 204 includes an air inlet 207 and a mist outlet 208.

[0204] In this example, the mist generator housing 204 is made of injection-molded plastic, specifically polypropylene which is commonly used in medical applications. In this example, the mist generator housing 204 is made of a multiphase copolymer, more specifically the BF970MO multiphase copolymer, which has an optimal combination of extremely high rigidity and high impact strength. The mist generator housing components molded with this material exhibit good antistatic properties.

[0205] Multiphase copolymers such as polypropylene are particularly suitable as the material for the mist generator housing 204 because this material does not cause aerosol condensation when flowing from the ultrasonic cavity 219 through the nozzle to the user. This plastic material can also be easily recycled directly through industrial shredding and cleaning processes.

[0206] In Figure 1 、 Figure 2 and Figure 4 , the mist outlet 208 is closed by a closure element 209. However, it should be understood that when the mist inhaler device 200 is in use, the closure element 209 is removed from the mist outlet 208, as shown in Figure 3 shown.

[0207] Now referring to Figure 6 and Figure 7 , the mist inhalation device 200 includes a transducer holder 210 fixed within the mist generator housing 204. The transducer holder 210 includes a body portion 211 which, in this example, is cylindrical or substantially cylindrical and has circular upper and lower openings 212, 213. As shown in Figure 7 shown, the transducer holder 210 is provided with an internal groove 214 for receiving the edge of the ultrasonic transducer 215.

[0208] The transducer holder 210 includes a cutout portion 216 through which the electrodes 217 extend from the ultrasonic transducer 215 so that the electrodes 217 can be electrically connected to the AC driver of the drive device. This will be described in more detail below.

[0209] Referring again to Figure 5 , the mist generating device 201 includes a liquid chamber 218 disposed within the mist generator housing 204 for containing a liquid to be atomized - such as a therapeutic agent. In some examples, the liquid chamber 218 is filled with liquid; in other examples, the liquid chamber 218 is initially empty and is subsequently filled with liquid.

[0210] The liquid preferably comprises at least one therapeutic agent suitable for delivery to the lungs of a patient by aerosol inhalation to provide the desired treatment to the patient. Examples of therapeutic agents include, but are not limited to: delivering a pharmacological agent to the lungs by aerosol to promote a systemic or direct clinical effect while producing minimal side effects. Therapeutic agents may also include - but are not limited to: natural medicines; cannabinoid derivatives such as CBD for pain relief and other treatments; herbal medicines; opioid drugs; RNA; DNA; chemotherapeutic drugs; subcellular components such as ribosomes, endoplasmic reticulum, cytoskeleton, and mitochondria; supplements for enhancing function; salbutamol for asthma patients; bactericidal antibiotics such as beta-lactams, polymyxins, and aminoglycosides; amphotericin B; morphine; fentanyl; prostacyclin, amiloride, and interferon-gamma; and cyclosporine as an anti-rejection rescue therapy for lung transplant patients and an asthma treatment drug.

[0211] The following description is given by way of example with nicotine, but in other examples of the present disclosure, nicotine may be replaced by a therapeutic agent, including but not limited to one or more of the therapeutic agents described herein.

[0212] A liquid (also referred to herein as an e-liquid) composition suitable for an ultrasonic device powered by a 3.7V lithium polymer (LiPo) battery at a frequency of 3.0 MHz (±0.2 MHz), comprising nicotine levulinate salt, wherein:

[0213] The relative content of vegetable glycerin in the composition is: 55 - 80% (w / w), or 60 - 80% (w / w), or 65 - 75% (w / w), or 70% (w / w); and / or,

[0214] The relative content of propylene glycol in the composition is: 5 - 30% (w / w), or 10 - 30% (w / w), or 15 - 25% (w / w), or 20% (w / w); and / or,

[0215] The relative content of water in the composition is: 5 - 15% (w / w), or 7 - 12% (w / w), or 10% (w / w); and / or,

[0216] The content of nicotine and / or nicotine salt in the composition is: 0.1 - 80 mg / ml, or 0.1 - 50 mg / ml, or 1 - 25 mg / ml, or 10 - 20 mg / ml, or 17 mg / ml.

[0217] In certain examples, the mist generating device 201 comprises an e-liquid having a kinematic viscosity between 1.05 Pa·s and 1.412 Pa·s.

[0218] In certain examples, the liquid chamber 218 comprises a nicotine levulinate salt liquid with a molar ratio of 1:1.

[0219] In some examples, the liquid chamber 218 contains an e-liquid or liquid containing a flavoring agent. In some examples, the liquid chamber 218 contains an e-liquid or liquid containing at least one cannabinoid or phytocannabinoid derived from the cannabis plant. In some examples, the at least one cannabinoid or phytocannabinoid includes one or more of tetrahydrocannabinol (THC), cannabidiol (CBD), and / or cannabinol (CBN).

[0220] In some examples, the liquid chamber 218 houses an e-liquid or liquid containing one or more psychedelic compounds as therapeutic agents. In some examples, the one or more psychedelic compounds are one or more of the following: lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), ketamine, esketamine, ibogaine, mescaline, tryptamine, substituted tryptamine, O-acetyl dephosphorylated psilocybin (4-AcO-DMT), psilocybin (4-PO-DMT), dephosphorylated psilocybin (4-HO-DMT), O-methyl bufotenine (5-MeO-DMT), bufotenine (5-HO-DMT), and / or N,N-dimethyltryptamine (DMT or N,N-DMT).

[0221] In some examples, the liquid chamber 218 contains a liquid having a kinematic viscosity between 1.05 Pa·s and 1.412 Pa·s and a liquid density between 1.1 g / ml and 1.3 g / ml.

[0222] By using an e-liquid having the correct viscosity and density parameters and having a target bubble volume for spraying the liquid into the air, it has been found that for a liquid viscosity range of 1.05 Pa·s and 1.412 Pa·s and a density of approximately 1.1 - 1.3 g / mL (density range obtained from Hertz), a frequency range of 2.8 MHz to 3.2 MHz produces droplet volumes where 90% of the droplets are less than 1 micron and where 50% are less than 0.5 micron.

[0223] The mist generating device 201 includes an ultrasonic cavity 219 disposed within the mist generator housing 204.

[0224] Back to Figure 6 and Figure 7, the transducer support 210 includes a partition portion 220 that provides a barrier between the liquid chamber 218 and the ultrasonic chamber 219. The barrier provided by the partition portion 220 minimizes the risk of the ultrasonic chamber 219 being flooded with the liquid in the liquid chamber 218 or the capillary element above the ultrasonic transducer 215 being supersaturated, both of which can overload the ultrasonic transducer 215 and reduce its efficiency. In addition, flooding of the ultrasonic chamber 219 or supersaturation of the capillary element may cause the user to inhale liquid during inhalation, resulting in an unpleasant experience. To reduce this risk, the partition portion 220 of the transducer support 210 serves as a wall between the ultrasonic chamber 219 and the liquid chamber 218.

[0225] The partition portion 220 includes a capillary hole 221, which is the only path for the liquid to flow from the liquid chamber 218 through the capillary element to the ultrasonic chamber 219. In this example, the capillary hole 221 is an elongated slit with a width of 0.2 mm to 0.4 mm. The size of the capillary hole 221 is such that its edges provide a biasing force acting on the capillary element extending through the capillary hole 221 to better control the liquid flow rate to the ultrasonic chamber 219.

[0226] In this example, the transducer support 210 is made of liquid silicone rubber (LSR), and in this example, the Shore A hardness of the liquid silicone rubber is 60. This LSR material ensures that the ultrasonic transducer 215 vibrates while the transducer support 210 does not damp the vibration. In this example, the vibration displacement of the ultrasonic transducer 215 is 2 - 5 nanometers, and any damping effect may reduce the efficiency of the ultrasonic transducer 215. Therefore, this LSR material and hardness are selected to achieve the best performance with minimal compromise.

[0227] Now refer to Figure 8 and Figure 9 , the mist generating device 201 includes a capillary or capillary element 222 for transferring a liquid (containing a drug, therapeutic agent, or other substance) from the liquid chamber 218 to the ultrasonic chamber 219. The capillary element 222 is planar or substantially planar and has a first portion 223 and a second portion 224. In this example, the first portion 223 is rectangular or substantially rectangular, and the second portion 224 is partially circular.

[0228] In this example, the capillary element 222 includes a third portion 225 and a fourth portion 226, which have the same shapes as the first portion and the second portion 223, 224 respectively. The capillary element 222 of this example is folded around a folding line 227 such that the first portion and the second portion 223, 224 are superimposed on the third portion and the fourth portion 225, 226, as Figure 9 shown.

[0229] In this example, the thickness of the capillary element is approximately 0.28 mm. When the capillary element 222 is folded into two layers, as Figure 9 shown, the total thickness of the capillary element is approximately 0.56 mm. This double-layer structure also ensures that there is always sufficient liquid on the ultrasonic transducer 215 for optimal aerosol generation.

[0230] In this example, when the capillary element 222 is folded, the lower ends of the first and third parts 223, 225 form an enlarged lower end 228, which increases the surface area of the part of the capillary element 222 located in the liquid within the liquid chamber 218 to maximize the rate of liquid absorption by the capillary element 222.

[0231] In this example, the capillary element 222 is 100% bamboo fiber; in other examples, at least 75% of the capillary element is bamboo fiber. The benefits of using bamboo fiber as the capillary element are as described above.

[0232] Now referring to Figure 10 and Figure 11 , the capillary element 222 is fixed by the transducer support 210 such that the transducer support 210 superimposes the second part 224 of the capillary element 222 on a part of the atomizing surface of the ultrasonic transducer 215. In this example, the circular second part 224 is located within the inner groove 214 of the transducer support 210.

[0233] The first part 223 of the capillary element 222 extends through the capillary hole 221 in the transducer support 210.

[0234] Now referring to Figures 12 to 14 , the second part 206 of the mist generator housing 204 includes a generally circular wall 229 for receiving the transducer support 210 and forming part of the wall of the ultrasonic cavity 219.

[0235] Contact holes 230 and 231 are provided on the side wall of the second part 206 for receiving electrical contacts 232 and 233 that form an electrical connection with the electrodes of the ultrasonic transducer 215.

[0236] In this example, an absorption tip or absorption element 234 is provided near the mist outlet 208 for absorbing the liquid at the mist outlet. The absorption element 234 is made of bamboo fiber.

[0237] Now referring to Figures 15 to 17 , the first part 205 of the mist generator housing 204 is similar in shape to the second part 206 and includes another generally circular wall portion 235 that forms another part of the wall of the ultrasonic cavity 219 and secures the transducer support 210.

[0238] In this example, another absorption element 236 is also provided near the mist outlet 208 for absorbing the liquid at the mist outlet.

[0239] As Figure 18 shown, in this example, the first part 205 of the mist generator housing 204 includes a spring support structure 237 for supporting the lower end of the fixed spring 238.

[0240] The upper end of the fixed spring 238 contacts the second part 224 of the capillary element 222, such that the fixed spring 238 provides a biasing force to press the capillary element 222 against the atomizing surface of the ultrasonic transducer 215.

[0241] Referring Figure 19 , before the two parts 205, 206 of the mist generator housing 204 are interconnected, the transducer bracket 210 is already installed in place and fixed by the second part 206.

[0242] Referring Figures 20 to 23 , in this example, the mist generating device 201 includes an identification device 239. The identification device 239 includes a printed circuit board 240 with electrical contacts 241 on one side and an integrated circuit 242 and another optional element 243 on the other side.

[0243] The memory of the integrated circuit 242 stores the unique identifier of the mist generating device 201, and the electrical contacts 241 provide an electronic interface for communicating with the integrated circuit 242.

[0244] In this example, the printed circuit board 240 is installed in a groove 244 on one side of the mist generator housing 204, and the integrated circuit 242 and the optional other electronic components 243 are located in another groove 245, making the printed circuit board 240 flush with the side of the mist generator housing 204.

[0245] In this example, the integrated circuit 242 is a one-time programmable (OTP) device. As an anti-counterfeiting feature, it only allows genuine mist inhalation devices manufactured by the manufacturer to cooperate with the equipment. This anti-counterfeiting feature is achieved by bonding a specific customized integrated circuit (IC) to the printed circuit board 240 and then to the mist generating device 201. The OTP as the IC contains truly unique information, enabling complete traceability throughout the entire life cycle of the mist generating device 201 (and its contents) and precisely monitoring the user's usage. The OTP IC only allows the mist generating device 201 to operate to generate mist when authorized.

[0246] The implementation of the OTP IC in the examples of the present disclosure will be described in detail below.

[0247] As a function, OTP determines the authorization status of a specific mist generating device 201. In fact, in order to prevent the emission of carbonyl compounds and make the aerosol meet safety standards, experiments have shown that the liquid chamber 218 of the mist generating device 201 is considered to be free of liquid after about 1000 seconds of atomization. Therefore, a non-genuine or used mist generating device 201 will not be activated after the predetermined usage time.

[0248] The OTP function can form a complete chain with the digital point of sale, the mobile companion application and the mist generating device 201. Only authentic mist generating devices 201 produced by a trusted party and sold at the digital point of sale can be used in the device. The mobile companion digital application serves as a link between the user account on the manufacturer's digital platform and the mist generating device 201, ensuring the use of known safe contents within a safe puffing time.

[0249] As a feature, OTP also supports the high-authority control and monitoring requirements required for medical drug management when working with trusted health institutions in business-to-business (B2B). The driver 202 can read the OTPIC to identify the inserted mist generating device 201 and its associated prescription. The driver 202 cannot use the mist generating device 201 outside the time range specified in the prescription, and the mobile companion application can provide reminders to reduce the user's missed doses.

[0250] In some examples, the OTPIC is disposable like the mist generating device 201. Whenever the mist generating device 201 is deemed to be used up, it will not be activated after being inserted into the drive device 202. Similarly, the counterfeit generator device 201 will not work in the drive device 202.

[0251] Figures 24 to 26 The air flow condition of the mist generating device 201 during operation is shown.

[0252] Ultrasonic treatment of liquid therapeutic agents (medical solutions, medical suspensions, protein solutions, supplements, etc.) converts them into mist (atomization), but unless there is sufficient ambient air to replace the rising aerosol, the mist will be deposited on the ultrasonic transducer 215. In the ultrasonic cavity 219, as the mist (aerosol) is generated and sucked out to the user through the nozzle, a continuous supply of air is required. To meet this requirement, an airflow channel is set. In this example, the average cross-sectional area of ​​the airflow channel is 11.5mm 2 , which is calculated based on the negative pressure of a normal user and designed into the ultrasound cavity 219. This also controls the ratio of mist to air in the inhaled aerosol, thereby controlling the amount of drug delivered to the user.

[0253] According to the design requirements, the air flow channel starts from the bottom of the ultrasonic cavity 219. The opening at the bottom of the atomization cavity is aligned and closely adjacent to the opening of the air flow bridge in the device. The air flow channel extends vertically upward along the liquid storage cavity until the center of the ultrasonic cavity (concentric with the ultrasonic transducer 215), where it turns inward by 90 degrees and then continues to extend to a position about 1.5 mm away from the ultrasonic transducer 215. This path design ensures that ambient air flows directly towards the atomization surface of the ultrasonic transducer 215 in the largest amount. The air flows through the channel, towards the transducer, and carries the generated mist during the process of being discharged through the nozzle and flowing towards the user.

[0254] Air flows into the mist generating device 201 through the air inlet 207, which is in fluid communication with the air flow bridge within the drive device 202 as described below. The air flows along the flow path, and its direction changes by approximately 90 degrees to direct the air flow towards the ultrasonic transducer 215.

[0255] In some examples, the air flow device is configured to change the direction of the air flow along the air flow path such that when the air flow enters the ultrasonic cavity, the air flow is substantially perpendicular to the atomization surface of the ultrasonic transducer.

[0256] Now referring to Figures 27 - 29 of the accompanying drawings, the mist inhalation device 400 of some examples of the present disclosure includes many elements that are the same as those of the mist generating device 201 described above. The equivalent elements in the mist inhalation device 400 to those of the mist generating device 201 use the same reference numerals. Each of the mist generating devices 201, 401 described herein may alternatively be referred to as an atomization chamber or an atomization cartridge.

[0257] The mist inhalation device 400 is configured to be detachably connected to the drive device 202 and operates in substantially the same manner as the mist generating device 201 described above. In other examples, the mist inhalation device 400 may be fixed to, integrally formed with, or otherwise non - detachably connected to the drive device 202.

[0258] The mist inhalation device 400 includes a housing 204, which contains a liquid cavity 218 for containing the liquid to be atomized. The liquid cavity 218 can accommodate any e - liquid or liquid described in the present disclosure, or any other liquid to be atomized.

[0259] The mist inhalation device 400 includes a nozzle 401 connected to the housing 204. The nozzle 401 includes a base 402, which has an opening 403 for accommodating the connecting portion 404 of the housing 204. The connecting portion 404 includes at least one latching element 405, which engages with a latching groove (not shown in the figure) to fix the nozzle 401 in the position connected to the housing 204.

[0260] The nozzle 401 tapers from the base 402 towards the distal end 406. The distal end 406 includes a mist outlet 208 that enables the mist to be output from the mist inhalation device 400 for inhalation by the user.

[0261] Referring now to the Figures 30 - 32 , the mist inhalation device 400 includes an ultrasonic transducer 215. In this example, the ultrasonic transducer 215 is housed within an ultrasonic transducer stack 407, which may also be referred to as an ultrasonic transducer assembly. The ultrasonic transducer stack 407 includes a generally cylindrical base 408 having a generally cylindrical groove 409. A generally cylindrical edge 410 surrounds the upper open end of the generally cylindrical groove 409. In this example, the surface presented by the edge 410 is a generally flat annular surface for contacting and supporting the ultrasonic transducer 215.

[0262] The base 408 is made of an elastically deformable material. In this example, the base 408 is made of silicone, but in other examples, the base 408 may be made of a different elastically deformable plastic.

[0263] In this example, the base 408 includes a partition wall 411 in the lower part of the generally cylindrical groove 409, and the partition wall 411 is provided with a central hole 412.

[0264] The ultrasonic transducer stack 407 includes a first electrical transducer contact 413. In this example, the first electrical transducer contact 413 includes a cylindrical lower portion 414 that is connected to a radial flange 415. An electrical connection 416 is connected to the upper side of the flange 415, on the side opposite to the cylindrical lower portion 414. In this example, the electrical connection 416 is spring-loaded and configured to move relative to the flange 415. In other examples, the electrical connection 416 is fixed relative to the flange 415.

[0265] When the first electrical transducer contact 413 is received within the central hole 412, the flange 415 abuts against the partition wall 411 around the perimeter of the central hole 412. The electrical connection 416 extends upward to the protruding edge 410. When the ultrasonic transducer 215 contacts the edge 410, the electrical connection 416 contacts the first electrical connection on the lower side of the ultrasonic transducer 215 and is biased against the first electrical connection of the transducer 215.

[0266] In this example, the base 408 includes a cut-out portion 417, and a portion of the base 408 on one side below the partition wall 411 is removed so as to contact the side of the cylindrical lower portion 414 of the first electrical transducer contact 413.

[0267] The ultrasonic transducer stack 407 includes a generally cylindrical metal housing 418 that at least partially surrounds the base 408 when the ultrasonic transducer stack 407 is assembled. The housing 418 includes a generally cylindrical internal groove 419 that has an opening 420 at one end. The ultrasonic transducer 215 includes an atomizing surface 215a located at the opening 420 of the housing 418, and the atomizing surface is planar or substantially planar in this example. There is a generally circular lip 421 that extends inwardly around the opening 420. The lower part of the housing 418 is cut away to correspond to the cut-away portion 417 of the base 408.

[0268] When the ultrasonic transducer stack 407 is assembled, the housing 418 covers the ultrasonic transducer 215, and the lip 421 contacts at least a portion of the perimeter of the ultrasonic transducer 215 to fix the ultrasonic transducer 215 in position relative to the base and maintain its contact with the edge 410 of the base 408. The edge 421 is electrically connected to a second electrical connection 422 provided at the perimeter of the ultrasonic transducer 215, so the housing 418 forms a second electrical transducer contact.

[0269] Similar to the transducer support 210 described above, the elastically deformable base 408 ensures that the ultrasonic transducer 215 vibrates without the base 408 damping the vibration. The height of the base 408 is selected to ensure that the ultrasonic transducer 215 is tightly clamped between the lip 421 of the housing 418 and the edge 410, which minimizes movement of the ultrasonic transducer 215 relative to the electrical connection 416 and the housing 418. Such movement may disrupt the electrical connection between the electrical connection on the ultrasonic transducer 215 and the electrical connection 416 and the lip 421 of the housing 418. Thus, the ultrasonic transducer stack 407 can achieve its optimal vibration while maintaining a reliable electrical connection with the ultrasonic transducer 215.

[0270] As described below, the first elongated device terminal 423 extends through the mist inhalation device 400 and is electrically connected to the cylindrical lower portion 414 of the first electrical transducer contact 413. The second elongated device terminal 424 extends through a portion of the mist inhalation device 400 and is electrically connected to the housing 418. The first and second elongated device terminals 423, 424 receive an AC drive signal from the drive device 202 and transmit the signal to the ultrasonic transducer 215.

[0271] The stacked structure of the transducer stack 407 enables it to be easily assembled by hand or automated machinery. Although the ultrasonic transducer stack 407 is generally cylindrical in this example, in other examples, its shape can be rectangular or cuboid, etc.

[0272] Although an ultrasonic transducer stack 407 for use with a mist inhalation device 400 is described and shown herein, it should be understood that the stack may be provided separately and / or integrated for use in any other device that includes an ultrasonic transducer. Thus, any device that uses an ultrasonic transducer can benefit from the secure fixation and reliable electrical connection of the transducer provided by the ultrasonic transducer stack 407.

[0273] Referring again to the Figure 29 drawings, the mist inhalation device 400 includes an ultrasonic assembly 425 that receives the ultrasonic transducer stack 407. The ultrasonic assembly 425 includes a first assembly portion 426 that has a recess 427 for receiving and securing the ultrasonic transducer 215 within the ultrasonic transducer stack 407.

[0274] The ultrasonic assembly 425 includes a second assembly portion 428 that is connected to the first assembly portion 426 when assembled. As described below, the structure of the first and second assembly portions 426, 428 allows for easy assembly, facilitating the assembly of the mist inhalation device 400. The components of the ultrasonic assembly 425 can be assembled on a production line by an automated robot with minimal human intervention. Thus, compared to traditional mist inhalation devices, the mist inhalation device 400 can be mass-produced relatively easily and at low cost on a production line.

[0275] At least one of the first assembly portion 426 and the second assembly portion 428 includes an elastically deformable portion that forms a seal therebetween to minimize or prevent fluid leakage therebetween. The elastically deformable structure of the first and second assembly portions 426, 428 obviates the need for a sealant or adhesive, reducing the complexity and cost of manufacturing the mist inhalation device 400.

[0276] In this example, both the first assembly portion 426 and the second assembly portion 428 are made of an elastically deformable material; in other examples, only one of the portions is made of an elastically deformable material.

[0277] In this example, the elastically deformable material is silicone; in other examples, it can be other elastically deformable plastic materials.

[0278] Referring now to the Figure 33 and Figure 34 drawings, the first assembly portion 426 includes an end wall 429 that is spaced apart from a barrier portion 430. The end wall 429 is provided with a mist outlet hole 431 that allows mist to flow from one side of the end wall 429 to the other side. A recess 432 ( Figure 29 visible in) is provided on the other side of the end wall 429. A flange 433 that extends outwardly surrounds the perimeter of the end wall 429 for contacting the housing 204.

[0279] The first component part 426 includes a central portion of the end wall 429 and a barrier portion 430. The central portion 434 is provided with a recess 427 for receiving the ultrasonic transducer 215 and, in the present example, also has first alignment fixing holes 435, 436. The central portion 434 includes an inlet hole 437 that allows air to flow into the ultrasonic assembly 425 from outside the mist inhalation device 400.

[0280] The first component part 426 holds the ultrasonic transducer 215 in a specific orientation such that the plane of the atomizing surface 215a of the ultrasonic transducer 215 is aligned with and substantially parallel to a plane extending longitudinally along the housing 204.

[0281] The barrier portion 430 includes an elastically deformable seal 438, which is, in the present example, a protrusion extending from the barrier portion 430 and is located between the ultrasonic assembly 428 and the inner wall of the inner cavity of the housing 204 for minimizing or preventing leakage of liquid from the liquid chamber 218.

[0282] The barrier portion 430 includes capillary holes 439, which are, in the present example, located at the center of the barrier portion 430 and are in the form of generally elongated slits formed between adjacent capillary hole walls 440, 441. In the present example, both the first and second capillary hole walls 440, 441 are elastically deformable, but in other examples only one of the hole walls is elastically deformable.

[0283] The capillary 222 extends from the liquid chamber 218 located at the lower part of the housing 204 through the capillary holes 439 such that a first portion 442 of the capillary 222 is located within the liquid chamber 218. The capillary 222 is made of a liquid-conducting material (such as bamboo fiber) described herein, and its second portion 443 is superimposed on the atomizing surface of the ultrasonic transducer 215.

[0284] Now referring to Figure 35 and Figure 36 , the second component part 428 includes a main body part 445, which is provided with an ultrasonic recess 446. When the ultrasonic assembly 425 is assembled, the ultrasonic recess 446 is superimposed on the ultrasonic transducer 215 to form an ultrasonic cavity 219.

[0285] In the present example, the main body part 445 is generally rectangular and is provided with holes 447, 448 that are respectively aligned with the recesses 435, 436 in the first component part 426. The ultrasonic recess 446 is formed in the middle of the main body part 445.

[0286] The main body part 445 includes a protrusion 449 extending outward from the main body part 445. The protrusion is adjacent to the ultrasonic recess 446 and is provided with an elongated channel 450. The channel 450 provides an air inlet such that when the ultrasonic assembly 425 is assembled, air can flow along a flow path through the ultrasonic assembly air inlet 451 to the ultrasonic recess 446.

[0287] The main body portion 445 includes an ultrasonic assembly mist outlet 452 that is in fluid communication with the ultrasonic groove 446. The airflow path extends from the ultrasonic assembly air inlet 451 through the ultrasonic groove 446 to the ultrasonic assembly mist outlet 452.

[0288] The second component portion 428 includes a cover or cover portion 453, which are joined together by moving the main body portion 445 and the cover portion 453 in the Figure 35 directions indicated by the arrows 454 and 455 therein.

[0289] The cover portion 453 is generally rectangular and has a cover side 456 that contacts the main body portion 445. The cover side 456 is provided with generally cylindrical pins 457, 458 that project outward from the cover side 456. The pins 457, 458 pass through holes 447, 448 in the main body portion 445 and into grooves 435, 436 in the first component portion 426, forming an interference fit with the holes 447, 448 and the grooves 435, 436 to hold the first component portion 426 and the second component portion 428 aligned and interconnected. This interference fit enables the main body portion 445 and the cover portion 453 to be firmly joined without the use of adhesives or other fixing means. Of course, in other examples, the pins 458, 457, the holes 447, 448, and the grooves 435, 436 may be omitted.

[0290] The cover portion 453 is provided with an air inlet passage 459 that is in fluid connection with the air inlet 450 of the main body portion 445. In this example, the air inlet passage 459 is straight or substantially straight, extending upward from the lower edge of the cover portion 453 and then turning - a 90-degree turn in this example - toward the middle of the cover portion 453 and is in fluid connection with a stepped passage 460 formed in the cover portion 453.

[0291] In this example, the stepped passage 460 includes a plurality of turns - each a 90-degree turn in this example; in other examples, the number of turns may be more or fewer and the angle of each turn may be an oblique angle. The first end 461 of the stepped passage 460 is in fluid connection with the inlet passage 459, and the second end 462 is in fluid connection with the ultrasonic assembly air inlet 451. As described below, the stepped passage 460 defines a part of the airflow path within the device, and this path can be configured to control the distance that air flows through the mist inhalation device 400. This configuration can be used to fine-tune the air flow rate through the mist inhalation device 400, as well as the draw amount and tightness experienced by the user of the device 400, so that the mist inhalation device 400 can be configured in a mouth-to-lung (MTL) mode to mimic a traditional cigarette and improve the experience of users who are accustomed to smoking traditional cigarettes with the mist inhalation device 400.

[0292] The cover part 453 is provided with a mist outlet channel 463 spaced apart from the stepped channel 460. The first end 464 of the mist outlet channel 463 is in fluid connection with the ultrasonic component mist outlet 452, and the second end 465 is in fluid connection with the mist outlet 208 through the nozzle 401.

[0293] In this example, the second component part 428 includes three biasing members 466 - 468 disposed within the ultrasonic recess 446; in other examples, only one biasing member may be included; in further examples, multiple biasing members may be included. Each of the biasing members 466 - 468 applies a biasing force to the second part 443 of the capillary 222, pressing it against the atomizing surface 215a of the ultrasonic transducer 215. The biasing force applied by each of the biasing members 466 - 468 helps to optimize the operation of the mist inhalation device 400 by ensuring tight contact between the capillary 222 and the atomizing surface 215a, so that the liquid carried by the capillary 222 is directly delivered onto or near the atomizing surface 215a for atomization.

[0294] In this example, each of the biasing members 466 - 468 is integrally formed with the second component part 428, which simplifies the manufacturing process of the mist inhalation device 400 compared to the way traditional devices require installing separate biasing components within the mist inhalation device in an additional manufacturing step. Another advantage is that each of the biasing members 466 - 468 can be precisely positioned on the second component part 428 to ensure that the capillary 222 is pressed against the atomizing surface 215a at the optimal position.

[0295] In this example, each of the biasing members 466 - 468 includes a connecting end 466a - 468a that is connected to the second component part 428 within the ultrasonic recess 446; and also includes a distal end 466b - 468b that contacts the second part 443 of the capillary 222. In this example, each of the distal ends 466b - 468b is narrower than the connecting end 466a - 468a of the corresponding biasing member 466 - 468.

[0296] In this example, each of the biasing members 466 - 468 is conical or substantially conical; in other examples, the shape may be different, but each of the distal ends 466b - 468b is preferably narrower than the corresponding connecting end 466a - 468a.

[0297] The narrow distal ends 466a - 468a minimize the contact points between the biasing members 466 - 468 and the capillary 222, optimizing the operation of the mist inhalation device 400 by ensuring that the capillary 222 is tightly pressed against the atomizing surface 215a without the biasing members 466 - 468 damping the vibration of the ultrasonic transducer 215. However, although not optimal, the biasing members in other examples may have wider distal ends, such as at least one cylindrical biasing member.

[0298] Referring now to FIGS. Figure 37 and Figure 38 , after the second component part 428 is assembled, the first component part 426 and the second component part 428 are connected to each other by moving them in the direction indicated by arrow 469 in Figure 37 . The main body part 445 of the second component part 428 abuts against the central part 434 of the first component part 426, and the pins 457 - 458 extend into the grooves 435, 436 of the first component part 426. The first and second component parts 426, 428 are fixed together by an interference fit, as shown in Figure 38 . Similarly, the interference fit avoids the use of adhesives or sealants and simplifies the manufacturing process, although the present disclosure does not exclude the use of adhesives or sealants.

[0299] Referring now to FIGS. Figure 39 and Figure 40 , after the ultrasonic component 425 is assembled, it is at least partially inserted into the inner cavity of the housing 204 in the directions indicated by arrows 470, 471 in Figure 39 .

[0300] The ultrasonic component 425 contacts the side wall of the housing 204 and forms a seal, minimizing or preventing fluid flow between the ultrasonic component 425 and the side wall of the housing 204. In this example, the seal is achieved by the deformation of the elastic material of the ultrasonic component 425 against the wall of the housing 204. Since the seal is achieved by the deformation of the elastic material, no additional sealant or adhesive is required between the ultrasonic component 425 and the housing 204, although the present disclosure does not exclude the use of them.

[0301] Referring now to FIGS. Figure 41 , a liquid chamber 218 is formed in a portion of the inner cavity of the housing 204 adjacent to the bottom of the housing, between the ultrasonic component 425 and the bottom of the housing 204. A capillary 222 extends into the interior of the liquid chamber 214, enabling liquid to be transported from the liquid chamber 218 to the ultrasonic transducer 215 through the capillary 222 by capillary action and atomized by the ultrasonic transducer 215.

[0302] Referring now to FIGS. Figure 42 and Figure 43 , a foam material layer 472 is inserted into the groove 432 of the ultrasonic component 425. The foam material layer 472 includes an air flow channel 473 cut into one side thereof, which slopes from a corner of the foam material layer 472 to the center. The foam material layer 472 also includes a cut portion 474. One end of the air flow channel 473 at the edge of the foam material layer 472 is aligned with the mist outlet hole 465 of the ultrasonic component 425, providing a passage for the mist to flow from the mist outlet hole 465 towards the center of the device 400. In other examples, the air flow channel 473 may be omitted, and the mist directly passes through the foam material layer 472 when the user sucks from the mist inhalation device 400.

[0303] The foam material layer 472 absorbs droplets larger than a predetermined size from the mist flowing out of the mist outlet hole 465 and can also absorb any condensed liquid, helping to minimize the leakage of liquid from the mist outlet 208 of the mist inhalation device 400. Although the foam material layer 472 optimizes the operation of the mist inhalation device 400 by reducing liquid leakage from the device, it may be omitted in other examples.

[0304] Now referring to Figure 44 and Figure 45 , the ultrasonic assembly 425 includes a filling hole that extends from the filling opening 476 through the first assembly portion 426 to the liquid chamber 218, allowing liquid to be injected into the liquid chamber 218 through the filling hole 475 (such as using a needle). The cut portion 474 of the foam material layer 472 is aligned with the opening 476, allowing access to the opening 476 without removing the foam material layer 472.

[0305] The liquid chamber 218 can also be pre-filled with liquid before the ultrasonic assembly 425 is inserted into the groove of the housing 204. At this time, the filling hole 475 and the filling opening 476 allow air to be discharged when the ultrasonic assembly 425 is inserted into the groove of the housing 204. In other examples, the filling hole 475 and the filling opening 476 can be omitted.

[0306] Now referring to Figure 46 , when the ultrasonic assembly 425 is inserted into the groove of the housing 204, the first portion 442 of the capillary 222 is located within the liquid chamber 218. The capillary 222 extends from the first portion 442 and passes through the capillary hole 439 such that the second end 443 of the capillary 222 overlays the ultrasonic transducer 215. The biasing members 466 - 468 press the capillary 222 against the atomizing surface 215a of the ultrasonic transducer 215.

[0307] Now referring to Figure 47 and Figure 48 , once the ultrasonic assembly 425 is inserted into the groove of the housing 204 and the foam material layer 472 has been inserted into the groove 32 of the ultrasonic assembly 425, the separator 477 overlays the foam material layer 472. In this example, the separator 477 is generally planar and made of an elastomeric deformable material such as silicone. The separator 477 includes a central hole 478 surrounded by an upwardly projecting cylindrical wall 479.

[0308] On the side of the separator 477 opposite the cylindrical wall 479, there is an elongated and generally cylindrical plug 480. The plug 480 at least partially fits within the opening 476 to seal the opening 476 and prevent liquid from leaking from the liquid chamber 418 via the filling hole 475.

[0309] Since the separator 477 is elastically deformable, the separator 477 forms a seal around the upper periphery of the ultrasonic assembly 475 to minimize or prevent leakage of liquid between the separator 477 and the ultrasonic assembly 425.

[0310] The mist inhalation device 400 minimizes or eliminates the possibility of any liquid leaking from the interior of the mist inhalation device 400. This is crucial for the consistency of drug administration. A leaking device may have less liquid (containing therapeutic agents, drugs, etc.) in the liquid chamber 218 than the prescribed amount.

[0311] Now referring to Figure 49 and Figure 50 in the accompanying drawings, once the separator 477 is in place, the nozzle 401 is attached to the housing 204 to substantially enclose the inner cavity of the housing 204. The nozzle 401 includes an inner tube 481. One end of the inner tube 481 is in fluid communication with the central hole 478 of the separator 477, and the other end of the inner tube 481 is in fluid communication with the mist outlet 208. The nozzle 401 provides a mist flow path from the ultrasonic assembly 425 to the mist outlet 208.

[0312] Now referring to Figure 51 and Figure 52 in the accompanying drawings, the first and second elongated device terminals 423, 424 are inserted through corresponding terminal holes 482, 483 in the bottom of the housing 204. The first elongated device terminal 423 extends through the mist inhalation device 400 to be electrically connected to the first transducer contact 413. The second elongated device terminal 424 extends through a portion of the mist inhalation device 400 to be electrically connected to the housing 418. The construction of the ultrasonic transducer stack 407 and the elastically deformable material of the ultrasonic assembly 425 ensure that no liquid can penetrate between the housing 418 and the ultrasonic assembly 425. Thus, both the first and second elongated device terminals 423, 424 are isolated from the liquid within the mist inhalation device 400, which otherwise could interfere with the AC drive signal transmitted to the ultrasonic transducer 215 and cause the mist inhalation device 400 to malfunction.

[0313] The first and second elongated device terminals 423, 424 provide an electrical connection from the ends of the elongated device terminals 423, 424 accessible at the bottom of the housing 204 to the terminals of the ultrasonic transducer 215. Thus, the AC drive signal generated by the drive device 202 can be transmitted to the ultrasonic transducer 215 via the elongated device terminals 423, 424.

[0314] In Figure 51 and Figure 52An air inlet hole 207 disposed at the bottom of the outer shell 204 can also be seen. The air inlet hole 207 is fluidly connected to an air passage 484 that extends through the mist inhalation device 400 to the ultrasonic assembly air inlet 451. As described above, air flows into the mist inhalation device 400 via the air inlet 207, which is in fluid communication with an air flow bridge within the drive device 202 as described below.

[0315] Now referring to Figure 53 and Figure 54 in the accompanying drawings, the mist inhalation device 400 includes an end cap 485 attached to the lower end of the outer shell 204. The end cap 485 includes four walls that define a groove 490 for receiving the end of the outer shell 204. Each of the opposing side walls 487, 489 includes a respective retainer groove 491, 492. Each retainer groove 491, 491 is respectively connected to an outwardly directed chamfer 493 (only one of which is visible in Figure 53 and Figure 54 ). Each chamfer 493 holds the end cap 485 attached to the outer shell 204.

[0316] The end cap 485 includes two inwardly directed tabs 494, 495 at the bottom of the end cap 485. When the end cap 485 is attached to the outer shell 204, the tabs 494, 495 are stacked on the respective ends of the printed circuit board 240. The printed circuit board 240 carries the OTPIC 242. The tabs 494, 495 hold the printed circuit board 240 in place within the groove 244 on the outer shell 204.

[0317] The end cap 484 includes a hole 496 to allow access to the electrical contacts 241 on the printed circuit board 240 and to the elongated device terminals 423, 424. The hole 496 also allows air to flow into the air inlet hole 207 on the outer shell 204.

[0318] In this example, the end cap 485 is made of metal, and the end cap 485 enables the mist inhalation device 400 to be held in the groove 203 of the drive device 202 by magnetic force via the attraction to a magnet disposed on the drive device 202. However, in other examples, the end cap 485 can be made of a different material or can be completely omitted.

[0319] Now referring to Figures 56 - 59 in the accompanying drawings, when the mist inhalation device 400 is in use and connected to the drive device 202, there is an air flow path from the air inlet 207 at the bottom of the mist inhalation device 400 through the mist inhalation device 400 to the mist outlet 208. After the air flows through the air inlet 207, it sequentially passes through the air passage 484, the elongated passage 450, and finally reaches the ultrasonic assembly air inlet 451.

[0320] As Figure 57As shown, the air flow path 497 includes multiple turns as air flows from the air inlet passage 459 through the stepped passage 460 to the ultrasonic assembly air inlet 451. Then, the air enters the ultrasonic cavity via the ultrasonic assembly air inlet 451 as Figure 58 shown. When the air flows through the ultrasonic cavity 219, the air is directed against the capillary 222 and flows along a portion of the length of the capillary 222. This optimizes the operation of the mist inhalation device 400 by ensuring that the air flow is directed against a portion of the capillary 222.

[0321] The ultrasonic transducer 215 vibrates and atomizes the aerosol liquid from the capillary 222 within the ultrasonic cavity 219. This generates mist within the ultrasonic cavity 219, which is withdrawn from the ultrasonic cavity 219 via the ultrasonic assembly mist outlet 452. The mist inhalation device 400 optimizes the operating efficiency by ensuring that all (or most) of the generated mist is thoroughly withdrawn from the ultrasonic cavity 219 after flowing along a portion of the capillary length.

[0322] The mist flows out of the mist outlet 465, passes through the air flow passage 473 provided in the foam material layer 472, and reaches the central hole 478 in the separator 477. Then, the mist passes through the inner tube 481 of the mouthpiece 401 and reaches the mist outlet 208 for the user to inhale.

[0323] Now, the drive device 202 will be described first with reference to Figure 60 and Figure 61 The drive device 202 includes a drive device housing 246 that is at least partially metallic. In some examples, the drive device housing 246 is made entirely of aluminum (AL6063T6), which protects the internal components from the environment (dust, splashing water, etc.) and also protects against impact (accidental dropping, etc.) damage.

[0324] In some examples, the drive device housing 246 is provided with ventilation openings on its sides, which allow ambient air to enter the device for two purposes; one is to ventilate and dissipate heat around the electronic components and keep them within the operating temperature range, and the other is that these ventilation openings also serve as air inlets, and the air enters the device through these ventilation openings and then enters the mist generating device 201 through the air flow bridge.

[0325] The drive device housing 246 is elongated and has an internal chamber 247 that houses the components of the drive device 202. One end of the drive device housing 246 is closed by an end cap 248. The other end of the drive device housing 247 has an opening 249 that provides an opening for the groove 203 of the drive device 202.

[0326] The drive device 202 includes a battery 250 connected to a printed circuit board 251. In some examples, the battery 250 is a 3.7V DC lithium polymer battery with a capacity of 1140 mAh and a discharge rate of 10C. The voltage amplification up to 15V required by the ultrasonic transducer 215 requires a high discharge rate to achieve ideal operation. Within physical limitations, the shape and size of the battery are designed according to the shape and size of the device and the space allocated for the power supply.

[0327] The printed circuit board 251 includes a processor, a memory, and other electronic components for implementing the electrical functions of the drive device 202. A charging pin 258 is provided at one end of the printed circuit board 251 and extends through the end cap 248 to provide a charging connection for charging the battery 250.

[0328] The printed circuit board 251 is held within the drive device housing 246 by a skeleton 252. The skeleton 252 has a channel 253 for receiving the printed circuit board 251. The skeleton 252 includes raised sides 254, 255 for supporting the battery 250.

[0329] In some examples, the skeleton 252 is manufactured using an industrial injection molding process. The molded plastic skeleton ensures that all components are fixed and do not loosen within the housing. When the mist generating device 201 is inserted into the drive device 202, it also forms a cover on the front of the printed circuit board (PCB) that is connected to the mist generating device 201.

[0330] The drive device 202 includes an airflow sensor that acts as a switch for activating the transducer and powering it for ultrasonic treatment and aerosol generation. The airflow sensor is mounted on the PCB in the device and requires a certain air pressure drop around it to activate the drive device 202. For this purpose, as Figures 64 to 66 shown, the airflow bridge 259 is designed with internal channels 260, 261 that direct air from the surrounding environment through the airflow bridge 259 into the atomization chamber 262. As Figure 67 shown, the skeleton 252 is provided with oppositely arranged channels 256, 257 for receiving corresponding portions of the airflow bridge 259.

[0331] The internal channels in the airflow bridge 259 have microchannels 263 (0.5 mm in diameter) that extend downward to a chamber 264 that completely covers the airflow sensor. When air flows in from the side inlet and upward to the atomization chamber 262, it creates a negative pressure in the microchannels 263 that triggers the airflow sensor to activate the device.

[0332] The device is a compact, portable, and highly advanced device that allows precise, safe, and monitored atomization. This is achieved by combining high-quality electronic components that take into account an IPC3-class - medical-grade design.

[0333] The drive device 202 includes the following electronic components:

[0334] 1. Ultrasonic treatment section

[0335] In order to obtain the most effective atomization for inhalation so far in a portable device, with a particle size of less than 1 μm, the ultrasonic treatment section must provide a high adaptive frequency (about 3 MHz) to the contact pads for receiving the ultrasonic transducer 215 (piezoelectric ceramic disk (PZT)).

[0336] This section must not only provide a high frequency, but also protect the ultrasonic transducer 215 from failure while providing a constant and optimal cavitation.

[0337] The mechanical deformation of the PZT is related to the amplitude of the alternating voltage applied to it, and in order to ensure the optimal function and delivery of the system during each ultrasonic treatment, the maximum deformation must always be provided to the PZT.

[0338] However, in order to prevent the failure of the PZT, the active power transmitted to it must be precisely controlled.

[0339] This can only be achieved by designing a custom power management integrated circuit (PMIC) chip that does not exist on the market, which is set on the printed circuit board of the drive device 202. This PMIC allows the active power given to the PZT to be modulated at any time without compromising the mechanical vibration amplitude of the PZT.

[0340] By pulse width modulation (PWM) of the alternating voltage applied to the PZT, the mechanical amplitude of the vibration remains unchanged.

[0341] The only available "off-the-shelf" option is to modify the output alternating voltage by using a digital-to-analog converter (DAC). The energy transmitted to the PZT will be reduced, but the mechanical deformation will also be reduced, and the result is complete degradation and prevention of proper atomization. In fact, the applied RMS voltage is the same as the effective duty cycle modulation, but the active power transmitted to the PZT is reduced. In fact, the following formula is given:

[0342] The active power applied to the PZT is:

[0343]

[0344] where

[0345] φ is the phase shift between the current and the voltage

[0346] Irms is the root mean square current

[0347] Vrms is the root mean square voltage.

[0348] When considering the fundamental harmonic, Irms is a function of the actual voltage amplitude applied to the transducer because pulse width modulation changes the duration of the voltage supplied to the transducer, thereby controlling Irms.

[0349] The specific design of the PMIC adopts state-of-the-art designs that enable ultra-precise control over the frequency range and steps applied to the PZT, including a complete set of feedback loops and monitoring paths for use by the control section.

[0350] The remainder of the atomization section consists of a DC / DC boost converter and a transformer that transfers the necessary power from the 3.7V battery to the PZT contact pads.

[0351] Now referring to Figure 68 in the accompanying drawings, the drive device 202 includes an ultrasonic transducer drive microchip, herein referred to as a power management integrated circuit or PMIC 300. The PMIC 300 is a microchip for driving a resonant circuit. The resonant circuit is an inductor (L) capacitor (C) circuit (LC resonant circuit), an antenna, or in this case a piezoelectric transducer (ultrasonic transducer 215).

[0352] In the present disclosure, the terms chip, microchip, and integrated circuit are interchangeable. A microchip or integrated circuit is a single unit that includes multiple interconnected embedded components and subsystems. A microchip is made, for example, at least in part of a semiconductor such as silicon and is manufactured using semiconductor manufacturing techniques.

[0353] The drive device 202 also includes a second microchip, herein referred to as a bridge integrated circuit or bridge IC 301, which is electrically connected to the PMIC 300. The bridge IC 301 is a microchip for driving a resonant circuit (such as an LC resonant circuit, an antenna, or a piezoelectric transducer). The bridge IC 301 is a single unit that includes multiple interconnected embedded components and subsystems.

[0354] In this example, the PMIC 300 and the bridge IC 301 are mounted on the same PCB of the drive device 202. In this example, the physical size of the PMIC 300 is 1 - 3 mm wide and 1 - 3 mm long, and the physical size of the bridge IC 301 is 1 - 3 mm wide and 1 - 3 mm long.

[0355] The mist generating device 201 includes a programmable or one-time programmable integrated circuit or OTPIC 242. When the mist generating device 201 is coupled to the drive device 202, the OTPIC is electrically connected to the PMIC 300 to receive power from the PMIC 300 such that the PMIC 300 can manage the voltage supplied to the OTPIC 242. The OTPIC 242 is also connected to the communication bus 302 in the drive device 202. In this example, the communication bus 302 is an I2C bus, but in other examples, the communication bus 302 is another type of digital serial communication bus.

[0356] The ultrasonic transducer 215 in the mist generating device 201 is electrically connected to the bridge IC 301 such that when the device 200 is in use, the ultrasonic transducer 215 can be driven by the AC drive signal generated by the bridge IC 301.

[0357] The drive device 202 includes a microcontroller 303 acting as a processor, which is electrically coupled to the communication bus to communicate with the communication bus 302. In this example, the microcontroller 303 is a Bluetooth TM low energy (BLE) microcontroller. The microcontroller 303 receives power from a low dropout regulator (LDO) 304 driven by the battery 250. The LDO 304 provides a stable regulated voltage to the microcontroller 303 so that the microcontroller 303 can operate consistently even when the voltage of the battery 250 changes.

[0358] The drive device 202 includes a boost converter 305 for DC-DC voltage regulation, which is powered by the battery 250. The boost converter 305 increases the voltage of the battery 250 to a programmable voltage VBOOST. The programmable voltage VBOOST is set by the boost converter 305 in response to the voltage control signal VCTL from the PMIC 300. As will be described in more detail below, the boost converter 305 outputs the voltage VBOOST to the bridge IC 301. In other examples, the voltage regulator is a buck converter or another type of voltage regulator that outputs an optional voltage.

[0359] The voltage control signal VCTL is generated by a digital-to-analog converter (DAC), which in this example is implemented within the PMIC 300. The DAC is Figure 68 not visible as the DAC is integrated within the PMIC 300. The DAC and the technical advantages of integrating the DAC within the PMIC 300 are described in detail below.

[0360] In this example, the PMIC 300 is connected to a universal serial bus (USB) connector 306 used as a power connector such that when the USB connector 306 is coupled to a USB charger, the PMIC 300 can receive the charging voltage VCHRG.

[0361] The drive device 202 includes a first pressure sensor 307, which is a static pressure sensor in this example. The drive device 202 also includes a second pressure sensor 308, which is a dynamic pressure sensor in this example. However, in other examples, the drive device 202 includes only one of the two pressure sensors 307, 308. As described above, the pressure sensors 307, 308 sense the pressure change in the atomization chamber 262 to sense when the user is inhaling on the mist inhaler device 200.

[0362] In this example, the drive device 202 includes a plurality of LED lights 321 - 326 controlled by the PMIC 300.

[0363] The microcontroller 303 acts as the master device on the communication bus 302, the PMIC 300 is the first slave device, the OTPIC 242 is the second slave device, the second pressure sensor 308 is the third slave device, and the first pressure sensor 307 is the fourth slave device. The communication bus 302 enables the microcontroller 303 to control the drive device 202 to have the following functions:

[0364] 1. All functions of the PMIC can be highly configured by the microcontroller 303.

[0365] 2. The current flowing through the ultrasonic transducer 215 is sensed by a high - bandwidth detection and rectification circuit at a high common - mode voltage (the high end of the bridge). The sensed current is converted into a voltage proportional to the root - mean - square current and provided as a buffered voltage at the current - detection output pin 309 of the bridge IC 301. This voltage is fed to the PMIC 300 and sampled therein, and provided in digital form via an I2C request. Sensing the current flowing through the ultrasonic transducer 215 is part of the resonant - frequency tracking function. As described herein, the ability of the device to implement this function within the bridge IC 301 provides significant technical advantages.

[0366] 3. The DAC integrated within the PMIC 300 ( Figure 68 not shown in the figure) enables the DC - DC boost - converter voltage VBOOST to be programmed between 10V and 20V.

[0367] 4. The microcontroller 303 enables the charger subsystem of the drive device 202 to manage the charging of the battery 250, which is a single - cell battery in this example.

[0368] 5. The light - emitting diode (LED) driver module (not shown) is powered by the PMIC 300 to digitally drive and dim the LED lights 321 - 326 in linear mode or gamma - correction mode.

[0369] 6. The microcontroller 303 is capable of reading the sensor values of pressure #1 and pressure #2 from the pressure sensors 307, 308.

[0370] Now referring to Figure 69 in the accompanying drawings, in this example, the PMIC 300 is a separate chip or integrated circuit that includes an integrated subsystem and a plurality of pins that provide electrical inputs and outputs to the PMIC 300. References to integrated circuits or chips in this disclosure are interchangeable, and either term encompasses, for example, semiconductor devices that may be made of silicon.

[0371] The PMIC 300 includes an analog core 310, which contains analog components, including a reference module (BG) 311, a low-dropout regulator (LDO) 312, a current sensor 313, a temperature sensor 314, and an oscillator 315.

[0372] As described in more detail below, the oscillator 315 is coupled to a delay-locked loop (DLL), which outputs pulse-width modulation (PWM) Phase A and B. The oscillator 315 and the DLL generate a two-phase center-aligned PWM output that drives the H-bridge in the bridge IC 301.

[0373] The DLL includes a plurality of delay lines connected end to end, where the total delay of the delay lines is equal to the period of the master clock signal clk_m. In this example, the DLL is implemented in the digital processor subsystem (referred to herein as the digital core 316) of the PMIC 300, which receives the clock signal from the oscillator 315 and the regulated power supply voltage from the LDO 312. The DLL is implemented in the digital core 316 by a large number (e.g., on the order of millions) of delay gates connected end to end.

[0374] Implementing the oscillator 315 and the DLL in the same integrated circuit of the PMIC 300 to generate a two-phase center-aligned PWM signal is unique because no signal generator component in the current integrated circuit market includes such an implementation.

[0375] As described herein, PWM is part of the function that enables the drive device 202 to accurately track the resonant frequency of the ultrasonic transducer 215 to maintain an efficient conversion of electrical energy to kinetic energy, thereby optimizing the generation of fog.

[0376] In this example, the PMIC 300 includes a charger circuit 317 that controls the charging of the battery 250, for example, through electricity from a USB power supply.

[0377] The PMIC 300 includes an integrated power switch VSYS, which configures the PMIC 300 to supply power to the analog core 310 through the power of the battery 250 or through an external power supply when the battery 250 is charging.

[0378] The PMIC 300 includes an embedded analog-to-digital converter (ADC) subsystem 318. Implementing the ADC 318 and the oscillator 315 in the same integrated circuit is unique in itself because no other integrated circuit in the integrated circuit market includes an oscillator and an ADC as sub-modules within the integrated circuit. In traditional devices, the ADC is typically provided as a separate component separate from the oscillator, and the separate ADC and oscillator are mounted on the same PCB. The problem with this traditional arrangement is that the two separate components, the ADC and the oscillator, unnecessarily occupy space on the PCB. Another problem is that traditional ADCs and oscillators are typically connected to each other via a serial data communication bus (such as an I2C bus), and the communication speed of this bus is limited, with a maximum of only 400 kHz. Compared with traditional devices, the PMIC 300 integrates the ADC 318 and the oscillator 315 within the same integrated circuit, eliminating the communication delay between the ADC 318 and the oscillator 315, which means that the ADC 318 and the oscillator 315 can communicate at high speed, for example, at the speed of the oscillator 315 (such as 3 MHz to 5 MHz).

[0379] In the PMIC 300 of this example, the oscillator 315 operates at 5 MHz and generates a clock signal SYSCLOCK of 5 MHz. However, in other examples, the oscillator 315 generates a clock signal with a higher frequency of up to 105 MHz. The integrated circuits described herein are all configured to operate at the high frequency of the oscillator 315.

[0380] The ADC 318 includes a plurality of feedback input terminals or analog inputs 319, which include a plurality of GPIO inputs (IF_GPIO1-3). At least one feedback input terminal or analog input 319 receives a feedback signal from the H-bridge circuit in the bridge IC 301, and this feedback signal indicates the operating parameters of the H-bridge circuit or the parameters of the AC drive signal when the H-bridge circuit drives a resonant circuit (such as the ultrasonic transducer 215) with an AC drive signal. As described below, the GPIO input is used to receive a current detection signal from the bridge IC 301, and this signal indicates the root mean square (rms) current reported by the bridge IC 301. In this example, one of the GPIO inputs is a feedback input terminal that receives a feedback signal from the H-bridge in the bridge IC 301.

[0381] The ADC subsystem 318 samples the analog signals received at the plurality of ADC input terminals 319 at a sampling frequency proportional to the frequency of the main clock signal. Then, the ADC subsystem 318 uses the sampled analog signals to generate an ADC digital signal.

[0382] In this example, the ADC318 included in the PMIC300 samples not only the RMS current flowing through the H-bridge 334 and the ultrasonic transducer 215, but also the available voltages in the system (such as VBAT, VCHRG, VBOOST), the temperature of the PMIC300, the temperature of the battery 250, and the GPIO inputs (IF_GPIO1-3) that allow for future expansion.

[0383] The digital core 316 receives the digital signals generated by the ADC from the ADC subsystem and processes the ADC digital signals to generate drive control signals. The digital core 316 transmits the drive control signals to the PWM signal generator subsystem (DLL332) to control the PWM signal generator subsystem.

[0384] The rectification circuit bandwidth in the current market is very limited (usually less than 1 MHz). Since the oscillator 315 of the PMIC300 operates at a frequency of up to 5 MHz or even up to 105 MHz, a high-bandwidth rectification circuit is implemented in the PMIC300. As described below, sensing the RMS current within the H-bridge of the sense bridge IC301 is part of a feedback loop that enables the drive device 202 to drive the ultrasonic transducer 215 with high precision. This feedback loop is a transformative technology in the ultrasonic transducer drive industry because it adapts to any process variations (changes in resonant frequency) in piezoelectric transducer production and compensates for the temperature effect of the resonant frequency. This is creatively achieved in part by integrating the ADC318, oscillator 315, and DLL within the same integrated circuit of the PMIC300. This integration enables these subsystems to communicate at high speed (e.g., at a clock frequency of 5 MHz or up to 105 MHz). Reducing the latency between these subsystems is a revolution in the ultrasonic industry, especially in the field of mist inhalation devices.

[0385] The ADC318 includes a battery voltage monitoring input VBAT, a charger input voltage monitoring input VCHG, as well as voltage monitoring inputs VMON and VRTH, and a temperature monitoring input TEMP.

[0386] The temperature monitoring input TEMP receives a temperature signal from the temperature sensor 314 embedded within the PMIC300. This enables the PMIC300 to accurately sense the actual temperature within the PMIC300 so that the PMIC300 can detect any faults within the PMIC300 and faults of other components on the printed circuit board that affect the temperature of the PMIC300. Then, the PMIC300 can control the bridge IC301 to prevent the ultrasonic transducer 215 from being excited in case of a fault to maintain the safety of the mist inhaler device 200.

[0387] An additional temperature sensor input VRTH receives a temperature sensing signal from an external temperature sensor within the drive device 202, which monitors the temperature of the battery 250. Thus, the PMIC 300 can react when the battery temperature is too high, stop charging the battery 250, or otherwise shut down the drive device 202 to reduce the risk of damage caused by an overheated battery.

[0388] The PMIC 300 includes an LED driver 320 that, in this example, receives a digital drive signal from the digital core 316 and provides an LED drive output signal to six LED lights 321 - 326 configured to be coupled to the output pins of the PMIC 300. Thus, the LED driver 320 can drive and dim the LED lights 321 - 326 in up to six independent channels.

[0389] The PMIC 300 includes a first digital - to - analog converter (DAC) 327 that converts a digital signal within the PMIC 300 into an analog voltage control signal, which is output from the PMIC 300 through the output pin VDAC0. The first DAC 327 converts a digital control signal generated by the digital core 316 into an analog voltage control signal, which is output through the output pin VDAC0 to control a voltage regulator circuit (such as the boost converter 305). Thus, the voltage control signal controls the voltage regulator circuit to generate a predetermined voltage for modulation by the H - bridge circuit to drive the resonant circuit in response to a feedback signal indicating the operation of the resonant circuit (ultrasonic transducer 215).

[0390] In this example, the PMIC 300 includes a second DAC 328 that converts a digital signal within the PMIC 300 into an analog signal, which is output from the PMIC 300 through the second analog output pin VDAC1.

[0391] The DACs 327, 328 and other subsystems of the PMIC 300 are embedded in the same microchip, enabling the DACs 327, 328 to communicate with the digital core 316 and other components within the PMIC 300 at high speed with zero or minimal communication latency. The DACs 327, 328 provide analog outputs that control an external feedback loop. For example, the first DAC 327 provides a control signal VCTL to the boost converter 305 to control the operation of the boost converter 305. In other examples, the DACs 327, 328 are configured to provide drive signals to a DC-DC buck converter instead of or in addition to the boost converter 305. Integrating two independent DAC channels in the PMIC 300 enables the PMIC 300 to manipulate the feedback loop of any regulator used in the drive device 202 and enables the drive device 202 to regulate the ultrasonic processing power of the ultrasonic transducer 215 or set analog thresholds for the absolute maximum current and temperature settings of the ultrasonic transducer 215.

[0392] The PMIC 300 includes a serial communication interface, which is an I2C interface in this example, and includes an external I2C address set through pins.

[0393] The PMIC 300 also includes various functional blocks, including a digital machine (FSM) that implements the functions of the microchip. These blocks will be described in more detail below.

[0394] Now referring to Figure 70 in the accompanying drawings, a pulse width modulation (PWM) signal generator subsystem 329 is embedded within the PMIC 300. The PWM generator system 329 includes an oscillator 315, a frequency divider 330, a multiplexer 331, and a delay locked loop (DLL) 332. As described below, the PWM generator system 329 is a two-phase center-aligned PWM generator.

[0395] The frequency divider 330, multiplexer 331, and DLL 332 are implemented in digital logic components (such as transistors, logic gates, etc.) within the digital core 316.

[0396] In an example of the present disclosure, the frequency ranges covered by the oscillator 315 and the PWM generator system 329 are 50 kHz to 5 MHz or up to 105 MHz, respectively. The frequency accuracy of the PWM generator system 329 is ±1%, and the deviation within the temperature range is ±1%. In today's IC market, no IC has an embedded oscillator and a two-phase center-aligned PWM generator that can provide a frequency range of 50 kHz to 5 MHz or up to 105 MHz.

[0397] Oscillator 315 generates a master clock signal (clk_m) with a frequency ranging from 50 kHz to 5 MHz or up to 105 MHz. The master clock clk_m is input to a divider 330, which divides the frequency of the master clock clk_m by one or more predetermined divisors. In this example, the divider 330 divides the frequency of the master clock clk_m by 2, 4, 8, and 16, and provides the divided clock as an output to a multiplexer 331. The multiplexer 331 multiplexes the divided clocks and provides a divided frequency output to the DLL 332. This signal passed to the DLL 332 is a frequency reference signal, which controls the DLL 332 to output a signal at the desired frequency. In other examples, the divider 330 and the multiplexer 331 are omitted.

[0398] Oscillator 315 also generates two phases: a first phase clock signal Phase1 and a second phase clock signal Phase2. The phases of the first phase clock signal and the second phase clock signal are centered-aligned. As Figure 71 shown:

[0399] · The first phase clock signal Phase1 is high during a variable time within the positive half-cycle of clk_m and low during the negative half-cycle of clk_m.

[0400] · The second phase clock signal Phase2 is high during a variable time within the negative half-cycle of clk_m and low during the positive half-cycle of clk_m.

[0401] Then, Phase1 and Phase2 are sent to the DLL 332, which uses the first phase clock signal Phase1 and the second phase clock signal Phase2 to generate a double-frequency clock signal. The frequency of the double-frequency clock signal is twice that of the master clock signal clk_m. In this example, an "OR" gate within the DLL 332 uses the first phase clock signal Phase1 and the second phase clock signal Phase2 to generate the double-frequency clock signal. This double-frequency clock or the divided frequency from the divider 330 is selected according to the selected target frequency and then used as a reference for the DLL 332.

[0402] Within the DLL 332, a signal hereafter referred to as "clock" represents the master clock clk_m multiplied by 2, and a signal hereafter referred to as "clock_del" is a copy of clock delayed by one cycle. clock and clock_del are processed by a phase frequency detector. Then, the node Vc is charged or discharged by a charge pump according to the phase error polarity. The control voltage is directly fed to control the delay of each delay unit within the DLL 332 until the total delay of the DLL 332 is exactly one cycle.

[0403] The DLL332 synchronizes the rising edges of the first-phase clock signal Phase1 and the second-phase clock signal Phase2 with the rising edge of the double-frequency clock signal. The DLL332 adjusts the frequencies and duty cycles of the first-phase clock signal Phase1 and the second-phase clock signal Phase2 in response to corresponding frequency reference signals and duty cycle control signals to generate a first-phase output signal PhaseA and a second-phase output signal PhaseB to drive an H-bridge or an inverter to generate an AC drive signal to drive an ultrasonic transducer.

[0404] The PMIC300 includes a first-phase output signal terminal PHASE_A that outputs the first-phase output signal PhaseA to the H-bridge circuit, and a second-phase output signal terminal PHASE_B that outputs the second-phase output signal PhaseB to the H-bridge circuit.

[0405] In this example, the DLL332 adjusts the duty cycles of the first-phase clock signal Phase1 and the second-phase clock signal Phase2 in response to the duty cycle control signal by changing the delay of each delay line in the DLL332.

[0406] The double-frequency clock is used because it guarantees higher precision. As Figure 72 shown, for the sake of illustration, if the frequency of the main clock clk_m (not used in the examples of the present disclosure) is used, then PhaseA is synchronized with the rising edge R of the clock, while PhaseB is synchronized with the falling edge F of the clock. The delay line of the DLL332 controls the rising edge R. Therefore, for the falling edge F, the PWM generator system 329 would need to rely on the perfect matching of the delay units of the DLL332, but there may be matching errors in the actual circuit. However, to eliminate this error, the PWM generator system 329 uses a double-frequency clock such that both PhaseA and PhaseB are synchronized with the rising edge R of the double-frequency clock.

[0407] To perform a duty cycle of 20% to 50% in 2% steps, the delay line of the DLL332 includes 25 delay units, and the output of each corresponding delay unit represents the nth phase. The output phase of the final stage delay unit will correspond to the input clock. Considering that all the delays are almost the same, a specific duty cycle can be obtained using the output of a specific delay unit through simple logic in the digital core 316.

[0408] The startup of DLL332 is important because DLL332 may not be able to lock in one delay cycle, but two or more cycles, causing DLL332 to enter the non-convergent region. To avoid this problem, a startup circuit is implemented in the PWM generator system 329, which allows DLL332 to start from a known and determined condition. The startup circuit also allows DLL332 to start with a minimum delay.

[0409] In an example of the present disclosure, the frequency range covered by the PWM generator system 329 is extended, so the delay cells in DLL332 can provide a delay from 4 nanoseconds (when the oscillator frequency is 5 MHz) to 400 nanoseconds (when the oscillator frequency is 50 kHz). To accommodate these different delays, a capacitor Cb is included in the PWM generator system 329, and its capacitance value is selected to provide the required delay.

[0410] PhaseA and PhaseB are output from DLL332 and transferred to the bridge IC301 through digital input / output (IO) to control the operation of the bridge IC301 using PhaseA and PhaseB.

[0411] Now, the battery charging function of the drive device 202 will be described in more detail. The battery charging subsystem includes a charger circuit 317 embedded in the PMIC300 and is controlled by a digital charging controller within the PMIC300. The charger circuit 317 is controlled by the microcontroller 303 through the communication bus 302. This battery charging subsystem is capable of charging a single lithium polymer (LiPo) or lithium-ion (Li-ion) battery (such as the battery 250 mentioned above).

[0412] In this example, the battery charging subsystem is capable of charging one or more batteries with a charging current of up to 1 A through a 5V power supply (such as a USB power supply). One or more of the following parameters can be programmed through the communication bus 302 (I2C interface) to adapt to the charging parameters of the battery:

[0413] · The charging voltage can be set between 3.9V and 4.3V in steps of 100 mV.

[0414] · The charging current can be set between 150 mA and 1000 mA in steps of 50 mA.

[0415] · The pre-charge current is 1 / 10 of the charging current.

[0416] · The pre-charge and fast charge timeout times can be set between 5 and 85 minutes and 20 and 340 minutes respectively.

[0417] · Optionally, an external negative temperature coefficient (NTC) thermistor can be used to monitor the battery temperature.

[0418] In some examples, the battery charging subsystem reports one or more of the following events by issuing an interrupt to the host microcontroller 303:

[0419] · Battery detected

[0420] · Battery is charging

[0421] · Battery is fully charged

[0422] · Battery does not exist

[0423] · Charge timeout reached

[0424] · Charge power is below the undervoltage limit

[0425] The main advantage of integrating the charger circuit 317 into the PMIC 300 is that it allows all the listed programming options and event indications to be implemented within the PMIC 300, thus ensuring the safe operation of the battery charging subsystem. Additionally, compared to traditional nebulizer devices where the discrete components of the charging system are separately mounted on the PCB, significant manufacturing cost and PCB space savings can be achieved. The charger circuit 317 also allows for a highly flexible setting of the charging current and voltage, different fault timeout times, and numerous event flags for detailed status analysis.

[0426] The analog-to-digital converter (ADC) 318 will now be described in more detail. The inventors had to overcome significant technical challenges when integrating the ADC 318 with the high-speed oscillator 315 within the PMIC 300. Additionally, integrating the ADC 318 within the PMIC 300 goes against the traditional approach in the art that relies on using one of the many discrete ADC devices available on the IC market.

[0427] In this example, the ADC 318 samples at least one parameter within the ultrasonic transducer driver chip (PMIC 300) at a sampling rate equal to the frequency of the main clock signal clk_m. In this example, the ADC 318 is a 10-bit analog-to-digital converter that can offload digital sampling from the microprocessor 303 to save the resources of the microprocessor 303. Integrating the ADC 318 within the PMIC 300 also avoids using the I2C bus, which would otherwise reduce the sampling ability of the ADC (traditional devices rely on the I2C bus to transfer data between a dedicated discrete ADC and a microcontroller at a limited clock speed typically up to 400 kHz).

[0428] In the examples of the present disclosure, the ADC 318 can sequentially sample one or more of the following parameters:

[0429] i. The root mean square (rms) current signal received at the ultrasonic transducer drive chip (PMIC300) from the external inverter circuit driving the ultrasonic transducer. In this example, this parameter is the rms current reported by the bridge IC301. Sensing the rms current is very important for implementing a feedback loop for driving the ultrasonic transducer 215. The ADC318 is capable of sensing the rms current directly from the bridge IC301 through the signal, with minimal or no delay, because the ADC318 does not rely on transmitting this information through the I2C bus. This provides significant speed and accuracy advantages compared to traditional devices limited by the relatively low speed of the I2C bus.

[0430] ii. The battery voltage connected to the PMIC300.

[0431] iii. The charger voltage connected to the PMIC300.

[0432] iv. A temperature signal, such as a temperature signal indicating the temperature of the PMIC300 chip. As described above, since the temperature sensor 314 and the oscillator 315 are embedded in the same IC, this temperature can be measured very precisely. For example, if the temperature of the PMIC300 increases, the PMIC300 adjusts the current, frequency, and PWM to control the transducer oscillation and thereby control the temperature.

[0433] v. Two external pins.

[0434] vi. An external NTC temperature sensor for monitoring the battery pack temperature.

[0435] In some examples, the ADC318 samples one or more of the above sources sequentially (e.g., in a cyclic scheme). The ADC318 samples the sources at a high speed, such as the speed of the oscillator 315, which may be up to 5 MHz or up to 105 MHz.

[0436] In some examples, the drive device 202 is configured such that the user or manufacturer of the device can specify how many samples to obtain from each source for averaging. For example, the user can configure the system to obtain 512 samples from the rms current input, 64 samples from the battery voltage, 64 samples from the charger input voltage, 32 samples from the external pins, and 8 samples from the NTC pins. Additionally, the user can also specify whether one of the above sources should be skipped.

[0437] In some examples, for each source, the user can specify two digital thresholds that divide the entire range into multiple regions (e.g., 3 regions). Subsequently, the user can set the system to issue an interrupt when the sampled value changes regions (e.g., from region 2 to region 3).

[0438] There is no traditional IC in the current market that can implement the above functions of PMIC300. When driving a resonant circuit or component (such as an ultrasonic transducer), it is crucial to sample with such flexibility and granularity.

[0439] In this example, PMIC300 includes an 8-bit general-purpose digital input / output port (GPIO). Each port can be configured as a digital input and a digital output. As shown in the table in Figure 73 , some ports have analog input functions.

[0440] The GPIO7 - GPIO5 ports of PMIC300 can be used to set the address of the device on the communication (I2C) bus 302. Subsequently, eight identical devices can be used on the same I2C bus. This is a unique feature in the IC industry because it allows eight identical devices to be used on the same I2C bus without any address conflicts. This is achieved by each device reading the status of GPIO7 - GPIO5 within the first 100 microseconds after PMIC300 starts up and storing this part of the address inside PMIC300. After PMIC300 starts up, the GPIO can be used for any other purpose.

[0441] As described above, PMIC300 includes a six-channel LED driver 320. In this example, LED driver 320 includes an N-channel metal-oxide-semiconductor (NMOS) current source that can withstand 5V. LED driver 320 is configured to set the LED current at four discrete levels (5mA, 10mA, 15mA, and 20mA). LED driver 320 is configured to dim each LED channel using a 12-bit PWM signal, with or without gamma correction. LED driver 320 is configured to vary the PWM frequency from 300Hz to 1.5KHz. This function is unique in the field of ultrasonic nebulizer devices because this function is embedded as a subsystem of PMIC300.

[0442] In this example, PMIC300 includes two independent 6-bit digital-to-analog converters (DACs) 327, 328 incorporated into PMIC300. The purpose of DACs 327, 328 is to output an analog voltage to manipulate the feedback path of an external regulator (such as a DC-DC boost converter 305, a buck converter, or an LDO). Additionally, in some examples, DACs 327, 328 can also be used to dynamically adjust the overcurrent turn-off level of bridge IC301, as described below.

[0443] The output voltage of each DAC327, 328 can be programmed between 0V and 1.5V or between 0V and the battery voltage (Vbat). In this example, the control of the DAC output voltage is done via I2C commands. Integrating two DACs in the PMIC300 is unique, which will allow for dynamic monitoring and control of the current. If any of the DAC327, 328 were external chips, due to the limitations of the I2C protocol, the speed would be subject to the same speed limit. If all of these embedded functions are in the PMIC, the active power monitoring device of the drive device 202 will operate with optimal efficiency. If they are external components, the active power monitoring device will be completely inefficient.

[0444] Now referring to Figure 74 in the accompanying drawings, the bridge IC301 is a microchip that includes an embedded power switch circuit 333. In this example, the power switch circuit 333 is Figure 75 the H-bridge 334 shown and will be described in detail below. However, it should be understood that the bridge IC301 of other examples may include an alternative power switch circuit other than the H-bridge 334, as long as the power switch circuit performs an equivalent function for generating an AC drive signal for driving the ultrasonic transducer 215.

[0445] The bridge IC301 includes a first phase terminal PHASEA that receives a first phase output signal PhaseA from the PWM signal generator subsystem of the PMIC300. The bridge IC301 also includes a second phase terminal PHASEB that receives a second phase output signal PhaseB from the PWM signal generator subsystem of the PMIC300.

[0446] The bridge IC301 includes a current sensing circuit 335 that directly senses the current flow in the H-bridge 334 and provides an RMS current output signal through the RMS_CURR pin of the bridge IC301. The current sensing circuit 335 is configured for overcurrent monitoring to detect when the current flowing in the H-bridge 334 is higher than a predetermined threshold. Integrating both the power switch circuit 333 that includes the H-bridge 334 and the current sensing circuit 335 in the same embedded circuit of the bridge IC301 is a unique combination in the IC market. Currently, there is no other integrated circuit in the IC market that includes an H-bridge with an embedded circuit for sensing the RMS current flowing through the H-bridge.

[0447] The bridge IC301 includes a temperature sensor 336 that includes an overheat monitoring function. The temperature sensor 336 is configured to turn off the bridge IC301 or disable at least a portion of the bridge IC336 when the temperature sensor 336 detects that the bridge IC301 is operating at a temperature higher than a predetermined threshold. Thus, the temperature sensor 336 provides an integrated safety function that can prevent damage to the bridge IC301 or other components within the drive device 202 when the bridge IC301 is operating at an excessive temperature.

[0448] The bridge IC301 includes a digital state machine 337 integrally connected to the power switch circuit 333. The digital state machine 337 receives the PhaseA and PhaseB signals from the PMIC300 and an enable signal, for example, from the microcontroller 303. The digital state machine 337 generates a timing signal based on the first-phase output signal PhaseA and the second-phase output signal PhaseB.

[0449] The digital state machine 337 outputs a timing signal corresponding to the PhaseA and PhaseB signals and the BRIDGEPR and BRIDGEEN signals to the power switch circuit 333 to control the power switch circuit 333. Therefore, the digital state machine 337 outputs a timing signal to the switches T1 - T4 of the H-bridge circuit 334 to control the sequential turn-on and turn-off of the switches T1 - T4, such that the H-bridge circuit outputs an AC drive signal for driving a resonant circuit (such as the ultrasonic transducer 215).

[0450] As described in more detail below, the switching sequence includes a free-floating period, in which the first switch T1 and the second switch T2 are off, and the third switch T3 and the fourth switch T4 are on, to dissipate the energy stored by the resonant circuit (ultrasonic transducer 215).

[0451] The bridge IC301 includes a test controller 338, which enables the bridge IC301 to be tested to determine whether the embedded components within the bridge IC301 are operating properly. The test controller 338 is coupled to the TESTDATA, TESTCLK, and TESTLOAD pins, so that the bridge IC301 can be connected to an external control device, which inputs and outputs data to the bridge IC301 to test the operation of the bridge IC301. The bridge IC301 also includes a TESTBUS, which enables the digital communication bus within the bridge IC301 to be tested via the TSTPAD pin.

[0452] The bridge IC301 includes a power-on reset circuit (POR) 339, which controls the startup operation of the bridge IC301. The POR339 ensures that the bridge IC301 starts up correctly only when the power supply voltage is within a predetermined range. If the power supply voltage exceeds the predetermined range (for example, the power supply voltage is too high), the POR339 delays the startup of the bridge IC301 until the power supply voltage is within the predetermined range.

[0453] The bridge IC301 includes a reference module (BG) 340, which provides an accurate reference voltage for use by other subsystems of the bridge IC301.

[0454] The bridge IC301 includes a current reference 341, which provides an accurate current to the power switch circuit 333 and / or other subsystems within the bridge IC301 (such as the current sensor 335).

[0455] The temperature sensor 336 continuously monitors the temperature of the silicon of the bridge IC 301. If the temperature exceeds a predetermined temperature threshold, the power switch circuit 333 automatically shuts down. Additionally, the overheat condition can be reported to an external host to notify the external host that an overheat event has occurred.

[0456] The digital state machine (FSM) 337 generates timing signals for the power switch circuit 333, which are used to control the H-bridge 334 in this example.

[0457] The bridge IC 301 includes comparators 342, 343 that compare signals from the respective subsystems of the bridge IC 301 with voltage and current references 340, 341 and provide reference output signals through the pins of the bridge IC 301.

[0458] Referring again to Figure 75 in the accompanying drawings, the H-bridge 334 of this example includes four switches in the form of NMOS field effect transistor (FET) switches on both sides of the H-bridge 334. The H-bridge 334 includes four switches or transistors T1 - T4 connected in an H-bridge configuration, and each transistor T1 - T4 is driven by its respective logic inputs A - D. The transistors T1 - T4 are configured to be driven by a bootstrap voltage that is internally generated by two external capacitors Cb connected as shown in Figure 75 .

[0459] The H-bridge 334 includes various power inputs and outputs connected to the respective pins of the bridge IC 301. The H-bridge 334 receives the programmable voltage VBOOST output from the boost converter 305 through a first power terminal labeled VBOOST in Figure 75 . The H-bridge 334 includes a second power terminal labeled VSS_P in Figure 75 .

[0460] The H-bridge 334 includes outputs OUTP, OUTN configured to be connected to the respective terminals of the ultrasonic transducer 215 so that the AC drive signal output from the H-bridge 334 can drive the ultrasonic transducer 215.

[0461] The switching of the four switches or transistors T1 - T4 is controlled by switch signals from the digital state machine 337 through the logic inputs A - D. It should be understood that although Figure 75 shows four transistors T1 - T4, in other examples, the H-bridge 334 includes more transistors or other switch components to implement the function of the H-bridge.

[0462] In this example, the H-bridge 334 operates at a switching power of 22W to 50W to provide an AC drive signal with sufficient power to drive the ultrasonic transducer 215 to generate fog in an optimal manner. The voltage switched by the H-bridge 334 of this example is ±15V. In other examples, the voltage is ±20V.

[0463] In this example, the H-bridge 334 switches at a frequency of 3 MHz to 5 MHz or up to 105 MHz. This is a high switching speed compared to traditional integrated circuit H-bridges available on the IC market. For example, traditional integrated circuit H-bridges available on the IC market today are configured to operate only at a maximum frequency of 2 MHz. Except for the bridge IC 301 described herein, no traditional integrated circuit H-bridge on the IC market can operate at a power of 22 V to 50 V at a frequency up to 5 MHz, let alone up to 105 MHz.

[0464] Now referring to Figure 76 in the accompanying drawings, the current sensor 335 includes a positive current sensing resistor RshuntP and a negative current sensing resistor RshuntN connected in series with the corresponding high and low ends of the H-bridge 334, as Figure 75 shown. In this example, the current sensing resistors RshuntP, RshuntN are low-value resistors with a resistance value of 0.1 Ω. The current sensor 335 includes a first operational amplifier 344 that measures the voltage drop across the first current sensing resistor RshuntP as a first voltage sensor; and a second operational amplifier 345 that measures the voltage drop across the second current sensing resistor RshuntN as a second voltage sensor. In this example, the gain of each operational amplifier 344, 345 is 2 V / V and the output is 1 mA / V. The current sensor 335 also includes a pull-down resistor Rcs, which has a resistance value of 2 kΩ in this example. The outputs of the operational amplifiers 344, 345 provide an output signal CSout, which is passed through a low-pass filter 346 to remove transient interference in the CSout signal. The output Vout of the low-pass filter 346 is the output signal of the current sensor 335.

[0465] The current sensor 335 thus measures the alternating current flowing through the H-bridge 334 and respectively through the ultrasonic transducer 215, and converts the alternating current into an equivalent root mean square (RMS) output voltage (Vout) with respect to ground. Since the H-bridge 334 can operate at a frequency up to 5 MHz (up to 105 MHz in some examples), the current sensor 335 has high bandwidth capabilities. The output Vout of the current sensor 335 is a positive voltage corresponding to the measured alternating RMS current flowing through the ultrasonic transducer 215. In this example, the output voltage Vout of the current sensor 335 is fed back to the control circuit within the bridge IC 301 so that the bridge IC 301 can turn off the H-bridge 334 when the current flowing through the H-bridge 334 (and the transducer 215) exceeds a predetermined threshold. In addition, an overcurrent threshold event is reported to the first comparator 342 in the bridge IC 301, so that the bridge IC 301 can report the overcurrent event through its OVCTRIGG pin.

[0466] Now referring to Figure 77, in combination with the equivalent piezoelectric model of the ultrasonic transducer 215, the control of the H-bridge 334 will be described.

[0467] To generate a positive voltage as shown by V_out in Figure 77 at both ends of the output OUTP and OUTN of the H-bridge 334 (note the direction of the arrow), the switching sequence of the input A-D control transistors T1-T4 is as follows:

[0468] 1. The two ends of the ultrasonic transducer 215 have a positive output voltage: A-on, B-off, C-off, D-on.

[0469] 2. Transition from the positive output voltage to zero voltage: A-off, B-off, C-off, D-on. During this transition, first turn off C to minimize or avoid the current flowing through A and C caused by switching errors or A delay, thereby minimizing or avoiding power loss.

[0470] 3. Zero output voltage: A-off, B-off, C-on, D-on. In the zero output voltage stage, the output OUTP and OUTN terminals of the H-bridge 334 are grounded through the C and D switches that are kept on, which dissipates the energy stored in the capacitor in the equivalent circuit of the ultrasonic transducer, thereby minimizing the overshoot in the switching waveform voltage applied to the ultrasonic transducer.

[0471] 4. Transition from zero voltage to negative output voltage: A-off, B-off, C-on, D-off.

[0472] 5. The two ends of the ultrasonic transducer 215 have a negative output voltage: A-off, B-on, C-on, D-off.

[0473] At high frequencies up to 5 MHz and even 105 MHz, the time of each switching sequence stage is extremely short, on the order of nanoseconds or picoseconds. For example, at a switching frequency of 6 MHz, each switching sequence stage lasts approximately 80 nanoseconds.

[0474] In the attached figure Figure 78 shows the waveform diagrams of the output voltages OUTP and OUTN of the H-bridge 334 according to the above switching sequence. The switching sequence includes a zero output voltage stage for handling the energy stored in the ultrasonic transducer 215 (such as the energy stored in the capacitor in the equivalent circuit of the ultrasonic transducer). As described above, this can minimize the overshoot in the switching waveform voltage applied to the ultrasonic transducer, thereby reducing unnecessary power loss and heating in the ultrasonic transducer.

[0475] Reducing or eliminating voltage overshoot can also prevent the transistors in bridge IC301 from being stressed beyond their rated voltage, thereby reducing the risk of transistor damage. Additionally, minimizing or eliminating voltage overshoot enables bridge IC301 to accurately drive the ultrasonic transducer while minimizing interference with the current detection feedback loop described herein. Thus, bridge IC301 can drive the ultrasonic transducer at high power levels of 22W to 50W, and even up to 70W, at high frequencies up to 5MHz and even 105MHz.

[0476] The bridge IC301 of this example is configured to be controlled by PMIC300 and operate in two different modes, herein referred to as forced mode and natural frequency mode. These two operating modes are innovative compared to existing bridge ICs. In particular, the natural frequency mode is a significant innovation and has significant advantages in terms of the accuracy and efficiency of driving the ultrasonic transducer compared to traditional devices.

[0477] Forced Frequency Mode (FFM)

[0478] In the forced frequency mode, H-bridge 334 is controlled according to the above sequence but operates at a user-selectable frequency. Thus, regardless of the natural resonance frequency of ultrasonic transducer 215, H-bridge transistors T1 - T4 are controlled in a forced manner to switch the output voltage across ultrasonic transducer 215. The forced frequency mode allows H-bridge 334 to drive ultrasonic transducer 215 with a natural resonance frequency of f1 at a different frequency f2.

[0479] To adapt the operation to different applications, it may be appropriate to drive the ultrasonic transducer at a frequency deviating from its natural resonance frequency. For example, it may be appropriate to drive the ultrasonic transducer at a frequency slightly deviating from the resonance frequency (for mechanical reasons to prevent mechanical damage to the transducer). Or, it may be appropriate to drive the ultrasonic transducer at a low frequency, but due to its size, the ultrasonic transducer has different natural resonance frequencies.

[0480] The drive device 202 controls bridge IC301 to drive ultrasonic transducer 215 in forced frequency mode in response to a specific application or the configuration of a specific ultrasonic transducer. For example, when the nebulizer device 200 is used for a specific application (such as generating a mist from a medicated liquid of a specific viscosity for delivery to the user), the drive device 202 can be configured to operate in forced frequency mode.

[0481] Natural Frequency Mode (NFM)

[0482] The natural frequency mode described below is an important advancement and has advantages in terms of accuracy and efficiency compared to traditional ultrasonic drivers in today's IC market.

[0483] The operating sequence of the natural frequency mode is the same as above, but the timing of the zero-output phase in the sequence is adjusted to minimize or avoid problems caused by current spikes in the forced frequency mode. These current spikes occur when the voltage across the ultrasonic transducer 215 switches to the opposite polarity. The ultrasonic transducer containing the piezoelectric crystal has an equivalent circuit including a parallel capacitor (as shown in the piezoelectric model of Figure 77 ). If the voltage across the ultrasonic transducer switches abruptly from a positive voltage to a negative voltage, due to the high dV / dt (rate of change of voltage), the energy stored in the capacitor is released, causing a large current to flow.

[0484] The natural frequency mode avoids abruptly switching the voltage across the ultrasonic transducer 215 from a positive voltage to a negative voltage (or vice versa). Instead, before applying the reverse voltage, the ultrasonic transducer 215 (piezoelectric crystal) remains floating freely during the floating period, with zero voltage applied to its terminals. The PMIC 300 sets the driving frequency of the bridge IC 301 such that the bridge 334 sets the floating period such that the current inside the ultrasonic transducer 215 (due to the energy stored in the piezoelectric crystal) reverses the voltage across the terminals of the ultrasonic transducer 215 during the floating period.

[0485] Therefore, when the H-bridge 334 applies a negative voltage to the terminals of the ultrasonic transducer 215, the ultrasonic transducer 215 (the capacitor in the equivalent circuit) has already been reverse-charged, and since there is no high dV / dt, no current spike occurs.

[0486] However, it should be noted that when the ultrasonic transducer 215 is first activated, it takes time for the charge accumulation inside it (in the piezoelectric crystal). Therefore, after the charge accumulates due to the oscillation inside the ultrasonic transducer 215, the energy during the floating period can reverse the voltage. For this reason, when the bridge IC 301 first activates the ultrasonic transducer 215, the PMIC 300 controls the power delivered to the ultrasonic transducer 215 through the H-bridge 334 to be a lower first value (such as 5V), and then gradually increases it to a second value higher than the first value (such as 15V) over a period of time to accumulate the energy stored in the ultrasonic transducer 215. During this ramp-up phase of the oscillation, current spikes still exist until the current inside the ultrasonic transducer 215 is fully established. However, by using a low voltage at startup, these current spikes can be kept at a low enough level to minimize the impact on the operation of the ultrasonic transducer 215.

[0487] To achieve the natural frequency mode, the driver 202 controls the frequency of the oscillator 315 and the duty cycle (ratio of on time to free floating time) of the AC drive signal output by the H-bridge 334 with high precision. In this example, the driver 202 implements three control loops to adjust the oscillator frequency and duty cycle so that the voltage reversal at the terminals of the ultrasonic transducer 215 is as precise as possible and current spikes are minimized or avoided as much as possible. The use of control loops to accurately control the oscillator and duty cycle is a major advancement in the field of IC ultrasonic drivers.

[0488] During the natural frequency mode operation, the current sensor 335 senses the current flowing through the ultrasonic transducer 215 (resonant circuit) during the free floating period. When the current sensor 335 senses that the current flowing through the ultrasonic transducer 215 (resonant circuit) during the free floating period is zero, the digital state machine 337 adjusts the timing signal to turn on the first switch T1 or the second switch T2.

[0489] In the attached figure Figure 79 The oscillator voltage waveform 347 (V(osc)), the switching waveform 348 generated by the on / off of the high-side switch T1 on the left side of the H-bridge 334, and the switching waveform 349 generated by the on / off of the high-side switch T2 on the right side are shown. During the free floating period 350 in the middle, both high-side switches T1 and T2 of the H-bridge 334 are turned off (free floating stage). The duration of the free floating period 350 is controlled by the size of the free floating control voltage 351 (Vphioff).

[0490] In the attached figure Figure 80 The voltage waveform 352 at the first terminal of the ultrasonic transducer 215 (the voltage waveform at the second terminal is in antiphase therewith) and the piezoelectric current 353 flowing through the ultrasonic transducer 215 are shown. The piezoelectric current 353 exhibits an (almost) ideal sinusoidal waveform (which cannot be achieved in any bridge in forced frequency mode or IC market).

[0491] Before the sine wave of the piezoelectric current 353 reaches zero, the left high-side switch T1 of the H-bridge 334 is turned off (here, the switch T1 is turned off when the piezoelectric current 353 is about 6A). The remaining piezoelectric current 353 in the ultrasonic transducer 215 is responsible for the voltage reversal during the free floating period 350 due to the energy stored in the ultrasonic transducer 215 (the capacitor of the piezoelectric equivalent circuit). The piezoelectric current 353 decays to zero during the free floating period 350 and then enters the negative current flow region. The terminal voltage of the ultrasonic transducer 215 drops from the power supply voltage (19V in this example) to less than 2V, and the voltage drop stops when the piezoelectric current 353 reaches zero. This is the ideal time to open the low-side switch T3 of the H-bridge 334 to minimize or avoid current spikes.

[0492] Compared with the above forced frequency mode, the natural frequency mode has at least the following three advantages:

[0493] 1. Current spikes associated with hard switching of the encapsulated capacitor are significantly reduced or completely avoided.

[0494] 2. Power losses caused by hard switching are almost eliminated.

[0495] 3. The frequency is regulated by a control loop and maintained close to the resonant frequency of the piezoelectric crystal (i.e., the natural resonant frequency of the piezoelectric crystal).

[0496] In the case of regulating the frequency by the control loop (advantage 3 above), the PMIC 300 first controls the bridge IC 301 to drive the ultrasonic transducer 215 at a frequency higher than the resonant frequency of the piezoelectric crystal, and then controls the bridge IC 301 to attenuate / reduce the frequency of the AC drive signal during startup. Once the frequency approaches the resonant frequency of the piezoelectric crystal, the piezoelectric current will increase rapidly. When the piezoelectric current is high enough to cause the desired voltage inversion, the PMIC 300 stops attenuating / reducing the frequency, and subsequently the control loop of the PMIC 300 takes over the regulation of the frequency and duty cycle of the AC drive signal.

[0497] In the forced frequency mode, the power delivered to the ultrasonic transducer 215 is controlled by duty cycle, frequency offset, and / or supply voltage variation. However, in the natural frequency mode of this example, the power delivered to the ultrasonic transducer 215 is controlled only by the supply voltage.

[0498] During the setup phase of the driving device, the bridge IC 301 is configured to measure the time required for the current flowing through the ultrasonic transducer 215 (resonant circuit) to drop to zero when the first switch T1 and the second switch T2 are off and the third switch T3 and the fourth switch T4 are on, and then set the duration of the free-floating period to be equal to the measured duration.

[0499] Now referring to Figure 81 in the accompanying drawings, the PMIC 300 and the bridge IC 301 of this example are designed to work together as a companion chipset, and they communicate through electrical connections. In this example, the interconnection between the PMIC 300 and the bridge IC 301 supports the following two types of communication:

[0500] 1. Control signals

[0501] 2. Feedback signals

[0502] The connection between the PHASE_A and PHASE_B pins of the PMIC 300 and the bridge IC 301 transmits the PWM modulation control signal for driving the H-bridge 334; the connection between the EN_BR pins of the PMIC 300 and the bridge IC 301 transmits the EN_BR control signal for triggering the startup of the H-bridge 334. The timing between the PHASE_A, PHASE_B, and EN_BR control signals is processed by the digital bridge control module of the PMIC 300.

[0503] The connections between the CS, OC, and OT pins of the PMIC 300 and the bridge IC 301 transmit CS (current sense), OC (overcurrent), and OT (overheat) feedback signals from the bridge IC 301. Most notably, the CS (current sense) feedback signal is a voltage equivalent to the RMS current flowing through the ultrasonic transducer 215, which is measured by the current sensor 335 of the bridge IC 301.

[0504] The OC (overcurrent) and OT (overheat) feedback signals are digital signals indicating that the bridge IC 301 has detected an overcurrent or overvoltage event. In this example, the overcurrent and overheat thresholds are set by external resistors; alternatively, the thresholds can also be set dynamically in response to a signal transmitted from one of the two DAC channels VDAC0, VDAC1 of the PMIC 300 to the OC_REF pin of the bridge IC 301.

[0505] In this example, the designs of the PMIC 300 and the bridge IC 301 allow the pins of the two to be directly connected (such as through copper tracks on a PCB), resulting in minimal or zero signal communication delay between the PMIC 300 and the bridge IC 301. This offers a significant speed advantage compared to traditional bridges typically controlled through digital communication buses in the IC market. For example, the clock frequency of the standard I2C bus is only 400 kHz, which is too slow for the communication of high clock speed sampled data up to 5 MHz in the examples of this disclosure.

[0506] Although the examples of this disclosure have been described above in conjunction with microchip hardware, it should be understood that other examples of this disclosure include methods of operating the components and subsystems of each microchip to perform the functions described herein, such as methods of operating the PMIC 300 and the bridge IC 301 in forced frequency mode or natural frequency mode.

[0507] Now referring to Figure 82 in the accompanying drawings, the OTPIC 242 includes a power-on reset circuit (POR) 354, a bandgap reference (BG) 355, a capacitorless low-dropout regulator (LDO) 356, a communication (such as I2C) interface 357, a one-time programmable memory bank (fuse) 358, an oscillator 359, and a general-purpose input / output interface 360. The OTPIC 242 also includes a digital core 361 that includes a cryptographic authenticator. In this example, the cryptographic authenticator uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to encrypt / decrypt data stored within the OTPIC 242 and data transmitted with the OTPIC 242.

[0508] The POR 354 ensures that the OTPIC 242 starts correctly only when the power supply voltage is within a predetermined range. If the power supply voltage exceeds the predetermined range, the POR 354 will reset the OTPIC 242 and wait until the power supply voltage returns to the predetermined range.

[0509] BG355 provides precise reference voltage and current to LDO356 and oscillator 359. LDO356 powers the digital core 361, communication interface 357, and the fuse memory bank 358.

[0510] OTPIC242 is set to operate in at least the following modes:

[0511] · Fuse programming mode (fusing): During the programming of the one-time programmable memory, a high current is required to blow the relevant fuses within the fuse memory bank 358. In this mode, a higher bias current is provided to maintain the gain and bandwidth of the regulation loop.

[0512] · Fuse read mode: A medium level of current is required in this mode to maintain the fuse read operation within the fuse memory bank 358. This mode is executed during the startup of OTPIC242 to transfer the fuse content to the shadow register. In this mode, the gain and bandwidth of the regulation loop are set to values lower than those in the fusing mode.

[0513] · Normal operating mode: In this mode, LDO356 is driven under very low bias current conditions, enabling OTPIC242 to operate with low power consumption, thus minimizing power consumption as much as possible.

[0514] Oscillator 359 provides the required clock to the digital core / engine 361 during testing (scan test), fusing, and normal operation. Oscillator 359 is fine-tuned to meet the strict timing requirements in the fusing mode.

[0515] In this example, the communication interface 357 complies with the FM+ specification of the I2C standard and is also compatible with the slow and fast modes. OTPIC242 uses the communication interface 357 to exchange data and keys with the driving device 202 (host).

[0516] The digital core 361 implements the control and communication functions of OTPIC242. The encryption authenticator of the digital core 361 enables OTPIC242 to authenticate itself to the driving device 202 (for a specific application, for example, using ECDSA encrypted messages) to ensure that OTPIC242 is genuine and authorized to connect to the driving device 202 (or another product).

[0517] Referring to the Figure 83 in the attached drawings, OTPIC242 executes the following public key infrastructure (PKI) process to authenticate OTPIC242 for use by the host (such as the driving device 202):

[0518] 1. Verify the signer's public key: The host requests the manufacturer's public key and certificate. The host uses the institutional public key to verify the certificate.

[0519] 2. Verify the device public key: If the verification is successful, the host requests the device public key and certificate. The host uses the manufacturer's public key to verify the certificate.

[0520] 3. Challenge - Response: If the verification is successful, the host generates a random number challenge and sends it to the device. The end - product uses the device private key to sign the random number challenge.

[0521] 4. Signature verification: The signature is sent back to the host and verified using the device public key.

[0522] If all steps of the authentication process are successfully completed, the trust chain can be traced back to the root of trust, and the OTPIC242 is successfully authenticated and can be used in conjunction with the host. However, if any step of the authentication process fails, the OTPIC242 cannot pass the host authentication, and the use of the device containing the OTPIC242 will be restricted or prohibited.

[0523] The drive device includes an AC driver for converting the voltage of the battery into an AC drive signal of a predetermined frequency to drive the ultrasonic transducer.

[0524] The drive device contains an active power monitoring device for monitoring the active power consumed by the ultrasonic transducer when driven by the AC drive signal (as described above). The active power monitoring device provides a monitoring signal indicating the active power consumed by the ultrasonic transducer.

[0525] The processor in the drive device controls the AC driver and receives the monitoring signal from the active power monitoring device.

[0526] The memory of the drive device stores instructions that, when executed by the processor, enable the processor to:

[0527] A. Control the AC driver to output an AC drive signal to the ultrasonic transducer at a predetermined scan frequency;

[0528] B. Calculate the active power consumed by the ultrasonic transducer based on the monitoring signal;

[0529] C. Control the AC driver to modulate the AC drive signal to maximize the active power consumed by the ultrasonic transducer;

[0530] D. Record in the memory the maximum power consumed by the ultrasonic transducer and the scan frequency of the AC drive signal;

[0531] E. Repeat steps A - D a predetermined number of times in a manner where the scan frequency is incremented or decremented by one each iteration, such that after the predetermined number of iterations is completed, the scan frequency is incremented or decremented from the starting scan frequency to the ending scan frequency;

[0532] F. Identify the optimal frequency of the alternating current (AC) drive signal from the records stored in the memory, i.e., the scanning frequency of the AC drive signal when the ultrasonic transducer consumes the maximum power.

[0533] G. Control the AC driver to output an AC drive signal to the ultrasonic transducer at the optimal frequency to drive the ultrasonic transducer to atomize the liquid.

[0534] In some examples, the active power monitoring device includes a current sensing device for sensing the drive current of the AC drive signal driving the ultrasonic transducer, where the active power monitoring device provides a monitoring signal indicating the sensed drive current.

[0535] In some examples, the current sensing device includes an analog-to-digital converter (ADC) that converts the sensed drive current into a digital signal for processing by the processor.

[0536] In some examples, the memory stores instructions that, when executed by the processor, enable the processor to: repeat the above steps A - D with the scanning frequency incrementing from a starting scanning frequency of 2900 kHz to an ending scanning frequency of 2960 kHz.

[0537] In some examples, the memory stores instructions that, when executed by the processor, enable the processor to: repeat the above steps A - D with the scanning frequency incrementing from a starting scanning frequency of 2900 kHz to an ending scanning frequency of 3100 kHz.

[0538] In some examples, the memory stores instructions that, when executed by the processor, enable the processor to: in step G, control the AC driver to output an AC drive signal to the ultrasonic transducer with a frequency offset from the optimal frequency by a predetermined offset.

[0539] In some examples, the predetermined offset is 1% - 10% of the optimal frequency.

[0540] 2. Control and Information (CI) Section

[0541] The control and information section includes an external EEPROM for data storage, an LED lamp for user indication, a pressure sensor for airflow detection, and a microcontroller supporting low - power Bluetooth (BLE) for continuously monitoring and managing the atomization section.

[0542] The pressure sensor used in this device has two purposes. The first purpose is to prevent the acoustic engine from accidentally starting (driving the ultrasonic transducer). This function is implemented in the processing device of the device and is optimized for low power consumption. It continuously measures environmental parameters such as temperature and ambient pressure through internal compensation and reference settings to accurately detect and classify so - called real inhalations.

[0543] Unlike all other nebulizer devices on the market, this solution takes advantage of a microcontroller and allows the use of only one sensor.

[0544] The second purpose of the pressure sensor is not only to be able to monitor the exact duration of the user's inhalation for precise measurement of the inhaled dose, but also to determine the intensity of the user's inhalation, which is key information for correct prescription and health monitoring in a medical context. All in all, we are able to fully map the pressure curve of each inhalation and predict the end of the inhalation in order to optimize aerosolization and understand the behavior of medical data.

[0545] This is achieved by using a low-power Bluetooth TM (BLE) microcontroller. In fact, this enables the device to provide extremely accurate inhalation times, optimized aerosolization, monitor numerous parameters to ensure safe atomization and prevent the use of non-genuine e-liquids or aerosol chambers, and protect the device from the risk of overheating and the user from over-atomization, which is different from any other product on the market.

[0546] Using a BLE microcontroller allows for wireless updates to continuously provide the user with improved software for PZT modeling based on anonymous data collection and trained AI.

[0547] 3. Power Management (PM) section

[0548] The power management section consists of a 3.7V LiPo battery path that is connected to a low-dropout regulator (LDO) that powers the control and information section and a battery management system (BMS) that provides high-level protection and charging for the internal LiPo battery.

[0549] The components of this section are carefully selected to achieve a highly integrated and compact device design, while providing high power to the ultrasonic section and ensuring a stable power supply for the control and information section.

[0550] In fact, when high power is supplied from a 3.7V lithium polymer battery to the atomization section, the power supply voltage fluctuates significantly during operation. Without a low-dropout regulator, when the battery voltage drops to only 0.3V higher than the minimum rated value of the components in the control and information section, this section will not be able to obtain the necessary stable power supply - this is why the LDO plays a key role here. An interruption in the power supply to the control and information section will interfere with or even stop the operation of the entire device.

[0551] Therefore, carefully selecting the components not only ensures the high reliability of the device, but also enables it to work under harsh conditions and operate continuously for a longer time between charging intervals.

[0552] Controlled atomization

[0553] The device is an accurate, reliable and safe atomization solution for medical prescriptions and daily user use, so it must provide a controllable and reliable atomization effect.

[0554] This is achieved through an internal method, which can be divided into the following parts:

[0555] 1. Ultrasonic treatment

[0556] To achieve the best atomization effect, the ultrasonic transducer (PZT) needs to vibrate with the highest efficiency.

[0557] Frequency

[0558] The electromechanical characteristics of the piezoelectric ceramic indicate that the component is most efficient at its resonant frequency. However, vibrating the PZT at the resonant frequency for a long time will inevitably cause component failure and damage, making the atomization chamber unusable. Another important factor to consider when using piezoelectric materials is the inherent differences during the manufacturing process and their variations with temperature and service life.

[0559] To vibrate the PZT at a resonant frequency of 3 MHz to produce droplets smaller than 1 micron, an adaptive method is needed to locate and target the "optimal point" of the specific PZT used in each atomization chamber in the device during each inhalation.

[0560] Scanning

[0561] Since the device must locate the "optimal point" for each inhalation, and due to overuse, the PZT temperature will change as the device uses the internal dual-scanning method.

[0562] When the device has not been used with a specific atomization chamber for a period of time and is considered to have dissipated enough heat and cooled the PZT to the "default temperature", the first scan will be performed. This process is also called a cold start. During this process, the PZT needs to be boosted to generate the required mist. This is achieved by scanning only within a small frequency range of 2900 kHz to 2960 kHz, which covers the resonant point after a large amount of research and experimentation. For each frequency within this range, the acoustic wave engine is started, and the microcontroller actively monitors and stores the current flowing through the PZT through the analog-to-digital converter (ADC) and converts it back to a current value to accurately infer the power consumed by the PZT. This will generate a cold start curve of the PZT with respect to frequency, and the frequency used during the entire inhalation process is the frequency that consumes the most current, that is, the frequency with the lowest impedance.

[0563] The second scan is performed during any subsequent inhalation. Due to the changes in PZT characteristics with temperature and deformation, the scanning range covers the entire frequency range of 2900 kHz to 3100 kHz. This thermal curve is used to determine the offset to be applied.

[0564] Offset

[0565] To achieve the best atomization effect, no offset is used during cold start inhalation, so the PZT will vibrate at the resonant frequency. This can only occur for a short period of time and not repeatedly, otherwise the PZT will surely be damaged. However, during most inhalations, an offset is used to still aim at the low impedance frequency, thus achieving quasi-optimal operation of the PZT while protecting it from failures. Since the thermal curve and the cold curve are stored during inhalation, the microcontroller can select an appropriate offset frequency based on the measured current value flowing through the PZT during the scan, ensuring safe mechanical operation. The selection of the offset direction is crucial because if the piezoelectric component is outside or inside the duplex resonant / anti-resonant frequency range, its behavior will be different. The selected offset should always be within the range defined by the resonant frequency to the anti-resonant frequency because the PZT is inductive rather than capacitive. Finally, the offset percentage is kept below 10% to ensure that it is still close to the lowest impedance but far from the resonant point.

[0566] Adjustment

[0567] Due to the inherent characteristics of the PZT, each inhalation is different. Besides the piezoelectric element, many parameters affect the inhalation effect, such as the amount of e-liquid remaining in the atomization chamber, the liquid guiding state of the gauze, or the battery power of the device. Therefore, the device continuously monitors the current consumed by the PZT in the atomization chamber, and the microcontroller continuously adjusts parameters such as the frequency and duty cycle to provide as stable a power as possible to the atomization chamber within a predefined range, which follows the research and experimental results to achieve the best safe atomization effect.

[0568] Battery monitoring

[0569] To provide an AC voltage of 15V and maintain the current in the PZT at around 2.5A, the current drawn from the battery reaches approximately 7 - 8A, which in turn causes the battery voltage to drop. No ordinary lithium polymer battery can withstand such a high load for an inhalation duration of up to 6 seconds.

[0570] Therefore, a custom lithium polymer battery has been developed that can handle a current of approximately 11A, which is 50% higher than the maximum allowable current of the PZT at any time, while still being easily used in a compactly integrated portable device.

[0571] Since the battery voltage drops significantly and fluctuates when starting the ultrasonic part, the microcontroller continuously monitors the power consumed by the PZT in the atomization chamber to ensure proper and safe atomization.

[0572] Since the key to atomization lies in control, the device first ensures that its control and information parts always operate properly and do not stop working due to the operation of the ultrasonic part.

[0573] Therefore, the adjustment method also fully considers the real-time battery level and will modify parameters such as the duty cycle when necessary to maintain the battery at a safe level. If insufficient battery level is detected before starting the sonic engine, the control and information section will prevent the device from activating.

[0574] Power control

[0575] As mentioned before, the key to atomization lies in control, and the method used in the device is a real-time multi-dimensional function that always takes into account PZT characteristics, the internal current of the PZT, and the device's battery level.

[0576] All of this is achieved only through the use of a microcontroller - it can monitor and control each component of the device to produce the best inhalation effect.

[0577] 1. Inhalation control

[0578] The device is a safe device certified by the BNS (Broughton Nicotine Services) report. However, to ensure the safety of atomization and the integrity of the atomization chamber and the device, each inhalation needs to be controlled.

[0579] Inhalation duration

[0580] To reduce the exposure to carbonyl compounds and other toxic components that may be generated by the heating of e-liquid, the maximum inhalation duration is set to 6 seconds, which can fully ensure that the exposure to these components is controlled.

[0581] Interval time

[0582] Since the device relies on piezoelectric elements, if inhalation stops, the device will prevent the activation of the ultrasonic part. The safe delay between two inhalations will be adaptively adjusted according to the duration of the previous inhalation, which allows the wick to fully conduct liquid before the next activation.

[0583] With this design, the device can operate safely with better atomization effect, without the risk of damaging the PZT components and without exposing users to toxic components.

[0584] Connectivity (BLE)

[0585] The control and information section of the device contains a wireless communication system in the form of a microcontroller that supports low-power Bluetooth (BLE). This wireless communication system communicates with the device's processor and is used to transmit data between the drive unit and computing devices such as smartphones.

[0586] By connecting to the companion mobile application via low-power Bluetooth, it ensures that only minimal communication power consumption is required. Therefore, compared with traditional wireless connection solutions such as Wi-Fi, traditional Bluetooth, GSM, and even LTE-M and NB-IoT, the device can maintain a standby state for a longer time when not in use.

[0587] Most importantly, this connectivity enables the OTP function and ensures full control and safety during the inhalation process. All data, from the resonant frequency of a single inhalation to the frequency used, or the negative pressure and duration generated by the user, is stored and transmitted via BLE for further analysis and improvement of the embedded software. Additionally, when the device is used in a medical program, all this information is crucial as it provides doctors and users with full information about the inhalation process and supports real-time tracking of prescriptions and usage.

[0588] Finally, this connectivity supports over-the-air (OTA) upgrades of the device firmware, ensuring that the latest version can always be quickly deployed, giving the device strong scalability and ensuring its long-term maintenance.

[0589] Clinical data collection

[0590] The device can collect user data such as the number of puffs and puff duration to determine the total amount of therapeutic agent consumed by the user in one use.

[0591] This data can be interpreted by an algorithm to set consumption limits for each time period according to the doctor's advice.

[0592] This will allow the administration of a controlled therapeutic dose of medication, controlled by a doctor or pharmacist, and prevent abuse by the end user.

[0593] Doctors can gradually reduce the dose through a user-safe and controllable method.

[0594] Puff limit

[0595] The process of ultrasonic cavitation has a significant impact on the nicotine concentration in the generated aerosol.

[0596] The device limits the puff duration to <7 seconds, which can reduce the user's exposure to carbonyl compounds commonly found in electronic nicotine delivery systems.

[0597] According to the experimental results of Broughton Nicotine Services, after 10 consecutive puffs of <7 seconds by the user, the total carbonyl content of formaldehyde is <2.67 μg / 10 puffs (average: 1.43 μg / 10 puffs), acetaldehyde is <0.87 μg / 10 puffs (average: 0.50 μg / 10 puffs), propionaldehyde is <0.40 μg / 10 puffs (average: 0.28 μg / 10 puffs), crotonaldehyde is <0.16 μg / 10 puffs (average: 0.16 μg / 10 puffs), butyraldehyde is <0.19 μg / 10 puffs (average: 0.17 μg / 10 puffs), diacetyl is <0.42 μg / 10 puffs (average: 0.25 μg / 10 puffs), and no acetylpropionyl is detected in the emissions after 10 consecutive puffs of <7 seconds.

[0598] Since the atomization of the e - liquid is achieved through the mechanical action of the piezoelectric disk rather than the direct heating of the liquid, each component of the e - liquid (propylene glycol, vegetable glycerin, flavoring components, etc.) remains substantially intact and does not decompose into harmful components such as acrolein, acetaldehyde, and formaldehyde in large amounts as in traditional ENDS.

[0599] To limit users' exposure to carbonyl compounds when using the ultrasonic device, the puff duration is limited to a maximum of 6 seconds. Therefore, the above results represent the absolute worst - case scenario for exposure levels.

[0600] Reference Figure 84 and Figure 85 When the end - cap 248 is installed onto the drive - unit housing 246, the aluminum drive - unit housing 246 acts as a Faraday cage, preventing the device from emitting any electromagnetic waves. The device with the drive - unit housing 246 has passed electromagnetic compatibility (EMC) testing, and the test shows that its radiation level is less than half of the device - allowed limit. The EMC test results are as shown in the chart of Figure 86 as shown.

[0601] The mist inhaler device of other examples of the present disclosure includes most or preferably all of the elements of the above - mentioned mist inhalation device 200, but the memory of the drive device 202 stores instructions that, when executed by a processor, provide additional functions for the mist inhaler device.

[0602] In one example, the mist inhaler device 200 includes an active - power monitor that includes a current sensor (such as the current sensor 335 mentioned above) for sensing the RMS drive current of the AC drive signal that drives the ultrasonic transducer 215. As previously mentioned, the active - power monitor provides a monitoring signal indicating the sensed drive current.

[0603] The additional functions of this example enable the mist inhaler device 200 to monitor its operation when the ultrasonic transducer is activated. The mist inhaler device 200 calculates a validity value or a quality index that indicates the effectiveness of the ultrasonic transducer in atomizing the liquid within the device. The device uses this validity value to calculate the actual amount of mist generated during the activation of the ultrasonic transducer.

[0604] Once the actual amount of mist is calculated, the device is configured to calculate the actual therapeutic dose present in the mist based on the concentration of the therapeutic agent in the liquid, thereby determining the actual therapeutic dose inhaled by the user. When the mist inhaler device is used as part of a treatment plan, it is particularly important to know the exact amount of therapeutic agent provided to the user. Compared with traditional devices that only calculate the number of inhalations or puffs (assuming the same amount of therapeutic agent is provided to the user with each inhalation or puff), monitoring the exact amount of therapeutic agent provided to the user with each inhalation or puff can make the treatment plan more accurate and effective.

[0605] In fact, as described above, there are many different factors that affect the operation of the ultrasonic transducer and the amount of mist generated by the ultrasonic transducer, which in turn affects the actual treatment dose provided to the user.

[0606] For example, if the ultrasonic transducer in the mist inhaler device cannot operate optimally due to a decrease in the current flowing through the ultrasonic transducer caused by insufficient battery power, the amount of mist generated will be reduced compared to when the device is operating optimally, and the treatment dose provided to the user will also be reduced. Compared to the number of inhalations allowed when the ultrasonic transducer is operating optimally, the device may therefore allow the user to make more inhalations in order to provide a set amount of therapeutic agent to the user over a period of time. This makes the treatment plan more efficient and precise compared to traditional plans that rely solely on counting and limiting the number of user inhalations.

[0607] The configuration of some example mist inhaler devices and the method of generating mist using the mist inhaler device will be described in detail below.

[0608] In this example, the mist inhaler device includes the components of the above-described mist inhaler device 200, but the memory of the drive device 202 further stores instructions that, when executed by the processor, cause the processor to activate the mist inhalation device 200 for a first predetermined duration. As described above, the mist inhalation device is activated by driving the ultrasonic transducer 215 in the mist inhalation device with an AC drive signal, causing the ultrasonic transducer 215 to atomize the liquid carried by the capillary element 222.

[0609] The executed instructions cause the processor to periodically sense the current of the AC drive signal flowing through the ultrasonic transducer 215 using a current sensor within the first predetermined duration and store the periodically measured current values in the memory.

[0610] The executed instructions cause the processor to calculate an effectiveness value using the current values stored in the memory. This effectiveness value indicates the effective degree to which the ultrasonic transducer atomizes the liquid.

[0611] In one example, the executed instructions cause the processor to calculate the effectiveness value using the following formula:

[0612]

[0613] Where:

[0614] QI is the effectiveness value,

[0615] QF is the frequency sub-effectiveness value based on the monitored frequency value (the frequency driving the ultrasonic transducer 215),

[0616] QA is the analog-to-digital converter sub-effectiveness value based on the measured current value (the root mean square current flowing through the ultrasonic transducer 215),

[0617] t = 0 is the start of the first predetermined duration,

[0618] t = D is the end of the first predetermined duration,

[0619] N is the number of periodic measurements (samples) within the first predetermined duration,

[0620] is a normalization factor.

[0621] In one example, the memory stores instructions that, when executed by the processor, cause the processor to periodically measure the duty cycle of the AC drive signal driving the ultrasonic transducer within the first predetermined duration and store the periodically measured duty cycle values in the memory. Then, the nebulizer device modifies the analog-to-digital converter sub-validity value QA based on the current value stored in the memory. Thus, the nebulizer device in this example takes into account the duty cycle changes that may occur during the activation of the ultrasonic transducer 215 when calculating the validity value. Therefore, the nebulizer device can accurately calculate the actual amount of mist generated by considering the duty cycle changes of the AC drive signal during the activation of the ultrasonic transducer.

[0622] In one example, the memory stores instructions that, when executed by the processor, cause the processor to periodically measure the battery voltage supplying power to the nebulizer device within the first predetermined duration and store the periodically measured battery voltage values in the memory. Then, the nebulizer device modifies the analog-to-digital converter sub-validity value QA based on the battery voltage value stored in the memory. Thus, the nebulizer device in this example takes into account the battery voltage changes that may occur during the activation of the ultrasonic transducer 215 when calculating the validity value. Therefore, the nebulizer device can accurately calculate the actual amount of mist generated by considering the battery voltage changes during the activation of the ultrasonic transducer.

[0623] The validity value is used by the nebulizer device as a weight to calculate the actual amount of mist generated by the nebulizer device by proportionally reducing the maximum mist amount value generated during the optimal operation of the device.

[0624] In one example, the memory stores instructions that, when executed by the processor, cause the processor to periodically measure the frequency of the AC drive signal driving the ultrasonic transducer 215 within the first predetermined duration and store the periodically measured frequency values in the memory. Then, in addition to the above current value, the device calculates the validity value using the frequency value stored in the memory.

[0625] In one example, the memory stores instructions that, when executed by the processor, cause the processor to calculate the maximum mist amount value that the ultrasonic transducer 215 will generate during optimal operation within the first predetermined duration. In one example, the maximum mist amount value is obtained based on a modeling calculation that determines the maximum mist amount generated during the optimal operation of the ultrasonic transducer.

[0626] Once the maximum mist volume value is calculated, the mist inhaler device can proportionally reduce the maximum mist volume value according to the effectiveness value to determine the actual mist volume generated within the first predetermined duration, thereby calculating the actual mist volume value.

[0627] Once the actual mist volume is calculated, the mist inhaler device can calculate the treatment dose value, which indicates the treatment dose in the actual mist volume generated within the first predetermined duration. Then, the mist inhaler device stores the record of the treatment dose value in the memory. In this way, the mist inhaler device can accurately record the actual treatment dose provided to the user in each inhalation or puff.

[0628] In one example, the memory stores instructions that, when executed by the processor, cause the processor to select a second predetermined duration according to the effectiveness value. In this case, the second predetermined duration is the duration during which the user activates the ultrasonic transducer 215 during the second inhalation or puff. In one example, the second predetermined duration is equal to the first predetermined duration, but is proportionally reduced or increased according to the effectiveness value. For example, if the effectiveness value indicates that the ultrasonic transducer 215 is operating inefficiently, the second predetermined duration is extended according to the effectiveness value so that the required amount of mist can be generated within the second predetermined duration.

[0629] During the next inhalation, the mist inhaler device activates the mist inhalation device for the second predetermined duration, causing the mist inhalation device to generate a predetermined amount of mist within the second predetermined duration. Therefore, the mist inhaler device takes into account the various parameters affecting its operation reflected by the effectiveness value and accurately controls the amount of mist generated within the second predetermined duration.

[0630] In one example, the memory stores instructions that, when executed by the processor, cause the processor to activate the mist inhalation device for multiple predetermined durations. For example, the mist inhalation device is activated during multiple consecutive inhalations or puffs of the user.

[0631] The mist inhaler device stores multiple treatment dose values in the memory, each treatment dose value indicating the treatment dose in the mist generated within the corresponding predetermined duration. In one example, if the total amount of the therapeutic agent in the mist generated within multiple predetermined durations is equal to or exceeds a predetermined threshold, the mist inhaler device prevents further activation of the mist inhalation device for a predetermined period. In one example, the predetermined period is 1 to 24 hours. In other examples, the predetermined period is 24 hours or 12 hours.

[0632] Some example mist inhalers of the present disclosure are configured to transmit data indicative of a therapeutic dose value from the mist inhalation device to a computing device (e.g., via low-power Bluetooth communication) for storage in the memory of the computing device (such as a smartphone). Thus, an executable application running on the computing device can record the therapeutic dose provided to the user. The executable application can also control the operation of the mist inhaler device to limit its activation, and thus limit the therapeutic dose provided to the user over a period of time.

[0633] Thus, some example mist inhalers of the present disclosure are configured to prevent further activation once the user has ingested a set amount of a therapeutic agent within a set time frame (such as within a day).

[0634] All of the above applications involving ultrasound technology can benefit from the optimization achieved by a frequency controller that optimizes the ultrasound frequency for optimal performance.

[0635] It should be understood that the disclosure herein is not limited to the delivery of nicotine. In fact, in some examples, the liquid contained in the mist inhaler device contains a therapeutic agent that does not contain nicotine. Some examples are configured for various medical purposes (e.g., delivering CBD for pain relief, supplements for enhanced performance, albuterol for asthma patients, etc.).

[0636] The devices disclosed herein can be used in conjunction with any therapeutic agent, drug, or other compound that is provided in liquid form within the liquid chamber of the device for atomization by the device. In some examples, the devices disclosed herein can be used in conjunction with the following therapeutic agents, drugs, and compounds, including but not limited to:

[0637] Respiratory system drugs

[0638] Bronchodilators

[0639] Olopatadine

[0640] Levalbuterol

[0641] Berodual (ipratropium bromide / fenoterol)

[0642] Combivent (ipratropium bromide / albuterol)

[0643] Anti-inflammatory drugs

[0644] Betamethasone

[0645] Dexamethasone

[0646] Methylprednisolone

[0647] Hydrocortisone

[0648] Mucolytics

[0649] N-acetylcysteine

[0650] Pulmonary hypertension drugs

[0651] Sildenafil

[0652] Tadalafil

[0653] Epoprostenol

[0654] Treprostinil

[0655] Iloprost

[0656] Infectious disease drugs

[0657] Antibacterial drugs

[0658] Aminoglycosides (gentamicin, tobramycin, amikacin, colistin, neomycin, liposomal amikacin)

[0659] Quinolones (ciprofloxacin, levofloxacin, moxifloxacin, ofloxacin)

[0660] Macrolides (azithromycin)

[0661] Minocycline

[0662] β-lactams (piperacillin-tazobactam, ceftazidime, ticarcillin)

[0663] Cephalosporins (cefotaxime, cefepime, ceftriaxone, cefotaxime)

[0664] Glycopeptides (vancomycin)

[0665] Meropenem

[0666] Polymyxins (colistin, polymyxin B) Antifungal drugs

[0667] Amphotericin

[0668] Fluconazole

[0669] Caspofungin

[0670] Antiviral drugs

[0671] Valganciclovir

[0672] Favipiravir

[0673] Remdesivir

[0674] Acyclovir

[0675] Antituberculosis drugs

[0676] Isoniazid

[0677] Pyrazinamide

[0678] Rifampicin

[0679] Ethambutol

[0680] Oncology drugs

[0681] Biological agents

[0682] Gilotrif

[0683] Afatinib

[0684] Caplacizumab

[0685] Dupilumab

[0686] Istaroxime

[0687] Alirocumab

[0688] Volasertib

[0689] Nintedanib

[0690] Imatinib

[0691] Sirolimus

[0692] Chemotherapy drugs

[0693] Azacitidine

[0694] Decitabine

[0695] Docetaxel

[0696] Gemcitabine

[0697] Cisplatin Central Nervous System and Mental Disorders Drug Sodium Valproate

[0698] Teriflunomide

[0699] Zolmitriptan Metabolism / Hormonal Drugs

[0700] Insulin

[0701] Estrogen

[0702] Immunology drugs

[0703] Vaccine

[0704] Monoclonal antibody

[0705] Stem cells

[0706] Vitamins

[0707] Zinc

[0708] Ascorbic acid (vitamin C)

[0709] Others

[0710] Niclosamide

[0711] Hydroxychloroquine

[0712] Ivermectin

[0713] In some examples, the ultrasonic nebulizer 100 is a more powerful version of current portable medical nebulizers. Other examples of ultrasonic nebulizer devices are easily imaginable, including drug delivery devices that do not look like cigarettes.

[0714] The foregoing has outlined the features of several examples or embodiments so that those of ordinary skill in the art may better understand various aspects of the present disclosure. Those of ordinary skill in the art should understand that they can readily use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same advantages as the various examples or embodiments introduced herein. Those of ordinary skill in the art should also recognize that such equivalent constructs do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations without departing from the spirit and scope of the present disclosure.

[0715] Although the subject matter has been described in language specific to structural features or method acts, it should be understood that the subject matter of the appended claims is not necessarily limited to the specific features or acts described above. Rather, the above specific features and acts are disclosed as example forms for implementing at least some of the claims.

[0716] Various operations of examples or embodiments are provided herein. The order of some or all of the operations described should not be construed as implying that these operations are necessarily order-dependent. Alternative orders can be understood by those benefiting from the content of this specification. Further, it should be understood that not every embodiment provided herein necessarily includes all of the operations. Moreover, it should be understood that not all operations are required in some examples or embodiments.

[0717] In addition, the term "exemplary" as used herein is intended to mean serving as an example, instance, illustration, etc., and does not necessarily imply being advantageous. As used in this application, "or" is intended to mean an inclusive "or" rather than an exclusive "or". Additionally, the articles "a" and "an" as used in this application and the appended claims generally should be construed to mean "one or more", unless otherwise stated or clearly indicated from the context as being in the singular form. Further, "at least one of A and B" and the like generally means A or B or both A and B. Moreover, with respect to the use of "comprising", "having", "including", "with" or variants thereof, such terms are intended to be inclusive in a manner similar to the term "including". Additionally, unless otherwise stated, "first", "second", etc. are not intended to imply any meaning in terms of time, space, order, etc., but are merely used as identifiers, names, etc. for features, elements, items, etc. For example, a first element and a second element generally correspond to element A and element B, or two different elements, two identical elements or the same element.

[0718] In addition, although the present disclosure has been shown and described with respect to one or more embodiments, equivalent changes and modifications will occur to those of ordinary skill in the art upon reading and understanding this specification and the drawings. The present disclosure includes all such modifications and changes and is limited only by the scope of the following claims. In particular, with respect to the various functions performed by the above-described features (e.g., elements, resources, etc.), the terms used to describe these features are intended to correspond to any feature that performs the specified function (e.g., functional equivalent) of the described feature, even if not structurally equivalent to the disclosed structure. Moreover, although a particular feature of the present disclosure has been disclosed with respect to only one of several embodiments, this feature may be combined with one or more other features of other embodiments, which may be desirable and advantageous for any given or particular application.

[0719] Examples or embodiments of the subject matter and functional operations described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware (including the structures disclosed in this specification and their structural equivalents), or in combinations of one or more of them.

[0720] Some examples or embodiments are implemented using one or more computer program instruction modules encoded on a computer-readable medium to be executed by, or to control the operation of, a data processing apparatus. The computer-readable medium can be a manufactured article, such as a hard disk drive in a computer system or an embedded system. The computer-readable medium can be obtained separately and subsequently encoded with one or more computer program instruction modules, such as by transmitting one or more computer program instruction modules via a wired or wireless network. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a storage device, or a combination of one or more of them.

[0721] The terms "computing device" and "data processing apparatus" cover all apparatus, devices, and machines that process data, including, by way of example, a programmable processor, a computer, or multiple processors or computers. The apparatus may also include code that creates an execution environment for relevant computer programs in addition to the hardware, such as code that constitutes processor firmware, a protocol stack, a database management system, an operating system, a runtime environment, or one or more combinations thereof. Additionally, the apparatus may adopt various different computing model architectures, such as web services, distributed computing, and grid computing architectures.

[0722] The processes and logical flows described in this specification may be executed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output.

[0723] Processors suitable for executing computer programs include, by way of example, both general and special purpose microprocessors, and any one or more processors of any type of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more storage devices for storing instructions and data. Generally, a computer will also include or be operatively coupled to receive data from or transfer data to one or more mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks. However, a computer need not have such devices. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices.

[0724] The features disclosed in the foregoing specification, the following claims, or the drawings, in their specific forms or in terms of the means for performing the disclosed functions or in terms of the method or process for achieving the disclosed results, as the case may be, may be used separately or in any combination of these features to implement the invention in many forms.

[0725] Representative features

[0726] Representative features are listed in the following clauses, which may exist alone or may be combined in any combination with one or more features disclosed in the specification text and / or the drawings.

[0727] 1. A mist inhalation device for generating a mist containing a therapeutic agent for inhalation by a user, the device comprising:

[0728] A mist generating device, comprising:

[0729] An elongated mist generator housing including an air inlet and a mist outlet;

[0730] A liquid chamber disposed within the housing of the mist generator, the liquid chamber containing a liquid to be atomized, the liquid comprising a therapeutic agent;

[0731] An ultrasonic chamber disposed within the housing of the mist generator;

[0732] A capillary element extending between the liquid chamber and the ultrasonic chamber such that a first portion of the capillary element is within the liquid chamber and a second portion is within the ultrasonic chamber;

[0733] An ultrasonic transducer having an atomizing surface, wherein a portion of the second portion of the capillary element overlaps a portion of the atomizing surface, and when the ultrasonic transducer is driven by an alternating current drive signal, the atomizing surface vibrates to atomize the liquid carried by the second portion of the capillary element, thereby generating a mist containing the atomized liquid and air within the ultrasonic chamber;

[0734] An air flow device providing an air flow path between an air inlet, the ultrasonic chamber, and an air outlet such that when a user sucks on the mist outlet, air is drawn in through the inlet, through the ultrasonic chamber, and discharged through the mist outlet, and the mist generated within the ultrasonic chamber is carried by the air through the mist outlet for inhalation by the user;

[0735] The device further comprises:

[0736] A drive device comprising:

[0737] A battery;

[0738] An H-bridge circuit connected to the ultrasonic transducer, the H-bridge circuit generating an alternating current drive signal to drive the ultrasonic transducer;

[0739] A microchip connected to the H-bridge circuit to control its generation of the alternating current drive signal, the microchip being a single unit comprising a plurality of interconnected embedded components and subsystems, including:

[0740] An oscillator that generates:

[0741] A main clock signal;

[0742] A first phase clock signal that is high during a first time period within the positive half-cycle of the main clock signal and low during the negative half-cycle;

[0743] A second phase clock signal that is high during a second time period within the negative half-cycle of the main clock signal and low during the positive half-cycle, wherein the phase centers of the first phase clock signal and the second phase clock signal are aligned;

[0744] A pulse width modulation (PWM) signal generator subsystem, including:

[0745] A delay locked loop that generates a double-frequency clock signal using a first-phase clock signal and a second-phase clock signal, where the frequency of the double-frequency clock signal is twice that of the master clock signal. The delay locked loop controls the rising edges of the first-phase clock signal and the second-phase clock signal to be synchronized with the rising edge of the double-frequency clock signal, and the delay locked loop adjusts the frequencies and duty cycles of the first-phase clock signal and the second-phase clock signal in response to a drive control signal to generate a first-phase output signal and a second-phase output signal. The first-phase output signal and the second-phase output signal are configured to drive an H-bridge circuit to generate an AC drive signal to drive an ultrasonic transducer;

[0746] A first-phase output signal terminal that outputs a first-phase output signal to the H-bridge circuit;

[0747] A second-phase output signal terminal that outputs a second-phase output signal to the H-bridge circuit;

[0748] A feedback input terminal that receives a feedback signal from the H-bridge circuit, where the feedback signal indicates an operating parameter of the H-bridge circuit or the AC drive signal when the H-bridge circuit drives the ultrasonic transducer with the AC drive signal to atomize a liquid;

[0749] An analog-to-digital converter (ADC) subsystem, including:

[0750] A plurality of ADC input terminals that receive a plurality of corresponding analog signals, where one of the plurality of ADC input terminals is connected to the feedback input terminal such that the ADC subsystem receives the feedback signal from the H-bridge circuit, and the ADC subsystem samples the analog signals received at the plurality of ADC input terminals at a sampling frequency proportional to the frequency of the master clock signal. The ADC subsystem uses the sampled analog signals to generate ADC digital signals;

[0751] A digital processor subsystem that receives the ADC digital signals from the ADC subsystem and processes them to generate a drive control signal, where the digital processor subsystem transmits the drive control signal to a PWM signal generator subsystem to control the subsystem;

[0752] A digital-to-analog converter (DAC) subsystem, including:

[0753] A digital-to-analog converter (DAC) that converts the digital control signal generated by the digital processor subsystem into an analog voltage control signal to control a voltage regulator circuit, which generates a voltage for modulation by the H-bridge circuit;

[0754] A DAC output terminal that outputs the analog voltage control signal to control the voltage regulator circuit to generate a predetermined voltage, which is modulated by the H-bridge circuit to drive the ultrasonic transducer in response to the feedback signal indicating the operation of the ultrasonic transducer.

[0755] 2. The device as described in clause 1, wherein the microchip further comprises:

[0756] A frequency divider connected to the oscillator to receive the main clock signal from the oscillator, the frequency divider dividing the main clock signal by a predetermined divisor and outputting a frequency reference signal to the delay locked loop.

[0757] 3. The device as described in clause 1, wherein the delay locked loop comprises a plurality of delay lines connected end to end, wherein the total delay of the delay lines is equal to the period of the main clock signal.

[0758] 4. The device as described in clause 3, wherein the delay locked loop adjusts the duty cycles of the first phase clock signal and the second phase clock signal in response to a drive control signal by changing the delay of each delay line in the delay locked loop.

[0759] 5. The device as described in clause 1, wherein the feedback input terminal receives a feedback signal in the form of a voltage from the H-bridge circuit, the signal indicating the root mean square current of the AC drive signal driving the resonant circuit.

[0760] 6. The device as described in clause 1, wherein the ADC subsystem comprises a plurality of other ADC input terminals, which receive feedback signals indicating at least one of the battery voltage or the battery charger voltage connected to the device.

[0761] 7. The device as described in clause 1, wherein the microchip further comprises: a temperature sensor embedded within the microchip, the temperature sensor generating a temperature signal indicating the temperature of the microchip, the temperature signal being received by another ADC input terminal of the ADC subsystem and sampled by the ADC.

[0762] 8. The device as described in clause 1, wherein the ADC subsystem samples the signals received at the plurality of ADC input terminals in sequence, each signal being sampled by the ADC subsystem a respective predetermined number of times.

[0763] 9. The device as described in clause 1, wherein the microchip further comprises: a battery charging subsystem for controlling battery charging.

[0764] 10. The device as described in clause 1, wherein the DAC subsystem comprises: another digital-to-analog converter (DAC) that converts another digital control signal generated by the digital processor subsystem into another analog voltage control signal to control the voltage regulator circuit.

[0765] 11. The device as described in clause 1, wherein the device further comprises: another microchip, the another microchip being a single unit comprising a plurality of interconnected embedded components and subsystems, comprising:

[0766] A first power supply terminal;

[0767] A second power supply terminal;

[0768] An H-bridge circuit, which includes a first switch, a second switch, a third switch, and a fourth switch, wherein:

[0769] The first switch and the third switch are connected in series between a first power supply terminal and a second power supply terminal;

[0770] A first output terminal is electrically connected between the first switch and the third switch, and this first output terminal is connected to a first terminal of an ultrasonic transducer;

[0771] The second switch and the fourth switch are connected in series between the first power supply terminal and the second power supply terminal; a second output terminal is electrically connected between the second switch and the fourth switch, and this second output terminal is connected to a second terminal of the ultrasonic transducer;

[0772] A first phase terminal, which receives a first phase output signal from a pulse width modulation (PWM) signal generator subsystem;

[0773] A second phase terminal, which receives a second phase output signal from the PWM signal generator subsystem;

[0774] A digital state machine, which generates a timing signal based on the first phase output signal and the second phase output signal, and outputs the timing signal to the switches of the H-bridge circuit to control the switches to turn on and off in sequence, so that the H-bridge circuit outputs an alternating current drive signal for driving the ultrasonic transducer, and this sequence includes a free-floating period, wherein the first switch and the second switch are off, and the third switch and the fourth switch are on, to dissipate the energy stored in the ultrasonic transducer;

[0775] A current sensor, which includes:

[0776] A first current detection resistor, connected in series between the first switch and the first power supply terminal;

[0777] A first voltage sensor, which measures the voltage drop across the first current detection resistor and provides a first voltage output indicating the current flowing through the first current detection resistor;

[0778] A second current detection resistor, connected in series between the second switch and the first power supply terminal; a second voltage sensor, which measures the voltage drop across the second current detection resistor and provides a second voltage output indicating the current flowing through the second current detection resistor;

[0779] A current sensor output terminal, which provides a root mean square output voltage relative to ground, and this voltage is equivalent to the first voltage output and the second voltage output, wherein the root mean square output voltage indicates the root mean square current flowing through the first switch or the second switch, and the current flowing through the ultrasonic transducer connected between the first output terminal and the second output terminal.

[0780] 12. The apparatus as described in clause 11, wherein the H-bridge circuit is configured to output power of 22 W to 50 W to an ultrasonic transducer connected to the first output terminal and the second output terminal.

[0781] 13. The apparatus as described in clause 11, wherein the other microchip includes: a temperature sensor embedded within the other microchip, the temperature sensor measuring the temperature of the other microchip and disabling at least a portion of the other microchip when the temperature sensor detects that the temperature of the other microchip exceeds a predetermined threshold.

[0782] 14. The apparatus as described in clause 11, wherein the device further includes:

[0783] A boost converter circuit configured to raise the voltage of a battery to a boost voltage in response to an analog voltage output signal from a DAC output terminal, wherein the boost converter circuit provides the boost voltage at a first power terminal such that the boost voltage is modulated by switching of switches of the H-bridge circuit.

[0784] 15. The apparatus as described in clause 11, wherein the current sensor senses the current flowing through the resonant circuit during a free-floating period, and when the current sensor senses that the current flowing through the resonant circuit during the free-floating period is zero, the digital state machine adjusts a timing signal to turn on the first switch or the second switch.

[0785] 16. The apparatus as described in clause 11, wherein during a setup phase of device operation, the other microchip: measures a length of time required for the current flowing through the resonant circuit to drop to zero when the first switch and the second switch are off and the third switch and the fourth switch are on; sets the length of the free-floating period to be equal to the measured length of time.

[0786] 17. The apparatus as described in clause 1, wherein the device further includes:

[0787] a processor for controlling a driving device; and

[0788] a memory storing instructions which, when executed by the processor, cause the driving device to:

[0789] A. control the driving device to output an AC driving signal to the ultrasonic transducer at a scanning frequency;

[0790] B. calculate the active power consumed by the ultrasonic transducer based on a feedback signal;

[0791] C. control the driving device to modulate the AC driving signal to maximize the active power consumed by the ultrasonic transducer;

[0792] D. record in the memory the maximum power consumed by the ultrasonic transducer and the scanning frequency of the AC driving signal;

[0793] E. Repeat the above steps A - D a predetermined number of times in a manner where the scanning frequency increases or decreases incrementally with each iteration, such that after the completion of the predetermined number of iterations, the scanning frequency increases or decreases from the starting scanning frequency to the ending scanning frequency;

[0794] F. Identify the optimal frequency of the AC drive signal from the records stored in the memory, i.e., the scanning frequency of the AC drive signal when the ultrasonic transducer consumes the maximum power;

[0795] G. Control the drive device to output an AC drive signal to the ultrasonic transducer at the optimal frequency to drive the ultrasonic transducer to atomize the liquid.

[0796] 18. The device according to clause 17, wherein the starting scanning frequency is 2900 kHz and the ending scanning frequency is 3100 kHz.

[0797] 19. The device according to clause 1, wherein the drive device is detachably connected to the mist inhalation device such that the drive device can be separated from the mist inhalation device.

[0798] 20. A mist inhalation device for generating mist for a user to inhale, the device comprising:

[0799] A mist generating device, comprising:

[0800] An ultrasonic cavity;

[0801] A liquid cavity containing the liquid to be atomized;

[0802] A capillary element extending between the liquid cavity and the ultrasonic cavity;

[0803] An ultrasonic transducer configured to vibrate to atomize the liquid carried from the liquid cavity to the ultrasonic cavity by the capillary element, thereby generating mist containing atomized liquid and air in the ultrasonic cavity;

[0804] A mist outlet in fluid communication with the ultrasonic cavity such that when the user sucks on the mist outlet, the mist is inhaled from the ultrasonic cavity;

[0805] The mist inhalation device further comprises:

[0806] A drive device, comprising:

[0807] A battery;

[0808] An AC driver for converting the voltage of the battery into an AC drive signal to drive the ultrasonic transducer to vibrate;

[0809] An active power monitor for monitoring the active power consumed by an ultrasonic transducer when driven by an AC drive signal, wherein the active power monitor includes a current sensor for sensing the drive current of the AC drive signal driving the ultrasonic transducer, and the active power monitoring device provides a monitoring signal indicating the sensed drive current;

[0810] A processor for controlling the AC driver and receiving the monitoring signal from the active power monitor;

[0811] A memory storing instructions which, when executed by the processor, cause the processor to:

[0812] Activate the mist inhalation device for a first predetermined duration, including driving the ultrasonic transducer in the mist inhalation device with an AC drive signal to atomize the liquid carried by the capillary element;

[0813] Within the first predetermined duration, periodically sense, using the current sensor, the current of the AC drive signal flowing through the ultrasonic transducer and store the periodically measured current values in the memory;

[0814] Calculate an effectiveness value using the current values stored in the memory, the effectiveness value indicating the effective degree of atomizing the liquid by the ultrasonic transducer;

[0815] Select a second predetermined duration according to the effectiveness value;

[0816] Activate the mist inhalation device for the second predetermined duration, causing the mist inhalation device to generate a predetermined amount of mist within the second predetermined duration.

[0817] 21. The device according to clause 20, wherein the memory stores instructions which, when executed by the processor, cause the processor to:

[0818] Periodically measure, within the first predetermined duration, the frequency of the AC drive signal driving the ultrasonic transducer and store the periodically measured frequency values in the memory; and

[0819] Calculate an effectiveness value using the frequency values stored in the memory.

[0820] 22. The device according to clause 21, wherein the memory stores instructions which, when executed by the processor, cause the processor to calculate the effectiveness value using the following formula:

[0821]

[0822] Wherein:

[0823] QI is the effectiveness value,

[0824] QF is the frequency sub-effectiveness value based on the monitored frequency values,

[0825] QA is the analog-to-digital converter (ADC) sub-validity value based on the measured current value.

[0826] t = 0 is the start of the first predetermined duration.

[0827] t = D is the end of the first predetermined duration.

[0828] N is the number of periodic measurements within the first predetermined duration.

[0829] is the normalization factor.

[0830] 23. The apparatus according to clause 22, wherein the memory stores instructions that, when executed by the processor, cause the processor to:

[0831] Periodically measure the duty cycle of the AC drive signal driving the ultrasonic transducer within the first predetermined duration and store the periodically measured duty cycle values in the memory;

[0832] Modify the analog-to-digital converter sub-validity value QA according to the current value stored in the memory.

[0833] 24. The apparatus according to clause 22 or 23, wherein the memory stores instructions that, when executed by the processor, cause the processor to:

[0834] Periodically measure the battery voltage powering the mist inhalation device within the first predetermined duration and store the periodically measured battery voltage values in the memory;

[0835] Modify the analog-to-digital converter sub-validity value QA according to the battery voltage value stored in the memory.

[0836] 25. The apparatus according to any of the preceding clauses, wherein the memory stores instructions that, when executed by the processor, cause the processor to:

[0837] Calculate the maximum mist volume value that will be generated when the ultrasonic transducer operates optimally within the first predetermined duration;

[0838] Reduce the maximum mist volume value proportionally according to the validity value to determine the actual mist volume generated within the first predetermined duration, thereby calculating the actual mist volume value.

[0839] 26. The apparatus according to clause 25, wherein the memory stores instructions that, when executed by the processor, cause the processor to:

[0840] Calculate the treatment dose value indicating the treatment dose in the actual mist volume generated within the first predetermined duration;

[0841] Store the treatment dose value in the memory.

[0842] 27. The apparatus as described in clause 26, wherein the memory stores instructions that, when executed by the processor, cause the processor to:

[0843] activate the mist inhalation device for a plurality of predetermined durations;

[0844] store a plurality of treatment dose values in the memory, each treatment dose value indicating the treatment dose in the mist generated within a corresponding predetermined duration;

[0845] if the total amount of the therapeutic agent in the mist generated within the plurality of predetermined durations is equal to or exceeds a predetermined threshold, prevent further activation of the mist inhalation device for a predetermined period of time.

[0846] 28. The apparatus as described in clause 27, wherein the predetermined period of time is from 1 to 24 hours.

[0847] 29. The apparatus as described in clause 27 or 28, wherein the memory stores instructions that, when executed by the processor, cause the processor to:

[0848] transmit data indicating the nicotine amount value from the mist inhalation device to a computing device for storage in the memory of the computing device.

[0849] 30. A method of generating a mist for a user to inhale, the method comprising:

[0850] activate the mist inhalation device for a first predetermined duration, including driving an ultrasonic transducer in the mist inhalation device with an alternating current drive signal to vibrate the ultrasonic transducer to atomize a liquid and generate a mist containing the atomized liquid and air;

[0851] periodically measure the current of the alternating current drive signal flowing through the ultrasonic transducer within the first predetermined duration and store the periodically measured current values in the memory;

[0852] calculate an effectiveness value using the current values stored in the memory, the effectiveness value indicating the effective degree of the ultrasonic transducer in atomizing the liquid;

[0853] select a second predetermined duration according to the effectiveness value;

[0854] activate the mist inhalation device for a second predetermined duration to cause the mist inhalation device to generate a predetermined amount of mist within the second predetermined duration.

[0855] 31. The method as described in clause 30, wherein the method further comprises:

[0856] periodically measure the frequency of the alternating current drive signal driving the ultrasonic transducer within the first predetermined duration and store the periodically measured frequency values in the memory;

[0857] calculate an effectiveness value using the frequency values stored in the memory.

[0858] 32. The method as described in clause 31, wherein the method includes calculating an effectiveness value using the following formula:

[0859]

[0860] Where:

[0861] QI is the effectiveness value,

[0862] QF is the frequency sub-effectiveness value based on the monitored frequency value,

[0863] QA is the analog-to-digital converter (ADC) sub-effectiveness value based on the measured current value,

[0864] t = 0 is the start of the first predetermined duration,

[0865] t = D is the end of the first predetermined duration,

[0866] N is the number of periodic measurements within the first predetermined duration,

[0867] is the normalization factor.

[0868] 33. The method as described in clause 32, wherein the method further includes:

[0869] Periodically measuring the duty cycle of the AC drive signal driving the ultrasonic transducer within the first predetermined duration and storing the periodically measured duty cycle values in a memory;

[0870] Modifying the analog-to-digital converter (ADC) sub-effectiveness value QA according to the current value stored in the memory.

[0871] 34. The method as described in clause 32 or 33, wherein the method further includes:

[0872] Periodically measuring the battery voltage supplying power to the mist inhalation device within the first predetermined duration and storing the periodically measured battery voltage values in a memory;

[0873] Modifying the analog-to-digital converter (ADC) sub-effectiveness value QA according to the battery voltage value stored in the memory.

[0874] 35. The method as described in any one of clauses 30 to 34, wherein the method further includes:

[0875] Calculating the maximum mist amount value that will be generated when the ultrasonic transducer operates optimally within the first predetermined duration;

[0876] Reducing the maximum mist amount value proportionally according to the effectiveness value to determine the actual mist amount generated within the first predetermined duration, thereby calculating the actual mist amount value.

[0877] 36. The method as described in clause 35, wherein the method further comprises:

[0878] Calculating a nicotine quantity value indicative of the amount of nicotine in the actual amount of mist generated within a first predetermined duration;

[0879] Storing the nicotine quantity value in a memory.

[0880] 38. The method as described in clause 37, wherein the method further comprises:

[0881] Activating the mist inhalation device at a plurality of predetermined durations; storing a plurality of therapeutic dose values in the memory, each therapeutic dose value indicative of the therapeutic dose in the mist generated within a corresponding predetermined duration;

[0882] If the total amount of the therapeutic agent in the mist generated within the plurality of predetermined durations is equal to or exceeds a predetermined threshold, preventing further activation of the mist inhalation device within a predetermined time period.

[0883] 38. The method as described in clause 37, wherein the predetermined time period is 1 to 24 hours.

[0884] 39. The method as described in clause 37 or 38, wherein the method further comprises:

[0885] Transmitting data indicative of the therapeutic dose values from the mist inhalation device to a computing device for storage in the memory of the computing device.

[0886] 40. A mist inhalation device for delivering a therapeutic agent to a user, the mist inhalation device being used in cooperation with a driving device, wherein the mist inhalation device comprises:

[0887] A housing containing a liquid chamber for containing a liquid to be atomized, the liquid containing the therapeutic agent;

[0888] An ultrasonic assembly connected to the housing, the ultrasonic assembly comprising:

[0889] An ultrasonic transducer having an atomizing surface, a first electrical transducer contact, and a second electrical transducer contact, the first and second electrical transducer contacts for receiving an alternating current driving signal from the driving device;

[0890] A first component part including a groove for fixing the ultrasonic transducer;

[0891] A second component part connected to the first component part, the second component part comprising:

[0892] An ultrasonic groove superimposed on the ultrasonic transducer to form an ultrasonic cavity;

[0893] An ultrasonic assembly air inlet in fluid communication with the ultrasonic groove;

[0894] The mist outlet of the ultrasonic component is in fluid communication with the ultrasonic groove;

[0895] The air flow path extends from the air inlet of the ultrasonic component through the ultrasonic groove to the mist outlet of the ultrasonic component;

[0896] At least one of the first component part and the second component part includes an elastically deformable part that forms a seal between the first component part and the second component part to minimize or prevent fluid leakage between the two;

[0897] The mist inhalation device further includes:

[0898] A barrier part includes an elastically deformable seal located between the ultrasonic component and the housing to minimize or prevent fluid leakage. The barrier part includes capillary pores having elastically deformable walls;

[0899] A capillary tube extends from the liquid chamber through the capillary pores to the ultrasonic chamber, such that a first part of the capillary tube is within the liquid chamber and a second part is within the ultrasonic chamber. The second part of the capillary tube is superimposed on the atomizing surface of the ultrasonic transducer. When the ultrasonic transducer is driven by an alternating current drive signal from the drive device, the atomizing surface vibrates and atomizes the liquid carried by the second part of the capillary tube, thereby generating a mist containing the atomized liquid and air in the ultrasonic chamber. The mist flows out through the mist outlet of the ultrasonic component for the user to inhale.

[0900] 41. The device according to clause 40, wherein the first component part is made of an elastically deformable material, and a part of the first component part forms a seal between the first component part and the second component part.

[0901] 42. The device according to clause 41, wherein the elastically deformable material is silicone.

[0902] 43. The device according to any one of clauses 40 to 42, wherein the second component part is made of an elastically deformable material, and a part of the second component part forms a seal between the first component part and the second component part.

[0903] 44. The device according to clause 43, wherein the elastically deformable material is silicone.

[0904] 45. The device according to clause 43 or 44, wherein the second component part includes:

[0905] A main body part is provided with an ultrasonic groove;

[0906] A cover part is connected to the main body part. The cover part is provided with a channel that defines at least part of the air flow path, wherein one end of the channel forms an air inlet and the other end forms a mist outlet.

[0907] 46. The device according to any one of clauses 40 to 45, wherein the second component part includes at least one biasing element disposed within the ultrasonic groove, and each biasing element applies a biasing force to the second portion of the capillary, pressing the second portion of the capillary towards the atomizing surface of the ultrasonic transducer.

[0908] 47. The device according to clause 46, wherein the second component part includes a plurality of biasing elements.

[0909] 48. The device according to clause 46 or 47, wherein each biasing element is integrally formed with the second component part.

[0910] 49. The device according to any one of clauses 46 to 48, wherein each biasing element includes a fixed end connected to the second component part and a distal end contacting the second portion of the capillary, and the distal end is narrower than the fixed end.

[0911] 50. The device according to any one of clauses 46 to 49, wherein each biasing element is generally conical in shape.

[0912] 51. The device according to any one of clauses 40 to 50, wherein the housing includes a lumen defined by a base and side walls extending upward from the base, a liquid chamber is formed in a part of the lumen adjacent to the base, and the ultrasonic assembly is at least partially received within the lumen such that the liquid chamber is located between the ultrasonic assembly and the base.

[0913] 52. The device according to clause 51, wherein the ultrasonic assembly contacts the side wall of the housing and forms a seal to minimize or prevent fluid flow between the ultrasonic assembly and the side wall of the housing.

[0914] 53. The device according to clause 51 or 52, wherein the ultrasonic assembly includes a filling hole that extends from a filling opening through a part of the ultrasonic assembly to the liquid chamber to allow fluid to be injected into the liquid chamber through the filling hole.

[0915] 54. The device according to any one of clauses 51 to 53, wherein the device includes a nozzle attached to the housing to substantially enclose the lumen, and the nozzle includes a mist outlet hole that is in fluid communication with the mist outlet of the ultrasonic assembly to provide a mist flow path from the ultrasonic assembly to the mist outlet hole.

[0916] 55. The device according to clause 54, including a foam material layer that is located in the mist flow path to absorb liquid droplets of a size greater than a predetermined size in the mist flowing along the mist flow path.

[0917] 56. The device according to clause 55, wherein the foam material layer is located between the ultrasonic assembly and a separator, and the separator includes a mist outlet hole to allow the mist to flow through the separator from the foam material layer.

[0918] 57. The device of clause 56 as described in clauses 53 to 55, wherein the separator includes a plug that seals the filling opening to minimize or prevent leakage of liquid from the liquid chamber to the outside of the device.

[0919] 58. The device as described in any one of clauses 41 to 57, wherein the atomizing surface of the ultrasonic transducer is substantially planar, and the plane of the atomizing surface is substantially parallel to the longitudinal length of the housing.

[0920] 59. The device as described in any one of clauses 40 to 58, wherein the ultrasonic transducer is housed within an ultrasonic transducer stack that includes:

[0921] A generally cylindrical silicone base having a central hole through which a first electrical transducer contact extends, wherein the silicone base includes a generally cylindrical recess that houses the ultrasonic transducer such that the contact surface of the ultrasonic transducer is electrically connected to the first electrical transducer contact;

[0922] A generally cylindrical metal shell that at least partially surrounds the silicone base, the metal shell including a lip that contacts at least a portion of the perimeter of the ultrasonic transducer to secure the ultrasonic transducer within the cylindrical recess, and the metal shell forms a second electrical transducer contact.

[0923] 60. The device as described in clause 59, wherein a portion of the metal shell is cut away to provide a passage for electrical connection of a first elongated device terminal to the first electrical transducer contact, and a second elongated device terminal is electrically connected to the metal shell, wherein the first and second elongated device terminals receive an alternating current drive signal from a drive device and transmit the alternating current drive signal to the ultrasonic transducer.

[0924] 61. The device as described in any one of clauses 40 to 60, wherein the housing includes a metal end cap that magnetically attracts a magnet on the drive device to hold the mist inhalation device in engagement with the drive device.

[0925] 62. The device as described in any one of clauses 40 to 61, wherein the airflow path includes a plurality of turns that change the direction of airflow multiple times as air flows from the air inlet to the ultrasonic recess.

[0926] 63. The device as described in any one of clauses 40 to 61, wherein at least 75% of the capillary is bamboo fiber.

[0927] 64. The device as described in any one of clauses 40 to 63, wherein the capillary is 100% bamboo fiber.

[0928] 65. The device as described in any one of clauses 40 to 64, wherein the device includes: an identification device carried by the housing to identify the mist inhalation device, the identification device including:

[0929] One - Time Programmable Integrated Circuit (OTPIC) whose memory stores a unique identifier of a mist inhalation device. The OTPIC includes a digital core containing an encryption authenticator and electrical connections providing an electronic interface for communicating with the OTPIC and a driving device.

[0930] 66. The device according to clause 65, wherein the one - time programmable (OTP) device includes an anti - counterfeiting feature to identify genuine mist inhalation devices and only allow the mist inhalation devices identified as genuine to be authorized to cooperate with the driving device.

[0931] 67. The device according to clause 65 or 66, wherein the OTP device controls the mist inhalation device to function to generate mist only when authorized.

[0932] 68. The device according to any one of clauses 65 to 67, wherein the memory of the OTPIC contains unique information data that allows tracing of the mist inhalation device and monitoring of the user's use of the mist inhalation device.

[0933] 69. The device according to any one of clauses 65 to 68, wherein the memory of the OTPIC stores a status record of the mist inhalation device, which indicates at least one of the historical usage of the mist inhalation device and the volume of liquid in the liquid chamber.

[0934] 70. The device according to any one of clauses 65 to 69, wherein the memory of the OTPIC stores a record of the atomization seconds such that after atomization for a predetermined usage duration of about 1000 seconds, the mist inhalation device is considered to have exhausted the liquid in the liquid chamber and cannot be activated after this predetermined usage duration.

[0935] 71. The device according to any one of clauses 65 to 70, wherein whenever the mist inhalation device is considered to be exhausted, if it is connected to the driving device, it will not be activated.

[0936] 72. The device according to any one of clauses 65 to 71, wherein the encryption authenticator uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to encrypt / decrypt the data stored in the OTPIC and the data transmitted to and from the OTPIC.

[0937] 73. The device according to any one of clauses 40 to 72, wherein the liquid chamber contains a liquid with a viscosity between 1.05 Pa·s and 1.412 Pa·s and a density between 1.1 g / ml and 1.3 g / ml.

[0938] 74. A mist - generating device for delivering mist to a user, the mist - generating device cooperating with a driving device, wherein the mist - generating device includes:

[0939] A housing, including a liquid chamber for containing a liquid to be atomized, the liquid including a therapeutic agent;

[0940] An ultrasonic assembly, connected to the housing, the ultrasonic assembly comprising:

[0941] An ultrasonic transducer having a first electrical connection and a second electrical connection for receiving an alternating current drive signal from a drive device;

[0942] A first component part including a groove for fixing the ultrasonic transducer;

[0943] A second component part, connected to the first component part, the second component part comprising:

[0944] An ultrasonic groove, superimposed on the ultrasonic transducer to form an ultrasonic chamber;

[0945] An ultrasonic assembly air inlet, in fluid communication with the ultrasonic groove;

[0946] An ultrasonic assembly mist outlet, in fluid communication with the ultrasonic groove;

[0947] An air flow path extending from the ultrasonic assembly air inlet through the ultrasonic groove to the ultrasonic assembly mist outlet;

[0948] At least one of the first component part and the second component part includes an elastically deformable part that forms a seal between the first component part and the second component part to minimize or prevent fluid leakage therebetween;

[0949] The mist inhalation device further comprises:

[0950] A barrier part including an elastically deformable seal located between the ultrasonic assembly and the housing to minimize or prevent fluid leakage, the barrier part including capillary pores having elastically deformable walls;

[0951] A capillary tube extending from the liquid chamber through the capillary pores to the ultrasonic chamber, such that a first part of the capillary tube is within the liquid chamber and a second part of the capillary tube is within the ultrasonic chamber, wherein the second part of the capillary tube is superimposed on the atomizing surface of the ultrasonic transducer, such that when the ultrasonic transducer is driven by the alternating current drive signal of the drive device, the atomizing surface vibrates and atomizes the liquid carried by the second part of the capillary tube, thereby generating a mist containing the atomized liquid and air in the ultrasonic chamber, and the mist flows out through the ultrasonic assembly mist outlet for the user to inhale.

[0952] 75. The device according to clause 74, wherein the first component part is made of an elastically deformable material, and a part of the first component part forms a seal between the first component part and the second component part.

[0953] 76. The device as described in clause 74 or 75, wherein the second component part is made of an elastically deformable material, and a part of the second component part forms a seal between the first component part and the second component part.

[0954] 77. The device as described in any of the preceding clauses, wherein the second component part includes:

[0955] a body provided with ultrasonic grooves;

[0956] a cover connected to the body, the cover being provided with a channel defining at least part of an air flow path, wherein one end of the channel forms an air inlet and the other end forms a mist outlet.

[0957] 78. The device as described in any of the preceding clauses, wherein the second component part includes at least one biasing element disposed within the ultrasonic grooves, each biasing element applying a biasing force to a second part of the capillary tube, pressing the second part of the capillary tube against the atomizing surface of the ultrasonic transducer.

[0958] 79. The device as described in clause 78, wherein each biasing element is integrally formed with the second component part.

[0959] 80. The device as described in clause 78 or 79, wherein each biasing element includes a fixed end connected to the second component part and a distal end contacting the second part of the capillary tube, the distal end being narrower than the fixed end.

[0960] 81. The device as described in any of clauses 78 to 80, wherein each biasing element is generally conical in shape.

[0961] 82. The device as described in any of the preceding clauses, wherein the housing includes a lumen defined by a base and side walls extending upward from the base, a liquid chamber being formed in a part of the lumen adjacent to the base, the ultrasonic assembly being at least partially received within the lumen, and the liquid chamber being located between the ultrasonic assembly and the base.

[0962] 83. The device as described in clause 82, wherein the ultrasonic assembly contacts the side walls of the housing and forms a seal to minimize or prevent fluid flow between the ultrasonic assembly and the side walls of the housing.

[0963] 84. The device as described in clause 82 or 83, wherein the ultrasonic assembly includes a filling hole that extends from a filling opening through a part of the ultrasonic assembly to the liquid chamber to allow liquid to be injected into the liquid chamber through the filling hole.

[0964] 85. The device as described in any of clauses 82 to 84, wherein the device includes a nozzle attached to the housing to substantially enclose the lumen, the nozzle including a mist outlet hole in fluid communication with the mist outlet of the ultrasonic assembly to provide a mist flow path from the ultrasonic assembly to the mist outlet hole.

[0965] 86. The device as described in clause 85, wherein the device includes a foam material layer disposed adjacent to the mist flow path to absorb liquid droplets of a size greater than a predetermined size in the mist flowing along the mist flow path.

[0966] 87. The device as described in clause 86, wherein the foam material layer is located between the ultrasonic assembly and the separator, and the separator includes mist outlet holes to allow the mist to flow through the separator from the foam material layer.

[0967] 88. The device of clause 87 as described in clauses 84 to 86, wherein the separator includes a plug that seals the filling opening to minimize or prevent leakage of liquid from the liquid chamber to the outside of the device.

[0968] 89. The device as described in any of the preceding clauses, wherein the ultrasonic transducer is housed within an ultrasonic transducer stack including:

[0969] A base provided with a central hole, and a portion of a first electrical transducer contact extends through the central hole for electrical connection to a first electrical connection of the ultrasonic transducer;

[0970] A metal shell at least partially surrounding the base, the metal shell including a lip that engages at least a portion of the periphery of the ultrasonic transducer to hold the ultrasonic transducer in position relative to the base, and a portion of the metal shell serves as a second electrical transducer contact that is electrically connected to a second electrical connection of the ultrasonic transducer.

[0971] 90. The device as described in clause 89, wherein a portion of the metal shell is cut away to provide a passage for electrical connection of a first device terminal to the first electrical transducer contact, and a second device terminal is electrically connected to the metal shell, wherein the first and second device terminals receive an alternating current drive signal from a drive device and transmit the alternating current drive signal to the ultrasonic transducer.

[0972] 91. The device as described in any of the preceding clauses, wherein the air flow path includes a plurality of turns that change the direction of the air flow multiple times as the air flows from the air inlet to the ultrasonic groove.

[0973] 92. A mist generator comprising:

[0974] A mist inhalation device as described in any of the preceding clauses;

[0975] A drive device connected to the mist inhalation device, wherein the drive device includes:

[0976] An alternating current drive signal generator electrically connected to a first electrical connection of the ultrasonic transducer and electrically connected to a second electrical connection of the ultrasonic transducer to drive the ultrasonic transducer with an alternating current drive signal.

[0977] 93. An ultrasonic transducer assembly comprising:

[0978] An ultrasonic transducer having a first electrical connection and a second electrical connection;

[0979] A first electrical transducer contact;

[0980] A base provided with a central hole, a portion of the first electrical transducer contact extending through the central hole for electrical connection to the first electrical connection of the ultrasonic transducer;

[0981] A metal shell at least partially surrounding the base, the metal shell including a lip that engages at least a portion of the periphery of the ultrasonic transducer to hold the ultrasonic transducer in position relative to the base, and a portion of the metal shell being a second electrical transducer contact that is electrically connected to the second electrical connection of the ultrasonic transducer.

[0982] Although certain example embodiments of the present invention have been described, the scope of the appended claims is not intended to be limited to these embodiments. The claims should be interpreted in a literal sense, purpose, and / or equivalents.

[0983] It should be understood that within the spirit and scope of the present invention, the various embodiments and features described and shown herein can be combined with each other in whole or in part.

[0984] The detailed description set forth below is intended as a description of various configurations of the present invention and is not intended to represent the only configurations in which the present invention may be practiced. However, it will be apparent to those of ordinary skill in the art that the present invention is not limited to the specific details set forth herein and can be practiced without these specific details.

[0985] As used in this specification and the appended claims, the term "comprising" and its variants mean including the specified features, steps, or integers. These terms should not be construed as excluding the presence of other features, steps, or components.

[0986] The present invention may also be broadly composed of the components, elements, steps, examples, and / or features singly or jointly mentioned or indicated in the specification in any combination of two or more of the said components, elements, steps, examples, and / or features. In particular, one or more features in any embodiment described herein may be combined with one or more features in any other embodiment described herein.

[0987] Protection may be sought for the combination of features disclosed in any one or more of the publicly available documents cited herein with the present disclosure.

[0988] Although certain example embodiments of the present invention have been described, the scope of the appended claims is not intended to be limited to these embodiments. The claims should be interpreted in a literal sense, purpose, and / or equivalents.

Claims

1. A mist generating device for delivering mist to a user, the mist generating device being used in cooperation with a driving device, wherein the mist generating device comprises: A housing including a liquid chamber for containing a liquid to be atomized, the liquid including a therapeutic agent; An ultrasonic assembly connected to the housing, the ultrasonic assembly comprising: An ultrasonic transducer having a first electrical connection and a second electrical connection for receiving an alternating current driving signal from the driving device; A first component part including a groove for fixing the ultrasonic transducer; A second component part connected to the first component part, the second component part comprising: An ultrasonic groove superposed on the ultrasonic transducer to form an ultrasonic chamber; An ultrasonic assembly air inlet fluidly connected to the ultrasonic groove; An ultrasonic assembly mist outlet fluidly connected to the ultrasonic groove; An air flow path extending from the ultrasonic assembly air inlet through the ultrasonic groove to the ultrasonic assembly mist outlet; At least one of the first component part and the second component part includes an elastically deformable part that forms a seal between the first component part and the second component part to minimize or prevent fluid leakage therebetween; The mist inhalation device further comprises: A barrier part including an elastically deformable seal located between the ultrasonic assembly and the housing to minimize or prevent fluid leakage, the barrier part including capillary pores having elastically deformable walls; A capillary tube extending from the liquid chamber through the capillary pores to the ultrasonic chamber, such that a first part of the capillary tube is within the liquid chamber and a second part of the capillary tube is within the ultrasonic chamber, wherein the second part of the capillary tube is superposed on the atomizing surface of the ultrasonic transducer, such that when the ultrasonic transducer is driven by the alternating current driving signal of the driving device, the atomizing surface vibrates and atomizes the liquid carried by the second part of the capillary tube, thereby generating a mist containing the atomized liquid and air in the ultrasonic chamber, and the mist flows out through the ultrasonic assembly mist outlet for the user to inhale.

2. The device according to claim 1, wherein the first component part is made of an elastically deformable material, and a part of the first component part forms a seal between the first component part and the second component part.

3. The device according to claim 1 or 2, wherein the second component part is made of an elastically deformable material, and a part of the second component part forms a seal between the first component part and the second component part.

4. The device according to any one of the preceding claims, wherein the second component part comprises: A main body provided with an ultrasonic groove; A cover connected to the main body, the cover being provided with a channel defining at least part of the air flow path, wherein one end of the channel forms an air inlet and the other end forms a mist outlet.

5. The device according to any one of the preceding claims, wherein the second component part includes at least one biasing element disposed in the ultrasonic groove, and each biasing element applies a biasing force to the second part of the capillary tube to press the second part of the capillary tube against the atomizing surface of the ultrasonic transducer.

6. The device according to claim 5, wherein each biasing element is integrally formed with the second component part.

7. The device according to claim 5 or 6, wherein each biasing element includes a fixed end connected to the second component part and a distal end contacting the second part of the capillary, the distal end being narrower than the fixed end.

8. The device according to any one of claims 5 to 7, wherein each biasing element is generally conical in shape.

9. The device according to any one of the preceding claims, wherein the housing includes a lumen defined by a base and side walls extending upward from the base, a liquid chamber being formed in a part of the lumen adjacent to the base, the ultrasonic assembly being at least partially received in the lumen, and the liquid chamber being located between the ultrasonic assembly and the base.

10. The device according to claim 9, wherein the ultrasonic assembly contacts the side wall of the housing and forms a seal to minimize or prevent fluid flow between the ultrasonic assembly and the side wall of the housing.

11. The device according to claim 9 or 10, wherein the ultrasonic assembly includes a filling hole that extends from a filling opening through a part of the ultrasonic assembly to the liquid chamber to allow liquid to be injected into the liquid chamber through the filling hole.

12. The device according to any one of claims 9 to 11, wherein the device includes a nozzle attached to the housing to substantially enclose the lumen, the nozzle including a mist outlet hole that is in fluid communication with the mist outlet of the ultrasonic assembly to provide a mist flow path from the ultrasonic assembly to the mist outlet hole.

13. The device according to claim 12, wherein the device includes a layer of foam material disposed adjacent to the mist flow path to absorb liquid droplets larger than a predetermined size in the mist flowing along the mist flow path.

14. The device according to claim 13, wherein the layer of foam material is located between the ultrasonic assembly and a separator, the separator including a mist outlet hole to allow mist to flow from the foam material layer through the separator.

15. The device according to claim 14 of claims 11 to 13, wherein the separator includes a plug that seals the filling opening to minimize or prevent leakage of liquid from the liquid chamber to the outside of the device.

16. The device according to any one of the preceding claims, wherein the ultrasonic transducer is received in an ultrasonic transducer stack including: a base provided with a central hole, a part of a first electrical transducer contact extending through the central hole for electrical connection to a first electrical connection of the ultrasonic transducer; a metal shell at least partially surrounding the base, the metal shell including a lip that engages at least a part of the periphery of the ultrasonic transducer to hold the ultrasonic transducer in position relative to the base, and a part of the metal shell being a second electrical transducer contact that is electrically connected to a second electrical connection of the ultrasonic transducer.

17. The device according to claim 16, wherein a part of the metal shell is cut away to provide a channel for electrical connection of a first device terminal to the first electrical transducer contact, and a second device terminal is electrically connected to the metal shell, wherein the first and second device terminals receive an alternating current drive signal from a drive device and transmit the alternating current drive signal to the ultrasonic transducer.

18. The device according to any one of the preceding claims, wherein the air flow path includes a plurality of turns that change the direction of air flow multiple times when air flows from the air inlet to the ultrasonic groove.

19. A mist generator, comprising: The mist inhalation device according to any one of the preceding claims; A driving device, connected to the mist inhalation device, wherein the driving device comprises: An alternating current driving signal generator, electrically connected to a first electrical connection of the ultrasonic transducer and electrically connected to a second electrical connection of the ultrasonic transducer to drive the ultrasonic transducer with an alternating current driving signal.

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