Mist inhaler device for therapeutic drug delivery

Abstract

A mist generator device (400) for delivering a mist to a user, the mist generator device (400) being used with a driver device (202). The mist generator device (400) includes a housing (204) including a liquid chamber (218), the liquid chamber containing a liquid to be atomized, the liquid including a therapeutic agent. An ultrasonic processing assembly (425) is coupled to the housing (204), the ultrasonic processing assembly (425) comprising an ultrasonic 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 part (426) and the second assembly part (428) includes an elastically deformable section that forms a seal between the first assembly part (426) and the second assembly part (428), which minimizes or prevents fluid leakage between the first assembly part (426) and the second assembly part (428).

Description

[Technical Field]

[0001] TECHNICAL FIELD The present invention relates to mist inhaler devices, and more particularly to ultrasonic mist inhaler devices for atomizing a liquid containing a therapeutic agent for inhalation by a user. [Background technology]

[0002] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 430,309, filed December 5, 2022. This application also claims the benefit of priority to European Patent Application No. 20168231.7, filed April 6, 2020, which is a continuation-in-part of U.S. Patent Application No. 17 / 220,189, filed April 1, 2021, which is a continuation-in-part of U.S. Patent Application No. 17 / 552,284 (the '284 application) (now Patent No. 11,589,610), filed December 15, 2021, which is a continuation-in-part of co-pending U.S. Patent Application No. 17 / 678,513, filed February 23, 202 ...552,284 (the '284 application) (now Patent No. 11,589,610), filed December 15, 2021, which is also a continuation-in-part of co-pending U.S. Patent Application No. 17 / 678,513, filed December 1, 2019. This is a continuation-in-part of U.S. Patent Application No. 17 / 122,025 (now U.S. Patent No. 11,672,928), filed December 15, 2020, which claims benefit of priority to International Patent Application No. PCT / IB2019 / 060808, filed December 5, 2019, International Patent Application No. PCT / IB2019 / 060810, filed December 15, 2019, International Patent Application No. PCT / IB2019 / 060811, filed December 15, 2019, and International Patent Application No. PCT / IB2019 / 060812, filed December 15, 2019. This application also claims priority to European Patent Application No. 20168245.7, filed April 6, 2020, European Patent Application No. 20168231.7, filed April 6, 2020, and European Patent Application No. 20168938.7, filed April 9, 2020. All of the foregoing applications are incorporated herein by reference in their entirety.

[0003] Mist inhaler devices are used to generate a mist or vapor for inhalation by a user. The mist may contain a therapeutic agent, drug, or medication that is inhaled by the user and absorbed into the user's bloodstream.

[0004] Therapeutic aerosol delivery is a mainstay of treatment for asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. Therapeutic aerosols also have applications for the treatment of influenza, osteoporosis, and for the delivery of vaccines.

[0005] Pulmonary delivery of therapeutic agents for the treatment of non-respiratory systemic diseases is attractive due to the high pulmonary vascularity, thin blood-alveolar barrier, large surface area, avoidance of gastric enzymes, and first-pass hepatic metabolism. It is also attractive due to improved patient comfort and adherence. The pulmonary system can be utilized to deliver antibodies, proteins, analgesics, and nucleic acids. Treatment of central nervous system disorders, such as tobacco addiction, can be significantly enhanced through efficient delivery of nicotine to the systemic circulation through the lungs.

[0006] The effectiveness of a therapeutic aerosol is related to the amount of drug deposited beyond the oropharyngeal region, the area where deposition occurs being a function of the size of the inhaled particles.

[0007] Devices currently used to administer inhaled medications fall into three categories: nebulizers, metered-dose inhalers, and dry powder inhalers. Nebulizers are typically divided into two types: jet and ultrasonic, but both types have weaknesses and present problems with conventional devices.

[0008] Jet nebulizers are based on Bernoulli's principle and produce relatively large droplets, which generally deposit in the oropharyngeal region and are therefore not particularly effective. Ultrasonic nebulizers use a piezoelectric crystal that vibrates at frequencies ranging from 1 MHz to 1.7 MHz, transferring vibrational energy to the liquid and converting it into an aerosol. Ultrasonic nebulizers are not effective when viscous suspensions or solutions are used and tend to heat the medication, thus disrupting the molecules and eliminating the benefit of inhalation.

[0009] Electronic vapor inhalers and other vapor inhalers typically have similar designs. Most electronic vapor inhalers feature a liquid reservoir with a capillary element, typically a cotton-like internal membrane, that holds the liquid and prevents leakage from the reservoir. Nevertheless, these devices are still prone to leaking because there is no barrier to prevent the liquid from flowing from the membrane into the mouthpiece. Leaky electronic vapor inhalers are problematic for several reasons. First, liquid can leak into the electronic components, which can cause serious damage to the device. Second, liquid can leak into the electronic vapor inhaler's mouthpiece, potentially resulting in the user inhaling unvaporized liquid.

[0010] Electronic vaporizers are also known to provide inconsistent doses during inhalation. The aforementioned leaks are one cause of inconsistent doses, as the membrane near the vaporizer can be oversaturated or undersaturated. If the membrane is oversaturated, the user may experience more vapor than desired, and if the membrane is undersaturated, the user may experience less vapor than desired. Furthermore, small changes in the strength of the user's inhalation can provide stronger or weaker doses. Inconsistent dosing, along with leaks, can lead to faster consumption of the vaporized liquid.

[0011] Furthermore, conventional electronic vaporizers tend to rely on inducing high temperatures in metal heating components configured to heat the liquid, thus vaporizing the liquid so that it can be inhaled. Problems with conventional electronic vaporizers include the possibility of the metal burning and then being inhaled along with the burnt liquid. Additionally, some people dislike the burnt smell from the heated liquid.

[0012] It is now recognized that electronic vapor inhalers can play an important role in smoking cessation programs by allowing users to receive a nicotine dose in a manner that is considered safer than traditional cigarettes. Users are generally more likely to adhere to smoking cessation programs using vapor inhalers compared to nicotine patches or chews. However, traditional vapor inhalers cannot deliver a consistent nicotine dose for every puff a user takes, and traditional vapor inhalers typically cannot mimic the mouth-to-lung (MTL) effect.

[0013] Therefore, there is a need in the art for an improved mist inhaler device that seeks to address at least some of the problems described herein. Summary of the Invention

[0014] The present invention provides a mist inhaler device according to claim 1 and a mist inhaler according to claim 19. The present invention also provides preferred embodiments according to the dependent claims.

[0015] The various examples of the present disclosure described below have several benefits and advantages over conventional mist inhaler devices, which are set forth in the following description.

[0016] Because the mist inhaler device of the present disclosure allows for more efficient operation than conventional mist inhaler devices, the mist inhaler device of the present disclosure has environmental advantages due to reduced power requirements.

[0017] It should be noted that the expression "mist" as used in the following disclosure means that the liquid is not usually heated in conventional inhalers known from the prior art: in fact, conventional inhalers use a heating element to heat the liquid above its boiling point, producing a vapor that is different from a mist.

[0018] Indeed, when sonicating a liquid at high intensity, the sound waves propagating through the liquid medium alternate between high-pressure (compression) and low-pressure (rarefaction) cycles, at different speeds depending on the frequency. During the low-pressure cycle, high-intensity ultrasound creates small vacuum bubbles or voids in the liquid. When the bubbles reach a volume where they can no longer absorb energy, they violently collapse during the high-pressure cycle. This phenomenon is called cavitation. During implosion, extremely high pressures are reached locally. In cavitation, disruptive capillary waves are generated, and small droplets break the surface tension of the liquid and are rapidly released into the air, taking the form of a mist.

[0019] The cavitation phenomenon will now be explained more precisely.

[0020] When a liquid is atomized by ultrasonic oscillation, tiny bubbles are generated in the liquid.

[0021] Bubble generation is a process of cavity formation created by negative pressure generated by the strong ultrasonic waves generated by the ultrasonic oscillator means.

[0022] High intensity ultrasound results in rapid growth of cavities with a relatively low and negligible decrease in cavity size during positive pressure cycles.

[0023] Ultrasound, like all sound waves, consists 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, pushing the molecules apart.

[0024] Intense ultrasound creates regions of positive and negative pressure. During the development of negative pressure, cavities can form and grow. When the cavities reach a critical size, they implode.

[0025] The amount of negative pressure required depends on the type and purity of the liquid. For truly pure liquids, the tensile strength is so great that available ultrasonic generators cannot generate sufficient negative pressure to create a cavity. For example, pure water requires a negative pressure of over 1,000 atmospheres, while the most powerful ultrasonic generators can only generate a negative pressure of about 50 atmospheres. The tensile strength of a liquid is reduced by gas trapped in the interstices between liquid particles. This effect is similar to the loss of strength that results from cracks in solid materials. When a gas-filled interstices are exposed to negative pressure cycles from sound waves, the reduced pressure causes the gas in the interstices to expand until tiny bubbles are released into the solution.

[0026] However, sonicated bubbles continually absorb energy from the alternating compression and expansion cycles of the sound waves. These cause the bubbles to grow and shrink, creating a dynamic balance between the void inside the bubble and the liquid outside. In some cases, ultrasound sustains the bubbles, which simply oscillate in size. In other cases, the average size of the bubbles increases.

[0027] The growth of cavities depends on the intensity of the sound. High-intensity ultrasound can expand the cavities so rapidly during the negative pressure cycle that the cavities never have a chance to contract during the positive pressure cycle. In this process, the cavities can grow rapidly over the course of a single sound cycle.

[0028] For low-intensity ultrasound, the size of the cavity oscillates in phase with the expansion and compression cycles. The surface of the cavity created by low-intensity ultrasound is slightly larger during an expansion cycle than during a compression cycle. Because the amount of gas diffusing into or out of the cavity depends on the surface area, diffusion into the cavity during an expansion cycle is slightly greater than diffusion out during a compression cycle. For each sound cycle, the cavity expands slightly more than it contracts. Over many cycles, the cavity grows slowly.

[0029] It has been found that growing cavities can eventually reach a critical size at which they most efficiently absorb energy from ultrasound. The critical size depends on the frequency of the ultrasound. Once a cavity experiences very rapid growth induced by high-intensity ultrasound, it can no longer efficiently absorb energy from the sound waves. Without this energy input, the cavity can no longer sustain itself. Liquid rushes in and the nonlinear response causes the cavity to implode.

[0030] The energy released from the implosion fragments the liquid into tiny particles, which are dispersed into the air as a mist.

[0031] The equation describing the above nonlinear response phenomenon can be expressed by the "Rayleigh-Plesset" equation, which can be derived from the "Navier-Stokes" equation used in fluid mechanics.

[0032] Our approach was to rewrite the "Rayleigh-Plesset" equation in which the bubble volume V is used as the dynamic parameter and the physics describing dissipation is identical to that used in the more classical form in which the radius is the dynamic parameter.

[0033] The formula used was derived as follows:

[0034]

number

[0035] During the ceremony, V is the bubble volume, V0 is the equilibrium bubble volume, ρ0 is the liquid density (assumed to be constant), σ is the surface tension, p V is the vapor pressure, p0 is the static pressure in the liquid just outside the bubble wall, κ is the polytropic exponent of the gas, t is the time, R(t) is the bubble radius, P(t) is the applied pressure, c is the velocity of the liquid, φ is the velocity potential, λ is the wavelength of the acoustic field.

[0036] In ultrasonic mist inhalers, the liquid has a kinematic viscosity of 1.05 Pa.sec to 1.412 Pa.sec.

[0037] By solving the above equation with the correct parameters for viscosity, density, and having the desired target bubble volume of the liquid spray into air, it was found that a frequency range of 2.8 MHz to 3.2 MHz would produce a bubble volume of approximately 0.25 to 0.5 microns for a liquid viscosity range of 1.05 Pa.s and 1.412 Pa.s.

[0038] The process of ultrasonic cavitation has a significant effect on the nicotine concentration in the generated mist.

[0039] No heating elements are included, thereby eliminating burnt elements and reducing the effects of secondhand smoke.

[0040] In the ultrasonic mist inhaler, a capillary element may extend between the sonication chamber and the liquid chamber.

[0041] In the ultrasonic mist inhaler, the capillary element is at least partially made of bamboo fiber material.

[0042] The capillary elements allow for high absorption capacity, high absorption rate as well as high fluid retention.

[0043] It was found that the inherent properties of the proposed material used for capillary action have a significant impact on the efficient functioning of the ultrasonic mist inhaler.

[0044] Furthermore, the inherent properties of the proposed material include good hygroscopicity while maintaining good permeability, which allows the aspirated liquid to efficiently permeate the capillaries, while the observed high absorption capacity allows it to retain a significant amount of liquid, thus enabling the ultrasonic mist inhaler to last for a longer period of time compared to other products available on the market.

[0045] Another important advantage of using bamboo fiber is the natural antibacterial bio-agent, or "Kun," that is inherently present within bamboo fiber, making it antibacterial, antifungal, and odor-resistant, making it suitable for medical applications.

[0046] The inherent properties were verified using numerical analysis on the benefits of bamboo fiber for ultrasonic treatment.

[0047] The formula below has been tested with bamboo fiber material, as well as other materials such as cotton, paper, or other fiber strands, for use as capillary elements, demonstrating that bamboo fiber has much better properties for use in ultrasonic processing.

[0048]

number

[0049] During the ceremony, C (cc / gm / gm of fluid) is the volume per mass of absorbed liquid divided by the dry mass of the capillary element; A(cm 2 ) is the total surface area of ​​the capillary elements, T (cm) is the thickness of the capillary element; W f (gm) is the mass of the dry capillary element, P f (cc / g.sec) is the density of the dry capillary element, α is the ratio of the increase in volume of the capillary element upon wetting to the volume of liquid diffused into the capillary element; V d(cc) is the volume of liquid diffused into the capillary element;

[0050]

number

[0051] Q (cc / sec) is the amount of liquid absorbed per unit time, r (cm) is the radius of the pore in the capillary element; γ (N / m) is the surface tension of the liquid, θ (degrees) is the contact angle of the fiber, η(m 2 / sec) is the viscosity of the fluid.

[0052] In the ultrasonic mist inhaler, the capillary element may be at least partially made of bamboo fiber material.

[0053] In the ultrasonic mist inhaler, the capillary element material may be 100% bamboo fiber.

[0054] Extensive testing concluded that 100% pure bamboo fiber is the best choice for ultrasonic processing.

[0055] In the ultrasonic mist inhaler, the capillary element material may be at least 75% bamboo fiber and optionally 25% cotton.

[0056] Capillary elements made from 100% pure bamboo fiber or with a high percentage of bamboo fiber exhibit high absorption capacity as well as improved fluid transfer, making them the optimal choice for ultrasonic mist inhaler applications. [Brief explanation of the drawings]

[0057] In order that the present disclosure may be more readily understood, preferred embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] 1 is a schematic perspective view of an example mist inhaler of the present disclosure. FIG. [Figure 2]1 is a schematic perspective view of an example mist inhaler of the present disclosure. FIG. [Figure 3] 1 is a schematic perspective view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 4] 1 is a schematic perspective view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 5] 1 is a schematic exploded perspective view of an exemplary mist inhaler device of the present disclosure; FIG. [Figure 6] FIG. 1 is a schematic perspective view of an example transducer holder of the present disclosure. [Figure 7] FIG. 1 is a schematic perspective view of an example transducer holder of the present disclosure. [Figure 8] 1 is a schematic perspective view of an example capillary element of the present disclosure; FIG. [Figure 9] 1 is a schematic perspective view of an example capillary element of the present disclosure; FIG. [Figure 10] FIG. 1 is a schematic perspective view of an example transducer holder of the present disclosure. [Figure 11] FIG. 1 is a schematic perspective view of an example transducer holder of the present disclosure. [Figure 12] FIG. 2 is a schematic perspective view of a portion of an example housing of the present disclosure. [Figure 13] 1 is a schematic perspective view of an example absorbent element of the present disclosure. FIG. [Figure 14] FIG. 2 is a schematic perspective view of a portion of an example housing of the present disclosure. [Figure 15] FIG. 2 is a schematic perspective view of a portion of an example housing of the present disclosure. [Figure 16] 1 is a schematic perspective view of an example absorbent element of the present disclosure. FIG. [Figure 17] FIG. 2 is a schematic perspective view of a portion of an example housing of the present disclosure. [Figure 18] FIG. 2 is a schematic perspective view of a portion of an example housing of the present disclosure. [Figure 19] FIG. 2 is a schematic perspective view of a portion of an example housing of the present disclosure. [Figure 20] FIG. 1 is a schematic perspective view of an example circuit board of the present disclosure. [Figure 21] FIG. 1 is a schematic perspective view of an example circuit board of the present disclosure. [Figure 22] 1 is a schematic exploded perspective view of an exemplary mist inhaler device of the present disclosure; FIG. [Figure 23] 1 is a schematic exploded perspective view of an exemplary mist inhaler device of the present disclosure; FIG. [Figure 24] FIG. 1 is a cross-sectional view of an exemplary mist inhaler device of the present disclosure. [Figure 25] FIG. 1 is a cross-sectional view of an exemplary mist inhaler device of the present disclosure. [Figure 26] FIG. 1 is a cross-sectional view of an exemplary mist inhaler device of the present disclosure. [Figure 27] 1 is a schematic perspective view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 28] 1 is a schematic perspective view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 29] 1 is a schematic exploded perspective view of an exemplary mist inhaler device of the present disclosure; FIG. [Figure 30] FIG. 1 is a schematic perspective view of an example transducer holder assembly of the present disclosure. [Figure 31] FIG. 1 is a schematic perspective view of an example transducer holder assembly of the present disclosure. [Figure 32] FIG. 1 is a schematic exploded perspective view of an example transducer holder assembly of the present disclosure. [Figure 33] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 34] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 35] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 36] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 37] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 38] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 39] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 40] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 41] 1 is a schematic perspective, partially cut-away view of a portion of an example mist inhaler device of the present disclosure. FIG. [Figure 42] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 43] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 44] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 45] 1 is a schematic perspective cross-sectional view of a portion of an example mist inhaler device of the present disclosure. FIG. [Figure 46] 1 is a schematic perspective cross-sectional view of a portion of an example mist inhaler device of the present disclosure. FIG. [Figure 47] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 48] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 49] FIG. 1 is a schematic perspective view of a portion of an example mist inhaler device of the present disclosure. [Figure 50] 1 is a schematic perspective view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 51] 1 is a schematic perspective view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 52] 1 is a schematic perspective cross-sectional view of a portion of an example mist inhaler device of the present disclosure. FIG. [Figure 53] 1 is a schematic perspective exploded view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 54] 1 is a schematic cross-sectional view of a portion of an example mist inhaler device of the present disclosure. [Figure 55] 1 is a schematic perspective view of an exemplary mist inhaler device of the present disclosure. FIG. [Figure 56] 1 is a schematic perspective cross-sectional view of a portion of an example mist inhaler device of the present disclosure. FIG. [Figure 57]FIG. 1 is a schematic perspective cross-sectional view of a portion of an example mist inhaler device of the present disclosure showing the air flow path. [Figure 58] FIG. 1 is a schematic perspective cross-sectional view of a portion of an example mist inhaler device of the present disclosure showing the air flow path. [Figure 59] FIG. 1 is a schematic perspective cross-sectional view of a portion of an example mist inhaler device of the present disclosure showing the air flow path. [Figure 60] FIG. 1 is a schematic exploded perspective view of a driver device of the present disclosure. [Figure 61] 1 is a schematic perspective view of a portion of a driver device of the present disclosure; [Figure 62] 1 is a schematic perspective view of a portion of a driver device of the present disclosure; [Figure 63] 1 is a schematic perspective view of a portion of a driver device of the present disclosure; [Figure 64] 1 is a schematic perspective view of a portion of a driver device of the present disclosure; [Figure 65] 1 is a schematic perspective view of a portion of a driver device of the present disclosure; [Figure 66] 1 is a schematic perspective view of a portion of a driver device of the present disclosure; [Figure 67] 1 is a schematic perspective view of a portion of a driver device of the present disclosure; [Figure 68] 1 is a schematic diagram of an integrated circuit configuration of the present disclosure. [Figure 69] FIG. 1 is a schematic diagram of an integrated circuit of the present disclosure. [Figure 70] FIG. 1 is a schematic diagram of a pulse width modulation generator of the present disclosure. [Figure 71] FIG. 2 is a timing diagram of an example of the present disclosure. [Figure 72] FIG. 2 is a timing diagram of an example of the present disclosure. [Figure 73] 1 is a table illustrating port functions of an example of the present disclosure. [Figure 74] FIG. 1 is a schematic diagram of an integrated circuit of the present disclosure. [Figure 75] FIG. 1 is a circuit diagram of an example H-bridge of the present disclosure. [Figure 76] FIG. 1 is a circuit diagram of an example current sensing configuration of the present disclosure. [Figure 77] FIG. 1 is a circuit diagram of an example H-bridge of the present disclosure. [Figure 78] 76 is a graph showing voltages during phases of operation of the H-bridge of FIG. 75. [Figure 79] 76 is a graph showing voltages during phases of operation of the H-bridge of FIG. 75. [Figure 80] 76 is a graph showing the voltage and current at the terminals of an ultrasonic transducer while the ultrasonic transducer is driven by the H-bridge of FIG. 75. [Figure 81] FIG. 1 is a schematic diagram illustrating connections between integrated circuits of the present disclosure. [Figure 82] FIG. 1 is a schematic diagram of an integrated circuit of the present disclosure. [Figure 83] FIG. 2 illustrates steps of an example authentication method of the present disclosure. [Figure 84] FIG. 1 is a schematic perspective view of an end cap of a driver device of the present disclosure. [Figure 85] FIG. 2 is a schematic perspective view of a housing of the driver device of the present disclosure. [Figure 86] 1 is a graph showing the results of EMC testing of a mist inhaler device of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0058] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, according to standard practice in the industry, various features have not been drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or decreased for clarity of illustration.

[0059] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. To simplify the disclosure, specific examples of components, concentrations, applications, and configurations are described below. Of course, these are merely examples and are not intended to be limiting. For example, the attachment of a first feature and a second feature in the following description may include embodiments in which the first feature and the second feature are attached in direct contact, or may also include embodiments in which an additional feature may be disposed between the first feature and the second feature such that the first feature and the second feature do not need to be in direct contact. Additionally, the present disclosure may repeat reference numerals and / or letters in various examples. This repetition is for purposes of brevity and clarity and does not, in itself, dictate a relationship between the various embodiments and / or configurations discussed.

[0060] The following disclosure describes representative examples, each of which may be considered an embodiment, and any reference to "example" may be changed to "embodiment" in this disclosure.

[0061] Some portions of this disclosure relate to electronic vapor inhalers. A specific example described below involves nicotine. However, other examples are envisioned, such as inhalers for therapeutic drugs, medications, and herbal supplements. Furthermore, the device can be packaged to look like a medical device that does not resemble a cigarette.

[0062] Ultrasonic mist inhalers are either disposable or reusable. As used herein, the term "reusable" means that the energy storage device is rechargeable or replaceable, or that the liquid can be replenished by either refilling or replacing the liquid reservoir structure. Alternatively, in some examples, the reusable electronic device is rechargeable and can be replenished with liquid.

[0063] Conventional electronic vaporizers tend to rely on inducing high temperatures in metal components configured to heat a liquid within the inhaler, thus vaporizing the liquid, which can be inhaled. The liquid typically contains nicotine and flavorings mixed in a solution of propylene glycol (PG) and vegetable glycerin (VG), which is vaporized via a heating component at high temperatures. Problems with conventional inhalers can include the possibility of burning the metal and then inhaling the metal along with the burnt liquid. Additionally, some people dislike the burnt odor and taste caused by the heated liquid.

[0064] For each different application of the mist generating system, there will be an optimum frequency or frequency range for driving the ultrasonic generating means 5 to optimize the generation of mist. In the example where the ultrasonic generating means 5 is a piezo transducer, the optimum frequency or frequency range will depend on at least the following four parameters:

[0065] 1. Transducer manufacturing process In some examples, the ultrasonic generating means 5 includes a piezoceramic. Piezoceramics are manufactured by mixing compounds to create a ceramic dough, and this mixing process may not be consistent throughout production. This inconsistency may result in different resonant frequency ranges for the cured piezoceramic.

[0066] If the resonant frequency of the piezo ceramic does not correspond to the required operating frequency of the device, no mist will be generated during operation of the device. In the case of a therapeutic mist inhaler, even a slight offset in the resonant frequency of the piezo ceramic is sufficient to affect mist generation, meaning that the device will not deliver the appropriate therapeutic level to the user.

[0067] 2. Transducer Load During operation, changes in the load on the piezoelectric transducer will suppress the overall displacement of the piezoelectric transducer's oscillation. To achieve the optimum displacement of the piezoelectric transducer's oscillation, the drive frequency must be adjusted to allow the circuit to provide adequate power for maximum displacement.

[0068] Types of loads that can affect the efficiency of the oscillator include the amount of liquid on the transducer (wetness of the wicking material) and the spring force applied to the wicking material to maintain permanent contact with the transducer, and may also include electrical connections.

[0069] 3.Temperature The ultrasonic oscillations of a piezoelectric transducer are partially damped by its assembly in the device, which may include the transducer positioned within a silicone / rubber ring and a spring exerting pressure on a wicking material above the transducer. This damping of oscillations causes a local temperature increase on and around the transducer.

[0070] Increasing temperature affects oscillation due to changes in the molecular behavior of the transducer. Increasing temperature means more energy for the ceramic molecules, which temporarily affects their crystalline structure. As the temperature decreases, this effect is reversed, but to maintain optimal oscillation, modulation of the supplied frequency is required. This frequency modulation cannot be achieved with conventional fixed-frequency devices.

[0071] Increasing temperature also reduces the viscosity of the solution being evaporated (e-liquid), which can induce cavitation and require a change in drive frequency to maintain continuous mist production. For conventional fixed-frequency devices, reducing the viscosity of the liquid without changing the drive frequency will reduce or completely stop mist production, rendering the device inoperable.

[0072] 4. Distance to power source The oscillation frequency of the electronic circuit can vary depending on the length of wire between the transducer and the oscillator driver. The frequency of the electronic circuit is inversely proportional to the distance between the transducer and the rest of the circuit.

[0073] The distance parameters are primarily fixed within the device, but can vary during the device manufacturing process, reducing the overall efficiency of the device. It is therefore desirable to vary the drive frequency of the device to compensate for variations and optimize the efficiency of the device.

[0074] A piezoelectric transducer can be modeled as an RLC circuit in an electronic circuit, as shown in Figure 5. The four parameters mentioned above can be modeled as changes to the overall inductance, capacitance, and / or resistance of the RLC circuit to change the resonant frequency range supplied to the transducer. As the frequency of the circuit increases near the transducer's resonance, the logarithmic impedance of the overall circuit drops to a minimum, then rises to a maximum, before settling in the mid-range.

[0075] Figure 6 shows a typical graph illustrating the change in overall impedance with increasing frequency in an RLC circuit. Figure 7 shows the change in overall impedance with increasing frequency in an RLC circuit when a piezoelectric transducer is driven at a first predetermined frequency f s At lower frequencies, in the first capacitive region, at a second predetermined frequency f p At higher frequencies, the piezoelectric transducer acts as a capacitor in a second capacitive region. s and a second predetermined frequency f p At frequencies between 0 and 100 kHz, the transducer acts as an inductor in the induction region. To maintain optimum oscillation and therefore maximum efficiency of the transducer, the current through the transducer must be kept at a frequency within the induction region.

[0076] The frequency controller of some example devices is configured to maintain the frequency of oscillation of the piezo transducer (ultrasonic oscillation means 5) within the induction region to maximize the efficiency of the device.

[0077] The frequency controller is configured to perform a sweep operation that drives the transducer at a frequency that tracks progressively over a predetermined sweep frequency range. As the frequency controller performs the sweep, the frequency controller monitors an analog-to-digital conversion (ADC) value of an analog-to-digital converter coupled to the transducer. In some examples, the ADC value is a parameter of the ADC that is proportional to a voltage across the transducer. In other examples, the ADC value is a parameter of the ADC that is proportional to a current through the transducer.

[0078] As will be described in more detail below, the frequency controller in some examples determines the active power being used by the ultrasonic transducer by monitoring the current flowing through the transducer.

[0079] During the sweep operation, the frequency controller identifies a frequency induction region of the transducer. Once the frequency controller identifies the induction region, the frequency controller records the ADC value and adjusts the driving frequency of the transducer to a frequency within the induction region (i.e., a first predetermined frequency f) in order to optimize ultrasonic cavitation by the transducer. s and a second predetermined frequency f p When the drive frequency is locked within the induction region, the electromechanical coupling coefficient of the transducer is maximized, thereby maximizing the efficiency of the device.

[0080] In some examples, the frequency controller is configured to perform a sweeping operation to identify the induced region each time oscillation is initiated or resumed. In examples, the frequency controller is configured to lock the drive frequency to a new frequency within the induced region each time oscillation is initiated, thereby compensating for any changes in parameters that affect the efficiency of operation of the device.

[0081] In some examples, the frequency controller ensures optimal mist generation and maximizes the efficiency of therapeutic / therapeutic agent delivery to the user. In some examples, the frequency controller optimizes the device, improving the efficiency and maximizing the therapeutic / therapeutic agent delivery to the user.

[0082] In other examples, the frequency controller optimizes the device and improves the efficiency of other devices that use ultrasound. In some examples, the frequency controller is configured for use with ultrasound technology for therapeutic applications to enhance the enhanced drug release from ultrasound-responsive drug delivery systems. Having a precise, optimal frequency during operation ensures that microbubbles, nanobubbles, nanodroplets, liposomes, emulsions, micelles, or any other delivery system is highly effective.

[0083] In some examples, to ensure optimal mist generation and optimal delivery of the compound as described above, the frequency controller is configured to operate in a recursive mode, where the frequency controller periodically performs frequency sweeps during operation of the device and monitors the ADC value to determine whether the ADC value exceeds a predetermined threshold indicating optimal oscillation of the transducer.

[0084] In some examples, if the frequency controller can identify a possible better frequency for the transducer, the frequency controller performs a sweep operation while the device is in the process of aerosolizing the liquid. If the frequency controller identifies a better frequency, the frequency controller locks the drive frequency to the newly identified better frequency to maintain optimal operation of the device.

[0085] In some examples, the frequency controller performs frequency sweeps for predetermined durations periodically during operation of the device. In the example device described above, the predetermined durations of the sweeps and the periods between sweeps are selected to optimize device function. When implemented in an ultrasonic mist inhaler device, this ensures optimal delivery to the user throughout their inhalation.

[0086] To ensure adequate aerosol generation, in this example the mist inhaler device is equipped with an ultrasonic / piezo transducer of exactly or substantially 16 mm diameter, which is manufactured to specific capacitance and impedance values ​​to control the frequency and power required to generate the desired aerosol volume.

[0087] A horizontally positioned, disk-shaped, 16 mm diameter ultrasonic transducer would result in a large device that may not be ergonomic for handheld use. To alleviate this concern, the ultrasonic transducer in this example is held vertically within the sonication chamber (the plane of the ultrasonic transducer is approximately parallel to the flow of aerosol mist into the mouthpiece and / or approximately parallel to the longitudinal length of the mist inhaler device). In other words, the ultrasonic transducer is approximately perpendicular to the base of the mist inhaler device.

[0088] 1 and 2 of the accompanying drawings, some example mist inhaler devices 200 comprise a mist generator device 201 and a driver device 202. The driver device 202, in this example, comprises a recess 203 that receives and holds a portion of the mist generator device 201. Thus, the mist generator 201 can be coupled with the driver device 202 to form a compact and portable mist inhaler device 200, as shown in FIG.

[0089] 3 to 5 of the accompanying drawings, the mist generator device 201 comprises a mist generator housing 204 which is elongated and formed from two housing parts 205, 206 which are optionally attached to one another. The mist generator housing 204 includes an air inlet port 207 and a mist outlet port 208.

[0090] In this example, the mist generator housing 204 is made of an injection-molded plastic, specifically polypropylene, which is typically used in medical applications. In this example, the mist generator housing 204 is made of a heterophase copolymer. More specifically, it is BF970MO heterophase copolymer, which has an optimal combination of very high stiffness and high impact strength. Mist generator housing components molded from this material exhibit good antistatic performance.

[0091] A heterophasic copolymer such as polypropylene is particularly suitable for the mist generator housing 204 because this material does not cause condensation of the aerosol as it flows from the sonication chamber 219 through the mouthpiece to the user. This plastic material can also be easily directly recycled using industrial crushing and cleaning processes.

[0092] 1, 2 and 4, the mist outlet port 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 port 208, as shown in FIG.

[0093] 6 and 7, mist generator device 200 includes a transducer holder 210 that is held within mist generator housing 204. Transducer holder 210 includes a body portion 211 that, in this example, is cylindrical or generally cylindrical in shape with circular upper and lower openings 212 and 213. Transducer holder 210 includes an internal recess 214 for receiving the edge of an ultrasonic transducer 215, as shown in FIG.

[0094] The transducer holder 210 incorporates a cutout 216 through which the electrode 217 extends from the ultrasonic transducer 215 so that the electrode 217 can be electrically connected to an AC driver of a driving device, as described in more detail below.

[0095] 5, the mist generator device 201 includes a liquid chamber 218 disposed within the mist generator housing 204. The liquid chamber 218 is for containing a liquid, such as a therapeutic liquid, to be atomized. In some examples, the liquid is contained in the liquid chamber 218. In other examples, the liquid chamber 218 is initially empty, and then the liquid chamber is filled with liquid.

[0096] The liquid preferably contains at least one therapeutic agent suitable for aerosol delivery to the lungs via inhalation by a patient to provide the patient with the desired treatment. Some examples of therapeutic agents include, but are not limited to, aerosol delivery of pharmacological agents to the lungs to promote systemic or direct clinical effects while minimizing side effects. Therapeutic agents may also include, but are not limited to, natural drugs, cannabinoid derivatives such as CBD for pain relief and other treatments, botanicals, opioids, RNA, DNA, chemotherapy, intracellular components including ribosomes, endoplasmic reticulum, cytoskeleton, and mitochondria, performance-enhancing supplements, drugs such as albuterol / salbutamol, beta-lactam, polymyxin, and aminoglycoside bactericidal antibiotics for asthma patients, amphotericin B, morphine, fentanyl, prostacyclin, amiloride, and interferon-g as rescue therapy for lung transplant patients and treatment of asthma, and cyclosporine.

[0097] Although the following description refers to nicotine, in other examples of the present disclosure, nicotine is replaced with a therapeutic agent, such as, but not limited to, one or more of the therapeutic agents described herein.

[0098] 1. A liquid (also referred to herein as e-liquid) composition suitable for use in an ultrasound device powered by a 3.7 V lithium polymer (LiPo) battery at a frequency of 3.0 MHz (±0.2 MHz), comprising a nicotine salt consisting of nicotine levulinate; the relative amount 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 the relative amount 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 the relative amount of water in the composition is 5-15% (w / w), or 7-12% (w / w), or 10% (w / w); and / or The amount of nicotine and / or nicotine salt in the composition is 0.1 to 80 mg / mL, or 0.1 to 50 mg / mL, or 1 to 25 mg / mL, or 10 to 20 mg / mL, or 17 mg / mL.

[0099] In some examples, the mist generator device 201 contains e-liquids with kinematic viscosities of 1.05 Pa·s and 1.412 Pa·s.

[0100] In some examples, the liquid chamber 218 contains a liquid comprising nicotine levulinate salts in a 1:1 molar ratio.

[0101] In some examples, the liquid chamber 218 contains e-liquid or a liquid containing a flavoring agent.

[0102] In some examples, the liquid chamber 218 contains an e-liquid or a liquid comprising at least one cannabinoid or phytocannabinoid derived from the cannabis plant. In some examples, the at least one cannabinoid or phytocannabinoid comprises one or more of tetrahydrocannabinol (THC), cannabidiol (CBD), and / or cannabinol (CBN).

[0103] In some examples, the liquid chamber 218 contains an e-liquid or liquid including one or more psychedelic compounds for use as a therapeutic agent. In some examples, the psychedelic compound is one or more of lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), ketamine, esketamine, ibogaine, mescaline, tryptamine, substituted tryptamines, O-acetylpsilocin (4-AcO-DMT), psilocybin (4-PO-DMT), psilocin (4-HO-DMT), O-methylbufotenin (5-MeO-DMT), -24-bufotenin (5-HO-DMT), and / or N,N-dimethyltryptamine (DMT or N,N-DMT).

[0104] 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.

[0105] By using an e-liquid with the correct parameters of viscosity, density, and the desired target bubble volume of the liquid spray into air, a frequency range of 2.8 MHz to 3.2 MHz for a liquid viscosity range of 1.05 Pa·s and 1.412 Pa·s and a density of approximately 1.1 to 1.3 g / mL (density range obtained from Hertz) was found to produce a droplet volume where 90% of the droplets are less than 1 micron and 50% of them are less than 0.5 microns.

[0106] The mist generator device 201 comprises an ultrasonic treatment chamber 219 disposed within the mist generator housing 204 .

[0107] 6 and 7 , the transducer holder 210 includes a divider portion 220 that provides a barrier between the liquid chamber 218 and the sonication chamber 219. The barrier provided by the divider portion 220 minimizes the risk of the sonication chamber 219 flooding with liquid from the liquid chamber 218 or the risk of the capillary elements on the ultrasonic transducer 215 becoming oversaturated, either of which risks overloading the ultrasonic transducer 215 and reducing its efficiency. Furthermore, flooding the sonication chamber 219 or oversaturating the capillary elements can also cause an unpleasant experience with the liquid being inhaled by the user during inhalation. To mitigate this risk, the divider portion 220 of the transducer holder 210 is positioned as a wall between the sonication chamber 219 and the liquid chamber 218.

[0108] Divider portion 220 comprises capillary opening 221, which is the only means by which liquid can flow from liquid chamber 218 to sonication chamber 219 via the capillary element. In this example, capillary opening 221 is an elongated slot having a width of 0.2 mm to 0.4 mm. The dimensions of capillary opening 221 are such that the edges of capillary opening 221 provide a biasing force acting on the capillary element extending through capillary opening 221 for further control of the flow of liquid into sonication chamber 219.

[0109] In this example, the transducer holder 210 is liquid silicone rubber (LSR). In this example, the liquid silicone rubber has a Shore A hardness of 60. This LSR material ensures that the ultrasonic transducer 215 can vibrate without the transducer holder 210 damping the vibrations. In this example, the vibration displacement of the ultrasonic transducer 215 is 2 to 5 nanometers, and any damping effect could reduce the efficiency of the ultrasonic transducer 215. Therefore, this LSR material and hardness are selected to provide optimal performance with minimal compromise.

[0110] 8 and 9, mist generator device 201 comprises a capillary or capillary element 222 for transporting a liquid (containing a drug, therapeutic agent, or other substance) from liquid chamber 218 to sonication chamber 219. Capillary element 222 is planar or generally planar having a first portion 223 and a second portion 224. In this example, first portion 223 has a rectangular or generally rectangular shape and second portion 224 has a partially circular shape.

[0111] In this example, the capillary element 222 includes a third portion 225 and a fourth portion 226 that are identical in shape to the first portion 223 and the second portion 224, respectively. The capillary element 222 in this example is folded about a fold line 227 so that the first portion 223 and the second portion 224 and the third portion 225 and the fourth portion 226 are superimposed on each other, as shown in Figure 9.

[0112] In this example, the capillary element has a thickness of approximately 0.28 mm. When the capillary element 222 is folded to have two layers, as shown in Figure 9, the overall thickness of the capillary element is approximately 0.56 mm. This double layer also ensures that there is always enough liquid above the ultrasonic transducer 215 for optimal aerosol generation.

[0113] In this example, when the capillary element 222 is folded, the lower ends of the first and third portions 223, 225 define an enlarged lower end 228 that increases the surface area of ​​the capillary element 222 in the portion of the capillary element 222 that is located in the liquid in the liquid chamber 218, thereby maximizing the rate at which the capillary element 222 absorbs liquid.

[0114] In this example, the capillary elements 222 are 100% bamboo fiber. In another example, the capillary elements are at least 75% bamboo fiber. The advantages of using bamboo fiber as the capillary elements have been discussed above.

[0115] 10 and 11, the capillary element 222 is held by the transducer holder 210 such that the transducer holder 210 holds a second portion 224 of the capillary element 222 superimposed on a portion of the atomizing surface of the ultrasonic transducer 215. In this example, the circular second portion 224 is located within the internal recess 214 of the transducer holder 210.

[0116] A first portion 223 of the capillary element 222 extends through a capillary opening 221 in the transducer holder 210 .

[0117] 12-14, the second portion 206 of the mist generator housing 204 receives the transducer holder 210 and includes a generally circular wall 229 that forms part of the wall of the ultrasonic treatment chamber 219.

[0118] Contact openings 230 and 231 are provided in the sidewalls of the second portion 206 for receiving electrical contacts 232 and 233 that form electrical connections with the electrodes of the ultrasound transducer 215 .

[0119] In this example, an absorbent tip or absorbent element 234 is provided adjacent the mist exit port 208 to absorb liquid at the mist exit port 208. In this example, the absorbent element 234 is bamboo fiber.

[0120] 15-17, the first portion 205 of the mist generator housing 204 is similar in shape to the second portion 206 and includes a further generally circular wall portion 235 which forms a further portion of the wall of the ultrasonic treatment chamber 219 and which holds the transducer holder 210.

[0121] In this example, a further absorbent element 236 is provided adjacent the mist outlet port 208 to absorb liquid at the mist outlet port 208 .

[0122] In this example, the first portion 205 of the mist generator housing 204 includes a spring support arrangement 237 that supports the lower end of a retainer spring 238, as shown in FIG.

[0123] The upper end of the retainer spring 238 contacts the second portion 224 of the capillary element 222 such that the retainer spring 238 provides a biasing force that biases the capillary element 222 against the atomizing surface of the ultrasonic transducer 215 .

[0124] Referring to Figure 19, the transducer holder 210 is shown in place and held by the second part 206 of the mist generator housing 204 before the two parts 205, 206 of the mist generator housing 204 are attached to each other.

[0125] 20-23, in this example, the mist generator device 201 includes an identification arrangement 239. The identification arrangement 239 includes a printed circuit board 240 having electrical contacts 241 on one side and an integrated circuit 242 and other optional components 243 on the other side.

[0126] The integrated circuit 242 has a memory that stores a unique identifier for the mist generator device 201. The electrical contacts 241 provide an electronic interface for communication with the integrated circuit 242.

[0127] The printed circuit board 240, in this example, is mounted in a recess 244 on one side of the mist generator housing 204. The integrated circuit 242 and optional other electronic components 243 are located in a further recess 245 so that the printed circuit board 240 is approximately flush with the side of the mist generator housing 204.

[0128] In this example, the integrated circuit 242 is a one-time programmable (OTP) device, an anti-counterfeiting feature that allows only authentic mist generator devices from the manufacturer to be used with the device. This anti-counterfeiting feature is implemented in the mist generator device 201 as a specific custom integrated circuit (IC) that is bonded to the mist generator device 201 (with the printed circuit board 240). The OTP as an IC contains truly unique information that allows full traceability of the mist generator device 201 (and its contents) over its lifetime, as well as accurate monitoring of consumption by the user. The OTP IC allows the mist generator device 201 to function to generate mist only when authorized.

[0129] An example OTP IC implementation of the present disclosure is described in detail below.

[0130] The OTP, as a feature, indicates the authorized state of a particular mist generator device 201. Indeed, to prevent carbonyl release and keep the aerosol to a safe standard, experiments have shown that the mist generator device 201 is considered empty of liquid in the liquid chamber 218 after approximately 1,000 seconds of aerosolization. In this manner, a non-authentic or non-empty mist generator device 201 cannot be activated after this predetermined period of use.

[0131] The OTP feature may be part of a complete chain of operations involving the digital point of sale, the mobile companion application, and the mist generator device 201. Only authentic mist generator devices 201 manufactured by trusted authorities and sold at the digital point of sale may be used with the device. The mobile companion digital app, which is the link between the user's account on the manufacturer's digital platform and the mist generator device 201, ensures safe use of known, safe content for a safe amount of puff duration.

[0132] The OTP feature also enables advanced access control and monitoring, which is required for business-to-business (B2B) use with trusted medical facilities, such as transmedicinal drug administration. The OTP IC is read by the driver device 202, which can recognize the inserted mist generator device 201 and its associated prescription. The driver device 202, along with the mist generator device 201, cannot use the device beyond or outside of the time frame specified by the prescription. Additionally, reminders on a mobile companion app can be provided to minimize missed doses for the user.

[0133] In some examples, the OTP IC is disposable, just like the mist generator device 201. Whenever the mist generator device 201 is considered empty, the mist generator device will not be activated if inserted into the driver device 202. Similarly, a counterfeit generator device 201 will not function in the driver device 202.

[0134] Figures 24-26 show how air flows through the mist generator device 201 during operation.

[0135] Sonication of a liquid therapeutic (medical solution, medical suspension, protein solution, supplement, etc.) converts it into a mist (aerosolization). However, this mist will settle on the ultrasonic transducer 215 unless sufficient ambient air is available to replace the rising aerosol. In the sonication chamber 219, there is a requirement for a continuous supply of air as the mist (aerosol) is generated and drawn to the user through the mouthpiece. To accommodate this requirement, an airflow channel is provided. In this example, the airflow channel is 11.5 mm 2 , which is calculated based on the negative air pressure from the average user and designed into the sonication chamber 219. This also controls the mist-to-air ratio of the inhaled aerosol and thus the amount of medication delivered to the user.

[0136] Based on design requirements, the airflow channel is routed to begin at the bottom of the sonication chamber 219. The opening at the bottom of the aerosol chamber is aligned with and closely adjacent to the opening of the device's airflow bridge. The airflow channel extends vertically upward along the reservoir and continues to the center of the sonication chamber (concentric with the ultrasonic transducer 215). Here, it makes a 90° inward turn. The flow path then continues approximately 1.5 mm from the ultrasonic transducer 215. This path ensures maximized ambient airflow is delivered directly toward the atomizing surface of the ultrasonic transducer 215. Air flows through the channel toward the transducer, collecting the generated mist as it travels through the mouthpiece to the user.

[0137] Air enters the mist generator device 201 through an air inlet port 207 that is in fluid communication with an air flow bridge in the driver device 202, as described below. The air flows along a flow path that changes the direction of the air flow by approximately 90 degrees, directing the air flow toward the ultrasonic transducer 215.

[0138] In some examples, the airflow configuration is configured to redirect the airflow along the airflow path so that the airflow is substantially perpendicular to the atomizing surface of the ultrasonic transducer as it enters the ultrasonic treatment chamber.

[0139] 27-29 of the accompanying drawings, mist generator devices 400 according to some examples of the present disclosure include many of the same elements as the mist generator device 201 described herein. The same reference numerals are used for elements of the mist generator device 400 that are equivalent to the mist generator device 201. Each of the mist generator devices 201, 401 described herein may alternatively be known as a pod or cartridge.

[0140] The mist generator device 400 is configured to be removably attached to the driver device 202 to operate in substantially the same manner as the mist generator device 201 described herein. In other examples, the mist generator device 400 may be fixed to the driver device 202, may be integrally formed with the driver device 202, or may otherwise be non-removably attached to the driver device 202.

[0141] The mist generator device 400 comprises a housing 204 that includes a liquid chamber 218 for containing the liquid to be atomized. The liquid chamber 218 may contain any e-liquid or liquid described in this disclosure, or any other liquid to be atomized.

[0142] The mist generator device 400 includes a mouthpiece 401 coupled to a housing 204. The mouthpiece 401 includes a base 402 having an opening 403 that receives a connector portion 404 of the housing 204. The connector portion 404 includes at least one latching element 405 that engages a latching recess (not shown) to maintain the mouthpiece 401 in connection with the housing 204.

[0143] The mouthpiece 401 narrows progressively from the base 402 to the distal end 406. The distal end 406 includes a mist exit port 208 to allow mist to be output from the mist generator device 400 for inhalation by a user.

[0144] Referring now to Figures 30-32 of the accompanying drawings, a mist generator device 400 comprises an ultrasonic transducer 215. In this example, the ultrasonic transducer 215 is received within an ultrasonic transducer stack 407, which may also be known as an ultrasonic transducer assembly. The ultrasonic transducer stack 407 comprises a generally cylindrical base 408 which defines a generally cylindrical recess 409. A generally cylindrical rim 410 surrounds the open upper end of the generally cylindrical recess 409. The rim 410 presents a surface, in this example a generally planar ring-shaped surface, which contacts and supports the ultrasonic transducer 215.

[0145] 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 is a different elastically deformable plastic.

[0146] In this example, the base 408 includes a divider wall 411 at the bottom of the generally cylindrical recess 409. The divider wall 411 includes a central opening 412.

[0147] 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 coupled to a radial flange 415. An electrical connection 416 is coupled to an upper side of the flange 415 on the opposite side of the flange 415 from 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.

[0148] When the first electrical transducer contact 413 is received within the central opening 412, the flange 415 rests against the divider wall 414 around the periphery of the central opening 412. The electrical connection 416 extends above the height of the rim 410. When the ultrasonic transducer 215 is in contact with the rim 410, the electrical connection 416 contacts the first electrical connection on the underside of the ultrasonic transducer 215 and is biased against the first electrical connection of the transducer 215.

[0149] In this example, the base 408 includes a cutout 417 where a portion of the base 408 below the divider 411 on one side of the base 408 is cut away to allow access to the side of the cylindrical lower portion 414 of the first electrical transducer contact 413.

[0150] The ultrasonic transducer stack 407 includes a generally cylindrical metal shell 418 that at least partially surrounds the base 408 when the ultrasonic transducer stack 407 is assembled. The shell 418 includes a generally cylindrical interior recess 419 with an opening 420 at one end. The ultrasonic transducer 215 includes an atomizing surface 215a disposed in the opening 420 of the shell 418. In this example, the atomizing surface 215a is flat or generally flat. An inwardly directed, generally circular lip 421 surrounds the opening 420. A lower portion of the shell 418 is cut out to correspond to the cutout 417 in the base 408.

[0151] When the ultrasonic transducer stack 407 is assembled, the shell 418 rests over the ultrasonic transducer 215 with the lip 421 contacting at least a portion of the periphery of the ultrasonic transducer 215, holding the ultrasonic transducer 215 in place relative to the base and holding the ultrasonic transducer 215 in contact with the rim 410 of the base 408. The rim 421 electrically connects to a second electrical connection 422 provided around the periphery of the ultrasonic transducer 215. Thus, the shell 418 forms the second electrical transducer contact.

[0152] Similar to the transducer holder 210 described herein, the elastically deformable base 408 ensures that the ultrasonic transducer 215 vibrates without the base 408 damping the vibrations. The height of the base 408 is selected to ensure that the ultrasonic transducer 215 is securely held between the lip 421 of the shell 418 and the rim 410. This minimizes movement of the ultrasonic transducer 215 relative to the electrical connections 416 and the shell 418 that could otherwise disrupt the electrical connection on the ultrasonic transducer 215 and between the electrical connections 416 and the lip 421 of the shell 418. Thus, the ultrasonic transducer stack 407 allows for optimal vibration of the ultrasonic transducer 215 while maintaining a secure electrical connection to the ultrasonic transducer 215.

[0153] As described below, the first elongated device terminal 423 extends through the mist generator device 400 and electrically connects 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 generator device 400 and electrically connects to the shell 418. The first elongated device terminal 423 and the second elongated device terminal 424 receive AC drive signals from the driver device 202 and transmit AC drive signals to the ultrasonic transducer 215.

[0154] The layered configuration of the transducer stack 407 is such that the ultrasonic transducer stack 407 can be easily assembled manually or using automated machinery.

[0155] In this example, the ultrasonic transducer stack 407 is generally cylindrical, but in other examples, the ultrasonic transducer stack 407 may be a different shape, such as rectangular or cuboid.

[0156] Although the ultrasonic transducer stack 407 is described and illustrated herein as being used with the mist generator device 400, it should be understood that the ultrasonic transducer stack 407 may be provided separately and / or integrally for use with any other type of device that includes an ultrasonic transducer. As a result, any device that uses ultrasonic waves can benefit from the secure retention of the ultrasonic transducer and the secure electrical connection to the ultrasonic transducer provided by the ultrasonic transducer stack 407.

[0157] 29 of the accompanying drawings, the mist generator device 400 comprises an ultrasonic processing assembly 425 that receives the ultrasonic transducer stack 407. The ultrasonic processing assembly 425 comprises a first assembly portion 426 that includes a recess 427 that receives and holds the ultrasonic transducer 215 within the ultrasonic transducer stack 407.

[0158] The ultrasonic processing assembly 425 includes a second assembly portion 428 that, when assembled, is coupled to the first assembly portion 426. As described below, the configuration of the first assembly portion 426 and the second assembly portion 428 allows the first assembly portion 426 and the second assembly portion 428 to easily mate together, which facilitates assembly of the mist generator device 400. The parts of the ultrasonic processing assembly 425 can be assembled using automated robots on a manufacturing line with minimal human intervention. Thus, the mist generator device 400 is configured to be mass-produced on a manufacturing line relatively easily and at low cost compared to conventional mist generator devices.

[0159] At least one of the first assembly part 426 and the second assembly part 428 includes an elastically deformable section that forms a seal between the first assembly part 426 and the second assembly part 428. The seal minimizes or prevents fluid leakage between the first assembly part 426 and the second assembly part 428. The elastically deformable configuration of the first assembly part 426 and the second assembly part 428 avoids the need to apply a sealant or adhesive, thereby reducing the complexity and cost of manufacturing the mist generator device 400.

[0160] In this example, both the first assembly part 426 and the second assembly part 428 are made of an elastically deformable material. In another example, only one of the first assembly part 426 and the second assembly part 428 is made of an elastically deformable material.

[0161] In this example, the elastically deformable material is silicone. In another example, the elastically deformable material is a different elastically deformable plastic material.

[0162] 33 and 34 of the accompanying drawings, the first assembly part 426 comprises an end wall 429 spaced from a barrier portion 430. The end wall 429 is provided with a mist outlet opening 431 to allow mist to flow from one side of the top wall 429 to the other. A recess 432 (visible in FIG. 29) is provided on the other side of the end wall 429. An outwardly directed flange 433 extends around the periphery of the end wall 429 and contacts the housing 204.

[0163] The first assembly part 426 includes a central portion of an end wall 429 and a barrier portion 430. The central portion 434 includes a recess 427 that receives the ultrasonic transducer 215. In this example, the central portion 434 is provided with first aligned retainer openings 435, 436. The central portion 434 includes an inlet opening 437 that allows the passage of air from outside the mist generator device 400 within the ultrasonic processing assembly 425.

[0164] The first assembly part 426 holds the ultrasonic transducer 215 in an 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 along the longitudinal length of the housing 204.

[0165] Barrier portion 430 includes a resiliently deformable seal 438, which in this example is a protrusion extending from barrier portion 430 that is disposed between sonication assembly 428 and the interior wall of the interior cavity of housing 204. The barrier portion minimizes or prevents leakage of fluid from liquid chamber 218.

[0166] The barrier portion 430 includes a capillary opening 439. In this example, the capillary opening 439 is centrally located in the barrier portion 430 and is generally in the form of an elongated slot. The capillary opening 439 is formed between adjacent capillary opening walls 440, 441. In this example, both the first capillary opening wall 440 and the second capillary opening wall 441 are elastically deformable, while in other examples, only one of the capillary opening walls 440, 441 is elastically deformable.

[0167] The capillary tube 222 extends from the liquid chamber 218 located in the lower portion of the housing 204 through a capillary opening 439 such that a first portion 442 of the capillary tube 222 is within the liquid chamber 218. The capillary tube 222 is a wicking material, such as bamboo of the type described herein. A second portion 443 of the capillary tube 222 is superimposed on the atomizing surface of the ultrasonic transducer 215.

[0168] 35 and 36 of the accompanying drawings, the second assembly part 428 comprises a body portion 445 which comprises a sonication recess 446. When the sonication assembly 425 is assembled, the sonication recess 446 is superimposed over the ultrasonic transducer 215 to form the sonication chamber 219.

[0169] Body portion 445, in this example, is generally rectangular and includes openings 447, 448 that align with recesses 435, 436, respectively, in first assembly part 426. An ultrasonic treatment recess 446 is formed in the center of a portion of body portion 445.

[0170] Body portion 445 includes a protrusion 449 extending outwardly from body portion 445 adjacent sonication recess 446. Protrusion 449 includes an elongated channel 450. Channel 450 provides an air inlet port that allows air to flow along a flow path through sonication assembly air inlet port 451 and into sonication recess 446 when sonication assembly 425 is assembled.

[0171] Body portion 445 includes a sonication assembly mist outlet port 452 in fluid communication with sonication recess 446. An air flow path extends from the sonication assembly air in port 451 through sonication recess 446 to sonication assembly mist outlet port 452.

[0172] The second assembly part 428 comprises a cover or cover portion 453 that is coupled to the body portion 445 by moving the body portion 445 and cover portion 453 together as generally indicated by arrows 454 and 455 in FIG. 35 .

[0173] The cover portion 453 is generally rectangular with a cover side 456 that contacts the body portion 445. The cover side 456 is provided with generally cylindrical pegs 457, 458 that protrude outward from the cover side 456. The pegs 457, 458 extend through the openings 447, 448 in the body portion 445 and into the recesses 435, 436 in the first assembly portion 426. The pegs 457, 458 form an interference fit with the openings 447, 448 and the recesses 435, 436 to align and connect the first assembly portion 426 and the second assembly portion 428 to one another. The interference fit allows the body portion 445 and the cover portion 453 to be securely coupled to one another without the need for adhesive or other attachment structures. However, in other examples, the pegs 458, 457, the openings 447, 448, and the recesses 435, 436 may be omitted.

[0174] Cover portion 453 is provided with an air inlet channel 459 that fluidly couples to air inlet 450 in body portion 445. In this example, air inlet channel 459 is straight or nearly straight and extends upward from the lower edge of cover portion 453. Air inlet channel 459 undergoes a bend, in this example a 90-degree turn, toward the center of cover portion 453. Air inlet channel 459 fluidly couples with a stepped channel 460 formed in cover portion 453.

[0175] In this example, the stepped channel 460 includes multiple turns, each a 90° turn in this example. In other examples, there may be a greater or lesser number of turns, and the angle of each turn may be oblique. The stepped channel 460 has a first end 416 fluidly coupled to the inlet channel 459 and a second end 462 fluidly coupled to the sonication assembly air inlet port 451. As described below, the stepped channel 460 defines a portion of the air flow path through the device, which can be configured to control the distance that air travels through the mist generator device 400. This configuration can be selected to fine-tune the airflow through the mist generator device 400 and the amount and strength of the draw experienced by a user of the device 400. As a result, the mist generator device 400 may be configured to operate in a mouth-to-lung (MTL) mode. The mist generator device 400 thus mimics a traditional cigarette, improving the experience of the mist generator device 400 for users accustomed to smoking traditional cigarettes.

[0176] The cover portion 453 defines a mist outlet channel 463 spaced from the stepped channel 460. The mist outlet channel 463 has a first end 464 fluidly coupled to the sonication assembly mist outlet port 208 and a second end 465 fluidly coupled to the mist outlet port 452 via the mouthpiece 401.

[0177] In this example, the second assembly part 428 includes three biasing members 466-468 disposed within the sonication recess 446. In other examples, the second assembly part 446 includes only one biasing member. In further examples, the second assembly part 428 includes multiple biasing members. Each biasing member 466-468 exerts a biasing force on the second portion 443 of the capillary tube 222, urging the second portion 443 of the capillary tube 222 against the atomizing surface 215a of the ultrasonic transducer 215. The biasing force exerted by each biasing member 466-468 helps optimize operation of the mist generator device 400 by ensuring intimate contact between the capillary tube 222 and the atomizing surface 215a. As a result, liquid conveyed by the capillary tube 222 is delivered directly onto or adjacent to the atomizing surface 215a for atomization.

[0178] In this example, each biasing member 466-468 is integrally formed with the second assembly portion 428. This simplifies the process for manufacturing the mist generator device 400 compared to conventional devices that require separate biasing components to be installed within the mist generator device in an additional manufacturing step. A further advantage is that each biasing member 466-468 can be precisely positioned on the second assembly portion 428 to ensure that the capillary tube 222 is biased in an optimal position relative to the atomizing surface 215a.

[0179] In this example, each biasing member 466-468 includes a mounting end 466a-468a that is attached to the second assembly portion 428 within the sonication recess 446. Each biasing member 466-468 includes a distal end 466b-468b that contacts the second portion 443 of the capillary tube 222. In this example, each distal end 466b-468b is narrower than the mounting end 466a-468a of each respective biasing member 466-468.

[0180] In this example, each biasing member 466-468 is conical or substantially conical in shape. In other examples, each biasing member 466-468 may be a different shape, with each distal end 466b-468b preferably being narrower than each respective attachment end 466a-468a.

[0181] The narrow distal ends 466a-468a minimize the points of contact between the biasing members 466-468 and the capillary tube 222. This optimizes the operation of the mist generator device 400 by ensuring that the capillary tube 222 is held firmly against the atomizing surface 215a without the biasing members 466-468 damping the vibrations of the ultrasonic transducer 215. Nevertheless, other examples, while not optimal, include biasing members that may have wider distal ends, such as at least one cylindrical biasing member.

[0182] 37 and 38 of the accompanying drawings, once the second assembly part 428 is assembled, it is coupled to the first assembly part 426 by moving the first assembly part 426 and the second assembly part 428 toward each other in the direction generally indicated by arrow 469 in FIG. 37. The body portion 445 of the second assembly part 428 is positioned relative to the central portion 434 of the first assembly part 426. Pegs 457-458 extend into the recesses 435, 436 of the first assembly part 426. The first assembly part 426 and the second assembly part 428 are held together with an interference fit, as shown in FIG. 38. Again, the interference fit simplifies the manufacturing process by avoiding the need to apply an adhesive or sealant, although the present disclosure does not preclude the use of an adhesive or sealant.

[0183] Referring now to Figures 39 and 40 of the accompanying drawings, once the ultrasonic processing assembly 425 is assembled, it is at least partially inserted into the internal cavity of the housing 204 in the direction generally indicated by arrows 470, 471 in Figure 39.

[0184] The ultrasonic processing assembly 425 contacts the sidewall of the housing 204 and forms a seal that minimizes or prevents fluid from flowing between the ultrasonic processing assembly 425 and the sidewall of the housing 204. In this example, the seal is achieved by deformation of the elastic material of the ultrasonic processing assembly 425 against the wall of the housing 204. In this example, because the seal is achieved by deformation of the elastic material, no additional sealant or adhesive is required between the ultrasonic processing assembly 425 and the housing 204. However, the present disclosure does not preclude the use of an adhesive or sealant.

[0185] 41 of the accompanying drawings, a liquid chamber 218 is formed in a portion of the interior cavity of the housing 204 adjacent the base of the housing 204. The liquid chamber 218 is disposed between the sonication assembly 425 and the base of the housing 204. A capillary 222 protrudes into the liquid chamber 214 to allow liquid to be transported by capillary action from the liquid chamber 218 through the capillary 222 for aerosolization by the ultrasonic transducer 215.

[0186] 42 and 43 of the accompanying drawings, a foam layer 472 is inserted into recess 432 of ultrasonic processing assembly 425. Foam layer 472 includes an air flow channel 473 cut into one side of foam layer 472 and angled from one corner of foam layer 472 toward the center of foam layer 472. Foam layer 472 includes a cutout 474. One end of air flow channel 473 in edge foam layer 472 is aligned with mist outlet opening 465 of ultrasonic processing assembly 425. Air flow channel 473 provides a channel for mist to flow from mist outlet opening 465 to the center of device 400. In other examples, air flow channel 473 is omitted, and instead, mist passes through foam layer 472 as it is drawn from mist generator device 400 by a user.

[0187] The foam layer 472 absorbs liquid droplets above a predetermined size in the mist exiting the mist outlet opening 465. The foam layer 472 also absorbs any condensed liquid, helping to minimize leakage of liquid from the mist outlet port 208 of the mist generator device 400. The foam layer 472 optimizes the operation of the mist generator device 400 by minimizing leakage of liquid from the device, although in other examples, the foam layer 472 may be omitted.

[0188] 44 and 45 of the accompanying drawings, sonication assembly 425 includes a fill hole 475 extending from the fill opening through first assembly part 426 to liquid chamber 218 to allow liquid to be injected (e.g., using a needle) into liquid chamber 218 through fill opening 476. Cutout 474 in foam layer 472 is aligned with opening 476 to allow access to opening 476 without having to remove foam layer 472.

[0189] Liquid chamber 218 may alternatively be pre-filled with liquid before sonication assembly 425 is inserted into the recess of housing 204. In this case, fill hole 475 and fill opening 476 allow air to be evacuated when sonication assembly 425 is inserted into the recess of housing 204.

[0190] In other examples, fill hole 475 and fill opening 476 may be omitted.

[0191] 46 of the accompanying drawings, when the ultrasonic processing assembly 425 is inserted into the recess of the housing 204, a first portion 442 of the capillary tube 222 is disposed within the liquid chamber 218. The capillary tube 222 extends from the first portion 442 through the capillary opening 439 such that a second end 443 of the capillary tube 222 is superimposed on the ultrasonic transducer 215. Biasing members 466-468 bias the capillary tube 222 against the atomizing surface 215a of the ultrasonic transducer 215.

[0192] 47 and 48 of the accompanying drawings, when ultrasonic processing assembly 425 is inserted into the recess of housing 204 and foam layer 472 is inserted into recess 32 of ultrasonic processing assembly 425, divider 477 is superimposed on foam layer 472. In this example, divider 477 is generally planar and made of a resiliently deformable material such as silicone. Divider 477 includes a central opening 478 surrounded by an upwardly projecting cylindrical wall 479.

[0193] On the opposite side of the divider 477 from the cylindrical wall 479 is an elongated, generally cylindrical plug 480. The plug 480 fits at least partially within the opening 476 to seal the opening 476 and prevent liquid from leaking from the liquid chamber 418 through the fill hole 475.

[0194] Because the divider 477 is elastically deformable, the divider 477 forms a seal around the upper periphery of the ultrasonic treatment assembly 475 to minimize or prevent liquid from leaking between the divider 477 and the ultrasonic treatment assembly 425.

[0195] The mist generator device 400 minimizes or eliminates the possibility of liquid leaking from within the mist generator device 400, which is important for consistency of dose delivery. A leaking device may have less liquid (containing a therapeutic agent, drug, etc.) in the liquid chamber 218 than would be prescribed for the treatment of the condition.

[0196] 49 and 50 of the accompanying drawings, mouthpiece 401 is attached to housing 204 such that, when divider 477 is in place, it substantially closes the interior cavity of housing 204. Mouthpiece 401 comprises an inner tube 481. One end of inner tube 481 is fluidly coupled to central opening 478 of divider 477 and the other end of inner tube 481 is fluidly coupled to mist outlet opening 208. Mouthpiece 401 provides a mist flow path from sonication assembly 425 to mist outlet opening 208.

[0197] 51 and 52 of the accompanying drawings, the first elongated device terminal 423 and the second elongated device terminal 424 are inserted through respective terminal openings 482, 483 in the base of the housing 204. The first elongated device terminal 423 extends through the mist generator device 400 and electrically connects to the first electrical transducer contact 413. The second elongated device terminal 424 extends through a portion of the mist generator device 400 and electrically connects to the shell 418. The configuration of the ultrasonic transducer stack 407 and the elastically deformable material of the ultrasonic processing assembly 425 ensure that liquid cannot seep between the shell 418 and the ultrasonic processing assembly 425. Thus, the first elongated device terminal 423 and the second elongated device terminal 424 are isolated from liquid within the mist generator device 400, which could interfere with the AC drive signal supplied to the ultrasonic transducer 215 and cause the mist generator device 400 to malfunction.

[0198] The first elongated device terminal 423 and the second elongated device terminal 424 provide electrical connections from the ends of the elongated device terminals 423, 424 accessible at the base of the housing 204 to terminals of the ultrasonic transducer 215. Thus, an AC drive signal generated by the driver device 202 can be transmitted to the ultrasonic transducer 215 via the elongated device terminals 423, 424.

[0199] 51 and 52 also show an air inlet opening 207 at the base of the housing 204. The air inlet opening 207 is fluidly coupled to an air channel 484 that extends through the mist generator device 400 to the ultrasonic processing assembly air inlet port 451. As mentioned above, air enters the mist generator device 400 through the air inlet port 207, which is in fluid communication with an air flow bridge in the driver device 202, as described below.

[0200] 53 and 54 of the accompanying drawings, mist generator device 400 includes an end cap 485 that attaches to the lower end of housing 204. End cap 485 includes four walls that define a recess 490 that receives the end of housing 204. Opposing side walls 487, 489 each include a respective retainer slot 491, 492. Each retainer slot 491, 491 receives a respective outwardly facing chamfer 493 (only one of which is visible in FIGS. 53 and 54). Each chamfer 493 retains end cap 485 attached to housing 204.

[0201] The end cap 485 includes two inwardly directed tabs 494, 495 at the base of the end cap 485. The tabs 494, 495 overlap respective ends of the printed circuit board 240 when the end cap 485 is attached to the housing 204. The printed circuit board 240 carries the OTP IC 242. The tabs 494, 495 hold the printed circuit board 240 in place within the recess 244 on the housing 204.

[0202] End cap 484 includes openings 496 to allow access to electrical contacts 241 on printed circuit board 240 and to elongated device terminals 423, 424. Openings 496 also allow air to enter air inlet opening 207 on housing 204.

[0203] In this example, the end caps 485 are metal, and the ends 485 allow the mist generator device 400 to be held within the recess 203 of the driver device 202 by magnetic force via attraction to a magnet provided in the driver device 202. However, in other examples, the end caps 485 may be a different material or may be omitted entirely.

[0204] 56-59 of the accompanying drawings, when the mist generator device 400 is in use and connected to the driver device 202, there is an air flow path from the air inlet port 207 at the base of the mist generator device 400, through the mist generator device 400 to the mist outlet port 208. Air flows through the air inlet port 207, through the air channel 484, through the elongated channel 450 and into the sonication assembly air inlet port 451.

[0205] As shown in FIG. 57, air flow path 497 includes multiple turns as air flows from air inlet channel 459, through stepped channel 460, and into sonication assembly air inlet 451. The air then enters the sonication chamber via sonication assembly air inlet port 451, as shown in FIG. 58. The air is directed into capillary tube 222 and flows along a portion of the length of capillary tube 222 as the air flows through sonication chamber 219. This optimizes the operation of mist generator device 400 by ensuring that the air flow is directed against a portion of capillary tube 222.

[0206] The ultrasonic transducer 215 vibrates within the sonication chamber 219, atomizing and aerosolizing the liquid from the capillary tube 222. This creates a mist within the sonication chamber 219, which is withdrawn from the sonication chamber 219 via the sonication assembly mist outlet port 452. Operation of the mist generator device 400 is optimized by ensuring that all or substantially all of the generated mist is exhausted from the sonication chamber 219 as the air flow path travels along a portion of the length of the capillary tube 222 before being withdrawn from the sonication chamber 219.

[0207] The mist flows from the mist exit opening 465 through airflow channels 473 in the foam layer 472 to the central opening 478 of the divider 477. The mist then passes through the inner tube 481 of the mouthpiece 401 to the mist exit port 208 for inhalation by the user.

[0208] The driver device 202 will now be described initially with reference to Figures 60 and 61. The driver device 202 comprises a driver device housing 246 that is at least partially metal. In some examples, the driver device housing 246 is made entirely of aluminum (AL6063 T6), which protects the internal components from the environment (dust, water splashes, etc.) and from damage due to impacts (such as accidental drops).

[0209] In some examples, the driver device housing 246 has vents on its sides that allow ambient air to enter the device for two purposes: one is to have ventilation around the electronic components and keep them within operating temperatures; these vents also function as air inlets, with air entering the device through these vents and then through the air flow bridge into the mist generator device 201.

[0210] The driver device housing 246 is elongated with an interior chamber 247 that houses the components of the driver device 202. One end of the driver device housing 246 is closed by an end cap 248. The other end of the driver device housing 247 has an opening 249 that provides an opening for the recess 203 of the driver device 202.

[0211] The driver device 202 includes a battery 250 connected to a printed circuit board 251. In some examples, the battery 250 is a 3.7V DC Li-Po battery with a capacity of 1140mAh and a discharge rate of 10C. The high discharge rate is required for the maximum 15V voltage amplification required by the ultrasonic transducer 215 for desired operation. The shape and size of the battery are designed according to the shape and size of the device and the space allotted for the power supply, within physical constraints.

[0212] Printed circuit board 251 incorporates a processor, memory, and other electronic components for implementing the electrical functions of driver device 202. Charging pins 258 are provided on one end of printed circuit board 251 and extend through end cap 248 to provide a charging connection for charging battery 250.

[0213] The printed circuit board 251 is held within the driver device housing 246 by a skeleton 252. The skeleton 252 has a channel 253 that receives the printed circuit board 251. The skeleton 252 incorporates raised sides 254, 255 that support the battery 250.

[0214] In some examples, the skeleton 252 is manufactured using an industrial injection molding process. The molded plastic skeleton ensures that all parts are fixed and do not fit loosely inside the case. It also forms a cover that covers the front of the PCB (printed circuit board) that receives the mist generator device 201 when the mist generator device 201 is inserted into the driver device 202.

[0215] The driver device 202 includes an airflow sensor that functions as a switch to activate and power the transducer for sonication and aerosol generation. The airflow sensor is mounted on a PCB within the device and requires a specific air pressure drop around it to activate the driver device 202. To this end, an airflow bridge 259, as shown in FIGS. 64-66, is designed with internal channels 260, 261 that direct air from the surroundings through the airflow bridge 259 and into the aerosol chamber 262. The skeleton 252 includes opposing channels 256, 257 for receiving portions of the airflow bridge 259, as shown in FIG. 67.

[0216] The interior channel of airflow bridge 259 has a microchannel 263 (0.5 mm diameter) that extends downward into chamber 264, which completely covers the airflow sensor. When air flows upward from the side inlet into aerosol chamber 262, a negative pressure is created within microchannel 263, which triggers the airflow sensor and activates the device.

[0217] The device is a small, portable, and highly advanced device that allows for accurate, safe, and monitored aerosolization by incorporating high-quality electronic components designed with IPC Class 3 – Medical Grade – in mind.

[0218] The electronics of the driver device 202 are divided as follows:

[0219] 1. Ultrasonic processing unit To obtain the most efficient aerosolization to date for inhalation in a handheld device with particle sizes less than 1 μm, the ultrasonic processor must provide a high adaptive frequency (approximately 3 MHz) to the contact pad that receives the ultrasonic transducer 215 (piezoceramic disk (PZT)).

[0220] This part must not only provide high frequency, but also protect the ultrasonic transducer 215 from failure while providing constant, optimized cavitation.

[0221] The mechanical deformation of the PZT is related to the AC voltage amplitude applied to it, and maximum deformation must always be supplied to the PZT to ensure optimal functioning of the system and delivery of each sonication treatment.

[0222] However, to prevent PZT failure, the active power delivered to the PZT must be precisely controlled.

[0223] This can only be achieved by designing a custom power management integrated circuit (PMIC) chip that does not exist on the market, which is mounted on the printed circuit board of the driver device 202. This PMIC allows modulation of the effective power applied to the PZT at any instant without compromising the mechanical amplitude of the PZT's vibration.

[0224] By pulse width modulation (PWM) of the AC voltage applied to the PZT, the mechanical amplitude of the vibration remains the same.

[0225] The only "off-the-shelf" option available was to modify the output AC voltage via the use of a digital-to-analog converter (DAC). While the energy transferred to the PZT is reduced, the mechanical deformation is also reduced, resulting in its complete degradation and preventing proper aerosolization. In fact, the applied RMS voltage is the same in the effective duty cycle modulation as in the voltage modulation case, but the effective power transferred to the PZT is reduced. In fact, the following equation is given: Active power displayed on PZT

[0226]

number

[0227] During the ceremony, φ is the phase shift between the current and voltage I rms is the root mean square current, V rms is the root mean square voltage.

[0228] When considering the first harmonic, Irms is a function of the actual voltage amplitude applied to the transducer, since pulse width modulation changes the duration of the voltage supplied to the transducer and controls Irms.

[0229] The specific design of the PMIC uses state-of-the-art design and allows ultra-precise control of the frequency range and steps applied to the PZT, including a complete set of feedback loops and monitoring paths for the control section used.

[0230] The remainder of the aerosolization section consists of a DC / DC boost converter and transformer that delivers the necessary power from a 3.7 V battery to the PZT contact pads.

[0231] Referring now to Figure 68 of the accompanying drawings, the driver device 202 comprises an ultrasonic transducer driver microchip, herein referred to as a power management integrated circuit or PMIC 300. The PMIC 300 is a microchip for driving a resonant circuit, which may be an inductance (L) capacitance (C) circuit (LC tank), an antenna, or in this case a piezo transducer (ultrasonic transducer 215).

[0232] In this disclosure, the terms chip, microchip, and integrated circuit are interchangeable. A microchip or integrated circuit is a single unit that comprises multiple interconnected embedded components and subsystems. A microchip is, for example, at least partially a semiconductor, such as silicon, and is fabricated using semiconductor fabrication techniques.

[0233] The driver device 202 also includes a second microchip, referred to herein as a bridge integrated circuit or bridge IC 301, electrically connected to the PMIC 300. The bridge IC 301 is a microchip for driving a resonant circuit such as an LC tank, an antenna, or a piezo transducer. The bridge IC 301 is a single unit that includes multiple interconnected embedded components and subsystems.

[0234] In this example, the PMIC 300 and the bridge IC 301 are mounted on the same PCB of the driver device 202. In this example, the physical dimensions of the PMIC 300 are 1-3 mm wide and 1-3 mm long, and the physical dimensions of the bridge IC 301 are 1-3 mm wide and 1-3 mm long.

[0235] The mist generator device 201 includes an optional programmable or one-time programmable integrated circuit or OTP IC 242. When the mist generator device 201 is coupled to the driver device 202, the OTP IC 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 OTP IC 242. The OTP IC 242 is also connected to a communication bus 302 within the driver device 202. In this example, the communication bus 302 is an I2C bus, although in other examples, the communication bus 302 is another type of digital serial communication bus.

[0236] The ultrasonic transducer 215 in the mist generator device 201 is electrically connected to the bridge IC 301 so that the ultrasonic transducer 215 can be driven by an AC drive signal generated by the bridge IC 301 when the device 200 is in use.

[0237] The driver device 202 comprises a processor in the form of a microcontroller 303 electrically coupled for communication with a communication bus 302. In this example, the microcontroller 303 is a Bluetooth® Low Energy (BLE) microcontroller. The microcontroller 303 receives power from a low dropout regulator (LDO) 304 that is powered by the battery 250. The LDO 304 provides a stable, regulated voltage to the microcontroller 303, allowing the microcontroller 303 to operate consistently despite fluctuations in the voltage of the battery 250.

[0238] Driver device 202 includes a voltage regulator in the form of a DC-DC boost converter 305 powered by battery 250. Boost converter 305 boosts the voltage of battery 250 to a programmable voltage VBOOST. The programmable voltage VBOOST is set by boost converter 305 in response to a voltage control signal VCTL from PMIC 300. As will be explained in more detail below, boost converter 305 outputs voltage VBOOST to bridge IC 301. In another example, the voltage regulator is a buck converter or another type of voltage regulator that outputs a selectable voltage.

[0239] The voltage control signal VCTL is generated by a digital-to-analog converter (DAC) that is implemented in this example within the PMIC 300. Because the DAC is integrated within the PMIC 300, the DAC is not visible in Figure 68. The DAC and the technical benefits of integrating the DAC within the PMIC 300 are described in detail below.

[0240] In this example, the PMIC 300 is connected to a power connector in the form of a Universal Serial Bus (USB) connector 306 such that the PMIC 300 can receive a charging voltage VCHRG when the USB connector 306 is coupled to a USB charger.

[0241] The driver device 202 includes a first pressure sensor 307, which in this example is a static pressure sensor. The driver device 202 also includes a second pressure sensor 308, which in this example is a dynamic pressure sensor. However, in other examples, the driver device 202 includes only one of the two pressure sensors 307, 308. As mentioned above, the pressure sensors 307, 308 sense changes in pressure in the aerosol chamber 262 to detect when the user is inhaling on the mist inhaler device 200.

[0242] In this example, the driver device 202 includes a plurality of LEDs 321 - 326 controlled by the PMIC 300 .

[0243] The microcontroller 303 acts as the master device on the communication bus 302, with the PMIC 300 being the first slave device, the OTP IC 242 being the second slave device, the second pressure sensor 308 being the third slave device, and the first pressure sensor 307 being the fourth slave device. The communication bus 302 allows the microcontroller 303 to control the following functions in the driver device 202: 1. All functions of the PMIC are highly configurable by the microcontroller 303. 2. The current flowing through the ultrasonic transducer 215 is sensed at a high common-mode voltage (the high side of the bridge) by a high-bandwidth sensing and rectifying circuit. The sensed current is converted to a voltage proportional to the rms current and provided as a buffered voltage at the current sense output pin 309 of the bridge IC 301. This voltage is provided to the PMIC 300 where it is sampled and made available as a digital representation via an I2C request. Sensing the current flowing through the ultrasonic transducer 215 forms part of the resonant frequency tracking function. As described herein, the device's ability to enable this function within the bridge IC 301 provides a significant technical advantage. 3. A DAC (not shown in FIG. 68) integrated within the PMIC 300 allows the DC-DC boost converter voltage VBOOST to be programmed to be between 10V and 20V. 4. The microcontroller 303 enables the charger subsystem of the driver device 202 to manage the charging of the battery 250, which in this example is a single cell battery. 5. A light emitting diode (LED) driver module (not shown) is powered by PMIC 300 to digitally drive and dim LEDs 321-326 in either linear or gamma corrected mode. 6. Microcontroller 303 can read the Pressure #1 and Pressure #2 sensor values ​​from pressure sensors 307, 308.

[0244] 69 of the accompanying drawings, PMIC 300, in this example, is a self-contained chip or integrated circuit that includes an integrated subsystem and a number of pins that provide electrical inputs and outputs to PMIC 300. References to integrated circuits or chips in this disclosure are interchangeable, and either term encompasses semiconductor devices that may be made of, for example, silicon.

[0245] The PMIC 300 comprises an analog core 310 that comprises analog components including a reference block (BG) 311 , an LDO 312 , a current sensor 313 , a temperature sensor 314 , and an oscillator 315 .

[0246] As described in more detail below, oscillator 315 is coupled to a delay-locked loop (DLL) that outputs pulse-width modulation (PWM) phases A and B. Oscillator 315 and the DLL generate a two-phase center-aligned PWM output that drives an H-bridge within bridge IC 301.

[0247] The DLL comprises multiple delay lines connected end-to-end, with the total delay of the delay lines equal to the period of the main clock signal clk_m. In this example, the DLL is implemented in a digital processor subsystem, referred to herein as digital core 316, of PMIC 300, which receives a clock signal from oscillator 315 and a regulated power supply voltage from LDO 312. The DLL is implemented in a large number (e.g., on the order of millions) of delay gates connected end-to-end in digital core 316.

[0248] The implementation of the oscillator 315 and DLL within the same integrated circuit of the PMIC 300 to generate a two-phase center-aligned PWM signal is unique as there are currently no signal generator components on the integrated circuit market that include this implementation.

[0249] As described herein, PWM is part of the functionality that allows the driver device 202 to accurately track the resonant frequency of the ultrasonic transducer 215 to maintain efficient transfer of electrical energy to kinetic energy to optimize mist production.

[0250] In this example, the PMIC 300 includes a charger circuit 317 that controls the charging of the battery 250 with power from, for example, a USB power source.

[0251] The PMIC 300 includes an integrated power switch VSYS that configures the PMIC 300 to power the analog core 310 with power from the battery 250 or, if the battery 250 is being charged, with power from an external power source.

[0252] The PMIC 300 includes an embedded analog-to-digital converter (ADC) subsystem 318. Implementing the ADC 318 along with the oscillator 315 within the same integrated circuit is unique in itself, as there are no other integrated circuits on the integrated circuit market that include an oscillator and an ADC implemented as sub-blocks within the integrated circuit. In conventional devices, the ADC is typically provided as a separate component from the oscillator, and the separate ADC and oscillator are mounted on the same PCB. A problem with this conventional configuration is that the two separate components, the ADC and the oscillator, unnecessarily occupy space on the PCB. A further problem is that conventional ADCs and oscillators are typically connected to each other by a serial data communication bus, such as an I2C bus, which has a limited communication speed of only up to 400 kHz. In contrast to conventional devices, the PMIC 300 has the ADC 318 and oscillator 315 integrated within the same integrated circuit, which eliminates any delay in communication between the ADC 318 and oscillator 315, meaning that the ADC 318 and oscillator 315 can communicate with each other at high speeds, such as the speed of the oscillator 315 (e.g., 3 MHz to 5 MHz).

[0253] In this example PMIC 300, oscillator 315 operates at 5 MHz and generates a 5 MHz clock signal, SYS CLOCK. However, in other examples, oscillator 315 generates a clock signal at a much higher frequency, up to 105 MHz. All of the integrated circuits described herein are configured to operate at the high frequency of oscillator 315.

[0254] The ADC 318 includes multiple feedback input terminals or analog inputs 319 that include multiple GPIO inputs (IF_GPIO1-3). At least one of the feedback input terminals or analog inputs 319 receives a feedback signal from the H-bridge circuit within the bridge IC 301, the feedback signal being indicative of a parameter of the operation of the H-bridge circuit or AC drive signal when the H-bridge circuit is driving a resonant circuit, such as the ultrasonic transducer 215, with the AC drive signal. As described below, the GPIO inputs are used to receive a current sense signal from the bridge IC 301 that is indicative of 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 within the bridge IC 301.

[0255] The ADC subsystem 318 samples the analog signals received at a plurality of ADC input terminals 319 at a sampling frequency proportional to the frequency of the main clock signal. The ADC subsystem 318 then uses the sampled analog signals to generate ADC digital signals.

[0256] In this example, the ADC 318 integrated into the PMIC 300 samples not only the RMS current flowing through the H-bridge 334 and the ultrasonic transducer 215, but also the voltages available in the system (e.g., VBAT, VCHRG, VBOOST), the temperature of the PMIC 300, the temperature of the battery 250, and GPIO inputs (IF_GPIO 1-3) to allow for future expansion.

[0257] The digital core 316 receives the ADC-generated digital signal from the ADC subsystem and processes the ADC digital signal to generate the driver control signal, which the digital core 316 communicates to the PWM signal generator subsystem (DLL 332) to control the PWM signal generator subsystem.

[0258] Rectification circuits on the market today have very limited bandwidth (typically less than 1 MHz). Because the oscillator 315 of the PMIC 300 operates at a maximum of 5 MHz or even 105 MHz, a high-bandwidth rectification circuit is implemented within the PMIC 300. As described below, sensing the RMS current within the H-bridge of the bridge IC 301 forms part of a feedback loop that enables the driver device 202 to drive the ultrasonic transducer 215 with high accuracy. The feedback loop is a game-changer in the ultrasonic transducer driving industry because it accounts for any process variations in piezo transducer manufacturing (variations in resonant frequency) and compensates for temperature effects on the resonant frequency. This is achieved, in part, by implementing the present invention, which integrates the ADC 318, oscillator 315, and DLL within the same integrated circuit of the PMIC 300. The integration allows these subsystems to communicate with each other at high speeds (e.g., clock frequencies up to 5 MHz or 105 MHz). Reducing the latency between these subsystems is a game-changer in the ultrasonic industry, particularly in the field of mist generator devices.

[0259] The ADC 318 has a battery voltage monitoring input VBAT and a charger input voltage monitoring input VCHG, as well as voltage monitoring inputs VMON and VRTH, and a temperature monitoring input TEMP.

[0260] The temperature monitoring input TEMP receives a temperature signal from a temperature sensor 314 embedded within the PMIC 300. This allows the PMIC 300 to accurately sense the actual temperature within the PMIC 300, so that the PMIC 300 can detect any faults within the PMIC 300, as well as faults to other components on the printed circuit board that affect the temperature of the PMIC 300. The PMIC 300 can then control the bridge IC 301 to prevent excitation of the ultrasonic transducer 215 in the event of a malfunction, in order to maintain the safety of the mist inhaler device 200.

[0261] An additional temperature sensor input VRTH receives a temperature sensing signal from an external temperature sensor within the driver device 202 that monitors the temperature of the battery 250. Thus, the PMIC 300 can react to stop the battery 250 from charging or otherwise shut down the driver device 202 in the event of a high battery temperature to reduce the risk of damage caused by an excessively high battery temperature.

[0262] The PMIC 300, in this example, includes an LED driver 320 that receives digital drive signals from the digital core 316 and provides LED drive output signals to six LEDs 321-326 that are configured to be coupled to output pins of the PMIC 300. Thus, the LED driver 320 can drive and dim the LEDs 321-326 on up to six independent channels.

[0263] The PMIC 300 includes a first digital-to-analog converter (DAC) 327 that converts digital signals within the PMIC 300 into an analog voltage control signal that is output from the PMIC 300 via output pin VDAC0. The first DAC 327 converts the digital control signal generated by the digital core 316 into an analog voltage control signal that is output via output pin VDAC0 to control a voltage regulator circuit, such as boost converter 305. Thus, the voltage control signal controls the voltage regulator circuit to generate a predetermined voltage for modulation by an H-bridge circuit to drive a resonant circuit, such as the ultrasonic transducer 215, in response to a feedback signal indicative of the operation of the resonant circuit (ultrasonic transducer 215).

[0264] In this example, the PMIC 300 includes a second DAC 328 that converts the digital signal within the PMIC 300 to an analog signal that is output from the PMIC 300 via a second analog output pin VDAC1.

[0265] Embedding the DACs 327 and 328 on the same microchip as other subsystems of the PMIC 300 allows the DACs 327 and 328 to communicate with the digital core 316 and other components within the PMIC 300 at high speeds with minimal or no communication delays. The DACs 327 and 328 provide analog outputs that control external feedback loops. For example, the first DAC 327 provides a control signal VCTL to the boost converter 305 to control its operation. In another example, the DACs 327 and 328 are configured to provide a drive signal to a DC-DC buck converter instead of or in addition to the boost converter 305. Integrating two independent DAC channels into the PMIC 300 allows the PMIC 300 to operate the feedback loop of any regulator used in the driver device 202, allowing the driver device 202 to adjust the ultrasonic processing power of the ultrasonic transducer 215 or to set analog thresholds for the absolute maximum current and temperature settings of the ultrasonic transducer 215.

[0266] The PMIC 300 includes a serial communication interface, which in this example is an I2C interface incorporating an external I2C address that is set via pins.

[0267] The PMIC 300 also includes various functional blocks, including a functionally similar to a digital machine (FSM), for implementing the functionality of the microchip, which are described in more detail below.

[0268] 70 of the accompanying drawings, a pulse width modulation (PWM) signal generator subsystem 329 is embedded within the PMIC 300. The PWM generator system 329 comprises 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-matched PWM generator.

[0269] Frequency divider 330 , multiplexer 331 , and DLL 332 are implemented in digital logic components (eg, transistors, logic gates, etc.) within digital core 316 .

[0270] In the example of the present disclosure, the frequency range covered by oscillator 315 and PWM generator system 329, respectively, is 50 kHz to 5 MHz or up to 105 MHz. The frequency accuracy of PWM generator system 329 is ±1% and the spread over temperature is ±1%. There are no ICs on the IC market today that have an embedded oscillator and a two-phase center-matched PWM generator that can provide a frequency range from 50 kHz to 5 MHz or 105 MHz.

[0271] Oscillator 315 generates a main clock signal (clk_m) having a frequency ranging from 50 kHz to 5 MHz or up to 105 MHz. Main clock clk_m is input to frequency divider 330, which divides the frequency of main clock clk_m by one or more predetermined divisor amounts. In this example, frequency divider 330 divides the frequency of main clock clk_m by 2, 4, 8, and 16 and provides the divided frequency clocks as outputs to multiplexer 331. Multiplexer 331 multiplexes the divided frequency clocks and provides the divided frequency output to DLL 332. This signal passed to DLL 332 is a frequency reference signal that controls DLL 332 to output a signal at the desired frequency. In other examples, frequency divider 330 and multiplexer 331 are omitted.

[0272] The oscillator 315 also generates two phases, a first phase clock signal Phase 1 and a second phase clock signal Phase 2. The phases of the first phase clock signal and the second phase clock signal are center aligned. As shown in FIG. The first phase clock signal, phase 1, is high for a variable amount of time during the positive half-period of clk_m and low during the negative half-period of clk_m. The second phase clock signal phase 2 is high for a variable amount of time during the negative half-period of clk_m and low during the positive half-period of clk_m.

[0273] Phase 1 and Phase 2 are then sent to DLL 332, which uses first phase clock signal Phase 1 and second phase clock signal Phase 2 to generate a double frequency clock signal. The double frequency clock signal is twice the frequency of the main clock signal clk_m. In this example, an "OR" gate within DLL 332 uses first phase clock signal Phase 1 and second phase clock signal Phase 2 to generate the double frequency clock signal. This double frequency clock, or divided frequency coming from frequency divider 330, is selected based on the selected target frequency and is then used as a reference for DLL 332.

[0274] In DLL 332, the signal hereafter referred to as "clock" represents the doubled main clock clk_m, and the signal hereafter referred to as "clock_del" is a replica of clock delayed by one period of frequency. Clock and clock_del pass through a phase frequency detector. Node Vc is then charged or discharged by a charge pump based on the phase error polarity. A control voltage is directly supplied to control the delay of every single delay unit in DLL 332 until the total delay of DLL 332 is exactly one period.

[0275] The DLL 332 controls the first phase clock signal, Phase 1, and the second phase clock signal, Phase 2, so that the rising edges of these signals are synchronized with the rising edges of the double frequency clock signal. The DLL 332 adjusts the frequency and duty cycle of the first phase clock signal, Phase 1, and the second phase clock signal, Phase 2, in response to the respective frequency reference signal and duty cycle control signal to generate the first phase output signal, Phase A, and the second phase output signal, Phase B, which drive an H-bridge or inverter to generate an AC drive signal for driving the ultrasonic transducer.

[0276] The PMIC 300 includes a first phase output signal terminal Phase_A that outputs a first phase output signal Phase A to the H-bridge circuit, and a second phase output signal terminal Phase_B that outputs a second phase output signal Phase B to the H-bridge circuit.

[0277] In this example, DLL 332 adjusts the duty cycle of first phase clock signal Phase 1 and second phase clock signal Phase 2 in response to the duty cycle control signal by varying the delay of each delay line within DLL 332 in response to the duty cycle control signal.

[0278] The clock is used at twice its frequency to ensure better accuracy. As shown in FIG. 72, for illustration purposes, if the frequency of the main clock clk_m is used (not used in the examples of this disclosure), phase A is synchronized with the rising edge R of the clock, and phase B is synchronized with the falling edge F of the clock. Because the delay line of DLL 332 controls the rising edge R, for the falling edge F, PWM generator system 329 must rely on perfect matching of the delay units of DLL 332, which may be imperfect. However, to eliminate this error, PWM generator system 329 uses a double-frequency clock such that both phase A and phase B are synchronized with the rising edge R of the double-frequency clock.

[0279] To implement a duty cycle from 20% to 50% with a 2% step size, the delay line of DLL 332 includes 25 delay units, with the output of each respective delay unit representing a phase n. Ultimately, the phase of the output of the last delay unit corresponds to the input clock. Considering that all delays are approximately the same, a particular duty cycle can be obtained using the output of a particular delay unit with simple logic in digital core 316.

[0280] It is important to handle the start-up of DLL 332 because DLL 332 can lock onto two or more periods rather than one delay period, potentially putting DLL 332 in a non-convergence zone. To avoid this problem, a start-up circuit is implemented in PWM generator system 329 that allows DLL 332 to start from a known deterministic condition. The start-up circuit also allows DLL 332 to start with a minimum delay.

[0281] In the example of the present disclosure, the frequency range covered by PWM generator system 329 is extended, and therefore the delay unit in DLL 332 can provide delays from 4 ns (for a 5 MHz oscillator frequency) to 400 ns (for a 50 kHz oscillator frequency). To accommodate these different delays, capacitors Cb are included in PWM generator system 329, with the capacitor values ​​selected to provide the required delays.

[0282] Phase A and Phase B are output from DLL 332 and passed to bridge IC 301 via digital IO so that Phase A and Phase B can be used to control the operation of bridge IC 301.

[0283] The battery charging functionality of driver device 202 will now be described in more detail. The battery charging subsystem comprises a charger circuit 317 embedded in PMIC 300 and controlled by a digital charge controller hosted in PMIC 300. Charger circuit 317 is controlled by microcontroller 303 via communication bus 302. The battery charging subsystem is capable of charging single cell lithium polymer (LiPo) or lithium ion (Li-ion) batteries, such as battery 250 described above.

[0284] In this example, the battery charging subsystem can charge one or more batteries from a 5V power supply (e.g., a USB power supply) with a charging current of up to 1 A. To adapt the charging parameters of the batteries, one or more of the following parameters can be programmed via the communication bus 302 (I2C interface): The charging voltage can be set between 3.9V and 4.3V in 100mV increments. The charging current can be set between 150mA and 1000mA in 50mA increments. The pre-charge current is 1 / 10 of the charge current. Precharge and fast charge timeouts can be set between 5 and 85 minutes at 20 and 340 minutes respectively. Optionally, an external negative temperature coefficient (NTC) thermistor can be used to monitor battery temperature.

[0285] In some examples, the battery charging subsystem reports one or more of the following events by generating an interrupt to the host microcontroller 303: Battery is detected The battery is charged The battery is fully charged No battery present Charging timeout reached Charging supply is below the undervoltage limit

[0286] A major advantage of having the charger circuit 317 embedded in the PMIC 300 is that it allows all of the enumerated programming options and event instructions to be implemented within the PMIC 300, ensuring safe operation of the battery charging subsystem. Furthermore, significant manufacturing cost and PCB space savings can be achieved compared to conventional mist inhaler devices with individual components of the charging system mounted separately on the PCB. The charger circuit 317 also allows for highly versatile settings of charging current and voltage, different fault timeouts, and multiple event flags for detailed condition analysis.

[0287] We now describe in more detail the analog-to-digital converter (ADC) 318. The inventors had to overcome significant technical challenges to integrate the ADC 318 with the high-speed oscillator 315 within the PMIC 300. Furthermore, integrating the ADC 318 within the PMIC 300 runs counter to conventional approaches in the art, which rely on using one of the many separate ADC devices available on the IC market.

[0288] In this example, ADC 318 samples at least one parameter within the ultrasound transducer driver chip (PMIC 300) at a sampling rate equal to the frequency of the main clock signal clk_m. In this example, ADC 318 is a 10-bit analog-to-digital converter that can offload digital sampling from microprocessor 303 to conserve microprocessor 303 resources. Integrating ADC 318 within PMIC 300 also avoids the need to use an I2C bus, which would otherwise slow down the ADC's sampling capability (traditional devices rely on an I2C bus to communicate data between a dedicated, separate ADC and a microcontroller, typically at a limited clock speed of up to 400 kHz).

[0289] In the example of the present disclosure, one or more of the following parameters may be sampled sequentially by the ADC 318: i. The rms current signal received at the ultrasonic transducer driver chip (PMIC 300) from the external inverter circuit driving the ultrasonic transducer. In this example, this parameter is the root-mean-square (rms) current reported by the bridge IC 301. Sensing the rms current is important for implementing the feedback loop used to drive the ultrasonic transducer 215. Because the ADC 318 does not rely on this information being transmitted over the I2C bus, the ADC 318 can sense the rms current directly from the bridge IC 301 via a signal with minimal or no delay. This provides significant speed and accuracy benefits over conventional devices that are constrained by the relatively slow speed of the I2C bus. ii. The voltage of the battery connected to the PMIC300. iii. The voltage of the charger connected to the PMIC300. iv. A temperature signal, such as a temperature signal indicating the PMIC 300 chip temperature. As mentioned above, this temperature can be measured very accurately because the temperature sensor 314 is embedded in the same IC as the oscillator 315. For example, if the temperature of the PMIC 300 increases, the current, frequency, and PWM are adjusted by the PMIC 300 to control the transducer oscillation, which in turn controls the temperature. v. Two external pins. vi. An external NTC temperature sensor to monitor the battery pack temperature.

[0290] In some examples, the ADC 318 sequentially samples one or more of the above sources, for example in a round-robin manner. The ADC 318 samples the sources at a high rate, such as the rate of the oscillator 315, which may be up to 5 MHz or up to 105 MHz.

[0291] In some examples, driver device 202 is configured to allow the device user or manufacturer to specify how many samples should be taken from each source for averaging. For example, a user may configure the system to take 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 pin, and 8 samples from the NTC pin. Additionally, the user may specify whether one of the above sources should be skipped.

[0292] In some examples, for each source, the user can specify two digital thresholds that divide the total range into multiple zones, such as three zones. The user can then configure the system to release an interrupt when the sampled value changes zone, for example, from zone 2 to zone 3.

[0293] Conventional ICs available on the market today cannot implement the above features of the PMIC 300. Sampling with such flexibility and granularity is most important when driving resonant circuits or components such as ultrasonic transducers.

[0294] In this example, the PMIC 300 has 8-bit general-purpose digital input / output ports (GPIOs). Each port can be configured as a digital input and a digital output. Some of the ports also have analog input functionality, as shown in the table in Figure 73.

[0295] The GPIO7-GPIO5 ports of the PMIC 300 can be used to set the address of a device on the communication (I2C) bus 302. Eight identical devices can then 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 conflicting addresses. This is implemented by each device reading the state of GPIO7-GPIO5 during the first 100 μs after the PMIC 300 powers up and storing that portion of the address internally in the PMIC 300. After the PMIC 300 powers up, the GPIOs can be used for any other purpose.

[0296] As described above, the PMIC 300 includes a six-channel LED driver 320. In this example, the LED driver 320 includes a 5V-tolerant N-channel metal-oxide semiconductor (NMOS) current source. The LED driver 320 is configured to set the LED current to four separate levels: 5 mA, 10 mA, 15 mA, and 20 mA. The LED driver 320 is configured to dim each LED channel with a 12-bit PWM signal, with or without gamma correction. The LED driver 320 is configured to vary the PWM frequency from 300 Hz to 1.5 kHz. This feature is unique in the field of ultrasonic mist inhaler devices, as the functionality is embedded as a subsystem of the PMIC 300.

[0297] In this example, the PMIC 300 includes two independent 6-bit digital-to-analog converters (DACs) 327, 328 that are integrated into the PMIC 300. The purpose of the DACs 327, 328 is to output an analog voltage to operate the feedback path of an external regulator (e.g., a DC-DC boost converter 305, a buck converter, or an LDO). Additionally, in some examples, the DACs 327, 328 may also be used to dynamically adjust the overcurrent shutdown level of the bridge IC 301, as described below.

[0298] The output voltage of each DAC 327, 328 is programmable between 0V and 1.5V or between 0V and V_battery (Vbat). In this example, control of the DAC output voltage is via I2C commands. Having two DACs built into the PMIC 300 is unique and allows for dynamic monitoring and control of current. If either of the DACs 327, 328 were external chips, the speed would be subject to the same speed limitations imposed by the I2C protocol. The active power monitoring architecture of the driver device 202 operates at optimal efficiency when all these embedded features are within the PMIC. If they are external components, the active power monitoring architecture would be overall inefficient.

[0299] Referring now to Figure 74 of the accompanying drawings, the bridge IC 301 is a microchip with embedded power switching circuitry 333. In this example, the power switching circuitry 333 is an H-bridge 334 shown in Figure 75 and described in detail below. However, it should be understood that other example bridge ICs 301 may incorporate alternative power switching circuits for the H-bridge 334, provided that the power switching circuitry performs an equivalent function for generating an AC drive signal to drive the ultrasonic transducer 215.

[0300] Bridge IC 301 includes a first phase terminal Phase A that receives a first phase output signal Phase A from the PWM signal generator subsystem of PMIC 300. Bridge IC 301 also includes a second phase terminal Phase B that receives a second phase output signal Phase B from the PWM signal generator subsystem of PMIC 300.

[0301] Bridge IC 301 includes a current sense circuit 335 that directly senses the current in H-bridge 334 and provides an RMS current output signal via the RMS_CURR pin of bridge IC 301. Current sense circuit 335 is configured for overcurrent monitoring and detects when the current through H-bridge 334 exceeds a predetermined threshold. The integration of power switching circuit 333 with H-bridge 334 and current sense circuit 335 all within the same embedded circuit of bridge IC 301 is a unique combination in the IC market. Currently, no other integrated circuit on the IC market includes an H-bridge with embedded circuitry for sensing the RMS current through the H-bridge.

[0302] Bridge IC 301 includes a temperature sensor 336 that includes over-temperature monitoring. Temperature sensor 336 is configured to shut down or disable at least a portion of bridge IC 301 if temperature sensor 336 detects that bridge IC 301 is operating at a temperature above a predetermined threshold. Temperature sensor 336 thus provides an integrated safety feature that prevents damage to bridge IC 301 or other components within driver device 202 if bridge IC 301 operates at an excessively high temperature.

[0303] Bridge IC 301 includes a digital state machine 337 integrally connected to power switching circuit 333. Digital state machine 337 receives Phase A and Phase B signals from PMIC 300 and an ENABLE signal from, for example, microcontroller 303. Digital state machine 337 generates timing signals based on the first phase output signal Phase A and the second phase output signal Phase B.

[0304] The digital state machine 337 outputs timing signals corresponding to the Phase A and Phase B signals, as well as a BRIDGE PR signal and a BRIDGE EN signal, to the power switching circuit 333 to control the power switching circuit 333. Thus, the digital state machine 337 outputs timing signals to the switches T1-T4 of the H-bridge circuit 334 to control the switches T1-T4 to turn on and off in sequence so that the H-bridge circuit outputs an AC drive signal to drive a resonant circuit such as the ultrasonic transducer 215.

[0305] As will be described in more detail below, the switching sequence includes a free-floating period during which the first switch T1 and the second switch T2 are turned off and the third switch T3 and the fourth switch T4 are turned on to dissipate energy stored by the resonant circuit (ultrasonic transducer 215).

[0306] Bridge IC 301 includes a test controller 338 that allows bridge IC 301 to be tested to determine whether embedded components within bridge IC 301 are operating correctly. Test controller 338 is coupled to the TEST DATA, TEST CLK, and TEST LOAD pins so that bridge IC 301 can be connected to an external control device that feeds data into and out of bridge IC 301 to test the operation of bridge IC 301. Bridge IC 301 also includes a TEST BUS that allows the digital communication bus within bridge IC 301 to be tested via the TST PAD pin.

[0307] Bridge IC 301 includes a power-on reset circuit (POR) 339 that controls the start-up operation of bridge IC 301. POR 339 ensures that bridge IC 301 starts up properly only if the supply voltage is within a predetermined range. If the power supply voltage is outside the predetermined range, for example, if the power supply voltage is too high, POR 339 delays the start-up of bridge IC 301 until the power supply voltage is within the predetermined range.

[0308] Bridge IC 301 includes a reference block (BG) 340 that provides a precise reference voltage for use by other subsystems of bridge IC 301.

[0309] Bridge IC 301 includes a current reference 341 that provides accurate current to other subsystems within bridge IC 301 , such as power switching circuit 333 and / or current sensor 335 .

[0310] Temperature sensor 336 continuously monitors the temperature of the silicon in bridge IC 301. If the temperature exceeds a predetermined temperature threshold, power switching circuit 333 is automatically switched off. Additionally, over-temperature can be reported to an external host to notify the external host that an over-temperature event has occurred.

[0311] A digital state machine (FSM) 337 generates timing signals for the power switching circuit 333 , which in this example are timing signals for controlling the H-bridge 334 .

[0312] Bridge IC 301 includes comparators 342, 343 that compare signals from various subsystems of bridge IC 301 with voltage and current references 340, 341 and provide reference output signals via pins of bridge IC 301.

[0313] Referring again to Figure 75 of the accompanying drawings, the H-bridge 334 in this example comprises four switches in the form of NMOS field effect transistor (FET) switches on either side of the H-bridge 334. The H-bridge 334 comprises four switches or transistors T1-T4 connected in an H-bridge configuration, with each transistor T1-T4 driven by a respective logic input A-D. The transistors T1-T4 are configured to be driven by a bootstrap voltage generated internally by two external capacitors Cb connected as shown in Figure 75.

[0314] H-bridge 334 has various power inputs and outputs that are connected to respective pins of bridge IC 301. H-bridge 334 receives the programmable voltage VBOOST output from boost converter 305 via a first power supply terminal labeled VBOOST in FIG. 75. H-bridge 334 has a second power supply terminal labeled VSS_P in FIG. 75.

[0315] The H-bridge 334 has outputs OUTP, OUTN configured to connect to 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.

[0316] The switching of the four switches or transistors T1-T4 is controlled by switching signals from digital state machine 337 via logic inputs A-D. While FIG. 75 shows four transistors T1-T4, it should be understood that in other examples, H-bridge 334 incorporates a greater number of transistors or other switching components to implement the functionality of the H-bridge.

[0317] In this example, the H-bridge 334 operates at a switching power of 22 W to 50 W to deliver an AC drive signal with enough power to drive the ultrasonic transducer 215 to optimally generate mist. The voltage switched by the H-bridge 334 in this example is ±15 V. In another example, the voltage is ±20 V.

[0318] In this example, 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 conventional integrated circuit H-bridges available on the IC market. For example, conventional integrated circuit H-bridges available on the IC market today are configured to operate at a maximum frequency of only 2 MHz. Aside from bridge IC 301 described herein, conventional integrated circuit H-bridges available on the IC market cannot operate at frequencies up to 5 MHz, let alone up to 105 MHz, with a power supply of 22 V to 50 V.

[0319] Referring now to Figure 76 of the accompanying drawings, the current sensor 335 comprises positive and negative current sensing resistors RshuntP, RshuntN connected in series with the respective high and low sides of the H-bridge 334, as shown in Figure 75. The current sensing resistors RshuntP, RshuntN are low value resistors, in this example 0.1 Ω. The current sensor 335 comprises a first voltage sensor in the form of a first operational amplifier 344 that measures the voltage drop across the first current sensor resistor RshuntP, and a second voltage sensor in the form of a second operational amplifier 345 that measures the voltage drop across the second current sensor resistor RshuntN. In this example, the gain of each operational amplifier 344, 345 is 2 V / V. The output of each operational amplifier 344, 345 is, in this example, 1 mA / V. The current sensor 335 comprises a pull-down resistor RshuntP, which in this example is 2 kΩ. cs The outputs of the operational amplifiers 344, 345 provide an output CSout that passes through a low pass filter 346 that removes transients in the signal CSout. The output Vout of the low pass filter 346 is the output signal of the current sensor 335.

[0320] Thus, current sensor 335 measures the AC current flowing through H-bridge 334 and ultrasonic transducer 215, respectively. Current sensor 335 converts the AC current into an equivalent RMS output voltage (Vout) relative to ground. Current sensor 335 has high bandwidth capability because H-bridge 334 can operate at frequencies up to 5 MHz, or in some examples, up to 105 MHz. The output Vout of current sensor 335 reports a positive voltage equal to the measured AC rms current flowing through ultrasonic transducer 215. The output voltage Vout of current sensor 335, in this example, is fed back to control circuitry within bridge IC 301, enabling bridge IC 301 to shut down H-bridge 334 if the current flowing through H-bridge 334, and therefore transducer 215, exceeds a predetermined threshold. Additionally, an overcurrent threshold event is reported to a first comparator 342 within bridge IC 301, allowing bridge IC 301 to report the overcurrent event via its OVC TRIGG pin.

[0321] Referring now to Figure 77 of the accompanying drawings, control of the H-bridge 334 will now be described, also with reference to an equivalent piezo model of the ultrasonic transducer 215.

[0322] To generate a positive voltage across the outputs OUTP, OUTN of the H-bridge 334 (note the direction of the arrows), as indicated by V_out in FIG. 77, the switching sequence of transistors T1-T4 via inputs A-D is as follows: 1. Positive output voltage across ultrasonic transducer 215: A-ON, B-OFF, C-OFF, D-ON. 2. Transition from positive output voltage to 0: A-OFF, B-OFF, C-OFF, D-ON. During this transition, if there is a switching error or delay in A, C is switched off first to minimize or avoid power loss by minimizing or avoiding current flow through A and C. 3.0 output voltage: A-OFF, B-OFF, C-ON, D-ON. During this 0 output voltage phase, the output terminals OUTP, OUTN of the H-bridge 334 are grounded by the C and D switches which remain on. This dissipates the energy stored by the capacitors in the equivalent circuit of the ultrasonic transducer and minimizes voltage overshoot in the switching waveform voltage applied to the ultrasonic transducer. 4. Transition from 0 to negative output voltage: A-OFF, B-OFF, C-ON, D-OFF. 5. Negative output voltage across ultrasonic transducer 215: A-OFF, B-ON, C-ON, D-OFF.

[0323] It will be appreciated that at high frequencies up to 5 MHz or even 105 MHz, the duration of each part of the switching sequence is very short, on the order of nanoseconds or picoseconds. For example, at a switching frequency of 6 MHz, each part of the switching sequence occurs in about 80 ns.

[0324] A graph showing the output voltages OUTP, OUTN of the H-bridge 334 according to the above switching sequence is shown in Figure 78 of the accompanying drawings. The zero output voltage portion of the switching sequence is included to accommodate energy stored by the ultrasonic transducer 215 (e.g., energy stored by a capacitor in the equivalent circuit of the ultrasonic transducer). As discussed above, this minimizes voltage overshoot in the switching waveform voltage applied to the ultrasonic transducer, and therefore minimizes unnecessary power dissipation and heating in the ultrasonic transducer.

[0325] Minimizing or eliminating voltage overshoot also reduces the risk of damage to the transistors in bridge IC 301 by preventing the transistors from experiencing voltages above their rated voltage. Furthermore, minimizing or eliminating voltage overshoot allows bridge IC 301 to accurately drive the ultrasonic transducer in a manner that minimizes disruptions to the current-sensing feedback loop described herein. As a result, bridge IC 301 can drive ultrasonic transducers at powers as high as 22 W to 50 W or 70 W at high frequencies up to 5 MHz or up to 105 MHz.

[0326] The bridge IC 301 in this example is configured to be controlled by the PMIC 300 to operate in two different modes, referred to herein as forced mode and natural frequency mode. These two modes of operation are novel with respect to existing bridge ICs. In particular, the natural frequency mode is a key innovation that provides substantial benefits in the accuracy and efficiency of driving ultrasonic transducers compared to conventional devices.

[0327] Forced Frequency Mode (FFM) In forced frequency mode, the H-bridge 334 is controlled in the above sequence, but at a user-selectable frequency. As a result, the H-bridge transistors T1-T4 are forcibly controlled to switch the output voltage across the ultrasonic transducer 215, regardless of the natural resonant frequency of the ultrasonic transducer 215. Thus, forced frequency mode allows the H-bridge 334 to drive an ultrasonic transducer 215 having a resonant frequency f1 at a different frequency f2.

[0328] Driving an ultrasonic transducer at a frequency different from its resonant frequency may be appropriate to adapt the operation to different applications. For example, it may be appropriate to drive an ultrasonic transducer at a frequency slightly off its resonant frequency (for mechanical reasons to prevent mechanical damage to the transducer). Alternatively, it may be appropriate to drive an ultrasonic transducer at a low frequency, but the ultrasonic transducer, due to its size, has a different natural resonant frequency.

[0329] The driver device 202 controls the bridge IC 301 to drive the ultrasonic transducer 215 in forced frequency mode in response to a configuration of the driver device 202 for a particular application or a particular ultrasonic transducer. For example, the driver device 202 may be configured to operate in forced frequency mode when the mist inhaler device 200 is being used for a particular application, such as generating a mist from a liquid of a particular viscosity containing a medication for delivery to a user.

[0330] Natural Frequency Mode (NFM) The following natural frequency operating mode is a significant development, offering benefits in improved accuracy and efficiency over conventional ultrasonic drivers available on the IC market today.

[0331] The natural frequency operating mode follows the same switching sequence described above, but the timing of the zero output portion of the sequence is adjusted to minimize or avoid problems that can arise due to current spikes in forced frequency mode operation. These current spikes occur when the voltage across the ultrasonic transducer 215 is switched to its opposite voltage polarity. Ultrasonic transducers that include piezo crystals have an electrical equivalent circuit that incorporates parallel-connected capacitors (see, for example, the piezo model in FIG. 77). When the voltage across the ultrasonic transducer is hard-switched from a positive voltage to a negative voltage, a high dV / dt can cause large currents to flow as the energy stored in the capacitor dissipates.

[0332] The natural frequency mode avoids hard switching the voltage across the ultrasonic transducer 215 from a positive voltage to a negative voltage (and vice versa). Instead, before applying the reverse voltage, the ultrasonic transducer 215 (piezo crystal) is left free-floating with zero voltage applied across its terminals for a free-floating period. The PMIC 300 sets the drive frequency of the bridge IC 301 such that the bridge 334 sets the free-floating period, so that current flow in the ultrasonic transducer 215 (due to energy stored in the piezo crystal) reverses the voltage across the terminals of the ultrasonic transducer 215 during the free-floating period.

[0333] As a result, 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) is already back-charged and there is no high dV / dt, so no current spike occurs.

[0334] However, it should be understood that when the ultrasonic transducer 215 is first activated, it takes time for the charge in the ultrasonic transducer 215 (piezo crystal) to accumulate. Therefore, the ideal situation in which the energy in the ultrasonic transducer 215 reverses the voltage during the free-floating period occurs only after oscillations in the ultrasonic transducer 215 have accumulated charge. To accommodate this, 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 a first value, which is a low value (e.g., 5 V). The PMIC 300 then controls the power delivered to the ultrasonic transducer 215 through the H-bridge 334 to increase to a second value (e.g., 15 V) higher than the first value over a period of time to accumulate the energy stored in the ultrasonic transducer 215. A current spike still occurs during this ramp of oscillation until the current in the ultrasonic transducer 215 is fully developed. However, by using a low first voltage at start-up, these current spikes are kept low enough to minimize their impact on the operation of the ultrasonic transducer 215.

[0335] To implement the natural frequency mode, the driver device 202 precisely 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 from the H-bridge 334. In this example, the driver device 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 precise control of the oscillator and duty cycle using control loops is a significant advancement in the field of IC ultrasonic drivers.

[0336] During the natural frequency operating mode, the current sensor 335 senses the current flowing through the ultrasonic transducer 215 (resonant circuit) during the free-floating period. The digital state machine 337 adapts the timing signals to switch on either the first switch T1 or the second switch T2 when the current sensor 335 senses that the current flowing through the ultrasonic transducer 215 (resonant circuit) is zero during the free-floating period.

[0337] Figure 79 of the accompanying drawings shows oscillator voltage waveform 347 (V(osc)), switching waveform 348 resulting from the on and off of left high switch T1 of H-bridge 334, and switching waveform 349 resulting from the on and off of right high switch T2 of H-bridge 334. During the intervening free-floating period 350, both high switches T1, T2 of H-bridge 334 are turned off (free-floating phase). The duration of free-floating period 350 is controlled by the magnitude of free-floating control voltage 351 (Vphioff).

[0338] Figure 80 of the accompanying drawings shows the voltage waveform 352 at a first terminal of the ultrasonic transducer 215 (the voltage waveform is inverted at a second terminal of the ultrasonic transducer 215) and the piezo current 353 flowing through the ultrasonic transducer 215. The piezo current 353 represents an (almost) ideal sinusoidal waveform (which is never possible in forced frequency mode or with any bridge on the IC market).

[0339] Before the sine wave of the piezoelectric current 353 reaches zero, the left high switch T1 of the H-bridge 334 is turned off (here, switch T1 is turned off when the piezoelectric current 353 is approximately 6 A). The remaining piezoelectric current 353 flowing in the ultrasonic transducer 215 due to the energy stored in the ultrasonic transducer 215 (the capacitor of the piezoelectric equivalent circuit) is responsible for the voltage reversal during the free-floating period 350. The piezoelectric current 353 decays to zero during the free-floating period 350 and then decays into a negative current flow domain. The terminal voltage at the ultrasonic transducer 215 drops from the supply voltage (19 V in this case) to less than 2 V, and this drop stops when the piezoelectric current 353 reaches zero. This is the perfect time to turn on the low-side switch T3 of the H-bridge 334 to minimize or avoid current spikes.

[0340] Compared to the forced frequency mode described above, the natural frequency mode has at least three advantages. 1. Current spikes associated with hard switching of package capacitors are significantly reduced or avoided entirely. 2. Power losses due to hard switching are almost eliminated. 3. The frequency is regulated by a control loop to keep it close to the resonance of the piezo crystal (i.e., the natural resonant frequency of the piezo crystal).

[0341] For frequency regulation by a control loop (benefit 3 above), the PMIC 300 starts by controlling the bridge IC 301 to drive the ultrasonic transducer 215 at a frequency above the resonance of the piezo crystal. The PMIC 300 then controls the bridge IC 301 to attenuate / reduce the frequency of the AC drive signal during startup. As soon as the frequency approaches the resonant frequency of the piezo crystal, a piezo current is rapidly generated / increased. Once the piezo current is high enough to cause the desired voltage reversal, the frequency attenuation / reduction is stopped by the PMIC 300. The control loop in the PMIC 300 then takes over regulating the frequency and duty cycle of the AC drive signal.

[0342] In forced frequency mode, the power delivered to the ultrasonic transducer 215 is controlled through duty cycle and / or frequency shifting and / or by varying the supply voltage. However, in this example, in natural frequency mode, the power delivered to the ultrasonic transducer 215 is controlled only by the supply voltage.

[0343] In this example, during a setup phase of the driver device's operation, bridge IC 301 is configured to measure the length of time it takes for the current through ultrasonic transducer 215 (resonant circuit) to fall to zero when first switch T1 and second switch T2 are turned off and third switch T3 and fourth switch T4 are turned on. Bridge IC 301 then sets the length of time of the free-floating period to be equal to the measured length of time.

[0344] Referring now to Figure 81 of the accompanying drawings, the PMIC 300 and bridge IC 301 in this example are designed to work together as a companion chip set. The PMIC 300 and bridge IC 301 are electrically connected to each other for communication with each other. In this example, there are interconnections between the PMIC 300 and bridge IC 301 that enable two categories of communication: 1. Control Signal 2. Feedback signal

[0345] The connections between the Phase_A and Phase_B pins of PMIC 300 and bridge IC 301 carry the PWM modulated control signals that drive H-bridge 334. The connection between the EN_BR pin of PMIC 300 and bridge IC 301 carries the EN_BR control signal that triggers the opening of H-bridge 334. The timing between the Phase_A, Phase_B, and EN_BR control signals is critical and is handled by the digital bridge control of PMIC 300.

[0346] The connections between the CS, OC, and OT pins of the PMIC 300 and the bridge IC 301 carry the CS (current sense), OC (overcurrent), and OT (overtemperature) feedback signals from the bridge IC 301 back to the PMIC 300. Most notably, the CS (current sense) feedback signal comprises a voltage equal to the rms current through the ultrasonic transducer 215, as measured by the current sensor 335 of the bridge IC 301.

[0347] The OC (overcurrent) and OT (overtemperature) feedback signals are digital signals that indicate either an overcurrent or overvoltage event has been detected by bridge IC 301. In this example, the overcurrent and overtemperature thresholds are set by external resistors. Alternatively, the thresholds can also be dynamically set in response to a signal passed from one of two DAC channels VDAC0, VDAC1 from PMIC 300 to the OC_REF pin of bridge IC 301.

[0348] In this example, the design of PMIC 300 and bridge IC 301 allows the pins of these two integrated circuits to be directly connected to each other (e.g., via copper tracks on a PCB), thereby ensuring minimal or no delay in the communication of signals between PMIC 300 and bridge IC 301. This provides a significant speed advantage over conventional bridges in the IC market, which are typically controlled by signals over a digital communication bus. For example, a standard I2C bus is clocked at only 400 kHz, which is too slow to communicate data sampled at the high clock rates of up to 5 MHz in the examples of this disclosure.

[0349] While examples of the present disclosure are described above with respect to microchip hardware, it should be understood that other examples of the present disclosure include methods of operating each microchip's components and subsystems to perform the functions described herein, such as operating the PMIC 300 and bridge IC 301 in either forced frequency mode or natural frequency mode.

[0350] Referring now to Figure 82 of the accompanying drawings, the OTP IC 242 comprises a power-on reset circuit (POR) 354, a bandgap reference (BG) 355, a capless low dropout regulator (LDO) 356, a communication (e.g., I2C) interface 357, a one-time programmable memory bank (e-fuse) 358, an oscillator 359, and a general-purpose input / output interface 360. The OTP IC 242 also comprises a digital core 361 that includes a cryptographic authentication device. In this example, the cryptographic authentication device uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to encrypt / decrypt data stored within the OTP IC as well as data communicated to and from the OTP IC 242.

[0351] The POR 354 ensures that the OTP IC 242 starts up properly only if the supply voltage is within a predetermined range. If the supply voltage is outside the predetermined range, the POR 354 resets the OTP IC 242 and waits until the supply voltage is within the predetermined range.

[0352] BG 355 provides precision reference voltage and current to LDO 356 and oscillator 359. LDO 356 supplies digital core 361, communication interface 357, and electronic fuse memory bank 358.

[0353] The OTP IC 242 is configured to operate in at least the following modes: Fuse Programming (Fusing): During e-Fuse programming (programming of one-time programmable memory), a high current is required to blow the associated fuses in the electronic fuse memory bank 358. In this mode, a higher bias current is provided to maintain the gain and bandwidth of the regulation loop. Fuse Read. In this mode, an intermediate level of current is required to maintain the e-fuse read in the e-fuse memory bank 358. This mode is performed during power-up of the OTP IC 242 to transfer the fuse contents to the shadow register. In this mode, the gain and bandwidth of the regulation loop are set to lower values ​​than in the Fusing mode. Normal operation: In this mode, the LDO356 is driven at a very low bias current condition to operate the OTP IC242 at low power so that the OTP IC242 consumes as little power as possible.

[0354] Oscillator 359 provides the necessary clocks for digital core / engine 361 during test (SCAN test), fusing, and normal operation. Oscillator 359 is trimmed to handle the strict timing requirements during fusing mode.

[0355] In this example, the communication interface 357 conforms to the FM+ specification of the I2C standard, but also conforms to the slow and fast modes. The OTP IC 242 uses the communication interface 357 to communicate with the driver device 202 (host) for data and key exchange.

[0356] Digital core 361 implements the control and communication functions of OTP IC 242. A cryptographic authentication unit in digital core 361 allows OTP IC 242 to authenticate itself (e.g., using ECDSA encrypted messages) with driver device 202 (e.g., for a particular application) to ensure that OTP IC 242 is authentic and authorized to connect to driver device 202 (or another product).

[0357] Referring to FIG. 83 of the accompanying drawings, the OTP IC 242 performs the following PKI procedures to authenticate the OTP IC 242 for use with a host (eg, driver device 202). 1. Verify signer public key: The host requests the manufacturing public key and certificate. The host verifies the certificate with the certification public key. 2. Verify Device Public Key: If verification is successful, the host requests the device public key and certificate. The host verifies the certificate with the manufacturing public key. 3. Challenge-Response: If the verification is successful, the host creates a random challenge and sends it to the device, which then signs the random challenge with the device's private key. 4. The signature is sent back to the host for verification using the device public key.

[0358] If all steps of the authentication procedure are completed successfully, the chain of trust is verified back to the root of trust and the OTP IC 242 is successfully authenticated for use with the host. However, if any step of the authentication procedure fails, the OTP IC 242 is not authenticated for use with the host and use of the device incorporating the OTP IC 242 may be limited or prevented.

[0359] The driver device includes an AC driver for converting voltage from the battery into an AC drive signal of a predetermined frequency to drive the ultrasonic transducer.

[0360] The driver device includes an active power monitoring arrangement for monitoring the active power used by the ultrasonic transducer when the ultrasonic transducer is driven by the AC drive signal (as described above). The active power monitoring arrangement provides a monitoring signal indicative of the active power used by the ultrasonic transducer.

[0361] A processor within the driver device controls the AC driver and receives a monitoring signal drive from the active power monitoring arrangement.

[0362] The memory of the driver device, when executed by the processor, provides the processor with A. controlling an AC driver to output an AC drive signal to an ultrasonic transducer at a predetermined sweep frequency; B. Calculating the active power being used by the ultrasonic transducer based on the monitoring signal; C. Controlling the AC driver to modulate the AC drive signal to maximize the effective power used by the ultrasonic transducer; D. storing in memory a record of the maximum available power and sweep frequency of the AC drive signal used by the ultrasonic transducer; E. repeating steps A-D for a predetermined number of iterations, incrementing or decrementing the sweep frequency with each iteration, such that after the predetermined number of iterations has occurred, the sweep frequency is incremented or decremented from the starting sweep frequency to the ending sweep frequency; F. identifying from the record stored in memory an optimum frequency of the AC drive signal, which is the sweep frequency of the AC drive signal at which the maximum effective power is used by the ultrasonic transducer; G. Control the AC driver to output an AC drive signal at an optimal frequency to the ultrasonic transducer to drive the ultrasonic transducer to atomize the liquid.

[0363] In some examples, the active power monitoring arrangement comprises a current sensing arrangement for sensing a drive current of an AC drive signal that drives the ultrasonic transducer, and the active power monitoring arrangement provides a monitor signal indicative of the sensed drive current.

[0364] In some examples, the current sensing arrangement comprises an analog-to-digital converter that converts the sensed drive current into a digital signal for processing by a processor.

[0365] In some examples, the memory stores instructions that, when executed by the processor, cause the processor to repeat steps A-D above, with the sweep frequency incremented from a starting sweep frequency of 2900 kHz to an ending sweep frequency of 2960 kHz.

[0366] In some examples, the memory stores instructions that, when executed by the processor, cause the processor to repeat steps A-D above, where the sweep frequency is incremented from a starting sweep frequency of 2900 kHz to an ending sweep frequency of 3100 kHz.

[0367] In some examples, the memory stores instructions that, when executed by the processor, in step G, control the AC driver to output an AC drive signal to the ultrasonic transducer at a frequency that is shifted from the optimal frequency by a predetermined shift amount.

[0368] In some examples, the predetermined shift amount is between 1 and 10% of the optimal frequency.

[0369] 2. Control and Information (CI) Section The control and information section includes an external EEPROM for data storage, LEDs for user indication, a pressure sensor for airflow detection, and a Bluetooth® Low Energy (BLE) enabled microcontroller for constant monitoring and management of the aerosolization section.

[0370] The pressure sensor used in this device serves two purposes. The first is to prevent unwanted accidental starting of the sonic engine (which drives the ultrasonic transducer). This function is implemented in the device's processing architecture, which is optimized for low power, constantly measuring environmental parameters such as temperature and ambient pressure with internal compensation and reference settings to accurately detect and classify what are called true inhalations.

[0371] Unlike all other mist inhaler devices on the market, this solution takes advantage of the strengths of microcontrollers to allow the use of only one sensor.

[0372] The second purpose of the pressure sensor is to be able to not only monitor the exact duration of a user's inhalation for accurate inhalation volume measurement, but also to determine the intensity of the user's inhalation, which is important information in medical conditions for both proper prescription and health monitoring. Overall, we can fully depict the pressure profile of every inhalation and predict the end of inhalation for both optimizing aerosolization and understanding medical data behavior.

[0373] This was made possible by the use of a Bluetooth® Low Energy (BLE) microcontroller, which in fact allows the settings to provide extremely accurate inhalation times, optimized aerosolization, monitor numerous parameters to guarantee a safe mist and prevent the use of non-genuine e-liquids or aerosol chambers, and, unlike other products on the market, protects the device from the risk of overheating after just one shot, protecting the user from excessive mist.

[0374] The use of a BLE microcontroller allows over-the-air updates to continually provide users with improved software based on anonymized data collection and trained AI for PZT modeling.

[0375] 3. Power Management (PM) Section The power management section consists of a 3.7V LiPo battery path to a low dropout regulator (LDO) that powers the control and information section, and a battery management system (BMS) that provides a high level of protection and charging for the internal LiPo battery.

[0376] The components of this section have been carefully and perfectly selected to provide such an integrated and compact device while providing high power to the ultrasonic processing section and ensuring a stable power supply for the control and information section.

[0377] Indeed, when supplying high power to the aerosolization section from a 3.7V LiPo battery, the supply voltage fluctuates significantly during operation. Without a low-dropout regulator, the control and information section would not be powered with the required stable supply when the battery voltage dropped as low as 0.3V above the minimum rating of the components in this section, which is why the LDO plays an important role here. Losses in the CI section could disrupt or even stop the functioning of the entire device.

[0378] This is why careful selection of components not only ensures high reliability of the device, but also enables it to operate under harsh conditions and for longer continuous times between recharges.

[0379] Controlled Aerosolization The device is an accurate, reliable and safe aerosolized solution for medical prescription and daily customer use and therefore must provide controlled and reliable aerosolization.

[0380] This is done through an internal method that can be divided into several sections as follows:

[0381] 1. Sonication To provide optimal aerosolization, the ultrasonic transducer (PZT) needs to vibrate in the most efficient manner.

[0382] frequency The electromechanical properties of piezo ceramics dictate that the component has maximum efficiency at its resonant frequency, but vibrating the PZT at resonance for extended periods inevitably results in breakdown and destruction of the component, rendering the aerosol chamber unusable.

[0383] Another important consideration when using piezoelectric materials is their inherent variability during manufacturing, as well as their variability over temperature and lifetime.

[0384] Resonating the PZT at 3 MHz to generate droplets of less than 1 μm size requires an adaptive method to identify and target the "sweet spot" of a specific PZT in every aerosol chamber used with the device for every single inhalation.

[0385] Sweep Because the device must identify the "sweet spot" for each inhalation, and because of overuse, the PZT temperature changes when the device uses an in-house double sweep method.

[0386] The first sweep is used when the device has not been used with a particular aerosol chamber for a period of time deemed sufficient for all heat dissipation to occur and for the PZT to cool to its "default temperature." This procedure is also known as a cold start. During this procedure, the PZT requires a boost to generate the required aerosol. This is accomplished by exceeding only a small subset of frequencies between 2900 kHz and 2960 kHz, which covers the resonant point, taking into account extensive research and experimentation.

[0387] For each frequency within this range, the sonic engine is activated and the current passing through the PZT is actively monitored by the microcontroller via an analog-to-digital converter (ADC), stored, and converted back to current so that the power used by the PZT can be accurately inferred.

[0388] This results in a cold profile for this PZT with respect to frequency, with the frequency used throughout inhalation being the one that uses the most current, representing the lowest impedance frequency.

[0389] A second sweep is performed during any subsequent inhalation, covering the full frequency range from 2900 kHz to 3100 kHz, due to the PZT profile changes with temperature and deformation. This hot profile is used to determine the shift to apply.

[0390] shift This shift is not used during any cryo-inhalation, as aerosolization must be optimal, and therefore the PZT oscillates at its resonant frequency. This can only occur for short, unrepeated periods of time, or the PZT will inevitably break down.

[0391] However, this shift is used during most of the inhalation as a way to still target the low impedance frequency, thus resulting in suboptimal operation of the PZT while protecting it from failure.

[0392] During inhalation, the hot and cold profiles are stored so that the microcontroller can select the appropriate shifted frequency according to measurements of the current through the PZT during the sweep to ensure safe mechanical operation.

[0393] The choice of the direction of the shift is important because piezo components behave differently outside the doublet resonance / anti-resonance frequency or inside this range. The selected shift should always be within this range defined by the resonance frequency to the anti-resonance frequency, since PZT is inductive and not capacitive.

[0394] Finally, the percentage shift is kept below 10% to stay close to the lowest impedance but still far enough away from resonance.

[0395] adjustment Due to the unique properties of PZT, every inhalation is different: many parameters other than the piezo element affect the outcome of an inhalation, such as the amount of e-liquid remaining in the aerosol chamber, the wicking condition of the gauze, or the device's battery level.

[0396] At this point, the device permanently monitors the current used by the PZT in the aerosol chamber, and the microcontroller permanently adjusts parameters such as frequency and duty cycle to provide the most stable power possible to the aerosol chamber within predetermined ranges that follow research and experimental results for the most optimal and safe aerosolization.

[0397] Battery Monitoring To supply a 15V AC voltage and maintain a current of about 2.5A inside the PZT, the current drawn from the battery reaches about 7-8 amps, which results in a drop in battery voltage. A typical LiPo battery will not sustain this demanding resource for the duration of a puff, which can exceed 6 seconds.

[0398] This is why custom LiPo batteries are developed that can handle about 11 amps, 50% more than the maximum allowed by PZTs, while still being easy to use in small, integrated portable devices.

[0399] When the ultrasonic processor is activated, the battery voltage drops and varies widely, so the microcontroller constantly monitors the power used by the PZT in the aerosol chamber to ensure adequate but safe aerosolization.

[0400] And because control is key to aerosolization, the device first ensures that the control and information sections of the device are always functioning and do not shut down due to damage to the ultrasonic processor.

[0401] This is why the regulation method also takes into account the real-time battery level and, if necessary, changes parameters such as duty cycle to keep the battery at a safe level, and before starting the sonic engine, the control and information section will prevent activation if the battery is low.

[0402] Power Control As mentioned above, the key to aerosolization is control, and the method used in the device is a real-time multidimensional function that constantly takes into account the profile of the PZT, the current flow inside the PZT, and the battery level of the device.

[0403] All of this can only be achieved through the use of a microcontroller that can monitor and control all elements of the device to provide optimal inhalation.

[0404] 1. Inhalation control The device is a safe device, confirmed by a BNS (Broughton Nicotine Services) report, but each inhalation must be controlled to ensure the safety of the mist and the integrity of both the aerosol chamber and the device.

[0405] Inhalation duration To reduce exposure to carbonyls and other toxic components that may result from heating the e-liquid, the maximum duration of inhalation is set at 6 seconds, which fully ensures that exposure to these components is contained.

[0406] interval Because the device relies on a piezoelectric component, it prevents activation of the ultrasonic processor if inhalation is stopped. The safety delay between two inhalations is adaptable depending on the duration of the previous inhalation. This allows the gauze to properly soak up before the next activation.

[0407] This feature allows the device to operate safely and aerosolization is more optimal without the risk of destroying the PZT elements or exposing the user to toxic components.

[0408] Connectivity (BLE) The device control and information section consists of a wireless communication system in the form of a Bluetooth® Low Energy (BLE) enabled microcontroller that communicates with the device's processor and is configured to send and receive data between the driver device and a computing device such as a smartphone.

[0409] Connectivity via Bluetooth® Low Energy to a companion mobile application ensures that less power is required for this communication, thus allowing the device to continue functioning for longer periods of time when not in use at all, compared to traditional wireless connectivity solutions such as Wi-Fi, classic Bluetooth®, GSM®, or even LTE-M and NB-IOT.

[0410] Most importantly, this connectivity allows for complete control and safety of the inhalation, featuring OTP: all data, from the resonant frequency of the inhalation to the used or negative pressure generated by the user and duration, are stored and transferred via BLE for further analysis and improvement of the embedded software.

[0411] Furthermore, all of this information is important when the device is used in a medical program, as it gives the doctor and user all the information about the inhalation process and the ability to track prescription and usage in real time.

[0412] Finally, this connectivity allows for over-the-air (OTA) updates of the embedded firmware within the device, ensuring that the latest version can always be rapidly deployed, giving the device great scalability and ensuring that the device is intended to be maintained.

[0413] Data collection for clinical purposes 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 a session.

[0414] This data can be interpreted by an algorithm that sets consumption limits per period based on a doctor's recommendations.

[0415] This allows a controlled therapeutic dose of medication to be administered to the user, which is controlled by a doctor or pharmacist and cannot be abused by the end user.

[0416] A physician can gradually decrease the dosage over time in a controlled manner that is safe for the user.

[0417] Spray limit The process of ultrasonic cavitation has a significant effect on the nicotine concentration in the generated mist.

[0418] The device's limitation of puff duration to less than 7 seconds limits the user's exposure to carbonyls commonly produced by electronic nicotine delivery systems.

[0419] Based on experimental results from Broughton Nicotine Services, after users take 10 consecutive puffs of <7 seconds, the total carbonyl levels are <2.67μg / 10 puffs (average: 1.43μg / 10 puffs) for formaldehyde, <0.87μg / 10 puffs (average: 0.50μg / 10 puffs) for acetaldehyde, and <0.40μg / 10 puffs (average: 0.28μg / 10 puffs) for propionaldehyde. puffs), <0.16 μg / 10 puffs for crotonaldehyde (average: 0.16 μg / 10 puffs), <0.19 μg / 10 puffs for butyraldehyde (average: 0.17 μg / 10 puffs), <0.42 μg / 10 puffs for diacetyl (average: 0.25 μg / 10 puffs), and no acetylpropionyl was detected in the emissions after 10 consecutive puffs of <7 seconds.

[0420] Because aerosolization of e-liquid is achieved through the mechanical action of the piezo disc, rather than by direct heating of the liquid, the individual components of the e-liquid (such as propylene glycol, vegetable glycerin, and flavoring ingredients) remain largely intact and do not break down into smaller, harmful components such as acrolein, acetaldehyde, and formaldehyde in high proportions as seen in conventional ENDS.

[0421] To limit user exposure to carbonyls while using ultrasonic devices, puff lengths are limited to a maximum of 6 seconds, resulting in the above results being the absolute worst-case scenario in terms of exposure.

[0422] 84 and 85, when the end caps 248 are attached to the driver device housing 246, the aluminum driver device housing 246 acts as a Faraday cage, preventing the device from emitting electromagnetic waves. The device with the driver device housing 246 has been tested for electromagnetic compatibility (EMC), and the tests reveal that emissions are less than half of the limit allowed for the device. The EMC test results are shown in the graph of FIG.

[0423] Other example mist inhaler devices of the present disclosure include most or preferably all of the elements of the mist generator device 200 described above, but the memory of the driver device 202 stores instructions that, when executed by the processor, provide additional functionality to the mist inhaler device.

[0424] In one example, the mist inhaler device 200 includes an active power monitor incorporating a current sensor, such as the current sensor 335 described above, for sensing the rms drive current of the AC drive signal that drives the ultrasonic transducer 215. The active power monitor provides a monitoring signal indicative of the sensed drive current, as described above.

[0425] An additional feature of this example allows the mist inhaler device 200 to monitor the operation of the ultrasonic transducer while it is activated. The mist inhaler device 200 calculates an effectiveness value or quality index that indicates how effectively the ultrasonic transducer is operating to atomize the liquid within the device. The device uses the effectiveness value to calculate the actual amount of mist generated over the duration of the ultrasonic transducer activation.

[0426] Once the actual volume of mist is calculated, the device is configured to calculate the actual amount of therapeutic agent inhaled by the user based on the actual amount of therapeutic agent present in the mist and, therefore, the concentration of the therapeutic agent in the liquid. Knowing the exact amount of therapeutic agent delivered to the user is particularly important when the mist inhaler device is being used as part of a therapeutic treatment program. Knowing the exact amount of therapeutic agent delivered to the user during each inhalation or puff allows the therapeutic treatment program to operate more accurately and effectively compared to using conventional devices that simply count the number of inhalations or puffs, assuming that each inhalation or puff delivers the same amount of therapeutic agent to the user.

[0427] In practice, as discussed above, there are many different factors that affect the operation of the ultrasonic transducer and affect the amount of mist produced by the ultrasonic transducer and therefore the actual amount of therapeutic agent delivered to the user.

[0428] For example, if the ultrasonic transducer in a mist inhaler device is not operating optimally due to a low battery charge that reduces the current flowing through the ultrasonic transducer, a smaller amount of mist will be produced and a smaller amount of therapeutic agent will be delivered to the user than if the device were operating optimally. Thus, the device may allow the user more puffs to deliver a set amount of therapeutic agent to the user over a period of time than would be allowed if the ultrasonic transducer were operating optimally. This allows a therapeutic treatment program to operate more effectively and accurately than conventional programs that rely on using devices that simply count and limit the number of puffs a user takes.

[0429] The configuration of some example mist inhaler devices and methods of generating mist using the mist inhaler devices are described in detail below.

[0430] In this example, the mist inhaler device incorporates the components of the mist inhaler device 200 described above, but the memory of the driver device 202 further stores instructions that, when executed by the processor, cause the processor to activate the mist generator device 200 for a first predetermined length of time. As described above, the mist generator device is activated by driving the ultrasonic transducer 215 in the mist generator device 200 with an AC drive signal such that the ultrasonic transducer 215 atomizes the liquid carried by the capillary element 222.

[0431] The executed instructions cause the processor to periodically sense the current of the AC drive signal flowing through the ultrasonic transducer 215 using the current sensor for a first predetermined length of time and store the periodically measured current values ​​in memory.

[0432] The executed instructions cause the processor to calculate an effectiveness value using the current values ​​stored in the memory, the effectiveness value indicating the effectiveness of the operation of the ultrasonic transducer in atomizing the liquid.

[0433] In one example, the executed instructions cause the processor to calculate the effectiveness value using this formula:

[0434]

number

[0435] During the ceremony, Q I is the effectiveness value, Q F is a frequency quasi-effectiveness value based on the monitored frequency value (the frequency at which the ultrasonic transducer 215 is driven), Q A is the analog-to-digital converter quasi-effectiveness value based on the measured current value (rms current through the ultrasonic transducer 215), t=0 is the start of the first predetermined time period; t=D is the end of the first predetermined period of time; N is the number of periodic measurements (samples) during the first predetermined length of time;

[0436]

number

[0437] is the normalization factor.

[0438] In one example, the memory stores instructions that, when executed by the processor, cause the processor to periodically measure a duty cycle of an AC drive signal that drives the ultrasonic transducer for a first predetermined length of time and store the periodically measured duty cycle value in the memory. AThe analog-to-digital converter modifies the quasi-effectiveness value based on the current value stored in memory. As a result, the mist inhaler device of this example takes into account variations in duty cycle that may occur throughout activation of the ultrasonic transducer 215 when the device calculates the effectiveness value. Thus, the mist inhaler device can accurately calculate the actual amount of mist produced by accounting for variations in duty cycle of the AC drive signal that may occur while the ultrasonic transducer is activated.

[0439] In one example, the memory stores instructions that, when executed by the processor, cause the processor to periodically measure a voltage of a battery powering the mist generator device for a first predetermined length of time and store the periodically measured battery voltage values ​​in the memory. A The analog-to-digital converter modifies the quasi-effectiveness value based on the battery voltage value stored in the memory. As a result, the mist inhaler device of this example takes into account fluctuations in battery voltage that may occur while the ultrasonic transducer 215 is activated when the device calculates the effectiveness value. Therefore, the mist inhaler device can accurately calculate the actual amount of mist to be produced by taking into account fluctuations in battery voltage that may occur while the ultrasonic transducer is activated.

[0440] The efficacy value is used by the mist inhaler device as a weighting to calculate the actual amount of mist produced by the mist inhaler device by proportionately reducing the value of the maximum amount of mist that would be produced if the device were operating optimally.

[0441] 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 for a first predetermined length of time and store the periodically measured frequency values ​​in the memory. The device then calculates an effectiveness value using the frequency values ​​stored in the memory in addition to the current values, as described above.

[0442] In one example, the memory stores instructions that, when executed by the processor, cause the processor to calculate a maximum mist volume value that would be generated if the ultrasonic transducer 215 were operating optimally for a duration of a first predetermined length of time. In one example, the maximum mist volume value is calculated based on modeling that determines the maximum amount of mist that would be generated when the ultrasonic transducer was operating optimally.

[0443] Once the maximum mist volume value is calculated, the mist inhaler device can calculate an actual mist volume value by proportionally reducing the maximum mist volume value based on the efficacy value to determine the actual volume of mist generated over a duration of the first predetermined length of time.

[0444] Once the actual mist volume is calculated, the mist inhaler device can calculate a therapeutic dose value indicating the amount of therapeutic agent in the actual mist volume generated over the duration of the first predetermined length of time. The mist inhaler device then stores a record of the therapeutic dose value in memory. In this way, the mist inhaler device can accurately record the actual amount of therapeutic agent delivered to the user in each inhalation or puff.

[0445] In one example, the memory stores instructions that, when executed by the processor, cause the processor to select a second predetermined length of time in response to the effectiveness value. In this case, the second predetermined length of time is the length of time the ultrasonic transducer 215 is activated during a second inhalation or puff by the user. In one example, the second predetermined length of time is equal to the first predetermined length of time, but this time is proportionally decreased or increased according to the effectiveness value. For example, if the effectiveness value indicates that the ultrasonic transducer 215 is not operating effectively, the second predetermined length of time is increased by the effectiveness value so that a desired amount of mist is generated during the second predetermined length of time.

[0446] For the next inhalation, the mist inhaler device activates the mist generator device for a second predetermined length of time, and the mist generator device generates a predetermined amount of mist for the second predetermined length of time. Thus, the mist inhaler device precisely controls the amount of mist generated during the second predetermined length of time, taking into account various parameters reflected by the efficacy value that affect the operation of the mist inhaler device.

[0447] In one example, the memory stores instructions that, when executed by the processor, cause the processor to activate the mist generator device for multiple predetermined periods of time, for example, the mist generator device is activated during multiple successive inhalations or puffs by the user.

[0448] The mist inhaler device stores a plurality of therapeutic dose values ​​in memory, each therapeutic dose value indicating an amount of therapeutic agent in the mist generated over a respective duration of a predetermined length of time. In one example, the mist inhaler device prevents further activation of the mist generator device for a predetermined duration if the total amount of therapeutic agent in the mist generated over the predetermined duration of time is equal to or exceeds a predetermined threshold. In one example, the predetermined duration is a duration in the range of 1 to 24 hours. In other examples, the predetermined duration is 24 hours or 12 hours.

[0449] The mist inhaler of some examples of the present disclosure is configured to transmit data indicative of a therapeutic dose value from the mist generator device to a computing device (e.g., a smartphone) (e.g., via Bluetooth™ low energy communication) for storage in the computing device's memory. Thus, an executable application running on the computing device can record the amount of therapeutic agent delivered to the user. The executable application can also control the operation of the mist inhaler device to limit activation of the mist inhaler device and limit the amount of therapeutic agent delivered to the user over a period of time.

[0450] Thus, some example mist inhaler devices of the present disclosure are configured to prevent further activation once a user has consumed a set amount of therapeutic agent within a set time frame, such as the amount of therapeutic agent consumed in a day.

[0451] All of the above applications involving ultrasonic technology can benefit from the optimization achieved by a frequency controller that optimizes the frequency of the ultrasonic treatment for optimal performance.

[0452] It should be understood that the disclosure herein is not limited to use for nicotine delivery. Indeed, in some examples, the mist inhaler device contains a liquid containing a nicotine-free therapeutic agent. Some examples are configured for use for various medical purposes (e.g., delivery of CBD for pain relief, supplements for performance enhancement, albuterol / salbutamol for asthma patients, etc.).

[0453] The devices disclosed herein are for use with any therapeutic agent, drug, or other compound, where the drug or compound is provided in a liquid within a liquid chamber of the device for aerosolization by the device. In some examples, the devices disclosed herein are for use with therapeutic agents, drugs, and compounds, including, but not limited to: respiratory system Bronchodilators Olodaterol Levalbuterol Belodual (ipratropium bromide / fenoterol) Combivent (ipratropium bromide / salbutamol) anti-inflammatory agents Betamethasone Dexamethasone Methylprednisolone Hydrocortisone Mucolytics N-acetylcysteine Pulmonary hypertension Sildenafil Tadalafil Epoprostenol Treprostenil Iloprost infectious disease antibacterial agents Aminoglycosides (gentamicin, tobramycin, amikacin, colomycin, neomycin, liposomal amikacin) Quinolones (ciprofloxacin, levofloxacin, moxifloxacin, ofloxacin) Macrolides (azithromycin) Minocycline Beta-lactams (piperacillin-tazobactam, ceftazidime-ticarcillin) Cephalosporins (cefotaxime, cefepime, ceftriaxone, cefotaxime) Glycopeptide (vancomycin) Meropenem Polymyxins (colistin, polymyxin B) antifungal agents Amphotericin Fluconazole Caspofungen antiviral agents Valganciclovir Favipiravir Remdesivir Acyclovir anti tb Isoniazid Pyrazinamide Rifampin Ethambutol Oncology Biologics Gilotrif Afatinib Caplacizumab Dupilumab Isarilumab Alirocumab Volasertib Nintedanib Imatinib Sirolimus chemotherapy Azacitidine Decitabine Docetaxel Gemcitabine Cisplatinum CNS & Psych Sodium valproate Teriflunomide Zomitriptan Metabolism / Hormones insulin estrogen immunology vaccine Monoclonal antibodies stem cells vitamin zinc Ascorbic acid others Niclosamide Hydroxychloroquine Ivermectin

[0454] The ultrasonic mist inhaler 100 in some examples is a more powerful version of current portable medical nebulizers.

[0455] Other examples of ultrasonic mist inhaler devices are readily envisioned, including medication delivery devices that do not have the appearance of a cigarette.

[0456] The foregoing outlines features of several examples or embodiments to enable those skilled in the art to better understand various aspects of the present disclosure. Those skilled in the art will appreciate that they may readily use this disclosure as a basis for designing or modifying other processes and structures to carry out the same purposes and / or achieve the same advantages of the various examples or embodiments presented herein. Those skilled in the art should also appreciate that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the present disclosure.

[0457] Although the subject matter has been described in language specific to structural features or methodological acts, it is to be understood that the appended claimed subject matter is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing at least some of the claims.

[0458] Various operations of example or embodiment are provided herein. The order in which some or all of the operations are described should not be construed as implying that these operations are necessarily order dependent. It will be understood that alternative orderings may have the benefit of this description. Furthermore, it will be understood that not all operations are necessarily present in each embodiment provided herein. It will also be understood that not all operations are required in some example or embodiment.

[0459] Furthermore, "exemplary" is used herein to mean serving as an example, instance, illustration, or the like, and is not necessarily advantageous. When used in this application, "or" is intended to mean an inclusive "or" rather than an exclusive "or." Furthermore, "a" and "an," as used in this application and the appended claims, are generally construed to mean "one or more" unless otherwise specified or unless it is clear from the context that the singular form is intended. Also, at least one of A and B, etc., generally refers to A or B, or both A and B. Furthermore, to the extent that "includes," "having," "has," "with," or variations thereof are used, such terms are intended to be inclusive in the same manner as the term "comprising." Also, unless otherwise specified, "first," "second," etc. are not intended to imply any temporal or spatial aspect, order, or the like; such terms are merely used as identifiers, names, or the like 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 or two identical or the same element.

[0460] Also, while the present disclosure has been shown and described with respect to one or more implementations, equivalent changes and modifications will occur to those skilled in the art upon reading and understanding this specification and the accompanying drawings. The present disclosure includes all such modifications and variations 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 such features are intended, unless otherwise specified, to correspond to any feature that is not structurally equivalent to the disclosed structure but performs the specified function (e.g., functionally equivalent) of the described feature. In addition, while a particular feature of the present disclosure may be disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of other implementations, as may be desired or advantageous for any given or particular application.

[0461] 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, or in combinations of one or more of them, including the structures disclosed herein and their structural equivalents.

[0462] Some examples or embodiments are implemented using one or more modules of computer program instructions encoded on a computer-readable medium for execution by or to control the operation of a data processing apparatus. The computer-readable medium may be an article of manufacture, such as a hard drive in a computer system or an embedded system. The computer-readable medium may be obtained separately and later encoded with one or more modules of computer program instructions, such as by delivery of one or more modules of computer program instructions over a wired or wireless network. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, or a combination of one or more thereof.

[0463] The terms "computing device" and "data processing apparatus" encompass all apparatus, devices, and machines for processing data, including, by way of example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, an apparatus can include code that creates an execution environment for the computer program in question, 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, an apparatus can employ a variety of different computing model infrastructures, such as web services, distributed computing, and grid computing infrastructures.

[0464] The processes and logic flows described herein may be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output.

[0465] Processors suitable for executing a computer program include, by way of example, both general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor receives 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 memory devices for storing instructions and data. Typically, a computer also includes one or more mass storage devices, such as magnetic, magneto-optical, or optical disks, for storing data, or is operatively coupled to receive data from them, transfer data to them, or both. 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 memory devices.

[0466] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, in their specific form, or in connection with means for performing a disclosed function, or methods or processes for achieving a disclosed result, may be utilized to realize the invention in various of its forms, either separately or in any combination of such features, as appropriate.

[0467] Typical features Representative features are described in the following clauses, which may be combined independently or in any combination with one or more features disclosed in the text and / or drawings of this specification. Clause 1. A mist inhaler device for generating a mist containing a therapeutic agent for inhalation by a user, comprising: 1. A mist generator device comprising: an elongated mist generator housing having an air inlet port and a mist outlet port; a liquid chamber disposed within the mist generator housing, the liquid chamber containing a liquid to be atomized, the liquid containing a therapeutic agent; an ultrasonic treatment chamber disposed within the mist generator housing; a capillary element extending between the liquid chamber and the sonication chamber, a first portion of the capillary element being within the liquid chamber and a second portion of the capillary element being within the sonication chamber; an ultrasonic transducer having an atomizing surface, wherein a portion of the second portion of the capillary element is superimposed on a portion of the atomizing surface, and when the ultrasonic transducer is driven by an AC drive signal, the atomizing surface vibrates to atomize the liquid carried by the second portion of the capillary element and generate a mist containing the atomized liquid and air within the sonication chamber; a mist generator device incorporating an air inlet port, an airflow arrangement providing an air flow path between the air inlet port, the ultrasonic treatment chamber, and the air outlet port such that a user sucking on the mist outlet port draws air through the inlet port, through the ultrasonic treatment chamber, and out through the mist outlet port, and mist generated within the ultrasonic treatment chamber is carried by the air out through the mist outlet port for inhalation by the user, the device comprising: a driver device, A battery, an H-bridge circuit connected to the ultrasonic transducer, the H-bridge circuit generating an AC drive signal to drive the ultrasonic transducer to generate and transmit ultrasonic waves; a second microchip connected to the first microchip and controlling an H-bridge circuit to generate an AC drive signal, the second microchip being a single unit comprising a plurality of interconnected embedded components and subsystems, the subsystems including: 1. An oscillator, comprising: A main clock signal; a first phase clock signal that is initially high during a positive half-cycle of the main clock signal and low during a negative half-cycle of the main clock signal; a second phase clock signal that is high a second time during the negative half-period of the main clock signal and low during the positive half-period of the main clock signal, wherein the phases of the first phase clock signal and the second phase clock signal are center-aligned; and a pulse width modulation (PWM) signal generator subsystem, comprising: a delay locked loop configured to generate a double frequency clock signal, which is twice the frequency of the main clock signal, using the first phase clock signal and the second phase clock signal, wherein the delay locked loop controls rising edges of the first phase clock signal and the second phase clock signal to synchronize with rising edges of the double frequency clock signal, and the delay locked loop adjusts frequencies and duty cycles of the first phase clock signal and the second phase clock signal in response to a driver control signal to generate first phase output signals and second phase output signals, which drive an H-bridge circuit to generate AC drive signals for driving an ultrasonic transducer; a first phase output signal terminal for outputting a first phase output signal to an H-bridge circuit; a second phase output signal terminal for outputting a second phase output signal to the H-bridge circuit; a PMW signal generator subsystem comprising: a feedback input terminal for receiving a feedback signal from the H-bridge circuit, the feedback signal being indicative of the operation of the H-bridge circuit or a parameter of the AC drive signal when the H-bridge circuit is driving the ultrasonic transducer with the AC drive signal to atomize the liquid; an analog-to-digital converter (ADC) subsystem, comprising: a plurality of ADC input terminals receiving a plurality of respective analog signals, one ADC input terminal of the plurality of ADC input terminals being connected to a feedback input terminal such that the ADC subsystem receives a feedback signal from the H-bridge circuit, the ADC subsystem sampling the analog signals received at the plurality of ADC input terminals at a sampling frequency proportional to the frequency of the main clock signal, and the ADC subsystem generating an ADC digital signal using the sampled analog signals; an ADC subsystem comprising: a digital processor subsystem that receives an ADC digital signal from the ADC subsystem and processes the ADC digital signal to generate a driver control signal, the digital processor subsystem communicating the driver control signal to the PWM signal generator subsystem to control the PWM signal generator subsystem; 1. A digital-to-analog converter (DAC) subsystem comprising: a digital-to-analog converter (DAC) that converts the digital control signals generated by the digital processor subsystem into analog voltage control signals to control a voltage regulator circuit that generates a voltage for modulation by the H-bridge circuit; and a DAC output terminal configured to output an analog voltage control signal for controlling a voltage regulator circuit to generate a predetermined voltage for modulation by an H-bridge circuit to drive the ultrasonic transducer in response to a feedback signal indicative of operation of the ultrasonic transducer. Article 2 Microchips: The device described in clause 1, further comprising a frequency divider connected to the oscillator to receive a main clock signal from the oscillator, dividing the main clock signal by a predetermined divisor amount, and outputting a frequency reference signal to the delay locked loop. Clause 3. The device of clause 1, wherein the delay locked loop comprises a plurality of delay lines connected end to end, the total delay of the delay lines being equal to the period of the main clock signal. Clause 4. The device of clause 3, wherein the delay-locked loop adjusts the duty cycle of the first phase clock signal and the second phase clock signal in response to the driver control signal by varying the delay of each delay line in the delay-locked loop. Clause 5. The device of clause 1, wherein the feedback input terminal receives a feedback signal from the H-bridge circuit in the form of a voltage indicative of the rms current of the AC drive signal driving the resonant circuit. Clause 6. The device of clause 1, wherein the ADC subsystem comprises a plurality of further ADC input terminals for receiving feedback signals indicative of at least one of the voltage of a battery connected to the device or the voltage of a battery charger connected to the device. Article 7 Microchips: The device described in clause 1 further comprises a temperature sensor embedded in the microchip, the temperature sensor generating a temperature signal indicative of the temperature of the microchip, the temperature signal being received by a further ADC input terminal of the ADC subsystem, and the temperature signal being sampled by the ADC. Clause 8. The device of clause 1, wherein the ADC subsystem sequentially samples signals received at a plurality of ADC input terminals, each signal being sampled by the ADC subsystem a respective predetermined number of times. Article 9 Microchips: 10. The device of claim 1, further comprising a battery charging subsystem that controls charging of the battery. Article 10 The DAC subsystem: 10. The device of claim 1, further comprising a digital-to-analog converter (DAC) that converts a further digital control signal generated by the digital processor subsystem into a further analog voltage control signal for controlling the voltage regulator circuit. Article 11 The device A further microchip, the further microchip being a single unit comprising a plurality of interconnected embedded components and subsystems, the subsystems comprising: a first power terminal; a second power terminal; 1. An H-bridge circuit incorporating a first switch, a second switch, a third switch, and a fourth switch, the first switch and the third switch are connected in series between the first power supply terminal and the second power supply terminal; the first output terminal is electrically connected between the first switch and the third switch, the first output terminal is connected to the first terminal of the ultrasonic transducer; the second switch and the fourth switch are connected in series between the first power supply terminal and the second power supply terminal; an H-bridge circuit, the second output terminal of which is electrically connected between the second switch and the fourth switch, the second output terminal of which is connected to a second terminal of the ultrasonic transducer; a first phase terminal configured to receive a first phase output signal from a pulse width modulation (PWM) signal generator subsystem; a second phase terminal configured to receive a second phase output signal from the PWM signal generator subsystem; a digital state machine configured to generate a timing signal based on the first phase output signal and the second phase output signal, and output the timing signal to switches of an H-bridge circuit to control the switches on and off in a sequence so that the H-bridge circuit outputs an AC drive signal for driving an ultrasonic transducer, the sequence including a free-floating period during which the first switch and the second switch are turned off and the third switch and the fourth switch are turned on to dissipate energy stored by the ultrasonic transducer; A current sensor, a first current sensing resistor connected in series between the first switch and the first power supply terminal; a first voltage sensor that measures a voltage drop across the first current sense resistor and provides a first voltage output indicative of the current flowing through the first current sense resistor; a second current sensing resistor connected in series between the second switch and the first power supply terminal; a second voltage sensor that measures the voltage drop across the second current sensor resistor and provides a second voltage output indicative of the current flowing through the second current sensing resistor; a current sensor output terminal providing an rms output voltage relative to ground equal to the first voltage output and the second voltage output, The device described in clause 1 further comprises a further microchip incorporating a power sensor and a current sensor output terminal, the rms output voltage of which indicates the rms current flowing through the first switch or the second switch and the current flowing through an ultrasonic transducer connected between the first output terminal and the second output terminal. Clause 12. The device of clause 11, wherein the H-bridge circuit is configured to output 22 W to 50 W of power to an ultrasonic transducer connected to the first output terminal and the second output terminal. Article 13 Further microchips may: 12. The device of clause 11, further comprising a temperature sensor embedded in the microchip, the temperature sensor configured to measure the temperature of the microchip and disable at least a portion of the microchip if the temperature sensor senses that the microchip is at a temperature above a predetermined threshold. Article 14 The system: The device described in clause 11, further comprising a boost converter circuit configured to increase the voltage of the battery to a boost voltage in response to an analog voltage output signal from the DAC output terminal, the boost converter circuit providing the boost voltage at the first power supply terminal such that the boost voltage is modulated by switching of the switches of the H-bridge circuit. Clause 15. The device of clause 11, wherein the current sensor senses the current through the resonant circuit during the free-floating period, and the digital state machine adapts the timing signals to switch on either the first switch or the second switch when the current sensor senses that the current through the resonant circuit is zero during the free-floating period. Article 16 During the setup phase of the device's operation, a further microchip: measuring a time length until a current flowing through the resonant circuit becomes zero when the first switch and the second switch are turned off and the third switch and the fourth switch are turned on; 12. The device of clause 11, wherein the length of time of the free-floating period is set to be equal to the measured length of time. Article 17 The device a processor for controlling a driver device; and a memory storing instructions that, when executed by the processor, cause the driver device to: A. controlling a driver device to output an AC drive signal to an ultrasonic transducer at a sweep frequency; B. Calculating the active power being used by the ultrasonic transducer based on the feedback signal; C. controlling a driver device to modulate an AC drive signal to maximize the effective power being used by the ultrasonic transducer; D. storing in memory a record of the maximum available power and sweep frequency of the AC drive signal used by the ultrasonic transducer; E. repeating steps A-D for a predetermined number of iterations, incrementing or decrementing the sweep frequency with each iteration, such that after the predetermined number of iterations has occurred, the sweep frequency is incremented or decremented from the starting sweep frequency to the ending sweep frequency; F. identifying from the record stored in memory an optimum frequency of the AC drive signal, which is the sweep frequency of the AC drive signal at which the maximum effective power is used by the ultrasonic transducer; G. The device of clause 1, further comprising: controlling the driver device to output an AC drive signal to the ultrasonic transducer at an optimal frequency to drive the ultrasonic transducer to atomize the liquid. Clause 18. The device of clause 17, wherein the starting sweep frequency is 2900 kHz and the ending sweep frequency is 3100 kHz. Clause 19. A device as described in clause 1, wherein the driver device is removably attached to the mist generator device such that the driver device is separable from the mist generator device. Clause 20 A mist inhaler device for generating a mist for inhalation by a user, comprising: 1. A mist generator device comprising: an ultrasonic treatment chamber; a liquid chamber containing the liquid to be atomized; a capillary element extending between the liquid chamber and the sonication chamber; an ultrasonic transducer configured to vibrate to atomize the liquid conveyed by the capillary element from the liquid chamber to the sonication chamber to generate a mist comprising the atomized liquid and air within the sonication chamber; a mist generator device comprising: a mist outlet port in fluid communication with the ultrasonic treatment chamber, the mist outlet port adapted for a user drawing on the mist outlet port to inhale mist from the ultrasonic treatment chamber; a driver device, A battery, An AC driver that converts the voltage from the battery into an AC drive signal to vibrate the ultrasonic transducer; an active power monitor for monitoring active power used by the ultrasonic transducer when the ultrasonic transducer is driven by an AC drive signal, the active power monitor comprising a current sensor for sensing a drive current of the AC drive signal driving the ultrasonic transducer, the active power monitor arrangement providing a monitor signal indicative of the sensed drive current; a processor that controls the AC driver and receives a monitoring signal from the active power monitor; a memory storing instructions that, when executed by the processor, cause the processor to: activating the mist generator device for a first predetermined length of time, where activating the mist generator device includes driving an ultrasonic transducer in the mist generator device with an AC drive signal such that the ultrasonic transducer atomizes liquid carried by the capillary element; using a current sensor to periodically sense a current of the AC drive signal flowing through the ultrasonic transducer for a first predetermined length of time and storing the periodically measured current values ​​in memory; calculating an effectiveness value indicative of the effectiveness of operation of the ultrasonic transducer in atomizing the liquid using the current values ​​stored in the memory; selecting a second predetermined length of time in response to the significance value; The mist inhaler device further comprises a driver device that activates the mist generator device for a second predetermined length of time, causing the mist generator device to generate a predetermined amount of mist for the second predetermined length of time. Clause 21 The memory, when executed by the processor, causes the processor to: periodically measuring a frequency of an AC drive signal driving the ultrasonic transducer for a first predetermined length of time and storing the periodically measured frequency values ​​in memory; 21. The device of clause 20, storing instructions causing the device to: calculate an effectiveness value using the frequency values ​​stored in the memory. Clause 22. The memory stores instructions that, when executed by the processor, cause the processor to calculate a validity value using the formula:

[0468]

number

[0469] During the ceremony, Q I is the effectiveness value, Q F is a frequency subavailability value based on the monitored frequency value, Q A is the quasi-effectiveness value of the analog-to-digital converter based on the measured current value, t=0 is the start of the first predetermined time period; t=D is the end of the first predetermined period of time; N is the number of periodic measurements during the first predetermined length of time;

[0470]

number

[0471] 22. The device of clause 21, wherein: Clause 23 The memory, when executed by the processor, causes the processor to: periodically measuring a duty cycle of an AC drive signal driving the ultrasonic transducer for a first predetermined length of time and storing the periodically measured duty cycle value in memory; Based on the current value stored in memory, Q A and changing a subeffectiveness value of the analog-to-digital converter. Clause 24 The memory, when executed by the processor, causes the processor to: periodically measuring a voltage of a battery powering the mist generator device for a first predetermined length of time and storing the periodically measured battery voltage values ​​in memory; Q based on the battery voltage value stored in memory A 24. A device according to clause 22 or 23, storing instructions to cause the device to: Clause 25 The memory, when executed by the processor, causes the processor to: Calculating a maximum mist volume value that would be produced if the ultrasonic transducer were operating optimally for a duration of a first predetermined length of time; 25. A device as described in any one of clauses 1 to 24, storing instructions to: calculate an actual mist volume value by proportionally reducing the maximum mist volume value based on the effectiveness value to determine the actual volume of mist generated over a duration of a first predetermined length of time. Clause 26 The memory, when executed by the processor, causes the processor to: calculating a therapeutic dose value indicative of the amount of therapeutic agent in the actual volume of mist generated over a duration of a first predetermined length of time; 26. The device of clause 25, further comprising instructions for storing a therapeutic dose value in memory. Clause 27 The memory, when executed by the processor, causes the processor to: activating the mist generator device for a plurality of predetermined lengths of time; storing a plurality of therapeutic dose values ​​in a memory, each therapeutic dose value indicating an amount of therapeutic agent in the generated mist for a respective duration of a predetermined length of time; 27. The device of claim 26, further comprising: storing instructions to prevent further activation of the mist generator device for a predetermined duration if the total amount of therapeutic agent in the mist generated over the predetermined duration is equal to or greater than a predetermined threshold. Clause 28. The device of clause 27, wherein the predetermined duration is a duration in the range of 1 to 24 hours. Clause 29 The memory, when executed by the processor, causes the processor to: 29. A device as described in clause 27 or 28, storing instructions to cause data indicative of a nicotine quantity value to be transmitted from the mist generator device to a computing device for storage in the memory of the computing device. Clause 30: A method of generating a mist for inhalation by a user, comprising: activating the mist generator device for a first predetermined length of time, where activating the mist generator device includes driving an ultrasonic transducer in the mist generator device with an AC drive signal, causing the ultrasonic transducer to vibrate and atomize the liquid to generate a mist comprising the atomized liquid and air; periodically measuring a current of the AC drive signal through the ultrasonic transducer for a first predetermined length of time and storing the periodically measured current values ​​in memory; calculating an effectiveness value indicative of the effectiveness of operation of the ultrasonic transducer in atomizing the liquid using the current values ​​stored in the memory; selecting a second predetermined length of time in response to the significance value; activating the mist generator device for a second predetermined length of time, causing the mist generator device to generate a predetermined amount of mist for the second predetermined length of time. Article 31 periodically measuring a frequency of an AC drive signal driving the ultrasonic transducer for a first predetermined length of time and storing the periodically measured frequency values ​​in memory; 31. The method of clause 30, further comprising: calculating an effectiveness value using the frequency values ​​stored in the memory. Clause 32 includes calculating the effectiveness value using the following formula:

[0472]

number

[0473] During the ceremony, Q I is the effectiveness value, Q F is a frequency subavailability value based on the monitored frequency value, Q A is the analog-to-digital converter ("ADC") quasi-effectiveness value based on the measured current value, t=0 is the start of the first predetermined time period; t=D is the end of the first predetermined period of time; N is the number of periodic measurements during the first predetermined length of time;

[0474]

number

[0475] 32. The method of claim 31, wherein: Article 33 periodically measuring a duty cycle of an AC drive signal driving the ultrasonic transducer for a first predetermined length of time and storing the periodically measured duty cycle value in memory; Based on the current value stored in memory, Q A 33. The method of claim 32, further comprising: modifying a subeffectiveness value of an analog-to-digital converter (“ADC”). Article 34 periodically measuring a voltage of a battery powering the mist generator device for a first predetermined length of time and storing the periodically measured battery voltage values ​​in memory; Based on the battery voltage value stored in memory, Q A 34. The method of claim 32 or 33, further comprising: modifying a subeffectiveness value of an analog-to-digital converter ("ADC"). Article 35 Calculating a maximum mist volume value that would be produced if the ultrasonic transducer were operating optimally for a duration of a first predetermined length of time; 35. The method of any one of clauses 30 to 34, further comprising: calculating an actual mist volume value by proportionally reducing the maximum mist volume value based on the effectiveness value to determine the actual volume of mist generated over the duration of the first predetermined length of time. Article 36 calculating a therapeutic dose value indicative of the amount of therapeutic agent in the actual volume of mist generated over a duration of a first predetermined length of time; 36. The method of clause 35, further comprising storing the therapeutic dose value in a memory. Article 37 activating the mist generator device for a plurality of predetermined lengths of time; storing a plurality of therapeutic dose values ​​in a memory, each therapeutic dose value indicating an amount of therapeutic agent in the generated mist for a respective duration of a predetermined length of time; 37. The method of claim 36, further comprising: preventing further activation of the mist generator device for a predetermined duration if the total amount of therapeutic agent in the mist generated over the predetermined duration is equal to or greater than a predetermined threshold. Clause 38. The method of clause 37, wherein the predetermined duration is a duration in the range of 1 to 24 hours. Article 39 39. The method of clause 37 or 38, further comprising transmitting data indicative of the therapeutic dose value from the mist generator device to a computing device for storage in a memory of the computing device. Clause 40. A mist generator device for delivering a therapeutic agent to a user, the mist generator device for use with a driver device, comprising: a housing having a liquid chamber for containing a liquid to be nebulized, the liquid containing a therapeutic agent; a sonication assembly coupled to a housing, an ultrasonic transducer comprising an atomizing surface, a first electrical transducer contact, and a second electrical transducer contact, the first electrical transducer contact and the second electrical transducer contact for receiving an AC drive signal from a driver device; a first assembly part having a recess for holding an ultrasonic transducer; a second assembly part coupled to the first assembly part, an ultrasonic treatment recess overlaid on the ultrasonic transducer to form an ultrasonic treatment chamber; a sonication assembly air inlet port in fluid communication with the sonication recess; a sonication assembly mist outlet port in fluid communication with the sonication recess; an ultrasonic treatment assembly comprising a second assembly portion comprising an air flow path extending from the ultrasonic treatment assembly air inlet port through the ultrasonic treatment recess to the ultrasonic treatment assembly mist outlet port; At least one of the first assembly part and the second assembly part comprises an elastically deformable section that forms a seal between the first assembly part and the second assembly part, the seal minimizing or preventing leakage of fluid between the first assembly part and the second assembly part, and the mist generator device comprises: a barrier portion disposed between the sonication assembly and the housing, the barrier portion comprising a resiliently deformable seal that minimizes or prevents fluid leakage, the barrier portion comprising a capillary opening having a resiliently deformable wall; a capillary tube extending from the liquid chamber to the ultrasonic treatment chamber through a capillary opening such that a first portion of the capillary tube is within the liquid chamber and a second portion of the capillary tube is within the ultrasonic treatment chamber, the second portion of the capillary tube being superimposed on an atomizing surface of the ultrasonic transducer, such that when the ultrasonic transducer is driven by an AC drive signal from a driver device, the atomizing surface vibrates and atomizes the liquid carried by the second portion of the capillary tube to generate a mist comprising the atomized liquid and air within the ultrasonic treatment chamber, the mist flowing out through the ultrasonic treatment assembly mist outlet port for inhalation by a user. Clause 41. A device according to clause 40, wherein the first assembly part is made of an elastically deformable material and a portion of the first assembly part forms a seal between the first assembly part and the second assembly part. Clause 42. A device according to clause 41, wherein the elastically deformable material is silicone. Clause 43. A device according to any one of clauses 40 to 42, wherein the second assembly part is made of an elastically deformable material and a part of the second assembly part forms a seal between the first assembly part and the second assembly part. Clause 44. A device according to clause 43, wherein the elastically deformable material is silicone. Clause 45 The second assembly part a body portion provided with an ultrasonic treatment recess; 45. The device of clause 43 or 44, comprising: a cover portion coupled to the body portion and provided with a channel defining at least a portion of the air flow path, one end of the channel forming the air inlet port and the other end of the channel forming the mist outlet port. Clause 46 A device described in any one of clauses 40 to 45, wherein the second assembly part comprises at least one biasing member provided within the ultrasonic processing recess, each biasing member exerting a biasing force on the second portion of the capillary tube that biases the second portion of the capillary tube against the atomization surface of the ultrasonic transducer. Clause 47. The device of Clause 46, wherein the second assembly portion comprises a plurality of biasing members. Clause 48. The device of clause 46 or 47, wherein each biasing member is integrally formed with the second assembly part. Clause 49. A device as described in any one of clauses 46 to 48, wherein each biasing member has an attachment end attached to the second assembly portion and a distal end contacting the second portion of the capillary tube, the distal end being narrower than the attachment end. Clause 50. A device according to any one of clauses 46 to 49, wherein each biasing member is substantially conical in shape. Clause 51 A device described in any one of clauses 40 to 50, wherein the housing comprises an internal cavity defined by a base and a sidewall projecting upwardly from the base, the liquid chamber being formed in a portion of the internal cavity adjacent the base, and the ultrasonic processing assembly being at least partially received in the internal cavity such that the liquid chamber is disposed between the ultrasonic processing assembly and the base. Clause 52. A device as described in clause 51, wherein the sonication assembly contacts the sidewall of the housing and forms a seal that minimizes or prevents fluid flow between the sonication assembly and the sidewall of the housing. Clause 53. A device as described in clause 51 or 52, wherein the ultrasonic treatment assembly comprises a fill hole extending from the fill opening through a portion of the ultrasonic treatment assembly to the liquid chamber, allowing fluid to be injected through the fill hole into the liquid chamber. Clause 54. A device as described in any one of clauses 51 to 53, wherein the device comprises a mouthpiece attached to the housing to substantially enclose the internal cavity, the mouthpiece comprising a mist outlet opening in fluid communication with the ultrasonic treatment assembly mist outlet port to provide a mist flow path from the ultrasonic treatment assembly to the mist outlet opening. Clause 55. A device as described in clause 54, wherein the device comprises a foam layer disposed within the mist flow path to absorb droplets of liquid above a predetermined size from the mist flowing along the mist flow path. Clause 56. A device as described in clause 55, wherein the foam layer is disposed between the ultrasonic treatment assembly and the divider, the divider comprising a mist outlet opening for allowing mist to flow from the foam layer and beyond the divider. Clause 57. A device according to clause 56 dependent on clauses 53 to 55, wherein the divider comprises a plug sealing the fill opening to minimize or prevent leakage of liquid from the liquid chamber to the exterior of the device. Clause 58. A device as claimed in any one of clauses 40 to 57, wherein the atomising surface of the ultrasonic transducer is substantially planar, the plane of the atomising surface being substantially parallel to the longitudinal extent of the housing. Clause 59: The ultrasonic transducer is received in an ultrasonic transducer stack, the ultrasonic transducer stack comprising: a generally cylindrical silicone base having a central opening through which a first electrical transducer contact extends, the silicone base including a generally cylindrical recess for receiving an ultrasound transducer such that a contact surface of the ultrasound transducer is electrically connected to the first electrical transducer contact; A device described in any one of clauses 40 to 58, comprising: a generally cylindrical metal shell at least partially surrounding the silicone base, the metal shell having a lip that contacts at least a portion of the circumference of the ultrasonic transducer to hold the ultrasonic transducer within the cylindrical recess, and forming a second electrical transducer contact. Clause 60. A device as described in clause 59, wherein a portion of the metal shell is cut away to provide access for the first elongated device terminal to electrically connect to the first electrical transducer contact, and the second elongated device terminal is electrically connected to the metal shell, and the first elongated device terminal and the second elongated device terminal receive an AC drive signal from the driver device and transmit the AC drive signal to the ultrasonic transducer. Clause 61. A device as claimed in any one of clauses 40 to 60, wherein the housing comprises metal end caps that are magnetically attracted to magnets on the driver device to hold the mist generator device in engagement with the driver device. Clause 62. A device according to any one of clauses 40 to 61, wherein the air flow path comprises multiple turns that change the direction of the air flow multiple times as the air flows from the air inlet port to the sonication recess. Clause 63 A device according to any one of clauses 40 to 61, wherein the capillary tube is at least 75% bamboo fibre. Clause 64. A device according to any one of clauses 40 to 63, wherein the capillary tube is 100% bamboo fibre. Article 65 If the device: an identification structure carried by the housing for identifying the mist generator device, 65. A device as described in any one of clauses 40 to 64 comprising an identification arrangement, the OTP IC comprising a one-time programmable integrated circuit (OTP IC) having a memory for storing a unique identifier of the mist generator device, the OTP IC comprising a digital core including a cryptographic authentication device and electrical connections providing an electronic interface for communication with the OTP IC and a driver device. Clause 66. A device as described in clause 65, wherein the one-time programmable (OTP) device includes an anti-counterfeiting feature that identifies genuine mist generator devices and enables only mist generator devices identified as genuine to be permitted for use with the driver device. Clause 67. A device as claimed in clause 65 or 66, wherein the OTP device controls the mist generator device so that it functions to generate mist only when authorised. Clause 68. A device as claimed in any one of clauses 65 to 67, wherein the OTP IC contains unique information data that enables traceability of the mist generator device and monitoring of consumption by users of the mist generator device. Clause 69. A device as described in any one of clauses 65 to 68, wherein the memory of the OTP IC stores a record of the state of the mist generator device indicating at least one of historical use of the mist generator device and the volume of liquid in the liquid chamber. Clause 70. A device as described in any one of clauses 65 to 69, wherein the memory of the OTP IC stores a record of seconds of aerosolization, whereby the mist generator is considered to be empty of liquid in the liquid chamber after a predetermined use period of about 1,000 seconds of aerosolization and cannot be activated after the predetermined use period. Clause 71. A device as claimed in any one of clauses 65 to 70, wherein whenever the mist generator device is deemed to be empty, the mist generator device is not activated if coupled to the driver device. Clause 72. A device as described in any one of clauses 65 to 71, wherein the cryptographic authentication device uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to encrypt / decrypt data stored in the OTP IC and data transmitted to and from the OTP IC. Clause 73 A device according to any one of clauses 40 to 72 wherein the liquid chamber contains a liquid having a liquid viscosity of between 1.05 Pa·s and 1.412 Pa·s and a liquid density of between 1.1 g / mL and 1.3 g / mL. Clause 74 A mist generator device for delivering mist to a user, the mist generator device for use with a driver device, comprising: a housing including a liquid chamber, the liquid chamber containing a liquid to be atomized, the liquid including a therapeutic agent; a sonication assembly coupled to a housing, an ultrasonic transducer including a first electrical connection and a second electrical connection, the first electrical connection and the second electrical connection for receiving an AC drive signal from a driver device; a first assembly part having a recess for holding an ultrasonic transducer; a second assembly part coupled to the first assembly part, an ultrasonic treatment recess overlaid on the ultrasonic transducer to form an ultrasonic treatment chamber; a sonication assembly air inlet port in fluid communication with the sonication recess; a sonication assembly mist outlet port in fluid communication with the sonication recess; an ultrasonic treatment assembly comprising a second assembly portion comprising an air flow path extending from the ultrasonic treatment assembly air inlet port through the ultrasonic treatment recess to the ultrasonic treatment assembly mist outlet port; At least one of the first assembly part and the second assembly part comprises an elastically deformable section that forms a seal between the first assembly part and the second assembly part, the seal minimizing or preventing leakage of fluid between the first assembly part and the second assembly part, and the mist generator device comprises: a barrier portion disposed between the sonication assembly and the housing, the barrier portion comprising a resiliently deformable seal that minimizes or prevents fluid leakage, the barrier portion comprising a capillary opening having a resiliently deformable wall; a capillary tube extending through a capillary opening from the liquid chamber to the ultrasonic treatment chamber such that a first portion of the capillary tube is within the liquid chamber and a second portion of the capillary tube is within the ultrasonic treatment chamber, wherein when the ultrasonic transducer is driven by an AC drive signal from a driver device, the atomizing surface vibrates and atomizes the liquid carried by the second portion of the capillary tube to generate a mist comprising the atomized liquid and air within the ultrasonic treatment chamber, and the second portion of the capillary tube is superimposed on the atomizing surface of the ultrasonic transducer so that the mist flows out through the ultrasonic treatment assembly mist outlet port for inhalation by a user. Clause 75. A device as described in clause 74, wherein the first assembly part is made of an elastically deformable material, and a portion of the first assembly part forms a seal between the first assembly part and the second assembly part. Clause 76. A device according to clause 75 or 75, wherein the second assembly part is made of an elastically deformable material, and a part of the second assembly part forms a seal between the first assembly part and the second assembly part. Article 77 The second assembly part a main body provided with an ultrasonic treatment recess; A device described in any one of clauses 1 to 76, comprising: a cover coupled to the body and provided with a channel defining at least a portion of the air flow path, one end of the channel forming an air inlet port and the other end of the channel forming a mist outlet port. Clause 78 A device described in any one of clauses 1 to 77, wherein the second assembly part comprises at least one biasing member provided within the ultrasonic processing recess, each biasing member exerting a biasing force on the second portion of the capillary tube to bias the second portion of the capillary tube against the atomization surface of the ultrasonic transducer. Clause 79. The device of Clause 78, wherein each biasing member is integrally formed with the second assembly portion. Clause 80. A device as described in clause 78 or 79, wherein each biasing member has an attachment end attached to the second assembly part and a distal end contacting the second portion of the capillary tube, the distal end being narrower than the attachment end. Clause 81. A device according to any one of clauses 78 to 80, wherein each biasing member is substantially conical. Clause 82 A device described in any one of clauses 1 to 81, wherein the housing has an internal cavity defined by a base and a sidewall projecting upwardly from the base, the liquid chamber is formed in a portion of the internal cavity adjacent the base, the ultrasonic processing assembly is at least partially received in the internal cavity, and the liquid chamber is disposed between the ultrasonic processing assembly and the base. Clause 83. A device as described in clause 82, wherein the sonication assembly contacts the sidewall of the housing and forms a seal that minimizes or prevents fluid flow between the sonication assembly and the sidewall of the housing. Clause 84. A device as described in clause 82 or 83, wherein the ultrasonic treatment assembly comprises a fill hole extending from the fill opening through a portion of the ultrasonic treatment assembly to the liquid chamber, allowing liquid to be injected through the fill hole into the liquid chamber. Clause 85. A device as described in any one of clauses 82 to 84, wherein the device comprises a mouthpiece attached to the housing to substantially close the internal cavity, the mouthpiece comprising a mist outlet opening in fluid communication with the ultrasonic treatment assembly mist outlet port to provide a mist flow path from the ultrasonic treatment assembly to the mist outlet opening. Clause 86. A device as described in clause 85, wherein the device comprises a foam layer disposed proximate the mist flow path for absorbing droplets of liquid above a predetermined size from the mist flowing along the mist flow path. Clause 87. A device as described in clause 86, wherein the foam layer is disposed between the ultrasonic treatment assembly and the divider, the divider comprising a mist outlet opening for allowing mist to flow from the foam layer and beyond the divider. Clause 88 A device according to clause 87 dependent on clauses 84 to 87, wherein the divider comprises a plug that seals the fill opening to minimize or prevent leakage of liquid from the liquid chamber to outside the device. Clause 89: The ultrasonic transducer is received in an ultrasonic transducer stack, the ultrasonic transducer stack comprising: a base having a central opening through which a portion of the first electrical transducer contact extends to electrically connect to a first electrical connection of the ultrasound transducer; A device described in any one of clauses 1 to 88, comprising a metal shell at least partially surrounding a base, the metal shell having a lip that engages with at least a portion of the circumference of the ultrasonic transducer to hold the ultrasonic transducer in place relative to the base, a portion of the metal shell being a second electrical transducer contact that electrically connects to a second electrical connection portion of the ultrasonic transducer. Clause 90. A device as described in clause 89, wherein a portion of the metal shell is cut away to provide access for the first device terminal to electrically connect to the first electrical transducer contact, and the second device terminal is electrically connected to the metal shell, and the first device terminal and the second device terminal receive an AC drive signal from the driver device and transmit the AC drive signal to the ultrasonic transducer. Clause 91. A device according to any one of clauses 1 to 90, wherein the air flow path comprises multiple turns that change the direction of the air flow multiple times as the air flows from the air inlet port to the sonication recess. Article 92 A mist generator, a mist generator device according to any one of clauses 1 to 91; a driver device coupled to the mist generator device, the driver device comprising: A mist generator comprising an AC drive signal generator electrically coupled to a first electrical connection of the ultrasonic transducer and electrically coupled to a second electrical connection of the ultrasonic transducer to drive the ultrasonic transducer with an AC drive signal. Clause 93 An ultrasonic transducer assembly comprising: an ultrasonic transducer having a first electrical connection and a second electrical connection; a first electrical transducer contact; a base having a central opening through which a portion of the first electrical transducer contact extends to electrically connect to a first electrical connection of the ultrasound transducer; an ultrasonic transducer assembly comprising: a metal shell at least partially surrounding a base, the metal shell having a lip that engages at least a portion of the periphery of the ultrasonic transducer to hold the ultrasonic transducer in place relative to the base, a portion of the metal shell being a second electrical transducer contact that electrically connects to a second electrical connection of the ultrasonic transducer.

[0476] Although specific exemplary embodiments of the present invention have been described, the appended claims are not intended to be limited to only these embodiments. The claims are to be interpreted literally, intentionally, and / or to encompass equivalents.

[0477] It will be understood that the various embodiments and features described and illustrated herein may be combined with one another in whole or in part within the spirit and scope of the present invention.

[0478] 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 skilled in the art that the present invention is not limited to the specific details set forth herein and may be practiced without these specific details.

[0479] As used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. These terms are not to be interpreted as excluding the presence of other features, steps or components.

[0480] The present invention may also broadly reside in any and all combinations of two or more of the parts, elements, steps, examples, and / or features referred to or indicated herein, individually or collectively. In particular, one or more features in any of the embodiments described herein may be combined with one or more features from any other embodiment(s) described herein.

[0481] Protection may be sought for any feature disclosed in any one or more of the publications referenced herein in connection with this disclosure.

[0482] Although specific exemplary embodiments of the present invention have been described, the appended claims are not intended to be limited to only these embodiments. The claims are to be interpreted literally, intentionally, and / or to encompass equivalents.

Claims

1. 1. A mist generator device for delivering mist to a user, the mist generator device for use with a driver device, comprising: a housing including a liquid chamber containing a liquid to be atomized, the liquid including a therapeutic agent; a sonication assembly coupled to the housing, an ultrasonic transducer including a first electrical connection and a second electrical connection, the first electrical connection and the second electrical connection for receiving an AC drive signal from a driver device; a first assembly part having a recess for holding the ultrasonic transducer; a second assembly part coupled to the first assembly part, an ultrasonic treatment recess overlaid on the ultrasonic transducer to form an ultrasonic treatment chamber; a sonication assembly air inlet port in fluid communication with the sonication recess; a sonication assembly mist outlet port in fluid communication with the sonication recess; an ultrasonic processing assembly comprising: a second assembly portion comprising: an air flow path extending from the ultrasonic processing assembly air inlet port through the ultrasonic processing recess to the ultrasonic processing assembly mist outlet port; at least one of the first assembly part and the second assembly part comprises an elastically deformable section that forms a seal between the first assembly part and the second assembly part, the seal minimizing or preventing leakage of fluid between the first assembly part and the second assembly part, and the mist generator device comprises: a barrier portion disposed between the sonication assembly and the housing, the barrier portion comprising a resiliently deformable seal that minimizes or prevents fluid leakage, the barrier portion comprising a capillary opening having a resiliently deformable wall; a capillary tube extending through the capillary opening from the liquid chamber to the ultrasonic treatment chamber such that a first portion of the capillary tube is within the liquid chamber and a second portion of the capillary tube is within the ultrasonic treatment chamber, wherein when the ultrasonic transducer is driven by an AC drive signal from the driver device, the atomization surface vibrates, atomizing the liquid carried by the second portion of the capillary tube to generate a mist comprising the atomized liquid and air within the ultrasonic treatment chamber, and the second portion of the capillary tube is superimposed on the atomization surface of the ultrasonic transducer so that the mist flows out through the ultrasonic treatment assembly mist outlet port for inhalation by a user.

2. The device of claim 1 , wherein the first assembly part is made of an elastically deformable material, and a portion of the first assembly part forms the seal between the first assembly part and the second assembly part.

3. 3. The device of claim 1, wherein the second assembly part is made of an elastically deformable material, and a portion of the second assembly part forms the seal between the first assembly part and the second assembly part.

4. the second assembly part: a main body in which the ultrasonic treatment recess is formed; 4. The device of claim 1, further comprising: a cover coupled to the body and provided with a channel that defines at least a portion of the air flow path, one end of the channel forming the air inlet port and the other end of the channel forming the mist outlet port.

5. 5. The device of claim 1, wherein the second assembly part comprises at least one biasing member disposed within the ultrasonic processing recess, each biasing member exerting a biasing force on the second portion of the capillary tube, the biasing force urging the second portion of the capillary tube against the atomization surface of the ultrasonic transducer.

6. The device of claim 5 , wherein each biasing member is integrally formed with the second assembly portion.

7. 7. The device of claim 5 or 6, wherein each biasing member comprises an attachment end attached to the second assembly portion and a distal end contacting the second portion of the capillary tube, the distal end being narrower than the attachment end.

8. A device according to any one of claims 5 to 7, wherein each biasing member is substantially conical in shape.

9. 9. The device of claim 1, wherein the housing comprises an internal cavity defined by a base and a sidewall projecting upwardly from the base, the liquid chamber being formed in a portion of the internal cavity adjacent the base, the ultrasonic processing assembly being at least partially received in the internal cavity, and the liquid chamber being disposed between the ultrasonic processing assembly and the base.

10. 10. The device of claim 9, wherein an ultrasonication assembly contacts the sidewall of the housing and forms a seal that minimizes or prevents fluid flow between the ultrasonication assembly and the sidewall of the housing.

11. 11. The device of claim 9 or 10, wherein the sonication assembly comprises a fill hole extending from a fill opening through a portion of the sonication assembly to the liquid chamber to allow liquid to be injected into the liquid chamber through the fill hole.

12. 12. The device of any one of claims 9 to 11, wherein the device comprises a mouthpiece attached to the housing to substantially enclose the internal cavity, the mouthpiece comprising a mist outlet opening in fluid communication with the ultrasonic treatment assembly mist outlet port to provide a mist flow path from the ultrasonic treatment assembly to the mist outlet opening.

13. 13. The device of claim 12, wherein the device comprises a foam layer disposed proximate the mist flow path to absorb droplets of liquid above a predetermined size from the mist flowing along the mist flow path.

14. 14. The device of claim 13, wherein the foam layer is disposed between the sonication assembly and a divider, the divider comprising a mist exit opening for allowing mist to flow from the foam layer and beyond the divider.

15. 15. A device according to claim 14 when dependent on claims 11 to 13, wherein the divider comprises a plug that seals the fill opening to minimize or prevent leakage of liquid from the liquid chamber to outside the device.

16. The ultrasonic transducer is received within an ultrasonic transducer stack, the ultrasonic transducer stack comprising: a base having a central opening through which a portion of a first electrical transducer contact extends to electrically connect to the first electrical connection of the ultrasonic transducer; 16. The device of claim 1, comprising: a metal shell at least partially surrounding the base, the metal shell having a lip that engages at least a portion of the periphery of the ultrasonic transducer to hold the ultrasonic transducer in place relative to the base, a portion of the metal shell being a second electrical transducer contact that electrically connects to the second electrical connection of the ultrasonic transducer.

17. 17. The device of claim 16, wherein a portion of the metal shell is cut away to provide access for a first device terminal to electrically connect to the first electrical transducer contact, and a second device terminal is electrically connected to the metal shell, and the first device terminal and the second device terminal receive an AC drive signal from a driver device and transmit the AC drive signal to the ultrasonic transducer.

18. 18. The device of any one of claims 1 to 17, wherein the air flow path includes multiple turns that change direction of the air flow multiple times as the air flows from the air inlet port to the sonication recess.

19. A mist generator comprising: A mist generator device according to any one of claims 1 to 18; a driver device coupled to the mist generator device, the driver device comprising: an AC drive signal generator electrically coupled to the first electrical connection of the ultrasonic transducer and electrically coupled to the second electrical connection of the ultrasonic transducer to drive the ultrasonic transducer with an AC drive signal.

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