Hookah Device

Abstract

A hookah device (202) is provided that is attached to a hookah (246). The hookah device (202) comprises a plurality of ultrasonic mist generators (201) for generating mist for inhalation by a user, and includes a drive unit (202) for controlling the mist generators (201) to maximize the efficiency of mist generation by the mist generators (201) and optimize the mist output from the hookah device (202).

Description

[Technical Field]

[0001] Cross-reference to related applications This application claims the benefit of, and incorporates by reference in its entirety, the priority claims of, U.S. Patent Application No. 17 / 122025, filed December 15, 2020, and U.S. Patent Application No. 17 / 220189, filed April 1, 2021, and UK Patent Application No. 2104872.3, filed April 6, 2021.

[0002] Field The present invention relates to a hookah device, and more particularly to a hookah device that generates mist using ultrasonic vibrations. [Background technology]

[0003] background A traditional hookah is a smoking device that uses ground tobacco leaves heated over a charcoal fire. The heat from the charcoal burns the crushed tobacco leaves, producing smoke that is then drawn through a glass chamber and delivered to the user. The water cools the hot smoke for easier inhalation.

[0004] Hookah is said to have originated in ancient Persia and India centuries ago, and today hookah cafes are popular all over the world, including the UK, France, Russia, the Middle East, and the US.

[0005] A typical modern hookah consists of a head (with a hole at the bottom), a metal body, a water bowl, and a flexible hose with a mouthpiece. Newer forms of electronic hookah products have also emerged, such as steam stones and hookah pens. These devices are battery or mains powered and work by heating a liquid containing nicotine, flavorings, and other chemicals to produce smoke, which is inhaled.

[0006] Although many users consider it less harmful than smoking cigarettes, smoking hookah carries many of the same health risks as smoking cigarettes.

[0007] Therefore, there is a need in the art for an improved hookah device that seeks to address at least some of the problems described herein.

[0008] SUMMARY OF THE INVENTION The present invention seeks to provide an improved hookah device. Summary of the Invention

[0009] overview The present invention provides a hookah device as claimed in claim 1 and a hookah as claimed in claim 19. The present invention also provides preferred embodiments as claimed in the dependent claims.

[0010] The various embodiments of the present disclosure described below have several advantages and benefits over conventional hookah devices and hookahs. These advantages and benefits are set forth in the following description.

[0011] The hookah devices of the embodiments of the present disclosure have environmental advantages because the hookah devices do not produce smoke and the hookah devices eliminate the need for burning charcoal.

[0012] According to some arrangements, there is provided a hookah device comprising: a plurality of ultrasonic mist generating devices each provided with a respective mist outlet; a driver device electrically connected to each mist generating device and configured to activate the mist generating device; a hookah mounting device configured to mount the hookah device to the hookah, and a hookah outlet port providing an outlet from the mist outlet ports of the mist generating devices to the hookah device, wherein when at least one of the mist generating devices is activated by the driver device, mist generated by each activated mist generating device flows along a fluid flow path from the hookah device to exit the hookah.

[0013] In some arrangements, the driver device is electrically connected to each of the mist generating devices by a data bus, and the driver device is configured to identify and control each mist generating device using a respective unique identifier for the mist generating device.

[0014] In some arrangements, each mist generating device further comprises an identification arrangement, the identification arrangement comprising an integrated circuit having a memory that stores a unique identifier of the mist generating device, and an electrical connection that provides an electronic interface for communicating with the integrated circuit.

[0015] In some arrangements, the driver device is configured to control each mist generating device to activate independently of the other mist generating devices.

[0016] In some arrangements, the driver device is configured to control each of the mist generating devices to operate in a predetermined sequence.

[0017] In some arrangements, each mist generating device comprises a manifold having a manifold pipe in fluid communication with a mist outlet port of the mist generating device, such that mist output from the mist outlet port combines within the manifold pipe and flows through the manifold pipe out of the hookah device.

[0018] In some arrangements, the hookah device comprises four mist generating devices releasably coupled to a manifold at 90 degrees relative to one another.

[0019] In some arrangements, each mist generating device is releasably attached to a driver device such that each mist generating device is separable from the driver device.

[0020] 10. The ultrasonic treatment apparatus of claim 1, wherein the mist generating housing is elongated and includes an air inlet port and a mist outlet port; a liquid chamber within the mist generating housing, the liquid chamber containing a liquid to be atomized; a sonication chamber within the mist generating housing; and a capillary element extending between the liquid chamber and the sonication chamber, the capillary element having a first portion within the liquid chamber and a second portion within the sonication chamber, the first portion including the capillary element. 11. The ultrasonic treatment apparatus of claim 1, wherein the second portion of the capillary element partially overlaps the second portion of the capillary element, and the ultrasonic treatment apparatus is configured to vibrate the mist generating surface to atomize the liquid carried by the second portion of the capillary element and generate a mist consisting of the mist-generated liquid and air within the sonication chamber. An air flow arrangement that provides an air flow path between the air inlet port, the sonication chamber, and the air outlet port.

[0021] In some arrangements, each mist generating device further comprises a transducer holder held within the mist generating housing, the transducer element holding an ultrasonic transducer, the transducer holder holding a second portion of the capillary element overlying a portion of the atomizing surface, and a partition providing a barrier between the liquid chamber and the ultrasonic treatment chamber, the partition defining a capillary opening through which a portion of the first portion of the capillary element extends.

[0022] In some arrangements, the capillary elements are 100% bamboo fiber.

[0023] In some arrangements, the air flow arrangement is configured to redirect the air flow along the air flow path as the air flow passes into the ultrasonic treatment chamber so that the air flow is substantially perpendicular to the atomizing surface of the ultrasonic transducer.

[0024] In some arrangements, the liquid chamber 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.

[0025] In some arrangements, the liquid chamber contains a liquid comprising about a 2:1 molar ratio of levulinic acid and nicotine.

[0026] In some arrangements, the driver device comprises: an AC drive configured to generate an AC drive signal at a predetermined frequency to drive a respective ultrasonic transducer in each mist generating device; an active power monitoring arrangement configured to monitor the active power used by the ultrasonic transducers when the ultrasonic transducers are driven by the AC drive signal, the active power monitoring arrangement configured to provide a monitor signal indicative of the active power used by the ultrasonic transducer; a processor configured to control the AC drive and to receive the monitor signal drive from the active power monitoring arrangement; and a memory storing instructions that, when executed by the processor, cause the processor to: A. Controlling the AC drive to output an AC drive signal to the ultrasonic transducer at a predetermined sweep frequency B. Calculate the active power being used by the ultrasonic transducer based on the monitoring signal C. Controlling the AC drive to modulate the AC drive signal to maximize the effective power used by the ultrasonic transducer D. Store in memory a record of the maximum available power used by the ultrasonic transducer and the sweep frequency of the AC drive signal. E. Repeat steps A-D a predetermined number of times, with the sweep frequency increasing with each iteration, so that after a predetermined number of iterations, the sweep frequency increases from the sweep start frequency to the sweep end frequency. F. From the records stored in memory, identify the 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 drive to output an AC drive signal at an optimal frequency to the ultrasonic transducer, driving the ultrasonic transducer to atomize the liquid.

[0027] In some arrangements, 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, the active power monitoring arrangement being designed to provide a monitor signal indicative of the sensed drive current.

[0028] In some arrangements, the memory stores a method that, when executed by the processor, instructs the processor to repeat steps A-D in which the sweep frequency increases from a sweep start frequency of 2900 kHz to a sweep end frequency of 2960 kHz.

[0029] In some arrangements, the memory stores a method that, when executed by the processor, instructs the processor to repeat steps A-D in which the sweep frequency increases from a sweep start frequency of 2900 kHz to a sweep end frequency of 3100 kHz.

[0030] In some arrangements, the AC drive modulates the AC drive signal by pulse width modulation to maximize the effective power being used by the ultrasonic transducer.

[0031] According to some arrangements there is provided a hookah comprising: a water chamber, an elongate stem having a first end attached to the water chamber, a mist flow path extending from a second end of the stem, through the stem to the first end. A hookah device according to any of claims 1 to 19 as defined below, characterised in that the hookah mounting arrangement of the hookah device is attached to the hookah stem at the second end of the stem. [Brief explanation of the drawings]

[0032] In order that the invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is an exploded perspective view of the components of an ultrasonic mist inhaler. [Figure 2] FIG. 2 is an exploded perspective view of the components of the inhaler liquid reservoir structure. [Figure 3] FIG. 3 is a cross-sectional view of components of an inhaler liquid reservoir structure. [Figure 4A] FIG. 4A is an isometric view of the airflow member of the inhaler liquid reservoir structure according to FIGS. [Figure 4B] FIG. 4B is a cross-sectional view of the air blowing member shown in FIG. 4A. [Figure 5] FIG. 5 is a schematic diagram showing a piezoelectric transducer modeled as an RLC circuit. [Figure 6] FIG. 6 is a graph of frequency versus logarithmic impedance for an RLC circuit. [Figure 7] FIG. 7 is a graph of frequency versus logarithmic impedance showing the inductive and capacitive regions of operation of a piezoelectric transducer. [Figure 8] FIG. 8 is a flow diagram illustrating the operation of the frequency controller. [Figure 9] FIG. 9 is a perspective view of the mist generating device of the present disclosure. [Figure 10] FIG. 10 is a perspective view of the mist generating device of the present disclosure. [Figure 11] FIG. 11 is a schematic exploded perspective view of a mist generating device of the present disclosure. [Figure 12] FIG. 12 is a perspective view of a transducer holder of the present disclosure. [Figure 13] FIG. 13 is a perspective view of a transducer holder of the present disclosure. [Figure 14] FIG. 14 is a perspective view of a capillary element of the present disclosure. [Figure 15] FIG. 15 is a perspective view of a capillary element of the present disclosure. [Figure 16] FIG. 16 is a perspective view of a transducer holder of the present disclosure. [Figure 17] FIG. 17 is a perspective view of a transducer holder of the present disclosure. [Figure 18]FIG. 18 is a schematic perspective view of a portion of a housing of the present disclosure. [Figure 19] FIG. 19 is a perspective view of an absorbent element of the present disclosure. [Figure 20] FIG. 20 is a schematic perspective view of a portion of a housing of the present disclosure. [Figure 21] FIG. 21 is a schematic perspective view of a portion of a housing of the present disclosure. [Figure 22] FIG. 22 is a perspective view of an absorbent element of the present disclosure. [Figure 23] FIG. 23 is a schematic perspective view of a portion of a housing of the present disclosure. [Figure 24] FIG. 24 is a schematic perspective view of a portion of a housing of the present disclosure. [Figure 25] FIG. 25 is a schematic perspective view of a portion of a housing of the present disclosure. [Figure 26] FIG. 26 is a schematic perspective view of a circuit board of the present disclosure. [Figure 27] FIG. 27 is a schematic perspective view of a circuit board of the present disclosure. [Figure 28] FIG. 28 is a schematic exploded perspective view of a mist generating device of the present disclosure. [Figure 29] FIG. 29 is a schematic exploded perspective view of a mist generating device of the present disclosure. [Figure 30] FIG. 30 is a schematic diagram of an integrated circuit layout of the present disclosure. [Figure 31] FIG. 31 is a schematic diagram of an integrated circuit of the present disclosure. [Figure 32] FIG. 32 is a schematic diagram of a pulse width modulation generator of the present disclosure. [Figure 33] FIG. 33 is a timing diagram of an example of the present disclosure. [Figure 34] FIG. 34 is a timing diagram of an example of the present disclosure. [Figure 35] FIG. 35 is a table illustrating example port functions of the present disclosure. [Figure 36] FIG. 36 is a schematic diagram of an integrated circuit of the present disclosure. [Figure 37]FIG. 37 is a circuit diagram of an example H-bridge of the present disclosure. [Figure 38] FIG. 38 is a circuit diagram of an example current sense arrangement of the present disclosure. [Figure 39] FIG. 39 is a circuit diagram of an example H-bridge of the present disclosure. [Figure 40] FIG. 40 is a graph showing the voltages during the phases of operation of the H-bridge of FIG. [Figure 41] FIG. 41 is a graph showing the voltages between the phases of operation of the H-bridge of FIG. [Figure 42] FIG. 42 is a graph showing the voltage and current at the terminals of an ultrasonic transducer while it is driven by the H-bridge of FIG. [Figure 43] FIG. 43 is a schematic diagram illustrating connections between integrated circuits of the present disclosure. [Figure 44] FIG. 44 is a schematic diagram of an integrated circuit of the present disclosure. [Figure 45] FIG. 45 is a diagram illustrating steps of an authentication method according to an example of the present disclosure. [Figure 46] FIG. 46 is a cross-sectional view showing the mist generating device of the present disclosure. [Figure 47] FIG. 47 is a cross-sectional view showing the mist generating device of the present disclosure. [Figure 48] FIG. 48 is a cross-sectional view showing the mist generating device of the present disclosure. [Figure 49] FIG. 49 is a perspective view of a hookah device of the present disclosure. [Figure 50] FIG. 50 is a perspective view of the hookah device of the present disclosure attached to the hookah body and water bowl. [Figure 51] FIG. 51 is a perspective exploded perspective view of a hookah device of the present disclosure. [Figure 52] FIG. 52 is a perspective view of the components of a hookah device of the present disclosure. [Figure 53] FIG. 53 is a perspective view of the components of a hookah device of the present disclosure. [Figure 54]FIG. 54 is a perspective view of one component of the hookah device of the present disclosure. [Figure 55] FIG. 55 is a perspective view of one component of the hookah device of the present disclosure. [Figure 56] FIG. 56 is a perspective view of one component of the hookah device and four mist generating devices of the present disclosure. [Figure 57] FIG. 57 is a perspective view of the components of a hookah device of the present disclosure. [Figure 58] FIG. 58 is a cross-sectional view of the components of a hookah device of the present disclosure. [Figure 59] FIG. 59 is a perspective view of the hookah device of the present disclosure attached to the hookah body and water bowl. DETAILED DESCRIPTION OF THE INVENTION

[0033] Detailed Description 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 discussion.

[0034] The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components, concentrations, applications, and arrangements are described below to simplify the disclosure. 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 include embodiments in which additional features 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 simplicity and clarity and does not, in itself, dictate a relationship between the various embodiments and / or configurations discussed.

[0035] The following disclosure describes representative arrangements or examples. Each arrangement or example may be considered an embodiment, and in this disclosure, references to "arrangements" or "examples" may be changed to "embodiments."

[0036] Some configurations of hookah devices incorporate ultrasonic aerosolization technology. Some configurations of hookah devices are configured to replace a traditional hookah head (either charcoal-heated or electronically heated). Some configurations of hookah devices releasably attach to an existing stem or metal body and water chamber / bowl in place of a traditional hookah head that houses tobacco and charcoal (or an electronic heating element).

[0037] In other configurations, the hookah device comprises a stem / body and a water chamber / bowl as a complete hookah device.

[0038] The tanks come in a variety of shapes and are decorated with traditional or futuristic décor, depending on personal preference. The design and development of several configurations of ultrasonic aerosolized hookah devices was carried out with tradition in mind, creating interchangeable heads that fit any existing hookah. The following disclosure describes the components and functionality of ultrasonic mist generators. The disclosure then describes several configurations of hookah devices incorporating multiple ultrasonic mist generators.

[0039] Conventional electronic vaporizers tend to rely on inducing high temperatures in metal components configured to heat the liquid within the inhaler, thus vaporizing the liquid for inhalation. The liquid typically contains nicotine and flavorings blended in a propylene glycol (PG) and vegetable glycerin (VG) solution, which are vaporized via the heating components at high temperatures. A problem with conventional inhalers is the potential for the metal to burn, which can then be inhaled along with the burnt liquid. Additionally, some people dislike the burnt smell and taste of the heated liquid.

[0040] 1 to 4 show an ultrasonic inhaler comprising an ultrasonic treatment chamber. It should be noted that the term "mist" used in the following disclosure means that the liquid is not heated, as is usually done in conventional inhalers known from the prior art. In fact, conventional inhalers use a heating element to heat the liquid above its boiling temperature to generate vapor, which is different from mist.

[0041] When a liquid is sonicated at high intensity, sound waves propagating through the liquid medium alternate between high-pressure (compression) and low-pressure (dilution) cycles at different speeds depending on the frequency. During the low-pressure cycle, high-intensity ultrasound creates tiny vacuum bubbles or voids in the liquid. This phenomenon is called cavitation. When these bubbles reach a volume where they cannot absorb the energy, they violently collapse during the high-pressure cycle. This creates extremely high localized pressures. Cavitation generates broken capillary waves, which break the liquid's surface tension and produce tiny droplets that are rapidly released into the air as a mist.

[0042] The cavitation phenomenon will be explained in more detail below.

[0043] When a liquid is atomized by ultrasonic vibration, minute bubbles are generated in the liquid.

[0044] The generation of bubbles is a process of cavity formation caused by negative pressure due to strong ultrasonic waves generated by means of ultrasonic vibrations.

[0045] During the positive pressure cycle, the size of the cavities becomes relatively small and negligible, and the high intensity ultrasound leads to rapid growth of the cavities.

[0046] Ultrasound, like other sound waves, consists of compression and expansion cycles. When in contact with a liquid, the compression cycle exerts positive pressure on the liquid, pushing the molecules together, while the expansion cycle exerts negative pressure, pushing the molecules apart.

[0047] Intense ultrasound creates regions of positive and negative pressure. In the negative pressure, cavities can form and grow. When the cavities reach a critical size, they collapse.

[0048] The amount of negative pressure required varies depending on the type and purity of the liquid. High-purity liquids have such high tensile strength that commercial ultrasonic generators cannot generate sufficient negative pressure to form cavities. For example, pure water requires a negative pressure of over 1,000 atmospheres, while even the most powerful ultrasonic generators can only generate a negative pressure of around 50 atmospheres. The tensile strength of a liquid is reduced by gas trapped in the gaps between liquid particles. This effect is similar to the strength loss caused by cracks in solid materials. When a gas-filled gap is subjected to a cycle of sonic negative pressure, the pressure drop causes the gas in the gap to expand, releasing tiny bubbles into the solution.

[0049] However, bubbles exposed to ultrasound continue to absorb energy by alternating cycles of compression and expansion of the sound waves. This causes the bubbles to grow and shrink repeatedly, maintaining a dynamic balance between the void inside the bubble and the liquid outside. Ultrasound can also cause the size of the bubbles to change. In some cases, the average size of the bubbles may also increase.

[0050] The growth of the cavity depends on the sound intensity. High-intensity ultrasound can rapidly expand the cavity during the negative pressure cycle, leaving the cavity with no opportunity to contract during the positive pressure cycle. In this way, the cavity can grow rapidly in one sound wave cycle. 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 the expansion cycle than during the compression cycle. Because the amount of gas entering and leaving the cavity depends on the surface area, diffusion into the cavity during the expansion cycle is slightly greater than diffusion during the compression cycle. This means that with each sound cycle, the cavity expands slightly more than it contracts. Over time, the cavity slowly grows larger.

[0051] It has been found that the growing cavities eventually reach a critical size at which they most efficiently absorb ultrasonic energy. This critical size depends on the frequency of the ultrasound. When high-intensity ultrasound causes cavities to grow very quickly, they can no longer efficiently absorb energy from the ultrasound. Without this energy input, the cavities can no longer sustain themselves. Liquid surges in and the cavities collapse due to a nonlinear response.

[0052] The energy released by the implosion breaks the liquid down into tiny particles that are dispersed into the air as a mist.

[0053] The equations that describe the above nonlinear response phenomenon can be expressed as the Rayleigh-Plesset equations, which can be derived from the Navier-Stokes equations used in fluid mechanics.

[0054] Our approach was to rewrite the "Rayleigh-Plesset" equation, where the bubble volume V is a dynamic parameter and the physics describing dissipation is identical to that used in the more classical form, where the radius is a dynamic parameter.

[0055] This equation is derived as follows:

[0056]

number

[0057] In ultrasonic atomizing inhalers, the liquid has a kinematic viscosity between 1.05 Pascal-seconds and 1.412 Pascal-seconds.

[0058] By solving the above equations using viscosity, density, and the desired target bubble volume of the liquid spray into air as appropriate parameters, it has been found that a frequency range of 2.8 MHz to 3.2 MHz for a liquid viscosity range of 1.05 Pascal-second and 1.412 Pascal-second will produce a bubble volume of approximately 0.25 microns to 0.5 microns.

[0059] The process of ultrasonic cavitation has a significant impact on the nicotine concentration in the generated mist.

[0060] Since no heating element is used, the heating element does not burn and the effects of sidestream smoke can be reduced.

[0061] In some arrangements, the liquid comprises 57-70% (w / w) vegetable glycerin and 30-43% (w / w) propylene glycol, the propylene glycol comprising nicotine and optionally flavouring.

[0062] In the ultrasonic mist inhaler, a capillary element may extend between the sonication chamber and the liquid chamber.

[0063] In the ultrasonic mist inhaler, the capillary element is a material that is at least partially bamboo fiber.

[0064] The capillary elements allow for high absorption capacity, high absorption speed, as well as high liquid retention.

[0065] The inherent properties of the proposed material used for the capillary tube were found to have a significant impact on the efficient functioning of the ultrasonic mist inhaler.

[0066] Furthermore, the unique properties of this material include good moisture absorption while maintaining good moisture permeability, which allows the sucked liquid to penetrate the capillaries efficiently and the high water absorption allows it to hold a large amount of liquid, allowing the ultrasonic mist inhaler to be used for a longer period of time compared to other products on the market.

[0067] Another major benefit of using bamboo fibre is that it has antibacterial, antifungal and anti-odour properties thanks to the naturally occurring antibacterial biological agent 'kun' present in bamboo fibre, making it suitable for medical use.

[0068] This unique property of bamboo fiber has been verified through numerical analysis regarding the advantages of bamboo fiber in ultrasonic processing.

[0069] The following formula has been tested on bamboo fiber material for use as a capillary element and on other materials such as cotton, paper, or other fiber strands, demonstrating that bamboo fiber has far superior properties for use in ultrasonic processing:

[0070]

number

[0071]

number

[0072] FIG. 1 illustrates a disposable ultrasonic mist inhaler 100. As can be seen from FIG. 1, the ultrasonic mist inhaler 100 has a cylindrical body with a relatively long length compared to its diameter. In terms of shape and appearance, the ultrasonic mist inhaler 100 is designed to mimic the appearance of a typical cigarette. For example, the inhaler may include a first section 101 that primarily simulates the tobacco rod portion of a cigarette, and a second section 102 that primarily simulates the filter. In a disposable configuration, the first and second sections are a single, yet separable, region of the device. The designations first section 101 and second section 102 are used for convenience to distinguish between the components primarily contained in each section.

[0073] As can be seen from Figure 1, the ultrasonic mist inhaler is composed of a mouthpiece 1, a reservoir structure 2, and a casing 3. A first part 101 constitutes the casing 3, and a second part 102 constitutes the mouthpiece 1 and the reservoir structure 2. do.

[0074] The first portion 101 contains the source energy.

[0075] The electrical storage device 30 provides power to the ultrasonic mist inhaler 100. The electrical storage device 30 can be, but is not limited to, a battery, such as a lithium-ion battery, an alkaline battery, a zinc-carbon battery, a nickel-metal hydride battery, or a nickel-cadmium battery, a supercapacitor, or a combination thereof. In a disposable configuration, the electrical storage device 30 is not rechargeable, while in a reusable configuration, the electrical storage device 30 would be selected to be rechargeable. In a disposable configuration, the electrical storage device 30 is primarily selected to provide a constant voltage over the life of the inhaler 100; otherwise, the performance of the inhaler would deteriorate over time. Preferred electrical storage devices capable of providing a constant voltage output over the life of the device include lithium-ion batteries and lithium polymer batteries.

[0076] The electrical storage device 30 has a first end 30a, which generally corresponds to a positive terminal, and a second end 30b, which generally corresponds to a negative terminal, the negative terminal extending to the first end 30a.

[0077] Because the electrical storage device 30 is located in the first portion 101 and the reservoir structure 2 is located in the second portion 102, a joint is required to provide electrical communication between those components. Electrical communication is established using at least electrodes or probes that are compressed together when the first portion 101 is clamped to the second portion 102.

[0078] In this device, the power storage device 30 is rechargeable to make it reusable. The casing 3 is provided with a charging port 32.

[0079] The integrated circuit 4 has a proximal end 4a and a distal end 4b. A positive terminal at the first end 30a of the electrical storage device 30 is in electrical communication with the positive lead of the flexible integrated circuit 4. A negative terminal at the second end 30b of the electrical storage device 30 is in electrical communication with the negative lead of the integrated circuit 4. The distal end 4b of the integrated circuit 4 includes a microprocessor. The microprocessor is configured to process data from the sensor, control the lights, direct the ultrasonic vibrations 5 in the second portion 102 to flow current, and terminate the flow of current after a preprogrammed time.

[0080] The sensor detects when the ultrasonic mist inhaler 100 is being used (when a user inhales on the inhaler) and activates the microprocessor. The sensor can be selected to detect changes in pressure, airflow, or vibration. In one arrangement, the sensor is a pressure sensor. In digital devices, the sensor takes continuous readings, and as a result, digital sensors must draw a continuous current, but the amount is small and the overall battery life will be negligibly affected.

[0081] In some arrangements, the integrated circuit 4 comprises an H-bridge which may be formed by four MOSFETs to convert DC to AC at high frequency.

[0082] 2 and 3, there is shown an illustration of one arrangement of the liquid reservoir structure 2. The liquid reservoir structure 2 comprises a liquid chamber 21 adapted to receive the liquid to be atomized, and an ultrasonic treatment chamber 22 in fluid communication with the liquid chamber 21.

[0083] In the arrangement shown, the liquid reservoir structure 2 comprises an intake channel 20 which provides an air passage from the sonication chamber 22 to the surroundings.

[0084] One arrangement of sensor locations may be to place the sensor in the sonication chamber 22 .

[0085] The intake channel 20 has a cone portion 20a and an inner container 20b.

[0086] As depicted in FIGS. 4A and 4B, the intake channel 20 further includes an air flow member 27 for providing air flow from the surroundings to the sonication chamber 22.

[0087] The airflow member 27 has an integrally formed airflow bridge 27a and airflow duct 27b, the airflow bridge 27a having two airway openings 27a' that form part of the inhalation channel 20, and the airflow duct 27b extending from the airflow bridge 27a into the ultrasonic treatment chamber 22 to provide airflow from the surroundings to the ultrasonic treatment chamber.

[0088] The airflow bridge 27a cooperates with the cone element 20a at the second diameter 20a2.

[0089] The airflow bridge 27a has two opposing peripheral openings 27a'' that feed the airflow into the airflow duct 27b.

[0090] The cooperation of the airflow bridge 27a with the frustoconical element 20a is arranged such that two opposing peripheral openings 27a'' cooperate with complementary openings 20a'' in the frustoconical element 20a.

[0091] The nozzle 1 and the cone portion 20a are spaced apart in the radial direction, with an airflow chamber 28 disposed therebetween.

[0092] As depicted in Figures 1 and 2, the mouthpiece 1 has two opposing peripheral openings 1''.

[0093] The peripheral openings 27 a ″, 20 a ″, 1 ″ of the airflow bridge 27 a, the frustoconical element 20 a and the mouthpiece 1 provide maximum airflow directly into the sonication chamber 22 .

[0094] Cone element 20a includes an internal passage aligned in a similar direction as intake channel 20, with first diameter 20a1 being smaller than second diameter 20a2, such that the internal passage decreases in diameter across cone element 20a.

[0095] The cone element 20a is arranged in alignment with the means of ultrasonic vibration 5 and the capillary element 7, with a first diameter 20a1 communicating with the internal duct 11 of the mouthpiece 1 and a second diameter 20a2 communicating with the internal container 20b.

[0096] The inner container 20b has an inner wall that separates the ultrasonic wave irradiation chamber 22 and the liquid chamber 21.

[0097] The liquid reservoir structure 2 has an outer container 20c that defines the outer wall of the liquid chamber 21.

[0098] The inner container 20b and the outer container 20c are the inner and outer walls of the liquid chamber 21, respectively.

[0099] The liquid reservoir structure 2 is disposed between the nozzle 1 and the casing 3 and is detachable from the nozzle 1 and the casing 3.

[0100] The liquid reservoir structure 2 and the mouthpiece 1 or casing 3 may include complementary arrangements for engaging with each other; further, such complementary arrangements may include any of a bayonet-type arrangement; a threaded engagement arrangement; a magnetic arrangement; or a friction fit arrangement, wherein the liquid reservoir structure 2 includes a portion of the arrangement and the mouthpiece 1 or casing 3 includes a complementary portion of the arrangement.

[0101] In the reusable arrangement, the components are substantially the same. The difference between the reusable arrangement and the disposable arrangement is the accommodation made for replacing the liquid reservoir structure 2.

[0102] As shown in FIG. 3, the liquid chamber 21 has a top wall 23 and a bottom wall 25 that enclose the inner and outer containers 20b and 20c of the liquid chamber 21.

[0103] The capillary element 7 is disposed between the first portion 20b1 and the second portion 20b2 of the inner container 20b.

[0104] The capillary element 7 has a flat shape that extends from the ultrasound irradiation chamber to the liquid chamber.

[0105] As depicted in FIG. 2 or 3, the capillary element 7 is composed of a U-shaped central portion 7a and an L-shaped peripheral portion 7b.

[0106] The L-shaped portion 7b extends along the bottom wall 25 into the liquid chamber 21 on the inner container 20b.

[0107] The U-shaped portion 7a is housed in the ultrasonic irradiation chamber 21. The U-shaped portion 7a is provided along the bottom wall 25 on the inner container 20b.

[0108] In the ultrasonic mist inhaler, the U-shaped portion 7a has an inner portion 7a1 and an outer portion 7a2, and the inner portion 7a1 is in surface contact with the atomization surface 50 of the ultrasonic vibration means 5, while the outer portion 7a2 is not in surface contact with the ultrasonic vibration means 5.

[0109] The bottom wall 25 of the liquid chamber 21 is a bottom plate 25 that closes the liquid chamber 21 and the ultrasonic wave irradiation chamber 22. Because the bottom plate 25 is sealed, leakage of liquid from the ultrasonic wave irradiation chamber 22 to the casing 3 is prevented.

[0110] The bottom plate 25 has an upper surface 25a with a recess 25b into which the elastic member 8 is inserted. The ultrasonic vibration means 5 is supported by the elastic member 8. The elastic member 8 is made of an annular plate-shaped rubber having an inner hole 8' with a groove designed to support the ultrasonic vibration means 5.

[0111] The upper wall 23 of the liquid chamber 21 is a cap 23 that closes the liquid chamber 21 .

[0112] The top wall 23 has an upper surface 23 which represents the maximum level of liquid that the liquid chamber 21 can contain, and a lower surface 25 which represents the minimum level of liquid within the liquid chamber 21 .

[0113] The top wall 23 is sealed, preventing leakage of liquid from the liquid chamber 21 to the mouthpiece 1.

[0114] The top wall 23 and the bottom wall 25 are fixed to the liquid storage structure 2 by fixing means such as screws, adhesive, or friction.

[0115] As shown in Figure 3, the elastic member is in line contact with the ultrasonic vibration means 5, and by preventing contact between the ultrasonic vibration means 5 and the wall of the inhaler, suppression of vibration of the liquid reservoir structure is more effectively prevented. Therefore, fine particles of the liquid atomized by the atomizing member can be sprayed over a longer distance.

[0116] As depicted in FIG. 3, the inner container 20b has an opening 20b' between the first portion 20b1 and the second portion 20b2 through which the capillary element 7 extends from the sonication chamber 21. The capillary element 7 absorbs liquid from the liquid chamber 21 through the opening 20b'. The capillary element 7 is a wick. The capillary element 7 transports the liquid to the sonication chamber 22 by capillary action. In some arrangements, the capillary element 7 is made of bamboo fiber. In some arrangements, the capillary element 7 is between 0.27 mm and 0.32 mm thick and weighs 38 g / m 2 and 48g / m 2 The density may be between .gtoreq..gtoreq.

[0117] As can be seen in FIG. 3, the means of ultrasonic vibration 5 is arranged directly below the capillary element 7 .

[0118] The ultrasonic vibration means 5 may be a transducer. In the configuration, the ultrasonic vibration means 5 may be a piezoelectric transducer and may be designed in the shape of a circular plate. The material of the piezoelectric transducer may be ceramic.

[0119] Furthermore, various transducer materials can be used for the ultrasonic vibration means 5 .

[0120] The end of the air duct 27b1 faces the ultrasonic vibration means 5. The ultrasonic vibration means 5 is in electrical communication with the electrical contactors 101a and 101b. It is noteworthy that the distal end 4b of the integrated circuit 4 has an inner electrode and an outer electrode. The inner electrode contacts the first electrical contactor 101a, which is a spring contact probe, and the outer electrode contacts the second electrical contactor 101b, which is a side pin. Through the integrated circuit 4, the first electrical contactor 101a electrically communicates with the positive terminal of the power storage device 30 via the microprocessor, and the second electrical contactor 101b electrically communicates with the negative terminal of the power storage device 30.

[0121] The electrical contacts 101 a, 101 b traverse the base plate 25. The base plate 25 is adapted to be received inside the peripheral wall 26 of the liquid storage structure 2. The base plate 25 rests on complementary ridges, thereby forming the liquid chamber 21 and the ultrasound irradiation chamber 22.

[0122] The inner container 20b consists of a circular inner slot 20d into which a mechanical spring is applied.

[0123] By pressing the central portion 7a1 against the ultrasonic vibration means 5, the mechanical spring 9 ensures a contact surface between them.

[0124] The reservoir structure 2 and base plate 25 can be made using a variety of thermoplastic materials.

[0125] When a user inhales into the ultrasonic mist inhaler 100, air is drawn in through the peripheral opening 1'' and passes through the airflow chamber 28, through the peripheral opening 27a'' of the airflow bridge 27a and the frustoconical element 20a, and down through the airflow duct 27b into the sonication chamber 22, directly onto the capillary element 7. At the same time, liquid is drawn by capillary action from the reservoir chamber 21 through the multiple openings 20b' and into the capillary element 7. The capillary element 7 brings the liquid into contact with the ultrasonic vibration means 5 of the inhaler 100. In addition, the user's inhalation causes the pressure sensor to activate the integrated circuit 4, which then conducts current to the ultrasonic vibration means 5. Thus, when a user draws on the mouthpiece 1 of the inhaler 100, two actions occur simultaneously: first, the sensor activates the integrated circuit 4, which triggers the ultrasonic vibration means 5 to begin vibrating. Second, the trigger reduces the pressure outside the reservoir chamber 21 so that liquid begins to flow through the opening 20b', which saturates the capillary element 7. The capillary element 7 transports the liquid to the ultrasonic vibration means 5, which causes bubbles to form in the capillary passage, turning the liquid into mist. The mist liquid is then inhaled by the user.

[0126] In some arrangements, the integrated circuit 4 includes a frequency controller configured to control the frequency at which the ultrasonic vibration means 5 operates. The frequency controller comprises a processor and a memory, the memory storing executable instructions that, when executed by the processor, cause the processor to perform at least one function of the frequency controller.

[0127] As mentioned above, in some configurations, the ultrasonic mist inhaler 100 drives the ultrasonic vibration means 5 with a signal having a frequency of 2.8 MHz to 3.2 MHz to vaporize a liquid having a liquid viscosity of 1.05 Pascal-seconds to 1.412 Pascal-seconds to generate bubble volumes of approximately 0.25 to 0.5 microns. However, for liquids having different viscosities or other applications, it is possible that the ultrasonic vibration means 5 is driven at a different frequency.

[0128] For different applications of the mist generating device there will be an optimum frequency or frequency range for driving the ultrasonic vibration means 5 to optimise the generation of mist. In arrangements where the ultrasonic vibration means 5 is a piezoelectric transducer, the optimum frequency or frequency range will depend on at least the following four parameters: 1.Converter manufacturing process In some arrangements, the ultrasonic vibration means 5 comprises a piezoelectric ceramic. Piezoelectric ceramics are manufactured by mixing compounds to create a ceramic dough, but this mixing process may not be consistent throughout production. This non-uniformity may result in variations in the resonant frequency of the cured piezoelectric ceramic.

[0129] If the resonant frequency of the piezoelectric ceramic does not correspond to the required operating frequency of the device, no mist will be produced during operation of the device. In the case of a nicotine mist inhaler, even a slight deviation in the resonant frequency of the piezoelectric ceramic will affect the production of mist, meaning that the device will not provide the appropriate nicotine level to the user.

[0130] 2. Load on the converter During operation, as the load on the piezoelectric transducer changes, the vibration displacement across the piezoelectric transducer is suppressed. To achieve optimal vibration displacement across the piezoelectric transducer, the drive frequency must be adjusted so that the circuit can provide enough power for maximum displacement.

[0131] Types of loads that affect the efficiency of the oscillator include the amount of liquid above the transducer (humidity of the wicking material), the spring force applied to the wicking material to maintain permanent contact with the transducer, and may also include electrical connections.

[0132] 3.Temperature The ultrasonic vibrations of the piezoelectric transducer can be partially damped by incorporating a device that encases the transducer in a silicone / rubber ring and uses a spring to apply pressure to a wicking material above the transducer. This damping of the vibrations causes a local increase in temperature above and around the transducer.

[0133] An increase in temperature affects the vibration due to changes in the molecular behavior of the transducer. An increase in temperature imparts more energy to the ceramic molecules, temporarily affecting their crystalline structure. This effect is reversed as the temperature decreases, but to maintain optimal oscillation, the supplied frequency must be modulated. This frequency modulation is not possible with conventional fixed frequency devices.

[0134] Additionally, increasing the temperature reduces the viscosity of the vaporizing solution (e-liquid), which may require a change in drive frequency to induce cavitation and maintain continuous mist production. In conventional fixed-frequency devices, reducing the liquid viscosity without changing the drive frequency will reduce or completely stop mist production, rendering the device inoperable.

[0135] 4. Distance to power source The oscillation frequency of an electronic circuit can be changed by the length of the wiring between the transducer and the oscillator-driver. The frequency of an electronic circuit is inversely proportional to the distance between the transducer and the rest of the circuit.

[0136] Although the distance parameters are primarily fixed for the device, they can vary during the device manufacturing process, reducing the overall efficiency of the device. Therefore, it is desirable to vary the device's drive frequency to compensate for the variations and optimize the device's efficiency.

[0137] 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 in the inductance, capacitance, and resistance of the overall RLC circuit, changing the resonant frequency range supplied to the transducer. As the frequency of the circuit increases near the transducer's resonance point, the logarithmic impedance of the overall circuit drops to a minimum, then rises to a maximum, before settling into the middle range. Figure 6 is a typical graph illustrating the change in overall impedance with increasing frequency in an RLC circuit. Figure 7 shows the change in the overall impedance of a piezoelectric transducer at a first predetermined frequency f s In the first capacitive region at frequencies below a second predetermined frequency fp 1 illustrates how the piezoelectric transducer acts as a capacitor in a second capacitive region at frequencies above the first and second predetermined frequencies f s , f p At frequencies between , the converter acts as an inductor in the inductive region. To maintain optimum converter oscillation and therefore maximum efficiency, the current through the converter must be kept at a frequency within the inductive region.

[0138] The frequency controller of the device in some configurations is configured to maintain the oscillation frequency of the piezoelectric transducer (ultrasonic vibration means 5) within the induction region to maximize the efficiency of the device.

[0139] The frequency controller is configured to perform a sweep operation that drives the converter 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 converter. In some arrangements, the ADC value is a parameter of the ADC that is proportional to a voltage across the converter. In other arrangements, the ADC value is a parameter of the ADC that is proportional to a current through the converter.

[0140] As will be explained in more detail below, the frequency controller in some arrangements determines the active power being used by the ultrasonic transducer by monitoring the current through the transducer.

[0141] During the sweep operation, the frequency controller locates the induction region of frequencies for the transducer. Once the frequency controller identifies the induction region, the frequency controller records the ADC values ​​and adjusts the drive frequency of the transducer to a frequency within the induction region (i.e., the first and second predetermined frequencies f) to optimize ultrasonic cavitation by the transducer. s , 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. In some arrangements, the frequency controller is configured to perform a sweep operation to identify the location of the induction region each time oscillation is initiated or restarted, and in arrangements, the frequency controller is configured to lock the drive frequency at a new frequency within the induction region each time oscillation is initiated, thereby compensating for changes in parameters that affect the operating efficiency of the device.

[0142] In some arrangements, the frequency controller ensures optimal mist production and maximizes the efficiency of drug delivery to the user. In some arrangements, the frequency controller optimizes the device, improving efficiency and maximizing nicotine delivery to the user. In other arrangements, the frequency controller optimizes the device and improves the efficiency of any other device that uses ultrasound. In some arrangements, the frequency controller is configured for use with therapeutic ultrasound technology 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. In some arrangements, 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 a frequency sweep during operation of the device and monitors the ADC value to determine whether the ADC value is greater than or equal to a predetermined threshold indicating optimal oscillation of the transducer.

[0143] In some arrangements, the frequency controller performs a sweep operation while the device is in the process of aerosolizing the liquid in case the frequency controller identifies a better possible frequency for the transducer, and if the frequency controller identifies a better frequency, the frequency controller locks the drive frequency at the newly identified better frequency to maintain optimal operation of the device.

[0144] In some arrangements, the frequency controller performs frequency sweeps for predetermined durations periodically during operation of the device. For devices of the above arrangements, the predetermined durations of the sweeps and the time periods between sweeps are selected to optimize device function. When implemented in an ultrasonic mist inhaler, this ensures optimal delivery to the user throughout their inhalation.

[0145] FIG. 8 is a flow diagram of the operation of the frequency controller in some configurations.

[0146] The following disclosure discloses additional mist inhaler arrangements that comprise many of the same elements as the arrangements described above, the elements of which may be interchanged with any of the elements of the arrangements described in the remainder of this disclosure.

[0147] The mist generating device described below is for use with or intended for use with the hookah device 202 described below. In other arrangements, the hookah device 202 comprises a number of other mist generating devices instead of the mist generating device 201 described herein.

[0148] To ensure sufficient aerosol production, some configurations of the mist inhaler 201 consist of an ultrasonic / piezoelectric transducer of exactly or substantially 16 mm diameter, manufactured to specific capacitance and impedance values ​​to control the frequency and power required to produce the desired aerosol volume.

[0149] A 16 mm diameter disk-shaped ultrasonic transducer placed horizontally can result in a large mist generator. To minimize size, the ultrasonic transducer in this configuration is held vertically within the sonication chamber (with the plane of the ultrasonic transducer generally parallel to the flow of the aerosol mist and / or the longitudinal length of the mist generator). In other words, the ultrasonic transducer is generally perpendicular to the base of the mist generator.

[0150] 9 to 11 of the accompanying drawings, mist generating device 201 comprises a mist generating housing 204 which is elongated and formed from two housing parts 205, 206 which are optionally attached to one another. Mist generating housing 204 comprises an air inlet port 207 and a mist outlet port 208.

[0151] In this configuration, the mist-generating housing 204 is an injection-molded plastic, specifically polypropylene, which is typically used in medical applications. In this configuration, the mist-generating housing 204 is a heterophase copolymer, specifically BF970MO, which has an optimal combination of very high stiffness and high impact strength. Mist-generating housing components molded from this material exhibit good antistatic performance. Heterophasic copolymers such as polypropylene are particularly suitable for the mist-generating housing 204 because this material does not cause condensation of the aerosol as it flows from the sonication chamber 219 through the mist exit port 208. This plastic material can also be easily and directly recycled using industrial crushing and cleaning processes.

[0152] 10, the mist outlet port 208 is closed by a closure element 209. However, it will be understood that when the mist inhaler 200 is in use, the closure element 209 is removed from the mist outlet port 208, as shown in FIG.

[0153] 12 and 13, mist generating device 200 includes a transducer holder 210 held within mist generating housing 204. In this arrangement, transducer holder 210 comprises a cylindrical or generally cylindrical body 211 and circular upper and lower openings 212, 213. Transducer holder 210 is provided with an internal channel 214 for receiving the end of an ultrasonic transducer 215, as shown in FIG.

[0154] The transducer holder 210 incorporates a cutting portion 216 through which an electrode 217 extends from the ultrasonic transducer 215 so that the electrode 217 can be electrically connected to an AC driver of the hookah device 202, as described in more detail below.

[0155] 11, the mist generating device 201 includes a liquid chamber 218 disposed within the mist generating housing 204. The liquid chamber 218 is for containing the liquid to be atomized. In some arrangements, the liquid is contained in the liquid chamber 218. In other arrangements, the liquid chamber 218 is initially empty, and then the liquid chamber is filled with liquid.

[0156] A liquid (also referred to herein as e-liquid) composition suitable for use in an ultrasonic mist generator 201 in several configurations comprising a nicotine salt of nicotine levulinate, the composition comprising: the relative amount of vegetable glycerin in the composition is: 55 to 80% (w / w), or 60 to 80% (w / w), or 65 to 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: 0.1-80 mg / ml, or 0.1-50 mg / ml, or 1-25 mg / ml, or 10-20 mg / ml, or 17 mg / ml.

[0157] In some arrangements, the mist generator 201 contains an e-liquid having a kinematic viscosity between 1.05 Pascal·seconds and 1.412 Pascal·seconds.

[0158] In some arrangements, the liquid chamber 218 contains a liquid comprising nicotine levulinate salt in a 1:1 molar ratio.

[0159] In some arrangements, the liquid chamber 218 contains an e-liquid that includes nicotine, propylene glycol, vegetable glycerin, water, and flavoring. In some examples, the % concentration of each component in the e-liquid is shown in Table 1, Table 2, Table 3, or Table 4 below.

[0160] [Table 1]

[0161] [Table 2]

[0162] [Table 3]

[0163] [Table 4]

[0164] In a non-limiting example, the nicotine in the solution is all or partly in the form of nicotine levulinate.

[0165] Levulinic acid nicotine salts are formed by combining nicotine with levulinic acid in solution, resulting in the formation of levulinic acid nicotine salts consisting of a levulinate anion and a nicotine cation.

[0166] The % concentrations of nicotine in the e-liquids shown in Tables 1, 2, 3 and 4 correspond approximately to 17 mg / ml.

[0167] In some arrangements, 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.

[0168] In some arrangements, the liquid in the liquid chamber 218 contains a flavoring (eg, fruit flavor) that is tasted by the user when the user inhales the mist produced by the hookah device.

[0169] By using e-liquids with the correct parameters of viscosity, density, and the desired target bubble volume of the liquid spray into air, frequencies between 2.8 MHz and 3.2 MHz for a liquid viscosity range of 1.05 Pascal·sec and 1.412 Pascal·sec and a density of approximately 1.1–1.3 g / mL (density range obtained from Hertz) have been found to produce droplet volumes where 90% of the droplets are less than 1 micron and 50% are less than 0.5 microns.

[0170] The mist generator 201 includes an ultrasonic wave irradiation chamber 219 provided in a mist generator housing 204 .

[0171] 12 and 13, the transducer holder 210 includes a divider 220 that provides a barrier between the liquid chamber 218 and the sonication chamber 219. The barrier provided by the divider 220 minimizes the risk of the sonication chamber 219 overflowing with liquid from the liquid chamber 218 or oversaturating the capillary element on the ultrasonic transducer 215, either of which could overload and reduce the efficiency of the ultrasonic transducer 215. Furthermore, overflowing the sonication chamber 219 or oversaturating the capillary element could also cause the user to have an unpleasant experience of inhaling liquid. To mitigate this risk, the divider 220 of the transducer holder 210 sits as a wall between the sonication chamber 219 and the liquid chamber 218.

[0172] The partition 220 defines a capillary opening 221, which is the only means by which liquid can flow from the liquid chamber 218 to the sonication chamber 219 via a capillary element. In this arrangement, the capillary opening 221 is an elongated slot having a width of 0.2 mm to 0.4 mm. The dimensions of the capillary opening 221 are such that the edges of the capillary opening 221 provide a bias force that acts on the capillary element extending through the capillary opening 221 to exert control over the liquid flow into the sonication chamber 219.

[0173] In this arrangement, the transducer holder 210 is liquid silicone rubber (LSR). In this arrangement, the liquid silicone rubber has a hardness of Shore A 60. The LSR material ensures that the ultrasonic transducer 215 can vibrate without the transducer holder 210 damping the vibrations. In this arrangement, 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, the material and hardness of this LSR are selected to obtain optimal performance with minimal compromise.

[0174] 14 and 15, mist generator 201 includes a capillary or capillary element 222 for transporting a liquid (containing a drug or other substance) from liquid chamber 218 to sonication chamber 219. Tube element 222 is planar or generally planar having a first portion 223 and a second portion 224. In this arrangement, first portion 223 has a rectangular or generally rectangular shape, and second portion 224 has a partially circular shape.

[0175] In this arrangement, the capillary element 222 is composed of a third portion 225 and a fourth portion 226 that are the same shape as the first and second portions 223, 224, respectively. The capillary element 222 in this arrangement is folded about a fold line 227 so that the first and second portions 223, 224 and the third and fourth portions 225, 226 are superimposed on one another, as shown in Figure 15 .

[0176] In this configuration, the capillary element has a thickness of approximately 0.28 mm. If the capillary element 222 is folded to have two layers, as shown in Figure 15, 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.

[0177] In this arrangement, 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 portion of the capillary element 222 that is located in the liquid in the liquid chamber 218 to maximize the rate at which the capillary element 222 absorbs the liquid.

[0178] In this arrangement, the capillary elements 222 are 100% bamboo fiber. In other arrangements, the capillary elements are at least 75% bamboo fiber. The advantages of using bamboo fiber as the capillary elements have been discussed above.

[0179] 16 and 17, the capillary element 222 is held by the transducer holder 210 such that the transducer holder 210 holds the second portion 224 of the capillary element 222 overlapping a portion of the atomizing surface of the ultrasonic transducer 215. In this arrangement, the circular second portion 224 rests within the inner recess 214 of the transducer holder 210.

[0180] A first portion 223 of the capillary element 222 extends through a capillary opening 221 in the transducer holder 210 .

[0181] 18-20, the second portion 206 of the mist-generating housing 204 comprises a generally circular wall 229 that receives the transducer holder 222 and forms part of the wall of the ultrasonic treatment chamber 219.

[0182] Contact openings 230 and 231 are provided in the sidewall of the second portion 206 for receiving electrical contacts 232 and 233 that make electrical connection with the electrodes of the ultrasonic transducer 215 .

[0183] In this arrangement, an absorbent tip or element 234 is provided adjacent the mist outlet port 208 to absorb liquid at the mist outlet port 208. In this arrangement, the capillary element 234 is 100% bamboo fiber.

[0184] 21 to 23, the first portion 205 of the mist generating housing 204 is similar in shape to the second portion 206 and further comprises a generally circular wall portion 235 which forms a further portion of the wall of the ultrasonic irradiation chamber 219 and which holds the transducer holder 210.

[0185] In this arrangement, an absorbent element 236 is further provided adjacent the mist outlet port 208 for absorbing liquid at the mist outlet port 208 .

[0186] In this arrangement, the first portion 205 of the mist generation housing 204 defines a spring support arrangement 237 that supports the lower end of a retainer spring 238, as shown in FIG.

[0187] 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 .

[0188] Referring to Figure 25, the transducer holder 210 is shown in place and held by the second part 206 of the mist-generating housing 204 before the two parts 205, 206 of the mist-generating housing 204 are attached to each other.

[0189] 26 to 29, in this arrangement, mist generator 201 is configured to include an identification array 239. Identification array 239 is configured from a printed circuit board 240 having electrical contacts 241 provided on one surface, and an integrated circuit 242 and another optional component 243 provided on the other surface.

[0190] The integrated circuit 242 has a memory that stores an identifier unique to the mist generating device 201. The electrical contacts 241 provide an electronic interface for communicating with the integrated circuit 242.

[0191] In this arrangement, the printed circuit board 240 is mounted in a recess 244 in one side of the mist-generating housing 204. The integrated circuit 242 and any other electronic components 243 are housed in a further recess 245 so that the printed circuit board 240 is generally flush with the side of the mist-generating housing 204.

[0192] In this arrangement, integrated circuit 242 is a one-time programmable (OTP) device that provides an anti-counterfeiting feature that allows only genuine mist generators from the manufacturer to be used with the device. This anti-counterfeiting feature is implemented in mist generator 201 as a specific custom integrated circuit (IC) that is bonded (with printed circuit board 240) to mist generator 201. The OTP as an IC contains truly unique information that allows full traceability of mist generator 201 (and its contents) over its lifetime, as well as accurate monitoring of consumption by the user. The OTP IC allows mist generator 201 to function to generate mist only when authorized.

[0193] The OTP, among other features, defines the authorized status of a particular mist generator 201. Indeed, to prevent carbonyl emissions and maintain aerosols at safe levels, experiments have shown that after approximately 1000 seconds of aerosolization, the mist generator 201 is considered to be empty of liquid in the liquid chamber 218. As such, counterfeit or empty mist generators 201 will not be able to operate after this predetermined time of use.

[0194] The OTP feature may be part of a complete chain of interaction between the digital sales point, the mobile companion application and the mist generator 201. Only genuine mist generators 201 manufactured by a trusted party and sold at the digital sales point may be used with the hookah device 202. The OTP IC is read by the hookah device 202, which is able to recognize the mist generator 201. In some arrangements, the OTP IC is disposable, just like the mist generator 201. Whenever the mist generator 201 is deemed empty, it will not be activated if inserted into the hookah device 202. Similarly, a counterfeit mist generator 201 will not function in the hookah device 202.

[0195] Referring now to Figure 30 of the accompanying drawings, the driver unit 202 is comprised of ultrasonic transducer driver microchips, referred to herein as power management integrated circuits or PMICs 300. Each PMIC 300 is a microchip for driving a respective ultrasonic transducer 215 in one of the mist generating devices 201. In embodiments of the present disclosure, the number of PMICs in the hookah device 202 corresponds to the number of mist generating devices 201 intended for use with the hookah device 202. In the example described below, there are four mist generating devices 201, and the hookah device 202 is comprised of four corresponding PMICs 300. In other examples, the hookah device 202 is comprised of two to eight PMICs 300 configured to drive two to eight mist generating devices 201 coupled to the hookah device 202.

[0196] In this disclosure, the terms chip, microchip, and integrated circuit are used interchangeably. A microchip or integrated circuit is a single unit comprised of multiple interconnected embedded components and subsystems. A microchip is, for example, at least partially made of a semiconductor, such as silicon, and is fabricated using semiconductor fabrication techniques.

[0197] The hookah device 202 also includes a plurality of second microchips, each of which is referred to herein as a bridge integrated circuit or bridge IC 301. Each bridge IC 301 is electrically connected to a respective one of the PMICs 300. Each bridge IC 301 is a microchip for driving a respective ultrasonic transducer 215 in one of the mist generating devices 201. In the embodiment of the present disclosure, the number of bridge ICs 301 in the hookah device 202 corresponds to the number of mist generating devices 201 intended for use with the hookah device 202. Each bridge IC 301 is a unit comprised of multiple interconnected built-in components and subsystems. In the example described below, there are four bridge ICs 301, and the hookah device 202 is comprised of four corresponding PMICs 300.

[0198] In this example, each PMIC 300 and its representative connecting bridge IC 301 are mounted on the same board of the hookah device 202. As will be described later, each bridge IC 301 is connected to its respective PMIC 300 via a connection on the PCB, not via a communication bus (e.g., an I2C bus, which will be described later). In this example, the physical dimensions of the PMIC 300 are 1 to 3 mm in width and 1 to 3 mm in length, and the physical dimensions of the bridge IC 301 are 1 to 3 mm in width and 1 to 3 mm in length. It is 1-3mm long and 1-3mm wide.

[0199] For simplicity, Figure 43 shows only one PMIC 300 and one bridge IC 301, and the following description will refer to only one PMIC 300 and one bridge IC 301. However, it will be understood that the hookah device 202 may incorporate multiple PMICs 300 and multiple bridge ICs 301 connected in the same configuration as shown in Figure 43. As will be described below, each PMIC 300 is connected to a communication (I2C) bus 302, allowing each PMIC 300 to be independently controlled by signals from a microcontroller 303 transmitted via the communication bus 302.

[0200] The mist generating device 201 includes a programmable integrated circuit, or one-time programmable integrated circuit, or OTP IC 242. When the mist generating device 201 is coupled to the hookah device 202, the OTP IC is electrically connected to the PMIC 300 to receive power from the PMIC 300 so that the PMIC 300 can manage the voltage supplied to the OTP IC 242. The OTP IC 242 is also connected to a data bus or communication bus 302 within the driver device 202. In this example, the communication bus 302 is an I2C bus, but in other examples, the communication bus 302 is another type of data bus.

[0201] The ultrasonic transducer 215 in the mist generating device 201 is electrically connected to the bridge IC 301, and when the hookah device 202 is in use, the ultrasonic transducer 215 can be driven by an AC drive signal generated by the bridge IC 301.

[0202] The hookah device 202 comprises a processor in the form of a microcontroller 303 communicatively and electrically coupled to a communication bus 302. In this example, the microcontroller 303 is a Bluetooth TM 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 a battery. The LDO 304 provides a stable, regulated voltage to the microcontroller 303 so that the microcontroller 303 can operate stably even if the voltage of the battery 250 fluctuates.

[0203] The hookah device 202 comprises a voltage regulator in the form of a DC-DC boost converter 305 powered by the battery 250. Although only one DC-DC boost converter 305 is shown in Figure 43, in some embodiments the hookah device 202 comprises multiple DC-DC boost converters 305, each powering a respective one of the multiple bridge ICs 301. In other embodiments the hookah device 305 comprises only one DC-DC boost converter 305 configured to power each of the multiple bridge ICs 301.

[0204] Boost converter 305 boosts the voltage of a battery or power source to a programmable voltage VBOOST, which is set by boost converter 305 in response to a voltage control signal VCTL from PMIC 300. As will be described in more detail below, boost converter 305 outputs voltage VBOOST to bridge IC 301. In other examples, the voltage regulator is a buck converter or other type of voltage regulator that outputs a selectable voltage.

[0205] The voltage control signal VCTL is generated in this example by a digital-to-analog converter (DAC) implemented within PMIC 300. Because the DAC is integrated within PMIC 300, it is not visible in FIG. 30. The DAC and the technical advantages of integrating the DAC within PMIC 300 are described in more detail below.

[0206] 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 the charging voltage VCHRG when the connector 306 is coupled to a USB charger. In another example, the PMIC 300 is connected to a separate power socket that allows the hookah device 202 to be connected to and powered by an external power source.

[0207] The hookah device 202 comprises a first pressure sensor 307, which in this example is a static pressure sensor. The hookah device 202 also comprises a second pressure sensor 308, which in this example is a dynamic pressure sensor. However, in other examples, the hookah device 202 comprises only one of the two pressure sensors 307, 308. The pressure sensors 307, 308 sense changes in air pressure to sense when a user is smoking the hookah and drawing air through the mist generating device 201. In this example, the hookah device 202 is configured with multiple LEDs 308 controlled by the PMIC 300. In other examples, one or more of the LEDs 308 are omitted. The microcontroller 303 acts as the master device on the communication bus 302, with the PMIC 300 as the first slave device, the OTP IC 242 as the second slave device, the second pressure sensor 308 as the third slave device, and the first pressure sensor 307 as the first slave device. Each additional PMIC 300 in the plurality of PMICs 300 is another slave device on the communication bus 302. The communication bus 302 enables the microcontroller 303 to control the following functions within the hookah device 202:

[0208] 1. All functions of each PMIC 300 are highly configurable by the microcontroller 303.

[0209] 2. The current through the ultrasonic transducer 215 is sensed at a high common-mode voltage (the high side of the bridge) by a high-bandwidth sense and rectifier circuit. The sensed current is converted to a voltage proportional to the effective current and provided as a buffered voltage at the current sense output terminal 309 of the bridge IC 301. This voltage is fed to the PMIC 300, where it is sampled and made available as a digital representation via an I2C request. Sensing the current through the ultrasonic transducer 215 forms part of the resonant frequency tracking function. As described herein, the device's ability to enable this functionality within the bridge IC 301 provides a significant technical advantage.

[0210] 3. The DC-DC boost converter voltage VBOOST can be programmed to be between 10V and 20V by a DAC (not shown in Figure 30) integrated within the PMIC 300.

[0211] 4. Microcontroller 303 enables the charger subsystem of device 202 to manage the charging of the battery, which is a single cell battery.

[0212] 5. A light emitting diode (LED) driver module (not shown) is powered by the PMIC 300 to drive and digitally dim the LEDs 308 in either linear or gamma corrected mode.

[0213] 6. Microcontroller 303 can read the Pressure #1 and Pressure #2 sensor values ​​from pressure sensors 307, 308.

[0214] 31 of the accompanying drawings, each PMIC 300 is, in this example, a self-contained chip or integrated circuit consisting of an integrated subsystem and a number of pins that provide electrical inputs and outputs to the PMIC 300. References to integrated circuits or chips in this disclosure are interchangeable, and either term encompasses semiconductor devices, which may be silicon, for example.

[0215] The PMIC 300 includes an analog core 310 that is comprised of analog components including a reference block (BG) 311 , an LDO 312 , a current sensor 313 , a temperature sensor 314 , and an oscillator 315 .

[0216] As described in more detail below, oscillator 315 is coupled to a delay-locked loop (DLL) that outputs pulse-width modulation (PWM) A and B stages, and oscillator 315 and DLL generate a two-phase center-matched PWM output that drives an H-bridge within bridge IC 301.

[0217] The DLL consists of multiple delay lines connected end-to-end, with the total delay time 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 with a large number (e.g., on the order of millions) of delay gates connected end-to-end in digital core 316.

[0218] Implementing the oscillator 315 and DLL in the same integrated circuit of the PMIC 300 to generate a two-phase center-aligned PWM signal is unique, as currently no signal generator components on the integrated circuit market comprise this implementation.

[0219] As described herein, PWM is part of the functionality that allows the hookah device 202 to accurately track the resonant frequency of the ultrasonic transducer 215 to maintain an efficient transfer of electrical energy to kinetic energy to optimize mist generation.

[0220] In this example, the PMIC 300 includes a charger circuit 317 that controls battery charging using power from, for example, a USB power source.

[0221] The PMIC 300 includes an integrated power switch VSYS that configures the PMIC 300 to power the analog core 310 with power from a battery or with power from an external power source.

[0222] The PMIC 300 comprises an embedded analog-to-digital converter (ADC) subsystem 318. The implementation of the ADC 318 together with the oscillator 315 within the same integrated circuit is unique in itself, as there are no other integrated circuits in the integrated circuit market that consist of an oscillator and an ADC implemented as sub-blocks within an integrated circuit. In conventional devices, the ADC is provided as a discrete component separate from the oscillator, and the ADC and oscillator are typically implemented on the same PCB. The problem with this conventional arrangement is that the two separate components—the ADC and the oscillator—take up unnecessary space on the PCB. Furthermore, conventional ADCs and oscillators are typically connected to each other via a serial data communication bus, such as the I2C bus, which is limited to a maximum communication speed of 400 kHz. In contrast to conventional devices, the PMIC 300 is configured with the ADC 318 and oscillator 315 integrated into the same integrated circuit, meaning that there is no lag in the communication between the ADC 318 and oscillator 315, and the ADC 318 and oscillator 315 can communicate with each other at high speeds, for example, at the speed of the oscillator 315 (e.g., 3 MHz to 5 MHz).

[0223] In this example PMIC 300, oscillator 315 operates at 5 MHz and generates the 5 MHz clock signal SYS CLOCK. However, in other examples, oscillator 315 generates clock signals at much higher frequencies, up to 105 MHz. All of the integrated circuits described herein are configured to operate at the higher oscillator 315 frequency.

[0224] ADC 318 comprises a plurality of feedback input terminals or analog inputs 319 comprising a plurality of 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 bridge IC 301, the feedback signal being indicative of a parameter of the operation of the H-bridge circuit or a parameter of an AC drive signal when the H-bridge circuit is driving a resonant circuit, such as ultrasonic transducer 215, with the AC drive signal. As described below, the GPIO inputs are used to receive a current sense signal from bridge IC 301 indicative of the root-mean-square (rms) current reported by 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 bridge IC 301.

[0225] The ADC subsystem 318 samples analog signals received at a plurality of ADC input terminals 319 at a sampling frequency proportional to the frequency of the main clock signal, and then uses the sampled analog signals to generate ADC digital signals.

[0226] In this example, the ADC 318 built into the PMIC 300 samples not only the RMS current through the H-bridge 334 and the ultrasonic transducer 215, but also voltages available in the system (e.g., VBAT, VCHRG, VBOOST), the temperature of the PMIC 300, the temperature of the battery, and GPIO inputs (IF_GPIO1-3) to allow for future expansion.

[0227] The digital core 316 receives the ADC-generated digital signal from the ADC subsystem, processes the ADC digital signal, and generates the driver control signal. The digital core 316 communicates the driver control signal to the PWM signal generator subsystem (DLL 332) to control the PWM signal generator subsystem.

[0228] Rectification circuits currently available on the market have very limited bandwidth (typically less than 1 MHz). Because the PMIC 300's oscillator 315 operates at a maximum of 5 MHz or even 105 MHz, a high-bandwidth rectification circuit is implemented in the PMIC 300. As described below, sensing the RMS current in the H-bridge of the bridge IC 301 forms part of a feedback loop that enables the hookah device 202 to drive the ultrasonic transducer 215 with high precision. The feedback loop accounts for any process variations in the manufacturing of piezoelectric transducers (variations in resonant frequency) and compensates for temperature effects on the resonant frequency, making it a game-changer in the ultrasonic transducer driving industry. This is achieved in part by the inventive implementation of integrating the ADC 318, oscillator 315, and DLL within the same integrated circuit of the PMIC 300. This integration allows these subsystems to communicate with each other at high speeds (e.g., at clock frequencies of 5 MHz or up to 105 MHz). Reducing the lag between these subsystems is a game-changer in the ultrasonic industry, especially in the field of mist generators.

[0229] The ADC318 consists of a battery voltage monitoring input VBAT, a charger input voltage monitoring input VCHG, as well as voltage monitoring inputs VMON and VRTH, and a temperature monitoring input TEMP.

[0230] The temperature monitoring input TEMP receives a temperature signal from a temperature sensor 314 built into the PMIC 300. This allows the PMIC 300 to accurately sense the actual temperature within the PMIC 300 and detect malfunctions within the PMIC 300 as well as malfunctions in other components on the printed circuit board that may affect the temperature of the PMIC 300. In order to maintain the safety of the mist inhaler 200, the PMIC 300 controls the bridge IC 301 to prevent excitation of the ultrasonic transducer 215 if a malfunction occurs, thereby ensuring the safety of the hookah device 202.

[0231] An additional temperature sensor input VRTH receives a temperature sensing signal from an external temperature sensor within the hookah device 202 that monitors the temperature of the hookah device 250. Thus, the PMIC 300 can react by shutting down the hookah device 202 to reduce the risk of damage caused by excessively high operating temperatures.

[0232] PMIC 300, in this example, comprises LED driver 320, which receives digital drive signals from digital core 316 and provides LED drive output signals to six LEDs 321-326 configured to be coupled to output pins of PMIC 300. LED driver 320 can therefore drive and dim LEDs 321-326 on up to six independent channels.

[0233] The PMIC 300 includes a first digital-to-analog converter (DAC) 327 that converts digital signals within the PMIC 300 into analog voltage control signals and outputs the signals from the PMIC 300 via an output terminal VDAC0. The first DAC 327 converts the digital control signals generated by the digital core 316 into analog voltage control signals and outputs the analog voltage control signals via an output terminal VDAC0 to control a voltage regulator circuit such as the boost converter 305. In this manner, the voltage control signals, in response to a feedback signal indicative of the operation of the resonant circuit (ultrasonic transducer 215), control the voltage regulator circuit to generate a predetermined voltage for modulation by an H-bridge circuit to drive the ultrasonic transducer 215.

[0234] In this example, the PMIC 300 includes a second DAC 328 that converts a digital signal within the PMIC 300 into an analog signal that is output from the PMIC 300 via a second analog output terminal VDAC1.

[0235] 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 and with minimal or no communication lag. 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, controlling 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. By integrating two independent DAC channels into the PMIC 300, the PMIC 300 can operate the feedback loop of any regulator used in the hookah device 202, allowing the hookah device 202 to adjust the ultrasonic power of the ultrasonic transducer 215 or to set analog thresholds for the absolute maximum current and temperature settings of the ultrasonic transducer 215.

[0236] The PMIC 300 implements a serial communication interface, in this example an I2C interface with an external I2C address set through a pin.

[0237] The PMIC 300 also comprises various functional blocks, including a functionally similar to a digital machine (FSM), for implementing the functions of the microchip. These blocks are described in more detail below.

[0238] 32 of the accompanying drawings, a pulse width modulation (PWM) signal generator subsystem 329 is incorporated within the PMIC 300. The PWM generator system 329 is comprised of an oscillator 315, a frequency divider 330, a multiplexer 331, and a delay locked loop (DLL) 332. As will be described below, the PWM generator system 329: This is a two-phase center-aligned PWM generator.

[0239] Divider 330 , multiplexer 331 and DLL 332 are implemented with digital logic components (eg, transistors, logic gates, etc.) within digital core 316 .

[0240] In the example of the present disclosure, the frequency range covered by oscillator 315 and respective PWM generation system 329 is 50 kHz to 5 MHz or up to 105 MHz. The frequency accuracy of PWM generation system 329 is ±1% and the temperature spread is ±1%. There are no ICs on the current IC market that have built-in oscillators and two-phase center-matched PWM generators that can provide a frequency range of 50 kHz to 5 MHz or up to 105 MHz.

[0241] Oscillator 315 generates a main clock signal (clk_m) with a frequency ranging from 50 kHz to 5 MHz, or up to 105 MHz. Main clock clk_m is input to divider 330, which divides the frequency of main clock clk_m by one or more predetermined divisors. In this example, divider 330 divides the frequency of main clock clk_m by 2, 4, 8, or 16, and supplies the divided-frequency clocks as outputs to multiplexer 331. Multiplexer 331 multiplexes the divided-frequency clocks and supplies the divided-frequency output to DLL 332. The signal passed to DLL 332 is a frequency reference signal that controls DLL 332 to output a signal at the desired frequency. Note that in other examples, divider 330 and multiplexer 331 are omitted.

[0242] 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 Figure 33: The first phase clock signal Phase1 goes high for a variable time during the positive half cycle of clk_m and goes low during the negative half cycle of clk_m. The second phase clock signal Phase2 goes high for a variable amount of time during the negative half cycle of clk_m and goes low during the positive half cycle of clk_m.

[0243] The first phase clock signal, Phase 1, and the second phase clock signal, Phase 2, are then sent to DLL 332, which uses the first phase clock signal, Phase 1, and the second phase clock signal, Phase 2, to generate a double frequency clock signal. This 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 the first phase clock signal, Phase 1, and the second phase clock signal, Phase 2, to generate the double frequency clock signal. This double frequency clock, or the divided frequency coming from divider 330, is selected based on the selected target frequency and is then used as the reference for DLL 332.

[0244] Within the DLL 332, a signal hereafter referred to as "clock" controls the main clock clk_m. The signal "clock_del" represents a replica of the clock signal, delayed by one period. The clock signal and clock_del pass through a phase-frequency detector. A charge pump then charges and discharges node Vc based on the polarity of the phase error. A control voltage is applied directly to control the delay of each individual delay unit within DLL 332 until the total delay of DLL 332 is exactly one period.

[0245] The DLL 332 controls the rising edges of the first phase clock signal Phase1 and the second phase clock signal Phase2 to synchronize 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 Phase1 and the second phase clock signal Phase2 according to the respective frequency reference signals and duty cycle control signals, and generates the first phase output signal PhaseA and the second phase output signal PhaseB to drive an H-bridge or an inverter to generate AC drive signals that drive the ultrasonic transducer.

[0246] The PMIC 300 is configured with a first phase output signal terminal PHASE_A that outputs a first phase output signal A stage to the H-bridge circuit, and a second phase output signal terminal PHASE_B that outputs a second phase output signal B stage to the H-bridge circuit.

[0247] In this example, the DLL 332 adjusts the duty cycle of the first phase clock signal Phase1 and the second phase clock signal Phase2 by changing the delay time of each delay line of the DLL 332 in response to the duty cycle control signal.

[0248] The clock is used at twice its frequency to ensure better accuracy. As shown in FIG. 34, if the frequency of the main clock clk_m is used for illustration purposes (not used in the examples of this disclosure), phase A is synchronized to the rising edge R of the clock, and phase B is synchronized to the falling edge F of the clock. The delay line of DLL 332 controls the rising edge R; therefore, for the falling edge F, PWM generation system 329 would need to rely on perfect matching of the delay units of DLL 332, which may be imperfect. However, to eliminate this error, PWM generation system 329 uses a double-frequency clock such that both the A and B phases are synchronized with the rising edge R of the double-frequency clock.

[0249] To achieve a duty cycle from 20% to 50% with a 2% step size, the delay line of DLL 332 consists of 25 delay units, each representing a phase nth at its output. Ultimately, the phase of the output of the last delay unit corresponds to the input clock. Considering that all delays are approximately the same, simple logic in digital core 316 determines a specific duty cycle at the output of a particular delay unit.

[0250] It is important to be careful about the startup of DLL 332 because DLL 332 may not be able to lock the period of the delay, but there may be more than one period, bringing DLL 332 into a non-convergence zone. To avoid this problem, a startup circuit is implemented in PWM generation system 329, which allows DLL 332 to start from a known, deterministic state. The startup circuit also allows DLL 332 to start with minimal delay.

[0251] In the example of the present disclosure, as the frequency range covered by PWM generator system 329 is extended, the delay unit in DLL 332 can provide delays of 4 ns (for an oscillator frequency of 5 MHz) to 400 ns (for an oscillator frequency of 50 kHz). To accommodate these different delays, a capacitor Cb is included in PWM generation system 329, with the capacitor value selected to provide the required delay.

[0252] The A and B stages are output from the DLL332 and passed to the bridge IC301 via the digital IO, so that the A and B stages can be used to control the operation of the bridge IC301.

[0253] The battery charging functionality of some examples of the hookah device 202 will now be described in more detail. However, it should be understood that in other embodiments where the hookah device 202 is configured to be powered by an external power source instead of a battery, the battery charging functionality may be omitted.

[0254] In this example, the battery charging subsystem consists of a charger circuit 317 integrated into the PMIC 300 and controlled by a digital charge controller hosted in the PMIC 300. The charger circuit 317 is controlled by a microcontroller 303 via a communication bus 302. The battery charging subsystem is capable of charging single cell Lithium Polymer (LiPo) or Lithium Ion (Li-ion) batteries. be.

[0255] In this example, the battery charging subsystem can charge the battery or batteries from a 5V power source (e.g., a USB power source) with a charging current of up to 1 A. Through the communication bus 302 (I2C interface), one or more of the following parameters can be programmed to adapt the charging parameters of the battery:

[0256] The charging voltage can be set between 3.9V and 4.3V in 100mV steps.

[0257] The charging current can be set in 50mA increments from 150mA to 1000mA.

[0258] The pre-charge current is 1 / 10 of the charge current.

[0259] The pre-charge and fast charge timeouts can be set between 5 and 85 minutes and 20 and 340 minutes, respectively.

[0260] Optionally, an external negative temperature coefficient (NTC) thermistor can be used to monitor battery temperature.

[0261] 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 Detection Battery charging The battery is fully charged No battery Charging Timeout The charging power supply is below the undervoltage limit

[0262] The primary advantage of embedding the charger circuit 317 in the PMIC 300 is that all of the described programming options and event indications can 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 inhalers, which consist of discrete charging system components implemented separately on a PCB. The charger circuit 317 also allows for versatile configuration of charging current and voltage, different fault timeouts, and multiple event flags for detailed status analysis.

[0263] Next, we will discuss in more detail the analog-to-digital converter (ADC) 318. The inventors had to overcome significant technical challenges in order to integrate the ADC 318 into the PMIC 300 with the high-speed oscillator 315. Furthermore, integrating the ADC 318 into the PMIC 300 runs counter to conventional approaches in the art, which rely on using one of the many discrete ADC devices available on the IC market.

[0264] In this example, ADC 318 samples at least one parameter within the ultrasonic transducer driver chip (PMIC 300) at a sampling rate equal to the frequency of the main clock signal clk_m. In this example, 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 the ADC's sampling capability (traditional devices rely on an I2C bus to communicate data between a dedicated discrete ADC and a microcontroller at limited clock speeds, typically up to 400 kHz).

[0265] In the example of the present disclosure, one or more of the following parameters may be sampled sequentially by the ADC 318:

[0266] i. The rms current signal received by 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 bridge IC 301. Sensing the rms current is important for implementing the feedback loop used to drive the ultrasonic transducer 215. Because ADC 318 does not rely on this information being transmitted over the I2C bus, it is able to sense the rms current directly from bridge IC 301 via a signal with minimal or no delay. This provides significant speed and accuracy advantages over conventional devices that are limited 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 indicating the chip temperature of the PMIC 300. As mentioned above, this temperature can be measured very accurately because the temperature sensor 314 is integrated into the same IC as the oscillator 315. For example, if the temperature of the PMIC 300 rises, the PMIC 300 controls the current, frequency, and PWM to control the oscillation of the converter, which in turn controls the temperature. v. Two external terminals. vi. An external NTC temperature sensor to monitor the temperature of the battery pack.

[0267] In some examples, the ADC 318 samples one or more of the above sources sequentially, 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.

[0268] In some examples, the device 202 is configured to allow a user or the device manufacturer to specify how many samples to take 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 to skip one of the above sources. In some examples, the hookah device 202 is configured by a user via an external computing device that wirelessly communicates with the hookah device 202 (e.g., via BLE).

[0269] In some examples, the user can specify two digital thresholds for each source that divide the total range into multiple zones (e.g., three zones), and then set an interrupt to occur when the sampled value changes from zone 2 to zone 3.

[0270] No conventional IC currently available on the market can perform the above functions of the PMIC 300. This level of flexibility and granularity in sampling is paramount when driving ultrasonic transducers.

[0271] In this example, the PMIC 300 is configured with 8-bit general-purpose digital input / output ports (GPIOs). Each port can be configured as a digital input and a digital output. Some ports also have analog input functionality, as shown in the table in Figure 35.

[0272] The GPIO7-GPIO5 ports of the PMIC 300 can be used to set the addresses of devices 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, as eight identical devices can be used on the same I2C bus without address conflicts. This is achieved 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 other purposes.

[0273] As described above, the PMIC 300 includes a six-channel LED driver 320. In this example, the LED driver 320 is configured with a 5V N-Channel Metal-Oxide Semiconductor (NMOS) current source. The LED driver 320 is configured to set the LED current at four discrete levels: 5mA, 10mA, 15mA, and 20mA. 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 between 300Hz and 1.5KHz. This functionality, integrated as a subsystem of the PMIC 300, is unique in the ultrasonic mist inhaler field.

[0274] In this example, the PMIC 300 is configured with two independent 6-bit digital-to-analog converters (DACs) 327 and 328 integrated into the PMIC 300. The purpose of the DACs 327 and 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 and 328 can be used to dynamically adjust the overcurrent shutdown level of the bridge IC 301, as described below.

[0275] 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 achieved via I2C commands. The incorporation of two DACs into the PMIC 300 is unique and allows for dynamic monitoring and control of current. If either DAC 327, 328 were an external chip, it would be subject to the same speed limitations imposed by the I2C protocol. With all these built-in functions within the PMIC, the active power monitoring arrangement of the device 202 functions at optimal efficiency. If these were external components, the active power monitoring arrangement would be quite inefficient.

[0276] Referring now to Figure 36 of the accompanying drawings, bridge IC 301 is a microchip that comprises an embedded power switching circuit 333. In this example, power switching circuit 333 is an H-bridge 334, shown in Figure 37, which is described in detail below. However, it will be appreciated that other examples of bridge IC 301 may incorporate power switching circuitry in place of 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.

[0277] Bridge IC 301 provides a first phase terminal A stage that receives a first phase output signal A stage from the PWM signal generation subsystem of PMIC 300. Bridge IC 301 also provides a second phase terminal B stage that receives a second phase output signal B stage from the PWM signal generator subsystem of PMIC 300.

[0278] Bridge IC 301 comprises a current sensing circuit 335 that directly senses the current flowing in H-bridge 334 and provides an RMS current output signal via the RMS_CURR terminal of bridge IC 301. Current sensing circuit 335 is configured for overcurrent monitoring, detecting when the current flowing through H-bridge 334 is above a predetermined threshold. The integration of power switching circuit 333 and current sensing circuit 335 that comprise H-bridge 334, all within the same embedded circuit of bridge IC 301, is a unique combination in the IC market. Currently, there are no other integrated circuits on the market that comprise an H-bridge with embedded circuitry for sensing the RMS current flowing through the H-bridge.

[0279] The bridge IC 301 is configured with a temperature sensor 336 that includes over-temperature monitoring. The temperature sensor 336 is configured to shut down the bridge IC 301 or disable at least a portion of the bridge IC 336 if the temperature sensor 336 detects that the bridge IC 301 is operating at a temperature above a predetermined threshold. The temperature sensor 336 thus provides an integrated safety feature that prevents damage to the bridge IC 301 or other components within the hookah device 202 if the bridge IC 301 operates at an excessively high temperature.

[0280] The bridge IC 301 includes a digital state machine 337 integrally connected to the power supply switching circuit 333. The digital state machine 337 receives the A-phase signal and the B-phase signal from the PMIC 300 and, for example, an ENABLE signal from the microcontroller 303. The digital state machine 337 generates a timing signal based on the A-phase of the first phase output signal and the B-phase of the second phase output signal.

[0281] The digital state machine 337 generates timing signals corresponding to the A-phase and B-phase signals, as well as the BRIDGE PR signaling and BRIDGE The EN signal is output to the power switching circuit 333. As a result, the digital state machine 337 outputs a timing signal to the switches T1-T4 of the H-bridge circuit 334, and controls the switches T1-T4 to turn on / off in sequence so that the H-bridge circuit outputs an AC drive signal for driving a resonant circuit such as the ultrasonic transducer 215.

[0282] As will be described in more detail below, the switching sequence consists of a free-float period in 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 the energy stored in the resonant circuit (ultrasonic transducer 215).

[0283] The bridge IC 301 includes a test controller 338 that can test the bridge IC 301 to determine whether the embedded components in the bridge IC 301 are operating properly. DATA, TEST CLK, TEST The bridge IC 301 is connected to the LOAD terminal, and can be connected to an external control device that sends data to the bridge IC 301 and tests the operation of the bridge IC 301. A TEST BUS is configured that can test the digital communication bus in the bridge IC 301 via the PAD terminal.

[0284] The bridge IC 301 includes a power-on reset circuit (POR) 339 that controls the startup of the bridge IC 301. The POR 339 ensures that the bridge IC 301 starts up normally only if the power 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, the POR 339 delays the startup of the bridge IC 301 until the power supply voltage falls within the predetermined range.

[0285] Bridge IC 301 includes a reference block (BG) 340 that provides a precise reference voltage for use by other subsystems of bridge IC 301.

[0286] Bridge IC 301 configures current reference 341 that provides accurate current to power switching circuit 333 and / or other subsystems within bridge IC 301 , such as current sensor 335 .

[0287] 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, overheating may be reported to an external host to notify the external host that an overheating event has occurred.

[0288] A digital state machine (FSM) 337 generates timing signals for the power switching circuit 333, in this example, timing signals for controlling the H-bridge 334.

[0289] Bridge IC 301 consists of comparators 342, 343 which 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.

[0290] Referring again to Figure 37 of the accompanying drawings, the H-bridge 334 in this example is comprised of four switches in the form of NMOS field effect transistor (FET) switches on either side of the H-bridge 334. The H-bridge 334 consists of 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 that is generated internally using two external capacitors Cb connected as shown in Figure 37.

[0291] The H-bridge 334 provides input and output for various power supplies connected to the pins of the bridge IC 301. The H-bridge 334 receives the programmable voltage VBOOST output from the boost converter 305 via a first power supply terminal labeled VBOOST in FIG. 37. The H-bridge 334 provides a second power supply terminal labeled VSS_P in FIG. 37.

[0292] The H-bridge 334 provides outputs OUTP, OUTN that are configured to connect to respective terminals of the ultrasonic transducer 215 such that the AC drive signal output from the H-bridge 334 can drive the ultrasonic transducer 215 .

[0293] The switching of the four switches or transistors T1-T4 is controlled by switching signals from digital state machine 337 via logic inputs A through D. While FIG. 37 shows four transistors T1-T4, it should be understood that in other examples, H-bridge 334 incorporates more transistors or other switching components to achieve the functionality of an H-bridge.

[0294] In this example, the H-bridge 334 operates at a switching power of 22 W to 37 W to provide an AC drive signal with sufficient 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, but in other examples it is ±20 V.

[0295] 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 currently available on the IC market are configured to operate at a maximum frequency of only 2 MHz. Aside from bridge IC 301 described herein, no conventional integrated circuit H-bridges available on the IC market can operate at frequencies up to 5 MHz, let alone up to 105 MHz, on power supplies between 22 V and 37 V.

[0296] Referring now to Figure 38 of the accompanying drawings, the current sensor 335 comprises positive and negative current sense resistors RshuntP, RshuntN connected in series with the respective high and low sides of the H-bridge 334, as shown in Figure 37. The current sense resistors RshuntP, RshuntN are low value resistors of 0.1 Ω in this example. 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 1 mA / V in this example. The current sensor 335 is connected to a pull-down resistor R cs The output of the operational amplifiers 344, 345 provides an output CSout that is passed 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.

[0297] In this way, current sensor 335 measures the AC current flowing through H-bridge 334 and, respectively, ultrasonic transducer 215. Current sensor 335 converts the AC current to an equivalent RMS output voltage (Vout) relative to ground. H-bridge 334 can be operated at frequencies up to 5 MHz, or in some examples, up to 105 MHz, so current sensor 335 has high bandwidth capabilities. The output Vout of current sensor 335 reports a positive voltage corresponding 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 the current flowing through transducer 215, exceeds a predetermined threshold. Additionally, an overcurrent threshold event is triggered by bridge IC 301 shutting down bridge IC 301's OVC. An overcurrent event is reported to the first comparator 342 of the bridge IC 301 so that it can be reported via the TRIGG pin.

[0298] Referring now to Figure 39 of the accompanying drawings, control of the H-bridge 334 will now be described, also with reference to an equivalent piezoelectric model of the ultrasonic transducer 215.

[0299] To generate a positive voltage across the outputs OUTP, OUTN of the H-bridge 334 (note the direction of the arrows), as shown by V_out in FIG. 39, the switching sequence of transistors T1-T4 via inputs A-D is as follows: 1. Positive output voltage across the ultrasonic transducer 215: A-on, B-off, C-off, D-on 2. Transition from positive output voltage to zero: A-OFF, B-OFF, C-OFF, D-ON. During this transition, if there is a switching error or delay in A, C will be switched off first to minimize or avoid the current flowing through A and C, thereby minimizing or avoiding power loss. 3. Zero output voltage: A-OFF, B-OFF, C-ON, D-ON. During this zero output voltage stage, the output terminals OUTP and OUTN of the H-bridge 334 are grounded by the C and D switches which remain on. This dissipates the energy stored in the capacitors of the equivalent circuit of the ultrasonic transducer and minimizes the voltage overshoot of the switching waveform voltage applied to the ultrasonic transducer. 4. Output voltage zero to negative transition: A-OFF, B-OFF, C-ON, D-OFF. 5. Negative output voltage across ultrasonic transducer 215: A-OFF, B-ON, C-ON, D-OFF.

[0300] It will be appreciated that at high frequencies up to 5 MHz, or even up to 105 MHz, the duration of each portion of the switching sequence is very short, on the order of nanoseconds or picoseconds. For example, at a switching frequency of 6 MHz, each portion of the switching sequence occurs in approximately 80 nanoseconds.

[0301] A graph showing the output voltages OUTP, OUTN of the H-bridge 334 according to the above switching sequence is shown in Figure 40 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). This, as discussed above, minimizes voltage overshoot in the switching waveform voltage applied to the ultrasonic transducer, thereby minimizing unnecessary power dissipation and heating in the ultrasonic transducer.

[0302] Additionally, minimizing or eliminating voltage overshoot prevents the transistors in bridge IC 301 from experiencing voltages exceeding their rated voltage, reducing the risk of damaging the transistors. Furthermore, minimizing or eliminating voltage overshoot enables bridge IC 301 to accurately drive ultrasonic transducers in a manner that minimizes disruption of the current-sense feedback loop described herein. As a result, bridge IC 301 can drive ultrasonic transducers at high frequencies, up to 5 MHz, or up to 105 MHz, and at powers as high as 22 W to 50 W, or even 70 W.

[0303] The bridge IC 301 in this example is controlled by the PMIC 300 and is configured to operate in two different modes, referred to herein as forced mode and native frequency mode. These two modes of operation are novel compared to existing bridge ICs. In particular, the native frequency mode is a key innovation that provides substantial advantages in the accuracy and efficiency of driving ultrasonic transducers compared to conventional devices.

[0304] 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, in forced frequency mode, the H-bridge 334 can drive an ultrasonic transducer 215 having a resonant frequency f1 at a different frequency f2.

[0305] Driving an ultrasonic transducer at a frequency different from its resonant frequency may be appropriate to adapt operation to different applications. For example, it may be appropriate to drive an ultrasonic transducer at a frequency slightly offset from 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 lower frequency, but the ultrasonic transducer, due to its size, has a different natural resonant frequency.

[0306] The hookah device 202 controls the bridge IC 301 to drive the ultrasonic transducer 215 in forced frequency mode, corresponding to the configuration of the hookah device 202 for a particular application or a particular ultrasonic transducer. For example, the hookah device 202 may be configured to operate in forced frequency mode when the mist inhaler 200 is being used for a particular application, such as generating mist from a liquid of a particular viscosity containing a medicinal agent for delivery to a user.

[0307] Native Frequency Mode (NFM) The following native frequency mode of operation is a significant development, offering advantages in improved accuracy and efficiency compared to conventional ultrasonic drivers currently available on the IC market.

[0308] Native frequency mode operation 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 occur due to current spikes in forced frequency mode operation. These current spikes occur when the voltage across the ultrasonic transducer 215 switches to its opposite voltage polarity. Ultrasonic transducers made of piezoelectric crystals have an electrical equivalent circuit incorporating a parallel-connected capacitor (see, for example, the piezo model in Figure 39). When the voltage across the ultrasonic transducer is hard-switched from a positive voltage to a negative voltage, there can be a large current flow as the energy stored in the capacitor dissipates due to the high dV / dt.

[0309] Native frequency mode avoids hard switching the voltage across the ultrasonic transducer 215 from a positive voltage to a negative voltage (or vice versa). Instead, before applying the reversal voltage, the ultrasonic transducer 215 (piezoelectric crystal) is allowed to free float with zero voltage applied across its terminals for a free-float period. The PMIC 300 sets the drive frequency of the bridge IC 301 such that the bridge 334 causes the current flowing inside the ultrasonic transducer 215 (due to the energy stored in the piezoelectric crystal) during the free-float period to reverse the voltage across the terminals of the ultrasonic transducer 215.

[0310] 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 no current spike occurs because there is no high dV / dt.

[0311] 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 (piezoelectric crystal) to build up.

[0312] Therefore, the ideal situation in which the energy in the ultrasonic transducer 215 reverses voltage during the free-float 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 supplied to the ultrasonic transducer 215 via the H-bridge 334 to a low first value (e.g., 5 V). The PMIC 300 then controls the power supplied to the ultrasonic transducer 215 via 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 build up the energy stored in the ultrasonic transducer 215. Current spikes also occur during this oscillation ramp until the current inside the ultrasonic transducer 215 is fully developed. However, by using a low first voltage at startup, these current spikes are kept sufficiently low to minimize their impact on the operation of the ultrasonic transducer 215.

[0313] To achieve the native frequency mode, the hookah device 202 precisely controls the frequency of the oscillator 315 and the duty cycle (ratio of turn-on time to free-float time) of the AC drive signal output from the H-bridge 334. In this example, the hookah device 202 implements three control loops to adjust the oscillator frequency and duty cycle to ensure as precise a voltage reversal as possible at the terminals of the ultrasonic transducer 215 and minimize or avoid current spikes. The precise control of the oscillator and duty cycle using control loops is a significant advancement in the field of IC ultrasonic drivers.

[0314] During native frequency mode operation, current sensor 335 senses the current through ultrasonic transducer 215 (resonant circuit) during the free-float period. Digital state machine 337 adapts timing signals to turn on either first switch T1 or second switch T2 when current sensor 335 senses that the current through ultrasonic transducer 215 (resonant circuit) is zero during the free-float period.

[0315] Figure 41 of the accompanying drawings shows oscillator voltage waveform 347 (V(osc)), switching waveform 348 due to the turn-on and turn-off of left high switch T1 of H-bridge 334, and switching waveform 349 due to the turn-on and turn-off of right high switch T2 of H-bridge 334. During free float period 350, both high switches T1 and T2 of H-bridge 334 are turned off (free float phase). The duration of free float period 350 is controlled by the magnitude of free float control voltage 351 (Vphioff).

[0316] Figure 42 of the accompanying drawings shows the voltage waveform 352 at a first terminal of the ultrasonic transducer 215 (with the voltage waveform 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 a (nearly) ideal sinusoidal waveform (which is never possible in forced frequency mode or with any bridge on the IC market).

[0317] Before the sine wave of the piezoelectric current 353 becomes 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 through the ultrasonic transducer 215 due to the energy stored in the ultrasonic transducer 215 (the capacitor of the piezoelectric equivalent circuit) acts as a voltage inversion during the free-float period 350. The piezoelectric current 353 decays to zero during the free-float period 350 and then transitions into a negative current flow region. The terminal voltage of the ultrasonic transducer 215 drops from the power supply voltage (19 V in this case) to below 2 V and stops decreasing when the piezoelectric current 353 becomes zero. This is the optimal timing to turn on the low-side switch T3 of the H-bridge 334 to minimize or avoid current spikes.

[0318] Compared to the forced frequency mode described above, the native frequency mode has at least three advantages. 1. Current spikes associated with hard switching of package capacitors are significantly reduced or completely avoided. 2. There is almost no power loss due to hard switching. 3. Frequency control can be performed in a control loop to approach the resonant frequency of the piezoelectric transducer (the natural resonant frequency of the piezoelectric transducer).

[0319] For frequency regulation by a control loop (advantage 3 above), the PMIC 300 begins by controlling the bridge IC 301 to drive the ultrasonic transducer 215 at a frequency above the piezoelectric transducer's resonance. The PMIC 300 then controls the bridge IC 301 to attenuate / decrease the frequency of the AC drive signal during startup. As the frequency approaches the piezoelectric transducer's resonance frequency, the piezoelectric current rapidly develops / increases. When the piezoelectric current is high enough to cause the desired voltage reversal, the PMIC 300 stops attenuating / decrease the frequency. The PMIC 300's control loop then takes over regulating the frequency and duty cycle of the AC drive signal.

[0320] In forced frequency mode, the power supplied 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 native frequency mode, the power supplied to the ultrasonic transducer 215 is controlled only through the supply voltage.

[0321] In this example, during the setup phase of operation of the hookah device, bridge IC301 is configured to measure the length of time it takes for the current through ultrasonic transducer 215 (resonant circuit) to reach zero when first switch T1 and second switch T2 are turned off and third switch T3 and fourth switch T4 are turned on, and then bridge IC301 sets the length of time of the free-float period to be equal to the measured length of time.

[0322] Referring now to Figure 43 of the accompanying drawings, the PMIC 300 and bridge IC 301 in this example are designed to operate together as a companion chip set. The PMIC 300 and bridge IC 301 are electrically connected to communicate with each other. The PMIC 300 and bridge IC 301 are electrically connected to communicate with each other.

[0323] In this example, there are interconnections between the PMIC 300 and the bridge IC 301 that allow for two categories of communication: 1. Control Signals 2. Feedback Signal

[0324] The connections between the PHASE_A and PHASE_B terminals of PMIC 300 and bridge IC 301 carry PWM modulated control signals that drive H-bridge 334. The connection between the EN_BR terminal of PMIC 300 and bridge IC 301 carries the EN_BR control signal that triggers activation 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.

[0325] The connections between the CS, OC, and OT terminals of PMIC 300 and bridge IC 301 provide CS (current sense), OC (overcurrent), and OT (overtemperature) feedback signals from bridge IC 301 back to PMIC 300. Most notably, the CS (current sense) feedback signal consists of a voltage corresponding to the rms current through ultrasonic transducer 215 as measured by current sensor 335 of bridge IC 301.

[0326] The OC (overcurrent) and OT (overtemperature) feedback signals are digital signals that indicate that either an overcurrent or overvoltage event has been detected by bridge IC 301. In this example, the overcurrent and overtemperature thresholds are set with external resistors. Alternatively, the thresholds can be dynamically set in response to a signal passed from one of two DAC channels VDAC0, VDAC1 from PMIC 300 to the OC_REF terminal of bridge IC 301.

[0327] 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 allowing for minimal delay in the communication of signals between PMIC 300 and bridge IC 301. This provides a significant speed advantage over traditional 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 speeds of up to 5 MHz in the examples of this disclosure.

[0328] While examples of the present disclosure have been described above in terms of microchip hardware, it will be appreciated that other examples of the present disclosure comprise methods of operating each microchip's components and subsystems to perform the functions described herein, such as operating PMIC 300 and bridge IC 301 in either forced frequency mode or native frequency mode.

[0329] 44 of the accompanying drawings, 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 (eFuse) 358, an oscillator 359, and a general-purpose input / output interface 360. OTP IC 242 also comprises a digital core 361 that includes a cryptographic authenticator. In this example, the cryptographic authenticator uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to encrypt and decrypt data stored within OTP IC 242 and data sent to and from OTP IC 242.

[0330] The POR 354 ensures that the OTP IC 242 starts up normally only if the power supply voltage is within a predetermined range. If the power supply voltage is outside the predetermined range, the POR 354 resets the OTP IC 242 and waits until the power supply voltage is within the predetermined range.

[0331] BG355 provides a precision reference voltage and current to LDO356 and oscillator 359. LDO356 supplies digital core 361, communication interface 357, and eFuse memory bank 358.

[0332] The OTP IC 242 is configured to operate in at least the following modes: Fuse Programming (Fusing): During fuse programming (programming of one-time programmable memory), a high current is required to burn the associated fuses in the eFuse memory bank 358. In this mode, a higher bias current is provided to maintain the gain and bandwidth of the regulation loop.

[0333] Fuse Read: In this mode, a moderate current is required to maintain the fuse read in the eFuse memory bank 358. This mode is executed at power-up of the OTP IC 242 and transfers 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 fuse mode.

[0334] Normal operation: In this mode, the LDO356 is driven with a very low bias current, allowing the OTP IC242 to operate at low power, thereby minimizing the power consumption of the OTP IC242.

[0335] Oscillator 359 provides the necessary clocks for digital core / engine 361 during test (SCAN Test), settling, and normal operation. Oscillator 359 is trimmed to handle the stringent timing requirements during settling mode.

[0336] In this example, the communication interface 357 is compliant with the FM+ specification of the I2C standard, but also with slow and fast modes. The OTP IC 242 uses the communication interface 357 to communicate with the hookah device 202 (host) for data and key exchange.

[0337] The digital core 361 implements the control and communication functions for the OTP IC 242. The cryptographic authenticator in the digital core 361 allows the OTP IC 242 to authenticate itself with the driver device 202 (e.g., using ECDSA encrypted messages) to ensure that the OTP IC 242 is authentic and authorized to connect with the hookah device 202.

[0338] Referring to Figure 45 of the accompanying drawings, the OTP IC 242 performs the following PKI procedures to authenticate the OTP IC 242 for use with a host (e.g., hookah device 202): 1. Verifying the signer's public key: The host requests the manufacturer's public key and certificate. The host verifies the certificate with the certificate authority's public key. 2. Verify the device public key: If the verification is successful, the host requests the device public key and certificate. The host verifies the certificate using 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 signs the random challenge with the device's private key. 4. The signature is sent back to the host for verification using the device's public key.

[0339] If all steps of the authentication procedure are completed successfully, the chain of trust is verified up to the root of trust and the OTP IC 242 is properly 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.

[0340] 46 to 48 are diagrams showing how air flows inside the mist generator 201 during operation.

[0341] A liquid medication (such as nicotine) is atomized (aerosolized) by sonication. However, this mist will settle above the ultrasonic transducer 215 if sufficient ambient air is not available to replace the rising aerosol. The sonication chamber 219 generates a mist (aerosol) that is then drawn out through the mist exit port 208, requiring a continuous delivery of air. To accommodate this requirement, an air flow path is provided. In this arrangement, the airflow channel is 11.5 mm 2 , which is calculated based on the negative pressure from the average user and designed into the ultrasound irradiation chamber 219. This also controls the mist-to-air ratio of the inhaled aerosol and the amount of medication delivered to the user.

[0342] Based on design requirements, the air flow path is routed to start 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 to the airflow bridge within the device. The air flow path runs 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 maximizes the amount of ambient air that is delivered directly toward the atomizing surface of the ultrasonic transducer 215. The air flows through the channel toward the transducer, collecting the generated mist before exiting through the mouthpiece to the user.

[0343] 49 and 50 of the accompanying drawings, some configurations of the hookah device 202 are configured to be releasably attached to an existing hookah 246. The hookah device 202 is attached to a stem 247 in place of a traditional hookah head that would otherwise house tobacco and charcoal (or an electronic heating element).

[0344] The hookah 246 comprises a water chamber and an elongated stem 247 having a first end attached to the water chamber, the stem 247 defining a mist flow path that extends from the second end of the stem 247, through the stem 247, to the first end and into the water chamber.

[0345] In this arrangement, the hookah device 202 is releasably attached to the second end of the stem 247 of the hookah 246. However, in other arrangements, the hookah device 202 is not designed to be removable, but instead is fixed to or integrally formed with the stem 247 of the hookah 246.

[0346] 51 to 59 of the accompanying drawings, the hookah device 202 comprises a housing 248 incorporating a base 249 and a cover 250 which are attached or releasably attached to one another. In this arrangement, the housing 248 is cylindrical and generally disc-shaped.

[0347] In this arrangement, the cover 250 includes a plurality of air inlets 251 to allow air to be drawn into the hookah device 202. The base 249 is provided with a hookah outlet port 252 for allowing air and mist to exit the hookah device 202 into the hookah 246. The diameter of the hookah outlet port 252 is sufficient to allow a user to quickly draw air through the hookah device 202 and into the hookah 246, generating bubbles of mist that move through the water within the hookah 246. be.

[0348] In this arrangement, the hookah outlet port 252 is a circular opening that receives the end of the stem 247 of the hookah 246. The hookah device 202 is supported on the stem 247 of the hookah 246, with a generally airtight seal formed between the hookah device 202 and the stem 247.

[0349] In this arrangement, the hookah device 202 is a self-contained device in which the electronic components, including the e-liquid, and the mist generator are contained within the housing 248 .

[0350] In this arrangement, the hookah device 202 is comprised of an upper support plate 253, a middle support plate 254, and a lower support plate 255 that are stacked on top of each other. The support plates 253-255 support a plurality of mist generators 201 within the hookah device 202. Each mist generator is a mist generator 201 as described in this disclosure. In this arrangement, the mist generators 201 are releasably attached to the hookah device 202 so that the mist generators 201 can be replaced when empty (i.e., when the e-liquid is partially or completely depleted).

[0351] In this arrangement, the hookah device 202 is comprised of four mist generators 201 controlled (via their respective PMICs 300 and bridge ICs 301) by the microcontroller 303 of the hookah device 202. In other arrangements, the hookah device 202 is comprised of multiple mist generators 201, such as at least two mist generators 201 or up to eight mist generators 201.

[0352] The hookah device 202 includes a first contact terminal 259 that establishes an electrical connection between the controller of the hookah device 202 and the electrical contacts 232, 233 of each mist generator 201. The hookah device 202 includes a second contact terminal 260 that establishes an electrical connection between the controller of the hookah device 202 and the electrical contacts 241 on the OTP PCB of each mist generator 201.

[0353] In this arrangement, the hookah device 202 comprises an upper printed circuit board (PCB) 256 disposed on an upper support plate 253, and an intermediate PCB 257 disposed between an intermediate support plate 254 and a lower support plate 255. A lower PCB 258 is disposed below the lower support plate 255. The PCBs 256-258 carry electronic components that form the driving mechanism of the hookah device 202. The PCBs 256-258 are electrically coupled to each other so that the electronic components on each PCB 256-258 can communicate with each other.

[0354] In this arrangement there are three PCBs 256-258, but other arrangements may consist of only one PCB or multiple PCBs performing the same function of the driver device of the hookah device 202.

[0355] In this arrangement, the hookah device 202 comprises a plurality of magnets 261 that allow the support plates 253-255 to be releasably attached to one another. Once the hookah device 202 is assembled with the support plates 253-255 and PCBs 256-258 stacked on top of one another and the mist generator 201 held between the support plates 253-255, the cover 250 is placed on the base 249 and releasably attached to the base 249 using a plurality of screws 262.

[0356] The upper support plate 253 defines a manifold 263 centrally located on one side of the upper support plate 253. In this arrangement, the manifold 263 has four openings 264 (only one of which is visible in Figure 56), each for receiving the outlet port 208 of a respective mist generator 201. In this arrangement, the hookah device 202 comprises four mist generators 201 that are releasably coupled to the manifold at 90° angles to one another. In other arrangements, the manifold 263 comprises a different number of openings 264 to correspond to the number of mist generators 201 used with the hookah device 202.

[0357] The manifold 263 comprises a manifold pipe 265 in fluid communication with the opening 264 so that mist generated by the mist generator 201 can combine and flow down from the manifold 263 and out of the manifold pipe 265. When the hookah device 202 is assembled, the manifold pipe 265 extends through an opening 266 in the middle support plate 254 and an opening 267 in the middle PCB 257. The manifold pipe 265 in turn connects to an outlet pipe 268 that extends through the lower support plate 255, providing a fluid flow path through the lower support plate to the hookah outlet port 252 of the hookah device 202.

[0358] In use, each of the mist generating devices 201 is held horizontally by the manifold, i.e., the longitudinal extent of each mist generating device 201 is perpendicular or approximately perpendicular to the direction of mist flow as it flows downward from the base of the hookah device 202.

[0359] The outlet pipe 268 extends downwardly from the underside of the lower support plate 255 through an opening 269 in the lower PCB 258. The outlet pipe 268 then extends through an opening 270 in the base 249 of the hookah device 202. In this arrangement, the outlet pipe 268 and the hookah outlet port 252 form a hookah attachment arrangement 271 that is configured to attach or mount the hookah device 202 to the hookah 246. In this arrangement, the hookah device 202 is attached to the hookah 246 by inserting a portion of the hookah stem 247 into the hookah outlet port 252.

[0360] The hookah outlet port 252 provides a fluid flow path 272 from the mist outlet port 208 of the mist generator 201 out of the hookah device 202, allowing the mist generated by the mist generator 201 to exit the hookah device 202 and enter the hookah 246, as shown in Figures 58 and 59. The mixture of air and mist creates air bubbles in the water of the hookah 246. Upon inhalation, the air bubbles escape the water surface along with the mist that rises above the surface of the hookah bowl, traveling down the pipe to the user.

[0361] In this arrangement, the upper PCB 256 carries a pressure sensor that senses the pressure of air proximate the mist outlet ports 208 of the mist generators 201. The pressure sensor thereby detects negative pressure proximate the mist outlet ports 208 when a user draws on the hookah and draws air through the mist generators 201 along the fluid flow path 272. The pressure sensor provides a signal to a controller of the hookah device, as described below, so that the controller activates at least one of the mist generators 201 to generate mist when a user draws on the hookah.

[0362] In this arrangement, the lower PCB 258 carries a power control component 273 that controls and distributes power to the other electronic components of the hookah device 202. In some arrangements, the power control component 273 receives power from an external power source, such as a mains power adapter that is releasably attached to the hookah device 202. In this arrangement, the hookah head 202 is configured to be powered from the external power adapter at a DC voltage in the range of 20V to 40V.

[0363] In other arrangements, the hookah device 202 comprises a battery integrated within the hookah device 202 and connected to the power control component 273. In some arrangements, the battery is a rechargeable Li-Po battery. In certain arrangements, the battery is configured to output a DC voltage of 20V to 40V. In some arrangements, the battery has a high discharge rate. A high discharge rate is necessary for the voltage amplification required by the ultrasonic transducer of the mist generating device 201. Due to the requirement of having a high discharge rate, the Li-Po battery in some arrangements is specially designed for continuous current draw. In some arrangements, a charging port is provided on the hookah device 202 to allow the battery to be charged by an external power source.

[0364] The intermediate PCB 257 houses the processor 274 and memory 275 of the controller or computing device of the hookah device 202. In this example, the PMIC 300 and bridge IC 301 are mounted on the PCB 257 along with other electronic components of the hookah device 202. In this arrangement, the processor 274 and memory 275 are components of a driver device within the hookah device 202. In this arrangement, the functionality of the driver device is implemented in executable instructions stored in the memory 275 that, when executed by the processor 274, cause the processor 274 to control the driver device to perform at least one function. The driver device is electrically connected to each of the mist generation devices 201. In this arrangement, the driver device of the hookah device 202 includes, as described above, 2The microcontroller 303 is coupled to communicate with each mist generator 201 by a communication or data bus, such as a C data bus. In this arrangement, each mist generator 201 is identified by a unique identifier that is used in controlling the mist generator 201 via the data bus (the microcontroller 303 controls each PMIC 300 via the data bus, which in turn controls the respective mist generator 201). In some arrangements, the unique identifier is stored in the OTP IC 242 of the mist generator 201.

[0365] In some arrangements, the driver device (microcontroller 303) independently controls each mist generating device. In some arrangements, the control functions are implemented in executable instructions stored in memory 275. The independent control configuration allows the driver device to activate or deactivate each mist generating device 201 independently of the other mist generating devices 201. Thus, the driver device can control one or more mist generating devices 201 to generate mist simultaneously or alternately according to predetermined requirements.

[0366] In some arrangements, the driver device controls the mist generators 201 to activate and / or deactivate them sequentially. In some arrangements, the sequence of activation of the mist generators 201 optimizes the operation of the hookah device 202 by ensuring that mist is generated quickly enough to bubble through the water in the water chamber of the hookah. Some hookah device 202 arrangements thereby enable mist bubbles to be drawn through the water in the water chamber at high speed when the user pulls on the hookah mouthpiece. As a result, water-soluble compounds (e.g., vegetable glycerin, flavorings, etc.) can travel through the water in the mist bubbles for inhalation by the user.

[0367] In some arrangements, the driver device controls the mist generating devices 201 to activate one after the other in a sequence for a predetermined length of time, and in some arrangements, the driver device controls the mist generating devices 201 to activate in a rotational manner, such that the mist generating devices 201 are activated one after the other in a clockwise or counterclockwise direction and / or one at a time.

[0368] In some arrangements, the driver device controls the mist generators 201 to operate in pairs. In some arrangements, the driver device controls two mist generators 201 to activate simultaneously; either two mist generators 201 adjacent to each other or two mist generators 201 opposite each other.

[0369] In some arrangements, the driver device is configured to not activate if the mist generator 201 is not properly aspirating e-liquid within its capillary 222 or if the liquid chamber 218 is empty or nearly empty of e-liquid. This provides protection for the hookah device 202 by ensuring that it maintains proper operation.

[0370] The electronics of the driver unit of the hookah machine 202 (distributed across PCBs 256-258) are partitioned as described below. In the following description, reference is made to the control of one mist generator 201, but it will be understood that the driver unit of the hookah machine 202 controls each mist generator 201 independently in a similar manner. To obtain the most efficient aerosolization to date, with particle diameters of 1 um or less, the ultrasonic processor must provide contact pads that receive the ultrasonic transducer 215 (piezoelectric ceramic disc (PZT)) at a high adaptive frequency (approximately 3 MHz). This section must not only provide high frequencies, but must also provide optimized cavitation at all times while protecting the ultrasonic transducer 215 from failure.

[0371] The mechanical deformation of the PZT is coupled to the AC voltage amplitude applied to it, and maximum deformation must always be supplied to the PZT to ensure optimal function and delivery of the system with each ultrasound exposure.

[0372] However, to prevent PZT failure, the active power delivered to the PZT must be precisely controlled.

[0373] The processor 274 and memory 275 are configured to instantaneously control the modulation of the active power applied to the PZT without compromising the mechanical vibration amplitude of the PZT.

[0374] By applying PWM (Pulse Width Modulation) to the AC voltage applied to the PZT, the mechanical amplitude of the vibration can be kept constant.

[0375] In fact, as with voltage modulation, effective duty cycle modulation results in the same applied effective voltage, but the effective power transferred to the PZT is degraded. In fact, it can be expressed as:

[0376]

number

[0377] When considering the first harmonic, Irms is a function of the amplitude of the real voltage applied to the transducer, and pulse width modulation varies the duration of the voltage supplied to the transducer, thus controlling Irms.

[0378] The specific design of the PMIC employs cutting-edge design techniques, including a complete set of feedback loops and monitoring paths used by the control unit, enabling ultra-precise control of the frequency range and step applied to the PZT.

[0379] In this case, the drive consists of a DC / DC step-up converter and a transformer to provide the necessary power to the PZT contact pads.

[0380] This arrangement consists of an AC driver that converts the voltage from the battery into an AC drive signal of a predetermined frequency to drive the ultrasonic transducer.

[0381] The driver device comprises an active power monitoring arrangement for monitoring the active power used by the ultrasonic transducer (described above) when the ultrasonic transducer is driven by the AC drive signal. The active power monitoring arrangement provides a monitoring signal indicative of the active power used by the ultrasonic transducer.

[0382] A processor 274 within the driver unit controls the AC driver and receives the monitoring signal drive from the active power monitoring arrangement.

[0383] The driver device memory 275 stores instructions that, when executed by the processor, cause the processor to: A. Control the AC driver to output an AC drive signal to the ultrasonic transducer at the sweep frequency. B. Calculate the active power being used by the ultrasonic transducer based on the monitoring signal C. Controlling the AC drive to modulate the AC drive signal to maximize the effective power used by the ultrasonic transducer D. Store in memory a record of the maximum available power used by the ultrasonic transducer and the sweep frequency of the AC drive signal. E. Repeat steps A through D a predetermined number of times, with the sweep frequency increasing or decreasing with each iteration, such that after a predetermined number of iterations, the sweep frequency increases or decreases from the sweep start frequency to the sweep end frequency. F. From the records stored in memory, identify the 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 drive to output an AC drive signal at an optimal frequency to the ultrasonic transducer, driving the ultrasonic transducer to atomize the liquid.

[0384] In some arrangements, 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, the active power monitoring arrangement providing a monitor signal indicative of the sensed drive current.

[0385] In some arrangements, 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.

[0386] In one arrangement, the start frequency is 2900 kHz and the end frequency is 3100 kHz. In another arrangement, the start frequency is 3100 kHz and the end frequency is 2900 kHz.

[0387] In some arrangements, the memory stores a method that, when executed by the processor, instructs the processor to repeat steps A-D described above, where the sweep frequency increases from a sweep start frequency of 2900 kHz to a sweep end frequency of 2960 kHz.

[0388] In some arrangements, the memory stores a method that, when executed by the processor, instructs the processor to repeat steps A-D described above, where the sweep frequency increases from a sweep start frequency of 2900 kHz to a sweep end frequency of 3100 kHz.

[0389] In some arrangements, the memory stores instructions that, when executed by the processor, cause the processor to: in step G, control the AC driver to output an AC drive signal to the ultrasonic transducer at a frequency shifted from the optimum frequency by a predetermined shift amount.

[0390] In some arrangements, the predetermined shift amount is between 1 and 10% of the optimum frequency.

[0391] The pressure sensor used in the device serves two purposes: first, to prevent unwanted and accidental activation of the sonic engine (driving the ultrasonic transducer). This function is implemented in the device's processing arrangement, which is optimized for low power consumption and constantly measures environmental parameters such as temperature and ambient pressure with internal compensation and reference settings to accurately detect and classify what is called a true inhalation.

[0392] The second purpose of the pressure sensor is to be able to accurately monitor the user's inhalation time for accurate inhalation volume measurement, as well as to be able to determine the strength of the user's inhalation. Overall, we can fully inhale the pressure profile of every inhalation and predict the end of inhalation for both operational understanding of aerosolization optimization.

[0393] In this example, the microcontroller 202 TM It is a low energy (BLE) microcontroller that simultaneously monitors multiple parameters to ensure extremely accurate inhalation time, optimized aerosolization, and a safe mist, preventing the use of non-genuine e-liquids and aerosol chambers, and protecting the device from overheating and the user from over-misting.

[0394] The use of a BLE microcontroller allows for over-the-air updates, providing users with continually improved software based on anonymized data collection and trained AI for PZT modeling. The BLE microcontroller also allows a remote computing device to communicate with the hookah device 202 so that the remote computing device can control the operation of the hookah device 202. In one embodiment, multiple hookah devices are controlled by one or more remote computing devices, for example, in a hookah or shisha bar, so that a bar manager can control the operation and / or monitor the status of each hookah device.

[0395] In one example, data indicating the status of each mist generator in each hookah device is transmitted by the hookah device to a remote computing device, allowing the remote computing device to monitor the status of each individual mist generator, allowing an administrator or user to track when each mist generator is low on liquid or not operating properly so that it can be replaced.

[0396] To be an accurate, reliable and safe aerosolization solution for everyday consumer use, the hookah device 202 must provide controlled and reliable aerosolization.

[0397] This is done by an internal method that can be divided into several sections:

[0398] Sonication To achieve optimal aerosolization, the ultrasonic transducer (PZT) needs to be vibrated in the most efficient way.

[0399] frequency The electromechanical properties of piezoelectric ceramics mean that the component is most efficient at its resonant frequency. However, if the PZT is allowed to resonate for an extended period of time, the component will inevitably break down, rendering the aerosol chamber unusable.

[0400] Furthermore, important points to consider when using piezoelectric materials are variations during manufacturing, and variations due to temperature and lifespan.

[0401] Resonating the PZT at 3 MHz to generate droplets smaller than 1 um requires an adaptive method to seek and target the specific PZT "sweet spot" within every aerosol chamber used in the device, every time you inhale.

[0402] sweep Due to the need to identify the "sweet spot" with each inhale, and due to overuse, the PZT temperature is varied using an in-house double sweep method.

[0403] The first sweep is used when the device has not been used for a specific aerosol chamber for a period of time deemed sufficient to allow all heat dissipation and for the PZT to cool to its "default temperature." This procedure is also known as a cold start. During this procedure, the PZT needs a boost to generate the required aerosol. This is achieved by passing only a small subset of frequencies between 2900 kHz and 2960 kHz, which takes into account extensive research and experimentation and covers the resonance point.

[0404] Each frequency within this range is converted into a current that the sonic engine activates and the current passing through the PZT is actively monitored and stored by the microcontroller via an analog-to-digital converter (ADC), allowing the power used by the PZT to be accurately deducted.

[0405] This gives a cold profile of the PZT with respect to frequency, and the frequency used during inhalation is the one that uses the most current, i.e. the frequency with the lowest impedance.

[0406] A second sweep is performed during the subsequent inhalation, covering the entire frequency range between 2900 kHz and 3100 kHz by modifying the PZT profile for temperature and deformation. This hot profile is used to determine the shift to apply.

[0407] shift Because aerosolization must be optimal, no shift is used during cryogenic inhalation, and the PZT will vibrate at its resonant frequency, which can only happen if repeated over a short period of time, otherwise the PZT will inevitably break down.

[0408] However, shifting is used during most inhalations as a way to target low impedance frequencies, resulting in suboptimal operation of the PZT while protecting it from breakdown.

[0409] Since hot and cold profiles are stored during inhalation, the microcontroller can select the appropriate shift frequency according to measurements of the current through the PZT during the sweep to ensure safe mechanical operation.

[0410] Piezoelectric components behave differently outside and inside the double resonance / anti-resonance frequency, so the choice of the direction of the shift is important. Since PZT is inductive, not capacitive, the shift you choose should always be within this range defined by the resonance and anti-resonance frequencies.

[0411] Finally, the percentage shift is kept below 10% to be close to the lowest impedance but far enough away from resonance.

[0412] adjustment Due to the inherent nature of PZT, every inhalation is different: In addition to the piezo element, numerous other parameters influence the outcome of the inhalation, including the amount of e-liquid remaining in the aerosol chamber, the wicking condition of the gauze, and the device's battery level.

[0413] To this end, the current used by the PZT in the aerosol chamber is constantly monitored, and the microcontroller constantly adjusts parameters such as frequency and duty cycle to provide the most stable power to the aerosol chamber within a predefined range, based on research and experimental results regarding optimal and safe aerosolization.

[0414] Battery Monitoring In some arrangements, the battery is integrated within the hookah device 202. In these arrangements, the hookah device 202 is powered by a DC Li-Po battery that provides the necessary voltage to the hookah device 202. Due to the requirement to have a high discharge rate, the Li-Po battery in some arrangements is specially designed for continuous current draw.

[0415] Because battery voltage drops and fluctuates significantly when the ultrasonic generator is activated, the microcontroller constantly monitors the power used by the PZT in the aerosol chamber to ensure proper and safe aerosol generation.

[0416] Additionally, because control is key to aerosolization, this device first ensures that the control and information portion of the device is always functioning and does not shut down to the detriment of the ultrasound processing portion.

[0417] For this reason, the adjustment method 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 if the battery level becomes low before the sonic engine starts, the control and information section will prevent starting.

[0418] Power Control As it is said that the key to aerosolization is control, the method used in this device is a real-time multidimensional function that constantly takes into account the PZT profile, the current flow inside the PZT, and the device's battery level.

[0419] All of this is only possible with the use of a microcontroller that can monitor and control every element of the device to ensure optimal inhalation.

[0420] Interval Relying on piezoelectric components, the ultrasound emitter is deactivated when inhalation stops. The safety delay between two inhalations is adapted depending on the duration of the previous inhalation, ensuring that the gauze is properly aspirated before the next activation.

[0421] This feature allows the device to operate safely and achieve more optimal aerosolization without damaging the PZT elements or exposing the user to toxic compounds.

[0422] Connectivity (BLE) The control and information section of the device consists of a wireless communication system with a Bluetooth Low Energy-enabled microcontroller that communicates with the device's processor and is configured to transmit and receive data between the driver device and a computing device such as a smartphone.

[0423] Bluetooth Low Energy connectivity to companion mobile applications requires less power for this communication, allowing devices to continue functioning for longer periods of time even when not in use, compared to traditional wireless connectivity solutions such as Wi-Fi, classic Bluetooth, GSM, and even LTE-M and NB-IOT.

[0424] Most importantly, this connectivity enables OTP functionality and full control and safety of the inhalation: everything from the resonant frequency of the inhalation to the amount and duration of negative pressure used or created by the user is stored and transmitted via BLE for further analysis and refinement of the embedded software.

[0425] Finally, this connectivity allows for embedded firmware updates both internally and over the air (OTA), ensuring the latest version is always deployed quickly, making the device scalable and ensuring it is maintained.

[0426] In one example, the mist inhaler 200 comprising a hookah device 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 driving the ultrasonic transducer 215. The active power monitor provides a monitoring signal indicative of the sensed drive current, as described above.

[0427] An additional feature of this example allows the mist inhaler 200 to monitor the operation of the ultrasonic transducer while it is activated. The mist inhaler 200 calculates an efficacy value or quality index that indicates how effectively the ultrasonic transducer is operating to atomize the liquid within the device. The device uses the efficacy value to calculate the actual amount of mist generated over the duration of ultrasonic transducer activation.

[0428] Once the actual amount of mist has been calculated, the device is configured to calculate the actual amount of drug that was present in the mist, and therefore the actual amount of drug inhaled by the user, based on the concentration of the drug in the liquid.

[0429] In practice, as noted above, there are a variety of factors that affect the operation of the ultrasonic transducer and therefore the amount of mist produced by the ultrasonic transducer and, therefore, the actual amount of medication delivered to the user.

[0430] Next, the configuration of some examples of mist inhalers and methods of generating mist using the mist inhalers will be described in detail below.

[0431] In this example, the mist inhaler incorporates the components of the mist inhaler 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 200 for a first predetermined period of time. As described above, the mist generator is activated by driving the ultrasonic transducer 215 within the mist generator 200 with an AC drive signal, causing the ultrasonic transducer 215 to atomize the liquid carried by the capillary element 222.

[0432] The executed instructions cause the processor to sense the current of the AC drive signal passing through the ultrasonic transducer 215 periodically for a first predetermined time period using the current sensor and store the periodically measured current value in memory.

[0433] The executed instructions cause the processor to calculate an effectiveness value using the current values ​​stored in the memory, the effectiveness value being indicative of the effectiveness of the operation of the ultrasonic transducer in atomizing the liquid.

[0434] In one example, the executed instructions cause the processor to calculate the validity value using this equation:

[0435]

number

[0436] In one example, the memory stores instructions that, when executed by the processor, cause the processor to periodically measure the duty cycle of an AC drive signal driving the ultrasonic transducer for a first predetermined time period and store the periodically measured duty cycle value in the memory. The mist inhaler then calculates an analog-to-digital converter side effect value Q based on the current value stored in the memory. A As a result, the mist inhaler of this example takes into account the variations in duty cycle that may occur throughout the activation of the ultrasonic transducer 215 when the device calculates the efficacy value. Thus, by taking into account the variations in duty cycle of the AC drive signal that may occur while the ultrasonic transducer is operating, the mist inhaler can accurately calculate the amount of mist actually produced.

[0437] The efficacy value is used as a weighting to calculate the actual amount of mist produced by the mist inhaler by proportionally reducing the value of the maximum amount of mist that would be produced by the mist inhaler if the device were operating optimally.

[0438] 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 time period and store the periodically measured frequency values ​​in the memory. The device then calculates the effect value using the frequency values ​​stored in the memory in addition to the current values, as described above.

[0439] In one example, the memory stores instructions that, when executed by the processor, cause the processor to calculate a value for a maximum amount of mist that would be generated if the ultrasonic transducer 215 were operating optimally for a first predetermined length of time duration. In one example, the value for the maximum amount of mist is calculated based on modeling that determines the maximum amount of mist that would be generated if the ultrasonic transducer were operating optimally.

[0440] Once the maximum mist volume value is calculated, the mist inhaler 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 a first predetermined length of time.

[0441] Once the actual mist volume is calculated, the mist inhaler can calculate a drug quantity value indicative of the amount of drug in the actual mist volume generated over the first predetermined duration, and the mist inhaler stores a record of the drug quantity value in memory.

[0442] 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 efficacy 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 is proportionally reduced or increased according to the efficacy value. For example, if the efficacy value indicates that the ultrasonic transducer 215 is not operating effectively, the second predetermined length of time is increased according to the efficacy value so that a desired amount of mist is generated during the second predetermined length of time.

[0443] Upon the next inhalation, the mist inhaler activates the mist generator for a second predetermined time period so that the mist generator generates a predetermined amount of mist for the second predetermined time period. In this manner, the mist inhaler precisely controls the amount of mist generated during the second predetermined time period, taking into account various parameters reflected by the efficacy value that affect the operation of the mist inhaler.

[0444] In one example, the memory stores instructions that, when executed by the processor, cause the processor to activate the mist generator for multiple predetermined lengths of time, for example, the mist generator is activated during multiple successive inhalations or puffs by the user.

[0445] The mist inhaler stores a plurality of dosage values ​​in memory, each dosage value being indicative of the amount of drug in the mist produced over the duration of a respective one of the predetermined lengths of time.

[0446] The mist inhaler of some examples of the present disclosure may transmit data indicative of a drug dosage value from a mist generating device to a computing device (e.g., via Bluetooth). TMThe application may be configured to transmit the information to a computing device (e.g., a smartphone) via a wireless low energy (WHE) communication and store it in a memory of the computing device (e.g., a smartphone). An executable application running on the computing device may record the amount of medication provided to the user. The executable application may also control the operation of the mist inhalation devices within the hookah device such that the operation of each mist inhalation device within the hookah device may be modified to address a mist inhalation device that is not performing optimally.

[0447] Because e-cigarette aerosolization is achieved by the mechanical action of a piezoelectric disc rather than by directly heating the liquid, the individual components of e-cigarettes (e.g., propylene glycol, vegetable glycerin, flavoring ingredients) remain largely intact and do not break down into smaller harmful components such as acrolein, acetaldehyde, and formaldehyde at high rates seen in traditional e-cigarettes.

[0448] 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.

[0449] It will be understood that the disclosure herein is not limited to use for nicotine delivery. The devices disclosed herein are for use with any drug or other compound (e.g., CBD) provided in liquid form within a liquid chamber of the device for aerosolization by the device.

[0450] Some configurations of the hookah device 202 are a healthier alternative to traditional hookah heads that use heat from charcoal or an electric element to burn tobacco. Nevertheless, some configurations of the hookah device 202 still provide the same user experience as traditional hookahs due to the mist bubbles in the hookah water. Therefore, users are likely to want to use some configurations of the ultrasonic hookah device 202 instead of traditional tobacco-burning hookahs, thereby avoiding the dangers of smoking tobacco with a hookah.

[0451] The foregoing has outlined 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 should appreciate that they may readily use this disclosure as a basis for designing or modifying other processes and structures which carry out the same purposes and / or achieve the same advantages of the various examples or embodiments introduced herein. Those skilled in the art should also recognize that such equivalent structures do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present disclosure.

[0452] Although the subject matter has been described in language specific to structural features or methodological acts, it is understood that the subject matter of the appended claims 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 a portion of the claims.

[0453] Various operations of examples or embodiments are provided herein. The order in which some or all of the operations are described should not be construed to imply that these operations are necessarily order dependent. It will be understood that alternative orders may have the benefit of this document. 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 examples or embodiments.

[0454] Furthermore, "exemplary" as used herein means serving as an example, instance, illustration, etc., and is not necessarily advantageous. "Or," as used herein, is intended to mean an inclusive "or," not 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 the context clearly directs to the singular form. Furthermore, to the extent that "comprises," "has," "having," "with," or variations thereof are used, such terms are intended to be inclusive in the same manner as the term "comprises." Furthermore, unless otherwise specified, terms such as "first," "second," etc. are not intended to imply temporal aspects, spatial aspects, order, etc. Rather, such terms are used merely as identifiers, names, etc. of features, elements, items, etc. For example, a first element and a second element generally correspond to element A and element B, or two different elements or two identical elements or identical elements.

[0455] Moreover, while the present disclosure has been shown and described with respect to one or more embodiments, equivalent alterations and modifications will occur to others skilled in the art upon reading and understanding this specification and the accompanying drawings. The present disclosure includes all such alterations and modifications, 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 indicated, to correspond to any feature that performs the specified function of the described feature (e.g., functionally equivalent), even if it is not structurally equivalent to the disclosed structure. In addition, while a particular feature of the present disclosure may be disclosed with respect to only one of several embodiments, such feature may be combined with one or more other features of other embodiments as desired and advantageous for any given or particular application.

[0456] Examples or embodiments of the subject matter and functional operations described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed herein and their structural equivalents, or in combinations of one or more of them.

[0457] 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 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 storage device, or a combination of one or more thereof.

[0458] The terms "computing device" and "data processing device" encompass all devices, apparatus, and machines for processing data, including, by way of example, a programmable processor, computer, or multiple processors or computers. In addition to hardware, a device may include code that establishes an execution environment for the computer program, such as code comprising processor firmware, a protocol stack, a database management system, an operating system, a runtime environment, or one or more combinations thereof. Furthermore, the device may employ a variety of different computing model infrastructures, such as web services, distributed computing, and grid computing infrastructures.

[0459] 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.

[0460] Processors suitable for executing a computer program include, by way of example, general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer. Typically, a processor will receive instructions and data from a read-only memory, 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 will include one or more mass storage devices for storing data, e.g., magnetic, magneto-optical, or optical disks, operatively coupled to receive data from, or transfer data to, either one 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.

[0461] In this document, "comprises" means "includes, comprises," and "comprises" means "includes, comprises."

[0462] The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, may be expressed in their specific form, or in terms of means for performing a disclosed function, or methods or processes for achieving a disclosed result, as appropriate, and may be utilized separately or in any combination of those features to realize the invention in various of its forms.

[0463] Typical features Representative features are described in the following paragraphs, which may be used alone or in any combination with one or more features disclosed in the text and / or drawings herein.

[0464] 1. The hookah device includes: a plurality of ultrasonic mist generators, each mist generator incorporating: An elongated mist generating housing having an air inlet port and a mist outlet port a liquid chamber provided within the mist generating housing for containing the liquid to be atomized; Ultrasonic treatment chamber installed within the mist generating housing a capillary element extending between the liquid chamber and the ultrasonic chamber, such that a first portion of the capillary element is in the liquid chamber and a second portion of the capillary element is in the ultrasonic chamber; an ultrasonic transducer having an atomizing surface, wherein a portion of the second portion of the capillary element overlaps a portion of the atomizing surface, and when the ultrasonic transducer is driven by an 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 ultrasonic irradiation chamber; The hookah device further comprises an air flow arrangement that provides an air flow path between the air inlet port, the sonication chamber, and the air outlet port.

[0465] a plurality of H-bridge circuits, each H-bridge circuit of the plurality of H-bridge circuits connected to a respective one of the ultrasonic transducers and configured to generate an AC drive signal to drive the ultrasonic transducer;

[0466] Microcontroller.

[0467] A data bus that is electrically connected to a microcontroller and communicates data with the microcontroller.

[0468] a plurality of microchips electrically connected to a data bus for receiving data from and transmitting data to a microcontroller, each microchip of the plurality of microchips connected to a respective one of the H-bridge circuits for controlling the H-bridge circuits to generate an AC drive signal, each microchip being a single unit comprised of a plurality of interconnected embedded components and subsystems, including:

[0469] an oscillator configured to generate: Main Clock Signal A first phase clock signal that goes high a first time during the positive half-cycle of the main clock signal and goes low during the negative half-cycle a second phase clock signal that goes high for a second time during the negative half-period of the master clock signal and goes low during the positive half-period of the master clock signal, the phases of the first phase clock signal and the second phase clock signal being center-aligned;

[0470] A pulse width modulation (PWM) signal generator subsystem, including: 10. The ultrasonic transducer system of claim 1, further comprising: a delay locked loop configured to generate a double frequency clock signal using a first phase clock signal and a second phase clock signal, the double frequency clock signal having twice the frequency of the main clock signal, and the delay locked loop configured to control 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 configured to adjust the frequency and duty cycle of the first phase clock signal and the second phase clock signal in response to a driver control signal to generate the first phase output signal and the second phase output signal, the first phase output signal and the second phase output signal configured to drive an H-bridge circuit connected to the microchip to generate an AC drive signal that drives the ultrasonic transducer. a first-phase output signal terminal configured to output a first-phase output signal to an H-bridge circuit connected to the microchip; a second-phase output signal terminal configured to output a second-phase output signal to an H-bridge circuit connected to the microchip; a feedback input terminal configured to receive a feedback signal from the H-bridge circuit, the feedback signal indicative of a parameter of operation of the H-bridge circuit or the AC drive signal connected to the microchip when the H-bridge circuit is driving the ultrasonic transducer with the AC drive signal to atomize the liquid;

[0471] An analog-to-digital converter (ADC) subsystem, including: an apparatus for converting a plurality of analog signals into analog signals, comprising: a plurality of ADC input terminals configured to receive a plurality of respective analog signals, one ADC input terminal of the plurality of ADC input terminals connected to a feedback input terminal such that the ADC subsystem receives a feedback signal from an H-bridge circuit connected to the microchip; the ADC subsystem configured to sample the analog signals received at the plurality of ADC input terminals at a sampling frequency proportional to the frequency of a main clock signal; and the ADC subsystem configured to generate an ADC digital signal using the sampled analog signals. a digital processing device configured to receive an ADC digital signal from the ADC subsystem and process the ADC digital signal to generate a driver control signal, the digital processor subsystem configured to communicate the driver control signal to the PWM signal generation subsystem to control the PWM signal generation subsystem;

[0472] A digital-to-analog converter (DAC) subsystem, including: A digital-to-analog converter (DAC) configured to convert 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 an H-bridge circuit connected to the microchip. and a DAC output terminal configured to output, in response to a feedback signal indicative of operation of the ultrasonic transducer, an analog voltage control signal for controlling a voltage regulation circuit to generate a predetermined voltage for modulation by an H-bridge circuit connected to the microchip for driving the ultrasonic transducer.

[0473] A hookah mounting arrangement configured to mount a hookah device to a hookah, the hookah mounting arrangement having a hookah outlet port that provides a fluid flow path from the mist outlet port of the mist generating device to exit the hookah device so that when at least one of the mist generating devices is activated by a driver device, mist generated by each activated mist generating device flows along the fluid flow path and exits the hookah device into the hookah.

[0474] 2. A hookah device according to paragraph 1, wherein the microcontroller is configured to identify and control each mist generating device using the unique identifier of each mist generating device.

[0475] 3. The device of paragraph 1 or 2, further comprising: An identification arrangement comprising: an integrated circuit having a memory that stores a unique identifier for the mist generating device; and An electrical connection that provides an electronic interface for communicating with an integrated circuit.

[0476] 4. In any of the hookah devices referred to in the preceding paragraphs, the microcontroller is configured to control each microchip and each respective mist generating device and to operate independently of the other mist generating devices.

[0477] 5. The hookah device described in paragraph 4, wherein the microcontroller is configured to control the mist generating device to operate in a predetermined sequence.

[0478] 6. A device according to any one of the preceding paragraphs, wherein the hookah device comprises: A manifold having a manifold pipe in fluid communication with a mist outlet port of a mist generating device, wherein the mist output from the mist outlet port combines within the manifold pipe and flows through the manifold pipe out of the hookah device.

[0479] 7. A hookah device as described in paragraph 6, wherein the hookah device comprises four mist generating devices releasably coupled to the manifold at 90° angles to each other.

[0480] 8. The apparatus of any one of the preceding clauses, wherein the feedback input terminal is configured to receive a feedback signal from the H-bridge circuit in the form of a voltage indicative of the effective current of the AC drive signal driving the resonant circuit.

[0481] 9. The device of any one of the preceding paragraphs, wherein each microchip further comprises: A temperature sensor embedded within the microchip, the temperature sensor configured to generate a temperature signal indicative of a 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.

[0482] 10. The hookah device of any one of the preceding paragraphs, wherein the ADC subsystem is configured to sample signals received at the plurality of ADC input terminals a predetermined number of times, with each signal sampled by the ADC subsystem.

[0483] 11. The device of any one of the preceding paragraphs, wherein the hookah device further comprises: a plurality of further microchips, each of the plurality of further microchips connected to a respective microchip of the plurality of microchips to form an H-bridge circuit of the plurality of H-bridge circuits, each further microchip being a single unit comprised of a plurality of interconnected embedded components and subsystems; a first power supply terminal; and The second power terminal, where: 1. An H-bridge circuit on a microchip incorporating a first switch, a second switch, a third switch, and a fourth switch, wherein: A first switch and a third switch are connected in series between the first power supply terminal and the second power supply terminal. 10. The method of claim 1, wherein the first output terminal is electrically connected between the first switch and the third switch, and the first output terminal is connected to the first terminal of the ultrasonic transducer. A second switch and a fourth switch are connected in series between the first power supply terminal and the second power supply terminal. 2. The ultrasonic transducer of claim 1, wherein a second output terminal is electrically connected between the second switch and the fourth switch, and the second output terminal is connected to a second terminal of the ultrasonic transducer. a first phase terminal configured to receive a first phase output signal from the 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 the H-bridge circuit to control the switches on and off in a sequence such that the H-bridge circuit outputs an AC drive signal for driving an ultrasonic transducer, the sequence comprising a free-float period during which the first switch and the second switch are turned off and the third switch and the fourth switch are turned on, and turning the switches to dissipate energy stored by the ultrasonic transducer. Current sensor with integrated: a first current sensing resistor connected in series between the first switch and the first power supply terminal; a first voltage sensor configured to measure a voltage drop across the first current sense resistor and provide a first voltage output indicative of a 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 configured to measure a voltage drop across a second current sensor resistor and provide a second voltage output indicative of a current flowing through the second current sensor resistor; a current sensor output terminal configured to output an effective voltage to ground equal to the first voltage output and the second voltage output; 2. The ultrasonic transducer of claim 1, wherein the effective output voltage represents an effective current through the first switch or the second switch and a current through the ultrasonic transducer connected between the first output terminal and the second output terminal.

[0484] 12. A hookah device as described in paragraph 11, wherein the H-bridge circuit is configured to output 22W to 50W of power to the ultrasonic transducer connected between the first output terminal and the second output terminal.

[0485] 13. A hookah device according to paragraph 11 or 12, further comprising: a temperature sensor embedded within the further microchip, the temperature sensor configured to measure a temperature of the further microchip and to disable at least a portion of the further microchip if the temperature sensor senses that the further microchip is at a temperature above a predetermined threshold;

[0486] 14. A hookah device according to any one of paragraphs 11 to 13, wherein the device further comprises: a boost converter circuit configured to raise the power supply voltage to a boost voltage in response to an analog voltage output signal from the DAC output terminal, the boost converter circuit configured to provide the boost voltage at the first power supply terminal such that the boost voltage is modulated by switching of switches in an H-bridge circuit.

[0487] 15. The hookah device of any of paragraphs 11 to 14, wherein the current sensor is configured to sense the current flowing through the resonant circuit during the free-float period, and the digital state machine is configured to adapt a timing signal to switch on either the first switch or the second switch when the current sensor senses that the current flowing through the resonant circuit is zero during the free-float period.

[0488] 16. A hookah device of any of paragraphs 11 to 15, wherein during the setup phase of operation of the device, a further microchip is configured as follows: measuring the length of time it takes for current through the resonant circuit to become zero when the first switch and the second switch are turned off and the third switch and the fourth switch are turned on; The length of time for the free float period is set equal to the measured length of time.

[0489] 17. A device according to any one of the preceding paragraphs, wherein the hookah device further comprises: Memory that stores instructions that, when executed by the microcontroller, cause the microchip to: A. Control the H-bridge circuit to output an AC drive signal at a sweep frequency to the ultrasonic transducer. B. Calculate the active power being used by the ultrasonic transducer based on the feedback signal C. Controlling the H-bridge circuit to modulate the AC drive signal to maximize the effective power being used by the ultrasonic transducer D. Store in memory a record of the maximum available power used by the ultrasonic transducer and the sweep frequency of the AC drive signal. E. Repeat steps A-D a predetermined number of times, with the sweep frequency increasing or decreasing with each iteration, such that after a predetermined number of iterations, the sweep frequency increases or decreases from the sweep start frequency to the sweep end frequency. F. From the records stored in memory, identify the 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 H-bridge circuit is controlled to output an AC driving signal at an optimal frequency to the ultrasonic transducer, which drives the ultrasonic transducer to atomize the liquid.

[0490] 18. A hookah device as set forth in paragraph 17, wherein the start sweep frequency is 2900 kHz and the end sweep frequency is 3100 kHz.

[0491] 19. Hookah includes: Water Chamber an elongated stem having a first end attached to the water chamber, the stem having a mist flow passage extending from a second end of the stem, through the stem, to the first end; and Hookah Device The hookah device arrangement of any one of the preceding paragraphs is attached to the hookah stem at the second end of the stem.

Claims

1. 1. A hookah device for use with a hookah, the hookah device having an elongated stem and a water chamber attached to a first end of the stem, the device comprising: A manifold having a manifold pipe and a plurality of openings, each opening of the plurality of openings being in fluid communication with the manifold pipe and receiving a mist outlet port of each ultrasonic mist generator, each opening of the plurality of openings being formed in each side wall of the manifold, and the manifold pipe being provided on an end wall perpendicular to each side wall of the manifold; a driver device electrically connected to each of the mist generating devices and configured to operate the mist generating devices; a hookah attachment device configured to attach the hookah device to the second end of the stem of the hookah, the hookah attachment device having a hookah outlet port in fluid communication with the manifold pipe and providing a fluid flow path from the hookah device, wherein when at least one of the mist generating devices is activated by the driver device, mist generated by each activated mist generating device meets at the manifold, flows through the manifold pipe and the hookah outlet port, and exits the hookah device to the hookah; A hookah device comprising:

2. 2. A hookah device according to claim 1, wherein the manifold receives four mist generating devices spaced 90 degrees apart from one another and releasably coupled to the manifold.

3. 3. A hookah device as claimed in claim 1 or claim 2, further comprising a plurality of mist generators, said plurality of mist generators being releasably coupled to said manifold.

4. 4. A hookah device as claimed in claim 3, wherein each mist generating device comprises: an elongated mist generating housing having an air inlet port and the mist outlet port; a liquid chamber disposed within the mist generating housing for containing a liquid to be atomized; an ultrasonic chamber provided within the mist generating housing; a capillary element extending between the liquid chamber and the ultrasonic chamber, such that a first portion of the capillary element is within the liquid chamber and a second portion of the capillary element is within the ultrasonic chamber; an ultrasonic transducer having a generally planar atomizing surface disposed within the ultrasonic chamber, the ultrasonic transducer being mounted within the mist-generating housing such that the plane of the atomizing surface is substantially parallel to the longitudinal length of the mist-generating housing, a portion of the second portion of the capillary element overlapping a portion of the atomizing surface, the ultrasonic transducer being configured to vibrate the atomizing surface to atomize liquid carried by the second portion of the capillary element and generate a mist comprised of atomized liquid and air within the ultrasonic chamber; A hookah device, wherein the air inlet port, the ultrasonic chamber, and the mist outlet port form an air flow path through which air can flow.

5. 5. A hookah device as claimed in claim 4, wherein each mist generating device comprises: a transducer holder held within the mist generating housing, the transducer holder holding the ultrasonic transducer and the second portion of the capillary element overlapping a portion of the atomizing surface; a partition portion providing a barrier between the liquid chamber and the ultrasonic chamber, the partition portion including a capillary opening through which a portion of the first portion of the capillary element extends; The hookah device further comprises:

6. 6. A hookah device according to claim 4 or claim 5, wherein the capillary element is made of 100% bamboo fibre.

7. 7. A hookah device as claimed in any one of claims 4 to 6, further configured to redirect the air flow along the air flow path as the air flow passes through the ultrasonic chamber so that the air flow is substantially perpendicular to the atomization surface of the ultrasonic transducer.

8. A hookah device as claimed in any one of claims 4 to 7, characterized in that the liquid chamber 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.

9. 9. A hookah device as claimed in any one of claims 4 to 8, wherein the liquid chamber contains a liquid comprised of levulinic acid and nicotine in a molar ratio of approximately 2:

1.

10. 10. A hookah device as claimed in any one of claims 1 to 9, wherein the driver device comprises: an AC driver configured to generate an AC drive signal at a predetermined frequency for driving each ultrasonic transducer of each mist generator; an active power monitor configured to monitor active power used by the ultrasonic transducer when the ultrasonic transducer is driven by the AC drive signal, the active power monitor configured to provide a monitor signal indicative of the active power used by the ultrasonic transducer; a processor configured to control the AC driver and to receive the monitoring signal from the active power monitor; a memory storing instructions that, when executed by the processor, cause the processor to: A. Controlling the AC driver to output an AC drive signal at a predetermined sweep frequency to the ultrasonic transducer; 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 available power used by the ultrasonic transducer; D. storing in said memory a record of the maximum available power used by said ultrasonic transducer and said sweep frequency of said AC drive signal; E. repeating steps A through D for a predetermined number of iterations, incrementing the sweep frequency with each iteration, such that after the predetermined number of iterations, the sweep frequency increments from a sweep start frequency to a sweep end frequency; F. Identifying from the record stored in the memory an optimal frequency of the AC drive signal, the sweep frequency of the AC drive signal at which the greatest effective power is used by the ultrasonic transducer; G. Controlling the AC driver to output an AC drive signal to the ultrasonic transducer at the optimum frequency, thereby driving the ultrasonic transducer to atomize the liquid. A hookah device comprising:

11. 11. The hookah device of claim 10, wherein the active power monitor comprises: A hookah device comprising a current sensor configured to sense a drive current of the AC drive signal that drives the ultrasonic transducer, and wherein the active power monitor is configured to provide a monitoring signal indicative of the sensed drive current.

12. 12. A hookah device as claimed in claim 10 or claim 11, which when executed by the processor causes the processor to: The memory stores instructions for repeating steps A through D while incrementing the sweep frequency from a sweep start frequency of 2900 kHz to a sweep end frequency of 2960 kHz.

13. 12. A hookah device as claimed in claim 10 or claim 11, which when executed by the processor causes the processor to: The memory stores instructions for repeating steps A through D while incrementing the sweep frequency from a sweep start frequency of 2900 kHz to a sweep end frequency of 3100 kHz.

14. 14. A hookah device as claimed in any one of claims 10 to 13, wherein the AC driver modulates the AC drive signal by pulse width modulation to maximise the available power used by the ultrasonic transducer.

15. It is a hookah a water chamber; an elongated stem having a first end attached to the water chamber, the stem having a mist flow path extending from a second end thereof through the stem to the first end; 15. A hookah device according to any one of claims 1 to 14, characterized in that the hookah attachment device of the hookah device is attached to the stem of the hookah at the second end of the stem. A hookah equipped with a hookah.

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