WO2023084195A1

WO2023084195A1 - Aerosol provision system with variable aerosol stream concentration

Info

Publication number: WO2023084195A1
Application number: PCT/GB2022/052804
Authority: WO
Inventors: Jeremy Campbell; Will ENGLAND
Original assignee: Nicoventures Trading Limited
Priority date: 2021-11-10
Filing date: 2022-11-07
Publication date: 2023-05-19

Abstract

An aerosol provision system (1) including at least an aerosol generator (48) for generating an aerosol from an aerosol-generating material (44) in an aerosol-generating region (45); a first air pathway (52) passing through the aerosol generation region (45); a second air pathway (53) not passing through the aerosol generation region (45); and an adjustment mechanism (170) configured to vary the ratio of the resistance-to-draw of the first air pathway (52) to the resistance-to-draw of the second air pathway (53) based upon a draw strength of a user inhalation.

Description

AEROSOL PROVISION SYSTEM WITH VARIABLE AEROSOL STREAM CONCENTRATION

TECHNICAL FIELD

The present invention relates to an aerosol provision system, an aerosol provision system comprising an article, a method of controlling an aerosol provision system.

BACKGROUND

Electronic aerosol provision systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol-generating material, such as a reservoir of a source liquid containing a formulation, typically including nicotine, or a solid material such as a tobaccobased product, from which an aerosol is generated for inhalation by a user, for example through heat vaporisation. Thus, an aerosol provision system will typically comprise an aerosol generator, e.g. a heating element, arranged to aerosolise a portion of aerosol-generating material to generate an aerosol in an aerosol generation region of an air channel through the aerosol provision system. As a user inhales on the system and electrical power is supplied to the aerosol generator, air is drawn into the system through one or more inlet holes and along the air channel to the aerosol generation region, where the air mixes with the vaporised aerosol generator and forms a condensation aerosol. The air drawn through the aerosol generation region continues along the air channel to a mouthpiece, carrying some of the aerosol with it, and out through the mouthpiece for inhalation by the user.

Additionally, in some aerosol provision systems, air containing the aerosol collected from the aerosol generation region can be mixed with air which has not passed through the aerosol generation region prior to being inhaled via the mouthpiece of the system. For example, as a user inhales on the system, air is drawn into the device through one or more other inlet holes and along an air channel that does not include the aerosol generation region. The force required to draw air through each channel of an aerosol provision system depends on the characteristics of the respective air channel of the system. For example, the cross- sectional shape of the air channels may determine their resistance-to-draw or pressure drop (i.e. the force required to draw air along a respective channel). The characteristics of the air inhaled by the user can depend at least in part on the ratio of air which has passed through the aerosol generation region and air which has not passed through the aerosol generation region, which in turn depends on the resistance to draw of the air channel(s) which pass through the aerosol generation region, and the resistance to draw of the air channel(s) which do not pass through the aerosol generation region.

The characteristics of the air inhaled by a user is dependent on construction of the aerosol provision system and its components. The characteristics of the air may not reflect or otherwise equate to what a user of a standard ignitable cigarette might expect thereby leading to a user having a poor quality experience. While some aerosol provision systems allow a user to vary the airflow through one or more channels of the system, this approach requires trial and error experimentation by a user to select the correct ratio for the particular user, and does not easily facilitate changes in the user’s behaviour (for example a user’s puffing switching from shallow breaths to deep breaths).

Various approaches are described herein which seek to help address or mitigate some of the issues discussed above.

SUMMARY

The disclosure is defined in the appended claims.

According to a first aspect of the present disclosure, there is provided an aerosol provision system comprising: an aerosol generator for generating an aerosol from an aerosolgenerating material in an aerosol-generating region; a first air pathway passing through the aerosol generation region; a second air pathway not passing through the aerosol generation region; and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

According to a second aspect of the present disclosure, there is provided a controller for controlling an aerosol provision system comprising an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region, a first air pathway passing through the aerosol generation region, a second air pathway not passing through the aerosol generation region; and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation, a controller configured to control the adjustment mechanism to vary the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway, a sensor configured to estimate the draw strength of the user inhalation, the controller configured to: receive an estimate of the draw strength of the user inhalation; and control the adjustment mechanism based on the estimated draw strength.

According to a third aspect of the present disclosure, there is provided a method of controlling an aerosol provision system comprising an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region, and a first air pathway passing through the aerosol generation region, a second air pathway not passing through the aerosol generation region, the method comprising: providing an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation; and adjusting the adjustment mechanism to vary the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway.

According to a fourth aspect of the present disclosure, there is provided a computer readable storage medium comprising instructions which, when executed by a processor, performs a method of the third aspect.

According to a fifth aspect of the present disclosure, there is provided an aerosol provision means comprising: aerosol generator means for generating an aerosol from an aerosol-generating material in an aerosol-generating region; a first air pathway passing through the aerosol generation region; a second air pathway not passing through the aerosol generation region; and adjustment means configured to vary the ratio of the resistance-to- draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

According to a sixth aspect of the present disclosure, there is provided an aerosol provision device for use with an aerosol generating article comprising aerosol generating material, which together form an aerosol provision system, wherein the aerosol provision system comprises an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region, a first air pathway passing through the aerosol generation region, a second air pathway not passing through the aerosol generation region, and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation, wherein the aerosol provision device comprises: circuitry configured to control the adjustment mechanism to cause the adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

These aspects and other aspects will be apparent from the following detailed description. In this regard, particular sections of the description are not to be read in isolation from other sections.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which:

Figure 1 is a schematic diagram of an example aerosol provision system;

Figure 2 is a schematic diagram of a further example aerosol provision system;

Figure 3 is a schematic diagram of a further examples aerosol provision system;

Figure 4 is a schematic diagram of certain electrical (including electronic) components of a control unit for use in an aerosol provision system.

Figure 5 is a flow chart of a method of controlling an aerosol provision system. Figure 6 is a flow chart of a further method of controlling an aerosol provision system.

DETAILED DESCRIPTION

Aspects and features of certain examples and embodiments are discussed/described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not discussed/described in detail in the interests of brevity. It will thus be appreciated that aspects and features of articles and systems discussed herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.

As will be explained below, the present disclosure relates to an aerosol provision device comprising: an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region; a first air pathway passing through the aerosol generation region; a second air pathway not passing through the aerosol generation region; and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway based upon a draw strength of a user inhalation. By providing an adjustment mechanism which is able vary the resistance to draw of the first pathway to the resistance to draw of the second pathway based upon a draw strength of a user inhalation, it is possible to tune the ratio of side-stream air vs main-stream air inhaled by the user. By main-stream air it is meant air travelling along the first pathway via the aerosol generation region for inhalation. By side-stream air it is meant air travelling along the second pathway for inhalation. Tuning the ratio of side-stream air vs main-stream air allows the device to provide different user experience (a sensorial) dependent for different strength user inhalations. This may be analogous to a user using a conventional cigarette in which different draw characteristics lead to different user experiences. As a result, the user can effectively use the device in multiple ways to have the experience they want. For example, a user can take shallow, slow, breaths and inhale air which is diluted more strongly by sidestream air. The user may consider this to be a smoother experience. Alternatively, a user can take deep, fast, breaths and inhale air which is less strongly diluted, or not diluted by sidestream air. The user may consider this to be a less smooth, more impactful experience. As such, a user puffing on an aerosol provision device in accordance with the present disclosure may feel that they are able to use the device intuitively to achieve the experience they want, without having to actively select different control settings for the device.

The present disclosure relates to non-combustible aerosol provision systems, which may also be referred to as aerosol provision systems. According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user. In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement. Throughout the following description the term “e-cigarette” or “electronic cigarette” may sometimes be used, but it will be appreciated this term may be used Interchangeably with aerosol provision system and electronic aerosol provision system.

In some embodiments, the non-combustible aerosol provision system is an aerosolgenerating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system.

In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosol-generating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product.

Typically, the non-combustible aerosol provision system may comprise a non- combustible aerosol provision device and a consumable for use with the non-combustible aerosol provision device.

In some embodiments, the disclosure relates to consumables comprising aerosolgenerating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.

In some embodiments, the non-combustible aerosol provision system, such as a non- combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source.

In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and/or an aerosol-modifying agent.

A consumable is an article comprising or consisting of aerosol-generating material, part or all of which is intended to be consumed during use by a user. A consumable may comprise one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generation area, a housing, a wrapper, a mouthpiece, a filter and/or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, that emits heat to cause the aerosol-generating material to generate aerosol in use. The heater may, for example, comprise combustible material, a material heatable by electrical conduction, or a susceptor.

An aerosol generator is an apparatus configured to cause aerosol to be generated from the aerosol-generating material. In some embodiments, the aerosol generator is a heater configured to subject the aerosol-generating material to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol. In some embodiments, the aerosol generator is configured to cause an aerosol to be generated from the aerosolgenerating material without heating. For example, the aerosol generator may be configured to subject the aerosol-generating material to one or more of vibration, increased pressure, or electrostatic energy.

Aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or gel which may comprise one or more active substances and/or flavours, one or more aerosol-former materials, and optionally one or more other functional materials.

In some embodiments, the aerosol-generating material may comprise an “amorphous solid”, which may alternatively be referred to as a “monolithic solid” (i.e. non-fibrous). In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the aerosol-generating material may for example comprise from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 1wt% of amorphous solid.

The active substance as used herein may be a legally permissible physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.

As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof, flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes , and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gas.

In some embodiments, the flavour comprises menthol, spearmint and/or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and/or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour comprises flavour components extracted from cannabis.

In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucolyptol, WS-3.

The aerosol-former material may comprise one or more constituents capable of forming an aerosol. In some embodiments, the aerosol-former material may comprise one or more of glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1 ,3-butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

The one or more other functional materials may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants.

The aerosol-former material may be present on or in a support, to form a substrate. The support may, for example, be or comprise paper, card, paperboard, cardboard, reconstituted material, a plastics material, a ceramic material, a composite material, glass, a metal, or a metal alloy. In some embodiments, the support comprises a susceptor. In some embodiments, the susceptor is embedded within the material. In some alternative embodiments, the susceptor is on one or either side of the material.

A susceptor is a material that is heatable by penetration with a varying magnetic field, such as an alternating magnetic field. The susceptor may be an electrically-conductive material, so that penetration thereof with a varying magnetic field causes induction heating of the heating material. The heating material may be magnetic material, so that penetration thereof with a varying magnetic field causes magnetic hysteresis heating of the heating material. The susceptor may be both electrically-conductive and magnetic, so that the susceptor is heatable by both heating mechanisms. The device that is configured to generate the varying magnetic field is referred to as a magnetic field generator, herein.

An aerosol-modifying agent is a substance, typically located downstream of the aerosol generation area, that is configured to modify the aerosol generated, for example by changing the taste, flavour, acidity or another characteristic of the aerosol. The aerosolmodifying agent may be provided in an aerosol-modifying agent release component that is operable to selectively release the aerosol-modifying agent

The aerosol-modifying agent may, for example, be an additive or a sorbent. The aerosol-modifying agent may, for example, comprise one or more of a flavourant, a colourant, water, and a carbon adsorbent. The aerosol-modifying agent may, for example, be a solid, a liquid, or a gel. The aerosol-modifying agent may be in powder, thread or granule form. The aerosol-modifying agent may be free from filtration material.

Figure 1 is a cross-sectional view through an example aerosol delivery system 1 in accordance with certain embodiments of the disclosure. The aerosol delivery system 1 comprises two main components, namely a reusable part 2 (e.g. a control part or device part) and a replaceable I disposable cartridge part 4 (which may more generally be referred to as a consumable or aerosol-generating article). In normal use the reusable part 2 and the cartridge part 4 are releasably coupled together at an interface 6. When the cartridge part is exhausted or the user simply wishes to switch to a different cartridge part, the cartridge part may be removed from the reusable part and a replacement cartridge part attached to the reusable part in its place. The interface 6 provides a structural, electrical and airflow path connection between the two parts and may be established in accordance with conventional techniques, for example based around a screw thread, magnetic or bayonet fixing with appropriately arranged electrical contacts and openings for establishing the electrical connection and airflow path between the two parts as appropriate. The specific manner by which the cartridge part 4 mechanically mounts to the reusable part 2 is not significant to the principles described herein, but for the sake of a concrete example is assumed here to comprise a magnetic coupling (not represented in Figure 1). It will also be appreciated the interface 6 in some implementations may not support an electrical and I or airflow path connection between the respective parts. For example, in some implementations an aerosol generator may be provided in the reusable part 2 rather than in the cartridge part 4, or the transfer of electrical power from the reusable part 2 to the cartridge part 4 may be wireless (e.g. based on electromagnetic induction), so that an electrical connection between the reusable part and the cartridge part is not needed. Furthermore, in some implementations the airflow through the electronic cigarette might not go through the reusable part so that an airflow path connection between the reusable part and the cartridge part is not needed. In some instances, a portion of the airflow path may be defined at the interface between portions of reusable part 2 and cartridge part 4 when these are coupled together for use.

In Figure 1 , the cartridge part 4 comprises a cartridge housing 42 formed of a plastics material. The cartridge housing 42 supports other components of the cartridge part and provides the mechanical interface 6 with the reusable part 2. The cartridge housing is generally circularly symmetric about a longitudinal axis along which the cartridge part couples to the reusable part 2. In this example the cartridge part has a length of around 4 cm and a diameter of around 1.5 cm. However, it will be appreciated the specific geometry, and more generally the overall shapes and materials used, may be different in different implementations.

Within the cartridge housing 42 is a reservoir 44 that contains aerosol generating material. Aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. In the example shown schematically in Figure 1 , a reservoir 44 is provided configured to store a supply of liquid aerosol generating material. In this example, the liquid reservoir 44 has a substantially annular shape with an outer wall defined by the cartridge housing 42 and an inner wall that defines an airflow path 52 through the cartridge part 4. The reservoir 44 is closed at each end with end walls to contain the aerosol generating material. The reservoir 44 may be formed in accordance with conventional techniques, for example it may comprise a plastics material and be integrally moulded with the cartridge housing 42. The cartridge part further comprises an aerosol generator 48 located towards an end of the reservoir 44 opposite to the mouthpiece outlet 50. In some embodiments, the aerosol generator is a heater configured to subject the aerosol-generating material to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol. In some embodiments, the aerosol generator is configured to cause an aerosol to be generated from the aerosol-generating material without heating. For example, the aerosol generator may be configured to subject the aerosolgenerating material to one or more of vibration, increased pressure, or electrostatic energy.

It will be appreciated that in a two-part device such as shown in Figure 1 , the aerosol generator may be in either of the reusable part 2 or the cartridge part 4. For example, in some embodiments, the aerosol generator 48 (e.g. a heater) may be comprised in the reusable part 2, and is brought into proximity with a portion of aerosol generating material in the cartridge 4 when the cartridge is engaged with the reusable part 2. In such embodiments, the cartridge may comprise a portion of aerosol generating material, and an aerosol generator 48 comprising a heater is at least partially inserted into or at least partially surrounds the portion of aerosol generating material as the cartridge 4 is engaged with the reusable part 2.

In the example of Figure 1 , a wick 46 in contact with a heater 48 extends transversely across the primary (or first) airflow path 52 with its ends extending into the reservoir 44 of a liquid aerosol generating material through openings in the inner wall of the reservoir 44. The openings in the inner wall of the reservoir are sized to broadly match the dimensions of the wick 46 to provide a reasonable seal against leakage from the liquid reservoir into the cartridge airflow path without unduly compressing the wick, which may be detrimental to its fluid transfer performance.

The wick 46 and heater 48 are arranged in the cartridge airflow path 52 such that a region of the first airflow path 52 around the wick 46 and heater 48 in effect defines an aerosol generation region 45 for the cartridge part 4. Aerosol generating material in the reservoir 44 infiltrates the wick 46 through the ends of the wick extending into the reservoir 44 and is drawn along the wick by surface tension I capillary action (i.e. wicking). The heater 48 in this example comprises an electrically resistive wire coiled around the wick 46. In the example of Figure 1 , the heater 48 comprises a nickel chrome alloy (Cr20Ni80) wire and the wick 46 comprises a glass fibre bundle, but it will be appreciated the specific aerosol generator configuration is not significant to the principles described herein. In use electrical power may be supplied to the heater 48 to vaporise an amount of aerosol generating material (aerosol generating material) drawn to the vicinity of the heater 48 by the wick 46. Vaporised aerosol generating material may then become entrained in air drawn along the cartridge airflow path from the vaporisation region towards the mouthpiece outlet 50 for user inhalation.

As noted above, the rate at which aerosol generating material is vaporised by the vaporiser (heater) 48 will depend on the amount (level) of power supplied to the heater 48. Thus electrical power can be applied to the heater to selectively generate aerosol from the aerosol generating material in the cartridge part 4, and furthermore, the rate of aerosol generation can be changed by changing the amount of power supplied to the heater 48, for example through pulse width and/or frequency modulation techniques.

The reusable part 2 comprises an outer housing 12 having an opening that defines an air inlet 28 for the e-cigarette, a power source 26 (for example a battery) for providing operating power for the electronic cigarette, control circuitry 18 for controlling and monitoring the operation of the electronic cigarette, a first user input button 14, a second user input button 16, and a visual display 24.

The outer housing 12 may be formed, for example, from a plastics or metallic material and in this example has a circular cross section generally conforming to the shape and size of the cartridge part 4 so as to provide a smooth transition between the two parts at the interface 6. In this example the reusable part has a length of around 8 cm so the overall length of the e-cigarette when the cartridge part and reusable part are coupled together is around 12 cm. However, and as already noted, it will be appreciated that the overall shape and scale of an electronic cigarette implementing an embodiment of the disclosure is not significant to the principles described herein. The power source 26 in this example is rechargeable and may be of a conventional type, for example of the kind normally used in electronic cigarettes and other applications requiring provision of relatively high currents over relatively short periods. The power source 26 may be recharged through a charging connector in the reusable part housing 12, for example a USB connector.

First and second user input buttons 14, 16 may be provided, which in this example are conventional mechanical buttons, for example comprising a spring mounted component which may be pressed by a user to establish an electrical contact. In this regard, the input buttons may be considered input devices for detecting user input and the specific manner in which the buttons are implemented is not significant. The buttons may be assigned to functions such as switching the aerosol delivery system 1 on and off, and adjusting user settings such as a power to be supplied from the power source 26 to an aerosol generator 48. However, the inclusion of user input buttons is optional, and in some embodiments buttons may not be included.

A display 24 may be provided to give a user with a visual indication of various characteristics associated with the aerosol delivery system, for example current power setting information, remaining power source power, and so forth. The display may be implemented in various ways. In this example the display 24 comprises a conventional pixilated LCD screen that may be driven to display the desired information in accordance with conventional techniques. In other implementations the display may comprise one or more discrete indicators, for example LEDs, that are arranged to display the desired information, for example through particular colours and I or flash sequences. More generally, the manner in which the display is provided and information is displayed to a user using the display is not significant to the principles described herein. For example some embodiments may not include a visual display and may include other means for providing a user with information relating to operating characteristics of the aerosol delivery system, for example using audio signalling, or may not include any means for providing a user with information relating to operating characteristics of the aerosol delivery system.

A controller 22 is suitably configured I programmed to control the operation of the aerosol delivery system to provide functionality in accordance with embodiments of the disclosure as described further herein, as well as for providing conventional operating functions of the aerosol delivery system in line with the established techniques for controlling such devices. The controller (processor circuitry) 22 may be considered to logically comprise various sub-units I circuitry elements associated with different aspects of the operation of the aerosol delivery system 1. In this example the controller 22 comprises power supply control circuitry for controlling the supply of power from the power source 26 to the aerosol generator 48 in response to user input, user programming circuitry 20 for establishing configuration settings (e.g. user-defined power settings) in response to user input, as well as other functional units I circuitry associated functionality in accordance with the principles described herein and conventional operating aspects of electronic cigarettes, such as display driving circuitry and user input detection circuitry. It will be appreciated the functionality of the controller 22 can be provided in various different ways, for example using one or more suitably programmed programmable computer(s) and I or one or more suitably configured application-specific integrated circuit(s) I circuitry I chip(s) I chipset(s) configured to provide the desired functionality. The functionality of the controller 22 is described further herein. For example, the controller 26 may comprise an application specific integrated circuit (ASIC) or microcontroller, for controlling the aerosol delivery device. The microcontroller or ASIC may include a CPU or micro-processor. The operations of a CPU and other electronic components are generally controlled at least in part by software programs running on the CPU (or other component). Such software programs may be stored in non-volatile memory, such as ROM, which can be integrated into the microcontroller itself, or provided as a separate component. The CPU may access the ROM to load and execute individual software programs as and when required.

Reusable part 2 comprises an airflow sensor 30 which is electrically connected to the controller 22. The airflow sensor 30 is positioned adjacent or within an airflow pathway such as the primary airflow pathway 52. In most embodiments, the airflow sensor 30 comprises a so-called “puff sensor”, in that the airflow sensor 30 is used to detect when a user is puffing on the device and I or to detect a strength of a user inhalation. In some embodiments, the airflow sensor 30 is connected to the controller 22, and the controller distributes electrical power from the power source 26 to the aerosol generator 48 in dependence of a signal received from the airflow sensor 30 by the controller 22. The specific manner in which the signal output from the airflow sensor 30 (which may comprise a measure of capacitance, resistance or other characteristic of the airflow sensor, made by the controller 22) is used by the controller 22 to control the supply of power from the power source 26 to the aerosol generator 48 can be carried out in accordance with any approach known to the skilled person.

The e-cigarette 10 is provided with one or more holes for use as an air inlet 28. These holes connect to air passages (airflow paths) running through the e-cigarette 10 from the air inlet 28 to the mouthpiece which may have an additional one or more holes for use an air outlet 50. Typically the air paths through such devices are relatively convoluted in that they have to pass various components and/or take multiple turns following entry into the e-cigarette.

As discussed above, there is a primary or first air passage 52 which passes through the aerosol generation region (i.e. to provide main-stream air during use). Additionally, there is a secondary or second air passage 53 which does not pass through the aerosol generation region 45 (i.e. to provide side-stream air during use). The (first) air passage 52 which passes through the aerosol generation region includes a section comprising an air channel connecting one or more holes of an air inlet 28 to the aerosol generation region 45, a region around the aerosol generation region 45 (e.g. passing through or adjacent to the aerosol generation region such that aerosol generated in the aerosol generation region becomes entrained in the air passing through the air passage) and a section comprising an air channel connecting from the aerosol generation region 45 to the outlet 50 of the mouthpiece.

In contrast, the air passage 53 which does not pass through the aerosol generation region 45 does not channel air through a region around the aerosol generation region 45 (e.g. the air passage is physically separated from the aerosol generation region by a wall or other air channelling feature). Instead in some examples, the air passage 53 which does not pass through the aerosol generation region comprises an air channel connecting one or more holes of an air inlet 28 to the outlet 50 in the mouthpiece, and either bypasses the aerosol generation region (e.g. via a separate distinct air channel) or starts at an inlet 28 provided at a location closer to the mouthpiece that the aerosol generation region 45. In some examples, the air passage 53 which does not pass through the aerosol generation region may share a portion of the section comprising an air channel connecting one or more holes of an air inlet 28 to the aerosol generation region 45 and / or a portion of the section comprising an air channel connecting from the aerosol generation region 45 to the outlet 50 in the mouthpiece with the air passage 52 which does pass through the aerosol generation region. For example, the first air pathway 52 and second air pathway 53 may be fluidly coupled at their downstream ends to a common airflow pathway comprising the mouthpiece outlet 50 through which a user inhales in use. Alternatively or additionally, the first air pathway 52 and second air pathway 53 may be fluidly coupled at their upstream ends to a second common airflow pathway comprising the air inlet(s) 28, through which air is drawn from outside the device when a user inhales on the mouthpiece.

When a user inhales through the mouthpiece outlet 50, air is drawn into these air passages 52,53 through the one or more air inlet holes 28, which are suitably located on the outside of the e-cigarette. This airflow (or the associated change in pressure) may be detected by an airflow sensor 30, in this case a pressure sensor, for detecting airflow in electronic cigarette 10 and outputting corresponding airflow detection signals to the control circuitry. The airflow sensor may operate in accordance with conventional techniques in terms of how it is arranged within the electronic cigarette to generate airflow detection signals indicating when there is a flow of air through the electronic cigarette (e.g. when a user inhales or blows on the mouthpiece).

When a user inhales (sucks I puffs) on the mouthpiece in use, the airflow passes through the air passages 52,53 (airflow paths) through the electronic cigarette and the portion of the airflow passing along the first airflow path 52 combines I mixes with the vapour in the region around the aerosol generation region 45 to generate the aerosol. The resulting combination of airflow and aerosol continues along the first airflow path 52 connecting from the aerosol generation region 45 to a junction, or mixing chamber, where it mixes with air which has travelled along the second air passage 53 which did not pass through the aerosol generation region 45. The new mixture (i.e. combination) of airflow and aerosol continues to the mouthpiece outlet 50 for inhalation by a user.

It will be appreciated that while Figure 1 is directed towards an e-cigarette having a reusable part 2 and a cartridge part 4 in the form of a cartomiser having a liquid reservoir; in other examples the cartridge part may comprise an aerosol-generating material in the form of a solid or gel rather than a liquid, and may or may not comprise an aerosol generator (instead the aerosol generator may be provided in the reusable part 2). Furthermore, it will be appreciated that while Figure 1 depicts the mouthpiece as being part of the cartridge part 4, in other examples the mouthpiece may be provided by the reusable part 2 or by a further attachable component.

As stated above, Figure 1 includes an air inlet 28, a first air pathway 52 (or passage) passing through an aerosol generation region 45, a second air pathway 53 (or passage) not passing through the aerosol generation region 45, a first junction 150 at which the first air pathway 52 and the second air pathway 53 connect upstream of the aerosol generation region 45, and a second junction 151 at which the first air pathway 52 and the second air pathway 53 connect downstream of the aerosol generation region 45, an air outlet 50, and an adjustment mechanism 170a.

An aerosol generator 48 and an aerosol generating material 44, as described above, can be provided within, adjacent to, or otherwise associated with the aerosol generation region 45, such that activation of the aerosol generator 48 (e.g. by applying power to the aerosol generator 48) causes aerosol (or vapour) to be generated from the aerosol-generating material 44 in the aerosol-generating region 45. For example an aerosol generator 48 may be a heated plate which is heated by induction or resistive heating, and which acts to heat the aerosol generating material 44 thereby volatising the aerosol generating material 44 to generating aerosol in the aerosol generating region 45.

The first air pathway 52 extends from the air inlet 28 to the air outlet 50, thereby providing a fluid pathway for air to travel between the air inlet 28 and the air outlet 50. The first air pathway 52 includes a section comprising an air channel (or fluid pathway) connecting the air inlet 28 to the aerosol generation region 45, the aerosol generation region 45 (e.g. passing through or adjacent to the aerosol generator and I or aerosol generation material) and a section comprising an air channel connecting from the aerosol generation region 45 to the air outlet 50. When a user inhales (sucks / puffs) on the mouthpiece in use, the airflow enters the aerosol provision system 1 via the air inlet 28, and passes through the first air passage 52 of the aerosol provision system and a portion of the airflow combines I mixes with the vapour (aerosol) in the aerosol generation region, before being inhaled by the user via the air outlet 50.

The second air pathway 53 extends from the air inlet 28 to the air outlet 50, thereby providing a fluid pathway for air to travel between the air inlet 28 and the air outlet 50. The second air pathway 53 comprises an air channel or fluid pathway connecting the air inlet 28 to the air outlet 12 without passing through the aerosol generation region 45. When a user inhales (sucks I puffs) on the mouthpiece in use, the airflow enters the aerosol provision system 1 via the air inlet 28 and passes through the second air passage 52 of the aerosol provision system 1 before exiting the aerosol provision system 1 via the air outlet 50 for inhalation by the user. The second air pathway 53 is separated from the aerosol generation region 45 such that aerosol generated in the aerosol generation region 45 in normal use (e.g. whilst a user is inhaling) is not provided into the second air pathway 53. In some examples, the second air pathway 53 may comprise a separate airflow channel to separate the second air pathway from the aerosol generation region 45. In some examples, the second air pathway and first air pathway may be separated by a membrane or partition that is impermeable to vapour/aerosol in the vicinity of the aerosol generation region 45.

The air inlet 28 may comprise a single hole, or a plurality of holes, configured to allow air into the aerosol provision system 1 during an inhalation. In some examples, the plurality of holes may be provided by a grate or mesh, or similar. In some examples, the first and second air pathway 52,53 may share a single air inlet 28 (as shown). In some examples, where the first and second air pathways 52, 53 share an air inlet 28 the first and second air pathways 52,53 split at a junction 150 which is upstream of the aerosol generation region 45 (for the first air pathway 52), thereby allowing the second air pathway 53 to bypass the aerosol generation region 45. By a junction it is meant that the air pathways are in fluid connection. In some examples (not shown), the first air pathway 52 may be connected to a first air inlet and the second air pathway 53 may be connected to a second distinct air inlet. In these examples, the first and air pathways 52,53 do not fluidly connect at least for the section of the first air pathway 52 between the first air inlet and the aerosol generation region 45.

The air outlet 50 is provided in a mouthpiece of the system 1 which is configured to allow a user to inhale on the device (e.g. shaped to facilitate the user engaging their lips with the mouthpiece). The air outlet 50 may comprise a single hole, a plurality of holes, configured to allow air to exit the aerosol provision system 1 during a puff. In some examples, the plurality of holes may be provided by a grate or mesh, or similar. In some examples, the first and second air pathway 52,53 may share a single air outlet 50 (as shown). In some examples, where the first and second air pathways 52, 53 share an air outlet 50 the first and second air pathways 52,53 join (i.e. be in fluid connection) at a junction 151 which is downstream of the aerosol generation region 45 (for the first air pathway 52), thereby allowing the second air pathway 53 to bypass the aerosol generation region 45. In some examples (not shown), the first air pathway 52 may be connected to a first air outlet and the second air pathway 53 may be connected to a second distinct air outlet. In these examples, the first and air pathways 52,53 do not fluidly connect at least for the section of the first air pathway 52 between the aerosol generation region 45 and the first outlet. In these examples, the first and second air outlets are provided in the mouthpiece such that the user can inhale through both simultaneously when using the system 1.

In examples in accordance with Figure 1 , the adjustment mechanism 170a is configured to vary the ratio of the resistance-to-draw of the first air pathway 52 to the resistance-to-draw of the second air pathway 53 based upon a draw strength of a user inhalation by varying the resistance to draw of the second air pathway 53. The adjustment mechanism 170a is provided adjacent and I or within the second air path 53, and configured such that changes to the state (e.g. position or configuration of the adjustment mechanism) of the adjustment mechanism 170a result in a changed in the resistance-to-draw of the second air pathway 53. By changing the resistance-to-draw of the second air pathway 53 (e.g. how easy it is for the user to inhale or “pull” air along the second air pathway) the ratio of the resistance-to-draw of the first air pathway 52 to the resistance-to-draw of the second air pathway is changed (because there is adjustment mechanism in the first air pathway 52 to make a compensatory change to the first air pathway 52). By resistance-to-draw of the first air pathway it is meant the resistance-to-draw of the first air pathway 52 measured separately from the resistance-to-draw of the second air pathway 53 (e.g. in isolation to the second air pathway). Similarly, by resistance-to-draw of the second air pathway it is meant the resistance- to-draw of the second air pathway 53 measured separately from the resistance-to-draw of the first air pathway 52 (e.g. in isolation to the first air pathway). For example, the resistance-to- draw of the first and second air pathways may be measured in the absence of any sections common to both the first and second air pathways. It will be appreciated that the resistance- to-draw of the first air pathway and the resistance-to-draw of the second air pathway are different to the resistance-to-draw of the whole aerosol provision system which is defined by the resistance-to-draw of all pathways (e.g. including the first and second air pathways) between the air inlet(s) 28 and the mouthpiece outlet(s) 50.

In some examples, the resistance-to-draw of the first air pathway is determined by the cross-section of the narrowest section (e.g. portion) of the first air pathway and the resistance- to-draw of the second air pathway is determined by the cross-section of the narrowest section of the second air pathway. Therefore to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway, an adjustment mechanism (e.g. adjustment mechanism 170a or adjustment mechanism 170b) may be configured to vary the cross-section of at least one of the first air pathway and the second air pathway. By configuring an adjustment mechanism to vary the cross-section, the adjustment mechanism may redefine the cross section of the narrowest section of the relevant air pathway. For example, in some examples, an adjustment mechanism, as described in the present specification, may increase the cross-section of the narrowest section of an air pathway, or may decrease the crosssection of the narrowest section of an air pathway. By narrowest it is meant that the cross- sectional separation between the boundaries (e.g. walls) of the air pathway is the smallest (e.g. least) value for any cross-sectional section between respective boundary walls of the air pathway. It will be appreciated that in other examples, the resistance-to-draw may instead be determined by a smallest cross-sectional area of a respective air pathway.

In some examples, by decreasing the cross-section of a section of an air pathway (e.g. a variable section adjusted by a relevant adjustment mechanism), that decreased section may become the narrowest section if a different section was previously the narrowest (e.g. a fixed section). Similarly, in some examples, by increasing the cross-section of a section of an air pathway (e.g. a variable section adjusted by a relevant adjustment mechanism) that previously defined the narrowest section prior to the adjustment, a different section may become the narrowest section if a different section (e.g. a fixed section) has a narrower cross-section. As such, an adjustment mechanism may effectively vary the resistance to draw of an air pathway by adjusting an element of the air pathway to change which portion or section of the air pathway is the primary restricting section (e.g. the cross-section of the narrowest section).

The adjustment mechanism 170a may be provided by a valve, or other obstruction (such as a movable iris), which is configured to move to constrict the air flow in the second air pathway 53. By constrict it is meant that the valve effectively narrows a cross-section of the air path to increase the resistance to draw of the second air pathway 53. The adjustment mechanism 170a is configured to change state to vary the resistance-to-draw based on (i.e. dependent on) the draw strength of a user’s inhalation. In particular, the adjustment mechanism 170a is configured to tune the ratio of airflow along the first and second air pathways 52,53 to decrease (at least proportionally with respect to the first air pathway) the airflow along the second air pathway when the user inhales more strongly (i.e. inhales at a greater rate). In some examples, a sufficiently strong user inhalation (i.e. above a particular threshold rate of inhalation) may temporarily close the second air pathway 52.

In some examples the adjustment mechanism 170a is passive in that it does not require any measurement or detection of the user’s inhalation, or control signals from suitable circuitry, to enable the adjustment mechanism 170a to vary the resistance-to draw of the second air pathway 170. Instead the adjustment mechanism 170a is responsive to the inhalation strength such that it changes state dependent on the inhalation strength. In some examples the adjustment mechanism 170a is active in that it is controlled by control signals from suitable circuitry in response to measurements by an airflow sensor, as discussed below in relation to Figure 4. In short, for active systems the state of the adjustment mechanism 170a can be adjusted based on a measured inhalation strength.

In some examples, the adjustment mechanism 170a is configured to vary its state (e.g. position or configuration) between a first state which provides a first resistance-to-draw when no inhalation is occurring, and a second state which provides a second resistance-to-draw when inhalation is occurring at a particular strength.. In some examples, the adjustment mechanism 170a may be configured to vary the resistance-to-draw gradually between the first and second resistance-to-draw, whilst in some other examples the adjustment mechanism 170a may be configured to vary the resistance-to-draw along the second pathway 53 in substantially a single step change when the draw strength of a user exceeds a threshold value. For example, the adjustment mechanism 170a can comprise a valve provided in the second air pathway 53 and configured to restrict air flow when the draw strength of a user exceeds a threshold value. In some of these examples, the adjustment mechanism 170a may be configured to completely close the second air pathway 53, such that the airflow along the second air pathway is reduced to substantially zero, when the draw strength of a user exceeds a threshold value.

Figure 2 is a schematic diagram of the air passages of an aerosol provision system 1 in accordance with the present invention. With the exception of the adjustment mechanism 170b which replaces adjustment mechanism 170a, the components of Figure 2 are substantially as described in relation to Figure 1. Figure 2 differs from Figure 1 in that the adjustment mechanism 170b is provided adjacent and I or within the first air path 52, and configured such that changes to the state (e.g. position or configuration of the adjustment mechanism) of the adjustment mechanism 170b result in a changed in the resistance-to-draw of the first air pathway 52. As such, adjustment mechanism 170b is configured to vary the ratio of the resistance-to-draw of the first air pathway 52 to the resistance-to-draw of the second air pathway 53 based upon a draw strength of a user inhalation by varying the resistance to draw of the first air pathway 52. By changing the resistance-to-draw of the first air pathway 52 (e.g. how easy it is for the user to inhale or “pull” air along the first air pathway) the ratio of the resistance-to-draw of the first air pathway 52 to the resistance-to-draw of the second air pathway 53 is changed (because there is adjustment mechanism in the second air pathway 53 to make a compensatory change to the second air pathway 53).

The adjustment mechanism 170b may be provided by a valve, or other obstruction (such as a movable iris), which is configured to move to constrict the air flow in the first air pathway 52. By constrict it is meant that the valve effectively narrows a cross-section of the air path to increase the resistance to draw of the first air pathway 52. The adjustment mechanism 170b is configured to change state to vary the resistance-to-draw based on (i.e. dependent on) the draw strength of a user’s inhalation. In particular, the adjustment mechanism 170b is configured to tune the ratio of airflow along the first and second air pathways 52,53 to increase the airflow along the first air pathway when the user inhales more strongly (i.e. inhales at a greater rate).

In some examples the adjustment mechanism 170b is passive in that it does not require any measurement or detection of the user’s inhalation, or control signals from suitable circuitry, to enable the adjustment mechanism 170b to vary the resistance-to draw of the first air pathway 52. Instead the adjustment mechanism 170b is responsive to the inhalation strength such that it changes state dependent on the inhalation strength. In some examples the adjustment mechanism 170b is active in that it is controlled by control signals from suitable circuitry in response to measurements by an airflow sensor, as discussed below in relation to Figure 4. In short, for active systems the state of the adjustment mechanism 170b can be adjusted based on a measured inhalation strength.

In some examples, the adjustment mechanism 170b is configured to vary its state (e.g. position or configuration) between a first state which provides a first resistance-to-draw when no inhalation is occurring, and a second state which provides a second resistance-to-draw when inhalation is occurring at a particular strength. In some examples, the adjustment mechanism 170b may be configured to vary the resistance-to-draw gradually between the first and second resistance-to-draw, whilst in some other examples the adjustment mechanism 170b may be configured to vary the resistance-to-draw along the first pathway 52 in substantially a single step change when the draw strength of a user exceeds a threshold value. For example, the adjustment mechanism 170b can comprise a valve provided in the first air pathway 52 and configured to reduce the resistance-to-draw when the draw strength of a user exceeds a threshold value.

Figure 3 is a schematic diagram of the air passages of an aerosol provision system 1 in accordance with the present invention. With the exception of the adjustment mechanism 170c which replaces adjustment mechanism 170a, the components of Figure 3 are substantially as described in relation to Figure 1 . Figure 3 differs from Figure 1 (and Figure 2) in that the adjustment mechanism 170c is provided adjacent to and I or within both the first air path 52 and the second air path 53, and is configured such that changes to the state (e.g. position or configuration of the adjustment mechanism) of the adjustment mechanism 170c result in a change in the resistance-to-draw of the first air pathway 52 and I or the second air pathway 53.

As such, adjustment mechanism 170c is configured to vary the ratio of the resistance- to-draw of the first air pathway 52 to the resistance-to-draw of the second air pathway 53 based upon a draw strength of a user inhalation by varying the resistance to draw of the first air pathway 52 and I or the second air pathway 53. By changing the resistance-to-draw of the first air pathway 52 or the second air pathway (e.g. how easy it is for the user to inhale or “pull” air along the first air pathway) the ratio of the resistance-to-draw of the first air pathway 52 to the resistance-to-draw of the second air pathway 53 is changed. In some examples, complementary changes can be made by the adjustment mechanism 170c to increase the resistance-to-draw of the first air pathway 52 and decrease the resistance-to-draw of the second air pathway 53 simultaneously, and vice versa.

In some examples in accordance with Figure 3, a single obstruction such as a sliding bar may be used to vary the resistance to draw of both the first and second air pathway 52,53 (e.g. by sliding the bar out of one pathway and into the other pathway). In some other examples in accordance with Figure 4, the adjustment mechanism 170c comprises a separate valve, or other obstruction, for each of the first and second air pathways 52,53. The adjustment mechanism 170c is configured to change state to vary the resistance-to-draw of the first and second air pathways 52,53 based on (i.e. dependent on) the draw strength of a user’s inhalation. In particular, the adjustment mechanism 170c is configured to tune the ratio of airflow along the first and second air pathways 52,53 to increase the airflow along the first air pathway with respect to the airflow along the second air pathway when the user inhales more strongly (i.e. inhales at a greater rate).

In some examples the adjustment mechanism 170c is passive in that it does not require any measurement or detection of the user’s inhalation, or control signals from suitable circuitry, to enable the adjustment mechanism 170c to vary the resistance-to draw of the first air pathway 52. Instead the adjustment mechanism 170c is responsive to the inhalation strength such that it changes state dependent on the inhalation strength. In some examples the adjustment mechanism 170c is active in that it is controlled by control signals from suitable circuitry in response to measurements by an airflow sensor, as discussed below in relation to Figure 4. In short, for active systems the state of the adjustment mechanism 170c can be adjusted based on a measured inhalation strength.

In some examples, the adjustment mechanism 170c is configured to vary between a first state (e.g. position or configuration) which provides a first set of resistances-to-draw along the first air pathway 52 and a second air pathway, respectively, when no inhalation is occurring, and a second state which provides a second set of resistances-to-draw along the first air pathway 52 and a second air pathway, respectively, when inhalation is occurring at a particular strength. In some examples, the adjustment mechanism 170c may be configured to vary the resistance-to-draw gradually between the first and second set of resistances-to-draw, whilst in some other examples the adjustment mechanism 170c may be configured to vary the resistances-to-draw along the along the first air pathway 52 and a second air pathway, in substantially a single step change when the draw strength of a user exceeds a threshold value. In some of these examples, the adjustment mechanism 170c may be configured to completely close the second air pathway 53, such that the airflow along the second air pathway is reduced to substantially zero, when the draw strength of a user exceeds a threshold value.

Figure 4 is a schematic diagram of certain electrical (including electronic) components of the reusable part 2 of Figure 1. Note that at least some of these components are shown by way of example only and may be omitted (and/or supplemented or replaced by other components) according to the circumstances of any given implementation. Furthermore, although the components shown in Figure 4 are assumed to be located in the reusable part 2 rather than in the cartridge part 4 (since a given reusable part may be re-used with many different cartomisers 30), other configurations may be adopted as desired. In addition, the components shown in Figure 4 may be located on one circuit board such as that of control circuitry 18, but other configurations may be adopted as desired, e.g. components may be distributed across multiple circuit boards, or may not (all) be mounted on circuit boards. Furthermore, for clarity Figure 4 omits various elements which are commonly present in this type of device, such as most power lines, memory (RAM) and/or (non-volatile) storage (ROM) and so on.

Figure 4 includes a connector 6 for coupling to a cartomiser (cartridge) 4, as discussed above, and a (re-chargeable) battery 26 and a (micro)controller 22, as discussed below. The battery 26 is further linked to a USB connector 235, e.g. a micro or mini or type C connector, which can be used to re-charge the battery 26 from an external power supply (typically via some re-charging circuit, not shown in Figure 4). Note that other forms of re-charging may be supported for battery 26 - for example, by charging through some other form of connector, by wireless charging (e.g. induction), by charging through connector 6, and/or by removing the battery 26 from the e-cigarette 10.

The device of Figure 4 further includes a communications interface 230 which can be used for wired and/or wireless communications with one or more external systems (not shown in Figure 4), such as a smartphone, laptop and/or other form of computer and/or other appliance. The wireless communications may be performed using (for example) Bluetooth and/or any other suitable wireless communications standard. It will be appreciated that USB interface 235 may also be used to provide a wired communications link instead of (or in addition to) the communications interface 230; for example, the USB interface 235 might be used to provide the system with wired communications while the communications interface 230 might be used to provide the system with wireless communications.

Communications to and/or from the electronic aerosol provision system 10 may be used for a wide variety of purposes, such as to collect and report (upload) operational data from the system 10, e.g. regarding usage levels, settings, any error conditions, and/or to download updated control programs, configuration data, and so on. Such communications may also be used to support interaction between the electronic aerosol provision system 10 and an external system such as a smartphone belonging to the user of the electronic aerosol provision system 10. This interaction may support a wide variety of applications (apps), including collaborative or social media based apps.

The device of Figure 4 further includes an airflow sensor 30 to provide an estimate of a draw strength of the user when the user is inhaling on the device. The airflow sensor 30 can be used to. The sensor 30 may detect airflow via any suitable mechanism, such as by monitoring for a flow of air and/or a change in pressure. A detection by the sensor 30 may trigger the microcontroller 22 to change an operational aspect of the device 20 or system 10. In some examples a detection by the sensor 30 may trigger a supply of power by the microcontroller 22 from the battery 26 to the cartridge part 4 (in particular to a heater or other aerosol generator) to produce a vapour output for inhalation by the user (this process is generally referred to as puff-activation) when the user’s draw strength is above a set value indicative of a user inhaling on the device. Note that some systems 10 do not support puff actuation; these systems are typically activated by a user pressing on a button (or some other form of direct input). In some examples, and as explained in more detail below, a detection may trigger the microcontroller 22 to cause a state (e.g. a position or configuration) of an adjustment mechanism 170 (which may be an adjustment mechanism in accordance with 170a, 170b or 170c) to change, thereby changing the resistance-to-draw of the first air pathway 52 and I or the second air pathway 53 and affecting the mixture of air inhaled by the user. Such an adjustment mechanism 170 may be considered to be electronically operated or configurable in that control signals from the microcontroller 22 a change to the adjustment mechanism 170.

The device of Figure 4 may further include user I/O functionality 250 to support direct user input into the system 10 (this user input/output may be provided instead of, or more commonly in addition to, the communications functionality discussed above). The user output may be provided as one or more of visual, audio, and/or haptic output (feedback), for example by first and second user input buttons 14, 16 and display 24. For example, visual output may be implemented by one or more light emitting diodes (LEDs) or any other form of lighting, and/or by a screen or other display - such as a liquid crystal display (LCD), which can provide more complex forms of output. The user input may be provided by any suitable facility, for example, by providing one or more buttons or switches on the system 10 and/or a touch screen (which supports both user input and output). Alternatively or additionally, user input may also be performed by movement of the device 20 (or of the whole system 10), such movement being detected using a motion sensor which can be considered as part of the user input/output facility 250. The microcontroller 22 may be located on a PCB, which may also be used for mounting other components as appropriate, e.g. the communications interface 230. Some components may be separately mounted, such as the airflow sensor 30, which may be located adjacent the airflow path through the system 10, and a user input facility (e.g. buttons) which may be located on the external housing of the system 10. The microcontroller 22 generally includes a processor (or other processing facility) and memory (ROM and/or RAM). The operations of the microcontroller 22 (and some other electronic components), are typically controlled at least in part by software programs running on the processor in the controller (or other electronic components as appropriate). Such software programs may be stored in a non-volatile memory which can be integrated into the microcontroller 22 itself, or provided as a separate component (e.g. on a PCB). The processor may access ROM or any other appropriate store to load individual software programs for execution as and when required. The microcontroller 22 also contains suitable interfaces (and control software) for interacting with the other components of system 10 (such as shown in Figure 4).

The microcontroller 22 may specify (and implement) one or more heating profiles for use with a heater; such a profile determines the variation with time in the level of power that is supplied to a heater. For example, the microcontroller may supply most power to the heater from the battery 26 at the start of a puff in order to rapidly warm the heater to its operating temperature, after which the microcontroller 22 may supply a reduced level of power to the heater sufficient to maintain this operating temperature. It will be appreciated that other operation profiles may be used for other types of aerosol generator (for example, a vibrating mesh or ejector) to control the variation with time in the level of power that is supplied to the aerosol generator.

As discussed above, in some examples in accordance with the present invention, an adjustment mechanism 170 of the aerosol provision system 1 can be active in that it is controlled by control signals from suitable circuitry (such as microcontroller 22) in response to measurements of the inhalation strength by an airflow sensor 30 or other suitable sensor. The detection or measurement may trigger the microcontroller 22 to control the adjustment mechanisms to vary the ratio of the resistance-to-draw of the first pathway to the resistance- to-draw of the second pathway, thereby affecting the mixture of air inhaled by the user. Such an adjustment mechanism 170 may be considered to be electronically operated or configurable in that control signals from the microcontroller 22 a change to the adjustment mechanism 170. The microcontroller 22 can be configured to control the adjustment mechanism 170 to cause a state (e.g. a position or configuration) of the adjustment mechanism 170 to change, thereby changing the resistance-to-draw of the first air pathway 52 and / or the second air pathway 53, and the ratio of the two. As stated above the sensor 30 is configured to measure the draw strength and to provide an estimate of a draw strength of the user when the user is inhaling on the device. The sensor 30 can provide or otherwise transmit, the estimate of the draw strength, or a representative value, to the microcontroller 22 which can then provide an electronic control signal to the adjustment mechanism 170 to alter the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway. As detailed above in relation to Figures 2, 3 and 4, an active adjustment mechanism 170 can be controlled such that it varies the resistance-to-draw of the first air pathway 52 and I or the second air pathway either gradually (e.g. substantially continuously) or in a step-like manner. In general, the controller will act to increase the proportion of airflow through the first air pathway when the user is inhaling strongly, in comparison to when the user is inhaling weakly. This provides the user with an intuitive sensorial experience in which the user is provided with less aerosol when they are inhaling weakly, and more aerosol when they are inhaling strongly.

In some example, the microcontroller 22 is further configured to control the adjustment mechanism based on a user input. The user input may be received via the user I/O functionality 250 and I or via an external device such as a smart phone via the communications interface 230 or the USB interface 235. The controller 22 may interpret the user input and control the adjustment mechanism 170 in response. For example, the control may be configured to select one of a number of modes of operation based on the user input. For each mode of operation, the controller 22 can be configured to control the adjustment mechanism 170 to vary the resistance-to-draw of the first and I or second air pathways within set ranges corresponding to that mode. In some examples, the user may be able to select a discrete mode of operation based on the user input, where the controller is configured to decrease the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway in comparison to a normal mode to reduce a visibility of an aerosol produced by the aerosol generator.

The configuration shown in Figure 4 may be varied as appropriate by the skilled person. For example, the functionality of the (micro)controller 22 may be distributed across one or more components which act in combination as a microcontroller. In addition, there may be a PCB or similar provided in combination with battery 26 to control re-charging of the battery, such as to detect and prevent voltage or current overload and/or overly long charging times, and likewise to control discharging of the battery, e.g. so that the battery does not get excessively discharged to the point of damage. It will be appreciated that the above set of alternatives and variations on the configuration is by no means exhaustive, and many further alternatives and variations will be apparent to the skilled person.

Figure 5 is a flow chart of a method 600 of controlling an aerosol provision system comprising an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region, and a first air pathway passing through the aerosol generation region, a second air pathway not passing through the aerosol generation region.

The method begins at step 610 with the system providing an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance- to-draw of the second air pathway based upon a draw strength of a user inhalation. As detailed above in relation to figures 1 ,2,3 and 4; in some examples, the adjustment mechanism can be a passive adjustment mechanism which is not controlled electronically whilst in other examples, the adjustment mechanism is an active adjustment mechanism which is controlled electronically by a controller. In some examples, passive adjustment mechanism may be provided upon manufacture or by modifying an existing aerosol provision system. In some examples, active adjustment mechanisms may be provided by programming or reconfiguring the system such that an existing adjustment mechanism is configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

The method 600 continues at step 620 with the system adjusting the adjustment mechanism to vary the ratio of the resistance-to-draw of the first pathway to the resistance-to- draw of the second pathway. In some examples, adjusting the adjustment mechanism occurs passively, or automatically, dependent on the air flow past the adjustment mechanism or the air pressure at the adjustment mechanism. In some examples, adjusting the adjustment mechanism is facilitated by a controller which is configured to control the adjustment mechanism based on a measured or estimated characteristic of the airflow through the device. The method 600 then ends.

Figure 6 is a flow chart of a method 700 of controlling an aerosol provision system 1 to adjust an adjustment mechanism to vary the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway, as per step 620 of method 600. The method begins at step 621 , with the system estimating the draw strength of the user inhalation. The step 621 can be performed by the control circuitry 22 or by the airflow sensor 30. For example the sensor readings (i.e. measured values) made by the sensor 30 may be the estimate, or the sensor 30 and I or the control circuitry 22 may process the sensor readings to produce an estimate of the draw strength of the user inhalation.

The method proceeds to step 622, with the system controlling the adjustment mechanism 170 based on the estimated draw strength. The step 622 can be performed by the control circuitry 22. In some examples, the estimated draw strength is compared to one or more threshold values and /or one or more threshold ranges to determine how to control the adjustment mechanism 170. For example, the controller 22 may determine whether the estimated draw strength is in a first range or a second range of values for the draw strength and control the adjustment mechanism to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based on which of the ranges the estimated draw strength is in. For example, if the first range covers a range of higher draw strengths and the second range covers a range of lower draw strengths, then the controller may increase the ratio of the resistance-to-draw of the first air pathway to the resistance-to- draw of the second air pathway if the estimated draw strength is in the first range thereby decreasing the amount of side-stream air inhaled, and may decrease the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway if the estimated draw strength is in the second range thereby increasing the amount of sidestream air inhaled. It will be appreciated that in some examples, the controller 22 may be configured to compare the estimated draw strength to more than two ranges of draw strength and to control the adjustment mechanism to select a particular ratio dependent on which range the estimated draw strength falls within. Furthermore, it will be appreciated that comparisons to a plurality of threshold draw strength values could be used instead of a plurality of draw strength ranges to determine how to control the adjustment mechanism 170. Furthermore, in some examples, the controller 22 is configured to process the estimated draw strength to calculate how to control the adjustment mechanism 170. For example by comparing the estimated draw strength to entries in a lookup table or by inputting the estimated draw strength into a formula that outputs control values for controlling the adjustment mechanism. These examples may enable a more continuous or gradual change of the ratio that feels more intuitive to the user. In some examples, the adjustment mechanism 170 can change (i.e. adjust) the resistance to draw of the first air pathway 52. In these examples, the adjustment mechanism 170 is controlled to decrease the resistance (either stepwise or continuously) to draw of the first air pathway 52, in response to the user increasing draw strength. In some examples, the adjustment mechanism 170 can change the resistance to draw of the second air pathway 53. In these examples, the adjustment mechanism 170 is controlled to increase the resistance (either stepwise or continuously) to draw of the second air pathway 53, in response to the user increasing draw strength. In some examples the adjustment mechanism 170 can change the resistance to draw of the first and second air pathways 52,53. In these examples, the adjustment mechanism 170 is controlled to decrease the resistance (either stepwise or continuously) to draw of the first air pathway 52 and to increase the resistance (either stepwise or continuously) to draw of the second air pathway 53, in response to the user increasing draw strength. The method then ends.

The methods 600 and 700 illustrated in Figures 5 and 6 may be stored as instructions on a computer readable storage medium, such that when the instructions are executed by a processor, the methods 600 and 700 described above are performed. The computer readable storage medium may be non-transitory. Thus it has been described that examples of the present disclosure comprise an aerosol provision system comprising: an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region; a first air pathway passing through the aerosol generation region; a second air pathway not passing through the aerosol generation region; and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

Furthermore, it has also been described that examples of the present disclosure may also comprise an aerosol provision device for use with an aerosol generating article comprising aerosol generating material, which together form an aerosol provision system, wherein the aerosol provision system comprises an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region, a first air pathway passing through the aerosol generation region, a second air pathway not passing through the aerosol generation region, and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation, wherein the aerosol provision device comprises: circuitry configured to control the adjustment mechanism to cause the adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation. In some of these examples, at least a part of the first air pathway is provided in the aerosol provision device and/or wherein at least a part of the second air pathway is provided in the aerosol provision device, and wherein the adjustment mechanism is provided in the aerosol provision device and is arranged to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway by varying the resistance-to-draw of the at least a part of the first air pathway and/or the resistance-to-draw of the at least a part of the second air pathway.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

29 CLAIMS

1. An aerosol provision system comprising: an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region; a first air pathway passing through the aerosol generation region; a second air pathway not passing through the aerosol generation region; and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

2. The aerosol provision system of claim 1 , wherein the adjustment mechanism is configured to vary the resistance-to-draw of the first air pathway.

3. The aerosol provision system of either claim 1 or claim 2, wherein the adjustment mechanism is configured to vary the resistance-to-draw of the second air pathway.

4. The aerosol provision system of any preceding claim, wherein the adjustment mechanism is configured to provide a first ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway when the draw strength of the user inhalation is a first value; and wherein the adjustment mechanism is configured to provide a second ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway when the draw strength of the user inhalation is a second value which is different to the first value.

5. The aerosol provision system of claim 4, wherein the first ratio is greater than the second ratio when the first value is greater than the second value.

6. The aerosol provision system of any preceding claim, wherein the resistance-to-draw of the first air pathway is determined by the cross-section of the narrowest section of the first air pathway and the resistance-to-draw of the second air pathway is determined by the crosssection of the narrowest section of the second air pathway, and wherein the adjustment mechanism is configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway by varying the cross-section of at least one of the first air pathway and the second air pathway. 30

7. The aerosol provision system of any preceding claim, wherein the adjustment mechanism comprises a valve provided in the second air pathway and configured to restrict air flow when the draw strength of a user inhalation exceeds a threshold value.

8. The aerosol provision system of claim 7, wherein the valve is configured to prevent the flow of air along the second air pathway when the draw strength of the user inhalation exceeds the threshold value.

9. The aerosol provision system of any preceding claim, wherein the first air pathway and second air pathway are fluidly coupled at their downstream ends to a common airflow pathway comprising a mouthpiece outlet through which a user inhales in use.

10. The aerosol provision system of any preceding claim, wherein the adjustment mechanism is electronically controlled, and wherein the aerosol provision system comprises a sensor configured to estimate the draw strength of the user inhalation and a controller configured to control the adjustment mechanism.

11 . The aerosol provision system of claim 10, wherein the controller is configured to further control the adjustment mechanism based on a user input.

12. The aerosol provision system of claim 11 , wherein controller is configured to select a discrete mode of operation based on the user input, where the controller is configured to decrease the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway in comparison to a normal mode to reduce a visibility of an aerosol produced by the aerosol generator.

13. A method of controlling an aerosol provision system comprising an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region, and a first air pathway passing through the aerosol generation region, a second air pathway not passing through the aerosol generation region, the method comprising: providing an adjustment mechanism configured to vary the ratio of the resistance-to- draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation; and adjusting the adjustment mechanism to vary the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway.

14. The method of claim 13, wherein adjusting the adjustment mechanism to vary the ratio of the resistance-to-draw of the first pathway to the resistance-to-draw of the second pathway comprises: estimating the draw strength of the user inhalation using a sensor; and controlling the adjustment mechanism based on the estimated draw strength using a controller.

15. A computer readable storage medium comprising instructions which, when executed by a processor, performs the method of claim 13 or claim 14.

16. Aerosol provision means comprising: aerosol generator means for generating an aerosol from an aerosol-generating material in an aerosol-generating region; a first air pathway passing through the aerosol generation region; a second air pathway not passing through the aerosol generation region; and adjustment means configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

17. An aerosol provision device for use with an aerosol generating article comprising aerosol generating material, which together form an aerosol provision system, wherein the aerosol provision system comprises an aerosol generator for generating an aerosol from an aerosol-generating material in an aerosol-generating region, a first air pathway passing through the aerosol generation region, a second air pathway not passing through the aerosol generation region, and an adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation, wherein the aerosol provision device comprises: circuitry configured to control the adjustment mechanism to cause the adjustment mechanism configured to vary the ratio of the resistance-to-draw of the first air pathway to the resistance-to-draw of the second air pathway based upon a draw strength of a user inhalation.

18. The aerosol provision device of claim 17, wherein at least a part of the first air pathway is provided in the aerosol provision device and/or wherein at least a part of the second air pathway is provided in the aerosol provision device, and wherein the adjustment mechanism is provided in the aerosol provision device and is arranged to vary the ratio of the resistance- to-draw of the first air pathway to the resistance-to-draw of the second air pathway by varying the resistance-to-draw of the at least a part of the first air pathway and/or the resistance-to- draw of the at least a part of the second air pathway.