An aerosol delivery controller and a method for controlling an aerosol delivery system

Abstract

A controller for an aerosol delivery system comprising an aerosol generator configured to generate aerosol from an aerosol-generating material using a power supply, the controller being configured to determine an accumulated puff duration for valid puffs within a predetermined time window, wherein a puff is only considered valid when power is supplied to the aerosol generator and / or airflow is detected for at least a threshold minimum time period.

Description

AN AEROSOL DELIVERY CONTROLLER AND A METHOD FOR CONTROLLING AN AEROSOL DELIVERY SYSTEMFieldThe present disclosure relates to aerosol delivery systems such as, but not exclusively, nicotine delivery systems (e.g. e-cigarettes). More specifically, the present disclosure relates to aerosol delivery controllers, systems and methods for preventing misuse / abuse.BackgroundAerosol delivery systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol generating material, such as a chamber of a source solid or liquid, which may contain an active substance and / or a flavour, from which an aerosol or vapour is generated for inhalation by a user, for example through heat vaporisation. Thus, an aerosol delivery system will typically comprise an aerosol generation area containing an aerosol generator, e.g. a heating element, arranged to vaporise or aerosolise a portion of precursor material to generate a vapour or aerosol in the aerosol generation area. As a user inhales on the device and electrical power is supplied to the vaporiser, air is drawn into the device through an inlet hole and along an inlet air channel connecting to the aerosol generation area, where the air mixes with vaporised precursor material to form a condensation aerosol. There is an outlet channel connecting the aerosol generation area to an outlet in the mouthpiece and the air drawn into the aerosol generation area as a user inhales on the mouthpiece continues along the outlet flow path to the mouthpiece outlet, carrying the aerosol with it, for inhalation by the user. Some electronic cigarettes may also include a flavour element in the air flow path through the device to impart additional flavours. Such devices may sometimes be referred to as hybrid devices, and the flavour element may, for example, include a portion of tobacco arranged in the air flow path between the aerosol generation area and the mouthpiece such that aerosol I condensation aerosol drawn through the device passes through the portion of tobacco before exiting the mouthpiece for user inhalation.It is of interest to develop approaches in which an aerosol delivery system comprises functionality to reduce the risk of misuse and / or abuse of the system by a user.Various approaches are described herein which seek to help address or mitigate at least some of the issues discussed above.TerminologyDelivery SystemAs used herein, the term “delivery system” is intended to encompass systems that deliver at least one substance to a user in use, and includes: combustible aerosol provision systems, such as cigarettes, cigarillos, cigars, and tobacco for pipes or for roll-your-own or for make-your-own cigarettes (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco substitutes or other smokable material); non-combustible aerosol provision systems that release compounds from an aerosolgenerating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials; and aerosol-free delivery systems that deliver the at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.Combustible Aerosol Provision SystemAccording to the present disclosure, a “combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is combusted or burned during use in order to facilitate delivery of at least one substance to a user.In some embodiments, the delivery system is a combustible aerosol provision system, such as a system selected from the group consisting of a cigarette, a cigarillo and a cigar. In some embodiments, the disclosure relates to a component for use in a combustible aerosol provision system, such as a filter, a filter rod, a filter segment, a tobacco rod, a spill, an aerosol-modifying agent release component such as a capsule, a thread, or a bead, or a paper such as a plug wrap, a tipping paper or a cigarette paper.Non-Combustible Aerosol Provision SystemAccording 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 delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system. 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. In some embodiments, the non-combustible aerosol provision system is an aerosol-generating 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 aerosolgenerating 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 aerosol-generating 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. In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosolgenerating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and / or an aerosol-modifying agent.Aerosol-Free Delivery SystemIn some embodiments, the delivery system is an aerosol-free delivery system that delivers at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.In some embodiments, the substance to be delivered may be an aerosol-generating material or a material that is not intended to be aerosolised. As appropriate, either material may comprise one or more active constituents, one or more flavours, one or more aerosol-former materials, and / or one or more other functional materials.Active SubstanceIn some embodiments, the substance to be delivered comprises an active substance. The active substance as used herein may be a 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.In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.As noted herein, the active substance may comprise one or more constituents, derivatives or extracts of cannabis, such as one or more cannabinoids or terpenes. As noted herein, the active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term "botanical" includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like.Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, Wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens.In some embodiments, the active substance comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is tobacco. In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from eucalyptus, star anise, cocoa and hemp. In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from rooibos and fennel.FlavoursIn some embodiments, the substance to be delivered comprises a flavour. 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 (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, Wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and / or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), 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, numbingeffect. 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.Aerosol-generating materialAerosol-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 or may not contain an active substance and / or flavourants. 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 100wt% of amorphous solid.The aerosol-generating material may comprise one or more active substances and / or flavours, one or more aerosol-former materials, and optionally one or more other functional material.Aerosol-former materialThe 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.Functional materialThe one or more other functional materials may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and / or antioxidants.SubstrateThe 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.ConsumableA 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 aerosolgenerating material to generate aerosol in use. The heater may, for example, comprise combustible material, a material heatable by electrical conduction, or a susceptor.SusceptorA 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.Aerosol-modifying agentAn 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 aerosol-modifying 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 aerosolmodifying agent may be in powder, thread or granule form. The aerosol-modifying agent may be free from filtration material.Aerosol generatorAn 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 aerosol-generating 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.The present disclosure relates to aerosol delivery systems (which may also be referred to as vapour delivery systems) such as nebulisers or e-cigarettes. 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 delivery system I device and electronic aerosol delivery system I device. Furthermore, and as is common in the technical field, the terms "aerosol" and "vapour", and related terms such as "vaporise", "volatilise" and "aerosolise", may generally be used interchangeably.Aerosol delivery systems (e-cigarettes) often, though not always, comprise a modular assembly comprising a reusable device part and a replaceable (disposable / consumable) cartridge part. Often, the replaceable cartridge part will comprise the aerosol generating material and the vaporiser (which may collectively be called a ‘cartomizer’) and the reusable device part will comprise the power supply (e.g. rechargeable power source) and control circuitry. It will be appreciated these different parts may comprise further elements depending on functionality. For example, the reusable device part will often comprise a user interface for receiving user input and displaying operating status characteristics, and the replaceable cartridge device part in some cases comprises a temperature sensor for helping to control temperature. Cartridges are electrically and mechanically coupled to the control unit for use, for example using a screw thread, bayonet, or magnetic coupling with appropriately arranged electrical contacts. When the aerosol generating material in a cartridge is exhausted, or the user wishes to switch to a different cartridge having a differentaerosol generating material, the cartridge may be removed from the reusable part and a replacement cartridge attached in its place. Systems and devices conforming to this type of two-part modular configuration may generally be referred to as two-part systems / devices.It is common for electronic cigarettes to have a generally elongate shape. For the sake of providing a concrete example, certain embodiments of the disclosure will be taken to comprise this kind of generally elongate two-part system employing disposable cartridges. However, it will be appreciated that the underlying principles described herein may equally be adopted for different configurations, for example single-part systems or modular systems comprising more than two parts, refillable devices and single-use disposables, as well as other overall shapes, for example based on so-called box-mod high performance devices that typically have a boxier shape. More generally, it will be appreciated certain embodiments of the disclosure are based on aerosol delivery systems which are operationally configured to provide functionality in accordance with the principles described herein and the constructional aspects of systems configured to provide the functionality in accordance with certain embodiments of the disclosure is not of primary significance.Brief summary of the inventionThe present invention provides a controller for an aerosol delivery system comprising an aerosol generator configured to generate aerosol from an aerosol-generating material using a power supply, the controller being configured to determine an accumulated puff duration for valid puffs within a predetermined time window, wherein a puff is only considered valid when power is supplied to the aerosol generator and / or airflow is detected for at least a threshold minimum time period.The present invention further provides a method for controlling an aerosol delivery system comprising an aerosol generator configured to generate aerosol from an aerosol-generating material using a power supply, comprising determining an accumulated puff duration for valid puffs within a predetermined time window, wherein a puff is only considered valid when power is supplied to the aerosol generator and / or airflow is detected for at least a threshold minimum time period. The present invention also provides a computer program product or computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the method.The present invention further provides additional embodiments as claimed in the dependent claims.The claimed invention generally provides a sub-assembly or sub-system suitable for use in an aerosol delivery system, or configured for use in an aerosol delivery system. The subsystem may generally form part of an aerosol delivery system and in particular may form part of the reusable device and / or the consumable cartridge.The clamed invention can help prevent a user from vaping excessively within a specific time window, helping to reduce or minimise vape misuse / abuse. At the same time, the claimed invention provides a cost-effective solution which may be retrofitted into existing systems, not necessarily requiring additional hardware.Brief description of the figuresEmbodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:Figure 1 is a schematic cross-section view of an aerosol delivery system in accordance with some embodiments of the disclosure;Figure 2 is a schematic diagram illustrating functions of a controller for an aerosol delivery system in accordance with some embodiments of the disclosure;Figure 3 is a schematic timeline illustrating the various stages in a puff-based interaction in accordance with some embodiments of the disclosure;Figure 4 is a schematic flow chart illustrating a process for preventing misuse of an aerosol delivery system in accordance with some embodiments of the disclosure; andFigure 5 is a schematic diagram illustrating a circular data array storing puff status data in accordance with some embodiments of the disclosure.Detailed description of the disclosureAspects and features of certain examples and embodiments are described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not described in detail in the interest of brevity. It will thus be appreciated that aspects and features of apparatuses and methods discussed herein whichare not described in detail may be implemented in accordance with any suitable conventional techniques.Figure 1 is a cross-sectional view through an example aerosol delivery system 1 in accordance with certain embodiments of the disclosure, providing an introduction to two-part aerosol delivery systems, the components therein and their functionality.The aerosol delivery system 1 comprises two main parts, namely a reusable part 2 and a replaceable I disposable consumable cartridge part 4. In normal use, the reusable part 2 and the cartridge part 4 are releasably coupled together at an interface 6. When the cartridge part 4 is exhausted or the user simply wishes to switch to a different cartridge part 4, the cartridge part 4 may be removed from the reusable part 2 and a replacement cartridge part 4 attached to the reusable part 2 in its place. The interface 6 provides a structural, electrical and airflow path connection between the two parts 2, 4 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 2, 4 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 2, 4. 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 2 and the cartridge part 4 is not needed. Furthermore, in some implementations the airflow through the electronic cigarette might not go through the reusable part 2, so that an airflow path connection between the reusable part 2 and the cartridge part 4 is not needed. In some instances, a portion of the airflow path may be defined at the interface between portions of the reusable part 2 and cartridge part 4 when these are coupled together for use.The cartridge I consumable part 4 may, in certain embodiments, be broadly conventional. 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 4 and provides the mechanical interface 6 with the reusable part 2. The cartridge housing 42 is generally circularly symmetrical about a longitudinal axis along which the cartridge part 4 couples tothe reusable part 2. In this example, the cartridge part 4 has a length of around 4 cm and a diameter of around 1.5 cm. However, the specific geometry and the overall shapes and materials used may vary.Within the cartridge housing 42 is a chamber or reservoir 44 that contains aerosolgenerating material. In the example of figure 1 , the reservoir 44 stores a supply of liquid aerosol generating material. In this example, the liquid reservoir 44 has an 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 I consumable part 4 further comprises an aerosol generator 48 located towards an end of the reservoir 44 opposite to a mouthpiece outlet 50. It will be appreciated that in a two-part system such as shown in figure 1 , the aerosol generator 48 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, which may be in the form of a wick and coil arrangement as shown, a distiller, which may be formed from a sintered metal fibre material or other porous conducting material, or any suitable alternative aerosol generator) may be comprised in the reusable part 2, and is brought into proximity with a portion of aerosol generating material in the cartridge part 4 when the cartridge part 4 is engaged with the reusable part 2. In such embodiments, the cartridge part 4 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 part 4 is engaged with the reusable part 2.In the example of figure 1 , a wick 46 in contact with the aerosol generator 48 extends transversely across the cartridge airflow path 52 with its ends extending into the reservoir 44 of the liquid aerosol generating material through openings in the inner wall of the reservoir 44. The openings in the inner wall of the reservoir 44 are sized to broadly match the dimensions of the wick 46 to provide a reasonable seal against leakage from the liquid reservoir 44 into the cartridge airflow path without unduly compressing the wick 46, which may be detrimental to its fluid transfer performance.The wick 46 and aerosol generator 48 are arranged in the cartridge airflow path 52 such that a region of the cartridge airflow path 52 around the wick 46 and heater 48 in effect defines avaporisation region 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 aerosol generator 48 in this example comprises an electrically resistive wire coiled around the wick 46. In figure 1, the heater 48 comprises a nickel chrome alloy (Cr20Ni80) wire and the wick 46 comprises a glass fibre bundle, but the specific aerosol generator configuration is not significant to the principles described herein. In use, electrical power may be supplied to the aerosol generator 48 to vaporise an amount of aerosol generating material (aerosol generating material) drawn to the vicinity of the aerosol generator 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 aerosol generator 48 will depend on the amount (level) of power supplied to the aerosol generator 48. Thus electrical power can be applied to the aerosol generator 48 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 aerosol generator 48, for example through pulse width and / or frequency modulation techniques.The reusable part 2 comprises an outer housing 12 having with an opening that defines an air inlet 28 for the e-cigarette, a power source 26 (e.g. a battery) for providing operating power for the electronic cigarette, control circuitry I controller 22 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 2, 4 at the interface 6. In this example, the reusable part 2 has a length of around 8 cm so the overall length of the e-cigarette when the cartridge part 4 and the reusable part 2 are coupled together is around 12 cm.The air inlet 28 connects to an airflow path 51 through the reusable part 2. The reusable part airflow path 51 in turn connects to the cartridge airflow path 52 across the interface 6 when the reusable part 2 and cartridge part 4 are connected together. Thus, when a user inhaleson the mouthpiece opening 50, air is drawn in through the air inlet 28, along the reusable part airflow path 51, across the interface 6, through the aerosol generation area in the vicinity of the aerosol generator 48 (where vaporised aerosol generating material becomes entrained in the air flow), along the cartridge airflow path 52, and out through the mouthpiece opening 50 for user inhalation.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.Optionally, first and / or 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 the aerosol generator 48.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 24 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 / or 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 1 to provide functionality as described herein, as well as for providing conventional operating functions of the aerosol delivery system 1. 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. 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).The controller 22 is preferably configured to prevent misuse / abuse of the system in accordance with the steps and processes as described further herein with reference to figures 2-5.The controller 22 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.The reusable part 2 comprises an airflow sensor 30 which is electrically connected to the controller 22. 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. In some embodiments, the airflow sensor 30 comprises a switch in an electrical path providing electrical power from the power source 26 to the aerosol generator 48. In such embodiments, the airflow sensor 30 generally comprises a pressure sensor configured to close the switch when subjected to a particular range of pressures, enabling current to flow from the power source 26 to the aerosol generator 48 once the pressure in the vicinity of theairflow sensor 30 drops below a threshold value. The threshold value can be set to a value determined by experimentation to correspond to a characteristic value associated with the initiation of a user puff. In other 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.In the example shown in figure 1, the airflow sensor 30 is mounted to a printed circuit board (PCB) 31 , but this is not essential. The airflow sensor 30 may comprise any sensor which is configured to determine a characteristic of airflow in an airflow path 51 disposed between air inlet 28 and mouthpiece opening 50, for example a pressure sensor or transducer (for example a membrane or solid-state pressure sensor), a combined temperature and pressure sensor, or a microphone (for example an electret-type microphone), which is sensitive to changes in air pressure, including acoustical signals. The airflow sensor 30 is situated within a sensor cavity or chamber 32, which comprises the interior space defined by one or more chamber walls 34. The sensor cavity 32 comprises a region internal to one or more chamber walls 34 in which an airflow sensor 30 can be fully or partially situated. In some embodiments, the PCB 31 comprises one of the chamber walls of a sensor housing comprising the sensor chamber I cavity 32.A deformable membrane is disposed across an opening communicating between the sensor cavity 32 containing the sensor 30, and a portion of the airflow path disposed between air inlet 28 and mouthpiece opening 50. The deformable membrane covers the opening, and is attached to one or more of the chamber walls according to approaches described further herein.As described further herein, the aerosol delivery system 1 comprises communication circuitry configured to enable a connection to be established with one or more further electronic devices (for example, a storage I charging case, and / or a refill I charging dock) to enable data transfer between the aerosol delivery system 1 and further electronic device(s). In some embodiments, the communication circuitry is integrated into controller 22, and in others it is implemented separately. For example, the communication circuitry may comprise a separate module to the controller 22 which, while connected to controller 22, providesdedicated data transfer functionality for the aerosol delivery device. In some embodiments, the communication circuitry is configured to support communication between the aerosol delivery system 1 and one or more further electronic devices over a wireless interface. The communication circuitry may be configured to support wireless communications between the aerosol delivery system 1 and other electronic devices such as a case, a dock, a computing device such as a smartphone or PC, a base station supporting cellular communications, a relay node providing an onward connection to a base station, a wearable device, or any other portable or fixed device which supports wireless communications.The controller 22, other components within the system 1 and other devices / systems may comprise one or more processors and data processing steps may be performed on any of these processors or on a remote processor, the data communicated by wire or wirelessly.Wireless communications between the aerosol delivery system 1 and a further electronic device may be configured according to data transfer protocols such as Bluetooth®, ZigBee, WiFi®, Wifi Direct, GSM, 2G, 3G, 4G, 5G, LTE, NFC, RFID, or generally any other wireless, and / or wired, network protocol or interface. The communication circuitry may comprise any suitable interface for wired data connection, such as LISB-C, micro-USB or Thunderbolt interfaces, and may comprise pin or contact pad arrangements configured to engage cooperating pins or contact pads on a dock, case, cable, or other external device which can be connected to the aerosol delivery system 1.The functionality of the controller 22 is now described in more detail with reference to figures 2-5.Figure 2 is a schematic diagram illustrating functions of a controller 22 for an aerosol delivery system 1 in accordance with some embodiments of the disclosure. As shown in figure 2, there are three key control aspects with sub-components, any of which may be performed individually (separately) or collectively by one or more controllers 22:1) Puff analysis, which may comprise one or more of: a. detecting puffs by the user; b. determining puff duration; c. determining if puffs valid; and d. determining the accumulated puff duration for valid puffs2) Power supply: controlling or preventing power supply to the aerosol generator 48 to generate aerosol e.g. via heating3) Indicate status: indicating a status of the system to the user, e.g. via LED, haptic feedback (motor) or buzzer / speaker.The ‘puff analysis’ stage is the first control aspect. In embodiments of the disclosure, the controller 22 is fundamentally configured to perform 1 d, i.e. determine an accumulated puff duration for valid puffs within a predetermined time window. In some embodiments, the same controller 22 may also be configured to perform one or more of 1a to 1c, i.e. to detect the puffs to be analysed and / or determine whether the / each puff is valid and / or determine the puff duration of at least valid (or, optionally, all) puffs before determining the accumulated puff duration for valid puffs, but any / all of this functionality 1a to 1c may be performed by another controller (e.g. with the data communicated to the controller 22) and so is not essential, core functionality.The puff duration defines the time between a ‘start’ and an ‘end’ of a puff and may be calculated in various ways, e.g. based on user or sensor input, or duration of power supply to generate aerosol for a puff, and these various ways are explained further with reference to figure 3 below. The accumulated puff duration is a sum of all (valid) puff durations within a predetermined preceding time window, which may be a rolling window, preferably of a relatively short duration, for example 1-60 minutes, 1-72 hours, 1-7 days.In accordance with the disclosure, a puff is only considered valid when either: power is supplied to the aerosol generator 48 for at least a threshold minimum time period (t min), and / or airflow is detected for at least a threshold minimum time period (tmin).Typically, any inhalation I puffing on an aerosol delivery system that is 0.3s or less in duration will not include a significant volume of aerosol (because normally, the system is unable to detect inhalation I puffing and then produce aerosol from the aerosol generator 48 within such a short timeframe) and therefore applying a minimum threshold time period (tmin) to ‘validate’ puffs discounts ‘puffs’ that are unlikely to provide aerosol to the user (e.g. stemming from false sensor readings, or when the user changes their mind and quickly stops inhaling), hence such interactions are not relevant for preventing I minimising misuse.Accordingly, the controller 22 for determining the accumulated puff duration for valid puffs may be configured to disregard puffs for which power is supplied to the aerosol generator 48 and / or airflow is detected for less than the threshold minimum time period (tmin) at any stageof the analysis. In some examples, the threshold minimum time period (tmin) is substantially 50 ms, 100 ms, 150 ms, 200 ms, 250 ms or 300 ms.The accumulated puff duration for valid puffs is used to prevent misuse / abuse of the system and is an input to the second ‘power supply’ control aspect shown in figure 2. In particular, the or another controller 22 may be configured to control power supplied to the aerosol generator 48, as shown in figure 2, if the accumulated puff duration within the predetermined time window is below a threshold accumulated puff duration; and / or prevent power being supplied to the aerosol generator 48 if the accumulated puff duration within the predetermined time window is at or above a threshold accumulated puff duration.Accordingly, the controller 22 permits further puffing if the accumulated puff duration within the predetermined time window is below a threshold, or prevents further puffing if the accumulated puff duration within the predetermined time window is at or above a threshold. The predetermined time window and threshold accumulated puff duration are explained further with reference to figure 3 below.The ‘power supply’ control aspect may optionally comprise pre-checks to determine if the system is ready for use. The pre-checks may include checking battery status (e.g. temperature, voltage) and / or aerosol generator temperature and are described further later with reference to figure 4.As illustrated in figure 2, the controller 22 may also provide a third ‘user feedback’ control aspect, configured to indicate a status of the system to the user. For example, the system may comprise a user interface (III) or a feedback device such as a LED, speaker / buzzer, display or haptic feedback. The Ul / feedback device may, for example, be configured to indicate normal operation and / or temporary disablement of power supply to the aerosol generator 48, dependent on the accumulated puff duration within the predetermined time window.Figure 3 is a schematic timeline illustrating the various stages in a puff-based interaction in accordance with some embodiments of the disclosure. The term ‘puff-based interaction’ encompasses all interactions that the user has with the system 1 where the system is not ‘idle’, including inhalation, thus defining the broadest ‘puff duration’.As illustrated in figure 3, there are multiple stages in a puff-based interaction, and there are multiple methods for calculating the puff duration in accordance with the disclosure. Whilst the terms puffing / inhaling may generally be used interchangeably, the puff duration andinhalation duration are not necessarily the same, since inhalation duration specifically refers to the time period in which the user is inhaling, whilst the puff duration may be considered to be slightly longer or shorter, e.g. based on the time for which power is supplied to the aerosol generator 48, or based on the user interacting with a III, as is explained further below with reference to figure 3.As shown, there are 4 key stages between the idle / inactive states at times to and ts respectively, defining the puff-based interaction between ti- These are:• t Start of inhalation (e.g. detected by the system I controller)• t2: Power supply starts• ts: End of inhalation (e.g. detected by the system I controller)• t4: Power supply ends t Start of inhalationThe start of inhalation may be detected by the system I controller 22 e.g. based on data from a ‘puff’ sensor. In particular, a sensor may be configured to detect airflow through the device (as described above with reference to figure 1) as the user inhales. Accordingly, data from the sensor(s) can be used to identify or detect the start (and / or equally the end) of inhalation.In some arrangements, the system comprises other sensors (e.g. a capacitive sensor may be used to detect contact with a user’s lips, optionally in combination with an accelerometer to detect a puffing orientation of the device) or a user input (e.g. a button) for a user to indicate their intention to puff, which may be used by the controller 22 to anticipate, determine or verify (e.g. cross-checking with sensor data) the start of inhalation and / or to conduct pre-checks to verify that the system is ready for power supply. Various such optional pre-checks are described further later with reference to figure 4. t2: Power supply startedAfter inhalation is detected, the system I controller 22 may supply power to the aerosol generator 48. In some systems, this may follow shortly (e.g. substantially immediately) after inhalation starts, assuming all applicable conditions are met (e.g. the accumulated puff duration within the predetermined time window is below a threshold accumulated puff duration).In other systems, particularly those without sensors to detect or a user input (e.g. a button) for a user to indicate an intention to puff, optional pre-checks may be conducted at this stage, prior to power supply, to verify that the system is ready, as detailed further below with reference to figure 4. t3: End of inhalationSimilar to the start of inhalation, the end of inhalation may be detected by the system I controller 22 e.g. based on data from a ‘puff’ sensor. For example, one or more of the capacitive sensor, accelerometer and / or airflow data may indicate that the user is no longer inhaling.In some arrangements, the system comprises a user input (e.g. a button) for a user to indicate they have finished puffing, which may be used by the controller 22 to determine or verify (e.g. cross-checking with sensor data) the end of inhalation. t4: Power supply endsAfter inhaling ends, the system I controller 22 may stop supplying power to the aerosol generator 48. This typically occurs substantially immediately after inhaling ends, to minimise energy use and consumption of aerosol-generating material.As outlined above, in embodiments of the disclosure, the controller 22 is configured to determine an accumulated puff duration for valid puffs within a predetermined time window, wherein a puff is only considered valid when power is supplied to the aerosol generator 48 for at least a threshold minimum time period (tmin) and / or airflow is detected for at least a threshold minimum time period (tmin).There are multiple methods for calculating the puff duration in accordance with the disclosure, including those illustrated in figure 3 and summarised below:• Pure airflow-based puff duration: ts-ti• Pure power-based puff duration: t4-t2• Combined airflow & power-based puff duration: t3-t2In examples, any combinations of the above methods for calculating the puff duration and threshold minimum time period (tmin) conditions may be used. Hence in some examples, theduration as defined by any one of the methods above must be > nto be considered a valid puff, else it is invalid and disregarded for the accumulated puff duration.Pure airflow-based puff duration reliably indicates the duration of inhalation of the user (Wi), since it is based on the sensed airflow. However, the duration of inhalation does not necessarily fully align with the receipt of aerosol by the user. In particular, whilst the user is inhaling between ti and t2 (as detected by airflow), any system pre-checks can delay the start of power supply after inhalation is detected and so in this period between ti and t2, assuming the aerosol generator 48 is cold (cold start), then no aerosol is being generated until (shortly after) power is supplied to the aerosol generator 48. Accordingly, depending on the exact configuration, a more accurate puff duration for indicating consumption of aerosol (generated from the aerosol-generating material) by the user may be based starting from t2, i.e. the start of power supply to the aerosol generator 48, rather than ti.In the reverse situation for establishing the end of receipt of aerosol by the user, in a typical airflow detection system, the user stops inhaling at t3and so the system I controller 22 stops supplying power substantially immediately (typically within 100-500 nanoseconds). Accordingly, unless there is a notable delay in stopping the power supply after inhalation stops (as detected by airflow), it is effectively immaterial as to whether time t3or t4 is used to determine the end of the puff, since t3and t4 are substantially the same - this delay is typically several orders of magnitude smaller than the puff duration (typically 0.5-5 seconds) and so effectively irrelevant.Accordingly, pure power-supply-based puff duration (t4-t2) indicates the time for which power is supplied to the aerosol generator 48 for a given puff, excluding the time t2-ti where the user is inhaling, but not receiving aerosol, and hence more accurately indicates the duration of aerosol generation by the system and inhaled by the user for each puff. Moreover, if the same controller 22 is also controlling the supply of power, the controller 22 can readily determine the power supply duration (e.g. based on timestamps) without needing to process sensor input, hence pure power-based puff duration determination may also be computationally less expensive than airflow-based puff duration.In some configurations, particularly with slower control cycles, an even more accurate puff duration can be calculated based on a combined airflow (inhalation) & power-based determination, i.e. the controller 22 may be configured to determine the duration of each valid puff based on the time for which power is supplied to the aerosol generator 48 between the start and the end of each inhalation e.g. as detected by the airflow sensor (i.e. t3-t2) , i.e.disregarding the time t4-ts for which power is supplied, but the user is not inhaling to receive aerosol. Alternatively, if the system comprises a user interface for the user to indicate when they are stopping puffing, used as the trigger to stop the supply of power but takes a short time period to become effective, then similarly, this indication might more accurately indicate the end of the puff than the slightly later end of power supply at t4.Following the above, applying the threshold minimum time period condition, in some examples a puff is only considered valid when power is supplied to the aerosol generator 48 for at least the threshold minimum time period between a start and an end of the puff (e.g. as indicated by the user using the III) and / or inhalation (e.g. for a valid puff, t3-t2s tmin).Figure 4 is a schematic flow chart illustrating a process for preventing misuse in accordance with some embodiments of the disclosure. In particular, figure 4 illustrates some pre-checks to determine whether or not the system 1 is ready for operation.The first pre-check comprises a ‘cool-down’ and involves the controller 22 determining if system components (e.g. the aerosol generator 48 and / or power supply 26) are within operating conditions e.g. temperature. If a temperature of the aerosol generator 48 and / or power supply 26 is / are at or above a temperature threshold then the controller 22 is configured to prevent the supply of power to the aerosol generator 48, otherwise the controller 22 controls the supply of power to the aerosol generator 48.The second pre-check comprises checking if the accumulated puff duration within the predetermined time window is below a threshold accumulated puff duration. This involves determining the accumulated puff duration for valid puffs within a predetermined preceding time window. The preceding time window may be a rolling window, preferably of a relatively short duration, for example 1-60 minutes, 1-72 hours, 1-7 days. The threshold accumulated puff duration may generally be substantially 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75% of the predetermined time window.In figure 4, the time window is 60 seconds (1 minute) and the threshold accumulated puff duration is 40 seconds, where if the accumulated puff duration is > 40s then power supply to the aerosol generator 48 is prevented, as per the cool-down pre-check, otherwise power is supplied to the aerosol generator 48 to generate aerosol for the user to inhale. The process shown in figure 4 is cyclic and repeated every time puffing is started or detected, hence the controller 22 is configured to repeatedly determine the accumulated puff duration for valid puffs within a rolling predetermined time window. This may comprise the steps of measuringthe duration of each puff, determining valid puffs by comparing to the threshold minimum time period and determining the accumulated puff duration for valid puffs within the rolling predetermined time window, as shown.Figure 5 is a schematic diagram illustrating a circular data array for storing puff status data in accordance with some embodiments of the disclosure. In general terms, the predetermined time window is divided into sub-windows. For each sub-window, a binary (one-byte) ‘valid puffing’ status is determined, indicating whether or not power was supplied to the aerosol generator 48 and / or airflow was detected for at least a threshold minimum time period during the sub-window. Then, the controller 22 determines the accumulated puff duration for valid puffs within the predetermined time window.This circular array arrangement beneficially minimises memory use for determining the accumulated puff duration, avoiding the need to calculate and sum precise start and end times for each puff.In this example, a one-minute time window is divided into 60 one-second intervals, where, for each interval, a power supply or airflow duration > 200ms is treated as ‘effective puffing’, with “1” assigned to that entry in the array, whilst a power supply or airflow duration < 200ms is treated as ineffective, with “0” assigned to that entry in the array. During each time interval, puffing status is checked against the threshold. puffing[x] = “1” or “0”, x= x+1 , while x = 1 if x > 60 puffing accumulation = puffing[1] + puffing[2] + puffing

[0060] At any point, if the accumulated ‘effective puffing’ duration is above a specific accumulated puff duration threshold, e.g. 30-45 or 40 seconds, then puffing is prevented by the system I controller.Of course, accuracy can be increased (at the expense of memory consumption) by utilising a smaller sub-window, ideally a factor / multiple of both the predetermined time window and the threshold minimum time period, e.g. of 1 s, 0.75s, 0.5s or 0.25s for a 60s window with a 250ms or 125ms threshold minimum time period, or 1s, 0.8s, 0.6s, 0.4s, 0.2s for a 60s window with a 200ms, 100ms or 50ms threshold minimum time period.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. Any functions of a processor (e.g. controller) may be shared between processors on the various devices / sy stems in the wider system and / or a remote server. 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. Protection may also be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure.Index to reference numerals1 aerosol delivery system2 reusable part4 cartridge part6 interface between reusable part and cartridge part12 reusable part housing14, 16 user input buttons20 user programming circuitry22 controller24 display26 power source28 air inlet30 airflow sensor31 printed circuit board (PCB)32 sensor cavity or chamber34 chamber wall42 cartridge housing44 chamber or reservoir46 wick48 aerosol generator50 mouthpiece outlet 51 airflow path through reusable part52 airflow path through cartridge

Claims

Claims1. A controller for an aerosol delivery system comprising an aerosol generator configured to generate aerosol from an aerosol-generating material using a power supply, the controller being configured to: a. determine an accumulated puff duration for valid puffs within a predetermined time window, wherein a puff is only considered valid when power is supplied to the aerosol generator and / or airflow is detected for at least a threshold minimum time period.

2. The controller of claim 1 , wherein the controller is configured to: a. determine a duration of each valid puff by the user; and b. determine the accumulated puff duration for valid puffs within the predetermined time window.

3. The controller of claim 1 or 2, wherein the controller is configured to: a. determine valid puffing by a user on the aerosol delivery system, wherein a puff is only considered valid when power is supplied to the aerosol generator for at least a threshold minimum time period; b. determine a duration of each valid puff by the user; and c. determine the accumulated puff duration for valid puffs within the predetermined time window.

4. The controller of any preceding claim, wherein the controller is configured to receive data from a puff sensor or a user input to detect or determine a start and / or an end of a puff.

5. The controller of any preceding claim, wherein, when determining the accumulated puff duration, the controller is configured to disregard puffs for which power is supplied to the aerosol generator and / or airflow is detected for less than the threshold minimum time period.

6. The controller of any preceding claim, wherein the threshold minimum time period is substantially 50 ms, 100 ms, 150 ms, 200 ms, 250 ms or 300 ms.

7. The controller of any preceding claim, wherein the controller is configured to determine the duration of each valid puff based on the time for which power is supplied to the aerosol generator for each puff.

8. The controller of any preceding claim, wherein the controller is configured to determine the duration of each valid puff based on the time for which power is supplied to the aerosol generator between the start and the end of each puff or inhalation.

9. The controller of any preceding claim, wherein a puff is only considered valid when power is supplied to the aerosol generator for at least the threshold minimum time period between a start and an end of the puff or inhalation.

10. The controller of any preceding claim, wherein the controller is configured to: a. control power supplied to the aerosol generator if the accumulated puff duration within the predetermined time window is below a threshold accumulated puff duration; and / or b. prevent power being supplied to the aerosol generator if the accumulated puff duration within the predetermined time window is at or above a threshold accumulated puff duration.

11. The controller of any preceding claim, wherein the controller is configured to: a. control power supplied to the aerosol generator if a temperature of the aerosol generator and / or power supply is / are below a temperature threshold; and / or b. prevent power being supplied to the aerosol generator if a temperature of the aerosol generator and / or power supply is / are at or above a temperature threshold.

12. The controller of claim 10, wherein the threshold accumulated puff duration is substantially 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75% of the predetermined time window.

13. The controller of any preceding claim, wherein the controller is configured to repeatedly determine the accumulated puff duration for valid puffs within a rolling predetermined time window.

14. The controller of claim 10 or any claim dependent thereon, wherein the threshold accumulated puff duration is 30-45 seconds or substantially 40 seconds in a rolling predetermined time window of substantially 60 seconds.

15. The controller of any preceding claim, wherein the controller is configured to: a. divide the predetermined time window into sub-windows; b. determine, for each sub-window, a binary valid puffing status, indicating whether or not power was supplied to the aerosol generator and / or airflow was detected for at least the threshold minimum time period during the subwindow; and c. determine the accumulated puff duration for valid puffs within the predetermined time window.

16. The controller of claim 15, wherein the sub-windows are substantially 1 second and / or the predetermined time window is a rolling predetermined time window of substantially 60 seconds.

17. The controller of any preceding claim, wherein the controller is configured to indicate a status of the system to the user.

18. An aerosol delivery system comprising the controller of any preceding claim.

19. A method for controlling an aerosol delivery system comprising an aerosol generator configured to generate aerosol from an aerosol-generating material using a power supply, comprising: determining an accumulated puff duration for valid puffs within a predetermined time window, wherein a puff is only considered valid when power is supplied to the aerosol generator and / or airflow is detected for at least a threshold minimum time period.

20. A computer program product or computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the method of claim 19.

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