EP4510864A1

EP4510864A1 - Aerosol provision systems

Info

Publication number: EP4510864A1
Application number: EP23715913.2A
Authority: EP
Inventors: Joseph Peter Sutton; Sally BELL; Samuel HOLTON; Toni ATTRILL; Jesse THISSEN; Krishna Prasad
Original assignee: Nicoventures Trading Ltd
Current assignee: Nicoventures Trading Ltd
Priority date: 2022-04-19
Filing date: 2023-03-27
Publication date: 2025-02-26
Also published as: GB202205700D0; CA3248281A1; WO2023203308A1; US20250268307A1

Abstract

The disclosure is directed to an electronic aerosol delivery device comprising: an aerosol generator configured to generate aerosol from an aerosol generating material, and a controller; wherein the controller is configured to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, wherein the controller is further configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

Description

AEROSOL PROVISION SYSTEMS

Field

The present disclosure relates to aerosol delivery systems comprising electronic aerosol delivery devices, as well as to circuitry and non-transitory tangible computer readable media, and devices comprising such circuitry and media for use in aerosol delivery systems.

Background

Aerosol delivery devices such as electronic cigarettes (e-cigarettes) generally contain a aerosol generating material, such as a reservoir of a source 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 heating or mechanical vaporisation. Thus, an aerosol provision device will typically comprise an aerosol generation chamber containing an aerosol / vapour 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 chamber. As a user inhales I puffs on the device and electrical power is supplied to the vaporiser, air is drawn into the device through one or more inlets and along an inlet air channel connecting to the aerosol generation chamber, where the air mixes with vaporised precursor material to form a condensation aerosol, or entrains existing aerosol generated by the aerosol generator. An outlet air channel connects from the aerosol generation chamber to an outlet in a mouthpiece section of the device, and the air drawn into the aerosol generation chamber as a user puffs on the mouthpiece continues along the outlet flow path to the mouthpiece outlet, carrying the entrained aerosol I vapour with it, for inhalation by the user.

Some aerosol delivery devices are configured to connect via a wired or wireless connection to one or more further devices of a wider delivery system, to exchange data with said devices. For instance, an aerosol delivery device may be able to establish a wireless data connection with an external computing device (e.g. a ‘smartphone’) in order to enable usage data acquired by the aerosol delivery device to be processed and / or displayed by a software application (‘APP’) running on the smartphone, or to receive control parameters or software updates from the smartphone / APP.

It is of interest to monitor an amount of aerosol precursor material (e.g. a liquid, gel, or solid aerosol precursor material) used during each of one or more puffs by a user on an aerosol delivery device of the general type described above. This may be considered advantageous for allowing a user to track an amount of aerosol precursor material used over one or more user puffs, and I or providing indications on an aerosol delivery device or external computing device relating to an amount of aerosol precursor material remaining for use in a cartridge and / or consumable contained in or otherwise configured for use with the aerosol delivery device. For instance, an aerosol delivery device may be configured for use with replaceable cartridges or articles, containing a predefined amount of aerosol precursor material. By tracking an amount (e.g. a mass) of aerosol generated (which may also be expressed as an amount of aerosol precursor material lost from the cartridge or article) during each of a plurality of user puffs associated with the cartridge or article, a user can be informed when the amount of aerosol generated / aerosol precursor material lost is within a predefined threshold amount of the initial amount of aerosol precursor material comprised in the cartridge. The inventors have recognised that approaches for determining an amount of aerosol precursor material generated during a puff can have limitations in terms of accuracy.

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

Summary

According to a first aspect of the present disclosure, there is provided an electronic aerosol delivery device comprising: an aerosol generator configured to generate aerosol from an aerosol generating material, and a controller; wherein the controller is configured to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, wherein the controller is further configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

According to a second aspect of the present disclosure, there is provided a method of operating an electronic aerosol delivery device comprising an aerosol generator configured to generate aerosol from an aerosol generating material, and a controller, the method comprising the steps of; causing the controller to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, causing the controller to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

According to a third aspect of the present disclosure, there is provided a non-transitory tangible computer readable medium having stored thereon software instructions that, when executed by circuitry comprised in a device of an aerosol delivery system, cause the circuitry to: receive data from an aerosol delivery device, the data comprising an indication of a level of power, P, supplied to an aerosol generator of the aerosol delivery device for each of a plurality of user puffs on the aerosol delivery device, and a first airflow parameter, A, associated with each of the plurality of user puffs; and estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

According to a fourth aspect of the present disclosure, there is provided a computing device for use with an aerosol delivery device; wherein the computing device comprises transceiver circuitry configured to receive data from the aerosol delivery device, the data comprising an indication of a level of power, P, supplied to an aerosol generator of the aerosol delivery device for each of a plurality of user puffs on the aerosol delivery device, and a first airflow parameter, A, associated with each of the plurality of user puffs; wherein the controller comprises controller circuitry configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

According to a fifth aspect of the present disclosure, there is provided an electronic aerosol delivery system comprising an aerosol delivery device and a computing device external to the aerosol delivery device, wherein the aerosol delivery device comprises an aerosol generator configured to generate aerosol from an aerosol generating material, a first controller, and first transceiver circuitry configured to transmit data to the computing device, and the computing device comprises a second controller and second transceiver circuitry configured to receive data from the aerosol delivery device; wherein the first controller is configured to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, and transmit this information to the computing device via the first transceiver circuitry; wherein the second transceiver is configured to receive the information from the aerosol delivery device, and the second controller is configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

Brief Description of the Drawings

Embodiments 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 diagram of an aerosol delivery device in accordance with some embodiments of the disclosure.

Figure 2 is a schematic diagram of a delivery system for use with an aerosol delivery device in accordance with some embodiments of the disclosure.

Figure 3 is a flow diagram detailing steps performed by circuitry of one or more devices of a delivery system in accordance with some embodiments of the disclosure.

Figure 4 is a schematic diagram showing exemplary profiles of power delivery to an aerosol generator of an aerosol delivery device, and a resulting rate of aerosol generation by the aerosol generator, during a user puff, in accordance with some embodiments of the disclosure.

Figure 5 is a schematic diagram showing an exemplary profile of airflow rate through an aerosol delivery device during a user puff, in accordance with some embodiments of the disclosure.

Figure 6 is a schematic diagram showing an exemplary profile of airflow rate through an aerosol delivery device during a user puff, in accordance with some embodiments of the disclosure.

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 I described in detail in the interests of brevity. It will thus be appreciated that aspects and features of apparatus and methods discussed herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.

The present disclosure relates to delivery system 1 comprising aerosol delivery device 10 (which may also be referred to as vapour delivery devices) such as nebulisers or e- cigarettes or tobacco heating products which generate aerosols by heating but not burning tobacco. 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 1 / device and electronic aerosol delivery system 1 / 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. In some embodiments, a delivery system 1 is a tobacco heating system, also known as a heat-not-burn system. In some embodiments, the delivery system 1 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 aero aerosol generating material. The solid aerosol generating material may comprise, for example, tobacco or a non-tobacco product. Meanwhile in some embodiments, the noncombustible aerosol provision system generates a vapour I aerosol from one or more such aerosolisable materials.

Aerosol delivery devices (e-cigarettes) often, though not always, comprise a modular assembly including both a reusable part and a replaceable (disposable) cartridge part. Often the replaceable cartridge part will comprise the aerosol generating material and the vaporiser and the reusable 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 part in some cases comprises a temperature sensor for helping to control temperature. Cartridges are electrically and mechanically coupled to a 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 different aerosol generating material, a cartridge may be removed from the control unit and a replacement cartridge attached in its place. Devices conforming to this type of two-part modular configuration may generally be referred to as two-part 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 described herein will be taken to comprise this kind of generally elongate two-part device employing disposable cartridges. However, it will be appreciated the underlying principles described herein may equally be adopted for different aerosol delivery device 10 configurations, for example single-part devices or modular devices comprising more than two parts, refillable devices and single-use disposable devices, as well as devices conforming to other overall shapes, for example based on so-called box-mod high performance devices that typically have a more boxy shape. More generally, it will be appreciated certain embodiments of the disclosure are based on aerosol delivery device 10 I systems which are operationally configured to provide functionality in accordance with the principles described herein and the constructional aspects of the aerosol delivery device 10 configured to provide the functionality in accordance with certain embodiments of the disclosure is not of primary significance.

Figure 1 is a cross-sectional view through an example delivery device 10 in accordance with certain embodiments of the disclosure. The delivery device 10 comprises two main components, namely a reusable part 2 and a replaceable / disposable 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 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 / 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.

The cartridge part 4 may in accordance with certain embodiments of the disclosure 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 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 may be 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. 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 plant material such as tobacco. 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. 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 glycerine, 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-generating 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 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 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 part may further comprise an aerosol generator 48 located towards an end of the reservoir 44 opposite to the mouthpiece outlet 50. 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 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.

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 cartridge 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 cartridge airflow path 52 around the wick 46 and heater 48 in effect defines a vaporisation 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 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 power level may be variable between upper and lower bounds by a user, such as between 2.5 and 6.5 watts.

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 (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 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 puffs I inhales on 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 region 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.

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 delivery device 10 on and off, initiating communication links with other electronic devices according to approaches set out further herein, 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 provide a user with a visual indication of various characteristics associated with the aerosol delivery device 10, for example current power setting information, remaining power source power, and information about an amount of aerosol generating material aerosolised during one or more puffs on the device, and I or remaining for use in a cartridge or article configured for use with the device, as determined using approaches described further herein. 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 device / system 10, 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 device / system 10.

A controller 22 is suitably configured / programmed to control the operation of the aerosol delivery device 10 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 device 10 in line with the established techniques for controlling such devices. The controller (processor circuitry) 22 may be considered to logically comprise various sub-units / circuitry elements associated with different aspects of the operation of the delivery device 10. 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 / 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 / chip(s) I chipset(s) configured to provide the desired functionality. In general, the controller 22 controls a level of power supplied to the aerosol generator, either through a predefined power delivery level or profile set in manufacture, and / or by allowing a user to change the power level I profile via input methods described further herein.

As described further herein, the aerosol delivery device 10 may optionally comprise communication I transceiver circuitry configured to enable a connection to be established with one or more further electronic devices to enable data transfer between the aerosol delivery device 10 and the further electronic device(s) in a delivery system 1. In some embodiments, the communication circuitry is integrated into controller 22, and in other embodiments it is implemented separately (comprising, for example, separate applicationspecific integrated circuit(s) / circuitry / chip(s) I chipset(s)). In some embodiments, the communication circuitry is configured to support communication between the aerosol delivery device 10 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 device 10 and other electronic devices according to known data transfer protocols such as Bluetooth, ZigBee, WiFi, Wifi Direct, GSM, 2G, 3G, 4G, 5G, LTE, NFC, RFID. More generally, it will be appreciated that any wireless network protocol can in principle be used to support wireless communication between the aerosol delivery device 10 and further devices of the delivery system 1. In some embodiments, the communication I transceiver circuitry is configured to support communication between the aerosol delivery device 10 and one or more further electronic devices over a wireless interface. This may be instead of or in addition to the configuration for wireless communications set out above. The communication circuitry may comprise any suitable interface for wired data connection, such as USB-C, micro-USB or Thunderbolt interfaces. More generally, it will be appreciated the communication circuitry, where included, may comprise any wired communication interface which enables the transfer of data, according to, for example, a packet data transfer protocol, and may comprise pin or contact pad arrangements configured to engage cooperating pins or contact pads on a dock, cable, or other external device which can be connected to the aerosol delivery device 10.

In some embodiments, 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 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 the airflow 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.

The aerosol delivery device 10 may further comprise other sensors, configured with connections to controller 22, which may provide controller 22 with signals / data relating to, for example, the geographical position of the aerosol delivery device 10 (e.g. using a GPS receiver), an orientation of the aerosol delivery device 10 (e.g. using one or more tilt sensors and / or accelerometers), a temperature of the aerosol delivery device 10 (e.g. using a thermocouple), an ambient light intensity in the vicinity of the aerosol delivery device 10 (e.g. using a photodiode), or a quantity of aerosol generating material in the aerosol delivery device 10 (e.g. using optical or capacitive sensing).

Referring now to Figure 2, the aerosol delivery device 10 (or more generally any delivery device as described elsewhere herein) may operate within a wider delivery system 1 I aerosol delivery system 1. Within the wider delivery system 1 , a number of devices may communicate with each other, either directly (shown with solid arrows) or indirectly (shown with dashed arrows). This system can otherwise be referred to as a delivery ecosystem I aerosol delivery ecosystem.

An example aerosol delivery device 10 such as an e-cigarette may communicate directly with one or more other classes of device including but not limited to a smartphone 100, a dock 200 (e.g. a recharging case or home refill and/or charging station), a vending machine 300, or a wearable device 400 (e.g. a smart watch). In a similar manner, the aerosol delivery device 10 such as an e-cigarette may communicate directly with another device of the same class, i.e. an aerosol delivery device. As noted above, these devices may cooperate in any suitable configuration to form a delivery system 1. This communication may be supported by wired communication circuitry of the aerosol delivery device 10 (for example, using an interface such as USB-C, micro-USB, Thunderbolt, or another wired communication interface as described further herein), or by wireless communication circuitry of the aerosol delivery device 10 (for example, a Bluetooth, ZigBee, WiFi, Wifi Direct, GSM, 2G, 3G, 4G, 5G, LTE, NFC or RFID module, or another wireless communication interface as described further herein). The aerosol delivery device 10 may be configured to connect to different ones of other classes of device using different wired or wireless communication protocols, and a data connection between the aerosol delivery device 10 and any given second device may be established using wired and / or wireless communication. It will be appreciated that other classes of device comprised in delivery system 1 may comprise communication circuitry for wired or wireless data transmission similar to that set out further herein in relation to the aerosol delivery device 10. Accordingly, a smartphone 100, a dock 200 (e.g. a home refill and/or charging station), a vending machine 300, a wearable device 400 (e.g. a smart watch) or a server may be equipped with communication circuitry comprising a Bluetooth, ZigBee, WiFi, Wifi Direct, GSM, 2G, 3G, 4G, 5G, LTE, NFC, RFID or other wireless transmission module, and / or a wired interface such as USB-C, micro-USB, Thunderbolt or other wired interface. Communication circuitry of the aerosol delivery device 10 (implemented as a single module or separate modules) may enable it to communicate with different ones of the further classes of device using different wired and / or wireless data transmission protocols. According to one non-limiting example, an aerosol delivery device 10 may be configured with communication circuitry enabling it to communicate data wirelessly with a smartphone 100 and a wearable device 400 over a Bluetooth interface, and in a wired manner with a dock / case 200 over a USB-C interface.

The aerosol delivery device 10 and other classes of device in the delivery system 1 may communicate directly or indirectly with a server 1000 via a network such as the internet 500. The aerosol delivery device 10 may establish such communication directly, using one of the wireless communication protocols described further herein to communicate with communication node / transceiver infrastructure (such as a ‘base station’ or ‘evolved node-B’ in LTE terminology) which provides connectivity with the server 1000 (e.g. over a backhaul communication link). Alternatively or in addition, the aerosol delivery device 10 may establish communication with the server 1000 via another device in the delivery system 1 , for example using a wired or wireless communication protocol to communicate with a smartphone 100, a dock / case 200, a vending machine 300, or a wearable device 400 which then communicates with the server 1000 (for example, via the internet 500) to either relay data to or from the aerosol delivery device 10, report upon its communications with the aerosol delivery device 10, or exchange information inferred about the aerosol delivery device 10 without a connection to the aerosol delivery device 10 being established. The smartphone 100, dock 200, or other device within the delivery ecosystem, such as a point of sale system / vending machine 300, may optionally act as a hub for one or more aerosol delivery devices 10 that only have short range transmission capabilities (provided, for example, by communication circuitry comprising a Bluetooth or RFID module). Such a hub may thus extend the battery life of an aerosol delivery device 10 whilst enabling data to be exchanged between the aerosol delivery device 10 and further devices of the aerosol delivery system 1 (for example, server 1000). The other classes of device in the aerosol delivery system 1 , such as the smartphone 100, dock 200, vending machine (or any other point of sale system) 300 and/or wearable 400 may also communicate indirectly with the server 1000 via a relay device, either to fulfil an aspect of their own functionality, or on behalf of the aerosol delivery system 10 (for example as a relay or co-processing unit). These devices may also transfer data with each other, either directly or indirectly via any of the wired or wireless communication protocols set out further herein.

A given first and second device of the delivery system 1 may generally be in either a connected or unconnected state. The unconnected state may also be referred to as an idle state, and in such a state a given first device may not be detectable by other second devices (i.e. the first device is not transmitting any signalling enabling its existence and / or identity to be determined), or it may be available for establishing a connection with a second device (i.e. it may be advertising its existence / identity using beacon I advertisement signalling). In a connected state, the first and second devices are configured such that data may be transferred from the first to the second device (e.g. ‘uplink’ transmission) and I or transferred from the second to the first device (e.g. ‘downlink’ transmission). Accordingly, establishment of a connection between a first and second device may be considered to comprise the establishment of any state wherein the two devices can exchange data, regardless of the direction of data transfer. Non-limiting examples of connected states are the establishment of an RRC connected state according to the Long Term Evolution (LTE) standard, or a bonded / paired state according to the Bluetooth standard. When a first and second device of the delivery system 1 are configured to communicate wirelessly, a transition from an unconnected to a connected state will generally follow a procedure such as the following. In an initial enquiry step, a first device (for example, an aerosol delivery device 10) establishes the existence of a second device (for example, a smartphone 100) by receiving a beacon signal or other identifying signal / message from the second device. In an authentication step, the first and second devices exchange messaging to establish information relating to the data transfer protocol to be used for exchanging data (for example comprising coding and encryption parameters to be used when exchanging data packets). In a data transfer step, the first and second devices transfer data over an air interface established in accordance with an agreed data transfer protocol (for example, Bluetooth, ZigBee, RFID, or other protocols described further herein). This data transmission may be bi- or unidirectional. The data communication process for wired communications may be broadly similar with the difference that data is transmitted over a wired interface as opposed to a wireless interface. Further aspects of implementation for establishment of wireless and wired communications may be found in the standard documents for communication protocols such as those listed further herein.

It will be appreciated that any two devices of the delivery system 1 (for example an aerosol delivery device 10 and a smartphone 100) may transition from an unconnected state to a connected state to exchange data for a variety of reasons. In general, a transition to a connected state between a first and second device of the delivery system 1 will be initiated because circuitry of the delivery system 1 described further herein determines data is available for transfer between the first and second device, for example, data relating to an amount of aerosol generated by an aerosol delivery device, a level of power supplied to the heater for each of a plurality of user puffs, as monitored by a controller of an aerosol delivery device, and I or an airflow parameter associated with each of the plurality of user puffs.

Turning to Figure 3, in accordance with aspects of the present disclosure, circuitry for the delivery system 1 comprising an aerosol delivery device is provided which is configured to carry out the following steps. In a first step S1 , the circuitry I controller is configured to monitor a level of power, P, supplied to a heater of an aerosol delivery device for each of a plurality of user puffs on the aerosol delivery device. In a second step S2, the circuitry is configured to monitor a first airflow parameter, A, associated with each of the plurality of user puffs. In a third step S3, the circuitry is configured to estimate an amount of aerosol generated by the heater during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A. These steps are described further herein. It will be appreciated herein that the terms ‘model’ and ‘equation’ may be used interchangeably, as ways to represent the expression of a dependent variable (i.e. aerosol amount), in terms of independent variables (i.e. at least a power parameter and an airflow parameter). It will be further appreciated that in the present disclosure, references to an ‘amount’ of aerosol may be described in terms of any metric known to the skilled person, for example, mass or volume, with unit conversions being carried out based on the skilled person’s knowledge of material properties (e.g. density) of the aerosol generating material.

In an aerosol delivery device 10, as described herein, aerosol is generated for user inhalation via an aerosol generator 48. In some embodiments, this is via heating of an aerosol generating material, causing elution of constituents of the aerosol generating material in the vapour phase. These constituents are eluted into an airflow channel 52, where they mix with air, causing droplets of condensation aerosol to form as the vapour cools. Formation of aerosol from vapour phase constituents may occur as vapour is drawn down the airflow channel 52 towards the mouthpiece 50, and may continue to occur as a mixture of aerosol and vapour enters the mouth of a user via the mouthpiece 50. The aerosol may additionally I alternatively comprise droplets directly drawn from the aerosol generator 48. In devices which generate aerosol from a solid or gel aerosol generating material, a wick may not be present, and vapour phase constituents may be eluted from a portion of aerosol generation material by direct aerosolisation I vaporisation of a supply of aerosol generating material. In other embodiments, aerosol may be generated mechanically, via for example, a piezoelectric aerosol generator 48 which forms aerosol droplets from aerosol generating material via an oscillating element such as a metal mesh, according to approaches known to the person skilled in the art.

An amount of aerosol generating material vaporised I aerosolised during one or more puffs by a user on the aerosol delivery device 10 may be referred to using a metric such as device mass loss (DML) or aerosol collected mass (ACM). DML may characteristically refer to an amount of aerosol generating material lost from a supply of aerosol generating material in an aerosol delivery device 10 as a consequence of aerosol generation. The DML may, as described further below, be determined for a given device under certain operating conditions, by measuring the mass of an aerosol delivery device 10 (or consumable part 4 alone) before and after one or more puffs, with the change in mass of the respective component being taken to equate to the amount of aerosol generating material lost from via aerosolisation. The ACM may characteristically refer to a mass of aerosol collected externally from the aerosol delivery device 10 during one or more puffs of the device. The ACM may, as described further below, be determined for a given device under certain operating conditions, by collecting aerosol in a laboratory aerosol analyser / puff analyser during one or more puffs carried out under controlled conditions of airflow (e.g. of airflow duration and airflow rate profile) by the aerosol analyser. Airflow rate profile may be expressed, for example, as a flow rate in ml / s, over time. The collected aerosol for a known number of one or more puffs (e.g. collected on a fibrous pad, or otherwise condensed out of the aerosol / vapour phase for analysis) is then weighed to determine its mass. It will however, be appreciated that ACM and DML are only two illustrative ways of quantifying an amount of aerosol generated during one or more puffs, and references herein to an amount of aerosol generated may apply to an amount of aerosol as determined by any suitable experimental method known to the skilled person. It will be appreciated that though the mass of aerosol generating material lost from the aerosol generator via aerosolisation may generally equate to an amount of aerosol received by a user, and / or lost from the aerosol delivery device 10, the mass lost and mass received may differ, for example, because of condensation of generated aerosol in or on parts of the aerosol delivery device, and I or in an aerosol analyser. What will be considered significant therefore is that an amount of aerosol for a puff, as discussed herein, generally refers to an amount of aerosol generated by an aerosol generator 48, regardless of what quantity of the aerosolised aerosol generating material generated during the puff is inhaled by a user or otherwise exits the aerosol delivery device 10. It will further be appreciated that references to a ‘heater’ herein may be taken to apply to other aerosol generators described herein.

It may be considered advantageous to track, monitor, or otherwise quantify an amount of aerosol generated from a supply of aerosol generating material by an aerosol delivery device 10 during one or more puffs of the aerosol delivery device. It will be appreciated that in some embodiments, the aerosol generating material may comprise a plurality of component materials, and the estimate of an amount of aerosol generated may comprise an estimated amount of a specific one or more of the component materials in the generated aerosol. In some embodiments the specific one or more of the component materials comprise(s) one or more active materials (such as nicotine), or one or more aerosol forming materials (such as PG and I or VG), or any other component material of an aerosol generating material for an electronic aerosol delivery system known to the skilled person. Thus according to embodiments of the disclosure, a controller 22 of the aerosol delivery device 10, and / or a controller 62 (not shown) of an external device such as a smartphone 100, a dock 200 (e.g. a recharging case or home refill and/or charging station), a vending machine 300, or a wearable device 400 (e.g. a smart watch), or a server 1000, is configured to determine an amount of aerosol generated during one or more puffs, on the basis of information about at least an amount I parameter of airflow through the aerosol delivery device 10 (and / or a consumable part of the aerosol delivery device) and an amount / level of power supplied to an aerosol generator 48 of the aerosol delivery device 10 during one or puffs. Thus an amount I mass / volume / quantity of aerosol generated may be determined with respect to a single puff, or a series of puffs (for example during a ‘session’ where a session refers to a set of puffs during a single, definable instance of use of the device). A ‘session’ as described herein may be characterised by sets of two or more puffs, where the elapsed duration between adjacent sessions is significantly longer than the elapsed duration between any two puffs in each session.

Though the term ‘puff’ may generally be considered to equate to a period during which a user is inhaling through an aerosol delivery device 10, it will be appreciated herein that it may also refer to a period during which aerosol is generated by an aerosol generator 48, whether or not this aerosol is entrained into a flow of air passing through the device, which may, though not always, equate to a period during which power is provided to an aerosol generator 48. However, in other instances, it may refer to an instance in which power is delivered to an aerosol generator 48. Thus determination of an amount of aerosol generated by an aerosol delivery device 10 during one or more puffs may comprise determination of an amount of aerosol generated within the aerosol delivery device 10 during periods which include durations of time when a user is not in fact drawing on the aerosol delivery device 10 to entrain the aerosol into a flow of air exiting the mouthpiece 50, but aerosol I vapour are nonetheless generated by the device 10.

The inventors have recognised that an amount of aerosol generated by an aerosol delivery device 10 during one or more puffs may be estimated on the basis of information about an airflow parameter associated with an amount of airflow through the aerosol delivery device 10 during the one or more puffs, and an amount of power delivered to an aerosol generator 48 of the aerosol delivery device 10 during the one or more puffs. In general, where the delivery rate of aerosol generating material to an aerosol generator 48 is not a limiting factor, delivery of a higher rate of electrical energy (i.e. higher power level) to the aerosol generator 48 will cause an increased rate of vapour I aerosol generation into a volume of air present in an airflow path 52 in which the aerosol generator 48 is in fluid communication. This may be the case, for example, because the aerosol generator 48 comprises a resistive heating element, such that higher power leads to a higher evaporation rate of aerosol generating material, or because the aerosol generator 48 comprises a piezoelectric actuator, such that higher power leads to a more rapid and / or higher-amplitude oscillation of an aerosol generating element (e.g. a metal or plastic mesh) of the aerosol generator 48, causing generation of larger aerosol particles and I or a higher rate of release of aerosol particles, such that a larger mass of aerosol is generated per unit time than at lower power.

The inventors have recognised that known approaches for attempting to estimate an amount of aerosol generated during one or more puffs on an aerosol delivery device 10 as described herein may lack accuracy. Thus according to embodiments of the present disclosure, there is provided an electronic aerosol delivery device comprising a heating element configured to generate aerosol from an aerosol generating material (otherwise referred to as a precursor material), and a controller, wherein the controller is configured to monitor a level of power, P, supplied to the heater for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, wherein the controller is further configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation or model wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

It will be appreciated herein that in some embodiments, any monitoring or estimating steps described may be carried out by a controller 62 of an external computing device, such as a smartphone 100, a dock 200 (e.g. a recharging case or home refill and/or charging station), a vending machine 300, or a wearable device 400 (e.g. a smart watch), or a server 1000, with data / information relating to these steps being provided to the external computing device by a controller 22 of an aerosol delivery device 10 over a wired or wireless data connection established according to approaches described further herein. Thus, though information relating to a level of power and I or an airflow parameter associated with one or more puffs of an aerosol delivery device 10 may be received by a controller 22 of the aerosol delivery device 10 during the one or more puffs, this information may be transmitted to a second controller 62 of an external device, such that the external device monitors the level of power and / or airflow parameter associated with the one or more puffs. Additionally, or alternatively, the controller 22 of the aerosol delivery device 10 may monitor one or both of these parameters during one or more puffs, and transmit data relating to them to the second controller 62 of the external device, such that the external device may use this data to estimate the amount of aerosol generated during the one or more puffs. The skilled person will thus appreciate that references herein to any operation carried out by the controller 22 of the aerosol delivery device 10 may in embodiments of the present disclosure be carried out by a second controller 62 comprised in an external computing device, with relevant data acquired by the controller 22 of the aerosol delivery device 10 being transmitted to the second controller 62 of the external computing device, and vice versa, via a data communication protocol established according to approaches described further herein (e.g. Bluetooth, ZigBee, WiFi, Wifi Direct, GSM, 2G, 3G, 4G, 5G, LTE, NFC, RFID, USB-C, micro- USB, Thunderbolt or any other data communication protocol I standard known to the skilled person).

Thus, according to embodiments of the present disclosure, the controller 22 of the aerosol delivery device is configured to monitor a level of power, P, supplied to an aerosol generator (e.g. heater) of the aerosol delivery device for each of a plurality of user puffs on the aerosol delivery device. This will generally be expressed in terms of watts, but it will be appreciated that references to monitoring power may in some embodiments comprise monitoring one of current and voltage, with the other of the two parameters determined separately. References to monitoring power herein may in some embodiments comprise monitoring energy supplied to the aerosol generator 48 over an aerosolisation time (e.g. an integral of power with respect to time over a power supply period). The controller 22 of the aerosol delivery device (or a separate controller) is in embodiments of the disclosure configured to supply electrical energy to an aerosol generator 48. Measurements of voltage across the aerosol generator 48 (e.g. measured using a voltage divider circuit known to the skilled person) may be used to monitor the level of power supplied to the aerosol generator, using the relationship P = I.V. where I is current measured via ammeter circuitry on a portion of the circuit suppling current to and from the aerosol generator from the battery, and V is the potential difference across the aerosol generator 48. Where a voltage divider circuit is used, the voltage across the aerosol generator 48 may be inferred from the voltage across a reference resistor wired in series with the aerosol generator 48. Voltmeter and ammeter circuitry, or functions corresponding to these components, may in embodiments be integrated I performed by the controller 22. Where the resistance, R, of the aerosol generator 48 is known, the power in watts delivered during supply of current to the aerosol generator 48 may be inferred by measuring one of current or voltage, with the other of these two parameters determined using one of the relationships V=I.R or l=V.R^-1. References to monitoring a level of power supplied to an aerosol generator during a puff may comprise monitoring of a power calculated at one or more points (e.g. at the point of maximum power delivery) during a puff using current and I or voltage measurements, or may comprise the value of a target level of power to be supplied by the controller 22 at said point(s), for example the set point power value(s), even if the actual power supplied to the aerosol generator 48 at said point(s) deviates slightly from this value, due, for example, to losses in the aerosol generator circuitry, varying aerosol generator resistance, or other factors known to the skilled person.

In some embodiments, control of the aerosol generator 48 is effected via a power control scheme in which the controller 22 targets a particular set-point or time-varying profile of power. In other embodiments, where the aerosol generator 48 comprises a heater, control of the aerosol generator is effected via a temperature control scheme, where the power supplied to the aerosol generator 48 is permitted to vary as the controller 22 seeks to maintain a target temperature or profile of temperature of the aerosol generator 48 (as inferred for example, by a thermocouple or other temperature sensor comprised in or located proximate to the heater), during supply of current to the aerosol generator 48. In some such embodiments, the temperature of a heater-based aerosol generator 48 is determined by the controller using the temperature coefficient of resistance of the heater, calculating the heater resistance using the relationship R = V.l’¹ and varying the power supplied to the heater to target a specific resistance value, and I or maintain the resistance within predefined upper and lower bounds, where the resistance value / range may be selected to correspond to an experimentally determined heater temperature / temperature range. Thus, in embodiments of the disclosure, the monitored power may comprise a level of power supplied according to a target power level or time varying power profile (e.g. the power is a target variable) or may comprise a level of power or time-varying power profile supplied as the controller 22 seeks to control a different parameter relating to the aerosol generator 48 (which may be temperature, but may also be, for example, current pulse frequency, or another variable known to the skilled person). A target power level, temperature level, or level of another control variable to use, or a profile of such a variable, may be a level or time-varying profile selected or set in manufacture of the device, or selected by a user, via, for example, an input device of the aerosol delivery device 10, or via an APP running on an external device such as a smartphone and transmitted to the aerosol delivery device.

Figure 4 shows, schematically, an exemplary profile of monitored heater power, P, (for example, in watts, on the leftmost Y axis) and aerosol generation rate (which may equate to a mass of aerosolisable materials vaporised / aerosolised by the aerosol generator 48 per unit time), G, (on the rightmost Y axis), over a time, t, in which an exemplary puff is taken (in respect of seconds, on the X axis). The solid profile shows an exemplary level of power delivered over a puff. It will be appreciated that the actual power profile, and maximum power, may be different for different devices and I or users, and thus in this example, the power is scaled by the maximum power. The actual maximum power may be, for example, between 1 and 10 watts, between 2 and 8 watts, between 2.5 and 6.5 watts, 6.5 watts, or any value appropriate to the skilled person, and I or resulting from the combination of power source, aerosol generator, and controller 22 used in the aerosol delivery device 22, and the power control scheme implemented by the controller 22. In the example of Figure 4, a timevarying power profile is implemented by the controller 22, whereby the power is controlled to rise linearly to a first dwell level (equating to 1 in the scale shown) for a first dwell duration (of approximately 0.5 seconds in this example), then drop down to a second dwell level (equating to 0.7 in the scale shown) for a second dwell duration (of approximately 1.8 seconds in this example), before the supply of power is switched off 2.5 seconds after being initiated. Time t=0, at which power supply to the aerosol generator is initiated, may equate to a time at which the controller 22 detects an input to an input device (such as a press of a button 14), or detects from an airflow sensor 30 that a user is puffing on the device, determines on this basis that there is a demand for aerosol, and initiates a supply of power to the aerosol generator 48 from a battery 26. The time at which power supply is stopped (i.e. at 2.5 seconds after initiation in this example) may equate to a predetermined period of time after initiation of power supply, which may be user selected, or predefined in manufacture, or a time at which a second input to an input device is detected (e g. release or a second press of button 14), or a time at which the controller 22 detects from an airflow sensor 30 that a user has stopped puffing on the device (e.g. a signal from airflow sensor 30 has dropped below a predefined threshold). The power profile of Figure 4 is exemplary, and in other embodiments may take any profile known to the skilled person, for example, comprising a single dwell period at a single maximum power, and / or a profile of differing duration. The dotted line shows an exemplary rate of aerosol I vapour generation (e.g. in terms of an amount of aerosol generating material released into the airflow passage 52 per unit of time) associated with the power profile. It will be appreciated that the relationship between power supplied to an aerosol generator 48 (for example, in terms of rate of power variation) and the rate of aerosol generation, be differently associated for different aerosol generators in different aerosol delivery devices 10. For example, depending on the thermal mass of the heater, the time taken for the heater to reach the aerosolisation temperature (or enter an optimal range of aerosolisation temperatures) of the aerosol generating material may mean that increases and decreases in aerosolisation rate may lag behind the rate of increase and decrease in power. Thus, as shown schematically in Figure 4, the exemplary aerosolisation rate reaches a maximum at a time delayed from the maximum power being reached, and falls to its second dwell level at a time delayed from the power reaching the second dwell level. Moreover, after the supply of power to the heater is cut off (at t=2.5 s in this example), it takes a further period of time (0.5 s in this example) for the aerosol generating rate to drop to zero. It will be appreciated the aerosol generation rate profile is exemplary, and will differ from that shown depending on the aerosol generator 48, the control scheme for power delivery, and the airflow through the device, among other factors known to the skilled person.

As described further herein, the controller 22 of the aerosol delivery device 10 (and / or controller 62 of an external device) is configured to monitor a level of power, P, supplied to the heater for each of a plurality of user puffs. With reference to the example of Figure 4 and accompanying description, this level of power may comprise a set-point of maximum power during a puff I single aerosolisation period, an average of the set-point power during a puff I single aerosolisation period, where this follows a time-varying profile, a maximum power during a puff / single aerosolisation period as measured by the controller as described herein, or a time-average of power during a puff I single aerosolisation period as measured by the controller as described herein. The level of power may also comprise an integral of power over time (e.g. a measure of energy dissipated by the aerosol generator 48) during a puff / single power delivery period. Herein, a level of power supplied to the heater during each of one or more puffs may be referred to by the parameter P. According to embodiments of the present disclosure, the controller 22 of the aerosol delivery device 10 (and I or controller 62 of an external device) is further configured to monitor a first airflow parameter, A, associated with each of a plurality of user puffs. Figure 5 shows schematically an exemplary profile of airflow rate through an aerosol delivery device 10 (or a consumable part / article thereof), scaled on the Y axis to the maximum airflow rate, with respect to time, on the X axis. At a time t=0 s, a user initiates inhalation on the device, with the airflow rate initially rising over a period of ~0.5 s, levelling off, then decreasing from ~1.7 s until the airflow rate returns to zero by around 3.0 s after puff initiation. It will be appreciated this profile is entirely exemplary, and in use, a user may take longer or shorter puffs, with differing profiles. According to embodiments of the disclosure, the controller 22 may monitor, via an airflow sensor 30, an airflow duration, comprising an elapsed time between an airflow parameter monitored by the controller meeting a first predefined condition, and the second airflow parameter meeting a second predefined condition following the first predefined condition being met. The controller 22 of the airflow delivery device 10 may be configured to receive input from an airflow sensor 30, indicative of an amount of airflow in an airflow passage I channel 52 of the aerosol delivery device 10, and to determine a duration of airflow during a puff by determining when the input from the airflow sensor 30 rises above a first threshold, and when the input from the airflow sensor 30 falls below a second threshold. In Figure 5, exemplary first and second thresholds take the same value of Athresh . Thus the controller 22 calculates the time between the input from the airflow sensor 30, indicative of airflow rate (e.g. an output of a pressure sensor, flow sensor, or microphone), rising above the first threshold, at time Ti, and falling below the second threshold, at time T₂. and in embodiments of the disclosure, stores this as an airflow parameter comprising an airflow duration T_a, given by T_a =T₂- Ti. In other embodiments, the controller 22 determines an airflow parameter comprising an integral of a parameter indicative of airflow rate (e.g. based on airflow sensor 30 output) which is representative of a volume of airflow during the airflow duration T_a. In other embodiments, the airflow parameter may comprise an average of airflow rate over the airflow duration T_a. In other embodiments, the airflow parameter may comprise a duration during which power is supplied to an aerosol generator 48 during a puff. In embodiments of the disclosure, the airflow parameter may comprise a predefined duration of time, selected based on an average duration of airflow during a plurality of puffs taken by one or more user. In embodiments of the disclosure, a supply of power to the aerosol generator 48 is initiated and stopped by the controller 22 by determining respectively when an input from the airflow sensor 30 rises above a third threshold, and when the input from the airflow sensor 30 falls below a fourth threshold. The airflow parameter comprising the input may be different to that used for determining the airflow duration, and may comprise, for example, an airflow rate or volume. In Figure 5, the third and fourth thresholds take the same value of Afresh, 2. Thus the controller 22 calculates the time between the input from the airflow sensor 30, indicative of airflow rate (e.g. an output of a pressure sensor, flow sensor, or microphone) rising above the third threshold, at time T3, and falling below the second fourth, at time T4, and in embodiments of the disclosure, stores this as a power supply duration T_p, given by T_p =T4- T3. Thus the controller may be configured to monitor a power delivery duration for each of the plurality of user puffs, the power delivery duration for each puff corresponding to a period of the puff during which power is supplied to the heater (i.e. T_p), and to separately determine an airflow duration over which the first airflow parameter, A, is monitored for each of the plurality of user puffs (i.e. T_a). In embodiments of the present disclosure, the first and third thresholds may be the same, and the second and fourth thresholds may be the same, such that the airflow duration T_a monitored by the controller 22 is the same as the power supply duration T_p, though in other embodiments the first and third thresholds may be different, and I or the second and fourth thresholds may be different. In the example of Figure 5, it will be noted that the controller is configured to supply power to the heater during a period, T_p, which is shorter than the airflow duration, T_a. In embodiments of the disclosure, the airflow parameter may comprise a duration of time obtained by adding a constant to the value of power supply duration T_p, with this duration determined following one of the approaches herein for determining a duration of power supply to an aerosol generator 48 associated with a puff. This constant may be determined experimentally to correspond to a period of time over which aerosol continues to be released from an aerosol generator 48 after a supply of power to the aerosol generator is stopped (e.g. arising for a heater due to the thermal mass of the heater causing aerosol to continue being released due to latent heat stored in the heater).

It will be appreciated that the initiation of a supply of power and stopping of a supply of power to an aerosol generator 48 by the controller 22 may be based on other conditions other than airflow sensing. For example, as described further herein, the first condition may respectively be detection of a first button press, and the second condition may be detection of a second button press or release of the button following the first button press. Figure 6 will be recognised from Figure 5, and shows the same exemplary airflow rate profile for a puff by a user. At time t=0 s, a user begins inhaling on the aerosol delivery device 10, drawing air through the airflow passage 52. At time t=Ts, ~0.25 s after inhalation begins, a user indicates via a user input (for example, a first button press) that controller 22 is to supply power to an aerosol generator 48. At time t=3 s, the user finishes inhaling. At t=T4, after the user finishes inhaling, the user indicates via another user input (e.g. a second button press, or release of a first button press) that the controller 22 should stop supplying power to the aerosol generator 48. Thus in the example of Figure 6, power is supplied by the controller 22 to the aerosol generator 48 over a power delivery duration T_p, which does not align with the start and end of user inhalation. However, in other examples, the power delivery duration may be aligned to the power delivery duration, or may be shorter or longer, beginning before or after the user begins inhaling. In some examples, power is supplied to the aerosol generator 48 without any airflow occurring through the device at all. This period may be considered a ‘puff’, despite the absence of airflow, since aerosol is nonetheless generated by the aerosol delivery device 10. It will also be appreciated that in all embodiments described herein, power may be delivered via pulsed approaches such as pulse width modulation (PWM) and I or pulse frequency modulation (PFM), where a supply of current to the aerosol generator is switched on and off by a controller at a fixed or varying frequency, and where the width of the current ‘on’ pulses is modulated by the controller to increase or decrease a level of power supplied to the aerosol generator. Such approaches are known to the person skilled in the art. Thus references herein to a ‘level’ of power provided at a given point in time, or over a period of time, may refer to an average level of power for a period centred on said point or over said period, where the average power (calculated for example as P = I.R) represents the time average of the power over a period in which the current is pulsed on and off as set out above. Thus the same level of power can be provided to the aerosol generator by either providing a continuous current of X amps, or by providing pulses of 2.X amps, where the pulse width is set to a duty cycle of 50% (i.e. where the current is on for half of the duration of each pulse width).

Thus as described above, the controller 22 of the aerosol delivery device 10 (and / or a controller 62 of an external device) is configured to monitor an airflow parameter, A, and a power level, P, during each of one or more puffs. This information is used by the controller 22 I 62 to estimate an amount of aerosol generated during the one or more puffs according to approaches set out herein. In embodiments of the disclosure, the amount of aerosol is determined by the controller 22 / 62 using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A. In embodiments of the disclosure, the first term comprises a product of P, A, and a constant, a. In embodiments of the disclosure, the second term does not comprise A, and may comprise a product of P and a constant, b. Alternatively, the second term does not comprise P, and may comprise a product of A, and a constant, b. In embodiments of the disclosure, the plurality of terms comprises a third term, comprising a function of at least one of P and A, and may not comprise A, for example comprising a product of P and a constant, c, or may not comprise P, for example comprising a product of A and a constant, c. In embodiments of the disclosure, the plurality of terms comprises a fourth term, comprising a constant, d. In other embodiments of the disclosure, the first term comprises a different function of at least one of P and A, for example, an integral with respect to time of a product of P, A, and a constant. The second term may also comprise an integral with respect to time of a product of at least one of P, A, and a constant (for example an integral with respect to time of a product of P and a constant, or of a product of A and a constant).

The inventors have recognised that particular selection of terms for a model / equation for aerosol amount estimation associated with aerosol delivery devices configured as described herein can provide greater accuracy and / or flexibility in estimation of an amount of aerosol generated by an aerosol generator 48 during a puff on an aerosol delivery device 10. Whilst a term comprising a function (e.g. a product) of P and A may approximate some of the aerosolisation dynamics of an electrical aerosol generator 48 during a puff, in terms of their effect on an amount of aerosol generated, other terms may be needed to more closely model the aerosol generation dynamics. Whilst not wishing to be bound by any particular physical theory, it is thought that this may be because (as shown schematically in the examples of Figures 5 and 6, and the supporting text) aerosolisation may occur outside a period of time in a puff when air is flowing past the aerosol generator 48 (i.e. when the airflow rate through the device is zero, and an airflow parameter, A, may be zero), and alternatively, or additionally, aerosolisation may occur during periods of time in which power has ceased to be provided to the aerosol generator 48, but in which airflow is still occurring through the device 10. Accordingly, the inventors have recognised that the use of terms which are not functions of A and P may be advantageous when seeking to more accurately estimate a mass of aerosol generated by an aerosol generator 48.

In embodiments of the present disclosure, experimental data describing the mass of aerosol generated during each of one or more puffs, under known conditions of power level, P, and airflow parameter, A, may be used to determine a suitable form of equation to use for estimating a mass of aerosol generated in one or more future puffs based on information about the power level and airflow parameter associated with each of the one or more future puffs, and monitored by the controller 22 / 62. These experimental data may be derived according to any approach known to the skilled person. An exemplary, non-limiting procedure for deriving experimental data and establishing a model / equation for estimating an amount of aerosol generated during each one of a plurality of puffs, based on a level of power, P, supplied to the heater for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, is set out below. An experimental procedure was carried out to determine aerosol collected mass (ACM) and device mass loss (DML) for an aerosol delivery device 10 as shown schematically in Figure 1 , the procedure comprising a plurality of tests during which a block of puffs were taken on the aerosol delivery device 10. The aerosol delivery device 10 comprised a consumable I cartridge part 4, comprising a supply of aerosol generating material in liquid form within a reservoir 44, the supply of aerosol generating material comprising 2.24 g (1.95 ml) of liquid, comprising an aerosol forming base of 50 wt% vegetable glycerine (VG) and 50 wt% propylene glycol (PB), the liquid also comprising a quantity of nicotine (1.6 wt% in this example), and a small quantity of flavouring compounds. A fresh cartridge / consumable part 4 was used for each test. A battery 26 of the device 10 was fully charged prior to each test, and the device connected to a laboratory aerosol analyser / puff analyser, known to the skilled person, configured to draw air through the device 10 via mouthpiece outlet 50, and condense the liquid from the aerosol onto a fibrous (e.g. cotton or glass-fibre) pad of known dry mass. The aerosol delivery device 10, with cartridge 4 attached to the reusable device part 2, was weighed prior to each test. Each test was run using predefined puff blocks of 25 simulated inhalations, being carried out under controlled conditions, comprising a controlled predefined volume of air being drawn through the aerosol delivery device, for a controlled predefined puff time duration (i.e. duration of each simulated inhalation), with a controlled predefined interval between each puff / simulated inhalation. A block of 25 puffs under the same simulated inhalation conditions was run, for each of 5 sub-tests, each sub-test being carried out at respective heater power levels of 2.5 W, 3.5 W, 4.5 W, 5.5 W, and 6.5 W. The sub-test power levels were the same for each of the 5 tests, the conditions for the 5 tests differing only in respect of the puff block parameters programmed into the puff analyser, these being as follows:

• Test 1 - 25 puffs / simulated inhalations, with volume (ml), puff duration (s), and inter-puff interval (s) of 18.5:1:30.

• Test 2 - 25 puffs / simulated inhalations, with volume (ml), puff duration (s), and inter-puff interval (s) of 37:2:30.

• Test 3 - 25 puffs / simulated inhalations, with volume (ml), puff duration (s), and inter-puff interval (s) of 55:3:30.

• Test 4 - 25 puffs / simulated inhalations, with volume (ml), puff duration (s), and inter-puff interval (s) of 74:4:30.

• Test 5 - 25 puffs / simulated inhalations, with volume (ml), puff duration (s), and inter-puff interval (s) of 92.5:5:30. Each sub-test (each conducted at a different predefined power level, as set out above) was run for 10 replicates. The aerosol delivery device 10 was weighed before and after each puff block, to determine the mass lost during the puff block (i.e. the puff block DML). A fresh cotton test pad (pre-weighed) was loaded into the puff analyser before each puff block. After each puff block, the fibrous / glass-fibre pad (e.g. Cambridge filter pad or ‘CFP’), having received aerosol drawn into the puff analyser from the aerosol delivery device during the puff block, was removed from the puff analyser and weighed to determine the mass gain during the puff block (i.e. the puff block ACM).

The data collected via the experimental approach outlined herein were analysed, to determine a per-puff ACM and per-puff DML value for each puff block, via averaging of puff block ACM and puff block DML values over the 25 puffs in each block, and over the 10 replicates for each block. Thus a per-puff ACM and per-puff DML value were separately obtained for each of the 5 power levels described above, under each of the 5 inhalation regimes described above. For these DML and ACM values of each puff (i.e. the amount of aerosol generated), the associated power level, P, was determined to be the set-point power assigned by the controller 22 of the aerosol delivery device 10 of the associated puff block (respectively 2.5 W, 3.5 W, 4.5 W, 5.5 W, or 6.5 W). The associated airflow parameter, A, was determined to be the per-puff simulated inhalation time of the associated puff block (respectively 1 , 2, 3, 4, or 5 s).

A form of model was selected, based on physical observations detailed further herein, which incorporated at least a first term, comprising a function of P and A, and a second term, comprising a function of at least one of P and A. In this example, a model I equation was fitted to the data which comprised a generalised linear model of the form M = A.P.a + A.b + P.c + d, where M is the amount of aerosol generated in the puff, A is the airflow duration of the puff, P is the target power level associated with the puff, and a, b, c, and d, are constants. A fitting procedure was carried out for aerosol amounts (M), as the dependent variable, with fits being separately carried out for M experimentally determined using each of ACM and DML. Effects of terms in fitting the model were considered significant if the p- values (Type 3 SS) for the effects were below the significance level (a) of 0.05. The fitting and analysis of significance was carried out by means of a Generalised Linear Model in SAS™ v9.4 software using the PROC GLM procedure. Following fitting of the initial generalised linear models, separately for ACM and DML derived values of M, stepwise models (backwards and forwards) were conducted to assess whether adding or removing terms from the model improved the fit to the experimental data, but no fits with improved significance were found. Model residuals were assessed for conformance to normality assumptions and general model fit. Both the ACM and the DML models had appropriate fits and passed the normality assumptions, but the assessment showed a better fit for the ACM- fitted model (adjusted R² = 0.9861) compared to the D L-fitted model (Adjusted R² = 0.9849). Each of the terms, A.P.a, A.b, and P.c, contributed significantly to the model fit, with a significance of <0.0001 in each case (relative to a significance level (a) of 0.05). Both models (the ACM-fitted model and the D L-fitted model) performed better than a model for M expressed only a term in terms of a product of P and A, and a constant term (R² = 0.9563). For the sake of providing a concrete example of coefficients for an equation as set out above, in one non-limiting example, an experimental fitting procedure was applied to an aerosol delivery device with an aerosol generator comprising a resistive heater with power adjustable between 2.5 W and 6.5 W, and configured to aerosolise an aerosol generating material comprising a liquid formed of a 50:50 ratio of PG to VG, with some flavourant material and some nicotine. The resulting ACM-fitted model based on the above experimental procedure was M = A.P.a + A.b + P.c - d, where a = 0.61156, b = -1.17366, c = -0.432436, and d = 0.757084, where M is the mass of aerosol per puff, P is the target power per puff (in Watts), where the target power was constant across each puff, and A is the puff duration (in seconds).

It will be appreciated that where a generalised linear model of the form above is used to estimate the amount of aerosol generated in each puff, the values of the coefficients a, b, c, and d, will typically be determined for a specific type of aerosol delivery device for which the amount of aerosol per puff is to be estimated, and the values of the coefficients may be different depending on a type of aerosol generating material. Thus separate equations / models may be determined for different types of aerosol delivery device and / or different aerosol generators, and / or different aerosol generating materials. Where a specific type of aerosol delivery device is configured for use with different types of aerosol generating material, a suitable equation with coefficients fitted for a specific one of the types of aerosol generating material may be selected based on a predefined relationship between the equation and the type of aerosol generating material (for example, stored in the controller of the aerosol delivery device, and / or in a controller of an external computing device, and I or in an APP). A user may provide input to the aerosol delivery device / external computing device / APP to indicate a type of aerosol generating material to be used, or the aerosol delivery device / external computing device / APP may automatically determine the type of aerosol generating material by, for example, reading an identifier associated with a consumable for the aerosol delivery device or its packaging. On the basis of the determined type of aerosol generating material, the aerosol delivery device / external computing device I APP may select the a predefined equation, and / or select a corresponding set of coefficients for an equation, where the equation I coefficients have a predefined relationship with the determined type of aerosol generating material. Where the estimation is carried out on an external computing device / APP, the same principle may be applied to selection of a suitable equation / coefficients to use for one of a plurality of types of aerosol delivery device which are configured to establish a data connection with the external computing device I APP.

It will be appreciated that the example given above may be modified in any appropriate way according to the knowledge of the skilled person, for example, in terms of the experimental parameters used to obtain data (e.g. in terms of puffs regime parameters such as puff volume, puff duration, and inter-puff interval, the power supplied to the heater in terms of a set point or actual supplied value, the composition of the aerosol generating material used, the type of aerosol delivery device 10, and the type of aerosol generator 48 used), and the means of determining a fitted model using an equation / expression / model, where an amount of aerosol generated per puff is expressed as a sum of a plurality of terms, the plurality of terms comprising a first term, comprising a function of P and A, and a second term, comprising a function of at least one of P and A (for example in terms of the software tools used to build and refine the model). It will be appreciated that machine learning approaches such as a neural network may be used to determine an appropriate model, using the amount of aerosol as a dependent variable, and a power level and airflow parameter, optionally including one or more constants and other variables selected by the skilled person, as a dependent variables, and training the model using data of the type described above, relating the aerosol mass to the dependent variables for a specific aerosol delivery device 10 and type I composition of aerosol generating material. It will be appreciated that in place of target power and airflow duration, any of the power level and airflow parameters described herein may be used in fitting the model, with the experiment used to obtain fitting data being modified to obtain power level and airflow parameter data corresponding to these parameters.

The fitted model can be loaded onto the controller 22 / 62 of the aerosol delivery device or external computing device (e.g. via a firmware or software update) and used by the controller to estimate an amount of aerosol generated in each puff of a plurality of puffs by inputting values of power level, P, and airflow parameter, A, to the model / equation. The amount of aerosol estimated to be generated during each of a plurality of puffs may be used by the controller 22 (and / or controller of an external device 62) in different ways, as described further herein. In embodiments of the disclosure, the controller 22 / 62 is configured to sum the estimated amount of aerosol generated per puff, over a plurality of puffs, and use this sum of aerosol generated to provide indications to a user relating to an amount of aerosol used and / or an amount of aerosol remaining for use. This information may be displayed via a display 24 associated with the aerosol delivery device 10, or via an audible or haptic indication. For example, when the amount of aerosol generated (expressed, for example, in terms of mass or volume) since a monitoring start time reaches a predefined amount, an indication expressing the amount may be provided. For example, the predefined amount may be a certain mass or volume of aerosol generating material (e.g. 0.1 , 0.2, 0.5, 1 , or 2 grams or millilitres) estimated to have been generated since the monitoring start time. The controller may convert between mass and volume using information about the density of the aerosol generating material provided for aerosolisation within a consumable. For example, in some consumables, the aerosol generating material comprises a mix of propylene glycol (PG) and vegetable glycerol (VG), and optionally a known quantity of a known active substance, and optionally a known quantity of one or more flavourant compounds, for which the density can be experimentally determined. For example, an aerosol generating material provided in a consumable may comprise a 50:50 mixture of PG and VG, with a known quantity of nicotine and a known quantity of flavourant compounds, with a density of 1.15 g / ml. The predefined amount of aerosol generating material may correspond to an amount of aerosol generating material supplied in a consumable configured for use with the aerosol delivery device 10, with the monitoring start time for summing the amount of aerosol estimated to be generated being triggered when an unused and / or freshly filled consumable is initially used with the aerosol delivery device (e.g. the user may provide input to an input device of the aerosol delivery device 10, or to an APP on an external computing device to indicate a new consumable has been or is about to be attached to the aerosol delivery device 10 for use). Alternatively, the controller 22 of the aerosol delivery device may use a sensor to detect when an unused or freshly filled consumable is attached to the aerosol delivery device 10 for use, for example by reading a unique optical identifier on a surface of the consumable. As well as indicating when a predefined amount of aerosol (e.g. equivalent to an amount of aerosol generating material comprised in an unused or freshly filled consumable) has been estimated to have been generated, the controller 22 162 may also trigger an indication at each of a set of time points at which the sum of the amount of aerosol generated since the monitoring start time reaches a predefined amount, where each of the time points equates to a time at which the amount reaches a predefined fraction of the predefined initial amount of aerosol generating material associated with the consumable at the start of the monitoring period (for example, at each of 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100% of the predefined amount). The predefined amount may be defined as an experimentally derived value which is less than the actual amount of aerosol generating material comprised in the aerosol delivery device 10 (and / or a consumable configured for use with the aerosol delivery device 10) at the start of the monitoring period, which may be referred to as an expected maximum aerosol generating material availability. The expected maximum aerosol generating material availability may be determined experimentally as the actual amount of aerosol derivable from a supply of aerosol generating material present in the aerosol delivery device 10 (and / or a consumable configured for use with the aerosol delivery device 10) before no further aerosol is derivable from the aerosol delivery device 10 (e.g. via analysis of ACM according to approaches described herein). The difference between the expected maximum aerosol generating material availability and the actual amount of aerosol generating material available in the aerosol delivery device 10 (and / or a consumable configured for use with the aerosol delivery device 10) may be accounted for by trapping of aerosol generating material in regions of a reservoir 44 where it cannot be transported to the aerosol generator 48, and I or condensation of aerosol within the aerosol delivery device 10 (e.g. in an airflow passage 52). Experimental determination of the expected maximum aerosol generating material availability may be carried out in the following exemplary manner. An aerosol generating device with a freshly filled I unused supply of aerosol generating material may be connected to an aerosol analyser as described further herein, programmed to take puffs in blocks of 25 puffs, using one of the sets of puff parameters set out in Tests 1 to 5 above. The D L is determined after each puff block, using approaches set out above. After the DML for a puff block n drops to below 25% of the DML for the first puff block, the cumulative DML from the start of the experiment to a time after block n and before block n+1 may be taken to be the expected maximum aerosol generating material availability for an aerosol generating device with a freshly filled I unused supply of the same aerosol generating material (e.g. where the aerosol generating material is supplied in a cartridge, and a nominal amount, for example 2 ml, of liquid aerosol generating material is provided in a freshly filled and I or unused cartridge, the expected maximum aerosol generating material availability as determined according to the above experimental approach, may be, for example, less than 95%, less than 90%, less than 85%, less than 80%, or less than 75%, of the nominal amount).

The controller 22 / 62 may determine when the amount of aerosol generated during a monitoring period, starting when a known, predefined quantity of aerosol generating material is available for aerosolisation (e.g. comprised in a consumable), has reached a predefined proportion of the predefined quantity, and use this information to trigger one or more further functions. For example, when the amount of aerosol generated during a monitoring period is equal to the amount of aerosol generating material comprised in the aerosol delivery device 10 (and / or a consumable configured for use with the aerosol delivery device 10) at the start of the monitoring period, and / or the amount of aerosol generating material corresponding to the expected maximum aerosol generating material availability, or is within 1%, 5%, 10%, 20%, or some other predefined threshold of this amount, the controller 22 may determine that the consumable and / or aerosol generating material which started to be used at the start of the monitoring period has been fully used, and may indicate this to a user via a display 24 of the aerosol delivery device 10, and / or a display of an external computing device. Optionally, the controller 22 may prevent delivery of power to the aerosol generator 48 when this point is reached, until an indication is received that a new and / or filled consumable has been coupled to the aerosol delivery device 10 for use. Based on the determination that the supply of aerosol generating material has been fully used, the controller 22 may also reset the summing of the estimated amount of aerosol generated, in other words, beginning a new monitoring period, and may re-initialise the amount of aerosol generating material determined to be available for aerosolisation (based on the assumption the user will attach a new consumable for use, and / or otherwise refill I replenish a supply of aerosol generating material available to the aerosol delivery device 10). The new monitoring period may also be manually triggered by a user, via an input on the aerosol delivery device 10 or an external device (e.g. via an APP).

In embodiments of the disclosure, the known, predefined quantity of aerosol generating material determined by the controller 22 I 62 to be available for aerosolisation at the start of the monitoring period may be based on an amount of aerosol generating material (and / or amount of aerosol generating material corresponding to the expected maximum aerosol generating material availability) associated with a plurality of consumables. For example, the controller 22 / 62 may determine based on ordering information associated with an APP, or by other inputs to the aerosol delivery device 10 or an external computing device, that a user has an inventory of a certain integer number of consumables available for use (for example, 1 , 2, 3, 4, 5, 10, 15, or any other number), each of which comprises a known, predefined amount of aerosol generating material. The inventory information may be updated when a user purchases or otherwise acquires further consumables (e.g. via user input, or automatically via ordering information associated with an APP). Thus at a first time, T_a, the controller 22 / 62 may determine the inventory contains n consumable articles (e.g. cartridges), each containing a known amount of aerosol generating material, and I or a known amount of aerosol generating material corresponding to the expected maximum aerosol generating material availability of each consumable. The controller 22 may sum this available amount of aerosol generating material over the known amount of aerosol generating material (and / or amount of aerosol generating material corresponding to the expected maximum aerosol generating material availability) per consumable article (as determined, for example, in manufacture), to derive a total amount of aerosol generating material associated with the inventory of consumables at time Ti. The controller 22 may track an amount of aerosol generated over each of a plurality of puffs starting at a monitoring start time of t=Ti, and sum this amount, according to approaches described herein, subtracting this summed amount from the total amount of aerosol generating material in the inventory at t=Ti to determine a remaining available amount of aerosol generating material at a second time t=T2. This information may be displayed to a user (for example, in response to user input to the aerosol delivery device 10, and I or an APP running on an external computing device), and / or used to trigger further operations. For example, when the controller 22 / 62 determines only a predefined amount of aerosol generation material remains in the inventory, which may equate to the amount of aerosol generating material equal to that comprised in an predefined integer number of consumables (e.g. 1 , 2, 3, 4, 5, or any other number of consumables), or the amount remaining at time t=Tz comprises a percentage of the total amount of aerosol generating material associated with the inventory at time t=Ti, a visual, audible, or haptic indication may be provided to a user. An APP associated with the aerosol delivery device 10 (e.g. running on an external computing device) may provide a suggestion to re-order consumables when it is determined that only a predefined amount of aerosol generation material remains in the inventory, which may equate to the amount of aerosol generating material comprised in an integer number of consumables which may be predefined in the APP, or set by a user (for example, ‘3 consumables remaining’). This re-order suggestion may comprise the APP automatically pre-filling a cart of an e-commerce interface accessible through the APP with a predefined number of consumables, for authorisation for purchase by a user.

In the above disclosure, it will be appreciated that circuitry may refer to hardware and / or may be used to refer to a software routine running on a multipurpose processing device. The required adaptation to existing parts of a conventional equivalent device of the delivery system 1 may be implemented in the form of a computer program product comprising processor implementable (computer executable) instructions stored on a non-transitory machine-readable medium such as a floppy disk, optical disk, hard disk, solid state disk, PROM, RAM, flash memory or any combination of these or other storage media, or realised in hardware as an ASIC (application specific integrated circuit) or an FPGA (field programmable gate array) or other configurable circuit suitable to use in adapting the conventional equivalent device. Separately, such a computer program may be transmitted via data signals on a network such as an Ethernet, a wireless network, the Internet, or any combination of these or other networks. Thus there has been described an electronic aerosol delivery device comprising: an aerosol generator configured to generate aerosol from an aerosol generating material, and a controller; wherein the controller is configured to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, wherein the controller is further configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A, along with corresponding methods, systems, computing devices, and non-transitory tangible computer readable media.

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. The delivery system 1 described herein can be implemented as a combustible aerosol provision system, a non-combustible aerosol provision system or an aerosol-free delivery system.

Claims

1. An electronic aerosol delivery device comprising: an aerosol generator configured to generate aerosol from an aerosol generating material, and a controller; wherein the controller is configured to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, wherein the controller is further configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

2. The electronic aerosol delivery device of claim 1, wherein the second term does not comprise A.

3. The electronic aerosol delivery device of claim 2, wherein the second term comprises a product of P and a constant.

4. The electronic aerosol delivery device of claim 1 , wherein the second term does not comprise P.

5. The electronic aerosol delivery device of claim 4, wherein the second term comprises a product of A and a constant.

6. The electronic aerosol delivery device of any preceding claim, wherein the plurality of terms comprises a third term, comprising a function of at least one of P and A.

7. The electronic aerosol delivery device of claim 6, wherein the third term does not comprise A

8. The electronic aerosol delivery device of claim 7, wherein the third term comprises a product of P and a constant.

9. The electronic aerosol delivery device of claim 6, wherein the third term does not comprise P.

10. The electronic aerosol delivery device of claim 9, wherein the third term comprises a product of A and a constant.

11 . The electronic aerosol delivery device of any preceding claim, wherein the plurality of terms comprises a fourth term, comprising a constant.

12. The electronic aerosol delivery device of any preceding claim, wherein the controller is configured to determine the airflow parameter, A, separately to determination of a power delivery duration for each of the plurality of user puffs, the power delivery duration corresponding to a period of each puff during which power is supplied to the aerosol generator to generate aerosol.

13. The electronic aerosol delivery device of claim 12, wherein the first airflow parameter is determined during an airflow duration which corresponds to a period during which an airflow is determined by the controller to be present in the aerosol delivery device.

14. The electronic aerosol delivery device of claim 13, wherein the controller is configured to supply power to the aerosol generator during a power delivery duration which is different to the airflow duration.

15. The electronic aerosol delivery device of any of claims 13 or 14, wherein the airflow duration comprises an elapsed time between a second airflow parameter monitored by the controller meeting a first predefined condition, and the second airflow parameter meeting a second predefined condition, after the first predefined condition is met.

16. The electronic aerosol delivery device of claim 15, wherein the first predefined condition comprises detecting the second airflow parameter is above a first threshold, and the second predefined condition comprises detecting the second airflow parameter being below a second threshold.

17. The electronic aerosol delivery device of claim 16, wherein the first and second thresholds are the same.

18. The electronic aerosol delivery device of any preceding claim, wherein the controller is configured to start a supply of power to the aerosol generator when a third predefined condition is met, and stop the supply of power to the aerosol generator when a fourth predefined condition is met, after the third predefined condition is met.

19. The electronic aerosol delivery device of claim 18, wherein the third condition comprises detection by the controller of a manual user input to an input device of the aerosol delivery device, and the fourth condition comprises detection by the controller of a second manual user input to the input device.

20. The electronic aerosol delivery device of claim 18, wherein the third predefined condition comprises detecting the second airflow parameter is above a third threshold, and the fourth predefined condition comprises detecting the second airflow parameter is below a fourth threshold.

21 . The electronic aerosol delivery device of claim 20, wherein the third threshold is higher than the first threshold.

22. The electronic aerosol delivery device of either of claims 20 and 21 , wherein the fourth threshold is higher than the second threshold.

23. The electronic aerosol delivery device of either of claims 20 and 22, wherein the third threshold is equal to the first threshold.

24. The electronic aerosol delivery device of any of claims 20, 21 , and 23, wherein the fourth threshold is equal to the second threshold.

25. The electronic aerosol delivery device of any of claims 12 to 24, wherein the first airflow parameter comprises a sum of the power delivery duration and a constant.

26. The electronic aerosol delivery device of any preceding claim, wherein the first airflow parameter comprises a measure of a duration of airflow through the aerosol delivery device.

27. The electronic aerosol delivery device of any preceding claim, wherein the first airflow parameter comprises a measure of a volume of air determined to have passed through the through the aerosol delivery device.

28. The electronic aerosol delivery device of any of claims 15 to 27, wherein the second airflow parameter comprises a measure of a rate of airflow through the aerosol delivery device.

29. The electronic aerosol delivery device of any preceding claim, wherein the level of power comprises a level of power predefined to be supplied to the aerosol generator to generate aerosol during each puff.

30. The electronic aerosol delivery device of any preceding claim, wherein the level of power comprises a level of power determined to have been supplied to the aerosol generator to generate aerosol during each puff.

31 . The electronic aerosol delivery device of either of claims 29 and 30, wherein the level of power comprises an average level of power over a power delivery duration associated with each puff.

32. The electronic aerosol delivery device of either of claims 29 and 30, wherein the level of power comprises a maximum level of power during a power delivery duration associated with each puff.

33. The electronic aerosol delivery device of either of claims 29 and 30, wherein the level of power comprises an amount of energy supplied to the aerosol generator over a power delivery duration associated with each puff.

34. The electronic aerosol delivery device of any preceding claim, wherein the controller is configured to determine a sum of the amount of aerosol generated over a plurality of puffs following a monitoring start time.

35. The electronic aerosol delivery device of claim 34, wherein the controller is configured to indicate to a user when an amount of aerosol determined to have been generated since the monitoring start time reaches a predefined amount.

36. The electronic aerosol delivery device of any preceding claim, further comprising first transceiver circuitry, configured for wired data transmission of data from the controller to an external computing device, the data relating to the level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and I or the first airflow parameter, A, associated with each of the plurality of user puffs, and / or the amount of aerosol generated during each one of the plurality of puffs.

37. The electronic aerosol delivery device of any preceding claim, further comprising first transceiver circuitry, configured for wireless data transmission of data from the controller to an external computing device, the data relating to the level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and / or the first airflow parameter, A, associated with each of the plurality of user puffs, and / or the amount of aerosol generated during each one of the plurality of puffs.

38. The electronic aerosol delivery device according to any preceding claim, wherein the aerosol generator comprises a heating element.

39. A method of operating an electronic aerosol delivery device comprising an aerosol generator configured to generate aerosol from an aerosol generating material, and a controller, the method comprising the steps of; causing the controller to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, causing the controller to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

40. A non-transitory tangible computer readable medium having stored thereon software instructions that, when executed by circuitry comprised in a device of an aerosol delivery system, cause the circuitry to: receive data from an aerosol delivery device, the data comprising an indication of a level of power, P, supplied to an aerosol generator of the aerosol delivery device for each of a plurality of user puffs on the aerosol delivery device, and a first airflow parameter, A, associated with each of the plurality of user puffs; and estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

41 . A computing device for use with an aerosol delivery device; wherein the computing device comprises transceiver circuitry configured to receive data from the aerosol delivery device, the data comprising an indication of a level of power, P, supplied to an aerosol generator of the aerosol delivery device for each of a plurality of user puffs on the aerosol delivery device, and a first airflow parameter, A, associated with each of the plurality of user puffs wherein the controller comprises controller circuitry configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

42. A computing device according to claim 41 , wherein the controller is configured to determine a sum of the amount of aerosol generated over a plurality of puffs from a monitoring start time.

43. A computing device according to claim 42, wherein the controller is configured to indicate to a user when an amount of aerosol determined to have been generated since the monitoring start time reaches a predefined amount.

44. An electronic aerosol delivery system comprising an aerosol delivery device and a computing device external to the aerosol delivery device, wherein the aerosol delivery device comprises an aerosol generator configured to generate aerosol from an aerosol generating material, a first controller, and first transceiver circuitry configured to transmit data to the computing device, and the computing device comprises a second controller and second transceiver circuitry configured to receive data from the aerosol delivery device; wherein the first controller is configured to monitor a level of power, P, supplied to the aerosol generator for each of a plurality of user puffs, and a first airflow parameter, A, associated with each of the plurality of user puffs, and transmit this information to the computing device via the first transceiver circuitry; wherein the second transceiver is configured to receive the information from the aerosol delivery device, and the second controller is configured to estimate an amount of aerosol generated during each one of the plurality of puffs by using an equation wherein the amount of aerosol generated during each puff is expressed as a sum of a plurality of terms, the plurality of terms comprising: a first term, comprising a function of P and A, a second term, comprising a function of at least one of P and A.

45. An electronic aerosol delivery system according to claim 44, wherein the first transceiver circuitry and second transceiver circuitry are configured for wired data transmission.

46. An electronic aerosol delivery system according to either of claims 45 or 45, wherein the first transceiver circuitry and second transceiver circuitry are configured for wireless data transmission.