Technical Field

The present invention relates to an interactive aerosol provision system.

Background

The "background" description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present disclosure.

Aerosol provision systems are popular with users as they enable the delivery of active ingredients (such as nicotine) to the user in a convenient manner and on demand.

As an example of an aerosol provision system, electronic cigarettes (e-cigarettes) generally contain a reservoir of a source liquid containing a formulation, typically including nicotine, from which an aerosol is generated, e.g. through heat vaporisation. An aerosol source for an aerosol provision system may thus comprise a heater having a heating element arranged to receive source liquid from the reservoir, for example through wicking / capillary action. Other source materials may be similarly heated to create an aerosol, such as botanical matter, or a gel comprising an active ingredient and/or flavouring. Hence more generally, the e-cigarette may be thought of as comprising or receiving a payload for heat vaporisation.

While a user inhales on the device, electrical power is supplied to the heating element to vaporise the aerosol source (a portion of the payload) in the vicinity of the heating element, to generate an aerosol for inhalation by the user. Such devices are usually provided with one or more air inlet holes located away from a mouthpiece end of the system. When a user sucks on a mouthpiece connected to the mouthpiece end of the system, air is drawn in through the inlet holes and past the aerosol source. There is a flow path connecting between the aerosol source and an opening in the mouthpiece so that air drawn past the aerosol source continues along the flow path to the mouthpiece opening, carrying some of the aerosol from the aerosol source with it. The aerosol-carrying air exits the aerosol provision system through the mouthpiece opening for inhalation by the user.

Usually an electric current is supplied to the heater when a user is drawing/ puffing on the device. Typically, the electric current is supplied to the heater, e.g. resistance heating element, in response to either the activation of an airflow sensor along the flow path as the user inhales/draw/puffs or in response to the activation of a button by the user. The heat generated by the heating element is used to vaporise a formulation. The released vapour mixes with air drawn through the device by the puffing consumer and forms an aerosol. Alternatively or in addition, the heating element is used to heat but typically not burn a botanical such as tobacco, to release active ingredients thereof as a vapour / aerosol.

The secure, efficient and/or timely operation of such an aerosol provision system can benefit from responding appropriately to how the user interacts with it.

It is in this context that the present invention arises.

SUMMARY OF THE INVENTION Various aspects and features of the present invention are defined in the appended claims and within the text of the accompanying description.

In a first aspect, an aerosol delivery system is provided in accordance with claim 1.

In another aspect, a method of control for an aerosol delivery system is provided in accordance with claim 16.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

Figure 1 is a schematic diagram of a delivery device in accordance with embodiments of the description.

Figure 2 is a schematic diagram of a body of a delivery device in accordance with embodiments of the description.

Figure 3 is a schematic diagram of a cartomiser of a delivery device in accordance with embodiments of the description.

Figure 4 is a schematic diagram of a body of a delivery device in accordance with embodiments of the description.

Figure 5 is a schematic diagram of a delivery ecosystem in accordance with embodiments of the description.

Figure 6 is a flow diagram of a method of control of an aerosol deliver system in accordance with embodiments of the description.

DESCRIPTION OF THE EMBODIMENTS

An interactive aerosol provision system is disclosed. In the following description, a number of specific details are presented in order to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent, however, to a person skilled in the art that these specific details need not be employed to practice embodiments of the present disclosure. Conversely, specific details known to the person skilled in the art are omitted for the purposes of clarity where appropriate.

The term 'interactive aerosol provision system', or similarly 'delivery device' may encompass systems that deliver a least one substance to a user, and include non-combustible aerosol provision systems that release compounds from an aerosol-generating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials; and aerosol-free delivery systems that deliver the at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.

The substance to be delivered may be an aerosol-generating material or a material that is not intended to be aerosolised. As appropriate, either material may comprise one or more active constituents, one or more flavours, one or more aerosol-former materials, and/or one or more other functional materials. Currently, the most common example of such a delivery device or aerosol provision system (e.g. a non combustible aerosol provision system) is an electronic vapour provision system (EVPS), such as an e- cigarette. Throughout the following description the term "e-cigarette" is sometimes used but this term may be used interchangeably with delivery device or aerosol provision system except where stated otherwise or where context indicates otherwise. Similarly the terms 'vapour' and 'aerosol' are referred to equivalently herein.

Generally, the electronic vapour / aerosol provision system may be an electronic cigarette, also known as a vaping device or electronic nicotine delivery device (END), although it is noted that the presence of nicotine in the aerosol-generating (e.g. aerosolisable) material is not a requirement. In some embodiments, a non-combustible aerosol provision system is a tobacco heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system. In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol generating material and a solid aerosol-generating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product. Meanwhile in some embodiments, the non combustible aerosol provision system generates a vapour / aerosol from one or more such aerosol generating materials.

Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and an article (otherwise referred to as a consumable) for use with the non combustible aerosol provision system. However, it is envisaged that articles which themselves comprise a means for powering an aerosol generating component (e.g. an aerosol generator such as a heater, vibrating mesh or the like) may themselves form the non-combustible aerosol provision system. In one embodiment, the non-combustible aerosol provision device may comprise a power source and a controller. The power source may be an electric power source or an exothermic power source. In one embodiment, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosolisable material or heat transfer material in proximity to the exothermic power source. In one embodiment, the power source, such as an exothermic power source, is provided in the article so as to form the non-combustible aerosol provision. In one embodiment, the article for use with the non-combustible aerosol provision device may comprise an aerosolisable material.

In some embodiments, the aerosol generating component is a heater capable of interacting with the aerosolisable material so as to release one or more volatiles from the aerosolisable material to form an aerosol. In one embodiment, the aerosol generating component is capable of generating an aerosol from the aerosolisable material without heating. For example, the aerosol generating component may be capable of generating an aerosol from the aerosolisable material without applying heat thereto, for example via one or more of vibrational, mechanical, pressurisation or electrostatic means.

In some embodiments, the aerosolisable material may comprise an active material, an aerosol forming material and optionally one or more functional materials. The active material may comprise nicotine (optionally contained in tobacco or a tobacco derivative) or one or more other non-olfactory physiologically active materials. A non-olfactory physiologically active material is a material which is included in the aerosolisable material in order to achieve a physiological response other than olfactory perception. The aerosol forming material may comprise one or more of glycerine, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso- Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate. The one or more functional materials may comprise one or more of flavours, carriers, pH regulators, stabilizers, and/or antioxidants.

In some embodiments, the article for use with the non-combustible aerosol provision device may comprise aerosolisable material or an area for receiving aerosolisable material. In one embodiment, the article for use with the non-combustible aerosol provision device may comprise a mouthpiece. The area for receiving aerosolisable material may be a storage area for storing aerosolisable material. For example, the storage area may be a reservoir. In one embodiment, the area for receiving aerosolisable material may be separate from, or combined with, an aerosol generating area.

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, Figure 1 is a schematic diagram of a vapour / aerosol provision system such as an e-cigarette 10 (not to scale), providing a non-limiting example of a delivery device in accordance with some embodiments of the disclosure.

The e-cigarette has a generally cylindrical shape, extending along a longitudinal axis indicated by dashed line LA, and comprises two main components, namely a body 20 and a cartomiser 30. The cartomiser includes an internal chamber containing a reservoir of a payload such as for example a liquid comprising nicotine, a vaporiser (such as a heater), and a mouthpiece 35. References to 'nicotine' hereafter will be understood to be merely an example and can be substituted with any suitable active ingredient. References to 'liquid' as a payload hereafter will be understood to be merely an example and can be substituted with any suitable payload such as botanical matter (for example tobacco that is to be heated rather than burned), or a gel comprising an active ingredient and/or flavouring. The reservoir may be a foam matrix or any other structure for retaining the liquid until such time that it is required to be delivered to the vaporiser. In the case of a liquid / flowing payload, the vaporiser is for vaporising the liquid, and the cartomiser 30 may further include a wick or similar facility to transport a small amount of liquid from the reservoir to a vaporising location on or adjacent the vaporiser. In the following, a heater is used as a specific example of a vaporiser. However, it will be appreciated that other forms of vaporiser (for example, those which utilise ultrasonic waves) could also be used and it will also be appreciated that the type of vaporiser used may also depend on the type of payload to be vaporised.

The body 20 includes a re-chargeable cell or battery to provide power to the e-cigarette 10 and a circuit board for generally controlling the e-cigarette. When the heater receives power from the battery, as controlled by the circuit board, the heater vaporises the liquid and this vapour is then inhaled by a user through the mouthpiece 35. In some specific embodiments the body is further provided with a manual activation device 265, e.g. a button, switch, or touch sensor located on the outside of the body.

The body 20 and cartomiser 30 may be detachable from one another by separating in a direction parallel to the longitudinal axis LA, as shown in Figure 1, but are joined together when the device 10 is in use by a connection, indicated schematically in Figure 1 as 25A and 25B, to provide mechanical and electrical connectivity between the body 20 and the cartomiser 30. The electrical connector 25B on the body 20 that is used to connect to the cartomiser 30 also serves as a socket for connecting a charging device (not shown) when the body 20 is detached from the cartomiser 30. The other end of the charging device may be plugged into a USB socket to re-charge the cell in the body 20 of the e-cigarette 10. In other implementations, a cable may be provided for direct connection between the electrical connector 25B on the body 20 and a USB socket.

The e-cigarette 10 is provided with one or more holes (not shown in Figure 1) for air inlets. These holes connect to an air passage through the e-cigarette 10 to the mouthpiece 35. When a user inhales through the mouthpiece 35, air is drawn into this air passage through the one or more air inlet holes, which are suitably located on the outside of the e-cigarette. When the heater is activated to vaporise the nicotine from the cartridge, the airflow passes through, and combines with, the generated vapour, and this combination of airflow and generated vapour then passes out of the mouthpiece 35 to be inhaled by a user. Except in single-use devices, the cartomiser 30 may be detached from the body 20 and disposed of when the supply of liquid is exhausted (and replaced with another cartomiser if so desired).

It will be appreciated that the e-cigarette 10 shown in Figure 1 is presented by way of example, and various other implementations can be adopted. For example, in some embodiments, the cartomiser 30 is provided as two separable components, namely a cartridge comprising the liquid reservoir and mouthpiece (which can be replaced when the liquid from the reservoir is exhausted), and a vaporiser comprising a heater (which is generally retained). As another example, the charging facility may connect to an additional or alternative power source, such as a car cigarette lighter.

Figure 2 is a schematic (simplified) diagram of the body 20 of the e-cigarette 10 of Figure 1 in accordance with some embodiments of the disclosure. Figure 2 can generally be regarded as a cross- section in a plane through the longitudinal axis LA of the e-cigarette 10. Note that various components and details of the body, e.g. such as wiring and more complex shaping, have been omitted from Figure 2 for reasons of clarity.

The body 20 includes a battery or cell 210 for powering the e-cigarette 10 in response to a user activation of the device. Additionally, the body 20 includes a control unit 205, for example a chip such as an application specific integrated circuit (ASIC) or microcontroller, for controlling the e-cigarette 10. The microcontroller or ASIC includes a CPU or micro-processor. The operations of the CPU and other electronic components are generally controlled at least in part by software programs running on the CPU (or other component). Such software programs may be stored in non-volatile memory, such as ROM, which can be integrated into the microcontroller itself, or provided as a separate component. The CPU may access the ROM to load and execute individual software programs as and when required. The microcontroller also contains appropriate communications interfaces (and control software) for communicating as appropriate with other devices in the body 10.

The body 20 further includes a cap 225 to seal and protect the far (distal) end of the e-cigarette 10. Typically there is an air inlet hole provided in or adjacent to the cap 225 to allow air to enter the body 20 when a user inhales on the mouthpiece 35. The control unit or ASIC may be positioned alongside or at one end of the battery 210. In some embodiments, the ASIC is attached to a sensor unit 215 to detect an inhalation on mouthpiece 35 (or alternatively the sensor unit 215 may be provided on the ASIC itself). An air path is provided from the air inlet through the e-cigarette, past the airflow sensor 215 and the heater (in the vaporiser or cartomiser 30), to the mouthpiece 35. Thus when a user inhales on the mouthpiece of the e-cigarette, the CPU detects such inhalation based on information from the airflow sensor 215. At the opposite end of the body 20 from the cap 225 is the connector 25B for joining the body 20 to the cartomiser 30. The connector 25B provides mechanical and electrical connectivity between the body 20 and the cartomiser 30. The connector 25B includes a body connector 240, which is metallic (silver- plated in some embodiments) to serve as one terminal for electrical connection (positive or negative) to the cartomiser 30. The connector 25B further includes an electrical contact 250 to provide a second terminal for electrical connection to the cartomiser 30 of opposite polarity to the first terminal, namely body connector 240. The electrical contact 250 is mounted on a coil spring 255. When the body20 is attached to the cartomiser 30, the connector 25A on the cartomiser 30 pushes against the electrical contact 250 in such a manner as to compress the coil spring in an axial direction, i.e. in a direction parallel to (co-aligned with) the longitudinal axis LA. In view of the resilient nature of the spring 255, this compression biases the spring 255 to expand, which has the effect of pushing the electrical contact 250 firmly against connector 25A of the cartomiser 30, thereby helping to ensure good electrical connectivity between the body 20 and the cartomiser 30. The body connector 240 and the electrical contact 250 are separated by a trestle 260, which is made of a non-conductor (such as plastic) to provide good insulation between the two electrical terminals. The trestle 260 is shaped to assist with the mutual mechanical engagement of connectors 25A and 25B.

As mentioned above, a button 265, which represents a form of manual activation device 265, may be located on the outer housing of the body 20. The button 265 may be implemented using any appropriate mechanism which is operable to be manually activated by the user - for example, as a mechanical button or switch, a capacitive or resistive touch sensor, and so on. It will also be appreciated that the manual activation device 265 may be located on the outer housing of the cartomiser 30, rather than the outer housing of the body 20, in which case, the manual activation device 265 may be attached to the ASIC via the connections 25A, 25B. The button 265 might also be located at the end of the body 20, in place of (or in addition to) cap 225.

Figure 3 is a schematic diagram of the cartomiser 30 of the e-cigarette 10 of Figure 1 in accordance with some embodiments of the disclosure. Figure 3 can generally be regarded as a cross-section in a plane through the longitudinal axis LA of the e-cigarette 10. Note that various components and details of the cartomiser 30, such as wiring and more complex shaping, have been omitted from Figure 3 for reasons of clarity.

The cartomiser 30 includes an air passage 355 extending along the central (longitudinal) axis of the cartomiser 30 from the mouthpiece 35 to the connector 25A for joining the cartomiser 30 to the body 20. A reservoir of liquid 360 is provided around the air passage 335. This reservoir 360 may be implemented, for example, by providing cotton or foam soaked in liquid. The cartomiser 30 also includes a heater 365 for heating liquid from reservoir 360 to generate vapour to flow through air passage 355 and out through mouthpiece 35 in response to a user inhaling on the e-cigarette 10. The heater 365 is powered through lines 366 and 367, which are in turn connected to opposing polarities (positive and negative, or vice versa) of the battery 210 of the main body 20 via connector 25A (the details of the wiring between the power lines 366 and 367 and connector 25A are omitted from Figure 3).

The connector 25A includes an inner electrode 375, which may be silver-plated or made of some other suitable metal or conducting material. When the cartomiser 30 is connected to the body 20, the inner electrode 375 contacts the electrical contact 250 of the body 20 to provide a first electrical path between the cartomiser 30 and the body 20. In particular, as the connectors 25A and 25B are engaged, the inner electrode 375 pushes against the electrical contact 250 so as to compress the coil spring 255, thereby helping to ensure good electrical contact between the inner electrode 375 and the electrical contact 250.

The inner electrode 375 is surrounded by an insulating ring 372, which may be made of plastic, rubber, silicone, or any other suitable material. The insulating ring is surrounded by the cartomiser connector 370, which may be silver-plated or made of some other suitable metal or conducting material. When the cartomiser 30 is connected to the body 20, the cartomiser connector 370 contacts the body connector 240 of the body 20 to provide a second electrical path between the cartomiser 30 and the body 20. In other words, the inner electrode 375 and the cartomiser connector 370 serve as positive and negative terminals (or vice versa) for supplying power from the battery 210 in the body 20 to the heater 365 in the cartomiser 30 via supply lines 366 and 367 as appropriate.

The cartomiser connector 370 is provided with two lugs or tabs 380A, 380B, which extend in opposite directions away from the longitudinal axis of the e-cigarette 10. These tabs are used to provide a bayonet fitting in conjunction with the body connector 240 for connecting the cartomiser 30 to the body 20. This bayonet fitting provides a secure and robust connection between the cartomiser 30 and the body 20, so that the cartomiser and body are held in a fixed position relative to one another, with minimal wobble or flexing, and the likelihood of any accidental disconnection is very small. At the same time, the bayonet fitting provides simple and rapid connection and disconnection by an insertion followed by a rotation for connection, and a rotation (in the reverse direction) followed by withdrawal for disconnection. It will be appreciated that other embodiments may use a different form of connection between the body 20 and the cartomiser 30, such as a snap fit or a screw connection.

Figure 4 is a schematic diagram of certain details of the connector 25B at the end of the body 20 in accordance with some embodiments of the disclosure (but omitting for clarity most of the internal structure of the connector as shown in Figure 2, such as trestle 260). In particular, Figure 4 shows the external housing 201 of the body 20, which generally has the form of a cylindrical tube. This external housing 201 may comprise, for example, an inner tube of metal with an outer covering of paper or similar. The external housing 201 may also comprise the manual activation device 265 (not shown in Figure 4) so that the manual activation device 265 is easily accessible to the user.

The body connector 240 extends from this external housing 201 of the body 20. The body connector 240 as shown in Figure 4 comprises two main portions, a shaft portion 241 in the shape of a hollow cylindrical tube, which is sized to fit just inside the external housing 201 of the body 20, and a lip portion 242 which is directed in a radially outward direction, away from the main longitudinal axis (LA) of the e- cigarette. Surrounding the shaft portion 241 of the body connector 240, where the shaft portion does not overlap with the external housing 201, is a collar or sleeve 290, which is again in a shape of a cylindrical tube. The collar 290 is retained between the lip portion 242 of the body connector 240 and the external housing 201 of the body, which together prevent movement of the collar 290 in an axial direction (i.e. parallel to axis LA). However, collar 290 is free to rotate around the shaft portion 241 (and hence also axis LA).

As mentioned above, the cap 225 is provided with an air inlet hole to allow air to flow when a user inhales on the mouthpiece 35. However, in some embodiments the majority of air that enters the device when a user inhales flows through collar 290 and body connector 240 as indicated by the two arrows in Figure 4. Referring now to Figure 5, the e-cigarette 10 (or more generally any delivery device as described elsewhere herein) may operate within a wider delivery ecosystem 1. Within the wider delivery ecosystem, a number of devices may communicate with each other, either directly (shown with solid arrows) or indirectly (shown with dashed arrows).

In Figure 5, as an example delivery device an e-cigarette 10 may communicate directly with one or more other classes of device (for example using Bluetooth ^® or Wifi Direct ^® ), including but not limited to a smartphone 100, a dock 200 (e.g. a home refill and/or charging station), a vending machine 300, or a wearable 400. As noted above, these devices may cooperate in any suitable configuration to form a delivery system.

Alternatively or in addition the delivery device, such as for example the e-cigarette 10, may communicate indirectly with one or more of these classes of device via a network such as the internet 500, for example using Wifi ^® , near field communication, a wired link or an integral mobile data scheme. Again, as noted above, in this manner these devices may cooperate in any suitable configuration to form a delivery system.

Alternatively or in addition the delivery device, such as for example the e-cigarette 10, may communicate indirectly with a server 1000 via a network such as the internet 500, either itself for example by using Wifi, or via another device in the delivery ecosystem, for example using Bluetooth ^® or Wifi Direct ^® to communicate with a smartphone 100, a dock 200, a vending machine 300, or a wearable 400 that then communicates with the server to either relay the e-cigarette's communications, or report upon its communications with the e-cigarette 10. The smartphone, dock, or other device within the delivery ecosystem, such as a point of sale system / vending machine, may hence optionally act as a hub for one or more delivery devices that only have short range transmission capabilities. Such a hub may thus extend the battery life of a delivery device that does not need to maintain an ongoing WiFi ^® or mobile data link. It will also be appreciated that different types of data may be transmitted with different levels of priority; for example data relating to the user feedback system (such as user factor data or feedback action data, as discussed herein) may be transmitted with a higher priority than more general usage statistics, or similarly some user factor data relating to more short-term variables (such as current physiological data) may be transmitted with a higher priority than user factor data relating to longer-term variables (such as current weather, or day of the week). A non-limiting example transmission scheme allowing higher and lower priority transmission is LoRaWAN.

Meanwhile, the other classes of device in the ecosystem such as the smartphone, dock, vending machine (or any other point of sale system) and/or wearable may also communicate indirectly with the server 1000 via a network such as the internet 500, either to fulfil an aspect of their own functionality, or on behalf of the delivery system (for example as a relay or co-processing unit). These devices may also communicate with each other, either directly or indirectly.

It will be appreciated that the delivery ecosystem may comprise multiple delivery devices (10), for example because the user owns multiple devices (for example so as to easily switch between different active ingredients or flavourings), or because multiple users share the same delivery ecosystem, at least in part (for example cohabiting users may share a charging dock, but have their own phones or wearables). Optionally such devices may similarly communicate directly or indirectly with each other, and/or with devices within the shared delivery ecosystem and/or the server. In embodiments of the present description, a user may wish to change the composition of the aerosol that they inhale, making the change either directly via a user interface, or indirectly via a managed program such as a nicotine reduction program or similar that may successively reduce the concentration of active ingredient(s) over time, for example over a period of days, weeks, or months. Alternatively or in addition they may wish to transition to a different payload that enables or provides a different concentration or mix of components, or transition from the delivery properties of an old device to a new device. Other causes and sources of changes to the composition of the aerosol may also be envisaged by the skilled person.

Typically such a change in aerosol composition is independent of any change in volume or mass of vapour generated, so that for an identical puff, an identical volume or mass of vapour is generated, but with a lower concentration of active ingredient(s) such as nicotine. Hence in general the alteration to the composition of the delivered aerosol does not substantially affect the overall aerosol mass delivery rate.

It is assumed herein that it is desirable for such changes to have an imperceptible or minor subjective effect for the user, so that for example they find their vaping action to still be satisfying as the concentration of active ingredient becomes progressively less, for example down to a target concentration.

An indication that the changes have had a material subjective effect for the user, whether conscious or unconscious, is if the user changes their average puff characteristics. Hence for example if the user (whether or not they realise it) is feeling less satisfied with their inhalation of a lower concentration puff, they are likely to start to puff for longer and/or with a greater intensity.

Such a transition within the user's puffing trend is thus indicative that the latest change made to the concentration of active ingredients was too large, and should be at least partially reversed to constitute a smaller step, or fully reversed to re-normalise the user before trying again with a smaller change.

Accordingly the aerosol delivery system 1, comprising an aerosol delivery device 10, may also comprise a puff characterisation processor (for example control unit 205) configured (for example by suitable software instruction) to estimate an average of a puff characteristic by a user of the aerosol delivery device for a plurality of puffs. As noted elsewhere herein, the puff characteristic may comprise one or more selected from the list consisting of puff duration, and puff intensity. These characteristics may be measured for example using the airflow sensor 215, by the puff characterisation processor.

The system may also comprise a control processor (again for example control unit 205) configured (for example by suitable software instruction) to alter a composition of an aerosol delivered to the user by the delivery device.

The aerosol delivery system may comprise a companion device from the delivery ecosystem, such as the users mobile phone 100. Hence optionally the companion device may comprise one or more selected from the list consisting of the puff characterisation processor and the control processor, or functionality of one or both of these processors may be shared between the companion device and another processor within the delivery ecosystem, such as the control unit of the delivery device.

The puff characterisation processor may be configured to detect any change in an estimated average puff characteristic after the composition of the aerosol has been altered, and the control processor may be configured to - if such a change exceeds a predetermined first threshold - at least partially reverse the alteration to the composition of the aerosol.

In this way the aerosol delivery system can characterise at least a first puff characteristic the user and implement one or more incremental changes in the composition of the delivered aerosol, evaluate whether this results in more than the threshold change in the puff characteristic, and if so then at least partially reverse the extent of the change made.

The average of a puff characteristic can be a rolling average, and can be based on the last N the puffs, or the puffs within the preceding predetermined time period (e.g. 1 hour, or 1 day). Optionally a plurality of averages can be maintained corresponding to different circumstances; for example an average can be maintained for use in the mornings and/or evenings versus use during office hours, used during weekdays versus weekends, and/or use at different locations, recognising that other factors than the concentration of active ingredients within the aerosol may affect puff characteristics; generating averages for these different circumstances helps to normalise for the contribution of these different influences.

The average of a puff characteristic can also comprise a short-term and long-term rolling average or period. For example a pair of rolling averages based on the last N and M puffs where N > M; this may enable the short term rolling average to detect a change in an estimated average puff characteristic more quickly and hence enable the system to act to at least partially reverse the alteration to the composition of the aerosol more quickly as well.

The threshold for detecting a change in puff characteristic may optionally be adaptive; for example it may be a function of a variance in the puff characteristic associated with the average puff characteristic. Hence for example when compiling an average based on the last N puffs, the variance for those N puffs may also be computed. Hence for users whose puff inhalation duration or intensity are relatively invariant, the threshold may be relatively sensitive, whereas for users who are highly variable in any case the threshold may be very insensitive, possibly to the extent that the system effectively does not implement the corrective steps for users where it is not practical to detect changes in behaviour.

As noted elsewhere herein, common sources of variability such as changes in behaviour due to time of day or location can be removed by compiling separate statistics for these respective conditions, thus improving the likely sensitivity of the system.

It will be appreciated that the average and optionally variance for historical puffs may be temporarily held for a short period of time after changes have been made, so that any differences in puff characteristics after the change do not start to contribute to the reference average.

Hence for example the average and variance for the last N puffs prior to a change (or the puffs in the predetermined period prior to the change) may be retained, whilst a separate average (and optionally variance) for the last N or M (where M<N) puffs, either initially spanning the change or only after the change may be used for the purposes of comparison; hence the change in an estimated average puff characteristic may be the change between the retained average prior to the change, and a separately computed average spanning or only after the change.

Hence for example a first rolling average based on the last N puffs prior to a change in composition can be used as the reference average, and then either a second rolling average can be cloned from it to continue with the last N puffs as these continue after the change in composition, or a second rolling average can be cloned from it to continue with the last M puffs (M<N) as these continue after the change in composition, or a second rolling average can start based on the puffs after the change in composition, optionally also including a predetermined number from beforehand to bootstrap the average.

If the puff characterisation processor determines that there is no significant change (i.e. any change remains below the threshold for a predetermined period of time), then the data from the latter average can be combined with or replace the retained earlier average so that the current puff characteristic from the user remain up-to-date. Alternatively however, the original average may be used as an ongoing benchmark, so that successive small changes in average puff characteristic below the threshold do not add up over time to mask a significant actual change in puff characteristic that has built up with respect to the original. Alternatively or in addition, the original average may be updated using a much longer rolling average, for example equating to usage over multiple composition changes, so that the influence of individual small step changes in puff characteristic are less.

If the change in an estimated average puff characteristic after the composition of the aerosol has been altered exceeds the predetermined first threshold, then as noted elsewhere herein this implies that the change has been too large and has had a material effect on the behaviour of the user (whether conscious or unconscious) and so the control processor is configured to at least partially reverse the alteration of the composition of the aerosol.

This reversal may for example comprise changing the composition 100% back to the prior composition, or 75%, 50% or 25%, as an example of four possible steps. Other ranges such as a set of three steps or five steps are clearly also conceivable.

Optionally the degree of reversal may be calculated or selected responsive to the degree of change in the estimated average puff characteristic; hence for example if the change equals or just exceeds the first threshold, the reversal may be 33%, whereas if the change exceeds the first threshold by a predetermined first additional threshold amount, the reversal may be 66% and if the change exceeds the first threshold by a predetermined second additional threshold amount, the reversal may be 100%.

Alternatively the first change threshold could represent a minimum or 0% reverse threshold and a second higher change threshold could represent a maximum 100% reverse threshold, and the amount reversal is then determined by where the actual change lies with respect to these thresholds. The relationship between these thresholds and the amount of reversal may be linear or non-linear.

Optionally, the aerosol delivery system is configured to evaluate a change in average puff characteristic corresponding to the at least partial reversal of the alteration to the composition of the aerosol. That is to say, the at least partial reversal can be treated like another change in composition, and a corresponding change in average puff characteristics can be evaluated to see whether and to what extent the user has changed back to their previous average puff characteristics in response to the reversal.

Hence for example if the system partially reversed a change in composition by 40%, but subsequently the users average puff characteristic only reverted 80% of the way back to the original, then the aerosol delivery system may change the reversal to 50%, in the expectation that this will cause the user's average puff characteristic to revert 100% of the way back to the original. In a case where the user exhibits a form of behavioural hysteresis, it may be that the reversal needs to be greater than 100% to revert back to the previous average puff characteristic. Hence in effect in this case the overall direction of change is slightly backwards, but enables a resetting of the user's behaviour for a subsequent and more cautious change of composition.

The degree to which the users average puff characteristic is expected to revert back in response to a reversal in the change of composition can be predetermined; whilst 100% may be preferred, a lower degree reversal may be acceptable such as 80, 75, 60, or 50%. Hence optionally the aerosol delivery system may be configured to alter a degree of partial reversal if the changed average puff characteristic is not within a predetermined second threshold of the original average puff characteristic.

The aerosol delivery system may optionally model a relationship between the alteration to the composition of the aerosol and average puff characteristic. At its most crude, this may be a gradient (e.g. a dy/dx line) modelling how a change in composition corresponds to a change in puff characteristic. To a second approximation, separate gradients may be determined for the initial change, and any reversals, to capture whether there is any difference in responsiveness when the change occurs in different directions. To a greater approximation, any suitable statistical model or models may be used to determine the relationship between a change in composition and a change in puff characteristic.

Where more than one puff characteristic is evaluated (for example duration and intensity), then separate averages, and separate optional models, may be used; or a combined average (for example after normalisation of the respective averages) and single optional model may be used.

Similarly, different models may be generated for different circumstances, such as work days and evenings, weekdays and weekends, and based upon location, to compensate for other influences on puff characteristic, as discussed elsewhere herein.

With such a model or models, the aerosol delivery system may be configured to predict an alteration to the composition of the aerosol that will keep the average puff characteristic within the first threshold, based on the modelled relationship.

In other words, given a gradient or other model of how a change in composition corresponds to a change in puff characteristic, a change in composition can be selected that can be expected to correspond to a change in puff characteristic that is less than the first threshold, and optionally by less than a safety margin below the first threshold.

Consequently, the aerosol delivery system can learn what changes in composition are likely to avoid causing a threshold change in puff characteristic that would necessitate at least a partial reversal in the changing composition according to the techniques herein, using such a model or models.

Such a model may also be provided for example from a remote repository such as a central server. This model may be an actual model for the user derived from the user's usage of a different delivery device, such as a previous delivery device, or where the user has more than one currently. This bootstraps the predictive capabilities of the aerosol delivery system. Alternatively or in addition such a model may be based upon data obtained for one or more other users with similar physiological properties to the current user, such as one or more of age, gender, weight, height, BMI, etc., as the pharmacological response of similar individuals to changes in composition are likely to also be similar and hence their changes in puff characteristics in response to changes in composition are also likely to be similar. It will be appreciated that the aerosol delivery system may also share its own modelled relationship(s) with such a remote repository. Where appropriate it may also share physiological properties of the current user, or these may already be known to the remote repository for example as part of a prior user registration process.

Whilst the description has so far referred to changes in composition of active ingredient and in particular nicotine, it is not limited to this. Rather, alterations in composition include changes to concentration of one or more selected from the list consisting of one or more active ingredients, one or more flavourings, and one or more cloud/opacity agents.

It will also be appreciated that the alteration in composition could include a change to a mix of active ingredients, for example a ratio of protonated and non-protonated nicotine, even if the overall concentration of total active ingredients remains the same.

Turning now to figure 6, a method of control for an aerosol delivery system comprising an aerosol delivery device comprises the following steps.

Firstly, a puff characterisation step s610 of estimating an average of a puff characteristic by a user of the aerosol delivery device for a plurality of puffs, for example implemented by the puff characterisation processor, as described elsewhere herein.

Secondly, a control step s620 of comprising altering a composition of an aerosol delivered to the user by the delivery device, for example implemented by the control processor, as described elsewhere herein.

Thirdly, a detection step s630 of detecting any change in an estimated average puff characteristic after the composition of the aerosol has been altered, for example implemented by the puff characterisation processor, as described elsewhere herein.

And fourthly, a reversal step s640 of, if such a change exceeds a predetermined first threshold, at least partially reversing the alteration to the composition of the aerosol, for example implemented by the control processor, as described elsewhere herein.

It will be apparent to a person skilled in the art that variations in the above method corresponding to operation of the various embodiments of the apparatus as described and claimed herein are considered within the scope of the present invention.

It will also be appreciated that the above methods may be carried out on conventional hardware suitably adapted as applicable by software instruction or by the inclusion or substitution of dedicated hardware. Examples of such conventional hardware include the control unit 205, and/or a CPU of the companion device (e.g. phone 100) or other device of the delivery ecosystem operating under suitable software instruction to implement the functionality of the puff characterisation processor and control processor as described elsewhere herein.

Thus the required adaptation to existing parts of a conventional equivalent device may be implemented in the form of a computer program product comprising processor implementable 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.

The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting of the scope of the invention, as well as other claims. The disclosure, including any readily discernible variants of the teachings herein, defines, in part, the scope of the foregoing claim terminology such that no inventive subject matter is dedicated to the public.