Profile selection based on smoke behavior

Abstract

An aerosol generating device for generating an aerosol from an aerosol-generating article. An aerosol-generating article comprising an aerosol-forming substrate. An aerosol generating device configured to generate an aerosol during a use session, the use session including a use session start, a use session end, and at least a first period and a second period between the use session start and the use session end. The aerosol generating device comprises a heater assembly for heating the aerosol-forming substrate, a power source configured to supply power to the heater assembly, and a control circuit comprising a memory having a plurality of different predefined heating profiles stored therein. The control circuit is configured to determine a user puff behavior during the first period of the use session, use the determined user puff behavior to select one of the plurality of predefined heating profiles, and control the supply of power to the heater assembly during a second period in accordance with the selected predefined heating profile.

Description

[Technical field]

[0001] The present disclosure relates to an aerosol generating device, an aerosol generating system including an aerosol generating device, and a method for controlling power supplied to a heater assembly of an aerosol generating system. [Background technology]

[0002] Aerosol generation systems configured to generate an aerosol from an aerosol-forming substrate, such as a tobacco-containing substrate, are known in the art. Many known aerosol generation systems generate an aerosol by application of heat to the substrate by a heater assembly. In electrically operated aerosol generation systems, heat is applied to the substrate when the heater assembly is supplied with power from a power source. The generated aerosol can then be inhaled by a user of the system as part of a user puff. A session of use of an aerosol generation system typically includes multiple user puffs.

[0003] Many aerosol generation systems include a controller configured to control the supply of power to the heater assembly according to a predetermined heating profile. The predetermined heating profile is typically optimized to generate a consistent aerosol throughout a usage session, assuming a particular puff behavior is followed during that usage session. The user puff behavior may be characterized, for example, by the puff frequency throughout the usage session, or the interval between subsequent puffs throughout the usage session.

[0004] If a user does not follow the particular puff behavior for which a given heating profile is optimized, the aerosol generated throughout a usage session may be inconsistent, for example, the amount of aerosol or the chemical composition of the aerosol may vary significantly from one user puff to the next. Summary of the Invention

[0005] In one particular example, it has been found that a first subset of users of the aerosol generation system prefer a first puff behavior comprising an interval between puffs of about 20 seconds, and a second subset of users of the aerosol generation system prefer a second puff behavior comprising a longer interval between puffs of about 40 seconds. While the second puff behavior is followed during a use session, if the predetermined heating profile implemented by the aerosol generation system is optimized for the first puff behavior, the aerosol generated throughout the use session may be inconsistent.

[0006] The longer puff intervals of the second subset of users are a puff behavior similar to the typical behavior of smokers of kretek conventional cigarettes.

[0007] It would be desirable to provide an aerosol generation system that provides consistent aerosol generation regardless of the puff profile followed during a usage session.It would be desirable to provide an aerosol generation device or system that provides consistent aerosol generation for two or more user puff profiles.It would be desirable to provide an aerosol generation system that can be optimized for users who were previously smokers of either or both kretek and non-kretek conventional cigarettes.

[0008] In a first aspect, there is provided an aerosol generating device. The aerosol generating device may be for generating an aerosol from an aerosol-generating article. The aerosol-generating article may comprise an aerosol-forming substrate. The aerosol generating device may be configured to generate an aerosol during a use session. The use session may comprise a use session start. The use session may comprise a use session end. The use session may comprise a first period of time. The use session may comprise a second period of time. The first period of time may be between a use session start and a use session end. The second period of time may be between a use session start and a use session end. The second period of time is preferably after the first period of time. The first period of time and the second period of time are preferably sequential.

[0009] The aerosol generating device may comprise a heater assembly. The heater assembly may be for heating the aerosol-forming substrate. The aerosol generating device may comprise a power source. The power source may be configured to provide power to the heater assembly. The aerosol generating device may comprise a control circuit. The control circuit may comprise a memory. A plurality of predefined heating profiles may be stored in the memory of the control circuit. The plurality of predefined heating profiles may be different from each other. For example, the plurality of predefined heating profiles may include a first predefined heating profile and a second predefined heating profile. Preferably, the duration of the first predefined heating profile may be longer than the second predefined heating profile.

[0010] The control circuitry may be configured to determine a user puff behavior during a first period of a use session. The control circuitry may be configured to use the determined user puff behavior to select one of a plurality of predefined heating profiles. The control circuitry may be configured to control the supply of power to the heater assembly during a second period of time in accordance with the selected predefined heating profile.

[0011] The control circuit being configured to select one of a plurality of predefined heating profiles using the determined user puff behavior in the first period advantageously means that a predefined heating profile optimized for the determined puff behavior in the first period can be selected and applied in the second period. In this way, a consistent aerosol may be generated throughout the second period of the use session for different puff behaviors. It has been found that users of an aerosol generating system tend to maintain a consistent puff behavior throughout the use session, so it may be assumed that the determined puff behavior in the first period will be maintained throughout the second period of the use session.

[0012] Using the determined puff behavior to select a predefined heating profile may advantageously enable a user to follow one of a variety of puff behaviors during a usage session using the same aerosol generating device and the same aerosol-forming substrate. The aerosol generating device may advantageously automatically select an appropriate predefined heating profile in accordance with the detected puff behavior.

[0013] Preferably, a use session comprises multiple puffs, even more preferably, a use session comprises more than 4 user puffs, even more preferably, more than 5 user puffs, even more preferably, more than 6 user puffs, even more preferably, more than 7 user puffs, even more preferably, more than 8 user puffs, even more preferably, more than 9 user puffs, even more preferably, more than 10 user puffs, even more preferably, more than 11 user puffs, even more preferably, more than 12 user puffs.

[0014] The first period of a use session may include one or more user puffs. Preferably, the first period of a use session includes multiple user puffs.

[0015] The control circuitry may be configured to determine a user puff behavior based on one or more user puffs during a first period of time of a use session. Preferably, the control circuitry is configured to evaluate the determined user puff behavior over a number of user puffs during the first period of time.

[0016] The control circuitry may be configured to determine an average puff behavior for a plurality of user puffs during the first period of time. While the user puff behavior may vary from puff to puff, it has been found that the puff behavior may be substantially consistent throughout a usage session for a plurality of puffs. In this manner, the average puff behavior may typically be substantially uniform throughout a usage session, and so the user puff behavior may be effectively characterized based on the average puff behavior during the first period of time. The average puff behavior may reduce the effect of differences in puff behavior from puff to puff.

[0017] The user puff behavior determined during the first period of time may relate to at least one of puff frequency, puff interval, puff intensity, puff length, number of puffs taken, amount of aerosol generated per puff, or amount of aerosol generated during the first period of time.

[0018] Preferably, the user puff behavior determined during the first period of time is at least one of average puff frequency, average time between puffs, average puff intensity, average puff length, or average amount of aerosol generated per puff.

[0019] The first period may include a first period start and a first period end. The first period end may be at least 20 seconds after the first period start, preferably the first period end may be at least 30 seconds after the first period start, preferably the first period end may be at least 40 seconds after the first period start, preferably the first period end may be at least 50 seconds after the first period start, preferably the first period end may be at least 75 seconds after the first period start, preferably the first period end may be at least 90 seconds after the first period start. The first period start may be 150 seconds or less, preferably 140 seconds or less, preferably 130 seconds or less, preferably 120 seconds or less, preferably 110 seconds or less from the first period start.

[0020] As mentioned above, the first period may include one or more puffs, preferably multiple puffs. Therefore, the duration between the start of the first period and the end of the first period may be long enough to include one or more puffs, preferably multiple puffs. Of course, the number of puffs in a given time may depend on the puffing behavior followed by the user of the device. In any case, at least 20 seconds between the start of the first period and the end of the first period may be longer than a time sufficient to include a single puff. The longer the first period, the more puffs are likely to be contained within the first period. Therefore, the longer values ​​disclosed above for the time between the end of the first period and the start of the first period may be preferred when the determined user puffing behavior is based on multiple user puffs, and especially when the determined user puffing behavior is an average user puffing behavior.

[0021] The end of the first period may be a predetermined time after the start of the first period. The predetermined time may be at least 20 seconds, preferably at least 30 seconds, preferably at least 40 seconds, preferably at least 50 seconds, preferably at least 75 seconds, preferably at least 90 seconds. The predetermined time may be 150 seconds or less, preferably 140 seconds or less, preferably 130 seconds or less, preferably 120 seconds or less, preferably 110 seconds or less.

[0022] The control circuit may be configured to monitor the number of puffs taken during the first period. The control circuit may be configured such that the end of the first period is when the control circuit detects that a predetermined number of puffs has been taken within the first period. The number of puffs taken by a given user during the first period may be at least two puffs, preferably at least three puffs. An advantage of the end of the first period depending on when the predetermined number of puffs is taken is that the first period may be dynamic. This means that if the user follows a puffing behavior with low intervals between puffs, the first period may be short, and the predetermined heating profile for the second period may be advantageously selected and followed sooner within a use session. However, if the user follows a slow puffing behavior with longer intervals between puffs, the dynamic first period may be advantageously extended to be sufficiently long to achieve a reliable measurement of the user's puffing behavior.

[0023] The first period start preferably corresponds to a usage session start, in other words the first period of the usage session may be an initial period of the usage session.

[0024] The second period of the use session may include a plurality of user puffs. The second period of the use session may preferably include more than 3, preferably more than 5, preferably more than 7, preferably more than 8, preferably more than 9 user puffs. The controller is preferably configured to control the supply of power to the heater assembly during each of the puffs of the second period in accordance with a selected predetermined heating profile.

[0025] The second time period may include a second time period start and a second time period end.

[0026] The start of the second time period may correspond to the end of the first time period, in other words, the second time period may immediately follow the first time period, such that the first time period and the second time period are sequential with respect to each other.

[0027] The end of the second time period may correspond to the end of a usage session, in which case the control circuitry may be configured to control the supply of power to the heater assembly in accordance with a predetermined heating profile selected using the determined user puff behavior for the first time period until the end of the usage session.

[0028] The length of the usage session may depend on the length of the selected predefined heating profile. The end of the usage session may correspond to the end of the selected predefined heating profile.

[0029] It has been found that users typically perform similar puffs regardless of other characteristics of their puff behavior, such as puff intervals and puff frequency. Thus, for example, a user following a first user puff behavior, having a longer interval or lower puff frequency, may perform the desired number of puffs in a longer time than a user following a second user puff behavior. Thus, it may be advantageous to vary the length of the usage session according to the determined user puff behavior and the selected predefined heating profile to accommodate the changing time that the user performs the desired number of puffs.

[0030] The aerosol generating device may comprise a detector, which may be configured to detect a parameter indicative of a user puff.

[0031] The control circuitry may be configured to detect a user puff based on the signal received from the detector. The control circuitry may be configured to determine a user puff behavior based on the signal received from the detector. For example, the control circuitry may be configured to detect a puff frequency, or puff interval, for a first period by measuring the time between subsequent detected user puffs. As another example, the control circuitry may be configured to detect a length of a detected user puff or an intensity of a detected user puff. If the user puff behavior is an average user puff behavior, the control circuitry may be configured to detect a plurality of user puffs and determine an average user puff behavior for the plurality of detected user puffs.

[0032] The aerosol generation device may comprise an airflow channel. The airflow channel may extend from an air inlet defined at least in part by a housing of the aerosol generation device. The airflow channel may extend to an air outlet defined at least in part by the aerosol generation device housing. The parameter indicative of a user puff that the detector is configured to detect may be a parameter of air in the airflow channel.

[0033] The parameter that the detector may be configured to detect may be at least one of flow, pressure, temperature, or aerosol volume.

[0034] The heater assembly may include a heating element. The heating element may be a resistive heating element. The heating element may include an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, alloys, and composites made of ceramic and metallic materials. Such composites may include doped and undoped ceramics.

[0035] The aerosol generating device may comprise a power supply which may be configured to supply an electrical current to the resistive heating element.

[0036] The heating element may comprise a substrate layer of flexible material. The substrate layer may comprise a thermally stable polymer, preferably a polyimide.

[0037] The heating element may be disposed on the substrate layer. The heating element may be a resistive heating element. The heating element may contain a wired connection configured to connect to a controller of the aerosol generating device. The heating element may comprise a heating track disposed on the substrate layer. The heating track may comprise a thermally conductive material, preferably a metal such as stainless steel. The heating track may be electrically connected to the wired connection.

[0038] The heating element may take other forms, such as one or more metal grids, flexible printed circuit boards, molded interconnect components (MIDs), ceramic heaters, flexible carbon fiber heaters, or may be formed using coating techniques such as plasma deposition onto a suitably shaped substrate.

[0039] In another embodiment, the heater assembly may include one or more inductor coils and the heating element may include one or more susceptor elements.

[0040] The one or more susceptor elements may be configured to be heatable by an alternating magnetic field generated by one or more inductor coils. In use, power supplied to the inductor coils (e.g., by the above-mentioned power supply of the apparatus) results in the inductor coil inducing eddy currents in the susceptor elements. These eddy currents in turn result in the susceptor elements generating heat. Power is supplied to the inductor coils as an alternating magnetic field. The alternating current may have any suitable frequency. The alternating current may preferably be a high frequency alternating current. The alternating current may have a frequency of 100 kilohertz (kHz) to 30 megahertz (MHz). When an aerosol-forming substrate is received in the chamber, the heat generated by the susceptor elements may heat the aerosol-forming substrate to a temperature sufficient to generate an aerosol from the substrate. The susceptor elements are formed of a material capable of absorbing electromagnetic energy and converting it into heat. By way of example and not limitation, the susceptor elements may be formed of a ferromagnetic material such as steel.

[0041] The detector may comprise a sensor, which may comprise a pressure sensor, a flow sensor, a temperature sensor, or an aerosol volume sensor.

[0042] When the heater assembly comprises a heating element, the heating element may form the detector. In such a case, the control circuitry may be configured to detect a user puff based on a change in temperature of the heating element during a use session. For example, the control circuitry may be configured to detect a user puff based on a decrease in temperature of the heating element. The control circuitry may be configured to detect the length or intensity of the user puff based on at least one of the length or magnitude of the decrease in temperature of the heating element.

[0043] The control circuitry may be configured to monitor the electrical resistance of the heating element. The electrical resistance of the heating element may preferably be temperature dependent. As such, the control circuitry may be configured to determine a change in temperature of the heating element based on a change in the electrical resistance of the heating element. In particular, the control circuitry may be configured to detect a user puff based on a drop in resistance of the heater element. The control circuitry may be configured to detect the length or intensity of a user puff based on at least one of the length or magnitude of the drop in resistance of the heater element.

[0044] The plurality of predetermined heating profiles may include a first predetermined heating profile. The plurality of predetermined heating profiles may include a second predetermined heating profile.

[0045] The control circuitry may be configured to select a first predetermined heating profile if a first user puff behavior is detected. The control circuitry may be configured to select a second predetermined heating profile if a second user puff behavior is detected. The first user puff behavior may be different from the second user puff behavior.

[0046] The control circuitry may be configured to select the first or second predetermined profile based on a comparison of the detected user puff behavior with a predetermined threshold value. The predetermined threshold value may be stored in a memory of the control circuitry. The control circuitry may advantageously use the predetermined threshold value to distinguish between the first and second user puff behaviors.

[0047] In one embodiment, the detected user puff behavior may be puff intervals during a first time period, preferably an average puff interval for the first time period. The control circuitry may be configured to select the first predetermined profile if the puff intervals are greater than a predefined threshold for the puff intervals. The control circuitry may be configured to select the second predetermined profile if the puff intervals are less than or equal to a predefined threshold for the puff intervals.

[0048] In another embodiment, the detected user puff behavior may be a puff frequency during a first time period, preferably an average puff frequency for the first time period. The control circuitry may be configured to select the first predetermined profile if the puff frequency is less than or equal to a predetermined threshold for the puff frequency. The control circuitry may be configured to select the second predetermined profile if the puff frequency is greater than a predetermined threshold for the puff interval.

[0049] The control circuitry may be configured to determine the puff frequency by measuring the number of puffs within a period of time and dividing by the length of the period. The period of time may be a first period of time.

[0050] The first predetermined heating profile may be optimized for longer intervals between puffs than the second predetermined heating profile.

[0051] Preferably, the first predefined heating profile may have a longer duration than the second predefined heating profile. This is because a user with a longer interval between puffs or a lower puff frequency will typically prefer to take the same number of puffs during a usage session as a user with a relatively shorter interval between puffs. To accommodate the longer intervals, the duration of the predefined heating profile optimized for that puff behavior may be longer. In particular, the first predefined heating profile may advantageously be longer to accommodate the longer intervals between puffs.

[0052] The duration between the use session start and the use session end may depend on the selected predefined heating profile, so that if a longer predefined heating profile is selected for the second period, the use session may be longer, specifically, if a first predefined heating profile is selected, the use session may be longer than if a second predefined heating profile is selected.

[0053] Each predefined heating profile may include one or more target temperatures. When the control circuit is configured to supply power to the heater assembly according to a particular predefined heating profile, the control circuit may be configured to heat the heater assembly with reference to one or more target temperatures. The one or more target temperatures may advantageously be selected to ensure a consistent amount of aerosol is generated throughout at least the second period of the use session. For example, an initial target temperature of the predefined heating profile may be high to ensure that the aerosol-forming substrate reaches an operating temperature. Subsequent target temperatures of the predefined heating profile may be lower than the initial target temperature to avoid overheating of the aerosol-forming substrate.

[0054] Preferably, the first predetermined heating profile may be configured such that an average target temperature throughout the duration of the first predetermined heating profile is lower than an average target temperature throughout the duration of the second predetermined heating profile.

[0055] The first user puff behavior may comprise an interval between puffs that is greater than 20 seconds, preferably greater than 22 seconds, preferably greater than 24 seconds, preferably greater than 26 seconds, preferably greater than 28 seconds, preferably greater than 30 seconds, preferably greater than 32 seconds, preferably greater than 34 seconds.

[0056] Preferably, the interval may be an average interval. The average interval may be the time between a number of subsequent pairs of puffs within the first period divided by the number of pairs of puffs.

[0057] The second user puff behavior may comprise an interval between puffs that is less than 34 seconds, preferably less than 32 seconds, preferably less than 30 seconds, preferably less than 28 seconds, preferably less than 26 seconds, preferably less than 24 seconds, preferably less than 22 seconds, preferably less than 20 seconds.

[0058] The predetermined threshold for the user puff behaviour stored in the memory may be a threshold for the puff interval or the average puff interval. The predetermined threshold may be a value between 20 seconds and 34 seconds, preferably between 22 seconds and 32 seconds, preferably between 24 seconds and 30 seconds.

[0059] Preferably, both the first predetermined heating profile and the second predetermined heating profile may have a duration greater than 1 minute, preferably greater than 2 minutes.

[0060] Preferably, the first predetermined heating profile may have a duration that is at least 30% longer than the second heating profile. Preferably, the first predetermined heating profile may have a duration that is at least 40% longer than the second heating profile. Preferably, the first predetermined heating profile may have a duration that is at least 50% longer than the second heating profile. Preferably, the first predetermined heating profile may have a duration that is at least 75% longer than the second heating profile.

[0061] The first predetermined heating profile may have a duration greater than 5 minutes, preferably greater than 6 minutes, preferably greater than 8 minutes.

[0062] The first predetermined heating profile may have a duration of 18 minutes or less, preferably 15 minutes or less, preferably 12 minutes or less, preferably 10 minutes or less.

[0063] The second predetermined heating profile may have a duration of 8 minutes or less, preferably 6 minutes or less, preferably 4 minutes or less.

[0064] The second predetermined heating profile may have a duration greater than 1 minute, preferably greater than 2 minutes.

[0065] The plurality of predetermined heating profiles may include a third predetermined heating profile different from the first predetermined heating profile and the second predetermined heating profile. The control circuit may be configured to control the supply of power to the heater assembly during the first time period in accordance with the third predetermined heating profile.

[0066] Where the first period includes a first period start and a first period end, and the first period end is a predetermined time after the first period start, the third predetermined heating profile may have a duration that is the same as the predetermined time.

[0067] The third predetermined heating profile may include a third profile onset. The third profile onset may correspond to the first time period onset. In other words, the control circuit may be configured to control the supply of power to the heater assembly throughout the first time period in accordance with the third predetermined heating profile.

[0068] The third predetermined heating profile may be shorter than the first predetermined heating profile and the second predetermined heating profile.

[0069] The third predetermined heating profile may include a target temperature that is higher than the target temperature of the first predetermined heating profile or the second predetermined heating profile.

[0070] Preferably, the third predetermined heating profile may include a target temperature that is higher than the target temperature of either the first predetermined heating profile or the second predetermined heating profile, which may be particularly advantageous where the control circuit is configured to control the heater assembly to rapidly increase the temperature to the vaporization temperature during a first period of a use session.

[0071] It may be advantageous for the control circuit to control the supply of power to the heater assembly during the first period of time in accordance with a third predetermined heating profile, regardless of puff behavior, which may be particularly preferred when the heater assembly is required to rapidly reach vaporization temperature during the first period of a use session.

[0072] At least one of the plurality of predetermined heating profiles may comprise a first portion that is substantially identical to a first portion of another of the plurality of predetermined heating profiles. Each of the plurality of predetermined heating profiles may comprise a first portion that is substantially identical to a first portion of another of the plurality of predetermined heating profiles. The first portion may be an initial portion of the respective predetermined heating profile.

[0073] In certain embodiments, at least a first portion of the first predetermined heating profile may be substantially identical to a first portion of the second predetermined heating profile. The first portion of the first predetermined heating profile may correspond to a first portion of the second predetermined heating profile. Preferably, the first portion of each of the first and second predetermined heating profiles may be an initial portion of the respective heating profile.

[0074] The control circuitry may be configured to control the supply of power to the heater assembly during a first time period according to a first portion of one of a plurality of predetermined heating profiles, which may be an alternative to controlling the supply of power to the heater assembly according to a third predetermined heating profile dedicated to the first time period, as described above.

[0075] The first portion of each of the predetermined heating profiles may comprise a target temperature at which the heater assembly is configured to rapidly increase in temperature to the vaporization temperature during a first period of a use session. It may be advantageous for the heater assembly to be controlled in this manner during the first period, regardless of the puff behavior or the selected predetermined heating profile.

[0076] The one or more of the plurality of predetermined heating profiles may comprise a second portion. The or each second portion may be subsequent to the first portion of the respective predetermined heating profile. The second portions of the first and second predetermined heating profiles, or each of the first and second predetermined heating profiles, may begin immediately after the end of the first portion of the respective predetermined heating profile.

[0077] The control circuitry may be configured to control the supply of power to the heater assembly in accordance with a second portion of the selected predetermined heating profile during a second time period. The control circuitry may be configured such that selecting to control the supply of power to the heater assembly during a second time period includes selecting to supply power in accordance with the second portion of one of the predetermined heating profiles.

[0078] The aerosol-generating device may be configured to generate an aerosol from an aerosol-forming substrate provided within the aerosol-generating article.

[0079] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may conveniently be part of an aerosol-generating article or a smoking article.

[0080] The aerosol-forming substrate may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may comprise both solid and liquid components. The aerosol-forming substrate may comprise a tobacco-containing material that contains volatile tobacco flavor compounds that are released from the substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may further comprise an aerosol former that facilitates the formation of a dense and stable aerosol. Examples of suitable aerosol formers are glycerin and propylene glycol.

[0081] The aerosol-forming substrate may comprise a congealed, crimped sheet of homogenized tobacco material. As used herein, the term "crimped sheet" refers to a sheet having a plurality of substantially parallel ridges or corrugations. Alternatively or additionally, the aerosol-forming substrate may comprise strands, shreds or strips of homogenized tobacco material. Preferably, the aerosol-forming substrate may comprise cut homogenized tobacco containing glycerin. The glycerin may be applied to the cut homogenized tobacco. Preferably, the glycerin may be sprayed onto the homogenized tobacco.

[0082] The aerosol generating system may comprise a cartridge containing the aerosol-forming substrate. The cartridge may be receivable in a chamber of an aerosol generating device. The aerosol-forming substrate may be solid or liquid, or may contain both solid and liquid components. Preferably, the aerosol-forming substrate is a liquid.

[0083] The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material that contains volatile tobacco flavour compounds that are released from the aerosol-forming substrate upon heating. Preferably, the aerosol-forming substrate may alternatively comprise a non-tobacco-containing material.

[0084] The aerosol-generating article may include a wrapper surrounding the aerosol-forming substrate. The aerosol-forming substrate may be a solid aerosol-forming substrate.

[0085] The aerosol generating device may comprise a device housing defining a cavity. The cavity may be for receiving the aerosol-forming substrate.

[0086] The control circuitry may be configured such that the selection of the pre-defined heating profile for the second time period is further based on the detected type of aerosol-forming substrate used with the aerosol generating device, which would preferably be in addition to the selection based on the detected user puffing behaviour during the first time period.

[0087] The plurality of predetermined heating profiles may include a subset of predetermined heating profiles for each type of aerosol-forming substrate with which the aerosol-generating device is configured to be used. For example, the plurality of predetermined heating profiles may include a first subset of predetermined heating profiles configured for a first type of aerosol-forming substrate and a second subset of predetermined heating profiles configured for a second type of aerosol-forming substrate. Each of the first and second subsets of predetermined heating profiles may include a first predetermined heating profile and a second predetermined heating profile. The first and second predetermined heating profiles may have characteristics as described above. For example, the first predetermined heating profile may preferably be longer than the second predetermined heating profile in each subset.

[0088] The control circuitry may be configured to determine a type of aerosol-forming substrate for use with the device. The control circuitry may be configured to select a subset of predetermined heating profiles based on the determined type of aerosol-forming substrate. Once the subset of predetermined heating profiles has been selected, the control circuitry may be configured to select a predetermined heating profile from the respective subset of predetermined heating profiles using the determined puff behavior during the first time period, as described above.

[0089] The aerosol-generating device may comprise a substrate detector configured to detect the type of aerosol-forming substrate used with the device. The substrate detector may be configured to detect a property of the aerosol-forming substrate used with the device, or a property of the aerosol-generating article comprising the aerosol-forming substrate. The property may be a physical or chemical property of the aerosol-forming substrate. The substrate detector may comprise an emitter of electromagnetic radiation and a receiver of electromagnetic radiation, and the property may be a spectroscopic property associated with the aerosol-forming substrate or the aerosol-generating article. The property may be associated with a taggant or other indicia incorporated into the aerosol-forming substrate or the aerosol-generating article.

[0090] The control circuitry may be configured to determine a type of aerosol-forming substrate for use with the device based on a signal received from the substrate detector. The control circuitry may be configured to determine a type of aerosol-forming substrate for use with the device during or prior to a use session. If the control circuitry is configured to determine a type of aerosol-forming substrate for use with the device during a use session, it may be configured to do so during a first period of time.

[0091] In a second aspect, there is provided an aerosol generation system, which may comprise an aerosol generation device, which may be an aerosol generation device according to the first aspect.

[0092] The aerosol generating system may further comprise one or more aerosol-generating articles. The one or more aerosol-generating articles, or each of the one or more aerosol-generating articles, may comprise a rod of aerosol-forming substrate.

[0093] The aerosol-forming substrate of the one or more aerosol-generating articles or each of the one or more aerosol-generating articles may be an aerosol-forming substrate of the first type.

[0094] As described with respect to the first aspect, the control circuitry of the aerosol generating device may advantageously select a predefined heating profile based on the detected user behavior. In one embodiment, the control circuitry may make this selection independently of the type of aerosol-forming substrate used with the device. In another embodiment, the control circuitry may be configured to use the detected type of aerosol-forming substrate in addition to the determined puff behavior to select the predefined heating profile.

[0095] The aerosol-generating system may comprise a plurality of aerosol-generating articles, at least two of which may comprise a rod of a first type of aerosol-forming substrate.

[0096] The length of the rod of aerosol-forming substrate may be at least 30 percent of the length of the aerosol-generating article.The rod of aerosol-forming substrate may have a tobacco content of from 30 percent by weight on a dry weight basis to 90 percent by weight on a dry weight basis.

[0097] The aerosol-generating article may comprise a hollow tubular element at the downstream end of the rod of aerosol-forming substrate.The aerosol-generating article may comprise a mouthpiece element at the downstream end of the hollow tubular element.

[0098] In some aerosol-generating articles, it may be desirable to include components and aerosol formers other than tobacco within the rod of the aerosol-forming substrate, for example, it may be desirable to include one or more flavorants within the rod of the aerosol-forming substrate.

[0099] The term "flavorant" refers to an organoleptic compound, composition, or material that modifies and is intended to modify the taste or aroma characteristics of one or more components of the aerosol-forming substrate during consumption or inhalation. A flavorant may, for example, modify and / or be intended to modify the taste or aroma characteristics of nicotine during consumption or inhalation. For purposes of this disclosure, nicotine is not considered a "flavorant" or flavor.

[0100] The rod of aerosol-forming substrate may comprise one of a number of flavourants.The rod of aerosol-forming substrate may comprise a number of flavourants.

[0101] The rod of the aerosol-forming substrate may have a flavourant content of at least 0.1 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 1 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 3 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 5 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 8 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 10 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 13 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 15 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of at least 18 percent by weight on a dry weight basis.

[0102] The rod of the aerosol-forming substrate may have a flavourant content of 25 percent by weight or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 20 percent by weight or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 18 percent by weight or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 15 percent by weight or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 13 percent by weight or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 10 percent by weight or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 8 percent by weight or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 5 percent by weight or less on a dry weight basis.

[0103] The rod of the aerosol-forming substrate may have a flavourant content of 0.1 to 25 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 0.1 to 20 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 5 to 20 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 10 to 20 percent by weight on a dry weight basis. The rod of the aerosol-forming substrate may have a flavourant content of 15 to 20 percent by weight on a dry weight basis.

[0104] The one or more flavorings may be one or more of clove, ginger, mint, rosemary, star anise, and tea. The plurality of flavorings may be a combination of two or more of clove, ginger, mint, rosemary, star anise, and tea.

[0105] In one embodiment, the rod of aerosol-forming substrate may also include cloves.

[0106] The rod of the aerosol-forming substrate may comprise at least 30 milligrams of flavourant. The rod of the aerosol-forming substrate may comprise at least 35 milligrams of flavourant. The rod of the aerosol-forming substrate may comprise at least 40 milligrams of flavourant. The rod of the aerosol-forming substrate may comprise at least 45 milligrams of flavourant. The rod of the aerosol-forming substrate may comprise at least 50 milligrams of flavourant.

[0107] The hollow tubular element may have a length of at least 15 millimeters.The hollow tubular element may have a length of at least 17 millimeters.The hollow tubular element may have a length of at least 19 millimeters.

[0108] The hollow tubular element may have a length of 30 millimeters or less.The hollow tubular element may have a length of 25 millimeters or less.The hollow tubular element may have a length of 23 millimeters or less.

[0109] The hollow tubular element may have a length between 15 mm and 30 mm. The hollow tubular element may have a length between 17 mm and 25 mm. The hollow tubular element may have a length between 19 mm and 23 mm. In one embodiment, the hollow tubular element has a length of 12 mm.

[0110] In a third aspect, there is provided a method of controlling power supplied to a heater assembly of an aerosol generating device for generation of an aerosol from an aerosol-forming substrate during a use session. The use session may include a use session start. The use session may include a use session end. The use session may comprise a first period between the use session start and the use session end. The use session may comprise a second period between the use session start and the use session end. Preferably, the use session includes both the first period and the second period. Preferably, the first period and the second period are sequential.

[0111] The method may include determining a user puffing behavior.The method may include determining a user puffing behavior during a first period of a use session.

[0112] The method may include using the determined user puffing behavior to select one of a plurality of predefined heating profiles that differ from one another.

[0113] The method may include controlling the supply of power to the heater assembly during a second period of time in accordance with a selected predetermined heating profile.

[0114] A usage session preferably comprises multiple puffs. A first period of a usage session may comprise one or more puffs, preferably multiple puffs.

[0115] The method may include determining a user puff behavior based on one or more user puffs during a first period of time of use. Preferably, the method may include evaluating the determined user puff behavior across a plurality of user puffs during the first period of time.

[0116] The method may include determining a plurality of average puffing behaviors during a first period of time when the user puffs.

[0117] The user puff behavior determined during the first period of time may relate to at least one of puff frequency, puff interval, puff intensity, puff length, number of puffs taken, amount of aerosol generated per puff, or amount of aerosol generated during the first period of time.

[0118] Preferably, the user puff behavior determined during the first period of time is at least one of average puff frequency, average time between puffs, average puff intensity, average puff length, or average amount of aerosol generated per puff.

[0119] The first period may include a first period start and a first period end, which may be at least 20 seconds, preferably at least 30 seconds, preferably at least 40 seconds, preferably at least 50 seconds, preferably at least 75 seconds, preferably at least 95 seconds after the first period start.

[0120] The end of the first period may be a predetermined time after the start of the first period.

[0121] The method may include monitoring the number of puffs taken during a first period of time. The method may include terminating the first period of time when a predetermined number of puffs is detected during the first period of time. The predetermined number of puffs during the first period of time may be at least two puffs, preferably at least three puffs.

[0122] The method may include detecting a parameter representative of a user puff. The method may include determining a user puff behavior based on a signal received from a detector used to detect the parameter representative of a user puff. For example, the method may include detecting a puff frequency or puff interval for a first period by measuring the time between subsequent detected user puffs. As another example, the method may include detecting a length of a detected user puff or an intensity of a detected user puff. If the user puff behavior is an average user puff behavior, the method may include detecting a plurality of user puffs and determining an average user puff behavior for the plurality of detected user puffs.

[0123] The method may include detecting a user puff based on a change in temperature of a heating element of the heater assembly during a use session. For example, the method may include detecting a user puff based on a decrease in temperature of the heating element. The method may include detecting a length or intensity of the user puff based on at least one of a length or magnitude of the decrease in temperature of the heating element.

[0124] The method may include monitoring the electrical resistance of the heating element, which may be particularly preferred if the electrical resistance of the heating element is temperature dependent.

[0125] A number of predefined heating profiles may be stored in a memory of the aerosol generating device control circuitry.

[0126] The plurality of predetermined heating profiles may include a first predetermined heating profile. The plurality of predetermined heating profiles may include a second predetermined heating profile. The first predetermined heating profile and the second predetermined heating profile may be as described in the first aspect.

[0127] The method may include selecting a first predetermined profile for a second time period if the first user smoking behavior type is detected.

[0128] The method may include selecting a second predetermined profile for a second time period if a second user smoking behavior type is detected.

[0129] The plurality of predetermined heating profiles may include a third predetermined heating profile different from the first predetermined heating profile and the second predetermined heating profile. The method may include controlling a supply of power to the heater assembly during the first time period in accordance with the third predetermined heating profile.

[0130] Alternatively or additionally, at least one of the plurality of predetermined heating profiles, and preferably each of them, may comprise a first portion that is substantially identical to a first portion of another of the plurality of predetermined heating profiles. The method may include controlling the supply of power to the heater assembly during a first time period in accordance with the first portion of one of the plurality of predetermined profiles. This may be an alternative to controlling the supply of power to the heater assembly in accordance with a third predetermined heating profile dedicated to the first time period, as described above.

[0131] Features described with respect to one aspect may apply to other aspects of the present disclosure. In particular, advantageous or optional features described with respect to the first aspect of the present disclosure may apply to the second and third aspects of the disclosure, and vice versa.

[0132] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of the other examples, embodiments, or aspects described herein. EXAMPLES

[0133] Example 1. An aerosol generating device for generating an aerosol from an aerosol-generating article comprising an aerosol-forming substrate, the aerosol generating device being configured to generate an aerosol during a use session including a start of a use session, an end of the use session, and at least a first period and a second period between the start of the use session and the end of the use session; a heater assembly for heating the aerosol-forming substrate; a power source configured to provide power to the heater assembly; a control circuit including a memory in which a plurality of different predefined heating profiles are stored; An aerosol generating device, wherein the control circuit is configured to determine a user's puffing behavior during a first period of a usage session, use the determined user's puffing behavior to select one of a plurality of predetermined heating profiles, and control the supply of power to the heater assembly during a second period in accordance with the selected predetermined heating profile.

[0134] Example 2. An aerosol generating device according to example 1, wherein the control circuitry is configured to evaluate the determined user puffs over a number of user puffs during a first period of time.

[0135] Example 3. An aerosol generating device according to Example 2, wherein the determined user puff behavior is an average puff behavior for a number of user puffs during a first period of time.

[0136] Example 4. An aerosol generating device according to any one of Examples 1 to 3, wherein the user puffing behavior determined during the first period relates to at least one of puff frequency, puff interval, puff intensity, puff length, number of puffs taken, amount of aerosol generated per puff, or amount of aerosol generated during the first period.

[0137] Example 5. An aerosol generating device according to any one of the preceding examples, wherein the user puffing behavior determined during the first period is at least one of average puff frequency, average puff interval, average puff strength, average puff length, or average amount of aerosol generated per puff.

[0138] Example 6. An aerosol generating device according to any one of the preceding examples, wherein the first period of time comprises a first period start and a first period end.

[0139] Example 7. An aerosol generating device according to Example 6, wherein the end of the first period is at least 20 seconds, preferably at least 30 seconds, preferably at least 40 seconds, preferably at least 50 seconds, preferably at least 75 seconds, preferably at least 90 seconds after the start of the first period.

[0140] Example 8. An aerosol generating device according to Example 6 or Example 7, wherein the end of the first period is a predetermined time after the start of the first period.

[0141] Example 9. An aerosol generating device according to example 8, wherein the predetermined time is at least 20 seconds, preferably at least 30 seconds, preferably at least 40 seconds, preferably at least 50 seconds, preferably at least 75 seconds, preferably at least 90 seconds.

[0142] Example 10. An aerosol generating device according to Example 6 or Example 7, wherein the control circuit is configured to monitor the number of puffs taken by the user during a first period of time, and the end of the first period is configured to be when the control circuit detects that a predetermined number of puffs have been taken during the first period of time.

[0143] Example 11. An aerosol generating device according to example 10, wherein the predetermined number of user puffs during the first period is at least two puffs, preferably at least three puffs.

[0144] Example 12. An aerosol generating device according to any one of Examples 6 to 11, wherein the start of the first period corresponds to the start of a session of use.

[0145] Example 13. An aerosol generating device according to any one of Examples 6 to 12, wherein the second period includes a second period start and a second period end.

[0146] Example 14. An aerosol generating device according to example 13, wherein the start of the second time period corresponds to the end of the first time period.

[0147] Example 15. An aerosol generating device according to Example 13 or Example 14, wherein the end of the second period corresponds to the end of a usage session.

[0148] Example 16. An aerosol generating device according to any one of Examples 6 to 15, wherein the control circuit is configured to select a predetermined heating profile for a second period at the end of the first period.

[0149] Example 17. An aerosol generating device according to any one of the preceding examples, wherein the end of a usage session corresponds to the end of a selected predefined heating profile.

[0150] Example 18. An aerosol generating device according to any one of the preceding examples, further comprising a detector configured to detect a parameter representative of a user puff.

[0151] Example 19. An aerosol generating device according to Example 18, wherein the control circuit is configured to determine a user's puffing behavior during a first period of a usage session based on a signal received from the detector.

[0152] Example 20. An aerosol generating device according to example 18 or example 19, wherein the control circuit is configured to detect a user puff based on a change in the detected parameter.

[0153] Example 21. An aerosol generating device according to any one of Examples 18 to 20, wherein the parameter that the detector is configured to detect is at least one of flow, pressure, temperature, or amount of aerosol.

[0154] Example 22. An aerosol generating device according to any one of Examples 18 to 21, wherein the detector is equipped with a sensor.

[0155] Example 23. An aerosol generating device according to example 22, wherein the sensor comprises a pressure sensor, a flow sensor, a temperature sensor, or an aerosol amount sensor.

[0156] Example 24. An aerosol generating device according to any one of Examples 18 to 23, wherein the heater assembly comprises a heating element, and the heating element forms the detector.

[0157] Example 25. An aerosol generating device according to Example 24, wherein the control circuit is configured to detect a user puff based on a change in temperature of the heating element during a usage session.

[0158] Example 26. An aerosol generating device according to example 24 or example 25, wherein the control circuit is configured to monitor the electrical resistance of the heating element.

[0159] Example 27. An aerosol generating device according to any one of the preceding examples, wherein the plurality of predetermined heating profiles includes a first predetermined heating profile and a second predetermined heating profile.

[0160] Example 28. An aerosol generating device according to Example 27, wherein the control circuit is configured to select a first predetermined profile for a second period of time when a first user puffing behavior type is detected.

[0161] Example 29. An aerosol generating device according to Example 28, wherein the first user puff behavior type comprises an interval between puffs that is greater than 20 seconds, preferably greater than 22 seconds, preferably greater than 24 seconds, preferably greater than 26 seconds, preferably greater than 28 seconds, preferably greater than 30 seconds, preferably greater than 32 seconds, preferably greater than 34 seconds.

[0162] Example 30. An aerosol generating device according to Examples 27 to 29, wherein the control circuit is configured to select a second predetermined profile for a second period of time when a second user smoking behavior type is detected.

[0163] Example 31. An aerosol generating device according to Example 30, wherein the second user puff behavior type comprises an interval between puffs that is less than 34 seconds, preferably less than 32 seconds, preferably less than 30 seconds, preferably less than 28 seconds, preferably less than 26 seconds, preferably less than 24 seconds, preferably less than 22 seconds, preferably less than 20 seconds.

[0164] Example 32. An aerosol generating device according to any one of Examples 18 to 31, wherein the control circuit is configured to determine the puff behavior type by measuring the interval between detected puffs or by measuring the puff frequency.

[0165] Example 33. An aerosol generating device according to example 32, wherein the control circuit is configured to measure puff frequency by measuring the number of puffs in a period of time and dividing by the length of that period.

[0166] Example 34. The aerosol generating device according to Example 33, wherein the period is a first period.

[0167] Example 35. An aerosol generating device according to any one of Examples 27 to 34, wherein both the first predetermined heating profile and the second predetermined heating profile have a duration longer than 1 minute, preferably longer than 2 minutes.

[0168] Example 36. An aerosol generating device according to any one of Examples 27 to 35, wherein the first predetermined heating profile has a longer duration than the second predetermined heating profile.

[0169] Example 37. An aerosol generating device according to example 36, wherein the first predetermined heating profile has a duration that is at least 30% longer, preferably at least 40% longer, preferably at least 50% longer, preferably at least 75% longer than the second heating profile.

[0170] Example 38. An aerosol generating device according to any one of Examples 27 to 37, wherein the first predetermined heating profile has a duration of 18 minutes or less, preferably 15 minutes or less, preferably 12 minutes or less, preferably 10 minutes or less.

[0171] Example 39. An aerosol generating device according to any one of Examples 27 to 38, wherein the first predetermined heating profile has a duration of more than 5 minutes, preferably more than 6 minutes, preferably more than 8 minutes.

[0172] Example 40. An aerosol generating device according to any one of Examples 27 to 39, wherein the second predetermined heating profile has a duration of 8 minutes or less, preferably 6 minutes or less, preferably 4 minutes or less.

[0173] Example 41. An aerosol generating device according to any one of Examples 27 to 40, wherein the second predetermined heating profile has a duration of greater than 1 minute, preferably greater than 2 minutes.

[0174] Example 42. An aerosol generating device according to any one of Examples 27 to 41, wherein the plurality of predetermined heating profiles includes a third predetermined heating profile that is different from the first predetermined heating profile and the second predetermined heating profile.

[0175] Example 43. An aerosol generating device according to example 42, wherein the control circuit is configured to control the supply of power to the heater assembly during the first period of time in accordance with a third predetermined heating profile.

[0176] Example 44. An aerosol generating device according to Example 42 or Example 43, wherein the first period includes a first start and a first period end, the first period end being a predetermined time after the first period start.

[0177] Example 45. An aerosol generating device according to example 44, wherein the third predetermined heating profile has a duration equal to the predetermined time.

[0178] Example 46. An aerosol generating device according to example 44 or example 45, wherein the third predetermined heating profile includes a third profile onset.

[0179] Example 47. An aerosol generating device according to example 46, wherein the third profile start corresponds to the first period start.

[0180] Example 48. An aerosol generating device according to any one of Examples 27 to 41, wherein at least a first portion of the first predetermined heating profile is substantially identical to a first portion of the second predetermined heating profile.

[0181] Example 49. An aerosol generating device according to example 48, wherein the first portion of the first predetermined heating profile corresponds to the first portion of the second predetermined heating profile.

[0182] Example 50. An aerosol generating device according to Example 49, wherein the first portion of each of the first predetermined heating profile and the second predetermined heating profile is an initial portion of the respective heating profile.

[0183] Example 51. An aerosol generating device according to any one of Examples 48 to 50, wherein the first period includes a first period start and a first period end, the first period end being a predetermined time after the first period start, and wherein the first predetermined heating profile or the first portion of the second predetermined heating profile, or each of them, has the same duration as the predetermined time.

[0184] Example 52. An aerosol generating device according to any one of Examples 48 to 51, wherein the control circuit is configured to control the supply of power to the heater assembly during a first period of time in accordance with a first portion of one of a plurality of predetermined heating profiles.

[0185] Example 53. An aerosol generating device according to any one of Examples 48 to 51, wherein the first predetermined heating profile and the second predetermined heating profile each comprise a second portion.

[0186] Example 54. An aerosol generating device according to Example 53, wherein the control circuit is configured to control the supply of power to the heater assembly during a second period of time in accordance with a second portion of the selected predetermined heating profile.

[0187] Example 55. An aerosol generating device according to example 53 or example 54, wherein the second portion of the selected predetermined heating profile follows each of the first portions.

[0188] Example 56. An aerosol generating device according to any one of Examples 53 to 55, wherein the control circuit is configured to control the supply of power to the heater assembly throughout the second period in accordance with each second portion of the selected predetermined heating profile.

[0189] Example 57. An aerosol generating device according to any one of Examples 53 to 56, wherein the second portion of the first predetermined profile is different from the second portion of the second predetermined heating profile.

[0190] Example 58. An aerosol generating device according to any one of Examples 53 to 57, wherein the second portion of each of the first predetermined heating profile and the second predetermined heating profile begins immediately after the end of the respective first portion.

[0191] Example 59. An aerosol generating device according to any one of Examples 53 to 58, wherein the control circuit is configured such that the selection for controlling the supply of power to the heater assembly during a second period includes selecting to supply power according to a second portion of one of the predetermined heating profiles.

[0192] Example 60. An aerosol generating device according to any one of Examples 53 to 59, wherein the control circuit is configured such that the selection for controlling the supply of power to the heater assembly during the second period includes selecting to continue to supply power according to a predetermined heating profile for the first period, or to supply power according to one of the other predetermined heating profiles.

[0193] Example 61. An aerosol generating device according to any one of the preceding examples, wherein the aerosol generating device is configured to generate an aerosol from an aerosol-forming substrate provided within the aerosol-generating article.

[0194] Example 62. An aerosol generating device according to example 61, wherein the aerosol-generating article comprises a wrapper surrounding the aerosol-forming substrate.

[0195] Example 63. An aerosol-generating apparatus according to example 62, wherein the aerosol-forming substrate is a solid aerosol-forming substrate.

[0196] Example 64. An aerosol generating device according to any one of the preceding examples, wherein the aerosol generating device comprises a device housing defining a cavity for receiving an aerosol-forming substrate.

[0197] Example 65. An aerosol generating system comprising an aerosol generating device according to any one of the preceding examples and an aerosol generating article comprising one or more rods of aerosol-forming substrate.

[0198] Example 66. An aerosol generating system according to example 65, wherein the rod of aerosol-forming substrate comprises one or more flavorants.

[0199] Example 67. An aerosol generating system according to example 66, wherein the rod of aerosol-forming substrate comprises a plurality of flavorants.

[0200] Example 68. An aerosol generating system according to example 68, wherein the rod of aerosol-forming substrate comprises one or more flavourings, being one or more of clove, ginger, mint, rosemary, star anise and tea.

[0201] Example 69. An aerosol-generating system according to example 68, wherein the rod of the aerosol-forming substrate comprises cloves.

[0202] Example 70. A method of controlling power supplied to a heater assembly of an aerosol generating device for generating an aerosol from an aerosol-forming substrate during a use session, including a use session start, a use session end, and at least a first period and a second period between the use session start and the use session end, comprising: determining a user's smoking behavior during a first period of a use session; selecting one of a plurality of predefined heating profiles that are distinct from one another using the determined user puff behavior; and controlling the supply of power to the heater assembly during a second period of time in accordance with a selected predetermined heating profile.

[0203] The embodiments will now be further described with reference to the figures. [Brief description of the drawings]

[0204] [Figure 1] FIG. 1 is a schematic diagram in cross section of a first embodiment of an aerosol generating system comprising an aerosol generating device according to the present disclosure and an aerosol generating article. [Diagram 2] FIG. 2 is a schematic diagram of a cross-section of the aerosol generating device of FIG. 1 shown separate from the aerosol generating article. [Diagram 3] FIG. 3 is a graph illustrating a first predetermined heating profile and a second predetermined heating profile stored in the memory of the control circuit of the aerosol generating device of FIG. [Figure 4] FIG. 4 is a flow chart illustrating a method of controlling power supplied to the heater assembly of the aerosol generating device of FIG. 1 during a use session. [Diagram 5] FIG. 5 is a graph of the temperature of a heater element of a heater assembly of an aerosol generating device during a usage session in which a user follows a first user puff behavior. [Figure 6] FIG. 6 is a graph of the temperature of a heater element of a heater assembly of an aerosol generating device during a usage session in which a user follows a second user puff behavior. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0205] 1 is a schematic diagram of a cross-sectional view of a first aerosol generating device 100. The aerosol generating device 100 comprises a cavity 10 defined by a device housing 11. The cavity 10 is tubular and has a base 12 at an upstream end. The cavity 10 is configured to receive an aerosol-generating article 200.

[0206] An aerosol-generating article 200 is received within the cavity 10. The aerosol-generating article 200 is shown separately from the aerosol generating device 100 in Figure 2. Figure 2 is also a schematic diagram of a cross-sectional view of the aerosol-generating article 200.

[0207] The aerosol-generating article 200 comprises a rod of aerosol-forming substrate 212 and a downstream section 214 at a location downstream of the rod of aerosol-forming substrate 212. The downstream section 214 comprises a hollow tubular element 220 and a mouthpiece element 204.

[0208] The aerosol-generating article 200 comprises an aerosol-forming substrate 212 and an upstream wrapper 244 that surrounds the hollow tubular element 220 .

[0209] The aerosol-generating article 200 also includes a tipping wrapper 252 that surrounds the hollow tubular element 220 and the mouthpiece element 204. The tipping wrapper 252 overlies the portion of the upstream wrapper 244 that overlies the hollow tubular element 220. In this manner, the tipping wrapper 252 effectively bonds the mouthpiece element 204 to the remaining components of the aerosol-generating article 200. In this embodiment, the width of the tipper wrapper 252 is about 26 millimeters.

[0210] The aerosol-generating article 200 has an overall length of about 45 millimeters and an outer diameter of about 7.2 mm.

[0211] The aerosol-forming substrate rod 212 includes a cut tobacco material. In this embodiment, the aerosol-forming substrate rod 212 also includes cloves. The aerosol-forming substrate rod 212 includes 150 milligrams of cut tobacco material with 13 percent to 16 percent by weight glycerin. The density of the aerosol-forming substrate is about 300 mg per cubic centimeter. The aerosol-forming substrate rod 212 has an RTD of about 6 to 8 mmH2O. The aerosol-forming substrate rod 212 also includes 52 milligrams of cloves. The aerosol-forming substrate rods 212 are individually wrapped with plug wrap (not shown).

[0212] The hollow tubular element 220 is located immediately downstream of the aerosol-forming substrate rod 212. The hollow tubular element 220 is in longitudinal alignment with the aerosol-forming substrate rod 212. The upstream end of the hollow tubular element 220 abuts the downstream end of the aerosol-forming substrate rod 212.

[0213] The hollow tubular element 220 defines a hollow section of the aerosol-generating article 10. The hollow tubular element does not contribute substantially to the overall RTD of the aerosol-generating article. More specifically, the RTD of the hollow tubular element 220 is about 0 mmH2O.

[0214] The hollow tubular element 220 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular element 220 defines an interior cavity 222 that extends from the upstream end of the hollow tubular element 220 all the way to the downstream end of the hollow tubular element 220. The interior cavity 222 is substantially empty and thus allows for substantially unrestricted airflow along the interior cavity 222. The hollow tubular element 220 does not substantially contribute to the overall RTD of the aerosol-generating article 200.

[0215] In this embodiment, hollow tubular element 220 has a length of about 21 millimeters, an outer diameter of about 7.2 millimeters, and an inner diameter of about 6.7 millimeters. The peripheral wall thickness of hollow tubular element 20 is therefore about 0.25 millimeters.

[0216] The aerosol-generating article 200 comprises a ventilation zone 230 provided at a location along the hollow tubular element 20. In this embodiment, the ventilation zone 230 is provided at a location that is about 16 millimeters from the downstream end 218 of the article 200. The ventilation zone 230 is provided at a location about 12 mm downstream from the downstream end of the aerosol-forming substrate rod 122. In this embodiment, the ventilation zone 230 is provided at a location about 9 millimeters upstream from the upstream end of the mouthpiece element 204. The ventilation zone 230 comprises a circumferential row of openings or perforations surrounding the hollow tubular element 220. The perforations of the ventilation zone 230 extend through the wall of the hollow tubular element 220 to allow ingress of fluid from the exterior of the article 200 into the interior cavity 22. The ventilation level of the aerosol-generating article 210 is about 16 percent.

[0217] The ventilation zone 230 may also include a circumferential row of perforations provided on the upstream wrapper 244. The perforations of the upstream wrapper 244 overlap the perforations provided on the hollow tubular element 220. As a result, the upstream wrapper 244 overlies the perforations of the ventilation zone 230 provided on the hollow tubular element 220.

[0218] The mouthpiece element 204 extends from the downstream end of the hollow tubular element 220 to the downstream or mouth end of the aerosol-generating article 200. The mouthpiece element 204 has a length of about 7 mm. The outer diameter of the mouthpiece element 204 is about 7.2 mm. The mouthpiece element 204 comprises a low density cellulose acetate filter segment. The RTD of the mouthpiece element 204 is about 8 millimeters HO. The mouthpiece element 204 may be individually wrapped with plug wrap (not shown).

[0219] The aerosol generating device 100, together with the aerosol-generating article 200 as shown in FIG. 1, may be referred to as an aerosol generating system.

[0220] The aerosol generating device 100 of the aerosol generating system comprises a heater assembly including a heating element 110. The heating element 110 surrounds the cavity 10 along with a portion of the cavity in which the aerosol-forming substrate of the aerosol-generating article 200 is received. In an alternative embodiment, the heating element 110 forms part of the housing 11 that defines a portion of the cavity that receives the aerosol-forming substrate. The heating element 110 is a resistive heating element.

[0221] The airflow channel 120 extends from an air inlet 122 of the aerosol generating device 100. Upstream of the cavity, the airflow channel 120 is defined primarily by airflow channel walls 124. Downstream of the airflow channel walls 124, the airflow channel 120 passes through an air outlet defined in the base 12 of the cavity. The airflow channel 120 then extends through the cavity 10. When an aerosol-generating article 200 is received within the cavity 10, the airflow channel 120 passes through the aerosol-generating article 200 and extends through the mouthpiece 204.

[0222] The aerosol generating device 100 further comprises a power source 130 in the form of a rechargeable battery for powering the heating element 110, which is controllable by a control circuit 132. The power source is connected to the control circuit 132 and the heating element 110 via wires and connections not shown in the figure. The aerosol generating device may comprise further elements not shown in the figure, such as a button for activating the aerosol generating device.

[0223] A use session of the aerosol generating device 100 begins after a user of the aerosol generating device turns the device on, for example, using a button or switch on the aerosol generating device. The use session includes a use session start corresponding to the point at which the aerosol generating device 100 is started, and a use session end corresponding to the point at which the aerosol generating device 100 is turned off.

[0224] Starting up the aerosol generating device 100 at the start of a use session causes the control circuit 132 to supply power from the power supply 130 to the heating element 110, causing current to pass through the heating element 110, causing heating of the heating element 110. Heat is transferred to the aerosol-forming substrate, causing volatile compounds to be vaporized from the aerosol-forming substrate.

[0225] During a usage session, the user takes multiple puffs on the mouthpiece 204 of the received aerosol-generating article 200. During each user puff, inhalation of the mouthpiece 204 of the received aerosol-generating article 200 results in air being drawn through the airflow channel 120 towards the user's mouth. During a puff, air is drawn from outside the aerosol-generating device through the air inlet 122 defined in the base 12 of the cavity 10 and into the cavity, through the air inlet and into the airflow channel 120. Because the aerosol-generating article 200 is received in the cavity 10, the air drawn into the cavity 10 will enter the aerosol-generating article 200 at its distal end 216. Thus, the air passes through the aerosol-forming substrate 212. In doing so, volatile compounds generated by heating of the substrate 212 become entrained in the air. As the air continues toward the mouth end of the aerosol-generating article 200, the volatile compounds cool and form an aerosol, which is then inhaled by the user of the device.

[0226] The control circuitry 132 includes a memory in which a plurality of distinct predetermined heating profiles are stored. As described in more detail below, the control circuitry 132 is configured to control the supply of power to the heater assembly in accordance with one or more of the predetermined heating profiles throughout a usage session. Specifically, a first predetermined heating profile and a second predetermined heating profile are stored in the memory of the control circuitry 132, and the control circuitry 132 is configured to select one of the first predetermined heating profile and the second predetermined heating profile based on the determined puff behavior.

[0227] The predefined heating profiles are effectively instructions for the control circuitry to control the supply of power to the heater assembly such that the heating element is heated with reference to a number of target temperatures. Each predefined heating profile includes information regarding the value of the target temperatures, the sequence of the target temperatures, and the length of time for which the control circuitry is configured to supply power to the heater assembly for each respective target temperature. Each predefined heating profile is configured to assume a particular user puff behavior to ensure consistent aerosol generation throughout an entire use session.

[0228] 3 is a graph 300 representing a first predetermined heating profile and a second predetermined heating profile stored in the memory of control circuit 132. Graph 300 is schematic and is not drawn to scale.

[0229] The graph 300 includes time on the x-axis 302 and temperature on the y-axis 304 and shows a complete use session with the use session beginning at t=0 seconds. The use session is divided into a first period 306 and second periods 308a, 308b.

[0230] The first period includes a first period starting at t=0 seconds and further includes a first period end corresponding to a second period start, whereby the first period and second period are sequential.

[0231] The first predetermined heating profile is represented on the graph 300 by 310 and the second predetermined heating profile is represented by 312. The first and second predetermined heating profiles each include four target temperatures that change in a step-wise manner as the use session progresses.

[0232] The initial target temperatures for each of the first and second predetermined heating profiles are the same throughout the first time period 306, such that an initial portion of the first predetermined heating profile is the same as an initial portion of the second predetermined heating profile.

[0233] The initial target temperature for each of the first and second predetermined heating profiles is higher than the subsequent target temperature of the predetermined heating profile. Thus, when either the first or second predetermined heating profile is selected, power is supplied to the heater assembly to rapidly increase the temperature of the heating element at the beginning of a use session.

[0234] The first predetermined heating profile 310 differs from the second predetermined heating profile 312 after the first time period 306. Specifically, each of the second through fourth target temperatures of the first heating profile 310 is lower than the respective second through fourth target temperatures of the second heating profile 312. Moreover, the first predetermined heating profile 310 includes heating the heating element to each of the second through fourth target temperatures for a longer period of time than each of the second through fourth target temperatures of the second heating profile 312.

[0235] The first predefined heating profile 310 is suitable for a different user puff behavior relative to the second predefined heating profile 312. In particular, the longer and cooler first predefined heating profile 310 is suitable for a user puff behavior having a longer average puff interval and a lower average puff frequency than the second user puff behavior.

[0236] The second time period includes the end of the second time period corresponding to the end of the usage session. Because the first predetermined heating profile is longer than the second predetermined heating profile, the second time period varies depending on which predetermined heating profile is selected. Specifically, second time period 308a on graph 300 corresponds to the second time period when the first predetermined heating profile is selected, and second time period 308b corresponds to the second time period when the second predetermined heating profile is selected.

[0237] Figure 4 is a flow diagram of a method for controlling power supplied to a heater assembly of an aerosol generating device 100 during a use session. Figure 5 is a graph 500 of the temperature of the heater element 110 during a use session in which a user follows a first user puff behavior and the method of Figure 4 is applied. Graph 500 is schematic and not drawn to scale.

[0238] Similar to graph 300, graph 500 includes time on x-axis 502 and temperature on y-axis 504, and shows a complete use session with the use session beginning at t=0 seconds. The use session is divided into a first period 506 and a second period 508a.

[0239] Step 402 of the method for controlling power supplied to a heater assembly of an aerosol generating device 100 during a use session includes supplying power to the heater assembly during a first time period 506 according to an initial portion of a first predetermined heating profile. As described with respect to Figure 3, the target temperature during the first time period 306, 506 is high so that the temperature of the heating element 100 rises rapidly to the operating temperature at the start of the first time period 506, thereby generating an aerosol for the user to inhale during the user puff.

[0240] The initial portions of the first and second predetermined heating profiles are the same, so in the alternative, method step 302 includes controlling the power supplied to the heater assembly during the first time period 506 according to the initial portion of the second predetermined heating profile. The graph 500 will look the same during the first time period 506 regardless of whether the first predetermined heating profile or the second predetermined heating profile is followed initially.

[0241] Method step 404 includes determining a user puff behavior during a first period of time 506 of the usage session. In particular, the user puff behavior is the average interval between puffs during the first period of time.

[0242] The average interval between puffs is determined by detecting individual user puffs during a first period of time by detecting a temporary decrease in temperature of the heating element 110. The decrease in temperature of the heating element 110 is caused by air being drawn through the aerosol generating device 100 during a user puff which, in use, has a cooling effect on the heating element 110. As such, puffs are indicated in Figure 5 by valleys 510. The valleys 510 can be used to identify individual puffs.

[0243] The interval between subsequent individual puffs can be determined once the individual puffs are identified by measuring the time between the start of each subsequent puff. Because the first period is long enough to produce three or more puffs, a number of puff intervals for subsequent puffs can be calculated throughout the first period. An average of those puff intervals can then be calculated. The average of the first period 506 is 36 seconds.

[0244] In this embodiment, the control circuitry 132 is configured to perform steps 402 and 404 of the method 400. The aerosol generating device 100 includes a temperature sensor (not shown) configured to measure the temperature of the heating element 110. The control circuitry 132 is configured to receive a signal from the temperature sensor and detect a user puff based on a change (e.g., a decrease) in the temperature of the heating element 110. The control circuitry is then configured to calculate an average puff interval based on the determined interval between subsequent puffs.

[0245] In an alternative embodiment, the heating element 110 comprises a material having a temperature-dependent electrical resistance. For example, the heating element 110 is preferably made of a material whose resistance increases as temperature resistance increases, and whose relationship between resistance and temperature is substantially linear, at least within the operating temperature range of the heating element 110. In this embodiment, the control circuitry 132 is configured to monitor the electrical resistance of the heating element 110. The electrical resistance can then be used to estimate or calculate the temperature of the heating element 110. Specifically, the control circuitry is configured to detect a user puff based on a decrease in the resistance of the heating element 110, which is indicative of a decrease in the temperature of the heating element 110.

[0246] Method step 406 includes using the determined user puff behavior for the first time period to select one of a plurality of predefined heating profiles stored in memory of control circuitry 132 for a second time period. Specifically, method step 406 includes comparing the determined average puff interval for the first time period 506 determined in method step 404 to a predefined threshold. If the determined average puff interval is greater than the predefined threshold, the first predefined heating profile is selected. If the determined average puff interval is less than or equal to the predefined threshold, the second predefined heating profile is selected.

[0247] In this example, the predetermined threshold is 25 seconds. The determined average time between puffs for the first time period 506 is 36 seconds (i.e., greater than the predetermined threshold). Therefore, a first predetermined heating profile is selected in method step 406.

[0248] Step 408 of the method includes controlling the supply of power to the heating assembly in accordance with the selected predetermined heating profile until the end of the second time period. Thus, as the first predetermined heating profile is selected in step 406 of the embodiment of Figure 5, the method includes continuing to control the supply of power to the heating assembly in accordance with the first predetermined heating profile during the second time period.

[0249] Graph 500 of Figure 5 shows the outcome of the method of Figure 4 when a user follows a first user puff behavior. Figure 6 shows a graph 600 of the temperature of the heater element 110 during a usage session where the user instead follows a second user puff behavior and the method of Figure 4 is applied. Graph 600 is schematic and not drawn to scale.

[0250] Steps 402 and 404 of method 400 are the same as described above. However, the puff interval in Figure 6 is shorter than the puff interval in Figure 5. Thus, the average puff interval determined in step 404 of the method is shorter when the user follows the second user puff behavior than the first user puff behavior. The average puff interval for the second user puff behavior of Figure 6 in the first time period is 20 seconds.

[0251] 20 seconds is less than the predetermined threshold, and so in method step 406, a second predetermined heating profile is selected. Method step 408 includes controlling the supply of power to the heating assembly during a second time period according to the second predetermined heating profile. Specifically, method step 408 includes controlling the supply of power to the heating assembly following an initial portion according to a portion of the second predetermined heating profile, which corresponds to the portion of the second predetermined heating profile in second time period 308b of FIG. 3.

[0252] Because the second predetermined heating profile is shorter than the first predetermined heating profile, the use session of Figure 6 is shorter than the use session of Figure 5. Similarly, the second period 508b of Figure 6 is shorter than the second period 508a of Figure 5.

[0253] In the embodiment described above, method step 402 includes supplying heat to the heater assembly according to an initial portion of the first (or second) predetermined heating profile for a first period of time 506. In an alternative embodiment, the first predetermined heating profile, the second predetermined heating profile, and the third predetermined heating profile are each stored in a memory of the control circuitry 132.

[0254] The third predetermined heating profile has a duration corresponding to the duration of the first period 506 and is identical to the initial portions of the first predetermined heating profile and the second predetermined heating profile described with respect to FIG.

[0255] The first and second predetermined heating profiles in this example do not include the initial portion and correspond to the portions of the first and second predetermined heating profiles described with respect to FIG. 3 for the second time periods 308a, 308b, respectively.

[0256] In this alternative, method step 402 includes supplying power to the heater assembly during a first time period 506 according to a third predetermined heating profile, step 406 includes selecting one of the first and second predetermined heating profiles for a second time period using the user puff behavior determined for the first time period, and step 408 includes controlling the supply of power to the heating assembly according to the selected predetermined heating profile until the end of the second time period.

[0257] In the above embodiment, the first period has a fixed duration of 100 seconds. Of course, other durations for the first period can be used, but it is advantageous for the first period to last for several puffs.

[0258] In some alternatives, the first period is not constant. Instead, the end of the first period is when the control circuit detects that a predetermined number of puffs have occurred since the start of the first period. Specifically, the predetermined number of puffs is three puffs. The method of controlling the power supplied to the heater assembly of the aerosol generating device 100 during a use session in this embodiment is essentially the same as that described with respect to FIG. 4. The only difference is that the first period has a dynamic length rather than a fixed length.

Claims

1. 1. An aerosol generating device for generating an aerosol from an aerosol-generating article comprising an aerosol-forming substrate, the aerosol being configured to generate the aerosol during a use session comprising a start of a use session, an end of the use session, and at least a first period and a second period between the start of the use session and the end of the use session; a heater assembly for heating the aerosol-forming substrate; a power source configured to provide power to the heater assembly; a control circuit including a memory in which a plurality of different predefined heating profiles are stored; the control circuitry is configured to determine a user puff behavior during the first period of the use session, to select one of the plurality of predefined heating profiles using the determined user puff behavior, and to control the supply of power to the heater assembly during the second period in accordance with the selected predefined heating profile; The end of the usage session corresponds to an end of the selected predefined heating profile.

2. 2. The aerosol generating device of claim 1, wherein the determined user puffing behavior during the first period relates to at least one of puff frequency, puff interval, puff intensity, puff length, number of puffs taken, amount of aerosol generated per puff, or amount of aerosol generated during the first period.

3. 3. The aerosol generating device of claim 1, wherein the first period includes a first period start and a first period end.

4. 4. The aerosol generating device of claim 3, wherein the end of the first period is at least 20 seconds after the start of the first period.

5. 5. An aerosol generating device according to any one of claims 1 to 4, further comprising a detector configured to detect a parameter indicative of a user puff.

6. 6. The aerosol generating device according to claim 1, wherein the plurality of predetermined heating profiles comprises a first predetermined heating profile and a second predetermined heating profile.

7. The aerosol generating device of claim 6, wherein the control circuit is configured to select the first predetermined profile or the second predetermined profile based on a comparison between the detected user puffing behavior and a predetermined threshold value stored in the memory of the control circuit.

8. 8. The aerosol generating device of claim 7, wherein the predetermined threshold for the user puff behavior stored in the memory is a threshold for puff interval, average puff interval, puff frequency, or average puff frequency.

9. 9. The aerosol generating device of claim 8, wherein the predetermined threshold corresponds to an interval between puffs of between 20 seconds and 34 seconds.

10. 10. An aerosol generating device according to any one of claims 6 to 9, wherein the first predetermined heating profile has a duration at least 30% longer than the second heating profile.

11. 11. An aerosol generating device according to any one of claims 1 to 10, wherein the aerosol generating device is configured to generate an aerosol from an aerosol-forming substrate comprising an aerosol-generating article.

12. 12. The aerosol generating device of claim 11, wherein the aerosol-generating article comprises a wrapper surrounding an aerosol-forming substrate.

13. 13. The aerosol generating device according to claim 11 or 12, wherein the aerosol-forming substrate is a solid aerosol-forming substrate.

14. 1. A method of controlling power supplied to a heater assembly of an aerosol generating device for generating an aerosol from an aerosol-forming substrate during a use session, the use session including a start of a use session, an end of the use session, and at least a first period and a second period between the start of the use session and the end of the use session, comprising: determining a user smoking behavior during the first period of the use session; selecting one of a plurality of predefined heating profiles that are distinct from one another using the determined user puff behavior; and controlling the supply of power to the heater assembly during the second period in accordance with the selected predetermined heating profile; The method, wherein the end of the usage session corresponds to an end of the selected predefined heating profile.

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