Adaptable aerosol generation system and method

Abstract

An aerosol generation system is provided. The aerosol generation system includes a heating element for heating an aerosol-forming substrate. The aerosol generation system further includes a power source for supplying power to the heating element. The aerosol generation system further includes a controller. In a first mode, the controller is configured to control power to the heating element from the power source. In the first mode, the controller is further configured to measure or determine a baseline resistance of the heating element. In the first mode, the controller is further configured to measure the resistance of the heating element during one or more puffing sessions. In the first mode, the controller is further configured to compare the resistance of the heating element to the baseline resistance or to a threshold value based on the baseline resistance. In the first mode, the controller is further configured to determine a harmful condition when the resistance exceeds the baseline resistance by a first amount. In the first mode, the controller is configured to continuously adjust the first amount during the session depending on one or more parameters measured or determined by the controller.

Description

[Technical Field]

[0001] The present disclosure relates to an adaptable aerosol generation system and an adaptable method of operation for an aerosol generation system. [Background technology]

[0002] Many aerosol generating systems include a liquid storage portion for storing a liquid aerosol-forming substrate and an electric heater for heating the liquid aerosol-forming substrate. These aerosol generating systems may also include an electric circuit configured to determine the level of liquid aerosol-forming substrate remaining in the liquid storage portion or whether the liquid storage portion is depleted of liquid aerosol-forming substrate. It is particularly beneficial to avoid depleting the liquid aerosol-forming substrate to a level where insufficient liquid is supplied to the electric heater. If insufficient liquid is supplied to the electric heater and the electric heater is powered, the electric heater may reach a temperature above its intended operating temperature. This is because less liquid aerosol-forming substrate is available for the electric heater to vaporize. Excessive heat can result in excessive carbonyl production from the liquid aerosol-forming substrate remaining in the heating element and the delivery of an undesirable burnt aerosol taste to the user.

[0003] WO2018019533A1 discloses a method for determining such a harmful condition. The initial electrical resistance of an electric heater is measured, and subsequent electrical resistances of the electric heater are measured. A harmful condition is detected when the difference between the initial electrical resistance and the subsequent electrical resistance is greater than a maximum threshold or less than a minimum threshold. However, users may use these aerosol generating systems in many different ways. For example, some users may take many short puffs in rapid succession, while other users may take longer puffs with long breaks between puffs. Therefore, the aerosol generating system may adapt certain parameters depending on how the user uses the aerosol generating system to ensure consistent aerosol generation. Changes in parameters associated with how the user uses the aerosol generating system may affect the ability of previous methods to detect such harmful conditions quickly and accurately. Therefore, it would be beneficial to provide an aerosol generating system and method for determining harmful conditions that can be adapted depending on the usage characteristics of the aerosol generating system in order to detect harmful conditions more quickly and accurately. Summary of the Invention

[0004] According to the present disclosure, there is provided an aerosol generation system. The aerosol generation system includes a heating element for heating an aerosol-forming substrate. The aerosol generation system further includes a power source for supplying power to the heating element. The aerosol generation system further includes a controller. The controller is configured to control power from the power source to the heating element in a first mode. The controller may be further configured to measure or determine a baseline resistance of the heating element in the first mode. The controller may be further configured to measure the resistance of the heating element during one or more puffing sessions in the first mode. The controller may be further configured to compare the resistance of the heating element to the baseline resistance or to a threshold value based on the baseline resistance in the first mode. The controller may be further configured to determine a harmful condition in the first mode if the resistance exceeds the baseline resistance by a first amount. In the first mode, the controller may be configured to continuously adjust the first amount during the session depending on one or more parameters measured or determined by the controller.

[0005] Thus, advantageously, the aerosol generating system according to the present disclosure can be precisely adapted to how the aerosol generating system is used by the user. By varying the first amount depending on one or more parameters measured or determined by the controller, the aerosol generating system can detect a harmful condition more quickly and accurately than previous aerosol generating systems known in the art. As a result, the risk of burnt taste and carbonyl generation from a dry heating element can be minimized.

[0006] Measuring the resistance of the heating element may include measuring or determining one or more characteristics of the heating element and calculating the resistance of the heating element based on the one or more characteristics of the heating element, for example, the one or more characteristics may include one or more of a voltage across the heating element, a current through the heating element, and a conductance of the heating element.

[0007] The heating element may form part of a heating element circuit. Measuring the resistance of the heating element may include measuring or determining one or more characteristics of the heating element circuit and calculating the resistance of the heating element based on the one or more characteristics of the heating element circuit. For example, the other characteristics may include one or more of a voltage across the heating element, a voltage across another component of the heating element circuit, a current through the heating element, a current through another component of the heating element circuit, a conductance of the heating element, a conductance of another component of the heating element circuit, and a resistance of another component of the heating element circuit. The other component of the heating element circuit may be in series with the heating element. The other component of the heating element circuit may be a resistor.

[0008] The controller may be further configured in the first mode to measure or determine a baseline characteristic of the heating element. The controller may be further configured in the first mode to measure the characteristic of the heating element during one or more puffing sessions. The controller may be further configured in the first mode to compare the characteristic of the heating element to the baseline characteristic or to a threshold based on the baseline characteristic. The controller may be further configured in the first mode to determine an adverse condition if the characteristic exceeds the baseline characteristic by a first amount. In the first mode, the controller may be configured to continuously adjust the first amount during the session depending on one or more parameters measured or determined by the controller.

[0009] The characteristic quantity may be a resistance of the heating element. The characteristic quantity may be a voltage across the heating element. The characteristic quantity may be a current through the heating element. The characteristic quantity may be a conductance of the heating element. If the characteristic quantity is a conductance of the heating element, the controller may be further configured, in the first mode, to determine an adverse condition when the baseline conductance exceeds the conductance by a first amount.

[0010] The controller may be further configured in the first mode to measure or determine a baseline characteristic of the heating element circuit. The controller may be further configured in the first mode to measure the characteristic of the heating element circuit during one or more puffing sessions. The controller may be further configured in the first mode to compare the characteristic of the heating element circuit to the baseline characteristic or to a threshold based on the baseline characteristic. The controller may be further configured in the first mode to determine an adverse condition if the characteristic exceeds the baseline characteristic by a first amount. In the first mode, the controller may be configured to continuously adjust the first amount during a session depending on one or more parameters measured or determined by the controller.

[0011] The characteristic of the heating element circuit may be a voltage across a component in series with the heating element. The characteristic of the heating element circuit may be a ratio or percentage of the voltage across the heating element and the component in series with the heating element. The characteristic of the heating element circuit may be a current through the component in series with the heating element. The characteristic of the heating element circuit may be a ratio or percentage of the current through the heating element and the component in series with the heating element. The characteristic of the heating element circuit may be a conductance of the component in series with the heating element. The characteristic of the heating element circuit may be a ratio or percentage of the conductance of the heating element and the component in series with the heating element. The component in series with the heating element may be a resistor.

[0012] The aerosol generation system may be configured to display a warning to the user if the controller determines a harmful condition during one or more puffs. The aerosol generation system may be configured to display a warning to the user if the controller determines a harmful condition during a single puff. The aerosol generation system may be configured to display a warning to the user if the controller determines a harmful condition during multiple puffs. Thus, advantageously, the user may be alerted to the harmful condition and adjust their behavior accordingly, for example, by not puffing on the aerosol generation system, by refilling or replacing the aerosol-forming substrate, or by replacing the cartridge.

[0013] The controller may be configured to terminate or reduce power supplied to the heating element if the controller determines an undesirable condition during one or more puffs. Preferably, the controller may be configured to terminate or reduce power supplied to the heating element such that aerosol is not generated in the aerosol generating system if the controller determines an undesirable condition during one or more puffs. Advantageously, therefore, a user cannot generate aerosol using the aerosol generating system and is therefore not exposed to the burnt taste and risk of carbonyl generation from a dried heating element.

[0014] The controller may be configured to measure the resistance of the heating element at regular time intervals during one or more puffs. The controller may be configured to measure the resistance of the heating element at regular time intervals during each puff of the one or more puffs. Advantageously, the controller may thus quickly detect a harmful condition if it exists mid-puff.

[0015] The controller may be configured to compare the resistance of the heating element to a baseline resistance or threshold value based on the baseline resistance at regular time intervals during one or more puffs. The controller may be configured to compare the resistance of the heating element to a baseline resistance or threshold value based on the baseline resistance at regular time intervals during each puff during one or more puffs. Thus, advantageously, the controller may quickly detect an adverse condition if it exists mid-puff.

[0016] The duration of the regular time interval may be between 10 ms and 250 ms. Preferably, the duration of the regular time interval is between 0.1 ms and 100 ms, more preferably, the duration of the regular time interval is between 1 ms and 20 ms, even more preferably, the duration of the regular time interval is between 1 ms and 10 ms, and even more preferably, the duration of the regular time interval is substantially equal to 3 ms.

[0017] The controller may be configured to adjust the first amount depending on the power supplied to the heating element. The controller may be configured to adjust the first amount during each of one or more puffs depending on the power supplied to the heating element. The resistance of the heating element depends on the temperature of the heating element. When more power is supplied to the heating element, the temperature of the heating element increases and the resistance of the heating element increases. Therefore, adjusting the first amount depending on the power supplied to the heating element is advantageous because more accurate detection of an adverse condition may be achieved.

[0018] The aerosol generation system may further include an air inlet and an air outlet. The aerosol generation system may further include an airflow passage extending between the air inlet and the air outlet. The aerosol generation system may further include a sensor assembly in communication with the airflow passage. The sensor assembly may be configured to measure the pressure or flow rate within the airflow passage. The controller may be configured to adjust the first amount during each of the one or more puffs depending on the pressure or flow rate measured by the sensor assembly. The resistance of the heating element depends on the temperature of the heating element. Assuming a greater flow rate exists within the airflow passage and the same power is supplied to the heating element, the temperature of the heating element will decrease. As a result, the resistance of the heating element will decrease. Therefore, it is advantageous to adjust the first amount depending on the pressure or flow rate within the airflow passage, because more accurate detection of the harmful condition is achieved.

[0019] The controller may be configured to detect the start of a puff when a user puffs on the aerosol generation system based on the pressure or flow rate measured by the sensor assembly. The controller may be configured to adjust the first amount depending on the total number of puffs elapsed during the session. The controller may be configured to adjust the first amount depending on the total time elapsed since the start of the session. During the session, other components of the aerosol generation system surrounding the heating element will increase in temperature. As a result, less heat is lost from the heating element to other components of the aerosol generation system surrounding the heating element as the session progresses. Therefore, the resistance of the heating element will increase as the session progresses. Therefore, it is advantageous to adjust the first amount depending on the total number of puffs elapsed during the session or the total time elapsed since the start of the session, because this achieves more accurate detection of the harmful condition.

[0020] The controller may be configured to adjust the first amount during each of the one or more puffs depending on the puff time elapsed since the start of each of the one or more puffs. The controller may be configured to linearly increase the first amount during each of the one or more puffs depending on the puff time elapsed since the start of each of the one or more puffs. During each puff, other components of the aerosol generation system surrounding the heating element will increase in temperature. As a result, less heat is lost from the heating element to other components of the aerosol generation system surrounding the heating element as each puff progresses. Therefore, the resistance of the heating element will increase as each puff progresses. Therefore, it is advantageous to adjust the first amount during each of the one or more puffs depending on the puff time elapsed since the start of each of the one or more puffs, because this achieves more accurate detection of a harmful condition.

[0021] The controller may be configured to adjust the first amount depending on the amount of time that has elapsed since the end of the previous puff in the session.

[0022] The controller may be configured to calculate the scale amount after the end of each puff in the session. The scale amount may depend on the maximum value of the first amount during the previous puff in the session. The controller may be configured to adjust the scale amount depending on the time elapsed since the end of the previous puff. The controller may be configured to continuously decrease the scale amount from the maximum value during the previous puff at regular time intervals after the end of the previous puff. The controller may be configured to continuously decrease the scale amount from the maximum value by a predetermined percentage of the maximum value at regular time intervals after the end of the previous puff. The controller may be configured to adjust the first amount so that the first amount is equal to the scale amount after the end of the previous puff in the session and before the start of a subsequent puff in the session.

[0023] The controller may be configured to calculate or determine the first quantity value during each subsequent puff. The controller may be further configured to adjust the first quantity during each subsequent puff in the session so that the first quantity equals the scaled quantity until the first quantity value exceeds the scaled quantity. The controller may be further configured to adjust the first quantity during each subsequent puff in the session so that the first quantity equals the first quantity value if the first quantity value exceeds the scaled quantity at the start of the subsequent puff. The controller may be further configured to adjust the first quantity during each subsequent puff in the session so that the first quantity equals the scaled quantity unless the first quantity value exceeds the scaled quantity. The controller may be configured to adjust the first quantity during a subsequent puff in the session so that the first quantity equals the first quantity value if the first quantity value exceeds the scaled quantity during the subsequent puff in the session. The controller may be configured to adjust the first quantity during a subsequent puff in the session so that the first quantity equals the first quantity value for the remainder of the subsequent puff. The controller may be configured to adjust the first amount during subsequent puffs in a session if the first amount value exceeds the scaled amount, depending on one or more parameters measured or determined by the controller, as disclosed above. Advantageously, this ensures that a more sensitive threshold is used to identify whether an adverse condition exists.

[0024] The controller may be configured to calculate or determine the first quantity value during each subsequent puff depending on the same parameters used to calculate or determine the first quantity during the first puff. That is, the controller may be configured to calculate or determine the first quantity value during each subsequent puff depending on the power supplied to the heating element. The controller may be configured to calculate or determine the first quantity value during each subsequent puff depending on the pressure or flow rate measured by the sensor assembly. The controller may be configured to calculate or determine the first quantity value during each subsequent puff depending on the total number of puffs elapsed during the session. The controller may be configured to calculate or determine the first quantity value during each subsequent puff depending on the total time elapsed since the start of the session. The controller may be configured to calculate or determine the first quantity value during each subsequent puff depending on the puff time elapsed since the start of each subsequent puff. The controller may be configured to linearly increase the first quantity value during each subsequent puff depending on the puff time elapsed since the start of each subsequent puff. The controller may be configured to calculate or determine the first quantity value during each subsequent puff depending on the amount of time that has elapsed since the end of the previous puff in the session.

[0025] The controller may be configured to adjust the first amount depending on the ambient temperature. The resistance of the heating element depends on the temperature of the heating element. If the ambient temperature of the environment in which the aerosol generation system is located increases, the temperature of the heating element also increases because the heating element loses heat less quickly when heated. Therefore, the resistance of the heating element will increase. Therefore, adjusting the first amount depending on the ambient temperature is advantageous because more accurate detection of a hazardous condition can be achieved. The baseline resistance may be adjusted as a function of the ambient temperature before proceeding to determine the hazardous condition.

[0026] The aerosol generation system may comprise an aerosol generator and a cartridge. The cartridge may be connectable to the aerosol generator. The aerosol generator may include a controller and a power source. The cartridge may include a heating element. The controller may be configured to determine a classification of the cartridge when the cartridge is connected to the aerosol generator. The controller may be configured to adjust the first amount depending on the classification of the cartridge. Advantageously, the characteristics of the cartridge may vary depending on the classification of the cartridge. For example, the cartridges may have different heating elements that exhibit different resistance increases with temperature. Therefore, adjusting the first amount depending on the classification of the cartridge is advantageous because more accurate detection of a harmful condition may be achieved.

[0027] The controller may be configured to determine a baseline resistance of the heating element after a user connects the cartridge to the aerosol generating device.

[0028] The controller may be configured to determine the baseline resistance of the heating element after either or both of the user turning on the aerosol generation system and the user not taking a puff on the device for a predetermined cool-down period. Advantageously, the baseline resistance of the heating element is thus determined when the heater has sufficiently cooled down.

[0029] The first amount may be a first resistance equal to a percentage of the baseline resistance. Advantageously, accurate detection of an adverse condition may be achieved regardless of the initial baseline resistance of the heating element.

[0030] The controller may be configured to continuously adjust the first amount at regular time intervals during a session. The controller may be configured to continuously adjust the first amount at regular time intervals between each puff of the session. The one or more puff sessions may be multiple puff sessions.

[0031] The heating element may be a resistive heating element. The resistive heating element may take the form of a mesh, array, or weave of conductive filaments. Preferably, the heating element comprises a mesh. The conductive filaments may define interstices between the filaments, which may have a width of 10 micrometers to 100 micrometers. The conductive filaments may form a mesh with a size of 160 to 600 mesh US (±10%) (i.e., 160 to 600 filaments per inch (±10%)). The interstices preferably have a width of 75 micrometers to 25 micrometers. The open area ratio of the mesh, which is the ratio of the interstices to the total area of ​​the mesh, is preferably 25 to 56%. The mesh may be formed using different types of weave or lattice structures. Alternatively, the conductive filaments may consist of an array of filaments arranged parallel to one another. The conductive filaments may have a diameter of 10 micrometers to 100 micrometers, preferably 8 micrometers to 50 micrometers, and more preferably 8 micrometers to 39 micrometers. The filaments may have a round or flattened cross section. The area of ​​the mesh may be small, preferably 25 mm2 or less, allowing it to be incorporated into a handheld system. The mesh, array, or fabric of conductive filaments may be rectangular, for example, with dimensions of 5 mm x 2 mm. The mesh or array of conductive filaments preferably covers 10% to 50% of the area of ​​the heater assembly. More preferably, the mesh or array of conductive filaments covers 15% to 25% of the area of ​​the heater assembly. The filaments may be formed by etching a sheet material (such as foil). This may be particularly advantageous when the heater assembly comprises an array of parallel filaments. When the heating element comprises a mesh or fabric of filaments, the filaments may be individually formed or woven together.

[0032] Resistive heating elements may include etched heater elements. For example, the resistive heater element is etched into a sheet or other form of conductive material. Resistive heating elements may include stamped heater elements. For example, resistive heater elements are stamped out of a sheet or other form of conductive material. Resistive heating elements may include coil heaters. For example, a single filament or strip of conductive material formed into a coil shape. Resistive heating elements may include ceramic heaters. For example, the resistive heating element may include conductive tracks on a porous ceramic. The conductive tracks may be formed from a conductive material.

[0033] Preferred materials for the resistance heating element are 304, 316, 304L, and 316L stainless steel.

[0034] The aerosol-forming substrate may be a liquid or gel aerosol-forming substrate.

[0035] If the controller determines an adverse condition during one or more puffs, the controller may be configured to switch from the first mode to a second mode. In the second mode, the controller may be configured to confirm an adverse condition if the resistance exceeds the baseline resistance by a second amount. Advantageously, this second mode feature may allow the controller to determine whether there is in fact an adverse condition or whether an erroneous reading has resulted in a false positive result that an adverse condition exists.

[0036] The second amount may be a predetermined amount. The second amount may be a second resistance equal to a percentage of the baseline resistance. The second amount may be a second resistance equal to a percentage of the first resistance. The second amount may be different from the first amount. In the second mode, the controller may be configured to control power supplied from the power source to the heating element. In the second mode, the power supplied from the power source to the heating element may be constant for the duration of each puff of the session. In the second mode, the power supplied from the power source to the heating element during each puff of the session may be insufficient to generate an aerosol from the aerosol-forming substrate. Advantageously, this feature may prevent the heating element from overheating if an adverse condition exists in the heating element, such as insufficient liquid being supplied to the heating element. In the second mode, the controller may be configured to switch to the first mode if no adverse condition is identified by the controller within N puffs of the controller switching to the second mode, where N is an integer number of puffs. N may be an integer greater than or equal to 10 and less than or equal to 10. Preferably, N is an integer greater than or equal to 2 and less than or equal to 10. Advantageously, this prevents the controller from switching back to the first mode if the readings result in a false negative that a harmful condition is not present. The controller may be configured to detect a change in cartridge, and to switch from the second mode to the first mode if a change in cartridge is detected. The controller may be configured to switch from the first mode to the second mode if the controller determines a harmful condition within M puffs, where M may be an integer greater than or equal to 2 and may be less than or equal to 10. Advantageously, this feature may prevent the controller from switching to the second mode if only one erroneous reading results in a false positive that a harmful condition is present.

[0037] The controller may include a computer-readable memory. The computer-readable memory may store a lookup table including a plurality of power profiles and a plurality of pressure or flow rate ranges. Each of the pressure or flow rate ranges may correspond to at least one of the power profiles. The pressure or flow rate ranges may be substantially equal in size. Alternatively, the pressure or flow rate ranges may be different in size. This may mean that the pressure or flow rate ranges better match typical changes in pressure during a puff. The number of pressure or flow rate ranges in the lookup table may be between 2 and 1000, preferably between 2 and 100, more preferably between 2 and 50, even more preferably between 2 and 20, even more preferably between 2 and 15, even more preferably between 4 and 10, and most preferably between 7 and 9. In the first mode, the controller may be further configured to select a power profile from the plurality of power profiles to control the supply of power to the heating element during a puff, the selection depending on the pressure or flow rate measured by the sensor assembly. Advantageously, this feature may minimize the amount of calculation required by the controller and reduce required computing power.

[0038] The lookup table may further include a plurality of system profiles. Each of the power profiles may correspond to one of the pressure or flow rate ranges and one of the system profiles. The controller may be configured in a first mode to select a power profile from the plurality of power profiles to control the supply of power to the heating element during a puff, the selection depending on the pressure and flow rate measured by the sensor assembly and the system profile selected by the user. Advantageously, this allows the user to at least partially control the desired characteristics of the aerosol generation.

[0039] Each power profile may include multiple power values. Each of the multiple power values ​​may correspond to a range of time from the start of a puff. The time ranges may be of equal length. The time ranges may be between 0 and 2000 milliseconds. Preferably, the length of the time ranges may be between 10 and 1800 milliseconds. More preferably, the length of the time ranges may be between 50 and 1500 milliseconds. Even more preferably, the length of the time ranges may be between 200 and 1200 milliseconds. Even more preferably, the length of the time ranges may be between 600 and 1200 milliseconds. The time ranges may be of different lengths. This may mean that the time ranges best match typical pressure changes during a puff. The number of time ranges in the lookup table may be between 2 and 1000. Preferably, the number of time ranges in the lookup table is between 2 and 100, more preferably between 2 and 50, and even more preferably between 2 and 20. Even more preferably, the number of time ranges in the lookup table is between 2 and 10, more preferably between 4 and 8, and even more preferably between 5 and 7. The controller may be configured in a first mode to control the supply of power to the heating element during a puff in dependence on a plurality of power values ​​and time since the start of the puff.

[0040] Each power profile may further include a plurality of first quantity values. Each of the plurality of first quantity values ​​may correspond to one of the plurality of power values. The controller may be configured to adjust the first quantity depending on a first quantity value selected from first quantity values ​​stored in a lookup table. Advantageously, this feature may eliminate the need for the controller to calculate the first quantity, significantly reducing required computational power. The controller may be configured to adjust the first quantity to be equal to the selected first quantity value. The first quantity value may be a percentage of the baseline resistance. The controller may be configured to determine the first resistance value from the product of the selected first quantity value and the baseline resistance. The controller may be configured to adjust the first quantity to be equal to the first resistance value.

[0041] Each power profile may further include a plurality of first maximum resistance values. Each of the plurality of first maximum resistance values ​​may correspond to one of the plurality of power values ​​and one of the plurality of first quantity values. The controller may be configured to adjust the first quantity depending on both the first quantity value selected from the plurality of first maximum resistance values ​​and the selected first maximum resistance value. The controller may be configured to adjust the first quantity to be equal to the lower of the first resistance value and the selected first maximum resistance value. Advantageously, this may prevent the first quantity from being too high and therefore the controller from failing to adequately sense an adverse condition when the baseline resistance is particularly high.

[0042] The present disclosure further provides a method for determining a harmful condition in an aerosol-generating system. The aerosol-generating system may include a heating element for heating an aerosol-forming substrate. The aerosol-generating system may include a power source for providing power to the heating element. The aerosol-generating system may include a controller. The method may include controlling power to the heating element from the power source in a first mode. The method may include measuring or determining a baseline resistance of the heating element. The method may include measuring the resistance of the heating element during one or more puffing sessions. The method may include comparing the resistance of the heating element to the baseline resistance or to a threshold value based on the baseline resistance. The method may include determining a harmful condition when the resistance exceeds the baseline resistance by a first amount. The method may include continuously adjusting the first amount during the session depending on one or more parameters measured or determined by the controller.

[0043] Therefore, advantageously, the method for determining a harmful condition in an aerosol generating system according to the present disclosure can be precisely adapted to how the aerosol generating system is used by a user. When a first quantity varies depending on one or more parameters measured or determined by the controller, the method can detect a harmful condition faster and more accurately than previous methods known in the art. As a result, the risk of burnt taste and carbonyl generation from a dry heating element can be minimized.

[0044] Continuously adjusting the first amount during a session depending on the one or more parameters may include continuously adjusting the first amount during each puff of the session depending on the one or more parameters.

[0045] The method may further include displaying a warning to the user if the controller determines the harmful condition during one or more puffs. The method may further include displaying a warning to the user if the controller determines the harmful condition during a single puff. The method may further include displaying a warning to the user if the controller determines the harmful condition during multiple puffs. Thus, advantageously, the user may be alerted to the harmful condition and adjust their behavior accordingly, for example, by not puffing on the aerosol-generating system, by refilling or replacing the aerosol-forming substrate, or by replacing the cartridge.

[0046] The method may further include terminating or reducing power supplied to the heating element if the controller determines the harmful condition during one or more puffs. The method may further include terminating or reducing power supplied to the heating element if the controller determines the harmful condition during a single puff. The method may further include terminating or reducing power supplied to the heating element if the controller determines the harmful condition during multiple puffs. Advantageously, therefore, a user cannot generate aerosol using the aerosol generating system and therefore is not exposed to the burnt taste and risk of carbonyl generation from a dried heating element.

[0047] Measuring the resistance of the heating element during the one or more puff sessions may include measuring the resistance of the heating element at regular time intervals during the one or more puff sessions. Measuring the resistance of the heating element during the one or more puff sessions may include measuring the resistance of the heating element at regular time intervals during each puff of the one or more puff sessions. Advantageously, the method may thus rapidly detect a harmful condition if it exists mid-puff.

[0048] Comparing the resistance of the heating element to a baseline resistance or to a threshold value based on the baseline resistance may include comparing the resistance of the heating element to the baseline resistance or to a baseline threshold value based on the baseline resistance at regular time intervals during the one or more puffs. Comparing the resistance of the heating element to the baseline resistance or to a threshold value based on the baseline resistance may include comparing the resistance of the heating element to the baseline resistance or to a threshold value based on the baseline resistance at regular time intervals during each puff of the one or more puffs. Thus, advantageously, the method may rapidly detect an adverse condition if it exists mid-puff.

[0049] The one or more parameters may include the power supplied to the heating element. Advantageously, therefore, for the reasons discussed above, more accurate detection of the adverse condition may be achieved.

[0050] The aerosol generation system may further include an air inlet and an air outlet, and an airflow passage extending between the air inlet and the air outlet. The aerosol generation system may further include a sensor assembly in communication with the airflow passage, the sensor assembly configured to measure the pressure or flow rate within the airflow passage. The controller may be configured to detect the start of a puff when a user puffs on the aerosol generation system based on the pressure or flow rate measured by the sensor assembly. The one or more parameters may include the pressure or flow rate measured by the sensor assembly. The resistance of the heating element depends on the temperature of the heating element. Assuming a greater flow rate exists in the airflow passage and the same power is supplied to the heating element, the temperature of the heating element will decrease. As a result, the resistance of the heating element will decrease. Therefore, it is advantageous to adjust the first amount depending on the pressure or flow rate within the airflow passage, because more accurate detection of a harmful condition may be achieved.

[0051] The one or more parameters may include the total number of puffs taken during the session. During the session, other components of the aerosol generation system surrounding the heating element will experience an increase in temperature. As a result, less heat is lost from the heating element to other components of the aerosol generation system surrounding the heating element as the session progresses. Therefore, the resistance of the heating element will increase as the session progresses. Therefore, it is advantageous to adjust the first amount depending on the total number of puffs taken during the session or the total time elapsed since the start of the session, since more accurate detection of a harmful condition may be achieved.

[0052] The one or more parameters may include a total time elapsed since the start of the session. The one or more parameters may include a puff time elapsed from the start of each of the one or more puffs. Continuously adjusting the first amount during the session depending on the puff time elapsed from the start of each of the one or more puffs may include linearly increasing the first amount during each of the one or more puffs depending on the puff time elapsed from the start of each of the one or more puffs. During each puff, other components of the aerosol generation system surrounding the heating element will increase in temperature. As a result, less heat is lost from the heating element to other components of the aerosol generation system surrounding the heating element as each puff progresses. Therefore, the resistance of the heating element will increase as each puff progresses. Therefore, it is advantageous to adjust the first amount during each of the one or more puffs depending on the puff time elapsed from the start of each of the one or more puffs, because more accurate detection of a harmful condition may be achieved.

[0053] The one or more parameters may include the time elapsed since the end of the previous puff in the session. After a puff, the heating element and surrounding components begin to cool, causing the temperature of the heating element to decrease. Therefore, the resistance of the heating element also decreases, requiring a lower resistance threshold at which the harmful condition can be detected in order to accurately detect the harmful condition. Therefore, advantageously, adjusting the first amount during each of one or more puffs depending on the time elapsed since the end of the previous puff in the session enables more accurate detection of the harmful condition. The method may include the controller calculating a scale amount after the end of each puff in the session, the scale amount depending on the maximum value of the first amount during the previous puff in the session. The method may include adjusting the scale amount depending on the time elapsed since the end of the previous puff. The method may include the controller continuously decreasing the scale amount from the maximum value during the previous puff at regular time intervals after the end of the previous puff. The method may include the controller continuously decreasing the scale amount from the maximum value by a predetermined percentage of the maximum value at regular time intervals after the end of the previous puff. The method may include adjusting the first amount so that the first amount is equal to the scaled amount after the end of a previous puff in the session and before the start of a subsequent puff in the session.

[0054] The method may include calculating or determining a first quantity value during each subsequent puff, and adjusting the first quantity during each subsequent puff in the session so that the first quantity equals the scaled quantity until the first quantity value exceeds the scaled quantity. The method may include adjusting the first quantity during each subsequent puff in the session so that the first quantity equals the first quantity value if the first quantity value exceeds the scaled quantity at the start of the subsequent puff. The method may include adjusting the first quantity during each subsequent puff in the session so that the first quantity equals the scaled quantity unless the first quantity value exceeds the scaled quantity. The method may include adjusting the first quantity during each subsequent puff in the session so that the first quantity equals the first quantity value if the first quantity value exceeds the scaled quantity at the start of the subsequent puff. The method may include adjusting the first quantity during each subsequent puff in the session so that the first quantity equals the scaled quantity unless the first quantity value exceeds the scaled quantity. The method may include adjusting the first quantity during each subsequent puff in the session so that the first quantity equals the scaled quantity if the first quantity value exceeds the scaled quantity during the subsequent puff in the session. The method may include, if the first quantity value exceeds the scaled amount during a subsequent puff in the session, adjusting the first quantity during the subsequent puff such that the first quantity is equal to the first quantity value for the remainder of the subsequent puff. The method may include, if the first quantity value exceeds the scaled amount during a subsequent puff in the session, adjusting the first quantity during the subsequent puff in dependence on one or more parameters measured or determined by the controller, as disclosed above. Advantageously, this ensures that a more sensitive threshold is used to identify whether an adverse condition exists.

[0055] The method may include calculating or determining the first quantity value during each subsequent puff depending on the same parameters used to calculate or determine the first quantity during the first puff. That is, the method may include calculating or determining the first quantity value during each subsequent puff depending on the power supplied to the heating element. The method may include calculating or determining the first quantity value during each subsequent puff depending on the pressure or flow rate measured by the sensor assembly. The method may include calculating or determining the first quantity value during each subsequent puff depending on the total number of puffs elapsed during the session. The method may include calculating or determining the first quantity value during each subsequent puff depending on the total time elapsed since the start of the session. The method may include calculating or determining the first quantity value during each subsequent puff depending on the puff time elapsed since the start of each subsequent puff. The method may include linearly increasing the first quantity value during each subsequent puff depending on the puff time elapsed since the start of each subsequent puff. The method may include calculating or determining a first quantity value during each subsequent puff depending on the time elapsed since the end of the previous puff in the session. The method may include the controller adjusting the first quantity after the end of each puff in the session such that the first quantity equals the scaled quantity until the first quantity exceeds the scaled quantity.

[0056] The one or more parameters may include ambient temperature. The resistance of the heating element depends on the temperature of the heating element. If the ambient temperature of the environment in which the aerosol generating system is located increases, the temperature of the heating element also increases because the heating element loses heat less quickly when heated. Therefore, the resistance of the heating element will increase. Therefore, it is advantageous to adjust the first amount depending on the ambient temperature, as more accurate detection of a harmful condition may be achieved. The method may further include adjusting the baseline resistance depending on the ambient temperature.

[0057] The aerosol generation system may include an aerosol generator and a cartridge, the cartridge being connectable to the aerosol generator. The aerosol generator may include a controller and a power source. The cartridge may include a heating element. The method may further include the controller determining a classification of the cartridge when the cartridge is connected to the aerosol generator, and the one or more parameters may include the classification of the cartridge. Advantageously, the characteristics of the cartridge may vary depending on the classification of the cartridge. For example, the cartridges may have different heating elements that exhibit different resistance increases with temperature. Therefore, it is advantageous to adjust the first amount depending on the classification of the cartridge, as more accurate detection of a harmful condition may be achieved.

[0058] Determining the baseline resistance of the heating element may include determining the baseline resistance of the heating element after a user connects the cartridge to the aerosol generation device. Determining the baseline resistance of the heating element may include determining the baseline resistance of the heating element after a user switches the aerosol generation system on or after the user has not taken a puff on the device for a predetermined cool-down period, or both. Advantageously, the baseline resistance of the heating element is thus determined when the heater has sufficiently cooled.

[0059] The first amount may be a first resistance equal to a percentage of the baseline resistance. Advantageously, accurate detection of an adverse condition may be achieved regardless of the initial baseline resistance of the heating element.

[0060] The step of continuously adjusting the first amount during a session may include continuously adjusting the first amount at regular time intervals during the session. The one or more puffing sessions may be multiple puffing sessions.

[0061] The heating element may comprise a mesh.The aerosol-forming substrate may be a liquid aerosol-forming substrate.

[0062] The method may further include switching from the first mode to the second mode if the controller determines a harmful condition during one or more puffs.

[0063] The method may include, in the second mode, identifying an adverse condition if the resistance exceeds the baseline resistance by a second amount. The second amount may be a predetermined amount. The second amount may be a second resistance equal to a percentage of the baseline resistance. The second amount may be a second resistance equal to a percentage of the first resistance. The second amount may be different from the first amount. The method may include, in the second mode, the controller controlling power supplied from the power source to the heating element. In the second mode, the power supplied from the power source to the heating element may be constant for the duration of each puff of the session. In the second mode, the power supplied from the power source to the heating element during each puff of the session may be insufficient to generate an aerosol from the aerosol-forming substrate. Advantageously, this feature may prevent the heating element from overheating if an adverse condition exists in the heating element, such as insufficient liquid being supplied to the heating element.

[0064] The method may include the controller, in the second mode, switching to the first mode if the harmful condition is not identified by the controller within N puffs of the controller switching to the second mode, where N is an integer number of puffs. N may be an integer greater than or equal to 1 and less than or equal to 10. N may be an integer greater than or equal to 2 and less than or equal to 10. Advantageously, this prevents the controller from switching back to the first mode if the reading provides a false negative result that the harmful condition is not present. The method may include the controller, in the second mode, detecting a change in cartridge and switching from the second mode to the first mode if the change in cartridge is detected. The step of switching from the first mode to the second mode if the controller determines the harmful condition during one or more puffs may include switching from the first mode to the second mode if the controller determines the harmful condition within M puffs, where M may be an integer greater than or equal to 1 and less than or equal to 10. Advantageously, this feature may prevent the controller from switching to the second mode if only one erroneous reading results in a false positive that an adverse condition exists.

[0065] The controller may include a computer-readable memory. The computer-readable memory may store a look-up table including a plurality of power profiles and a plurality of pressure or flow rate ranges, each of the pressure or flow rate ranges corresponding to at least one of the power profiles. The method may include, in a first mode, selecting a power profile from the plurality of power profiles to control the supply of power to the heating element during a puff, the selection being dependent on the pressure or flow rate measured by the sensor assembly. Advantageously, this feature may minimize the amount of calculation required by the controller and reduce required computing power.

[0066] The lookup table may further include a plurality of system profiles. Each of the power profiles may correspond to one of the pressure or flow rate ranges and one of the system profiles. Selecting a power profile from the plurality of power profiles to control the supply of power to the heating element during a puff may depend on the system profile selected by the user. Advantageously, this allows the user to at least partially control the desired characteristics of the aerosol generation.

[0067] Each power profile may include a plurality of power values, each of which may correspond to a range of time from the start of the puff. The method may include, in a first mode, controlling the supply of power to the heating element during the puff in dependence on the plurality of power values ​​and the time from the start of the puff.

[0068] Each power profile may further include a plurality of first quantity values. Each of the plurality of first quantity values ​​may correspond to one of the plurality of power values. Adjusting the first quantity may include adjusting the first quantity depending on a first quantity value selected from a plurality of first quantity values ​​stored in a lookup table. Advantageously, this feature may eliminate the need for the controller to calculate the first quantity, significantly reducing required computational power. Adjusting the first quantity may include adjusting the first quantity to be equal to a selected first quantity value stored in the lookup table. The first quantity value is a percentage of a baseline resistance. Adjusting the first quantity may include determining a first resistance value from a product of the selected first quantity value and the baseline resistance. Adjusting the first quantity may include adjusting the first quantity to be equal to the first resistance value.

[0069] Each power profile may further include a plurality of first maximum resistance values. Each of the plurality of first maximum resistance values ​​may correspond to one of the plurality of power values ​​and one of the plurality of first quantity values. Adjusting the first quantity may include adjusting the first quantity depending on both the first quantity value selected from the plurality of first maximum resistance values ​​and the selected first maximum resistance value. Adjusting the first quantity may include adjusting the first quantity to be equal to the lower of the first resistance value and the selected first maximum resistance value. Advantageously, this may prevent the first quantity from being too high and therefore the method from failing to adequately sense an adverse condition when the baseline resistance is particularly high.

[0070] As used herein in connection with the present invention, the term "aerosol" is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. Aerosols can be visible or invisible. Aerosols may include vapors of substances that are normally liquids or solids at room temperature, as well as solid particles, or liquid droplets, or a combination of solid particles and liquid droplets.

[0071] As used herein, "aerosol-generating system" means a system that generates an aerosol from one or more aerosol-forming substrates.

[0072] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate.

[0073] As used herein, the term "puff" is used to describe the action of a user generating an aerosol using an aerosol generation system. The user performs this action by drawing air through the aerosol generation system by inhaling.

[0074] As used herein, the term "session" refers to a period of time during which the aerosol generating system is activated, for example, by a user, and includes at least one puff. During a session, the aerosol generating system may automatically detect a puff and provide power to the heating element accordingly, as described above.

[0075] As used herein, the term "puff count" refers to the number assigned to a puff of a session based on the total number of individual puffs prior to the puff.

[0076] As used herein, the term "cumulative puff time" refers to the total time elapsed during each individual puff to date during at least one puffing session.

[0077] As used herein, the term "lookup table" refers to a table or matrix stored in computer-readable memory that is accessible by a controller and from which the controller can obtain values.

[0078] As used herein, the term "power profile" refers to a look-up table that includes at least one power value and an associated duration over which the at least one power value is applied in sequence.

[0079] As used herein, the terms "air inlet" and "air outlet" are used to describe one or more openings through which air may be drawn into and out of a component or portion of a component of a cartridge, an aerosol generation system, or an aerosol generation device, respectively.

[0080] The term "cartridge" as used herein also refers to an article that includes an aerosol-forming substrate capable of emitting a volatile compound capable of forming an aerosol. The cartridge may also be disposable.

[0081] The cartridge may contain a liquid. The liquid may include a volatile compound capable of forming an aerosol. The liquid may form an aerosol upon heating the liquid. The aerosol-forming substrate may be a liquid. The aerosol-forming substrate may be a liquid at room temperature. The aerosol-forming substrate may be in another condensed form, such as a solid, at room temperature, or in another condensed form, such as a gel, at room temperature. The volatile compound may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may include both liquid and solid components. The liquid aerosol-forming substrate may include nicotine. The nicotine-containing liquid aerosol-forming substrate may be a nicotine salt matrix. The liquid aerosol-forming substrate may include a plant-derived material. The liquid aerosol-forming substrate may include tobacco. The liquid aerosol-forming substrate may include a tobacco-containing material containing volatile tobacco flavor compounds that are released from the aerosol-forming substrate upon heating. The liquid aerosol-forming substrate may include a homogenized tobacco material. The liquid aerosol-forming substrate may include a non-tobacco-containing material. The liquid aerosol-forming substrate may include a homogenized plant-derived material.

[0082] The liquid aerosol-forming substrate may contain one or more aerosol formers. The aerosol former is any suitable known compound or mixture of compounds that facilitates the formation of a dense, stable aerosol during use and is substantially resistant to thermal decomposition at the operating temperature of the system. Examples of suitable aerosol formers include glycerin and propylene glycol. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, glycerin), esters of polyhydric alcohols (e.g., glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of monocarboxylic, dicarboxylic, or polycarboxylic acids (e.g., dimethyl dodecanedioate, dimethyl tetradecanedioate). The liquid aerosol-forming substrate may contain water, solvents, ethanol, plant extracts, and natural or artificial flavors. The liquid aerosol-forming substrate may contain nicotine and at least one aerosol former. The aerosol former may be glycerin or propylene glycol. The aerosol former may include both glycerin and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of from about 0.5% to about 10%, for example, about 2%.

[0083] The heating element may be configured to be resistively heated by application of an electric current therethrough, the heating element may be configured to be inductively heated by an electric current induced in the heating element by a varying magnetic field, or the heating element may be configured to be inductively heated by the hysteresis effect.

[0084] The heating element may take any form suitable for heating the aerosol-forming substrate. In some embodiments, the heating element is fluid-permeable. The heating element may include a plurality of conductive filaments. The aerosol-generating element may include a fluid-permeable mesh. The heating element may include a plurality of gaps or openings extending from the second side to the first side and through which fluid can pass. The heating element may be, for example, an array of filaments arranged parallel to one another. Preferably, the filaments may form a mesh. Alternatively, the conductive heating element may comprise an array of filaments or a woven filament. The conductive filaments may define gaps between the filaments, which may have a width of 10 micrometers to 100 micrometers. The filaments preferably create capillary action within the gaps so that the liquid to be vaporized during use is drawn into the gaps, increasing the contact area between the heating element and the liquid aerosol-forming substrate.

[0085] The conductive filaments may have a diameter of 8 micrometers to 100 micrometers, preferably 10 micrometers to 50 micrometers, more preferably 12 micrometers to 25 micrometers, and most preferably approximately 16 micrometers. The filaments may have a round or flattened cross section.

[0086] The aerosol-generating element may be configured to be resistively heated. In other words, the aerosol-generating element may be configured to generate heat when an electric current is passed through the heating element. The heating element, or portions thereof, may comprise or be formed from any material having suitable electrical and mechanical properties, such as a suitable electrically resistive material. Suitable materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals.

[0087] The electrical resistance of the mesh, array, or weave of conductive filaments of the heater element is preferably 0.3 to 4 ohms. More preferably, the electrical resistance of the mesh, array, or weave of conductive filaments is 0.5 to 3 ohms, and more preferably about 1 ohm. The electrical resistance is preferably 0.5 ohms or greater. More preferably, the electrical resistance of the mesh, array, or weave of conductive filaments is 0.6 to 0.8 ohms, and most preferably about 0.68 ohms. Alternatively, the heating element may comprise a heating plate having an array of openings formed therein. The openings may be formed, for example, by etching or machining. The plate may be formed of any material having suitable electrical properties, such as those materials described above for the filaments of the heating element.

[0088] The aerosol generating device may include a power source, such as a battery. The power source may be a DC power source. The power source may be a battery. The battery may be a lithium-based battery, such as a lithium cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery. The battery may be a nickel metal hydride battery or a nickel cadmium battery. The power source may be another form of charge storage device, such as a capacitor.

[0089] The power source may be connected to the heating element. The aerosol generating device may comprise a controller. The controller may be connected to the power source. The controller may be connected to the heating element. The controller may control the supply of power from the power source to the heating element. The controller may control the temperature of the heating element. The controller may comprise a microcontroller. The microcontroller may be a programmable microcontroller.

[0090] The aerosol generation system may be a handheld aerosol generation system. The aerosol generation system may be a handheld aerosol generation system configured to allow a user to draw on the mouthpiece to draw the aerosol through the first air outlet. The aerosol generation system may have a size comparable to a conventional cigar or cigarette. The aerosol generation system may have a total length of about 25 mm to about 150 mm. The aerosol generation system may have an outer diameter of about 5 mm to about 30 mm. [Example]

[0091] 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 any other example, embodiment, or aspect described herein.

[0092] Example 1 1. An aerosol generating system comprising: a heating element for heating the aerosol-forming substrate; a power supply for supplying power to the heating element; a controller, In a first mode, controlling power from a power supply to a heating element; measuring or determining the baseline resistance of the heating element; measuring the resistance of the heating element during one or more smoking sessions; comparing the resistance of the heating element to a baseline resistance or to a threshold value based on the baseline resistance; a controller configured to determine an adverse condition when the resistance exceeds a baseline resistance by a first amount; An aerosol generation system, wherein in a first mode, the controller is configured to continuously adjust the first amount during a session depending on one or more parameters measured or determined by the controller. Example 2. 2. The aerosol generation system of example 1, wherein the aerosol generation system is configured to display a warning to a user if the controller determines a harmful condition during one or more puffs. Example 3 An aerosol generation system as described in either Example 1 or 2, wherein the controller is configured to terminate or reduce the power supplied to the heating element if the controller determines a harmful condition during one or more puffs. Example 4. An aerosol generating system as described in any one of Examples 1 to 3, wherein the controller is configured to measure the resistance of the heating element at regular time intervals during one or more smoking sessions. Example 5. An aerosol generation system as described in Example 4, wherein the controller is configured to compare the resistance of the heating element with a baseline resistance or threshold value based on the baseline resistance at certain time intervals during one or more smoking sessions. Example 6 An aerosol generation system described in any of Examples 1 to 5, wherein the controller is configured to adjust the first amount during each of one or more puffs depending on the power supplied to the heating element. Example 7 7. The aerosol generation system according to any one of Examples 1 to 6, further comprising an air inlet and an air outlet, and an airflow passage extending between the air inlet and the air outlet. Example 8 An aerosol generation system as described in Example 7, wherein the aerosol generation system further comprises a sensor assembly in communication with the airflow passage, the sensor assembly being configured to measure pressure or flow within the airflow passage. Example 9. An aerosol generation system as described in Example 8, wherein the controller is configured to adjust the first amount during each of the one or more puffs depending on the pressure or flow rate measured by the sensor assembly. Example 10. An aerosol generation system as described in Example 8 or 9, wherein the controller is configured to detect the start of a puff when a user puffs on the aerosol generation system based on the pressure or flow rate measured by the sensor assembly. Example 11 An aerosol generation system as described in any of Examples 1 to 10, wherein the controller is configured to adjust the first amount depending on the total number of puffs elapsed during the session. Example 12 12. An aerosol generation system according to any one of Examples 1 to 11, wherein the controller is configured to adjust the first amount depending on the total time elapsed since the start of the session. Example 13 An aerosol generation system described in any of Examples 1 to 12, wherein the controller is configured to adjust the first amount during each of the one or more puffs depending on the puffing time elapsed from the start of each of the one or more puffs. Example 14. An aerosol generation system as described in Example 13, wherein the controller is configured to linearly increase the first amount during each of the one or more puffs depending on the puffing time elapsed from the start of each of the one or more puffs. Example 15. An aerosol generation system as described in any of Examples 1 to 14, wherein the controller is configured to adjust the first amount depending on the time elapsed since the end of the previous puff in the session. Example 16. An aerosol generating system described in any of Examples 1 to 15, wherein the controller is configured to calculate the amount of scale after the end of each puff in a session, and the amount of scale depends on the maximum value of the first amount in the previous puff in the session, and is configured to adjust the amount of scale depending on the time elapsed since the end of the previous puff. Example 17. An aerosol generating system as described in Example 16, wherein the controller is configured to continuously reduce the amount of scale from the maximum value during the previous puff at regular time intervals after the end of the previous puff. Example 18. An aerosol generating system as described in Example 17, wherein the controller is configured to continuously reduce the scale amount from the maximum value by a predetermined percentage of the maximum value at regular time intervals after the end of the previous puff. Example 19. An aerosol generation system described in any of Examples 16 to 18, wherein the controller is configured to adjust the first amount so that the first amount is equal to the scaled amount after the end of a previous puff in a session and before the start of a subsequent puff in the session. Example 20. An aerosol generation system as described in Example 19, wherein the controller is configured to calculate or determine the first quantity value during each subsequent puff, and the controller is further configured to adjust the first quantity during each subsequent puff in the session so that the first quantity is equal to the scaled quantity until the first quantity value exceeds the scaled quantity. Example 21. An aerosol generation system as described in Example 20, wherein the controller is configured to calculate or determine the first quantity value during each subsequent puff depending on the power supplied to the heating element. Example 22. An aerosol generation system as described in Example 20 or 21 when dependent on Example 8, wherein the controller is configured to calculate or determine a first quantity value during each subsequent puff depending on the pressure or flow rate measured by the sensor assembly. Example 23. An aerosol generation system described in any of Examples 20 to 22, wherein the controller is configured to calculate or determine the first quantity value during each subsequent puff depending on the total number of puffs elapsed during the session. Example 24. An aerosol generation system described in any of Examples 20 to 23, wherein the controller is configured to calculate or determine the first quantity value during each subsequent puff depending on the total time elapsed since the start of the session. Example 25. An aerosol generation system described in any of Examples 20 to 24, wherein the controller is configured to calculate or determine the first quantity value during each subsequent puff depending on the puff time elapsed from the start of each subsequent puff. Example 26. An aerosol generation system as described in Example 25, wherein the controller is configured to linearly increase the first quantity value during each subsequent puff depending on the puff time elapsed from the start of each subsequent puff. Example 27. An aerosol generation system described in any of Examples 20 to 26, wherein the controller is configured to calculate or determine the first quantity value during each subsequent puff depending on the time elapsed since the end of the previous puff in the session. Example 28. 28. An aerosol generation system according to any one of Examples 1 to 27, wherein the controller is configured to adjust the first amount depending on the ambient temperature. Example 29. 29. The aerosol generation system according to any one of Examples 1 to 28, comprising an aerosol generation device and a cartridge, the cartridge being connectable to the aerosol generation device. Example 30. 30. The aerosol generation system of Example 29, wherein the aerosol generation device comprises a controller and a power supply. Example 31. An aerosol generation system as described in Example 29 or 30, wherein the cartridge contains a heating element. Example 32. An aerosol generation system as described in Example 31, wherein the controller is configured to determine a classification of the cartridge when the cartridge is connected to the aerosol generation device, and the controller is configured to adjust the first amount depending on the classification of the cartridge. Example 33. An aerosol generation system described in any of Examples 29 to 32, wherein the controller is configured to determine the baseline resistance of the heating element after a user connects the cartridge to the aerosol generation device. Example 34. An aerosol generation system described in any of Examples 1 to 33, wherein the controller is configured to determine the baseline resistance of the heating element after one or both of the user turning the aerosol generation system on or the user not taking a puff on the device for a predetermined cooling period. Example 35. 35. The aerosol generating system of any of Examples 1-34, wherein the first amount is a first resistance equal to a percentage of the baseline resistance. Example 36. An aerosol generation system described in any of Examples 1 to 35, wherein the controller is configured to continuously adjust the first amount at regular time intervals during a session. Example 37. 37. The aerosol generating system of any one of Examples 1 to 36, wherein the one or more puffing sessions is a plurality of puffing sessions. Example 38. 38. The aerosol generating system of any one of Examples 1 to 37, wherein the heating element comprises a mesh. Example 39. 39. The aerosol-generating system according to any one of Examples 1 to 38, wherein the aerosol-forming substrate is a liquid or gel aerosol-forming substrate. Example 40. An aerosol generation system described in any of Examples 1 to 39, wherein the controller is configured to switch from the first mode to the second mode if the controller determines a harmful condition during one or more puffs. Example 41. An aerosol generation system as described in Example 40, wherein in the second mode, the controller is configured to identify a harmful condition when the resistance exceeds the baseline resistance by a second amount. Example 42. The aerosol generation system of Example 41, wherein the second amount is a second resistance equal to a percentage of the baseline resistance. Example 43. 43. An aerosol generating system according to any one of Examples 40 to 42, wherein in the second mode, the controller is configured to control the power supplied from the power source to the heating element. Example 44. An aerosol generation system as described in Example 43, wherein in the second mode, the power supplied from the power source to the heating element is constant for the duration of each puff of the session. Example 45. 45. An aerosol generation system as described in Example 43 or 44, wherein in the second mode, the power supplied from the power source to the heating element during each puff of the session is insufficient to generate an aerosol from the aerosol-forming substrate. Example 46. An aerosol generation system described in any of Examples 40 to 45, configured to switch to the first mode if, in the second mode, a harmful condition is not identified by the controller within N puffs of the controller switching to the second mode, where N is an integer number of puffs. Example 47. An aerosol generation system as described in Example 46, wherein N is an integer greater than or equal to 1 and less than or equal to 10. Example 48. An aerosol generation system described in any of Examples 40 to 46 when dependent on Example 29, wherein the controller is configured to detect a change in the cartridge and to switch from the second mode to the first mode when a change in the cartridge is detected. Example 49. An aerosol generating system described in any of Examples 40 to 48, wherein the controller is configured to switch from the first mode to the second mode if the controller determines a harmful condition during M puffs, where M is an integer greater than or equal to 1 and less than or equal to 10. Example 50. 50. An aerosol generation system as described in any one of Examples 1 to 49, wherein the controller comprises a computer-readable memory. Example 51. An aerosol generation system as described in Example 50, when dependent on Example 8, wherein the computer-readable memory stores a lookup table including a plurality of power profiles and a plurality of pressure or flow rate ranges, each of the pressure or flow rate ranges corresponding to at least one of the power profiles, and the controller is further configured, in the first mode, to select a power profile from the plurality of power profiles to control the supply of power to the heating element during puffing, the selection depending on the pressure or flow rate measured by the sensor assembly. Example 52. An aerosol generation system as described in Example 51, wherein the lookup table further includes a plurality of system profiles, each of the power profiles corresponding to one of the pressure or flow rate ranges and one of the system profiles, and the controller is configured, in the first mode, to select a power profile from the plurality of power profiles to control the supply of power to the heating element during puffing, the selection depending on the pressure or flow rate measured by the sensor assembly and the system profile selected by the user. Example 53. An aerosol generation system as described in Example 51 or 52, wherein each power profile includes multiple power values, each of the multiple power values ​​corresponding to a range of time from the start of the puff, and the controller is configured, in a first mode, to control the supply of power to the heating element during the puff depending on the multiple power values ​​and the time from the start of the puff. Example 54. An aerosol generation system as described in Example 53, wherein each power profile further includes a plurality of first quantity values, each of the plurality of first quantity values ​​corresponding to one of the plurality of power values. Example 55. An aerosol generating system as described in Example 54, wherein the controller is configured to adjust the first amount depending on a first amount value selected from first amount values ​​stored in a lookup table. Example 56. 56. An aerosol generation system as described in Example 55, wherein the controller is configured to adjust the first amount to be equal to a selected first amount value. Example 57. 57. The aerosol generating system of any one of Examples 54 to 56, wherein the first quantity is a percentage of the baseline resistance. Example 58. An aerosol generation system as described in Example 57, wherein the controller is configured to determine the first resistance value from the product of the selected first quantity value and the baseline resistance. Example 59. An aerosol generation system as described in Example 58, wherein the controller is configured to adjust the first amount to be equal to the first resistance value. Example 60. An aerosol generation system as described in Example 55, wherein each power profile further includes a plurality of first maximum resistance values, each of the plurality of first maximum resistance values ​​corresponding to one of the plurality of power values ​​and one of the plurality of first quantity values, and the controller is configured to adjust the first quantity from the plurality of first maximum resistance values ​​depending on both the selected first quantity value and the selected first maximum resistance value. Example 61. An aerosol generation system as described in Example 60, wherein the controller is configured to adjust the first amount to be equal to the lower of the first resistance value and a selected first maximum resistance value. Example 62. 1. A method for determining a harmful condition in an aerosol-generating system, comprising: a heating element for heating the aerosol-forming substrate; a power supply for supplying power to the heating element; a controller; The method is controlling power from a power supply to a heating element in a first mode; measuring or determining the baseline resistance of the heating element; measuring the resistance of the heating element during one or more puffing sessions; comparing the resistance of the heating element to a baseline resistance or to a threshold value based on the baseline resistance; determining an adverse condition if the resistance exceeds the baseline resistance by a first amount; and continually adjusting the first amount during the session depending on one or more parameters measured or determined by the controller. Example 63. The method of example 62, wherein the method further comprises displaying a warning to the user if the controller determines a harmful condition during one or more puffs. Example 64. The method of example 62 or 63, wherein the method further comprises the step of terminating or reducing the power supplied to the heating element if the controller determines a harmful condition during one or more puffs. Example 65. The method of any of Examples 62-64, wherein measuring the resistance of the heating element during one or more puffing sessions comprises measuring the resistance of the heating element at regular time intervals during the one or more puffing sessions. Example 66. The method described in Example 65, wherein comparing the resistance of the heating element to a baseline resistance or to a threshold value based on the baseline resistance comprises comparing the resistance of the heating element to a baseline resistance or to a threshold value based on the baseline resistance at regular time intervals during one or more smoking sessions. Example 67. 67. The method of any of Examples 62-66, wherein the one or more parameters include power supplied to the heating element. Example 68. 68. The method of any one of Examples 62-67, wherein the aerosol generation system further comprises an air inlet and an air outlet, and an airflow passage extending between the air inlet and the air outlet. Example 69. The method of Example 68, wherein the aerosol generation system further comprises a sensor assembly in communication with the airflow passage, the sensor assembly configured to measure pressure or flow within the airflow passage. Example 70. 70. The method of example 69, wherein the one or more parameters include a pressure or a flow rate measured by the sensor assembly. Example 71. The method described in example 69 or 70, wherein the controller is configured to detect the start of a puff when a user puffs on the aerosol generation system based on the pressure or flow rate measured by the sensor assembly. Example 72. The method of any one of Examples 62-71, wherein the one or more parameters include the total number of puffs elapsed during the session. Example 73. 73. The method of any one of Examples 62 to 72, wherein the one or more parameters include a total time elapsed since the start of the session. Example 74. 74. The method of any one of Examples 62-73, wherein the one or more parameters comprise puff time elapsed from the start of each of the one or more puffs. Example 75. The method described in Example 74, wherein continuously adjusting the first amount during a session depending on the puff time elapsed from the start of each of the one or more puffs comprises linearly increasing the first amount during each of the one or more puffs depending on the puff time elapsed from the start of each of the one or more puffs. Example 76. The method of any one of Examples 62-75, wherein the one or more parameters include the time elapsed since the end of the previous puff in the session. Example 77. 77. A method according to any of Examples 62 to 76, wherein the method includes the controller calculating the scale amount after the end of each puff in the session, the scale amount being dependent on the maximum value of the first amount in the previous puff in the session, and adjusting the scale amount depending on the time elapsed since the end of the previous puff. Example 78. 78. The method of example 77, wherein the method includes the controller continuously decreasing the amount of scale from the maximum value during the previous puff at regular time intervals after the end of the previous puff. Example 79. The method of Example 78, wherein the controller continuously reduces the scale amount from the maximum value by a predetermined percentage of the maximum value at regular time intervals after the end of the previous puff. Example 80. 80. The method of any one of Examples 77-79, comprising adjusting the first amount such that the first amount is equal to the scaled amount after the end of a previous puff in a session and before the start of a subsequent puff in the session. Example 81. The method of Example 80, wherein the method includes calculating or determining the first quantity value during each subsequent puff, and adjusting the first quantity during each subsequent puff in the session so that the first quantity is equal to the scaled quantity until the first quantity value exceeds the scaled quantity. Example 82. 82. The method of example 81, wherein the method comprises calculating or determining the first quantity value during each subsequent puff depending on the power supplied to the heating element. Example 83. The method of example 81 or 82 when dependent on example 69, wherein the method includes calculating or determining a first quantity value during each subsequent puff depending on the pressure or flow rate measured by the sensor assembly. Example 84. 84. The method of any of Examples 81 to 83, wherein the method comprises calculating or determining a first quantity value during each subsequent puff depending on the total number of puffs elapsed during the session. Example 85. 85. The method of any of Examples 81-84, wherein the method comprises calculating or determining the first quantity value during each subsequent puff depending on the total time elapsed since the start of the session. Example 86. 86. The method of any of Examples 81-85, wherein the method comprises calculating or determining the first quantity value during each subsequent puff depending on the amount of puff time that has elapsed since the start of each subsequent puff. Example 87. 87. The method of example 86, wherein the method comprises linearly increasing the first amount value during each subsequent puff depending on the amount of puff time that has elapsed since the start of each subsequent puff. Example 88. 88. The method of any of Examples 81-87, wherein the method comprises calculating or determining the first quantity value during each subsequent puff depending on the time elapsed since the end of the previous puff in the session. Example 89. 89. The method of any one of Examples 81-88, wherein the method includes the controller adjusting the first amount after the end of each puff in the session such that the first amount is equal to the scaled amount until the first amount exceeds the scaled amount. Example 90. The method of any one of Examples 62-89, wherein the one or more parameters include ambient temperature. Example 91. The method of any one of Examples 62 to 90, wherein the aerosol generation system comprises an aerosol generation device and a cartridge, the cartridge being connectable to the aerosol generation device. Example 92. 92. The method of example 91, wherein the aerosol generating device comprises a controller and a power source. Example 93. 93. The method of example 91 or 92, wherein the cartridge comprises a heating element. Example 94. 94. The method of example 93, wherein the method further comprises the step of the controller determining a classification of the cartridge when the cartridge is coupled to the aerosol generating device, and the one or more parameters comprise a classification of the cartridge. Example 95. The method of any of Examples 91 to 94, wherein the step of determining the baseline resistance of the heating element comprises determining the baseline resistance of the heating element after the user connects the cartridge to the aerosol generating device. Example 96. The method described in any one of Examples 62 to 95, wherein the step of determining the baseline resistance of the heating element includes determining the baseline resistance of the heating element after one or both of the user turning on the aerosol generation system or the user not taking a puff on the device for a predetermined cooling period. Example 97. The method of any one of Examples 62-96, wherein the first amount is a first resistance equal to a percentage of the baseline resistance. Example 98. The method described in any one of Examples 62 to 97, wherein the step of continuously adjusting the first amount during the session comprises continuously adjusting the first amount at regular time intervals during the session. Example 99. The method of any one of Examples 62 to 98, wherein the one or more puffing sessions is a plurality of puffing sessions. Example 100. The method of any one of Examples 62 to 99, wherein the heating element comprises a mesh. Example 101. The method of any one of Examples 62 to 100, wherein the aerosol-forming substrate is a liquid aerosol-forming substrate. Example 102. The method of any one of Examples 62-101, wherein the method further comprises switching from the first mode to the second mode if the controller determines a harmful condition during one or more puffs. Example 103. The method of example 102, wherein the method includes, in the second mode, identifying an adverse condition if the resistance exceeds the baseline resistance by a second amount. Example 104. The method of example 103, wherein the second amount is a second resistance equal to a percentage of the baseline resistance. Example 105. 105. The method of example 103 or 104, wherein the method includes, in the second mode, the controller controlling power supplied from the power source to the heating element. Example 106. The method of example 105, wherein in the second mode, the power supplied from the power source to the heating element is constant for the duration of each puff of the session. Example 107. 107. The method of any one of claims 105 to 106, wherein in the second mode, the power supplied by the power source to the heating element during each puff of the session is insufficient to generate an aerosol from the aerosol-forming substrate. Example 108. 108. The method of any one of Examples 102-107, wherein the method includes the controller switching to the first mode if, in the second mode, no harmful condition is identified by the controller within N puffs of the controller switching to the second mode, where N is an integer number of puffs. Example 109. The method of Example 108, wherein N is an integer greater than or equal to 1 and less than or equal to 10. Example 110. A method according to any one of Examples 102 to 109 when dependent on Example 91, wherein the method includes, in the second mode, the controller detecting a change in the cartridge, and switching from the second mode to the first mode when the change in the cartridge is detected. Example 111. 111. The method of any of Examples 102-110, wherein switching from the first mode to the second mode when the controller determines a harmful condition during one or more puffs comprises switching from the first mode to the second mode when the controller determines a harmful condition during M puffs, where M is an integer greater than or equal to 1 and less than or equal to 10. Example 112. 112. The method of any one of embodiments 62 to 111, wherein the controller comprises a computer-readable memory. Example 113. The method of Example 112 when dependent on Example 69, wherein the computer-readable memory stores a lookup table including a plurality of power profiles and a plurality of pressure or flow rate ranges, each of the pressure or flow rate ranges corresponding to at least one of the power profiles, and the method includes, in a first mode, selecting a power profile from the plurality of power profiles to control the supply of power to the heating element during puffing, wherein the selection depends on the pressure or flow rate measured by the sensor assembly. Example 114. The method described in Example 113, wherein the lookup table further includes a plurality of system profiles, each of the power profiles corresponding to one of the pressure or flow rate ranges and one of the system profiles, and in the step of selecting a power profile from the plurality of power profiles to control the supply of power to the heating element during puffing, the selection also depends on the system profile selected by the user. Example 115. A method as described in Example 113 or 114, wherein each power profile includes a plurality of power values, each of the plurality of power values ​​corresponding to a range of time from the start of the puff, and the method is configured, in a first mode, to control the supply of power to the heating element during the puff depending on the plurality of power values ​​and the time from the start of the puff. Example 116. The method of example 115, wherein each power profile further includes a plurality of first quantity values, each of the plurality of first quantity values ​​corresponding to one of the plurality of power values. Example 117. 117. The method of example 116, wherein adjusting the first amount comprises adjusting the first amount depending on a first amount value selected from a plurality of first amount values ​​stored in a lookup table. Example 118. 118. The method of example 117, wherein adjusting the first amount comprises adjusting the first amount to be equal to a selected first amount value stored in a lookup table. Example 119. The method of any one of Examples 116-118, wherein the first quantity is a percentage of baseline resistance. Example 120. 120. The method of example 119, wherein adjusting the first amount comprises determining the first resistance value from the product of the selected first amount value and the baseline resistance. Example 121. 121. The method of example 120, wherein adjusting the first amount comprises adjusting the first amount to be equal to the first resistance value. Example 122. The method described in Example 117, wherein each power profile further includes a plurality of first maximum resistance values, each of the plurality of first maximum resistance values ​​corresponding to one of the plurality of power values ​​and one of the plurality of first quantity values, and the step of adjusting the first quantity includes adjusting the first quantity depending on both the first quantity value selected from the plurality of first maximum resistance values ​​and the selected first maximum resistance value. Example 123. 123. The method of example 122, wherein adjusting the first amount comprises adjusting the first amount to be equal to the lower of the first resistance value and a selected first maximum resistance value.

[0093] The embodiments will now be further described with reference to the figures. [Brief explanation of the drawings]

[0094] [Figure 1a] FIG. 1a is a schematic diagram of a system according to an embodiment of the present invention. [Figure 1b]FIG. 1b is a schematic diagram of a system according to an embodiment of the present invention. [Figure 1c] FIG. 1c is a schematic diagram of a system according to an embodiment of the present invention. [Figure 1d] FIG. 1d is a schematic diagram of a system according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded view of a cartridge for use in the system shown in FIGS. 1a-1d. [Figure 3] FIG. 3 is a detailed view of the heater filaments showing the meniscus of the liquid aerosol-forming substrate between the filaments. [Figure 4a] FIG. 4a is a schematic diagram of the change in resistance of the heater during a user puff. [Figure 4b] FIG. 4b is a schematic illustration of the change in resistance of the heater during a user puff. [Figure 5] FIG. 5 is an electrical diagram illustrating how the resistance of a heating element may be measured. [Figure 6] FIG. 6 is a flow chart illustrating a method for determining a hazardous condition in an aerosol generating system. [Figure 7a] FIG. 7a is a table showing multiple power profiles, each associated with a system profile value and a pressure differential range. [Figure 7b] FIG. 7b is a table showing one of several power profiles. [Figure 8] FIG. 8 is a graph showing the change in the first amount during a sequence of two puffs. [Figure 9a] FIG. 9a is a graph showing the change in first volume during a series of four puffs and the corresponding measured change in resistance of the heating element. [Figure 9b] FIG. 9b is a graph showing the change in pressure drop and power supplied to the heating element during a sequence of four puffs as shown in FIG. 9a. DETAILED DESCRIPTION OF THE INVENTION

[0095] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are understood to be modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Accordingly, in this context, the number A is understood as A ± 10%. Within this context, the number A may be considered to include a numerical value that is within the typical standard error for measurement of the property that the number A modifies. In some instances, as used in the appended claims, the number A may deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

[0096] 1a-1d are schematic diagrams of an aerosol generation system including a cartridge according to an embodiment of the present invention. Figure 1a is a schematic diagram of an aerosol generation device 10 and a separate cartridge 20, which together form the aerosol generation system. In this example, the aerosol generation system is an electrically operated smoking system.

[0097] The cartridge 20 contains an aerosol-forming substrate and is configured to be received within a cavity 18 in the device. The cartridge 20 should be replaceable by the user when the aerosol-forming substrate provided therein is depleted. Figure 1a shows the cartridge 20 just prior to insertion into the device, with arrow 1 in Figure 1a indicating the direction of insertion of the cartridge.

[0098] The aerosol generating device 10 is portable and has a size comparable to that of a conventional cigar or cigarette. The device 10 includes a main body 11 and a mouthpiece portion 12. The main body 11 contains a battery 14 (e.g., a lithium iron phosphate battery), an electrical circuit 16, and a cavity 18. The electrical circuit 16 includes a programmable microprocessor. The mouthpiece portion 12 is connected to the main body 11 by a hinged connection 21 and is movable between an open position shown in FIG. 1 and a closed position shown in FIG. 1d. The mouthpiece portion 12 is positioned in the open position to allow insertion and removal of a cartridge 20 and in the closed position when the system is used to generate aerosol. The mouthpiece portion includes multiple air inlets 13 and air outlets 15. During use, a user inhales or puffs on the outlets, drawing air from the air inlets 13 through the mouthpiece portion and into the outlets 15, then into the user's mouth or lungs. An internal baffle 17 is provided to force air flow through the mouthpiece portion 12 and past the cartridge.

[0099] Cavity 18 has a circular cross section and is sized to receive housing 24 of cartridge 20. Electrical connectors 19 are provided on the sides of cavity 18 to provide electrical connections between control electronics 16 and battery 14 and corresponding electrical contacts on cartridge 20.

[0100] Figure 1b shows the system of Figure 1a with the cartridge inserted into cavity 18 and cover 26 removed. In this position, the electrical connector rests against the electrical contacts on the cartridge.

[0101] FIG. 1c shows the system of FIG. 1b with cover 26 completely removed and mouthpiece portion 12 moved to the closed position.

[0102] Figure 1d shows the system of Figure 1c with mouthpiece portion 12 in the closed position. Mouthpiece portion 12 is held in the closed position by a clasp mechanism. In the closed position, mouthpiece portion 12 keeps the cartridge in electrical contact with electrical connector 19 so that a good electrical connection is maintained during use regardless of the orientation of the system.

[0103] FIG. 2 is an exploded view of cartridge 20. Cartridge 20 includes a generally cylindrical housing 24 having a size and shape selected to be received within cavity 18. The housing contains capillary material 27, 28 immersed in a liquid aerosol-forming substrate. In this example, the aerosol-forming substrate comprises 39 weight percent glycerin, 39 weight percent propylene glycol, 20 weight percent water and flavorings, and 2 weight percent nicotine. The capillary material is a material that actively transports liquid from one end to the other and may be made from any suitable material. In this example, the capillary material is formed from polyester.

[0104] The housing has an open end in which a heater assembly 30 is secured. The heater assembly 30 includes a base 34 having an opening 35 formed therein, a pair of electrical contacts 32 secured to the base and separated from one another by a gap 33, and a plurality of conductive heater filaments 36 secured across the opening to the electrical contacts on opposite sides of the opening 35.

[0105] The heater assembly 30 is covered by a removable cover 26. The cover comprises a liquid-impermeable plastic sheet that is adhered to the heater assembly but can be easily peeled away. Tabs are provided on the sides of the cover to allow the user to grasp the cover when peeling it away. It will be apparent to those skilled in the art that although adhesion is described as a method of securing the impermeable plastic sheet to the heater assembly, other methods familiar to those skilled in the art may also be used, including heat sealing or ultrasonic welding, so long as the cover can be easily removed by the consumer.

[0106] The cartridge of FIG. 2 includes two separate capillary materials 27, 28. A disk of the first capillary material 27 is provided to contact the heater elements 36, 32 during use. A larger body of the second capillary material 28 is provided on the opposite side of the first capillary material 27 to the heater assembly. Both the first and second capillary materials hold a liquid aerosol-forming substrate. The first capillary material 27, which contacts the heater elements, has a higher thermal decomposition temperature (at least 160°C or higher, e.g., about 250°C) than the second capillary material 28. The first capillary material 27 effectively acts as a spacer, separating the heater elements 36, 32 from the second capillary material 28, so that the second capillary material is not exposed to temperatures above its thermal decomposition temperature. A thermal gradient across the first capillary material ensures that the second capillary material is exposed to temperatures below its thermal decomposition temperature. The second capillary material 28 can be selected to have superior wicking performance to the first capillary material 27, can hold more liquid per unit volume than the first capillary material, and can be less expensive than the first capillary material. In this example, the first capillary material is a heat-resistant element such as glass fiber or a glass fiber-containing element, and the second capillary material is a polymer, such as a suitable capillary material. Exemplary suitable capillary materials include those discussed herein and, in alternative embodiments, can include high density polyethylene (HDPE) or polyethylene terephthalate (PET).

[0107] The capillary material 27, 28 is advantageously oriented within the housing 24 to deliver the liquid to the heater assembly 30. When the cartridge is assembled, the heater filaments 36, 37, 38 may contact the capillary material 27 so that the aerosol-forming substrate can be delivered directly to the mesh heater. Figure 3 is a detailed view of the filaments 36 of the heater assembly, showing the meniscus 40 of the liquid aerosol-forming substrate between the heater filaments 36. It can be seen that the aerosol-forming substrate contacts most of the surface of each filament, such that most of the heat generated by the heater assembly enters directly into the aerosol-forming substrate.

[0108] Thus, during normal operation, the liquid aerosol-forming substrate contacts a large portion of the surface of the heater filament 36. However, when most of the liquid substrate in the cartridge is used, less liquid aerosol-forming substrate is delivered to the heater filament. With less liquid to vaporize, less energy is taken up by the enthalpy of vaporization, and more of the energy supplied to the heater filament is directed toward raising its temperature. As the heater element dries out, the rate at which the heater element heats up for a given applied power increases. The heater element may dry out because the aerosol-forming substrate in the cartridge is nearly used up, or because the user takes very long or very frequent puffs and is unable to deliver liquid to the heater filament as fast as it can vaporize.

[0109] In use, the heater assembly operates by resistive heating. Under the control of the control electronics 16, an electrical current is passed through the filament 36, heating it to a desired temperature range. The mesh or array of filaments has a significantly higher electrical resistance than the electrical contacts 32 and electrical connector 19, so that the high temperature is localized to the filament. In this example, the system is configured to generate heat by providing an electrical current to the heater assembly in response to a user's puff. In another embodiment, the system may be configured to generate heat continuously while the device is in the "on" state. Different materials for the filament may be appropriate for different systems. For example, in a continuous heating system, a Ni-Cr filament is appropriate because of its relatively low specific heat capacity and compatibility with low-current heating. In a puff-operated system in which heat is generated in short bursts using high-current pulses, a stainless steel filament with a high specific heat capacity may be more appropriate.

[0110] The system includes a puff sensor configured to detect when a user draws air through the mouthpiece portion. The puff sensor (not shown) is connected to the control electronics 16, which is configured to supply current to the heater assembly 30 only when it is determined that the user is puffing on the device. Any suitable airflow sensor, such as a microphone or pressure sensor, may be used as the puff sensor.

[0111] To detect this increase in the rate of temperature change, electrical circuitry 16 is configured to measure the electrical resistance of the heater filament. The heater filament in this embodiment is made from stainless steel and therefore has a positive temperature coefficient of resistance. This means that as the temperature of the heater filament increases, so does its electrical resistance.

[0112] FIG. 4a is a schematic diagram of the change in resistance R of the heater during a user puff P1. The x-axis is time after detection of the initial user puff and the resulting application of power to the heater. The y-axis is the electrical resistance of the heater assembly. The heater assembly has an initial resistance R before heating occurs. base It can be seen that R base is composed of the parasitic resistance (Rp) resulting from the electrical contacts 32 and electrical connector 19 and the contacts therebetween, and the resistance of the heater filament (R0). When power is applied to the heater during a user's puff, the temperature of the heater filament increases, causing the electrical resistance of the heater filament to increase. Illustratively, at time t1, the resistance of the heater assembly is R base At time t2, the resistance of the heater assembly is R base +ΔR.

[0113] Thus, the change in electrical resistance of the heater assembly from the initial resistance at time t1 to the resistance at time t2 is AR.

[0114] In this example, it is assumed that the parasitic resistance Rp does not change as the heater filament heats up, since Rp is due to unheated components such as electrical contacts 32 and electrical connector 19. The value of Rp is assumed to be the same for all cartridges, and the value is stored in the memory of the electrical circuitry.

[0115] The relationship between the resistance of a heater filament and its temperature is given by the following equation: R = R0(1+αΔT)+Rp (1) where α is the temperature coefficient of electrical resistance of the heater filament, and ΔT is the change in temperature between the initial temperature before power is applied to the heater at time t1 and the temperature at time t2.

[0116] In this example, the first quantity is the baseline resistance R base The ratio value is stored in a computer readable memory and is a ratio of the first quantity ΔR ac is the percentage value and the baseline resistance R base In another embodiment, the ratio value is determined from the product of a first quantity ΔR stored in computer readable memory. ac It may be itself.

[0117] A harmful condition, such as a dry condition in the heating element, is deemed to exist if the temperature of the heating element rises above a maximum temperature by time t2, causing the resistance of the heating element to rise by more than a first amount. In other words, if the resistance of the heating element rises above the adverse event resistance limit R ac If the blood pressure rises above this level, an adverse condition is considered to exist.

[0118] An example of a detected adverse event is shown in Figure 4b. Figure 4b is a schematic diagram of the change in resistance R of the heater during a user puff P2 after P1. At the start of the puff at time t3, the resistance R is higher than the baseline resistance determined before the first puff P1. This is because residual heat remains in the heating element from the first puff P1. After the first puff P1, insufficient liquid remains in the capillary material 27, 28 of the cartridge 20 to be delivered to the heating element. Therefore, during the second puff P2, the temperature of the heating element, and therefore the resistance, increases at a fast rate, and the resistance decreases at time t ac In R ac Exceeds.

[0119] If an unsafe condition is determined by the aerosol generating system, the aerosol generating system may display a warning to the user, for example, via an LED light on the aerosol generating device body 11. The aerosol generating system may also, or alternatively, shut off or reduce the power supplied to the heating element from the power source. The aerosol generating system may also, or alternatively, enter a second operating mode to determine if an unsafe condition exists within the aerosol generating system. The second mode is described in more detail with reference to FIG. 8.

[0120] The resistance of the heater R is a measurement. Specifically, the resistance R is measured at regular time intervals throughout each puff, and R base is compared with the value of R base The value of R is measured before any heating occurs, i.e., before the heater is first turned on, and that measured value is used for all subsequent puffs. This avoids any errors introduced by residual heat from previous puffs. base R may be measured only once for each cartridge and a detection system used to determine when a new cartridge is inserted, or R base may be measured every time the system is switched on.

[0121] Other adverse conditions besides a dry heater condition may also be detected in this manner. For example, if a cartridge has a damaged or incompatible heater, the electrical circuitry can be configured to detect this and not provide power to it. In this example, the heater filaments are formed from stainless steel. If one or more heater filaments break, the resistance of the heating element increases. This increase in resistance can then be detected using the process described above.

[0122] Figure 5 is a schematic electrical diagram showing how the resistance of a heating element may be measured. In Figure 5, heater 501 is connected to a battery 503 that provides a voltage V2. The heater resistance measured at a particular time is R. An additional resistor 505 with known resistance r is inserted in series with heater 501 and connected to voltage V1, which is midway between ground and voltage V2. In order for microprocessor 507 to measure the resistance R of heater 501, it can determine both the current through heater 501 and the voltage across heater 501. The resistance can then be determined using the well-known formula: V=IR (2)

[0123] In Figure 5, the voltage across the heater is V2-V1 and the current through the heater is I. That is,

number

[0124] Using an additional resistor 505 whose resistance r is known, again using (1) above, determine the current I. The current through resistor 505 is I and the voltage across resistor 505 is V. That is,

number

[0125] Therefore, combining (5) and (6) gives:

number

[0126] Thus, the microprocessor 507 can measure V2 and V1, and since r is known, determine the heater resistance R heater at different times when the aerosol generating system is in use. The electrical circuitry can then control the power supply to the heater in several different ways after a hazardous condition is detected. Alternatively, or additionally, the electrical circuitry may simply indicate to the user that a hazardous condition has been detected. The system may include an LED or display, or may be equipped with a microphone, and these components may be used to alert the user to the hazardous condition.

[0127] 6 is a flow chart illustrating a method for detecting a harmful condition in an aerosol generation system. In a first step 600, the insertion of a cartridge into the device, including a heater, is detected. Then, in step 610, the device is powered on by a user pressing a button on the device housing from an off state to an on state. In step 610, the baseline electrical resistance R of the heater is measured. base At step 620, the user initiates a session by puffing on the aerosol generating system. The pressure sensor detects the start of the session due to a pressure drop across the pressure sensor. Power is then supplied to the heating element from the power supply. Also at step 620, the controller determines a first quantity, ΔR ac Determine the first quantity ΔR ac is dependent on one or more parameters determined by the controller. For example, the first quantity ΔR ac may depend on the power supplied to the heating element from the power supply. ac may depend on the pressure or flow rate measured by the pressure sensor. ac may depend on the number of previous puffs in the session, and / or the total elapsed time in the session, and / or the time elapsed since the start of the current puff.ac may depend on the ambient temperature, which may be provided by a temperature sensor within the aerosol generating device or from a remote server to which the aerosol generating system is connected. ac may depend on the classification of the cartridge coupled to the aerosol generating device. Methods and devices for determining the classification of the cartridge are common in the art and include, but are not limited to, optical sensing of an indicator on the cartridge using a sensor in the aerosol generating device and measuring the resistance of the heating element of the cartridge. In step 630, the controller measures the resistance R of the heating element using the method described in connection with FIG. 5. Also in step 630, the controller compares the resistance R of the heating element with the baseline resistance R. base The resistance R of the heating element is compared to at least a first amount ΔR ac Only the baseline resistance R base If the first quantity ΔR exceeds the first quantity ΔR, a harmful condition is determined. If a harmful condition is not determined, the method proceeds to step 640. At step 640, the controller determines whether a session is still in progress. This is determined by whether a button on the housing is still in the on state. An alternative method of determining whether a session is still in progress may also be based on comparing the time since the end of the last puff to a threshold time. If a session is not in progress, the method proceeds to 650, where the system is turned off. If a session is still in progress, the method loops back to step 620, where the first quantity ΔR is ac is again determined and the resistance R of the heating element is measured.

[0128] Alternatively, if an adverse condition is determined in step 630, the method proceeds to step 660. In this embodiment, only one occurrence of the adverse condition is necessary for the method to proceed to step 660. However, in an alternative embodiment, the method proceeds to step 660 only if the adverse condition is detected within a predetermined number of puffs (a predetermined number stored in computer-readable memory).

[0129] In step 660, the controller switches from the first mode described in steps 620-640 to a second mode in which an adverse condition is identified. In step 660, the controller determines a second amount. In this example, the second amount is a second resistance equal to a percentage of the baseline resistance. The controller also provides power to the heating element. During the second mode, the power is insufficient to generate an aerosol from the aerosol-forming substrate.

[0130] In step 670, the controller measures the resistance R of the heating element using the method described in connection with Figure 5. Also in step 670, the controller compares the resistance R of the heating element with a baseline resistance R base The resistance R of the heating element is compared to the baseline resistance R by at least a second amount. base If the value of R exceeds the first amount, an adverse condition is confirmed. If an adverse condition is not confirmed, the method proceeds to step 680. This may indicate, for example, a random large error in reading the heating element resistance R during step 630. At step 680, the controller determines whether a session is still in progress. This is determined by whether the button on the housing is still in the on state. If a session is not in progress, the method proceeds to 650, where the system is turned off. If a session is still in progress, the method loops back to step 620, where the system returns to operating in the first mode and measures the first amount ΔR ac is again determined and the resistance R of the heating element is measured.

[0131] In this example, only one adverse condition needs to be identified in order for the method to proceed to step 680. However, in an alternative embodiment, the method proceeds to step 680 only if the adverse condition has not been identified for a predetermined number of puffs (a predetermined number stored in computer-readable memory). In this alternative embodiment, the method instead loops back to steps 660 and 670 until the adverse condition has not been identified for the predetermined number of puffs.

[0132] Alternatively, if an hazardous condition is identified in step 670, the method proceeds to step 690. In this example, only one hazardous condition needs to be identified for the method to proceed to step 690. In step 690, the user is alerted to the hazardous condition by turning on an LED light. Power to the heating element is also stopped. In this example, the aerosol-generating system may be operable in the first mode again once the cartridge is replaced with a new cartridge or once the cartridge is refilled with an aerosol-forming substrate.

[0133] In step 620, the controller calculates a first quantity ΔR, which may depend on a number of the parameters listed above. ac In an alternative embodiment, the first amount may be calculated by the controller based on one or more of the above parameters. However, in this embodiment, during each puff, the first amount is determined from a lookup table stored in computer-readable memory. FIG. 7a shows an example of the first lookup table. The first lookup table includes a plurality of power profile values, each associated with a system profile value and a pressure differential. During each puff of a session, the controller selects a power profile from the first lookup table depending on the system profile value and the instantaneous pressure differential measured by the pressure sensor. The system profile value is selected by a user and stored in computer-readable memory. In this example, the system profile value is selected by the user using an external device, such as a smartphone, connected to the aerosol generating device. In another embodiment, the system profile value may be selected by the user using at least one button or interface located on the housing of the aerosol generating device. Thus, by adjusting the system profile, the user can control at least a portion of the aerosol generation.

[0134] FIG. 7b shows an example of a power profile table. This power profile table has an associated power profile value and can be selected by the controller using a first lookup table depending on the system profile value and the pressure differential. The power profile table includes multiple phases, six in this example. Each phase has an associated duration. In this example, each duration is 1000 milliseconds long. Each phase also has an associated power value that is delivered to the heating element for the associated duration. When each duration expires, the controller moves to the next phase in the power profile and delivers power according to the power value of the next phase. In this example, during the first phase, 4500 milliwatts of power is delivered from the power supply to the heating element. In each of the following phases, 4000 milliwatts of power is delivered to the heating element.

[0135] Each power profile is generated using multiple percent resistance increases (ΔR % Each resistance percentage increase value is associated with one of each of the phases and one of each of the power values. In each phase, a first quantity ΔR ac is the baseline resistance ΔR base and the percent increase in resistance ΔR %The first amount is calculated by the controller from the product of (a) and (b). Thus, the first amount is equal to a percentage of the baseline resistance. In this example, during the first phase, the percent increase in resistance is 90%. In the second phase, the percent increase in resistance is lower, at 85%. This is because the power supplied to the heating element is lower during the second phase compared to the first phase. Therefore, the temperature of the heating element, and therefore the expected resistance, is lower during the second phase than during the first phase. From the third through sixth phases, the percent increase in resistance steadily increases, up to 89% in the sixth phase. This is due to the increasing length of time since the start of the puff, which in turn increases the temperature of the aerosol-generating device components surrounding the heating element. Therefore, heat loss from the heating element to these surrounding components decreases as the length of time since the start of the puff increases, which in turn increases the resistance of the heating element.

[0136] Each power profile has multiple maximum resistance increases (ΔR max Each maximum resistance increase value is associated with one of the phases and further includes a first quantity ΔR ac The controller acts as a maximum value for the baseline resistance ΔR base and the percent increase in resistance ΔR % and if the output value is greater than the associated maximum resistance increase value, the first quantity is instead set equal to the associated maximum resistance increase value. This can be done, for example, by base This example implements a more accurate method for determining whether a harmful condition exists when the resistance is abnormally high. max ) value is set equal to 100 milliohms. However, multiples of the maximum resistance increase (ΔR max ) value may be adjusted based on the resistance of the heating element used, so that multiples of the maximum resistance increase (ΔR max ) value may be, for example, 50 milliohms to 500 milliohms.

[0137] FIG. 8 shows a graph of a first quantity varying during a session including two puffs, P1 and P2. During the first puff, the first quantity, represented by a first solid line 702, reaches a first maximum value 704. During the first puff P1, the controller periodically determines the resistance of the heating element to determine whether a harmful condition exists. The end of the first puff P1 is determined by the controller when the pressure difference measured by the pressure sensor falls below a predetermined threshold. After the first puff ends, the controller begins determining a scaled quantity, represented by a dashed line 708. The scaled quantity 708 depends on the first maximum value 704 and the time elapsed since the end of the first puff P1. The time after the first puff is divided into five different periods 706. During each period 706, the maximum value is further reduced. In this example, each period 706 is 1 second long. In the first period, the maximum value is reduced by 1%. In the second period, the maximum value is reduced by 1.5%. In the third period, the maximum value is reduced by 2%. In the fourth period, the maximum value is reduced by 2.5%. In the fifth period, the maximum value is reduced by 3%. A second puff P2 is detected by the controller and pressure sensor during four of these periods. The controller determines a first quantity value for the second puff as described above, indicated by dashed line 710. However, for a first portion of the second puff, the first quantity value determined by the controller is less than the scaled quantity. Therefore, the first quantity is made equal to the scaled quantity until the first quantity value equals the scaled quantity. The first quantity used by the controller to determine whether a harmful condition exists is indicated by solid line 712. Once the first quantity value equals the scaled quantity, the first quantity equals the first quantity value determined by the controller. This scaling process is repeated for sessions including three or more puffs. The maximum value 714 of the first quantity during the second puff is used in determining the first quantity during the third puff.

[0138] Figure 9a shows the change in pressure difference measured by the pressure sensor during four different puff sessions. Figure 9a also shows the power supplied to the heating element during four puff sessions. During the first two puffs, the pressure difference and the power supplied to the heating element follow similar patterns. During the third puff, the pressure difference measured by the pressure sensor is significantly greater throughout the duration of the puff. During the third puff, the power supplied to the heating element follows a similar pattern to that of the first two puffs. This indicates that the user is puffing much harder on the aerosol-generating system. During the fourth puff, the pressure difference follows a similar pattern to that of the first two puffs. However, in the fourth puff, the power supplied to the heating element is significantly reduced compared to the first three puffs.

[0139] Figure 9b shows the change in resistance of the heating element as measured by the controller during the same four puffs as Figure 9a. Figure 9b also shows the adverse event resistance limit R during the session. ac During the first two puffs, the resistance of the heating element and the adverse event resistance limit R ac follows a similar pattern. The resistance of the heating element rises throughout each of the first two puffs, and the rate of increase decreases during each puff. The adverse event resistance limit R ac increases as each of the first two puffs progresses until leveling off, as described with respect to Figure 7b. During the third puff, the resistance measured by the controller is lower than the first two puffs. This is due to the stronger puff by the user resulting in more rapid heat loss from the heating element, hence the reduced resistance. At the start of the third puff, the adverse event resistance limit R determined by the controller ac is lower than at the beginning of the first puff and the second puff. This is because the power delivered at the beginning of the third puff is lower than the power delivered at the beginning of the first puff and the second puff. During the third puff, the adverse event resistance limit R acthen rises as the third puff progresses, as described with respect to Figure 7b. During the fourth puff, the resistance of the heating element as measured by the controller is lower than the first two puffs, but follows a pattern similar to that of the first two puffs. The resistance rises throughout the fourth puff, rising more rapidly at first before slowing down. At the start of the fourth puff, the adverse event resistance limit R determined by the controller ac is higher than the start of the first, second, and third puffs because the time between the third and fourth puffs is less than the time between the first and second puffs or the time between the second and third puffs. Thus, the scaling process described in Figure 8 scales the adverse event resistance limit R ac Adverse Event Resistance Limit R ac is the adverse event resistance limit R from the third puff. ac decreases at the beginning of the fourth puff after scaling of the previous maximum value of . Since the power supplied to the heating element throughout the fourth puff is lower than for the first, second, and third puffs, the adverse event resistance limit R ac is lower than the first, second and third puffs.

[0140] It will also be apparent that the present invention may be implemented within existing aerosol generation systems as a computer program product for execution on a programmable controller, which may be provided as a piece of downloadable software or on a computer-readable medium such as a compact disc.

[0141] The above-described exemplary embodiments are illustrative and not limiting. In light of the exemplary embodiments discussed above, other embodiments consistent with the above exemplary embodiments will be apparent to those skilled in the art.

Claims

1. 1. An aerosol generating system comprising: a heating element for heating the aerosol-forming substrate; a power source for supplying power to the heating element; a controller, in a first mode, controlling the power from the power source to the heating element; measuring or determining the baseline resistance of the heating element; measuring the resistance of the heating element during one or more smoking sessions; comparing the resistance of the heating element to the baseline resistance or to a threshold value based on the baseline resistance; a controller configured to determine an adverse condition when the resistance exceeds the baseline resistance by a first amount; An aerosol generation system wherein, in the first mode, the controller is configured to continuously adjust the first amount during the session depending on one or more parameters measured or determined by the controller.

2. 10. The aerosol generating system of claim 1, wherein the aerosol generating system is configured to display a warning to a user if the controller determines a harmful condition during one or more puffs.

3. 3. The aerosol generating system of claim 1 or 2, wherein the controller is configured to stop or reduce power supplied to the heating element if the controller determines a harmful condition during one or more puffs.

4. An aerosol generating system as described in any one of claims 1 to 3, wherein the controller is configured to adjust the first amount during each of the one or more puffs depending on the power supplied to the heating element.

5. An aerosol generating system as described in any one of claims 1 to 4, wherein the controller is configured to adjust the first amount depending on the time elapsed since the end of the previous puff in the session.

6. 6. The aerosol generating system of claim 5, wherein the controller is configured to calculate a scale amount after the end of each puff in the session, the scale amount being dependent on the maximum value of the first amount in the previous puff in the session, and to adjust the scale amount depending on the time elapsed since the end of the previous puff.

7. 7. The aerosol generating system of claim 6, wherein the controller is configured to calculate or determine a first quantity value during each subsequent puff, and the controller is further configured to adjust the first quantity during each subsequent puff in the session so that the first quantity is equal to the scaled quantity until the first quantity value exceeds the scaled quantity.

8. An aerosol generation system as described in any one of claims 1 to 7, wherein the controller is configured to switch from the first mode to a second mode when the controller determines a harmful condition during one or more puffs, and in the second mode, the controller is configured to confirm a harmful condition when the resistance exceeds the baseline resistance by a second amount.

9. 9. The aerosol generation system according to claim 1, further comprising an air inlet and an air outlet, and an airflow passage extending between the air inlet and the air outlet.

10. 10. The aerosol generation system of claim 9, further comprising a sensor assembly in communication with the airflow passage, the sensor assembly configured to measure pressure or flow within the airflow passage.

11. The aerosol generating system of claim 10 , wherein the controller comprises a computer-readable memory.

12. The aerosol generation system of claim 11, wherein the computer-readable memory stores a lookup table including a plurality of power profiles and a plurality of pressure or flow rate ranges, each of the ranges of the pressure or flow rate corresponding to at least one of the power profiles, and the controller is further configured to select a power profile from the plurality of power profiles in the first mode to control the supply of power to the heating element during puffing, the selection depending on the pressure or flow rate measured by the sensor assembly.

13. 13. The aerosol generation system of claim 12, wherein each power profile includes a plurality of power values, each of which corresponds to a range of time from the start of the puff, and wherein the controller is configured in the first mode to control the supply of power to the heating element during puffing depending on the plurality of power values ​​and the time from the start of the puff.

14. 14. The aerosol generating system of claim 13, wherein each power profile further includes a plurality of first quantity values, each of the plurality of first quantity values ​​corresponding to one of the plurality of power values, and the controller is configured to adjust the first quantity depending on a first quantity value selected from the first quantity values ​​stored in the lookup table.

15. 1. A method for determining a hazardous condition in an aerosol generating system, the aerosol generating system comprising: a heating element for heating the aerosol-forming substrate; a power source for supplying power to the heating element; a controller; The method comprises: controlling the power from the power source to the heating element in a first mode; measuring or determining the baseline resistance of the heating element; measuring the resistance of the heating element during one or more smoking sessions; comparing the resistance of the heating element to the baseline resistance or to a threshold value based on the baseline resistance; determining an adverse condition if the resistance exceeds the baseline resistance by a first amount; and continually adjusting the first amount during the session depending on one or more parameters measured or determined by the controller.

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