Patent Description:
Aerosol generation systems comprise a storage portion for storing an aerosol-forming precursor. The precursor may comprise a liquid. A heating system may be formed of one or more electrically activated resistive heating elements, which are arranged to heat said precursor to generate the aerosol. The aerosol is released into a flow path extending between an inlet and outlet of the system. The outlet may be arranged as a mouthpiece, which a user inhales through for delivery of the aerosol to the user.

The system may implement measurement of the depletion of the precursor to determine the quantity of one or more components thereof delivered to a user. Measurement may also be implemented to determine the quantity of precursor that remains in the storage portion so that the user can be notified when replenishment is required. Such measurement may be implemented by means of a flow meter or a level sensing system associated with the storage portion. It may be desirable to develop a cost-effective and/ or reliable means for measuring depletion.

In spite of the effort already invested in the development of aerosol generation systems further improvements are desirable.

<CIT> and <CIT> disclose aerosol generation systems for generation of an aerosol from an aerosol-forming precursor.

The present invention provides an aerosol generation system according to claim <NUM>, a method of determining a property of a flow of an aerosol generation system according to claim <NUM>, a computer program according to claim <NUM>, an electric circuitry for an electrically operated aerosol generation system according to claim <NUM>, and a non-transitory computer readable medium according to claim <NUM>.

The present disclosure provides an aerosol generation system for generation of an aerosol from an aerosol-forming precursor, the system comprising: an electrically operated heating system to heat said precursor to generate the aerosol; a flow path for transmission of flow, including the aerosol, to a user; the heating system arranged in fluid communication with the flow path; electrical circuitry to determine a characteristic associated with a second order time derivative of a property of electrical energy through the heating system, and to determine a property related to the flow of the flow path based on the characteristic of the second order time derivative.

By implementing determination of the characteristic from the second order time derivative it has been found that the characteristic (such as an amplitude, period, rise time or time of peak or area associated with an oscillation in said property) may be most accurately located and determined. Consequently, the property of the flow may be most accurately calculated. In particular, in implementations wherein the property (e.g. power, current or voltage) is maintained as a constant or to maintain a constant temperature, it has been found that the second order time derivative converges faster to a nominal value than current without numerical differentiation, whereby the characteristic can be most easily determined.

In embodiments, the property related to the flow is one or more of: an amount of one or more components of the aerosol; a start of an inhale; an end of an inhale; a duration of an inhale. "amount" may refer to a numerical quantity (e.g. a mass) as opposed to the presence or absence of the one or more components.

In embodiments, the characteristic comprises one or more of: an amplitude; a period; an area bounded by the maxima and/or minima of the oscillation from which an intensity, i.e. flow rate, of the inhalation can be inferred.

In embodiments, a characteristic of said feature is directly related to an amount of the one or more components of aerosol dispensed. By directly related it is meant that the greater the magnitude of the feature the greater the amount of the component dispensed, e.g. via direct proportionality or other mathematical function relationship.

In embodiments, the circuitry may implement control to regulate a property of the heating system as a constant, e.g. a temperature of the heating system is regulated to a target temperature or a voltage over the heating system is regulated to a target voltage. Said control may be implemented by pulse width modulation (PWM) or other appropriate means such as a DC:DC converter. In embodiments, a temporal displacement of said regulated property from a target magnitude may be determined as a result of an inhalation through the flow path and cooling of the heating system. The characteristic associated with a property of electrical energy can be based at least partially on said displacement.

In embodiments, the circuitry may implement measurement of a temperature of the heating system, e.g. by measuring an electrical resistance of the heating system and determining a temperature from said resistance based on an empirical relationship between the resistance and temperature or by a dedicated temperature sensor.

The present disclosure provides a method of determining a property of a flow of an aerosol generation system, the method comprising: determining a characteristic associated with a second order time derivative of a property of electrical energy through a heating system; determining the property related to the flow based on the characteristic of the second order time derivative. The method may implement any method of embodiments disclosed herein.

The present disclosure provides an aerosol generation system for generation of an aerosol from an aerosol-forming precursor, the system comprising: an electrically operated heating system to heat said precursor to generate the aerosol; a flow path for transmission of flow, including the aerosol, to a user; the heating system arranged in fluid communication with the flow path; electrical circuitry to determine a feature of an oscillation of a property of electrical energy through the heating system, the oscillation due to initiation and/or termination of a user inhale through the flow path, and to determine an amount of one or more components of aerosol dispensed in the inhale based (including at least partially based) on the feature of the oscillation.

By at least partially basing calculation of the amount of one or more components of aerosol dispensed in the inhale on a characteristic of oscillation, which is due to initiation and/or termination of the user inhale, the characteristics during the entire inhalation may not be required to be determined, for example, if only one of said initiation or termination oscillations can be identified.

In embodiments, the feature comprises one or more of: an amplitude; a period; an area bounded by the maxima and/or minima of the oscillation from which an intensity, i.e. flow rate, of the inhalation can be inferred.

It is to be understood that the oscillation due to initiation and/or termination of a user inhale refers to the change or fluctuation in the property of the electrical energy at the respective start and end of an inhalation, and in particular not an overall oscillation that may occur from start to end of an inhalation. The duration of the oscillation due to initiation and/or termination of a user inhale may for example be less than <NUM> or <NUM> % of the overall duration of the inhalation. In embodiments, this fluctuation may be particularly apparent from the second order time derivative.

In embodiments, a magnitude of said feature is directly related to an amount of the one or more components of aerosol dispensed. By directly related it is meant that the greater the magnitude of the feature the greater the amount of the component dispensed, e.g. via direct proportionality or other mathematical function relationship.

The present disclosure provides a method of determining a feature of an oscillation of a property of electrical energy through a heating system, the oscillation due to initiation and/or termination of a user inhale through the flow path, determining an amount of aerosol dispensed in the inhale based on the feature of the oscillation. The method may implement any method of embodiments disclosed herein.

The present disclosure provides an aerosol generation system for generation of an aerosol from an aerosol-forming precursor, the system comprising: an electrically operated heating system to heat said precursor to generate the aerosol; a flow path for transmission of flow, including the aerosol, to a user; the heating system arranged in fluid communication with the flow path. The circuitry to: measure a property of the electrical energy through the heating system; determine one or more characteristics from said measured property of the electrical energy (e.g. during a user inhalation through the flow path, which imparts a cooling effect on the heating system that can be determined by said measured property); select, based on the determined characteristics, one from a plurality of different empirical relationships between the measured property of the electrical energy and a property of the flow; implement said relationship to determine the property of the flow.

By selecting a particular empirically obtained relationship, which is to relate the characteristics of the electrical energy to the property of the flow, based on a property of the measured electrical energy, the most appropriate relationship of several can be implemented to most accurately calculate said property of the flow.

In embodiments the property of the electrical energy may comprise the electrical current or power through or the electrical potential over the heating system. All of which can be conveniently measured by the circuitry, e.g. by various current and/or electrical potential measuring implementations.

In embodiments the property related to the flow is an amount of one or more components of the aerosol in the flow path, wherein the aerosol is generated from the precursor by an atomizer of the system. The flow may also comprise air sucked through the flow path by a user inhalation.

In embodiments, the characteristic is based on one or more of an: amplitude or period or area of an oscillation of said electrical energy or a time derivative thereof; an initiation time of a user inhale through the flow path; a duration of a user inhale through the flow path; a duration of electrical energy applied to the heating system. By selecting the amplitude or period or area of an oscillation of said electrical energy, a determination of the intensity of the inhalation, e.g. the flow rate, may be provided.

In embodiments, the empirical relationship comprises an empirically obtained mathematical formula. The empirical relationship may comprise an output value as the property of the flow. The output value may be related to one or more input values, each comprising the determined characteristic or another characteristic of the flow (e.g. the same characteristics used to select the relationship may be used as input and/or different characteristics).

In embodiments the electrical circuitry is configured to determine if said first one or more input values can be obtained from the measured property of the electrical energy, and to select said relationship based on the input values obtained. By selecting the relationship based on whether the associated input values can all be obtained, only a relationship that can provide a representative output value may be implemented.

In embodiments, a first relationship comprises as input a first set of one or more input values and a second relationship comprises a different second set of one or more input values, the circuitry to implement the first relationship if the first set of input values are obtainable else to implement the second relationship if the second set of input values are obtainable. By selecting a second relationship for which the input values can all be obtained instead of a first relationship for which the one or more input values cannot be obtained, a representative output can be obtained.

In embodiments, the second set of input values form a subset of the first set of input values. By selecting the second set of input values to consist of one or more of the first set of input values (whilst being numerically fewer than the first set), the second set can be determined when partially determining the first set, hence the second set does not require separate steps of computation to obtain.

In embodiments, the first set of one or more input values includes amplitude or period or an area of an oscillation of said electrical energy or a time derivative thereof, and the second set of one or more input values does not include an amplitude of an oscillation or said electrical energy or a time derivative thereof. By selecting the first set to include amplitude or period or an area of an oscillation, the first relationship can be based on intensity of the inhalation, e.g. the flow rate, and provides an accurate output value, and by not basing the second relationship on intensity a less accurate, but more reliable second relationship is provided.

In embodiments, the first and second set of input values includes a duration of a user inhale through the flow path and/or a duration of electrical energy applied to the heating system (e.g. a duration of an actuation of a vaping button). By selecting common input values to include said durations, the duration of an inhalation through the flow path can be accounted for, as opposed to just the flow rate, when determining the overall quantity of aerosol delivered for an inhalation.

In embodiments, the circuitry is configured such that if a set of input values is unobtainable, the output value is determined from an output value determined from a prior user inhale. By determining the output value from a prior inhalation in the instance that the first (or both first and second) relationship cannot be implemented (e.g. due to the associated input values not being obtainable), the system includes a reliable means for determining an output value.

The present disclosure provides a method of determining a property of a flow of an aerosol generation system, the method comprising: measuring a property of the electrical energy through the heating system; determining one or more characteristics from said measured property of the electrical energy; selecting, based on the determined characteristics, one from a plurality of different empirical relationships between the measured property of the electrical energy and a property of the flow; implementing said relationship to determine the property of the flow. The method may implement any method of embodiments disclosed herein.

The present disclosure provides an aerosol generation system for generation of an aerosol from an aerosol-forming precursor, the system comprising: an electrically operated heating system to heat said precursor to generate the aerosol; a flow path for transmission of flow, including the aerosol, to a user; the heating system arranged in fluid communication with the flow path; electrical circuitry to apply a predetermined amount of electrical energy to the heating system to stabilise a property of electrical energy through the heating system, the electrical circuitry to determine a property related to the flow of the flow path based on the stabilised property of the electrical energy through the heating system, wherein the property related to the flow is one or more of: an amount of one or more components of the aerosol.

By applying a predetermined amount of electrical energy to the heating system to stabilise a property of the electrical energy therethrough, a particular feature of the property of the electrical energy (such as an amplitude, period or area of an oscillation) may be extracted with increased accuracy and thus used to determine the property related to the flow with corresponding increased accuracy.

The present disclosure provides a method of determining a property of a flow of an aerosol generation system, the method comprising: applying a predetermined amount of electrical energy to a heating system to stabilise a property of electrical energy through the heating system; determining the property related to the flow based on the stabilised property of the electrical energy through the heating system, wherein the property related to the flow is one or more of: an amount of one or more components of the aerosol.

The present disclosure provides a computer program or electrical circuitry or a computer readable medium including the computer program to implement one or more of the previously disclosed methods.

Aspects, features and advantages of embodiments of the present disclosure will become apparent from the following description of embodiments in reference to the appended drawings, in which like numerals denote like elements.

Before describing several embodiments of an aerosol generation system, it is to be understood that the system is not limited to the details of construction or process steps set forth in the following description. It will be apparent to those skilled in the art having the benefit of the present disclosure that the system is capable of other embodiments and of being practiced or being carried out in various ways.

The present disclosure may be better understood in view of the following explanations:
As used herein, the term "aerosol generation apparatus" or "apparatus" may include a smoking apparatus to deliver an aerosol to a user, including an aerosol for smoking, by means of an aerosol generating unit (e.g. a heater or atomiser which generates a vapour which condenses into an aerosol before delivery to an outlet of the apparatus at, for example, a mouthpiece, for inhalation by a user). An aerosol for smoking may refer to an aerosol with particle sizes of <NUM>-<NUM> microns. The particle size may be less than <NUM> or <NUM> microns. The apparatus may be portable. "Portable" may refer to the apparatus being for use when held by a user. The apparatus may be adapted to generate a variable amount of aerosol, e.g. by activating an atomizer for a variable amount of time (as opposed to a metered dose of aerosol), which can be controlled by a trigger. The trigger may be user activated, such as a vaping button and/or inhalation sensor. The apparatus may be adapted to generate a variable amount of aerosol, e.g. by activating an atomizer for a variable amount of time (as opposed to a metered dose of aerosol), which can be controlled by a trigger. The trigger may be user activated, such as a vaping button and/or inhalation sensor. The inhalation sensor may be sensitive to the strength of inhalation as well as the duration of inhalation so as to enable more or less vapour to be provided based on the strength of inhalation (so as to mimic the effect of smoking a conventional combustible smoking article such as a cigarette, cigar or pipe, etc.). The apparatus may include a temperature regulation control such as for example a Proportional, Integral, Differential (PID) controller to quickly drive the temperature of the heater and/or the heated aerosol generating substance (aerosol pre-cursor) to a specified target temperature and thereafter to maintain the temperature at the target temperature regardless of the amount of substrate (pre-cursor) available at the aerosol generating unit and regardless of the strength with which a user inhales.

As used herein, the term "aerosol generation system" or "system" may include the apparatus and optionally other circuitry/componentry associated with the function of the apparatus, e.g. a peripheral device and/or other remote computing device.

As used herein, the term "aerosol" may include a suspension of precursor as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. Aerosol herein may generally refer to/include a vapour. Aerosol may include one or more components of the precursor.

As used herein, the term "aerosol-forming precursor" or "precursor" or "aerosol-forming substance" or "substance" may refer to one or more of a: liquid; solid; gel; other substance. The precursor may be processable by an atomizer of the apparatus to form an aerosol as defined herein. The precursor may comprise one or more of: nicotine; caffeine or other active component. The active component may be carried with a carrier, which may be a liquid. The carrier may include propylene glycol or glycerine. A flavouring may also be present. The flavouring may include Ethylvanillin (vanilla), menthol, Isoamyl acetate (banana oil) or similar.

As used herein, the term "electrical circuitry" or "electric circuitry" or "circuitry" or "control circuitry" may refer to, be part of, or include one or more of the following or other suitable hardware or software components: an Application Specific Integrated Circuit (ASIC); electronic/electrical circuit (e.g. passive components, which may include combinations of transistors, transformers, resistors, capacitors); a processor (shared, dedicated, or group); a memory (shared, dedicated, or group), that may execute one or more software or firmware programs; a combinational logic circuit. The electrical circuitry may be centralised on the apparatus or distributed, including distributed on board the apparatus and/or on one or more components in communication with the apparatus, e.g. as part of the system. The component may include one or more of a: network-based computer (e.g. a remote server); cloud-based computer; peripheral device. The circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. The circuitry may include logic, at least partially operable in hardware.

As used herein, the term "processor" or "processing resource" may refer to one or more units for processing including an ASIC, microcontroller, FPGA, microprocessor, digital signal processor (DSP) capability, state machine or other suitable component. A processor may include a computer program, as machine readable instructions stored on a memory and/or programmable logic. The processor may have various arrangements corresponding to those discussed for the circuitry, e.g. on-board and/or off board the apparatus as part of the system.

As used herein, the term "computer readable medium/media" may include conventional non-transient memory, for example one or more of: random access memory (RAM); a CD-ROM; a hard drive; a solid state drive; a flash drive; a memory card; a DVD-ROM; a floppy disk; an optical drive. The memory may have various arrangements corresponding to those discussed for the circuitry/processor.

As used herein, the term "communication resources" may refer to hardware and/or firmware for electronic information transfer. Wireless communication resources may include hardware to transmit and receive signals by radio and may include various protocol implementations e.g. the <NUM> standard described in the Institute of Electronics Engineers (IEEE) and Bluetooth™ from the Bluetooth Special Interest Group of Kirkland Wash. Wired communication resources may include Universal Serial Bus (USB); High-Definition Multimedia Interface (HDMI) or other protocol implementations. The apparatus may include communication resources for communication with a peripheral device.

As used herein, the "heating system (being) arranged in fluid communication with the flow path" may refer to an interaction or exchange between the heating system and the flow transmitted by the flow path, such as (but not limited to) between components of the heating system, such a heating coil, and air, precursor, solid materials and/or aerosol comprised in the flow. For example, the heating system is in fluid communication with the flow path if a heating element such as a coil is located in the flow path. In this case, the heating element heats the flow, and vice versa the flow may have a cooling effect on the heating element.

As used herein, the term "network" or "computer network" may refer to a system for electronic information transfer. The network may include one or more networks of any type, which may include: a Public Land Mobile Network (PLMN); a telephone network (e.g. a Public Switched Telephone Network (PSTN) and/or a wireless network); a local area network (LAN); a metropolitan area network (MAN); a wide area network (WAN); an Internet Protocol Multimedia Subsystem (IMS) network; a private network; the Internet; an intranet.

As used herein, the term "peripheral device" may include electronic components peripheral to an apparatus. The peripheral device may comprise electronic computer devices including: a smartphone; a PDA; a video game controller; a tablet; a laptop; or other like device.

As used herein, the term "storage portion" may refer to a portion of the apparatus adapted to store the precursor.

As used herein, the term "delivery system" may refer to a system operative to deliver, by inhalation, aerosol to a user. The delivery system may include a mouthpiece or an assembly comprising a mouthpiece.

As used herein, the term "flow path" may refer to a path or enclosed passageway through the apparatus, through which the user may inhale for delivery of the aerosol. The flow path may be arranged to receive aerosol.

As used herein, the term "flow" may refer to a flow in the flow path, and may include air, which may be induced into the flow path due to an inhalation through the flow path and/or aerosol.

As used herein, the term "inhale" may refer to a user inhaling (e.g. due to an expansion from their lungs) to create a pressure reduction to induce flow through the flow path.

As used herein, the term "atomizer" may refer to a device to form the aerosol from the precursor. The atomizer may include a heating system, ultrasonic or other suitable system.

As used herein, the term "property of electrical energy through the heating system" or "measured property of electrical energy" may refer to or be based on one or more of the: current; electrical potential; power; phase; other related property, of the electrical energy through and/or over the heating system (e.g. one or more electrically resistive elements thereof) or a component associated therewith (e.g. a resistor, that may include a shunt resistor, arranged in series with or parallel to the heating system or with other suitable operative arrangement). It also includes a like property measured through a component different from but arranged in operative proximity to the heating system (i.e. to provide a representative measure of the electrical energy through the heating system) such as a temperature sensor, which may operate based on temperature dependent electrical resistance. The property may refer to the time dependency of the property of the electrical energy.

As used herein, the term "property related to the flow" or "property of the flow" may refer to one or more of the following associated with the flow in the flow path: a flow rate (e.g. volumetric or mass) of aerosol and/or air; duration of an inhale; start of an inhale; end of an inhale; intensity of an inhale; flow velocity; a quantity of flow (e.g. volumetric or mass), including one or more components of the aerosol of the flow (e.g. nicotine, caffeine) and/or air, which may be associated with an inhale.

As used herein, the term "characteristic of the second order time derivative" in respect of the measured property of the electrical energy may include/refer to one or more of the following features: a stationary point, e.g. a maximum or minimum; other point of inflection, including a saddle point; a period associated with a stationary point, which may be in respect of a baseline value; a period between stationary points, which may be immediately consecutive or separated, e.g. by a period of baseline; a step or other discontinuity; a rise or fall from baseline, e.g. for a pulse; a position associated with an amplitude of a pulse, e.g. <NUM>% of amplitude. The various points may be characterised in respect of magnitude and/or position in time.

Referring to <FIG>, embodiment aerosol generation apparatus <NUM> includes a power supply <NUM>, for supply of electrical energy. The electrical energy may be supplied to an atomizer <NUM> and/or electrical circuitry <NUM>. The power supply <NUM> may include an electric power supply in the form of a battery and/or an electrical connection to an external power source. The apparatus <NUM> may include a precursor transmission system <NUM> to transmit precursor to the atomizer <NUM> for formation of aerosol therefrom. A delivery system <NUM> delivers the aerosol to a user.

Referring to <FIG>, embodiment aerosol generation apparatus <NUM> includes the precursor transmission system <NUM> having a storage portion <NUM> for storage of the precursor. The storage portion <NUM> may be arranged as a reservoir (not shown) or other suitable arrangement portion depending on the physical state of the precursor. The precursor transmission system <NUM> includes a transmission unit <NUM> to transmit the precursor from the storage portion <NUM> to the atomizer <NUM>. The transmission unit <NUM> may include one or more of: an absorbent member (e.g. cotton) arranged for transmission by capillary action; a conduit; a valve; a pumping system, which may include an electrically operated pump.

In an embodiment, which is not illustrated, the precursor transmission system <NUM> may be omitted. In such an embodiment the precursor may be arranged as a consumable pod (e.g. as a liquid or gel), wherein an atomizer includes a heated receptacle for the pod.

The delivery system <NUM> includes a flow path <NUM> to transmit aerosol from the atomizer <NUM> to a user. The atomizer <NUM> includes a precursor inlet <NUM>. The atomizer <NUM> includes a flow inlet <NUM> and an outlet <NUM> of the flow path <NUM> for passage of flow through the atomizer <NUM>. In an embodiment, which is not illustrated, the flow path <NUM> receives aerosol from the outlet <NUM> and does not pass through the atomizer <NUM>.

The flow path <NUM> includes an inlet <NUM>, which may be arranged through a housing of the apparatus <NUM>. The flow path <NUM> includes an outlet <NUM> for delivery of the aerosol and inlet flow to the user. The outlet <NUM> may be arranged as a mouthpiece or other suitable delivery member.

The atomizer <NUM> includes a heating system <NUM>, which may be arranged as one or more electrically resistive heating elements (not shown). A heating element may be arranged as a wire or filament. A heating element may be operatively connected to the precursor transmission unit <NUM> to heat precursor of the transmission unit <NUM>. The one or more heating elements may be arranged within and/or in fluid communication with the flow path <NUM>, e.g. to be cooled by said flow.

In an embodiment, which is not shown, a cartomizer integrates a storage portion <NUM> and transmission unit <NUM> of the transmission system <NUM> and heating system <NUM> in a common housing. The cartomizer including a predetermined amount of the precursor.

The circuitry <NUM> regulates electrical energy from the power supply <NUM> to the heating system <NUM>. Proximal a heating element the precursor may be converted to a supersaturated vapour, which subsequently condenses to form an inhalable aerosol. As precursor is converted to aerosol, it is replaced by further precursor supplied by the transmission unit <NUM>, e.g. by a pumping action, until the storage portion <NUM> is spent.

The electrical energy supplied to the heating system <NUM> may be controlled with the circuitry <NUM> by one of the following or other like circuitry: pulse width modulation (PWM) via an electrically operated switch, or by other suitable means, e.g. by chopping of an alternating current waveform; a direct current (DC): DC converter, such as a Buck converter; a linear regulator.

The circuitry <NUM> implements some form of control of the temperature of the heating system <NUM>, e.g. by closed loop control. Depending on the embodiment, the control may comprise regulating one of the: electrical potential; current; power; temperature; other related quantity to remain at a target value through (or over) the heating system <NUM>.

Since the heating system <NUM> may include resistive elements arranged within the flow path <NUM>, inhalation through the flow path has the effect of cooling the heating system <NUM>. Said cooling influences the electrical resistance of the resistive elements, and therefore the degree of cooling can be representative of the intensity of the user inhalation, i.e. the flow rate through the flow path, and since the amount of precursor delivered as an aerosol from the transmission unit <NUM> may have a dependency on the intensity of the inhalation, the resistance can be used to determine the property of the flow as defined herein.

In embodiments wherein the voltage is regulated as constant over the heating system <NUM>, the change in electrical current to maintain a constant voltage during an inhalation can be representative of the intensity of the inhalation.

In embodiments wherein a temperature of the heating system is regulated at a target temperature, e.g. by proportional-integral-derivative (PID) or other like control algorithm, the power (or other related quantity such as electrical current) to maintain the target temperature during an inhalation can therefore be representative of the intensity of the inhalation.

A temperature of the heating system <NUM> may be determined by measuring the electrical resistance as described above and by implementation of an empirically determined relationship between electrical resistance and temperature. Alternatively, the circuitry may implement a dedicated temperature sensor arranged in operative proximity to the heating system <NUM>.

It will be understood that the examples presented in the subsequent embodiments may be adapted for the various aforementioned forms of heating system <NUM> control.

The circuitry <NUM> may comprise a trigger (not shown) to detect when aerosol formation is required. The circuity <NUM> may effect the supply of electrical energy to the heating system <NUM> upon the determination of triggering of the trigger. The trigger may detect when a user action suggests aerosol formation is required. Such a request may be implicit, such as via inhalation, or explicit, such as via a button press. The trigger may comprise an actuator being actuated by physical contact (e.g. a vaping button), including by a digit of a hand of the user. Examples include a button or a dial. The trigger may comprise an inhalation sensor operable to detect user inhalation through the flow path <NUM>. The inhalation sensor may comprise a flow meter or a pressure sensor operable to determine flow pressure, including by capacitive sensing of a pressure respondent displaceable diaphragm.

Referring to <FIG> an embodiment arrangement of the apparatus <NUM> comprises: a cartomizer <NUM> interconnecting a power supply <NUM> and a mouthpiece <NUM>. The mentioned components may be connected in a modular fashion, including by bayonetted or threaded connection types or other suitable connection. The apparatus <NUM> is geometrically elongated along a longitudinal axis. The mentioned components can be arranged in the form of an elongated cylindrical shape, so as to replicate that of a cigar or cigarette. In embodiments, which are not illustrated, the mentioned components are alternatively arranged; e.g. the atomizer may be arranged separable from a storage portion. One or more of the mentioned components may be arranged in a common housing <NUM>.

Referring to <FIG>, an electrically operated aerosol generation system <NUM> for generation of an aerosol may implement features of any of the preceding embodiments or other embodiments disclosed herein. The system <NUM> is configured to generate an aerosol from an aerosol-forming precursor and comprises the heating system <NUM> to heat said precursor to generate the aerosol. The flow path <NUM> includes the inlet <NUM> for air inlet and the outlet <NUM> for delivery of the aerosol and inlet air. The heating system <NUM> is arranged in fluid communication with the flow path <NUM>, including to receive flow <NUM> of the flow path.

Electrical circuitry <NUM> at block <NUM> determines (e.g. measures) a property of electrical energy through the heating system <NUM>. The dependency of the property with respect to time may be determined. Examples of suitable properties are as disclosed herein, which include current or voltage. As used herein, the term "determining a property of electrical energy through the heating system" or "a property of electrical energy through the heating system" may refer to direct measurement of the property of the electrical energy through the heating system and/or a representative measurement of the property of the electrical energy elsewhere in the circuitry associated with the heating system (e.g. a resistor in parallel or series with the heating system, which may include a shunt resistor).

The electrical circuitry <NUM> at block <NUM> determines a second order time derivative of the determined property of the electrical energy through the heating system <NUM>. As used herein, "determination of a second order time derivative" or "based on the second order time derivative" (or a like term) may include a representative quantity without explicit formulation, as well as with explicit formulation. Exemplary derivation methods for the second order derivative will be provided.

Electrical circuitry <NUM> at block <NUM> determines a characteristic of the second order time derivative, examples of which are as disclosed herein, which include features such as a peak to peak value of maxima and minima. The term "characteristic of the second order time derivative" is to be understood as not limited to a single feature; e.g. it may comprise said peak to peak value and a time of a maximum; further examples will be provided.

Electrical circuitry <NUM> at block <NUM> processes the determined characteristic of the second order time derivative to determine the property related to the flow. Examples of the property related to the flow are as disclosed herein, which include an amount of one or more components of the aerosol dispensed during a user inhale through the flow path <NUM>.

In embodiments, the property related to the flow may be determined based on a relationship between the property related to the flow and the characteristic of the second order time derivative; e.g. the relationship may be based on empirical data, examples of which will be provided. In other embodiments, which are not illustrated, the circuitry <NUM> may implement alternative procedural steps, e.g. a fixed operation is performed on the characteristic.

Electrical circuitry <NUM> at optional block <NUM> outputs the determined property related to the flow, which may include providing instructions to a user interface to display the determined property and/or to store said property, examples of which will be provided.

In accordance with the definition of circuitry <NUM> herein, it will be understood that the process blocks <NUM>-<NUM> (or any other block associated therewith and like process steps of other embodiments disclosed herein) may be executed centrally on the apparatus <NUM> and/or distributed on other circuitry associated with the system <NUM>, e.g. a peripheral device <NUM>, which may be implemented as a smartphone.

The procedural steps exemplified by the blocks of <FIG> will now be described in more detail, commencing with block <NUM>. The circuitry <NUM> for determination of the property of electrical energy through the heating system <NUM> may be implemented in various manners.

Referring to <FIG>, the circuitry <NUM> implements a circuit for determining the property of the electrical energy through the heating system <NUM>. The circuitry <NUM> includes a measurement unit <NUM> to measure a property of the electrical energy through or over a heating element of the heating system <NUM>. The measurement unit <NUM> may be implemented as a resistor (e.g. a shunt resistor, not shown) arranged in series with the heating system <NUM> and a potentiometer (not shown) arranged to measure the electrical potential over the resistor. The electrical potential over the resistor may be converted to current by division of the resistance. Accordingly, the property of the electrical energy through the heating system <NUM> may be based on current and/or electrical potential. A processor <NUM> determines the property of the electrical energy based on a signal from the measurement system <NUM>.

In embodiments, which are not illustrated, the measurement unit may have other implementations, e.g. a potentiometer arranged to measure the electrical potential directly over the heating system or other property that may include phase or power. Moreover, the processor may implement elements of the measurement unit, e.g. the potentiometer as an algorithm and/or a combinational logic circuit. The processor may also implement elements of a control system to control the electrical energy to the heating system, e.g. for PWM control, or DC:DC conversion. The processor <NUM> may implement determination of the second order time derivative of the variation of the property of the electrical energy through the heating system <NUM> and subsequent determination of a property related to the flow as will be discussed.

The heating system <NUM> may comprise a single or multiple heating elements. The material of the heating element may be selected to have a high temperature coefficient of resistance α, e.g. <NUM>-<NUM> x10<NUM>, such as Nickel. In the embodiments, the or each heating element of the heating system <NUM> may be heated to a range to cause vaporisation of the precursor without combustion of the precursor, e.g. to <NUM>-<NUM>.

Referring to <FIG>, which is a more detailed implementation of the circuitry <NUM> of <FIG>, the circuitry <NUM> includes exemplary componentry for illustrative purposes. The measurement system <NUM> is implemented as <NUM> mΩ shunt resistor <NUM>, which is arranged in series with the heating system <NUM>. The heating system <NUM> has a <NUM> mΩ electrically resistive load. An amplifier <NUM> amplifies the electrical potential over the shunt resistor <NUM>. The amplifier is an INA215 by Texas Instruments with a gain of <NUM>. Filter <NUM> is arranged to filter the amplifier <NUM> output, e.g. to remove noise including spurious modes. The processor <NUM> is implemented as a microcontroller <NUM>. The microcontroller <NUM> is a CC2540 by Texas instruments.

A DC-DC converter <NUM> (which in the embodiment is implemented as a buck converter) is arranged to provide a stabilised continuous voltage from the power supply <NUM>. The DC-DC converter is a LM212 Buck by Texas Instruments. The power supply <NUM> has a nominal supply of <NUM> V. The DC-DC converter <NUM> outputs a continuous voltage of <NUM>. 5V, but may be controlled to <NUM>-<NUM>. The microcontroller <NUM> provides control of the DC-DC converter <NUM>. A potentiometer <NUM> is arranged to provide a reference voltage to the microcontroller <NUM> and DC-DC converter <NUM>. The potentiometer <NUM> is an MCP4013 by Microchip. The voltage is controlled by the microcontroller <NUM>, which sets the reference voltage of the potentiometer <NUM>.

Since the resistance of the shunt resistor <NUM> is relatively constant, the electrical potential over the shut resistor <NUM> may be converted to current by division of said resistance. Accordingly, the property of the electrical energy through the heating system <NUM> may be based on current and/or electrical potential, or other quantities that may be derived therefrom, such as power.

It will be understood that the second order time derivative of the determined property of the electrical energy through the heating system <NUM> is relatively independent of the specific implementation (e.g. resistances) of components of the circuitry <NUM>. Moreover, said independence may reduce any effect of variations of electrical componentry (e.g. manufacturing tolerances) implementing the same circuitry <NUM>, e.g. for batches of the same apparatus <NUM>.

The filter <NUM> may be implemented as a low pass filter, e.g. a resistor-capacitor (RC) filter. The pass frequency may be below <NUM>. In an embodiment, the filter (or an additional filter) is implemented as a digital filtering algorithm (or logic circuit) optionally arranged on the processor <NUM>. A digital filter can advantageously be field configured by the processor <NUM>. The filter may implement a smoothing algorithm to increase signal-to-noise ratio with minimal distortion; a suitable implementation includes a Savitzky-Golay filtering algorithm. In an embodiment, the filter is selected to filter out oscillations due to bubbles in the reservoir or other fluctuations.

Referring to <FIG>, line <NUM> represents the time dependency of electrical current through the heating system <NUM> when measured using the embodiment circuitry <NUM> shown in <FIG> or <FIG>. A similar time dependency may be obtained when measuring other properties of the electrical energy through the heating system; examples include power.

In the embodiment (as discussed previously), a constant electrical potential is maintained over the heating system <NUM>. The electrical current through the heating system <NUM> causes the or each heating element thereof to heat up. The temperature increase of the heating element causes a resistance increase, which due to regulation of a constant electrical potential has a resultant effect of decreasing the electrical current through the heating system <NUM>.

Referring to <FIG>, at To the electrical energy is applied to the heating system <NUM>. It can be observed that the electrical current through the heating system <NUM> decreases in an exponential manner. This is due to the heating system <NUM> exhibiting a substantial initial temperature increase as it is heated, followed by convergence to a constant temperature. Since the electrical resistance is proportional to the temperature, to maintain the constant electrical potential, the current exhibits corresponding exponential decay.

In an embodiment, which is not illustrated, the circuitry <NUM> implements a constant current source, which is arranged to maintain a constant current over the heating system <NUM>. As the resistance of the heating element increases, the electrical potential over the constant current source increases, thus the electrical potential exhibits a similar time dependency as for the electrical current of the preceding embodiments. A similar time dependency may be obtained when measuring the power over the heating system or other representative quantity. It will thus be understood that the relationship between the property of electrical energy through the heating system <NUM> and the property related to the flow of the flow path may apply to various electrical quantities that are selected based on the implementation of the circuitry <NUM>.

When a user inhales through the flow path <NUM>, heat is dissipated from the heating system <NUM> to the flow <NUM>, e.g. by convective heat transfer of thermal energy from the heating element to the flow stream. The heat dissipation of the heating system <NUM> is thus related to the flow <NUM> through the flow path <NUM>. Since the temperature of the heating element is related to its electrical resistance, the temperature thus influences the property of the electrical energy through the heating system <NUM> (e.g. the electrical potential over the heating system <NUM> or current through the heating system <NUM> depending on the implementation of the circuitry <NUM>). The electrical energy through the heating system <NUM> is thus related to various properties of the flow <NUM> in the flow path <NUM> as will be discussed.

Referring to <FIG>, the influence of a user inhale through the flow path <NUM> on the electrical current is more clearly illustrated, wherein line <NUM> shows the current during an inhalation and line <NUM> shows the current in absence of an inhalation. Line <NUM> is the second order time derivative of line <NUM>. In particular at reference lines <NUM> and <NUM> a user inhalation is initiated and terminated respectively. It can be seen that the initiation of the inhale causes an initial oscillation <NUM> in the current followed by a period of increased current <NUM> and an oscillation <NUM> at termination. The effect is more pronounced in the second order time derivative <NUM> of the current. At line <NUM> the initial oscillation <NUM> ceases to have an effect on the second order time derivative <NUM>. At line <NUM> the termination oscillation <NUM> initiates an effect on the second order time derivative <NUM>.

Referring to <FIG> and <FIG>, the current decreases from an initial magnitude of over <NUM> amps to: <NUM>-<NUM> amps between <NUM> and <NUM> seconds; <NUM>-<NUM> amps between <NUM> and <NUM> seconds; a nominal value of <NUM>-<NUM> amps after about <NUM> seconds. With the nominal value as a reference, current thus falls by over <NUM>% in the first <NUM> seconds. It may be preferable to measure the effect of the user inhale on the current through the heating system <NUM> following <NUM> seconds, wherein the current has stabilised and the effect of the oscillations due to inhalation may appear more pronounced.

It is thus desirable that the user inhale occurs following the supply of a predetermined amount of electrical energy and/or with some preheating of the heating element to enable the effect of the initiation of the user inhale to be captured.

A used herein "nominal value" may refer to a normal operating value of a signal of the electrical energy, which the circuitry <NUM> may be designed to operate with. Nominal may refer to a value that the signal converges to or about.

Referring to <FIG>, circuitry <NUM> implements an embodiment process for stabilising a property of the electrical energy through the heating system <NUM>. The process may be implemented in combination with the embodiment process illustrated in <FIG>, or another embodiment disclosed herein. At block <NUM> the circuitry <NUM> applies a predetermined amount of electrical energy to the heating system <NUM>. At block <NUM> the predetermined amount of electrical energy stabilises the property of electrical energy (e.g. the current in the exemplary embodiment) through the heating system <NUM>. At block <NUM> the circuitry <NUM> determines a property related to the flow <NUM> of the flow path <NUM> based on the property of the electrical energy through the heating system <NUM> subsequent to the applied predetermined amount of electrical energy, i.e. with said property stabilised, examples of which will be provided.

Inhalation (which may include initiation of inhalation) following application of the predetermined amount of electrical energy may be ensured by implementing one or more embodiment modes of operation of the circuitry <NUM>. In an embodiment, at block <NUM>, the predetermined amount of electrical energy is applied upon determination of a trigger as previously described. The trigger may comprise an actuator actuated by physical contact (e.g. a vaping button), including by a digit of a hand of the user. The electrical circuitry <NUM> may implement the actuator with electrical energy applied to the atomizer <NUM> for the duration of the actuation. It has been found that with such an actuator most users initiate inhalation after <NUM> or <NUM> seconds of actuation. Thus, the circuitry <NUM> can be specifically configured to apply the predetermined amount of electrical energy before <NUM>-<NUM> second. Said configuration can be implemented by the control system of the processor <NUM> for regulation of electrical energy to the heating system <NUM> (e.g. the DC:DC converter or PWM based control system applies the predetermined amount of electrical energy in the first <NUM>-<NUM> second or other suitable time period T<NUM>).

In other embodiments, the circuitry <NUM> implements the trigger as a motion sensor or facial recognition sensor (e.g. a camera with image processing) to determine intent to initiate an inhalation.

In an embodiment, the circuitry <NUM> may implement enabling of inhalation through the flow path <NUM> only when the heating system <NUM> is heated to a predetermined temperature and/or the current is within a particular range of the nominal value (e.g. ± <NUM> % or ± <NUM> %). The circuitry <NUM> may enable inhalation by means of an electrically operated value or other flow regulation device.

Referring to <FIG> and <FIG>, the circuitry <NUM> applies the predetermined amount of electrical energy over the first time period T<NUM>. Initiation of the inhale through the flow path <NUM> is indicated by line <NUM> at Ti, which occurs after T<NUM> and during a subsequent time period. The circuitry <NUM> thus determines the property related to the flow through the flow path as will be discussed. The circuitry <NUM> may be configured to apply the predetermined amount of electrical energy over a T1 duration of <NUM>-<NUM>, or <NUM>-<NUM> or less than <NUM> or <NUM> seconds.

Whilst it is preferable to ensure Ti occurs after the predetermined amount of electrical energy has been applied, in an embodiment the property of the flow is based on an oscillation at termination of the inhalation (examples of which will be provided); thus, in some examples, the Ti occurs before the predetermined amount of electrical energy has been fully applied.

The predetermined amount of electrical energy may be <NUM>, <NUM> or <NUM> Joules (each ± <NUM> % or ± <NUM> % or ± <NUM> %). In the embodiment implementations of <FIG> and <FIG>, the predetermined amount of electrical energy can include <NUM>. 5V applied for T<NUM> (as defined by the previous ranges).

The predetermined amount of electrical energy may be to preheat a heating element of the heating system <NUM> to a predetermined temperature range from which may be cooled during said inhale. The predetermined temperature range may be selected to cause vaporisation of the precursor without combustion of the precursor, e.g. to <NUM>-<NUM> or <NUM>-<NUM>. The temperature of the heating element may be determined by various implementations, which include: resistance of the heating system; a dedicated temperature sensor; empirical data (e.g. a particular amount of energy is known to effect an experimentally determined temperature range).

The predetermined amount of electrical energy may be to stabilise the property of the electrical energy through the heating system <NUM> to ± <NUM> % or ± <NUM> % of the nominal value. In the example the nominal value of the current may be taken as <NUM> amps, thus + <NUM> % or + <NUM> % equates to <NUM> amps and <NUM> amps respectively, <NUM> amps occurs during T<NUM>. The same ranges may be applied to other properties (e.g. electrical potential) of the electrical energy through the heating system <NUM> in other embedment implementations of the circuitry <NUM>.

The predetermined amount of electrical energy may be to stabilise the property of the electrical energy through the heating system so that oscillations caused by the user inhale through the flow path can be extracted and processed. The oscillations may include those in a first or second order time derivative as will be discussed.

The specific amount of electrical energy to achieve the aforementioned stabilisation will depend on the implementation of the apparatus <NUM>, which includes implementation of: the circuitry <NUM>; heating system <NUM>, including the resistance of the heating element; the flow path. Thus, it will be understood that the specific amount of electrical energy may be determined based on empirical data.

Referring to <FIG>, after approximately <NUM> seconds the current <NUM> exhibits notable oscillation (which can be more clearly seen in the corresponding second order time derivative <NUM>). The oscillation is electrical noise caused by overheating of the heating element of the heating system <NUM>. It may therefore be desirable to configure the circuitry <NUM> such that the user inhale through the flow path <NUM> occurs prior to the electrical noise, such that the electrical noise may not interfere with measurement of the inhale. This may be achieved by application of the predetermined amount of electrical energy as close to initiation of the user inhale as possible.

Since the second order time derivatives are particularly vulnerable to interference as the electrical energy through the heating system <NUM> decreases from its initial value to the nominal value, it may be desirable to implement circuitry <NUM> that applies the predetermined amount of electrical energy in combination with processing of the second order time derivative to calculate the property of the flow, examples of which will be provided.

However, in some embodiments, the property of the electrical energy through the heating system <NUM> without numerical differentiation may be processed to calculate the property of the flow, examples of which will be provided.

Referring <FIG>, and <FIG>, the circuitry <NUM> at block <NUM> determines a second order derivative with respect to time of the determined property of the electrical energy through the heating system <NUM>.

Determination of the second order time derivative may be implemented by an algorithm (or logic circuit), which may be arranged on the processor. The finite difference method (e.g. Newton's difference quotient, symmetric difference or a higher-order method), or other methods such as differential quadrature, may be implemented. Derivation of the derivative may also be determined by electrical componentry, e.g. a finite difference method is implemented by a capacitor arranged to introduce a delay in the property of the electrical energy through the heating system <NUM> and a differential amplifier to determine a derivative from the property of the electrical energy and delayed property of the electrical energy.

It will be understood that explicit determination of the second order time derivative is not required, e.g. when implementing a finite difference method, the small change in time may not be divided by if the change in time between the function sampling points remains constant. In embodiments explicit formulation of the derivative is implemented.

Referring to <FIG>, at block <NUM> the characteristic feature of the second order time derivative may be extracted by the circuitry <NUM>, including by an algorithm (or logic circuit) arranged on the processor.

The specific characteristic to be extracted may depend on the particular relationship that is implemented to determine the property of the flow of the flow path <NUM>, examples of which will be provided.

The relationship may require extraction of a class comprising one or more features (referred to as input values), of the second order derivative, all of which are encompassed by the term "characteristic feature of the second order time derivative".

It will be understood that depending on the specific class to be extracted, various processes for feature extraction may be implemented, e.g. stationary points or initial rises/falls from baseline can be determined via comparison of a magnitude of a data point to an adjacent data point, a peak to peak amplitude of adjacent maxima and minima or an amplitude of a maximum or minimum may subsequently be determined.

Referring to <FIG>, at block <NUM> the determined characteristic feature of the second order time derivative is processed to determine the property of the flow. Processing may include the implementation of a particular relationship to determine the property of the flow <NUM> of the flow path <NUM>. The relationship can be implemented by the circuitry <NUM>, including by an algorithm (or logic circuit) arranged on the processor.

As used herein the term "relationship" may refer to a relationship between the property of the electrical energy through the heating system <NUM> and the property of the flow of the flow path <NUM>. The relationship may be an empirical relationship, e.g. one obtained by experimentally obtained data. The empirical data can be stored on a memory associated with the circuitry <NUM>. Thus, in embodiments, an "empirical relationship" may also be referred to as a "stored relationship", and the terms "empirical" and "stored" may be used interchangeably. The relationship may include a mathematical function, with one or more input variables and an output variable. The output variable comprises the property of the flow. The one or more input variables comprises the previously described class of one or more characteristics.

A range of suitable output values is provided under the definition of the "property related to the flow". A range of suitable input values (i.e. a class) is provided under the definition of the "characteristic of the second order time derivative", and/or other features of the electrical energy through the heating system <NUM>.

The herein defined relationships may be better understood in view of the following example:.

An exemplary embodiment that implements one or more features of the previously described embodiments, or another embodiment disclosed herein, will now be provided.

The relationship provided in equation (<NUM>) may be implemented by circuitry <NUM> to determine the property of the flow, <MAT> wherein the output value is the mass M of aerosol present in a user inhale through the flow path <NUM>. Coefficients A - F are determined by regression of empirical data and have the respective values: <NUM>; <NUM>; <NUM>; <NUM>; <NUM>;<NUM>. Referring to <FIG>, the input values comprise: a peak to peak magnitude <NUM>, which is denoted as "I"; the constant voltage maintained over the heating system <NUM>, which is denoted as "V" in mV; the duration of the electrical energy applied to the heating system "Td" in mSec; the initiation time of the inhalation "Ti" in mSec. Since the voltage V is generally a constant, E and V may be replaced as a single coefficient.

The above relationship will now be utilised by way of example:
The input values include: a voltage V of <NUM> V; a duration of the electrical energy Td of <NUM> seconds; Ti of <NUM> seconds; an intensity I of <NUM>. The above relationship determines M as <NUM> with an experimental error of ± <NUM>-<NUM> %. The experimentally obtained value of M was obtained by measuring the depletion of a storage portion containing the precursor. A user inhale through the flow path was replicated by a pump with a calibrated representative flow rate of <NUM>/s.

The amount of individual components of the aerosol, e.g. nicotine, can be determined based on their concentration in the precursor, e.g. by the product of the concentration andM.

Referring to <FIG>, it can be seen that, by using the second order time derivative, characteristics (e.g. the stationary points) are more pronounced for line <NUM> (than what would be observed for the first order time derivative or line <NUM>). The derivative <NUM> is processed to determine the peak to peak magnitude <NUM> for an adjacent maximum <NUM> and minimum <NUM>, which is associated with initiation of the inhale. The initiation of inhale is determined as the maximum <NUM> as indicated by line <NUM>.

The circuitry <NUM> may implement various conditions to search and locate the correct maximum <NUM> and minimum <NUM>. These are exemplified for the implementation of the circuitry <NUM> shown in <FIG> as: determine possible maxima and minima for <NUM> seconds following initiation of the electrical energy to the heating system; determine greatest difference between adjacent maxima <NUM> and minima <NUM>; disregard if time difference between adjacent maxima <NUM> and minima <NUM> is greater than <NUM> second; disregard if the absolute of peak to peak <NUM> is not greater than <NUM>; the absolute of peak to peak <NUM> must be greater than that of an absolute of the peak to peak of a later occurring adjacent maximum and minimum multiplied by <NUM>; the absolute of peak to peak <NUM> must be greater than that of an absolute of the peak to peak of an earlier occurring adjacent maximum and minimum multiplied by <NUM>.

The circuitry <NUM> may determine the time duration Td of the electrical energy being applied to the heating system <NUM> by the previously described duration of actuation of the trigger (e.g. the vaping button or other suitable trigger). The circuitry <NUM> may determine the initiation of inhalation Ti by the time of the maxima <NUM>. A representative time duration of inhalation (which is not used in equation <NUM>) may be determined by Td-Ti.

Referring to <FIG>, which exemplify the current <NUM> and second order time derivative <NUM> for instances where the inhalation is initiated when the current has achieved the nominal value and is converging to the nominal value respectively, it can be seen that the peak to peak <NUM> may exhibit a similar magnitude in both instances. It may therefore be advantageous to utilise the second order derivative (as opposed to the first order derivative, or current without numerical differentiation) for determination of input values. Any dependency of the peak to peak magnitude <NUM> and the initiation time Ti (due to exponential decay of the current) may be accounted for based on the dependence of Equation (<NUM>) on the initiation time Ti. Moreover, it is apparent that the second order derivative converges faster to a nominal value than current without numerical differentiation.

In a variant of Equation (<NUM>), if the inhalation is initiated sufficiently early, a saddle point in the current <NUM> may occur at line <NUM>; consequently, the relationship may be adapted to search for a saddle point and to utilise the initiation of the point of zero gradient in the saddle (instead of the maxima at <NUM>) to derive the peak to peak <NUM>.

An exemplary embodiment that implements one or more features of the previously described embodiments, or other embodiment disclosed herein, will now be provided.

The relationship provided in equation (<NUM>) may be implemented by circuitry <NUM> to determine the property of the flow, <MAT> wherein the output value is the mass M (in mg) of aerosol present in a user inhale through the flow path <NUM>. Coefficients X - Z are determined by regression of empirical data and have the respective values: -<NUM>; <NUM>; <NUM>. The input values comprise: the constant voltage maintained over the heating system <NUM>, denoted as "V" (in mV); the duration of the electrical energy applied to the heating system "Td" (in mSec).

The above relationship will now be utilised by way of example:
The input values include: a voltage V of <NUM> V; a duration of the electrical energy Td of <NUM> seconds. The above relationship determines M as <NUM> with an experimental error of ± <NUM> - <NUM> %. The experimentally obtained value of M was obtained by measuring the depletion of a storage portion containing the precursor. A user inhale through the flow path was replicated by a pump with a calibrated representative flow rate of <NUM>/s.

The duration of the electrical energy Td through the heating system <NUM> can be determined as discussed for Example <NUM>.

In instances wherein initiation of inhale cannot be determined (e.g. the maxima <NUM> cannot be identified), thus precluding implementation of Equation (<NUM>), then Equation (<NUM>) may be implemented to determine the property of the flow.

It is to be understood that Example <NUM> and Example <NUM> provide example relationships between the electrical energy through the heating system <NUM> and the property of the flow of the flow path <NUM>. Other relationships may be implemented.

A variant of Example <NUM> may include, as input values, one or more of: the period between the maximum <NUM> and minimum <NUM>, or other period related thereto; the area under the maximum <NUM> and/or minimum <NUM>; a magnitude of the maximum or minimum <NUM> (as opposed to the peak to peak value <NUM>); alternative maxima and or minima may be used, including those associated with the end of the inhale. Alternatively, a gradient/period of the period between the oscillations caused by initiation and termination of inhalation may be utilised. In other variants, the input values may be obtained from a first derivative of the property of the electrical energy through the heating system <NUM>, or of the property of the electrical energy through the heating system <NUM> (i.e. without numerical differentiation).

In a further variant, a feature of an oscillation in a property of the electrical energy through the heating system may be used as an input value, including as the only input value; e.g. Equation (<NUM>) is adapted to have, as the only input value, the peak to peak <NUM>, which may be based on empirical data, which thus replaces the time dependency in the equation.

In a further variant, the duration of the user inhale may be obtained from the second order time derivative and may be used as an input value instead of the initiation time of the inhalation and/or duration of the electrical energy applied to the heating system.

A variant of Example <NUM> may include, as an input value, the duration of the user inhale, which may be determined from the second derivative of the property of the electrical energy through the heating system <NUM>, or the property of the electrical energy through the heating system <NUM> (i.e. without numerical differentiation).

In other variants an alternative property related to the flow may be determined; e.g. equations (<NUM>) or (<NUM>) may be alternatively formulated to determine: volume of aerosol; mass or volume of flow (i.e. the summation of the aerosol and air); velocity of the flow.

The determined property of the flow may be utilised in various manners, depending on what it is. It may be utilised as one or more of the following: display to a user on a user interface (e.g. on a peripheral device, such as a smartphone <NUM>, or on the apparatus <NUM>); stored on a memory associated with the system <NUM>; used as a basis for control of the apparatus <NUM> (e.g. it is determined that the depletion of precursor is greater than a threshold and aerosol generation is reduced or otherwise controlled).

Referring to <FIG>, in embodiments where the property of the flow is displayed on a user interface <NUM>, the circuitry <NUM> generates instructions for the user interface <NUM> to display information based on the determined property of the flow. The instructions may be for processing, by a display driver, for driving the user interface <NUM>. In embodiments wherein the property of the flow is an amount of one or more components of the aerosol present in an inhale, the quantity of said amount(s), and/or the amount from an aggregate of a plurality of inhales, may be displayed.

Referring to <FIG>, the described embodiments include circuitry <NUM> at block <NUM>, to determine a property of electrical energy through the heating system <NUM>; at block <NUM>, the circuitry <NUM>, to determine an oscillation due to initiation and/or termination of a user inhale through the flow path <NUM>. The process may be implemented in combination with the embodiment process illustrated in <FIG>, and/or <NUM>, or another embodiment disclosed herein.

As used herein "oscillation" may refer to one or more of: maxima; minima; saddle point. The maxima and minima may be adjacent. The oscillation may be caused by an inhalation through the flow path <NUM> (rather than by electrical noise or other interference). Furthermore, in embodiments, "oscillation" may refer to a certain feature or pattern of a parameter, such as (but not limited to) a feature or pattern of a property of electrical energy through the heating system. Referring to <FIG>, such a property may be, e.g., a current over time, and/or a first/second order derivative thereof. Hence, in such embodiments, an "oscillation" may occur at a portion of a function of a property, such as the functions illustrated by the graphs in <FIG>. For example, in <FIG> the portions of graphs <NUM> and/or <NUM> between line <NUM> and the vertical line (not shown) through point <NUM>, or relatively close thereto, may be referred to as an "oscillation". Referring to <FIG>, an "oscillation" may be seen in the portions of graphs <NUM> and/or <NUM> between lines <NUM> and <NUM> or between <NUM> and <NUM>.

As used herein, an "area of an oscillation" may refer to an area at least a section of whose boundary is formed by at least a section of the graph over time representing the oscillation. In an example, referring to <FIG>, the area of the oscillation represented by the portion of graph <NUM> between lines <NUM> and <NUM> may thus refer to an area which is on one side bounded by the entire or part(s) of the portion of graph <NUM> between lines <NUM> and <NUM>. Other sides of the area may be bounded by horizontal lines, such as the axis in the coordinate system which is denoted by "t" (the time axis) and/or by vertical lines, such as dashed lines <NUM> and <NUM> (or their extensions); or any other lines that are suited to define boundaries of an area.

As used herein, a "maximum" (of or comprised by an oscillation) may refer to a local maximum. Similarly, in embodiments, a "minimum" (of or comprised by an oscillation) may refer to a local minimum. In an example, referring to <FIG>, the local maximum <NUM> and/or <NUM> of the oscillation as described above may be referred to as a "maximum". Similarly, the local minimum <NUM> and/or <NUM> of the oscillation as described above may be referred to as a "minimum". As can be seen in these examples, in preferred embodiments, an oscillation is bounded by a minimum and/or a maximum.

As used herein, an "amplitude" may refer to the absolute difference of a property of electrical energy through the heating system between different points of time. In an example, referring to <FIG>, an "amplitude" may thus refer to the difference between a "maximum" and/or a "minimum" (peak to peak amplitude) as described above, such as illustrated by references <NUM> or <NUM>. Alternatively, an "amplitude" may refer to the distance of a maximum or a minimum from the time axis (peak amplitude).

In embodiments, a "period of an oscillation" may refer to a duration of an "oscillation" as described above. Thus, in an example, a "period" may start and end at the endpoints of a respective "oscillation". However, the startpoint and endpoint of the oscillation may be freely chosen.

Referring to <FIG>, at block <NUM>, the circuitry <NUM> is configured to process one or more features of the oscillation to determine a property related to flow. The processing may include the one or more features used as the input values for the described relationship between the property of the electrical energy through the heating system <NUM> and the property of the flow of the flow path <NUM>, with the property of the flow being the output value. At block <NUM>, the circuitry <NUM> is configured to optionally output the property related to flow (as discussed previously).

Referring to the previously discussed Example <NUM>, the property related to the flow of block <NUM> may include an amount of one or more components of aerosol dispensed in the inhale through the flow path <NUM>. As discussed for Example <NUM>, and with reference to <FIG>, an input value can be determined from the oscillation due to initiation of a user inhale through the flow path <NUM>. The oscillation may be based on the second order time derivative <NUM>, and includes a maximum <NUM> and an adjacent minimum <NUM>. The peak to peak amplitude <NUM> can be extracted from the maximum <NUM> and minimum <NUM> and used as the input value.

In an embodiment, an input value can be determined from the oscillation due to termination of a user inhale through the flow path <NUM>. The oscillation may be based on the second order time derivative <NUM>, and includes a maximum <NUM> and an adjacent minimum <NUM>. The peak to peak amplitude <NUM> can be extracted from the maxima <NUM> and minima <NUM> and used as the input value.

It has been found that the oscillation from either or both the initiation and termination of the inhale are related to an amount of one or more components of aerosol dispensed in the inhale through the flow path <NUM>. In embodiments, input values may be determined from the oscillation due to termination and initiation. In embodiments, input values from one of the oscillation due to initiation or termination of the inhale may be used if the other is not available.

It will be understood that the implemented relationship between the electrical energy through the heating system <NUM> and the property of the flow of the flow path <NUM> can be selected, based on which input values are determined.

Referring to <FIG>, after approximately <NUM> seconds, the current <NUM> exhibits notable oscillation (which can be more clearly seen in the corresponding second order time derivative <NUM>). The oscillation is electrical noise caused by overheating of the heating element of the heating system <NUM>. Depending on when the electrical noise occurs, the electrical noise may interfere with determination of the oscillation associated with the initiation and/or termination of inhalation. It may therefore be desirable to configure the circuitry <NUM> such that the user inhale through the flow path <NUM> occurs prior to the electrical noise, such that the electrical noise may not interfere with measurement of the inhale.

Referring to <FIG>, the oscillation due to termination of inhale is interfered with by the electrical noise. It may therefore be difficult to accurately determine the oscillation due to termination of inhalation. Accordingly, it may be desirable to implement relationships (e.g. those discussed under Example <NUM>) between the electrical energy through the heating system <NUM> and the property of the flow of the flow path <NUM> which do not require determination of the oscillation at termination of inhalation and require determination of oscillation at the initiation, since this oscillation is less likely to be subject to interference.

In variants, for determining the oscillation, the first derivative of the property of the electrical energy through the heating system <NUM> or the property of the electrical energy through the heating system <NUM> (i.e. without numerical differentiation) may be utilised.

However, with reference to <FIG> it can be seen that the second order derivative provides a more pronounced oscillation and may yield more accurate output values.

In embodiments, the circuitry <NUM> may determine the oscillation due to inhalation and/or termination of the inhalation by comparison to one or more predetermined conditions, which are exemplified under Example <NUM> in relation to conditions to search and locate the maxima and minima.

In variants embodiments, other features of the oscillation may be utilised as the input value, e.g. the period between the maxima and minima, or other periods related thereto; the area under the maxima and/or minima; a magnitude of the maxima or minima (as opposed to the peak to peak value).

Considering Example <NUM>, it can be understood that the magnitude of the amplitude <NUM> is directly related to an amount of the one or more components M of aerosol dispensed, i.e. via the empirical relationship of Equation <NUM>; the greater the magnitude of the amplitude the greater the amount of the component dispensed, e.g. via direct proportionality or other mathematical function relationship.

The described embodiments may be implemented with the electrical circuitry <NUM> to determine a property related to the flow of the flow path <NUM> based on one of a plurality of different relationships between the electrical energy through the heating system and said property.

In particular, the circuitry may implement a process comprising: measuring a property of the electrical energy through the heating system (e.g. the current as described previously or another property such as power or voltage); determining one or more characteristics from said measured property of the electrical energy (e.g. the input values for the previously described Example <NUM> or Example <NUM> or the herein described related variants or other like characteristics); selecting, based on the determined characteristics, one from a plurality of different empirical relationships between the measured property of the electrical energy and a property of the flow as defined herein (e.g. selecting Example <NUM> or Example <NUM> or another of the herein described related variants); implementing said relationship to determine the property of the flow as defined herein.

Suitable examples of relationships are provided as Example <NUM> and Example <NUM> and the herein described related variants. Accordingly, in an embodiment, the circuitry <NUM> may implement the relationship (e.g. Example <NUM> or Example <NUM> or other variant) according to an order of preference or a set of input values, which may be referred to as a "class".

Referring to <FIG>, an embodiment process for implementing the plurality of relationships includes, at block <NUM>, the circuitry <NUM> measuring the property of the electrical energy through the heating system <NUM> (examples of which were previously discussed).

At condition <NUM>, the circuitry <NUM> determines whether a first class of one or more input values can be determined from the determined property of the electrical energy through the heating system <NUM>. If the first class can be determined, then block <NUM> is executed to output the property of the flow at block <NUM>. Block <NUM> implements a first relationship.

In an embodiment which implements Equation (<NUM>) of Example <NUM>, the first class would be: the peak to peak magnitude <NUM>, which is denoted as "I"; the constant voltage maintained over the heating system <NUM>, which is denoted as "V"; the duration of the electrical energy applied to the heating system "Td"; the initiation time of the inhalation "Ti". Hence at condition <NUM>, if the first class can be determined, then at block <NUM> Equation (<NUM>) is implemented. At block <NUM> the output value is the mass M of aerosol present in a user inhale through the flow path <NUM>.

If at condition <NUM> the first class cannot be determined (e.g. one or more of the input values cannot be computed), then condition <NUM> is executed. At condition <NUM> the circuitry <NUM> determines whether a second class of one or more input values can be determined from the determined property of the electrical energy through the heating system <NUM>. If the second class can be determined, then block <NUM> is executed to output the property of the flow at block <NUM>. Block <NUM> implements a second relationship.

In an embodiment which implements Equation (<NUM>) of Example <NUM>, the second class would be: the duration of the electrical energy applied to the heating system "Td". Hence, at condition <NUM>, if the second class can be determined, then at block <NUM> Equation (<NUM>) is implemented. At block <NUM> the output value is the mass M of aerosol present in a user inhale through the flow path <NUM>.

In variant embodiments, a greater number than two relationships are implemented. In embodiments, the classes associated with a plurality of relationships may be determined, with the particular relationship implemented according to an order of preference.

If at condition <NUM> the second class cannot be determined (e.g. one or more of the input values cannot be computed), then block <NUM> is executed. At block <NUM> the circuitry <NUM> may determine the output value based on an output value determined from one or more prior user inhales through the flow path <NUM> (e.g. the output value from the previous inhalation is utilised as the output value or an average or other suitable representation based on output values from a plurality of prior inhalations is utilised as the output value). The information relating to prior output values may be stored on a memory communicatively coupled to a processor of the circuitry <NUM>.

Referring to the preceding embodiment in which Equation (<NUM>) and (<NUM>) were implemented as the first and second relationships, the input values of the second class associated with the second relationship is a subset of the input values of the first class associated with the first relationship. Electrical circuitry <NUM> implemented in this manner allows the second relationship to be conveniently implemented using one or more of the input values of the first class in the event that all of those from the first class cannot be determined. Such an implementation may have reduced processing overhead.

It will be appreciated that any of the disclosed methods (or corresponding apparatuses, programs, data carriers, etc.) may be carried out by either a host or client, depending on the specific implementation (i.e. the disclosed methods/apparatuses are a form of communication(s), and as such, may be carried out from either 'point of view', i.e. in corresponding to each other fashion). Furthermore, it will be understood that the terms "receiving" and "transmitting" encompass "inputting" and "outputting" and are not limited to an RF context of transmitting and receiving radio waves. Therefore, for example, a chip or other device or component for realizing embodiments could generate data for output to another chip, device or component, or have as an input data from another chip, device or component, and such an output or input could be referred to as "transmit" and "receive" including gerund forms, that is, "transmitting" and "receiving", as well as such "transmitting" and "receiving" within an RF context.

As used in this specification, any formulation used of the style "at least one of A, B or C", and the formulation "at least one of A, B and C" use a disjunctive "or" and a disjunctive "and" such that those formulations comprise any and all joint and several permutations of A, B, C, that is, A alone, B alone, C alone, A and B in any order, A and C in any order, B and C in any order and A, B, C in any order. There may be more or less than three features used in such formulations.

The word 'comprising' does not exclude the presence of other elements or steps then those listed in a claim. Unless stated otherwise, terms such as "first" and "second" are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

Unless otherwise explicitly stated as incompatible, or the physics or otherwise of the embodiments, example or claims prevent such a combination, the features of the foregoing embodiments and examples, and of the following claims may be integrated together in any suitable arrangement, especially ones where there is a beneficial effect in doing so. This is not limited to only any specified benefit, and instead may arise from an "ex post facto" benefit. This is to say that the combination of features is not limited by the described forms, particularly the form (e.g. numbering) of the example(s), embodiment(s), or dependency of the claim(s). Moreover, this also applies to the phrase "in one embodiment", "according to an embodiment" and the like, which are merely a stylistic form of wording and are not to be construed as limiting the following features to a separate embodiment to all other instances of the same or similar wording. This is to say, a reference to 'an', 'one' or 'some' embodiment(s) may be a reference to any one or more, and/or all embodiments, or combination(s) thereof, disclosed. Also, similarly, the reference to "the" embodiment may not be limited to the immediately preceding embodiment.

As used herein, any machine executable instructions, or compute readable media, may carry out a disclosed method, and may therefore be used synonymously with the term method, or each other.

The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various implementations of the present disclosure.

Claim 1:
An aerosol generation system (<NUM>) for generation of an aerosol from an aerosol-forming precursor, the system comprising:
- an electrically operated heating system (<NUM>) to heat said precursor to generate the aerosol;
- a flow path (<NUM>) for transmission of flow, including the aerosol, to a user; the heating system arranged in fluid communication with the flow path; and
- electrical circuitry (<NUM>),
characterized in that the electrical circuitry (<NUM>) is configured
- to determine a characteristic associated with a second order time derivative of a property of electrical energy through the heating system,
and
- to determine a property related to the flow of the flow path based on the characteristic of the second order time derivative.