The present disclosure relates to an electronic vapour provision system, e.g. an e-cigarette, and to a control unit for such a system.
Electronic vapour provision systems such as e-cigarettes and other electronic nicotine delivery systems generally contain a cartridge to provide a reservoir of liquid which is to be vaporised, typically containing nicotine. When a user inhales on the device, a control unit operates a battery to provide power to a heater. This activates the heater to vaporise a small amount of liquid, which is then inhaled by the user.
This type of e-cigarette therefore generally incorporates two consumables, firstly the liquid to be vapourised, and secondly power in the battery. Regarding the former, once the reservoir of liquid has been exhausted, at least a portion of the device containing the cartridge may be discarded to allow replacement with a new cartridge. Regarding the latter, an e-cigarette usually provides some form of electrical connector to receive power from an external charging device, thereby allowing the battery within the e-cigarette to be re-charged.
Most e-cigarettes are powered by re-chargeable lithium ion batteries (or cells), which are to be found in a very widespread range of devices, not just e-cigarettes. (N.B. the terms “battery” and “cell” will be used inter-changeably herein, since due to the limited space within an e-cigarette, the battery in such an e-cigarette usually comprises just a single cell). Conventional lithium ion batteries used in e-cigarettes typically have an energy storage capacity in the range 70-3500 mAh, depending on the size of device, etc. Such batteries produce a voltage output that tends to decline as the battery discharges, for example, from about 4.2V when fully charged, down to about 3.6V just before being fully discharged, i.e. a decline of about 14%. Furthermore, since the power output across a given heating resistor R goes with V2/R, this implies that there would generally be a corresponding drop in power output such that the final operational power output (at a voltage of 3.6V) is only 73% of the initial power output (at a voltage of 4.2V). This change in power supplied by the battery to the heater, from being fully charged to being nearly discharged, can therefore significantly impact the amount of liquid vaporised, and hence inhaled by a user.
Some e-cigarettes may try to compensate for the loss of voltage, for example, by drawing extra current from the battery (such as by using pulse-width modulation, PWM). However, this type of approach may drain the battery more quickly, whereby the user ends up unexpectedly and inconveniently with a fully discharged e-cigarette.
The disclosure is defined in the appended claims.
An electronic vapour provision system comprises a control unit including: a battery for providing electrical power to a heater which is used to produce vapour, and a controller. The controller is configured to collect information, during user operation of the electronic vapour provision system, relating to: (i) power consumption from the battery due to operation of the heater to produce vapour, and (ii) re-charging of the battery. The controller is further configured to maintain a model of power consumption from the battery by the electronic vapour provision system and of the timings of re-charging the battery, wherein said model is formed or updated from said collected information. The model is further configured to predict from the model whether an estimated power consumption from the battery by the electronic vapour provision system will discharge down the a threshold level of charge before an estimated next re-charging time, and if so, perform a user notification and/or mitigation action in response to said prediction.
In some implementations, the model may be run on an external device, such as a smart-phone or server.
Various embodiments of the invention will now be described in detail by way of example only with reference to the following drawings:
As described above, the present disclosure relates to an electronic vapour provision system, such as an e-cigarette. Throughout the following description the term “e-cigarette” is used; however, this term may be used interchangeably with electronic vapour provision system, electronic aerosol delivery system, and other similar expressions.
The control unit 20 and cartomiser 30 are detachable from one another by separating in a direction parallel to the longitudinal axis (LA) of the e-cigarette, as shown in
The control unit is provided with one or more holes (not shown in
It will be appreciated that the e-cigarette 10 shown in
As shown in
The tip end 225 of the control unit 20 includes a cap to seal and protect the far (distal) end of the e-cigarette. There is an air inlet hole provided in or adjacent to the cap to allow air to enter the body and flow past the sensor unit 215 when a user inhales on the mouthpiece 35. This airflow therefore allows the sensor unit 215 to detect the user inhalation. In some implementations, the tip end 225 may be provided with a light, such as a light emitting diode (LED) that is illuminated by the chip in response to the detection of inhalation by the sensor unit 225. The tip end 225 may also (or alternatively) be provided with an electrical contact (not shown in
At the opposite end of the body 20 from the tip end 225 is the connector 25B for joining the control unit 20 to the cartomiser 30. As noted above, the connector 25B provides mechanical and electrical connectivity between the control unit 20 and the cartomiser 30. As shown in
The electrical contact 250 is mounted on a coil spring 255. When the control unit 20 is attached to the cartomiser 30, the connector 25A on the cartomiser pushes against the electrical contact 250 in such a manner as to compress the coil spring in an axial direction, i.e. in a direction parallel to (co-aligned with) the longitudinal axis LA. In view of the resilient nature of the spring 255, this compression biases the spring 255 to expand, which has the effect of pushing the electrical contact 250 firmly against connector 25A, thereby helping to ensure good electrical connectivity between the control unit 20 and the cartomiser 30. The body connector 240 and the electrical contact 250 are separated by a trestle 260, which is made of a non-conductor (such as plastic) to provide good insulation between the two electrical terminals. The trestle 260 is shaped to assist with the mutual mechanical engagement of connectors 25A and 25B.
The cartomiser 30 includes an air passage 355 extending along the central (longitudinal) axis of the cartomiser 30 from the mouthpiece 35 to the connector 25A for joining the cartomiser to the control unit 20. A reservoir of liquid 360 (typically including nicotine in a solvent) is provided around the air passage 335. This reservoir 360 may be implemented, for example, by providing cotton or foam soaked in the liquid. The cartomiser also includes a heater 365 for heating the liquid from reservoir 360 to generate (nicotine-containing) vapour to flow through air passage 355 and out through mouthpiece 35 in response to a user inhaling on the e-cigarette 10. The heater is powered through lines 366 and 367, which are in turn connected to opposing polarities (positive and negative, or vice versa) of the battery 210 via connector 25A. (As noted above, the details of the wiring between the power lines 366 and 367 and connector 25A are omitted from
The connector 25A includes an inner electrode 375, which may be silver-plated or made of some other suitable metal. When the cartomiser 30 is connected to the control unit 20, the inner electrode 375 contacts the electrical contact 250 of the control unit 20 to provide a first electrical path between the cartomiser and the control unit. In particular, as the connectors 25A and 25B are engaged, the inner electrode 375 pushes against the electrical contact 250 so as to compress the coil spring 255, thereby helping to ensure good electrical contact between the inner electrode 375 and the electrical contact 250.
The inner electrode 375 is surrounded by an insulating ring 372, which may be made of plastic, rubber, silicone, or any other suitable material. The insulating ring is surrounded by the cartomiser connector 370, which may be silver-plated or made of some other suitable metal or conducting material. When the cartomiser 30 is connected to the control unit 20, the cartomiser connector 370 contacts the body connector 240 of the control unit 20 to provide a second electrical path between the cartomiser and the control unit. In other words, the inner electrode 375 and the cartomiser connector 370 serve as positive and negative terminals (or vice versa) for supplying power from the battery 210 in the control unit to the heater 365 in the cartomiser via supply lines 366 and 367 as appropriate.
The cartomiser connector 370 is provided with two lugs or tabs 380A, 380B, which extend in opposite directions away from the longitudinal axis of the e-cigarette. These tabs are used to provide a bayonet fitting in conjunction with the body connector 240 for connecting the cartomiser 30 to the control unit 20. This bayonet fitting provides a secure and robust connection between the cartomiser 30 and the control unit 20, so that the cartomiser and control unit are held in a fixed position relative to one another, without wobble or flexing, and the likelihood of any accidental disconnection is very small. At the same time, the bayonet fitting provides simple and rapid connection and disconnection by an insertion followed by a rotation for connection, and a rotation (in the reverse direction) followed by withdrawal for disconnection. It will be appreciated that other embodiments may use a different form of connection between the control unit 20 and the cartomiser 30, such as a snap fit or a screw connection.
As shown in
The sensor unit 215 is located in or adjacent to the air path through the control unit 20 from the air inlet to the air outlet (to the vaporiser). The sensor unit includes a pressure sensor 562 and a temperature sensor 563 (also in or adjacent to this air path). Note that in some embodiments, there may be additional sensors (not shown in
The controller 555 includes a processor such as a CPU and memory (ROM and RAM). The operations of the controller 555 and other electronic components, such as the pressure sensor 562, are generally controlled at least in part by software programs running on the processor (or on the other electronic components as appropriate). Such software programs may be stored in non-volatile memory 218, which can be integrated into the controller 555 itself, or provided as a separate component (e.g. on PCB 202). The processor may access the ROM to load and execute individual software programs as and when required. The controller 555 also contains suitable interfaces (and control software) for interacting with the other devices, such as with the sensor unit 215.
The controller 555 utilises the speaker 58 as an output device for producing audio signals to indicate conditions or states within the e-cigarette, such as a low battery warning. Different signals for signalling different states or conditions may be provided by utilising tones or beeps of different pitch and/or duration, and/or by providing multiple such beeps or tones. Other forms of output device may be provided as well as or instead of the speaker 58. For example, as mentioned above the tip end 225 may be provided with a light emitting diode (LED) which may be used for signalling and/or ornamentation. There may also (or alternatively) be a light output at one or more other locations on the e-cigarette 10.
The communications interface 217 may be a wired or wireless connection to allow the e-cigarette 10 to communicate with an external device. For example, the communications interface 217 may support one or more of Bluetooth, (the IEEE 802.11 family), and/or near field communications (NFC) for establishing wireless communications. Alternatively, or additionally, the communications link may support wired communications, potentially via connector 25B and/or some other communications facility. The communications interface may be used, inter alia, to allow an external device to provide and update control settings on the e-cigarette 10, and/or to retrieve status and usage information from the e-cigarette.
As noted above, the e-cigarette 10 provides an air path from the air inlet through the e-cigarette 10, past the pressure sensor 562 and the heater 365 (in the vaporiser), to the mouthpiece 35. Thus when a user inhales on the mouthpiece of the e-cigarette, the controller 555 detects such inhalation based on information from the pressure sensor. In response to such a detection, the CPU supplies power from the battery or cell 210 to the heater 365, which thereby heats and vaporises the liquid from the wick for inhalation by the user.
The battery 210 is linked to the heater 365 via a power switch 212 and connector 25B (plus connector 25A on the cartomiser 30). The power switch 212 supports the flow (and switching on/off) of the relatively large current supplied from the battery 210 in order to power the heater 365—this is typically of the order of 1 amp or more. The power switch 212 is controlled by the controller 555. For example, the controller 555 may close the power switch 212 in response to the pressure sensor 562 sensing an airflow through the e-cigarette 10, thereby allowing power to flow from the battery to the heater. Conversely, the controller 555 may open the power switch 212 in response to the pressure sensor 562 sensing that the airflow through the e-cigarette 10 has now ended, thereby terminating the power flow from the battery to the heater. In addition, the controller 555 may use switch 212 to implement a PWM scheme, as described above, to regulate the amount of power supplied from the battery 210 to the heater 365 during an inhalation.
It will be appreciated that the electrical configuration shown in
The functionality of the controller 555 may be distributed across one or more components which act in combination as a controller. For example, there may be a PCB provided in combination with battery 210 to control re-charging of the battery, such as to detect and thereby prevent voltage or current overload and/or overly long charging, and likewise to control discharging of the battery, e.g. so that the battery does not get excessively discharged to the point of damage.
The e-cigarette 10 may record multiple different types of event into a log. For example, the e-cigarette 10 may treat an inhalation as an event, and record various information about the event—e.g. start time of the inhalation, duration of the inhalation, and the total energy utilised from the battery to power the heater during the inhalation. The latter parameter (energy) can be determined, for example, from the integral of voltage multiplied by current during the period of inhalation, which in turn might be obtained from a series of rapid measurements of the current and voltage during the inhalation. Alternatively, the amount of energy for an inhalation might be estimated, at least in part, e.g. based on the duration of the inhalation, the setting of any output level control, etc.
Similarly, the e-cigarette may also record into memory 218 generally similar information about re-charging events—for example, start time of the re-charging, duration of the re-charging, and energy supplied to the battery by the re-charging (this again can be determined by a series of voltage and current measurements, or just estimated). Note that the time(s) may reflect the period of actual re-charging rather than when the device is plugged into an external power supply (since the re-charging per se will end once the battery is fully charged).
Note that rather than recording a start time and duration for an event, another option is to regard starting and stopping as separate events—e.g. a first event to denote the start of re-charging, and a second event to denote finishing re-charging. The timer 218 may also supplied date information and/or day of the week information.
The e-cigarette 10 may also record at predetermined times (for example), the battery output level of battery 210. In addition, the e-cigarette may record a wide variety of further types of events and/or parameter into the log, such as error states, operating temperature, etc. These other event/parameter types are less relevant for the processing of the present application, and will not be described herein.
Table 1 is an example of the information that may be stored into the log, as maintained in memory. This information is shown in the form of a table for ease of understanding, but the log may be based on any suitable data structure. Each row of the table corresponds to an event, and is associated with a unique event number, and a timestamp denoting date and time. In general there are different codes for each type of event, but for each of understanding, each event recorded in Table 1 is given a descriptive name. The first event is end-charge, representing the termination of charging. The second event is a measurement of battery charge level. Such measurements (and recording them into the log) may be performed on a predetermined timescale—for example every 15 minutes, and/or in response to various other events. For example, a battery charge level might be measured after every termination of charging (as shown in Table 1 above), and also whenever the device is unlocked, as described below.
The third and fourth events (as well as the fifth and sixth events, etc.) are detections of the start of inhalation and end of inhalation respectively. It will be appreciated that there may be many of these event pairs during a day. Table 2 also records the device being locked, which might occur automatically following a time-out period if the device is not used during the period (e.g. no inhalation detected during the period). Additionally or alternatively, the user might explicitly lock the e-cigarette, such as by pressing a particular button (or combination of buttons). Subsequently unlocking might then be performed by some appropriate manipulation (which might, for example, be difficult for children to perform), or perhaps by entering a suitable code into a smart-phone, which then sends an authorisation signal to unlock the e-cigarette via communications interface 217.
A final column in the Table above may be used to store ancillary information, e.g. parameters (if any) associated with a particular event—N.B. the type of event information stored will generally depend on the type of event. For example, a parameter for the charge reading event may denote the current voltage or charge level of the battery. A parameter for the begin-inhalation event might correspond to a power setting (which might be used to control how much vapour is to be produced for a given strength of inhalation). A parameter for the end-inhalation event might correspond to the volume of air inhaled, which may be measured or at least estimated by (for example) sensor unit 215.
It will be appreciated that the log structure shown in the Table is for illustrative purposes only, and many variations will be apparent for the skilled person. For example, an inhalation might be recorded as a single event, with the parameters for such an event providing information on the start time and duration of the inhalation. The event number may also be omitted if not required—for example, the time-stamp may uniquely identify each event (perhaps in combination with the event type).
The middle portion of
In some implementations, the event data when generated may be applied directly, on an ongoing basis, to update the model (rather than being read back out of a log). Note that the event data might still be recorded into a log however, since this might (for example) still provide useful information—i.e. for diagnostics in case of some form of failure of the e-cigarette 10. Also, having a log of events separate from the model can help to reduce data access conflicts between saving new events to the log, and updating and exploiting the model. For example, one possibility is to copy recent events from the log to the model, perhaps at a time of low activity (e.g. at night), and therefore with minimal interruption to ongoing operation of the log to record new events. This then allows the log and model to be used in parallel, without conflict, at other times. A further possibility is for the log and model to run on different devices, as described in more detail below.
The right hand portion of
The action of operation 670 may comprise making (for example) information available to the user, whether actively or passively (in the former, the user receives an explicit notification of the information becoming available; in the latter, the information is available if the user looks in the right place—which of course may already be known to them). The action may also comprise modifying one or more operating parameters or characteristics of the device, whether on a fully automatic basis, or else subject to some form of user confirmation.
In some implementations, the model itself may be located on another device (not on the e-cigarette itself). In such circumstances, it will be appreciated that only some, but not all, of the operations shown in
In particular,
The results in
The plots illustrated in
If the remaining charge on the battery is greater than the expected total power usage (typically by a threshold amount), then the trigger detection at operation 665 in
The trigger action comprises one or more actions arising from the trigger detection. One possible action in this situation is to issue a notification or warning to the user of the prediction that the battery does not have adequate charge for likely usage. Note that this is different from a conventional “low battery” warning, since the latter typically occur when the remaining charge on a battery falls below a specified amount. In contrast, a warning that the battery does not have an adequate charge for likely usage may occur while there is still substantial charge on the battery (above the level for a conventional “low battery warning”), if there is expected to be a significant time interval until the next predicted re-charging.
The notification may take any appropriate form, depending upon the available facilities of the e-cigarette. For example, the e-cigarette may provide a particular audio warning (one or more beeps) via speaker 558, or set one or more indicator lights. Another possibility is to set an internal status which can then be detected over communications interface 217, e.g. by using an app on a smartphone, and the app then provides the relevant notification to the user. Note that the form of the notification may vary according to the severity or estimated likelihood of the e-cigarette running out of charge. For example, if the expected usage is significantly above the battery charge level, the notification may be pushed more assiduously than if the expected usage is marginally below the battery charge level—e.g. an alarm status is made available to a smartphone app in both cases, but an audio or light notification on the e-cigarette itself is only provided in the former case, where the expected usage is significantly above the battery charge level. In response to the notification or warning, the user may choose some appropriate action, for example, actively seeking an earlier opportunity to re-charge the e-cigarette and/or scaling back their usage of the e-cigarette.
Another form of trigger action at operation 670, which may be adopted instead of or in addition to the user notification described above, is to reduce power consumption levels. This reduction in power consumption levels may be performed by controller 555 itself, or instructed by an external mechanism (such as a smartphone app), or by a combination of both. In addition, the reduction in power consumption levels may be performed automatically, or may, at least in part, first require confirmation or instruction from a user. Examples of mechanisms for reducing power consumption are: if the e-cigarette illuminates during an inhalation, turn off such illumination, or reduce the period and/or intensity of the illumination; reduce the power level supplied to the heater during an inhalation, and/or reduce the time for which power is supplied. Also, if the e-cigarette has a “sleep” mode with generally lower levels of power consumption, the e-cigarette may transition more quickly to this lower level power mode (after a shorter period of non-use).
It will be appreciated that the model described above for power usage is relatively simple, and more sophisticated models can readily be employed, e.g. by having a model which is probability based. For example, we can define t as the time interval from the current time until the next re-charge commences, where 0<t<T, with T being some maximum likely time until the next re-charge. We define a probability (density) distribution for t, denoted as p(t), where ∫p(t) dt between 0 and T is 1 (assuming the e-cigarette will definitely be recharged within time T). Thus p(t) represents the probability of having to wait time t (no more, no less) until the next recharge occurs.
We can use the plot of
Once we have p(t), one approach is to estimate the time until the next re-charging according to ∫p(t).t dt between integral limits 0 and T—this is the standard formula for the expected value of t (denoted E[t]). Assuming we do wait for a time period E[t] until the next re-charging, we can then follow the approach described above for determining whether or not the expected power usage over this period E[t] exceeds the charge capacity remaining in the battery.
A further refinement is that rather than using the expected value E[t] for assessing the risk of the battery being exhausted, we can use the probability distribution p(t) directly. Thus if the total charge level on the battery is currently C, and the expected power usage in the next time t (starting from the current time) is E[P(t)], the probability of battery depletion (Prob) can be determined as:
Prob=∫p(t)·kdt (integral for 0<t<T)
where k=1 if E[P(t)]>C, and k=0 otherwise. Note that since E[P(t)] is necessarily an increasing (or at least, non-decreasing) function with respect to increasing t (the e-cigarette only consumes power), then if we define t′ as the value of t for which E[P(t)]>C, the above expression can be re-written as:
Prob=∫p(t)dt (for 0<t<f)
In such a situation, we can consider the model as incorporating the distribution of start times for the next re-charge and the rate of expected usage (based on inhalations), as derived from the log data, including the dependency on current time. The model is then supplied with present status parameters (namely current time and battery charge level), which serve as inputs to the model to determine the probability specified above. The trigger detection of operation 665 may then produce a positive outcome if the determined probability exceeds a certain threshold. One possibility might be to have a “traffic light” system in which a probability of 30% or less is regarded as “green”, a probability of battery depletion of between 30% and 65% is regarded as “amber”, perhaps with an appropriate notification to the user, and a probability of battery depletion of above 65% is regarded as “red”, with a more significant (e.g. more frequent or direct) notification to a user, and perhaps the automatic implementation of power saving measures as discussed above.
Accordingly, the skilled person will understand that although the inhalation information shown in
Furthermore, the duration of inhalations (and hence the power consumed by each inhalation) may itself vary according to a distribution (and the distribution may vary with time of day, etc.). Again, the log information allows such a distribution to be determined, and this again allows a more sophisticated probability model for estimated power usage to be developed and exploited.
It will be appreciated that the analysis described above represents just some examples of a model based on the collected information, and many others will be available. For example, the usage patterns shown in
It will be appreciated that the average charge level, shown as a percentage of the full battery level, is dependent largely on both re-charging times and also inhalation, hence there is a close inter-relationship between the three lines plotted in
The models described herein can be based on a wide range of statistical and computing structures of varying sophistication, such as principle component analysis (PCA), correlation models, neural networks, etc. For example, the model may show from the usage data that number (or duration and/or strength) of inhalations are correlated not only with time, but also with specific day of the week, as well as immediate past usage of the e-cigarette—for example, heavier usage (than average) during the afternoon might tend to be followed by lighter usage (than average) in the evening. These correlations, etc., can then be exploited by the model to give a more accurate estimate of the (distribution of) expected energy usage.
Note that the model may refine itself with increasing usage of the device. For example, at a given point in time, the model may predict a certain expected usage over a set time period. The actual usage over this time period (as subsequently recorded in the log) may then be accessed and compared with the prediction. If the prediction is discrepant from the actual usage, this can be used to help refine and improve the model via any suitable machine learning technique.
As noted above, the model may be implemented on the e-cigarette itself, and/or on an external device, such as a smartphone or tablet computer. The external device connects to the e-cigarette via interface 217 to read the log data (operation 640) in order to update the model accordingly (operation 645). The results of running the model on the external device may be presented directly from the device to the user (it will be appreciated that the user interface of a device such as smartphone is typically much more powerful than for an e-cigarette, e.g. with a touch-screen interface, etc., and such a device generally also has much more processing power). The results of running the model may also be loaded back to the e-cigarette, possibly in the form of instructions to adopt power-saving measures.
A further possibility is that the model itself is maintained on a server accessible by the external device (and/or possibly the e-cigarette) over the Internet or other appropriate network. In this case, the usage data may be uploaded to the server for analysis and modelling (somewhat akin to uploading position tracking data from a GPS device for analysis).
In order to address various issues and advance the art, this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and to teach the claimed invention(s). It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claims. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. other than those specifically described herein. The disclosure may include other inventions not presently claimed, but which may be claimed in future.
Number | Date | Country | Kind |
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1517086.3 | Sep 2015 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/GB2016/052679 | 8/30/2016 | WO | 00 |