Electronic cigarette sensor interference signal shielding method, control component, electronic cigarette and sensor
By monitoring and analyzing the signal changes of the electronic cigarette sensor, identifying and blocking interference signals caused by impact or chaotic airflow, the problems of electronic cigarettes are solved and the safety hazards are significantly improved. The safety and user experience of the equipment are significantly improved.
Patent Information
- Application Number
- CN202510366583.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2025-05-16
AI Technical Summary
When the electronic cigarette sensor is affected by impact or chaotic airflow, it will generate interference signals, resulting in false touch and safety hazards of the electronic cigarette.
By monitoring the sensing signal to trigger both the inhalation comparator and the exhalation comparator within the preset period, we can determine whether an abnormal situation has occurred, and perform corresponding masking and reset operations during the timing period to prevent accidental contact.
It realizes identification and shielding of interference signals generated by more than 95% of electronic cigarette sensors being impacted or affected by turbulent airflow, which significantly improves the safety and user experience of electronic cigarettes.
Smart Images
Figure CN119999970A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the manufacture of sensitive components and sensors in the core electronics industry, and in particular to an electronic cigarette sensor interference signal shielding method, a control component, an electronic cigarette sensor, and an electronic cigarette. Background Art
[0002] Electronic cigarettes are electronic products that imitate cigarettes. The principle is to heat liquid oil to produce a mist aerosol and inhale it into the mouth to imitate the effect of smoking real cigarettes. Since electronic cigarettes do not contain major harmful substances such as carbon monoxide and tar, the harm is far less than that of real cigarettes, so they are loved by more and more smokers and young people.
[0003] MEMS piezoelectric sensors use negative pressure to trigger the deformation (mechanical energy) of the piezoelectric MEMS film, which generates a characteristic voltage that can be read by the ASIC chip inside the piezoelectric MEMS, thereby identifying the smoking action. Compared with traditional capacitive sensors, MEMS piezoelectric sensors have the advantages of dustproof, waterproof, and oilproof, and can work stably in harsh environments with high humidity and strong corrosion.
[0004] Safety is the most important factor for e-cigarette products, and the applicant has conducted a lot of testing work on this. The violent vibration of the sensor chip causes a large and violent fluctuation in the sensor signal. The rising edge of the interference signal is similar to the rising edge generated by normal inhalation, which will affect the normal triggering of the e-cigarette. In addition, after the abnormal action ends, if the sensor signal does not return to the baseline position, but drifts above the inhalation trigger threshold or below the blowing trigger threshold, and lasts for a long time, it may cause false touches, causing spontaneous combustion and posing a safety hazard. Summary of the invention
[0005] 1. Technical issues to be solved
[0006] The present invention is expected to at least partially solve one of the above technical problems.
[0007] 2. Technical Solution
[0008] The first aspect of the present invention provides a method for shielding interference signals of electronic cigarette sensors. The method for shielding interference signals of electronic cigarette sensors comprises:
[0009] Step A: if the sensing signal triggers both the inhalation comparator and the exhalation comparator within the preset time period t1, then step B is executed, 0.1ms≤t1≤20ms;
[0010] Step B, turning off the output of the OUT pin of the electronic cigarette sensor;
[0011] Step C, start timing. During the timing period T, if the sensor signal is detected to trigger both the inhalation comparator and the exhalation comparator within the preset period t1, then execute step D; otherwise, execute step E after the timing period T ends; 1ms≤T≤5s, T>t1;
[0012] Step D, reset the timer and execute step C;
[0013] Step E: reset the sensing signal and restore the OUT pin output of the electronic cigarette sensor.
[0014] In some embodiments of the present invention, 0.5ms≤t1≤5ms, preferably, 0.2ms≤t1≤3ms.
[0015] In some embodiments of the present invention, 100ms≤T≤2s, preferably, 500ms≤T≤1.5s.
[0016] In some embodiments of the present invention, in step E, the reset time length t2 of the reset sensing signal satisfies: 1ms≤t2≤256ms.
[0017] In some embodiments of the present invention, in step B, the digital shielding signal of the electronic cigarette sensor is enabled, so that the OUT pin of the electronic cigarette sensor is cut off from output; in step E, the abnormal trigger circuit of the electronic cigarette sensor is enabled, so that the OUT pin of the electronic cigarette sensor outputs normally.
[0018] In some embodiments of the present invention, the interference signal comes from one of the following: the electronic cigarette sensor is hit; the electronic cigarette sensor is affected by turbulent airflow; the electronic cigarette sensor is blown through the air.
[0019] The second aspect of the present invention provides a control component. The control component includes: a processor; a memory on which a computer program is stored; wherein the processor receives a sensor signal and executes the computer program to implement the above electronic cigarette sensor interference signal shielding method to obtain a sensor digital signal output.
[0020] In some embodiments of the present invention, the control component is selected from one of the following types: a dedicated integrated circuit chip, a microcontroller unit, a single-chip microcomputer, and a field programmable gate array.
[0021] The third aspect of the present invention provides an electronic cigarette sensor. The electronic cigarette sensor comprises: a sensor chip; and the above control component; wherein the sensor chip generates a sensing signal in response to the air pressure change caused by the user's inhalation; and the sensing signal is transmitted to the control component to obtain a sensing digital signal output.
[0022] In some embodiments of the present invention, the sensor chip is selected from one of the following types: a MEMS piezoelectric sensor chip; a capacitive sensor chip.
[0023] The fourth aspect of the present invention provides an electronic cigarette. The electronic cigarette comprises: an electronic cigarette body, an atomizer is arranged inside the electronic cigarette body; a micro control unit is encapsulated in the electronic cigarette body, and its signal is connected to the atomizer; the electronic cigarette sensor as above is encapsulated in the electronic cigarette body; wherein the micro control unit controls the opening and closing of the atomizer according to the digital signal output provided by the electronic cigarette sensor.
[0024] 3. Beneficial Effects
[0025] The present invention conducts a large number of tests and analyses on the interference signals of electronic cigarette sensors to obtain the rules of interference signals, and uses the rules of interference signals to identify the start, end and other time points of the interference signals. Combined with relevant control logic, it can identify and shield more than 95% of the interference signals generated by abnormal situations such as electronic cigarette sensors being hit or blown through the air, which can greatly improve the safety of electronic cigarettes and user experience. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 Schematic diagram of analog sensor signal jitter caused by abnormal conditions such as impact and air blowing.
[0027] Figure 2 The figure is a flow chart of a method for shielding interference signals of an electronic cigarette sensor according to an embodiment of the present invention.
[0028] Figure 3 To use Figure 2 The waveform diagram of each signal in the process of processing the electronic cigarette sensor signal by the electronic cigarette sensor interference signal shielding method is shown. DETAILED DESCRIPTION
[0029] The purpose of the present invention is to identify and shield interference signals generated by an electronic cigarette sensor being hit or blown through the air, so as to improve the safety and user experience of the electronic cigarette.
[0030] After summarizing and analyzing a large number of test results, the applicant found that when impact and turbulent airflow occur, the piezoelectric MEMS will vibrate violently, thereby causing the analog sensor signal to vibrate. The more obvious feature is the number of jumps of the suction comparator and the blowing comparator within a period of time (for example, 1ms), such as Figure 1 The “jump” here means that the inhalation comparator or the exhalation comparator is triggered, that is, the sensing signal exceeds the inhalation / exhalation trigger threshold. Figure 1 In the figure, VTH1 is the inhalation trigger threshold, and VTH2 is the exhalation trigger threshold.
[0031] The applicant needs to explain the difference between "blowing through the air" and "normal blowing". "Normal blowing" is just blowing close to the mouthpiece of the electronic cigarette. In this case, the airflow entering the mouthpiece is stable, and the generated sensor signal can be normally recognized by the electronic cigarette sensor. Different from "normal blowing", "blowing through the air" means blowing towards the mouthpiece of the electronic cigarette at a certain distance. In this case, the airflow entering the mouthpiece is turbulent, and the air pressure cannot be kept stable, so the corresponding sensor signal generated shows the characteristics of short-term large oscillations. In addition, some abnormal situations that can produce turbulent airflow are similar to this "blowing through the air" and are handled in the same way.
[0032] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific implementation methods and with reference to the accompanying drawings.
[0033] A first aspect of the present invention provides a method for shielding interference signals of an electronic cigarette sensor. Figure 2 The figure is a flow chart of a method for shielding interference signals of an electronic cigarette sensor according to an embodiment of the present invention. Figure 3 To use Figure 2 The waveform diagram of each signal in the process of processing the electronic cigarette sensor signal by the electronic cigarette sensor interference signal shielding method is shown.
[0034] In this embodiment, the sampling period of the ASIC (Application Specific Integrated Circuit) chip as the control component is 1μs. Based on this, if the analog signal jitter is found during the t1=2ms period monitored by the ASIC chip, it can be judged that an abnormal situation such as collision or turbulent airflow has occurred, and thus it is necessary to cut off the digital signal output of the ASIC chip to prevent the electronic cigarette from being triggered by mistake.
[0035] Figure 3 In the figure, (a) is the sensing signal waveform; (b) is the digital shielding signal waveform; (c) is the timing signal waveform; (d) is the forced reset signal waveform; (e) is the output digital signal waveform of the electronic cigarette sensor OUT pin. Figure 3 The example of "electronic cigarette sensor being hit" is mainly used for explanation. Other abnormal situations involved in the present invention are similar to this and will not be described in detail here.
[0036] Please refer to Figure 2 and Figure 3 The electronic cigarette sensor interference signal shielding method of this embodiment includes:
[0037] Step A: if the sensing signal triggers both the inhalation comparator and the exhalation comparator within the preset time period t1, then step B is executed, 0.1ms≤t1≤20ms;
[0038] The applicant found that when an abnormal situation occurs, such as when the electronic cigarette sensor is hit or affected by turbulent airflow, the sensor signal will vibrate violently, which is manifested as the sensor signal triggering the inhalation comparator and the exhalation comparator in a short time. This rule can be used to determine whether an abnormal situation has occurred.
[0039] By summarizing and analyzing a large number of test results and combining the sampling frequency of control components such as ASIC chips, the present invention sets the preset time period t1 to: 0.1ms≤t1≤20ms; preferably, 0.5ms≤t1≤5ms; more preferably, 0.2ms≤t1≤3ms. In this embodiment, t1=2ms.
[0040] Through summarizing and analyzing a large number of test results, the applicant found that when the sensor signal vibrates violently due to an abnormal situation, it may first vibrate in the inhalation direction and then in the exhalation direction, or it may first vibrate in the exhalation direction and then in the inhalation direction. Therefore, as long as both the inhalation comparator and the exhalation comparator are triggered within the preset time period t1, regardless of the order, it is determined that an abnormal situation has occurred.
[0041] Those skilled in the art should understand that the above-mentioned “triggering the inhalation sensor” means that the sensor signal crosses the inhalation trigger threshold; and “triggering the exhalation comparator” means that the sensor signal crosses the exhalation trigger threshold.
[0042] exist Figure 3 In (a), the interval between two adjacent vertical lines represents the preset time period t1 = 2ms. For ease of understanding, if both the inhalation comparator and the exhalation comparator are triggered within the preset time period t1, it is marked as state "1"; otherwise, it is marked as state "0". In this step, the corresponding Figure 3 The first state "1" in (a) is considered to be the beginning of impact or turbulent airflow.
[0043] Those skilled in the art should understand that this step is to monitor whether there is an abnormal situation that "the sensor signal triggers both the inhalation comparator and the exhalation comparator within the preset time period t1". If an abnormal situation occurs, the subsequent steps will be triggered. Otherwise, it means that there is no abnormal situation and the electronic cigarette sensor can sense normally, which will not be repeated here.
[0044] Step B, turning off the output of the OUT pin of the electronic cigarette sensor;
[0045] In this step, after the abnormal situation described in step A is detected, the digital shielding signal of the electronic cigarette sensor is enabled to generate a high-level digital shielding signal. Figure 3After the second t1 in (c) ends, the digital shielding signal rises to a high level. The digital shielding signal stops the output of the OUT pin of the electronic cigarette sensor, that is, no matter what the MEMS sensor signal is, the electronic cigarette sensor always outputs a low level to prevent the electronic cigarette sensor from being falsely triggered during impact / turbulent airflow.
[0046] Step C, start timing. During the timing period T, if the sensor signal is detected to trigger both the inhalation comparator and the exhalation comparator within the preset period t1, then execute step D; otherwise, execute step E after the timing period T ends; 1ms≤T≤5s, T>t1;
[0047] Step D, reset the timer and execute step C;
[0048] Step E: reset the sensing signal and restore the OUT pin output of the electronic cigarette sensor.
[0049] When an abnormal situation is detected in step A, the timer starts timing. The timer is sometimes also called a "counter", and its function is to trigger a corresponding action after the timing starts and reaches a preset time period.
[0050] Since abnormal conditions such as impact or turbulent airflow may last only for a short time or for a long time, it is necessary to accurately determine when these abnormal conditions end in order to reset the electronic cigarette sensor. The timing period is used to determine whether abnormal conditions such as impact or turbulent airflow have ended. The applicant found that if the situation of "both the inhalation comparator and the exhalation comparator are triggered within the preset period t1" does not occur within the timing period, it is determined that the abnormal condition has ended and the electronic cigarette sensor can be reset for normal output.
[0051] By summarizing and analyzing a large number of test results and combining with the coordination of other parts of the control logic, the present invention sets the timing period T to: 1ms≤T≤5s, T>t1; preferably, 100ms≤T≤2s, more preferably, 500ms≤T≤1.5s. In this embodiment, T=1s.
[0052] like Figure 3 As shown in (b), the timer starts timing after the second t1 ends, and the timing period is T. The timer has a delay function to avoid resetting the analog signal before the impact ends. In the 3rd to 8th t1s, there is a situation of "both the inhalation comparator and the exhalation comparator are triggered". Therefore, after each t1 ends, the timer is reset and restarted. In the 9th t1, the situation of "both the inhalation comparator and the exhalation comparator are triggered" is not detected. Therefore, the timer is not reset, and the timing continues until the timing period T ends. Step E is executed, as shown in Figure 3 As shown in the “impact end interval”.
[0053] Those skilled in the art should understand that, although the 3rd to 8th t1s in this embodiment continuously trigger abnormal conditions, if the abnormal condition occurs discontinuously within the timing period T, for example, the 3rd to 5th t1s do not trigger an abnormal condition, but the 6th t1 triggers an abnormal condition, the timing is also reset and step C is executed again.
[0054] When the timing is completed, that is, there is no abnormal situation in the continuous timing period T, it can be regarded as the end of the impact action, and the MEMS sensor signal is forced to reset, such as Figure 3 The reset time t2 of the reset signal of the reset sensor signal satisfies: 1ms≤t2≤256ms. Figure 3 In this embodiment, the reset time t2 is 128ms. This step is mainly to release the residual charge inside the MEMS, so that the analog signal is stabilized at zero point, which does not affect the chip's judgment of the smoking action, thereby improving the sensor accuracy.
[0055] When the MEMS sensor signal is forced to reset, the abnormal trigger circuit of the electronic cigarette sensor is released, and the digital shielding signal is set low. Figure 3 As shown in (b), the OUT pin output of the electronic cigarette sensor has just returned to normal, that is, when a smoking action occurs, a digital signal 1 is output, otherwise, a digital signal 0 is output.
[0056] like Figure 3 As shown in (e), in the smoking trigger interval, the electronic cigarette sensor senses the negative pressure generated by the user's smoking, the sensor signal exceeds the inhalation trigger threshold, the inhalation comparator is triggered, and the electronic cigarette sensor outputs a digital signal 1 to the micro control unit, thereby triggering the corresponding action.
[0057] Experiments have shown that through the above method, more than 95% of the interference signals generated by abnormal situations such as electronic cigarette sensors being hit or affected by turbulent airflow can be identified and shielded, thereby greatly improving the safety and user experience of electronic cigarettes.
[0058] Based on the above-mentioned electronic cigarette sensor interference signal shielding method, the second aspect of the present invention provides a control component. In an exemplary embodiment of the present invention, the control component includes: a processor; a memory on which a computer program is stored; wherein the processor receives a sensor signal and executes the computer program to implement the above-mentioned electronic cigarette sensor interference signal shielding method to obtain a sensor digital signal output.
[0059] In this embodiment, the control component is an ASIC (Application Specific Integrated Circuit) chip, but the present invention is not limited thereto. In other embodiments of the present invention, the control component may also be: an FPGA (Field-Programmable Gate Array) chip, an MCU (Micro-controller Unit) chip, a single-chip microcomputer, etc., all of which can implement the present invention and are within the protection scope of the present invention.
[0060] Based on the above control component, the third aspect of the present invention provides an electronic cigarette sensor. In an exemplary embodiment of the present invention, the electronic cigarette sensor includes: a sensor chip; the above control component; wherein the sensor chip generates a sensing signal in response to the air pressure change caused by the user's inhalation; the sensing signal is transmitted to the control component to obtain a sensing digital signal output.
[0061] In this embodiment, the implementation of the control component can refer to the previous description.
[0062] In this embodiment, the sensor chip is a MEMS piezoelectric sensor chip, but the present invention is not limited thereto. In other embodiments of the present invention, the sensor chip may also be other types of sensor chips that can be applied to electronic cigarettes, such as a capacitive sensor chip. These variations can also implement the present invention and are within the protection scope of the present invention.
[0063] Based on the above electronic cigarette sensor, the fourth aspect of the present invention provides an electronic cigarette. In an exemplary embodiment of the present invention, the electronic cigarette includes: an electronic cigarette body, an atomizer is arranged inside the electronic cigarette body; a micro control unit is encapsulated in the electronic cigarette body, and its signal is connected to the atomizer; the above electronic cigarette sensor is encapsulated in the electronic cigarette body; wherein the micro control unit controls the opening and closing of the atomizer according to the digital signal output provided by the electronic cigarette sensor.
[0064] At this point, the various embodiments of the present invention have been introduced. According to the above description, those skilled in the art should have a clear understanding of the present invention.
[0065] It should be noted that, for certain implementations, if they are not the key content of the present invention and are well known to ordinary technicians in the relevant technical field, they are not described in detail in the drawings or text of the specification due to space limitations. In this case, reference can be made to relevant existing technologies for understanding.
[0066] For the numerical values and numerical ranges mentioned in the present invention, unless explicitly indicated to the contrary, the numerical parameters in the specification and claims of the present invention may be approximate values and can be changed according to the content of the present invention. Specifically, all the numbers recorded in the specification and claims indicating the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases, and the meaning of the expression is to include a change of ±10% in some embodiments from a specific number.
[0067] The ordinal numbers used in the present invention, such as "first", "second", "third", "primary", "secondary", as well as Arabic numerals, letters, etc., to modify the corresponding elements (or steps), are intended only to clearly distinguish an element (or step) with a certain name from another element (or step) with the same name, and do not mean that the element (or step) has any ordinal number, nor do they represent the order of one element (or step) and another element (or step).
[0068] For the steps in the present invention, unless specifically described or the steps must occur in sequence, the order of the steps is not limited to the above list and can be changed or rearranged according to the desired design.
[0069] The present invention may also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for performing a portion or all of the methods described herein. Such a program implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.
[0070] The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. The various component embodiments of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. The physical implementation of the hardware structure includes but is not limited to physical devices, which include but are not limited to transistors, memristors, DNA computers, single-chip microcomputers, microprocessors or digital signal processors (DSPs). In addition, the present invention is not directed to any specific programming language. It should be understood that the content of the present invention can be implemented using various programming languages, and the description of specific languages herein is to disclose the best implementation of the present invention.
[0071] Those skilled in the art should understand that in the claims and description of the present invention, the word "comprising" does not exclude the existence of elements (or steps) not listed in the claims. The word "a" or "an" preceding an element (or step) does not exclude the existence of multiple such elements (or steps).
[0072] Furthermore, the above embodiments are provided merely to enable the present invention to satisfy legal requirements, and the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
[0073] Similarly, it should be understood that in order to simplify the present invention, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the claims, each inventive aspect lies in less than all the features of the previous single embodiment. Moreover, the embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.
[0074] The above specific embodiments provide a detailed description of the objectives, technical means and beneficial effects of the present invention. It should be understood that the purpose of the detailed description is to enable those skilled in the art to understand the present invention more clearly, and it is not used to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for shielding interference signals of electronic cigarette sensors, characterized in that: include: Step A: if the sensing signal triggers both the inhalation comparator and the exhalation comparator within the preset time period t1, then step B is executed, 0.1ms≤t1≤20ms; Step B, turning off the output of the OUT pin of the electronic cigarette sensor; Step C, start timing. During the timing period T, if it is detected that the sensing signal triggers both the inhalation comparator and the exhalation comparator within the preset period t1, then execute step D; Otherwise, after the timing period T ends, execute step E; 1ms≤T≤5s, T>t1; Step D, reset the timer and execute step C; Step E: reset the sensing signal and restore the OUT pin output of the electronic cigarette sensor.
2. The electronic cigarette sensor interference signal shielding method according to claim 1, characterized in that: 0.5ms≤t1≤5ms, preferably, 0.2ms≤t1≤3ms; And / or, 100ms≤T≤2s, preferably, 500ms≤T≤1.5s.
3. The electronic cigarette sensor interference signal shielding method according to claim 2, characterized in that: In the step E, the reset time length t2 of the reset sensing signal satisfies: 1ms≤t2≤256ms.
4. The electronic cigarette sensor interference signal shielding method according to claim 1, characterized in that: In the step B, a digital shielding signal of the electronic cigarette sensor is enabled, so that the OUT pin of the electronic cigarette sensor is cut off from output; In the step E, the abnormal trigger circuit of the electronic cigarette sensor is disabled to enable the OUT pin of the electronic cigarette sensor to output normally.
5. The electronic cigarette sensor interference signal shielding method according to any one of claims 1 to 4, characterized in that: The interference signal comes from one of the following: the electronic cigarette sensor is hit; the electronic cigarette sensor is affected by turbulent airflow; the electronic cigarette sensor is blown through the air.
6. A control component, characterized in that: include: processor; a memory having a computer program stored thereon; The processor receives the sensing signal and executes the computer program to implement the electronic cigarette sensor interference signal shielding method according to any one of claims 1 to 5 to obtain a sensing digital signal output.
7. The control component according to claim 6, characterized in that The control component is selected from one of the following types: a dedicated integrated circuit chip, a micro control unit, a single chip microcomputer, and a field programmable gate array.
8. An electronic cigarette sensor, characterized in that: include: Sensor chip; A control unit as claimed in claim 6 or 7; The sensor chip generates a sensing signal in response to the air pressure change caused by the user's suction; the sensing signal is transmitted to the control component to obtain a sensing digital signal output.
9. The electronic cigarette sensor according to claim 8, characterized in that: The sensor chip is selected from one of the following types: a MEMS piezoelectric sensor chip; a capacitive sensor chip.
10. An electronic cigarette, characterized in that: include: The electronic cigarette body has an atomizer disposed inside; A micro control unit is encapsulated in the electronic cigarette body, and its signal is connected to the atomizer; The electronic cigarette sensor according to claim 8 or 9, encapsulated in the electronic cigarette body; The micro control unit controls the opening and closing of the atomizer according to the digital signal output provided by the electronic cigarette sensor.