Smoking Through a Topography Device Diminishes Some of the Acute Rewarding Effects of Smoking

SmokeMon: Unobtrusive Extraction of Smoking Topography Using Wearable Energy-Efficient Thermal

Smoking is the leading cause of preventable death worldwide. Cigarette smoke includes thousands of chemicals that are harmful and cause tobacco-related diseases. To date, the causality between human exposure to specific compounds and the harmful effects is unknown. A first step in closing the gap in knowledge has been measuring smoking topography, or how the smoker smokes the cigarette (puffs, puff volume, and duration). However, current gold-standard approaches to smoking topography involve expensive, bulky, and obtrusive sensor devices, creating unnatural smoking behavior and preventing their potential for real-time interventions in the wild. Although motion-based wearable sensors and their corresponding machine-learned models have shown promise in unobtrusively tracking smoking gestures, they are notorious for confounding smoking with other similar hand-to-mouth gestures such as eating and drinking. In this paper, we present SmokeMon, a chest-worn thermal-sensing wearable system that can capture spatial, temporal, and thermal information around the wearer and cigarette all day to unobtrusively and passively detect smoking events. We also developed a deep learning-based framework to extract puffs and smoking topography. We evaluate SmokeMon in both controlled and free-living experiments with a total of 19 participants, more than 110 hours of data, and 115 smoking sessions achieving an F1-score of 0.9 for puff detection in the laboratory and 0.8 in the wild. By providing SmokeMon as an open platform, we provide measurement of smoking topography in free-living settings to enable testing of smoking topography in the real world, with potential to facilitate timely smoking cessation interventions.

Cigarette filter ventilation, smoking topography, and subjective effects: A mediational analysis

BACKGROUND

Filter ventilation in cigarettes has been associated with alterations in smoking topography in order to compensate for the lower nicotine yields. Subjective effects of cigarettes include sensations, which can be affected by how a person smokes a cigarette. We look at smoking topography as a mediator in the relationship between filter ventilation levels and subjective effects.

METHODS

Smoking topography and subjective effects data come from the baseline usual cigarette brand laboratory visits of participants (N = 607) in a randomized clinical trial on reduced nicotine cigarettes. Conditional process analysis was done using PROCESS macro version 3.5 in SPSS.

RESULTS

There was a positive indirect effect of ventilation on satisfaction through total puff volume (0.004, 95% CI: 0.002, 0.007]) as well as ventilation on satisfaction through puff count then total puff volume, sequentially (0.001, 95% CI: [0.000, 0.003]). There was a positive indirect effect of ventilation on enjoyment through puff count for individuals less than 43 years of age (0.01, 95% CI: [0.002, 0.013]). There was a positive indirect effect of ventilation on enjoyment through total puff volume for individuals who smoke less than 14.33 cigarettes per day (0.009, 95% CI: [0.004, 0.015]).

CONCLUSIONS

We found preliminary evidence that topography measures (puff count and total puff volume), mediate the relationship between filter ventilation and specific subjective effects of smoking (satisfaction and enjoyment). Age and cigarettes smoked per day moderated these relationships. These results could have implications regarding filter ventilation restrictions and smokers' perceptions of using such cigarettes.

Validation of a High Flow Rate Puff Topography System Designed for Measurement of Sub-Ohm, Third Generation Electronic Nicotine Delivery Systems

There are few known puff topography devices designed solely for gathering electronic cigarette puff topography information, and none made for high-powered sub-ohm devices. Ten replicate Bernoulli flow cells were designed and 3D printed. The relationship between square root of pressure difference and flow rate was determined across 0−70 L/min. One representative flow cell was used to estimate puff volume and flow rate under six simulated puffing regimes (0.710 L, 2.000 L and 3.000 L, at low and high flow rates) to determine the system’s accuracy and utility of using dual pressure sensors for flow measurement. The relationship between flow rate and square root of pressure differential for the ten replicate cells was best fit with a quadratic model (R2 = 0.9991, p < 0.0001). The higher-pressure sensor was accurate at both low and high flow rates for 0.71 L (102% and 111% respectively), 2.00 L (96% and 103% respectively), and 3.00 L (100.1% and 107% respectively) but the lower-pressure sensor provided no utility, underpredicting volume and flow. This puff topography system generates very little resistance to flow, easily fits between user’s atomizer and mouthpiece, and is calibrated to measure flows up to 70 L/min.

Naturalistic Topography Assessment in a Randomized Clinical Trial of Smoking Unfiltered Cigarettes: Challenges, Opportunities, and Recommendations

Smoking topography (ST) is a set of measures profiling the behavioral characteristics of smoking in various settings. The CReSS portable device can measure ST in the natural environment. No standard protocol exists for measuring ST longitudinally with the CReSS. This study examined the utilization of the CReSS to measure ST and highlights challenges and opportunities in a naturalistic setting. This study is part of a randomized cross-over clinical trial of smoking filtered or unfiltered cigarettes. Participants (n = 43) smoked in each study condition for two weeks using the CReSS device for five days in their naturalistic smoking setting. The devices were calibrated and cleaned during the washout period, and data were downloaded every visit. Five test puffs were administered to calibrate each device. Moderate compliance rates (74.1%) were found with device usage, and the issues encountered were overheating/clogging, incorrectly registered date/time-stamped data, and device repair/replacement. Routine inspection/cleaning and training in device usage were instrumental in mitigating device malfunctioning. The CReSS device proved to be a feasible tool to examine naturalistic smoking topography and the potential impact of changes in tobacco product design on smoking unfiltered cigarettes. This is the first study to examine ST variables longitudinally, measured at multiple time points, and using unfiltered cigarettes.

Changes in puffing topography and subjective effects over a 2-week period in e-cigarette naïve smokers: Effects of device type and nicotine concentrations

INTRODUCTION

This study aimed to document changes in puffing topography and, the effects of device type and nicotine concentration on puffing topography, subjective effects and smoking behaviour over two weeks of e-cigarette (EC) use.

METHODS

EC naïve smokers (N = 50; 64% female) were randomly allocated to a cigalike (18 mg/mL) or tank containing either 18 (Tank18) or 6 mg/mL nicotine concentrations (Tank6). In 3 separate sessions (Baseline, 1 and 2 weeks post-baseline), participants vaped 20 min ad-libitum. Puff duration, puff number, inter-puff intervals (IPI), exhaled carbon monoxide (CO), cigarettes per day (CPD), cigarette dependence, craving, withdrawal, and subjective effects were recorded.

RESULTS

Two weeks post-baseline, puff duration and IPI significantly increased whilst puff number decreased. Cigalikes were associated with greater puff number and shorter IPI compared to Tanks; there was no difference between Tank18 and Tank6. CPD, CO and cigarette dependence reduced significantly from baseline to week1 but did not differ between conditions. During each session, there was a significant reduction in craving, whilst withdrawal symptoms were only alleviated in week1 and 2; there was no difference between conditions. Tank18 consistently rated highest on positive effects including satisfaction; satisfaction scores for Cigalikes and Tank6 declined overtime.

CONCLUSIONS

Cigalikes and tanks were both effective for reducing craving, withdrawal symptoms and CPD although for the former, this may only be achieved through more frequent puffing. That the Tank18 yielded greater satisfaction suggests tank devices and higher nicotine concentrations may be more suitable in the early stage of a smoking cessation attempt.

Comparing video observation to electronic topography device as a method for measuring cigarette puffing behavior

BACKGROUND

Smoking topography, or puffing behavior, is an important measure of how consumers may use tobacco products. However, numerous issues may prevent collection of this data via in-person, electronic topography device (e.g., CReSS). This study compared cigarette topography measures collected by video observation and electronic device.

METHODS

Laboratory smoking sessions were video recorded and scored for 96 cigarettes collected from 34 daily, adult non-treatment-seeking smokers (73.5 % male, 82.4 % White). Participants smoked three of their preferred brand cigarettes using an electronic topography device, providing carbon monoxide (CO) samples before and after each cigarette. Analyses compared measures from both assessment methods and examined associations with device-obtained total puff volume and CO boost.

RESULTS

Agreement analyses indicated robust similarity between methods for measures of puff count and total interpuff interval (Intraclass Correlation Coefficient [ICC]'s > 0.96,p's < 0.001; Bland-Altman [B-A] plotted differences within a priori limit of clinical significance) but diverged on total duration (ICC's > .93, p's < .001, yet B-A plots outside a priori limits). Regardless of assessment method, total duration and puff count (but not total interpuff interval) predicted total puff volume (p's < .001). None predicted CO boost (p's = .07-.90)."

CONCLUSIONS

Although some topography outcomes (e.g., total puff volume) cannot be assessed via video observation, video-observed measures of puff count, total duration, and total interpuff interval are generally interchangeable with their topography device-obtained counterparts. Thus, video observation is likely a sufficient substitute method for assessing cigarette topography when using an electronic device is not possible.

Characterization and Validation of the Second-generation wPUM Topography Monitors

INTRODUCTION

Little is known about the natural use behavior of new and emerging tobacco products due to the limited availability of reliable puff topography monitors suitable for ambulatory deployment. An understanding of use behavior is needed to assess the health impact of emerging tobacco products and inform realistic standardized topography profiles for emissions studies. The purpose of this study is to validate four monitors: the wPUM cigalike, vapepen, hookah, and cigarette monitors.

AIMS AND METHODS

Each wPUM monitor was characterized and validated for range, accuracy, and resolution for puff flow rate, duration, volume, and interpuff gap in a controlled laboratory environment. Monitor repeatability was assessed for each wPUM monitor using four separate week-long natural environment monitoring studies including cigalike, vapepen, hookah, and cigarette users.

RESULTS

The valid flow rate range was 10 to 100 mL/s for cigalike and cigarette monitors, 10 to 95 mL/s for vapepen monitors, and 50 to 400 mL/s hookah monitors. Flow rate accuracy was within ±2 mL/s for cigalike, vapepen, and cigarette monitors and ±6 mL/s for the hookah monitor. Durations and interpuff gaps as small as 0.2 s were measured to within ±0.07 s. Monitor calibrations changed by 4.7% (vapepen), 1.5% (cigarette), 0.5% (cigalike), and 0.1% (hookah) after 1 week of natural environment use.

CONCLUSIONS

The wPUM topography monitors were demonstrated to be reliable when deployed in the natural environment for a range of emerging tobacco products.

IMPLICATIONS

The current study addresses the lack of available techniques to reliably monitor topography in the natural environment, across multiple emerging tobacco products. Natural environment topography data will inform standardized puffing protocols for premarket tobacco product applications. The ability to quantify topography over extended periods of time will lead to a better understanding of use behavior and better-informed regulations to protect public health.

Differences in Smoking Topography and Subjective Responses to Smoking Among African American and White Menthol and Non-Menthol Smokers

INTRODUCTION

It has been suggested that menthol increases exposure to harmful elements of smoking and makes smoking more rewarding, easier to initiate, and harder to quit. Isolating the direct effects of menthol is challenging as African American (AA) race and menthol preference are highly overlapping. This study evaluated smoking behavior and subjective responses among a balanced sample of AA and white menthol and non-menthol smokers. In addition, smoking topography (ST) was compared to naturalistic smoking (NS) and interactions with menthol and race were explored.

AIMS AND METHODS

Smokers (N = 100) smoked and rated their preferred brand of cigarettes via ST or NS during two laboratory visits (counterbalanced).

RESULTS

Controlling for baseline differences among the groups (eg, nicotine dependence), menthol smokers took shorter and smaller puffs and AA smokers took longer puffs, but there were no differences in total puff volume, carbon monoxide, or other ST parameters. Menthol smokers reported greater urge reduction and lower sensory stimulation. The smoking method (ST vs. NS) had no effects on smoking behavior or exposure. Cigarettes smoked via ST were rated stronger. Differences in satisfaction based on the smoking method interacted with race and menthol status. Ratings of aversion differed by race and menthol status.

CONCLUSIONS

Menthol was not associated with increased smoke exposure or reward (except for urge reduction). ST caused minimal experimental reactivity relative to NS. Additional research that isolates the effects of menthol and examines potential interactive effects with race and other variables is needed to better understand its role in smoking-related health disparities.

IMPLICATIONS

Menthol and non-menthol smokers differed on some demographic variables and menthol preference was associated with greater nicotine dependence and greater urge reduction after smoking. Menthol was not associated with greater smoke exposure. Future research that investigates the unique risks associated with menthol and examines potential interactive effects with race and other related variables is warranted to better understand the role of menthol in smoking-related health disparities.

A Procedure to Standardize Puff Topography During Evaluations of Acute Tobacco or Electronic Cigarette Exposure

INTRODUCTION

Documenting factors that influence differential sensitivity to acutely inhaled nicotine products requires carefully controlling the amount of exposure (dose), and thus a procedure by which to control such exposure.

METHODS

We evaluated consistency of puff volume from intermittent acute exposures to smoked tobacco cigarettes (study 1, n = 45, plus a comparison study of uninstructed use with n = 59) and to vaped electronic cigarettes (e-cigarettes; study 2, n = 27 naive to e-cigarettes) in adult-dependent smokers. All in primary studies 1 and 2 participated in research administering different nicotine levels in each product under blind conditions, one per session using within-subject designs. In both studies, participants followed an automated instructional procedure on a computer monitor standardizing the timing and amount of exposure to each product during a given trial, with four trials per session, each separated by 20 minutes. Puff volume per trial via Clinical Research Support System (CReSS) was the primary dependent measure to determine consistency across trials via intraclass correlation coefficients (ICCs).

RESULTS

Control over topography with both inhaled products was demonstrated by highly significant ICCs for puff volume across trials. Instructed control with own brand was generally better in study 1 than with uninstructed smoking in the comparison sample, as expected. As intended, reliability of puff volume generally did not differ by menthol preference or sex in either study, but ICCs in study 2 tended to be lower for some men using the placebo e-cigarette.

CONCLUSIONS

This instructional procedure may substantially improve control over amounts of acute exposure to tobacco or e-cigarette use.

IMPLICATIONS

Control over topography in studies of acute exposure to these inhaled products can potentially aid validity of research into differential sensitivity to use, so findings can be attributed to factors of interest and not to variable exposure. Our procedure minimized variability in exposure to the same product and between moderate nicotine products, but remaining differences suggest that compensation for very low or no nicotine commercial products may be difficult to totally eliminate with these instructions alone. Further study is needed to determine this procedure's utility with other inhaled products among experienced users and when comparing different products in between-groups analyses.

The Application of Commercially Available Mobile Cigarette Topography Devices for E-cigarette Vaping Behavior Measurements

INTRODUCTION

The ability to reliably measure real-world vaping behavior is critical to understand exposures to potential toxins. Commercially available mobile topography devices were originally designed to measure cigarette puffing behavior. Information regarding how applicable these devices are to the measurement of electronic cigarette (e-cigarette) vaping topography is needed.

METHODS

Clinical Research Support System (CReSS; Pocket) and Smoking Puff Analyzer Mobile (SPA-M) topography devices were tested against the calibrated laboratory-based smoking puff analyzer duplicator (SPA-D) device combined with an analytical smoking machine that generates programmable puffs with high precision. Puff topography of e-cigarettes was measured over a range of puff volumes (10-130 mL) at 2 and 5 s puff durations (using bell- and square-shaped puffs). "Real-world" topography data collected from 10 participants during 1 week of at-home vaping were also analyzed. Recording anomalies and limitations of the devices, such as accuracy of detection of the puff end, flow rate dropouts, unreported puffs, and abandoned vaping sessions for the CReSS, and multi-peak puffs for the SPA-M were defined.

RESULTS

The accuracy of puff volumes and durations was determined for both devices. The error for SPA-M was generally within ±10%, whereas that for the CReSS varied more widely. The CReSS consistently underestimated puff duration at higher flow rates.

CONCLUSIONS

CReSS and SPA-M topography devices can be used for real-world e-cigarette topography measurements, but researchers have to be aware of the limitations. Both devices can provide accurate measurements only under certain puff parameter ranges. The SPA-M provided more accurate measurements under a wider range of puffing parameters than the CReSS. Summary data reported by both devices require thorough analysis of the raw data to avoid misleading data interpretation.

IMPLICATIONS

Results of this study provide researchers with valuable information about the capability of commercially available cigarette topography devices to measure real-world vaping behaviors. The differing measurement ranges of the two devices and puff recording limitations and anomalies should be taken into account during analysis and interpretation of real-world data.

Effect of e-cigarette flavors on nicotine delivery and puffing topography: results from a randomized clinical trial of daily smokers

RATIONALE

There is limited understanding regarding how various e-cigarette flavorings may influence the behavior of non-regular e-cigarette users who are regular cigarette smokers.

OBJECTIVES

To assess differences in nicotine delivery, puffing topography, subjective effects, and user satisfaction from different flavored e-liquids.

METHODS

Eighteen daily smokers (average age, 44.1 ± 7.0; 9 males; average CPD, 13.0 ± 5.8) smoked their tobacco cigarettes during an initial visit and returned five times to try an e-cigarette (eGo type) refilled with a nicotine solution (24 mg/ml) of five different flavors: cherry, tobacco, espresso, menthol, and vanilla (randomized order). Assessments at each visit included puffing topography, blood samples for nicotine analysis, and subjective reports of nicotine effects and flavor satisfaction.

RESULTS

Vaping different flavors resulted in different levels of plasma nicotine. The flavor producing the highest plasma nicotine concentration (C_max) was cherry (median 21.2 ng/ml), which was not significantly different than nicotine delivery from a combustible cigarette (29.2 ng/ml, p > .05). Vanilla e-liquid produced the lowest C_max (9.7 ng/ml), and participants tended to puff less frequently on vanilla compared to tobacco flavor (p = .013). Flavors did not differ significantly in the speed of nicotine delivery (T_max). During controlled use, puff duration for all flavors was significantly longer than a combustible cigarette (p < 0.05). After controlling for nicotine delivery, significant differences in flavor enjoyment were detected. Menthol flavored e-liquid was rated as more enjoyable than vanilla and tobacco flavored e-liquids (p < 0.05).

CONCLUSIONS

Flavors tested in this study yielded different patterns of nicotine delivery and led to differences in reduction in smoking urges.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: #NCT02575885.

Impact of e-liquid flavors on e-cigarette vaping behavior

OBJECTIVE

The primary objective of this pilot study was to describe the impact of e-cigarette liquid flavors on experienced e-cigarette users' vaping behavior.

METHODS

11 males and 3 females participated in a 3-day inpatient crossover study using e-cigarettes with strawberry, tobacco, and their usual brand e-liquid. Nicotine levels were nominally 18 mg/mL in the strawberry and tobacco e-liquids and ranged between 3-18 mg/mL in the usual brands. On each day, participants had access to the study e-cigarette (KangerTech mini ProTank 3, 1.5 Ohms, 3.7 V) and the assigned e-liquid during a 90-minute videotaped ad libitum session.

RESULTS

Average puff duration was significantly longer when using the strawberry e-liquid (3.2 ± 1.3 s, mean ± SD) compared to the tobacco e-liquid (2.8 ± 1.1 s) but the average number of puffs was not significantly different (strawberry, 73 ± 35; tobacco, 69 ± 46). Compared to the strawberry- and tobacco-flavored e-liquids, average puff duration was significantly longer (4.3 ± 1.6 s) and the average number of puffs was significantly higher (106 ± 67 puffs) when participants used their usual brand of e-liquid. Participants generally puffed more frequently in small groups of puffs (1-5 puffs) with the strawberry compared to the tobacco e-liquid and more frequently in larger groups (>10 puffs) with their usual brand. The strength of the relationship between vaping topography and nicotine intake and exposure were not consistent across e-liquids.

CONCLUSION

Vaping behavior changes across e-liquids and influences nicotine intake. Research is needed to understand the mechanisms that underlie these behavioral changes, including e-liquid pH and related sensory effects, subjective liking, and nicotine effects.

Development, validation and application of a device to measure e-cigarette users' puffing topography

With the rapidly rising popularity and substantial evolution of electronic cigarettes (e-cigarettes) in the past 5-6 years, how these devices are used by vapers and consumers' exposure to aerosol emissions need to be understood. We used puffing topography to measure directly product use. We adapted a cigarette puffing topography device for use with e-cigarettes. We performed validation using air and e-cigarette aerosol under multiple regimes. Consumer puffing topography was measured for 60 vapers provided with rechargeable "cig-a-like" or larger button-activated e-cigarettes, to use ad-libitum in two sessions. Under all regimes, air puff volumes were within 1 mL of the target and aerosol volumes within 5 mL for all device types, serving to validate the device. Vapers' mean puff durations (2.0 s and 2.2 s) were similar with both types of e-cigarette, but mean puff volumes (52.2 mL and 83.0 mL) and mean inter-puff intervals (23.2 s and 29.3 s) differed significantly. The differing data show that product characteristics influence puffing topography and, therefore, the results obtained from a given e-cigarette might not read across to other products. Understanding the factors that affect puffing topography will be important for standardising testing protocols for e-cigarette emissions.

Nicotine Delivery and Vaping Behavior During ad Libitum E-cigarette Access

OBJECTIVE

To characterize vaping behavior and nicotine intake during ad libitum e-cigarette access.

METHODS

Thirteen adult e-cigarette users had 90 minutes of videotaped ad libitum access to their usual e-cigarette. Plasma nicotine was measured before and every 15 minutes after the first puff; subjective effects were measured before and after the session.

RESULTS

Average puff duration and interpuff interval were 3.5±1.4 seconds (±SD) and 118±141 seconds, respectively. 12% of puffs were unclustered puffs while 43%, 28%, and 17% were clustered in groups of 2-5, 6-10, and >10 puffs, respectively. On average, 4.0±3.3 mg of nicotine was inhaled; the maximum plasma nicotine concentration (C_max) was 12.8±8.5 ng/mL. Among the 8 tank users, number of puffs was positively correlated with amount of nicotine inhaled, C_max, and area under the plasma nicotine concentration-time curve (AUC_0→90min) while interpuff interval was negatively correlated with C_max and AUC_0→90.

CONCLUSION

Vaping patterns differ from cigarette smoking. Plasma nicotine levels were consistent with intermittent dosing of nicotine from e-cigarettes compared to the more bolus dosing from cigarettes. Differences in delivery patterns and peak levels of nicotine achieved could influence the addictiveness of e-cigarettes compared to conventional cigarettes.