Development and validation of a device for measuring puffing topography of e-cigarette users CUNNINGHAM A. 1 ; SLAYFORD S. 1 ; VAS C. 1 ; GEE J. 1 ; COSTIGAN S. 2 ; PRASAD K. 1 1 British American Tobacco, Group Research & Development, Regents Park Road, Southampton, SO15 8TL, U.K. Krishna_Prasad@bat.com 2 Nicoventures, 22 Tudor Street, London, EC4Y OAY, U.K ST 56, CORESTA Congress, Québec City, Canada 12 th 16 th October 2014 1
Background E-cigarettes are gaining popularity, with limited data available on users puffing behaviour Acknowledged that large variation exists in smokers puffing behaviour - International Standard method (ISO 3308.2000) - Indirect method: filter analysis - Direct method: puffing topography - Video We aimed to validate a topography device for recording puffing behaviour of e-cigarette users 2
The Current SA7 System Initial approach to use existing Smoking Analyser Number 7 technology 1 Inaccurate puff volumes observed following repeated puffing on commercially available products Condensation of excipients in topography holder and partial blocking of tubes to pressure transducer Re-design of the SA7 topography measurement device undertaken 1 A Device to Measure a Smoker s Puffing Topography and Real-Time Puff-by- Puff Tar Delivery, Slayford S.J., Frost B.E., Beitrage zur Tabakforschung, 2014. 26 (2), 74 84. 3
Modified SA7 Pressure & Flow Calibration Calibration - Pressure calibration: 0 120 mmwg - Flow calibration: 2 120 ml/sec - Calibrated pressure gauge & Borgwaldt A14 syringe driver E-cigarette holder demonstrated extremely good linearity for puff volume measurements Measured Puff Volume (ml) 100 80 60 40 20 n = 3 y = 1.006x - 0.700 0 0 20 40 60 80 100 Set Puff Volume as measured by burette (ml) 4
Puffing Regimes & Profiles Without e-cigarette Performance of e-cigarette holder used to measure a range of puffing regimes and puff flow profiles Puff Flow Profile Shape Puffing Regime Set Puff Volume (ml) Set Puff Duration (s) Sine Rectangle Triangle Early Triangle 1 20 1.5 2 40 2.0 3 60 2.5 4 80 3.0 5 20 1.5 6 40 2.0 7 60 2.5 8 80 3.0 9 20 1.5 10 40 2.0 11 60 2.5 12 80 3.0 13 20 1.5 14 40 2.0 15 60 2.5 16 80 3.0 5
Puffing Regimes & Profiles Without e-cigarette Flow Rate (ml/sec) 60 40 20 0 Sine Wave 0 1 2 3 4 Puff Duration (s) Flow Rate (ml/sec) 30 20 10 0 Square Wave 0 1 2 3 4 Puff Duration (s) Flow Rate (ml/sec) 60 40 20 0 Triangle 0 1 2 3 4 Puff Duration (s) Flow Rate (ml/sec) 80 60 40 20 0 Early Triangle 0 1 2 3 4 Puff Duration (s) 6
Puffing Regimes & Profiles Results Testing completed for sine, triangle, square and early triangle profiles Three replicates of each puffing regime were measured and recorded using the e-cigarette holder without the use of an e-cigarette in-line Accurate determination of puff volume and puff duration using e-cigarette holder Puff volumes: ±1.0 ml across a 20 80 ml range Puff durations: ±0.1 s across a 1.5 3.0 s range 7
Testing of e-cigarette devices Tested a range of e-cigarette devices - Disposable - Rechargeable cartomiser-based - Rechargeable modular / tank system Puffing Regime (#) Puff Volume (ml) Puff Duration (s) Puff Frequency (s) Flow Rate (ml/s) Puff Flow Profile (#) 1 55 3.0 30 18.3 Square 2 80 3.0 30 26.7 Square 3 120 3.0 30 40.0 Square E-cigarette devices puffed to exhaustion of battery, or to 150 puffs 3 replicates per product per regime tested 8
Testing of devices using e-cigarette holder Device 55 80 120 Disposable Rechargeable cartomiser-based n = 267 55.1 (0.2) n = 434 54.8 (0.2) Set Puff Volume (ml) a ) n = 266 80.5 (0.3) n = 399 80.0 (0.3) n = 234 120.0 (1.1) n = 423 119.1 (0.6) Rechargeable modular / tank system n = 450 55.0 (0.8) a Presented as Mean values (Standard Deviation) n = 451 80.4 (1.2) n = 452 120.0 (1.2) The largest deviation across all tests gave puff volumes within 8.2% (4.5 ml) of pre-set values Comparable accuracy to combustible cigarette measurements of 6% 1 1 A Device to Measure a Smoker s Puffing Topography and Real-Time Puff-by-Puff Tar Delivery, Slayford S.J., Frost B.E., Beitrage zur Tabakforschung, 2014. 26 (2), 74 84. 9
Conclusion of laboratory validation E-cigarette holder accurately measures: - Puff Volumes - Puff Durations (Allows for the determination of puff frequency) For a range of e-cigarette devices, tested using three puffing regimes Next Steps e-cigarette holder used to measure users puffing behaviour in field trial 10
Field Study Validation Recruitment Demographics 32 users of re-chargeable e-cigarette products recruited 28 users of modular e-cigarette products recruited Age ranging between 21 64 years Male / Female equal gender split Use of e-cigarettes a minimum of two or more days per week ideally daily e-cigarette usage Volunteers could be dual users of e-cigarettes and tobacco products 11
Field Study Validation Experimental Products: Volunteers provided with either a Vype Reload or Vype epen device Number of Replicates: Volunteers vaped through the e- cigarette holder on two separate occasions on different days Topography Measurement: A new cartomiser was used for each replicate, with a fully charged battery 12
Field Study Validation Results (Vype Reload) Puffing Behaviour a Length of Session (Min:Sec) Number of Puffs (#) Total Puff Volume (ml) Mean Puff Volume (ml) Mean Puff Duration (s) Mean Puff Frequency (s) Rep. 1 (n=32) 7:10 (4:12) 22.0 (16.3) 1017 (642) 50.4 (21.0) 2.0 (0.6) 22.8 (10.8) Rep. 2 (n=32) 6:38 (3:13) 20.3 (13.6) 979 (555) 54.0 (22.4) 2.1 (0.7) 22.6 (10.7) Total dataset (n=64) 6:54 (3:43) 21.1 (14.9) 998 (596) 52.2 (21.6) 2.0 (0.7) 23.2 (10.6) a Presented as Mean values (Standard Deviation) Paired Comparison b (n=32) Length of Session Number of Puffs Total Puff Volume Puff Volume Puff Duration Puff Frequency p value 0.372 0.588 0.734 0.079 0.393 0.717 b Paired t-test, α 0.05 No statistical difference in replicate data 13
Field Study Validation Results (Vype epen) Puffing Behaviour a High Setting (n=28) Low Setting (n=27) Total dataset (n=55) Length of Session (Min:Sec) Number of Puffs (#) Total Puff Volume (ml) Mean Puff Volume (ml) Mean Puff Duration (s) Mean Puff Frequency (s) 7:04 (5:33) 14.3 (6.0) 1212 (722) 83.9 (42.4) 2.3 (1.0) 30.2 (19.7) 8:19 (7.00) 18.1 (9.3) 1420 (876) 82.1 (46.9) 2.1 (0.9) 28.5 (19.0) 7:41 (6:17) 16.1 (8.0) 1314 (801) 83.0 (44.2) 2.20 (0.93) 29.4 (19.2) a Presented as Mean values (Standard Deviation) Paired Comparison b (n=27) Length of Session Number of Puffs Total Puff Volume Puff Volume Puff Duration Puff Frequency p value 0.409 0.068 0.115 0.926 0.252 0.564 b Paired t-test, α 0.05 No statistical difference between the two settings 14
Summary The e-cigarette holder accurately records the puffing topography of e-cigarette users, number of puffs taken, puff durations and puff intervals This record, if required, can be duplicated in the laboratory, reproducing the individual s puffing behaviour to determine their exposure to aerosol constituents of interest Puffing topography data can be used to develop testing regimes for e-cigarettes in a manner reflective of users behaviour Further work may be required to validate the device using a wide range of commercial e-cigarette devices 15
Acknowledgements Mr N. Oakes of Turquoise Engineering for manufacturing the e-cigarette holders Thank you for listening! This presentation is available on bat-science.com 16
www.bat-science.com we welcome your comments