A portable puff topography instrument for electronic cigarettes

Abstract

Knowing puff topography, occurring with electronic cigarette (ECIG) users is essential for running simulations on smoking machines and assessing aerosol generation. Topography recording devices that log the smoking pattern of ECIG users exist; however, these devices have some limitations and do not log the ECIG voltage which has become user-controlled in recent ECIGs. As a result, the puff topography would be missing the dosage which is likely a changing factor of users’ suction. The proposed device (eTopII-A) is a hand-held ambulatory data-logging tool that also serves to power the coil of the ECIG, replacing its normal battery. Unlike existing topography loggers that sense differential air pressure, thus air flow, across an orifice between the cigarette and a designed mouthpiece, eTopII-A measures the flow entering the electronic cigarette, eliminating the mouthpiece and any restriction on the shape of the cigarette tip. In this research, a method is developed for simultaneously measuring puff topography and coil voltage. In addition, a method to sense the flow entering the ECIG is presented. Also, a testing and evaluation protocol for the developed eTopII-A is shown. First, an embedded circuit is designed to meet the device objectives. Second, the connection of the ECIG and the overall package are designed to meet the flow sensing requirements. Finally, the accuracy of the device is validated through experimental comparisons with a laboratory smoking robot.