A digital image analysis system for identifying filter vent blocking on ultralight cigarettes.

Filter ventilation is the dominant design feature on modern cigarettes, diluting the mainstream smoke with air and reducing tar and nicotine yields in the standard assay. Smokers are generally unaware of vent holes and often cover them with lips or fingers while smoking, reducing or eliminating the air dilution effect and increasing intake of tar and nicotine particularly on ultra-low tar brands. A digital imaging and analysis system for the detection of vent blocking was developed. Two studies were designed to evaluate the effectiveness of three color measures (hue, saturation, and value) at discriminating whether at least 50% blocking had occurred. In study 1, saturation showed perfect discrimination between unblocked Carlton butts and butts with at least 50% of the vents blocked during syringe smoking. In study 2, saturation showed 95% accuracy at identifying Marlboro Ultra Light butts with at least four puffs blocked by smokers' lips. The results indicate that the pattern of color saturation is related to vent blocking. Implications for tobacco control research and policy are discussed.