Historically, studies on the deposition of tobacco smoke and other particles have often shown a wide range of depositions between subjects but with consistency by each subject. Previous review papers on the deposition of tobacco smoke in the human respiratory tract (Bernstein, 2004 and Baker and Dixon, 2006) have suggested that depth and time of inhalation may be an important parameter for the subsequent deposition in the airways of smokers. For tobacco smoking, differences in inhalation behavior have been addressed by controlling the depth of smoke inhalation to 15% and 25% of the subject’s vital capacity. Measurement of breathing and puffing parameters will provide additional information that may allow the control to be dropped, allowing subjects to inhale the tobacco smoke in a more natural manner.
The Lifeshirt® System is a non-invasive ambulatory monitoring system that continuously collects, records and analyzes a broad range of cardiopulmonary parameters, including inhalation and exhalation volume and rate. The Lifeshirt® utilises a respiratory monitoring method called inductive plethysmography, which monitors breathing patterns by passing a continuous, low voltage electrical current through externally placed wires that surround the wearer’s rib cage and abdomen. Users wear a lightweight, machine washable garment with embedded sensors that collect cardiopulmonary data. Figure 1 shows a graphical representation of the Lifeshirt® system.