Flow and Pressure Measurement in a Selective Laser Sintered Human Tracheobronchial Airway Model Under Cyclic Flow Conditions

A selectively laser sintered human tracheobronchial airway model was used to study periodic flows at different frequencies corresponding to inhalation and exhalation. The model was fabricated from a 3-d point could based on the Visible Human Male Project. The objective was to document the volumetric flow rate and pressure drop under periodic flow conditions and compare these values with those obtained in steady flow. The flow was cycled via a Programmable Logic computer (PLC) at a specified breathing frequency of 12 breaths per minute. The tracheal flows rate studied were 30, 50, and 120 liters per minute. The results indicated that significant differences existed between flow measurements made under steady conditions and periodic conditions; these differences became significant at high flow rates. The flow distribution in the right and left side of the airway model was asymmetric. The results also indicated the existence of both turbulent and laminar flow regimes at all tracheal flow rates.