Abstract: A tracheal tube is equipped with two air lines to the inflatable cuff, one for monitoring cuff pressure and another of larger diameter for inflating the cuff. Intra-cuff pressure monitored via the smaller diameter line is continuously displayed. A cuff pressure control system allows independent adjustment of cuff pressure via the larger diameter line from high pressure during inspiration to low pressure during expiration. The switchover point is determined by a threshold detecting pressure monitor in the mechanical ventilator inspiration line. The circuit also adjusts automatically to changes in the baseline expiration pressure. The output of a bidirectional mass flow sensor tracks airflow in the cuff inflation line and is integrated to indicate volume. Volume into the cuff is then compared to volume out of the cuff to detect cuff leakage.

Abstract: A tracheal tube is equipped with two air lines to the inflatable cuff, one for monitoring cuff pressure and another of larger diameter for inflating the cuff. Intracuff pressure monitored via the smaller diameter line is continuously displayed. A cuff pressure control system allows independent adjustment of cuff pressure via the larger diameter line from high pressure during inspiration to low pressure during expiration. The switchover point is determined by a detecting pressure monitor in the mechanical ventilator inspiration line. The circuit also adjusts automatically to changes in the baseline expiration pressure. The output of a bidirectional mass flow sensor tracks airflow in the cuff inflation line and is integrated to indicate volume. Volume into the cuff is then compared to volume out of the cuff to detect cuff leakage.

Abstract: An inflation control system for the cuff of a tracheal tube includes an adjustable pressure relief valve with an inlet and an outlet connected in series between the cuff and a source of pressurized gas, and a valved exhaust port urged toward the closed condition. When the tracheal tube is connected to an exhalation valve and a volume ventilator with a pulsed exhalation valve drive line, two relief valves are preferred: a low pressure valve in series with a high pressure valve. The low pressure relief valve is controlled by the exhalation drive line, preferably by means of an inflatable balloon in communication with the exhalation drive line. A flow detector in the cuff inflation line produces an electrical output signal indicative of airflow to activate an alarm signifying a continuous airflow condition due to cuff leak. The airflow detector preferably includes a mechanical flow meter in combination with a photoelectric sensor.