ボランティアにおける陽圧呼吸（PAP）システム評価

Sedation procedures involve administering drugs to patients that reduce awareness and pain without complete loss of consciousness. A common side effect of these drugs is partial or complete obstruction of the airway by the airway tissue, inhibiting the flow of oxygen to the lungs. Research has shown that this risk can be effectively reduced by administering PAP therapy during sedation, which involves directing air flow into a tight-fitting mask over the patient's nostrils and/or mouth. However, non-invasive ventilators used for administering PAP therapy are expensive and large, and often not available in areas of the hospital where sedation procedures take place.

The investigators have developed a small and low-cost novel PAP system for use in sedation procedures that controls airway pressure to desired levels (a feature that is generally only available in larger and higher-cost devices), provides estimates for tidal volumes (generally only available with a non-invasive ventilator), provides respiratory rate estimates, and allows for more accurate monitoring of exhaled carbon dioxide with a standard carbon dioxide monitor using a novel approach that to the investigator's knowledge has not been published. The goal of investigator's study is to demonstrate the accuracy of these features in human subjects. The system is much smaller and less expensive than a non-invasive ventilator, provides enhanced respiratory monitoring, and has the potential to be a practical alternative that would make PAP therapy during sedation much more feasible.

The investigator's evaluation will primarily include evaluating the investigator's system's performance against an FDA cleared commercial respiratory monitor to verify accuracy. The investigators anticipate that the investigator's system will automatically adjust oxygen flow to maintain a desired airway pressure even in the presence of variables such as mask leak and patient inhalation flow. The investigators also anticipate that the investigator's system will provide tidal volume estimates within 15% of the respiratory monitor reference measurement, as well as respiratory rate estimates that closely match the respiratory monitor. The investigator's system employs a method that detects when the patient exhales and removes mask pressure during exhalation, and the investigators anticipate that this will result in improved comfort for the patient, as well as improved carbon dioxide monitoring accuracy, since removing flow during exhalation reduces dilution of the expired gas sample that is used for measuring exhaled carbon dioxide levels.