Conduct human trials in the endoscopy suite of our continuous positive airway pressure (CPAP) ventilator approach using an FDA approved ventilator.

All study procedures will be performed in adult patients following informed consent at the endoscopy suite of the University of Utah Health Sciences Center in Salt Lake City, Utah. A ventilation mask will be placed on the patient's face and connected to the ventilator. Supplemental oxygen will be delivered by the ventilator through the mask; the concentration of oxygen delivered will be left to the clinician's discretion. A modified mask with multiple small leaks will be used with a standard elastomeric H-strap to secure it to the patient's face.

The endoscopy suite nurse and technicians will attach all clinically necessary standard sensors and connect them to the patient and monitoring system. Height, weight, and neck circumference will be measured and recorded digitally on an encrypted laptop. In addition to the standard of care monitors, the investigators will collect data from additional non-invasive modalities and save the data to a laptop using custom software for later analysis.

Pressure and flow sensors included in the ventilator will be used to monitor the patients' tidal volumes and respiratory rate during the procedure. The data that will be collected and recorded on the laptop will include: RIP data, mask pressure, flow, and breath rate. An additional flow sensor will be placed in line with the ventilator.

The objective of this study is threefold: Demonstrate in patients undergoing procedural sedation (e.g., for colonoscopy) that obstructive apnea can successfully be avoided by stenting the airway open using CPAP, demonstrate that we can successfully detect periods of zero ventilation, and demonstrate the functionality of the modified standard mask.

Inclusion Criteria:

• > 18 years of age
• undergoing a colonoscopy procedure
• receiving registered nurse-administered procedural sedation at the University of Utah Health Sciences Center
• agree to participate
• written informed consent

Exclusion Criteria:

• Inability/refusal of subject to provide informed consent.
• Standard colonoscopy exclusion criteria used at the GI lab at the University of Utah.
• Pregnant patients and patients with an ASA (American Society of Anesthesiology) physical status of IV or V.
• Patients with severe medical condition(s) that in the view of the acting physician prohibits participation in the study.
• Patients with a BMI > 35 will not be included in the study

Participation and adverse event reporting was limited to the study intervention, mean of 24 minutes (SD 11).

This was not a randomized clinical trial involving multiple facilities.

The pharmacodynamic effect of the sedation were unknown.

The CPAP machine and the tight-fitting mask may have provided enough of a stimulus as to maintain the patient in a lighter sedation state.

The proprietary C-flex and Auto-Trak algorithms are integrated into the V60 ventilator and could not be disabled. The algorithms did cause some variation in pressure levels delivered to the patients.