Safety & Initial Efficacy of the LunGuard PFT Sys. on Enteral-Fed, Sedated and Mechanically Ventilated Patients Peristaltic Feeding Tube

Inclusion Criteria: * Informed consent. * Patients who are expected for at least 12 hours to be: * Mechanically ventilated and sedated. * Requiring a nasogastric tube. * Included are: * Patients who have undergone tracheostomy. * Patients who require use of pro-kinetic drugs and proton pump inhibitors. * All levels of Gastric Residual Volume (GRV) Exclusion Criteria: * • Patients with a contraindication for insertion of a nasogastric tube. * Patients with a known esophageal obstruction, preventing passage of the device. * Esophageal disease including: achalasia, hiatal hernia or any other anatomical anomaly and/or esophageal pathology, esophagitis, Zenkers diverticulum, para-esophageal hernia, esophageal varices. (not excluded are minor GERD patients) * Acute and severe coagulation disorders * (INR\> 2 or platelets below 30,000) * Diabetic patients with documented gastrointestinal neuropathy * Pregnancy or lactation * Allergy to Silicon * Patients who are currently enrolled in another clinical investigation in which the intervention might compromise the safety of the patient's participation in this study.