OCT Guided Trans Nasal Imaging of the Small Intestine in Adults

The investigators are seeking healthy adult participants 18-60 years and healthy pregnant women in their 2nd trimester of pregnancy for a research study to assess a new imaging device. The Tearney Laboratory at the Wellman Center for Photomedicine at Massachusetts General Hospital is developing high-resolution imaging devices that can be used to improve diagnostics in gastrointestinal diseases.

Inclusion Criteria: * Healthy participants * Participants who are in their 2nd trimester of pregnancy * Participant must be 18-60 years of age * Participant must be able to consent to the procedure. * Participant must fast (no solid food) for at least 8 hours and have no liquids within 2 hours prior to the procedure. Exclusion Criteria: * Participants with a history of upper respiratory disease or surgery * Pregnant women with high-risk pregnancies such as history of: hyperemesis gravidarum, HIV, severe anemia or any other high-risk pregnancy conditions at the discretion of the subject's physician and the PI * Participants with a history of upper gastrointestinal surgery * Pregnant women with Type 1 diabetes * Pregnant women with Type 2 diabetes on medication and gestational diabetes requiring medication * Pregnant women with gestational thrombocytopenia * Participants with upper respiratory infection at least 7 days prior to the procedure * Pariticipants with any contraindications to the placement of the NJ tube including deviated septum or any other anatomical abnormalities of the nasopharynx or upper gastrointestinal region, history of trans-sphenoidal surgery, facial or cranial trauma and fractures, chronic sinusitis, esophageal strictures, varices etc. * Participants on medications that delay gastric emptying. * Participants on drugs which impair clotting like anticoagulants and antiplatelet drugs, NSAIDS, history of bleeding disorders. * Participants using nasal steroids or any steroids for environmental allergies.