Abstract: A system comprising: a nasogastric tube comprising: (a) a main lumen having one or more proximal connectors for connecting to a source of substances or pressure, (b) at least four vacuum lumens peripherally surrounding said main lumen, (c) at least four suction ports for sealingly drawing an inner wall of an esophagus thereagainst, each of said at least four suction ports associated with a different one of said four vacuum lumens, wherein said at least four suction ports are distributed between at least two different locations along a longitudinal axis of said nasogastric tube; and an imaging system for capturing and rendering one or more images of an area accessible by said tube, said imaging system comprising: (d) a camera disposed at a distal end of said nasogastric tube, for capturing said images; (e) an illuminator disposed at said distal end of said nasogastric tube, and (f) a processing unit provided at a proximal end of said nasogastric tube, that is configured to receive and process said captured ima