Esophageal pressure monitoring device

Claim 1

An esophageal pressure monitoring nasogastric tube comprising a distal end portion that terminates in a rounded tip, a proximal end portion that terminates in tube connector means, a central body portion joining the distal end portion to the proximal end portion, a major lumen extending within said tube from said tip to said tube connector means, a plurality of side ports through said distal end portion communicating with said major lumen, a secondary lumen extending longitudinally within said tube, a very thin balloon cuff having a length substantially longer than the diameter thereof sealed at its ends to the outside of said central body portion of said tube, said diameter being such that said balloon cuff can be appreciably inflated with about 0.5 to 1 cc of air and it is compliant over a volume range of 0 to 4 ml., said secondary lumen being closed at a point positioned distally of the proximal end of said balloon cuff, at least one port through the wall of said central body portion communicating said secondary lumen with the interior of said balloon cuff for flow of fluid from said secondary lumen into said balloon cuff, a first opening in the wall of said proximal end portion of said tube communicating with said secondary lumen, a first connector tube fixed to said first opening for introduction of fluid into said secondary lumen, a tertiary lumen extending longitudinally within said tube, said tertiary lumen opening at its distal end into said major lumen adjacent said rounded tip of said tube providing a passage to vent said tube to prevent excessive vacuum from developing when suction is applied to said major lumen, a second opening in the wall of said proximal end portion of said tube communicating with said tertiary lumen, and a second connector tube fixed to said second opening for introduction of fluid into said tertiary lumen.