An Observer-Blinded Study to Determine the Feasibility of Pressure-Based Swedish Adjustable Gastric Band (SAGB) Adjustments in aiding weight loss

Gastric Band adjustments are performed to vary the degree of restriction the band delivers hence allowing more or less food consumption. The adjustment is made by injection of saline into the band. The frequency of routine band adjustment is dependent on degree of weight loss. The subject will be asked to swallow a measured amount of water, the band will be adjusted per standard hospital procedure, then another measured amount of water and one of three food or juice substances will be consumed. A pressure transducer (sensor) which is connected to the standard adjustment equipment (outside the body) will detect the pressure within the gastric band as the food is swallowed. The pressure will be recorded on a computer. The procedure may take up to 30 minutes. The measurements will be taken during one adjustment only. The study consists of three parts, Phase one Part one assesses which substance provides the most consistent pressure pattern, Phase 1 Part 2 tests what volume provides the most consistent pressure reading. Phase 2 tests the differences and consistency in pressures within the band. Assignment to each phase is sequential and is dependent on the preceeding number of patients enrolled.