文档介绍：Vanderbilt University
Department of Biomedical Engineering,
Center for Surgical Weight-Loss
In-Vivo Device for Measuring and Adjusting Lap-Band Pressure
Team Members:
Mark Fritz
John Huidekoper
Andrew Koivuniemi
David Mayhew
Chris Schroeder
Advisors:
Robert J. Roselli
Thomas P. Rauth
Date of Submission:
24 April 2007
Abstract
Obesity affects 20% of the adult population costing an estimated $100 billion annually in the United States. One of the current surgical solutions is the adjustable gastric band (Lap-Band). To maintain steady weight loss, the pressure in the band must increase during the treatment. Currently, a surgeon manually adjusts the pressure inside the Lap-Band by accessing a subcutaneous port with a hypodermic needle. Infusion-plications include infection, infusion-port leakage and damage to the connecting tubing. Our goal is to replace the port by creating an implantable device that monitors and adjusts the pressure in the Lap-Band. Our device will be adjustable to a doctor-prescribed band pressure via munication after the device is implanted. To plish this, our device consists of the following ponents: pump, motor, radio frequency chip, pressure sensor, microcontroller, battery, and a patible case. We designed and fabricated a pump, which theoretically maximized pressure and volume output while minimizing its size. We then tested the pressure and volume limits of the pump and found that it operated well within the Lap-Band's pressure requirements (1-3 atm). We attached a stepper motor to the pump and determined it could produce the necessary torque pletely fill the Lap-Band. We then programmed a LabView module to accept a pressure input from the user and drive the motor to either increase or lower the pressure to the input point. We found that the pressure inside the device could be reliably controlled by the pressure sensor, computer, and motor negative feedback loop to within ±% of the desired value. Before our devic