1. In-vivo Device for Measuring and Adjusting Lap-Band Pressure
©Bill Watterson
John Huidekoper
Mark Fritz
Andrew Koivuniemi
David Mayhew
Chris Schroeder

2. Reasons for Design Choices
Problems
Device Failure
Leaks (Maude Database)
Patient Pain
Fixes
Implantable Pump
Autonomous Control as well as Non-Invasive Control

3. Design basics Pump to maintain, increase, or decrease pressure
Implantable
To stop need for risky insertion with the pump
To have a more smooth volume increase
Which leads to smoother weight loss
Keep it small like a pacemaker
Pacemaker_GuidantMeridianSR.jpg/180px-Pacemaker_
GuidantMeridianSR.jpg

4. Pump Design Connected to lap-band catheter
Fluid filled bag within pacemaker sized device
Pressure sensor
Rf antenna
Circuitry
Titanium box, encased in biocompatible material, and sutured to the abdominal wall

5. AutoCAD

6. Motor Control Motor is driving the pump need a control
Precise bi-directional speed control
Pseudo-tachometer feedback circuit
Active breaking

7. Computing and Control
Need a circuit to integrate the following functions
Receive information from the pressure sensor
Store data from pressure sensor
Receive protocol from RF circuit
Follow protocol
Send signal to motor control circuit
Run off DC power

8. Electronics Schematic
RF Transceiver
Microprocessor
Pressure
Sensor
Data
Storage
Signal
Processing
Motor Control Circuit

9. Solution
AMIS Frequency Agile Transceiver

10. Advantages Greatly simplifies circuit Easy to program and test
Designed to be in medical implants
Medical Implant Communication Services (MICS) standard

11. Fluid Bag Support Frame
Wire frame
Flexible material
Accordion folding

12. Fluid Bag Support Frame
Wire frame
Flexible material
Accordion folding

13. Grant Proposal Submitted 30 November, 2006
Current Status: Under Committee Review
Expected Notification: February 2007