Device for Measuring Esophageal Tissue Compliance TEAM MEMBERS: Kristen Seashore Janelle Anderson Lynn Murray Chris Goplen CLIENT: Mark Reichelderfer, M.D. Department of Gastoenterology Eric Gaumnitz, M.D. Deepak Gopal, M.D. Patrick Pfau, M.D. ADVISOR: Professor Naomi Chesler

Background Information Stricture = scar tissue build up Causes: Achalasia, reflux, cancer… Treatments: surgery or dilation Want to know stricture characteristics Compliance, size, length, location, number Balloon dilatation of esophageal stricture

Esophageal Stricture Compliance Problem Statement “Smart Balloon” Project Computer interface Pressure vs. Volume curve Tissue compliance Feedback for doctor Prevent esophageal perforation Chance to abort procedure Speed up procedures Reduce number of procedures Testing Esophageal Stricture Compliance Pressure (atm) High compliance Low compliance Volume (mL)

Current Devices No comparable devices Radiographs Liquid bolus, solid spheres Barium, film, and ruler Balloon, Syringe, Dispenser Balloon and Syringe Device

Competition Limited due to specificity Only previous work from 2002 No funding

Design Constraints Low cost Reusable Easy to Use Safe Accurate Durable Approval for testing

Problem Overview Reduce the frequency of esophageal perforations Safe, Easy to learn and use Provide accurate and reliable information Replaceable, low-cost balloon Reusable inflating device Speed up and reduce number of procedures

Design 1: Linear Position Transducer Transducer measures linear distance plunger moves Use distance to convert to volume Second transducer records balloon pressure

Design 1: Pros/Cons Pros Minimal adjustment to current device Easy to use Least expensive Produces accurate data Feasible to construct Cons Linear position transducer may be bulky

Design 2: Flow Meter Attach flow meter to record volume Replace pressure gauge with transducer to directly record pressure

Design 2: Pros/Cons Pros Cons Small device with only a flow meter attached Easy to use Produces accurate data Cons Not very durable Not feasible unless flow meter is small

Design 3: T-Piece and Laser Laser to measure distance pump moves Convert distance to volume “T-piece” wire and pressure transducer

Design 3: Pros/Cons Pros Cons Produces accurate data No tampering with pressure gauge Cons Most expensive design Less durable Not very feasible

Feature (Possible Points) Design Matrix Feature (Possible Points) Design 1 Design 2 Design 3 Size (5) 4 5 3 Ease of Use (6) 6 Cost (12) 9 2 Accuracy (20) 15 Reproducibility (8) 7 Durability (10) 8 Aesthetics (4) Feasibility (15) 14 Safety (20) 20 10 TOTALS: 86 74 55

Future Work Obtain materials Separate balloon and esophageal compliance Learn more about circuitry Write software program using LabView Testing on animals

References http://www.endoatlas.com/es_es_03.html http://en.wikipedia.org/wiki/Image:Barostat_Balloon_rectal.jpg htt[p://www.gicare.com/pated/epdgs25.htm http://www.endonurse.com/articles/4c1feat1.html Dyet, J. et al. 1983. Radiological Measurement of Oesophageal Stricture Diameter. Clinical Radiology, 34: 647-49.

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