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Mass Flow Controller System. Client: Brad Hodgeman– Instrumentation Specialist, Comparative Biosciences Advisor: Professor Emeritus John G. Webster Team Members: Aaron Huser, Cole Kreofsky, Dana Nadler, Joe Poblocki.
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Mass Flow Controller System Client: Brad Hodgeman– Instrumentation Specialist, Comparative Biosciences Advisor: Professor Emeritus John G. Webster Team Members: Aaron Huser, Cole Kreofsky, Dana Nadler, Joe Poblocki
University of Wisconsin - MadisonBiomedical Engineering Design CoursesINTELLECTUAL PROPERTY STATEMENT
Problem Motivation • Brad Hodgeman researches hypoxia and hyperoxia with rats at the Veterinary Science Building. • Current mass flow controllers are too inaccurate, and the software is outdated. • There are undesirable, manual aspects to protocol that need to be eliminated.
Problem Statement The purpose of this project is to design a system that can create a reproducible and accurate hypoxic/hyperoxic environment with the capability of oscillating between various concentrations of oxygen and nitrogen.
Background • Hypoxia and hyperoxia are atmospheric conditions, where the oxygen level deviates below or above normal (21%) concentration, respectively. • Hypoxia is a form of respiratory distress which induces certain physiological responses by the neuro-respiratory system. These responses have been associated with SIDS, sleep disorders, spinal cord injury, etc.
Mass Flow Controllers • Mass flow controllers often aid in hypoxia research due to their ability to alter Oxygen concentrations to desirable levels for testable consequences.
Current Gas Control System • Computer controlled Command Module (HyperTerminal Software) • Four Analog Mass Flow Controllers • Two Manual Mass Flow Controllers • Four Chambers
Design Constraints • Variable gas concentrations and flow rates through a chamber • Software with an easy to use interface and customizable features • Accurate mass flow controllers, digital or analog • Uniform tubing resistance • Low sound level • Capability for further expansion
Software Development • LabVIEW • Graphical programming environment made for engineers and scientists • Client has had previous experience using DASYLab – a program similar to LabVIEW • Ability to customize programs easily and efficiently • Variety of open source examples of current programs available
Main Areas of Focus • Mass Flow Controller Manufacturers • Sierra Instruments – Series 100 Smart-Trak™ • Advanced Energy – Aera® Mach One • Mykrolis – Intelliflow ™ II • Interface types • Analog • Digital • DeviceNet • RS485 • RS232
Digital Accuracy is a function of set point (sp) Multiple gas calibration curves Multiple set point calibration More cost efficient Analog Accuracy is a function of full scale (fs) Manual individual gas calibrations Digital vs. Analog
Digital Interface DeviceNet • Most Expensive • Too sophisticated for this system RS232 • Least Expensive • Ergonomically incompatible RS485 • Moderately Expensive • Ability to daisy-chain cables
Questions Any Questions?