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 Madison Biomedical Engineering Design Courses INTELLECTUAL 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with rats at the Veterinary Science Building Current mass flow controllers are too inaccurate and the software is outdated There are undesirable manual aspects to protocol that need to be eliminated Problem Statement The purpose of this project is to design a system that can create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 Manufacturer Matrix Accuracy Response Time Advanced Energy 0 5 4 Mykrolis 0 25 sp plus 0 35 fs 3 Company Sierra Instruments 0 7 of reading 0 3 fs 2 Low 1 5 High Price Customer Service Flow Range Total 250 ms 5 1675 00 US 3 3 3 L min 2 17 1 sec 3 1880 00 US 2 3 5 min 5 16 2 sec 2 1370 00 US 4 4 6 L min 4 16 The Numbers Don t Lie Digital vs Analog 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 Interface DeviceNet Most Expensive Too sophisticated for this system RS232 Least Expensive Ergonomically incompatible RS485 Moderately Expensive Ability to daisy chain cables System Design LabVIEW software RS485 interface and AE MFCs Questions Any Questions
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