myDAQ Biomedical
Instrumentation Board
Group May1212
Jeremy Bruecken, Kossi Sessou, Alex Weiss
Mani Mina - Advisor
Andrew Watchorn - Client
National Instruments myDAQ
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Low cost portable data acquisition unit
Interfaces with NI LabView software
Allows students to generate, measure, and analyze
signals in real time
myDAQ Details
Problem Statement
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National Instruments would like an add-on board to
the myDAQ that will directly compete with the
BioPac at a 40x price margin
The board should provide the necessary connections
and LabView interface to allow for measurements
done in an introductory Biomedical Engineering
course at Iowa State University
Market Survey
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BioPac currently sole competitor in market
Iowa State recently purchased BioPac kits for
introductory class
Our product would be a simple unique solution
Functional Requirements
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Gain and filter signal from contact patches for EKG
and EMG to the myDAQ analog input
Power to two LEDs and collect light transmittance
information for pulse oximeter
Provide user interface for sending, receiving, and
analyzing signals in LabView via myDAQ
Protect end user per IEC regulations
Non-Functional Requirements
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Simple plug and play hardware interface
Provide user friendly software interface in LabView
40x lower price than BioPac
Allow for cheap and reliable manufacture
Concept Sketch
EKG & EMG Measurement
Burr-Brown INA121Application Note
EKG & EMG Filter and Gain
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ANSI/AAMI EC-11
requires low-pass of
40Hz and high pass
filter of .67 Hz
Helps reduce 60Hz
power noise
Will limit capability
of EMG measurement
Gain of ~2000
EKG & EMG Safety
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Still researching IEC specification
Options include optoelectric
isolation, diode shunts, etc.
Pulse Oximeter Measurement
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Use variation in light transmittance to
determine blood oxygen level and pulse
Images Courtesy of freescale.com
Pulse Oximeter Measurement
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Pulse LEDs to get infrared and red absorption
Gain photodector signal and filter for analysis
www.ti.com/solution/pulseoximetry
Pulse Oximeter Gain
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Use a transimpedance amplifier to generate a
voltage signal
Gain will require adjustment depending on finger
thickness
Images Courtesy of freescale.com
Pulse Oximeter Filter
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60Hz notch filter
Low pass 6Hz filter
High Pass .8Hz filter
Images Courtesy of freescale.com
Pulse Oximeter Analysis
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Signal will have AC and DC components
Use only AC to calculate oxygen level
Provides pulse reading
Images Courtesy of freescale.com
System Flow Diagram
LabView Interface

Easy to use environment for capturing and
analyzing biometrics
Labview Interface
Deliverables
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Prototype add-on board with sensors
LabView software to collect and interpret data
Design document
Specification test document
Project Plan
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Create design document for December 4th
Review design through Spice testing and analysis
Parts ordered November 15th
Begin hardware testing over break
Resource Requirements
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Access to BioPac for comparison testing
IEC Safety Documentation
Spice simulation tools
Ability to order devices
Circuit testing equipment (Oscilloscope, DMM, Power
supply)
Risks
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Injury when performing tests of human body
 Proper
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Unable to meet 40x price margin goal
 Client
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safety circuitry will prevent injury
is aware this is likely
Inability to compete with BioPac
 Focus
on price should attract wide customer base
Task Breakdown
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Jeremy
 Complete
circuit design
 Perform Spice circuit analysis
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Kossi
 Create
LabView interface
 Perform interface and hardware testing
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Alex
 Perform
hardware testing
 Design webpage
Questions?
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myDAQ
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EKG & EMG
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Filter and Gain
Safety
Pulse Oximeter
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NI instrumentation learning tool
Add-on board to compete with BioPac
660nm and 940nm light absorption comparison
Filter and Gain
System Diagram
Project Plan
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Resource Requirements
Risks
Tasks