biopac slides 090921

8/8/2019 Biopac Slides 090921

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BIOPAC Systems, Inc.

Training Seminar


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About BIOPAC

Hardware Setup

Software Setup

Subject Preparation Data Acquisition Demonstration

Data Analysis

Application Notes and Other Resources Question and Answer Session


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MP150


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MP150 Range of the MP150 system: from -10 to +10 Volts

A/D resolution: 16 bit

Dual A/D converters: Reduce Channel/Channeltiming latency

65536 levels or 30 microvolts resolution

Minimum change that can be detected is 30 uvolts. If

the signal is not strong, it must be amplified.

A/D Conversion

Sample Rate

Max Sample Rate = 200 K Samples/Sec. Maxaggregate of 400 kHz


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Sampling RateECG waveform sampled with relatively fewsamples per second. The black dots arethe sample points.

Above waveform as it would look if plotted.

Representation of the same ECGwaveform sampled at a relatively highersampling rate.


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Recommended sample rates for physiological signalsSampling RateECG 200 Hz (1,000 Hz for HRV)

Respiration 50 Hz

GSR 50 Hz

EMG 1,000 Hz to 10,000 Hz

EEG 200 Hz

EOG 200 HzBlood pressure 100 Hz

Flow rate 50 Hz

EGG (electrogastrogram) 1 Hz


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UIM100C Universal Interface 16 analog channels

Input range between

100 mv and 10 v

16 digital outputs

Digital Trigger

Channels are input andoutput


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Amplifier Settings Red Channel Switch

Only one amplifier per channel

Gain

Depends on application

Filters AC for Biopotential Recording

DC for Transducer Recording

Transducer Amplifiers: Calibration Required

Biopotential Amplifiers: No Calibration Required


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ECG100C Amplifier Designed to pass the ECG signal (P, Q, R, S,

T waves) with minimal distortion

Works with disposable or reusable electrodes

Typical Human Settings:

GAIN: 2000

MODE: NORM35Hz LP: ON

HP: 0.5 Hz


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Filters: Low pass, High Pass, Band Pass, Band Stop, Notch

Low Pass at 5Hz

High Pass at 5Hz


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Filters: A practical Low Pass Filter

example with ECG Part I

Noisy ECG data

Data after applying a low pass filter at 35Hz


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Filters: A practical high pass filter

example with ECG Part II

Drifting ECG data

Data after applying a high pass filter at 1Hz


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DC vs. AC example with skin conductance


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Software SetupBeforeyou start

recording:

MP150 Menu

Set Up Acquisition

Manual recording

Automatic recording

Sample rates

Acquisition length

Online Averaging

Evoked Response


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Software SetupBeforeyou start

recording:

MP150 Menu Set Up Channels

Analog, Digital, andCalculation Channels

Scaling andCalibration


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CALIBRATION GSR Scaling


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Software Checklist Set analog, digital, and calculation channels

Make sure analog channels match amplifierchannels

Make sure Source channels are set in calculationchannel setup

Set Acquisition Type and Length

Set up triggering or stimulator if desired

Make sure green light is on


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Electrodes, Leads, and Gels


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Subject Preparation Abrade the skin (ELPADs)

Electrode Gel

Wait 5 minutes for best results

Minimal movement

Impedance check (EEG, etc.)

One ground per subject!


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Einthovens Triangle


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Hints for minimizing data error Subject should remain as relaxed as possible

Subject must avoid excessive extraneous movement

Press ESC to add a marker every time you give the subjectan instruction

Add text to describe all interventions

During comparative data analysis, ensure that all scales arethe same for every channel

Remove all jewelry or other metal objects

Check all cable connections

RECORD BASELINE PERIOD!


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Hardware ChecklistBeforeyou start recording:

Make sure there is only one amp per channel

Check the GAIN and filter settings

Check Subject

Check electrode placement

Let gel soak in (5 minutes)Make sure there is only one ground per subject


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Software Setup Set Up Triggering

Set Up Stimulator

Set Up EventHotkey

Show Input Values

Show ManualControl


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Data Analysis Transform and Analysis Menus

All post-acquisition processes Offline filtering Waveform math

Fast-Fourier Transform Automated analysis

Find Rate functions Find Cycle/Peak functions Specialized Analysis Package

AcqKnowledge4 Windows AcqKnowledge3.9 Mac

Always duplicate waveform!!

Specialized Analysis package included


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Controlling the Display Vertical Scaling

Autoscaling

Horizontal Scaling

Scrolling vs. Autoplot

Zoom Tool

Display Modes

Chart mode, Scope mode,

X/Y plot, Stacked Plot

Hiding and DisplayingChannels


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Filters: Role of coefficients in FIR filters

Original data

FIR 35Hz LP coefficients = 4


Frequency response for FIR 35Hz LPwith 4 coefficients:

Frequency response for FIR 35Hz LPwith 22 coefficients:


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Filters: Performance of FIR filters vs. IIR filters

Original data


IIR 35Hz LP


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Online Resources Application notes

Knowledge base

Product Resources tab

Publications
http://www.biopac.com/ApplicationNotes.asphttp://www.biopac.com/ApplicationNotes.asphttp://www.biopac.com/ApplicationNotes.asphttp://www.biopac.com/FAQs.asp

biopac slides 090921

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