front-end signal conditioners og

http://slidepdf.com/reader/full/front-end-signal-conditioners-og 1/228
Tis document was, as ar as possible, accurate at the time o release. However, changes may have been made to the sofware and hardware it describes since then. ADInstruments Pty Ltd reserves the right to alter
specifications as required. Late-breaking inormation may be supplied separately.
Trademarks of ADInstruments
PowerLab®, LabChart®, Labutor®, LabAuthor® and MacLab® are registered trademarks o ADInstruments Pty Ltd. Te names o specific recording units, such as PowerLab 8/35, are trademarks o ADInstruments Pty Ltd. Labutor Server, Chart and Scope (application programs) and Labutor Online are trademarks o ADInstruments Pty Ltd.
Other Trademarks
Apple, Mac and Macintosh are registered trademarks o Apple Computer, Inc. Windows, Windows 7 and Windows Vista are either registered trademarks or trademarks o Microsof Corporation.
All other trademarks are the property o their respective owners.
Document Number: U-FE/OG-35C
Part Number: 5820-E
Copyright © ADInstruments Pty Ltd, 2000 - 2014. All rights reserved. PowerLab, MacLab, LabChart, Labutor and LabAuthor are registered trademarks o ADInstruments Pty Ltd. Chart and Scope (application programs), Labutor Server and Labutor Online are trademarks o ADInstruments Pty Ltd. Te names o specific recording units, such as PowerLab 16/35, are trademarks o ADInstruments Pty Ltd. Windows 8, Windows 7, Windows Vista and .NE Framework are trademarks o Microsof Corporation. Apple, the Apple logo, MacOS, and Macintosh are trademarks o Apple Computer Inc. registered in the U.S. and other countries. Acrobat and Adobe are registered trademarks o Adobe Systems Incorporated. Igor is a trademark o Wavemetrics Inc. MALAB is a registered trademark o Te MathWorks Inc. Grass is a trademark o Astro- Med Inc. All other trademarks are the property o their respective owners.
Web: www.adinstruments.com
Reg. No. 1053 ii Front-ends Owner’s Guide
8/20/2019 Front-End Signal Conditioners OG
iii Front-ends Owner’s Guide
1 Safety Notes 1 Statement o Intended Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Saety and Quality Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 General Saety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Bio Amp Saety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Stimulus Isolator Saety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Earthing and Ground Loop Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Cleaning and Sterilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Inspection and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Storage Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2 Overview 8 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Checking the Front-end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Single Front-ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Multiple Front-ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Special Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Connecting Stimulator Front-Ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Maximum Number o Front-Ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Using ADInstruments Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Front-end Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Te Front-end Sel-test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Sofware Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Preventing Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Aliasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Frequency Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Saturation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Ground Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Mains filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Notch Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Contents
Electrode Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Motion Artiacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3 Animal Bio Amp 18 Te Animal Bio Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Te Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Te Bio Amp dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 Using the Animal Bio Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Some Suitable Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Some Unsuitable Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Te Animal Bio Amp Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
4 Bio Amp 34 Bio Amp Saety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Te Bio Amp ront-ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Using More Tan One Bio Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Te Bio Amp Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Te Bio Amp dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Using the Bio Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Some Suitable Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Some Unsuitable Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 Recording echnique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Single Bio Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Electromagnetic Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63 Equipment and echnique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Te Disposable BP ransducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Te BP Amp dialog. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67 echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
6 Bridge Amp 75 Te Bridge Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
Setting Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79 Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79 Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
Te Bridge Amp dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 Using ransducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85
Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85 Suitable ransducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85 Unsuitable ransducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86 How ransducers Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86 Checking the ransducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Using Grass ransducers with Bridge Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88 Adapting ransducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88 ransducer Adaptations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89 Setting the Excitation Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89
Wiring Up the ransducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96
7 Dual Bio Amp/Stimulator 98 Te Dual Bio Amp/Stimulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99
Te Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99 Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102
Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104 Te Bio Amp dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
Te Stimulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108 Using the Dual Bio Amp/Stimulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
Some Suitable Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112 Some Unsuitable Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113 Recording echnique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113
echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120
8 GSR Amp 123 Te GSR Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Te Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124 Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125 Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126
Te GSR Amp dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127 Equipment and echnique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129 echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134
9 Neuro Amp EX 136 Te Neuro Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137
Te Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137
Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139 Single Front-end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139 Multiple Front-ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139
Using More Tan One Neuro Amp EX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140 Sofware Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140
Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141 Neuro Amp EX dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141
ypes o Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144 Te Neuro Amp EX Headstage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144 Recording echnique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145
Setting up to Record From a Subject . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145 Motion Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147 Electrode Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147
echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .148 Te Neuro Amp EX Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150
roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .151 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .153
Neuro Amp EX Front-end [FE185] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .153 Neuro Amp EX Headstage [ML185] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154 Electromagnetic Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155
10 pH Amp 156 Te pH Amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157
Te Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158 Single Front-end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159 Multiple Front-ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159
Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160 Te pH Amp dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160
vii Front-ends Owner’s Guide
Calibrating the pH Amp Electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163 Setting Up the emperature Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163
Te emperature Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165 echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .166 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .167 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .168
11 Spirometer 170 Te Spirometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .171
Te Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .171 Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .172
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .172 Using LabChart and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .174
Te Spirometer dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .174 Using the Spirometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .176
Fitting the Flow Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177
Calibrating the Flow Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178 Using an approximate conversion actor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178 Injecting a known volume and integrating . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178 Using the Spirometry Extension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179 Reducing Drif . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180
echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184
12 Stimulator HC 186
Te Saety Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188 Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188
Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189 Te Stimulator HC dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191
Choosing How Stimulation Should Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193 Creating a Custom Stimulus Waveorm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193 Te Stimulator Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194 PowerLabs with Independent versus Differential Analog Outputs . . . . . . . . . . . .195
echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196 roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199
13 Stimulus Isolator 201 Te Stimulus Isolator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Te Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 Te Saety Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .203
Te Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .203 Connecting to the PowerLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
viii Front-ends Owner’s Guide
Te Stimulus Isolator dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 Choosing How Stimulation Should Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Choosing a Stimulus ype . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Setting Stimulus Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Te Stimulator Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
echnical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .210
roubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .211Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .213
14 Warranty 215
1 Front-ends Owner’s Guide
Statement of Intended Use All products manuactured by ADInstruments are intended or use in teaching and research applications and environments only. ADInstruments products are NO intended to be used as medical devices or in medical environments. Tat is, no product supplied by
ADInstruments is intended to be used to diagnose, treat or monitor a subject. Furthermore no product is intended or the prevention, curing or alleviation o disease, injury or handicap.
Where a product meets IEC 60601-1 it is under the principle that:
• this is a more rigorous standard than other standards that could be chosen. • it provides a high saety level or subjects and operators.
Te choice to meet IEC 60601-1 is in no way to be interpreted to mean that a product:
• is a medical device,
•
may be interpreted as a medical device, or • is sae to be used as a medical device.
Safety and Quality Standards When used with ADInstruments isolated ront-ends, PowerLab systems are sae or connection to subjects. Te FE132 Bio Amp, FE135 Dual Bio Amp, FE136 Animal Bio Amp, FE185 Neuro Amp EX, ML408 Dual Bio Amp/Stimulator, FE116 GSR Amp, FE117 BP Amp and FE180 Stimulus Isolator ront-ends conorm to international saety
requirements. Specifically these are IEC60601-1 and its addenda (Saety Standards, page 2) and various harmonized standards worldwide (CSA601.1 in Canada and AS/NZS 3200.1 in Australia and New Zealand).
In accordance with European standards they also comply with the electromagnetic compatibility requirements under EN61326-1, which encompasses the EMC directive.
Quality Management System ISO 9001:2008
ADInstruments manuactures products under a quality system certified as complying with ISO 9001:2008 by an accredited certification body.
Safety Notes
Safety Symbols Devices manuactured by ADInstruments that are designed or direct connection to humans and animals are tested to IEC60601-1:1998 (including amendments 1 and 2) and EN61326-1:2006, and carry one or more o the saety symbols below. Tese symbols appear next to those inputs and output connectors that can be directly connected to human
subjects.
!
BF (body protected) symbol. Tis means that the input connectors are suitable or connection to humans provided there is no direct electrical connection to the heart.
Warning symbol. Te exclamation mark inside a triangle means that the supplied documentation must be consulted or operating, cautionary or saety inormation beore using the device.
CE Mark. All ront-end amplifiers and PowerLab systems carry the CEmark and meet the appropriate EU directives.
UL Mark. ADInstruments isolated preamplifiers and 35 series PowerLab data acquisition units meet standards set by Underwriters Laboratories. ISOLAED SIGNAL AMPLIFIERS FE116, 117, 132, 135, 136, 185 AND ISOLAED SIMULAOR FE180 WIH RESPEC O ELECRICAL SHOCK, FIRE AND MECHANICAL HAZARDS ONLY, IN ACCORDANCE WIH UL 606011 AND CAN/CSAC22.2 NO. 601.1.
Further inormation is available on request.
Safety Standards
IEC 60601-1:1998 General requirements for safety
IEC 60601-1-1:1992 Safety requirements for medical electrical systems
EN61326-1:2006 Electrical equipment for measurement, control and laboratory use – EMC requirements
IEC 61010-1ed2.0 Safety requirements for electrical equipment for measurement, control and laboratory use.
UL Standard - Medical Electrical Equipment
UL 60601-1 Medical Electrical Equipment, Part 1: General Requirements for Safety - Edition 1.
CSA C22.2 NO. 601.1 Medical Electrical Equipment, Part 1: General Requirements for Safety - Edition 1.
General Safety Instructions o achieve the optimal degree o subject and operator saety, consideration should be given to the ollowing guidelines when setting up a PowerLab system either as stand-alone equipment or when using PowerLab equipment in conjunction with other equipment. Failure to do so may compromise the inherent saety measures designed into PowerLab
equipment. ADInstruments ront-ends are only suitable or operation with ADInstruments PowerLabs. Front-ends are suitable or use with any S/, SP/, /20, /25, /30 and /35 series and 15 PowerLabs. Note that compliance with IEC60601-1 can only be achieved when ront- ends are used with a /35 series Powerlab.
Te ollowing guidelines are based on principles outlined in the international saety standard IEC 60601-1: General requirements for safety – Collateral standard: Safety requirements for medical systems. Reerence to this standard is required when setting up a system or human connection. Te user is responsible or ensuring any particular configuration o equipment complies with IEC60601-1-1.
PowerLab systems (and many other devices) require the connection o a personal computeror operation. Tis personal computer should be certified as complying with IEC 60950 and should be located outside a 1.8 m radius rom the subject (so that the subject cannot touch it while connected to the system). Within this 1.8 m radius, only equipment complying with IEC 60601-1 should be present. Connecting a system in this way obviates the provision o additional saety measures and the measurement o leakage currents.
Accompanying documents or each piece o equipment in the system should be thoroughly examined prior to connection o the system.
While it is not possible to cover all arrangements o equipment in a system, some general guidelines or sae use o the equipment are presented below:
• Any electrical equipment which is located within the SUBJEC AREA should be approved to IEC 60601-1.
• Only connect those parts o equipment that are marked as an APPLIED PAR to the subject. APPLIED PARS may be recognized by the BF symbol which appears in the Saety Symbols section o these Saety Notes.
• Never connect parts which are marked as an APPLIED PAR to those which are not marked as APPLIED PARS.
• Do not touch the subject to which the PowerLab (or its peripherals) is connected at the same time as making contact with parts o the PowerLab (or its peripherals) that are not intended or contact to the subject.
• Cleaning and sterilization o equipment should be perormed in accordance with manuacturer’s instructions. Te isolation barrier may be compromised i manuacturer’s cleaning instructions are not ollowed.
• Te ambient environment (such as the temperature and relative humidity) o the system should be kept within the manuacturer’s specified range or the isolation barrier may be compromised.
• Te entry o liquids into equipment may also compromise the isolation barrier. I spillage occurs, the manuacturer o the affected equipment should be contacted beore using the equipment.
• Many electrical systems (particularly those in metal enclosures) depend upon the presence o a protective earth or electrical saety. Tis is generally provided rom the power outlet through a power cord, but may also be supplied as a dedicated saety earth conductor. Power cords should never be modified so as to remove the earth connection. Te integrity o the protective earth connection between each piece o equipment and the protective earth should be verified regularly by qualified
personnel. • Avoid using multiple portable socket-outlets (such as power boards) where possible
as they provide an inherently less sae environment with respect to electrical hazards. Individual connection o each piece o equipment to fixed mains socket- outlets is the preerred means o connection.
I multiple portable socket outlets are used, they are subject to the ollowing constraints:
• Tey shall not be placed on the floor. • Additional multiple portable socket outlets or extension cords shall not be connected
to the system. • Tey shall only be used or supplying power to equipment which is intended to orm
part o the system.
Bio Amp Safety Instructions
Te Bio Amp inputs displaying any o the saety symbols are electrically isolated rom the mains supply in order to prevent current flow that may otherwise result in injury to the subject. Several points must be observed or sae operation o the Bio Amp:
• All Bio Amp ront-ends (except or the ML138 Octal Bio Amp) and all PowerLab units with a built-in Bio Amp are supplied with a 3-lead or 5-lead Bio Amp subject
cable and lead wire system. Te ML138 Octal Bio Amp is supplied with unshieldedlead wires (1.8 m). Bio Amps are only sae or human connection i used with the supplied subject cable and lead wires.
• All Bio Amp ront-ends and PowerLab units with a built-in Bio Amp are not defibrillator-protected. Using the Bio Amp to record signals during defibrillator discharges may damage the input stages o the amplifiers. Tis may result in a saety hazard.
• Never use damaged Bio Amp cables or leads. Damaged cables and leads must always be replaced beore any connection to humans is made.
Stimulus Isolator Safety Instructions Te Stimulator outputs rom the Stimulus Isolator ront-end (or any PowerLab with a built- in isolated stimulator) are electrically isolated and sae or human connection. However, they can produce pulses o up to 100 V at up to 20 mA. Injury can still occur rom careless use o these devices. Several points must be observed or sae operation o the Stimulus Isolator ront-end:
• Te FE180 Stimulus Isolator ront-end must only be used with the supplied power pack (product code: SP0108), which complies with medical saety standards.
• Te Stimulus Isolator must only be used with the supplied bar stimulus electrode.
• Te Isolated Stimulator output must not be used with individual (physically separate) stimulating electrodes.
• Stimulation must not be applied across the chest or head. • Do not hold one electrode in each hand. • Always use a suitable electrode cream or gel and proper skin preparation to ensure
a low-impedance electrode contact. Using electrodes without electrode cream can
result in burns to the skin or discomort or the subject. • Subjects with implantable or external cardiac pacemakers, a cardiac condition, or a history o epileptic episodes must not be subject to electrical stimulation.
• Always commence stimulation at the lowest current setting and slowly increase the current.
• Stop stimulation i the subject experiences pain or discomort. • Do not use aulty cables, or those that have exhibited intermittent aults.
Do not attempt to measure or record the Isolated Stimulator output while connected to a subject using a PowerLab input or any other piece o equipment that does not carry the appropriate saety symbol (see Saety Symbols above).
Always check the status indicator on the ront panel. It will always flash green each time the stimulator delivers a current pulse. A yellow flash indicates an ‘out-o-compliance’ (OOC) condition that may be due to poor electrode contact or electrode cream drying up. Always ensure that there is good electrode contact at all times. Electrodes that are lef on a subject or some time need to be checked or dry contacts. An electrode impedance meter can be used or this task.
• Always be alert or any adverse physiological effects in the subject. At the first sign o a problem, stimulation must be stopped, either rom the sofware or by flicking down the saety switch on the ront panel o any built-in Isolated Stimulator or the FE180 Stimulus Isolator.
• Te FE180 Stimulus Isolator is supplied with a special transormer power pack, which complies with medical saety requirements. Tereore, under no circumstances should any other transormer be used with the Stimulus Isolator. For a replacement transormer power pack please contact your nearest ADInstruments representative.
• Te FE155 Stimulator HC is not sae or human connection and should never be used or human stimulation.
Earthing and Ground Loop Noise
Te prime unction o earthing is saety, that is, protection against atal electrocution.
Saety concerns should always override concerns about signal quality. Secondary unctions o earthing are to provide a reerence potential or the electrical equipment and to mitigate against intererence.
Te earthing (grounding) stud provided on the back panel o the PowerLab is a potential equalization post and is compatible with the DIN 42801 standard. It is directly connected to the earth pin o the power socket and the PowerLab chassis. Te earthing stud can be used where other electronic equipment is connected to the PowerLab, and where conductive shields are used to reduce radiative electrical pick-up. Connection to the stud provides a common earth or all linked devices and shields, to reduce ground-loops.
Te earthing stud can also be used where a suitable ground connection is not provided with the mains supply by connecting the stud to an earthed metal inrastructure, such as a metal stake driven into the ground, or metal water piping. Tis may also be required in laboratories where saety standards require additional grounding protection when equipment is connected to human subjects. Always observe the relevant saety standards and instructions.
Note that electromagnetically-induced intererence in the recorded signal can be reduced by minimizing the loop area o signal cables, or example by twisting them together, or by moving power supplies away rom sensitive equipment to reduce the inductive pick-up o mains requency fields. Please consult a good text or urther discussion o noise reduction.
Cleaning and Sterilization ADInstruments products may be wiped down with a lint ree cloth moistened with industrial methylated spirit. Reer to the manuacturer’s guidelines or the Data Card
supplied with transducers and accessories or specific cleaning and sterilizing instructions.
Inspection and Maintenance PowerLab systems and ADInstruments ront-ends are all maintenance-ree and do not require periodic calibration or adjustment to ensure sae operation. Internal diagnostic sofware perorms system checks during power up and will report errors i a significant problem is ound. Tere is no need to open the instrument or inspection or maintenance, and doing so within the warranty period will void the warranty.
Your PowerLab system can be periodically checked or basic saety by using an appropriate
saety testing device. ests such as earth leakage, earth bond, insulation resistance, subject leakage and auxiliary currents and power cable integrity can all be perormed on the PowerLab system without having to remove the covers. Follow the instructions or the testing device i perorming such tests. I the PowerLab system is ound not to comply with such testing you should contact your PowerLab representative to arrange or the equipment to be checked and serviced.
Environment Electronic components are susceptible to corrosive substances and atmospheres, and must be kept away rom laboratory chemicals.
Storage Conditions
• emperature in the range 0–40 °C • Non-condensing humidity in the range 0–95%.
Operating Conditions
• emperature in the range 5–35 °C • Non-condensing humidity in the range 0–90%.
Disposal
• Forward to recycling center or return to manuacturer.
• Unwanted equipment bearing the Waste Electrical and Electronic Equipment (WEEE) Directive symbol requires separate waste collection. For a product labeled with this symbol, either orward to a recycling center or contact your nearest
ADInstruments representative or methods o disposal at the end o its working lie.WEEE Directive
symbol
Te PowerLab system consists o a recording unit and application programs that run on the computer to which the unit is connected. It provides an integrated system o hardware and sofware designed to record, display, and analyze experimental data.
Front-ends are ancillary devices that connect to the PowerLab recording unit to extend the system’s capabilities. Tey provide additional signal conditioning, and other eatures, and extend the types o experiments that you can conduct and the data you can record.
Te ront-ends are compatible with PowerLab and MacLab hardware and require the ollowing ADInstruments sofware versions unless otherwise specified: Chart v4 or Chart
v5, LabChart v6 or later, or Scope v3.6 or later.
All ADInstruments ront-ends are designed to be operated under ull sofware control. No knobs, dials, or switches are needed, although some may be provided or reasons o convenience or saety.
Overview
22
Introduction Te PowerLab controls ront-ends through an expansion connector called the I2C (eye- squared-sea) bus. Tis makes it very easy to add ront-ends to the system or to transer them between PowerLabs. Many ront-ends can be added to the system by connecting the I2C sockets in a simple daisy-chain structure. Te PowerLab provides control and low-
voltage power to ront-ends through the I2C bus so, in general, no separate power supply is required.
In addition, each ront-end requires a separate connection to one or more analog input channel(s) o the PowerLab. External signals are acquired through the PowerLab analog inputs and amplified beore being digitized by the PowerLab. Te digitized signal is transmitted to the computer using a ast USB connection. ADInstruments sofware applications LabChart, Labutor and Scope, receive, display, and record the data and your analysis to the computer’s hard disk.
Front-ends are automatically recognized by the PowerLab system. Once connected, the
eatures o the ront-end are combined with the appropriate eatures o the PowerLab (orexample, range and filtering options) and are presented as a single set o sofware controls.
Note: Te Stimulator ront-ends differ rom other ront-ends in two respects:
1. Since they need to produce a reasonably high voltage and current, the Stimulator ront-ends require a power supply in addition to the power provided by the I2C bus.
2. As they produce voltage output or stimulation, they are connected to a positive analog output socket o the PowerLab as a source or timing and producing pulses.
A variety o accessory products are available with ADInstruments Front-ends, such as transducers, signal cables and recording electrodes. Some o these are listed in the Getting Started with Front-end Signal Conditioners booklet, supplied with your Front-end. For more details see: http://www.adinstruments.com/ or contact your local ADInstruments representative.
Checking the Front-end Beore connecting the ront-end to anything, check it careully or signs o physical damage.
1. Check that there are no obvious signs o damage to the outside o the ront-end casing.
2. Check that there is no obvious sign o internal damage, such as rattling. Pick up the
ront-end, tilt it gently rom side to side, and listen or anything that appears to be loose.
I you have ound a problem, contact your authorized ADInstruments representative immediately and describe the problem. Arrangements can be made to replace or repair the ront-end.
Connecting to the PowerLab o connect a ront-end to the PowerLab, first ensure that the PowerLab is turned off. Failure to do this may damage the PowerLab, the ront-end, or both.
Te BNC cable rom the ront-end signal output must connect to an analog input on the
PowerLab. I you have an older PowerLab that has differential (rather than single-ended)inputs, the ront-end must connect to a positive input.
Single Front-ends
Connect the I2C output o the PowerLab to the I2C input o the ront-end using the I2C cable provided. Figure 2–1 shows how to connect up a single ront-end to your recording unit.
I2C connector cable
PowerLab I2C output
Front-end Signal output
Front-end I2C input
Check that the connectors or the I2C bus are screwed in firmly. Check the BNC cable or firm connections as well. Loose connectors can cause erratic ront-end behavior, or may cause the ront-end to ail to work at all.
The Signal Output Socket
Te BNC socket labelled Signal Output on the back panel o the ront-end provides the signal output to connect to an analog input socket on the ront o the PowerLab. A BNC- to-BNC cable is supplied or this connection. I necessary, use a BNC to DIN smart adapter [MLAC22] to connect the BNC cable to your PowerLab’s input.
Note: I you have an older PowerLab with differential (rather than single-ended) inputs, the BNC cable must connect to a positive analog input on the PowerLab.
Figure 2–1
Multiple Front-ends
Multiple separate ront-ends can be connected up to a PowerLab. Te initial ront-end should be connected with the I2C cable as in Figure 2–1. Te remainder are daisy-chained
via I2C cables, connecting the I2C output o the last connected ront-end to the I2C input o the ront-end to be added (Figure 2–2).
Second I2C cable connected to
Front-end I2C output
First I2C cable connected
to PowerLab I2C output
Te number o normal ront-ends that can be connected to a PowerLab depends on the number o analog input channels on the PowerLab. Each BNC cable rom a ront-end should be connected to one analog input channel on the PowerLab, or example, Input 1 on a /30 or /35 series PowerLab.
Note: Only one Stimulator ront-end such as a Stimulus Isolator can be connected to thepositive output o the PowerLab.
Special Cases
Some ront-ends have their own specific connection requirements. Please reer to the individual chapter or each ront-end in this guide.
Connecting Stimulator Front-Ends
Te PowerLab analog outputs provide a variable, computer-controlled voltage output that
can be used with LabChart, Labutor or Scope to connect a Stimulator ront-end, or to stimulate directly, or to control a peripheral device. A voltage output is generated by the PowerLab and delivered via the BNC output sockets, giving positive, negative, differential, or independent stimuli, depending on the PowerLab used and the sofware settings.
Te /20, /25, and /26 series PowerLabs have analog outputs labeled + and –. In contrast, the SP, S, /30 and /35 series PowerLabs have the outputs labeled Output 1 and Output 2.
Figure 2–2
For the /20, /25 and /26 series PowerLabs:
Te negative (–) output is the complement o the positive (+) output, so the stimuli rom the two outputs are mirror images. I one output gives a positive voltage, the other gives a negative one, and the two together give a differential voltage. One Stimulator ront-end such as a Stimulus Isolator or Stimulator HC can be connected to the positive output o
these PowerLabs. Note: I you connect the Stimulator HC to a PowerLab that has an in-built Isolated Stimulator, such as a PowerLab 26, only the external, connected stimulator is used.
For /SP, /ST, /30 and /35 series PowerLabs:
Output 1 and Output 2 can unction independently. However, only one Stimulator ront- end such as a Stimulus Isolator or Stimulator HC can be connected to the positive output (Output 1) o these PowerLabs. With a Stimulator ront-end connected, the second output (Output 2) can unction independently, and a second tab appears in the Stimulator dialog in LabChart 7 or Windows. Tereore Output 2 remains available or other uses, such as
creating analog waveorms and triggering other systems.
Maximum Number of Front-Ends
Te I2C bus can control a maximum o sixteen ront-ends. Tereore, i you are using a PowerLab 16/30, which has sixteen input channels, you can record rom sixteen single channel ront-ends. However, please note that the Dual Bio Amp/Stimulator is an exception because it counts as our ront-ends, not three as one would expect. Tereore, you cannot use all the analog inputs or normal ront-ends while using the Dual Bio Amp/Stimulator.
For example, i you are using the Dual Bio Amp/Stimulator with a PowerLab 16/30, you can
only use an additional twelve single channel ront-ends or, or example, one Octal Bridge Amp plus one Quad Bridge Amp.
Using ADInstruments Programs Front-ends are designed or use with PowerLabs and ADInstruments programs such as LabChart, Labutor and Scope. Te unctions o the ront-end are combined with those o the PowerLab, and are presented as a single set o sofware controls in the ADInstruments program. Depending on the ront-end(s) connected, ront-end-specific dialogs replace the Input Amplifier dialogs or the Stimulator dialog.
Te LabChart Help and Scope User’s Guide detail the Input Amplifier and Stimulator dialogs, and explain relevant terms and concepts, but they do not cover ront-end-specific eatures. Tese eatures are described in detail in the ollowing chapters or each ront-end.
Front-end Drivers
A device driver is a piece o sofware that allows the computer’s operating system and other sofware to interact with a hardware device. ADInstruments applications like LabChart communicate with a ront-end via an appropriate ront-end driver. Tese drivers are
automatically set up on the computer when ADInstruments applications are installed, and their operation is usually invisible to the user.
However, under certain circumstances you may receive an error message during the startup o LabChart or Scope indicating that there is a problem with the ront-end driver. Subsequently, the ront-end will not unction. Tis is invariably caused by the absence or incompatibility o a driver required or communication with the ront-end due to an old
version o the sofware being run. Te problem can be remedied simply by reinstalling and rerunning a current version o the sofware, which will include the latest ront-end drivers.
The Front-end Self-test
Once the ront-end is properly connected to the PowerLab, and the proper sofware is installed on the computer, a quick check can be perormed on the ront-end. o perorm the sel-test:
• urn on the PowerLab and check that it is working properly, as described in the owner’s guide that was supplied with it.
• Once the PowerLab is ready, start LabChart, Labutor or Scope. • While the program is starting, watch the Status indicator on the ront-end’s ront
panel. During initialization, you should see the indicator flash briefly and then remain lit.
I the indicator lights correctly, the ront-end has been ound by the PowerLab and is working properly. I the indicator doesn’t light, check your cable connections and repeat the start-up procedure.
Software Behavior
When a ront-end is connected to a PowerLab and the ADInstruments sofware is successully installed, the Input Amplifier… menu command rom the Channel Function pop-up menu in LabChart should be replaced by the <Front-end>... menu command.
For example, with a Bio Amp ront-end connected, Bio Amp… should appear in the Channel unction pop-up menu. In Scope the Input Amplifier… button in the Input A panel (or Input B panel) is replaced by the Bio Amplifier… button.
Figure 2–3
Bio Amp front-end
I the application ails to find a ront-end attached to a channel, the normal Input Amplifier… command or button remains. I you were expecting a connected ront-end, you should close the program, turn everything off, check the connections, restart the PowerLab and then relaunch LabChart, Labutor or Scope.
Preventing Problems Several problems can arise when using the PowerLab system or recording biological signals. It is important to understand the types o problems that can occur, how they maniest themselves, and what can be done to remove them or to minimize their effect. Tese are usually problems o technique, and should be addressed beore you set up your equipment.
Aliasing
Recordings o periodic waveorms that have been undersampled may have misleading
shapes and may also have artiacts introduced by aliasing. Aliasing occurs when a regular signal is digitized at too low a sampling rate, causing the alse appearance o lower requency signals. An analogy to aliasing can be seen in old films: spoked wagon wheels may appear to stop, rotate too slowly or even go backwards when their rate o rotation matches the film rame speed – this is obviously not an accurate record.
Te Nyquist–Shannon sampling theorem states that the minimum sampling rate ( s ) to
accurately describe an analog signal must be at least twice the highest requency in the original signal. Tereore, the signal must not contain components greater or equal to s/2. Te term s/2 is known as the Nyquist requency ( n) or the ‘olding requency’ because requencies greater than or equal to n old down to lower requencies about the axis o n.
When aliasing o noise or signals is seen, or even suspected, the first action you should take is to increase the sampling rate. Te highest available sampling rates are 100k /s or 200k /s, depending on your PowerLab. o view the requencies present in your recorded signal open the Spectrum window in LabChart. For more inormation about Spectrum, see the LabChart Help Center.
I unwanted high-requency components are present in the sampled signal, you will achieve better results by using a low-pass filter to remove them. Te best kind o filter or this purpose is the Anti-alias filter option available in the ront-end-specific Input Amplifier... dialog. Tis is a special low-pass filter that is configured to automatically remove all signals
that could alias; i.e., those whose requency is greater or equal to hal the sampling rate. For certain PowerLabs, the Anti-alias filter option is not available. Tereore you should select an appropriate low-pass filter to remove any unwanted signals (or noise) occurring at requencies greater or equal to hal the sampling rate.
Frequency Distortion
Frequency distortion will occur i the bandwidth o your recording is made smaller than the bandwidth o the incoming signal. For example, i an ECG was measured with a sampling rate o 100 samples per second (100 Hz) and the Bio Amp had a low-pass filter applied at 50
Hz, the ast-changing sections o the waveorm (the QRS complex) may appear smaller and ‘blunted’, while the slower -wave sections remain relatively unchanged. Tis overall effect is called requency distortion.
It can be eliminated by increasing the requency cut-off o the low-pass filter in the ront- end-specific Input Amplifier... dialog to obtain an undistorted waveorm.
Similarly, i the high-pass filter was set too high, the amplitude o the -wave sections maybe reduced. Te Input Amplifier... dialog allows you to examine ECGs and similar slowly changing waveorms to fine-tune filter settings beore recording.
Saturation
Saturation occurs when the range is set too low or the signal being measured (the amplification, or gain, is too high). As the signal amplitude exceeds the allocated range, the recorded waveorm appears as i part o the waveorm had been cut off, an effect reerred to as clipping.
Clipping can also be caused by excessive baseline offset: the offset effectively moves thewhole waveorm positively or negatively to an extent that causes all or part o it to be clipped. Tis problem is overcome by selecting a higher range rom the Range menu in the ront-end-specific Input Amplifier... dialog. In the case o excessive baseline offset, you may wish to apply a high-pass filter with a higher requency cut-off.
Ground Loops
Ground loops occur when multiple connected pieces o recording equipment are connected to mains power grounds. For saety reasons, all electrical equipment should have a proper connection to the mains power grounds, or to a primary earth connection in situations where a mains ground connection is not available. Connecting linked electrical equipment to a common earth connection (equipotential connection point) – such as the earthing (grounding) stud provided on the rear o all PowerLabs – can prevent ground loops.
Te electric fields generated by power lines can introduce intererence at the line requency into the recorded signal. Electromagnetic fields rom other sources can also cause intererence: fluorescent tubes, apparatus with large transormers, computers, laptop batteries, network cables, x-ray machines, microwave ovens, electron microscopes, even cyclic air conditioning.
Reasonable care in the arrangement o equipment to minimize the ground loop area,
together with proper shielding, can reduce electrical requency intererence. For example,use shielded cables, keep recording leads as short as possible, and try twisting recording leads together. For sensitive measurements, it may be necessary to place the subject (the biological source) in a Faraday cage.
Intererence should first be minimized, and then you can turn on the Mains or notch filter in the ront-end-specific Input Amplifier... dialog.
Mains filter
Te Mains filter (/20, /25, /30, /35 and 26 PowerLabs) allows you to filter out intererence at the mains requency (typically 50 or 60 Hz). Te mains filter is an adaptive filter which tracks the input signal over approximately 1 second. A template o mains-requency signal present in the input is computed rom the signal. Te width o the template is the mains
power period (typically 16.6 or 20 ms) as determined rom zero-crossings o the mainspower. Te filtered signal is obtained by subtracting the template rom the incoming signal.
In comparison with a conventional notch filter, this method produces little waveorm distortion. It attenuates harmonics o the mains requency as well as the 50 or 60 Hz undamental and thereore effectively removes non-sinusoidal intererence, such as that commonly caused by fluorescent lights.
Te filter should not be used when:
• the intererence changes rapidly. Te filter takes about 1 second to adapt to the present level. I intererence is present and then is suddenly removed, intererence in the filtered signal will temporarily worsen.
• your signal contains exact actors or harmonics o requencies close to the mains requencies, or example, a 30 Hz signal with 60 Hz mains requency.
• your signal is already ree rom intererence. I the signal-to-noise ratio is greater than about 64 the mains filter introduces more noise than it removes.
• you are recording at close to maximum sampling rates. Te mains filter uses some o the PowerLab’s processing power and thereore reduces the maximum rate at which you can sample.
Notch Filter
Te notch filter is automatically set to either 50 or 60 Hz, depending on the powerline voltage requency being used by the PowerLab (the mains requency). It provides approximately 32 dB o attenuation, thus reducing the effect o the 50 or 60 Hz signals that can easily be picked up by long leads. Te notch filter is only available with older model PowerLabs, such as the /20 series.
Electrode Contact
Occasionally one o the lead wires connecting the subject to the ront-end may become disconnected, or an electrode contact may become poor. I this should happen, relatively high voltages (potentials) can be induced in the open wire by electric fields generated by power lines or other sources close to the ront-end or the subject. Such induced potentials will result in a constant amplitude disturbance in the recorded waveorm at the power line requency (50 or 60 Hz), and loss o the desired signal. I the problem is a recurring one, one o the leads may be aulty. Check connections and replace aulty leads, i necessary.
Motion Artifacts
A common source o artiacts when recording biological signals is due to motion o the subject or equipment. Ofen applying a high-pass filter can help to remove slowly changing components in a recorded signal.
• Muscular activity generates its own electrical signals, which may be recorded along with an ECG, say, depending on the location o the electrodes.
• I an electrode is not firmly attached, impedance (and hence the recorded signal) may vary as the contact area changes shape owing to movement.
• Movement o patient cables, particularly bending or rubbing together (triboelectric effects) may generate artiacts in a signal.
• Subject respiration can also generate a signal; breathing can result in a slowlychanging baseline corresponding to inspiration and expiration.
I the subject is liable to move during recording, then special care needs to be taken when attaching the electrodes and securing the patient leads. Make sure the skin is cleaned and lightly abraded beore attaching the electrodes.
Te FE136 Animal Bio Amp is a modular device, in a amily called ront-ends, designed to extend the capabilities o the PowerLab system. Te Animal Bio Amp is designed to allow the PowerLab system to record bioelectrical signals, such as ECG, EOG, ERG, EMG, and EEG, rom animals or isolated tissues, or action potentials rom isolated nerves.
Warning! Te Animal Bio Amp is not intended or human use and should never be
connected to a human subject.
Te Animal Bio Amp provides:
• a low-noise, high-gain differential amplifier specifically designed or biological signal measurements;
• sofware-controlled low-pass, high-pass, and notch filters to remove unwanted signal requencies or particular uses;
• audio output, or use with EMG or EEG signals, and so on.
Animal Bio Amp
The Animal Bio Amp Te Animal Bio Amp has been designed to integrate ully into the PowerLab system. Te Animal Bio Amp is essentially an extension o the PowerLab’s input amplifiers, so the amplification (and hence the ranges) you see offered in the LabChart, Labutor and Scope sofware will be the combination o both pieces o hardware.
Tis chapter contains general inormation about the eatures, connections, and uses o the Animal Bio Amp. More detailed inormation can be ound in the echnical Aspects and Specifications sections.
The Front Panel
Te ront panel o the Animal Bio Amp has three input connectors and one indicator light.
Input Sockets
Status indicator
The Input Sockets
Connections are made to the Animal Bio Amp are made using the three shrouded 1.5 mm male pin sockets on the ront panel. A separate socket is provided or each o the positive (+), negative (–) and Ground/Reerence (Re) cables. Tree cables are provided and each is terminated with a miniature alligator clip suitable or use with a wide variety o electrodes (not supplied).
The Status Indicator
Located at the bottom right o the ront panel o the Animal Bio Amp is the status indicator light. When lit, it indicates that the PowerLab sofware (such as LabChart or Scope) has ound the Animal Bio Amp and that it is ready to use. I the light does not go on, then the Animal Bio Amp is not connected properly, or there is a sofware or hardware problem.
The Back Panel
Te back panel o the Animal Bio Amp provides all the sockets or connection o the Animal Bio Amp to the PowerLab and to other ront-ends.
Figure 3–1
Amp
I2C Input and Output Sockets
wo nine-pin sockets are used to communicate with the PowerLab (they are marked ‘I2C Bus’: a ‘bus’ is simply an inormation transmission connection such as connectors and cabling). Tese sockets in conjunction with the proper cables allow multiple ront-ends to be used independently with one PowerLab: power and control signals to connected ront-
ends come rom the PowerLab. Multiple ront-ends can be connected to each other inseries, ‘output to input’. Tis is discussed in detail in Chapter 2.
Signal output to the
I2C connection from
the PowerLab or
Signal Output Socket
Te BNC socket labeled Signal Output is used to connect the Animal Bio Amp to one o the analog input channel sockets on the ront o the PowerLab. Te supplied BNC-to-BNC cable is used or this purpose.
Audio Output Socket
Te Animal Bio Amp has an audio monitor output that can be used with a wide range o headphones or externally powered speakers. Te 3.5 mm stereo socket is wired to provide mono sound (the same signal to a set o stereo speakers or headphones. Tis audio output is o particular use when monitoring bursts or nerve activity.
Connecting to the PowerLab o connect a ront-end, such as your Animal Bio Amp, to the PowerLab, first make sure that the PowerLab is turned off. Failure to do this may damage the PowerLab, the Animal Bio Amp, or both.
Figure 3–2
The back panel
Single Front-end
Connect the I2C output o the PowerLab to the I2C input o the ront-end using the I2C cable provided. Figure 3–3 shows how to connect up a single ront-end to your PowerLab.
Check that the plugs or the I2C bus are screwed in firmly. Check the BNC cable or firm connections as well. Loose connectors can cause erratic ront-end behavior, or may cause
the ront-end to ail to work at all. Te BNC cable can be tucked under the ront-end to keep it out o the way i desired. Once the Animal Bio Amp is connected, turn the PowerLab on and launch LabChart.
Multiple Front-ends
Multiple ront-ends can be connected up to a PowerLab; up to sixteen, depending on the number o input channels on the PowerLab. Te initial ront-end should be connected as shown in Figure 3–3. Te remainder are daisy-chained via I2C cables, connecting the I2C output o the last connected ront-end to the I2C input o the ront-end to be added (see Figure 2–2). Te BNC cable or each ront-end is connected to one o the analog inputs o the PowerLab. Note that signal degradation can be expected i multiple Bio Amps are connected to a single subject.
Using LabChart and Scope When the Animal Bio Amp is connected to a channel and successully installed, the Input Amplifier… menu command rom the Channel Function pop-up menu in LabChart is replaced by the Bio Amp… menu command. In Scope, the Input Amplifier… button in the Input A (or Input B) panel is replaced by the Bio Amplifier… button.
I the application ails to find a ront-end attached to a channel, the normal Input
Amplifier… command or button remains. I you were expecting a connected ront-end,
Figure 3–3
Animal Bio Amp
BNC connector cable
you should close the program, turn everything off, check the connections, then start things up again.
Note: Leaving the PowerLab on while changing connections can damage the PowerLab, the Animal Bio Amp, or both.
Choosing the Bio Amp… menu command will bring up the Bio Amp dialog, which
replaces the Input Amplifier dialog or the channel. Te LabChart Help Center and ScopeUser’s Guide have urther details on the Input Amplifier dialog, and explain some o the sofware terms used here.
The Bio Amp dialog
Te Bio Amp dialog is similar or LabChart and Scope. It allows sofware control o the various amplifiers and filters in the Animal Bio Amp (and PowerLab) or a channel. Te signal present at that channel’s input is displayed so that you can immediately see the effects o any changes. Once you have changed the settings in the dialog, click OK to apply the changes to the Chart or Scope window. Te channel that the dialog applies to is shown next to the arrows, and the channel title or axis label (i any) is shown along the vertical Amplitude axis.
Signal Display
Te input signal is displayed so that you can see the effect o changing the settings — no data is actually recorded when setting up the Animal Bio Amp. Te average signal value is displayed at the top lef o the display area. Slowly changing waveorms will be represented quite accurately, whereas quickly changing signals will be displayed as a solid dark area showing only the envelope (shape) o the signal ormed by the minimum and maximum recorded values.
Figure 3–4
The Bio Amp
Range
Te Range pop-up menu lets you select the input range or sensitivity o the channel — the combined range o the Animal Bio Amp and the PowerLab. Changing the range in the Bio Amp dialog is equivalent to changing it in the Chart or Scope window (all dialog changes are made in the main window afer clicking OK). For the Animal Bio Amp, the deault
setting is 100 mV, and the ranges go down to 5 µV in 14 steps.
EEG Mode
Te EEG Mode changes the available filters o the Animal Bio Amp to suit EEG applications. When this checkbox is on, the High Pass pop-up menu gives filter settings o 0.03, 0.1, 0.3 and 1 seconds, and the Low Pass pop-up menu gives filter settings o 3, 10, 30, 60, and 120 Hz. It is a convention in EEG to deal with high-pass filter settings in terms o seconds (giving the time constant o the first-order filter).
Filtering
Te Animal Bio Amp provides signal filtering options that can be adjusted to suit your requirements. Te deault settings are appropriate to the signals usually measured, which tend to be o lower requency.
Te notch filter and the mains filter are used to remove excessive mains requency intererence. Te high-pass filter limits the bandwidth o low-requency signals and the low-pass filter limits the bandwidth o high-requency signals.
Not all possible combinations o high-pass and low-pass filters are available, or instance, i the 5 kHz low-pass filter is selected, then high-pass filtering cannot be below 1 Hz.
Notch Filter. Click the Notch checkbox to turn the notch filter on and off (it is on whenchecked). Te notch filter is set to either 50 or 60 Hz depending on the power line voltage (mains) requency. It provides 32 dB o attenuation to remove electrical intererence, thus reducing the effect o 50/60 Hz signals that can be picked up by long patient leads.
Mains Filter. Select or deselect the Mains filter checkbox to turn the mains filter on and off. Te mains filter allows you to remove intererence related to the mains requency (both undamental and harmonic requencies). Tis is an adaptive filter. It adjusts to filter the intererence by tracking the input signal or a second, creating a template o the interering requencies and then subtracting this template rom the input signal. Because o this, in general, using the mains filter is better than using the notch filter. However, the mains filter
does have some limitations, such as not being useul or very short recordings o less thanone second. More details on the mains filter can be ound in the LabChart Help Center.
High-Pass Filtering. Tere are normally five options in the High Pass pop-up menu: 0.1, 0.3, 1, 3 and 10 Hz. When the EEG Mode checkbox is on, our options are provided in the High Pass pop-up menu: 0.03, 0.1, 0.3 and 1 seconds. (Units o seconds give the time constant o the first-order filter.) When any o the options is chosen, a high-pass filter removes any DC components and attenuates those requency components below the AC filter requency rom the signal. Tis is useul to remove slowly changing baselines, such as motion or respiration artiacts, commonly ound in ECG (EKG) recordings.
Low-Pass Filtering. Te Low Pass pop-up menu normally gives a choice o six low-pass filters to remove high-requency components rom an input signal: 50, 100, 200 and 500 Hz, and 1 and 5 kHz. When the EEG Mode checkbox is on, five options are provided in the Low Pass pop-up menu: 3, 10, 30, 60 and 120 Hz. Tese settings are useul to eliminate high-requency components, such as noise, and to prevent aliasing in the recorded signal.
Anti-alias. Click the Anti-alias checkbox to turn the anti-aliasing filter on and off. Tis applies a low-pass filter that attenuates requencies in the incoming signal that are greater than or equal to hal the sampling requency. Tis filter helps to eliminate aliasing, in which such requencies ‘old down’ to lower requencies, and the recorded waveorm appears quite different rom the actual signal.
Inverting the Signal
Te Invert checkbox allows you to invert the signal on the screen. It provides a simple way to change the polarity o the recorded signal without having to rewire a circuit or reconnect to the signal. Select the Invert checkbox to change the signal polarity.
Units
Click Units… to display the Units Conversion dialog, with which you speciy the units or the channel and, using waveorm measurements, calibrate the channel. Units conversion is not normally required or measurements taken using the Animal Bio Amp, but is provided
just in case.
When the button is clicked, the waveorm currently in the data display area o the dialog is transerred to the data display area o the Units Conversion dialog. (Use the Pause button to capture any specific signal that you want to use.) Te units conversion only applies to
subsequently recorded signals, so it is more limited than choosing Units Conversion…rom a Channel Function pop-up menu, as it does not allow the conversion o individual blocks or pages o data. For more inormation about units conversion, see the LabChart
Help Center and Scope User’s Guide.
Using the Animal Bio Amp Tis section looks at the use o the Animal Bio Amp or measurements, describes the input connection in detail, and looks at how to avoid some common problems when setting up. It is recommended that you read the material in this section beore you attempt to record biological signals with the Animal Bio Amp, especially i you intend to use your own cables
or are unsure about how to connect to the Animal Bio Amp. Te Animal Bio Amp amplifies the signal rom a biological signal source so it can be used by the PowerLab, and provides appropriate filtering. Te tasks listed below, and the basics o setting up measurement, are covered in detail in standard electrophysiology texts. Note that signal degradation can be expected i multiple Bio Amps are connected to a single subject.
Some Suitable Uses
Tis version o the Animal Bio Amp [FE136] has been designed to measure a wide variety
o biological signal sources. Some o the tasks or which it is suitable include: ECG. Electrocardiogram (also reerred to as EKG); a recording o the electrical currents that constitute the cardiac action potential.
EOG. Electro-oculogram; a recording o the electrical activity o the muscles which control movement o the eyeball. For bilateral measurement, a Dual Bio Amp [FE135] is recommended, although two Animal Bio Amps can be used. Te lowest possible high-pass filter setting is recommended or EOG measurements.
ERG. Electroretinogram; a recording o the electrical currents produced in the retina by a light stimulus. wo Animal Bio Amps are required or bilateral measurement.
EMG. Electromyography (surace electrode electromyography); a recording o the electrical activity o a muscle, using surace or needle electrodes: voluntary, M-wave (nerve stimulation), and so on.
EEG. Electroencephalogram; a recording o the electrical activity o the brain. Te Animal Bio Amp is suitable or both ‘bioeedback’ and clinical types o EEG recording, i the environment is electrically quiet.
Cortical Evoked Potentials. Averaged recordings o the electrical activity o the brain when subject to stimulation: visual evoked response, auditory evoked response, and somatosensory response. Tis should be done with signal averaging, using Scope.
SNAP. Sensory nerve action potentials; a recording o evoked response in stimulated nerves. Tis is usually done with signal averaging, using Scope.
Slow Waves. For some smooth muscle studies; recording the long-term electrical activity involved in involuntary muscle contractions.
Some Unsuitable Uses
Te Animal Bio Amp is not recommended or work requiring high-impedance electrodes or using a high bandwidth. Some o the tasks or which it is not really suitable include:
• Intracellular micropipette recordings. Recordings rom a very fine, electrolyte-filled tube inserted into a nerve or muscle cell. Tese require an electrometer amplifier.
• Any biopotential recordings requiring low input capacitance and a driven guard circuit.
The Animal Bio Amp Input
Connections are made to the Animal Bio Amp using the three shrouded 1.5 mm male pin sockets on the ront panel. Te sockets are o a sort commonly used with lie science connection leads, and their arrangement is shown below.
Tree cables are provided and each is terminated with a miniature alligator clip suitable or use with a wide variety o electrodes (not supplied).
Ref + -
Ground/Reference
(green)
(black)
Te sockets provide two pins or a differential input signal (+ or red, – or black), and an input or an isolated Ground/reerence (Re or green). Te Ground/reerence electrode should always be attached to the subject under investigation (or to the recording preparation), providing a zero reerence or the differential amplifier. Ten the active (+) and reerence (-) electrodes should be securely attached to the subject or recording preparation, or example, ECG recording leads on opposite sides o the chest, or needle electrodes at different sites over a nerve.
Note: Te Animal Bio Amp should never be used on humans. For human connection, the Bio Amp [FE132] or Dual Bio Amp [FE135] should be used with their associated approved subject cables.
Figure 3–5
Technical Aspects Tis section describes some o the important technical eatures o the Animal Bio Amp. It describes the capabilities o the Animal Bio Amp, and its suitability or particular purposes. Be advised that user modification o the equipment voids the warranty agreement.
Technical Description
As with other ADInstruments ront-ends, all internal unctions o the Animal Bio Amp are controlled rom the PowerLab through a special communications connector called the I2C bus. Tis connection also supplies power to the Animal Bio Amp. Front-ends are also connected to the analog input channels o the PowerLab via a BNC-to-BNC cable, through which the amplified and filtered signal is sent to the PowerLab. Te overall operation o the Animal Bio Amp can be better understood by reerring to Figure 3–6.
Te input amplifier o the Animal Bio Amp starts with an electrically isolated differential amplifier. Te output o this amplifier is ed into a low-noise demodulator and then to a
programmable gain stage, beore being ed across an isolation transormer to the non- isolated circuitry. Control o the isolated gain is provided via a high-isolation-voltage optocoupler. An auto-restore circuit monitors the level o the input signal and restores the input beore the signal produces amplifier ‘blocking’. Isolated power comes rom a second isolation transormer driven by a power oscillator circuit running at about 38 kHz.
Te signal rom the isolated input amplifier is synchronously demodulated and then ed to a programmable, switched-capacitor, high-pass filter. Any switching clock noise is filtered by the low-pass filter ollowing this stage.
Te signal then passes to the first non-isolated gain stage, where it is amplified 1, 10 or 100
times. A switched-capacitor notch filter ollows (this is automatically set to 50 or 60 Hzdepending on the mains requency o your power supply). Afer this, the signal passes to the final programmable gain stage, where it is amplified 1, 2 or 5 times. Te last part o the signal-conditioning circuitry is the low-pass filter.
Te output o the Animal Bio Amp is buffered with an amplifier with a fixed gain (nominally X 1.66), to compensate or gain differences through the previous stages o the device. An audio signal output, capable o driving headphones or powered speakers, is provided by tapping off the output stage and buffering it.
Te control or the various filters and gain stages in the Animal Bio Amp is provided by on-board microprocessors, which also communicate with the PowerLab over the I2C bus.
Note that the Animal Bio Amp is an extremely sensitive instrument, and it is important that under no circumstances should you try to repair or adjust it yoursel. I you experience problems with the Animal Bio Amp, it should be returned to your ADInstruments representative or repair under the terms o your Warranty & Licensing Agreement.
8/20/2019 Fron

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