Re: EMG impedance measurement

[Daniel P. Ferris]

Dear BIOMCH-L subscribers,

I recently sent out a request for information regarding instrumentation
and/or methods pertaining to EMG impedance measurement. Below is a
posting of the original message and the replies that I received.

Thanks to all who sent messages.


Dan Ferris
University of Miami
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Dear BIOMCH-Lers,

I am interested in finding literature or information related to the
measurement of impedance in surface EMG data collection. Any information
regarding instrumentation and/or methods would be greatly appreciated.
Please send messages to "dferris@students.miami.edu"

Thank you for your help.


Dan Ferris
Human Performance Laboratory
University of Miami

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Dear Daniel,

I can't offer you much information other than we check resistance with a
standard voltmeter prior to testing with EMG. It seems if we reduce
levels to less than 5KOhms we reduce noise in the telemetered EMG signal.
However, I would be very interested in the responses you get.


Julie Steele
j.steele@uow.edu.au

University of Wollongong
Australia

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Dan

I cannot help you personally but I used surface EMG for my MSc
research 2-3 years ago. Met a gentleman who had produced EMG
equipemnt commercially who gave me some information about
impedance.
Suggest you contact him
company name

MIE Medical Research Ltd
6 Wortely Moor Rd
Leeds LS12 4JF
UNITED KINGDOM
Ask for Richard Malier

Fax
(0532) 310820

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Dan

The stuff on EMG for the company in Leeds UK came from a colleague
of mine Jim Pickard (who doesn't have e-mail access), please contact
him if you require further information.
Tel (0484) 422288 ext 2853

Sorry I forgot to sign the first message
A.C. Redmond
School of Human & Health Sciences
University of Huddersfield
0484 422288 x 2096

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I have some info re:impedance measurements that perhaps you might
find useful:

Dunseath,WJRoss;
A low cost precision electrode impedance meter
Psychophysiology
19
117-119
1982
EMG circuits,electrodes;
A circuit is described which measures applied electrode impedance
sing a 7 uA RMS, 10 Hz sine wave current, and displays the readin
in ohms on a small analog meter. The design uses a minimum of
parts and power, drawing only 2mA from a 9 volt battery, yet is
accurate to within 2% and can easily be modified to fit a wide
range of frequencies.

Gary Kamen
Boston University

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Hi Dan,

The Grass Instruments makes the electrode impedance meter for EMG, EEG, EKG
measurement. Their phone number is 1-800-225-5167.

Li-Qun Zhang
Rehabilitation Institute of Chicago

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Hi Dan:

Try the book "EMG for experimentalists" by Loeb and Gans.
page 191-194.

Rodger Kram
University of California, Berkeley

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