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SUMMARY: Portable data recorders

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  • SUMMARY: Portable data recorders

    From: John Eric Nelson

    Subject: SUMMARY: Portable data recorders

    Thanks to all who responded to my post for infomation about portable data
    recorders. The information I received was helpful and much more than I could
    have found on my own.

    __________________________________________________ ______________
    My original post was as follows:

    Subject: Portable data recorder?

    Does anyone know of a portable/battery powered data recorder that could be worn
    on a subject's belt. I need to be able to record multiple channels at 100 or
    1000 hz and download the data at a later time. The device would be used in an
    EMG related study. I have had no luck finding such a device so any help would
    be appreciated.

    Eric Nelson
    GM, NAO R&D Center, RTP, Bldg. 1-3
    30500 Mound Road, Box 9055, Warren, MI 48090-9055
    (810)986-1829 fax810)986-0294
    __________________________________________________ ______________
    __________________________________________________ ______________

    The following are the replies that I received. I generally deleted the senders
    personal information. If you would like to get in touch with the sender of one
    of these relies please contact me and I will give you that info.

    __________________________________________________ ______________

    We have developped and we are using in our lab a static data recorder with
    the following specifications:

    8 or 16 analog channel inputs (selected by software)
    0 to 5V or +/-5V (set with a switch)
    12 bits +/-1 Analog to Digital Converter
    25 Hz up to 1600 Hz (8 channels) or 800Hz (16 channels) sampling frequency
    (selected by software).
    The memory is size is 4 megabytes in our model by I know that it is possible
    to get 16 megabyte model.
    The maximal sampling time depends of number of channels, sampling frequency
    an memory. For instance with 8 channels, 100 Hz, 4 MBytes, the maximal
    sampling time is about 500 seconds.
    The weight is 400 grams (including battery).

    The data are transfered into a PC file throught the parallel interface
    (Centronic type). The static recorder is also programmed before sampling
    throught the parallel interface.

    For more details on the methods (transducers, experiments ...) you can
    contact me.

    For more technical details on the static recorder you can fax to:
    Mr Regis BONNEFOY
    Fax: (33) 77 39 91 07 (France)
    __________________________________________________ ______________

    This bit of info probably won't be very helpful to you, but here goes.
    About one month ago, a woman named Cheryl Faye, from a company called
    Digitrace, came to speak to us about a portable footswitch system.
    Unfortunately, for both of us, their current system has only 2 channels.
    Since no other information, besides footfalls, could be recorded, the
    device did not seem to be very useful to us, especially since we have our
    own footswitch system in house with kinematics, kinetics, and EMG
    data collection available as well. Anyway, the company is located in
    Massachusetts, but I do not recall exactly where or what their phone # is.
    Good Luck!
    __________________________________________________ ______________

    In response to your request regarding a portable data recorder. I am
    curious as to the application that you may be using this for. If it is
    solely for EMG there are very good telemetry EMG systems that may suit your
    need. That permits portability and does not require downloading later. We
    have such a system. We purchased it from Konigsberg Instruments at 2000
    Foothill Boulevard, Pasadena, CA 91107 Phone# (818) 449-0016. The contact
    there is Bill Mills. He has supervised custom system development for
    similary telemetry EMG systems for UCLA, Georgia Tech, Centinela Hospital in
    LA, our company, and is currently developing a system for USC. I know
    personnel at all of these facilities and all seem to be pleased with the
    service, quality, and the price. Please contact Bill Mills for
    specification information, etc. He is happy to work with you to develop a
    system for your needs. They have also developed very custom instrumentation
    for NASA.

    If your system needs to be more flexible in terms of the type of sensors
    used (strain gauges, transducers, accelerometers?) then you are in a similar
    boat we are ... that is finding a portable system that can do these in the
    budget of a small company. We have made some progress in finding market
    available systems that do some of the things we need. One such system
    (DataPak - I believe German built?) is similar to your description ... a
    portable system that saves data on cards to be downloaded later. The
    Biomechanics Lab at Penn State served as a Beta Test Site and some Ph.D.
    students under Dick Nelson used the system on cross-country skiers and
    golfers, and I think one or two channels may have been EMG compatible. I
    believe that system is now being marketed through a company in the Colorado
    Springs area called Peak Performance. You may be fimiliar with their name
    as providers of high speed video motion analysis systems. With a call or
    two I could find out the contact there for the DataPak system.

    Sorry I couldn't provide many specifics off the top of my head, but I hope
    this limited information helps some. If you have any more questions, please
    contact me directly.
    __________________________________________________ ______________

    For a similar probem I am successfully using a
    standard portable DAT-tape recorder by SONY. If you need more than two
    channels, you can develop an analog or digital multiplexer, which cost you
    a little bit of labour, but is very cost effective.
    Proffessional portable data loggers are (at least for me) way out too


    I am using the TCD-D3 DAT recorder by Sony, but any other portable DAT
    recorder should also do the job. This recorder is battery operated. A
    fully charged battery results in 2 hrs recording time.
    Nominal bandwidth 1hz to 20 khz. I modified the input stage, so that this
    thing now handles frequencies down to 50 miliHz.
    The Signal Nois ratio is about 90 dB, which frees me from the necessity of
    frequent adjustment of the input level.
    Nominal input Voltage is about 2 V rms maximum on the standard line input.
    If you use the microphone input you can get as low as 1 mVrms. In this case
    the SNR drops to about 60 dB.
    I am generally using the line input and handle the analog pre-processing
    externally with a couple of low-noise Op Amps.
    You can purchase tapes between 45 mins and 120 mins recording time. The
    TCD-D3 also offers a slow recording feature, which multiplies possible
    recording time by a factor of 2. In this case, the bandwidth is limited to
    15 khz and the digital encoding is nolinear.

    Date is being downloaded to the PC via an A/D Converter Board along with
    data aquisition software written by one of our students. Commercially
    available data aquisition packages (such as View DAC) should also do this
    I am also feeding the recordet signals into a fourier analyzer for
    additional data processing. This analyzer returns a plot in HPGL, which is
    postprocessed with Corel Draw and then pasted into my documents.

    A small warning: do not use a mini disk (MD) recorder or a digital audio tape
    recorder (DCC). These recorders have a built in data reduction algorithm,
    which is fine for music, but no good for stochastic bioelectrical signals.
    I tried it once - the results were funny, but showed no association to the
    original signal.
    __________________________________________________ ______________

    I do not know of any commercially available portable data acquisition
    systems. However, several such systems have been developed by various
    research institutions. At the UC Davis, Prof. Maury Hull and Jeff
    Newmiller developed a system carried in a fanny pack and used for
    skiing and cycling research. I also think the USOTC (Colorado Springs)
    has some portably system, perhaps a telemetry system.
    __________________________________________________ ______________

    In response to your request for data logging hardware leads I have the

    Mega Electronics ME3000P - a four channel EMG data collection system with
    1Meg on board ram which we have been using for 2-3 years with good
    success in the automotive industry.

    Premed as Physiometer-PHY400 - A similar system with position sensors,
    made in Finland (fax +47 22637581). Untested by me so...

    A Data logging system developped for a large scale research project in
    Sweden (the stuff is not mass marketed but I hear it _is_ for sale in
    some form). This system is geared to collect LOT's of data over long
    periods of time. Again - I've only really seen the picture/demo so beware.
    __________________________________________________ ______________

    Hi, Try one of two sources:
    1) the Medilog system by Ambulatory Monitoring. Unfortunately I don't have
    their address handy. It was somewhere in New York state.
    2) Ergonomic Concepts (Krishna Menon) 201-667-1052, has a portable system
    that measures EMG and other measurements.
    __________________________________________________ ______________

    We use a portable TEAC 9-channel data recorder (cassette tapes downloaded
    post data collection) to record free floating astronaut EMG during space
    flight. It has the capability of sampling at the rate you need. If you'd
    like more information, please respond or call me and we can talk more.
    __________________________________________________ ______________

    We found a similar problem and built one ourselves which we could
    "clone" for youif it would work. The unit is based on a TMS 320
    microprocessor, an 8 channel A/D front end and 512K of nonvolitile
    memory. As configured, four channels are "tuned" for electro
    myography and the other four are more general purpose. The
    differences are quite minor gain and offset modifications. We
    routinely can sample in the 100 to 1000 hz range, although the
    ]recording time is farily short if you want to save all the
    data at 1000 hz. In our uses, we usually have the TMS 320
    programmed to extract the "features" we want and just save those.

    The logger communicates on a serial connection to a PC and we use
    Microsoft Excel for simple data display.

    Componet costs are about $1500/unit and we don't really have a
    price yet.

    If this looks to be of interest, let me know and I'll have one of
    our more technical people get in touch with specs.
    __________________________________________________ ______________

    A company called TEAC manufacture a small portable data recorder
    (2"x4"x8", or something like that), that saves data onto basically
    ordinary cassette tapes. I have used it to record EMG data from as many
    as nine channels. I think if I remember right that the frequency
    range was up to 1300Hz, but this also was dependent on the amps used
    inside the data recorder. But as always, this doesn't come cheap! The
    data recorders themselves cost a bundle, and you also need a data
    downloading unit, and of course your A-D board and software. However,
    that was a couple of years back and the prices and/or technology may have
    changed to you might want to look into it....
    __________________________________________________ ______________

    NASA uses such a device during a week long interview for potential
    astronauts. To get more info you might want to call the NASA JSC ((Johnson
    Space Center) Medical offices at (713) 483 7999. It is called a "holter
    __________________________________________________ ______________

    We have a device here at the UVA Auto Safety Lab that we use to
    monitor 4 channels of data for temperature studies in
    cadavers. The device is battery powered powered and can be
    connected to your PC and the data periodically downloaded with
    a very simple program. The device is the Pocket Logger made by
    Pace Scientific. Joe Dobson is the sole owner/employee. His
    telephone number in Charlotte N.C. is (704) 568-3691.
    __________________________________________________ ______________

    Last I checked TEAC made a 4 channel recorder that was compatible with
    their bench model 7 channel instrumentation recorder. East coast
    (or maybe new england) rep is Brian Kiley: 617-272-4550. I have
    the 7 channel recorder and it has worked pretty well.
    __________________________________________________ ______________

    You may want to look up the TattleTale product line. It has
    been a few years since I last looked up this information so I
    do not have the address now. This company is sure to
    have what you want, though. You can buy a variety of small
    data recorders or just the circuit board.
    __________________________________________________ ______________

    A company by the name of BIOMATION markets a surface emg
    system that has a portable unit that allows you to
    collect sEMG for a short period of time for later
    downloading. The person to contact is Dave Hanneson at
    (613) 256-2821.
    __________________________________________________ ______________

    TEAC Corporation, Japan has a portable tape recorder (analogue data), maybe
    8 ch. If I remember correct the type is MR-10. Its rather expensive and has no
    final amplifiers.
    TEAC Corp. has representatives in most countries.
    __________________________________________________ ______________

    there are several companies in Germany selling portable data recording
    systems for EMG, HR, 1 V analog input etc. I don't know if this is of
    any help for you, but maybe they have also addresses in the US. We use PARPORT
    from PAR Electronic in Berlin, which is a 6 channel system (e.g. 4 EMG + 2 HR)
    that records at max. 10 Hz (newer version works at max. 1kHz) and is restricted
    as it already integrates the EMG (integration time for the EMG is 0,5 s). The
    complete system costs about $20.000 and has DOS software.
    medNATICs system offers multichannel telemetry, has a recording rate
    of 1kHz, a 20 Mbyte flash memory card and Windows software. It costs
    $17.000 + VAT for the complete system.


    PAR Elektronik GmbH
    D-10787 Berlin
    Tel. +30 2139055
    Fax +30 2138542

    medNATIC GmbH
    Harthauser Str. 21
    D-81545 Muenchen
    Tel. +89 6422958
    Fax. +89 6422978

    __________________________________________________ ______________

    The LogIT data logging system is about the size you need. However, I
    think its maximum sampling rate may be too low; my impression is that
    100Hz would be as much as you would expect.

    For information on the hardware, fax DCP Microdevelopments Ltd
    (Cambridge, England) 0n +44 1480 830 534

    For info.on hard programming of the device and downloading/analysis
    software, fax SCC Research (Chelmsford, England) on +44 1245 250 934

    In th UK, the device is also marketed by Fisons Scientific Equipment,
    fax +44 1509 321 893.
    __________________________________________________ ______________

    We have done some good experience with Tattletales. Try the following
    ONSET Comp. Corp.
    536 MacArthur Blvd.
    P.O. Box 3450
    Pocasset, MA 02559
    __________________________________________________ ______________

    I have had such a device made by Logger Techn. AB, Trelleborgveien 10, S-21435
    Malmo, Sweden. The technology is based upon a "credit-card" PCMCIA memory card
    which can be dumped into your PC at intervals. My cards are 20Mb each and can
    hold 1 hour 20 min at a sampling frequency of 1500 Hz. When the card is full yo
    just switch to another card. The only disadvantage is that the format is memory
    mapped which is good for programming in C++ but needs to be converted in your
    want your PC data in ASCII. The logger is so light you will not notice it's in
    your belt. It can be used for EMG and othe data sources. I use is to store data
    from a triaxial accellerometer.
    __________________________________________________ ______________

    Try Tattletale computers. They are very small and will do the rates you
    need. I don't know about emg, though. You may have to build some
    amplifiers for those.
    __________________________________________________ ______________

    How far from your site do you want to record this data? BTS carries their
    TELEMG system,a telemetry system which sends the EMG data from a portable
    patient unit to a receiver. I'm not really sure about the range that this has
    but I can check on it if you are interested in this information.
    __________________________________________________ ______________

    I have been using a TEAC HR-30E Cassette FM data recorder for a project on
    skiing biomechanics the past two years. It can record up to 7 channels of
    data, although in fact one channel is used for noise reduction, and another
    is a memo (voiced messages) channel.

    It weighs about 400g, and is about 15 x 10 x5 cm in dimension. It uses a
    TEAC cassette tape, standard size, to record an FM signal. It can use a
    standard 9 volt battery, or can be powered with an external supply.

    A larger TEAC "desktop" recorder is used to playback, and A-D the signal.

    I use the recorder in a skier's "bum-bag" (hip bag), but I'm sure you could
    secure it off a belt if the subject were not too vigorous. Cost a few years
    ago was (I'm told) around AUS$8,000; I'm not sure if you can get them
    anymore, or if so what their price would be.

    The alternative that I'm looking at is a PDA (Hewlett Packard HP200LX) with
    a National Instruments PCMCIA A-D card, which would be smaller, have less
    noise, and save the A-D step. The PDA would be around $1,000, the card (I
    believe) around $2,000. You may need to develop some software to interface
    the card and PDA.
    __________________________________________________ ______________
    Try Thought Technologies in West Chazy, NY.
    __________________________________________________ ______________

    Do you actually need to store the EMG? I just designed a nice little gadget
    (an "EMG Horometer") that measures the time that the EMG is on and stores
    it on a clock display. You simply read off the duration of EMG for a given
    number of strides or a given test period (for upper limb use etc.)

    I'd be willing to sell you one for $500.
    __________________________________________________ ______________

    For portable data recorders try:

    Onset Computer Corp.
    P.O. Box 3450
    536 MacArthur Blvd.
    Pocasset, MA, 02559
    Tel: (508) 563-9000
    Fax: (508) 563-9477.

    I haven't dealt with them but understand they make a line of portable data
    logging products. An article in the August 1995 issue of "Sensors" magazine
    described the use of their loggers to measure the temperature in astronaut
    gloves during extravehicular activities on a shuttle mission. They have a
    web site which might include the article at
    __________________________________________________ ______________

    We use the TEAC HR10/HR30 data recorder. The HR10 has 4 tracks (channels).
    The HR30 which we use has 7 channels. Different types have different tape
    speeds and hence different bandwidths for the data. Type E (dc to 1250 Hz,
    45 mins) Type G (dc to 313, 3 hours), Type J (dc to 39 Hz, 24 Hrs).
    Signal to noise is only 38 dB and drift +/- 1%. So you have to make sure you
    use the full dynamic range of the record/playback system. By the way it is
    only a recorder so you need their recorder/player type R71, R81 or MR 10/30.
    __________________________________________________ ______________

    We have a unit which will handle up to 1000 Hz/channel with upgradable storage
    memory and from 2 to eight channels of EMG, It starts at $1995. It comes with
    software for downloading to a PC at a later time. Or you can port it directly t
    a serial printer. You can also create your own protocols on a PC and upload the
    to the portable unit. It is amazingly small, only about 2.5 by 5 by 1 inch. You
    can also use it for biofeedback, since it has a two column digital LCD display
    for alpha-numeric or histogram displays,,, and audio. We'll soon have it
    running on Signalysis, our multimedia windows data acquisition program.

    . Rob Kall
    3171 Rail Ave Trevose PA 19053, 215-364-4445, fax 215-364-4447 (temporary beta site)
    __________________________________________________ ______________

    At the August ASB conference at Stanford University, I saw a Paromed
    datalogger offered by Peak Performance Technologies. The unit has
    eight EMG channels, apparently to 250 samples/sec. Storage is to a
    PCMCIA card. Email address is Phone
    number is 303/799-8686.
    __________________________________________________ ______________

    Try talking to manufacturers of Holter monitors. These devices record
    cardiac rhythms for periods of about 24 hours, on multiple channels.
    __________________________________________________ ______________

    The DATABEAR may meet your needs.
    Here is the information on the manufacturer:

    Langan Products
    2660 California Street
    San Francisco, CA 94115
    (415) 398-7664
    __________________________________________________ ______________

    In collaboration with Dr David Fyhrie at Henry Ford Hospital, Bone and Joint
    Centre, we used a portable data recorder to record 3 channels of strain data
    from in vivo gauges mounted on human tibiae. The recorder was small enough
    to be carried while subjects undertook vigorous activities. I believe the
    device came from one of the Unis close to Detroit. You can send Dave Fyhrie
    a message at,to get details, or call him direct at Henry
    __________________________________________________ ______________

    We are using a portable data recorder from Onset Computer
    Corporation. The one we're using is the Tattletale model 5F. It
    is programmable in BASIC (program in non-volatile RAM), so you
    can program an entire protocol for data collection, including
    downloading to PC. To get high sampling rates, part of the
    program has to be in machine code, but it's not hard to do if
    you're somewhat familiar with microprocessors. I can give you a
    sample program if you want.

    Their address is:
    PO Box 1030, N. Falmouth, MA 02556, (508) 563-9000, fax (508)
    __________________________________________________ ______________

    Check the system at:
    This system is used in NASA utilizing a Note-Book to collect up to 32
    channels of EMG and Load Cells data through wireless transmitters.

    Eric Nelson
    GM, NAO R&D Center, RTP, Bldg. 1-3
    30500 Mound Road, Box 9055, Warren, MI 48090-9055
    (810)986-1829 fax810)986-0294