Hardware FAQ
Where is the connector information for your pre-amplifiers and event-switches?
There are links to information about the connectors that we use and the pin-outs for the various EMG electrodes and event switches here. Please contact us if you need additional information.
Do you still support your older (MA-100 and MA-200) EMG systems?
Yes - both the MA-100 and MA-200 systems are obsolete and are no longer officially supported but we will continue to provide limited support for these systems and will repair defective systems wherever possible. Please remember that many of the components of these systems are not manufactured any longer so continued support or operation of these EMG systems can not be guaranteed in the future.
Do you have manuals for your older EMG systems?
Complete user manuals for the discontinued MA-100 and MA-200 EMG systems are available in Adobe PDF format can be downloaded and printed at your convenience.
How can I clean sticky tape adhesive from your preamplifier wires?
We use and recommend Goo Gone - this product is available in most US hardware stores - it works well on our preamplifier cables and is safe and effective in the lab. OSHA Material Safety Datasheets are available from the manufacturer.
I've heard that some companies use "internationally patented technology" in their EMG systems and that this "patent-protected signal processing technology is recognized as the standard of excellence worldwide." Why don't you use these techniques?
These companies are often using circuits developed 10 years ago (check the dates on the patents) - we use state of the art electronic components and solid construction techniques to build some of the best quality EMG systems available anywhere. Our EMG signals are widely recognized as some of the cleanest available anywhere. If you are interested, copies of any US or EU patent can be viewed over the Internet.
What signal processing techniques do you use to overcome interference and noise (artifact) in the EMG signal?
None - Motion Lab Systems does no signal processing beyond the minimum low pass filtering that is required in any system to ensure that the data is sampled correctly. We use EMG preamplifiers of our own design placed directly over the muscle (surface EMG) or very close to the insertion site (indwelling EMG). We find that these techniques produce exceptionally clean, wide-band EMG signals that reproduce the signal available at the subject skin surface.
Why do your EMG systems include a Low Pass Filter?
Other EMG systems do not include variable LP filters . . . An EMG system without a variable Low Pass filter must always produce signals at the full bandwidth of the system. The Nyquist data sampling theorem states that you must sample any signal at a rate that is at least twice as fast as the highest frequency component that can be present in the raw signal. Thus, if you use a systems with (for example) a maximum EMG signal response of 1,000Hz then you must always sample the data at a rate that is at least 2,000 samples per second! The Low Pass filter that is built into our EMG systems allows the user to limit the signal bandwidth under investigation to as low as 350Hz or as high as 2,000Hz so that the data sampling rates can be optimized for various situations and data collection capabilities.
This other system is cheaper - how can you say that your systems cost less?
Our system does not use any batteries or disposable gel electrodes - if you run 2 studies a week for a year and your EMG system uses 9V batteries ($2.50 ea) and 16 sets of disposable electrodes ($1 per pair) then you'll need to spend almost $2,000 per year on disposable supplies! We have some EMG systems that have been in almost daily use for 10 years - based on this estimate these customers have saved over $20,000 over this period!