FAQ - Frequently Asked Questions
This is the first place to look when you have a questions about a Motion Lab Systems product. The answers here are catagorized into three seperate sections covering:
- Questions about any physical item (hardware questions).
- Questions about software applications (software questions).
- Questions about EMG usage.
Hardware FAQ
What are the connector details for the preamplifiers and event-switches?
Information about the connectors that we use, part numbers and the pin-outs for the various EMG electrodes and event switches are available here.
We use a number of different connectors in our systems and publish full details of the signals on each pin to make it easy for anyone owning a Motion Mab Systems EMG system to repair connectors or connet other equipment to our systems. Please contact us if you need additional information - we are always happy to help customers who have any doubts about repairing sensors or connecting additional equipment.
Do you still support your older (MA100 and MA200) EMG systems?
Yes - both the MA100 and MA200 systems are obsolete but we will continue to provide support for these systems wherever possible. While the original "IOMED" preamplifiers supplied with these systems are no longer available, we continue to offer a range of compatible preamplifiers.
Both the MA100 and MA200 systems are officialy "unsupported" but we till maintain some spare parts and circuit boards for these systemss. Please remember that many of the components of the older systems are no longer manufactured so continued support or operation of these EMG systems can not be guaranteed in the future.
Are user manuals and schematics available for obsolete systems?
Yes - complete user manuals for the discontinued MA100 and MA200 EMG systems are available in Adobe PDF format.
The user manuals can be downloaded and printed at your convenience from our FTP site via a link on our support documentation page here.
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.
Simply pour a little "Goo Gone" onto a clean rag and wipe the preamplifiers casing and the surface of the wires to remove tape and other dirt from the preamplifiers and cables. OSHA Material Safety Datasheets are available from the manufacturer.
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 low pass filtering 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). By paying particular attention to the design and other parameters of the preamplifiers we find that these techniques produce exceptionally clean, wide-band EMG signals that reproduce the signal available at the subject skin surface.
Why do MA300 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.