System Components
System Components and Specifications
- A dEMG sensor consisting of 5 pins located on the corners and the center of a 5 mm square. It provides 4 channels of differential sEMG signals.
- A Bagnoli 16-channel amplifier and A/D card that:
- Accepts up to 2 dEMG sensors, and up to 8 biosignal sensors.
- Uses a sEMG bandwidth of 20-450 Hz.
- Supports 16 bit resolution and 20 kHz sampling rate per channel.
- The EMGworks® Acquisition and Analysis software that has:
- Adaptive filtering to maximize Signal to Noise ratio (SNR).
- Signal quality check that automatically evaluates baseline noise, signal to noise ratio and line interference to ensure high quality data is acquired.
- Descriptive assistance for improving electrode skin contact, when necessary.
- dEMGTM decomposition algorithm.
- Data processing and presentation.
Refer to the dEMGTM User's Guide for component arrangement for collecting data.
Exploring the Decomposition Output
- Firing Instances
- Inter-Pulse Intervals
- Mean Firing Rates
- MUAP Shapes
How do I obtain motor unit data?
- Design the force profile
- Select RMS or force feedback
- Locate and apply the dEMGTM sensor
- Verify signal quality
- Collect and decompose the data
More in detail
- How does the dEMGTM algorithm work?
- Does the dEMGTM algorithm imbue behavioral patterns in the output data?
- Can I test decomposition accuracy with mathematically synthesized data?
- Are there other accuracy verification tests?
dEMGTM Publications
dEMGTM User's Guide
Technical Publications
The following peer-reviewed articles describe the techniques incorporated in the dEMGTM system.
De Luca CJ and Nawab SH. Reply to Farina and Enoka: The Reconstruct-and-Test Approach Is the Most Appropriate Validation for Surface EMG Signal Decomposition to Date. Journal of Neurophysiology, 105: 983-984, 2011.Application-Specific Publications
The following peer-reviewed articles report scientific findings utilizing the dEMGTM system.
Overview
We define dEMGTM as the process by which the surface EMG (sEMG) signal is decomposed into its constituent motor unit action potential trains (MUAPTs). It works only on signals obtained during isometric contractions ranging from minimal to maximal force. It is limited to superficial muscles, but it is successful even when they are covered with up to 1.5 cm of adipose tissue.
The technology contains guided assistance for collecting signals that can be automatically decomposed by complex Artificial Intelligence algorithms containing over 250,000 lines of code. This Tutorial provides guidance on setting up experiments and interpreting results. The technology provides the firing instances, firing rates, and MUAP shapes of 25 to 40 motor units from individual isometric contractions.
The dEMGTM system is a highly accurate technology that provides reliable information beyond that of any other system that has ever attempted to identify the firing instances and MUAP shapes of multiple concurrently active motor units. But, bear in mind that any sophisticated algorithm working on complex signals is subject to some error. The decomposition is subject to minor amounts of errors, on the order of 5%. See further explanation in How is the Accuracy of the decomposed sEMG signals verified and the following two sections.
The methodology, the technology and the algorithm have been extensively published in high-level peer-reviewed journals.