The Myoscan-Pro v2 (SA9401M-60) surface EMG sensor consists of 3 snap style receptacles - 2 active (positive & negative) and 1 reference (ground).
This EMG sensor kit (T9401M-60) is for use with Thought Technology ProComp Plus, ProComp Infiniti, ProComp 2, Procomp5, or Flexcomp series biofeedback and neurofeedback systems. Includes cable that connects the Sensor Head to the ProComp Infiniti encoder and snap lead cable. Operates in 60Hz environment.
The sEMG has a positive, a negative and a ground sensor. The signal is measured between the positive and negative. The ground acts as a reference point, and is used in filtering out electrical "noise" that is picked up from all three sensors.
Because some biofeedback sensors are applied directly to the skin or scalp, some consideration must be given to using proper hygienic controls. Whenever possible, we recommend the use of disposable sensors.
sEMG (Surface Electromyography) measures muscle activity by detecting and amplifying the tiny electrical impulses that are generated by muscle fibers when they contract. Since all the muscle fibers within the viewing and recording area of the sensor contract at different rates, the signal detected by the sensor is a constantly varying difference of potential between its positive and negative sensors. The number of muscle fibers that are recruited during any given contraction depends on the force required to perform the movement. Because of this, the intensity (amplitude) of the resulting electrical signal in proportional to the strength of contraction.
When placing the sEMG sensor on the muscle site, the best reading are obtained when the sensor is placed on the muscle belly and its positive and negative sensors are parallel to the muscle fibers. When using the extender cable, though, the direction of the fibers becomes irrelevant since the electrodes are frequently placed on different muscle groups. The positive and negative sensors should still be placed on the muscle bellies. The reference electrode is best placed on a relatively neutral site, like a bony prominence, preferably at an equal distance from the other two sensors.
1 Year manufacturer warranty.