Band-Pass Filter option for EMG

The Motion Lab Systems Band Pass Filter option installs inside the Desk Top Unit of any six, ten or sixteen channel MA-300 EMG system and provides easy to use High Pass and Low Pass filtering over the frequency ranges used in most Clinical and Biomechanical Electromyography applications.

The Band Pass Filter is implemented, using modern surface mount technology, as two independent digital filters. It provides an affordable, high quality, motion artifact filter (high pass) and data collection anti-alias filter (low pass) in one package. Its installation inside the MA-300 case, as an integral part of the system, guarantees compatibility and eliminates the ground loops and interfacing problems common with external electronic filters required by many other systems.

The artifact filter can be easily set to remove all signals below any one of six filter points from 25 to 120 Hz via a rotary switch on the rear of the MA-300. The 8th order anti-alias filter covers the range of 300 to 2,200 Hz in twelve steps and can be preset to eliminate signals that might cause alias artifact in some A/D recording systems. Alias artifact occurs when the EMG signal changes faster than the data collection system can measure. It can be prevented by a high quality low pass filter with a sharp roll-off such as the -52 db attenuation at 1.4 times filter set point provided by the Motion Lab Systems Band Pass Filter option.

MA-300-F FEATURES

  • Requires no additional desk space - mounts inside any MA-300 system.
  • Easy to use - the High Pass Filter is easily adjustable across all EMG channels.
  • Built-in, high performance Low Pass Filter can be preset to prevent signal alias artifact.
  • Internal installation eliminates interface problems such as ground loops.

SPECIFICATIONS

  • Digital RC High Pass Filter. User adjustable by external rotary switch to any of the following frequencies - 25, 40, 60, 80, 100, and 120 Hz (-3dB).
  • 8th Order Progressive Elliptic Low Pass Filter. - 135dB per octave roll off
  • Low Pass Filter is preset via an internal DIP switch to any one of the following frequencies - 300, 400, 500, 600, 800, 1000, 1200, 1400, 1500, 1800, 2000, and 2200 Hz (- 3dB). Default setting is 2000Hz S response is -52 dB at 2800 Hz
  • Powered internally from the MA-300 system. - no external power supply is required.