A band pass filter allows the energy concentrated between two given frequencies (X and Y) to pass while it attenuates the signal's energy at other frequencies. It is equivalent to applying a high-pass filter at X and a low pass filter at Y.
A band stop filter attenuates the energy in the frequencies between two given frequencies (X and Y). It is equivalent to applying a low pass
filter at X and a high pass filter at Y.
Note that filters do not remove all of the energy outside of their pass band (the pass band is the frequencies between X and Y for a band pass filter, and below X and above Y for a band stop filter). Generally, the further away from the cut off frequencies (X and Y), the greater the attenuation of the energy. How fast the attenuation increases as a function of frequency is established by parameters (primarily “Q”) of the filter. Real filters will also attenuate within the pass band, and there are some tradeoffs in the selection of parameters.
SMI Eye Tracking Glasses 2W with HD Scene Camera Now researchers can easily record, synchronize, and analyze biometric data and mobile eye tracking data during interactive tasks using SMI Eye Tracking Glasses 2 Wireless (ETG 2w) by SensoMotoric Instruments (SMI) BIOPAC wireless, wearable BioNomadix Logger, and BIOPAC AcqKnowledge software. The ETG 2w eye tracking glasses […]
BIOPAC provides software and hardware that allow for research teams to record and analyze respiration activity in physiological experimentation. Here are a few notable studies in monitoring respiration and cardiovascular activity. The coupling between peripheral microcirculation and slow breathing: The purpose of this study was to investigate the coupling of breathing movements and microcirculatory blood […]
CBS News | 60 Minutes | Brain Hacking APRIL 9, 2017| Why can’t we stop looking at our smartphones? And are the designers of the apps and content on them using brain science to keep us hooked? Anderson Cooper reports. BIOPAC users Larry D. Rosen, Ph.D. and Nancy A. Cheever, Ph.D. from California State […]