visual3d:documentation:emg:filtering:integrate_emg
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visual3d:documentation:emg:filtering:integrate_emg [2024/06/14 17:11] – created sgranger | visual3d:documentation:emg:filtering:integrate_emg [2024/07/17 15:45] (current) – created sgranger | ||
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- | |**Language: | + | ====== |
- | |===== Contents | + | ===== Linear Envelope |
- | ====== Integrate | + | === Computing the EMG Envelope using rectify and lowpass filter |
- | ==== Integrating an EMG envelope between events ==== | + | This section will compute the EMG Envelope using rectify and lowpass filter. Rectify takes the absolute value of every element of a signal. Visual3D calculates signal rectification using the following formula: x(ti)= abs(x(ti)) |
- | The result of integrating a signal | + | === Lowpass Filter Cutoff === |
+ | |||
+ | The default lowpass filter in Visual3D | ||
+ | |||
+ | Butterworth filters have an upper limit on the magnitude of the cutoff frequency. | ||
+ | |||
+ | The maximum theoretical cutoff frequency is (sampling_rate*0.802/2). | ||
+ | |||
+ | VIsual3D is a little more conservative than that because we have found the filter | ||
+ | |||
+ | The highest cutoff frequency that VIsual3D will allow you is 0.393* sampling-rate. | ||
+ | |||
+ | If your EMG signals are sampled at 1000 Hz, the highest cutoff frequency is 393 Hz. | ||
+ | |||
+ | === Example Script === | ||
+ | |||
+ | The highpass filter is not part of the linear envelope, but is used to remove the [[Visual3D: | ||
< | < | ||
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/ | / | ||
! / | ! / | ||
- | ! / | + | / |
! / | ! / | ||
/ | / | ||
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; | ; | ||
- | ! Apply low pass filter with 500 hz cutoff | + | ! Rectify the signals |
- | Lowpass_Filter | + | Rectify |
- | / | + | |
- | / | + | |
- | / | + | |
- | ! / | + | |
- | ! / | + | |
- | ! / | + | |
- | / | + | |
- | / | + | |
- | / | + | |
- | / | + | |
- | ; | + | |
- | + | ||
- | ! RMS moving average with a 100ms window | + | |
- | Moving_RMS | + | |
- | / | + | |
- | / | + | |
- | / | + | |
- | ! / | + | |
- | / | + | |
- | / | + | |
- | ; | + | |
- | + | ||
- | ! Integrates an EMG signal between events from Start to End | + | |
- | Metric_Integrate | + | |
- | / | + | |
- | / | + | |
- | ! / | + | |
/ | / | ||
/ | / | ||
- | / | + | / |
- | ! /SIGNAL_COMPONENTS=ALL_COMPONENTS | + | ! /RESULT_NAMES= |
- | /EVENT_SEQUENCE=START+END | + | ! /RESULT_TYPES= |
- | /EXCLUDE_EVENTS= | + | /RESULT_FOLDER=RECTIFY |
- | /GENERATE_MEAN_AND_STDDEV=FALSE | + | ! /RESULT_SUFFIX= |
- | / | + | |
; | ; | ||
- | </ | ||
+ | ! Apply a low pass filter | ||
+ | Lowpass_Filter | ||
+ | / | ||
+ | / | ||
+ | / | ||
+ | ! / | ||
+ | / | ||
+ | / | ||
+ | / | ||
+ | ; | ||
+ | </ | ||
- | Retrieved from "" | ||
visual3d/documentation/emg/filtering/integrate_emg.1718385094.txt.gz · Last modified: 2024/06/14 17:11 by sgranger