envelope {biosignalEMG} | R Documentation |

## RMS or MA Envelope of an EMG

### Description

Computes the RMS-envelope, the MA-envelope ot the LE-envelope of an EMG signal.

### Usage

```
envelope(data, channel, method = c("MA","RMS","LE"), wsize, cutoff, n = 2, data.name, ...)
```

### Arguments

`data` |
an ‘emg’ object. |

`channel` |
in case of multi-channel data, |

`method` |
a string, "MA" (default) for MA-envelope, "RMS" for the RMS-envelope and "LE" for the LE-envelope. |

`wsize` |
determines the length of the moving window that is used to calculate the local averages of the data in RMS and MA envelopes. |

`cutoff` |
cutoff frequency in Hertz for the lowpass filter used in LE-envelope. |

`n` |
filter order for the lowpass filter used in LE-envelope. |

`data.name` |
a string specifying the name of the variable which will appears on the plots. If empty or not provided is taken from the object given as |

`...` |
Optional parameters for a MA-envelope: |

### Details

The MA-envelope corresponds to the moving average of the rectified EMG.

The RMS-envelope corresponds to the moving average of

`y_i=(x_i-\mu_{x})^2`

where `x_i`

is each value of the EMG signal and `\mu_{x}`

is the overall mean of the EMG signal.

LE-envelope or linear envelope is lowpass filtered rectified signal.

### Value

An ‘emg’ object containing the envelope of the EMG.

### Author(s)

J.A. Guerrero jaguerrero@correo.uaa.mx

### References

Konrad P. (2005) The ABC of EMG: A Practical Introduction to Kinesiological Electromyography. Version 1.0, Noraxon INC. USA.

### See Also

### Examples

```
# Simulate 5 seconds of an EMG
emgx <- syntheticemg(n.length.out = 5000, on.sd = 1, on.duration.mean = 350,
on.duration.sd = 10, off.sd = 0.05, off.duration.mean = 300, off.duration.sd = 20,
on.mode.pos = 0.75, shape.factor = 0.5, samplingrate = 1000, units = "mV",
data.name = "Synthetic EMG")
# MA-envelope
emgma <- envelope(emgx, method = "MA", wsize = 60)
# Superimpose the envelope on the EMG
plot(emgx, main = "MA-envelope")
plot(emgma, add = TRUE, lwd = 4, col = "red")
# RMS-envelope
emgrms <- envelope(emgx, method = "RMS", wsize = 60)
# Superimpose the envelope on the EMG
plot(emgx, main = "RMS-envelope")
plot(emgrms, add = TRUE, lwd = 4, col = "red")
# RMS-envelope
emgle <- envelope(emgx, method = "LE", cutoff = 10) #10Hz
# Superimpose the envelope on the EMG
plot(emgx, main = "LE-envelope")
plot(emgle, add = TRUE, lwd = 4, col = "red")
```

*biosignalEMG*version 2.1.0 Index]