biosignalEMG (version 2.0.0)

integration: Integration of an EMG

Description

Computes the integrated EMG, with or without reset points.

Usage

integration(data, channel, reset = FALSE, reset.criteria = c("samples", "time", "value"), vreset, units, data.name)

Arguments

data

an ‘emg’ object, usually rectified, a moving averaged rectified EMG or a computed envelope of an EMG.

channel

in case of multi-channel data, channel is the specific channel to be considered by the procedure. Possible values: a character vector specifying the name of the channel to be considered (case sensitive) or a numeric value specifying the channel to be considered (number of column in data).

reset, reset.criteria

if reset=TRUE, The integrated signal is reset to zero at a regular number of samples (reset.criteria="samples"), at regular intervals of time (reset.criteria="time") or when a voltage level is reached (reset.criteria="value").

vreset

a value to determine the reset points in an EMG, see Details.

units

a character vector specifying the units (usually "mV.s") of the integrated EMG data.

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 data.

Value

An ‘iemg’ object storing the integrated EMG.

Details

If reset=FALSE, the integrated EMG is the cumulative sum of the values in data. If reset=TRUE, the cumulative sum is reset to zero at some points, which are determined based on the value of reset.criteria and vreset:

• reset.criteria = samples : reset points are located every vreset samples.
• reset.criteria = time : reset points are located every vreset seconds.
• reset.criteria = value : reset points appear every time a value vreset is reached in the cumulative sum.

References

Winter D.A., Rau G., Kadefors R., Broman H., Deluca C.J. (1980) Units, Terms, and Sandards in the Reporting of EMG Research: A Report by the AdHoc Committee of the International Society of Electrophysiology and Kinesiology.

See Also

iemg

Examples

# change graphical parameters to show multiple plots
op <- par(mfrow = c(2, 2))

# 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")
plot(emgx, main = "Synthetic EMG")

# Full-wave rectified EMG
emgr <- rectification(emgx, rtype = "fullwave")

# Integration of the full-wave rectified EMG without reset points
emgi1 <- integration(emgr, reset = FALSE)
plot(emgi1, main = "Integrated EMG (no reset)")

# Integration of the full-wave rectified EMG with reset points every
# 200 samples
emgi2 <- integration(emgr, reset = TRUE, reset.criteria = "samples", vreset = 200)
plot(emgi2, main = "Integrated EMG (with reset)")

# Integration of the full-wave rectified EMG with a reset point each
# time the value 200 is reached
emgi3 <- integration(emgr, reset = TRUE, reset.criteria = "value", vreset = 200)
plot(emgi3, main = "Integrated EMG (with reset)")

# reset graphical parameters
par(op)