EMGONOFF

Finds the "on" and "off" indicies of a single raw surface EMG burst (muscle contraction).

This function takes as input the raw EMG data of a single muscle contraction. Output is a 1x2 array, the first number is the EMG onset, the second number is the EMG "offset" index.

There needs to be enough data before the "on" burst to establish an average resting EMG level.

The resting levels (before and after burst) are defined by the user with MATLAB's ginput function.

One option is available by editing the .m file at line 65. By setting "xi" to x(2), the search for onset begins with the end of the ginput-defined resting EMG zone, and thus ignores any muscle bursts within the user-defined resting zone.

Algorythm for EMG onset & offset taken from Hodges, P.W. and B.H. Bui, _A comparison of computer-based methods for the determination of onset of muscle contraction using electromyography._ Electroencephalography & Clinical Neurophysiology, 1996. 101(6): p. 511-9

Created by: Kieran A. Coghlan, BSME, MSES
SUNY at Buffalo, New York
Last modified: 1 May, 2006