System and method for determining a pulse rate by predictive filtering and intercorrelation of sounds sensed in a trachea of an individual

A method comprising:

• determining a pulse rate through the use of a sound detector placed on an individual's trachea, the determining comprising a preliminary act of recording sound signals for a lengthy duration wherein and subsequently the following acts:
• filtering digital signals representative of the sound signals by using an adaptive filter,
• applying a lowpass filter to the signals obtained in order to select signals comprised in a specified passband,
• selecting a first temporal portion of filtered digital signals of a specified duration,
• intercorrelation with a temporal portion of filtered digital signals that follows the first temporal portion in time and is of a same duration,
• searching for, for each portion, the temporal position of the intercorrelation maximum,
• computing the time interval corresponding to this temporal position and computing the corresponding pulse rate,
• repeating the acts of selection, intercorrelation, searching for the maximum and computing the pulse rate throughout the duration of the recording, to obtain a temporal series of pulse rates.