Patent ID: 8152733

Claim:
A method for improving the recognition of a respiratory wave, which is used for a data processing module of a respiratory rate measuring or monitoring device, said method comprising the steps of: A. receiving, via a data processing module, analog-to-digital converted respiratory wave data from a measuring circuit; B. sequentially searching, via the data processing module, the respiratory wave data for data corresponding to crests and troughs, each crest and trough comprising rising stairs and falling stairs; and C. identifying the crests and troughs of the respiratory wave data, wherein identifying the crests and troughs comprises determining that an amplitude or frequency variation of the waveform extends beyond a predetermined range and, based on the determination, filtering components of the waveform associated with a heartbeat through heartbeat filtering processing using a finite impulse response filter defined by y ⁡ ( n ) = 1 L ⁢ ∑ k = 0 L - 1 ⁢ ( n - k ) , where x(n) is the measured respiratory wave data, y(n) is the result obtained after the heartbeat filtering of said data, and L is approximately the number of sampling points of the respiration in a heartbeat cycle.