Patent ID: 7033323

Claim:
A method for determining airflow in a portion of a respiratory tract comprising: determining an average acoustic energy in a region of a body surface overlying the portion of the respiratory tract, wherein the average acoustic energy is determined in a process comprising: (a) obtaining signals P(xi,t) from N transducers placed at predetermined locations x i for i from 1 to N in the region of the body surface; (b) determining an average acoustic energy (x,ti,ti+1) over one or more time intervals ti to t i+1 , at a plurality of locations x in the region in a calculation involving at least one of the signals P(x i ,t); and (c) integrating the functions (x,ti,ti+1) with respect to x, ∑ x ⁢ P ~ ⁡ ( x , t i , t i + 1 ) in order to obtain an airflow in the region during each of the time intervals.