Patent ID: 6699204
Filing Date: 2004-03-02
Classification: A61B

Abstract:
A device for analyzing mediate-auscultation noises, in particular respiratory noises, comprising:an input for receiving a time-domain signal (S(t)) representative of an acoustic noise, sampled in a multiplicity of intensities (I(m)) each associated with a chosen instant (m), storage means including, a processing module configured to work together with calculating means with a view to evaluating a set of transformed intensities (IT(fk)), each associated with a predetermined audio frequency (fk), while the storage means are further configured to store said transformed intensities in memory, and an output (26) linked, on the one hand, to the storage means in order to deliver each transformed intensity in correspondence with an associated frequency, and, on the other hand, to means for representing the transformed intensities as a function of the frequencies, with a view to obtaining a spectral representation of the auscultation noise, characterized in that the processing module is configured to evaluate a phase for each intensity (&PHgr;[I(m)]), as a function of a difference between the associated chosen instant (m) and a chosen start instant (m0), with a view to attributing, to each intensity, a complex value (Ic(n)) and its conjugate value (Ic*(n)), in that the processing module is further configured to evaluate a set of transformed intensities (IT(m, fk)) for each chosen instant (m), by producing, for each frequency (fk), a sum over a multiplicity of current instants (n) of terms resulting from a product involving, for each current instant (n), a) the complex intensity (Ic(m+n)) associated with the sum of the chosen instant (m) and of the current instant (n), b) the conjugate complex intensity (Ic*(mâˆ’n)), associated with the difference in the chosen instant and in the current instant, and c) a complex exponential of a pure imaginary product of the frequency (fk) and the current instant (n), and in that the storage means are configured to store in memory each transformed intensity (IT) as a function of an associated frequency (fK), on the one hand, and of a chosen instant (m), on the other hand, which makes it possible to obtain a three-dimensional representation in terms of time (m) and of frequencies (fk) of the auscultation noise, while preserving a real-time scale.