Method for analyzing an event such as a surgical intervention on a blood vessel

1/ Apparatus for analyzing an event, in particular surgery on a duct (2) such as a duct forming part of a human or animal body, e.g. a blood vessel, the apparatus being characterized in that it comprises:

• gathering means for gathering at least one series of measurements of a physical phenomenon associated with the event or likely to be associated therewith, for example measurements of flow rate for a fluid flowing in the duct;
• and
• determining means for using a predetermined mother wavelet Ψ to determine for at least one value of a predetermined parameter a:
• the partition function Z(q,a) such that:
• 14 Z ⁡ ( q , a ) = ∑ b i ⁢ ⁢ [LeftBracketingBar] T Ψ ⁡ [ s ] ⁢ ( b i , a ) [RightBracketingBar] q
• where:
• s is a signal representing variation in the measurements of the series as a function of a variable such as time;
• TΨ[s](b,a)=1/a∫{overscore (Ψ)}((x−b)/a)s(x)dx
• where {overscore (Ψ)} is the complex conjugate of the function Ψ(x) in an orthonormal base;
• and
• {(bi,a)}i is the set of local maxima in T as a function of a;
• the spectrum of the function τ(q) such that:
• Z(q,a)≈aτ(q) in the limit a→0+;
• the spectrum of the function D(h) such that:
• 15 D ⁡ ( h ) = min q ⁢ ( qh - τ ⁡ ( q ) )
• and
• an index I(a) depending on said spectrum, which index is calculated by means of a predetermined formula.