Patent ID: 7011631

Claim:
A method of noninvasively measuring fluid density of a pulsed flow system with non-rigid vessel walls, comprising: a) noninvasively measuring a local relative fluid volume ratio V b /ΔV b where V b is a basal volume of fluid in a vessel and ΔV b is a volume change of the fluid in the vessel due to the pulse; b) noninvasively measuring a fluid pulse propagation velocity v; c) noninvasively measuring a basal fluid pressure P and a local change in fluid pressure ΔP; d) calculating fluid density ρ b as a function of the local relative fluid volume ratio, the fluid pulse propagation velocity, the basal fluid pressure, and local change in fluid pressure according to the generalized functional relationship F ⁡ ( ρ b ⁢ v 2 Δ ⁢ ⁢ P ) = G ⁡ ( V b Δ ⁢ ⁢ V b , P Δ ⁢ ⁢ P ) or its derivatives.