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US 2014/0371583 A1Published application
Quantification of absolute blood flow in tissue using fluorescence mediated photoplethysmography
AssigneeNovadaq Technologies ULC
InventorRobert W. FLOWER
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Abstract
There is provided a method and a system for quantification of absolute blood flow in tissue using near-infrared fluorescence angiography in conjunction with photoplethysmography (fluorescence-mediated photoplethysmography). The method and system of the present invention provide absolute, real-time measurements of flow in terms of volume/time/area based upon measurement of fluorescence intensity.
Claims14
A method for determining aggregate flow of blood through vasculature in a tissue area of interest, comprising:
- measuring a cross-sectional area of a tissue volume end;
- measuring a thickness increase of a blood volume layer;
- determining a pulse duty cycle;
- determining a duration of a single blood pressure pulse;
- and
- deriving the aggregate blood flow, F, according to the inequality
- F=(A)(ΔL)(PDC)/Δt,
- wherein
- ΔV=(cross-sectional area of the tissue volume end, A)×(thickness increase, ΔL, of the blood volume layer, L), PDC is the pulse duty cycle and Δt=duration of a single pressure pulse.
6 more elements
A method for quantifying absolute blood flow through a tissue volume, comprising:
- administering an appropriate volume of a fluorescence dye into the vasculature supplying the tissue volume;
- obtaining a sequence of angiographic images of the tissue volume;
- calculating average fluorescence intensities for the sequence of angiographic images of the tissue volume;
- and
- generating a plot of time-varying average fluorescence intensity.
2 more elements
Dependencies are inferred from the claim text.