Carl Zeiss Meditec Ag

Ady Naber

Christoph Hauger

Roland Guckler

Werner Nahm

Daniel Berwanger

The invention relates to a computer-implemented method () for determining the blood volume flow (I) through a portion (, i=1, 2, 3, . . . ) of a blood vessel () in an operating region () using a fluorophore. A plurality of images (, . . . ) are provided, which are based on fluorescent light in the form of light having wavelengths lying within a fluorescence spectrum of the fluorophore, and which show the portion () of the blood vessel () at different recording times (t, t, t, t, . . . ). By processing at least one of the provided images (, . . . ), a diameter (D) and a length (L) of the portion () of the blood vessel () and also a time interval for a propagation of the fluorophore through the portion () of the blood vessel () are determined, which time interval describes a characteristic transit time (&#x3c4;) for the fluorophore in the portion () of the blood vessel (), in which a blood vessel model (M) for the portion () of the blood vessel () is specified, which blood vessel model describes the portion () of the blood vessel () as a flow channel () having a length (L), having a wall () with a wall thickness (d), and having a free cross section Q. A fluid flow model Mfor the blood vessel model (M) is assumed, which fluid flow model describes a local flow velocity () at different positions over the free cross section Q of the flow channel () in the blood vessel model (M), and a fluorescent light model Mis assumed, which describes a spatial probability density for the intensity of the remitted light at different positions over the free cross section Q of the flow channel () in the blood vessel model (M), which light is emitted by a fluid, which is mixed with fluorophore and flows through the free cross section Q of the flow channel () in the blood vessel model (M), when said fluid is irradiated with fluorescence excitation light. The blood volume flow (I) is determined as a fluid flow guided through the flow channel () in the blood vessel model (M), which fluid flow is calculated from the length (L) and the diameter (D) of the portion () of the blood vessel () and from the characteristic transit time (&#x3c4;) for the fluorophore in the portion () of the blood vessel (), using the fluid flow model Mand the fluorescent light model M.

Computer-implemented method, computer program and surgical system for determining the volumetric flow rate of blood through a portion of a blood vessel in a surgical field

A computer-implemented method determines a geometric feature of a section of a blood vessel in an operating region. An image of the section is provided. An adapted blood vessel model is provided via image processing for the section by adapting a blood vessel model, which describes the section as a flow channel with a wall delimiting the latter and with an axis of symmetry. A centerline of the section of the blood vessel is determined as a contiguous pixel line. A relative spatial position of the side of the wall is ascertained based on the centerline and the image provided. The geometric feature is derived from the adapted blood vessel model. The disclosure also relates to a method for determining the length of a contiguous pixel line in an image and a system for determining a geometric feature of a section of an object.

Computer-implemented method, computer program and diagnostic system, in particular for determining at least one geometric feature of a section of a blood vessel

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Karlsruhe, Germany

Ady Naber