Method and device for establishing blood vessel cross-section function, blood stress vessel pressure difference and blood vessel stress

A system for obtaining a blood vessel pressure difference, comprising:

• an image device configured to obtain image data in at least one cardiac cycle;
• a processor configured to:
• select a plurality of feature times in the one cardiac cycle;
• generate spatial models of a target region blood vessel corresponding to each of the feature times according to the image data;
• establish a first cross-section model of the target region blood vessel at each position along an axial direction of the target region blood vessel according to each of the spatial models;
• establish a corresponding first cross-section function according to each first cross-section model;
• along the time sequence, the plurality of feature times are sequentially t1, t2, . . . , tq;
• along the axial direction of the target region blood vessel, the first cross-section functions corresponding to the first cross-section models at each position 1, 2, . . . ,r from a proximal end to a distal end of the target region blood vessel are d1, d2, . . . , dr;
• and the processor being further configured to:
• establish a first cross-section matrix A according to a correspondence relationship between the first cross-section function and the feature time and position,
• A
• =
• [
• A
• 11
• A
• 12
• …
• A
• 1
• ⁢
• q
• A
• 21
• A
• 22
• …
• A
• 2
• ⁢
• q
• ⋮
• ⋮
• ⋮
• ⋮
• A
• r
• ⁢
• ⁢
• 1
• A
• r
• ⁢
• ⁢
• 2
• …
• A
• rq
• ]
• wherein, Arq is the first cross-section function dr corresponding to the first cross-section model at the feature time tq, at the position r of the target region blood vessel;
• q=r or q≠r, and q and r are positive integers;
• wherein the first cross-section model comprises a second cross-section model at different scales, and the processor being further configured to:
• establish a corresponding second cross-section function according to the second cross-section model at each scale;
• and
• establish a second cross-section matrix at different scales according to a correspondence relationship between the second cross-section function and the feature time and position,
• wherein, the scale is the distance between two adjacent positions;
• wherein the scale includes a first scale, a second scale, . . . , an nth scale, and the processor being further configured to:
• establish, according to the second cross-section matrix at each scale, a second difference function between the second cross-section functions corresponding to two adjacent positions of the target region blood vessel at different scales in a column direction;
• and
• establish, according to the second difference function at the first scale, the second scale, . . . , the nth scale, a second variation function ƒ1x, ƒ2x, . . . , ƒnx of the corresponding target region blood vessel that is changed with a distance x from any position to a reference point,
• wherein, n is a positive integer greater than 1;
• and the processor being further configured to:
• obtain a blood flow model of the target region blood vessel according to the image data;
• obtain a blood flow velocity V of the target region blood vessel according to the blood flow model;
• obtain a first blood vessel pressure difference Δp1 at each feature time according to the blood flow velocity V and the second variation functions ƒ1x, ƒ2x, . . . ,ƒnx;
• and
• weight and sum the first blood vessel pressure difference Δp1 according to a ratio of a time interval between each feature time and the adjacent feature time in one cardiac cycle so as to obtain a second blood vessel difference Δp2.