CN101814195A - Three-dimensional modeling method - Google Patents

Abstract

The invention discloses a three-dimensional modeling method. The method comprises the following steps: generating a topological surface morphology of medicinal three-dimensional marking data through a convex hull algorithm; initially generating a deformable sealed cambered surface which envelops all the acquired three-dimensional marking data points; iteratively approaching the deformable sealed cambered surface to the topological surface morphology by using a level set reconstruction method; and partially adjusting the deformable sealed cambered surface near each medicinal three-dimensional marking data, so that part of the deformable sealed cambered surface can be superposed with each three-dimensional marking data, thereby establishing a sealed smooth superpose model of which the accuracy approaches to the topological surface morphology of the medicinal three-dimensional marking data. By acquiring the medicinal three-dimensional marking data with medicinal ducts in the cardiac chamber, the medicinal three-dimensional mark data is performed three-dimensional surface reconstruction ao as to establish a three-dimensional surface model of which the accuracy approaches to the surface morphology of the endomembrane in the cardiac chamber; and the three-dimensional surface model can be used for supervising and assisting doctors to do researches of cardiac electrophysiology or arrhythmia.

Description

Three-dimensional modeling method

Technical field

The present invention relates to a kind of three-dimensional modeling method, particularly relate to a kind of three-dimensional modeling method of the discretize medical 3 D mapping data based on least energy constraint.

Background technology

In medical domain, particularly research aspect cardiac electrophysiology and treatment aspect, need to analyze, study and with reference to the three-dimensional surface form of chambers of the heart inner membrance, and the intracardiac electrophysiology information that is attached to this configuration of surface, in order to analyze the abnormal conditions and all kinds of arrhythmia cordis of intracardiac electrophysiology.The 3 d surface model of chambers of the heart inner membrance can intuitively be described the three-dimensional surface form of chambers of the heart inner membrance compactly and be attached to the modal intracardiac electrophysiology information of this three-dimensional surface.

All kinds of medical 3 D modeling methods has a lot, and mainly be divided into two big classes: one is based on the three-dimensional modeling method of CT/MRI sequence image; Two are based on the Medical Devices three-dimensional modeling method of the discretize data of collection in real time.

Described a kind ofly based on the 3 d medical images resurfacing algorithm of cutting apart in " based on the 3 d medical images resurfacing algorithm of cutting apart " that people such as what sunshine light delivered in " software journal " the 13rd the 2nd phase of volume, the disclosure of this paper is incorporated herein for your guidance.Image segmentation is combined with MC (Marching Cubes) algorithm, adopt the dividing method that is fit to, image is cut apart.Utilize the contour surface of segmentation result, use the MC algorithm and carry out three-dimensionalreconstruction.This method is applicable to the three-dimensionalreconstruction of CT/MRI image density data, does not fit into the three-dimensionalreconstruction of the discretize data with sparse characteristic.

People such as Tan Jianrong have described a kind of based on curved surface office flat characteristic in " based on the scattered data being topology rebuilding algorithm of curved surface office flat characteristic " that " software journal " the 13rd volume o. 11th is delivered, with scattered point set and density index thereof as input, with the topology rebuilding algorithm of triangle burst linear surface as output, the disclosure of this paper is incorporated herein for your guidance.This algorithm utilizes curved surface office flat characteristic, finishes each sampling point local topology reconstruction on every side from the field structure of the three-dimensional Delaunay triangulation of scattered point set, from the triangular plate and the concentrated result who obtains three-dimensional reconstruction of partial reconstruction.This algorithm goes out easily than large curved surface cavity, problem such as curved-surface shape is rough and topological structure is unusual when scattered point set is more sparse.

Described a kind of methods of three-dimensional graphical modelling in people's such as MP Si Tefannuo the Chinese patent 200780030522, the disclosure of this patent is incorporated herein for your guidance.This method comprises at least: at least two elements, determine the step of one or more parameters of the element relevant with interface; In the step of software resource level by means of the three-dimensional graphical modelling of determined parameter display interface.

Described a kind of three-dimensional modeling method that is used to generate vascular pattern in people's such as the ancient Ademilson of MA the Chinese patent 200710101291, the disclosure of this patent is incorporated herein for your guidance.This method is provided with a series of seed points along the center line of blood vessel, is that concentrically ringed series of loops generates the blood vessel curved surface based on seed points.This method only is confined to the field of blood vessel modeling, can not wide in rangely be applicable to the modeling field of complicated chambers of the heart inner membrance.

Described a kind of method that is used for three-dimensional modeling in the chambers of the heart in people's such as Reisfeld the United States Patent (USP) 6,226,542, the disclosure of this patent is incorporated herein for your guidance.This method generates the initialization net point near three-dimensional localization point; For each net point, all determine a unique vector according to the displacement of some anchor points and some net points; According to vectorial mobile network lattice point realize reconstructed surface near or be similar to the three-dimensional surface form of object.

Summary of the invention

In order to overcome the above-mentioned shortcoming of prior art, the invention provides a kind of three-dimensional modeling method, use medical conduit and in the chambers of the heart, gather medical 3 D mapping data, medical 3 D mapping data are carried out three-dimensional surface reconstruct.

Technical scheme of the present invention is: a kind of three-dimensional modeling method comprises the steps:

The first step according to discretize medical 3 D mapping data, by the convex hull computing, generates the topological configuration of surface of medical 3 D mapping data;

In second step, according to discretize medical 3 D mapping data, but generate three-dimensional deformation occluding surface, but be somebody's turn to do the three-dimensional mapping data point that the deformation curved surface surrounds all collections;

The 3rd step, but according to the energy response of deformation occluding surface and the topological configuration of surface of medical 3 D mapping data, under least energy constraint condition, adopt the level set reconstructing method, but with deformation occluding surface iterative approach topology configuration of surface;

The 4th step, but near the deformation curved surface each medical 3 D mapping data is carried out part adjustment, but deformation curved surface in part is overlapped with each three-dimensional mapping data, make up the sealing smooth surface model of accurately approaching medical 3 D mapping data topology configuration of surface.

Described level set reconstructing method is the arrowband method.

Compared with prior art, good effect of the present invention is: use medical conduit and gather medical 3 D mapping data in the chambers of the heart, medical 3 D mapping data are carried out three-dimensional surface reconstruct, the 3 d surface model that accurately approaches chambers of the heart intimal surface form be can generate, cardiac electrophysiology or ARR medical research carried out in order to guidance and auxiliary doctor.

Embodiment

Disclosed all features in this instructions, or the step in disclosed all methods or the process except mutually exclusive feature and/or step, all can make up by any way.

Disclosed arbitrary feature in this instructions (comprising any accessory claim, summary and accompanying drawing) is unless special narration all can be replaced by other equivalences or the alternative features with similar purpose.That is, unless special narration, each feature is an example in a series of equivalences or the similar characteristics.

A kind of three-dimensional modeling method comprises the steps:

The first step according to discretize medical 3 D mapping data, by the convex hull computing, generates the topological configuration of surface of medical 3 D mapping data:

Generate the three-dimensional topology configuration of surface by the positive tangent algorithm, comprise the steps:

Known: original convex hull C is by vertex sequence V ₁, V ₂..., V _mForm.P is pending real-time point.

Algorithm steps:

Steps A, on C optional 3 V _I0, V _J0, V _K0

Whether step B, judgement P are the interior point of C, if ∠ is V _I0PV _J0, ∠ V _J0PV _K0And ∠ V _K0PV _I0Polarity is all identical, and then P is the interior point of C, and algorithm stops; Otherwise must be two positive one negative or two negative one just;

Step C, get two different angles of a pair of polarity, if ∠ V _I0PV _J0With ∠ V _J0PV _K0The polarity difference:

(a), if V _I0, V _K0Be V _J0Adjacent vertex, V then _J0Be a point of contact, enter step D and look for another point of contact;

(b), if V _I0Not V _J0Adjacent vertex, find out V _I0V _J0Intermediate point V ',

If V _K0Not V _J0Adjacent vertex, find out V _J0V _K0Intermediate point V ";

(c), press V _I0V ' V _J0V " V _K0Order ∠ V relatively successively _I0PV ' and ∠ V ' PV _J0, ∠ V ' PV _J0With ∠ V _J0PV " and ∠ V _J0PV " and ∠ V " PV _K0These three pairs of polarity.

Different three the adjacent two jiaos points of a pair of polarity that at first finds as new V _I0, V _J0, V _K0, repeating step C.If three pairs of polarity are all identical, then P is the interior point of C, and algorithm stops.

Step D, get another two angles different, in this interval, ask another point of contact polarity.Remove and press V _I0V ' V _J0V " V _K0Outside reversed sequence compared, treatment step and step C were just the same;

Step e, make V _tThe point of contact that the representative numbering is less, V ' _tThe point of contact that the representative numbering is bigger;

Step F, as ∠ V _T+1V _tV _T-1With ∠ V _T-1V _tWhen the polarity of P was identical, new convex hull was by P, V _t, V _T+1..., V ' _tForm, otherwise, by P, V ' _t, V ' _T+1..., V _m, V _tForm.

In second step, according to discretize medical 3 D mapping data, but generate three-dimensional deformation occluding surface, but be somebody's turn to do the three-dimensional mapping data point that the deformation curved surface surrounds all collections:

But generate three-dimensional deformation occluding surface, comprise the steps:

The data center of gravity can be selected to be calculated as in steps A, calculating three-dimensional mapping data center position, perhaps is the data geometric center;

Step B, calculating mapping data object radius according to solstics in center and the data, calculate ultimate range as the object radius;

Step C, according to minimum data amount sphere grid generating algorithm, but generate the deformation occluding surface:

At first, initially generate the square-shaped planar of six finite net lattice points; Secondly, six square net point planes are spliced into a cube; At last, according to the spherical radius size that needs, be the centre of sphere with the cube center, moving to each net point apart from centre of sphere distance on this point and centre of sphere direction is the radius size place.Thereby construct the centre of sphere, radius is the even sphere grid model of appointment.

The 3rd step, but according to the energy response of deformation occluding surface and the topological configuration of surface of medical 3 D mapping data, under least energy constraint condition, adopt the level set reconstructing method, but with deformation occluding surface iterative approach topology configuration of surface.

The main thought of level set reconstructing method is curve, curved surface and image to be developed be expressed as the more lineoid level set of higher-dimension, and its evolution speed is exactly the function of the local curvature of this curve and surface, and the level set reconstructing method comprises that step is as follows:

But steps A, setting deformation curved surface are Г, but the in-depth velocity function of deformation curved surface is F, but the higher-dimension smooth function φ of deformation curved surface:

Г(t)＝{x，y，z|φ(x，y，z，t)＝0}

But the energy response of step B, foundation deformation curved surface and the topological configuration of surface of mapping data, but the deformation curved surface is approached object module, that is, make curved surface energy minimum:

E(Г)＝∫ _Гd(x，y，z)dC

But ask the single order local derviation of deformation curved surface Г about energy:

$\frac{\mathrm{\δE}\left(\mathrm{\Γ}\right)}{\mathrm{\δ\Γ}}\left[{\∫}_{\mathrm{\Γ}}d(x,y,z)\mathrm{dC}\right][d\▿\mathrm{dgn}+\mathrm{dk}]$

$d(x,y,z)[\▿d(x,y,z)\mathrm{gn}+d(x,y,z)k]=0$

Wherein, n is a unit normal vector, but k is the mean curvature of deformation curved surface Г, and C is discrete vertex set,

But be the internal energy characteristic of deformation curved surface, and d (x, y, but z) k is the external energy characteristic of deformation curved surface, but ask the minimizing of inside and outside energy of deformation curved surface.

Step C, by Level Set Method, change net point position in the curved surface according to the energy minimization characteristic, realize that surface model progressively approaches:

$E\left(\mathrm{\Γ}\right)=E\left(\mathrm{\φ}\right)=d(x,y,z)\mathrm{\δ}\left(\mathrm{\φ}(x,y,z)\right)|\▿\mathrm{\φ}(x,y,z)|d(x,y,z)$

The 4th step, but near the deformation curved surface each medical 3 D mapping data is carried out part adjustment, but deformation curved surface in part is overlapped with each three-dimensional mapping data, thereby makes up the sealing smooth surface model of accurately approaching medical 3 D mapping data topology configuration of surface:

Make up the sealing smooth surface model of accurately approaching medical 3 D mapping data topology configuration of surface, make each three-dimensional mapping data point all on surface model; In surperficial closed model, search the point of the nearest grid of each three-dimensional mapping data point, net point is fixed on the three-dimensional mapping point, and carry out smoothing processing.

The present invention is not limited to aforesaid embodiment.The present invention expands to any new feature or any new combination that discloses in this manual, and the arbitrary new method that discloses or step or any new combination of process.

Claims (1)

1. a three-dimensional modeling method is characterized in that: comprise the steps:

The first step according to discretize medical 3 D mapping data, by the convex hull computing, generates the topological configuration of surface of medical 3 D mapping data;

In second step, according to discretize medical 3 D mapping data, but generate three-dimensional deformation occluding surface, but be somebody's turn to do the three-dimensional mapping data point that the deformation curved surface surrounds all collections;

The 3rd step, but according to the energy response of deformation occluding surface and the topological configuration of surface of medical 3 D mapping data, under least energy constraint condition, adopt the level set reconstructing method, but with deformation occluding surface iterative approach topology configuration of surface;

The 4th step, but near the deformation curved surface each medical 3 D mapping data is carried out part adjustment, but deformation curved surface in part is overlapped with each three-dimensional mapping data, make up the sealing smooth surface model of accurately approaching medical 3 D mapping data topology configuration of surface.