DE102008033641A1 - Medical examination and treatment device for visualization and treatment of ablation lesion in tissue or vascular surface of heart, has pattern recognizing unit identifying ablation lesion, and display displaying conditioned endoscope image - Google Patents

Abstract

The device has a flexible catheter (2) arranged at a distal end (6), and an endoscope (12) inserted into a catheter hollow space (10) with an objective (20) positioned in a monitoring position within a balloon (28). A digital image processing system real-time processes an image produced by the endoscope, and includes a pattern recognizing unit that identifies an ablation lesion based on color difference compared to surrounding tissue and local distribution of image entropy marked at the image. A display displays a conditioned endoscope image.

Description

The The invention relates to a medical examination and treatment device for the visualization and treatment of ablation lesions on tissue or vessel surfaces, in particular in the heart, according to the preamble of the claim 1.

ablation procedures for elimination or sclerotherapy of pathological centers of excitement or Stimulation lanes in the heart are nowadays usually minimally invasive performed as so-called high-frequency or radiofrequency ablation (RF ablation). RF ablation in the heart usually becomes more flexible Catheter over a vein or artery in the body introduced and advanced into the affected ventricle. There it is then arranged with the aid of a catheter tip Induction coil applied a high-frequency radio signal to pass through the associated heat exposure to the affected tissue desolate and so the pathological centers of excitement or "Disconnect" stimulus pathways. alternative can also provide a so-called cryoablation with a cryocatheter be, in which the affected tissue undercooled targeted is (at temperatures of, for example -75 ° C or colder).

One specific application is the Pulmonalvenenisolation, the To remedy atrial fibrillation or atrial flutter: The pathological Stimulation pathways run from the pulmonary veins via myocardial fibers into the left atrium, which causes the atrial contraction faulty (sometimes with a frequency of over 200 contraction cycles per minute). The goal of pulmonary vein isolation is the electrophysiological of the four pulmonary veins from the left Isolate atria. This is done by circular RF ablation in the ostium of the pulmonary veins. In addition will in certain patients with atrial fibrillation with the help of RF ablation a linear lesion that runs along an imaginary connecting line of the four pulmonary veins runs with the mitral valve produced.

To Common doctrines should be those during the ablation procedure lesions as possible without interruption (i.e., as continuous lines) are introduced into the tissue because of the continuity of the lines the probability an undesirable remodeling of the heart tissue presumably can be lowered.

In As a rule, such Ablationsprozeduren without visual inspection the generated ablation lesions. The effectiveness of the lesions is alone assessed electrophysiological criteria. So are electroanatomical Mapping systems used to stimulate electrophysiological stimulation to visualize within the heart chamber. In addition will be so-called lasso catheter with ring-shaped arranged Electrodes introduced into the pulmonary vein ostia to pathological To record leads between pulmonary veins and left atrium or the elimination of these leads through the ablation lesions to verify.

One Problem with this procedure is that the lesions Although they are generated during or after ablation but not by common imaging techniques (such as MR, CT, X-ray, ultrasound) can be visualized. A Statement about the continuity of the lesions so can not be taken. That's how it would be beneficial, the tissue of the heart wall, the so-called endocardial tissue, during and after tissue obliteration with help an endoscope located inside the ventricle to be treated to be able to visualize, thereby becoming desolate Areas or ablation lesions could be visualized. However, this visualization is not with normal endoscopes possible because the blood inside the ventricle is a free one Field of view on the endocardium prevented.

To work around this problem is from the publication "Nonfluoroscopic Guidance for Catheter Placement Into the Coronary Sinus under Direct Vision Using a Balloon-Tipped Cardioscope"; Yamamoto et al .; PACE, Vol. 21; Pages 1724 to 1727 (1998) a there known as "Cardioscope" catheter known which has at its distal end an optically transparent latex balloon, which is revisable expandable by an optically transparent fluid, such as air. The expanded, translucent balloon is pressed against the heart wall. The blood is displaced in this area. As a result, an endoscope integrated in the catheter, with a lens arranged inside the balloon envelope, receives an unobstructed view of the endocardium of the heart chamber to be treated, and in particular of the ablation lesions produced with a separate ablation catheter. This allows continuous intracardiac monitoring and control of the ablation procedure.

A disadvantage of this procedure is that the field of vision that can be realized with the endoscope is comparatively cramped and therefore the doctor supervising the intervention has a relatively poor overview. Furthermore, the lesions produced during ablation are sometimes difficult to recognize on the endoscopy image and can be quantified with regard to their quality (in particular patency, extent, penetration depth). Finally, it is expensive and risky, an ablation catheter on the one hand and a cardioscope on the other hand, via different accesses, eg. B. via the upper and lower vena cava, simultaneously introduce into the heart and to coordinate.

Of the The present invention is therefore based on the object, a medical Investigation and treatment facility of the aforementioned Specify type that avoids the above problems and the Doctor better at planning, implementation and control supports a catheter-based ablation.

These The object is achieved by a digital image processing system for real time processing of with the endoscope recorded images, which includes a pattern recognition unit, the ablation lesions based on color differences towards the surrounding tissue and / or local Distribution of image entropy identified and in each picture marked, the thus prepared endoscopy images on a associated display are displayed.

The Invention is based on the consideration that the recognition and subsequent quantification of the ablation lesions in digitized endoscopy image through interactive, semi-automatic or preferably automatic image processing or pattern recognition algorithms is possible. The detection of ablation lesions is done by distinguishing between intact ones ablated endocardial tissue. The distinction is made, for example based on an evaluation of color information: Ablated tissue areas namely in the endoscopy image usually darker or brownish imaged as intact tissue areas. Alternatively or additionally, information contained in the image is transmitted via the homogeneity of the tissue used: intact tissue areas they are usually more homogeneously imaged than ablated ones Tissue areas where the ablation is vesicular lesions caused. Advantageously, both evaluation methods with each other combined.

The Differentiation based on the color information can, for example, about a threshold for color saturation or the like within a certain spatial window of the endoscopic image to be hit. The distinction based on tissue homogeneity can with the help of an entropy calculation within a given spatial Window of the endoscopic image are taken. So will those Image areas containing ablation sites larger Entropy have as those image detail, the undamaged tissue play. Under this assumption can be made by thresholding. entropy (or other entropy-based Metrics) to isolate intact tissue from lesions. Based on this, the ablation lesions can color-coded, quantified and in the digital endoscopy image to other imaging modalities or electroanatomical Mapping systems are transferred to there as additional information to be represented. For documentation purposes or for a later link with the images of other modalities The digital endoscopy images can be saved.

Based of local entropy measurement and / or hue and / or color saturation is in an advantageous implementation the evaluation algorithms also possible, conclusions about the quality of ablation lesions, e.g. B. over their depth, to draw. Such additional information can on the digitally prepared endoscopy images for easier acquisition or perception by the doctor z. B. in the manner of color coding or false color representation. Furthermore, can with known image scale an automatic or interactive Measurement of the ablation lines with regard to their spatial (lateral) extension can be provided.

In an optional variant of the invention is the balloon catheter at the distal end with an ablation unit for cryogenic, laser, HiFU or RF ablation equipped to soil the tissue and to visualize the lesion at the same time. Thus, on the simultaneous introduction and handling of two different catheters are dispensed with. advantageously, In this embodiment, the objective of the endoscope is in the observation position aligned with the ablation tool.

In advantageous embodiment, the medical examination and processing means a position detecting system for detecting the spatial position and orientation of the respective endoscopy image visible ablation lesions. For example, you can in the area of the catheter tip electromagnetic position sensors Position sensor or the like may be arranged so that based on the position data transmitted or issued by them the spatial location or orientation of the catheter tip or the endoscope objective is derivable. In turn, lets it out with a known orientation of the endoscope lens easily the Determine the location and orientation of the ablation lesions.

On the basis of the positional data thus obtained, the endoscopy images can be relatively easily and reliably registered with other 2D or 3D images of the examination and treatment region, which were recorded, for example, as part of a preliminary examination with the aid of a further modality, ie assigned to one another in terms of size and position, and be merged as needed. Alternatively or additionally, an image-based or object-based registration, for. B. with the help of X-ray impermeable marks or the like may be provided. Thus, the endoscopic images with the ablation lesions marked therein can be inserted, for example, in the correct position into morphological image data of the ventricle based, for example, on 2D ultrasound, 3D ultrasound, 3D computed tomography, 3D magnetic resonance tomography, 2D fluoroscopy or 3D X-ray rotational angiography.

So can remove the lesions extracted from the endoscopy image for example, on the wall of a 3D segmentation computerized tomography or 3D X-ray rotational angiography or magnetic resonance image data 3D model of a ventricle can be projected. By the Presentation of the lesions in the 3D model of the treatment to be treated Cardiac chamber receives information to the electrophysiologist the location of ablation lesions relative to 3D morphology (eg relative to the location of the lesions in the left atrium relative to the pulmonary vein ostia).

As well The lesions may be during the ablation procedure in live fluoroscopy images or live ultrasound images in which then possibly also the ablation catheter is visible with the endoscope itself.

The particular advantages of the invention are that by a digital processing of a balloon catheter with integrated endoscope images taken using pattern recognition algorithms Ablation lesions during and after an electrophysiological ablation procedure visualized, extracted and quantified. As a result, the quality, in particular permeability, Extent and depth of penetration of ablation lesions be assessed. If the desired quality is not given, an immediate repetition of tissue obliteration can take place. Also in re-ablation (follow-up procedures) is the visualization the ablation lesions of the last performed Ablation procedure advantageous.

• – elektrophysiologische Signale (intrakardiales EKG sowie Oberflächen-EKG),
• – Ablationsläsionen (aus dem Endoskopiebild), und die
• – Morphologie der Herzkammer (mittels der oben angeführten weiteren bildgebenden Modalitäten)

in die Ablationsprozedur integriert und zielgerichtet miteinander verknüpft werden.By combining this endoscopic visualization with other imaging modalities, the precision and long-term success of the ablation can be improved by providing combined, complementary information about

• - electrophysiological signals (intracardiac ECG and surface ECG),
• - Ablation lesions (from the endoscopy image), and the
• - Morphology of the ventricle (by means of the above-mentioned further imaging modalities)

integrated into the ablation procedure and purposefully linked together.

One Embodiment of the invention will be described with reference to a drawing explained in more detail. Therein show in each strong simplified and schematic representation:

1 a longitudinal section through a catheter, and

2 a medical examination and treatment device with such a catheter.

The catheter 2 according to 1 is used to observe ablation lesions during an ablation procedure in the heart. It comprises a substantially hollow cylindrical, flexible catheter sheath 4 which is inserted into the vascular tract of a patient until the distal end 6 of the catheter 2 in the affected ventricle 8th located. When feeding is the catheter 2 via a system of into the catheter sheath 4 integrated, not shown here cables controllable (deflectable). About one of the catheter sleeve 4 surrounded cylindrical cavity 10 can be a flexible endoscope 12 to the distal end 6 the catheter sheath 4 advance.

This in 1 already in his viewing position located endoscope 12 comprises a light guide formed from a glass fiber bundle 14 , About the light guide is on the one hand by a cold light source 16 at the proximal end 18 of the catheter 2 generated light to illuminate the examination and treatment region and conducted in the heart chamber 8th extracted. On the other hand, over the light guide 14 from the lens 20 at the distal end 6 collected scattered or reflected light to a digitizing unit 22 at the proximal end 18 of the catheter 2 transfer. Alternatively, the endoscope 12 also be configured as a so-called video endoscope, with one at the "lens" 20 of the endoscope 12 attached CCD chip directly a digital image of the examination object, here the innermost layer of the heart wall 24 (Endocard), and generates corresponding electrical signals via a in the catheter cavity 10 transferred transmission cable to the downstream electronic units. If necessary, the illumination of the examination object can also be done via a near the objective 20 attached LED (LED) done.

To achieve a magnification effect or an extension of the field of view, the lens 20 equipped with a suitable lens system (so-called bullseye lens). The field of vision 26 defining opening angle of the lens 20 is in 1 indicated schematically. The endoscope 12 is in the catheter sheath 4 can be pushed forward and retracted to the size of the field of view over the distance to the examination subject 26 to be able to vary. Advantageously, the lens can be 20 supporting endoscope tip via an integrated cable system independent of the outer catheter sheath 4 control (deflect). To control rotation and deflection of catheter sheath 4 and endoscope 12 may be one at the proximal end 18 of the catheter 2 mounted multifunction handle (not shown) can be used.

For an unobstructed view of the endocardium 24 is the forward in his observation position objective 20 inside an optically transparent balloon 28 , the gas-tight at the distal end 6 the catheter sheath 4 is attached. About one in the catheter sleeve 4 extending channel or a supply line 30 Can the balloon when it is in the affected ventricle 8th is pressurized with compressed air or a transparent liquid and unfolded therewith. The unfolded balloon 28 is against the heart wall 24 pressed and displaces the blood in this area. The field of vision 26 of the lens inside the balloon envelope 20 is therefore not affected by the blood flow. At the end of the procedure, the compressed air or liquid is supplied via the supply line 30 back out of the balloon 28 drained, which then contracts again due to its elasticity or folds.

At the distal end of the catheter 2 are also position or orientation sensors 32 attached, which allow the current spatial position (coordinates) and orientation (direction vector) of the catheter tip, in particular the lens 20 to derive or calculate by means of corresponding position signals. For identification in X-ray images, the endoscope 12 and / or the catheter sheath 4 at the distal end 6 be provided with radiopaque markings.

In an optional embodiment, moreover, an ablation tool, not shown here, can be provided at the distal end 6 of the catheter 2 be arranged, for. B. to perform an RF or Kryoablation.

The catheter 2 is part of an in 2 schematically illustrated medical examination and treatment facility 34 , The with the help of the endoscope 12 recorded live images of the examination and treatment area in the patient's heart 60 (here on a patient table 62 lying) after their digitization in the digitization unit 22 in the form of a video stream of a pattern recognition unit 36 fed here in the exemplary embodiment in a generally by the reference numeral 38 characterized electronic image processing system is integrated. In the pattern recognition unit 36 Real-time computer-implemented algorithms automatically detect and identify ablation lesions in endoscopic video images. This recognition is based on the fact that on the one hand the ablation sites differ in color from the surrounding tissue, and on the other hand on the ablated areas because of their vesicular structuring greater image entropy (in the sense of information density according to a common notion of information theory) in comparison to the intact tissue assigned. The thus identified ablation lesions are color-coded in the video images, and the thus electronically / digitally processed video images are displayed 40 displayed.

In addition, a monitoring of the procedure can be provided on the basis of live fluoroscopy images, which are eg. B. with the in 2 illustrated C-arm X-ray angiography system 42 be recorded. Based on the position or orientation sensors 32 supplied position data for the catheter 2 it is at known position of the C-arm 44 with the beam source 46 and the image detector 48 it is possible to register the fluoroscopic and the endoscopic images in real time, ie to associate each other with dimensional and positional accuracy by means of suitable coordinate transformations, and to merge or superimpose each other. For example, those of the pattern recognition unit 36 identified ablation lesions in the live fluoroscopic images of the X-ray angiography system 42 are displayed and marked in color. Such fusion images are then also on display if necessary 40 displayed. Furthermore, it is possible to provide a fusion of the reprocessed endoscopy images with morphological image data which were recorded as part of a preliminary examination with the aid of further medical modalities (eg MR, CT) and, if required, into the image processing system 38 getting charged.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - "Nonfluoroscopic Guidance for Catheter Placement Into the Coronary Sinus under Direct Vision Using a Balloon-Tipped Cardioscope"; Yamamoto et al .; PACE, Vol. 21; Pages 1724 to 1727 (1998) [0007]

Claims (5)

Medical examination and treatment facility ( 34 ) for the visualization and treatment of ablation lesions on tissue or vascular surfaces, in particular in the heart, comprising a flexible catheter ( 2 ) with at least one catheter cavity ( 10 ) enclosing catheter sheath ( 4 ), • one at the distal end ( 6 ) of the catheter ( 2 ), with an optically transparent fluid, in particular with air, reversibly expandable optically transparent balloon ( 28 ), and • into the catheter cavity ( 10 ) retractable endoscope ( 12 ) with one in an observation position within the balloon ( 28 ) insertable lens ( 20 ), characterized by • a digital image processing system ( 38 ) for real-time processing of the endoscope ( 12 ), which is a pattern recognition unit ( 36 ), which identifies the ablation lesions by color differences with respect to the surrounding tissue and / or by means of the local distribution of the image entropy and marks them in the respective image, and 40 ) for displaying the thus prepared endoscopy images. Medical examination and treatment facility ( 34 ) according to claim 1 with means for measuring ablation lesions. Medical examination and treatment facility ( 34 ) according to claim 1 or 2 with one at the distal end ( 6 ) of the catheter ( 2 ) arranged ablation tool. Medical examination and treatment facility ( 34 ) according to claim 3, wherein the objective ( 20 ) of the endoscope ( 12 ) is aligned with the ablation tool in the viewing position. Medical examination and treatment facility ( 34 ) according to one of claims 1 to 4 with a position recognition system for determining the spatial position and orientation of the ablation lesions visible in the respective endoscopy image, with means for registering the endoscopy images with 2D images recorded during a preliminary examination or in real time during the catheter engagement with another imaging modality. or 3D images of the examination and treatment region and with means for fade-in or projection from the pattern recognition unit ( 36 ) identified ablation lesions in the 2D or 3D images.