EP-4570181-B1 - DETERMINING AN INFLATION DURATION OF A BALLOON CATHETER

Inventors

• RADHAKRISHNA, Pooja

Dates

Publication Date

20260506

Application Date

20231214

Claims (12)

1. Computer implemented method for determining an inflation duration of a balloon catheter (6), wherein - a sequence of X-ray images depicting the balloon catheter (6) inside a vessel (19) of a patient (5) is received; - at least one geometric parameter including a diameter (18) of the balloon catheter (6) is determined based on the sequence of X-ray images and is tracked over the sequence of X-ray images; - a first inflation starting time of a first inflation phase, during which the diameter (18) is increasing, is determined based on the tracked diameter (18); - a first deflation starting time of a first deflation phase, during which the diameter (18) is decreasing and which lies after the first inflation phase, is determined based on the tracked diameter (18); - the inflation duration is computed depending on a first time difference between the first inflation starting time and the first deflation starting time.
2. Computer implemented method according to claim 1, wherein the first inflation starting time is determined as a time of a transition from a first static phase, during which the diameter (18) is essentially constant, to the first inflation phase.
3. Computer implemented method according to claim 2, wherein - the at least one geometric parameter includes a longitudinal end position of the balloon catheter (6); - the longitudinal end position is determined to be essentially constant during the first static phase.
4. Computer implemented method according to one of the preceding claims, wherein the first deflation starting time is determined - as a time of a transition from the first inflation phase to the first deflation phase; or - as a time of a transition from a second static phase, during which the diameter (18) is essentially constant and which lies between the first inflation phase and the first deflation phase, to the first deflation phase.
5. Computer implemented method according to one of the preceding claims, wherein a first lateral edge position of the balloon catheter (6) and a second lateral edge position of the balloon catheter (6) are determined based on the sequence of X-ray images and the diameter (18) is determined as a distance between the first lateral edge position and the second lateral edge position.
6. Computer implemented method according to claim 5, wherein - the at least one geometric parameter includes a lateral center position of the balloon catheter (6); - a first lateral distance between the first lateral edge position and the lateral center position is determined and a second lateral distance between the second lateral edge position and the lateral center position is determined; and - the first lateral distance and the second lateral distance are determined to be essentially equal during the static phase.
7. Computer implemented method according to claim 6, wherein - a first marker position of a first radio-opaque marker (7) of the balloon catheter (6) and a second marker position of a second radio-opaque marker (8) of the balloon catheter (6) are determined based on the sequence of x-ray images; - the lateral center position is determined depending on a straight line (13) connecting the first marker position to the second marker position.
8. Computer implemented method according to one of the preceding claims, wherein - a second inflation starting time of a second inflation phase, during which the diameter (18) is increasing and which lies after the first deflation phase, is determined based on the tracked diameter (18); - a second deflation starting time of a second deflation phase, during which the diameter (18) is decreasing and which lies after the second inflation phase, is determined based on the tracked diameter (18); - the inflation duration is computed depending on a second time difference between the second inflation starting time and the second deflation starting time.
9. Computer implemented method according to claim 8, wherein the inflation duration is computed depending on a sum of the first time difference and the second time difference.
10. Data processing apparatus (2) comprising at least one computing unit, which is adapted to carry out a computer implemented method according to one of claims 1 to 9.
11. X-ray imaging device (1) comprising a data processing apparatus (2) according to claim 10, an X-ray source (4), and an X-ray detector (3), wherein - the at least one computing unit is configured to control the X-ray source (4) to emit respective X-rays for a sequence of frame intervals; - the X-ray detector (3) is configured to generate a respective detector dataset for each of the sequence of frame intervals depending on portions of the respective X-rays passing through a region of interest containing the vessel (19) and the balloon catheter (6) during the respective frame interval; and - the at least one computing unit is configured to generate the sequence of X-ray images depending on the detector datasets generated for the sequence of frame intervals.
12. Computer program product comprising instructions, which, when executed by a data processing apparatus (2), cause the data processing apparatus (2) to carry out a computer implemented method according to one of claims 1 to 9.

Description

The present invention is directed to a computer implemented method for determining an inflation duration of a balloon catheter and to a corresponding method for x-ray imaging. The invention is further directed to a data processing apparatus for carrying out such a computer implemented method, to an x-ray imaging device comprising such a data processing apparatus, and to corresponding computer program products. Balloon angioplasty is a procedure used to open narrowed or blocked vessels, in particular arteries. It uses a balloon catheter that is inserted into the vessel. At the place where deposits of plaque have closed off or narrowed the channel for blood flow, the balloon catheter is inflated. The balloon catheter may in some cases be drug coated or act as a carrier for a stent to be deployed in the vessel depending on the intended therapy. Balloon angioplasty is commonly carried out under x-ray supervision. The inflation duration of the balloon catheter corresponds to a time period during which it is inflated or stays at its maximum inflation state until it starts to be deflated or to an accordingly cumulated time in case of multiple inflation and deflation phases. The inflation duration is known to be a critical parameter in view of the success of therapy and in view of the risk for unintended damage of the vessel. Usually, the inflation duration is determined by manually starting and stopping a timer. This is, however, error-prone and potentially leads to a low accuracy of the determined inflation duration. Patent application WO 2023/085253 A1 discloses an image processing apparatus with the capability to recognize a specific surgical situation. Scientific publication Morgan T. Harloff: "A step-by-step guide to transseptal valve-in-valve transcatheter mitral valve replacement",Annals of Cardiothoracic Surgery, vol. 10, no. 1, 1 January 2021 (2021-01-01), pages 113-121, XP093159646,ISSN: 2225-319X, 001: 10.21037/acs-2020-mv-104 discloses example images of balloon catheters and implants. It is an objective of the present invention to increase the accuracy and/or reliability of determining the inflation duration of a balloon catheter, in particular in real-time. This objective is achieved by the subject matter of the independent claim. Further implementations and preferred embodiments are subject matter of the dependent claims. The invention is based on the idea to determine and track the diameter of the balloon catheter during x-ray supervision based on the respective x-ray images automatically and to determine the inflation duration based on the tracked diameter, in particular by determining respective starting times of an inflation phase and a deflation phase. According to an aspect of the invention, a computer implemented method for determining an inflation duration of a balloon catheter is provided. Therein, a sequence of x-ray images depicting the balloon catheter inside a vessel of a patient is received. At least one geometric parameter including a diameter of the balloon catheter is determined based on the sequence of x-ray images and tracked over the sequence of x-ray images. A first inflation starting time of a first inflation phase, during which the diameter is increasing, is determined based on the tracked diameter. A first deflation starting time of a first deflation phase, during which the diameter is decreasing and which lies after the first inflation phase, is determined based on the tracked diameter. The inflation duration is computed depending on a first time difference between the first inflation starting time and the first deflation starting time. Unless stated otherwise, all steps of the computer-implemented method may be performed by a data processing apparatus, which comprises at least one computing unit. In particular, the at least one computing unit is configured or adapted to perform the steps of the computer-implemented method. For this purpose, the at least one computing unit may for example store a computer program comprising instructions which, when executed by the at least one computing unit, cause the at least one computing unit to execute the computer-implemented method. For each implementation of the computer implemented method, a corresponding implementation of a method for determining the inflation duration of the balloon catheter, which is not purely computer implemented, is obtained by including respective steps for generating the sequence of X-ray images, in particular using X-ray source and an X-ray detector. The sequence of X-ray images corresponds, for example, to a sequence of frame intervals, wherein one x-ray image is received for each of the frame intervals. The frame intervals are, in particular, consecutive frame intervals following each other, in particular in a sequence. In particular, the positions of the X-ray source and the X-ray detector with respect to a region of interest containing the vessel and the balloon catheter, is constant during the sequence