Security alerts based on 4D intracardiac ultrasound (ICE) catheter tracking

Abstract

A medical system includes an ultrasound probe, a treatment probe, and a processor. The ultrasound probe and the treatment probe are configured for insertion into an organ to image a volume of the organ, respectively, and to introduce a treatment device into the volume of the organ. The probes respectively include a first sensor configured to output a first signal indicative of a first position of the ultrasound transducer array of the probe within the organ and a second sensor configured to output a second signal indicative of a second position of the treatment device within the organ. The processor is configured to receive a marker that is added to an ultrasound image acquired using the ultrasound probe and identifies a tissue region of the organ; registering the first position of the ultrasound transducer array and the second position of the treatment device to each other; tracking a relative position between the treatment device and the marked tissue region using the registration; and (iv) alerting the user when the treatment device is located within the predefined proximity of the marked tissue region.

Description

Technical Field

[0001] The present disclosure relates generally to therapeutic systems utilizing in-vivo medical probes, and particularly to using a position-tracked medical ultrasound (US) probe to warn of potential dangers from the position-tracked therapeutic probe. Background Art

[0002] Various methods for guiding a catheter using a medical ultrasound probe have been proposed. For example, U.S. Pat. No. 7,981,038 describes a method and system for generating an image of an object, such as a human heart. The method may include acquiring an ultrasound image of an object using a catheter including a position sensor. The method may also include capturing a plurality of 4D surface registration points corresponding to points on the object in the acquired ultrasound image. The method may also include registering a high-resolution 4D model of the object with a plurality of 4D surface registration points in space and time. The method may also include displaying a high-resolution real-time image of the object based on the registration of the high-resolution 4D model with the 4D surface registration points during a medical procedure. The examples disclosed herein are particularly useful in left atrial ablation procedures. According to other embodiments, two or more catheters may be used. In such examples, a clinician may insert a second catheter into a relevant area of ​​the heart, wherein the second catheter includes an ablation device. Preferably, such an ablation catheter will also include a position sensor so that a position tracking system can track the position and orientation of the second catheter. In this way, a clinician may use one catheter to acquire an ultrasound image and use another catheter to perform ablation.

[0003] The present disclosure will be more fully understood through the following detailed description of examples of the present disclosure in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 is a schematic illustration of an ultrasound imaging-based system according to an example of the present disclosure that can warn a user who is performing ablation in real time when an ablation catheter is too close to a sensitive area;

[0005] Figure 2 According to the example of the present disclosure Figure 1 The system generates in real time a schematic illustration of an ultrasound image to visualize the cause of the warning; and

[0006] Figure 3 is a flow chart schematically describing a method for alerting a physician who is performing treatment in real time when a treatment probe is too close to a marked tissue region according to an example of the present disclosure. DETAILED DESCRIPTION

[0007] Overview

[0008] When using a probe to perform invasive treatments of internal organs, such as surgical incisions or ablations, there may be specific areas of the organ that the physician may want to avoid. For example, when making a transseptal puncture of the heart, it is important to avoid puncturing the aorta. When radiofrequency (RF) ablating the ostia of the pulmonary veins, it is important to avoid lesions through the esophageal wall.

[0009] If ultrasound imaging (e.g., intracardiac echography (ICE)) is available, the physician can scan the area surrounding the target treatment site to search for sensitive tissue regions (hereinafter also referred to as "landmark locations") and note such specific landmarks that should be avoided before selecting a location for performing treatment (e.g., puncture or ablation). During an invasive procedure, the system can display one or more selected ultrasound image slices captured in real time by the ICE probe so that the physician can verify the safety of the invasive procedure.

[0010] However, the sensitive tissue area to be avoided may not appear in the selected ultrasound image slice that is displayed to the physician during the procedure. The sensitive tissue area may also move during surgery. Furthermore, increasing the number of ultrasound image slices displayed may not be practical and may not help the user understand the 3D information that is updated in real time.

[0011] Examples of the present disclosure described herein provide methods and systems for alerting a physician when a treatment device mounted on a treatment probe is placed at a specific area that the physician may want to avoid. In some examples, the physician scans a volume with a 4D ICE ultrasound probe prior to ablation or puncture. The physician uses a graphical user interface (GUI) to mark (e.g., depict with a single click) the locations of landmarks to be avoided on the image. Once the landmarks are marked, 4D ultrasound acquisition of the marked tissue area in the image continues without having to show the physician an image of the marked area. A software module uses real-time ultrasound data to track the locations of the landmarks in real time.

[0012] To this end, the disclosed technology uses a 4D ICE probe that performs real-time imaging of a treatment device mounted on a treatment probe. Using a position sensor (e.g., a magnetic sensor) mounted to the probe, both the 4D ICE probe and the treatment probe are positionally tracked by a position tracking system. The sensor outputs a first signal that indicates a first position of an ultrasound transducer array within an organ. Since the position sensor in the 4D ICE probe is pre-registered with the 2D ultrasound array of the 4D ICE probe, the position of the image voxels of the anatomical structure is also known.

[0013] The 2D array of the 4D ICE probe produces a fan-shaped ultrasound beam with a wide field of view (FOV), and is therefore capable of imaging large anatomical structures of an organ, such as an entire heart chamber. The wide FOV of the ultrasound beam enables the US probe to acquire a variety of sensitive tissue areas, even those that are not currently displayed to the physician. In other words, the US probe is able to capture all relevant landmarks, including landmarks that are not currently displayed to the physician, while performing an invasive procedure.

[0014] As described above, the position of the treatment device is also known, for example based on a precise integrated position sensor (e.g., a magnetic sensor) mounted to the treatment probe, wherein the sensor outputs a second signal indicating a second position of the treatment device within the organ. In order to correlate the positions of the two different probes, the processor of the position tracking system aligns the positions of the US probe and the treatment probe with each other. The processor further compares the tracked landmark positions with the tracked positions of the invasive treatment probe tip (e.g., the position of the electrode of the ablation catheter or the position of the surgical cutting / puncturing tool (such as a transseptal puncture needle)) in real time. In this way, the processor can correlate the position of the treatment device with the position of the marked landmark positions to an accuracy of 1 mm in real time. Based on this capability, the processor alerts the physician if the treatment probe tip is too close to the marked tissue area.

[0015] Thus, in some examples, a medical system is provided that includes a 4D ultrasound probe, a therapy probe, and a processor configured to: (i) receive markings of an ultrasound image acquired using the 4D ultrasound probe of one or more tissue regions of an organ, (ii) register positions of integrated position sensors of the ultrasound imaging and therapy probes with each other, (iii) track the position of a therapy device mounted to the therapy probe relative to the one or more marked tissue regions using the registered positions, and (iv) alert a user in real time when the therapy device is within a predefined proximity of the marked tissue region.

[0016] Before providing an alert to the user, the user can set a threshold for defining proximity to a marked tissue region (e.g., to a marked landmark location). The alert can be visual, audible, and / or tactile. Such alerts serve as a safety precaution for the physician. Even if the landmark location is not in the FOV of the real-time image slice being displayed on the screen, the system still identifies the proximity and provides an alert.

[0017] System Description

[0018] Figure 12 is a schematic illustration of an ultrasound (US) imaging-based system 20 according to an example of the present disclosure, which can warn a user who is performing ablation in real time when an ablation catheter is too close to a sensitive tissue area. The system 20 uses a 4D ultrasound probe 21 having a US probe distal assembly 60 (shown in inset 25) including a 2D ultrasound array 65 and an integrated position sensor 67 to monitor in real time a position tracking radio frequency (RF) ablation catheter 40 having a catheter distal assembly 62 including a position sensor 47 and an ablation electrode 48.

[0019] The physician 30 advances the distal assembly 60 of the US probe 21 into the right atrium of the heart 26 via the inferior vena cava (IVC) 43. Once in the right atrium, the physician images the septal wall 50 between the atria (usually before performing a transseptal puncture). In the example shown, the ablation catheter 40 is inserted via the superior vena cava (SVC) 42 using a sheath 44.

[0020] As shown, the 2D ultrasound array 65 array generates a 3D fan-shaped ultrasound beam 265 that occupies a defined solid angle; (such a beam is referred to herein as a "wedge 265"). With the wide FOV covered by the wedge 265, the 2D ultrasound array is able to image large volumes of viscera such as an entire cardiac chamber (e.g., the entire left atrium (LA) 45).

[0021] The distal tip assembly 60 is mounted at the distal end of the catheter's shaft 22. The catheter 22 is inserted through the sheath 23 into the heart 26 of a patient 28 lying on an operating table 29. The proximal end of the shaft 22 is connected to the console 24. To direct the ultrasound array to the desired orientation, the physician may, for example, use the manipulator 32 near the proximal end of the US probe 21.

[0022] The integrated position sensor 67 of the US probe 21 is pre-registered with the array 65 of the US probe. Due to the integrated position sensor, the spatial coordinates of each voxel in the imaged heart chamber are known. Specifically, the sensor 67 is configured to output a first signal indicating the position and orientation of the ultrasound transducer array 65 within the heart 26.

[0023] Any imaged target anatomy (eg, left atrium 45 , including pulmonary vein ostia 55 ) may be presented to physician 30 by processor 41 on monitor 27 , for example, as a volumetric rendering 33 .

[0024] After piercing the septal wall 50 (eg, using the sheath 44), the US probe 21 images the entire LA 45 while the ablation catheter 40 is positioned therein, for example, near the ostium 55. The image produced by the 2D ultrasound array thus includes the ablation electrode 48.

[0025] Thus, further seen is the distal assembly 62 of the RF ablation catheter 40, which is inserted into the LA 45 via the sheath 44 to perform ablation therein using the electrodes 48 while being imaged in real time with the 4D ICE probe 21. As shown, the esophagus 99 passes near the posterior wall of the LA 45, and the sensitive esophageal 99 tissue may suffer thermal damage if exposed to ablative heat.

[0026] To warn that the RF ablation electrode 48 is located close to a sensitive tissue area (e.g., the esophagus 99), the user or processor marks the sensitive area, such as the portion of the posterior wall that overlaps the esophagus 99. The physician uses a graphical user interface (GUI) 100 to mark or draw (e.g., depict with one click) the landmark locations to be avoided on the ultrasound image. To do this, the physician scans the volume with a 4D ICE ultrasound probe before ablation or puncture. The GUI 100 may include a touch screen 27, as well as a keyboard and a trackball.

[0027] Once marked, for example, by a physician, ultrasound acquisition of the marked tissue region continues without having to show the physician the marked region. A software module uses real-time ultrasound data to track the location of the landmark in real time. Using the software, the processor further compares the tracked landmark location with the real-time location of the invasive probe tip (e.g., ablation catheter or transseptal puncture needle) and alerts the physician if the RF probe tip electrode 48 is too close to the marked tissue region. If the ablation electrode 48 is too close to an unrelated tissue region that may be damaged by RF ablation, the system alerts the physician.

[0028] The console 24 includes a processor 41 (typically a general purpose computer) having a suitable front end and interface circuitry 38 for receiving signals from the catheter 21. The console 24 also includes a drive circuit 34 configured to drive the magnetic field generator 36. During navigation of the distal end 22 in the heart 26, the console 24 receives position and orientation signals from the position sensors 67 and 47 in response to the magnetic field from the external field generator 36. The magnetic field generator 36 is placed at a known location external to the patient 28, such as below the table 29 on which the patient lies. These positioning and orientation signals indicate the location and orientation of the ultrasound array 65 in the coordinate system of the position tracking system.

[0029] Position and orientation sensing methods using external magnetic fields are implemented in various medical applications, such as in the CARTO TM The system is implemented in the present invention and is described in detail in U.S. Patents 6,618,612 and 6,332,089, PCT Patent Publication WO 96 / 05768, and U.S. Patent Application Publications 2002 / 0065455, 2003 / 0120150, and 2004 / 0068178, the disclosures of which are incorporated herein by reference.

[0030] The processor 41 is programmed with software to implement the functions described herein. The software may be downloaded to the computer's memory 35 in electronic form over a network, for example, or it may alternatively or additionally be provided and / or stored on a non-transitory tangible medium such as magnetic, optical or electronic memory. Specifically, the processor 41 executes the software disclosed herein including in Figure 2 , which enables the processor 41 to perform the disclosed steps, as further described below.

[0031] Figure 1 The exemplary configuration shown is chosen solely for conceptual clarity. The disclosed techniques may be similarly applied using probe / catheter access other than through the IVC 43 / SVC 44, such as via another vein or via an artery. Although in the above example, the warning is directed to hazards to the esophagus 99, any sensitive anatomical structure may be marked to avoid injury, such as the left atrial appendage (LAA) 57 and the ridge region near the septum 50.

[0032] Real-time monitoring of fixed-position treatment catheters using a fixed-position 4D ICE probe

[0033] As described above, in order to track the position of the landmark in real time using 4D ultrasound data, the processor runs a software module. In the process, the processor further compares the tracked landmark position with the real-time position of the invasive probe tip (e.g., the electrode of the ablation catheter or the transseptal puncture needle). If the probe tip is too close to the marked tissue area, the processor alerts the physician. This warning can be provided without displaying the relevant image to the physician. However, in some examples, it is beneficial that the physician will receive a relevant view (e.g., 2D or 3D reconstruction) that images the cause of the alarm.

[0034] Figure 2 According to the example of the present disclosure Figure 1 The system 20 generates in real time a schematic illustration of an ultrasound image 200 to visualize the cause of the warning. Figure 2 The images shown in are images of slices, but in general the images may be 3D renderings.

[0035] Figure 2 is generated and presented by processor 41 after the processor issues a warning (e.g., an audio-visual warning). Image 200 (e.g., ultrasound view 200) highlights ablation electrode 248 of catheter 240 in contact with marked area 245 of the posterior wall of LA 45, thereby being too close to delineated esophageal area 299. (As determined using a distal sensor of probe 240, the sensor is Figure 2 Not shown, but in Figure 147). As shown, the physician receives a view showing why the system is alerting, the displayed view clearly showing the spatial relationship between the aforementioned elements in the vicinity (ie, the ablation electrode relative to the esophagus).

[0036] The user may instruct the processor to generate other views, such as from different viewing directions of the treatment device relative to the marked tissue region, or to generate a 3D rendering.

[0037] Method for real-time monitoring of a fixed-position treatment catheter using a fixed-position 4D ICE probe

[0038] Figure 3 is a flowchart schematically describing a method for real-time warning a physician who is performing treatment when a treatment probe is too close to a marked tissue region according to an example of the present disclosure. By way of example, the system involved is Figure 1 The system 20, wherein the treatment probe is an ablation catheter 40. Figure 1 As shown, at ICE step 302, the process of algorithm execution according to the presented example begins with physician 30 imaging heart 26. Processor 41 displays a 3D rendering of the imaged portion of the heart.

[0039] At a marking step 304, processor 41 receives (eg, from physician 30) markings indicating landmark locations (one or more tissue regions, such as within the posterior wall of LA 45) to be avoided during RF ablation.

[0040] Next, at a tracking step 306, the processor 41 uses the 4D ICE and software to track the tags in real time as the physician places the ablation catheter 40 with the electrodes 48 in the desired position for ablation. The tags facilitate the wide FOV of the wedge 265, where even the marked tissue areas that are not currently displayed to the physician 30 are still acquired with the US probe 21, and the acquisition data is processed to enable tracking.

[0041] In parallel, at treatment device tracking step 308, processor 41 uses the magnetic tracking system to track the position electrode 48 while the physician places ablation catheter 40 to begin ablation. Since the tracking system has the US probe tracking signals (from sensor 67) as well as those from sensor 47 of catheter 40, processor 41 can correlate the position of electrode 48 to the position of the landmark locations in real time and within 1 mm accuracy.

[0042] Finally, at a warning step 310, the processor 41 issues a warning (e.g., a flashing message accompanied by a short squeak) whenever the processor identifies that the location of the electrode 48 and one of the landmark locations are closer to each other than a predefined minimum distance. For example, if the electrode contacts the posterior wall of the LA 45 just in front of the esophagus 99, the processor issues a warning.

[0043] Figure 3 The example flow chart shown in is chosen purely for conceptual clarity. For example, additional steps may be performed, such as incidental X-ray imaging.

[0044] Although the examples described herein primarily address monitoring of cardiac therapy probes using a cardiac ultrasound imaging probe, the techniques described herein may also be used for other organs, such as organs of the gastric system.

[0045] {Is this correct?}

[0046] Example

[0047] Example 1

[0048] A medical system (20) includes an ultrasound probe (21), a therapeutic probe (40, 240), and a processor (41). The ultrasound probe is configured to be inserted into an organ of the body and includes an ultrasound transducer array (65) configured to image a volume of the organ, and a first sensor (67) configured to output a first signal indicating a first position of the ultrasound transducer array within the organ. The therapeutic probe is configured to be inserted into the organ and includes a therapeutic device (48, 248) mounted at a distal end of the therapeutic probe, and a second sensor (47) configured to output a second signal indicating a second position of the therapeutic device within the organ. The processor is configured to: (i) receive a marker that has been added by a user to one or more ultrasound images (200) acquired using an ultrasound probe and identifies one or more tissue regions (245) of an organ; (ii) align a first position of an ultrasound transducer array and a second position of a treatment device with each other; (iii) track a relative position between the treatment device and the one or more marked tissue regions using the aligned first and second positions; and (iv) alert the user when the treatment device (248) is within a predefined proximity of the marked tissue region (245).

[0049] Example 2

[0050] The system (20) of embodiment 1, wherein the first sensor and the second sensor are magnetic position sensors configured to generate the first signal and the second signal in response to a magnetic field applied by the position tracking system.

[0051] Example 3

[0052] A system according to any one of embodiments 1 and 2, wherein the processor (41) is configured to warn the user by issuing an audio-visual warning.

[0053] Example 4

[0054] A system according to any one of embodiments 1 to 3, wherein the processor (41) is configured to generate an ultrasound view (200) showing the treatment device relative to the marked tissue region.

[0055] Example 5

[0056] A system according to any one of embodiments 1 to 4, wherein the processor (41) is configured to generate an ultrasound view (200) having a field of view (FOV) that does not include a marked tissue region, and to alert a user when a treatment device is within a predefined proximity of the marked tissue region, even if the marked tissue region is not visible in the ultrasound view.

[0057] Example 6

[0058] A system according to any one of embodiments 1 to 5, wherein the treatment device includes one of a surgical cutting tool, a transseptal access device, and an ablation electrode (48, 248).

[0059] Example 7

[0060] A system according to any one of embodiments 1 to 6, wherein the processor (41) is configured to receive markings by a user marking the ultrasound image using a graphical user interface (GUI) (100).

[0061] Example 8

[0062] A system according to any one of embodiments 1 to 7, wherein the processor (41) is configured to receive the label by: receiving an anatomical map of the label registered with the ultrasound image, and labeling the ultrasound image using the anatomical map of the label.

[0063] Example 9

[0064] A system according to any one of embodiments 1 to 8, wherein the organ is a heart (26).

[0065] Example 10

[0066] A method includes inserting an ultrasound probe into an organ of a body, the ultrasound probe including: an ultrasound transducer array configured to image a volume of the organ, and a first sensor configured to output a first signal indicating a first position of the ultrasound transducer array within the organ. Inserting a therapeutic probe into the organ, the therapeutic probe including a therapeutic device mounted at a distal end of the therapeutic probe, and a second sensor configured to output a second signal indicating a second position of the therapeutic device within the organ. Receiving a marker that has been added by a user to one or more ultrasound images acquired using the ultrasound probe and identifies one or more tissue regions of the organ. Registering the first position of the ultrasound transducer array and the second position of the therapeutic device to each other. Using the registered first and second positions, tracking the relative position between the therapeutic device and one or more marked tissue regions. Alerting the user when the therapeutic device is within a predefined proximity of the marked tissue region.

[0067] It should therefore be understood that the above embodiments are cited by way of example, and the present disclosure is not limited to what is specifically shown and described above. On the contrary, the scope of the present disclosure includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which will occur to a person skilled in the art when reading the above description, and which are not disclosed in the prior art. The documents incorporated by reference into this patent application are deemed to be an integral part of this application, unless any term defined in these incorporated documents conflicts with a definition explicitly or implicitly given in this specification, in which case only the definition in this specification shall be considered.

Claims

1. A medical system, comprising: An ultrasound probe, the ultrasound probe being used to be inserted into an organ of a body, the ultrasound probe comprising: an ultrasound transducer array configured to image a volume of the organ; and a first sensor configured to output a first signal indicative of a first position of the ultrasound transducer array within the organ; A treatment probe, the treatment probe is used to be inserted into the organ, and the treatment probe comprises: a treatment device mounted at a distal end of the treatment probe; and a second sensor configured to output a second signal indicative of a second position of the therapeutic device within the organ; and A processor, the processor being configured to: receiving a marker that has been added by a user to one or more ultrasound images acquired using the ultrasound probe and that identifies one or more tissue regions of the organ; registering the first position of the ultrasound transducer array and the second position of the therapeutic device with each other; tracking a relative position between the treatment device and one or more marked tissue regions using the registered first and second positions; and A user is alerted when the treatment device is within a predefined proximity of a marked tissue region.

2. The system according to claim 1, wherein: The first sensor and the second sensor are magnetic position sensors configured to generate the first signal and the second signal in response to a magnetic field applied by a position tracking system.

3. The system according to claim 1, wherein: The processor is configured to alert the user by issuing an audio-visual warning.

4. The system according to claim 1, wherein: The processor is configured to generate an ultrasound view showing the treatment device relative to the marked tissue region.

5. The system according to claim 1, wherein: The processor is configured to generate an ultrasound view having a field of view (FOV) that does not include the marked tissue region, and to alert the user when the treatment device is within the predefined proximity of the marked tissue region, even if the marked tissue region is not visible in the ultrasound view.

6. The system according to claim 1, wherein: The treatment device includes one of a surgical cutting tool, a transseptal access device, and an ablation electrode.

7. The system according to claim 1, wherein: The processor is configured to receive the markings by the user marking the ultrasound image using a graphical user interface (GUI).

8. The system according to claim 1, wherein: The processor is configured to receive the marking by receiving a marked anatomical map registered with an ultrasound image and marking the ultrasound image using the marked anatomical map.

9. The system according to claim 1, wherein: The organ is the heart.

10. A method comprising: An ultrasound probe is inserted into an organ of the body, the ultrasound probe comprising: an ultrasound transducer array configured to image a volume of the organ; and a first sensor configured to output a first signal indicative of a first position of the ultrasound transducer array within the organ; Inserting a treatment probe into the organ, the treatment probe comprising: a treatment device mounted at a distal end of the treatment probe; and a second sensor configured to output a second signal indicative of a second position of the therapeutic device within the organ; receiving a marker that has been added by a user to one or more ultrasound images acquired using the ultrasound probe and that identifies one or more tissue regions of the organ; registering the first position of the ultrasound transducer array and the second position of the therapeutic device with each other; tracking a relative position between the treatment device and one or more marked tissue regions using the registered first and second positions; and A user is alerted when the treatment device is within a predefined proximity of a marked tissue region.

11. The method according to claim 10, wherein: The first sensor and the second sensor are magnetic position sensors configured to generate the first signal and the second signal in response to a magnetic field applied by a position tracking system.

12. The method according to claim 10, wherein: Alerting the user includes issuing an audio-visual warning.

13. The method according to claim 10, wherein: Generating an ultrasound view includes showing the treatment device relative to the marked tissue region.

14. A method according to claim 10, and including generating an ultrasound view having a field of view (FOV) that does not include the marked tissue region, and alerting the user when the treatment device is within the predefined proximity of the marked tissue region, even if the marked tissue region is not visible in the ultrasound view.

15. The method according to claim 10, wherein: The treatment device includes one of a surgical cutting tool, a transseptal access device, and an ablation electrode.

16. The method according to claim 10, wherein: Receiving the marking includes the user marking the ultrasound image using a graphical user interface (GUI).

17. The method according to claim 10, wherein: Receiving the marking includes receiving a marked anatomical map registered with the ultrasound image and marking the ultrasound image using the marked anatomical map.

18. The method according to claim 10, wherein: The organ is the heart.

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