Guided entrance to epicardial sack with transthoracic ultrasound

Abstract

To guide invasive medical probes.SOLUTION: A method includes using an imaging system external to a body of a patient, the imaging system being fitted with a first position sensor. An image of an anatomical landmark of an organ of the patient is acquired while a position and an orientation of the imaging system are tracked using a positioning system. The anatomical landmark is marked on the image. A location of the mark is computed in a 3D coordinate system of the positioning system. The computed location is stored in a memory.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure generally relates to guiding invasive medical probes, and more particularly to guiding a magnetically position-tracked needle inserted trans-thoracically using further an ultrasound reference image.

Background Art

[0002] Techniques for assisting in guiding invasive medical probes have been previously proposed in the patent literature. For example, U.S. Patent No. 7,918,793 describes how an electroanatomical map image of a body structure having a cyclic motion is overlaid on a 3D ultrasound image of the structure. The electroanatomical data and the anatomical image data are synchronized by gate controlling both the electroanatomical data acquisition and the anatomical image at a particular point in the motion cycle. The transfer of the image data includes the identification of the point within the motion cycle at which the three-dimensional image was captured or is to be displayed.

[0003] As another example, U.S. Patent No. 9,414,770 describes a method that includes making galvanic contact with a patient's body to position body electrodes and identifying a probe within the patient's body. The position of the probe is tracked during the patient's respiration, and an indication related to the impedance between the body electrodes during respiration is determined. The method also includes calculating a function that associates the position of the probe with the indication and applying the function to identify the end-expiration point of respiration based on subsequent indications associated with the impedance.

[0004] A more complete understanding of the present disclosure will be obtained by reading the following detailed description of the embodiments of the present disclosure in conjunction with the drawings.

Brief Description of the Drawings

[0005]

Figure 1

Figure 2

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[0006] Overview Pericardial procedures such as radiofrequency (RF) ablation and / or pulsed field ablation (PFA) can be used to alleviate heart disorders such as certain types of ventricular arrhythmia (VA). VA can be treated by catheter ablation where the catheter is inserted trans-thoracically through a needle. However, it is difficult to guide a physician to insert a needle through the chest and pericardium at the apex because the exact location of the apex is not fully known during the procedure (e.g., due to different patient postures). The apex location is also sensitive to the respiratory cycle. One possible way to address this is the use of fluoroscopy, which involves applying a high dose of X-ray radiation.

[0007] The examples of the present disclosure described below provide a technique that shows a physician a direct line of sight to the apex during trans-thoracic insertion of a position-tracking needle and subsequent insertion of a catheter through the needle for treating the apex tissue. This is done without the need for fluoroscopy during catheter insertion into the pericardium.

[0008] This technique involves obtaining reference images of the chest and heart using an imaging system with a first position sensor (e.g., a magnetic tree axial sensor (TAS)). The US transducer is outside the patient's body. US imaging is performed within the working volume of a positioning system (e.g., CARTO® with a location pad placed under the patient). The user acquires a US image of an anatomical landmark (e.g., the LV apex) of the patient's organ and tracks the position and orientation of the US transducer held based on the signal received by the positioning system from the TAS. The position and orientation of the handheld US transducer are determined in the coordinate system of the positioning system.

[0009] In some examples, the imaging system is a US transducer with a handle. In other examples, the imaging system may be a single-plane fluoroscopic imaging system or a two-plane fluoroscopic imaging system. There is an exposure associated with capturing a reference image using fluoroscopy, but the exposure is required to be significantly less than that required to guide a catheter during the procedure.

[0010] When the user locates the apex on the reference image, the user marks the apex location on the image, and this marked location is calculated in the 3D coordinate system of the positioning system. The calculated location, along with the orientation of the transducer when the apex was observed, is used to identify the three-dimensional location of the marked apex within the working volume of the positioning system. This is later used to determine how to insert a needle through the chest region to reach the apex of the heart.

[0011] For this purpose, after the physician marks the apex in the US image, the processor calculates the location of the mark in the 3D coordinate system of the positioning system and stores that location in space. The processor calculates this location using the known position and orientation of the US handle and the known field of view of the US image relative to the US handle. The calculated (i.e., computed) location is stored in memory.

[0012] In a subsequent clinical procedure, the physician inserts a needle with a second position sensor (e.g., a magnetic position sensor) trans-thoracically into the patient's body. The physician can navigate the needle to an anatomical landmark by using the same or a similar positioning system to track the position of the needle inside the body in real time relative to the recorded and computed apex location.

[0013] In one example, the processor of the positioning system provides a linear trajectory that aligns the trajectory, e.g., the estimated orientation of the US relative to the computed location of the LV apex, with the orientation of the needle. The disclosed technique provides further guidance of the needle using a visual tool that shows the apex location marked in the 3D coordinate system of the positioning system and the current location of the needle.

[0014] The disclosed technique obviates the need for real-time US imaging during needle insertion since the location is already marked. However, insertion through the pericardium at the apex remains a challenge due to the LV apex location sensitivity to the respiratory cycle.

[0015] In some examples, the processor monitors the impedance between patches of an electrical location detection system to estimate the resulting apex movement. In one example, some patches are positioned on the chest and three patches are positioned on the patient's back. The impedance changes between the patches are correlated with the observed movement of the apex and can be used by the processor to motion correct the marked location of the apex to guide the physician in reaching the apex during successive cyclic motion of the apex.

[0016] Description of the System FIG. 1 is a schematic depiction of a catheter-based electroanatomical (EA) mapping and ablation system 10, according to one embodiment of the present disclosure. FIG. 1 shows a physician 24 inserting a trans-thoracic location tracking needle 66 into the chest of a patient 23 and then inserting a catheter 214 through the needle, as shown in more detail in FIG. 2.

[0017] As seen in the inset FIG. 45, a magnetic base position sensor 114 is disposed on the distal end 128 of the needle 66. Using a positioning system that employs the position sensor 114, the processor guides the needle 66 (or cannula 66) in the vicinity of the heart 12, as described below.

[0018] Using the trans-thoracic needle 66 insertion, the catheter 214 is inserted into the patient's chest through the needle 66, as further shown in FIG. 2, to access the heart 12 and sense and ablate arrhythmogenic epicardial tissue at the LV apex 99.

[0019] The system 10 may include multiple catheters and in the inset FIG. 45, the catheter 14 is shown as being inserted separately from the needle 66 for clarity (however, it may be inserted by the physician 24 through the needle 66). The catheter 214 and the catheter 14 may be the same type of catheter.

[0020] The plurality of catheters may include catheters dedicated to sensing intracardiac electrograms (IEGMs), and / or both sensing and ablation, and an imaging catheter. Also illustrated herein is an exemplary tip catheter 14 configured to sense an IEGM and perform electrical ablation (in inset figure 45, physician 24 contacts tip assembly 28 attached to the shaft 44 of catheter 14 to the heart wall to sense and / or ablate a target site within heart 12 using tip electrode 26).

[0021] As described above, magnetic - based position sensors 114 and 29 are attached to the distal end 128 of needle 66 and the distal end 28 of catheter 14, respectively. Sensors 114 and 29 can be operated in conjunction with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. Details of this example of a positioning system, i.e., a magnetic - based position sensing (i.e., 3D magnetic positioning) technique, are described in U.S. Pat. Nos. 5,539,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, 6,892,091.

[0022] System 10 includes one or more electrode patches 38 positioned in contact with the skin of patient 23 to establish a location reference for location pad 25 and an impedance - based tracking function for electrodes 26. For impedance - based tracking, a current is directed to electrodes 26 and sensed at electrode - skin patches 38, whereby the location of each electrode can be triangulated via electrode patches 38. Details of impedance - based location tracking techniques are described in U.S. Pat. Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182.

[0023] The signal from the electrode patch 38 is used by an electrical positioning system that employs a processor 56 to provide respiratory motion compensation while guiding the catheter 11 to the LV apex 99, as further described in FIG. 2.

[0024] The recorder 11 displays the body surface ECG potential map 21 captured by the body surface ECG electrodes 18 and the intracardiac electrogram (IEGM) captured by the electrodes 26 of the catheter 14. The recorder 11 may include pacing capabilities for pacing the heart rhythm and / or may be electrically connected to an independent pacer.

[0025] The system 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes at the distal tip of a catheter configured to ablate. The energy generated by the ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed field ablation (PFA) energy, such as unipolar or bipolar high voltage DC pulses that can be used to effect irreversible electroporation (IRE), or combinations thereof.

[0026] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiology device, the power source, and a workstation 55 for controlling the operation of the system 10. The electrophysiology devices of the system 10 may include, for example, a plurality of catheters, location pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for performing real-time calculations of catheter location and executing ECG calculations.

[0027] Workstation 55 includes a memory 57, a processor 56 unit having a memory or storage device loaded with appropriate operating software, and a user interface function. The workstation 55 optionally provides a plurality of functions including: (i) rendering to model the endocardial anatomical structure in three dimensions (3D) and display a model or anatomical map 20 on a display device 27; (ii) displaying on the display device 27, in a representative visual display or image overlaid on the rendered electroanatomical (EA) map 20, an activation sequence (or other data) compiled from the recorded electrogram 21; (iii) displaying the real-time locations and orientations of a plurality of catheters within the ventricle; and (iv) displaying on the display device 27 a site of interest such as a location where ablation energy has been applied. One commercially available product embodying the elements of the system 10 is available as the CARTO (trademark) 3 system, commercially available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618.

[0028] Motion Compensation Guidance System for LV Apex Target FIG. 2 is a schematic depiction of a combined ultrasonic, magnetic tracking, and electrical tracking system configured for motion compensation guidance of a trans-thoracically inserted needle 66 and catheter 214 through the needle 66, according to an embodiment of the present disclosure. The present embodiment shows the ultrasonic acquisition and the rest of the system elements together, but generally, the US image can be acquired and marked (e.g., tagged) separately (e.g., at an earlier time and at a different location) from that of the catheter guidance procedure. This is possible because the needle guide relies only on the US image that has been location-marked, and the location information of the US handheld transducer is acquired during the US procedure and not during real-time US acquisition.

[0029] FIG. 2 shows an imaging system such as a handheld US transducer 211 to which is attached a magnetic position sensor 222 (e.g., TAS222) that emits signals indicative of the position and orientation obtained by a positioning system (such as the same magnetic position tracking system included in system 10 of FIG. 1 used when guiding needle 66).

[0030] The US system generates a US image 234 of the heart including the LV 256 and the LV apex 299. The location and orientation of the handheld US transducer 211 are analyzed and recorded by processor 56 after the user marks the LV apex 299 on at least one of the US images.

[0031] Alternatively, other imaging systems such as a single-plane fluoroscopic imaging system or a bi-plane fluoroscopic imaging system are used, and the position sensor is mounted on the imaging portion of the system.

[0032] As described in the flowchart of FIG. 3 below, processor 56 uses the stored position information of the LV mark 299 to display the LV marks 288 calculated (up to 299) on the anatomical model 244 of the LV 276 respectively (27). Processor 56 further displays the needle 66 on the anatomical model and adds a straight (i.e., linear) trajectory 255 to the calculated LV apex mark 288. Alternatively, the processor can display the linear trajectory 255 between the needle position and the marked anatomical location in the 3D coordinate system of the positioning system.

[0033] When the needle 66 is advanced and placed, the physician inserts a catheter 214 (e.g., a catheter such as catheter 14) through the needle 66 to diagnose and / or treat the LV apex tissue.

[0034] Motion compensation method for guiding a catheter to an LV apex target Figure 3 is a flowchart illustrating a method for guiding a trans-thoracically inserted probe according to an embodiment of the present disclosure. The method includes two stages, namely, a US tracking stage 300 and a subsequent catheter tracking stage 320. These stages can be performed in this order at different times and different locations.

[0035] According to the presented example, the algorithm executes a process that starts from stage 300 by a US operator, such as a physician 24, who performs a non-invasive US scan of the heart 12 using a handheld US transducer 211 in the US imaging step 302. The handheld US transducer 211 includes a TAS sensor, and the imaging is performed within the working volume of a positioning system, such as CARTO (registered trademark).

[0036] In parallel, the processor records the location and orientation of the handheld US transducer 211 in the handheld US transducer tracking step 304. The location and orientation are determined in the coordinate system of the positioning system.

[0037] In the tagging step 306, the physician marks (299) the LV apex on the US image 234 of the heart LV region 256.

[0038] In the landmark location calculation step 308, after the physician marks the apex on the US image, the processor calculates the location of the mark in the 3D coordinate system of the positioning system. The processor calculates this location using the known location and orientation of the handle and the known field of view of the US image with respect to the handle. The relationship may be determined, for example, during a calibration procedure.

[0039] In the data storage step 310, the user stores that location.

[0040] The process described by stage 320 starts from data upload step 317 when a user such as doctor 24 uploads the LV apex location calculated and stored during steps 308 - 310 above to system 10.

[0041] Next, in the visual guidance tool operation step, the user or the processor opens a visual guidance tool such as one that shows the 3D coordinate system of the positioning system.

[0042] Assuming the visual tool is opened, in the LV mark display step 321, the processor displays an LV mark (identifying the clinical target of the catheter) on the tool. The LV apex location can be marked there (e.g., as a star), and the current location of the distal end of the needle can also be marked (e.g., as a cursor). Additionally, the visual tool can show a line extending between the current location of the needle and the location of the star, indicating the path to follow during needle insertion. As the doctor inserts the needle, the cursor advances based on its tracked location. The doctor can give commands to change the orientation of the view (e.g., rotate the 3D coordinate system).

[0043] In the needle insertion step 322, doctor 24 inserts the position - tracking needle into the patient's body (e.g., chest). The needle preferably includes a TAS sensor at its distal tip.

[0044] In the needle position tracking step 324, the processor records the location and orientation of the distal end 128 inside the patient's body.

[0045] In the needle visualization step 326, after the processor identifies the position of the needle, the processor marks it on the screen and extends a line between the location of the needle and the apex.

[0046] In needle guide step 328, using the position signal from sensor 114 of needle 66, the processor can guide distal end 128, for example, in needle guide step 328, by calculating and displaying the advancement of distal end 128 superimposed on the anatomical model relative to the LV apex mark (e.g., tag 288) on the anatomical model.

[0047] As described in FIG. 4 below, guiding the needle in real time includes adjusting the trajectory 255 to the LV to compensate for respiratory motion.

[0048] Once the needle 66 is in place, the physician can puncture the sac and then insert a catheter through the puncture site.

[0049] The flowchart shown in FIG. 3 was selected merely for the purpose of clarity of concept. This embodiment may also include additional steps of algorithms such as sometimes using X-ray imaging. This step and other possible steps have been intentionally omitted from the disclosure herein to provide a more simplified flowchart.

[0050] FIG. 4 is a flowchart schematically illustrating a method for motion compensation during guidance of a trans-thoracically inserted needle of FIG. 3 according to an embodiment of the present disclosure.

[0051] The process starts from visualization step 402, and the processor shows on display 27 the location of the apex and the location of the distal end of the needle inside the body.

[0052] In the electrical detection step 404 of body movement, the processor receives electrical position signals from an electrical location system that employs patches 38 as described in FIGS. 1 and 2. These signals indicate the LV mark movement due to body movement (e.g., patient's respiration).

[0053] In vertex location monitoring and adjustment 406, the processor calculates and displays the new location of the vertex.

[0054] In adjustment step 408, the processor adjusts the extending virtual line 255 based on the current location of the needle and the marked location 288 of the newly (due to body movement) calculated (i.e., computed) vertex.

[0055] When the needle reaches the target location, the physician inserts a catheter through the needle and performs the intended procedure (e.g., ablation to eliminate LV arrhythmia).

Example

[0056] (Example 1) The method includes using an imaging system (211) with a first position sensor (222) that is external to the patient's body. An image (234) of the anatomical landmarks (99) of the patient's organ (12) is acquired, and the position and orientation of the imaging system (211) are tracked using a positioning system. The anatomical landmarks (99) are marked (299) on the image (234). The location of the mark is calculated in the 3D coordinate system of the positioning system. The calculated location (288) is stored in the memory (57).

[0057] (Example 2) The method according to Example 1, including inserting a needle (66) with a second position sensor (114) into the patient's body. The position of the needle (66) is tracked inside the body. Using the positioning system and the location, the user is guided to navigate the needle to the anatomical landmark (99).

[0058] (Example 3) The method according to Example 1 or 2, wherein guiding the needle (66) to the anatomical landmark (99) includes using a visual tool (244) with a marked location.

[0059] (Example 4) The method according to any one of Examples 1 to 3, wherein the visual tool (244) shows the 3D coordinate system of the positioning system.

[0060] (Example 5) The method according to any one of Examples 1 to 4, wherein guiding further includes displaying a linear trajectory (255) between the needle (66) position and the calculated anatomical location (288) in the 3D coordinate system of the positioning system.

[0061] (Example 6) The method according to any one of Examples 1 to 5, including adjusting the marked location (288) to compensate for body movement using body movement tracking (238).

[0062] (Example 7) The method according to any one of Examples 1 to 6, wherein the first and second position sensors (222, 114) are magnetic position sensors used by a magnetic positioning system.

[0063] (Example 8) The method according to any one of Examples 1 to 7, wherein the imaging system is a hand-held ultrasonic probe.

[0064] (Example 9) The method according to any one of Examples 1 to 7, wherein the imaging system is a single-plane fluoroscopic imaging system or a two-plane fluoroscopic imaging system.

[0065] (Example 10) The system (10) includes an imaging system (211) and a processor (56). The imaging system (211) is located outside the patient's body and has a first position sensor (222) attached thereto, and is configured to acquire an image (234) of anatomical landmarks (99) of the patient's organ (12) while the position and orientation of the imaging system (211) are tracked using the first position sensor (222) by a positioning system. The processor (56) is configured to (i) mark (299) the anatomical landmarks (99) on the image (234), (ii) calculate the location (288) of the marks in the 3D coordinate system of the positioning system, and (iii) store the marked locations in a memory (57).

[0066] The embodiments described herein mainly address cardiac diagnostic applications, but the methods and systems described herein can also be used for other medical applications.

[0067] It should be understood that the embodiments described above are given by way of example, and the present disclosure is not limited to what is particularly illustrated and described above in this specification. Rather, the scope of the present disclosure includes both various combinations and sub - combinations of the features described above in this specification, as well as those variations and modifications thereof that would occur to a person skilled in the art upon reading the foregoing description and that are not disclosed in the prior art.

[0068] 〔Embodiments〕 (1) A method comprising: using an imaging system that is outside the patient's body and has a first position sensor attached thereto to acquire an image of anatomical landmarks of the patient's organ and to track the position and orientation of the imaging system using a positioning system; marking the anatomical landmarks on the image; calculating the location of the marks in the 3D coordinate system of the positioning system; and storing the calculated locations in a memory. (2) Inserting a needle with a second position sensor attached therein into the body of the patient, tracking the position of the needle inside the body, using the positioning system and the location to guide a user to navigate the needle to the anatomical landmark, the method according to Embodiment 1. (3) The method according to Embodiment 1, wherein guiding the needle to the anatomical landmark includes using a visual tool marked with the location. (4) The method according to Embodiment 3, wherein the visual tool shows the 3D coordinate system of the positioning system. (5) The method according to Embodiment 4, wherein guiding further includes displaying a linear trajectory between the needle position and the calculated anatomical location in the 3D coordinate system of the positioning system.

[0069] (6) The method according to Embodiment 1, including adjusting the calculated location to compensate for body movement using body movement tracking. (7) The method according to Embodiment 1, wherein the first position sensor and the second position sensor are magnetic position sensors used by a magnetic positioning system. (8) The method according to Embodiment 1, wherein the imaging system is a handheld ultrasound probe. (9) The method according to Embodiment 1, wherein the imaging system is a single-plane fluoroscopic imaging system or a biplane fluoroscopic imaging system. (10) A system, an imaging system outside the body of a patient, wherein a first position sensor is attached to the imaging system, and the imaging system is configured to acquire an image of an anatomical landmark of an organ of the patient while the position and orientation of the imaging system are tracked by the positioning system using the first position sensor, the imaging system; a processor, and the processor is Marking the anatomical landmarks on the image; Calculating the location of the mark in the 3D coordinate system of the positioning system; A system configured to perform storing the calculated location in a memory.

[0070] (11) A needle configured to be inserted into the body of the patient, with a second position sensor attached thereto; A processor configured to track the position of the needle inside the body and guide a user to navigate the needle to the anatomical landmark using the positioning system and the location, the system according to embodiment 10. (12) The system according to embodiment 10, wherein the processor is configured to guide the needle to the anatomical landmark by using a visual tool marked with the location. (13) The system according to embodiment 12, wherein the visual tool shows the 3D coordinate system of the positioning system. (14) The system according to embodiment 13, wherein the processor is further configured to guide by displaying a linear trajectory between the needle position and the calculated anatomical location in the 3D coordinate system of the positioning system. (15) The system according to embodiment 10, wherein the processor is configured to adjust the calculated location to compensate for body movement using body movement tracking.

[0071] (16) The system according to embodiment 10, wherein the first position sensor and the second position sensor are magnetic position sensors used by a magnetic positioning system. (17) The system according to embodiment 10, wherein the imaging system is a hand-held ultrasonic probe. (18) The system according to embodiment 10, wherein the imaging system is a single-plane fluoroscopic imaging system or a two-plane fluoroscopic imaging system.

Claims

1. 1. A system comprising: an imaging system external to the patient's body, the imaging system having a first position sensor attached thereto, the imaging system configured to acquire images of anatomical landmarks of an organ of the patient while a position and orientation of the imaging system is tracked by a positioning system using the first position sensor; a processor, the processor comprising: marking the anatomical landmarks on the image; Calculating a location of the mark in a 3D coordinate system of the positioning system; storing the calculated location in a memory.

2. a needle configured to be inserted into the body of the patient, the needle having a second position sensor attached thereto; 2. The system of claim 1, comprising: a processor configured to track a position of the needle within the body and to guide a user to navigate the needle to the anatomical landmark using the positioning system and the location.

3. The system of claim 1 , wherein the processor is configured to guide the needle to the anatomical landmark by using a visual tool with the location marked.

4. The system of claim 3 , wherein the visual tool shows a 3D coordinate system of the positioning system.

5. 5. The system of claim 4, wherein the processor is further configured to guide by displaying a linear trajectory between a needle position and a calculated anatomical location in the 3D coordinate system of the positioning system.

6. The system of claim 1 , wherein the processor is configured to use body movement tracking to adjust the calculated location to compensate for body movement.

7. The system of claim 1 , wherein the first position sensor and the second position sensor are magnetic position sensors used by a magnetic positioning system.

8. The system of claim 1 , wherein the imaging system is a handheld ultrasound probe.

9. The system of claim 1 , wherein the imaging system is a single-plane fluoroscopic imaging system or a biplane fluoroscopic imaging system.

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