Systems and Methods for Vascular Visualization

Abstract

Multiple embodiments of the present disclosure relate to an intravascular imaging display system and related methods. In one embodiment, an intravascular imaging display system having a control circuit and a video output circuit is included. The video output circuit is configured to generate a display output including a user interface. The user interface includes a plurality of graphical elements related to the imaged vasculature. The plurality of graphical elements includes a first detected feature portion at least partially defined by a first graphic indicator and a second detected feature portion at least partially defined by a second graphic indicator. The first graphic indicator is visually different from the second graphic indicator. The first detected feature portion and the second detected feature portion are assigned by the control circuit to indicate one or more positions along the vessel wall based on whether the attenuation degree of the ultrasonic feedback signal exceeds a threshold value.

Description

Technical Field

[0001] Multiple embodiments of the present disclosure relate to intravascular imaging display systems and related methods.

Background Art

[0002] Imaging systems, such as intravascular ultrasound (“IVUS”) imaging systems, have been developed to provide diagnostic tools for visualizing various diseases or disorders. For example, an IVUS imaging system is used as an imaging modality that diagnoses occluded blood vessels and provides information to assist a physician in selecting and placing stents and other devices to restore or increase blood flow. The IVUS imaging system is also used to diagnose the accumulation of atherosclerotic plaque at specific locations within a blood vessel. The IVUS imaging system can also be used to determine the presence of obstructions or stenoses within a blood vessel, as well as the nature and extent of the obstructions or stenoses. The IVUS imaging system can be used, for example, to visualize multiple segments of the vasculature that may be difficult to visualize using other intravascular imaging techniques, such as angiography, due to movement (e.g., a beating heart) or obstructions by one or more structures (e.g., one or more blood vessels that are not desired to be imaged). The IVUS imaging system can also be used to monitor or evaluate ongoing intravascular treatments, such as angiography and stent placement, in real time (or near real time). Additionally, the IVUS imaging system can be used to monitor one or more heart chambers.

Summary of the Invention

[0003] Multiple embodiments of the present disclosure relate to intravascular imaging display systems and related methods. In a first aspect, an intravascular imaging display system having a control circuit and a video output circuit is included. The video output circuit may be configured to generate a display output including a user interface. The user interface may include a plurality of graphical elements related to the imaged vasculature. The plurality of graphical elements may include a first detected feature portion that may be at least partially defined by a first graphic indicator. The plurality of graphical elements may include a second detected feature portion that may be at least partially defined by a second graphic indicator. The first graphic indicator may be visually different from the second graphic indicator. The first detected feature portion and the second detected feature portion may be assigned by the control circuit to indicate one or more positions along the vessel wall based on whether the attenuation degree of the ultrasonic feedback signal exceeds a threshold.

[0004] In a second aspect, in addition to or as an alternative to one or more of the aspects described above or below, the first graphic indicator may include a solid boundary. In a third aspect, in addition to or as an alternative to one or more of the aspects described above or below, the second graphic indicator may include a dashed boundary.

[0005] In a fourth aspect, in addition to or as an alternative to one or more of the aspects described above or below, the plurality of graphical elements may be related to a longitudinal cross-section of the vasculature.

[0006] In a fifth aspect, in addition to or as an alternative to one or more of the aspects described above or below, the plurality of graphical elements may be related to a radial cross-section of the vasculature.

[0007] In a sixth aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the first detected feature portion may include a display of a first lumen boundary and a display of a first vasculature boundary. The second detected feature portion may include a display of a second lumen boundary and a display of a second vasculature boundary.

[0008] In a seventh aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the positions of the plurality of displays of the first vasculature boundary, the second vasculature boundary, the first lumen boundary, and the second lumen boundary may be determined using a machine learning-derived model.

[0009] In an eighth aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the positions of the plurality of displays of the first vasculature boundary, the second vasculature boundary, the first lumen boundary, and the second lumen boundary may be determined using a deep learning-derived model.

[0010] In a ninth aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the user interface includes one or more numerical parameters related to the vasculature being imaged, and the one or more numerical parameters may include typographical features indicating whether the one or more numerical parameters are related to the first detected feature portion or the second detected feature portion.

[0011] In a tenth aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the user interface may be configured to receive user input regarding the positions of a plurality of graphical elements from a system user.

[0012] In the 11th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the user interface may be configured to receive user input from a system user regarding at least one of the position of the display of the first vascular boundary and the position of the display of the second vascular boundary.

[0013] In the 12th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the intravascular imaging display system may be configured to use user input as part of a dataset for generating a machine learning model.

[0014] In the 13th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the first detected feature portion includes one or more distinct portions separated by one or more distinct portions of the second detected feature portion.

[0015] In the 14th aspect, a method of providing a display of an intravascular imaging display system can be included. The method can include distinguishing a first vascular wall portion and a second vascular wall portion based on the attenuation degree of the ultrasonic feedback signal. The method includes generating a display output including a user interface, and the user interface can include a plurality of graphical elements related to the imaged blood vessel including a first detected feature portion corresponding to the first vascular wall portion and a second detected feature portion corresponding to the second vascular wall portion. The first detected feature portion can be at least partially defined by a first graphic indicator, and the second detected feature portion can be at least partially defined by a second graphic indicator. The first graphic indicator can be visually different from the second graphic indicator.

[0016] In a 15th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the first graphic indicator may include a solid-line boundary and the second graphic indicator may include a dashed-line boundary.

[0017] In a 16th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the method may further include using a machine learning-derived model to determine the positions of a plurality of graphical elements associated with the imaged vasculature.

[0018] In a 17th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the method may further include using a deep learning-derived model to determine the positions of a plurality of graphical elements associated with the imaged vasculature.

[0019] In an 18th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the method may further include receiving user input from a system user regarding a plurality of graphical elements associated with the imaged vasculature.

[0020] In a 19th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the method may include receiving user input from a system user regarding the position of the vasculature boundary.

[0021] In a 20th aspect, in addition to one or more of the aspects described above or below, or as an alternative to some aspects, the method may include using the user input as part of a training data set for generating a machine learning model.

[0022] This summary is a partial summary of the teachings of this application and is not intended to be an exclusive or exhaustive treatment of the subject matter. Further details are found in the detailed description and the appended claims. Other aspects will be apparent to those of ordinary skill in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, which are to be construed in a non-limiting sense. The scope of the application is defined by the appended claims and their legal equivalents. **Brief Description of the Drawings**

[0023] The various aspects can be more fully understood in connection with the following drawings.

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DETAILED DESCRIPTION OF THE INVENTION

[0024] The plurality of embodiments may have various modifications and alternative forms, the details of which are shown by way of example and the drawings and will be described in detail below. However, it should be understood that the scope of the present application is not limited to the specific embodiments described. Rather, the present invention encompasses modifications, equivalents, and alternative forms that are included within the spirit and scope of the present application.

[0025] As described above, imaging systems have been developed to provide diagnostic tools for visualizing various diseases or disorders. As an example, an IVUS imaging system can include a control module (comprising a pulse generator, an image processor, and a display or monitor), a catheter, and one or more transducers disposed on the catheter. The catheter containing the transducer can be disposed within or adjacent to a lumen or cavity within or adjacent to the region to be imaged, such as the vessel wall or patient tissue adjacent to the vessel wall. The pulse generator of the control module generates an electrical pulse, which is delivered to one or more transducers and converted into an acoustic pulse that is transmitted through the patient tissue. The reflected pulse of the transmitted acoustic pulse is absorbed by one or more transducers and converted into an electrical pulse. The converted electrical pulse is delivered to the image processor and converted into an image that can be displayed on a monitor.

[0026] The value of an imaging system can be enhanced by automatically identifying multiple portions of an anatomically structure of clinical interest and / or automatically calculating measurements thereof. For example, in some scenarios, the system can automatically determine the location of anatomical features of interest (such as the lumen boundary of a vessel and / or the boundary of the vessel wall) by evaluating the imaging signal using machine learning techniques. Specifically, the model can be generated through machine learning techniques (such as supervised learning methods, deep learning methods, and / or the like), and then applied to the imaging signal to identify the location and / or measurements of the anatomical features of interest. The locations and / or measurements of multiple anatomical features of interest can be displayed within the user interface of the system herein in the form of a graphical element that indicates the multiple anatomical features of interest and / or their measurements or characteristics.

[0027] However, in many cases, the ability of a system to accurately determine the location of multiple anatomical features of interest in an automated manner depends on the ability to collect an imaging signal with a sufficient signal-to-noise ratio. Some conditions (such as the presence of plaque that attenuates ultrasonic signals) interfere with the imaging process and specifically can attenuate the signal collected by the system and / or reduce its signal-to-noise ratio to a level that hinders the accurate and reliable identification of the location of multiple anatomical features of interest in an automated manner by the system. In such cases, the system may still be able to estimate the location of such features, but the estimate may lack the typical level of positional accuracy for the system. In such cases, it may be important for a system user (such as a clinician) to be aware of the positional accuracy of the multiple features depicted by the system, such as instances of possible degradation in positional accuracy.

[0028] Embodiments of this specification can provide information regarding the identified positions of a plurality of anatomical features of interest and / or the accuracy of their measurements to a system user, for example, through a user interface. In various embodiments of this specification, an intravascular imaging display system can display a plurality of graphical components to provide information regarding its positional accuracy. For example, in various embodiments of this specification, an intravascular imaging display system can include a first vascular wall portion at least partially defined by a first graphic indicator and a second vascular wall portion at least partially defined by a second graphic indicator that is visually different from the first graphic indicator, and display a plurality of graphic components related to the vascular wall. The first vascular wall portion and the second vascular wall portion can each indicate one or more positions along the vascular wall with different degrees of positional accuracy or reliability as determined by a control circuit based on the attenuation degree of the ultrasonic feedback signal or based on another metric or technique. Therefore, the visually different first vascular wall portion and second vascular wall portion can be used to visually inform the system user of the difference in the accuracy of determining their positions.

[0029] In various embodiments, a method of providing a display of the intravascular imaging display system of this specification can include a plurality of operations of distinguishing a first vascular wall portion from a second vascular wall portion based on the attenuation degree of the ultrasonic feedback signal or another metric or technique (such as signal-to-noise ratio or the like) indicating the position and / or the accuracy of the measurement of a plurality of anatomical features of interest, and generating a display output including a user interface. The user interface can include a plurality of graphical components related to the display of the vascular wall including the display of the first vascular wall portion and the display of the second vascular wall portion. The display of the first vascular wall portion can be at least partially defined by a first graphic indicator, and the display of the second vascular wall portion can be at least partially defined by a second graphic indicator.

[0030] Referring now to FIG. 1, a schematic diagram of an intravascular imaging system 100 according to various embodiments of the present specification is shown. In this example, the intravascular imaging system 100 takes the form of an IVUS imaging system. However, other imaging systems including optical coherence tomography imaging systems are also contemplated. The intravascular imaging system 100 includes a catheter 102 that can be coupled to a processing unit or control module 104. The control module 104 can include, for example, a control circuit 106, a pulse generator 108, a drive unit 110, a video output circuit 112, and one or more displays or display units 114. In some examples, the pulse generator 108 forms electrical pulses that can be input to one or more transducers disposed within the catheter 102.

[0031] For the purposes of this specification, the term "display" can refer to either an electronic device (e.g., a monitor, etc.) used for visual display of data and / or the visual display of the data itself. In other words, the term "display" can, depending on the context, refer to the hardware device for displaying data, as well as the data displayed on the hardware device.

[0032] In some examples, mechanical energy from the drive unit 110 can be used to drive an imaging core disposed within the catheter 102. In some examples, electrical signals transmitted from one or more transducers can be input to the control circuit 106 for processing. In some examples, the processed electrical signals from one or more transducers can be displayed as one or more images on one or more display units 114. For example, a scan converter can be used to map scan line samples (e.g., radial scan line samples, etc.) to a two-dimensional Cartesian grid to display one or more images on one or more display units 114.

[0033] In some examples, control circuit 106 may be used to control the function of one or more of the other components of control module 104. For example, control circuit 106 may control the frequency or duration of the electrical pulses transmitted from pulse generator 108, the rotational speed of the imaging core by drive unit 110, the speed or length of the retraction of the imaging core by drive unit 110, or at least one of one or more characteristics of one or more images formed on one or more display units 114.

[0034] Referring now to FIG. 2, a schematic radial cross-sectional view of an imaged vasculature according to various embodiments of the present specification is shown. FIG. 2 shows catheter 102 and ultrasonic acoustic pulse 204 from catheter 102. The imaged vasculature includes a vascular lumen 202 and a lumen boundary 206. The vasculature also includes a vascular boundary 208. FIG. 2 also shows surrounding tissue 210. Ultrasonic acoustic pulse 204 is reflected by such multiple portions of the tissue to generate an image such as that shown in FIGS. 4-15 and is then processed by the system.

[0035] However, plaques that attenuate ultrasonic signals may interfere with ultrasonic imaging by reaching and / or attenuating the amount of signal reflected back from anatomical features such as the vascular boundary. Referring now to FIG. 3, a schematic radial cross-sectional view of an imaged vasculature according to various embodiments of the present specification is shown. Similar to FIG. 2, FIG. 3 shows catheter 102 and ultrasonic acoustic pulse 204 from catheter 102, along with vascular lumen 202, lumen boundary 206, vascular boundary 208, and surrounding tissue 210. However, FIG. 3 also shows a plaque 302 that attenuates ultrasonic signals, which may reduce the accuracy of automatically determining the location of multiple features such as vascular boundary 208.

[0036] Embodiments of the plurality of imaging systems of this specification include a user interface, and the ultrasonic image and / or its display can be shown including a plurality of graphical elements indicating the locations of a plurality of anatomical features such that the location accuracy of the locations is visually apparent to the system user. Referring now to FIG. 4, a schematic diagram of a display 114 of an intravascular imaging system according to various embodiments of this specification is shown. FIG. 4 shows a user interface 402. The user interface 402 includes a plurality of features regarding a radial cross-section 404 of the imaged vasculature. The user interface 402 also includes a measurement parameter region 406. The user interface 402 also includes a plurality of features regarding a longitudinal cross-section 408 of the imaged vasculature.

[0037] Referring now to FIG. 5, a schematic diagram of a plurality of specific components of a display 114 of an intravascular imaging system according to various embodiments of this specification is shown. The user interface includes a plurality of features regarding a radial cross-section 404 of the imaged vasculature. In this example, the plurality of features associated with the radial cross-section 404 include a depicted lumen boundary 502 and a depicted vasculature boundary 504. In this example, the depicted lumen boundary 502 is shown as a graphic indicator or graphical element in the form of a solid line, and the depicted vasculature boundary 504 is shown as a graphic indicator in the form of a dashed or broken line. This visual distinction in these lines can be used to indicate a region where signal attenuation (or another effect) can affect the accuracy of the location of the depicted vasculature boundary 504 such that it is shown through the user interface. In contrast, if the depicted vasculature boundary 504 is considered to be shown with high location accuracy, the depicted vasculature boundary 504 can be shown within the user interface with a solid or continuous line.

[0038] The user interface may also include a measurement parameter area 406. The measurement parameter area 406 may include various measurement values such as lumen (lumen) measurement values 506, vascular measurement values 508, plaque data 510, and the like. In this example, the lumen measurement value 506 is shown in a font including a solid line, and the vascular measurement value 508 is shown in a font including a dashed line or a broken line. This can be used to indicate to the system user that while the lumen measurement value 506 is highly accurate, the vascular measurement value 508 may not be as accurate due to signal attenuation or other effects in that portion of the vasculature. Instead of or in addition to using the difference between the dashed line and the solid line to clearly indicate the data, other visually distinguishable techniques (such as other typographical features) can be used, such as using different colors, different fonts, italic fonts, bold fonts, underlines, different kerning, different fillings, or different borders, to indicate measurement values that may not be as accurate.

[0039] The user interface may also include a plurality of graphical components related to the longitudinal cross-section 408 of the imaged vasculature. In this example, the plurality of graphical components related to the longitudinal cross-section 408 may include a distal-to-proximal navigation guide 512 and a navigation slider 516 that can be used by the system user to quickly navigate the image data longitudinally along the length of the imaged vasculature.

[0040] The user interface may also include a display 514 of the longitudinal blood vessel wall. The display 514 of the longitudinal blood vessel wall may include a focus region 524 that includes a lumen 520 and a blood vessel wall 518. The blood vessel wall 518 may include a first blood vessel wall portion 528 and a second blood vessel wall portion 526. The first blood vessel wall portion 528 includes a first lumen boundary 502. The first blood vessel wall portion 528 also includes a first blood vessel boundary 504. The user interface may also include a marker of the minimum cross-sectional area 522 of the lumen.

[0041] The first blood vessel wall portion 528 and the second blood vessel wall portion 526 can be assigned by the control circuit 106 to indicate one or more positions along the blood vessel wall 518 based on whether the attenuation degree of the ultrasonic feedback signal exceeds a threshold value. The first blood vessel wall portion 528 may be a specific continuous segment or may be divided into a plurality of separate segments. Similarly, the second blood vessel wall portion 526 may be a specific continuous segment or may be divided into a plurality of separate segments. In various embodiments, the first blood vessel wall portion 528 can be divided into a plurality of discrete portions separated by the second blood vessel wall portion 526. In various embodiments, the first blood vessel wall portion 528 can be at least partially defined by a first graphic indicator. In various embodiments, the first graphic indicator may include a solid boundary. In various embodiments, the second blood vessel wall portion 526 can be at least partially defined by a second graphic indicator. In various embodiments, the second graphic indicator may include a dotted, dashed, or interrupted boundary.

[0042] In various embodiments, the system can use a threshold of signal attenuation to distinguish which portions of the longitudinal display 514 of the vessel wall are the first vessel wall portion 528 and which portions of the longitudinal display 514 of the vessel wall are the second vessel wall portion 526. In some embodiments, this threshold can be preset. In some embodiments, this threshold may be set dynamically. The threshold of attenuation degree may be preset or may be set dynamically. In some embodiments, the threshold of signal attenuation degree can be a value that falls within a range of 1, 2, 3, 5, 7, 10, 20, 30, 40, 50, 60, 70, 80, 90 percent attenuation or less or more, or between any of the above.

[0043] In various embodiments, the positions of the first vessel boundary 504 and the second vessel boundary 208 are determined using a machine learning-derived model. In various embodiments, the first vessel boundary 504 and the second vessel boundary 208 are determined using a deep learning-derived model.

[0044] Many different techniques can be used to make the display of the first vessel wall portion and the display of the second vessel wall portion visually distinguishable from each other. Referring now to FIG. 6, a schematic diagram of a plurality of components of a display of an intravascular imaging system according to various embodiments herein is shown. FIG. 6 shows a plurality of graphical components related to a longitudinal cross-section 408 of the imaged vessel. Similar to FIG. 5, the longitudinal cross-section 408 includes a distal-to-proximal navigation guide 512, a navigation slider 516, and a longitudinal display 514 of the vessel wall. The longitudinal display 514 of the vessel wall includes a plurality of graphic elements representing the vessel wall 518, the vessel lumen 520, and markers of the minimum cross-sectional area 522 of the lumen. The vessel wall can be visually distinguished into a first vessel wall portion 528 and a second vessel wall portion 526. In this embodiment, the vessel wall 518 includes a filled portion 602 associated with the first vessel wall portion 528. The filled portion 602 can make the first vessel wall portion 528 even more visually distinct.

[0045] When a system user moves to a portion of the vasculature where the signal attenuation is sufficiently low, the depicted vasculature boundary 504 can be shown as a solid line. Referring now to FIG. 7, a schematic diagram of a plurality of components of a display of an intravascular imaging system according to various embodiments herein is shown. The user interface includes a plurality of features associated with a radial cross-section 404 of the imaged vasculature including the depicted lumen boundary 502 and the depicted vasculature boundary 504. In this example, both the depicted lumen boundary 502 and the depicted vasculature boundary 504 are shown as solid lines.

[0046] In some scenarios, simply displaying the positions of a plurality of features other than the vasculature boundary can indicate a decrease in the confidence of the position accuracy. Referring now to FIG. 8, a schematic diagram of a plurality of components of a display of an intravascular imaging system according to various embodiments herein is shown. The user interface includes a plurality of features associated with a radial cross-section 404 of the imaged vasculature including the depicted lumen boundary 502 and the depicted vasculature boundary 504, and both the depicted lumen boundary 502 and the depicted vasculature boundary 504 are shown as dashed lines.

[0047] In some embodiments, overlapping lines can be used to indicate a decreased confidence in the position accuracy. Referring now to FIG. 9, a schematic diagram of a plurality of components of a display of an intravascular imaging system according to various embodiments herein is shown. The user interface includes a plurality of features associated with a radial cross-section 404 of the imaged vasculature including the depicted lumen boundary 502 and the depicted vasculature boundary 504. In this example, the depicted vasculature boundary 504 is shown as a double line. However, triple lines or different numbers of offset lines are also contemplated herein.

[0048] In some embodiments, one or more filled sections can be included in the user interface to indicate a reduced confidence in the positional accuracy. Referring now to FIG. 10, a schematic view of a plurality of graphical components of the user interface of a display of an intravascular imaging system according to various embodiments herein is shown. The user interface includes a plurality of features related to a radial cross-section 404 of the imaged vasculature that includes the depicted lumen boundary 502 and the depicted vasculature boundary 504. The user interface may also include a filled portion 1002 between the depicted lumen boundary 502 and the depicted vasculature boundary 504.

[0049] In some embodiments, irregular lines and / or zig-zag lines may be included in the user interface to indicate a reduced confidence in the positional accuracy. Referring now to FIG. 11, a schematic view of a plurality of components of a display including the user interface of an intravascular imaging system according to various embodiments herein is shown. The user interface includes a plurality of features related to a radial cross-section 404 of the imaged vasculature that includes the depicted lumen boundary 502 and the depicted vasculature boundary 504. In this example, the depicted vasculature boundary 504 is shown as a zig-zag line to visually indicate a reduction in the confidence of the positional accuracy.

[0050] In some embodiments, the reliability of the positional accuracy may be reduced for only a part of the radial cross-section. For example, the plaque that attenuates the signal is not attached to the vasculature at 360°. In such a scenario, the reliability of the positional accuracy may be reduced for a specific radial portion of the anatomical feature of interest, but may not be reduced for the remaining portions. Thus, in some embodiments, a part of a graphic element such as a line can be displayed in a specific manner, and the remaining part can be displayed in a different manner. Referring now to FIG. 12, a schematic diagram of a plurality of components of a display of an intravascular imaging system according to various embodiments of the present specification is shown. The user interface includes a plurality of features related to a radial cross-section 404 of the imaged vasculature including the depicted lumen boundary 502 and the depicted vasculature boundary 504. In this example, the depicted vasculature boundary 504 includes a portion 1202 as a solid line and another portion 1204 as a dotted or dashed line.

[0051] In various embodiments of the present specification, an actual ultrasound image can be shown as part of the display. For example, in various embodiments of the present specification, at least some of the components of the display described herein can be overlaid on, superimposed on or near, or otherwise shown in conjunction with an ultrasound image such as a radial cross-section ultrasound image or a longitudinal cross-section ultrasound image. As a specific example, the depicted lumen boundary and / or the depicted vasculature boundary can be overlaid on a radial cross-section ultrasound image. In this way, the system user can simultaneously view the actual ultrasound image and the locations where the lumen boundary and the vasculature boundary (e.g., the depicted boundaries) where the system is located are determined.

[0052] Referring now to FIG. 13, a schematic diagram of a plurality of components of a display including a user interface of an intravascular imaging system according to various embodiments of the present specification is shown. In particular, FIG. 13 shows a plurality of features associated with a radial cross-section 404 of an imaged vasculature including a depicted lumen boundary 502 and a depicted vasculature boundary 504. The depicted lumen boundary 502 and the depicted vasculature boundary 504 are shown superimposed on an actual ultrasound image 1302 representing a radial cross-section of the vasculature.

[0053] In various embodiments, the user interface can be configured to receive user input from a system user regarding a plurality of displayed graphical features such as the depicted lumen boundary and / or the depicted vasculature boundary. For example, in some scenarios, the system user may look at the ultrasound image and may not agree with the position of some anatomical features depicted by the system. Therefore, the user interface can be configured to receive user input regarding the user's determination of the position of a plurality of anatomical features. For example, the user interface can be configured to receive user input from a system user regarding at least one of the position of a first vasculature boundary and the position of a second vasculature boundary. In various embodiments, the intravascular imaging display system can be configured to use the user input as part of a dataset for the generation of a machine learning model. For example, the user input can be used as training data as part of a supervised machine learning technique to generate an improved model that is used to automatically determine the position of a plurality of anatomical features.

[0054] Referring now to FIG. 14, a schematic diagram of a plurality of components of a display of an intravascular imaging system according to various embodiments of the present specification is shown. The user interface includes a plurality of graphical features related to a radial cross-section 404 of the imaged vasculature that includes the depicted lumen boundary 502 and the depicted vasculature boundary 504. The imaged vasculature may also include a hand-drawn boundary 1402. The hand-drawn boundary 1402 can reflect user input provided using a user input device 1404 such as a stylus, touch screen input, mouse, or other pointer. Data regarding the hand-drawn boundary 1402 (such as its position) can be stored by the system and / or transmitted to remote computing resources such as computing resources in the cloud. In some embodiments, a spatial difference between the depicted vasculature boundary 504 as shown by the system and the hand-drawn boundary 1402 can be calculated. This difference can be stored and / or transmitted to remote computing resources.

[0055] In some embodiments, the synthesis of a plurality of actual ultrasonic images (frames) representing a longitudinal cross-section of a vasculature can be shown within a display. Referring now to FIG. 15, a schematic diagram of a plurality of components of a display of an intravascular imaging system according to various embodiments of the present disclosure is shown. Similar to that described with respect to FIG. 5, FIG. 15 shows a plurality of graphic components associated with a longitudinal cross-section 408. In this example, the plurality of graphical components associated with the longitudinal cross-section 408 can include a navigation slider 516 that can be used by a system user to rapidly move longitudinally along the length of the vasculature for which the image data was acquired. FIG. 15 also shows a display 514 of a longitudinal vasculature wall that includes a focus region 524 that includes a lumen 520 and a vasculature wall 518. The vasculature wall 518 can include a first vasculature wall portion 528 and a second vasculature wall portion 526. The first vasculature wall portion 528 includes a first lumen boundary 502. The first vasculature wall portion 528 also includes a first vasculature boundary 504. The user interface can also include a marker for the minimum cross-sectional area 522 of the lumen (lumen). The first vasculature wall portion 528 and the second vasculature wall portion 526 can be assigned by the control circuit 106 to indicate one or more positions along the vasculature wall 518 based on whether the attenuation level of the ultrasonic feedback signal exceeds a threshold. However, FIG. 15 also shows the synthesis of a plurality of ultrasonic images (frames) 1512 representing a longitudinal cross-section of the imaged vasculature.

[0056] Referring now to FIG. 16, a schematic side view of a catheter 102 of an IVUS imaging system according to various embodiments of the present specification is shown. Although an IVUS system is shown as an example, it will be understood that a plurality of features described herein may also be applicable to other intravascular imaging systems. The catheter 102 includes an elongate member 1602 and a hub 1604. The elongate member 1602 includes a proximal end 1606 and a distal end 1608. In FIG. 16, the proximal end 1606 of the elongate member 1602 is coupled to the catheter hub 1604, and the distal end 1608 of the elongate member is configured and arranged for percutaneous insertion into a patient. Optionally, the catheter 1602 can define at least one flush port, such as flush port 1610. The flush port 1610 may be defined within the hub 1604. The hub 1604 can be configured and arranged to couple to a control module. In some examples, the elongate member 1602 and the hub 1604 are integrally formed. In other examples, the elongate member 1602 and the catheter hub 1604 are formed separately and then assembled together.

[0057] Referring now to FIG. 17, a schematic perspective view of the distal end 1608 of the elongate member 1602 of the catheter 102 according to various embodiments of the present specification is shown. The elongate member 1602 includes a sheath 1702 having a longitudinal axis (e.g., a central longitudinal axis extending axially through the center of the sheath 1702 and / or the catheter 102) and a lumen 1704. An imaging core 1706 is disposed within the lumen 1704. The imaging core 1706 includes an imaging device 1708 coupled to the distal end of a drive shaft 1710 that is rotatable manually or using a computer-controlled drive mechanism. One or more transducers 1712 may be attached to the imaging device 1708 and employed to transmit and receive acoustic signals. The sheath 1702 may be formed from any suitable flexible biocompatible material suitable for insertion into a patient. Examples of suitable materials include, for example, polyethylene, polyurethane, plastic, spiral cut stainless steel, nitinol hypo tubes, etc., or combinations thereof.

[0058] In some examples, as shown, for example, in FIG. 17, an array of transducers 1712 is attached to the imaging device 1708. Alternatively, a single transducer may be used. Any suitable number of transducers 1712 can be used. For example, there may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 16, 20, 25, 50, 100, 500, 1000 or more transducers. As will be appreciated, other numbers of transducers can also be used. When multiple transducers 1712 are employed, the transducers 1712 can be configured in any suitable arrangement, including, for example, a circular arrangement, a rectangular arrangement, etc.

[0059] One or more transducers 1712 can be formed from a material that can convert an applied electrical pulse into a pressure strain on the surface of the one or more transducers 1712 and vice versa. Examples of suitable materials include piezoelectric ceramic materials, piezoelectric composite materials, piezoelectric plastics, barium titanate, lead zirconate titanate, lead metaniobate, polyvinylidene fluoride, and the like. Other transducer technologies include composite materials, single crystal composite materials, and semiconductor devices (e.g., capacitive micromachined ultrasound transducers ("cMUT"), piezoelectric micromachined ultrasound transducers ("pMUT"), etc.).

[0060] The pressure strain on the surface of the one or more transducers 1712 forms an acoustic pulse at a frequency based on the resonant frequency of the one or more transducers 1712. The resonant frequency of the one or more transducers 1712 can be affected by the size, shape, and material used to form the one or more transducers 1712. The one or more transducers 1712 can be disposed within the catheter 102 and formed in any shape suitable for propagating an acoustic pulse at a desired frequency in one or more selected directions. For example, the transducer can be disk-shaped, block-shaped, rectangular-shaped, elliptical-shaped, etc. The one or more transducers can be formed into the desired shape by any process, including, for example, dicing, dice and fill, machining, micromachining, etc.

[0061] As an example, each of the one or more transducers 1712 may include a layer of piezoelectric material sandwiched between a matching layer and a conductive backing material formed from an acoustic absorbing material (e.g., an epoxy substrate having tungsten particles). During operation, the piezoelectric layer can be electrically excited to cause the emission of an acoustic pulse.

[0062] One or more transducers 1712 can be used to form a radial cross-sectional image of the surrounding space. Thus, for example, when one or more transducers 1712 are disposed within catheter 102 and inserted into a patient's blood vessel, the one or more transducers 1712 can be used to form an image of the wall of the blood vessel and the tissue surrounding the blood vessel.

[0063] The imaging core 1706 is rotated about the longitudinal axis of the catheter 102. As the imaging core 1706 rotates, the one or more transducers 1712 emit acoustic signals in different radial directions (e.g., along different radial scan lines). For example, the one or more transducers 1712 can emit acoustic signals at regular (or irregular) increments, such as 256 radial scan lines per rotation. Alternatively, it will be understood that other numbers of radial scan lines per rotation are possible.

[0064] When an emitted acoustic pulse having sufficient energy encounters one or more media boundaries, such as one or more tissue boundaries, a portion of the emitted acoustic pulse is reflected back to the emitting transducer as an echo pulse. Each echo pulse that reaches the transducer with sufficient energy to be detected is converted into an electrical signal at the receiving transducer. The one or more converted electrical signals are transmitted to a control module, where a processor processes the electrical signal characteristics to form a displayable image of the imaged region, at least in part based on a set of information from each of the transmitted acoustic pulse and the received echo pulse. In some examples, rotation of the imaging core 1706 is driven by a drive unit 110 disposed within the control module. In an alternative embodiment, one or more transducers 1712 are fixedly positioned and do not rotate. In that case, the drive shaft 1710 can instead rotate a mirror that reflects acoustic signals to and from the one or more fixed transducers 1712.

[0065] When one or more transducers 1712 are rotated about the longitudinal axis of the catheter 102 that emits the acoustic pulse, a plurality of images can be formed that collectively form a radial cross-sectional image (e.g., a tomographic image) of a portion of the region surrounding the one or more transducers 1712, such as the wall of a blood vessel of interest and the tissue surrounding the blood vessel. The radial cross-sectional images can optionally be displayed on one or more display units 114. The imaging core 1706 can be rotated manually or using a computer control mechanism.

[0066] The imaging core 1706 may move longitudinally along the blood vessel (shown in FIG. 1) into which the catheter is inserted, and as a result, a plurality of cross-sectional images may be formed along the longitudinal length of the blood vessel. During the imaging procedure, one or more transducers 1712 can be retracted (e.g., pulled back) along the longitudinal length of the catheter 102. The catheter can include at least one telescopic portion that can be retracted during the retraction of one or more transducers 1712. In some examples, the drive unit drives the retraction of the imaging core 1706 within the catheter. The retraction distance by the drive unit of the imaging core can be any suitable distance, including, for example, at least 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, or more. Regardless of whether the imaging core 1706 moves longitudinally independently of the catheter, the entire catheter can be retracted during the imaging procedure.

[0067] Optionally, a stepper motor may be used to retract the imaging core 1706. The stepper motor retracts the imaging core 1706 by a short distance and stops at a length sufficient for one or more transducers 1712 to capture one image or a series of images, and then the imaging core 1706 can be retracted by another short distance and another image or a series of images can be captured again, etc.

[0068] The quality of the images generated at different depths from one or more transducers 1712 can be affected by one or more factors, including, for example, bandwidth, transducer focus, beam pattern, and the frequency of the acoustic pulse. The frequency of the acoustic pulse output from one or more transducers 1712 can also affect the penetration depth of the acoustic pulse output from one or more transducers 1712. Generally, as the frequency of the acoustic pulse decreases, the penetration depth of the acoustic pulse in the patient tissue increases. In some examples, the intravascular imaging system 100 operates within a frequency range from 5 MHz to 100 MHz.

[0069] One or more conductors 1714 can electrically couple the transducer 1712 to the control module (shown in FIG. 1). In that case, the one or more conductors 1714 can extend along the longitudinal length of the rotatable drive shaft 1710.

[0070] A catheter with one or more transducers 1712 attached to the distal end 1608 of the imaging core 1708 can be percutaneously inserted into a patient through an accessible blood vessel such as the femoral artery, femoral vein, or jugular vein at a site remote from a selected portion of a selected region such as a blood vessel to be imaged. The catheter can then be advanced through the patient's blood vessel to a selected imaging site such as a portion of the selected blood vessel.

[0071] An image or image frame ("frame") can be generated each time one or more acoustic signals are output into the surrounding tissue, one or more corresponding echo signals are received by the imaging device 1708, and transmitted to the processor. Alternatively, the image or image frame can be a synthesis of scan lines from a full or partial rotation of the imaging core or device. Multiple frames (e.g., a sequence of frames) can be acquired over time during any type of movement of the imaging device 1708. For example, a frame can be acquired during rotation and retraction of the imaging device 1708 along a target imaging position. It should be understood that frames can be acquired with or without rotation of the imaging device 1708 and with or without retraction. Further, it will be understood that frames can be acquired using other types of movement procedures in addition to, or instead of, at least one of rotation or retraction of the imaging device 1708.

[0072] In some examples, when retraction is performed, the retraction may be at a constant speed, and thus provides a tool for potential uses where longitudinal vessel / plaque measurements can be calculated. In some examples, the imaging device 1708 is retracted at a constant speed of about 0.3 - 0.9 mm / second or about 0.5 - 0.8 mm / second. In some examples, the imaging device 1708 is retracted at a constant speed of at least 0.3 mm / second. In some examples, the imaging device 1708 is retracted at a constant speed of at least 0.4 mm / second. In some examples, the imaging device 1708 is retracted at a constant speed of at least 0.5 mm / second. In some examples, the imaging device 1708 is retracted at a constant speed of at least 0.6 mm / second. In some examples, the imaging device 1708 is retracted at a constant speed of at least 0.7 mm / second. In some examples, the imaging device 1708 is retracted at a constant speed of at least 0.8 mm / second.

[0073] In some examples, one or more acoustic signals are output to the surrounding tissue at regular time intervals. In some examples, one or more corresponding echo signals are received by the imaging device 1708 and transmitted to a control circuit 106 (which may include a processor) at regular time intervals. In some examples, the resulting frames are generated at regular time intervals.

[0074] At least some conventional IVUS imaging systems display only a single (e.g., cross-sectional, longitudinal, etc.) image during or after an IVUS procedure, such as a retraction procedure. However, it may be useful to simultaneously display in real-time at least two images during an IVUS procedure (e.g., a retraction procedure), such as the most recently processed image and a previously acquired image having certain or selected image characteristics (e.g., maximum or minimum lumen area or diameter).

[0075] Some diagnostic and / or therapeutic interventions may involve the analysis of images generated by an IVUS imaging system. However, this analysis may require a significant amount of training / experience to efficiently interpret the images. Further, due to the presence of speckles on IVUS images, automated analysis and / or evaluation may also be difficult. Methods for processing and / or analyzing images such as those generated by an IVUS imaging system are disclosed herein. Such methods may utilize machine learning, artificial intelligence, deep neural networks, etc. to improve the processing and / or analysis of images generated by an IVUS imaging system.

[0076] The processes / methods described in this specification may include the generation and / or collection of images of blood vessels (e.g., IVUS images generated via an IVUS pullback procedure, cross-sectional images, etc.). The generated / collected images are processed and / or segmented using a deep learning network (e.g., a deep neural network such as a U-net deep neural network) to obtain image segmentation for quantitative analysis and image classification for the automatic identification of lesion types, stent detection, etc., the identification of lumen boundaries, the identification of lumen dimensions, the determination of the minimal lumen area (MLA), the identification of the media boundary (e.g., the identification of the media boundary of the media in a blood vessel), the identification of media dimensions, the identification of calcification angles / arcs, the identification of calcification coverage, the identification of lesion types, combinations thereof, and / or the like. In addition to the identification of such boundaries / dimensions, the output may be displayed on a display unit in an appropriate format (e.g., graphically, numerically, as an actual image or a schematic image, along with words or symbols, etc.). In some examples, multiple images of an IVUS pullback or "run" may be analyzed. The output of this performance analysis includes a lumen contour (e.g., including a longitudinal section or "long view" for example), a blood vessel contour (e.g., including a longitudinal section or "long view" for example), a representation of the calcification length (e.g., visualization or image, numerical visualization, graphical visualization, etc.), the depiction / display of a reference frame (e.g., the minimal lumen area or "MLA", the minimal stent area or "MSA", etc.), the display of the side branch position (e.g., visualization or image, numerical visualization, graphical visualization, etc.), the display of the distance between two frames of interest (e.g., visualization or image, numerical visualization, graphical visualization, etc.), the display of stent expansion (e.g., visualization or image, numerical visualization, graphical visualization, etc.), combinations thereof, and the like.This may also include analyzing the image using a deep neural network (e.g., a UNet deep neural network, a convolutional neural network developed for the segmentation of biomedical images, or another neural network) and / or other machine learning and / or artificial intelligence techniques. Other deep learning neural networks that may be applicable in some scenarios may include deep belief networks, adversarial generative networks, recurrent neural networks, and other types of convolutional deep neural networks.

[0077] For example, some exemplary IVUS imaging systems that may be used with the embodiments and / or operations of this specification include, but are not limited to, those disclosed in U.S. Patent Nos. 7,246,959, 7,306,561, and 6,945,938, and U.S. Patent Application Publication Nos. 2006 / 0100522, 2006 / 0106320, 2006 / 0173350, 2006 / 0253028, 2007 / 0016054, and 2007 / 0038111, and International Publication No. 2021 / 062006, all of which are hereby incorporated by reference herein.

[0078] Method Many different methods are contemplated herein, including, but not limited to, methods for generating a plurality of images of an intravascular imaging display system, methods for generating or controlling a user interface of an intravascular imaging display system, methods for using an intravascular imaging display system, etc. The various aspects of the system / device operations described elsewhere in this specification can be implemented as the operations of one or more methods according to the various embodiments of this specification, and can be executed using a control circuit or its components such as a processor, a microcontroller, an ASIC, or other local or remote hardware components such as a cloud.

[0079] In various embodiments, the operations and / or method steps described herein can be performed as part of a computer-implemented method executed by one or more processors of one or more computing devices. In various embodiments, when the operations and method steps described herein are executed by one or more processors, they can be implemented as a plurality of instructions stored on a non-transitory computer-readable medium that causes the system to perform the operations and / or steps.

[0080] One embodiment includes a method for providing a display of an intravascular imaging display system, the method including differentiating a first vessel wall portion from a second vessel wall portion based on an attenuation degree of an ultrasonic feedback signal. The method can also include generating a display output including a user interface, the user interface including a display of a vessel wall including the first vessel wall portion and the second vessel wall portion. The display of the first vessel wall portion can be at least partially defined by a first graphic indicator, and the display of the second vessel wall portion can be at least partially defined by a second graphic indicator.

[0081] In one embodiment, the first graphic indicator can include a solid line boundary. In one embodiment, the second graphic indicator can include a dashed line boundary. However, many other variations, including those described elsewhere in this specification, are also contemplated herein.

[0082] In one embodiment of the method, the display of the vessel wall is displayed as a longitudinal cross-section of the vessel. In one embodiment of the method, the display of the vessel wall is displayed as a radial cross-section of the vessel. In one embodiment of the method, the display of the vessel wall is displayed as both a longitudinal cross-section of the vessel and a radial cross-section of the vessel.

[0083] In one embodiment of the method, the positions of the plurality of components of the display of the vessel wall are determined using a machine learning-derived model. In one embodiment of the method, the positions of the plurality of components of the display of the vessel wall are determined using a deep learning-derived model.

[0084] In one embodiment, the method may further include receiving user input from a system user regarding the display of the vessel wall, such as the location of a plurality of anatomical features of the vessel wall. In one embodiment, the method may further include receiving user input regarding the vessel boundary. In one embodiment, the method may further include receiving user input from a system user regarding the position of the vessel boundary. In one embodiment of the method, the user input may be used as part of a training data set for generating a machine learning model for determining the positions of a plurality of anatomical features of interest within an ultrasound image.

[0085] Note that as used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the content clearly dictates otherwise. Also note that the term "or" is generally used in the sense of "and / or" unless the content clearly dictates otherwise.

[0086] Note also that as used in this specification and the appended claims, the phrase "configured" describes a system, apparatus, or other structure that is constructed or configured to perform a particular task or adopt a particular configuration. The phrase "configured" can be used interchangeably with other similar phrases such as arranged and configured, constructed and arranged, constructed, manufactured and arranged, etc.

[0087] All publications and patent applications cited in this specification are indicative of the level of those skilled in the art to which the present invention pertains. All publications and patent applications are incorporated herein by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

[0088] As used herein, the recitation of numerical ranges by endpoints shall include all numbers subsumed within that range (e.g., 2 to 8 shall include 2.1, 2.8, 5.3, 7, etc.). The headings used herein are provided either for consistency with the proposals under 37 CFR 1.77 or, alternatively, to provide organizational cues. These headings should not be regarded as limiting or characterizing the invention claimed in any claim arising from this disclosure. By way of example, a heading refers to "Field", but the claims should not be limited by the language selected under this heading to describe the so-called field of technology. Further, the description of the technology in the "Background" does not admit that such technology is prior art to any invention in this disclosure. The "Summary" of the invention should also not be considered as a feature of the invention recited in the claims.

[0089] The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are selected and described so that others skilled in the art may appreciate and understand their principles and practice. Accordingly, aspects have been described with reference to various particular preferred embodiments and techniques. However, it is to be understood that many variations and modifications can be made within the spirit and scope of this application.

Claims

1. An intravascular imaging display system, comprising: a control circuit; a video output circuit, wherein the video output circuit communicates electronically with the control circuit, the video output circuit is configured to generate a display output including a user interface, the user interface includes a plurality of graphical elements related to the imaged blood vessel, the plurality of graphical elements including a first detected feature portion at least partially defined by a first graphic indicator, and a second detected feature portion at least partially defined by a second graphic indicator, the first graphic indicator is visually different from the second graphic indicator, the first detected feature portion and the second detected feature portion are assigned by the control circuit to indicate one or more positions along the blood vessel wall based on whether the attenuation degree of the ultrasonic feedback signal exceeds a threshold value. An intravascular imaging display system.

2. The intravascular imaging display system according to any one of Claims 1 and 3 to 11, wherein the first graphic indicator includes a solid boundary.

3. The intravascular imaging display system according to any one of Claims 1 to 2 and 4 to 11, wherein the second graphic indicator includes a dashed boundary.

4. The intravascular imaging display system according to any one of Claims 1 to 3 and 5 to 11, wherein the plurality of graphical elements are related to a longitudinal cross-section of the blood vessel.

5. The intravascular imaging display system according to any one of Claims 1 to 4 and 6 to 11, wherein the plurality of graphical elements are related to a radial cross-section of the blood vessel.

6. The first detected feature portion includes a display of a first lumen boundary, and a display of a first blood vessel boundary, and the second detected feature portion includes a display of a second lumen boundary, and a display of a second blood vessel boundary. The intravascular imaging display system according to any one of Claims 1 to 5 and 7 to 11.

7. The intravascular imaging display system according to any one of Claims 1 to 6 and 8 to 11, wherein the positions of the plurality of displays of the first blood vessel boundary, the second blood vessel boundary, the first lumen boundary, and the second lumen boundary are determined using a machine learning-derived model.

8. The positions of a plurality of displays of the first vascular boundary, the second vascular boundary, the first lumen boundary, and the second lumen boundary are determined using a deep learning-derived model, according to any one of claims 1 to 7 and 9 to 11. The intravascular imaging display system described.

9. The user interface includes one or more numerical parameters related to the imaged blood vessel, and the one or more numerical parameters include typographic features indicating whether the one or more numerical parameters are related to the first detected feature portion or the second detected feature portion. The intravascular imaging display system according to any one of claims 1 to 8 and 10 to 11.

10. The user interface is configured to receive user input regarding at least one of the position of the display of the first vascular boundary and the position of the display of the second vascular boundary from a system user, according to any one of claims 1 to 9 and 11. The intravascular imaging display system described.

11. The intravascular imaging display system is configured to use the user input as part of a data set for generating a machine learning model, according to any one of claims 1 to 10. The intravascular imaging display system described.

12. A method for providing a display of an intravascular imaging display system, comprising: distinguishing a first blood vessel wall portion and a second blood vessel wall portion based on the attenuation degree of the ultrasonic feedback signal; generating a display output including a user interface, wherein the user interface includes a plurality of graphical elements related to an imaged blood vessel including a first detected feature portion corresponding to the first blood vessel wall portion and a second detected feature portion corresponding to the second blood vessel wall portion; the first detected feature portion is at least partially defined by a first graphic indicator, and the second detected feature portion is at least partially defined by a second graphic indicator; the first graphic indicator is visually different from the second graphic indicator.

13. The method according to any one of claims 12 and 14 to 15, wherein the first graphic indicator includes a solid line boundary and the second graphic indicator includes a dashed line boundary. **Claim 14** The method according to any one of claims 12, 13, and 15, further comprising receiving user input from a system user regarding the location of a vascular boundary. **Claim 15** The method according to any one of claims 12 to 14, further comprising using the user input as part of a training data set for generating a machine learning model.

Images