Medical device systems for automatic lesion assessment

Abstract

To provide systems and methods for automatic lesion assessment and / or processing imaging data.SOLUTION: An example intravascular imaging system may include a catheter including an imaging device. A processor may be coupled to the catheter. The processor may be configured to process imaging data received from the imaging device. The processor may be configured to generate a longitudinal section view of a blood vessel from the imaging data received from the imaging device. The processor may be configured to identify a minimum lumen area along the longitudinal section view of the blood vessel, a distal reference point, and a proximal reference point. A display unit may be coupled to the processor. The display unit may be configured to show a display including the longitudinal section view of the blood vessel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to medical devices and / or medical device systems, and more particularly, to medical device systems for automated lesion assessment. [Background technology]

[0002] A wide variety of medical devices have been developed for medical applications, such as intravascular applications. Some of these devices include guidewires, catheters, and the like. These devices can be manufactured by any one of a variety of different manufacturing methods and used according to any one of a variety of methods. Known medical devices and methods each have certain advantages and disadvantages. There is a continuing need to provide alternative medical devices and alternative methods for manufacturing and using medical devices. Summary of the Invention

[0003] The present disclosure provides design, material, manufacturing, and use alternatives for medical devices. An exemplary intravascular imaging system is disclosed. The intravascular imaging system includes a catheter including an imaging device; a processor coupled to the catheter and configured to process imaging data received from the imaging device, the processor configured to generate a longitudinal cross-sectional view of the blood vessel from the imaging data received from the imaging device, the processor configured to identify a minimum lumen area, a distal reference point, and a proximal reference point along the longitudinal cross-sectional view of the blood vessel; and a display unit coupled to the processor and configured to present a display including the longitudinal cross-sectional view of the blood vessel.

[0004] Alternatively or additionally to any of the above embodiments, the display includes an indicator of the minimum lumen area. Alternatively or additionally to any of the above embodiments, the minimum lumen area indicator is movable by a user along the longitudinal cross-sectional view of the blood vessel.

[0005] Alternatively or additionally to any of the above embodiments, the display includes an indicator of a distal reference point. Alternatively or additionally to any of the above embodiments, the distal reference point indicator is movable by a user along the longitudinal cross-sectional view of the vessel.

[0006] Alternatively or additionally to any of the above embodiments, the display includes an indicator of a proximal reference point. Alternatively or additionally to any of the above embodiments, the indicator of the proximal reference point is movable by a user along the longitudinal cross-sectional view of the vessel.

[0007] Alternatively or additionally to any of the above embodiments, the processor is configured to identify a second minimum lumen area along a longitudinal cross-sectional view of the blood vessel. Alternatively or additionally to any of the above embodiments, the processor is configured to identify secondary reference points along a longitudinal cross-sectional view of the vessel.

[0008] An intravascular imaging system is disclosed that includes an imaging catheter, a processor coupled to the catheter and configured to process imaging data received from the imaging catheter, the processor configured to generate a longitudinal cross-sectional view of a blood vessel from the imaging data, the processor configured to identify a minimum lumen area location along the longitudinal cross-sectional view of the blood vessel, a distal reference point located distal to the minimum lumen area location, and a proximal reference point located proximal to the minimum lumen area location, and a display unit coupled to the processor and configured to present a display including the longitudinal cross-sectional view of the blood vessel, the display including an indicator of the minimum lumen area location, an indicator of the distal reference point, and an indicator of the proximal reference point along the longitudinal cross-sectional view of the blood vessel.

[0009] Alternatively or additionally to any of the above embodiments, the indicator of the minimum lumen area location is movable by a user along the longitudinal cross-sectional view of the blood vessel. Alternatively or additionally to any of the above embodiments, the distal reference point indicator is movable by a user along the longitudinal cross-sectional view of the vessel.

[0010] Alternatively or additionally to any of the above embodiments, the indicator of the proximal reference point is movable by a user along the longitudinal cross-sectional view of the vessel. Alternatively or additionally to any of the above embodiments, the processor is configured to identify a second minimum lumen area along a longitudinal cross-sectional view of the blood vessel.

[0011] Alternatively or additionally to any of the above embodiments, the processor is configured to identify secondary reference points along a longitudinal cross-sectional view of the vessel. A method for processing imaging data is disclosed that includes obtaining imaging data from an imaging catheter, processing the imaging data with a processor to generate a longitudinal cross-sectional view of a blood vessel, where processing the imaging data includes identifying a minimum lumen area location of the blood vessel along the longitudinal cross-sectional view of the blood vessel, identifying a distal reference point of the blood vessel along the longitudinal cross-sectional view of the blood vessel, and identifying a proximal reference point of the blood vessel along the longitudinal cross-sectional view of the blood vessel, modifying one or more of the minimum lumen area location, the distal reference point, and the proximal reference point to a secondary position, and confirming the secondary position.

[0012] Alternatively or additionally to any of the above embodiments, modifying one or more of the minimum lumen area position, the distal reference point, and the proximal reference point to a secondary position includes translating a bookmark corresponding to the minimum lumen area position, the distal reference point, or the proximal reference point to the secondary position along the longitudinal cross-sectional view of the vessel.

[0013] Alternatively or additionally to any of the above embodiments, processing the imaging data with a processor to generate a longitudinal cross-sectional view of the vessel includes identifying secondary reference points.

[0014] Alternatively or additionally to any of the above embodiments, processing the imaging data with a processor to generate a longitudinal cross-sectional view of the blood vessel includes processing the imaging data before treating the blood vessel with a stent.

[0015] Alternatively or additionally to any of the above embodiments, processing the imaging data using a processor to generate a longitudinal cross-sectional view of the blood vessel includes processing the imaging data after treating the blood vessel with a stent.

[0016] An intravascular imaging system is disclosed that includes a catheter including an imaging device, a processor coupled to the catheter and configured to process imaging data received from the imaging device, the processor configured to generate a longitudinal cross-sectional view of the blood vessel from the imaging data received from the imaging device, the processor configured to identify a minimum stent area, a distal reference point, and a proximal reference point along the longitudinal cross-sectional view of the blood vessel, and a display unit coupled to the processor and configured to present a display including the longitudinal cross-sectional view of the blood vessel.

[0017] Alternatively or additionally to any of the above embodiments, the display includes an indicator of the minimum stent area. Alternatively or additionally to any of the above embodiments, the minimum stent area indicator is movable by a user along the longitudinal cross-sectional view of the vessel.

[0018] Alternatively or additionally to any of the above embodiments, the display includes an indicator of a distal reference point. Alternatively or additionally to any of the above embodiments, the distal reference point indicator is movable by a user along the longitudinal cross-sectional view of the vessel.

[0019] Alternatively or additionally to any of the above embodiments, the display includes an indicator of a proximal reference point. Alternatively or additionally to any of the above embodiments, the indicator of the proximal reference point is movable by a user along the longitudinal cross-sectional view of the vessel.

[0020] Alternatively or additionally to any of the above embodiments, the processor is configured to identify a second minimum stent area along a longitudinal cross-sectional view of the vessel. Alternatively or additionally to any of the above embodiments, the processor is configured to identify secondary reference points along a longitudinal cross-sectional view of the vessel.

[0021] An intravascular imaging system is disclosed that includes an imaging catheter, a processor coupled to the catheter and configured to process imaging data received from the imaging catheter, the processor configured to generate a longitudinal cross-sectional view of the blood vessel from the imaging data, the processor configured to identify a minimum stent area location along the longitudinal cross-sectional view of the blood vessel, a distal reference point located distal to the minimum stent area location, and a proximal reference point located proximal to the minimum stent area location, and a display unit coupled to the processor and configured to present a display including the longitudinal cross-sectional view of the blood vessel, the display including an indicator of the minimum stent area location, an indicator of the distal reference point, and an indicator of the proximal reference point along the longitudinal cross-sectional view of the blood vessel.

[0022] Alternatively or additionally to any of the above embodiments, the minimum stent area location indicator is movable by a user along the longitudinal cross-sectional view of the vessel. Alternatively or additionally to any of the above embodiments, the distal reference point indicator is movable by a user along the longitudinal cross-sectional view of the vessel.

[0023] Alternatively or additionally to any of the above embodiments, the indicator of the proximal reference point is movable by a user along the longitudinal cross-sectional view of the vessel. Alternatively or additionally to any of the above embodiments, the processor is configured to identify a second minimum stent area along a longitudinal cross-sectional view of the vessel.

[0024] Alternatively or additionally to any of the above embodiments, the processor is configured to identify secondary reference points along a longitudinal cross-sectional view of the vessel. A method for processing imaging data is disclosed that includes obtaining imaging data from an imaging catheter, processing the imaging data with a processor to generate a longitudinal cross-sectional view of a blood vessel, where processing the imaging data includes identifying a minimum stent area location of the blood vessel along the longitudinal cross-sectional view of the blood vessel, identifying a distal reference point of the blood vessel along the longitudinal cross-sectional view of the blood vessel, and identifying a proximal reference point of the blood vessel along the longitudinal cross-sectional view of the blood vessel, modifying one or more of the minimum stent area location, the distal reference point, and the proximal reference point to a secondary position, and confirming the secondary position.

[0025] Alternatively or additionally to any of the above embodiments, modifying one or more of the minimum stent area position, the distal reference point, and the proximal reference point to a secondary position includes translating a bookmark corresponding to the minimum stent area position, the distal reference point, or the proximal reference point to the secondary position along a longitudinal cross-sectional view of the blood vessel.

[0026] Alternatively or additionally to any of the above embodiments, processing the imaging data with a processor to generate a longitudinal cross-sectional view of the vessel includes identifying secondary reference points.

[0027] Alternatively or additionally to any of the above embodiments, processing the imaging data with a processor to generate a longitudinal cross-sectional view of the blood vessel includes processing the imaging data before treating the blood vessel with a stent.

[0028] Alternatively or additionally to any of the above embodiments, processing the imaging data using a processor to generate a longitudinal cross-sectional view of the blood vessel includes processing the imaging data after treating the blood vessel with a stent.

[0029] Alternatively or additionally to any of the above embodiments, the device may further comprise an indicator or graphic depicting an appropriate stent expansion rate for treating the vessel. Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined from the minimum stent area.

[0030] Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined by comparing the minimum stent area to the diameter of the vessel at a proximal reference point.

[0031] Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined by comparing the minimum stent area to the diameter of the vessel at a distal reference point.

[0032] Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined by comparing the minimum stent area to the average vessel diameter at the proximal and distal reference points.

[0033] An intravascular imaging system is disclosed that includes a catheter including an imaging device, a processor coupled to the catheter and configured to process imaging data received from the imaging device, the processor configured to generate a vascular profile view of the blood vessel from the imaging data received from the imaging device, the processor configured to identify a minimum stent area, a distal reference point, and a proximal reference point along the vascular profile view of the blood vessel, and a display unit coupled to the processor and configured to present a display including the vascular profile view of the blood vessel.

[0034] Alternatively or additionally to any of the above embodiments, the device may further comprise an indicator or graphic depicting an appropriate stent expansion rate for treating the vessel. Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined from the minimum stent area.

[0035] Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined by comparing the minimum stent area to the diameter of the vessel at a proximal reference point.

[0036] Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined by comparing the minimum stent area to the diameter of the vessel at a distal reference point.

[0037] Alternatively or additionally to any of the above embodiments, the appropriate stent expansion ratio is determined by comparing the minimum stent area to the average vessel diameter at the proximal and distal reference points.

[0038] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The following figures and detailed description more particularly exemplify these embodiments. [Brief explanation of the drawings]

[0039] The present disclosure may be more fully understood from the following detailed description considered in conjunction with the accompanying drawings, in which: [Figure 1] 1 is a diagram that schematically depicts an exemplary intravascular imaging system. [Figure 2] 1 is a perspective view of an exemplary intravascular imaging catheter system. [Figure 3] 1 is a side view of a portion of an exemplary intravascular imaging catheter system. [Figure 4] FIG. 1 illustrates an exemplary display. [Figure 5] FIG. 1 illustrates a flowchart of an exemplary process. [Figure 6] FIG. 1 illustrates a flowchart of an exemplary process. [Figure 7] FIG. 1 illustrates a flowchart of an exemplary process. [Figure 8] FIG. 1 illustrates an exemplary display. [Figure 9] FIG. 1 illustrates an exemplary display. [Figure 10] FIG. 1 illustrates an exemplary display. [Figure 11] FIG. 1 illustrates an exemplary display. [Figure 12] FIG. 1 illustrates an exemplary display. DETAILED DESCRIPTION OF THE INVENTION

[0040] While the present disclosure is amenable to various modifications and alternative forms, specifics of which have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure.

[0041] For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. All numerical values, whether explicitly stated or not, are assumed herein to be modified by the term "about." The term "about" generally refers to a range of numbers that one of ordinary skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the term "about" may include numbers that are rounded to the nearest significant figure.

[0042] The recitation of numerical ranges by endpoints includes every number within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). 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. As used in this specification and the appended claims, the term "or" is generally employed in its sense, including "and / or," unless the content clearly dictates otherwise.

[0043] It is noted that references herein to "one embodiment," "some embodiments," "other embodiments," etc., indicate that the described embodiment may include one or more particular features, structures, and / or characteristics. However, such descriptions do not necessarily imply that all embodiments include the particular feature, structure, and / or characteristic. Additionally, if a particular feature, structure, and / or characteristic is described in connection with one embodiment, it should be understood that such feature, structure, and / or characteristic may also be used in connection with other embodiments, whether or not explicitly described, unless otherwise specified.

[0044] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

[0045] Intravascular imaging devices that can be inserted into patients have proven diagnostic capabilities for a variety of diseases and disorders. For example, intravascular ultrasound ("IVUS") imaging systems and / or optical coherence tomography ("OCT") imaging systems can be used as imaging modalities to diagnose blocked blood vessels and provide information to assist physicians in selecting and placing stents and other devices to restore or increase blood flow. IVUS / OCT imaging systems can also be used to diagnose atherosclerotic plaques that form at specific locations within blood vessels. IVUS / OCT imaging systems can also be used to determine the presence of a lesion or stenosis within a blood vessel, as well as the nature and extent of that lesion or stenosis. IVUS / OCT imaging systems can also be used to visualize segments of the vascular system that may be difficult to visualize using other intravascular imaging techniques, such as angiography, due to, for example, motion (e.g., a beating heart) or obstruction by one or more structures (e.g., one or more blood vessels not desired to be imaged). IVUS / OCT imaging systems may also be used to monitor or evaluate ongoing intravascular procedures, such as real-time (or near-real-time) angiography and stent placement, etc. Additionally, IVUS / OCT imaging systems may be used to monitor one or more cardiac chambers.

[0046] 1 schematically illustrates an exemplary intravascular imaging system 100. However, other imaging systems, including optical coherence tomography imaging systems, are also contemplated. IVUS imaging system 100 includes a catheter 102 that can be coupled to a processing unit or control module 104. Control module 104 can include, for example, a processor 106, a pulse generator 108, a drive unit 110, and one or more displays or display units 112. In some examples, pulse generator 108 forms electrical pulses that can be input to one or more transducers (312 in FIG. 3 ) disposed within catheter 102.

[0047] For purposes of this disclosure, the term "display" may refer to an electronic device (e.g., a monitor) used for visually representing data, or may refer to the visual representation of data itself. In other words, the term "display" may refer to a hardware device for displaying data, or the term "display" may refer to data displayed on a hardware device. In some instances, it may be convenient to use the phrase "display unit" to refer to a hardware component and the term "display" to refer to the visual / data component displayed on the display unit. However, such terminology need not be strictly adhered to in this disclosure or in the art generally. Those skilled in the art will be able to distinguish between instances when the term "display" refers to a hardware component and instances when the term "display" refers to a visual / data component.

[0048] In some examples, mechanical energy from the drive unit 110 may be used to drive an imaging core (306 in FIG. 3 ) disposed within the catheter 102. In some examples, electrical signals transmitted from one or more transducers (312 in FIG. 3 ) may be input to the processor 106 for processing. In some examples, the processed electrical signals from the one or more transducers (312 in FIG. 3 ) may be displayed as one or more images on one or more display units 112. For example, a scan converter may 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 the one or more display units 112.

[0049] In some examples, the processor 106 may also be used to control the functions of one or more of the other components of the control module 104. For example, the processor 106 may be used to control at least one of the frequency or duration of electrical pulses transmitted from the pulse generator 108, the rate of rotation of the imaging core (306 in FIG. 3) by the drive unit 110, the speed or length of pullback of the imaging core (306 in FIG. 3) by the drive unit 110, or one or more characteristics of one or more images formed on the one or more display units 112.

[0050] FIG. 2 is a schematic side view of one embodiment of the catheter 102 of the IVUS imaging system (100 in FIG. 1). The catheter 102 includes an elongate member 202 and a hub 204. The elongate member 202 includes a proximal end 206 and a distal end 208. In FIG. 2, the proximal end 206 of the elongate member 202 is coupled to the catheter hub 204, and the distal end 208 of the elongate member is configured and arranged for percutaneous insertion into a patient. Optionally, the catheter 102 may define at least one flush port, such as flush port 210. The flush port 210 may be defined in the hub 204. The hub 204 may be configured and arranged for coupling to a control module (104 in FIG. 1). In some examples, the elongate member 202 and the hub 204 are formed as a single body. In other examples, the elongate member 202 and catheter hub 204 are formed separately and then assembled together.

[0051] FIG. 3 is a schematic perspective view of one embodiment of the distal end 208 of the elongate member 202 of the catheter 102. The elongate member 202 includes a sheath 302 having a longitudinal axis (e.g., a central longitudinal axis extending axially through the center of the sheath 302 and / or catheter 102) and a lumen 304. An imaging core 306 is disposed within the lumen 304. The imaging core 306 includes an imaging device 308 coupled to the distal end of a rotatable drive shaft 310 either manually or using a computer-controlled drive mechanism. One or more transducers 312 are attached to the imaging device 308 and may be employed to transmit and receive acoustic signals. The sheath 302 may be formed from any flexible, biocompatible material suitable for insertion into a patient. Examples of suitable materials include, for example, polyethylene, polyurethane, plastic, spiral-cut stainless steel, nitinol hypotubing, or the like, or combinations thereof.

[0052] In some examples, an array of transducers 312 is attached to the imaging device 308, for example, as shown in FIG. 3 . Alternatively, a single transducer may be employed. Any suitable number of transducers 312 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 may also be used. When multiple transducers 312 are employed, the transducers 312 can be configured into any suitable arrangement, including, for example, a circular arrangement, a rectangular arrangement, etc.

[0053] The transducer(s) 312 may be formed from a material capable of converting an applied electrical pulse into a pressure strain on the surface of the transducer(s) 312, and vice versa. Examples of suitable materials include piezoelectric ceramic materials, piezoelectric composites, piezoelectric plastics, barium titanate, lead zirconate titanate, lead metaniobate, polyvinylidene fluoride, and the like. Other transducer technologies include composite materials, single crystal composites, and semiconductor devices (e.g., capacitive micromachined ultrasound transducers (“cMUT”), piezoelectric micromachined ultrasound transducers (“pMUT”), etc.).

[0054] The pressure distortion on the surface of the one or more transducers 312 forms an acoustic pulse of a frequency based on the resonant frequency of the one or more transducers 312. The resonant frequency of the one or more transducers 312 can be affected by the size, shape, and material used to form the one or more transducers 312. The one or more transducers 312 can be formed in any shape suitable for placement within the catheter 102 and for propagating acoustic pulses of a desired frequency in one or more selected directions. For example, the transducers can be disk-shaped, block-shaped, rectangular, elliptical, etc. The one or more transducers can be formed into the desired shape by any process including, for example, dicing, die-and-fill, machining, micromachining, etc.

[0055] As an example, each of the one or more transducers 312 may include a layer of piezoelectric material sandwiched between a matching layer and a conductive backing material formed from an acoustically absorbing material (e.g., an epoxy substrate with tungsten particles). During operation, the piezoelectric layer may be electrically excited, causing the emission of an acoustic pulse.

[0056] The one or more transducers 312 can be used to form radial cross-sectional images of the surrounding space. Thus, for example, if the one or more transducers 312 are disposed within the catheter 102 and inserted into a patient's blood vessel, the one or more transducers 312 can be used to form images of the wall of the blood vessel and the tissue surrounding the blood vessel.

[0057] The imaging core 306 is rotated about the longitudinal axis of the catheter 102. As the imaging core 306 rotates, the one or more transducers 312 emit acoustic signals in different radial directions (e.g., along different radial scan lines). For example, the one or more transducers 312 may emit acoustic signals at regular (or irregular) increments, such as 256 radial scan lines per rotation, etc. It will be understood that other numbers of radial scan lines can be emitted per rotation instead.

[0058] When an emitted acoustic pulse with sufficient energy encounters one or more medial 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 with sufficient energy to be detected and reaching the transducer is converted to an electrical signal at the receiving transducer. The one or more converted electrical signals are transmitted to a control module (104 in FIG. 1 ), where a processor 106 processes electrical signal characteristics to form a displayable image of the imaged area based at least in part on the collection of information from each of the transmitted acoustic pulses and received echo pulses. In some examples, rotation of the imaging core 306 is driven by a drive unit 110 disposed within the control module (104 in FIG. 1 ). In an alternative embodiment, one or more transducers 312 are fixed in place and do not rotate. In that case, the drive shaft 310 may instead rotate a mirror that reflects acoustic signals to and from the fixed transducer(s) 312 .

[0059] When one or more transducers 312 are rotated about the longitudinal axis 303 of the catheter 102 emitting the acoustic pulses, multiple images can be formed that collectively form a radial cross-sectional image (e.g., a tomographic image) of a portion of the area around the one or more transducers 312, such as the wall of a blood vessel of interest and the tissue surrounding that vessel. The radial cross-sectional images can optionally be displayed on one or more display units 112. At least one of the imaging cores 306 can be rotated manually or using a computer-controlled mechanism.

[0060] The imaging core 306 may also move longitudinally along the blood vessel into which the catheter 102 is inserted, such that multiple cross-sectional images may be formed along the longitudinal length of the blood vessel. During an imaging procedure, one or more transducers 312 may be retracted (e.g., pulled back) along the longitudinal length of the catheter 102. The catheter 102 may include at least one retractable section that can be retracted during pullback of the one or more transducers 312. In some examples, the drive unit 110 drives the pullback of the imaging core 306 into the catheter 102. The pullback distance of the imaging core by the drive unit 110 can be any suitable distance, including, for example, at least 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, or more. Whether the imaging core 306 is moving longitudinally independently of the catheter 102 or not, the entire catheter 102 can be retracted during an imaging procedure.

[0061] A stepper motor may optionally be used to pull back the imaging core 306. The stepper motor may pull back the imaging core 306 a short distance, stop long enough for the one or more transducers 306 to capture an image or series of images before pulling back the imaging core 306 a short distance again, capture another image or series of images again, etc.

[0062] The quality of images produced at different depths from one or more transducers 312 may be affected by one or more factors, including, for example, bandwidth, transducer focus, beam pattern, and frequency of the acoustic pulses. The frequency of the acoustic pulses output from one or more transducers 312 may also affect the penetration depth of the acoustic pulses output from the one or more transducers 312. Generally, as the frequency of the acoustic pulses is lowered, the penetration depth of the acoustic pulses within patient tissue increases. In some examples, the IVUS imaging system 100 operates within a frequency range of 5 MHz to 100 MHz.

[0063] One or more conductors 314 may electrically couple the transducer 312 to the control module 104 (see, e.g., FIG. 1 ), in which case the one or more conductors 314 may extend along the longitudinal length of the rotatable drive shaft 310.

[0064] A catheter 102 having one or more transducers 312 attached to the distal end 208 of the imaging core 308 may be percutaneously inserted into a patient via an accessible blood vessel, such as the femoral artery, femoral vein, or jugular vein, at a site, such as a blood vessel, away from a selected portion of a selected region to be imaged. The catheter 102 may then be advanced through the patient's blood vessels to a selected imaging site, such as a portion of a selected blood vessel.

[0065] An image or image frame (“frame”) can be generated each time one or more acoustic signals are output into the surrounding tissue, and one or more corresponding echo signals are received by the imager 308 and transmitted to the processor 106. Alternatively, an image or image frame can be a composite of scan lines from a full or partial rotation of the imaging core or device. Multiple frames (e.g., a sequence of frames) are acquired over time during any type of movement of the imaging device 308. For example, frames can be acquired during rotation and pullback of the imaging device 308 along the target imaging location. It will be understood that frames can be acquired with or without rotation of the imaging device 308, and with or without pullback. It will also be understood that frames can be acquired using other types of movement procedures in addition to, or instead of, at least one of rotation and pullback of the imaging device 308.

[0066] In some examples, if pullback is performed, the pullback may be at a constant speed, thus providing a tool for potential applications that can calculate longitudinal vessel / plaque measurements. In some examples, the imaging device 308 is pulled back at a constant speed of about 0.3-0.9 mm / s or about 0.5-0.8 mm / s. The imaging device 308 is pulled back at a constant speed of at least 0.3 mm / s. In some examples, the imaging device 308 is pulled back at a constant speed of at least 0.4 mm / s. In some examples, the imaging device 308 is pulled back at a constant speed of at least 0.5 mm / s. In some examples, the imaging device 308 is pulled back at a constant speed of at least 0.6 mm / s. In some examples, the imaging device 308 is pulled back at a constant speed of at least 0.7 mm / s. In some examples, the imaging device 308 is pulled back at a constant speed of at least 0.8 mm / s.

[0067] 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 imager 308 and transmitted to the processor 106 at regular time intervals. In some examples, the resulting frames are generated at regular time intervals.

[0068] 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 pullback procedure. However, it may be beneficial to simultaneously display at least two images in real time during the IVUS procedure (e.g., a pullback procedure), for example, a most recently processed image and a previously acquired image having some particular or selected image characteristic (e.g., maximum or minimum lumen area or diameter).

[0069] Some diagnostic and / or therapeutic interventions may involve analysis of images generated by an IVUS imaging system. However, this analysis may require a significant amount of training / experience to effectively interpret the images. Furthermore, automated analysis and / or evaluation may be difficult due to the high presence of speckles on IVUS images. Disclosed herein are methods for processing and / or analyzing images, such as images generated using / by an IVUS imaging system. Such methods may utilize machine learning, artificial intelligence, deep neural networks, etc. to improve the processing and / or analysis of images generated using / by an IVUS imaging system.

[0070] The processes / methods described herein may include generating and / or collecting images of a blood vessel (e.g., IVUS images generated via an IVUS pullback procedure, cross-sectional images, etc.). The generated / collected images may include image processing and / or segmentation 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 automatic identification of lesion type, stent detection, etc., identification of lumen boundary, identification of lumen dimension, determination of minimal lumen area (MLA), identification of media boundary (e.g., identification of the media boundary of the tunica media in a vessel), identification of media dimension, identification of calcification angle / arc, identification of calcification coverage, identification of lesion type, combinations thereof, and / or the like. In addition to identifying such boundary / dimension, the output may be displayed on a display unit in an appropriate format (e.g., with words or symbols, as an actual or schematic image, graphically, numerically, etc.). In some examples, multiple images of an IVUS pullback or "run" may be analyzed. Output of this run analysis may include lumen contour (e.g., including, for example, a longitudinal section or "long view"), vessel contour (e.g., including, for example, a longitudinal section or "long view"), representation of calcification length (e.g., visualization or image, numerical visualization, graphical visualization, etc.), depiction / display of a frame of reference (e.g., minimum lumen area or "MLA", minimum stent area or "MSA", etc.), representation of side branch location (e.g., visualization or image, numerical visualization, graphical visualization, etc.), representation of the distance between two frames of interest (e.g., visualization or image, numerical visualization, graphical visualization, etc.), representation of stent expansion (e.g., visualization or image, numerical visualization, graphical visualization, etc.), combinations thereof, etc. This may also include analyzing the images using deep neural networks (such as, for example, U-Net deep neural networks) and / or machine learning and / or artificial intelligence.

[0071] FIG. 4 illustrates an exemplary display 416 that may be displayed on the display / display unit 112. Among other things, the display 416 includes an exemplary cross-sectional image 418 of a blood vessel and a longitudinal cross-sectional image / display 420 of the blood vessel. In this example, the processor 106 may be configured to automatically identify a minimum lumen area (MLA) of the blood vessel and then output / display an indicator or bookmark corresponding to the MLA 422 along the longitudinal cross-sectional display 420. This may include the use of a deep neural network (e.g., a UNet deep neural network, etc.) and / or machine learning and / or artificial intelligence. The processor 106 may also be configured to identify proximal and distal reference points. This may also include the use of a deep neural network (e.g., a UNet deep neural network, etc.) and / or machine learning and / or artificial intelligence. The processor 106 may also be configured to output / display an indicator or bookmark corresponding to a distal reference point 424 and an indicator or bookmark corresponding to a proximal reference point 426 along the longitudinal cross-sectional display 420. Generally, the proximal and distal reference points may be selected as potential locations where the ends of a stent may be positioned to treat a lesion formed around the MLA. Thus, indicators 422, 424, 426 may assist a clinician in identifying potential deployment locations for a stent.

[0072] It can be appreciated that indicator 422 can be used to indicate MLA in IVUS pullback / operation before percutaneous coronary intervention (PCI). After PCI, indicator 422 can correspond to minimum stent area (MSA). Thus, in pullback / operation after PCI, indicator 422 can have the label MSA.

[0073] In addition, the longitudinal cross-sectional display 420 may provide useful information to the clinician. In some examples, the longitudinal cross-sectional display 420 may include, or alternatively be replaced by, a vessel profile view that provides information about the vessel, including a representation of calcification angle / arc (e.g., visualization or image, numerical visualization, graphical visualization, and / or the like), a representation of calcification length (e.g., visualization or image, numerical visualization, graphical visualization, and / or the like), a depiction / display of a reference frame (e.g., MLA, MSA, and / or the like), a representation of side branch position (e.g., visualization or image, numerical visualization, graphical visualization, and / or the like), a representation of the distance between two frames of interest (e.g., visualization or image, numerical visualization, graphical visualization, and / or the like), a representation of stent expansion (e.g., visualization or image, numerical visualization, graphical visualization, and / or the like), combinations thereof, and / or the like. In some examples, the display 416 may include a longitudinal section display 420, a vascular profile display, or both.

[0074] In some examples, processor 106 may be configured to output / display another indicator or bookmark other than indicators 422, 424, 426. This may include additional automatic indicators (e.g., additional MLA indicators and / or additional / secondary reference point indicators), which may be displayed along longitudinal cross-sectional display 420 without user intervention. In some of these and other examples, manual indicators or bookmarks may be added by the user. For example, the user may desire to add an indicator or bookmark (e.g., a secondary indicator or bookmark) to longitudinal cross-sectional display 420, and by using an appropriate input device (e.g., a mouse, keyboard, touchpad, finger or gestures on a touchscreen, etc.), the user may add the additional indicator.

[0075] Although the processor 106 may provide a reliable level of precision and accuracy when identifying the MLA, distal and proximal reference points, and / or when identifying other features of the vessel, the clinician may still wish to review the locations of these points and, if necessary, confirm and / or modify the locations of these points.

[0076] 5-7 are flowcharts illustrating the workflow for pre-PCI and post-PCI IVUS pullback / activation and how indicators 422, 424, 426 may be selected, modified, and confirmed on display 416. In FIG. 5, the flowchart corresponds to the process for pre-PCI IVUS pullback. In FIG. 6, the flowchart corresponds to the process for post-PCI IVUS pullback. Finally, FIG. 7 is a flowchart illustrating the steps for adjusting / confirming indicators 422, 424, 426.

[0077] 5, the process may include selecting an IVUS modality (e.g., on the control module 104) in box 428. This may include selecting the IVUS modality from a list of possible modalities using appropriate user input (e.g., a mouse, keyboard, touchpad, touchscreen on the display / display unit 112, etc.). In box 429, the user may activate the recording function by pressing a record (REC) button to begin recording. Box 430 corresponds to the IVUS pullback / run being recorded. As shown in box 431, the processor 106 may utilize artificial intelligence to determine whether the IVUS pullback / run is occurring pre-PCI or post-PCI.

[0078] For pre-PCI operations in box 432, the processor may utilize artificial intelligence to automatically place indicators 422, 424, 426 on the longitudinal display 420 as soft bookmarks corresponding to, for example, the proximal reference point (RefP), the distal reference point (RefD), and the MLA. The indicators / bookmarks 422, 424, 426 are considered “soft” in that the user can continue to review the positions of the indicators / bookmarks 422, 424, 426 and make desired changes, if necessary, before locking / confirming or otherwise making the indicators / bookmarks 422, 424, 426 “hard.” In boxes 433, 434, 435, the user can adjust / confirm the indicators / bookmarks for RefD, RefP, and the MLA, respectively. The process for adjusting / confirming the indicators / bookmarks is shown in FIG. 7.

[0079] In box 436, the stent diameter (e.g., this may be displayed adjacent to the MLA indicator 422; see FIG. 11 ) and the proposed stent length for the intervention (e.g., this may be displayed using a bar positioned between the distal reference point indicator 424 and the proximal reference point indicator 426; see FIG. 11 ) are displayed. The displayed value of “Stent Diameter” may be the actual diameter of the vessel at the MLA indicator 422 (e.g., which may be used to determine an appropriate stent diameter size that may be used during the intervention) or the proposed stent diameter to be used for the intervention. In some examples, the user may be able to toggle between the actual diameter and the proposed stent diameter. Similarly, the value of “Stent Length” may be the actual length between the reference points (e.g., which may be used to determine an appropriate stent length that may be used during the intervention) or the proposed stent length to be used for the intervention. In some examples, the user may be able to toggle between the actual length and the proposed stent length. The user may review the stent diameter and length information in box 437 and then end the process in box 438.

[0080] For the post-PCI operation in box 439 of FIG. 6, the processor may utilize artificial intelligence to place indicators 422, 424, 426 on the longitudinal cross-sectional display 420 as keyframes and / or soft bookmarks corresponding to, for example, the proximal reference point (RefP), the distal reference point (RefD), and the minimum stent area (MSA). Note that in this description of the post-PCI operation, reference numeral 422 is used for the MSA indicator, which may be output to the display 416. In boxes 440, 441, 442, the user may adjust / confirm the RefD, RefP, and MSA indicators / bookmarks, respectively. The process for adjusting / confirming the indicators / bookmarks is shown in FIG. 7.

[0081] In box 444, the stent diameter (e.g., this may be displayed adjacent to the MLA / MSA indicator 422; see FIG. 11 ) and the proposed stent length for the intervention (e.g., this may be displayed using a bar positioned between the distal and proximal reference point indicators 424 and 426; see FIG. 11 ) are displayed. The user may review the degree of stent expansion (e.g., stent expansion rate) in box 445 and then end the process in box 446.

[0082] FIG. 7 is a flowchart illustrating a process for adjusting / establishing indicators 422, 424, and 426. FIG. 7 is an expanded view of boxes 433, 434, and 435 of FIG. 5 and boxes 440, 441, and 443 of FIG. 6. In this flowchart, "X" is a general designation corresponding to any one of the given indicators 422, 424, and 426, and the process may be utilized to adjust / establish any one or all of the given indicators. In box 447, a user may select a bookmark or indicator 422, 424, and 426. In box 448, a user may move the scrubber to identify a more desirable position for the particular bookmark or indicator 422, 424, and 426. In doing so, the selected indicator / bookmark 422, 424, and 426 moves / translates along the profile display 420. It may be appreciated that each of the indicators 422, 424, and 426 is independently movable along the profile display 420. In box 449, the user may determine whether a more desirable location has been identified. If not, the user may select a particular bookmark or indicator 422, 424, 426 (box 450) and long tap / hold the scrubber (box 451), which will cause a context menu to appear in box 452. Within the context menu, the user may confirm the indicator's location (box 453), which will cause the indicator / bookmark to become "hard" and a checked checkbox will appear for that particular bookmark or indicator 422, 424, 426 (box 454). This confirms the particular bookmark or indicator 422, 424, 426 (box 455).

[0083] If, in box 449, a more desirable location is found for a particular bookmark or indicator 422, 424, 426, the user long taps / holds the scrubber while it is in the alternate / secondary location (box 456), which causes a context menu to appear (box 457). The user selects to mark the new location (box 458), and the particular bookmark or indicator 422, 424, 426 may be moved to the new / secondary / alternate location (box 459). This causes the indicator / bookmark to become "hard," a checked checkbox appears for that particular bookmark or indicator 422, 424, 426 (box 454), and the particular bookmark or indicator 422, 424, 426 is then confirmed (box 455).

[0084] 8-11 illustrate longitudinal cross-sectional displays (e.g., similar to longitudinal cross-sectional display 420 of FIG. 4) at several illustrative points along the process described with reference to FIGS. 5-7. For example, FIG. 8 illustrates longitudinal cross-sectional display 520, in which "soft" indicators / bookmarks 522, 524, 526 are shown along longitudinal cross-sectional display 520, corresponding to box 432 of FIG. 5 and / or box 439 of FIG. 6 (note that in post-PCT runs, indicator 522 may be an indicator of MSA). FIG. 8 also illustrates menu 460, which indicates that none of indicators 522, 524, 526 have been confirmed (e.g., by the checkboxes next to the given labels not being selected).

[0085] A process for adjusting / establishing a particular indicator is shown in FIG. 9. In this example, the process involves adjusting / establishing a distal reference point (RefD) indicator 524. In FIG. 9, three separate representations of the longitudinal cross-sectional display 520 are shown: representations 520a, 520b, and 520c. In representation 520a, a user may select an indicator / bookmark 524 by touching a scrubber 561 (e.g., when using a touchscreen display, the user may use a finger or a suitable input device) (e.g., box 447 in FIG. 7). The scrubber 561 may be moved to a new position (e.g., by translating a slider using a finger or a suitable input device) as shown in representation 520b (e.g., box 448 in FIG. 7). If the user does not find a new position that is more desirable, the user may long-tap / hold the scrubber 561 (e.g., box 451 in FIG. 7), which may cause a context menu 562 to appear (box 452 in FIG. 7). The user confirms the location (box 453 in FIG. 7) and then the indicator / bookmark 524 becomes "hard" (box 454 in FIG. 7) and can be confirmed by checking in menu 560 (box 455 in FIG. 7).

[0086] In FIG. 10 , this process may be similarly performed for another one of the indicators / bookmarks, in this example, indicator / bookmark 526 corresponding to the proximal reference point (RefP). In FIG. 10 , two separate depictions of longitudinal cross-sectional display 520 are shown, i.e., depictions 520a and 520b. In depiction 520a, a user may select indicator / bookmark 526 by touching scrubber 561 (e.g., box 447 in FIG. 7 ). Scrubber 561 may be moved to a new position (e.g., box 448 in FIG. 7 ), as shown in depiction 520b. If the user finds the new position more desirable, the user may long-tap / hold scrubber 561 (e.g., box 456 in FIG. 7 ), and context menu 563 may be displayed (e.g., box 457 in FIG. 7 ). The user may mark the new position (box 458 in FIG. 7 ), and indicator / bookmark 526 may be moved to the new position (box 459 in FIG. 7 ). The indicator / bookmark 526 then becomes "hard" (box 454 in FIG. 7) and can be confirmed by a check in menu 560 (box 455 in FIG. 7).

[0087] 11 shows a longitudinal cross-sectional display 620. In the longitudinal cross-sectional display 620, a menu 660 indicates that each of the indicators / bookmarks has been confirmed by checking within the menu 660. Also, as described above, the MLA indicator 622 can also display the diameter at the MLA 664, which can assist the clinician in determining the appropriate stent diameter size to be used for the intervention. The distance between indicators 624 and 626 is also shown by a bar 665. The bar can be labeled with the distance between indicators 624, 626, which can help the clinician determine the appropriate stent length that can be used to treat the lesion.

[0088] The longitudinal cross-sectional display 620 and / or other longitudinal cross-sectional displays disclosed herein may also provide an indicator or graphic depicting the stent expansion rate. For example, the processor 106 may be able to determine the desired amount / rate of stent expansion appropriate for treating a vessel based solely on the MSA. Alternatively, the processor 106 may compare the MSA to (a) the vessel diameter at the proximal reference point, (b) the vessel diameter at the proximal reference point, or (c) the mean or average of the diameters at the proximal and distal reference points. Based on these comparisons, an indicator or graphic may be positioned adjacent to the longitudinal cross-sectional display 620 to indicate one or more of: (a) a desired stent expansion rate for treatment based on the MSA alone; (b) a desired stent expansion rate for treatment based on comparing the MSA to the vessel diameter at a proximal reference point; (c) a desired stent expansion rate for treatment based on comparing the MSA to the vessel diameter at a distal reference point; and / or (d) a desired stent expansion rate for treatment based on comparing the MSA to the mean or average of the vessel diameters at the proximal and distal reference points.

[0089] It should be understood that some profile displays may include more than one area depicting an indicator / bookmark. For example, FIG. 12 shows a profile display 720 that may include multiple indicators 722a, 722b, 722c for MLAs. While only shown schematically in FIG. 12, it should be understood that each MLA indicator 722a, 722b, 722c may have a distal reference point and a proximal reference point, etc.

[0090] US Provisional Patent Application No. 62 / 906,546 is incorporated herein by reference. WO 2021 / 062006 is incorporated herein by reference. US Provisional Patent Application No. 63 / 157,427 is incorporated herein by reference.

[0091] US Provisional Patent Application No. 63 / 233,875 is incorporated herein by reference. It should be understood that this disclosure is, in many respects, merely illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the disclosure. This may include, to the extent appropriate, the use of any of the features of one illustrative embodiment in other embodiments. The scope of the invention is, of course, defined in the language in which the appended claims are set forth.

Claims

[Claim 1] The invention described in the specification.

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