WO2025221788A1 - Vascular segment assessment system - Google Patents

Abstract

An apparatus for detecting position and/or motion of an interventional device during movement of the interventional device is provided. The apparatus includes a housing, a sensor and a processor. The housing has a passage disposed therethrough that is configured to receive an interventional device such that a proximal tubular segment of the interventional device can slide proximally and/or distally through the passage. The sensor is disposed adjacent to the passage and is configured to detect motion of the proximal tubular segment of the interventional device in at least one degree of freedom, e.g., linear motion in the passage. The motion of the proximal tubular segment of the interventional device that is detected corresponds to motion of a distal segment of the interventional device. The processor is configured to output position data from the position sensor to a user interface system.

Description

VASCULAR SEGMENT ASSESSMENT SYSTEM

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

[0001] This application claims benefit of U.S. Provisional Patent Application Serial No. 63/635,109 entitled “Vascular Segment Assessment System” filed April 17, 2024, which is hereby incorporated by reference in its entirety.

BACKGROUND

Field of the Invention

[0002] This application is directed to systems, methods and apparatuses for conducting vascular lesion assessments, e.g., diagnosing the nature, severity, location and/or treatment approach for coronary artery disease.

Description of the Related Art

[0003] Clinicians use certain diagnostic evaluations to determine the nature, severity, location and/or treatment approach for vascular disease, such as coronary artery disease. Coronary artery disease can result in blockages of coronary arteries from accumulation of plaque in blood vessels. These blockages are sometimes referred to as lesions. Coronary artery disease can be treated with medication and in some cases with catheter-based techniques such as balloon angioplasty and stents. Diagnostic evaluations can provide for more informed treatments. When a diagnostic evaluation indicates that the disease is more diffuse, the disease may be treated with medication. On the other hand, when diagnostics indicate that the disease is more focalized (discrete), the disease may be treated with stents.

[0004] One approach to diagnose the nature, location and extent of coronary artery disease is to measure pressure in and around a lesion. A sensor can be used to collect pressure data distal to and proximal to a lesion. A ratio of the distal to the proximal pressure can indicate the extent of the blockage. Another technique involves collecting pressure at several positions, from distal to the blockage, through the blockage and even proximal to the blockage. The pressures at several points can be collected by positioning a pressure sensor distal to the lesion and then pulling the sensor back through the lesion. This technique, called a pullback, is often performed manually by a cardiologist using a pressure sensing device such as a pressure sensing guidewire. [0005] Typically, following a pullback technique, the results are displayed as a pressure ratio (y axis) over time (x axis). If the cardiologist moves the pressure sensing device faster or slower, the curve looks different. This variation in the shape of the graph can result in variability in decision making that is a function of how the pullback is performed and not based on the condition of the patient.

SUMMARY

[0006] It would be beneficial to improve presentation of results of blood vessel assessment techniques. Some implementations discussed herein make such an improvement by displaying a pressure ratio or other diagnostic value as a function of distance moved through or position within the blood vessel rather than as a function of time. A position sensor able to measure the displacement of the pressure sensor would be advantageous to enable such a presentation. This would facilitate an output in which time on one axis is replaced by an absolute or relative position in a pullback evaluation. Having the absolute position or relative position will allow more precise analysis. For example, this enables one to compute the pullback pressure gradient and other similar indices among other benefits.

[0007] In one aspect, a system for assessing a vascular segment is provided that includes, a processor, a display, an interventional device, and a position sensor. The interventional device has a proximal end, a distal end, a tubular segment disposed between the proximal end and the distal end thereof, and an intravascular sensor. The intravascular sensor is positioned at or adjacent to the distal end of the interventional device. The interventional device is configured to output intravascular sensor data to the processor. The position sensor is configured to be disposed adjacent to the tubular segment. The position sensor is configured to detect motion of the tubular segment and output position data to the processor. The processor is configured to process the intravascular sensor data and the position data and to cause presentation of a synchronized user interface on the display of diagnostic information.

[0008] In some variations of the aspect recited in the preceding paragraph, the interventional device can comprise a guidewire with a pressure sensor. The intravascular sensor data can comprise pressure sensor data. The pressure sensor data can be synchronized with the position sensor data. The pressure sensor data and/or the position sensor data can be synchronized with angiography images to cause the presentation of a synchronized user interface on the display of diagnostic information in combination with an angiogram. In other variations of the aspect recited in the preceding paragraph, the interventional device can comprise an intravascular ultrasound (IVUS) device and the intravascular sensor can comprise an IVUS ultrasound transducer. The intravascular sensor data can comprise ultrasound transducer data. The ultrasound transducer data can be synchronized with the position sensor data. The ultrasound transducer data and/or the position sensor data can be synchronized with angiography images to cause the presentation of a synchronized user interface on the display providing diagnostic information including IVUS images and angiographic images. In other variations of the aspect recited in the preceding paragraph, the interventional device can comprise an optical coherence tomography (OCT) device and the intravascular sensor can include an OCT sensor. The intravascular sensor data can comprise OCT sensor data. The OCT sensor data can be synchronized with the position sensor data. The OCT sensor data and/or the position sensor data can be synchronized with angiography images to cause the presentation of a synchronized user interface on the display of diagnostic information including OCT images and angiographic image.

[0009] A guidewire disclosed herein (and many other interventional devices) have a radiopaque tip. The guidewire has a pressure sensor located adjacent to the tip of the wire, e.g., right at the proximal end of the tip. In the guidewire (or other interventional device), the distance from the radiopaque tip to the sensor can be known. As a result, it is possible to precisely establish the position of the pressure readings (or in the case of OCT or IVUS, the images taken) in an angiographic image. Also, seeing the position of the pressure sensor (or image sensor) on the angiography enables the assessment system disclosed herein to put visual markers in specific places of interest. For example, coronary entrance, a start of a lesion and an end of a lesion, or start and end of multiple lesions, a zone of diffuse disease, or multiple clinically different zones, e.g., diffuse disease zone and focal disease locations. Such markers would contribute in determining the lesion length, thus the stent needed length, and the needed position for stent delivery, as well as regions to avoid stenting. Although markers are placed on a 2D image, the assessment system disclosed herein provides the corresponding real length or distance. This enables the assessment system or the clinician to close the loop and/or link multiple modalities involved, e.g., linking simple pressure readings, distance to or between pressure readings (replacing the time axis by a real distance axis), and position and distance on the angiographic images. The assessment system disclosed herein can combine two- dimensional angiographic images, one-dimensional coronary axial length measurements from the position sensor disclosed herein and basic heart anatomy to reconstruct a coronary path displayed with three dimensions.

[0010] In another aspect, a method is provided. In the method, an introducer sheath is positioned in a peripheral arterial access site of a patient. The peripheral arterial access site can include a femoral artery access site, a radial artery access site, or another peripheral arterial or venous access site or another superficial vascular access site such as a carotid artery. An access catheter optionally is positioned through the introducer sheath such that a distal end of the access catheter is disposed adjacent to a vessel segment to be assessed and a proximal end is disposed outside of the patient. The access catheter can be positioned through the introducer sheath such that a distal end of the access catheter is disposed upstream or downstream of a vessel segment to be assessed and a proximal end can be disposed outside of the patient. An interventional device is positioned through the access catheter into the vessel segment to be assessed. The interventional device has a tubular segment disposed between proximal and distal ends thereof and a sensor disposed at or adjacent to the distal end. The interventional device is moved through the vessel segment to be assessed. In some variations, the interventional device is withdrawn, or pulled back through the vessel segment to be assessed from a distal position (e.g., a start position) to a proximal position (e.g., a finish position). In some variations, the interventional device is advanced, or pushed forward through the vessel segment to be assessed from a proximal position (e.g., a start position) to a distal position (e.g., a finish position). Data from the sensor of the interventional device and position data obtained during the moving of the pressure guidewire are processed. Processing the data from the interventional device and the position data obtained during the moving of the interventional device can include synchronizing the data from the interventional device with the position data. The position data are generated by a position sensor disposed adjacent to the tubular segment of the interventional device. A user interface is caused to be presented on a display of a value (e.g., a pressure value, ratio and/or gradient) or an image or images (e.g., an intravascular image and an angiographic image) as a function of position within the vessel.

[0011] The method of the preceding paragraph can be performed on a coronary vessel segment. In one variation, the access catheter is positioned such that the distal end is disposed in an ascending aorta adjacent to a coronary ostium. The interventional device is positioned through the access catheter into the coronary ostium. The interventional device is advanced such that the sensor is located adjacent to a coronary artery segment to be assessed. The method can be performed where the interventional device comprises a guidewire and the sensor comprises a pressure sensor of the guidewire. The sensor data from the interventional device can comprise pressure sensor data. Processing data can include synchronizing the pressure sensor data with the position data. The pressure sensor data and/or the position sensor data can be synchronized with angiographic images to cause the presentation of the synchronized user interface on the display that includes diagnostic information combining at least one of pressure data and angiographic images with reference to position data. In other variations of the aspect recited in the preceding paragraph, the interventional device can comprise an IVUS device with an IVUS ultrasound transducer. The data from the sensor of the IVUS device can comprise ultrasound transducer data. The data from the ultrasound transducer can be synchronized with the position sensor data. The processing of data from the ultrasound transducer and position data can include synchronizing the data from the ultrasound transducer and/or the position sensor data with angiography images. The presentation caused to be presented can include a combination of values, ultrasound images and angiographic images. In other variations of the aspect recited in the preceding paragraph, the interventional device can comprise OCT device with an OCT sensor. The intravascular sensor data can comprise OCT sensor data. The processing of data from the sensor of the OCT device and position data can include synchronizing the data from the OCT sensor and/or the position sensor data with angiographic images. The user interface caused to be presented can include a combination of values, OCT images and angiographic images.

[0012] In another aspect, an apparatus for detecting position and/or motion of an interventional device during movement of the interventional device is provided. The apparatus includes a housing, a sensor and a processor. The housing has a top portion, a bottom portion and a passage disposed therethrough. The passage is configured to receive an interventional device such that a proximal tubular segment of the interventional device can slide proximally and/or distally through the passage. The sensor is disposed adjacent to the passage and is configured to detect motion of the proximal tubular segment of the interventional device in at least one degree of freedom, e.g., linear motion in the passage. The motion of the proximal tubular segment of the interventional device that is detected corresponds to motion of a distal segment of the interventional device. The processor is configured to output position data from the position sensor to a user interface system.

[0013] The apparatus of the preceding paragraph can be configured to detect position and/or motion of a guidewire during movement of the guidewire. The position data can be synchronized with sensor data output by the guidewire. The sensor data can include pressure data. The apparatus of the preceding paragraph can be configured to detect position and/or motion of an IVUS device movement of the IVUS device. The position data can be synchronized with sensor data (e.g., ultrasound transducer data) output by the IVUS device. The sensor data can include ultrasound data. The apparatus of the preceding paragraph can be configured to detect position and/or motion of an OCT device during movement of the OCT device. The position data can be synchronized with sensor data (e g., OCT data) output by the OCT device. The sensor data can include OCT data.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] These and other features, aspects and advantages are described below with reference to the drawings, which are intended for illustrative purposes and should in no way be interpreted as limiting the scope of the embodiments. Furthermore, various features of different disclosed embodiments can be combined to form additional embodiments, which are part of this disclosure. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments. The following is a brief description of each of the drawings.

[0015] FIG. 1 is a schematic view of a heart and a coronary artery, comparing a normal artery with a blocked artery, the blockage or lesion formed by plaque deposits in a coronary artery;

[0016] FIG. 2A shows a pullback method for characterizing two lesions formed in a coronary artery;

[0017] FIG. 2B shows a user interface that can be presented on a display illustrating a diagnostic pressure ratio over time during the pullback method;

[0018] FIG. 3 is a system for collecting position data using a position sensor and other diagnostic data using an interventional device during vessel assessment; [0019] FIG. 4 shows a portion of the system of FIG. 3 illustrating a position sensor for monitoring the relative position of the interventional device during linear movement of the interventional device;

[0020] FIGS 5A-5B are top perspective and exploded views, respectively, of the position sensor of FIG. 4; and

[0021] FIGS. 6A and 6B illustrate providing one or both of two graphs illustrating the pressure ratio data collected using the system of FIG. 3.

DETAILED DESCRIPTION

[0022] This application is directed to providing enhanced detection and display of data, e.g., position data, pressure data, pressure ratio data and/or image data detected or calculated using a position sensor and an interventional device having an intravascular sensor. The position data can include linear position data that is indicative of linear position of the intravascular sensor along a path of movement through a blood vessel segment. The position data can be collected outside the patient. The position data can correspond to motion of a tubular segment of an interventional device. The tubular segment can be coupled with the intravascular sensor such that motion of the tubular segment corresponds to motion of the intravascular sensor. The tubular segment where motion is detected can be that of a portion of the interventional device disposed outside the patient. The position data can be associated with, e.g., synchronized with or registered with sensor data output by the intravascular sensor. The position data can correspond to linear position relative to a start of a pullback method. Diagnostic information can be seen or derived from a user interface generated following the association of or registration of the sensor data and the position data. The user interface can provide diagnostic information. For example, pressure sensor data collected from a pressure sensing guidewire can be combined with position sensor data obtained while pulling the guidewire proximally. Change in pressure can be used by a clinician to accurately distinguish focal disease from diffuse disease. By presenting pressure data as a function of position, variability of conventional display output of such data introduced by using time as the x-axis of a pullback user interface output where user pullback velocity is not controlled or measured can be reduced or eliminated. The display output information can then be more effectively used in determining an appropriate course of treatment for a patient. Improvements can be derived in the use of interventional devices with OCT sensors and IVUS transducers. In these cases, the position of the OCT sensor or the IVUS transducer in the vasculature when a specific image was taken can be known, which can enable registration of the intravascular images with angiographic images and/or better inform the clinician of the location of specific forms of vascular disease.

[0023] FIG. 1 shows a human heart and two conditions of a coronary artery of the heart. In a normal artery, there is no blockage of the artery that would unnaturally impede blood flow, preventing or reducing the flow of oxygenated blood to the tissues of the heart. The blocked artery condition is one in which the artery is at least partially blocked by a lesion, which can be formed by calcium deposits and other plaque matter. The blocked artery limits the flow of oxygenated blood to heart tissue, which can result in damage to the heart tissue, and progressively worse heart disease.

[0024] FIGS. 2A and 2B illustrate a technique for diagnosing the condition of a patient’s heart. FIG. 2A, left image, is an angiographic image of the heart in which the circumflex artery and the anterior interventricular artery are visible. The image shows a start and a finish line (labeled START and FINISH) for a pullback technique for assessing the condition of the anterior interventricular artery to determine the presence and extent of coronary artery disease. FIG. 2A, right image, shows the anterior interventricular artery in a schematic manner, enlarged with an interventional device positioned distal to a distalmost of two lesions LI. A guidewire 108 (one example of an interventional device) with a pressure sensor 152 (one example of an intravascular sensor) located adjacent to a distal end thereof is placed in the anterior interventricular artery. To reach the illustrated position, the guidewire 108 is advanced through an access catheter 116 positioned in an ascending aorta of a patient. The access catheter 116 can be advanced through an introducer sheath (not shown), which is inserted into a peripheral blood vessel (e.g., femoral or radial artery) using the Seidinger or similar technique.

[0025] The access catheter 116 can be positioned such that a distal end thereof is adjacent to and oriented toward the coronary artery ostium OS. The guidewire 108 can then be advanced through the access catheter 116 and then through the coronary artery ostium OS into a coronary artery to be assessed. In FIG. 2A, right image, the guidewire 108 is seen advanced well into the anterior interventricular artery such that the pressure sensor 152 is distal to a first lesion LI . In this patient the first lesion LI is one of two lesions. A second lesion L2 is located proximal to the first lesion LI. FIG. 2A, right image, illustrated the pullback technique in which the pressure sensor 152 is moved proximally from the location START to the location FINISH. The pressure sensor 152 is moved by withdrawing the guidewire 108 as indicated by the arrow AL Withdrawing the guidewire 108 can be performed by manually moving the proximal end of the guidewire 108. In some variations, the pullback is machine controlled. The structure for moving the guidewire 108 is discussed below in connection with FIG. 3.

[0026] The data collected by the pressure sensor 152 provides a distal pressure. The distal pressure can be combined with a proximal pressure to provide diagnostic information. The proximal pressure can be collected using the access catheter 116. A lumen in the access catheter 116 can be in pressure communication with a pressure transducer outside the patient. The distal and proximal pressures can be combined into a pressure ratio, e g., distal pressure divided by proximal pressure. This ratio can be compared to a benchmark to determine whether the constriction at the location where the distal pressure is collected is severe enough to warrant treatment. Variations of the foregoing are possible. For example, the pressure sensor 152 can be advanced through the vessel segment of interest rather than being withdrawn. Thus, the START and FINISH lines can be reversed and the direction of movement would be the opposite of that illustrated by the arrow AL Also, the pressures can be collected in any of several ways. In some cases, these pressures are collected without inducing hyperemia, e.g., by collecting pressure data only or primarily during a diastolic part of one or more heartbeat cycles. Or data can be collected throughout the heartbeat cycle but only diastolic pressure data can be used in calculating a ratio to be compared to a benchmark. In some cases, the pressures can be collected after administering adenosine, which can induce hyperemia. The pressure can be collected in the patient at rest. In some embodiments, the access catheter includes a lumen extending from the distal end to the proximal end thereof. The lumen can provide pressure communication between blood at the distal end and a pressure sensor at the proximal end.

[0027] In some embodiments, the system determines a distribution of pressure losses and the system presents diagnostic information including an indication of the distribution of pressure losses. The indication of pressure losses can correspond to a focal disease state or a diffuse disease state. In some embodiments, the system determines a pullback pressure gradient and the system presents diagnostic information including the pullback pressure gradient. In some embodiments, the intravascular sensor data can include distal pressure sensor data. The system can process proximal pressure sensor data to generate a diagnostic metric combining the distal pressure sensor data and the proximal pressure sensor data.

[0028] FIG. 2B shows one way in which data from the pullback can be presented. The Y-axis indicates a pressure ratio of Pd (measured from the pressure sensor 152) to Pa (measured via the pressure lumen in the access catheter 116). The sloped lines intersected by the dashed lines labeled LI and L2 show the location of the first lesion LI and the second lesion L2. This graphical output provides good diagnostic information to distinguish, for example, diffuse disease from focalized disease. Focal disease, treatable with stents, can present as distinct spaced apart sloped lines as shown. Diffuse disease can present as a gradual decline in the line in FIG. 2B without distinct sloped areas. Diffuse disease may be treated with medication and in some cases without deploying stents. While the graphs of FIG. 2B provides a diagnostic benefit, it is subject to variability if the pullback rate varies. A rapid pullback will result in much steeper drop-off in focal disease while a very slow pullback would have more gradual drop off. This could make distinguishing focal from diffuse disease more difficult.

[0029] FIG. 3 shows an assessment system 100 that can be used in the pullback method of FIG. 2A for assessing a vascular segment and that can enhance consistency of a user. The assessment system 100 includes a position sensor 104, a monitor 112, and an access catheter 116. The assessment system 100 can also include an interventional device, such as a guidewire 108. The position sensor 104 and the guidewire 108 provide data that is used to generate improved user interface displays. The position sensor 104 is configured to detect a linear motion 160 of a portion of the guidewire 108 located outside the patient. The linear motion 160 of the proximal portion corresponds to a linear motion 160 of a distal end of the guidewire 108, which can be of a same magnitude as the linear motion of the proximal portion.

[0030] The monitor 112 includes a processor 120 and a display 124. The processor 120 is configured to receive data from the position sensor 104 and the guidewire 108 as discussed further below. The processor 120 is configured to synchronize the data from the position sensor 104 and the data from the guidewire 108 such that a user interface can be generated to be presented on the display 124. In this context, synchronizing means that if two data points are collected between the START and the FINISH lines at spaced apart positions, the user interface display illustrates these data points at proportionally spaced apart positions on the display. The processor 120 also can synchronize the position and interventional device sensor data with angiographic image data in some cases. The angiographic image data can include images generated during the process of the pullback. The actual position of the pressure sensor 152 at the START, the FINISH, or any point therebetween can be captured in one or more angiographic images. These images can be synchronized or registered with the position sensor and interventional device sensor data such that more complex user interface outputs can be generated. For example, a static or dynamic presentation of angiographic images can be augmented with diagnostic information generated in the pullback. An angiographic image can be augmented with a pressure ratio at a particular location. An angiographic image can be augmented with a distance measurement corresponding to the distance from a distal end of the first lesion LI and/or the second lesion L2 to the proximal end thereof. The distance measured can be indicative of the stent length to be used, the number of stents to be used and the position of multiple stents in spaced apart lesion, for example. This represents an improvement over systems in which determining the length of the lesion involves a visual estimation from an angiogram. The use of the processor 120 in the monitor 112 to calculate length based on position data from the position sensor 104 provides improved decision making capability as to stent length.

[0031] In other variations, the position sensor 104 and the monitor 112 can be used with other types of interventional devices. An IVUS device can be substituted for the guidewire 108. An IVUS device is another example of an interventional device that can provide ultrasound based imaging from an ultrasound transducer (also called a sensor) disposed intravascularly. An OCT device can be substituted for the guidewire 108. An OCT device is another example of an interventional device that can provide optical coherence tomography based images from an OCT transducer (also called a sensor) disposed intravascularly. If the processor 120 is used to synchronize OCT or IVUS images with an angiographic image, the display 124 can be used to output a user interface that illustrates two modalities of imaging. The images can be displayed selectively, sequentially, or at the same time, e.g., angiographic and OCT or IVUS images side-by-side. The position sensor 104 provides a relatively simple way to synchronize or register diagnostic data and position and/or two or more modes of imaging.

[0032] FIG. 3 shows that the position sensor 104 can be configured to communicate wirelessly with the monitor 112. The wireless communications allows position sensor data to be transferred to the processor 120. The processor 120 can process the position sensor data as discussed further below.

[0033] As discussed above, the access catheter 116 facilitates advancing of the guidewire 108 into the coronary artery ostium OS. The access catheter 116 may be delivered in a straight configuration over an initial guidewire. The initial guidewire may be relatively stiff to force the distal tip of the access catheter 116 to be advanced in a straight configuration. Once positioned in the ascending aorta the initial guidewire may be withdrawn, allowing the distal tip of the access catheter 116 to return to a pre-defined shape that allows a distal opening of the access catheter 116 to face the coronary artery ostium OS. Then, the guidewire 108 can be advanced out of the access catheter 116 and into the coronary arteries. The access catheter 116 can have a proximal end Y-shaped connector with two access points, one of which receives the guidewire 108 for advancement through the distal tip. The other access point of the Y- shaped connector of the access catheter 116 can be coupled with a pressure transducer for detecting proximal pressure.

[0034] Although FIGS. 2A and 2B discuss coronary diagnostic vessel assessment methods, the assessment system 100 can be used in other vessels. The assessment system 100 could be used in carotid or neurovascular vessel assessment. In that case, the distal tip of the access catheter 116 may be configured to track a guidewire to an access point for the carotid or of the neurovascular vessels. The assessment system 100 could be used in peripheral vessel assessment, such as in the legs or arms. In such cases, the access catheter 116 may not be used or the distal tip of the access catheter 116 may be configured to track a guidewire to an access point within the peripheral vasculature, e.g., defining an access path from one peripheral artery to another peripheral artery.

[0035] FIGS. 3-4 illustrate the guidewire 108 in further detail. The guidewire 108 includes a proximal end 140 and a distal end 144. The proximal end 140 is configured to be coupled with a control handle 156. The control handle 156 can be configured to couple with and decouple from the proximal end 140 one or more times during a procedure. The control handle 156 provides a grippable structure that a cardiologist can use to manipulate the guidewire 108, which is very small. As discussed above, the guidewire 108 has a pressure sensor 152 disposed adjacent to the distal end 144. The pressure sensor 152 can have any configuration, including an optical MEMS device communicating through the body of the guidewire 108 through an optical fiber. The pressure sensor 152 could include an electrical based sensor that can detect pressure. The guidewire 108 includes a tubular segment 148 disposed between the proximal end 140 and the distal end 144. The tubular segment 148 can comprise a tubular body of the guidewire 108. In one example, the guidewire 108 includes an outer tube that includes the outer surface of the guidewire 108. The outer tube can have an inner surface within which an optical fiber is centrally mounted. The outer tube could enclose the optical fiber mounted off-center in some embodiments. A section of the outer tube of the tubular segment 148 can be metallic and can have a surface roughness that is above a threshold below which the position sensor 104 would not be able to detect motion of the tubular segment 148. In one embodiment, the tubular segment 148 is coated with a lubricious coating, e.g., coated with PTFE, to facilitate movement of the guidewire 108 with the access catheter 116. The coating is of sufficient roughness for the position sensor 104 to detect motion of the guidewire 108 therethrough.

[0036] The control handle 156 can have a connector at the proximal end thereof that can be physically connected to the monitor 112 or to a connector unit coupled therewith. In this way, pressure sensor 152 can output pressure sensor data to the monitor 112. In variations, wireless transmission of pressure sensor data can be provided to the monitor 112 via a wireless transmitter disposed in or coupled with the handle 156.

[0037] FIGS. 5 A and 5B illustrate one implementation of the position sensor 104 The proximal end 140 includes a housing 180 enclosing components thereof. The housing 180 can have any suitable form and in one example, includes top portion, e.g., a upper cover 184 and bottom potion, e.g., a lower cover 188. The upper cover 184 and the lower cover 188 enclose an optical sensor 196 and a processor 200. The optical sensor 196 is configured to detect motion of the guidewire 108. The optical sensor 196 can employ a tracking technique that is similar to an optical computer mouse but that is adapted to focus on a portion of the tubular segment 148 of the guidewire 108. Notably, the tubular segment 148 is a cylindrical segment. That is, the outer surface of the guidewire 108 in the tubular segment 148 is cylindrical. A transverse cross-section at the tubular segment 148 includes a circular outer periphery. Optical motion tracking is not typically adapted for tacking structures that curve out of plane. The approach for tracking the guidewire 108 therefore involves focusing the optical detector on a line segment corresponding to a portion of the periphery of the tubular segment 148. The portion upon which the optical sensor 196 may be focused may include an arc segment of less than 15 degrees, e.g., less than 10 degrees, e.g., less than 7.5 degrees, e.g., less than 5 degrees, e.g., less than 2.5 degrees, e.g., less than 2 degrees, e.g., about 1 degree or less than 1 degree.

[0038] The optical sensor 196 is mounted within the housing 180 such that the optical detector faces a passage 192 through which the guidewire 108 can be advanced. The passage 192 provides a pathway for the guidewire 108 to traverse through the housing 180. In doing so, the tubular segment 148 moves past the optical sensor 196. FIG. 5B shows that the proximal end 140 of the guidewire 108 can be disposed outside of the housing 180 while a portion of the tubular segment 148 is disposed within the passage 192 in the housing 180. The guidewire 108 can extend distally of the housing 180. The position sensor 104 can include or can be coupled with a connector 220 providing access to the access catheter 116 when the position sensor 104 is coupled with the access catheter 116. The connector 220 can include a valve that can prevent substantial amounts of blood from flowing or seeping through the connector 220 into the housing 180. The tubular segment 148 can be exposed in a well or open volume formed in a central area of the housing 180 within which the optical sensor 196 is located. The passage 192 can be enlarged in this area, while having a diameter proximal and distal of the optical sensor 196 that is close in size to the outer diameter of the guidewire 108. The passage 192 can be circular with a dimension suitable for low friction sliding of the guidewire 108, e.g., 5-20 percent larger than the diameter of the guidewire 108. Being close in size to the guidewire 108, the passage 192 can provide side-support to the guidewire 108 if pushed distally or proximally through the passage 192 within the housing 180. In one variation, the passage 192 comprises first and second passages and a span between these passages exposes the tubular segment 148. The tubular segment 148 can be unsupported in the span between the first and second passage. A background to the span can be suitable for enhancing the visibility of the tubular segment 148, e.g., a dark or other high contrast background can be provided. The tubular segment 148 can move in the volume between the optical sensor 196 and the high contrast background.

[0039] In some embodiments, the housing 180 has a passage for slidably receiving the interventional device in a pathway disposed adjacent to the position sensor. In some embodiments, the housing 180 includes an integral portion of a proximal portion of an introducer or an integral portion of a proximal portion of a coronary artery access catheter. In some embodiments, the position sensor 104 can be coupled with a proximal fitting of an access catheter adjacent to an access port thereof. In some embodiments, a sensor is disposed adjacent to the passage and is configured to detect motion of a proximal tubular segment of the interventional device in at least one degree of freedom. The motion of the proximal tubular segment of the interventional device can correspond to motion of a distal segment of the interventional device. The one degree of freedom can include distal axial motion. The one degree of freedom can include linear motion.

[0040] The position sensor 104 also includes a battery 204 that can be rechargeable. The battery 204 advantageously eliminate any need to provide wired power from outside the housing 180 to power the position sensor 104. The position sensor 104 can include a user interface 208, which may be one or more lights that indicate the state of power and of other components, such as the state of a wireless transmitter 216, if provided. The wireless transmitter 216 enables wireless transmission 218 as discussed in connection with FIG. 3. The operation of the position sensor 104 can be selectively activated by a switch 212 that extends through the housing 180 to be accessible by users.

[0041] One of many possible variations of the position sensor 104 is to provide a non-optical sensor in place of the optical sensor 196. In one variation, a mechanical sensor is provided. A Hall sensor could be used in which magnetic fields generated from a source on the guidewire 108 are detected by a sensor mounted within the housing 180. In another variation, one or more sets of mechanical rollers are mounted in the position sensor 104. The rollers rolls over the outside surface of the guidewire 108 (or other interventional device) as it moves linearly through the housing 180. The size of the rollers is known, thus one form of sensor need only count the revolutions of the rollers to be able to determine the linear displacement of the guidewire 108. Another sort of optical sensor that could be used is an optical encoder that can detect markings (e.g., a regular linear array of lines spaced a known di stance from each other) on the surface of the guidewire 108 (or other interventional device) as the guidewire 108 (or other interventional device) moves through the housing 180. A proximity sensor could be used (optical or magnetic) that detects a distance from a part of the guidewire 108 (or other interventional device) or a component coupled therewith to the detector mounted within the housing 180.

[0042] The position sensor 104 can be used in many different methods for tracking interventional devices during procedures. As discussed herein, these methods are particularly useful for tracking a pressure sensor in performing a coronary vessel diagnostic procedure. Applications can also be found outside of coronary vessels and with other interventional devices. As with many cardiology interventions, access to the vasculature is first obtained. The access can be through a peripheral blood vessel such as a femoral artery or a radial artery. Venous access could also be provided in various methods using the position sensor 104. Such access may be provided using an introducer sheath.

[0043] Thereafter an interventional device can be inserted into the patient. This can be done directly through the introducer sheath or can be done through an access catheter, such as the access catheter 116. An interventional device intended to access and perform diagnostic procedures or to treat peripheral conditions may be performed without a separate access catheter. FIG 2A illustrates the use of the access catheter 116 to introduce an interventional device, e g., the guidewire 108, into the coronary vasculature. The distal end of the access catheter 116 is positioned near the coronary artery ostium OS to provide for access to the coronary vessels. The proximal end of the access catheter 116 is disposed outside the patient in this method. As shown in FIG. 3, the proximal end of the access catheter 116 can include a connector or an access port to which the position sensor 104 can be coupled.

[0044] FIG. 2A shows that the method also includes advancing the guidewire 108 such that the pressure sensor 152 is located adjacent to a coronary artery segment to be assessed. In other methods, an interventional device can be used to image a coronary vessel segment, such as using an IVUS transducer or an OCT imaging device. The guidewire 108 (or another interventional device) can be positioned proximal to, within or distal to a vessel segment to be assessed. The guidewire 108 (or another interventional device) can be initially positioned distal to or toward a distal end of the vessel segment to be assessed. [0045] After the guidewire 108 (or another interventional device) has been initially positioned, the guidewire 108 (or other interventional device) can be moved through the vessel. FIG. 2A shows that the motion of the guidewire 108 can be in a proximal direction. The guidewire 108 can be moved in an anterior interventricular artery proximally toward the circumflex artery, as indicated by the START and FINISH lines. The movement can be as indicated by the arrow Al. During the movement, pressure data can be generated by the pressure sensor 152 disposed adjacent to the distal end of the guidewire 108. The pressure data optionally can be processed in the position sensor 104, e.g., by the processor 200, and can be provided to the processor 120 of the monitor 112.

[0046] The position sensor 104 is configured to track the movement of the guidewire 108. The position sensor 104 can be integrated into a connector of the access catheter 116 or into a connector of an introducer. For example, a Y-shaped connector in the access catheter 116 can be provided to allow the guidewire 108 (or another interventional device) to be advanced into the coronary arteries. The position sensor 104 can be integrated into the branch of the Y-connector through which the guidewire 108 (or another interventional device) is inserted. By integrating the position sensor 104 into the Y-connector or other proximal end fixture, the position sensor 104 is unobtrusive to the clinician, for example not requiring any additional steps in the procedure. The position sensor 104 can be a separate component that can be coupled by the cardiologist to the introducer catheter or to the access catheter 116. The position sensor 104 can be coupled with a valve connector of the access catheter 116 or can have a connector 220 to replace the valve connector of the access catheter 116. By providing the position sensor 104 as a separate component, off-the-shelf access catheter and/or introducer sheaths can be equipped with position sensing capability. This approach makes the use of the position sensor 104 possible in more situations.

[0047] The guidewire 108 (or other interventional device) can be inserted through the passage 192 of the position sensor 104. A distal end of the guidewire 108 (or other interventional device) can be inserted into a proximal end of the passage 192 and threaded through to a distal end of the passage 192. A proximal end of the guidewire 108 (or other interventional device) can be inserted into a distal end of the passage 192 and threaded through to a proximal end of the passage 192. The housing 180 can have a clam-shell configuration where the upper cover 184 and the lower cover 188 hinge apart allowing the guidewire 108 (or other interventional device) to be side loaded into the housing 180.

[0048] After the guidewire 108 (or other interventional device) is positioned through the position sensor 104, the device can be advanced to the vessel segment to be assessed, as discussed above. Sensor data from the interventional device, such as the guidewire 108, can be processed along with position data from the position sensor 104. The position data can be taken from observations of the tubular segment 148 of the guidewire 108 made by the optical sensor 196. In some variations, the position sensor 104 has a non-optical sensor, such as any of the mechanical sensors/detectors discussed herein. The observations by the position sensor 104 can be processed by the processor 200 prior to being sent, e.g., by a wireless transmission 218 to the processor 120. The processor 120 enables a user interface to be presented on the display 124. The user interface can include a graph of sensor data obtained by the guidewire 108 alone or in combination with data obtained from the access catheter 116. The sensor data from the guidewire 108 can be combined with pressure data from the access catheter 116, e.g., in a ratio of distal pressure divided by proximal pressure.

[0049] FIGS. 6A and 6B illustrate the capability of the position sensor 104. FIG. 6A shows a high quality pullback as detected by the position sensor 104. The rate of pullback (solid line) is very close to the predicted ideal pullback (dotted line). FIG. 6B shows a graph of pressure ratios taken over time and over distance. Trace T1 shows a graph of pressure ratios taken over position as measured by the position sensor 104. The graph suggest that the vessel includes two lesions spaced apart by 68 mm. The shape of the T1 curve is very similar to that of the high quality pullback (T2 trace). The data that is illustrated was taken in an experimental set up with a tube segment in which two lesions were created 70.375 mm apart. The difference in distance estimation using the position sensor 104 versus the actual distance is within a reasonable degree of error.

[0050] By providing the position sensor 104 capable of tracking position of the guidewire 108, the processor 120 is able to generate a user interface output of pressure values or ratios plotted against position rather than time. This approach eliminates the variable of the rate of retraction of the guidewire 108 in a pullback method. This reduces variability in the presentation of this data, making it possible to more consistently diagnose the nature of coronary artery disease, and ultimately to more effectively treat patients. [0051] For interventional devices with intravascular sensors providing imaging modalities (e.g., OCT or IVUS), the position sensor 104 allows images to be synchronized relative to position. This data would enable images taken intravascularly to be matched with (e.g., registered with) angiographic images to give cardiologists multiple modes of presentation of images, providing more information about the location and state of disease of patients.

Advantages

[0052] The position sensor 104 provides a number of advantages. The position sensor 104 enables better decision-making in interventional cardiology, e.g., for percutaneous coronary intervention. The position sensor 104 provides real-time guidewire position acquisition, which enables distance-based instead of time-based pressure and hemodynamics indices pullback acquisition. The position data is provided by the position sensor 104 with no additional steps, e.g., the position sensor 104 need only be clipped onto the access catheter 116 or an introducer sheath and no image analysis is needed to know the relative position of the pressure sensor 152. Moreover, the position sensor 104 enables procedures that benefit from an approximation of or a knowledge of absolute position. The position sensor 104 can determine a zero position in some techniques. For example, a user can input into the user interface 208 when the pressure sensor 152 of the guidewire 108 (or a sensor of another interventional device) is located at the distal end opening of the access catheter 116. Then movement forward into the coronary vasculature can be detected, recorded, presented, and/or used in calculations relative to this zero point. Any subsequent recorded/di splayed position would be equal to the real length of the coronary path assessed. Another zero point could be input, e.g., by depressing a zero button of the user interface 208 when the pressure sensor 152 (or a sensor of another interventional device) is located at the START position in FIG. 2A. Another zero point could be input, e.g., by depressing a zero button of the user interface 208 when the pressure sensor 152 (or a sensor of another interventional device) is located at the location marked FINISH in FIG. 2A if, for example, the clinician prefers to push the pressure sensor 152 (or a sensor of another interventional device) through the vessel segment. Pushing may be preferred in that it may avoid at least one traverse of lesions in the vessel segment. Another advantage is that co-regi strati on of intravascular data and images with angiographic images is possible by a simpler method. By using the optical sensor 196, there is no mechanical impact on guidewire handling feeling as there is no contact with guidewire. Also, optical sensing allows the user to move the guidewire 108 (or other interventional device) without speed restrictions, e.g., at any speed and without requiring a generally constant speed. In contrast, co-regi strati on with angiographic images is limited by the angiographic image frequency and by image quality. It is believed that the position sensor 104 enables high accuracy in stent length determination (better than 0.5mm) and high accuracy in lesion/stent position (better than 0.5mm). The position sensor 104 and systems including the sensor provide better diagnosis of focal versus diffuse disease. Because the position sensor 104 provides real distance output, the sensor enables the calculation of pullback pressure gradient and similar indices.

Terminology

[0053] As used herein, the relative terms “proximal” and “distal” are used to describe locations relative to the display. The term “proximal” refers to being nearer towards the console. Conversely, the term “distal” refers to being farther away from the console.

[0054] As used herein, the relative terms “upstream” and “downstream” shall be defined from the perspective of blood flow. Thus, downstream refers to the direction toward the aorta relative to the left ventricle.

[0055] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments.

[0056] The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.

[0057] The terms “approximately,” “about,” “generally,” and “substantially” as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within less than 5% of the stated amount, as the context may dictate.

[0058] The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between” and the like includes the number recited. Numbers preceded by a term such as “about” or “approximately” include the recited numbers. For example, “about four” includes “four.”

[0059] Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication. For example, actions such as “distally moving a locking element” include “instructing distal movement of the locking element.”

[0060] Although certain embodiments and examples have been described herein, it will be understood by those skilled in the art that many aspects of the humeral assemblies shown and described in the present disclosure may be differently combined and/or modified to form still further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. A wide variety of designs and approaches are possible. No feature, structure, or step disclosed herein is essential or indispensable.

[0061] Some embodiments have been described in connection with the accompanying drawings. However, it should be understood that the figures are not drawn to scale. Distances, angles, etc. are merely illustrative and do not necessarily bear an exact relationship to actual dimensions and layout of the devices illustrated. Components can be added, removed, and/or rearranged. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with various embodiments can be used in all other embodiments set forth herein. Additionally, it will be recognized that any methods described herein may be practiced using any device suitable for performing the recited steps.

[0062] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0063] Moreover, while illustrative embodiments have been described herein, the scope of any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. Further, the actions of the disclosed processes and methods may be modified in any manner, including by reordering actions and/or inserting additional actions and/or deleting actions. It is intended, therefore, that the specification and examples be considered as illustrative only, with a true scope and spirit being indicated by the claims and their full scope of equivalents.

Claims

WHAT IS CLAIMED IS:

1. A system for assessing a vascular segment, comprising: a processor and a display; an interventional device having a proximal end, a distal end, a tubular segment disposed between the proximal end and the distal end thereof, and an intravascular sensor positioned at or adjacent to the distal end of the interventional device, the interventional device configured to output intravascular sensor data to the processor; and a position sensor configured to be disposed adjacent to the tubular segment, the position sensor configured to detect motion of the tubular segment and output position data to the processor; wherein the processor is configured to process the intravascular sensor data and the position data and to cause presentation of a synchronized user interface on the display of diagnostic information.

2. The system of Claim 1, wherein the diagnostic information comprises a pressure value and/or a pressure ratio as a function of position.

3. The system of Claim 1, wherein the diagnostic information comprises a length value corresponding to a distance traversed by the interventional device from a first end of a vessel segment to a second end of the vessel segment.

4. The system of Claim 1, wherein the diagnostic information comprises an indication of distribution of pressure losses.

5. The system of Claim 4, wherein the indication of pressure losses correspond to a focal disease state or a diffuse disease state.

6. The system of Claim 1, wherein the diagnostic information comprises a pullback pressure gradient.

7. The system of Claim 1, wherein the processor is configured to synchronize position sensor data or intravascular sensor data with angiography images.

8. The system of Claim 1, wherein the position sensor comprises an optical sensor.

9. The system of Claim 8, wherein the optical sensor is configured to detect motion of an outer surface of the tubular segment of the interventional device.

10. The system of Claim 8, wherein the optical sensor is configured to detect motion of a central portion of a partial cylindrical surface of the tubular segment.

11. The system of Claim 1, wherein the position sensor comprises a mechanical detector.

12. The system of Claim 1, wherein the intravascular sensor data comprises distal pressure sensor data and the processor is configured to process proximal pressure sensor data to generate a diagnostic metric combining the distal pressure sensor data and the proximal pressure sensor data.

13. The system of Claim 1, further comprising a housing having a passage for slidably receiving the interventional device in a pathway disposed adjacent to the position sensor.

14. The system of Claim 13, further comprising a wireless transmitter disposed in the housing for transmitting position sensor data to the processor.

15. The system of Claim 13, wherein the housing comprises a connector for coupling with a proximal connector of an introducer sheath.

16. The system of Claim 13, wherein the housing comprises an integral portion of a proximal portion of an introducer or an integral portion of a proximal portion of a coronary artery access catheter.

17. The system of Claim 1, wherein the diagnostic information comprises an image generated from sensor data from an IVUS transducer.

18. The system of Claim 1, wherein the diagnostic information comprises an image generated from sensor data from an OCT sensor.

19. A method, comprising: positioning an introducer sheath in a peripheral arterial access site of a patient; positioning an access catheter through the introducer sheath such that a distal end of the access catheter is disposed adjacent to a vessel segment to be assessed and a proximal end disposed outside of the patient; positioning an interventional device through the access catheter proximal of, within or distal of the vessel segment to be assessed, the interventional device having a tubular segment disposed between proximal and distal ends thereof and a sensor disposed at or adjacent to the distal end; moving the interventional device through the vessel segment to be assessed; processing sensor data from the sensor of the interventional device and position data obtained during the moving of the interventional device, the position data generated by a position sensor disposed adjacent to the tubular segment of the interventional device; and causing presentation of a user interface on a display of a value or an image as a function of position.

20. The method of Claim 19, further comprising coupling the position sensor with a proximal fitting of the access catheter adjacent to an access port thereof.

21. The method of Claim 19, further comprising connecting a housing disposed around the position sensor with the access catheter.

22. The method of Claim 19, further comprising positioning an end of the interventional device through a passage disposed through a housing disposed around the position sensor.

23. The method of Claim 19, wherein the access catheter comprises a lumen extending from the distal end to the proximal end thereof, the lumen providing pressure communication between blood at the distal end and a pressure sensor at the proximal end.

24. The method of Claim 23, wherein the user interface comprises a graph illustrating a plurality of pressure ratios corresponding to a plurality of positions displayed with reference to position.

25. The method of Claim 24, wherein the plurality of pressure ratios comprise ratios of distal pressure values divided by proximal pressure values.

26. The method of Claim 25, wherein the plurality of pressure ratios are determined from pressure values from a diastolic portion of one or more heartbeats.

27. The method of Claim 25, wherein the plurality of pressure ratios are determined from pressure values obtained while the patient is in hyperemia or at rest.

28. The method of Claim 19, wherein the interventional device comprises a pressure guidewire and the sensor data comprises pressure data.

29. The method of Claim 19, wherein the interventional device comprises an IVUS transducer and the sensor data comprises IVUS image data.

30. The method of Claim 19, wherein the interventional device comprises an OCT sensor and the sensor data comprises OCT image data.

31. An apparatus for detecting position and/or motion of an interventional device during movement of the interventional device, comprising: a housing having a top portion, a bottom portion and a passage disposed therethrough, the passage configured to receive an interventional device such that a proximal tubular segment of the interventional device can slide proximally and/or distally through the passage; a sensor disposed adjacent to the passage and is configured to detect motion of the proximal tubular segment of the interventional device in at least one degree of freedom, the motion of the proximal tubular segment of the interventional device corresponding to motion of a distal segment of the interventional device; and a processor configured to output a user interface based at least in part on position data from the sensor.

32. The apparatus of Claim 31, wherein the sensor comprises an optical sensor.

33. The apparatus of Claim 31, wherein the sensor comprises a mechanical position sensor.

34. The apparatus of Claim 31, wherein the at least one degree of freedom comprises distal axial motion.

35. The apparatus of Claim 31, wherein the at least one degree of freedom comprises linear motion.

36. The apparatus of Claim 31, further comprising a battery disposed in the housing configured to provide power to at least one of the sensor and the processor.

37. A system, comprising: the apparatus of Claim 31; and a processor and a display, the processor configured to process position data and register, store, and cause the display present the position data relative to pressure sensor data.