System for vascular assessment using continuous physiological measurements

Abstract

Methods, apparatus and systems for evaluating a patient's vessel, particularly the hemodynamic effects of a stenosis in a patient's vessel. Proximal and distal pressure measurements are made using a first and a second instrument while the first instrument is moved longitudinally in the vessel and the second instrument is maintained in a fixed position. A series of pressure ratio values ​​are calculated and a pressure ratio curve is generated. The pressure ratio curve can be output to a display. An automatic step detection algorithm is used to identify one or more step changes in the pressure ratio curve. An image is obtained showing the position of the first instrument in the vessel corresponding to the identified step change. The image is registered to the identified step change in the pressure ratio curve. The image can be output to a display.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Application No. 62 / 659,514, filed on April 18, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to medical devices, medical systems and methods of using medical systems and devices. More particularly, the present invention relates to devices, systems and methods configured for assessing the severity of one or more blockages in a blood vessel. Background Art

[0004] A wide variety of in vivo medical devices, systems and methods have been developed for medical uses, such as intravascular use. Some of these devices and systems include guidewires, catheters, processors, displays, etc. These devices and systems are manufactured by any of a variety of different manufacturing methods and can be used according to any of a variety of methods. Each of the known medical devices, systems and methods has certain advantages and disadvantages. There remains a need to provide alternative medical devices and systems and alternative methods of manufacturing and using medical devices and systems. Summary of the invention

[0005] The present invention provides designs, materials, manufacturing methods and use alternatives for medical devices, systems and methods. One example is a system for evaluating a patient's vasculature using pressure measurements. The system includes: a processor configured to: obtain a series of first pressure measurements from a first instrument in a vasculature over a period of time as the first instrument moves longitudinally through the vasculature from a first position to a second position; obtain a series of second pressure measurements from a second instrument positioned in the vasculature over the period of time as the second instrument remains in a fixed longitudinal position in the vasculature; calculate a series of pressure ratios using the first pressure measurements and the second pressure measurements; generate a pressure ratio curve for the period of time using the series of pressure ratios; output the pressure ratio curve to a display system; identify a step change in the pressure ratio curve using an automatic step detection process; obtain an image showing the position of the first instrument in the vasculature corresponding to the step change identified in the pressure ratio curve; register the image to the step change identified in the pressure ratio curve; and output the image to a display system.

[0006] Alternatively or additionally, the processor includes a user interface, and the processor is configured to selectively output the image to the display system upon command by a user via the user interface.

[0007] Alternatively or additionally, the user issuing the command includes the user positioning a cursor at a predetermined location on the display system.

[0008] Alternatively or additionally, the predetermined position on the display system comprises a position of a step change indicator on the pressure ratio curve.

[0009] Alternatively or additionally, the processor is configured to output to the display system a step change indicator on the pressure ratio curve corresponding to the identified step change on the pressure ratio curve.

[0010] Alternatively or additionally, the step change indicator includes an indicator of the start of the step change on the pressure ratio curve, an indicator of the end of the step change on the pressure ratio curve, an indicator showing the difference between the start and end of the step change on the pressure ratio curve, or a combination of these.

[0011] Alternatively or additionally, the processor includes user interface functionality, wherein the user interface functionality allows a user to position a cursor on the image, and in response, the processor is configured to output to the display system an indicator showing a location on the pressure ratio curve corresponding to the image.

[0012] Alternatively or additionally, the processor being configured to identify the step change comprises the processor being configured to identify a starting point of the step change, and wherein the image illustrates a position of the first instrument within the vessel at the starting point of the step change.

[0013] Alternatively or additionally, configuring the processor to identify the step change includes configuring the processor to identify an endpoint of the step change.

[0014] Alternatively or additionally, the processor is further configured to obtain a second image showing a position of the first instrument within the vessel at the endpoint of the step change, and to register the second image to the identified endpoint of the step change.

[0015] Alternatively or additionally, the system further comprises a display system.

[0016] Alternatively or additionally, images are acquired and registered in real time as the step change is identified, or images are acquired from a series of images captured over a period of time and subsequently registered to the identified step change.

[0017] Alternatively or additionally, the automatic step detection process includes: identifying the approximate location of the starting point of the step change by identifying a pressure ratio change at or above a first threshold change value within a first window along the pressure ratio curve; and identifying the optimized location of the starting point by identifying a pressure ratio change at or above a second threshold change value within a second window along the pressure ratio curve, wherein the second window is smaller than the first window and the second threshold change value is smaller than the first threshold change value.

[0018] Alternatively or additionally, the automatic step detection process also includes: identifying the approximate location of the end point of the step change by identifying a pressure ratio change at or below a third threshold change value within a third window along the pressure ratio curve, and identifying the optimized location of the end point along the curve by identifying a pressure ratio change at or below a fourth threshold change value within a fourth window along the pressure ratio curve, wherein the fourth window is smaller than the third window and the fourth threshold change value is smaller than the third threshold change value.

[0019] Alternatively or additionally, the processor is further configured to identify one or more additional step changes in the curve using an automatic step detection process, and to obtain one or more additional images showing a position of the first instrument within the vessel corresponding to the one or more additional step changes, and to register the one or more additional images to the corresponding one or more additional step changes.

[0020] Alternatively or additionally, wherein the system further comprises a first instrument, and the first instrument comprises a pressure sensing guidewire.

[0021] Alternatively or additionally, the system further comprises a pullback mechanism, and the pullback mechanism is configured to move the first instrument longitudinally through the vessel from the first position to the second position.

[0022] Alternatively or additionally, wherein the system further comprises an imaging device configured to create an image showing the first instrument at a location within the vessel corresponding to the identified step change, and transmit the image to the processor.

[0023] Another embodiment includes a system for evaluating a patient's vasculature. The system includes: a display system; and a processor in communication with the display system, the processor configured to: obtain a series of first pressure measurements from a first instrument in the vasculature over a period of time as the first instrument moves longitudinally through the vasculature from a first position to a second position; obtain a series of second pressure measurements from a second instrument positioned in the vasculature over the period of time as the second instrument remains in a fixed longitudinal position in the vasculature; calculate a series of pressure ratios using the first pressure measurements and the second pressure measurements; generate a pressure ratio curve for the period of time using the series of pressure ratios; output the pressure ratio curve to the display system; identify a start and end point of a step change in the pressure ratio curve using an automatic step detection process; obtain an image showing the first instrument in the vasculature corresponding to the identified start point position of the step change in the pressure ratio curve; register the image to the identified start point in the pressure ratio curve; and output the image to the display system.

[0024] Alternatively or additionally, the processor is further configured to: obtain a second image showing a position of the first instrument within the vessel corresponding to an endpoint identified by a step change in the pressure ratio curve; register the second image to the endpoint identified in the pressure ratio curve; and output the second image to a display system.

[0025] Alternatively or additionally, the system also includes a user interface, and in response to one or more predetermined user commands issued through the user interface, the processor is configured to: output an image showing the first instrument corresponding to the step change position in the vessel to the display, and output a mark on the pressure ratio curve corresponding to the image to the display.

[0026] Another embodiment includes a method of evaluating a patient's vessel. The method includes obtaining a series of first pressure measurements from a first instrument within the vessel over a period of time as the first instrument moves longitudinally through the vessel from a first position to a second position; obtaining a series of second pressure measurements from a second instrument positioned within the vessel over the period of time as the second instrument remains at a fixed longitudinal position within the vessel; calculating a series of pressure ratios using the first pressure measurements and the second pressure measurements; generating a pressure ratio curve for the period of time using the series of pressure ratios; displaying the pressure ratio curve; identifying a step change in the pressure ratio curve using an automatic step detection process; obtaining an image showing a position of the first instrument within the vessel corresponding to the step change identified in the pressure ratio curve; registering the image to the step change identified in the pressure ratio curve; and displaying the image.

[0027] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention. The following figures and detailed description more particularly exemplify these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention may be more fully understood from the following detailed description considered in conjunction with the accompanying drawings, in which:

[0029] Figure 1 An example system that may be used to assess a blood vessel is schematically illustrated.

[0030] Figure 2 is an example flow chart illustrating example steps of an automatic step detection (ASD) process or algorithm.

[0031] Figure 3 An example blood pressure ratio curve is graphically illustrated showing pressure ratio values ​​measured over time during an example pullback procedure.

[0032] Figure 3A is a schematic representation of an image showing a medical device at a first position within a blood vessel during an example pullback procedure.

[0033] Figure 3B is a schematic representation of an image showing a medical device at a second location within a blood vessel during an example pullback procedure.

[0034] Figure 3Cis a schematic representation of an image showing a medical device at a third location within a blood vessel during an example pullback procedure.

[0035] Figure 3D is a schematic representation of an image showing a medical device at a fourth location within a blood vessel during an example pullback procedure.

[0036] Figure 3E is a schematic representation of an image showing a medical device at a fifth position within a blood vessel during an example pullback procedure.

[0037] Figure 3F is a schematic representation of an image showing a medical device at a sixth position within a blood vessel during an example pullback procedure.

[0038] Figure 4 Another example blood pressure ratio curve is graphically illustrated, showing pressure ratio values ​​measured over time during another example pullback procedure.

[0039] Figure 4A is a schematic representation of an image showing a medical device at a first position within a blood vessel during another example pullback procedure.

[0040] Figure 4B is a schematic representation of an image showing a medical device at a second location within a blood vessel during another example pullback procedure.

[0041] Figure 5 is a partial cross-sectional side view of a portion of an example medical device.

[0042] Although the present invention can make various modifications and alternative forms, its specific details have been shown in the drawings by way of example and will be described in detail. However, it should be understood that the present invention is not intended to limit the present invention to the specific embodiments described. On the contrary, the present invention covers all modifications, equivalents and substitutes that fall within the spirit and scope of the present invention. DETAILED DESCRIPTION

[0043] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification.

[0044] It is assumed herein that all numerical values ​​are modified by the term "about", whether or not explicitly indicated. The term "about" generally refers to a numerical range that one skilled in the art considers to be equivalent to the stated value (i.e., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant figure.

[0045] Numerical ranges recited by endpoints include all numbers within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0046] 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 used in its sense including "and / or" unless the content clearly dictates otherwise.

[0047] It should be noted that when the specification refers to "one embodiment", "some embodiments", "other embodiments", etc., it indicates that the embodiment may include one or more specific features, structures and / or characteristics. However, such a description does not necessarily mean that all embodiments include the specific features, structures and / or characteristics. In addition, when a specific feature, structure and / or characteristic is described in conjunction with one embodiment, it should be understood that such feature, structure and / or characteristic may also be used in conjunction with other embodiments, whether or not explicitly described, unless explicitly stated to the contrary.

[0048] The following detailed description should be read with reference to the accompanying drawings, in which similar elements in different drawings have the same reference numerals. The drawings, which are not necessarily drawn to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

[0049] During some medical interventions and / or diagnostic procedures, it may be desirable to provide a physiological assessment of the hemodynamic effects of one or more stenoses within a blood vessel. Such an assessment may be accomplished by obtaining pressure measurements within the vessel from a first instrument positioned distal to a region of interest (such as one or more stenoses) and a second instrument positioned proximal to the region of interest. The pressure difference between two pressure measurements within the vessel (e.g., a distal pressure measurement and a proximal pressure measurement) may be used to calculate a pressure ratio of the two pressure measurements (the distal pressure measurement divided by the proximal pressure measurement). This pressure ratio is useful in assessing the hemodynamic effects of one or more stenoses within a blood vessel. In the context of the present application, these ratios may be collectively referred to as pressure ratios. As used herein, the distal pressure measurement may generally be referred to as a pressure ratio. d , which is the proximal pressure measurement of the aorta, is often referred to as P a .

[0050] Some examples of such useful pressure ratios include fractional flow reserve (FFR), resting full cycle distal pressure / proximal pressure (resting P d / P a ), resting distal pressure / proximal pressure during diastole (dPR), instantaneous waveform-free ratio (iFR), etc. These ratios may be useful for assessing the hemodynamic effects of, for example, a stenosis in a coronary artery. FFR is a pressure ratio (P) calculated from the average pressure measurements over multiple heartbeats during the entire cardiac cycle under the influence of hyperemic agents such as adenosine. d / P a ). Resting P d / Pa The pressure ratio (P) is calculated at rest (ie, without the influence of hyperemic agents) using the average pressure measurements over multiple heartbeats throughout the cardiac cycle. d / P a dPR is the pressure ratio (P) calculated during diastole using the average pressure measurements over multiple heart beats. d / P a iFR is the pressure ratio (P) calculated during diastole using the average pressure measurements over multiple heartbeats limited to the identified waveform-free periods. d / P a In this regard, each of these different pressure ratios may be understood as a ratio P d / P a , the difference between them lies in the time parameters and conditions when basic proximal and distal pressure measurements are made.

[0051] Comparing the calculated pressure ratio to a threshold or predetermined value can help medical personnel determine whether interventional treatment is necessary or warranted. For example, in the context of evaluating the hemodynamic effects of coronary artery stenosis, a pressure ratio below a threshold of 0.8 indicates that the stenosis may warrant a more invasive or invasive treatment, such as angioplasty or stent implantation, while a pressure ratio at or above the threshold of 0.8 may indicate that the stenosis may warrant a less invasive or invasive treatment (or no stenosis), such as drug therapy or no treatment at all. Although the above examples represent pressure ratios that can be used in the coronary vasculature, the devices, systems, and methods described herein may also be used in a variety of other vascular applications. Other vascular applications may include peripheral vasculature, including lower extremities, carotid arteries, and neural vasculature; renal vasculature; and / or venous vasculature.

[0052] In some cases, it is useful to obtain and / or calculate a series of pressure ratio values ​​along a portion of the length of the vessel in a region of interest. A significant and / or rapid step change in the pressure ratio values ​​along a portion of the length of the vessel may indicate one or more significant or focal stenoses at certain locations within the vessel. This may be particularly valuable in cases where there is a complex stenoses and / or a series of stenoses along a portion of the length of the vessel. In order to obtain pressure measurement data to calculate a series of pressure ratio values ​​along a portion of the length of the vessel, one of the pressure measuring instruments, typically an instrument that obtains distal pressure measurements, is moved longitudinally from one side through the region of interest within the vessel, while another pressure measuring instrument, typically an instrument that obtains proximal pressure measurements, remains stationary on the other side of the region of interest within the vessel for a period of time to obtain basic distal and proximal pressure measurements, for example, P d and P aThe moving instrument is typically moved longitudinally through the region of interest, e.g., a stenotic region, back proximally toward the stationary instrument. This procedure may be referred to as a "pull back." However, it is contemplated that in other embodiments, the moving instrument may begin close to or adjacent to the stationary instrument, move longitudinally away from the stationary instrument, and pass distally through the region of interest. This procedure may be referred to as a "push through."

[0053] It is often useful to generate a pressure ratio curve using a series of pressure ratio values ​​obtained during a pullback and / or push-through. A pressure ratio curve showing pressure ratio values ​​over a period of time during a pullback or push-through can be used to identify significant step changes in pressure ratio values ​​along a portion of the vessel length (e.g., more concentrated or larger or more aggressive or faster step changes), as opposed to less significant changes in pressure ratio values ​​(e.g., less concentrated or smaller or less aggressive or more gradual changes). Changes in the pressure ratio curve within a given window can be compared to certain set (e.g., predetermined) thresholds to identify significant step changes compared to less significant step changes. During a pullback procedure, a step change above a certain / predetermined threshold within a certain window will be represented by a significant increase in the pressure ratio values. However, during a push-through, the opposite is true, in which case a step change above a certain / predetermined threshold within a window will be represented by a significant decrease in the pressure ratio values. A more significant step change along the pressure ratio curve can be used to identify the presence of a significant (e.g., more concentrated or larger or more aggressive) stenotic area, which may then be the focus of a more aggressive treatment option. A less significant change in the pressure ratio curve can be used to identify the presence of a less significant (e.g., less concentrated or smaller or less aggressive or more gradual) stenotic area, which may then be the focus of a less aggressive treatment or no treatment at all.

[0054] One problem and / or difficulty that may be associated with using a pressure ratio curve in this analysis relates to the accurate and / or consistent identification and possible labeling of significant step changes in the pressure ratio curve, which can then be used to identify the presence of one or more significant stenotic areas for treatment. In particular, it may be desirable to provide accurate and / or consistent identification of the start and / or end positions of significant step increases in the pressure ratio curve, and optionally labeling them. It may also be desirable to determine, indicate and / or mark the size or amplitude of certain significant step changes in the pressure ratio curve. It may also be desirable to have a system and / or process to consistently identify what can be considered a "significant" step change in the pressure ratio curve, and what can be considered a "less significant" step change. For example, it may be desirable to set and apply a consistent threshold value to determine the approximate location of the start and / or end position of a significant step increase in the pressure ratio curve. It may also be desirable to consistently optimize the location of the start and / or end position of a significant step increase in the pressure ratio curve. For example, it may be desirable to set and apply a consistent threshold value to determine the optimal location of the start and / or end position of a significant step increase in the pressure ratio curve. Such a system and / or process may be used to better identify the onset and cessation of significant stenosis areas for treatment.

[0055] In this context, an exemplary automatic step detection (ASD) process and / or algorithm is disclosed herein that can be used to help address these issues and / or difficulties and achieve desired results (e.g., identifying and / or marking the start and / or end and / or magnitude of a significant step change in a pressure ratio curve). The ASD process consistently applies a threshold within a set window to identify the approximate start and / or end location of a significant step change in a pressure ratio curve. The ASD process can also consistently apply a set threshold within a set window to optimize the location of the start and / or end location of a significant step change in a pressure ratio curve.

[0056] Methods and systems using ASD processes and / or algorithms are disclosed herein. For example, a method for analyzing a vessel may include obtaining pressure measurements (e.g., P) from an instrument during pullback and / or push-through. d and P a ), calculating a series of pressure ratio values, generating a pressure ratio curve, and using an ASD process and / or algorithm to identify whether there are one or more significant step changes in the pressure ratio curve. Some example systems disclosed herein include a processor configured to perform such a method, including using an ASD process and / or algorithm. Some example embodiments of systems, methods, and processors are described in more detail herein, including a more detailed discussion of the ASD process and / or algorithm.

[0057] More particularly, it may also be useful to provide systems and methods that can assist a user in determining the location and / or properties of one or more identified significant stenosis areas within an anatomical structure. More information about the specific location (e.g., including the start and end points) and / or properties of the significant stenosis area can assist a medical professional in applying appropriate treatment to the specific location within the anatomical structure. For example, providing an image showing the location and / or properties of the significant stenosis area identified on a pressure ratio curve while using an ASD would be useful information.

[0058] In this regard, during the pull-back and / or push-through procedure, an imaging device may be operated, for example, so that the position of the mobile instrument within the anatomical structure can be determined. When a significant step change is detected along the pressure ratio curve, the mobile instrument will be located at a location within the anatomical structure corresponding to the significant step change (e.g., a significant stenosis area). In this regard, an image from the imaging device may be obtained and / or captured, which shows the location of the mobile instrument within the anatomical structure when the step change is detected. Using the location of the mobile instrument as a reference point in the captured image, the location of the significant step change within the anatomical structure (e.g., a significant stenosis area) can be determined. In this regard, the captured image will show the location of the mobile instrument within the anatomical structure at the time of the significant step change.

[0059] The captured image may be linked and / or registered to a corresponding significant step change on the pressure ratio curve. In addition, one or more additional step changes in the curve may be identified using the ASD process, and one or more additional images showing the position of the mobile instrument in the vessel corresponding to the one or more additional step changes may be captured and linked and / or registered to the corresponding one or more additional step changes on the pressure ratio curve. The pressure ratio curve and / or the linked / registered image may be output to a display system, which may then be viewed by a medical professional to help determine the location of the significant step change within the anatomical structure. In some embodiments, when a significant step change in the pressure ratio curve is identified, the image may be captured in real time and linked to the pressure ratio curve. In other embodiments, a series or sequence of images (e.g., flow) may be captured during a pullback or push-through procedure (e.g., during a period of time when the mobile instrument is longitudinally moved through the vessel), and the images may be time-stamped and stored in a memory. After the procedure is partially or completely completed, the corresponding images may then be separately registered and / or linked to the corresponding positions (e.g., significant step changes) on the pressure ratio curve.

[0060] Some illustrative embodiments will now be discussed with reference to the accompanying drawings. Figure 1 An example system 100 is schematically shown in FIG. The system 100 may be configured to evaluate / determine a pressure ratio, such as FFR, iFR, dPR, or resting P, either statically or during a pullback procedure. d / Pa The system 100 may include a first pressure sensing medical device 10. In at least some cases, the first pressure sensing medical device 10 may take the form of a pressure sensing guidewire 10. Some additional details regarding examples of such guidewires 10 are disclosed herein and are described in detail below. Figure 5 In other cases, the first pressure sensing medical device 10 may be a catheter or other type of pressure sensing medical device. The pressure sensing medical device 10 may be used to measure blood pressure distal to a region of interest (such as one or more vascular stenoses) (e.g., measuring distal pressure P d ). The first pressure sensing medical device 10 can be configured to measure blood pressure while at rest or while being moved longitudinally through the vessel from a first position to a second position. In this regard, the first pressure sensing medical device 10 can be moved longitudinally within the vessel during a "pull back" or "push through" procedure.

[0061] In some embodiments, the system 100 may include a device or mechanism (not shown) for imparting longitudinal movement to the first pressure sensing medical device 10, for example, during a pull-back or push-through procedure. In some embodiments, the pull-back / push-through device or mechanism may be configured to engage the first pressure sensing medical device 10 at a continuous speed and / or set distance and impart longitudinal movement thereto. In some embodiments, the pull-back / push-through device is configured to move the first pressure sensing medical device 10 at a variable speed and / or in a stepwise or intermittent manner, optionally in coordination with the patient's heartbeat. In some embodiments, the system 100 does not include a pull-back or push-through device, but rather the first pressure sensing medical device 10 may be manually moved longitudinally through the vessel by an operator as needed or desired.

[0062] The first pressure sensing medical device 10 can be coupled to the linking device 70. In some cases, this can include attaching the first pressure sensing medical device 10 directly to the linking device 70. In other cases, another structure, such as a connector cable (not shown), can be used to couple the first pressure sensing medical device 10 to the linking device 70. When the first pressure sensing medical device 10 is coupled to the linking device 70, the first pressure data 72 can be communicated between the first pressure sensing medical device 10 and the linking device 70. Note that in Figure 1 In FIG. 1 , a line is drawn between the first pressure sensing medical device 10 and the linking device 70 to indicate the connection of the first pressure sensing medical device 10 and the linking device 70. In addition, the line between the first pressure sensing medical device 10 and the linking device 70 is marked with reference numeral 72 to indicate the transmission of the first pressure data 72 (and / or the first pressure data 72 itself). In at least some cases, the first pressure data 72 is the distal pressure P d .

[0063] The system 100 may also include a second pressure sensing medical device 74. In at least some cases, the second pressure sensing medical device 74 may take the form of a pressure sensing catheter. However, other devices including pressure sensing guidewires or other devices are also contemplated. The second pressure sensing medical device 74 may be used to measure, for example, blood pressure proximal to the region of interest. In some cases, the second pressure sensing medical device 74 may be used to measure aortic pressure. The second pressure sensing medical device 74 may be configured to remain stationary during use, for example, during a pull-back or push-through procedure.

[0064] The second pressure sensing medical device 74 may also be coupled to the linking device 70 and second pressure data 76 may be communicated between the second pressure sensing medical device 74 and the linking device 70. Figure 1 In the figure, a line is drawn between the second pressure sensing medical device 74 and the linking device 70 to indicate the connection of the second pressure sensing medical device 74 and the linking device 70. In addition, the line between the second pressure sensing medical device 74 and the linking device 70 is marked with reference numeral 76 to indicate the transmission of the second pressure data 76 (and / or the second pressure data 76 itself). In at least some cases, the second pressure data 76 is a proximal pressure, such as an aortic pressure Pa.

[0065] In some cases, the linking device 70 may communicate with the hemodynamic system 78 (eg, the hemodynamic display system 78). When doing so, the distal pressure P d The data (indicated by reference numeral 80) may be transmitted to the hemodynamic system 78 and represent the aortic pressure P a The data (indicated by reference numeral 82) can be transmitted to the hemodynamic system 78. In some cases, the two connections between the link device 70 and the hemodynamic system 78 (e.g., for transmitting P d and P a ) may be a wired connection. In other cases, one or both of the connections may be wireless connections. In other cases, P d and P a Both can be transmitted along a single wired connection.

[0066] In some cases, the linking device 70 may also communicate with the processing and / or display system 84. When doing so, the distal pressure P d The data and represent the proximal or aortic pressure P a Data (distal pressure P d and aortic pressure P a Data from both Figure 1 86 in the figure) can be transmitted to a processing and / or display system 84. In at least some cases, P d and P aA wireless connection may be used between the linking device 70 and the processing and / or display system 84. d and P a One or both may be transmitted between the linking device 70 and the processing and / or display system 84 using a wired connection.

[0067] The processing and / or display system 84 may include a processor 88. The processor 88 may be an integral component of the processing and / or display system 84 (e.g., the processor 88 may be disposed within the same housing as the processing and / or display system 84) or the processor 88 may be a separate component from and coupled to the processing and / or display system 84. The processor 88 may be coupled to the first pressure sensing medical device 10 and to the second pressure sensing medical device 74 and may be configured to cause the first and second pressure measurements (e.g., P d and P a ) may be received and / or obtained by the processor 88 from the pressure sensing medical devices 10 and 74. The processor 88 may be configured to receive and / or obtain the first and second pressure measurements while the pressure sensing medical devices remain stationary in the vessel, or while at least one of the pressure sensing medical devices is moving longitudinally within the vessel (e.g., during a pull-back or push-through). For example, the processor 88 may be configured to receive and / or obtain a first series of pressure measurements from the first pressure sensing medical device 10 during a period of time while it is moving longitudinally through the vessel, and to receive and / or obtain a second series of pressure measurements from the second pressure sensing medical device 74 during that period of time while the second device is maintained at a fixed longitudinal position within the vessel.

[0068] Processor 88 may be configured and / or otherwise capable of performing any number of calculations, executing instructions, etc. For example, processor 88 may be configured to calculate / determine the average distal pressure P d (e.g., as measured by the first pressure sensing medical device 10 over one or more cardiac cycles), calculate / determine the mean proximal pressure P a (e.g., as measured by the second pressure sensing medical device 74 during one or more cardiac cycles), plotting and / or generating a display of the distal pressure P d and / or proximal pressure P a Curve changing with time, calculate / determine distal pressure P d The slope of the graph and / or the proximal pressure P a The slope of the graph (e.g., at various points along the graph), etc. Processor 88 may be configured to output any of this information to display 90 as desired. Processing and / or display system 84 may include one or more memories, and processor 88 may be configured to store any of this information in the memories, as desired.

[0069] The processor 88 may be configured to calculate and / or determine a given distal pressure P d and proximal pressure P a Pressure ratios of pressure measurements (eg, FFR, iFR, dPR, resting P d / P a For example, the processor 88 may be configured to use the P values ​​received or obtained from the first and second instruments and / or calculated by the processor 88 (e.g., using the P values ​​obtained from the first and second pressure sensing medical devices 10 / 74). d and P a The pressure measurements (P) are used to calculate one or more or a series of pressure ratios (e.g., d / P a In some examples, P is obtained when at least one of the pressure sensing medical devices is longitudinally moved within the vessel (e.g., during a pull-back or push-through). d and P a The series of pressure ratio values ​​may represent pressure ratio values ​​along a portion of the length of the vascular vessel. The processor 88 may be configured to plot and / or generate a pressure ratio curve using the series of pressure ratio values. The processor 88 may also be configured to calculate / determine the slope of the pressure ratio curve (e.g., at various points along the pressure ratio curve or graph), etc. As desired, the processor 88 may be configured to output the pressure ratio values ​​and / or graph and / or generated pressure ratio curve to the display 90, and / or the processor 88 may be configured to store any of the information in a memory.

[0070] As suggested herein, the display system 90 may be coupled to or otherwise integrated with the processing and / or display system 84. The display system 90 may include one or more displays and / or screens that may display various data received from the processor, the first pressure sensing medical device 10, and the second pressure sensing medical device 74, images, graphs, charts, and / or plots of pressure data and / or pressure ratios generated by the processor 88 as desired, and may display any indicia, labels, numbers, etc. The display system 90 may also display various data (e.g., images) received from or through the processor 88 and / or from or through one or more imaging devices or systems (such as the imaging devices or systems 89 discussed herein).

[0071] As suggested herein, the memory may be coupled to or otherwise integrated with the processing and / or display system 84. The memory may include one or more memory devices or systems that may store various data received from and / or by the processor, the first pressure sensing medical device 10 and the second pressure sensing medical device 74, images, graphs, charts, and / or plots of pressure data and / or pressure ratios received or generated by the processor 88 as desired, and may store any indicia, labels, numbers, etc. The memory may also store various data (e.g., images) received from or by the processor 88 and / or from or by one or more imaging devices or systems (such as the imaging device or system 89 discussed herein).

[0072] The processing and / or display system 84, including the processor 88, may be configured to use and / or provide raw data and / or calculations, or alternatively, may be configured to use and / or provide enhanced data or calculations. For example, the mean distal pressure P d , mean proximal pressure P a , Displays the distal pressure P over time d and / or proximal pressure P a Graphs and / or curves, pressure ratios (P d / P a ), a graph or curve of pressure ratio values ​​varying over time, etc. may be used or shown as raw data and / or calculations, or may be optionally filtered, smoothed, enhanced, conditioned and / or otherwise processed by a processor, for example, to remove noise and / or anomalies. Some examples of filters may include a moving maximum filter, a median builder filter, or other commonly known filters, etc.

[0073] In some embodiments, the calculations performed by the processor 88, the execution of instructions, the output of data or images to a display, etc., including the ASD and images discussed herein, may be performed, for example, in real time or live to identify pressure ratio values ​​and curves, pressure ratio curves and / or step changes in pressure ratio curves (including the starting and ending points of the step changes) and / or display images received and / or obtained during the procedure. In the context of the present application, "real time" or "live" is intended to mean that data is calculated and / or displayed within 10 seconds of data acquisition. This may include calculations that occur within 5 seconds or within 1 second, or even during the procedure, at the same time as data acquisition. In some other cases, some or all of the calculations, execution of instructions, output to a display, etc. may occur after some delay after data acquisition. For example, the system may be configured to acquire and / or capture data (including images), and then perform calculations and / or display data and / or images and / or results at a later point in time. For example, processor 88 may be configured to provide a review and / or playback mode that occurs some time after data is collected during a procedure, and at least some of the calculations, executed instructions, images, etc. may be displayed during the review or playback mode.

[0074] It is also contemplated that the hemodynamic system 78, the linking device 70, or both may include a processor and / or display system and / or a processing and / or display system similar to the processor 80, display system 90, or processing and display system 84 configured as described herein. For example, such a processor and / or display may be configured to perform the methods and procedures disclosed herein, including the functions and methods described herein, including the ASD processes and / or algorithms, the generation of pressure ratio curves, linking images to curves, and the display of curves and images, as described in more detail below.

[0075] The processor 88 may be configured to identify step changes in one or more curves or graphs. For example, the processor 88 may be configured to use an automatic step detection (ASD) process and / or algorithm to identify step changes in the pressure ratio curve (e.g., significant step changes at and / or above a certain set threshold). The ASD process can be used to identify and mark significant step changes in the pressure ratio curve, which can then be used to identify the presence of one or more significant stenoses in the vessel for possible treatment. In particular, ASD can be used to identify, and optionally mark the start and / or end positions of significant step increases in the pressure ratio curve, and can also be used to determine, indicate and / or mark the size or amplitude of certain significant step changes in the pressure ratio curve. In addition, the processor 88 may be configured to output one or more step change indicators corresponding to the step changes identified on the pressure ratio curve to the display 88. The one or more step change indicators may, for example, include an indicator of the position of the starting point of the step change, an indicator of the position of the end point of the step change, a step change label showing the difference between the starting point and the end point of the step change, or any combination of these.

[0076] As noted herein, the system 100 may also include and / or communicate with an imaging device or system 89. In at least some cases, a wireless connection may be used to transmit data between the processing and / or display system 84 and the imaging device or system 89. In other cases, a wired connection may be used to transmit data between the processing and / or display system 84 and the imaging device or system 89. Communication between the imaging device or system 89 and the processing and / or display system 84 may be used to capture and / or transmit imaging data. Data representing images of anatomical structures and / or images showing the position of instruments (e.g., the first and / or second pressure sensing medical devices 10 or 74) within the anatomical structures may be transmitted from the imaging device or system 89 to the processing and / or display system 84 continuously or at specific points in time during the procedure. The processing and / or display system 84 may then be configured to output the image data to the display system 90 as desired.

[0077] In some embodiments, the processing and / or display system 84 including the processor 88 may be configured to obtain and / or capture an image showing the position of an instrument (e.g., a first pressure sensing instrument) within the vessel corresponding to a particular location on the pressure ratio curve (e.g., corresponding to a step change identified in the pressure ratio curve), and to register and / or link the obtained image to the particular location on the pressure ratio curve. For example, when a step change in the pressure ratio curve is detected, the first pressure sensing instrument will be positioned in the anatomical structure at a location corresponding to the detected step change in the anatomical structure. In this regard, by using the location of the first pressure sensing instrument as a reference point, the captured image will show the location of the detected step change. In some embodiments, when a step change is identified and / or detected on the pressure ratio curve, the processor 88 may issue a command to the imaging system 89 to capture or obtain an image showing the position of the first pressure sensing instrument within the vessel corresponding to the step change identified in the pressure ratio curve, and then transmit the image to the processor 88 (e.g., the processor thereby obtains the image). In other embodiments, imaging data (e.g., a series of images or a video) may be continuously streamed and / or transmitted from the imaging system 89 to the processor 88, which may then capture and / or obtain an image showing the location of the first pressure sensing instrument within the vessel corresponding to the step change identified in the pressure ratio curve when the step change is identified and / or detected. In other embodiments, the imaging data may be continuously streamed and / or transmitted and / or stored in a memory, for example, with appropriate time stamps. The time stamps may then be used to select an appropriate image from those stored. The processor 88 may be configured to output the captured images to the display system 90 and may store the obtained images in a memory.

[0078] The processor 88 may be configured to link and / or register the acquired image to a corresponding location on the pressure ratio curve. The linking and / or registration may occur in real time, or the pressure ratio curve and the image may be stored in a memory, and the linking or registration may occur at a later time, for example, by matching time data between the pressure ratio curve and the image. The acquired image may be linked and / or registered to a specific location on the pressure ratio curve itself, and / or it may be linked to one or more indicators and / or labels on the pressure ratio curve. (e.g., labels, markings, highlights, etc.). The processor 88 may be configured to output the pressure ratio curve and / or the linked / registered image to a display system, which may then be viewed by a medical professional to help determine the location of a significant step change within the anatomical structure.

[0079] For example, the system 100 (e.g., the processing and / or display system 84 and / or the processor 88 of the system 100) may include a user interface mechanism and / or functionality that allows a user to interact with the processor 88 and / or the display 90. In some embodiments, the user interface functionality allows a user to interact with the displayed pressure ratio curve and activate one or more of the images obtained that are linked to a specific location on it. For example, the user interface may allow a user to activate a link at a specific location on the pressure ratio curve, and in response, the processor may be configured to output to the display an image showing the position of the first medical device 10 corresponding to that location on the pressure ratio curve. In some embodiments, the user interface may include a cursor, and the user interface may allow a user to position the cursor at a location where the pressure ratio curve includes a link to an image, for example, at a step change or at a location of one or more step change indicators. In response, the processor 88 may be configured to open the linked image and output to the display an image obtained showing the position of the first instrument in the vessel corresponding to the step change on the pressure ratio curve. Additionally or alternatively, in some embodiments, the user interface functionality may allow a user to interact with one or more of the images obtained and, in response, activate a link to an indicator showing or highlighting a specific image location on the pressure ratio curve. For example, the user interface may allow the user to position a cursor on the displayed acquired image (e.g., showing the location of the first instrument within the vessel corresponding to the identified step change), and in response, the processor may be configured to output to the display a marker on the pressure ratio curve corresponding to the location on the acquired image. As used herein, a "cursor" is merely an indicator for displaying the current location of a user interaction on a computer monitor or other display device, and may take any form as desired.

[0080] Reference now Figure 2 , which shows a flow chart including an example ASD process or algorithm. In this example flow chart, a raw pressure ratio curve 410 is schematically shown in box 410. The raw pressure ratio curve 410 can be calculated / generated by the processor 88, for example, using a series of pressure ratio values, which in turn use pressure measurements (e.g., P) obtained from the first and second pressure sensing medical devices 10 / 74 during pullback and / or push-through. d and P a As shown in block 412, the raw pressure ratio curve 410 may optionally be filtered, smoothed, enhanced, conditioned, and / or otherwise processed to remove noise and / or anomalies in the raw pressure ratio curve 410. In other embodiments, the pressure ratio curve may not be filtered or conditioned, and the raw pressure ratio curve 410 may be used - in which case block 412 may be skipped. The pressure ratio curve (raw or enhanced) may be output to the display 84.

[0081] The ASD process or algorithm may be used to identify and / or locate one or more step changes (e.g., significant step changes above a certain / predetermined threshold) that may be present in the pressure ratio curve. The ASD includes a step window function (SWF) 414. The SWF 414 includes identifying the approximate location of the starting point (e.g., "step start") of a step change along the pressure ratio curve by identifying a change in pressure ratio values ​​(e.g., D1) within a first window along the pressure ratio curve that is at and / or above a first threshold change value (e.g., T1). This is done in the example of FIG. Figure 2 4 is shown as an arrow leaving the left side of the SWF box 414, labeled D1>=T1. D1 represents the actual change in the pressure ratio value within the first window along the pressure ratio curve, and T1 represents the first threshold change value set when the system is programmed. If D1 (the actual change within the first window) is at and / or above T1 (the first threshold), the condition that a significant step change in the pressure ratio curve may begin is met.

[0082] The first window may have a set duration along the pressure ratio curve, typically set during programming. Thus, the first window has a duration and / or width along the pressure ratio curve, and D1 is a representation of the actual change in the pressure ratio value for a given duration of the first window along the pressure ratio curve. The duration of the first window may be selected as desired and may be measured in units as desired, for example, in time (e.g., seconds, minutes, etc.) or in physiological terms (e.g., heartbeats, respirations, etc.). In some embodiments, the first window will have a duration in the range of 2 to 10 heartbeats, 2 to 8 heartbeats, 3 to 5 heartbeats, or in some cases a duration of 4 heartbeats. In some cases, the first window duration may be measured and / or set in seconds, for example, in the range of 2 to 30 seconds, 2 to 20 seconds, 3 to 10 seconds, 3 to 5 seconds, or as desired.

[0083] The first threshold value T1 and the actual change value in the first window D1 are typically unitless because they represent only the change in the pressure ratio value within the first window. Given the first window duration, the threshold value T1 can be selected as desired. Typically, the value of the threshold value T1 is set at a level that will indicate a significant change in the pressure ratio value within a given first window, which in turn indicates a significant stenosis within the vessel. In this regard, during programming, the threshold value T1 is typically set at a level that will indicate a clinically significant change in the pressure ratio value within the first window duration. In some embodiments, the threshold value T1 may be set in the range of 0.01 to 0.06, or in the range of 0.02 to 0.05, or in the range of 0.025 to 0.04.

[0084] If the condition D1>=T1 is met in the step window function (SWF) 414, the ASD process can be used to determine whether the identified D1>=T1 condition indicates the start of a step (e.g., the approximate location of the beginning of the step change). This is represented by the "Step Start?" box 416 in the flowchart. If a step start condition currently exists and a step end has not yet been detected (as discussed below), then the currently detected D1>=T1 condition should not be considered a step start (because the step start already exists-there is no end). In this regard, the answer to the "Step Start?" question is "no", so the step start is not identified, no label is attached, as indicated by the box 422 in the flowchart, and the process returns to the step window function and starts again, as indicated by the arrow looping from the box 422 back to the step window function 414.

[0085] However, if a step start did not previously exist, or if a step start previously existed but had a corresponding step end identified and associated therewith (e.g., a step increase previously identified with a start point and an end point), then the currently detected D1>=T1 condition is considered a step start. In this regard, the answer to "Step Start?" in block 416 is "yes," so proceed to "Step Start Optimization" as represented by block 418.

[0086] The "Step Start Optimization" (SOO) function, represented by box 418 on the flow chart, includes identifying an optimized location for a step change start point (e.g., a point on the pressure ratio curve where a significant step first begins) by identifying a change in pressure ratio values ​​(e.g., D2) at or above a second threshold change value T2 within a second window along the pressure ratio curve, wherein the second window is smaller than the first window, and the second threshold change value T2 is smaller than the first threshold change value T1. In essence, the SOO function further refines and / or optimizes the location of the step change start point in the pressure ratio curve by focusing on a window that is tighter than the first window and looking for a change value that satisfies a threshold value (e.g., T2) that is smaller than the first threshold value (e.g., T1).

[0087] The second window may have a duration set along the pressure ratio curve and is set during programming. The second window has a duration and / or width along the pressure ratio curve and typically overlaps and / or includes a portion of the pressure ratio curve containing the approximate location of the starting point of the step change identified by the SWF (e.g., the start of the step). In essence, the second window "zooms in" on the area of ​​the pressure ratio curve along the approximate location of the starting point identified in the first window during the SWF. The duration of the second window can be selected as desired and can be measured in units (e.g., those units given for the first window) as desired. The second window is smaller than the first window. In some embodiments, the second window has a duration in the range of 1 to 5 heartbeats, 1 to 3 heartbeats, or in some cases a duration of 2 heartbeats. In other cases, the duration of the second window can be measured and / or set in seconds, for example, in the range of 1 to 10 seconds, 1 to 5 seconds, 1 to 3 seconds, or in some cases 2 seconds.

[0088] The threshold value T2 and the actual change value D2 are typically unitless because they represent only the change in the pressure ratio value within the second window. Given the second window duration, the second threshold value T2 can be selected as desired. Typically, the value of T2 is set at a level that will indicate a significant change in the pressure ratio value within the given second window, which in turn indicates the onset of a significant stenosis within the vessel. In this regard, during programming, the threshold value T2 is typically set at a level that will indicate a clinically significant change in the pressure ratio value within the given second window duration. In some embodiments, the threshold value T2 may be set within the range of 0.002 to 0.012, or within the range of 0.004 to 0.01, or within the range of 0.006 to 0.008.

[0089] Step start optimization (SOO) 418 identifies a more specific and / or optimized location along the pressure ratio curve where the condition D2>=T2 is first satisfied, and then identifies this point as a more specific and / or optimized location where the step increase begins. Once the optimized location is identified, the process may include marking the point accordingly as a step start, as shown in block 420. For example, the optimized step start location and / or label may be output to a display to display the step start in conjunction with the pressure ratio curve.

[0090] Additionally, as shown in block 420, once the step onset is detected and optionally labeled, an image showing the location of the first pressure sensing medical device 10 within the vessel corresponding to the detected / identified step change may be captured and / or obtained by the processor (e.g., captured and / or obtained from the display 90 and / or captured and / or obtained based on data from the imaging device 89). In this regard, the processor 88 may be configured to obtain and / or capture an image showing the location of the first pressure sensing instrument within the vessel corresponding to the step change identified in the pressure ratio curve. The processor 88 may then link and / or register the obtained image (e.g., showing the location of the first instrument within the vessel corresponding to the identified step change) to the corresponding identified step change in the pressure ratio curve. In this case, the obtained image will show the location of the first instrument within the vessel at the start of the step change, and the image may be linked and / or registered to the identified start of the step change on the pressure ratio curve. As discussed herein, the system may include a user interface that then allows a user to display an image by activating a link on the pressure ratio curve.

[0091] The process then returns to the step window function 414 and begins again, as indicated by the arrow looping back to the step window function. In particular, the process can then be used to identify and optimize the location of the step end to be associated with a subsequently identified step start, thereby defining the parameters of the step increase.

[0092] In this regard, the ASD process may also include identifying the approximate location of the end point of the step change by identifying a change in the pressure ratio value below a third threshold change value within a third window along the pressure ratio curve. For example, SWF 414 includes identifying the approximate location of the end point of the step change (e.g., the end of the step) along the pressure ratio curve by identifying a change D3 in the pressure ratio value at or below a third threshold change value T3 within the third window along the pressure ratio curve. This is Figure 2 It is shown as an arrow leaving the right side of the SWF box, which is labeled D3<=T3. D3 represents the actual change in the pressure ratio value within the third window along the pressure ratio curve, and T3 represents the third threshold change value set when programming the system. If D3 (the actual change within the third window) is at and / or below T3 (the third threshold), the condition that the step change may end is met.

[0093] The third window may have a duration set along the pressure ratio curve and is set during programming. Therefore, the third window has a duration and / or width along the pressure ratio curve, and D3 is the actual change value of the pressure ratio value given in the duration of the third window. The duration of the third window can be selected as desired and can be measured in units as desired, for example, by time (e.g., seconds, minutes, etc.) or can be in physiological terms (e.g., heartbeats, respirations, etc.). In some embodiments, the third window has a duration in the range of 2 to 10 heartbeats, 2 to 8 heartbeats, 3 to 5 heartbeats, or in some cases a duration of 4 heartbeats. In other cases, the duration of the third window can be measured and / or set in seconds, for example, in the range of 2 to 30 seconds, 2 to 20 seconds, 3 to 10 seconds, or as desired.

[0094] The third threshold value T3 and the actual change value D3 are generally unitless because they only represent the change in the pressure ratio value within the third window. Given the duration of the third window, the threshold value T3 can be selected as desired. Typically, the T3 threshold is set at a level so that the actual change value at or below it will indicate a smaller or less significant change in the pressure ratio value within the given third window, which in turn can indicate a less significant stenosis area within the vessel. In this regard, during programming, the threshold value T3 is generally set at a level that will indicate a clinically non-significant change in the pressure ratio value within the duration of the third window. In some embodiments, T3 can be set in the range of 0.01 to 0.06, or in the range of 0.02 to 0.05, or in the range of 0.025 to 0.04.

[0095] In some embodiments, the first and third windows may have the same duration, and the first and third thresholds T1 and T3 may also be the same. In this case, the same threshold (e.g., T1=T3) is used to determine the approximate location where a significant step in the pressure ratio curve begins and ends. A change value (e.g., D1) that is at and / or above the threshold will indicate the approximate location where the step may begin, while a change value (e.g., D3) that is at and / or below the threshold will indicate the approximate location where the step may end. As can be appreciated, in these cases, the logic in the SWF may be set accordingly so that only one of D1 and / or D3 may be equal to the threshold for the necessary condition to be met. It may be logically expected that both the D1 and D3 change values ​​cannot be equal to the threshold (e.g., T1=T3). In this regard, it may be desirable to modify Figure 2Those equations shown. For example, for a general step start function, the equation can make the change value D1 greater than or equal to the threshold (e.g., D1 >= T1, as shown), while for a step end function, the change value D3 can only be less than the threshold (e.g., D3 < T3). Another alternative can be that for a general step start function, the change value D1 can only be greater than the threshold (e.g., D1 > T1), and for a step end function, the change value D3 can be less than or equal to the threshold (e.g., D3 <= T3, as shown).

[0096] Reference Figure 2 , if the condition D3 <= T3 is satisfied in the step window function (SWF) 414, the next possible step in the ASD process can be to determine whether the condition D3 <= T3 indicates the end of the step, as indicated by the "Step End?" box 424 of the flowchart. If there is currently no step start condition, the currently detected condition D3 <= T1 cannot be regarded as the step end. (For example, the detected condition cannot be the end because there is no start). In this regard, the answer to the "Step End?" question in box 424 is "No", so the step end is not recognized, no label is attached, as indicated by box 422 of the flowchart, and then the process returns to the step window function and starts again, as indicated by the loop arrow from box 422 back to the step window function 414.

[0097] However, if there is currently a step start condition and the corresponding step end for this step start has not been detected yet, then the currently detected condition D1 <= T1 is regarded as the step end (because there is a step start - an end is needed). In this regard, the answer to "Step End?" is "Yes", and the process proceeds to the "Step End Optimization" represented by box 426.

[0098] The "Step End Optimization" (SEO) function represented by box 426 includes identifying the optimized position (e.g., step end) of the step increase end point by identifying the change in the pressure ratio value (e.g., D4) that is at or below the fourth threshold change value (e.g., T4) within the fourth window along the pressure ratio curve, where the fourth window is smaller than the third window, and the fourth threshold change value T4 is smaller than the third threshold change value T3. Essentially, SEO further improves and / or optimizes the position of the step change end point in the pressure ratio curve by focusing on a more compact window than the third window and looking for a change value that satisfies a threshold smaller than the third threshold.

[0099] The fourth window may have a duration set along the pressure ratio curve and is set during programming. The fourth window has a duration and / or width along the pressure ratio curve and generally overlaps and / or includes a portion of the pressure ratio curve containing the approximate location of the end point of the step change (e.g., the end of the step) identified by the SWF. In essence, the fourth window "zooms in" the pressure ratio curve along the area in the third window where the approximate location of the end point is identified. The duration of the fourth window can be selected as desired and can be measured in units (e.g., those given for the third window) as desired. The fourth window will be smaller than the third window. In some embodiments, the fourth window has a duration in the range of 1 to 5 heartbeats, 1 to 3 heartbeats, or in some cases a duration of 2 heartbeats. In other cases, the duration of the fourth window can be measured and / or set in seconds, for example, in the range of 1 to 10 seconds, 1 to 5 seconds, 1 to 3 seconds, or in some cases 2 seconds.

[0100] The T4 threshold and the actual change value of D4 are usually unitless because they only represent the change in the pressure ratio within the fourth window. Given the fourth window duration, the fourth threshold value T4 can be selected as desired. Typically, the T4 threshold is set at a level so that the change value at or below it will indicate a smaller or less significant change in the pressure ratio within the given fourth window, which in turn can indicate a less significant stenosis area within the vessel. In this regard, during programming, the threshold value T4 is usually set at a level that will indicate a clinically small or non-significant change in the pressure ratio within the fourth window duration. In some embodiments, T4 can be set in the range of 0.002 to 0.012, or in the range of 0.004 to 0.01, or in the range of 0.006 to 0.008. As can be appreciated, in some embodiments, the second and fourth windows may have the same duration, and the second and fourth threshold values ​​T2 and T4 may also be the same.

[0101] Step end optimization (SEO) 426 identifies a more specific and / or optimized position along the pressure ratio curve where the condition D4<=T2 is first satisfied, and then identifies the point as a more specific and / or optimized position for the end of the step increase. The process may include marking the point as the step end accordingly, as shown in box 422. For example, the optimized step end position and / or mark may be output to a display to display the step end in conjunction with the pressure ratio curve. The position and / or mark of the step end may be output to a display and displayed at an appropriate position along the pressure ratio curve. The process then returns to the step window function and starts again, as indicated by the arrow looped from box 422 back to the step window function 414. In particular, the process may then be used to identify and optimize any additional step increase positions, including identifying and optimizing the positions of the step start and step end of any such additional step increase.

[0102] Additionally, as shown in block 422, once the end of a step is detected and optionally labeled, an image showing the location of the first pressure sensing medical device 10 within the vessel corresponding to the detected / identified step change may be captured and / or obtained by the processor (e.g., captured and / or obtained from the display 90 and / or data from the imaging device 89). In this regard, the processor 88 may be configured to obtain and / or capture an image showing the location of the first pressure sensing instrument within the vessel corresponding to the step change identified in the pressure ratio curve. The processor 88 may then link and / or register the obtained image (e.g., showing the location of the first instrument within the vessel corresponding to the identified step change) to the corresponding step change identified in the pressure ratio curve. In this case, the obtained image will show the location of the first instrument within the vessel at the end of the step change, and the image may be linked and / or registered to the end of the step change identified on the pressure ratio curve. As discussed herein, the system may include a user interface that then allows a user to display an image by activating a link on the pressure ratio curve.

[0103] As described above, the step increase position including the step start and step end position can be output to the display and displayed at an appropriate position along the pressure ratio curve, for example, with a mark or a tag. Such marks and / or tags can be used as indicators with any desired shape or form as desired. For example, the marks and / or tags can include points, dots, lines, stars or other indicators at the step start and / or step end positions on the pressure ratio curve. The marks and / or tags can also include and / or display, for example, digital indicators, which show the pressure ratio value at a specific point on the pressure ratio curve where the step start and / or step end are identified. In addition, for any specific step change identified, the processor can calculate parameters related to the specific step change and output those parameters to the display to be displayed in conjunction with the pressure ratio curve. For example, the processor can be configured to calculate the size and / or amplitude of the step change (for example, the pressure ratio difference between the step start and the step end on the pressure ratio curve), and output this information to the display, for example, as a digital mark, which is displayed in conjunction with a specific step increase on the pressure ratio curve. As noted herein, such markings, labels, etc. may also be used as link indicators for captured images linked to pressure ratio curves.

[0104] Reference now Figure 3-3F Prophetic example embodiments of methods of evaluating a patient's vasculature using a system configured to perform the methods in accordance with the present disclosure are discussed. Figure 3 is a schematic diagram of a graph 40 showing a pressure ratio curve 42 that may be calculated / generated, for example, by a processor 88 and output to a display 90. The pressure ratio curve 42 may be generated using and / or in conjunction with methods and systems as disclosed herein.

[0105] In particular, the method may include obtaining a first series of pressure measurements from a first instrument 10 within the vessel over a period of time while the first instrument 10 is longitudinally moved through the vessel from a first position to a second position, and obtaining a second series of pressure measurements from a second instrument 74 positioned within the vessel over the period of time while the second instrument remains at a fixed longitudinal position within the vessel. The method may also include calculating a series of pressure ratios using the first pressure measurements and the second pressure measurements; and generating a pressure ratio curve 42 using the series of pressure ratios. The method may then require using an ASD process to identify one or more step changes in the pressure ratio curve, as discussed above. The method may then also obtain one or more images showing the position of the first instrument within the vessel corresponding to one or more identified step changes in the pressure ratio curve; and registering and / or linking the obtained one or more images to the identified step changes in the pressure ratio curve. The method may also include outputting the pressure ratio curve to a display system; and / or outputting an image to a display system.

[0106] The system may include a processor, such as processor 88, configured and / or programmed to perform a method including: generating a pressure ratio curve, performing an ASD process to identify a step change in the pressure ratio curve, and obtaining and linking / registering an image to the pressure ratio curve. In this particular example, the pressure ratio curve 42 may be generated using FFR pressure ratio values ​​obtained from pressure measurements during pullback. Graph 40 illustrates the pressure ratio curve 42, such that the pressure ratio values ​​(P d / P a ) and time is represented along the x-axis. Curve 42 represents the pressure ratio along the vessel during the pullback, wherein the zero time point along the x-axis represents the P obtained using the first instrument 10 at its most distal position (e.g., distal to the region of interest) during the pullback. d The right end of curve 42 along the x-axis represents the pressure ratio calculated from the pressure measurements, P obtained using the first instrument 10 in its most proximal position (e.g., at the coronary ostium) during pullback. d The pressure measurements are used to calculate the pressure ratio, and the remainder of curve 42 between these two endpoints represents the pressure ratio along the vessel therebetween.

[0107] like Figure 3As shown, the example pressure ratio curve 42 may include one or more step changes (e.g., 44, 144, 244) in the pressure ratio curve, wherein the step change in pressure ratio is more significant or rapid (e.g., above a threshold change) within a certain window compared to one or more non-step regions (e.g., 43, 143, 243) along the pressure ratio curve 42, where the pressure ratio value changes within a certain window are less significant or more gradual (e.g., below a threshold change) in the non-step regions. The processor 88 may use the ASD process and / or algorithm described above to identify the location of the step changes (e.g., 44, 144, 244) and optionally mark them as desired.

[0108] For example, the processor 88 may use the ASD process to identify a step change 44 in the pressure ratio curve 42 and optimize the location of the starting point 48 and / or end point 54 of the step change 44 in the pressure ratio curve 42. The processor 88 may then also identify and / or mark the identified starting point 48 and end point 54 and output to a display. For example, the starting point may be marked with a line 46, and the pressure ratio value at the starting point may be displayed in a label 56. Similarly, the end point 54 may be marked with a line 50, and the pressure ratio value at the end point 54 may be displayed in a label 58. Moreover, a label 59 may also be generated that shows the size, amplitude and / or magnitude of the step increase (e.g., the difference between the pressure ratio values ​​at the end point 54 and the starting point 48). For example, as Figure 3 As can be seen in FIG. 5 , with the step increase 44, the pressure ratio at the start point 48 is 0.66, as shown by label 56, and the pressure ratio at the end point 54 is 0.72, as shown by label 58. Therefore, the magnitude of the step increase 44 is 0.72-0.66=0.06, which is shown in label 59.

[0109] Processor 88 may be configured to obtain and / or capture an image showing a location of first pressure sensing instrument 10 within vessel 99 corresponding to a specific location on pressure ratio curve 42 and to register and / or link the obtained image to the specific location on pressure ratio curve 42. For example, Figure 3A is a schematic diagram showing an image of the position of the first medical device 10 captured at a time corresponding to the start 48 of the step change 44 in the pressure ratio curve 42 . Figure 3AThe image shown in may be appropriately linked to the starting point 48 on the pressure ratio curve 42. For example, a link may exist at the starting point 48 on the curve itself, or a link may exist in the marker line 46, in the label 56, or at some other indicator associated with the starting point 48 on the curve 42. For example, activating a link on the curve using a user interface will instruct the processor 88 to output image 3A to the display. Additionally or alternatively, image 3A may include a link to the starting point 48 such that, for example, activating a link on image 3A using a user interface will prompt the processor 88 to output an indicator on the curve 42 that corresponds to the position of image 3A on the curve. (For example, an indicator or highlighted area of ​​the starting point 48 on the curve 42). Similarly, Figure 3B is a schematic diagram showing an image of the position of the first medical device 10 captured at a time corresponding to the end point 54 of the step change 44 in the pressure ratio curve 42 . Figure 3B This image in may be linked to the end point 54 on the pressure ratio curve 42, and / or the end point 54 may be linked to image 3B in a similar manner. These links may be similarly activated, as discussed herein.

[0110] The processor 88 may also use the ASD process to identify one or more additional step changes (e.g., 144 and 244) in the pressure ratio curve 42 and may optimize the location of the starting point (e.g., 148 and 248) and the end point (e.g., 154 and 254) of the one or more other step changes 144 and 244 in the pressure ratio curve 42. Similarly, the processor 88 may then also identify and output to the display the identification and / or markings for the starting point (e.g., 148 and 248) and the end point (e.g., 154 and 254). For example, the starting points 148 and 248 may be marked with lines 146 and 246, respectively, and the pressure ratio values ​​at each starting point 148 and 248 may be displayed in labels 156 and 256, respectively. Similarly, the end points 154 and 254 may be marked with lines 150 and 250, and the pressure ratio values ​​at each end point 154 and 254 may be displayed in labels 158 and 258, respectively. Furthermore, labels 159 and 259 may also be generated that show the size, magnitude, and / or amplitude of the step increases (e.g., the difference between the pressure ratio at the end and the start of each step increase). Figure 3 As can be seen in FIG. 1 , in the case of the step increase 144, the pressure ratio at the starting point 148 is 0.72, as shown by label 156, and the pressure ratio at the end point 154 is 0.83, as shown by label 158. Therefore, the magnitude of the step increase 144 is 0.83-0.72=0.11, which is shown in label 159. As also shown in FIG. Figure 3As can be seen in FIG. 2 , in the case of the step increase 244, the pressure ratio value at the starting point 248 is 0.83, as shown by label 256, and the pressure ratio value at the end point 254 is 0.98, as shown by label 258. Therefore, the magnitude of the step increase 244 is 0.98-0.83=0.15, which is shown in label 259.

[0111] In addition, processor 88 may be configured to obtain and / or capture a corresponding image showing first pressure sensing instrument 10 within vessel 99 corresponding to a specific location on pressure ratio curve 42, and to register and / or link the obtained image to the specific location on pressure ratio curve 42. For example, Figure 3C is a schematic diagram showing an image of the position of the first medical device 10 captured at a time corresponding to the starting point 148, which image may be registered and / or linked to the starting point 148 on the pressure ratio curve 42; Figure 3D is a schematic diagram showing an image of the position of the first medical device 10 captured at a time corresponding to an endpoint 154, which image may be registered and / or linked to the endpoint 154 on the pressure ratio curve 42; Figure 3E is a schematic diagram showing an image of the position of the first medical device 10 captured at a time corresponding to the starting point 248, which image may be registered and / or linked to the starting point 248 on the pressure ratio curve 42; and Figure 3F is a schematic diagram showing images of the position of the first medical device 10 captured at a time corresponding to the end point 254, which can be registered and / or linked to the end point 254 on the pressure ratio curve 42. Each of these images can be linked to the pressure ratio curve 42 by a link on the pressure ratio curve 42 located at or adjacent to its corresponding position on the curve (e.g., time). Likewise, each of these images can include a link back to its corresponding position on the pressure ratio curve, as shown above Figure 3A and 3B discussed.

[0112] In this particular example, there are significant changes in the curve pressure ratio along the length of the curve, including three step changes 44, 144, 244 identified using the ADS process during the pullback. This would indicate three focal lesions within that portion of the vessel. The ADS process is able to identify and optimize the locations of these step changes, and provide markings for the start and end points of these step changes, and indicate the magnitude of each. Thus, the systems and methods can provide medical personnel with useful information about specific areas of the examination to determine whether interventional treatment is necessary or necessary, and / or how to treat and what treatment to use. For example, areas of step changes 44, 144, 244 can indicate locations within the vessel that may be worthy of more invasive invasive treatments, such as angioplasty or stenting, while non-step areas (e.g., 43, 143, 243) can indicate locations within the vessel that may be suitable for less invasive or invasive treatments, such as drug treatments or no treatment at all. In addition, the areas of step changes (e.g., 44, 144, 244) can be compared to each other so that medical personnel can focus treatment on the areas that may have the most significant hemodynamic impact. For example, in this particular case, the most significant stenotic area or lesion appears to be the most proximal one, where the amplitude of the step increase 244 is measured as 0.15.

[0113] Reference now Figure 4 Another prophetic example embodiment is discussed. Figure 4 340 is a schematic diagram of a pressure ratio curve 342 that may be calculated / generated, for example, by the processor 88 and output to the display 90. The pressure ratio curve 342 may be generated using and / or in conjunction with the methods and systems disclosed herein, including using an ASD process. Figure 4As shown, the example pressure ratio curve 342 may include a large area of ​​non-step portion 343, where the change in pressure ratio value is more gradual and / or less rapid, and only one step change 344 in the pressure ratio curve 342, where the change in pressure ratio is more significant or rapid within a certain window (e.g., above a certain threshold change). The processor 88 may use the ASD process and / or algorithm described above to identify the location of the step change 344 and optionally mark it as desired. For example, the processor 88 may use the ASD process to identify the step change 344 in the pressure ratio curve 342 and optimize the location of the starting point 348 and / or end point 354 of the step change 344. The processor 88 may then also identify and output to the display the identification and / or marking for the identified starting point 348 and end point 354. For example, the starting point may be marked with line 346, and the pressure ratio value at the starting point may be displayed in label 356. Similarly, the end point 354 may be marked with line 350, and the pressure ratio value at the end point 354 may be displayed in label 358. Furthermore, a label 359 may also be generated that shows the size, dimension, and / or magnitude of the step increase (e.g., the difference between the pressure ratio values ​​at the end point 354 and the start point 348). Figure 4 As can be seen in FIG. 3 , in the case of the step increase 344, the pressure ratio value at the starting point 348 is 0.88, as shown by label 356, and the pressure ratio value at the end point 354 is 0.96, as shown by label 358. Therefore, the magnitude of the step increase 344 is 0.96-0.88=0.08, which is shown in label 359.

[0114] Again, the processor may be configured to obtain and / or capture images showing the location of the first pressure sensing instrument 10 within the vessel 99 corresponding to specific locations on the pressure ratio curve 342, and to register and / or link the obtained images to those specific locations on the pressure ratio curve 342. For example, Figure 4A is a schematic diagram showing an image of the position of the first medical device 10 captured at a time corresponding to the starting point 348 of the step change 344 of the pressure ratio curve 342, Figure 4B 354. Each of these images may be linked to the pressure ratio curve 342 by a link on the pressure ratio curve 342 located at or adjacent to its corresponding position on the curve (e.g., time). Likewise, each of these images may include a link back to its corresponding position on the pressure ratio curve, as shown above. Figure 3A and 3B discussed.

[0115] In this prophetic example, the pressure ratio curve 342 is generally more gradual over a majority of its length compared to the pressure ratio curve 242 discussed above. While there is a significant change in the overall pressure ratio values ​​along the entire length of the curve 342, a majority of the curve 342 is more gradual and / or does not include a step increase, and only a small step change 344 is identified using the ASD process. This can provide useful information to medical personnel in determining how to treat this situation. Because there is only a small step change 344 with an amplitude measurement of only 0.08, certain treatments may not be appropriate. For example, removing the more proximal step increase 344 through stent implantation and / or angioplasty may not be sufficient to return the pressure ratio values ​​along this segment to an acceptable level. In this regard, due to the diffuse nature of this stenotic area, other treatments, such as bypass surgery, may be more appropriate.

[0116] Figure 5 An example embodiment of a blood pressure sensing guidewire 10 that can be used, for example, as a first pressure sensing medical device 10 is shown. The guidewire 10 may include a shaft or tubular member 12. The tubular member 12 may include a proximal region 14 and a distal region 16. The materials used for the proximal region 14 and the distal region 16 may vary and may include those disclosed herein. For example, the distal region 16 may include a nickel-cobalt-chromium-molybdenum alloy (e.g., MP35-N). The proximal region 14 may be made of the same material as the distal region 16 or a different material, such as stainless steel. These are merely examples. Other materials are also contemplated.

[0117] In some embodiments, the proximal region 14 and the distal region 16 are formed by the same material monolith. In other words, the proximal region 14 and the distal region 16 are parts of the same tube that define the tubular member 12. In other embodiments, the proximal region 14 and the distal region 16 are separate tubular members that are combined together. For example, a section of the outer surface of the removable portion 14 / 16, and the sleeve 17 can be arranged on the removed section to combine the region 14 / 16. Alternatively, the sleeve 17 can be arranged only on the region 14 / 16. Other combinations can also be used, including welding, thermal bonding, adhesive bonding, etc. If used, the sleeve 17 for combining the proximal region 14 with the distal region 16 may include a material that is ideally combined with both the proximal region 14 and the distal region 16. For example, the sleeve 17 may include a nickel-chromium-molybdenum alloy (e.g., INCONEL).

[0118] A plurality of slots 18 may be formed on the tubular member 12. In at least some embodiments, the slots 18 are formed in the distal region 16. In at least some embodiments, the proximal region 14 lacks the slots 18. However, the proximal region 14 may include the slots 18. For a variety of reasons, the slots 18 may be desirable. For example, the slots 18 may provide a desired level of flexibility (e.g., along the distal region 16) to the tubular member 12 while also allowing for suitable torque transmission. The slots 18 may be arranged / distributed along the distal region 16 in a suitable manner. For example, the slots 18 may be arranged into pairs of opposite slots 18 that are distributed along the length of the distal region 16. In some embodiments, adjacent pairs of slots 18 may have substantially constant spacing relative to each other. Alternatively, the spacing between adjacent pairs may vary. For example, a more distal region of the distal region 16 may have a reduced spacing (and / or an increased slot density), which may provide increased flexibility. In other embodiments, more distal regions of the distal region 16 may have increased spacing (and / or decreased slot density). These are merely examples. Other arrangements are contemplated.

[0119] The pressure sensor 20 may be disposed within the tubular member 12 (eg, within the lumen of the tubular member 12). Figure 3 The pressure sensor 20 is schematically shown in FIG. 1 , but it is understood that the structural form and / or type of the pressure sensor 20 may vary. For example, the pressure sensor 20 may include a semiconductor (e.g., silicon wafer) pressure sensor, a piezoelectric pressure sensor, an optical fiber or optical pressure sensor, a Fabry-Perot pressure sensor, an ultrasonic transducer and / or an ultrasonic pressure sensor, a magnetic pressure sensor, a solid-state pressure sensor, etc., or any other suitable pressure sensor.

[0120] As described above, the pressure sensor 20 may include an optical pressure sensor. In at least some of these embodiments, an optical fiber or fiber optic cable 24 (e.g., a multimode optical fiber) may be attached to the pressure sensor 20 and may extend proximally therefrom. The optical fiber 24 may include a central core 60 and an outer coating 62. In some cases, a sealing member (not shown) may attach the optical fiber 24 to the tubular member 12. Such an attachment member may be circumferentially disposed around the optical fiber 24 and attached to the optical fiber 24 and may be fixed to the inner surface (e.g., distal region 16) of the tubular member 12. In addition, a centering member 26 may also be incorporated into the optical fiber 24. In at least some embodiments, the centering member 26 is spaced proximally from the pressure sensor 20. Other arrangements may be envisioned. The centering member 26 may help reduce the force exposed to the pressure sensor 20 during guidewire navigation and / or during use.

[0121] In at least some embodiments, the distal region 16 may include a region having thinned walls and / or an increased inner diameter that defines a sensor receiving region 52. Generally, the sensor receiving region 52 is the region of the distal region 16 that ultimately "receives" the pressure sensor 20. By removing a portion of the inner wall of the tubular member 12 at the sensor receiving region 52, additional space capable of receiving the sensor 20 may be created or otherwise defined. The sensor receiving region 52 may include one or more openings, such as one or more distal porthole openings 66, that provide fluid access to the pressure sensor 20.

[0122] The end member 30 can be coupled to the distal region 16. The end member 30 can include a core member 32 and a spring or coil member 34. A distal tip 36 can be attached to the core member 32 and / or the spring 34. In at least some embodiments, the distal tip 36 can take the form of a solder ball tip. The end member 30 can be joined to the distal region 16 of the tubular member 12 with a bonding member 46, such as solder.

[0123] The tubular member 12 may include an outer coating 19. In some embodiments, the coating 19 may extend along substantially the entire length of the tubular member 12. In other embodiments, one or more discrete segments of the tubular member 12 may include the coating 19. The coating 19 may be a hydrophobic coating, a hydrophilic coating, etc. The tubular member 12 may also include an inner coating 64 (e.g., a hydrophobic coating, a hydrophilic coating, etc.) disposed along its inner surface. For example, the hydrophilic coating 64 may be disposed along the inner surface of the housing region 52. In some of these and in other cases, the core member 32 may include a coating (e.g., a hydrophilic coating). For example, the proximal region and / or the proximal end of the core member 32 may include a coating. In some of these and in other cases, the pressure sensor 20 may also include a coating (e.g., a hydrophilic coating).

[0124] The various components that can be used for the system 100 and / or the materials of the guidewire 10 may include those commonly associated with medical devices. For simplicity, the following discussion refers to the tubular member 12 and other components of the guidewire 10. However, this is not intended to limit the devices and methods described herein, as the discussion can be applied to other tubular members and / or components of the tubular members or devices disclosed herein.

[0125] The tubular member 12 and / or other components of the guidewire 10 may be made of metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, or the like, or other suitable materials. Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, available from DuPont, for example). ), polyether block esters, polyurethanes (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., available from DSM Engineering Plastics ), ether- or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalate and / or other polyester elastomers, such as those available from DuPont ), polyamide (e.g., available from Bayer Or available from Elf Atochem ), elastic polyamides, block polyamide / ether, polyether block amide (PEBA, for example, available under the trade name obtained), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low-density polyethylene (e.g., ), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly(p-phenylene terephthalamide) (e.g., ), polysulfone, nylon, nylon-12 (such as, available from EMS American Grilon ), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, etc. thereof. In some embodiments, the sheath may be blended with a liquid crystal polymer (LCP). For example, the mixture may contain up to about six percent LCP.

[0126] Some examples of suitable metals and metal alloys include stainless steels, such as 304V, 304L, and 316LV stainless steels; mild steels; nickel-titanium alloys, such as linear elastic and / or superelastic nitinol; other nickel alloys, such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as 625; UNS:N06022, such as UNS:N10276, such as other alloys, etc.), nickel copper alloys (e.g., UNS: N04400, such as 400, 400, 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as etc.), nickel-molybdenum alloys (e.g., UNS: N10665, such as ALLOY ), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten alloys or tungsten alloys, etc., cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as etc.), platinum-rich stainless steel, titanium, combinations thereof, etc., or any other suitable material.

[0127] In at least some embodiments, the guide wire 10 may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials that can produce a relatively bright image on a fluoroscopic screen or another imaging technique during a medical procedure. This relatively bright image helps the user of the guide wire 10 determine its position. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymer materials loaded with radiopaque fillers (e.g., barium sulfate, bismuth subcarbonate, etc.), etc. Additionally, other radiopaque marker bands and / or coils may also be incorporated into the design of the guide wire 10 to achieve the same result.

[0128] In some embodiments, the guidewire 10 is given a degree of magnetic resonance imaging (MRI) compatibility. For example, the guidewire 10 or some portion thereof may be made of a material that does not substantially distort the image and generate a large number of artifacts (e.g., gaps in the image). For example, certain ferromagnetic materials may be unsuitable because they may generate artifacts in the MRI image. The guidewire 10 or some portion thereof may also be made of a material that can be imaged by an MRI machine. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R44003, such as etc.), nickel-cobalt-chromium-molybdenum alloys (e.g. UNS: R44035, such as etc.), Nitinol etc. and others.

[0129] It should be understood that the present disclosure is in many respects illustrative only. Without exceeding the scope of the present disclosure, changes may be made in detail, particularly with respect to shape, size, and arrangement of steps. To an appropriate degree, this may include using any of the features of an example embodiment in other embodiments. Of course, the scope of the present invention is defined in the language of the appended claims.

Claims

1. A system for evaluating a patient's vasculature, the system include: A processor, wherein the processor is configured as: obtaining a series of first pressure measurements from the first instrument within the vessel over a period of time as the first instrument moves longitudinally through the vessel from a first position to a second position; obtaining a series of second pressure measurements from the second instrument positioned within the vessel over the period of time while the second instrument remains in a fixed longitudinal position within the vessel; calculating a series of pressure ratio values ​​using the first pressure measurement and the second pressure measurement; generating a pressure ratio curve for the period of time using the series of pressure ratio values; Outputting the pressure ratio curve to a display system; identifying a step change in the pressure ratio curve using an automatic step detection process; obtaining an image showing a location of the first instrument within the vessel corresponding to the step change identified in the pressure ratio curve; registering the image to the step change identified in the pressure ratio curve; as well as outputting the image to the display system; The automatic step detection process includes: identifying an approximate location of a starting point of the step change by identifying a change in pressure ratio value at or above a first threshold change value within a first window along the pressure ratio curve; as well as The optimal location of the starting point is identified by identifying a pressure ratio change at or above a second threshold change value within a second window along the pressure ratio curve, wherein the second window is smaller than the first window and the second threshold change value is smaller than the first threshold change value.

2. The system of claim 1, wherein the processor includes a user interface, and the processor is configured to selectively output the image to the display system upon a command issued by a user through the user interface.

3. The system of claim 2, wherein the user issuing the command comprises the user positioning a cursor at a predetermined location on the display system.

4. The system of claim 3, wherein the predetermined position of the display system comprises a position of a step change indicator on the pressure ratio curve.

5. The system of any one of claims 1 to 4, wherein the processor is configured to output to the display system a step change indicator on the pressure ratio curve corresponding to the step change identified on the pressure ratio curve.

6. The system of claim 5, wherein the step change indicator comprises an indicator of a starting point of the step change on the pressure ratio curve, an indicator of an end point of the step change on the pressure ratio curve, an indicator showing a difference between a starting point and an end point of the step change on the pressure ratio curve, or a combination of these.

7. A system according to any one of claims 1 to 4, wherein the processor includes a user interface function, wherein the user interface function allows a user to position a cursor on the image, and in response, the processor is configured to output to the display system an indicator showing a position on the pressure ratio curve corresponding to the image.

8. The system of any one of claims 1 to 4, wherein the processor is configured to identify the step change comprises the processor being configured to identify a starting point of the step change, and wherein the image shows a position of the first instrument within the vessel at the starting point of the step change.

9. The system of any one of claims 1 to 4, wherein the processor being configured to identify the step change comprises the processor being configured to identify an endpoint of the step change.

10. The system of claim 9, wherein the processor is further configured to obtain a second image showing a position of the first instrument within the vessel at the endpoint of the step change, and to register the second image to the endpoint identified in the step change.

11. The system according to any one of claims 1 to 4, further comprising the display system.

12. A system according to any one of claims 1 to 4, wherein the image is acquired and registered in real time when the step change is identified, or the image is acquired from a series of images captured over time and subsequently registered to the identified step change.

13. The system of claim 1, wherein the automatic step detection process further include: identifying the approximate location of an end point of the step change by identifying a change in pressure ratio value at or below a third threshold change value within a third window along the pressure ratio curve, and The optimal position of the endpoint along the curve is identified by identifying a pressure ratio change at or below a fourth threshold change value within a fourth window along the pressure ratio curve, wherein the fourth window is smaller than the third window and the fourth threshold change value is smaller than the third threshold change value.

14. The system of any one of claims 1 to 4, wherein the processor is further configured to use the automatic step detection process to identify one or more additional step changes in the curve, and to obtain one or more additional images showing the position of the first instrument within the vessel corresponding to the one or more additional step changes, and to register the one or more additional images to the corresponding one or more additional step changes.

15. The system of any one of claims 1 to 4, wherein the second window overlaps with and / or includes a portion of the pressure ratio curve containing the approximate location of the starting point.

Images