Pressure-Based Structural Cardiac Assessment System and Method - Patent application

Abstract

The system evaluates a heart valve, such as a heart valve after deployment. The system performs the valve evaluation using pressure sensor calibration, waveform conditioning, feature detection, and / or valve status generation. The graphical user interface presents metrics related to the valve evaluation. The graphical user interface presents graphs, physiological parameters, and / or values ​​indicative of heart valve status (e.g., gradient, regurgitant index, regurgitant ratio, etc.) for two recordings simultaneously.

Description

[Technical field]

[0001] INCORPORATION BY REFERENCE TO PRIORITY APPLICATION This application claims the benefit of U.S. Provisional Patent Application No. 63 / 269,770, filed March 22, 2022, entitled "Pressure Based Structural Heart Assessment Systems and Methods," which is incorporated by reference in its entirety.

[0002] The present application relates to devices, user interfaces, algorithms, and systems associated with a structural heart guidewire configured to sense blood pressure to provide information regarding blood flow through a heart valve before, during, and / or immediately after a structural heart procedure. [Background technology]

[0003] Guidewires are known to deliver catheters to many vascular sites in the body. Access to vascular sites is facilitated by a combination of mechanical properties such as flexibility, pushability, and torqueability. In coronary procedures, they are known to include pressure sensors that provide information about blood flow through static occlusions to help cardiologists decide whether to treat a patient.

[0004] Although pressure sensing around static lesions in coronary vessels is known, such concepts have not been applied to structural heart procedures such as repairing heart valves and improving the pumping function of the heart. The pumping function of the heart has been addressed with various types of mechanical pumps. Heart valves have historically been repaired by open heart surgery. However, heart valves are now increasingly being replaced by cardiologists using catheters through which percutaneous heart valves are fitted and delivered. Summary of the Invention [Means for solving the problem]

[0005] For purposes of summarizing the disclosure, certain aspects, advantages, and novel features are described herein. It is to be understood that not necessarily all such aspects, advantages, or features are embodied in any particular embodiment of the invention, and one of ordinary skill in the art will recognize from this disclosure that there are myriad combinations of such aspects, advantages, or features.

[0006] According to one embodiment, the disclosed method includes determining a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart, determining a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart, determining a heart rate of the heart, calculating from the first plurality of pressure values ​​(i) a first end-diastolic pressure of the first portion of the heart and (ii) a systolic pressure of the first portion of the heart, calculating from the second plurality of pressure values ​​a second end-diastolic pressure of the cardiovascular region adjacent to the first portion of the heart, determining a regurgitation index, where determining the regurgitation index further includes calculating a pressure difference between the first end-diastolic pressure and the second end-diastolic pressure and calculating a value from the pressure difference that is normalized at least in part based on the systolic pressure and the heart rate, and causing presentation of the regurgitation index in a user interface.

[0007] According to one embodiment, the disclosed method includes controlling a heart rate; determining a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart; determining a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart; determining a regurgitation index based at least in part on (i) a first value from the first plurality of pressure values ​​and (ii) a second value from the second plurality of pressure values; and causing presentation of the regurgitation index in a user interface.

[0008] According to one embodiment, the method further includes calculating from the first plurality of pressure values ​​(i) a first end-diastolic pressure in the first portion of the heart and (ii) a systolic pressure in the first portion of the heart, and calculating from the second plurality of pressure values ​​a second end-diastolic pressure in a cardiac vascular region adjacent to the first portion of the heart, wherein determining the regurgitant index is further based at least in part on the first end-diastolic pressure, the second end-diastolic pressure, and the systolic pressure.

[0009] According to another aspect, controlling the heart rate may further include ventricular pacing the heart at predefined heart rate intervals.

[0010] According to yet another aspect, controlling the heart rate may further include administering a drug to the patient.

[0011] According to yet another aspect, the method may further include calculating a time constant from the first plurality of pressure values ​​and the second plurality of pressure values, and causing presentation of the time constant in a user interface.

[0012] According to yet another aspect, the reflux index may further include a time integrated reflux index.

[0013] According to one embodiment, the disclosed method includes causing a premature systole of the heart having a non-ejecting ventricular beat into the aorta, determining a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart, determining a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart, calculating from the first plurality of pressure values ​​(i) a first end-diastolic pressure of the first portion of the heart and (ii) a systolic pressure of the first portion of the heart, calculating from the second plurality of pressure values ​​a second end-diastolic pressure of the cardiovascular region adjacent to the first portion of the heart, determining a regurgitation index based at least in part on the first end-diastolic pressure, the second end-diastolic pressure, and the systolic pressure, and causing presentation of the regurgitation index in a user interface.

[0014] According to one embodiment, inducing a premature cardiac contraction may further include programming a pacemaker coupled to the heart to induce the premature cardiac contraction.

[0015] According to another embodiment, a disclosed system comprises a non-transitory computer storage medium configured to store at least computer-executable instructions; and one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions to at least: before a cardiac procedure, determine a first plurality of pressure values ​​from (i) a first pressure sensor positioned at a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart and calculate a first regurgitation index from the first plurality of pressure values; after the cardiac procedure, determine a second plurality of pressure values ​​from (i) the first pressure sensor positioned at the first portion of the heart and (ii) the second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart and calculate a second regurgitation index from the second plurality of pressure values; determine a regurgitation differential value based, at least in part, on the second regurgitation index and the first regurgitation index; and cause presentation of the regurgitation differential value in a user interface.

[0016] According to one aspect, determining the backflow difference value may further include calculating a normalized difference value by (i) dividing the difference between the second backflow index and the first backflow index by (ii) the first backflow index, and assigning the normalized difference value to the backflow difference value.

[0017] According to one embodiment, the disclosed method includes determining a time series of pressure values ​​from a pressure sensor positioned in a portion of the heart, identifying a subset of the time series of pressure values ​​corresponding to at least a portion of a diastolic phase, calculating a first slope from the subset of the time series of pressure values, identifying a first regurgitation index based at least in part on the first slope, where identifying the first regurgitation index further includes finding a first regurgitation index that correlates with the first slope, and causing presentation of the first regurgitation index in a user interface.

[0018] According to one aspect, the method may further include accessing a plurality of pressure measurements, each pressure measurement from the plurality of measurements corresponding to a patient, and for each pressure measurement from the plurality of pressure measurements, calculating a pair from the pressure measurements including a diastolic slope and a reflux index, and determining a correlation between the diastolic slope and the reflux index based at least in part on the pair of the diastolic slope and the reflux index, wherein finding the first reflux index further includes applying the correlation between the diastolic slope and the reflux index to the first slope.

[0019] According to another embodiment, the portion of the heart may include at least the left ventricle, such that, for example, a first pressure sensor is positioned in the left ventricle during at least a portion of the method.

[0020] According to yet another aspect, calculating the first slope from the subset of the time series of pressure values ​​may further include determining a linear fit from the subset of the time series of pressure values ​​and calculating the first slope from the linear fit.

[0021] According to yet another aspect, calculating the first slope from the subset of the time series of pressure values ​​may further include determining a polynomial function from the subset of the time series of pressure values ​​and calculating the first slope from the polynomial function.

[0022] According to yet another aspect, calculating the first slope from the subset of the time series of pressure values ​​may further include determining an exponential function from the subset of the time series of pressure values ​​and calculating the first slope from the exponential function.

[0023] According to one embodiment, the disclosed method includes determining a first time series of pressure values ​​from a first pressure sensor positioned in a first portion of the heart, determining a second time series of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart, identifying a subset of the first time series of pressure values ​​corresponding to at least a portion of a diastolic phase, identifying the subset of the second time series of pressure values ​​corresponding to at least a portion of the diastolic phase, calculating (i) a first slope from the subset of the first time series of pressure values ​​and (ii) a second slope from the subset of the second time series of pressure values, determining a regurgitation index based at least in part on the first slope and the second slope, and causing presentation of the regurgitation index in a user interface.

[0024] According to one embodiment, the first portion of the heart may include at least the left ventricle and the cardiovascular region adjacent the first portion includes at least the aorta, so that, for example, in at least a portion of the method, a first pressure sensor is positioned within the left ventricle and a second pressure sensor is positioned in the aorta.

[0025] According to another aspect, the method may further include calculating a first plurality of slopes from a subset of a first time series of pressure values, the first plurality of slopes including a first slope, and calculating a second plurality of slopes from a subset of a second time series of pressure values, the second plurality of slopes including a second slope, and determining a slope angle for each slope of the first and second plurality of slopes, wherein determining the reflux index further includes determining a first statistical measure from the slope angle for each slope of the first plurality of slopes, determining a second statistical measure from the slope angle for each slope of the second plurality of slopes, calculating a combined statistical measure from the first and second statistical measures, and assigning the combined statistical measure as the reflux index.

[0026] According to yet another aspect, calculating the combined statistical measure may further include at least one of adding or subtracting the first statistical measure and the second statistical measure.

[0027] According to yet another aspect, the method may further include determining a first slope angle for the first slope and determining a second slope angle for the second slope, and determining the reflux index further includes calculating a combined slope angle from the first slope angle and the second slope angle and assigning the combined slope angle as the reflux index.

[0028] According to yet another aspect, calculating the combined gradient angle may further include at least one of adding, subtracting, multiplying, or dividing the first gradient angle and the second gradient angle.

[0029] According to yet another aspect, calculating the second slope may further include determining an initial slope from a subset of the second time series of pressure values, determining a correction factor from the second time series of pressure values, and calculating a corrected diastolic slope from the initial slope, where calculating the corrected diastolic slope further includes applying the correction factor to the initial slope and assigning the corrected diastolic slope to the second slope.

[0030] According to yet another aspect, determining the correction factor may further include calculating at least one of an augmentation index or a pressure increase from the second time series of pressure values ​​and identifying the correction factor based at least in part on one of the augmentation index or the pressure increase.

[0031] According to another embodiment, a disclosed system comprises a non-transitory computer storage medium configured to store at least computer-executable instructions; and one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions to at least: before a cardiac procedure, determine a first set of time-series pressure values ​​from (i) a first pressure sensor positioned at a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart and calculate a first time constant from the first set of time-series pressure values; after the cardiac procedure, determine a second set of time-series pressure values ​​from (i) the first pressure sensor positioned at the first portion of the heart and (ii) the second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart and calculate a second time constant from the second set of time-series pressure values; determine a time constant difference value based at least in part on the first time constant and the second time constant; and cause presentation of the time constant difference value in a user interface.

[0032] According to one embodiment, the first portion of the heart may include at least the left ventricle and the cardiovascular region adjacent to the first portion may include at least the aorta, whereby when the one or more hardware processors execute the computer-executable instructions, the determined time constant difference is based on a pressure value sensed by the first pressure sensor while the first pressure sensor is in the left ventricle and a pressure value sensed by the second pressure sensor while the second pressure sensor is in the aorta.

[0033] According to another aspect, calculating the first time constant from the first set of time series pressure values ​​comprises substantially

number

[0034] According to yet another aspect of the method, the first time and the second time can be within a diastolic phase.

[0035] According to another embodiment, a disclosed system includes a non-transitory computer storage medium configured to store at least computer-executable instructions; and one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions including: determining a set of time series pressure values ​​from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; and calculating a time constant from the set of time series pressure values, wherein calculating the time constant substantially comprises:

number

[0036] According to one aspect of the system comprising the non-transitory computer storage medium, the first time and the second time can be within a diastolic phase.

[0037] According to another embodiment, a disclosed system comprises a non-transitory computer storage medium configured to store at least computer-executable instructions; and one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions to at least determine a first time series of pressure values ​​from a pressure sensor positioned on a portion of the heart before the cardiac procedure and calculate a first time constant from the first time series of pressure values, determine a second time series of pressure values ​​from a pressure sensor positioned on a portion of the heart after the cardiac procedure and calculate a second time constant from the second time series of pressure values, determine a time constant difference value based at least in part on the first time constant and the second time constant, and cause presentation of the time constant difference value in a user interface.

[0038] According to one embodiment, the portion of the heart may include the left ventricle or the aorta, whereby when the one or more hardware processors execute the computer-executable instructions, the determined time constant difference is based on a pressure value sensed by a first pressure sensor while the first pressure sensor is in the left ventricle and a pressure value sensed by a second pressure sensor while the second pressure sensor is in the aorta.

[0039] According to another aspect, calculating the first time constant from the first time series of pressure values ​​comprises substantially:

number

[0040] According to yet another embodiment, the first time and the second time can be within the diastolic phase.

[0041] According to another embodiment, a system is disclosed that includes a non-transitory computer storage medium configured to store at least computer-executable instructions; and one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions including: determining a first time series of pressure values ​​from a first pressure sensor positioned in at least a first portion of the heart; determining a second time series of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; identifying a first heart beat and a second heart beat from the first time series and the second time series; associating the first heart beat with a first category based at least in part on a first characteristic of the first heart beat; and associating the first category with a second category based at least in part on a first characteristic of the first heart beat. and one or more hardware processors indicating that one heart beat is rejected, associating a second heart beat with a second category based at least in part on a second characteristic of the second heart beat, the second category indicating that the second heart beat is accepted, and determining a regurgitation index, wherein determining the regurgitation index further includes excluding the first heart beat as rejected based at least in part on the first category and including the second heart beat as accepted based at least in part on the second category, and calculating the regurgitation index based at least in part on (i) a first portion of the first time series associated with the second heart beat and (ii) a second portion of the second time series associated with the second heart beat, and causing presentation of the regurgitation index in a user interface.

[0042] According to one aspect, the first characteristic of the first heart beat may correspond to an elapsed time of the first heart beat, and associating the first heart beat with a first category based at least in part on the first characteristic may further include determining that the elapsed time of the first heart beat is outside a threshold range.

[0043] According to another aspect, the first characteristic of the first heart beat may correspond to a duration of a diastolic phase of the first heart beat, and associating the first heart beat with a first category based at least in part on the first characteristic further includes determining that the duration of the diastolic phase of the first heart beat exceeds a threshold time.

[0044] According to yet another aspect, the first characteristic of the first heart beat may correspond to a pressure from a systolic phase of the first heart beat, and associating the first heart beat with a first category based at least in part on the first characteristic may further include determining that the pressure from the systolic phase of the first heart beat exceeds a threshold.

[0045] According to yet another aspect, the first portion of the heart may include the aorta or the left ventricle, whereby when the one or more hardware processors execute the computer-executable instructions, the calculated regurgitation index is based on a pressure value sensed by the first pressure sensor while the first pressure sensor is within the aorta or the left ventricle.

[0046] According to another embodiment, a disclosed system includes a non-transitory computer storage medium configured to store at least computer-executable instructions; and one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions including receiving, during at least a first time period, a first set of time-series pressure values ​​from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; and calculating a first regurgitation index from the first set of time-series pressure values. and one or more hardware processors to calculate, during a second time period, receive a second set of time-series pressure values ​​from (i) a first pressure sensor positioned in the first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart, calculate a second regurgitation index from the second set of time-series pressure values, and cause presentation within a user interface of a first set of graphs for the first set of time-series pressure values, a first visual representation of the first regurgitation index on the first set of graphs, a second set of graphs for the second set of time-series pressure values, and a second visual representation of the second regurgitation index on the second set of graphs.

[0047] According to another embodiment, a disclosed system includes a non-transitory computer storage medium configured to store at least computer-executable instructions; and one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions receiving, during at least a first time period, a first set of time-series pressure values ​​from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; and determining a first hemodynamic profile from the first set of time-series pressure values. and one or more hardware processors to receive, during a second time period, a second set of time-series pressure values ​​from (i) a first pressure sensor positioned in the first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart, calculate a second hemodynamic parameter from the second set of time-series pressure values, and cause presentation within the user interface of a first set of graphs for the first set of time-series pressure values, a first visual representation of the first hemodynamic parameter, a second set of graphs for the second set of time-series pressure values, and a second visual representation of the second hemodynamic parameter.

[0048] According to one embodiment, the first time period may correspond to before a cardiac procedure and the second time period may correspond to after a cardiac procedure.

[0049] According to another embodiment, the cardiac procedure may include a balloon aortic valvuloplasty (BAV) procedure or a prosthesis insertion procedure.

[0050] In various embodiments, a system and / or computer system is disclosed that includes a computer-readable storage medium having program instructions embodied therein and one or more processors configured to execute the program instructions that cause the one or more processors to perform operations including one or more aspects of the embodiments described above and / or below (including one or more aspects of the appended claims).

[0051] In various embodiments, computer-implemented methods are disclosed in which one or more aspects of the embodiments described above and / or below (including one or more aspects of the appended claims) are implemented and / or performed by one or more processors executing program instructions.

[0052] In various embodiments, a computer program product is disclosed that includes a computer-readable storage medium having program instructions embodied therein that are executable by one or more processors to cause the one or more processors to perform operations including one or more aspects of the embodiments described above and / or below (including one or more aspects of the appended claims).

[0053] These and other features, aspects, and advantages are described below with reference to the drawings, which are intended for illustrative purposes and should not be construed as limiting the scope of the embodiments in any way. Moreover, various features of different disclosed embodiments can be combined to form additional embodiments that are part of this disclosure. In the drawings, like reference characters indicate corresponding features consistently throughout like embodiments. Following is a brief description of each of the drawings. [Brief description of the drawings]

[0054] [Figure 1A] 1 is a schematic diagram of a pressure guidewire deployed within the heart. [Figure 1B] 1 is a schematic diagram of a pressure guidewire deployed within the heart. [Figure 1C] 1 is a schematic diagram of a pressure guidewire deployed within the heart. [Figure 1D] 1 is a schematic diagram of a pressure guidewire deployed within the heart. [Figure 1E] 1 is a schematic diagram of a pressure guidewire deployed within the heart. [Figure 1F] 1 is a schematic diagram of a pressure guidewire deployed within the heart. [Figure 2A] FIG. 1 is a schematic diagram of a system including a console and a guidewire adapted to facilitate delivery of a structural cardiac device. [Figure 2B] FIG. 2B is a plan view of a coiled distal tip of a pressure-sensing guidewire that can be incorporated into the system of FIG. 2A. [Figure 2C] FIG. 1 is a cross-sectional view showing a system including an aortic pigtail catheter and a guide catheter for a TAVR delivery system. [Figure 2D] FIG. 1 is a cross-sectional view of a system including a guide catheter for a TMVR delivery system. [Figure 2E] FIG. 13 is a diagram of another system including a console for facilitating delivery of a structural cardiac device. [Diagram 3] FIG. 2C is a schematic diagram of a variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 4] 2C is a cross-sectional view of another variation of the pressure sensing guidewire shown in FIG. 2B. [Diagram 5] 2C is a schematic diagram of another variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 6A] 2C is a cross-sectional view of another variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 6B] 2C is a cross-sectional view of yet another variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 6C] 2C is a cross-sectional view of yet another variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 7]2C is a schematic diagram of another variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 8] 2C is a schematic diagram of another variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 9] 2C is a cross-sectional view of another variation of the pressure sensing guidewire shown in FIG. 2B. [Figure 10A] FIG. 1 illustrates a user interface for the cardiac valve evaluation system. [Figure 10B] FIG. 1 illustrates a user interface for the cardiac valve evaluation system. [Figure 10C] FIG. 1 illustrates a user interface for the cardiac valve evaluation system. [Figure 10D] FIG. 1 illustrates a user interface for the cardiac valve evaluation system. [Figure 10E] FIG. 1 illustrates a user interface for the cardiac valve evaluation system. [Figure 11A] FIG. 13 illustrates an additional user interface for the cardiac valve evaluation system. [Figure 11B] FIG. 13 illustrates an additional user interface for the cardiac valve evaluation system. [Figure 11C] FIG. 13 illustrates an additional user interface for the cardiac valve evaluation system. [Figure 11D] FIG. 13 illustrates an additional user interface for the cardiac valve evaluation system. [Figure 11E] FIG. 13 illustrates an additional user interface for the cardiac valve evaluation system. [Figure 12] FIG. 1 illustrates a configuration user interface for the cardiac valve assessment system. [Figure 13] 1 is a flow chart of a user interface generation process. [Figure 14] FIG. 1 is a diagram of a heart valve assessment system. [Figure 15] 1 is a flow chart of a heart valve evaluation process. [Figure 16]1 is a flow chart of a calibration process. [Figure 17] FIG. 1 is an exemplary waveform analysis diagram. [Figure 18] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Figure 19] 1 is a flow chart of a calibration process. [Figure 20] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Figure 21] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Figure 22] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Diagram 23] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Figure 24] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Diagram 25] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Figure 26] 11A-11C are diagrams of additional example waveforms and / or example waveform analyses. [Figure 27] 11 is a flowchart of another calibration process. [Figure 28] 13 is a flow chart of an additional heart valve evaluation process. [Figure 29] FIG. 2 is another diagram of a heart valve evaluation system with which the various methods and systems described herein may be implemented. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] The present application is directed to systems and methods for providing pressure curves in cardiac procedures, including valvuloplasty procedures, transcatheter aortic valve replacement (TAVR) procedures, sometimes referred to as transcatheter aortic valve implantation (TAVI) procedures, transcatheter mitral valve replacement (TAMR) procedures, and other catheter-based procedures. These systems and methods may be used to assist cardiologists completing critical aspects of structural heart procedures. The embodiments herein may be used to communicate, by a user interface output, for example by a graphical display, the status of a heart valve before, during, and / or immediately after the deployment of a structural heart device, such as an aortic valve, mitral valve, or another heart valve. The embodiments herein may be used to communicate the status of a heart valve long after the deployment of such a device. The embodiments herein may be used to communicate the nature of blood flow through a heart valve before, during, and / or after (e.g., immediately after or long after) the deployment of a structural heart device, such as an aortic valve, mitral valve, or another heart valve. The embodiments described herein can simultaneously present graphs, physiological parameters, and / or values ​​indicative of heart valve status (such as gradients, regurgitant index, regurgitant ratio, etc.) for two recordings. For example, a first recording may be pre-procedure for a patient and a second recording may be post-procedure for the same patient. As another example, the first recording may be from a first portion of a procedure and the second recording may be from a second portion of the procedure. The new kind of display provides an intuitive and / or immediate sense of the patient's condition to simplify, expedite, and increase the success of the procedure. Further description of the user interface output is provided in Section III of this application.

[0056] The pressure measurements obtained from the systems and methods described herein can be used to calculate heart valve or blood flow indices, such as valve regurgitation index or pressure gradient across a biological heart valve, a previously placed replacement heart valve, or a currently implanted replacement heart valve. The valve regurgitation index and pressure gradient allow cardiologists to properly evaluate heart valves. During systole, a higher pressure gradient across the aortic valve (or a lower pressure in the aorta) may indicate more advanced valve calcification. A lower regurgitation index at the end of diastole may indicate more regurgitation. Further explanation of such calculations is provided in Sections III and IV of this application.

[0057] I. Exemplary Methods 1A-1F illustrate various methods of accessing the heart during structural heart procedures. One of the pressure guidewire 30 or pressure sensing device (e.g., pigtail catheter 10 or access catheter 20) may be used to calculate an upstream pressure curve (relative to flow), and the other of the pressure guidewire 30 or pressure sensing device may be used to calculate a downstream pressure curve (relative to flow). Although specific methods are described below with respect to specific heart valves and access approaches, similar systems may be used to evaluate other valves, such as the tricuspid valve or the pulmonary valve. Additionally, although specific examples may refer to a pressure sensing guidewire, pressure sensing device, or pigtail catheter, it should be understood that the device may be any elongated structure, such as a guidewire, pigtail catheter, diagnostic catheter, or guiding catheter, having similar structure and / or function.

[0058] FIG. 1A illustrates a system and method for measuring the performance of an existing or replacement aortic heart valve. The existing heart valve may be a biological but diseased valve or a previously implanted replacement heart valve that is to be evaluated in a subsequent procedure. As shown, a pigtail catheter 10 may be positioned downstream of the treatment site, for example in the aorta A downstream of the aortic valve, to provide a downstream pressure curve. The pigtail catheter 10 may also be used to deliver contrast to facilitate visualization of the treatment site. The access catheter 20 may be delivered to the heart from the same or a different access site as the pigtail catheter 10. The access catheter 20 or a separate delivery catheter exchanged for the access catheter 20 may be used to advance a pressure guidewire 30. The pressure guidewire 30 may be used to advance a valve expansion balloon, a replacement valve, and / or other devices to the treatment site. The pressure guidewire 30 may extend through the access catheter 20 to an upstream of the treatment site, for example, to a location within the left ventricle LV, to provide an upstream pressure curve. The pressure guidewire 30 may include a pressure sensor 40 at the transition to the intact curve or anywhere along the distal segment of the pressure guidewire 30 proximal to the intact curve, for example within the curved portion of the guidewire 30 (sometimes referred to herein as the intact curve) (see FIG. 2B). Prior to entering the heart, access is provided using an arterial approach, such as a femoral or radial approach. FIG. 1B illustrates a configuration similar to FIG. 1A, except that one or both of the pigtail catheter 10 and / or the access catheter 20 may be used to provide pressure readings using external pressure sensing capabilities. The catheter 20 may allow for measurement of downstream pressure, as well as pressures read by the pressure guidewire 30. This configuration may be used to level the external pressure sensor and the pressure guidewire. Alternatively, another delivery catheter, replaced with the access catheter, may be used to provide a downstream pressure curve. In some cases, the downstream pressure output may be received by a console that may be coupled with the pressure signals of either or both of the pigtail catheter 10 and the access catheter 20.

[0059] It may be important to equalize pressure readings between the downstream and upstream pressure sensing devices. Equalization may be done with respect to pressure accuracy (gain and offset), but also with respect to phase delay between the two pressure curves. For example, pressure readings may be obtained from downstream and upstream pressure sensing devices in the same general anatomical region, and the pressure measurements may be adjusted manually or automatically to match the phase delay between the two pressure curves. As shown in FIG. 1B, pressure measurements for equalization may be obtained from the left ventricle LV. In this approach, the downstream pressure output is provided by the access catheter 20, and the upstream pressure output is provided by the pressure guidewire 30. The sensing feature of the access catheter 20 (e.g., the distal end of the fluid column within the catheter 20) is advanced adjacent to the sensing feature of the pressure guidewire 30. The sensing features of the access catheter 20 and the pressure guidewire 30 may be confirmed to be placed within the left ventricle LV. The sensing features of the access catheter 20 and the pressure guidewire 30 may be confirmed to be in similar locations within the left ventricle LV.

[0060] 1C illustrates a configuration similar to FIG. 1A, except that the pressure sensor 40 is positioned proximal to the intact curve of the pressure guidewire 30. For example, the sensing feature of the pigtail catheter 10 (e.g., the distal end of the fluid column within the catheter 10) is advanced adjacent to the sensor 40 or other pressure sensing feature of the pressure guidewire 30. The sensing features of the pigtail catheter 10 and pressure guidewire 30 may be confirmed to be placed within the aorta A. In this configuration, pressure leveling may be performed within the aorta A. After pressure leveling, the pressure guidewire 30 is advanced into the left ventricle LV to provide an upstream pressure curve, while the pigtail catheter 10 remains in the aorta A to provide a downstream pressure curve.

[0061] In FIG. 1D, the pigtail catheter 10 may be positioned within the aorta A to provide a downstream pressure curve. The pressure guidewire 30 may extend through the pigtail catheter 10 in this embodiment to provide an upstream pressure curve. In this configuration, pressure equalization may be performed within the aorta A. For example, the sensing feature of the pressure guidewire 30 may be advanced to or just distal to the end of the fluid column within the pigtail catheter 10. The signals from the sensing feature of the pressure guidewire 30 and the signals from the fluid column may be compared, thereby equalizing the signals (as further described below in section IV). After pressure equalization, the pressure guidewire 30 may be removed from the aortic pigtail and inserted into the left ventricle via the access catheter 20, while the pigtail catheter 10 remains within the aorta A to provide a downstream pressure curve.

[0062] The system described herein may also be used to measure the performance of an existing or replacement mitral valve. For example, as shown in FIG. 1E, the access catheter 20 may be advanced through the venous vasculature, for example, through the inferior or superior vena cava VC, for example, from a femoral approach to the right atrium RA. The access catheter 20 may then be advanced through the atrial septum to a location in the left atrium LA. In some variations, the access catheter 20 may be configured to provide access through the patent foramen ovale, or to track a guidewire or device that provided such access. The access catheter 20, or a separate delivery catheter replaced with the access catheter 20, may be used to advance a valve expansion balloon, a replacement valve, and / or other devices to the treatment site. The pressure guidewire 30 may extend through the access catheter 20 to the left ventricle LV. The access catheter 20 may provide a pressure signal that may be used to generate an upstream pressure curve, and the pressure guidewire 30 provides a pressure signal that may be used to generate a downstream pressure curve. Alternatively, another delivery catheter replaced with the access catheter may be used to provide an upstream pressure curve.

[0063] A similar system may be used in an apical approach for aortic or mitral valve procedures. For example, as shown in FIG. 1F, an access catheter 20 may access the left ventricle LV through the apex P of the heart. A separate device (not shown) may be used to open a pathway through the apex P. The access catheter 20 may be advanced through such a device. The access catheter 20 or a separate delivery catheter exchanged with the access catheter 20 may be used to advance a valve expansion balloon, a replacement valve, and / or other devices to the treatment site. A pressure guidewire 30 may extend through the access catheter 20 to the aorta A in an aortic valve procedure. The access catheter 20 may provide a pressure signal that may be used to calculate an upstream pressure curve, and the pressure guidewire 30 provides a signal that may be used to calculate a downstream pressure curve. Alternatively, another delivery catheter exchanged with the access catheter may be used to provide an upstream pressure curve.

[0064] FIG. 1F illustrates evaluation or treatment of the aortic valve via the apex P of the heart, while the pressure guidewire 30 can be advanced through the mitral valve M such that its sensing feature is in the left atrium. In this manner, the pressure guidewire can provide a pressure signal that can be used to calculate the left atrial pressure curve (the proximal or upstream pressure curve from a flow perspective). The access catheter 20 can generate a pressure signal that can be used to calculate the left ventricular pressure curve (the distal or downstream pressure curve from a flow perspective).

[0065] In a valve expansion procedure, sometimes called a valvuloplasty or valve placement procedure, natural circulation through the heart valve may be blocked by a valvuloplasty balloon, a valve replacement delivery system, or other therapeutic device. However, when the heart is beating, pressure from the left ventricle LV or compression of the myocardium may push the therapeutic device back into the aorta A, making it difficult to properly position the therapeutic device. Rapidly pacing or defibrillating the left ventricle LV may reduce the pressure gradient between the aorta A and the left ventricle LV and may also reduce the force of the myocardium, allowing the clinician to complete the procedure. Conventional rapid pacing may involve introducing a temporary pacemaker into the heart, which usually requires another access point, for example a venous access point. The temporary pacemaker may also puncture the heart and cause other complications. Alternatively, a pressure guidewire 30 may be used to perform the rapid pacing. As explained above, the pressure guidewire 30 may be introduced through the same access point as the access catheter 20 or other delivery catheter, which reduces the total number of access points. As described in further detail below, current may be delivered to the proximal segment pressure guidewire and transmitted to the distal segment of the pressure guidewire via the connector tube and / or core wire. The access catheter 20 or other delivery catheter may insulate at least the intermediate segment of the rapid pacing pressure guidewire 30 from the patient to prevent current loss through the ventricular access. Alternatively, or in addition, the pressure guidewire 30 may include an insulation section to insulate the pressure guidewire 30. As shown in FIG. 2B, the distal segment of the pressure guidewire includes a curved section, which may allow current to flow to contact the ventricular wall at multiple locations.

[0066] II. Overview of Pressure Wire Systems and Their Use 2A illustrates a diagnostic system 200 that may be used within a patient's vasculature. Diagnostic system 200 is configured to determine whether the extent of valve damage is great enough to indicate that balloon dilation (e.g., valvuloplasty), valve replacement, or other catheter intervention should be performed.

[0067] The diagnostic system 200 can include a monitor assembly 204 configured to be coupled to a pressure guidewire 208. The diagnostic system 200 can include a connection (indicated by dashed line A) that facilitates connection and disconnection of the pressure guidewire 208 from the monitor assembly 204. Connection and disconnection to the monitor assembly 204 is useful in allowing a clinician to initially use the pressure guidewire 208 to assess the effects of heart valve damage. The pressure guidewire 208 can also be used to deliver a therapeutic device, such as a balloon catheter or a valve delivery system.

[0068] A fiber optic interface cable 202 may be used to couple a pressure guidewire 208 to the monitor assembly 204 with a handle 207. In some embodiments, the system 200 receives input from a tubular catheter body used to access the vasculature. For example, the access catheter 20 may be an access catheter. A pressure-sensing distal tip of or within the access catheter 20 may be positioned adjacent to the treatment site such that a pressure signal corresponding to pressure on a first side of the treatment site, e.g., within the aorta, may be obtained. This pressure measurement is sometimes referred to herein as Pa. In other configurations, the system 200 may include a pressure-sensing device, such as a pigtail catheter, delivered separately from the pressure guidewire to obtain Pa.

[0069] The pressure guidewire 208 can take any suitable form. For example, the pressure guidewire 208 can include a proximal segment having a proximal end positioned outside the patient and a distal end that can be advanced through the access catheter 20 and into the vasculature. The pressure guidewire 208 can be configured with flexibility to navigate a tortuous vasculature while maintaining structural integrity for pushability and torqueability. For example, at least the proximal section of the pressure guidewire 208 can be supported by a connector tube and / or core to preserve structural integrity, while the distal section of the pressure guidewire 208 can be formed to include an atraumatic curve 250, such as the coiled end shown in FIG. 2B, to enhance flexibility and prevent punctures. In other configurations, a curved distal section can be coupled to the pressure guidewire 208 to provide the atraumatic curve 250.

[0070] Any sensing modality may be used. For example, an optical sensor may be configured to sense pressure when exposed to blood. The optical sensor may be disposed within an interior space of the pressure guidewire 208 in fluid communication with the exterior of the pressure guidewire 208. The sensor may be an optical or electrical pressure sensor. The sensor may be selectively placed in communication with the monitor assembly 204 by a pressure wire lead disposed between the sensor and a proximal end of the pressure guidewire 208. The pressure wire lead may be an optical fiber or an electrical wire.

[0071] 2B, the pressure sensor may be positioned anywhere along the distal section of pressure guidewire 208. For example, the pressure sensor may be positioned near the most distal tip of the guidewire at location 206D, along the curved portion 250 of the guidewire at location 206C, at the transition to the curved portion 250 of the guidewire at location 206B, or proximal to the curved portion 250 of the guidewire at location 206A. For example, location 206C may be approximately 270 degrees around the curved portion 250 from the straight region of the pressure guidewire (around location 206A), and location 206D may be approximately 540 degrees around the curve from the straight region of the pressure guidewire. However, the pressure sensor may be positioned at any location within the curved distal region of the pressure guidewire, for example, within a range of about 0 degrees to about 90 degrees, within a range of about 90 degrees to about 180 degrees, within a range of about 180 degrees to about 270 degrees, within a range of about 270 degrees to about 360 degrees, within a range of about 360 degrees to about 450 degrees, or within a range of about 450 degrees to about 540 degrees from the straight region of the pressure guidewire.

[0072] When the distal section is curled, the pressure sensor may be positioned approximately 270 degrees along the curve 250 from the straight section of the pressure guidewire 208. The location of the pressure sensor in the distal section of the guidewire may affect the accuracy of the pressure measurement. For example, when the pressure sensor is at a more distal location 206C, 206D, the pressure sensor may be more centrally located within the ventricle, e.g., the left ventricle LV, and offset from the ventricular wall. Also, at a more distal location 206C, 206D, the pressure sensor is less likely to be obstructed by an access catheter or other delivery catheter during a valvuloplasty or heart replacement procedure. At a more proximal location 206A, 206B, the pressure measurement is closer to the heart valve, but it is possible to perform the leveling in the aorta A while maintaining the distal tip of the pressure guidewire 208 within the left ventricle LV. In some procedures, performing the leveling in the aorta A may require less manipulation of the pigtail catheter or other pressure sensing devices. For example, in an aortic valve procedure, the pigtail catheter is already in place in the aorta. The pressure sensor can be proximal to the curve 250, but distal enough to make pressure measurements distal to the heart valve. The distal tip of the pressure guidewire 208 is left in the left ventricle LV to maintain access to the left ventricle LV.

[0073] FIG. 2C illustrates a cross-section of a TAVR system in a patient's descending aorta, with anatomy removed for clarity. The TAVR system can also be used in conjunction with a monitor display 204. For example, a pressure guidewire 208 passes through other sheaths, such as an access catheter 210 and / or a delivery system 212. The same access catheter 210 can be used to advance a delivery system 212 over the pressure guidewire 208. The delivery system 212 can be used to advance a valve replacement or other therapeutic device. Other configurations are possible. For example, a catheter for the access catheter 210 can be exchanged for the delivery system 212 and then advanced over the pressure guidewire 208. As shown, the pressure sensing device used to provide a pressure signal for the pressure of blood in the aorta is an aortic pigtail catheter 214 delivered separately from the access catheter 210. See FIGS. 1A-1C for further details of the relative positions of the aortic pigtail catheter and the pressure guidewire. The access catheter 210 may be similar to the access catheter 20 that is advanced over the pressure guidewire 208 after the access catheter 20 is removed.

[0074] In other configurations, the access catheter 210 or delivery system 212 is used to obtain a pressure signal for the pressure of blood in the aorta and thus may be a pressure sensing device for aortic pressure. As shown in FIG. 2D, for a mitral valve replacement procedure, the access catheter 211 may be a pressure sensing device. A pressure guidewire 208 passes through the access catheter 211. The access catheter may be removed and exchanged for the delivery system 213 by advancing the delivery system 213 over the pressure guidewire 208. The delivery system 213 may be used to deliver a mitral valve or other replacement or treatment device.

[0075] Figure 2E illustrates a portion of another diagnostic system 251. Diagnostic system 251 of Figure 2E may be similar to diagnostic system 200 of Figure 2A. Diagnostic system 251 of Figure 2E may include a monitor assembly 254 configured to be coupled to pressure guidewire 208 (not shown). Monitor assembly 254 of Figure 2E may be similar to monitor assembly 204 of Figure 2A.

[0076] A wire-based pressure guidewire 3 and 4 illustrate different pressure guidewires 308, 408 that may be used in any of the methods described above. The numbers used to identify features of pressure guidewire 308 have been incremented by 100 to identify similar features of pressure guidewire 408. This numbering convention generally applies to the remainder of the figures. Any components of pressure guidewires 308, 408 are interchangeable.

[0077] In general, the pressure guidewire 308, 408 comprises an outer tube 310, 410 defining a lumen, a core wire 316, 416 extending at least partially through the lumen of the outer tube 310, 410, a pressure sensor assembly 318, 418 disposed within the lumen of the outer tube 310, 410, and / or a distal tip 432. The pressure guidewire 308 may also comprise a distal tip, which may be the same as or similar to the tip 432 or any of the other tips disclosed herein. The outer diameter of the pressure guidewire 308, 408 may be uniform or substantially uniform along substantially the entire length or working length of the pressure guidewire 308, 408. For example, the outer diameter of the pressure guidewire 308 may be uniform or substantially uniform along the distal tip 432 or the entire working length except for the intact curved portion 250. The pressure guidewire 308, 408 can include an outer diameter of up to 0.035 inches, for example between 0.018 inches and 0.035 inches. In some configurations, the distal portion of the pressure guidewire 308, 408 can form an intact curve 250, such as the coiled portion shown in FIG. 2B. In other configurations, the distal portion of the pressure guidewire 308, 408 can remain straight from at least the pressure sensor of the pressure sensor assembly to the distal tip of the pressure guidewire.

[0078] FIG. 3 is a schematic diagram of one variation of a pressure sensing guidewire 308. As illustrated, at least a distal portion of the outer tube 310 may be coiled. For example, the coil portion 312 may be a flat ribbon coil or a circular coil. The coil portion 312 may extend along a majority of the working length of the pressure guidewire 308, along substantially the entire working length of the pressure guidewire 308, or along the entire working length of the pressure guidewire 308. With a substantial length of the outer tube 310 being coiled, the coil portion 312 provides sufficient flexibility and softness to avoid trauma (e.g., puncture and / or dissection) during use. The coil portion 312 also provides increased safety in the event of distal tip failure. The coil portion 312 may also ensure electrical contact with the heart when performing rapid pacing.

[0079] 3, at least a proximal portion 328 of the core wire 316 may be concentric with the outer tube 310 and may extend through at least a portion of the lumen of the outer tube 310. For example, the core wire 316 may extend along a majority of the working length of the pressure guidewire 308, along substantially the entire working length of the pressure guidewire 308, or along the entire working length of the pressure guidewire 308. The core wire 316 provides the pressure guidewire 308 with sufficient stiffness to make it easy to push and to prevent kinking, and also provides sufficient stiffness to support the delivery catheter during valve implementation.

[0080] At least a portion of the core wire 316 may include a reduced diameter section 326 to provide space for the pressure sensor 322 within the extraluminal tube 310. For example, as shown in FIG. 3, the reduced diameter section 326 may be tapered toward the distal end of the pressure guidewire 308. The transition between the proximal section 328 and the reduced diameter section 326 of the core wire 316 may be positioned proximal to at least a portion or all of the intact curve 250 in the distal section of the pressure guidewire 308 (shown in FIG. 2B) to enhance the flexible transition to the intact curve 250 of the pressure guidewire 308. The core wire 316 continues to pass through at least a portion of the intact curve 250. This flexible transition acts as a force absorber and ensures that no kinks form in the proximal section of the intact curve 250 of the pressure guidewire 308. Kinking can complicate procedures such as advancing another catheter over the guidewire 308 or atraumatically removing the guidewire 308 from the patient.

[0081] The proximal portion 328 of core wire 316 may include an outer diameter of up to 0.03 inches, e.g., 0.015 to 0.03 inches. The smaller diameter portion 326 of core wire 316 may include an outer diameter that is less than one-third or less than one-quarter of the outer diameter of the proximal portion 328 of core wire 316. For example, the smaller diameter portion 326 of core wire 316 may include an outer diameter of less than 0.01 inches or less than 0.0075 inches.

[0082] The core wire 316 may include a conductive material, such as stainless steel, that provides a conductive path for electrical current applied to the guide wire 308 for rapid pacing techniques as described above. The proximal end of the core wire 316 may be exposed from the proximal end of the outer tube 310 for connection to the monitor display 204 and / or to a current generator. Less than ten percent, or less than five percent, of the length of the core wire 316 may be exposed from the proximal end of the outer tube 310 for connection to a current source for rapid pacing.

[0083] The pressure sensor assembly 318 may include a pressure sensor 322 and one or more pressure wire leads 320 extending from the pressure sensor 322. The pressure wire leads 320 may extend along the core wire 316. For example, the pressure sensor 322 may be an optical or electrical sensor, a membrane-based sensor, a MEMS sensor, or other device capable of generating a signal in response to a pressure level or variation. The one or more pressure wire leads 320 may be optical fibers or electrical wires. As shown in FIG. 3, the pressure sensor assembly 318 may also include a sensor housing 324 disposed over the pressure sensor 322 and positioned between the outer tube 310 and the core wire 316. The sensor housing 324 may include a ring or short tubular member or cylinder on which the membrane is supported. The sensor housing 324 may improve handling during assembly to the coil portion 312.

[0084] The pressure sensor assembly 318 may be disposed radially between the core wire 316 and the outer tube 310, with the pressure sensor 322 disposed radially between the reduced diameter portion 326 of the core wire 316 and the coil portion 312 of the outer tube 310. At least a portion of the pressure sensor assembly 318 may be off-axis with respect to the longitudinal axis L of the pressure guidewire 308. In some configurations, the entire pressure sensor assembly 318 may be off-axis with respect to the longitudinal axis L of the pressure guidewire 308.

[0085] The pressure sensor 322 may be exposed to blood or other fluids through a space or gap 314 in the coil portion 312. In other variations, the outer tube 310 may include a sensor housing section having one or more openings for exposing the pressure sensor 322 to blood or other fluids. The sensor housing section may be stiffer than the remainder of the coil portion 312. For example, the sensor housing section may be a metal tube that divides the coil portion 312 into two sections. The sensor housing section may be attached to a distal portion of a first coil section of the coil portion 312 and a proximal portion of a second coil section of the coil portion 312. As another example, the coil portion 312 may include two coils welded together to form a reinforcement section.

[0086] At least a portion of the pressure guidewire 308 may be covered by a lubricious insulator, e.g., a polymeric layer such as PTFE. The insulator may secure one or more pressure wire leads 320 in place. The insulator may electrically insulate the corewire 316 from the patient along its length when rapid pacing is induced through the corewire 316. The insulator may replace the need for a separate catheter to electrically insulate the pressure guidewire 308.

[0087] FIG. 4 illustrates another variation of the pressure guidewire 408. The pressure guidewire 408 can include any of the features described with respect to the pressure guidewire 308. In this variation, the distal portion of the outer tube 410 can be formed by the coil portion 412. The proximal portion of the outer tube 410 can be formed by the connector tube 430. The connector tube 430 can include a conductive material to facilitate rapid pacing. For example, the connector tube 430 can be formed using a metallic structure such as a stainless steel tube. The connector tube 430 is not covered with a coating or other insulation to enable rapid pacing. In some configurations, the current can alternatively or additionally flow through one or more pressure wire leads 420. The connector tube 430 can be directly or indirectly connected to the coil portion 412 and / or the distal tip 432. For example, the coil portions 412, 414 can be indirectly connected to the connector tube 430 by an insulating portion. The insulation portion may provide a length that is insulated from the patient, and thus in some embodiments may be the insulation portion 434. The insulation portion 434 may insulate the patient from the core wire 416. In some configurations, the insulation portion 434 may include a polymer layer, such as PTFE.

[0088] At least a non-small diameter portion of core wire 416 can be concentric with outer tube 410. Core wire 416 can pass through at least coil portion 412. Additionally, core wire 416 can pass through at least a portion of insulation portion 434 of outer tube 410 and / or connector tube 430. For example, a proximal end of core wire 416 can be sealed to a distal end of connector tube 430 using, for example, adhesive 436, and extend distally from the distal end of connector tube 430.

[0089] Core wire 416 may include any of the features of core wire 316. For example, a distal portion of core wire 416 may include a reduced diameter portion 426. A proximal end of coil portion 412 may be distal to the transition between non-reduced diameter portion 428 and reduced diameter portion 426 of core wire 416.

[0090] The pressure sensor assembly 418 may be disposed radially between the core wire 416 and the outer tube 410, with the pressure sensor 422 positioned radially between the reduced diameter portion 426 of the core wire 416 and the coil portion 412. At least a portion of the pressure sensor assembly 418 may be off-axis with respect to the longitudinal axis L of the pressure guidewire 408. For example, a first section 438a of at least one pressure wire lead 420 may be concentric with the outer tube 410 and a second section 438b of the pressure wire lead 420 may be off-axis with respect to the longitudinal axis of the outer tube 410. The outer tube 410 may include an opening 440 that allows the pressure wire lead 420 to transition from the first section 438a, which is concentric with the outer tube 410, to the second section 438b, which is off-axis with respect to the longitudinal axis of the outer tube 410. The opening 440 may be cut partially through the thickness or may extend through the entire thickness of the outer tube 410. If the opening 440 penetrates the entire thickness of the outer tube 410, the opening 440 may be sealed, for example with adhesive 436, to prevent blood or other fluids from entering the pressure guidewire through the opening 440. As shown in FIG. 4, the opening 440 is disposed in the connector tube 430. However, in other configurations, the opening 440 may be disposed in the insulator portion 434.

[0091] As an alternative to the opening 440, the core wire 416 may be sized or offset relative to the longitudinal axis of the pressure guidewire 408 to allow the pressure wire lead 420 to transition from a first section 438a, which is concentric with the outer tube 410, to a second section 438b, which is off-axis relative to the longitudinal axis of the outer tube 410. The core wire 416 may have a groove on one side configured to receive a length of the lead to allow the pressure wire lead 420 to transition from the first section 438a to the second section 438b.

[0092] Pressure guidewire 408 may include a distal tip 432 that is rounded to form an atraumatic tip. For example, distal tip 432 may have a hemispherical shape. Tip 432 may also reduce or even prevent unwanted foreign matter from entering through the distal end of pressure guidewire 408.

[0093] In some configurations, the distal tip 432 is a separate component that is glued, welded, and / or otherwise coupled to the coil portion 412 and / or the core wire 416. The distal tip may be coupled to the inner surface of the coil portion 412 and / or the distal-most edge of the coil portion 412. The core wire 416 may be bent up to 180 degrees within the outer tube 410 to strengthen the adhesive coupling to the distal tip 432. In other configurations, the distal tip 432 may be an enlarged distal end of the core wire 416 distal to the reduced diameter section 426. The distal end of the core wire 416 may be glued, welded, and / or otherwise coupled to the inner surface and / or the distal-most edge of the coil portion 412. In one method, the distal tip 432 is formed by transforming an enlarged segment of the core wire 416 into a hemispherical member. The enlarged segment may be melted to form the hemispherical member. The hemispherical member may be coupled to a distal portion of the coil portion 412. In any of these configurations, the intact portion of the distal tip 432 may be formed from the core wire 416, adhesives, and / or welds.

[0094] b. Tube-based pressure guidewire 5-9 illustrate further variations of pressure guidewires that may be used in any of the methods described above. The pressure guidewires described below may include any of the features of the pressure guidewires 308, 408 described above. In general, the pressure guidewires shown in FIGS. 5-9 include an outer tube defining a lumen, a connector tube positioned radially inward of the outer tube, a pressure sensor assembly disposed within the lumen of the outer tube, and / or a distal tip. The outer diameter of the pressure guidewire may be uniform or substantially uniform along substantially the entire length or working length of the pressure guidewire. For example, the outer diameter of the pressure guidewire may be uniform or substantially uniform along the entire working length, except for the distal tip or the cut curve. The pressure guidewire may include an outer diameter of up to 0.035 inches, for example between 0.018 inches and 0.035 inches. In some configurations, the distal portion of the pressure guidewire may be formed to an intact curve 250 as shown in FIG. 2B. In other configurations, the distal portion of the pressure guidewire may remain straight.

[0095] The connector tube may have an inner diameter less than one-third or less than one-quarter of the outer diameter of the connector tube. For example, the connector tube may have an outer diameter of up to 0.035 inches, e.g., between 0.018 inches and 0.035 inches, and an inner diameter less than 0.01 inches, e.g., less than 0.007 inches. The connector tube may have a uniform outer diameter (see FIG. 5) or a non-uniform diameter (see FIG. 6A). In a non-uniform configuration, the small diameter portion of the connector tube may have an outer diameter of about 0.033 inches or less. The connector tube may extend along a majority or substantially the entire working length of the pressure guidewire. For example, the connector tube may extend at least 80 percent, or at least 90 percent, of the working length of the pressure guidewire.

[0096] The connector tube may be made of a conductive metal. For example, the connector tube may be a stainless steel tube. A proximal end of the connector tube may be exposed from the proximal end of the outer tube for connection to a monitor display and / or connection to a current generator. Thus, at least the proximal end of the connector tube may be uncoated.

[0097] The pressure guidewire may also include a core wire distal to the connector tube. In venous or transapical aortic applications, the section with the core wire may be disposed in the bloodstream downstream of the section with the connector tube. In arterial or transapical mitral applications, the section with the core wire may be disposed in the bloodstream upstream of the section with the connector tube. The core wire may include an outer diameter of up to 0.03 inches, e.g., between 0.018 inches and 0.03 inches. The small diameter section of the core wire may include an outer diameter that is less than one-third or less than one-quarter of the outer diameter of the remainder of the core wire. For example, the small diameter section of the core wire may include an outer diameter of less than 0.01 inches or less than 0.0075 inches. The core wire may extend along only the distal portion of the pressure guidewire, e.g., less than 20 percent, less than 10 percent, or less than 5 percent of the working length of the pressure guidewire.

[0098] FIG. 5 is a schematic diagram of another variation of the pressure sensing guidewire 508. As illustrated, at least a distal portion of the outer tube 510 may be coiled. For example, the coiled portion may be a flat ribbon coil or a circular coil. As shown in FIG. 5, the coiled portion may include two coiled sections 512a, 512b separated from each other by a sensor housing 542. In some embodiments, there may be a plastic layer in place of the coiled portion 512b. The plastic layer may be made of or include polytetrafluoroethylene (PTFE) or an elastomer. Additional details regarding the plastic layer are described below with respect to FIG. 9. Taken together, the coiled portions 512a, 512b may extend along a majority of the working length of the pressure guidewire 508 or along substantially the entire working length of the pressure guidewire 508. For example, taken together, the coiled portions 512a, 512b may extend at least 80 percent, or at least 90 percent, of the working length of the pressure guidewire 508. With a substantial length of the outer tube 510 being coiled, the coil portions 512a, 512b provide sufficient flexibility to navigate tortuous vasculature. The distal coil portion 512a also provides increased safety in the event of failure along the coiled portion, e.g., distal tip failure. When used for rapid pacing, the distal coil portion 512a may also ensure electrical contact with the inner wall of the patient's heart, e.g., the inner wall of the left ventricle.

[0099] As shown in FIG. 5, at least a proximal portion 528 of the core wire 516 may be concentric with the outer tube 510 and may extend through at least a portion of the lumen of the outer tube 510. The diameter of the proximal portion 528 of the core wire 516 may be the same as the outermost diameter of the connector tube 530. At least a portion of the core wire 516 may include a reduced diameter portion 526, such as a tapered portion that tapers toward the distal end of the pressure guidewire 508. The transition between the proximal portion 528 and the reduced diameter portion 526 of the core wire 516 may be positioned proximal to the intact curve 250 within the distal section of the pressure guidewire 508 to enhance the flexibility transition to the intact curve 250 of the pressure guidewire 508. This flexible transition acts as a force absorber and ensures that no kinks form in the proximal section of the intact curve 250 of the pressure guidewire 508. Kinking can complicate procedures such as advancing another catheter over the guidewire 508 or atraumatically removing the guidewire 308 from the patient. The corewire 516 can include a conductive material such as stainless steel to provide rapid pacing as described above.

[0100] The pressure sensor assembly 508 may include a pressure sensor 522 and one or more pressure wire leads 520 extending from the pressure sensor 522. For example, the pressure sensor 522 may be an optical or electrical sensor, a membrane-based sensor, or some other device. The pressure wire leads 520 may be optical fibers or electrical wires. The pressure wire leads 520 may pass through a lumen of a connector tube 530. The connector tube 530 positions the pressure wire leads 520 along a central longitudinal axis L of the pressure guidewire 508. The pressure wire leads 520 may be secured to, and in some cases sealed to, the connector tube 530, for example, using an adhesive. In some cases, the adhesive provides a seal that prevents fluid from flowing proximally through the connector tube 530. An adhesive may also be used at the proximal end of the connector tube 530 to concentrically secure the optical fiber 520 to the connector tube 530.

[0101] 5, the pressure sensor 522 may be disposed within a pressure sensor housing 542 of the outer tube 510. The sensor housing 542 protects the pressure sensor 522 but also provides a connection between the coil portions 512a, 512b. The pressure sensor 522 may be exposed to blood or other fluids through at least one opening 544 in the sensor housing 542. As illustrated, the sensor housing 542 may be a metal tube that connects the two coil portions 512a, 512b, but in other variations, the sensor housing 542 may be formed by welding multiple coils together to form a weld that connects the coil portions 512a, 512b.

[0102] The sensor housing 542 and pressure sensor 522 may be positioned proximal to the intact curve 250 shown in Figure 2B, for example at location 206A. However, as described above, the pressure sensor may be positioned anywhere along the curve 250 of the distal section of the pressure guidewire 508.

[0103] At least a portion of the pressure guidewire 508 may be covered by a lubricious insulator, e.g., a polymeric layer such as PTFE. The insulator may electrically insulate a portion of the pressure guidewire 508 when rapid pacing is induced through the connector tube 530 and / or the corewire 516. The insulator may replace a separate catheter body that would be required to electrically insulate the pressure guidewire 508.

[0104] 6A is a cross-sectional view of another variation of a pressure sensing guidewire 608. The pressure sensing guidewire 608 may include a pressure sensor 622 and one or more pressure wire leads 620 extending from the pressure sensor 622. The diameter of the proximal portion 628 of the core wire 616 may be the same as the outermost diameter of the connector tube 630. The pressure sensor 622 may be disposed within a pressure sensor housing 642 of the outer tube 610. The sensor housing 642 may protect the pressure sensor 622. The sensor housing 642 may also provide a connection between the coil portions 612a, 612b. The pressure sensor 622 may be exposed to blood or other fluids through at least one opening 644 in the sensor housing 642. As illustrated, the sensor housing 642 may be a metal tube connecting the two coil portions 612a, 612b. In other embodiments, the sensor housing 642 may be formed by welding multiple coils together to form a weld connecting the coil portions 612a, 612b.

[0105] Pressure sensing guidewire 608 is similar to pressure sensing guidewire 508, except as described differently below. The disclosure associated with FIG. 6A may be considered supplemental to the disclosure of FIG. 5. Pressure sensing guidewire 608 includes distal tip 632. Distal tip 632 is similar to distal tip 432, except as described differently below. Distal tip 632 provides atraumatic interaction with blood vessels, valves, and heart wall chambers. Tip 632 may also reduce or prevent the ingress of foreign objects, e.g., components or fluids, through the distal end of pressure guidewire 608. Distal tip 632 may have a hemispherical shape.

[0106] In some configurations, distal tip 632 is a separate component that is glued, welded, and / or otherwise coupled to coil portion 612a and / or core wire 616. Distal tip 632 may be coupled to the inner surface and / or distal-most edge of coil portion 612a. Core wire 616 may be bent up to 180 degrees within outer tube 610 to enhance adhesive coupling to distal tip 632, as described in more detail below with respect to FIG. 6C. In other configurations, distal tip 632 may be an enlarged distal end of core wire 616 distal to reduced diameter section 626. The distal end of core wire 616 may be glued, welded, and / or otherwise coupled to the inner surface and / or distal-most edge of coil portion 612a. In any of these configurations, the intact portion of the distal tip 632 may be formed from the core wire 616, such as by melting or otherwise reshaping an enlarged segment of the core wire 616 to create the desired shape.

[0107] Figure 6B is a cross-sectional view of yet another variation of pressure sensing guidewire 608'. Pressure sensing guidewire 608' may be similar to pressure sensing guidewire 608, except that Figure 6B includes insulation portion 634 instead of coil portion 612b. Insulation portion 634 may include a polymer layer, such as PTFE.

[0108] FIG. 6C is a cross-sectional view of yet another variation of pressure sensing guidewire 608″. Pressure sensing guidewire 608″ can include any of the features of pressure sensing guidewire 608 or 608′. In FIG. 6C, the distal end of corewire 616″ can include a bent configuration to enhance the adhesive connection with distal tip 632″. For example, the distal end of corewire 616″ can be bent up to 180 degrees relative to the remainder of corewire 616″, thereby forming a U-shaped distal end.

[0109] FIG. 7 is a schematic diagram of another variation of a pressure sensing guidewire 708. The pressure sensing guidewire 708 may include a pressure sensor 722 and one or more pressure wire leads 720 extending from the pressure sensor 722. The core wire 716 may have a proximal portion 728. At least a portion of the core wire 716 may include a reduced diameter portion 726, such as a tapered portion that tapers toward the distal end of the pressure guidewire 708. The pressure sensor 722 may be disposed within a pressure sensor housing 742 of the outer tube 710. The sensor housing 742 may protect the pressure sensor 722. The sensor housing 742 may also provide a connection between the coil portions 712a, 712b. The pressure sensor 722 may be exposed to blood or other fluids through at least one opening 744 in the sensor housing 742. As illustrated, the sensor housing 742 may be a metal tube connecting the two coil portions 712a, 712b. In other embodiments, the sensor housing 742 may be formed by welding multiple coils together to form a weld connecting the coil portions 712a, 712b.

[0110] The pressure sensing guidewire 708 is similar to the pressure sensing guidewire 508, except that the sensor housing 742 and pressure sensor 722 may be positioned more distally within the distal curve 250 of the pressure guidewire 708, for example at locations 206B or 206C shown in FIG. 2B. However, as explained above, it may be beneficial to reduce the diameter of the inner core wire to increase flexibility at the transition to the distal curve 250. Thus, the sensor housing 742 and pressure sensor 722 may be positioned within the region where the connector tube 730 and / or core wire 716 transition to a smaller diameter. For example, as shown in FIG. 7, the connector tube 730 may have a reduced diameter section 746 at the distal end of the connector tube 730. The connector tube 730 may taper to the reduced diameter section 746 at a tapered portion 754. The diameter of the proximal end of the core wire 716, for example at its distal end or region, may be smaller than the outermost diameter of the connector tube 730. In this configuration, the outer diameter of the sensor housing 742 may also be reduced as compared to the sensor housing 542.

[0111] FIG. 8 is a schematic diagram of another variation of a pressure sensing guidewire 808. Corewire 816 may have a proximal portion 828. Connector tube 830 may have a reduced diameter section 846 at a distal end of connector tube 830. Pressure sensing guidewire 808 is similar to pressure sensing guidewire 708, except that sensor housing 842 and pressure sensor 822 may be positioned more distally within distal curve 250 of pressure guidewire 808, for example at location 206D shown in FIG. 2B. However, as explained above, it may be beneficial to reduce the diameter of the inner core wire to increase flexibility at the transition to distal curve 250. Thus, in the region of location 206D of distal curve 250, reduced diameter portion 826 of corewire 816 may have a sufficiently reduced diameter to allow positioning of sensor 822 radially between distal coil portion 812a and reduced diameter portion 826 of corewire 816. As shown in FIG. 8, the sensor 822 may have a separate sensor housing 842 positioned around the sensor 822 .

[0112] Instead of a sensor housing along the outer tube 810, the pressure guidewire 808 includes a connector 848 extending between the coil portions 812a, 812b. The connector 848 may include an opening 852 that allows at least one pressure wire lead 820 to transition from a first section 838a, concentric with the outer tube 810 and within the connector tube 830, to a second section 838b that is off-axis with respect to the longitudinal axis L of the outer tube 810. The opening 852 may be cut partially through the thickness or may extend through the entire thickness of the outer tube 810. If the opening 852 extends through the entire thickness of the outer tube 810, the opening 852 may be sealed, for example with an adhesive, to prevent fluid from entering the pressure guidewire through the opening 852.

[0113] FIG. 9 is a cross-sectional view of another variation of a pressure sensing guidewire 908. The pressure guidewire 908 can include a connector 948 extending between the insulation portion 934 and the coil portion 912a. The connector 948 can include an opening 952 that allows at least one pressure wire lead 920 to transition from a first section 938a, concentric with the outer tube 910 and within the connector tube 930, to a second section 938b. The opening 952 can be partially cut out or extend through the entire thickness of the outer tube 810. If the opening 952 extends through the entire thickness of the outer tube 810, the opening 952 can be sealed, for example with an adhesive, to prevent fluid from entering the pressure guidewire through the opening 952. The corewire 916 can have a proximal portion 928, a reduced diameter portion 926, and a distal portion 922. The pressure sensing guidewire 908 can include a pressure sensor. Pressure sensing guidewire 908 is similar to pressure sensing guidewire 808. Figure 9 includes a distal tip 932. Distal tip 932 may include any of the features of distal tip 632 shown in Figures 6A-6C.

[0114] The outer tube 910 comprises an insulator portion 934 and a coil portion 912a coupled by a connector 948. The insulator portion 934 surrounds at least a portion of the connector tube 930. The insulator portion 934 may comprise a polymer layer, such as PTFE, to electrically insulate the connector tube 930 from the patient during rapid pacing. A proximal end 956 of the connector tube 930 may be exposed from the proximal end of the insulator portion 934 for connection to a monitor display and / or connection to a current generator. Thus, at least the proximal end of the connector tube 930 may be uncoated.

[0115] As illustrated, the connector 948 may be a metal tube connecting the insulator portion 934 and the coil portion 912a, but in other variations, the connector 948 may be a welded portion connecting the insulator portion 934 and the coil portion 912a.

[0116] One or more pressure wire leads 920 may be sealed to the lumen of the connector tube 930 using, for example, an adhesive, to prevent fluid from flowing proximally and to ensure concentricity of the optical fiber for signal transmission.

[0117] The pressure sensor may be exposed to blood or other fluids through a space or gap in the coil portion 912a. The outer tube 910 may also include a sensor housing section 924. The sensor housing section may be stiffer than the remainder of the coil portion 912a. For example, the sensor housing section 924 may be a metal tube that divides the coil portion 912a into two sections. The sensor housing section 924 may be attached to a distal portion of a first coil section of the coil portion 912a and a proximal portion of a second coil section of the coil portion 912a. The sensor housing section 924 may include one or more openings for exposing the pressure sensor to blood or other fluids. As another example, the coil portion 912a may include two coils welded together to form a reinforcement section that serves as the sensor housing section 924.

[0118] III. Heart Valve Evaluation User Interface System Existing user interfaces may be unable or lack the ability to indicate the status of a heart valve before, during, and / or immediately after deployment of a structural heart device. During a structural heart procedure, existing user interfaces may be unable to provide one or more pressure curves or indicators of heart valve status, such as a valve regurgitation index or pressure gradient. Furthermore, existing user interfaces for structural heart procedures may have limited user interaction capabilities, such as lacking options that allow a user to customize one or more user interfaces. Existing patient monitors and / or displays may have limited display space for presenting indicators, such as values ​​indicative of heart valve status, diagnoses, physiological parameters, or other data.

[0119] Thus, the user interface of the heart valve evaluation system disclosed herein may be an improvement over existing user interfaces. During a structural heart procedure, one or more indicators of heart valve status may be provided to a clinician via a user interface. The user interface may be organized to provide information in an efficient manner. A particular graphical representation or indicator may be presented or selected by the user that allows the clinician to quickly assess a heart valve status or problem. The systems and techniques described herein may enable a clinician to access data, perform analysis, and / or interact with one or more user interfaces faster (such as by reducing the number of clicks or selections by the user) than with existing graphical user interface systems. The user interfaces described herein may improve existing user interfaces by allowing more efficient use of limited display space on a small monitor or display. For example, visual indicators, graphical representations, and / or combinations thereof may provide a user with information related to heart valve status in an efficient manner configured for a monitor or display with limited space. Thus, the systems and techniques described herein may improve conventional user interfaces.

[0120] As used herein, in addition to its ordinary meaning, "cardiovascular region" refers broadly to any region involving or around the heart, such as the left or right ventricle, the aorta, the left or right atrium, the vena cava, and / or blood flow passageways adjacent to portions of the heart (blood flow chambers, blood vessels, pulmonary arteries, etc.).

[0121] The heart valve assessment system described herein can advantageously provide an indicator of heart valve status, such as a pressure gradient or a valve regurgitation index. As used herein, in addition to its ordinary meaning, a "pressure gradient" or "gradient" can refer to the severity or measurement of valve narrowing (or stenosis) due to an increase in pressure behind the valve. Exemplary gradients are provided herein, such as a peak-to-peak gradient, an area gradient, or an instantaneous gradient. A peak-to-peak gradient can indicate a pressure difference between a maximum or regional systolic pressure of a first cardiovascular region (such as the left ventricle LV) and a second cardiovascular region (such as the aorta Ao). An area gradient can indicate an area between two graphs, such as pressure curves. An instantaneous gradient can indicate a maximum or regional pressure between a first cardiovascular region and a second cardiovascular region in a cardiac cycle. As used herein, in addition to its ordinary meaning, a "valve regurgitation index," "regurgitation index," or "regurgitation" can refer to a valve leakage measurement. The regurgitation calculation may include a pressure difference at the end of the diastolic cycle divided by the systolic pressure or normalized value. The aortic regurgitation calculation may correspond to the following equation: Aortic Regurgitation Index = (Aortic Diastolic Pressure - Left Ventricular End Diastolic Pressure) / Aortic Systolic Pressure. The systems, techniques, and / or graphical user interfaces described herein may provide clinicians with additional data on which to base treatment / surgical decisions. For example, values ​​indicative of heart valve status and / or related user interfaces may provide additional information for clinicians to treat valve disease, modify replacement valves during treatment, and / or make recommendations after valve treatment.

[0122] Regurgitation can occur when blood leaks and flows backwards through a valve. Regurgitation can be caused by valve disease or, in the case of prosthetic valve replacement, by misplacement of the replacement valve relative to the native valve.

[0123] a. Exemplary User Interface 10A-10E, 11A-11C, and 12 depict exemplary heart valve evaluation user interfaces. The heart valve evaluation system may be the same as, similar to, or include similar components as the diagnostic system 200 described above in FIG. 2A. For convenience, the user interfaces are described as being presented by the diagnostic system 200 of FIG. 2A, including the monitor 204, although other computing systems may present user interfaces as well. These user interfaces may be presented by the monitor 204 described above, for example, using data received from the pressure guidewire 208, the pressure sensing access catheter 20, or the pressure sensing pigtail catheter 10. Thus, each of the illustrated user interfaces may be output for presentation by electronic hardware as a graphical user interface.

[0124] Each of the illustrated user interfaces includes one or more user interface elements or controls that may be selected by a user. The user interfaces may enable receipt of user input. The illustrated user interface elements are merely illustrative examples and may differ in other embodiments. For example, aspects of the user interfaces may be rearranged and / or configured from those shown and described below, and / or certain aspects may or may not be included. Additionally, the illustrated user interfaces may be combined or divided with other user interfaces such that similar or the same functionality may be provided. The user interfaces of FIGS. 10A-10E, for example, user interfaces 1000, 1020, 1040, 1060, and / or 1080, may have similar user interface elements and / or functions. Additionally, each of the user interface elements may be selected by a user using one or more input options, such as a mouse, a touch screen input (e.g., finger or pen), or a keyboard input, among other user interface input options.

[0125] 10A-10E depict exemplary user interfaces that may be presented by the monitor 204 of the system 200 described above and / or the system 1400 described herein. In FIG. 10A, the user interface 1000 may be presented before, during, and / or immediately after the performance of a cardiac procedure. The user interface 1000 may include one or more graphs 1002, 1004, 1006, 1008 and one or more physiological parameters 1010, 1012. The exemplary graphs 1002, 1004, 1006, 1008 may include or be pressure waves. The graphs 1002, 1004, 1006, 1008 may represent pressure values ​​corresponding to measurements from cardiovascular regions. The pressure values ​​may include a series of pressure numbers that change over time. The cardiovascular region may include a portion of the heart (such as the left ventricle LV, the right ventricle RV, or the mitral valve) and / or a blood flow passageway adjacent to the portion of the heart (such as the aorta Ao, the vena cava, or the pulmonary artery). One or more graphs 1002, 1004, 1006, 1008 and / or one or more physiological parameters 1010, 1012 may be updated in near real-time or real-time as pressure measurements are taken from the patient.

[0126] As shown, the user interface 1000 can include a first graph 1002 for a first cardiovascular region, such as the aorta Ao, and a second graph 1006 for a second cardiovascular region, such as the left ventricle LV. The additional graphs 1004, 1008 can correspond to statistical measures of pressure values ​​from the cardiovascular regions, such as mean or average pressure values ​​for the aorta Ao or the left ventricle LV. The statistical measures can be based on configuration parameters that can be user selected indicating a statistical measure period, such as heart rate or a time period for which the statistical measures are calculated. In some embodiments, one or more of the graphs 1002, 1004, 1006, 1008 can have an indicator that indicates the corresponding cardiovascular region for the graph (e.g., the aorta Ao graphs 1002, 1004 can be color coded red and the left ventricle LV graphs 1006, 1008 can be color coded blue).

[0127] As shown, the user interface 1000 can include a first physiological parameter 1010 for a first cardiovascular region, such as the aorta Ao, and a second physiological parameter 1012 for a second cardiovascular region, such as the left ventricle LV. The physiological parameters 1010, 1012 can include a statistical measure for blood pressure, such as systolic blood pressure, diastolic blood pressure, and / or an average or mean systolic or diastolic blood pressure or a combination thereof for a particular cardiovascular region. The statistical measure physiological parameter can correspond to additional graphs 1004, 1008.

[0128] The user interface 1000 may include one or more user interface options, such as a record option 1014. A clinician may select the record option 1014 to record blood pressure values, other measurements, and / or other values ​​associated with a procedure. The clinician may then play back the recorded data. In some embodiments, during the playback mode, values ​​indicative of a heart valve condition, such as, but not limited to, a gradient or regurgitation index, may be presented to the user.

[0129] 10B, another user interface 1020 is depicted. The additional user interface 1020 may be similar to the user interface 1000 of FIG. 10A. However, the additional user interface 1020 may include a stop recording option 1022 that may allow the user to stop recording the patient data. In some embodiments, once stopped, the user may enter a playback mode to display values ​​indicative of the heart valve status, such as, but not limited to, gradient or regurgitation index.

[0130] 10C, yet another user interface 1040 is depicted. The additional user interface 1040 may be similar to the user interface 1000 of FIG. 10A. The additional user interface 1040 may include a first graph 1002 and a second graph 1006 similar to the first and second graphs of FIG. 10A. However, the additional user interface 1040 may present one or more gradient representations 1042a, 1042b, 1042c that visually present a gradient measurement between a first peak in the first graph 1002 and a second peak in the second graph 1006. The one or more gradient representations 1042a, 1042b, 1042c may correspond to a gradient type, such as a peak-to-peak gradient type.

[0131] The user interface 1040 may include a first numeric value 1046 corresponding to a gradient type, such as a peak-to-peak gradient type. The first numeric value 1046 may correspond to a pressure difference between a maximum or regional systolic pressure of a first cardiovascular region (such as the left ventricle LV) and a second cardiovascular region (such as the aorta Ao). In some embodiments, the first numeric value 1046 may include a statistical measure, such as an average or mean pressure difference between the maximum or regional systolic pressures, for multiple cardiac cycles. As shown, the first numeric value 1046 (here 28) may be a statistical measure of peak-to-peak measurements for multiple cardiac cycles corresponding to three graphical peak-to-peak measurements 1042a, 1042b, 1042c.

[0132] The user interface 1040 can present one or more reflux representations 1044a, 1044b, 1044c. As shown, the one or more reflux representations 1044a, 1044b, 1044c can visually present a reflux measurement between a first point in the first graph 1002 and a second point in the second graph 1006. The one or more reflux representations 1044a, 1044b, 1044c can correspond to a calculation of the difference in pressure at the end of the diastolic cycle (here, aortic Ao end-diastolic pressure minus left ventricular LV end-diastolic pressure) divided by the systolic pressure (here, aortic systolic pressure) or in normalized values.

[0133] The user interface 1040 can include a second number 1048 corresponding to a regurgitant index. The second number 1048 can correspond to a pressure difference at the end of the diastolic cycle divided by the systolic pressure or a normalized value. In some embodiments, the second number 1048 can include a statistical measure such as an average regurgitant or mean regurgitant over multiple cardiac cycles. As shown, the second number 1048 (here 22) can be a statistical measure of the regurgitant calculations over multiple cardiac cycles corresponding to three regurgitant representations 1044a, 1044b, 1044c.

[0134] The user interface 1040 may include an electrocardiogram 1050. The electrocardiogram 1050 may be disabled or enabled by the user. Thus, the electrocardiogram 1050 may be removed or omitted from the user interface 1040. Although not shown, in some embodiments, if the electrocardiogram 1050 is removed or omitted, the pressure graph display 1051 may increase in size within the user interface 1040.

[0135] The user interface 1040 may include a playback control 1052 and a gradient type selector 1056. As shown, the playback control 1052 may present a time (here 0:01:18) and a current playback position 1054. In some embodiments, a user may interactively manipulate the playback control 1052 to advance or rewind the playback of one or more graphs and corresponding indicators of heart valve status. A user may change the gradient type of the user interface 1040 by selecting the gradient type selector 1056, which may cause an updated user interface to be presented in place of the current user interface 1040.

[0136] 10D, yet another user interface 1060 is depicted. The additional user interface 1060 may be similar to the user interface 1040 of FIG. 10C. The additional user interface 1040 may include a first graph 1002 and a second graph 1006 similar to the first and second graphs of FIG. 10C in addition to other similar user interface elements. However, the additional user interface 1060 may present one or more gradient representations 1062a, 1062b, 1062c that visually present a gradient measurement between a first point in the first graph 1002 and a second point in the second graph 1006. The one or more gradient representations 1062a, 1062b, 1062c of the additional user interface 1060 may be presented in response to a user selection, such as a user selection of the gradient type selector 1056 of FIG. 10C.

[0137] One or more of the gradient representations 1062a, 1062b, 1062c may correspond to a gradient type, such as an instantaneous gradient type. The instantaneous gradient representations 1062a, 1062b, 1062c may indicate a maximum or regional pressure difference between a first cardiovascular region and a second cardiovascular region in a cardiac cycle. The user interface 1060 may include a numerical value 1064 (here, 64) corresponding to a gradient type, such as an instantaneous gradient type. The numerical value 1064 may indicate a maximum or regional pressure difference between a first cardiovascular region (such as the left ventricle LV) and a second cardiovascular region (such as the aorta Ao) in a cardiac cycle. In some embodiments, the numerical value 1064 may include a statistical measure, such as an average or mean maximum or regional pressure difference over multiple cardiac cycles. As illustrated, the numerical value 1064 may be a statistical measure of an instantaneous gradient measurement over multiple cardiac beats corresponding to the three graphical instantaneous measurements 1062a, 1062b, 1062c.

[0138] 10E, yet another user interface 1080 is depicted. The additional user interface 1080 may be similar to the user interface 1040 of FIG. 10C. The additional user interface 1080 may include a first graph 1002 and a second graph 1006 similar to the first and second graphs of FIG. 10C in addition to other similar user interface elements. However, the additional user interface 1080 may present one or more gradient representations 1082a, 1082b, 1082c that visually present the area between the first graph 1002 and the second graph 1006. The one or more gradient representations 1082a, 1082b, 1082c of the additional user interface 1060 may be presented in response to a user selection, such as one or more user selections of the gradient type selector 1056 of FIG. 10C.

[0139] The one or more gradient representations 1082a, 1082b, 1082c may correspond to a gradient type, such as an area gradient type. The area gradient representations 1082a, 1082b, 1082c may indicate a pressure difference between a first cardiovascular region and a second cardiovascular region. The user interface 1080 may include a numerical value 1084 (here, 56) corresponding to a gradient type, such as an area gradient type. The numerical value 1084 may indicate an area between two graphs corresponding to a first cardiovascular region (such as the left ventricle LV) and a second cardiovascular region (such as the aorta Ao). In some embodiments, the numerical value 1084 may include a statistical measure, such as an average area or mean area between two graphs or pressure curves for multiple cardiac cycles. As illustrated, the numerical value 1084 may be a statistical measure of area gradient measurements for multiple cardiac beats corresponding to the three graphical instantaneous measurements 1082a, 1082b, 1082c.

[0140] 11A-11C depict additional exemplary user interfaces that may be presented by the monitor 204 of the system 200 described above and / or the system 1400 described herein. The user interfaces 1100, 1120, 1140 of FIGS. 11A, 11B, 11C may be similar to the user interfaces 1040, 1060, 1080 of FIGS. 10C, 10D, 10E, respectively. In particular, the user interfaces 1100, 1120, 1140 of FIGS. 11A, 11B, 11C may present alternative gradient representations to the gradient representations of the user interfaces 1040, 1060, 1080 of FIGS. 10C, 10D, 10E, respectively. Additionally, user interfaces 1100, 1120, 1140 of FIGS. 11A, 11B, and 11C may depict user interfaces presenting values ​​indicative of heart valve status for the mitral valve.

[0141] In Fig. 11A, the user interface 1100 may include a gradient representation 1102. The gradient representation 1102 may be for a peak-to-peak gradient type that may be similar to the peak-to-peak gradient type of Fig. 10C. However, instead of a measurement visualization between two peaks, the gradient representation 1102 may depict one or more pressure values ​​corresponding to the peak-to-peak gradient in graphical form. An advantage of the gradient representation 1102 of Fig. 11A is that it may allow a clinician to quickly see relative peak-to-peak pressure changes over time, which may include past and current measurements.

[0142] The regurgitation representation 1104 of Figure 11A may be similar to the regurgitation representations 1044a, 1044b, 1044c of Figure 10C. However, like the gradient representation 1102, the regurgitation representation 1104 may depict one or more pressure values ​​corresponding to valve regurgitation in a graphical format instead of a point-to-point measurement visualization.

[0143] 11B, the user interface 1120 can include another slope representation 1112. The slope representation 1112 can be for an instantaneous slope type, which can be similar to the instantaneous slope type of FIG. 10D. However, instead of a measurement visualization between two points, the slope representation 1112 can depict one or more pressure values ​​corresponding to a peak-to-peak slope in graphical form. Similar to the slope representation 1102 of FIG. 11A, an advantage of the slope representation 1112 of FIG. 11B is that it can allow a clinician to quickly see relative instantaneous pressure changes over time, which can include past and current measurements.

[0144] 11C, the user interface 1140 can include another gradient representation 1142. The gradient representation 1142 can be similar to the area gradient type of FIG. 10E, for an area gradient type. However, instead of or in addition to depicting the area between two graphs as the exclusive visualization, the gradient representation 1142 can depict one or more pressure values ​​corresponding to the area gradient in a graph format. Similar to the gradient representation 1102 of FIG. 11A, an advantage of the gradient representation 1142 of FIG. 11C is that it can allow a clinician to quickly see relative pressure changes over time, which can include past and current measurements.

[0145] 11D and 11E depict additional exemplary user interfaces that may be presented by the monitor 204 of the system 200 described above and / or the system 1400 described herein. The user interfaces 1150, 1170 of FIG. 11D, 11E may be similar to the user interfaces described herein with respect to FIG. 10A, 10B, 10C, 10D, 10E, 11A, 11B, 11C. In particular, the user interfaces 1150, 1170 of FIG. 11D, 11E may be comparative user interfaces. As used herein, a "comparative user interface" refers to a user interface in which graphs, physiological parameters, values ​​indicative of a heart valve condition (such as gradients, regurgitant index, regurgitant ratio, etc.), and / or other metrics are simultaneously shown for two recordings (such as recordings before and after a procedure). As described herein, the first recording may be pre-treatment for a patient and the second recording may be post-treatment for the same patient. As another example, a first recording may be from a first portion of a procedure and a second recording may be from a second portion of the procedure. The user interfaces 1150, 1170 of Figures 11D, 11E may advantageously allow a clinician to quickly compare hemodynamic information from two different recordings.

[0146] 11D, the user interface 1150 may include a first region 1152A and a second region 1152B. As shown, the first region 1152A and the second region 1152B may include one or more first graphs and / or indicators 1154A and one or more second graphs and / or indicators 1154B, which may be similar to the graphs and indicators described herein. For example, the one or more first graphs and / or indicators 1154A may include a pressure wave for one or more cardiovascular regions (such as the left ventricle LV, the right ventricle RV, the aorta Ao, the vena cava, or the pulmonary artery) for a first recording (which may be a pre-treatment recording for the patient), and / or a value indicative of a heart valve status, such as, but not limited to, a gradient or regurgitation index, for any cardiovascular region. Similarly, the second graph and / or indicator 1154B may be of the same type as the first graph and / or indicator 1154A, but for a second recording (which may be a post-treatment recording for the same patient).

[0147] The user interface 1150 may include a parameter area 1156. The parameter area 1156 may present parameters for both the first and second recordings simultaneously. For example, the parameter area 1156 may present both pre-treatment and post-treatment parameters for the same patient simultaneously. Exemplary parameters may include physiological parameters, such as pressure values ​​for the aorta Ao and the left ventricle LV, for both recordings (such as the pre-treatment and post-treatment recordings). Another exemplary parameter may include a slope value (such as an average or mean area between the two graphs) for both recordings (such as the pre-treatment and post-treatment recordings). The average or mean slope may be calculated from the heartbeats shown in the graphs of the first area 1152A or the second area 1152B. Additional exemplary parameters (for both recordings) may include a time integrated regurgitant index (TIARI), a regurgitant ratio, and / or a patient's heart rate. A regurgitant index and / or indicator (such as a regurgitant ratio) may be calculated from the heart rates shown on the graph in the first area 1152A or the second area 1152B. Any other indexes, slopes, and / or indicators described herein may be presented for both recordings (such as pre-treatment and post-treatment recordings) in the parameter area 1156 and / or user interface 1150.

[0148] The user interface 1150 may include record selectors 1158A, 1158B and / or parameter selectors 1160, 1162. The first and second record selectors 1158A, 1158B may allow the clinician to select a respective record to be presented in the first area 1152A and the second area 1152B, respectively. The selection of a record may also cause the parameter area 1156 to be updated accordingly. The first parameter selector 1160 may allow the clinician to select and change a parameter type for the gradient (such as a peak-to-peak gradient type, an instantaneous gradient type, or an area gradient type), which may cause the first area 1152A, the second area 1152B, and the parameter area 1156 to be updated accordingly. Similarly, the second parameter selector 1162 may enable the clinician to select and change the parameter type for regurgitation (such as Aortic Regurgitation Index (ARI) or Time Integrated Aortic Regurgitation Index (TIARI)), which may cause the first field 1152A, the second field 1152B, and the parameter field 1156 to be updated accordingly.

[0149] FIG 11E may present another comparison user interface 1170. The user interface 1170 of FIG 11E may be similar to the user interface 1150 of FIG 11D. However, instead of presenting the graphs side-by-side, the user interface 1170 of FIG 11E may present the graphs stacked, e.g., stacked one on top of the other vertically on the screen, and / or larger than the graph from the user interface 1150 of FIG 11D. In some embodiments, the stacked graphs may be illustrated with one or more heartbeat features aligned in a left-to-right direction.

[0150] 12 depicts a configuration user interface 1200 for a cardiac valve assessment system. A clinician can configure one or more user interfaces using the configuration user interface 1200. The configuration user interface 1200 can allow a clinician to select a procedure type, a default regurgitation type, a time scale, a pressure scale, and / or other customizable user interface options. The configuration user interface 1200 can include a statistical measure period selector 1202 that can allow a user to select a heart rate for statistical measure calculation.

[0151] b. User interface generation process Referring to FIG. 13, an exemplary user interface generation process 1300 is shown. The process 1300 is described in conjunction with a heart valve evaluation system, such as the system 200 of FIG. 2A or the system 1400 of FIG. 14 described below, however, any system configured to perform the process, in any order, is within the scope of the present disclosure. The process 1300 may be performed by various components of the system 200 of FIG. 2A or the system 1400 of FIG. 14 as described herein. Depending on the embodiment, the process 1300 may include fewer or additional blocks and / or the blocks may be performed in a different order than illustrated. Other embodiments of the process 1300 may include fewer blocks than illustrated or the blocks may be performed in a different order than illustrated.

[0152] Beginning at block 1302, pressure values ​​may be received. In particular, the system 200, 1400 may receive pressure values. The system 200, 1400 may receive a first set of pressure values ​​and a second set of pressure values. Each pressure value from the first set of pressure values ​​may correspond to a first signal received from a first pressure sensor measuring a first cardiovascular region, such as a first portion of the heart. Each pressure value from the second set of pressure values ​​may correspond to a second signal received from a second pressure sensor measuring a second cardiovascular region, such as a blood flow passage adjacent to the first portion of the heart. Thus, the system 200, 1400 may determine the first and second sets of pressure values ​​from the first and second sensors, respectively. As described above in sections I and / or II, the pressure sensor may be housed within a treatment device, such as a pressure guidewire, an access catheter, a pigtail catheter, or a heart valve expansion balloon, a heart valve delivery device adapted to sense pressure, or other pressure sensing device. Additional details regarding receiving pressure values ​​may be described in further detail below with respect to process 1500 of FIG. 15, such as blocks 1502 and / or 1504 of process 1500.

[0153] At block 1304, configuration parameters may be received. In particular, the system 200, 1400 may receive the configuration parameters. Exemplary configuration parameters may include a heart rate or a default slope type to present in the user interface. Additional details regarding the configuration parameters are described in more detail above with respect to FIG.

[0154] At block 1306, a user selection may be received. An exemplary user selection may include a change in gradient type. A user may select gradient type selector 1056 of FIG. 10C to change the gradient type, such as an instantaneous gradient type of FIG. 10D or an area gradient type of FIG. 10E. Additional user selections may include changes to configuration parameters of configuration user interface 1200 described above in FIG. 12. For example, a user selection may include a user heart rate selection. A user heart rate selection may specify a heart rate to be used for the statistical measures (e.g., heart rate 2, 3, or 4, etc.). A user heart rate selection may also include a selection of one or more particular heart beats. For example, a user may interactively manipulate a user interface described herein to select a portion of a graph corresponding to a particular heart beat and / or may select an identifier for a particular heart beat.

[0155] At block 1308, a value indicative of a heart valve state may be determined. As described herein, exemplary values ​​indicative of a heart valve state may include a regurgitation index or a gradient pressure. The system 200, 1400 may determine a value indicative of a heart valve state based on the data of the previous blocks 1302, 1304, 1306. For example, the system 200, 1400 may calculate a particular value indicative of a heart valve state from the received pressure values ​​according to configuration parameters or user selections that may specify a particular gradient type, a heart rate to use in the calculation, and / or a particular heart rate to use or exclude. As described herein, the heart rate may be used to calculate a statistical measure for a value indicative of a particular heart valve state, such as a regurgitation index or a gradient. The system 200, 1400 may detect rapid pacing from one of the first set of pressure values ​​or the second set of pressure values, such as by detecting that the number of beats exceeds a threshold period. Additional details regarding determining a value indicative of a cardiac valve state are described below in Section IV, such as with respect to process 1500 of Figure 15 and process 2800 of Figure 28. Some of the blocks of process 1500 of Figure 15 may further describe determining a value indicative of a cardiac valve state, such as blocks 1504, 1506, 1508, 1510.

[0156] At block 1310, a user interface may be presented. The system 200, 1400 may present a user interface on the monitor 204. Exemplary user interfaces are described above with respect to FIGS. 10A-10E and 11A-11C. The first presented user interface may include a first graph based at least in part on a first set of pressure values ​​and a second graph based at least in part on a second set of pressure values. The first presented user interface may correspond to any of the user interfaces 1040, 1060, 1080, 1100, 1120, 1140 of FIGS. 10C, 10D, 10E, 11A, 11B, 11C, respectively. The first presented user interface may also include a gradient representation indicating the gradient of the valve, such as a peak-to-peak gradient, an instantaneous gradient, and / or an area gradient. For example, the first gradient representation may visually depict the area between the first graph and the second graph (such as gradient representations 1082a, 1082b, 1082c in FIG. 10E). The presented area may indicate the pressure difference between the first and second cardiovascular regions. The first user interface may also include a numerical value (such as second numerical value 1048 in FIG. 10C) indicating the amount of regurgitation of the valve. The first user interface may also include a regurgitation representation (such as regurgitation representations 1044a, 1044b, 1044c in FIG. 10C) visually presenting the regurgitation measurement between a first point in the first graph and a second point in the second graph. Thus, the regurgitation measurement may indicate the amount of regurgitation of the valve. The first user interface may also include a numerical value of the first gradient of the valve according to a statistical measure (such as first numerical value 1084 in FIG. 10E, which may be a mean gradient value or an average gradient value). The first user interface may also include an electrocardiogram, described in further detail above with respect to FIG 10C. In some embodiments, the first user interface may present a rapid pacing warning if rapid pacing is detected.

[0157] In some embodiments, the first user interface can include multiple values ​​for different slope types on the same graphical display, for example, two or more values ​​from among a peak-to-peak slope value, an instantaneous slope value, and / or an area slope value can be selected and presented simultaneously on the same graphical display.

[0158] As shown, after the presentation block 1310 is executed, the previous block is revisited to receive additional pressure value data, user selections, and / or updates to configuration parameters, which may cause one or more user interfaces to update. For example, the system 200, 1400 may receive a user selection of a second slope type (such as a peak-to-peak slope type) via the first user interface. Thus, the system 200, 1400 may present a second user interface for the second slope type (such as a peak-to-peak slope type) in place of the first user interface. The second user interface may include a first graph and a second graph and a second slope representation (such as slope representations 1042a, 1042b, 1042c in FIG. 10C) that visually presents a slope measurement between a first peak in the first graph and a second peak in the second graph.

[0159] The user can make any number of changes to the user interface. For example, another user interface selection can be received for a third gradient type (such as an instantaneous gradient type). Thus, the system 200, 1400 can present a third user interface for the third gradient type (such as an instantaneous gradient type) instead of the second user interface. The third user interface can include the first graph and the second graph and a third gradient representation (such as gradient representations 1062a, 1062b, 1062c of FIG. 10D) that visually presents a second gradient measurement between a first point in the first graph and a second point in the second graph. Although gradient type changes have been described herein in a particular order, any order of gradient type changes can be accepted by the cardiac valve evaluation system.

[0160] IV. SYSTEMS AND METHODS FOR CARDIAC VALVE ASSESSMENT The systems and methods described herein can evaluate heart valves. Pressure values ​​can be used to evaluate the valves. The valves can be diagnosed using various signal processing methods involving the pressure gradient across the valve. The pressure gradient across the valve in the systolic phase can indicate pressure loss caused by blood flowing through the valve, which can indicate a restriction in blood flow. The pressure gradient at the end of diastole, for example after the valve closes, can indicate the amount of blood leaking through the valve while it is closed. As described herein, normalizing or dividing this gradient by the systolic pressure from a cardiovascular region, such as the aorta, can be referred to as regurgitation. Various techniques described herein can be used to improve the accuracy of valve evaluation or diagnostic methods, such as, but not limited to, pressure sensor calibration, waveform conditioning, feature detection, and / or valve state generation.

[0161] a. Overview of systems and methods for cardiac valve evaluation Referring to FIG. 14, a block diagram of a heart valve system 1400 is illustrated. In FIG. 14, a heart valve evaluation environment 1402 includes an input 1404, such as a pressure signal, a heart valve evaluation system 1400, and an output 1406, such as a valve state, a valve diagnostic index, and / or a waveform. An exemplary waveform can include time series data, such as a series of respective pressure and time stamp paired values. The heart valve evaluation system 1400 of FIG. 14 can be similar to the system 200 of FIG. 2A, and / or the components of the heart valve evaluation system 1400 can be embodied in the monitor 204. The pressure signal 1406 can be received from one or more pressure sensors described herein, such as the pressure guidewire 208, the pressure sensing access catheter 20, or the pressure sensing pigtail catheter 10.

[0162] The cardiac valve evaluation system 1400 may include a calibration service 1408, a waveform adjustment service 1410, a feature detection service 1412, and / or a valve state determination service 1414. The calibration service 1408 may calibrate one pressure sensor against another pressure sensor. The waveform adjustment service 1410 may adjust one or more pressure waveforms such that two or more pressure waveforms may be generally synchronized. The feature detection service 1412 may detect one or more features from a pressure waveform, such as detecting a systolic phase, a diastolic phase, a dicrotic ridge, an end of diastole, and / or an onset of systole. The valve state determination service 1414 may determine one or more valve states. The valve state determination service 1414 may include an index calculator 1416 and / or a slope calculator 1418. The index calculator 1416 may generate an index, such as a valve regurgitation index, a time integrated regurgitation index (TIARI), and / or an indicator (such as an aortic regurgitation ratio or a time constant). The gradient calculator 1418 can generate a pressure gradient and / or a statistical measure of the pressure gradient. The generated output data 1406, such as valve states, valve diagnostic indices, and / or waveforms, can be presented to a user interface as described herein or can be presented to another device or system.

[0163] Referring to FIG. 15, an exemplary valve evaluation process 1500 is shown. The process 1500 is described in conjunction with a heart valve evaluation system, such as the system 200 of FIG. 2A or the system 1400 of FIG. 14, however, any system configured to perform the process, in any order, is within the scope of the present disclosure. The process 1500 may be performed by various components of the system 200 of FIG. 2A or the system 1400 of FIG. 14, as described herein. Depending on the embodiment, the process 1500 may include fewer or additional blocks and / or the blocks may be performed in a different order than illustrated. Other embodiments of the process 1500 may include fewer blocks than illustrated or the blocks may be performed in a different order than illustrated.

[0164] Beginning at block 1502, a pressure value or signal may be received or determined. In particular, the cardiac valve evaluation system 1400 may receive a pressure signal from a pressure sensor, such as the pressure guidewire 208, the pressure sensing access catheter 20, or the pressure sensing pigtail catheter 10. The cardiac valve evaluation system 1400 may determine a first set of pressure values ​​and a second set of pressure values ​​from the received pressure signal. Each pressure value from the first set of pressure values ​​may correspond to a first signal received from a first pressure sensor measuring a first cardiac vascular region. Each pressure value from the second set of pressure values ​​may correspond to a second signal received from a second pressure sensor measuring a second cardiac vascular region, which may be the same or different from the first cardiac vascular region. The cardiac valve evaluation system 1400 may determine the first and second sets of pressure values ​​from the first and second sensors, respectively. As described above in sections I and / or II, the pressure sensor may be housed within the pressure guidewire or other pressure sensing device. In some embodiments, such as when a calibration is performed, the first pressure sensor and the second pressure sensor may be located in the same or different cardiovascular regions. In such cases, the process may proceed to block 1504.

[0165] At block 1504, a calibration may be performed. The calibration service 1408 may perform the calibration. The second sensor may be calibrated against the first sensor to determine a more accurate pressure measurement. Similarly, the first sensor may be calibrated against the second sensor to determine a more accurate pressure measurement. In some embodiments, each of the first sensor and the second sensor may both be calibrated together. The pressure value determined from the second sensor may be adjusted based on the calibration. As a result of the calibration of the first sensor and the second sensor, one or more calibration parameters may be generated. The one or more calibration parameters may be used to adjust one or more pressure values ​​determined from the calibrated pressure sensor. Additional details regarding calibration are described in more detail below with respect to process 1600 of FIG. 16 and / or process 2700 of FIG. 27. As used herein, the terms "calibration" and "equalization" may be used interchangeably.

[0166] The process may return to block 1502. Once the calibration is complete, one or more pressure sensors may be moved to a different cardiovascular region and additional pressure signals may be received at block 1502. The pressure signals may be received from two or more pressure sensors located in different cardiovascular regions. Examples of different cardiovascular regions may include adjacent blood passages, such as, but not limited to, opposite sides of a heart valve, such as the left ventricle and aorta, the left ventricle and left atrium, the right ventricle and pulmonary artery, the right atrium and right ventricle, the vena cava and the right atrium, etc. The heart valve evaluation system 1400 may determine a first and second set of pressure values ​​from the pressure signals, such as by applying the determined calibration parameters.

[0167] At block 1506, waveform adjustments may be performed. Because some valve conditions (such as diagnoses) may be based on intrabeat waveform analysis where a particular portion within the cardiac cycle may be used, it may be important to adjust one or more pressure waveforms so that two or more pressure waveforms are generally synchronized or aligned. The adjustment of the waveforms may correspond to one or more time shifts of the waveforms so that corresponding features are aligned. In some embodiments, the waveform adjustment service 1410 may automatically adjust one or more waveforms. In other embodiments, some aspects of the waveform adjustments may include receiving user input, such as an operator manually adjusting one or more waveforms.

[0168] The waveform adjustment service 1410 can adjust the phase between one or both pressure waveforms by adding a delay to one or both pressure waveforms during installation, maintenance, or use with a particular patient. This technique can assume that the set-up process during installation or maintenance is representative of the set-up process when performing a procedure such as TAVI. For example, the aortic pressure signal time delay can be representative of the aortic pressure line delay induced in a TAVI procedure. The waveform adjustment service 1410 can adjust the phase for each particular patient.

[0169] The waveform adjustment service 1410 may include or communicate with an automatic phase delay recognition system that may advise an operator to verify and adjust the phase delay between both pressure signals. The waveform adjustment service 1410 may verify such time delays while equalization is requested or occurring, such as when both pressure signals have the same source (e.g., positioned in the same location so that they should experience similar pressure) or when the pressure signals are from different locations.

[0170] The waveform conditioning service 1410 can detect the phase delay based on a time delay between one or more pressure waveform features. The pressure waveform features can include one or more of the following: systolic pressure relative position, diastolic ridge relative position, or end of diastole relative position. The waveform conditioning service 1410 can use the feature of maximum systolic rising edge slope relative position, which can be a reliable feature.

[0171] Additionally or alternatively, the waveform adjustment service 1410 can systematically adjust the time delay when pressure equalization is requested. Similar to the technique for detecting phase delay, the time adjustment can be measured by comparing the relative positions of certain pressure waveform features. For example, the waveform adjustment service 1410 can delay the timing of pressure sampling during equalization based on the recognition of the pressure waveform features. The waveform adjustment service 1410 can use cross-correlation between both signals, i.e., by calculating the correlation of one signal with the other while shifted in time. This time shift can result in an increased or even maximum correlation value between both signals, which can correspond to a time shift that can be applied to one pressure signal or the other pressure signal.

[0172] Feature detection may be performed at block 1508. The feature detection service 1412 may perform the feature detection. Exemplary features that may be detected from the pressure waveform may include systolic phase, diastolic phase, dicrotic ridge, end of diastole, and / or beginning of systole. Additional details regarding feature detection are described in more detail below with respect to process 1900 of FIG. 19.

[0173] In block 1510, a value indicative of a heart valve state may be determined. The valve state determination service 1414 may determine the valve state. In particular, the index calculator 1416 may generate an index such as a valve regurgitation index, and the slope calculator 1418 may generate a pressure gradient and / or a statistical measure of the pressure gradient. The index calculator 1416 and / or the slope calculator 1418 may generate the valve state using the calibrated or adjusted waveform or the detected features of the previous block. The index calculator 1416 may calculate the regurgitation index based at least in part on a first subset of the first set of pressure values ​​according to the systolic or diastolic phase and a second subset of the adjusted pressure values ​​according to the systolic or diastolic phase. For example, the index calculator 1416 may calculate the regurgitation index according to the following formula: aortic regurgitation index=(aortic diastolic pressure−left ventricular diastolic pressure) / aortic systolic pressure. The gradient calculator 1418 may calculate a gradient value (such as an area gradient value, a peak-to-peak gradient value, and / or an instantaneous gradient value, described in further detail above in Section III) based at least in part on the difference between a first subset of pressure values ​​in the systolic phase and a second subset of adjusted pressure values ​​in the systolic phase. Additional details regarding the determination of the valve state are described in more detail above in Section III and below in this Section IV.

[0174] At block 1512, a value indicative of the heart valve status may be presented in a user interface. The heart valve evaluation system 1400 may present the value indicative of the heart valve status. Additional details regarding the presentation of the valve status are described in more detail above with respect to block 1310 of FIG. 13 and the user interfaces of FIGS. 10A-10E and 11A-11C.

[0175] b. Pressure sensor calibration As described herein, a first sensor may be calibrated against a second sensor to determine a more accurate pressure measurement, which may also be referred to as leveling. For example, a pressure guidewire may be at or near the valve location along with another pressure device. The other pressure device may be a catheter, pigtail, or other device used to deliver the valve and equipped with a lumen connected to a pressure transducer. The pressure device may be another pressure guidewire or a catheter equipped with a tip pressure sensor. The pressure guidewire and pressure device are positioned to measure the same pressure. The pressure sensors may be positioned in the same cardiovascular region, such as the aorta, ventricle, atrium, or other location. It may be understood that pressure sensors at the same location should display the same pressure, but there may be a difference between the first pressure and the second pressure (such as the aortic pressure Pa and the distal pressure Pd). Thus, once at the same location, one pressure sensor may be calibrated against the other pressure sensor.

[0176] The systems and methods described herein for calibrating pressure sensors can improve the accuracy of pressure devices. For example, as described above, even if two pressure devices are located in the same cardiovascular region, there may be differences in pressure based on the proximal or distal location of each pressure device. Furthermore, pressure differences may result from other factors, such as different device types between multiple pressure devices. Thus, the systems and methods described herein for calibration can improve pressure device technology by providing more accurate pressure readings.

[0177] Referring to FIG. 16, an exemplary calibration process 1600 is shown. The process 1600 is described in conjunction with a heart valve evaluation system, such as the system 200 of FIG. 2A or the system 1400 of FIG. 14, however, any system configured to perform the process, in any order, is within the scope of the present disclosure. The process 1600 may be performed by various components of the system 200 of FIG. 2A or the system 1400 of FIG. 14, as described herein. Depending on the embodiment, the process 1600 may include fewer or additional blocks and / or the blocks may be performed in a different order than illustrated. Other embodiments of the process 1600 may include fewer blocks than illustrated or the blocks may be performed in a different order than illustrated.

[0178] Beginning at block 1602, one or more calibration pressure values ​​may be determined from one or more pressure sensors. The calibration service 1600 may determine the one or more calibration pressure values ​​from the one or more pressure sensors. The calibration service 1600 may receive a first calibration pressure value corresponding to a first calibration signal received from a first pressure sensor measuring a cardiovascular area and a second calibration pressure value corresponding to a second calibration signal received from a second pressure sensor measuring the same cardiovascular area. The calibration service 1600 may receive a first set of calibration pressure values ​​determined from the first pressure sensor and a second set of calibration pressure values ​​determined from the second pressure sensor.

[0179] At block 1604, calibration parameters may be calculated. The calibration service 1600 may calculate one or more calibration parameters. The calibration service 1600 may calculate the calibration parameters, such as an offset or gain (G) using one or more techniques. The calibration service 1600 may determine the offset or gain (G). The calibration service 1600 may calculate the offset, P1=P2+offset, using an offset equation, where P1 may be Pd and P2 may be Pa. The offset may be used by the calibration service 1600 to determine that the pressure is equal (e.g., average pressure) between the two pressure sensors. Additionally or alternatively, the calibration service 1600 may adjust the gain (G) of one pressure sensor so that the pressure (e.g., average pressure) between the two sensors is equal. The calibration service 1600 may calculate the gain (G): P1=G*P2, using a gain equation, where P1 may be Pd and P2 may be Pa.

[0180] The calibration service 1600 can determine the calibration parameters using a linear fit. The first and second sets of pressure values ​​can be or include a first or second vector, respectively. The calibration service 1600 can determine a linear fit between the first and second vectors. The first vector can correspond to [P1] (e.g., [Pd]) and the second vector can correspond to [P2] (e.g., [Pa]). The calibration service 1600 can calculate the offset using an offset formula: [P1]=K*[P2]+b. The calibration service 1600 can apply a linear fit between the pressure measurements of one pressure sensor to another pressure sensor to determine the calibration parameters K and b. A linear fit calibration may be desirable when equalizing both pressure measurements positioned in a heart chamber, e.g., a ventricle. Contrary to aortic pressure, ventricular pressure (and atrial pressure) varies over a wide pressure range, from approximately venous pressure to aortic systolic pressure (and even higher in terms of pressure loss across the aortic valve), and therefore the risk of obtaining a linear fit with a significant offset (b) is minimized. [P1] can correspond to a vector including multiple P1 pressure values ​​(e.g., Pd) and [P2] can correspond to a vector including multiple P2 pressure values ​​(e.g., Pa). The pressure measurements that the calibration service 1600 can use to calculate the linear fit can be a subset of the pressure measurements, and can include, for example, only systolic pressure measurements, diastolic pressure measurements, or other parts of the cardiac cycle.

[0181] Calibration parameters may be applied at block 1606. The calibration service 1600 can apply one or more calibration parameters to the pressure values. The calibration service 1600 can apply an offset, a gain (G), or linear fit parameters (K and b) to the one or more pressure values ​​to determine one or more adjusted pressure values.

[0182] c. Feature detection The cardiac valve evaluation system 1400 may rely on determining the phase of the cardiac cycle to determine the valve status, such as the regurgitation index. Thus, the cardiac valve evaluation system 1400 may detect one or more features, such as, but not limited to, the systolic phase, the diastolic phase, the dicrotic ridge, the end of diastolic phase, and / or the beginning of systolic phase. The dicrotic ridge is a feature that may indicate a phase change from the diastolic phase to the systolic phase. The end of diastolic phase or the beginning of systolic phase is another feature that may be detected. The end of diastolic phase may be identified using an electrocardiogram (ECG). In some embodiments, it may be desirable to identify the end of diastolic phase using pressure, since an ECG signal may not be available or may not be clean enough. The transition from diastolic to systolic phase is often not clearly distinguishable, as it may be quite rounded, and / or the transition may also include various pressure features that may lead to poor identification. The cardiac valve evaluation system 1400 may rely on features such as the systolic pressure rise region. The cardiac valve evaluation system 1400 can identify the location of the maximum or major gradient of the systolic pressure upstroke, which is more reliable than other features. In particular, the cardiac valve evaluation system 1400 can identify the location of the maximum gradient of the conditioned pressure signal.

[0183] Referring to FIG. 17, a waveform analysis environment 1700 is depicted. The waveform analysis environment 1700 includes a first set 1702 of pressure data points and a second set 1704 of pressure data points. The cardiac valve analysis system 1400 can analyze the data points in the environment 1700 to detect the dicrotic feature. The cardiac valve analysis system 1400 can detect the dicrotic feature by calculating and identifying the data point that has the smallest angle with the nearby data points. An example of the angle calculation is shown in FIG. 17. For the first set 1702 of data points, the cardiac valve analysis system 1400 can obtain the angle α(i) by calculating the angle between a first line extending from a center point P(i) and a predecessor point P(i-1) and a second line extending from the same center point P(i) and a successor point P(i+1). For the first and second sets of data points 1702, 1704, the angle α(i+1) about point P(i+1) may be less than the angle α(i) about P(i). Thus, the cardiac valve analysis system 1400 may identify a dicrotic ridge feature at point P(i+1). In this example, the angle is calculated using adjacent points, but the technique may include using non-adjacent points. In some embodiments, the technique may include using n or more data points (such as two or more data points) for the calculation of a line forming a portion of the angle. In some embodiments, the signals for the data points may or may not be preconditioned.

[0184] Referring to FIG. 18, another waveform analysis environment 1800 is depicted. The cardiac valve analysis system 1400 can analyze data points in the environment 1800 to detect the end of diastole and / or the beginning of systole. The environment 1800 can include a waveform 1806. A gradient 1802 extending from a location of a maximum or major gradient of the rising portion of the systole 1801 is illustrated in FIG. 18. The cardiac valve analysis system 1400 can trace a horizontal line 1804 that intersects with a minimum or minor pressure value 1803. An intersection 1805 of the gradient 1802 and the horizontal line 1804 can provide a reliable location for the midpoint of the transition from the end of diastole to the beginning of systole. In some embodiments, when using aortic pressure to identify the end of diastole or the beginning of systole, a more accurate positioning of the end of diastole can be obtained by moving the location by a time period 1807, which can be predetermined. The end of diastole may be obtained by shifting the node 1805 by about 40 to 100 ms. In some embodiments, shifting the location by 60 ms may provide a good estimate of the end of diastole. The cardiac valve analysis system 1400 may use other techniques, such as shifting the node a percentage of the cardiac cycle, such as between 8% and 12%, or between 5% and 8%, etc.

[0185] The technique described herein may be adapted to identify the end of diastole when using aortic pressure. The technique may also be adapted when the pressure being processed is an intraventricular pressure. As a result of the intraventricular pressure, the end of diastole may be determined more accurately since there is no need to move the location of the intersection point 1805. After the location of the first intersection point 1805 is determined, a more accurate determination of the end of diastole may include changing the gradient extending from the location of the maximum gradient to a new gradient extending from a location located between the location of the maximum gradient and the first intersection point 1805. In particular, the determination of the end of diastole may include changing the gradient extending from the location of the maximum gradient to a new gradient extending from a location closer to the first intersection point 1805. The new gradient extending from a location closer to the first intersection point 1805 may then be extended to intersect with a horizontal line. The new intersection point may be found and used as the end of diastole.

[0186] Referring to FIG. 19, a feature detection process 1900 is shown. The process 1900 is described in conjunction with a heart valve evaluation system, such as the system 200 of FIG. 2A or the system 1400 of FIG. 14, however, any system configured to perform the process, in any order, is within the scope of the present disclosure. The process 1900 may be performed by various components of the system 200 of FIG. 2A or the system 1400 of FIG. 14, as described herein. Depending on the embodiment, the process 1900 may include fewer or additional blocks and / or the blocks may be performed in a different order than illustrated. Other embodiments of the process 1900 may include fewer blocks than illustrated or the blocks may be performed in a different order than illustrated.

[0187] Beginning at block 1902, the signal may be conditioned. The cardiac valve analysis system 1400 may condition the signal. The cardiac valve analysis system 1400 may filter the pressure signal, such as by convolving the signal with a window function. The window may be square or of other shape and may be two or more samples in duration. It may be preferable to condition the signal in some circumstances, such as to find the location of maximum gradient, since there may be oscillatory features caused by air bubbles or other factors.

[0188] In block 1904, the overlap ridge feature may be detected. The feature detection service 1412 may perform overlap ridge feature detection. Various techniques may be used to determine the overlap ridge feature. The feature detection service 1412 may calculate a second derivative of one of the pressure signals and identify the location of the zero crossing. More specifically, the feature detection service 1412 may calculate a second derivative value from a first set of pressure values ​​and may identify a zero crossing point based at least in part on the second derivative value, the zero crossing point corresponding to the first overlap ridge feature. These techniques may allow for identifying the overlap ridge feature in the absence of a clear ridge, i.e., a ridge visible on the graphical representation of the pressure waveform itself. When a clear ridge is present, i.e., the ridge includes a returning short pressure signal feature that is visible on the graphical representation of the pressure waveform, the feature detection service 1412 may search for a nearby first derivative zero crossing. These techniques may be performed on the unconditioned pressure signal, but may also be performed on the conditioned pressure signal.

[0189] The feature detection service 1412 can detect the double ridge feature by calculating and identifying the data point that forms the smallest angle with nearby data points. The feature detection service 1412 can calculate a first angle for the first point based at least in part on the first predecessor point and the first successor point from the set of pressure values. The feature detection service 1412 can calculate a second angle for the second point based at least in part on the second predecessor point and the second successor point from the first set of pressure values. The feature detection service 1412 can determine that the second angle is less than the first angle and identify the second point as a first double ridge feature. Additional details regarding detecting double ridge features are described above with respect to FIG. 17.

[0190] In block 1906, an end of diastole or an onset of systole feature may be detected. The feature detection service 1412 may detect an end of diastole or an onset of systole feature. The feature detection service 1412 may identify a first subset of rising pressure values ​​from the first set of pressure values. The feature detection service 1412 may identify a local minor pressure value from the first plurality of pressure values. The feature detection service 1412 may determine a tangent line from the first subset. The feature detection service 1412 may then identify a horizontal line that intersects with the local minor pressure value and identify a first intersection point between the tangent line and the horizontal line. The feature detection service 1412 may identify a first point from the first set of pressure values ​​as an end of a first diastolic phase or a beginning of a first systolic phase based at least in part on the first intersection point. Identifying the first point may further include adjusting the first intersection point by a predetermined period of time. The predetermined period of time may be or may include approximately 60 milliseconds. The predetermined time period can include a time between about 40 milliseconds and about 100 milliseconds. Identifying the first point can further include adjusting the first intersection point by a percentage of the cardiac cycle. The percentage can include or be between about 8 percent and 12 percent of the cardiac cycle. The percentage can include or be between 5 percent and 8 percent of the cardiac cycle. Additional details regarding detecting the end of diastole or beginning of systole features are described above with respect to FIG. 18.

[0191] In block 1908, the systolic or diastolic phase may be determined. The feature detection service 1412 may detect the diastolic or systolic phase feature. The feature detection service 1412 may use a diastolic bulge feature to identify the phase change from the diastolic phase to the systolic phase. The end of diastole or the beginning of systole is another feature that may be detected.

[0192] d. Additional valve states The cardiac valve evaluation system 1400 can determine additional valve conditions. Additional exemplary valve conditions can include, but are not limited to, a transvalvular dysfunction diagnostic, a valve stenosis severity index, an aortic regurgitation index, a corrected aortic regurgitation index, a time integrated regurgitation index, an aortic regurgitation ratio, and / or a time constant.

[0193] i. Valve stenosis severity index Although an aortic valve is used to illustrate some embodiments, it will be understood that the techniques described herein can be applied to other valves, such as the mitral valve, the pulmonary valve, the tricuspid valve, etc. Referring to FIG. 20, a left ventricular pressure waveform (LVEP) 2010 and an aortic pressure waveform (AOP) 2011 are depicted. In the example of FIG. 20, aortic valve stenosis may be present. Aortic valve stenosis may prevent blood from crossing the valve, resulting in pressure loss or pressure drop. Pressure loss may occur during systole. In particular, pressure loss may occur during the period when blood is ejected from the left ventricle into the aorta (ejection period). The ejection period 2012 is defined as the period bounded by the point where the left ventricular pressure crosses the aortic pressure.

[0194] In normal healthy subjects, the left ventricular pressure and the aortic pressure should be equal during the ejection period. However, in aortic stenosis, the left ventricular pressure can be higher than the aortic pressure. The pressure loss increases with the severity of aortic stenosis. Techniques for assessing the severity of aortic stenosis (AS) can include calculating the pressure gradient between the LVP and the AOP during the entire ejection period. In particular, the severity of aortic stenosis (AS) can be calculated based on the gradient between the mean LVP and the mean AOP during the ejection period ( <lvsp> - <asp>) can be determined. As described below, LVSP can be the mean left ventricular systolic pressure during the ejection period, and ASP can be the mean aortic systolic pressure during the ejection period. An improved technique can include removing the edge portions of the ejection period and calculating the pressure gradient in the region where the instantaneous pressure gradient is more constant. This is done by calculating the average pressure gradient in the central 50% of the ejection period, thus eliminating 25% of the period at both edges. Other percentages of the central portion are possible, such as 30%, 40%, 60%, 70%, or 80%.

[0195] However, this technique can be sensitive to pressure amplitude. Another technique consists of normalizing the aortic stenosis index (AS) by dividing the gradient of the mean pressure by the mean LVEP, which is given by the following formula:

number

[0196] At rest, it may be assumed that the total blood supply is sufficient, i.e., the aortic pressure during the ejection period allows for sufficient total perfusion. In the absence of aortic stenosis, it may be reasonable to assume that the left ventricular pressure during the ejection period would be equal to the aortic pressure in the presence of aortic stenosis. The total vascular resistance may not change whether aortic stenosis is present or not. Value

number

number

number

number

number

number

number

[0197] ii. Aortic Regurgitation Index Regurgitation can occur when blood leaks and flows backwards through a valve. Regurgitation can be caused by valve disease or, in the case of prosthetic valve replacement, by malpositioning of the replacement valve relative to the biological valve. Postoperative outcomes for patients after valve replacement can be adversely affected by valve regurgitation. Therefore, diagnosing post-TAVI valve regurgitation, and possibly pre-TAVI valve regurgitation, is important for valve adjustment.

[0198] Figure 21 illustrates a pressure waveform in a normal healthy individual. Figure 22 illustrates a similar pressure waveform, but with aortic regurgitation. As blood flows through the valve and back into the left ventricle, left ventricular diastolic pressure can increase. This can also cause a decrease in aortic diastolic pressure as a result of blood volume lost through the closed aortic valve. Systolic pressure can increase to compensate for the loss of available blood perfusion.

[0199] The aortic regurgitation index (ARI) may consist of calculating the gradient between the aortic end diastolic pressure (AEDP) 2220 and the ventricular end diastolic pressure (LVEDP), normalized by the aortic systolic pressure (ASP), as shown in the following formula:

number

[0200] In some embodiments, the calculation may include multiplying the initial result by 100, as shown in the following formula:

number

[0201] Multiplying the initial result by 100 can make the aortic regurgitation index (ARI) easier to understand and / or compare. For example, if the aortic pressure at the end of diastole (AEDP) is 65, the left ventricular end diastolic pressure (LVEDP) is 10, and the aortic systolic pressure (ASP) is 160, the first aortic regurgitation index (AR) may be calculated as 34.375 (or 34.38, 34.4, 34, etc., depending on the rounding rule used). Similarly, if the aortic pressure at the end of diastole (AEDP) is 40, the left ventricular end diastolic pressure (LVEDP) is 20, and the aortic systolic pressure (ASP) is 130, the second aortic regurgitation index (ARI) may be calculated as 15.384 (or 15.38, 15.4, 15, etc., depending on the rounding rule used). Therefore, the multiplication by 100 in the above calculation may facilitate comparison between the first and second aortic regurgitation indexes.

[0202] Another index that may provide better stability and reproducibility is obtained from calculating the slope of the mean left ventricular diastolic pressure (LVDP) and the mean aortic diastolic pressure (ADP) 2221 divided by the aortic systolic pressure (ASP). Another index is obtained by calculating the same slope over a portion of the diastolic phase, for example, over a period during which the left ventricular pressure is below a certain value 2222, more specifically within a region where the LVDP is relatively flat. A predefined portion of the diastole may be used to calculate the regurgitation index, for example by taking 75% of the left portion of the diastole. Instead of (or in addition to) calculating the regurgitation index using the aortic pressure at the end of diastole (AEDP) 2220 and the ventricular pressure at the end of diastole (LVEDP), a time integrated regurgitation index (TIARI) may be calculated by integrating the systolic and diastolic times, in other words, the time integrated regurgitation index (TIARI) may be determined by calculating the area between the aortic pressure curve and the left ventricular pressure curve divided by the area of ​​the aortic systolic pressure curve.

[0203] As mentioned above, the aortic regurgitation index (ARI) or time-integrated aortic regurgitation index (TIARI) may be calculated using only a portion of the diastolic phase. Following valve closure, there may (and often is) some pressure oscillation. Advantageously, in some embodiments, the beginning of the diastolic phase may be removed (to avoid this noisy portion of the signal) from the data used to calculate the index. Furthermore, patients undergoing cardiac procedures, such as transcatheter aortic valve replacement (TAVR) procedures, often have extra heart beats (ectopic beats) that occur just before regular heart beats and / or significantly regulated heart rates. Thus, some improved algorithms described herein can advantageously reduce or counteract the effect of heart rate variability in the calculation of the aortic regurgitation index.

[0204] In some embodiments, the aortic regurgitation index may be normalized over heart rate. For example, the aortic regurgitation index may be calculated using a particular heart rate, such as 60 beats per minute (BPM), which may be a normal resting heart rate for an adult. In other embodiments, ventricular pacing may be used to cause the heart to beat at a predefined heart rate. In some embodiments, the heart rate may be varied (60 BPM, 100 BPM, 140 BPM, etc.), and the aortic regurgitation index may be calculated at one or more heart rates.

[0205] In some embodiments, lowering the heart rate can advantageously provide a longer diastolic portion of the aortic pressure signal. For example, in some cases, the diastolic portion of the pressure curve may be described by an exponential decay curve, and thus, by lowering the heart rate, the diastolic portion of the pressure curve may be stretched, thereby improving the calculated regurgitation index. In some embodiments, a method other than standard ventricular pacing (e.g., electrical stimulation provided to the ventricles of the heart by a pacemaker) may be used to lower the heart rate. For example, a drug such as adenosine or another type of drug with a similar pacing effect may be administered to lower the heart rate. Thus, in some embodiments, the heart rate may be varied (60 BPM, 50 BPM, 40 BPM, 30 BPM, 20 BPM, etc.) and the aortic regurgitation index may be calculated at one or more heart rates.

[0206] In some embodiments, inducing a premature systole (also called an early systole, early systolic beat, or short beat) can advantageously provide a longer diastolic portion of the aortic pressure signal. Some pacemakers can be configured / programmed to induce a premature systole. For example, the pacemaker can be set to a relatively low heart rate, such as 60 BPM. In some embodiments, higher or lower heart rates can be used. The goal can be to induce a premature systole that causes the ventricles to contract but not enough to open the aortic valve, which can result in a longer diastolic portion of the aortic pressure signal. This advantageous technique can therefore be used to calculate an improved regurgitation index.

[0207] In FIG. 23A, a left ventricular pressure waveform (LVEP) 2302 and an aortic pressure waveform (AOP) 2306 depict a situation in which a premature systole occurs that may be used to calculate an improved regurgitation index. As shown, a premature systole 2304 (short beat) close to the previous beat causes the ventricle to contract, but not enough to open the aortic valve. Also, as shown, the premature systole 2304 can cause a longer portion 2308 of the aortic pressure waveform 2306 that has a distinctly different curve with respect to other portions of the aortic pressure waveform 2306. As described herein, this longer diastolic portion 2308 of the aortic pressure waveform 2306 may be used to calculate an improved regurgitation index.

[0208] In some embodiments, wire manipulation during a procedure may be advantageously used to calculate an improved regurgitation index. For example, during a procedure, such as a transcatheter aortic valve replacement (TAVR), wire manipulation in the ventricle may cause some instability in the patient's heart rate. As a result, there may be a longer diastolic portion and / or longer beats in the aortic pressure signal, which may be used to calculate the regurgitation index. As described herein, the length of the heart beat and / or diastolic phase may be used to classify the heart beat or diastolic phase for inclusion or exclusion as part of the index or indicator calculation. The regurgitation index may be calculated for the longer diastolic portion and / or longer beats in the aortic pressure signal, but exclude the shorter diastolic portion and / or shorter beats in the aortic pressure signal. In some embodiments, the system may automatically select the longer diastolic portion and / or longer beats in the aortic pressure signal to use to calculate the regurgitation index.

[0209] In FIG. 23B, a left ventricular pressure waveform (LVEP) 2310 and an aortic pressure waveform (AOP) 2312 are depicted that may correspond to pressure waveforms generated during a procedure, such as a transcatheter aortic valve replacement (TAVR), that may be used to calculate an improved regurgitation index. As noted above, wire manipulation within the ventricle may cause the patient's heart rate to become unstable during the procedure. As shown, the instability in the heart rate may result in longer portions 2314A, 2314B, 2314C of the aortic pressure waveform 2312 that have a distinctly different curve with respect to other portions of the aortic pressure waveform 2312. Depending on the embodiment, one or more methods may be used to select portions of the aortic pressure waveform 2312 from which the regurgitation index calculation may be performed. The length of the heartbeat may be used to identify portions of the aortic pressure waveform 2312 to include or exclude for the calculation. For example, if the time between two systolic phases of adjacent beats of the pressure waveform or signal is too short or too long, those portions of the signal may be discarded. Additionally or alternatively, the length of the diastolic phase may be used. As described herein, these longer diastolic portions 2314A, 2314B, 2314C of the aortic pressure waveform 2306 can be used to calculate an improved regurgitant index.

[0210] In some embodiments, a reflux index may be calculated from beats that meet a threshold (such as beats having a diastolic phase with a predefined length). Beats that are not long enough, such as ectopic beats, are rejected by the system and are not used to calculate one or more reflux indices.

[0211] iii. Aortic Regurgitation Indicator The regurgitation index may be used for a variety of purposes, such as for diagnostic and / or evaluation purposes. In particular, the system 200 and / or system 1400 described above may be used to generate an indicator from the regurgitation index, which may also be referred to herein as a "composite valve status." For example, the indicator may be useful to a clinician to help answer questions, such as: After a procedure (such as a transcatheter aortic, mitral, tricuspid, or pulmonary valve replacement procedure), did the regurgitation improve, remain stable, or worsen?

[0212] The above-described system 200 and / or system 1400 can calculate an indicator from any index described herein (both post-procedure and pre-procedure), such as calculating an indicator from an aortic regurgitation index or a time-integrated aortic regurgitation index. An exemplary indicator is a ratio calculated from the post-procedure and pre-procedure index. The aortic regurgitation ratio can be a strong predictor of one-year mortality after a transcatheter aortic valve replacement procedure. The above-described system 200 and / or system 1400 can calculate the aortic regurgitation ratio by dividing the post-procedure aortic regurgitation index value by the pre-procedure aortic regurgitation index value. An exemplary formula for calculating the aortic regurgitation ratio indicator is provided below.

number

[0213] Additional exemplary regurgitation indicators are described below that may be useful to clinicians in determining whether regurgitation has improved or worsened after a procedure. If a patient's aortic regurgitation ratio remains stable or improves, some studies have shown that the patient may have a better outcome or fewer adverse events after a procedure. Similarly, if other aortic regurgitation indicators, such as those described below, remain stable or improve, the patient may have a better outcome or fewer adverse events after a procedure.

[0214] Another exemplary indicator is the difference between the post-treatment index and the pre-treatment index. For example, the system can calculate the aortic regurgitation difference by subtracting the pre-treatment aortic regurgitation index value from the post-treatment aortic regurgitation index value. An exemplary formula for calculating the aortic regurgitation difference indicator is provided below. Aortic regurgitation difference = AR Post -AR Pre

[0215] Yet another exemplary indicator may be a normalized difference between the post-treatment index and the pre-treatment index. For example, the system may calculate a normalized aortic regurgitation difference by subtracting the pre-treatment aortic regurgitation index value from the post-treatment aortic regurgitation index value and dividing by the pre-treatment aortic regurgitation index value. An exemplary formula for calculating the aortic regurgitation difference indicator is provided below.

number

[0216] In some embodiments, the system can present information in addition to the aortic regurgitation indicator that may be useful for diagnostic and / or evaluation purposes. For example, the system can present the patient's heart rate (such as resting heart rate) both post-procedure and pre-procedure.

[0217] iv. Corrected Aortic Regurgitation Index Arterial sclerosis, common in patients who have undergone valve replacement surgery, affects the pressure waveform in a similar manner to aortic regurgitation. In these cases, the aortic regurgitation index described above may lead to an erroneous determination of positive regurgitation and thus to unnecessary valve adjustments. More specifically, arterial sclerosis has the effect of increasing systolic pressure. In FIG. 23C, this pressure increase 2330 may be caused by a reflected pressure wave from the sclerotic vasculature that occurs earlier than in normal vasculature. In normal vasculature, the reflected wave occurs later in diastole, and therefore may increase the early phase of diastolic pressure.

[0218] Pressure during diastole can be maintained by the compliance of the vascular system. The elasticity of the arteries, mainly the aorta, continues to apply pressure within the vascular system by trying to return to an undesired state. Stiffened arteries do not have the same degree of compliance, and therefore the arteries do not have the ability to maintain pressure for long periods during diastole. As diastolic pressure falls more rapidly, the aortic pressure at the end of diastole (AEDP) also falls, and therefore aortic regurgitation is lower.

[0219] Diastolic pressure can be represented by a two-component model that includes vascular compliance (C) and total vascular resistance (R). Diastolic pressure relaxes as described by the diastolic equation:

number

[0220] If the compliance is known, this formula makes it possible to calculate the total vascular resistance (R). The aortic pressure at the end of diastole could also be recalculated using the general normal compliance together with the previously calculated total vascular resistance.

[0221] Compliance refers to the expansion of arterial volume caused by a given change in pressure, as shown in the following equation:

number

[0222] Arterial stiffness correlates well with pressure augmentation (PA) 2330 or conversely, compliance correlates well with the inverse of pressure augmentation. It may be preferable to use pressure augmentation to correct aortic regurgitation as this may be easier to implement in a clinical set-up. Pressure augmentation may be accompanied by a visible change in the rising part of systole 2331, allowing estimation of the pressure augmentation. Another method may be to inject nitroglycerin into the patient to relax the arterial system and reduce the pressure augmentation. The change in aortic systolic pressure caused by nitroglycerin may result in a pressure augmentation. Compliance is calculated using the pressure augmentation and a relationship taking the form of the compliance equation below, or an assumed general normal compliance C n can be estimated by any relation f(PA) that adjusts C=f(PA)=C n -k·PA

[0223] R may be calculated by applying C from the above equation to the diastolic equation using a measurement of the diastolic aortic pressure. Corrected aortic diastolic pressure (CADP) is the product of the calculated R and C n Corrected aortic regurgitation is calculated by replacing aortic diastolic pressure (ADP) with corrected aortic diastolic pressure (CADP) as shown in the following equation:

number

[0224] Another method is to replace the measured aortic systolic pressure with a corrected aortic systolic pressure, i.e., remove the pressure augmentation contribution from the ASP. Rather than using a pressure value at the end of diastole alone, the corrected aortic regurgitation may also use the mean diastolic calculation as explained above.

[0225] Left ventricular diastolic upward pressure caused by abnormal venous pressure can also lead to an erroneous calculation of the aortic regurgitation index. Another improved method is to subtract the contribution of the venous or atrial pressure from the left ventricular diastolic pressure component, as shown in the following equation:

number

[0226] v. Reflux index based on diastolic gradient When there is backflow, blood from the aorta returns to the left ventricle during the diastolic portion of the cycle. This can occur due to paravalvular leakage. When blood from the aorta returns to the left ventricle, the aortic pressure decreases, i.e., the downward slope of a graph illustrating the value of aortic pressure over time changes more rapidly than in the absence of backflow. Conversely, the slope of a graph of left ventricular diastolic pressure over time becomes larger compared to such a graph in the absence of backflow. This occurs because the blood entering the left ventricle is at a higher pressure than the blood in the ventricle during that portion of the beat. The left ventricular diastolic pressure (LVDP) may not vary significantly from patient to patient, taking into account various factors or conditions. Conversely, the aortic gradient may have a relatively large change taking into account one or more factors or conditions, such as vascular stiffness (e.g., stiffness of the aorta or vasculature). Thus, the backflow index may be corrected to take into account vascular stiffness.

[0227] In Figure 23D, the left ventricular pressure waveform (LVEP) 2340 and the aortic pressure waveform (AOP) 2342 may depict a situation where there is backflow. As discussed above, during the diastolic portion of the cycle 2344, blood returns from the aorta to the ventricle, the aortic pressure falls, and the downward slope (as shown) is generally steeper than in the absence of backflow. Conversely, during the diastolic portion of the cycle 2344, the left ventricular pressure 2340 may rise, with a generally upward slope (as shown).

[0228] During the diastolic portion of the cycle 2344, some of the illustrated oscillations may be caused by the fluid filling the pressure line. In particular, the oscillations may be caused by a sudden pressure difference with the fluid filling the line. In some embodiments, these oscillations can be reduced by using a pressure transducer included in the pressure device. The pressure transducer may be configured, for example, to generate an electrical or optical signal indicative of the pressure. For example, smoother pressure tracings (such as the waveforms shown in FIG. 23A or FIG. 23B) may be achieved by using an invasive pressure transducer. These improved pressure tracings may be used to calculate an improved reflux index.

[0229] As described herein, one method of assessing vascular stiffness is through pressure augmentation. In FIG. 23E, an aortic pressure waveform 2350 is depicted in the presence of some vascular stiffness. As shown, the aortic valve opens at time "t1." Due to stiffness, instead of the aortic dilation due to pressure augmentation, a pressure wave may be generated that may return to the aortic root, valve region, and / or ventricle. As shown, the pressure "p" from the forward wave f ” is the increased pressure “p aug " causing the first step in waveform 2350. In late systole, the pressure decreases and reaches the second step which ends with the closure of the aortic valve at time "t3." The aortic pressure waveform 2350 in FIG. 23E, where there is some vascular stiffness, can be contrasted with the aortic pressure waveform 2342 in FIG. 23D, where the vasculature has higher compliance.

[0230] A mathematically derived expression of pressure augmentation, called the Augmentation Index (AI), can indicate the stiffness of the aorta or blood vessels and can be used to analyze the physical condition of the arterial system. The Augmentation Index is the distance from the first step of the ascending portion of the aortic waveform to the wave peak (p aug ) can be calculated as a percentage of the pressure pulse (PP). PP is calculated as the change in pressure from the pressure minimum at the time just before the aortic valve opens to p f andp aug An exemplary formula for calculating the Augmentation Index is provided below:

number

[0231] In FIG. 23F, the pressure change (p aug ) and pressure pulse (PP) are shown.

[0232] In some cases, there may be problems measuring pressure in one or more cardiovascular regions, which may affect the calculation of the augmentation index. For example, the measured pressure and / or the recorded pressure waveform may be inaccurate in some cases. In particular, some existing procedures use a short guidewire with a distal pigtail tip for contrast injection and also measure pressure. This approach may result in inaccurate pressure measurements and therefore inaccurate waveforms. Therefore, it may be important to use a sensor configured to accurately measure pressure in one or more cardiovascular regions, such as in the aorta or another cardiovascular region or regions. As described herein, one or more pressure devices (such as a pressure guidewire, an aortic wire, a catheter with a tip pressure sensor, and / or a catheter capable of measuring distal pressure) may be used to measure pressure in the aorta and / or at a location near the valve. Preferably, the pressure device may be configured or used to dramatically improve the accuracy of pressure measurements for calculating the augmentation index. For example, as an improvement to existing procedures, a guidewire configured to more accurately measure pressure may be included at the distal end of the aortic pigtail.

[0233] As explained herein, vascular stiffness results in increased pressure (p aug ), and the stiffness of the blood vessel can be estimated using the augmentation index. Stiffer blood vessels do not deform as much as normal blood vessels during the systolic phase of the cycle, resulting in less stored energy. The stored energy can be converted into pressure during the diastolic phase. Thus, the augmentation index (AI) and / or pressure augmentation (p aug ) may be used to at least partially correct for the aortic diastolic gradient. For example, the correction factor may be the augmentation index (AI) and / or the pressure augmentation (p aug ) value may be applied to the aortic diastolic gradient.

[0234] One or more methods may be used to calculate the aortic diastolic pressure gradient. The aortic diastolic pressure gradient may be calculated from the gradient of two points in diastole (such as the dicrotic ridge and the minimum). The aortic diastolic pressure gradient may be calculated from the gradient of a linear fit of the left ventricular diastolic pressure (part or all). For example, with reference to FIG. 23D, a linear fit of the left ventricular pressure waveform (LVEP) 2340 during the diastolic portion (part or all) of the cycle 2344 may be calculated. For example, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the diastole may be used. As another example, pressure data at the midpoint of the diastolic phase may be used, and 20% or 75% of the diastolic phase may be used by removing a portion proximal (early in the beat) and distal (late in the beat) from the midpoint. The aortic diastolic pressure gradient may be calculated from the gradient of a linear fit of the filtered pressure signal of the aortic diastolic pressure (part or all). The aortic diastolic pressure gradient may be calculated (in part or in whole) from the gradient of a polynomial or exponential order distribution of aortic diastolic pressure.

[0235] The left ventricular diastolic pressure gradient may be used (in some cases exclusively) to assess regurgitation. For example, pressure tracings with identified regurgitation may be used to form a correlation between the left ventricular diastolic pressure gradient and regurgitation. One or more methods may be used to calculate the left ventricular diastolic pressure gradient. The left ventricular diastolic pressure gradient may be calculated from the gradient between the points of left ventricular diastolic pressure (LVDP) and / or end diastolic ventricular pressure (LVEDP). The left ventricular diastolic pressure gradient may be calculated from the gradient of a linear fit of the left ventricular diastolic pressure (part or all). The left ventricular diastolic pressure gradient may be calculated from the gradient of a linear fit of the filtered pressure signal of the left ventricular diastolic pressure (part or all). The left ventricular diastolic pressure gradient may be calculated (part or all) from the gradient of a polynomial order distribution or an exponential order distribution of the left ventricular diastolic pressure.

[0236] Some backflow calculations may be based on the gradient of the left ventricular diastolic pressure and the gradient of the aortic diastolic pressure. One or more methods may be used to calculate backflow from the diastolic pressure gradient. Backflow may be calculated (in part or in whole) by adding and / or subtracting at least the (possibly averaged) angled left ventricular diastolic pressure gradient and the angled aortic diastolic pressure gradient. As used herein, in addition to its ordinary meaning, "angled gradient" refers to the inclination angle of the gradient. Backflow index may be calculated by multiplying and / or dividing at least the left ventricular diastolic pressure gradient and the aortic diastolic pressure gradient. As described herein, the corrected aortic diastolic gradient may be used in the backflow calculation based on the augmentation index and / or pressure augmentation.

[0237] vi. Time constant indicator Variation in the time constant of diastolic pressure decay (both pre- and post-procedure) may correlate with patient outcome after the procedure. In other words, the time constant indicator may be useful to clinicians to determine whether regurgitation has improved or worsened after a procedure, such as a transcatheter aortic valve replacement (TAVR) procedure.

[0238] An exemplary equation for estimating the time constant τ (which may be in seconds) is presented below: τ = A 12 / (P1-P2)

[0239] In the exemplary formula, A 12 is the integral of pressure between time t1 and time t2 of the arterial pressure wave in diastole, P1 is the arterial pressure at time t1, and P2 is the arterial pressure at time t2. Time t1 may be selected to be shortly after ejection ends, and time t2 may be selected to be shortly before the next ejection begins. An exemplary equation for estimating the time constant may be used to estimate arterial compliance in a three-element Windkessel model.

[0240] Advantageously, the time constant may be independent of heart rate (which may be different from the Aortic Regurgitation Index (ARI) and / or the Time Integrated Aortic Regurgitation Index (TIARI)). On the other hand, the time constant is sensitive to aortic stiffness since it is measured in the aortic pressure signal. Therefore, the variation of the time constant may be more meaningful than the time constant itself in terms of evaluating the outcome of the treatment.

[0241] The time constant (and / or its variation) between aortic and ventricular pressures during diastole may also be useful. An exemplary formula for estimating the time constant (which may be in seconds) between aortic and ventricular pressures is presented below.

number

[0242] In this example formula, Area(AO-LV) 12 where AO1, AO2, LV1, and LV2 are the aortic and left ventricular pressure waves between times t1 and t2 during diastole, and AO1, AO2, LV1, and LV2 are the aortic and left ventricular pressures at times t1 and t2, respectively. As described herein, the aortic and left ventricular pressure measurements may be obtained via pressure sensing devices, such as diagnostic catheters, guide catheters, pigtail catheters, and / or pressure guidewires, in the aorta and / or left ventricle.

[0243] The time constant (and / or its variation) of left ventricular pressure during diastole may also be useful since left ventricular diastolic pressure is significantly affected by regurgitant flow. An exemplary formula for estimating the time constant (which may be in seconds) for ventricular pressure is presented below:

number

[0244] In the exemplary formula, Area(LV) 12 where LV1 and LV2 are the left ventricular pressures at times t1 and t2, respectively, during diastole. Here again, as described herein, the left ventricular pressure measurements may be obtained via a pressure sensing device, such as a catheter or pressure guidewire.

[0245] vii. Heart Rate Selection Diastole may be the region of interest or the heartbeat phase of interest when assessing regurgitation in a patient (e.g., the calculation of a regurgitation index for a patient may use diastole). Furthermore, procedures such as transcatheter aortic valve replacement (TAVR) procedures may often cause premature ventricular contractions and / or multiple ectopic beats, which may significantly reduce the diastolic portion of the cycle. Therefore, it may be advantageous to use adequate or sufficient heartbeats when calculating the respective index or indicator for one or more of the indices and / or indicators described herein. In other words, it may be advantageous to exclude inappropriate heartbeats, such as premature ventricular contractions and / or multiple ectopic beats, when calculating one or more of the indices and / or indicators described herein.

[0246] In some embodiments, the system can classify the heart beat using the heart beat length. The system can then use the heart beat classification to determine whether the heart beat should be included or excluded from the calculation of an index or indicator. For example, if the system identifies a heart beat as inappropriate based on the heart beat length, the system can exclude the heart beat from being used in the calculation of an index or indicator. The system can exclude heart beats that are above or below a certain threshold time. For example, a patient's average (or other statistical measure) heart rate is 65 beats per minute, which can be converted to heart beat length in seconds. In some embodiments, the system can reject heart beats that are 10%, 20%, 30% longer, or shorter than a certain heart beat length (e.g., the average heart beat length at a resting heart rate or a treatment-induced rate).

[0247] In some embodiments, the system can classify heart beats using the length of the aortic or left ventricular pressure trace in diastole. The system can then use the heart beat classification to determine whether the heart beat should be included or excluded from the calculation of an index or indicator. For example, if the system identifies a heart beat as inappropriate based on the length of the aortic or left ventricular pressure trace in diastole within a heart beat, the system can exclude the heart beat from being used in the calculation of an index or indicator. The system can exclude short heart beats with an aortic diastolic length or left ventricular diastolic length that exceeds or falls below a certain threshold time. For example, the average (or other statistical measure) aortic diastolic length or left ventricular diastolic length (in seconds) can be pre-determined, determined in the procedure, and / or received. In some embodiments, the system can reject heart beats with an aortic diastolic length or left ventricular diastolic length that is 10%, 20%, 30% longer or shorter than a particular aortic diastolic length or left ventricular diastolic length (such as an average aortic diastolic length or an average left ventricular diastolic length).

[0248] In some embodiments, the system can classify a heartbeat using an aortic or left ventricular pressure value during systole within the heartbeat. The system can then use the heartbeat classification to determine whether the heartbeat should be included or excluded from the calculation of an index or indicator. For example, if the system identifies a heartbeat as inappropriate based on the aortic or left ventricular systolic pressure within the heartbeat, the system can exclude the heartbeat from being used in the calculation of the index or indicator. The system can exclude heartbeats with aortic or left ventricular systolic pressures higher or lower than a particular threshold pressure. For example, the average (or other statistical measure) aortic or left ventricular systolic pressure can be pre-determined, determined in the procedure, and / or received. In some embodiments, the system can reject heartbeats with aortic or left ventricular systolic pressures that are 10%, 20%, 30% longer or shorter than a particular aortic or left ventricular systolic pressure (such as the average aortic or left ventricular systolic pressure).

[0249] Additional techniques based on pressure measurements and / or ECG tracings may be used to identify irregular heartbeats for potential exclusion. For example, the ECG tracing may be compared to a first library of ECG tracings associated with normal heartbeat cycles. Similarly, the ECG tracing may be compared to a second library of ECG tracings associated with irregular heartbeat cycles. The system may determine whether the ECG tracing matches (or does not match) an ECG tracing from the library using one or more mathematical techniques, such as, but not limited to, partial least squares regression, linear regression, non-linear regression, and / or other comparative analysis techniques. In some embodiments, a threshold for determining how close (or far) an ECG tracing must be to an ECG tracing from the library to be considered a match (or not a match) may be selected based on user preferences, empirical results, and / or combinations thereof. In some embodiments, the ECG tracing may be compared to an objective metric to determine whether an associated heartbeat cycle is considered normal or irregular. For example, in some implementations, heart rate is used to evaluate the ECG tracing. If the heart rate is faster or slower than the normal range, the corresponding heart rate cycle may be considered irregular.

[0250] A similar matching and comparison approach may be used for pressure measurements. For example, the waveform for an acquired pressure measurement may be compared to a library of pressure measurement waveforms for normal and / or irregular cardiac cycles, respectively. The system may determine whether the pressure waveform matches (or does not match) a pressure waveform from the library using any of the techniques described herein, such as, but not limited to, partial least squares regression, linear regression, non-linear regression, and / or other comparative analysis techniques.

[0251] In some embodiments, the pressure measurements and / or ECG traces may be compared to other pressure measurements and / or ECG traces. In that regard, if a pressure measurement and / or ECG trace deviates too far from other pressure measurements and / or ECG traces, respectively, the heartbeat associated with that pressure measurement and / or ECG trace may be considered an irregular heartbeat cycle. The assessment of whether a pressure measurement and / or ECG trace deviates too far from other pressure measurements and / or ECG traces, respectively, may be determined using statistical analysis techniques, such as, but not limited to, deviation from the mean, deviation from the median, and / or other suitable deviation analysis techniques.

[0252] e. Calibrating additional pressure sensors As described herein, a first sensor may be calibrated against a second sensor to determine a more accurate pressure measurement, which may also be referred to as equalization. For example, a pressure guidewire may be at or near the valve location along with another pressure device. The other pressure device may be a catheter, pigtail, or other device with a lumen used to deliver the valve and connected to a pressure transducer. The pressure device may be another pressure guidewire or a catheter with a tip pressure sensor. The additional pressure device may include a piezoelectric sensor and / or an optical sensor. Exemplary pressure devices that may be equalized may be selected from, but are not limited to, a pressure guidewire, a catheter, a pigtail, a tip pressure sensor, a piezoelectric sensor, and / or an optical sensor. Thus, exemplary combinations of pressure devices that may be equalized may include two pigtails, two piezoelectric sensors, two optical sensors, and / or any other combination of pressure devices. However, unlike some of the calibration techniques described herein where the pressure devices are placed in the same cardiac vascular region for calibration purposes, other calibration techniques described herein may be performed while there are pressure devices placed in different cardiac vascular regions, such as a first device placed in the left ventricle and a second device placed in the aorta. As described herein, calibration of pressure devices while they are placed in different cardiac vascular regions of the heart may be accomplished by detecting one or more features from the pressure waveform. In particular, the detected one or more features in the pressure waveform may be used to perform time and / or gain adjustments on the pressure waveform for equalization purposes.

[0253] The systems and methods described herein for calibrating pressure sensors while pressure devices are in different locations can improve the efficiency of pressure readings. For example, as noted above, pressure calibration can be performed when pressure devices are positioned in the same cardiovascular region. However, ensuring that both pressure devices are positioned in the same cardiovascular region can add additional steps to a cardiac procedure. The techniques described herein relating to calibrating by time adjustments and / or gain adjustments from waveform features can be advantageously performed while the pressure devices are in different locations as required in a cardiac procedure. Thus, the systems and methods described herein for calibrating while pressure devices are in different locations can improve pressure device technology by being able to provide more accurate pressure readings without adding additional steps to a cardiac procedure.

[0254] The aortic pressure waveform may differ from the ventricular pressure waveform. For example, with respect to FIG. 20 described above, the aortic pressure may begin to rise at the beginning of the systolic phase, as shown by aortic pressure waveform 2011. In particular, the aortic pressure may begin to rise when the aortic valve opens at the beginning of aortic valve open time period 2012. The aortic pressure waveform 2011 grows until it reaches a maximum value at time period 2012, which is at least the systolic pressure, and then rapidly decreases until it reaches a dicrotic crest at the end of time period 2012. The dicrotic crest represents the moment the aortic valve closes. These two moments when the aortic valve opens and closes may be useful for equalization, as they may represent the only points at which the ventricular pressure and the aortic pressure can be equal. These two moments, the opening and closing of the aortic valve, may generally correspond to the beginning and end of time period 2012, respectively. The left ventricular pressure waveform 2010 may cross the aortic pressure waveform 2011 at the beginning and end of a time period 2012 .

[0255] In FIG. 24, pressure waveforms that may include a phase delay are depicted. In particular, a left ventricular pressure waveform 2402 and an aortic pressure waveform 2404 are depicted. In contrast to the intersection of the left ventricular pressure waveform 2010 and the aortic pressure waveform 2011 in FIG. 20, the left ventricular pressure waveform 2402 may intersect with the aortic pressure waveform 2404 in FIG. 24 at different instants with respect to the characteristics of the aortic pressure waveform 2404. In particular, in FIG. 24, the left ventricular pressure waveform 2402 does not intersect with the aortic pressure waveform 2404 at the time of valve opening 2406 or at the time of the dicrotic ridge 2408. The calibration techniques described herein may be applied to the pressure waveforms 2402, 2404 in FIG. 24. In particular, a time adjustment may be applied to the pressure waveforms in FIG. 24.

[0256] In FIG. 25, pressure waveforms that may include gain errors are depicted. In particular, a left ventricular pressure waveform 2502 and an aortic pressure waveform 2504 are depicted. In the pressure waveforms of FIG. 25, there may be errors in gain that may cause amplitude variations. For example, the left ventricular pressure waveform 2502 may include a gain error of about 1.3, which may cause a broadening of the point where the left ventricular pressure waveform 2502 crosses the aortic pressure waveform 2504. In particular, the pressure value 2508 of the left ventricular pressure waveform 2502 may be higher than the pressure value 2506 of the aortic pressure waveform 2504 at the dicrotic feature of the aortic pressure waveform 2504. In another example, when the gain is less than 1, the crossing points are closer together (not illustrated). The calibration techniques described herein may be applied to the pressure waveforms 2502, 2504 of FIG. 25. In particular, gain adjustments may be applied to the pressure waveforms of FIG. 25.

[0257] In Figure 26, pressure waveforms are depicted that may include phase delay and gain error. In particular, a left ventricular pressure waveform 2602 and an aortic pressure waveform 2604 are depicted. The calibration techniques described herein may be applied to the pressure waveforms 2602, 2604 of Figure 26. In particular, time adjustments and / or gain adjustments may be applied to the pressure waveforms of Figure 26.

[0258] Another exemplary calibration process 2700 is shown in FIG. 27. The process 2700 is described in conjunction with a heart valve evaluation system such as the system 200 of FIG. 2A or the system 1400 of FIG. 14, however, any system configured to perform the process, in any order, is within the scope of the present disclosure. The process 2700 may be performed by various components of the system 200 of FIG. 2A or the system 1400 of FIG. 14, as described herein. Depending on the embodiment, the process 2700 may include fewer or additional blocks and / or the blocks may be performed in a different order than illustrated. Other embodiments of the process 2700 may include fewer blocks than illustrated or the blocks may be performed in a different order than illustrated.

[0259] In some embodiments, one set of pressure values ​​may be from a pressure sensor (such as a pressure fluid-filled line) positioned in the left ventricle, and the other set of pressure values ​​may be from a different pressure sensor (such as a pressure guidewire) positioned in the aorta. Furthermore, in some embodiments, the heart valve evaluation system 1400 may adjust the pressure values ​​for the left ventricle based on the output of the calibration process 2700. In some cases, the pressure fluid-filled line has a relatively large delay compared to the pressure guidewire due to pressure propagation time in the fluid-filled line. Therefore, it may be advantageous to adjust the left ventricular pressure instead of the aortic pressure. As described herein, there may be multiple options. For example, in addition or alternatively, the heart valve evaluation system 1400 may adjust the pressure values ​​for the aorta based on the output of the calibration process 2700.

[0260] Beginning at block 2702, pressure devices may be zeroed. In particular, the cardiac valve evaluation system 1400 may zero one or more pressure devices. As used herein, "zeroing" may refer to a process in which an external pressure, such as atmospheric pressure, on the system 1400 may be counteracted. The system 1400 may zero one or more pressure devices to eliminate other pressure signals other than the actual pressure from the patient. As a result of zeroing, more accurate data may be obtained on which to base treatment / surgical decisions.

[0261] In block 2704, pressure values ​​or signals may be received or determined. In particular, the cardiac valve evaluation system 1400 may receive pressure signals from a pressure sensor, such as the pressure guidewire 208, the pressure sensing access catheter 20, the pressure sensing pigtail catheter 10, a tip pressure sensor, a piezoelectric sensor, and / or an optical sensor. The cardiac valve evaluation system 1400 may determine a first set of pressure values ​​and a second set of pressure values ​​from the received pressure signals. Each pressure value from the first set of pressure values ​​may correspond to a first signal received from a first pressure sensor measuring a first cardiac vascular region. Each pressure value from the second set of pressure values ​​may correspond to a second signal received from a second pressure sensor measuring a second cardiac vascular region different from the first cardiac vascular region. For example, the first pressure sensor may be positioned in a first portion of the heart and the second pressure sensor may be positioned in a cardiac vascular region adjacent to the first portion of the heart. The cardiac valve evaluation system 1400 can determine first and second sets of pressure values ​​from the first and second sensors, respectively. The present block 2704 for receiving a pressure value or signal can be similar to block 1502 of FIG. 15 for receiving a pressure value or signal.

[0262] At block 2706, feature detection may be performed. The feature detection service 1412 may perform feature detection. Exemplary features that may be detected from a pressure waveform may include a systolic phase, a diastolic phase, a dicrotic ridge, an end of diastole, and / or a beginning of systole. The feature detection service 1412 may identify features within the exemplary pressure waveforms of FIGS. 24-26. In particular, the feature detection service 1412 may determine a substantial beginning of a systolic phase in a set of pressure values. As another example, the feature detection service 1412 may determine a dicrotic ridge feature in a set of pressure values. Additional details regarding feature detection are described in more detail above with respect to the process 1900 of FIG. 19. The present block 2706 for performing feature detection may be similar to the block 1508 of FIG. 15 for performing feature detection.

[0263] In some embodiments, the feature detection service 1412 can perform feature detection by applying one or more thresholds. In some pressure waveforms, the valve opening crossing point may not be completely at the beginning of systole, but slightly after or before. For example, the pressure required to open highly calcified valve leaflets may delay the aortic pressure transmission, resulting in a flatter aortic pressure curve and changing the crossing point. For example, the feature detection service 1412 can identify the substantial beginning of the systolic phase within a percentage of the heartbeat period before or after the end of the diastolic phase in the set of pressure values. As another example, the feature detection service 1412 can identify a timestamp corresponding to a dicrotic ridge feature, the timestamp may be within a percentage of the heartbeat period before or after the dicrotic ridge in the set of pressure values. Exemplary threshold percentages may include between approximately 0 percent and 1 percent of the heartbeat period, between 0 percent and 2 percent, between 0 percent and 5 percent, and between 0 percent and 10 percent.

[0264] At block 2708, a time adjustment may be calculated. In particular, the calibration service 1408 may calculate a time adjustment. The calibration service 1408 may calculate a time adjustment that causes the set of pressure values ​​to cross the basis set of pressure values ​​at a substantial onset of the systolic phase in the basis set of pressure values. For example, in the context of the pressure waveforms of FIG. 24, the calibration service 1408 may calculate a time adjustment that causes the left ventricular pressure waveform 2402 to cross the aortic pressure waveform 2404 at a substantial onset of the systolic phase / valve opening 2406. An exemplary time adjustment may be a time value in units of time, such as milliseconds or seconds. At block 2710, a time adjustment may be applied. In particular, the calibration service 1408 may apply a time adjustment to the set of pressure values ​​such that a value from the set of pressure values ​​corresponds to a value at a substantial onset of the systolic phase in the basis set of pressure values.

[0265] At block 2712, a gain adjustment may be calculated. In particular, the calibration service 1408 may calculate the gain adjustment. The calibration service 1408 may measure the pressure difference at the dicrotic ridge location and calculate the needed gain correction. In particular, the calibration service 1408 may use the dicrotic ridge feature detected in the basis set of pressure values. The calibration service 1408 may identify a timestamp corresponding to the dicrotic ridge feature and determine a first value at that timestamp from the basis set of pressure values. The calibration service 1408 may further determine a second value at that timestamp from another set of pressure values. Where the first value corresponds to V1 and the second value corresponds to V2, and the gain adjustment may include g, an exemplary formula for calculating the gain adjustment may be substantially

[0266]

number

[0267] For example, in the context of the pressure waveforms of FIG. 25, the calibration service 1408 can calculate a gain adjustment from the pressure value 2506 of the aortic pressure waveform 2504 divided by the pressure value 2508 of the left ventricular pressure waveform 2502 (i.e., Gain correction =Ao Dicrotic / Lv Dicrotic ).

[0268] A gain adjustment may be applied at block 2714. In particular, the calibration service 1408 can apply a gain adjustment to the set of pressure values ​​to achieve gain correction. In some embodiments, the calibration service 1408 can multiply each value forming the set of pressure values ​​by a gain adjustment to modify the amplitude of the pressure values.

[0269] At block 2716, it may be determined whether an exit condition for the calibration process 2700 has been met. In particular, the calibration service 1408 may determine whether an exit condition has been met. An exemplary exit condition may include determining whether an intersection point for a set of pressure values ​​is within a threshold range of a basis set of pressure values ​​at one or more detected features. For example, the calibration service 1408 may determine that an intersection point from the left ventricular pressure waveform is within a threshold range from a substantial beginning of the systolic phase at the aortic pressure value. As another example, the calibration service 1408 may determine that an intersection point from the left ventricular pressure waveform is within a threshold range from a dicrotic ridge feature at the aortic pressure value. If the condition is not met, the process may return to previous blocks 2708, 2710, 2712, 2714 to recalculate and apply calibration parameters, such as time and / or gain adjustments. Thus, the calibration service 1408 may operate in a loop until an exit condition is met. For example, the calibration service 1408, in some embodiments, can operate in a loop until a pressure waveform intersection coincides with a valve opening as indicated by a feature in the pressure waveform. If an exit condition is met, the process continues to block 2718.

[0270] The determined calibration parameters may be stored and / or used at block 2718. In particular, the calibration service 1408 may store and / or use time adjustments and / or gain adjustments. For example, the calibration service 1408 may apply time adjustments and / or gain adjustments to a set pressure value and / or signal received from the pressure device after the calibration is completed.

[0271] f. Additional heart valve evaluation methods Referring to FIG. 28, an exemplary valve evaluation process 2800 is shown. The process 2800 is described in conjunction with a heart valve evaluation system, such as the system 200 of FIG. 2A or the system 1400 of FIG. 14, however, any system configured to perform the process, in any order, is within the scope of the present disclosure. The process 2800 may be performed by various components of the system 200 of FIG. 2A or the system 1400 of FIG. 14, as described herein. Depending on the embodiment, the process 2800 may include fewer or additional blocks and / or the blocks may be performed in a different order than illustrated. Other embodiments of the process 2800 may include fewer blocks than illustrated or the blocks may be performed in a different order than illustrated.

[0272] In block 2802, it may be determined whether to control the heart rate. In particular, the clinician may determine whether to control the patient's heart rate. For example, slowing the heart rate may advantageously provide a longer diastolic portion of the aortic pressure signal, which may be used to calculate an improved index or indicator, such as an improved regurgitant index (as described herein). In some embodiments, controlling the heart rate may be included as a step in a cardiac procedure performed for additional reasons. For example, adenosine may be administered to reduce the risk of inducing myocardial ischemia during the procedure. Thus, there may be several reasons to control the heart rate during the procedure. If it is determined that the heart rate should be controlled, the process 2800 proceeds to block 2804 to control the heart rate. If not, the process 2800 proceeds to the next block 2806.

[0273] At block 2804, the heart rate may be controlled. In particular, a clinician may control the patient's heart rate. For example, a clinician may administer a drug, such as adenosine or another type of drug that has a similar pacing effect, to slow the patient's heart rate. Additionally or alternatively, ventricular pacing may be applied to the heart (e.g., electrical stimulation provided by a pacemaker to the ventricles of the heart) at predefined heartbeat intervals. Guidewire 308 or other guidewires configured for pacing as described above may be used to guide ventricular pacing at block 2804 in some applications.

[0274] In block 2806, it may be determined whether to induce an extra-systole. In particular, the clinician may determine whether to induce an extra-systole in the patient. For example, an extra-systole without ejection into the aorta may have the same effect of lowering the heart rate. This will increase the length of the diastolic phase of the pressure signal, which may be used to calculate an improved index or indicator, such as an improved regurgitation index (as described herein). If it is determined that an extra-systole without ejection should be induced, the process 2800 proceeds to block 2808 and induces an extra-systole. If not, the process 2800 proceeds to the next block 2810.

[0275] In block 2808, a premature systole may be induced. In particular, the pacemaker may be configured / programmed to induce a premature systole that does not eject into the aorta. The pacemaker may be configured / programmed to induce a relatively low heart rate, such as 60 BPM or another heart rate, that can induce a premature systole. The pacemaker may induce a premature systole of the heart at a ventricular beat that does not eject into the aorta, which can result in a longer diastolic portion of the aortic pressure signal. The guidewire 308 or other guidewires configured for pacing as described above may be used in some applications in the process of inducing a premature systole in block 2808.

[0276] In block 2810, pressure values ​​or signals may be received or determined. In particular, the system 200, 1400 may receive pressure signals from a pressure sensor, such as the pressure guidewire 208, 308, 408, the pressure sensing access catheter 20, the pressure sensing pigtail catheter 10, a tip pressure sensor, a piezoelectric sensor, and / or an optical sensor. The system 200, 1400 may determine a first set of pressure values ​​and a second set of pressure values ​​from the received pressure signals. Each pressure value from the first set of pressure values ​​may correspond to a first signal received from a first pressure sensor measuring a first portion of the heart. Each pressure value from the second set of pressure values ​​may correspond to a second signal received from a second pressure sensor measuring a cardiovascular region adjacent to the first portion of the heart. For example, the first pressure sensor may be positioned at least in the left ventricle and the second pressure sensor may be positioned at least in the aorta. The system 200, 1400 may determine the first and second sets of pressure values ​​from the first and second sensors, respectively. In some embodiments, the system 200, 1400 can determine or receive one or more time series of pressure values. For example, the system 200, 1400 can determine a time series of pressure values ​​from a pressure sensor positioned at a portion of the heart. As another example, the system 200, 1400 can determine or receive a first set of time series pressure values ​​from a first pressure sensor positioned at a first portion of the heart and a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart. Exemplary time series pressure values ​​may include pairs of pressure values ​​and time. The present block 2810 for receiving pressure values ​​or signals may be similar to block 1502 of FIG. 15 for receiving pressure values ​​or signals.

[0277] At block 2812, it may be determined whether to select a heart beat. In particular, the system 200, 1400 may determine whether to select a heart beat. A configuration setting may indicate whether the system 200, 1400 should select a heart beat. In some embodiments, the configuration setting may be user selected. As described herein, it may be advantageous to filter out inappropriate heart beats when the system 200, 1400 determines an index or indicator. If it is determined that a heart beat should be selected, the process 2800 proceeds to block 2814 to select a heart beat. If not, the process 2800 proceeds to the next block 2816.

[0278] At block 2814, a heart beat or a series or other plurality of heart beats may be selected. In an example, the system 200, 1400 may select a heart beat. For example, the system 200, 1400 may identify a first heart beat and a second heart beat from the first time series and / or the second time series. The system 200, 1400 may determine characteristics of the first heart beat and the second heart beat. The system 200, 1400 may associate the first heart beat with a first category based at least in part on a first characteristic of the first heart beat. Similarly, the system 200, 1400 may associate the second heart beat with a second category based at least in part on a second characteristic of the second heart beat. Either the first category or the second category may indicate that the first heart beat and the second heart beat have been accepted or rejected, respectively. The system 200, 1400 can include beats in the calculation of which beats were accepted and can exclude rejected beats.

[0279] Exemplary features of a heartbeat may correspond to the elapsed time of the heartbeat, the elapsed time of the diastolic phase of the heartbeat, and the pressure from the systolic phase of the heartbeat. In some embodiments, the system 200, 1400 can classify the heartbeat based on the length of the heartbeat. For example, the system 200, 1400 can determine that the elapsed time of the heartbeat is outside a threshold range and reject the heartbeat. In other words, the system 200, 1400 can determine that the length of the heartbeat is either too long or too short and reject the heartbeat accordingly. In some embodiments, the system 200, 1400 can classify the heartbeat based on the length of the diastolic phase of the heartbeat. For example, the system 200, 1400 can determine that the elapsed time of the diastolic phase of the heartbeat is above a threshold time and reject the heartbeat accordingly. In some embodiments, the system 200, 1400 can classify the heartbeat based on the pressure value of the heartbeat. For example, the system 200, 1400 may determine that the pressure from the systolic phase of the heartbeat exceeds a threshold and reject the heartbeat.

[0280] At block 2816, the heart rate may be determined. In particular, the system 200, 1400 may determine or receive the patient's heart rate. For example, the system 200, 1400 may determine the patient's heart rate from an electrocardiogram (ECG). In other embodiments, the heart rate may be determined from other physiological sensors monitoring the patient, such as a photoplethysmography (PPG) based heart rate monitor.

[0281] In block 2818, a value indicative of the heart valve status, such as an index or indicator, may be determined. In particular, the system 200, 1400 may determine the heart valve status based on the data of the previous block. As described herein, exemplary values ​​indicative of the heart valve status may include a regurgitation index, a time-integrated regurgitation index, a time constant, a hemodynamic, and other indexes and indicators described herein. In some embodiments, the system 200, 1400 may determine the regurgitation index based at least in part on (i) a first value from the first pressure value and (ii) a second value from the second pressure value. The current block 2810 for determining a value indicative of the heart valve status may be similar to block 1308 of FIG. 13 and / or block 1510 of FIG. 15 or determining a value indicative of the heart valve status. Additional details regarding determining a value indicative of the heart valve status are described above in sections III and IV.

[0282] In some embodiments, the system 200, 1400 can determine a regurgitation index normalized over heartbeat length. From the first pressure value, the system 200, 1400 can calculate (i) a first end-diastolic pressure in the first portion of the heart and (ii) a systolic pressure in the first portion of the heart. From the second pressure value, the system 200, 1400 can calculate a second end-diastolic pressure in a cardiovascular region adjacent to the first portion of the heart. The system 200, 1400 can determine the regurgitation index from calculating a pressure difference between the first end-diastolic pressure and the second end-diastolic pressure and calculating a value from the pressure difference that is normalized at least in part based on the systolic pressure and the heart rate. For example, the system 200, 1400 can calculate the aortic regurgitation index using a heart rate, such as 60 beats per minute (BPM). As described above in block 2804 for controlling the heart rate, one or more techniques may be used to control the heart rate (e.g., administer a drug or initiate ventricular pacing) before the system 200, 1400 calculates an index or indicator.

[0283] In some embodiments, the system 200, 1400 can determine a regurgitation index as described herein. The system 200, 1400 can calculate (i) a first end-diastolic pressure in the first portion of the heart and (ii) a systolic pressure in the first portion of the heart from the first pressure value. The system 200, 1400 can calculate a second end-diastolic pressure in a cardiac vascular region adjacent to the first portion of the heart from the second pressure value. The system 200, 1400 can determine a regurgitation index based at least in part on the first end-diastolic pressure, the second end-diastolic pressure, and the systolic pressure.

[0284] In some embodiments, the system 200, 1400 can determine a regurgitation index based on at least the diastolic slope as described herein. The system 200, 1400 can identify a subset of the time series of pressure values ​​that corresponds to at least a portion of the diastolic phase. The system 200, 1400 can calculate a first slope from the subset of the time series of pressure values. One exemplary method for the system 200, 1400 to calculate the first slope can include determining a linear fit from the subset of the time series of pressure values ​​and calculating the first slope from the linear fit. Another exemplary method for the system 200, 1400 to calculate the first slope can include determining a polynomial function from the subset of the time series of pressure values ​​and calculating the first slope from the polynomial function. Yet another exemplary method for the system 200, 1400 to calculate the first slope can include determining an exponential function from the subset of the time series of pressure values ​​and calculating the first slope from the exponential function. The system 200, 1400 can identify a first regurgitation index based at least in part on the first slope, where identifying the first regurgitation index can include finding a first regurgitation index that correlates with the first slope. As described herein, a time series of pressure values ​​can be obtained from a sensor location in at least a portion of the left ventricle. Additional details regarding using the diastolic slope are described in more detail above in Section IV.

[0285] In some embodiments, the system 200, 1400 can determine a correlation between the gradient and the reflux index. The system 200, 1400 can access pressure measurements, where each pressure measurement from the pressure measurements corresponds to a patient. For each pressure measurement from the pressure measurements, the system 200, 1400 can calculate a pair including a diastolic gradient and a reflux index from the pressure measurements. The system 200, 1400 can determine a correlation between the diastolic gradient and the reflux index based at least in part on the pair of the diastolic gradient and the reflux index. Thus, the system 200, 1400 can find the reflux index from the first gradient by applying the determined correlation between the diastolic gradient and the reflux index to the first gradient.

[0286] In some embodiments, the system 200, 1400 can determine a regurgitation index based on at least two diastolic gradients as described herein. The system 200, 1400 can identify a first subset of time series of pressure values ​​corresponding to at least a portion of the diastolic phase and identify a second subset of time series of pressure values ​​corresponding to at least a portion of the diastolic phase. As described herein, the first and second time series can be from sensors positioned at least in the left ventricle and the aorta, respectively. The system 200, 1400 can calculate (i) a first gradient from the first subset of time series of pressure values ​​and (ii) a second gradient from the second subset of time series of pressure values. The system 200, 1400 can determine a regurgitation index based at least in part on the first gradient and the second gradient. Additional details regarding using multiple diastolic gradients are described in more detail above in Section IV.

[0287] In some embodiments, the system 200, 1400 can determine a reflux index from the multiple diastolic slopes using a statistical measure (such as an average). The system 200, 1400 can calculate a first slope from a subset of a first time series of pressure values, the first slope including the first slope, and a second slope from a subset of a second time series of pressure values, the second slope including the second slope. The system 200, 1400 can determine a slope angle for each slope of the first slope and the second slope. The system 200, 1400 determining the reflux index can include determining a first statistical measure from the slope angle for each slope of the first slope, determining a second statistical measure from the slope angle for each slope of the second slope, and calculating a combined statistical measure from the first statistical measure and the second statistical measure. The system 200, 1400 can assign the combined statistical measure as the reflux index. In some embodiments, the system 200, 1400 can calculate a combined statistical measure by at least one of adding and subtracting a first statistical measure and a second statistical measure. In particular, the system 200, 1400 can calculate an exemplary combined statistical measure by adding and / or subtracting at least a first gradient of the (possibly averaged) angle (such as a left ventricular diastolic pressure gradient) and a second gradient of the angle (such as an aortic diastolic pressure gradient).

[0288] In some embodiments, the system 200, 1400 can determine a regurgitation index by combining multiple diastolic gradients. The system 200, 1400 can determine a first gradient angle for the first gradient and a second gradient angle for the second gradient. The system 200, 1400 can determine the regurgitation index by at least calculating a combined gradient angle from the first gradient angle and the second gradient angle and assigning the combined gradient angle as the regurgitation index. In some embodiments, the system 200, 1400 calculating the combined gradient angle can include at least one of adding, subtracting, multiplying, or dividing the first gradient angle and the second gradient angle. For example, the system 200, 1400 can calculate the regurgitation index by multiplying and / or dividing at least the left ventricular diastolic pressure gradient and the aortic diastolic pressure gradient.

[0289] In some embodiments, the system 200, 1400 can correct the diastolic slope. The system 200, 1400 can determine an initial slope from a subset of the second time series of pressure values. The system 200, 1400 can determine a correction factor from the second time series of pressure values. The system 200, 1400 can calculate a corrected diastolic slope from the initial slope by applying the correction factor to the initial slope. The system 200, 1400 can assign the corrected diastolic slope to the second slope, which can be used as described above. As described herein, the system 200, 1400 can determine the correction factor by calculating at least one of an augmentation index or a pressure augmentation from the second time series of pressure values ​​and identifying the correction factor based at least in part on one of the augmentation index or the pressure augmentation.

[0290] In some embodiments, the system 200, 1400 can determine a regurgitation index based at least on the beat selection. For example, the system 200, 1400 determining the regurgitation index can include excluding the first heart beat as rejected based at least in part on a first category and including the second heart beat as accepted based at least in part on a second category. The system 200, 1400 can calculate the regurgitation index based at least in part on (i) a first portion of the first time series associated with the second heart beat and (ii) a second portion of the second time series associated with the second heart beat.

[0291] In some embodiments, the system 200, 1400 can determine a time constant and / or an indicator based on a time constant as a value indicative of a cardiac valve condition. In particular, the system 200, 1400 can calculate a time constant from a set of time series pressure values. As described herein, the system 200, 1400 can calculate a time constant at least substantially

number

[0292] Area (PR) 12 may be the area between (i) a first time series of pressure values ​​from a first portion of the heart and (ii) a second time series of pressure values ​​from a cardiovascular region adjacent to the first portion of the heart, and between the first time and the second time. P1 is a first pressure value from the first time series of pressure values. R1 is a first pressure value from the second time series of pressure values ​​at the first time. P2 is a second pressure value from the first time series of pressure values ​​at the second time. R2 is a second pressure value from the second time series of pressure values ​​at the second time. As described herein, the first portion of the heart may include at least the left ventricle, and the cardiovascular region adjacent to the first portion may include at least the aorta. The first time and the second time may be in the diastolic phase.

[0293] In some embodiments, the system 200, 1400 can determine the time constant from a time series from a pressure sensor positioned within a single portion of the heart. In particular, the system 200, 1400 can calculate the time constant from a set of time series pressure values ​​obtained from a single portion of the heart. As described herein, the system 200, 1400 can calculate the time constant at least substantially

number

[0294] Area(P) 12 P may be the area under the time series of pressure values ​​between the first time and the second time. P1 is a first pressure value from the time series of pressure values ​​at the first time. P2 is a second pressure value from the time series of pressure values ​​at the second time. As described herein, the single portion of the heart may include at least the left ventricle or the aorta. The first time and the second time may be within the diastolic phase.

[0295] In block 2820, it may be determined whether multiple values ​​indicative of a cardiac valve state should be determined. In particular, the system 200, 1400 may determine whether multiple values ​​indicative of a cardiac valve state should be determined based on a particular configuration setting of the system 200, 1400 and / or a user selection via a graphical user interface. Some graphical user interfaces described herein may present multiple indices or indicators from different time periods and / or values ​​indicative of a cardiac valve state including multiple indices or indicators. For example, the graphical user interface of the system 200, 1400 may present a regurgitation difference value from a first and a second regurgitation index from different time periods (such as before and after a cardiac procedure). If multiple valve states are to be determined and the valve state is not ready, the process 2800 returns to the first block 2802. If multiple valve states are to be determined and the valve state is ready, the process 2800 proceeds to block 2824 to determine a combined valve state, if applicable. Otherwise, the process 2800 proceeds to block 2822 to present a value indicative of the heart valve status.

[0296] In some embodiments, the system 200, 1400 allows a user to tag regurgitant calculations for comparison purposes. For example, the graphical user interface of the system 200, 1400 can receive a user selection to tag a regurgitant value for later comparison. A later graphical user interface, which may be similar to the user interface 1000 of FIG. 10A, can then present a combined value indicative of a heart valve status using the tagged regurgitant values. For example, the graphical user interface, which may be presented during a live procedure, can present a regurgitant ratio using the tagged values.

[0297] At block 2822, a value indicative of the heart valve status may be presented. In particular, the system 200, 1400 may present a value (such as an index or indicator) indicative of the heart valve status in a user interface. The value indicative of the heart valve status may be presented in a user interface as described herein. Additional details regarding the presentation of the valve status are described in more detail above with respect to block 1310 of FIG. 13 and the user interfaces of FIGS. 10A-10E and 11A-11E.

[0298] As noted above, multiple valve states are to be determined, and if the valve state is not ready, the process 2800 returns to the first block 2802. Thus, in some embodiments, the previous blocks 2802, 2804, 2806, 2808, 2810, 2812, 2814, 2816, 2818 may correspond to a first time period, such as a time period before a cardiac procedure. Thus, prior to a cardiac procedure, the system 200, 1400 may determine a first pressure value (e.g., a first set of time series pressure values) from at least (i) a first pressure sensor positioned in a first portion of the heart, and (ii) a second pressure sensor positioned in a cardiac vascular region adjacent the first portion of the heart. The system 200, 1400 may calculate a first value indicative of a cardiac valve state, such as a first regurgitation index and / or a second time constant, from the first pressure value from the first time period.

[0299] Thus, the process 2800 may pass through blocks 2802, 2804, 2806, 2808, 2810, 2812, 2814, 2816, 2818 a second time. For example, the system 200, 1400 may determine a second value indicative of a heart valve status for a second time period, such as after a cardiac procedure. Thus, after the cardiac procedure, the system 200, 1400 may determine second pressure values ​​(e.g., a second set of time series pressure values) from at least (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart. The system 200, 1400 may calculate a second value indicative of a heart valve status, such as a second regurgitation index and / or a second time constant, from the second pressure values ​​from the second time period.

[0300] In block 2824, a combined valve state may be determined. In particular, the system 200, 1400 may determine a combined value indicative of a heart valve state, if applicable. In some embodiments, the system 200, 1400 may determine a regurgitation difference value based at least in part on the second regurgitation index and the first regurgitation index. For example, the system 200, 1400 may calculate a regurgitation difference value by (i) calculating a normalized difference value by dividing the difference between the second regurgitation index and the first regurgitation index by (ii) the first regurgitation index, and assigning the normalized difference value to the regurgitation difference value. Additional details regarding the combined value indicative of a heart valve state are described above in Section IV. In other embodiments, instead of a value indicative of a heart valve state being determined, the process 2800 may skip block 2824 to determine the combined valve state and proceed to the next block 2826. For example, if the previously determined values ​​indicative of the heart valve state are sufficient, the process may proceed to the next block 2826, such as in a situation where the current user interface does not show a combined value indicative of the heart valve state, but instead may present multiple previously determined values ​​indicative of the heart valve state.

[0301] In some embodiments, the system 200, 1400 can determine the time constant difference value as a combined value indicative of the heart valve status. For example, the system 200, 1400 can determine the time constant difference value based at least in part on the first time constant and the second time constant. In some embodiments, the system 200, 1400 can calculate the time constant difference value by subtracting at least one of the first time constant and the second time constant from the other. In some embodiments, the system 200, 1400 allows the user to tag the time constants for comparison purposes. For example, the graphical user interface of the system 200, 1400 can receive a user selection to tag the time constants for later comparison. A later graphical user interface, which may be similar to the user interface 1000 of FIG. 10A, can then present the combined value indicative of the heart valve status using the tagged time constants. For example, the graphical user interface, which may be presented during a live procedure, can present the time constant difference value using the tagged values.

[0302] In block 2826, a combined value indicative of the heart valve state and / or a plurality of values ​​indicative of the heart valve state may be presented. In particular, the system 200, 1400 may present a combined value indicative of the heart valve state (such as a regurgitation difference value or a time constant difference value) and / or a plurality of values ​​indicative of the heart valve state (such as a pre-treatment regurgitation index and a post-treatment regurgitation index) in a user interface. The presentation of the combined value indicative of the heart valve state and / or a plurality of values ​​indicative of the heart valve state may be similar to or the same as the presentation of values ​​indicative of the heart valve state described in more detail above with respect to block 1310 of FIG. 13 and the user interfaces of FIGS. 10A-10E and 11A-11E.

[0303] In some embodiments, the system 200, 1400 can present a combined value indicative of the cardiac valve status (such as a regurgitation difference value or a time constant difference value) and / or multiple values ​​indicative of the cardiac valve status (such as a pre-procedure regurgitation index and a post-procedure regurgitation index) in a comparison user interface. As described herein, the system 200, 1400 can determine first and second regurgitation indices, first and second hemodynamics, and / or other physiological parameters from the first and second time periods, respectively. As described herein, the first time period can be before the cardiac procedure and the second time period can be after the cardiac procedure. Exemplary cardiac procedures can include a balloon aortic valvuloplasty (BAV) procedure or a prosthesis insertion procedure. As described herein, the comparison user interface may include a first set of graphs for a first set of time series pressure values, a first visual representation of a first reflux index on the first set of graphs, a second set of graphs for a second set of time series pressure values, and a second visual representation of a second reflux index on the second set of graphs. Another exemplary comparison user interface presented by the system 200, 1400 may include a first set of graphs for a first set of time series pressure values, a first visual representation of a first hemodynamic parameter, a second set of graphs for the second set of time series pressure values, and a second visual representation of a second hemodynamic parameter. Additional details regarding the presentation of the comparison user interface are described in more detail above with respect to Figures 11D and 11E.

[0304] As described herein, a graphical user interface, which may be similar to the user interface 1000 of FIG. 10A, may present a combined value indicative of a heart valve state. For example, a graphical user interface, which may be presented during a live procedure, may present a regurgitation ratio or aortic regurgitation difference using tagged regurgitation values. As another example, a graphical user interface, which may be presented during a live procedure, may present a time constant difference value using tagged time constants. Although not shown in FIG. 10A, the user interface 1000 may additionally present a combined value indicative of a heart valve state (such as a regurgitation ratio and / or a time constant difference value).

[0305] Implementation Mechanism Fig. 29 is a block diagram illustrating exemplary components of a cardiac valve evaluation system 1400. Although the cardiac valve evaluation system 1400 of Fig. 29 is depicted as a single device, the cardiac valve evaluation system 1400 may be implemented in a server cluster, server farm, data center, mainframe, cloud computing environment, or the like. The cardiac valve evaluation system 1400 may include any number of devices operating as a distributed computing resource providing services such as storage, computing, networking, etc.

[0306] The cardiac valve evaluation system 1400 may include a hardware processor 2902, a data storage device 2904, a memory device 2906, a bus 2908, a display 2912, and one or more input / output devices 2914. The processor 2902 may be realized as a combination of multiple computing devices, for example, a combination of a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a digital signal processor, or any other such configuration. The processor 2902 may be configured to process data or execute instructions to perform one or more functions, among other things. The data storage device 2904 may include a magnetic disk, optical disk, flash drive, or the like, and may be provided for storing information and instructions and coupled to the bus 2908. The memory 2906 may include one or more memory devices for storing data, including but not limited to a random access memory (RAM) and a read-only memory (ROM). The cardiac valve evaluation system 1400 may be coupled via bus 2908 to a display 2912, such as an LCD display or touch screen, for displaying information to a user, such as a patient. The cardiac valve evaluation system 1400 may be coupled via bus 2908 to one or more input / output devices 2914. The input devices 2914 may include, but are not limited to, a keyboard, a mouse, a digital pen, a microphone, a touch screen, a gesture recognition system, a voice recognition system, an imaging device (which may capture tracking data and / or positioning of the eyes, hands, head, or body), a game pad, an accelerometer, or a gyroscope.

[0307] The cardiac valve evaluation system 1400 may include one or more software engines (or services) for performing the processes and functions described herein. The software engines may include programming instructions for performing processes as described herein (and illustrated in the flow charts) for detecting input conditions, such as pressure signals, and generating output conditions, such as values ​​indicative of cardiac valve status. The engines may be executed by one or more hardware processors 2902. The programming instructions may be stored in a data storage device 2904 and / or loaded into a memory 2906. The programming instructions may be implemented in C, C++, JAVA, or any other suitable programming language. In some embodiments, some or all of the portions of the cardiac valve evaluation system 1400, including the engines, may be implemented in hardware processors in application-specific circuits such as ASICs and FPGAs. Some aspects of the functionality of the cardiac valve evaluation system 1400 may be executed on a server (not shown) that is remote over a network. Additionally, some aspects of the functionality of the cardiac valve evaluation system 1400 may be executed within one or more sensors or external devices.

[0308] The heart valve evaluation system 1400 can be in communication with one or more sensor devices 2916 described herein, such as the pressure guidewire 208, the pressure sensing access catheter 20, or the pressure sensing pigtail catheter 10.

[0309] term As used herein, the relative terms "proximal" and "distal" are intended to be defined from the perspective of a user of the system, such that proximal refers to a direction toward the user of the system and distal refers to a direction away from the user of the system.

[0310] As used herein, the relative terms "upstream" and "downstream" are intended to be defined in terms of blood flow. Thus, downstream refers to the direction toward the aorta with respect to the left ventricle.

[0311] Conditional language such as "can," "may," "might," "would," and the like, unless specifically noted otherwise or should be understood otherwise within the context in which it is used, is generally intended to convey that some embodiments include certain features, elements, and / or steps, while other embodiments do not. Thus, such conditional language is generally not intended to imply that a feature, element, and / or step is in any way required for one or more embodiments.

[0312] The terms "including," "comprising," "having," and similar terms are synonymous and are used in an inclusive, open-ended manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or" is used in an inclusive sense (and not an exclusive sense) so that, for example, when used to connect a list of elements, the term "or" means one, some, or all of the elements in that list.

[0313] As used herein, the terms "approximately," "about," "generally," and "substantially" refer to an amount close to the stated amount that still performs the desired function or produces the desired result. For example, the terms "approximately," "about," "generally," and "substantially" may refer to an amount that is within 5% of the stated amount, as the context may dictate.

[0314] Ranges disclosed herein encompass all overlaps, subranges, and combinations thereof. Words such as "up to," "at least," "more than," "less than," "between," and the like, include the number recited. Numbers preceded by phrases such as "about" or "approximately" include the recited number. For example, "about 4" includes "4."

[0315] The methods disclosed herein do not have to be performed in the order described. The methods disclosed herein include certain actions performed by one of ordinary skill in the art, but they may also include, explicitly or implicitly, any third party instruction of those actions. For example, an action such as "distally move a locking element" includes "commanding distal movement of the locking element."

[0316] Although several embodiments and examples are described herein, those skilled in the art will appreciate that many aspects of the humerus assembly shown and described in this disclosure can be combined and / or modified in different ways to form further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. A wide variety of designs and approaches are possible. No feature, structure, or step disclosed herein is essential or required.

[0317] Some embodiments are described with reference to the accompanying drawings. However, it should be understood that the figures are not drawn to scale. Distances, angles, etc. are merely illustrative and do not necessarily bear precise relationship to the actual dimensions and layout of the illustrated devices. Components may be added, removed, and / or rearranged. Furthermore, disclosure herein of specific features, aspects, methods, properties, characteristics, qualities, attributes, elements, or the like in conjunction with various embodiments may be used in all other embodiments described herein. In addition, it will be recognized that any method described herein may be implemented using any device suitable for performing the steps described.

[0318] For purposes of the present disclosure, certain aspects, advantages, and novel features have been described herein. It should be understood that not all such advantages are necessarily achieved in accordance with a particular embodiment. Thus, for example, a person skilled in the art will understand that the present disclosure can be embodied or implemented in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as taught or suggested herein.

[0319] Furthermore, while exemplary embodiments have been described herein, the scope of any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and / or alterations will be understood by those skilled in the art based on this disclosure. Any limitations in the claims should be interpreted broadly based on the language employed in the claims, and not limited to the examples described in this specification or during the prosecution of the application, which examples should be interpreted as non-exclusive. Furthermore, the operations of the disclosed processes and methods may be modified in any manner, including by changing the order of operations and / or inserting additional operations and / or deleting operations. The specification and examples are therefore intended to be considered only as illustrative, with the true scope and spirit being indicated by the claims and their full scope of equivalents. [Explanation of symbols]

[0320] A. Aorta L central longitudinal axis LV left ventricle M Mitral valve P apex 10 Pigtail Catheter 20 Access Catheter 30 Pressure Guidewire 40 Pressure Sensor 200 Diagnostic System 202 Optical fiber interface cable 204 Monitor Assembly 206A arrangement 206B Placement 206C arrangement 206D arrangement 207 Handle 208 Pressure Guidewire 210 Access Catheter 211 Access Catheter 212 Delivery Systems 214 Aortic Pigtail Catheter 250 Curved section 251 Diagnostic Systems 254 Monitor Assembly 308, 408 Pressure guidewire 310 Outer tube 312 Coil part 316 Core Wire 318 Pressure Sensor Assembly 320 Pressure Wire Lead 322 Pressure Sensor 324 Sensor Housing 326 Small diameter part 328 Proximal part 410 Outer tube 412 Coil part 416 Core Wire 418 Pressure Sensor Assembly 420 Pressure Wire Lead 422 Pressure Sensor 426 Small diameter section 430 Connector Tube 432 Distal tip 434 Insulation part 436 Adhesive 438a First Section 438b Second Section 440 Opening 508 Pressure Guidewire 510 Outer tube 512a, 512b Coiled Sections 516 Core Wire 520 Pressure Wire Lead 522 Pressure Sensor 526 Small diameter part 528 Proximal part 530 Connector Tube 542 Sensor Housing 608 Pressure Sensing Guidewire 608' Pressure Sensing Guidewire 608” Pressure Sensing Guidewire 610 Outer tube 612a, 612b Coil part 616 Core Wire 616” core wire 620 Pressure Wire Lead 622 Pressure Sensor 626 Small diameter part 628 Proximal part 630 Connector Tube 632 Distal tip 632” Distal Tip 634 Insulation part 642 Pressure Sensor Housing 644 Opening 708 Pressure Sensing Guidewire 710 Outer tube 712a, 712b Coil part 716 Core Wire 720 Pressure Wire Lead 722 Pressure Sensor 726 Small diameter section 728 Proximal part 730 Connector Tube 742 Pressure Sensor Housing 744 Opening 746 Small Diameter Section 754 Tapered section 808 Pressure Sensing Guidewire 810 Outer tube 812a Distal coil section 816 Core Wire 822 Pressure Sensor 826 Small diameter section 828 Proximal part 830 Connector Tube 838a First Section 838b Second Section 842 Sensor Housing 846 Small Diameter Section 848 Connector 852 Opening 908 Pressure Guidewire 910 Outer tube 912a Coil part 916 Core Wire 920 Pressure Wire Lead 922 Distal part 924 Sensor Housing Section 926 Small diameter part 928 Proximal part 930 Connector Tube 932 Distal tip 934 Insulation part 938a First Section 938b Second Section 948 Connector 952 Opening 1000, 1020, 1040 User Interface 1002, 1004, 1006, 1008 graphs 1010, 1012 Physiological parameters 1014 Recording Options 1022 Recording stop option 1042a, 1042b, 1042c Gradient representation 1044a, 1044b, 1044c backflow expression 1046 First Number 1048 Second Number 1050 Electrocardiogram 1051 Pressure graph display 1052 Playback Control 1054 Play position 1056 Gradient Type Selector 1060 User Interface 1062a, 1062b, 1062c Gradient representation 1064 Number 1080 User Interface 1082a, 1082b, 1082c Gradient representation 1084 Number 1100 User Interface 1102 Gradient Expression 1104 Regurgitation 1112 Gradient Representation 1120 User Interface 1140 User Interface 1142 Gradient Expression 1150 User Interface 1152A First Area 1152B Second Area 1154A First Graph and / or Indicator 1154B Secondary Graph and / or Indicator 1156 Parameter Area 1160 First Parameter Selector 1162 Second Parameter Selector 1170 Comparison User Interface 1200 Configuration User Interface 1202 Statistical Scale Period Selector 1300 Processes 1400 System 1400 Heart Valve Assessment System 1402 Heart valve evaluation environment 1404 Input 1406 Output 1408 Calibration Service 1410 Waveform Adjustment Service 1412 Feature Detection Service 1414 Valve Status Determination Service 1416 Index Calculator 1418 Gradient Calculator 1500 Valve Evaluation Process 1600 processes 1700 waveform analysis environment 1702 First set of pressure data points 1704 Second set of pressure data points 1800 waveform analysis environment 1801 systolic 1802 Gradient 1803 Minimum or local pressure value 1804 horizontal line 1805 intersection 1806 waveform 1807 Time Period 1900 Process 2010 Left ventricular pressure waveform (LVEP) 2011 Aortic Pressure Waveform (AOP) 2012 Ejection Period 2013 area 2221 Mean aortic diastolic pressure (ADP) 2222 Value 2302 Left ventricular pressure waveform (LVEP) 2304 Premature ventricular contraction 2306 Aortic pressure waveform (AOP) 2308 Longer part 2310 Left ventricular pressure waveform (LVEP) 2312 Aortic pressure waveform (AOP) Longer parts than 2314A, 2314B, and 2314C 2330 Pressure Increase (PA) 2340 Left ventricular pressure waveform (LVEP) 2342 Aortic pressure waveform (AOP) 2344 cycles 2350 Aortic Pressure Waveform 2402 Left ventricular pressure waveform 2404 Aortic pressure waveform 2406 Valve opening 2408 Duplicate prominence 2502 Left ventricular pressure waveform 2504 Aortic pressure waveform 2506 Pressure Value 2508 Pressure value 2602 Left ventricular pressure waveform 2604 Aortic pressure waveform 2700 processes 2800 Valve Evaluation Process 2902 Hardware Processor 2904 Data Storage Devices 2906 Memory Devices 2908 Bus 2912 Display 2914 Input / Output Devices 2916 Sensor Device< / asp> < / lvsp> < / asp> < / lvsp>

Claims

1. 1. A method comprising: determining a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart; determining a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; determining a heart rate of the heart; calculating from the first plurality of pressure values: (i) a first end-diastolic pressure in the first portion of the heart, and (ii) a first systolic pressure in the first portion of the heart; calculating a second end-diastolic pressure in the cardiac vascular region adjacent the first portion of the heart from the second plurality of pressure values; determining a reflux index, said determining the reflux index comprising: calculating a pressure difference between the first end-diastolic pressure and the second end-diastolic pressure; calculating a value from a normalized pressure difference based at least in part on the systolic pressure and the heart rate; and causing presentation of the reflux index in a user interface.

2. 1. A method comprising: controlling the heart rate; determining a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart; determining a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; determining a reflux index based at least in part on (i) a first value from the first plurality of pressure values ​​and (ii) a second value from the second plurality of pressure values; and causing presentation of the reflux index in a user interface.

3. calculating from the first plurality of pressure values: (i) a first end-diastolic pressure in the first portion of the heart, and (ii) a first systolic pressure in the first portion of the heart; and calculating a second end-diastolic pressure in the cardiac vascular region adjacent the first portion of the heart from the second plurality of pressure values, wherein determining the regurgitation index is further based at least in part on the first end-diastolic pressure, the second end-diastolic pressure, and the systolic pressure.

4. The step of controlling the heart rate of the heart includes:

4. The method of claim 2 or 3, further comprising the step of ventricular pacing the heart at predefined heart rate intervals.

5. The step of controlling the heart rate of the heart includes:

5. The method of claim 2, further comprising administering a drug to the patient.

6. calculating a time constant from the first plurality of pressure values ​​and the second plurality of pressure values; The method of claim 2 , further comprising the step of: causing presentation of the time constant in the user interface.

7. The method of claim 2 , wherein the reflux index comprises a time-integrated reflux index.

8. 1. A method comprising: inducing a premature cardiac contraction having a non-ejecting ventricular beat into the aorta; determining a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart; determining a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; calculating from the first plurality of pressure values: (i) a first end-diastolic pressure in the first portion of the heart, and (ii) a first systolic pressure in the first portion of the heart; calculating a second end-diastolic pressure in the cardiac vascular region adjacent the first portion of the heart from the second plurality of pressure values; determining a reflux index based at least in part on the first end-diastolic pressure, the second end-diastolic pressure, and the systolic pressure; and causing presentation of the reflux index in a user interface.

9. The step of inducing the premature contraction of the heart includes:

9. The method of claim 8, further comprising the step of programming a pacemaker connected to the heart to induce the extrasystole.

10. 1. A system comprising: a non-transitory computer storage medium configured to store at least computer-executable instructions; one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions comprising at least determining, prior to the cardiac procedure, a first plurality of pressure values ​​from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; calculating a first reflux index from the first plurality of pressure values; determining, after the cardiac procedure, a second plurality of pressure values ​​from (i) the first pressure sensor positioned in the first portion of the heart and (ii) the second pressure sensor positioned in the cardiovascular region adjacent the first portion of the heart; calculating a second reflux index from the second plurality of pressure values; determining a backflow differential value based at least in part on the second backflow index and the first backflow index; and one or more hardware processors that cause presentation of the backflow differential value in a user interface.

11. Determining the backflow differential value comprises: (i) calculating a normalized difference value by dividing the difference between the second reflux index and the first reflux index by (ii) the first reflux index; and assigning the normalized difference value to the backflow difference value.

12. 1. A method comprising: determining a time series of pressure values ​​from a pressure sensor positioned in a portion of the heart; identifying a subset of the time series of pressure values ​​corresponding to at least a portion of a diastolic phase; calculating a first gradient from the subset of the time series of pressure values; Identifying a first reflux index based at least in part on the first slope, the identifying the first reflux index comprising: finding the first reflux index that correlates with the first slope; and causing presentation of the first reflux index in a user interface.

13. accessing a plurality of pressure measurements, each pressure measurement from the plurality of measurements corresponding to a patient; For each pressure measurement from the plurality of pressure measurements: calculating a pair including a diastolic gradient and a regurgitant index from said pressure measurements; and determining a correlation between a diastolic gradient and a reflux index based at least in part on the pair of diastolic gradient and reflux index, wherein finding the first reflux index comprises: The method of claim 12 , further comprising applying the correlation between diastolic gradient and reflux index to the first gradient.

14. 14. The method of claim 12 or 13, wherein the portion of the heart includes at least the left ventricle.

15. Calculating the first gradient from the subset of the time series of pressure values ​​comprises: determining a linear fit from said subset of said time series of pressure values; and calculating the first gradient from the linear fit.

16. Calculating the first gradient from the subset of the time series of pressure values ​​comprises: determining a polynomial function from said subset of said time series of pressure values; The method of claim 12 , further comprising the step of: calculating the first gradient from the polynomial function.

17. Calculating the first gradient from the subset of the time series of pressure values ​​comprises: determining an exponential function from said subset of said time series of pressure values; and calculating the first slope from the exponential function.

18. 1. A method comprising: determining a first time series of pressure values ​​from a first pressure sensor positioned in a first portion of the heart; determining a second time series of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; identifying a subset of the first time series of pressure values ​​that corresponds to at least a portion of a diastolic phase; identifying a subset of the second time series of pressure values ​​corresponding to at least the portion of the diastolic phase; (i) calculating a first gradient from the subset of the first time series of pressure values; and (ii) calculating a second gradient from the subset of the second time series of pressure values; determining a reflux index based at least in part on the first slope and the second slope; and causing presentation of the reflux index in a user interface.

19. 20. The method of claim 18, wherein the first portion of the heart includes at least a left ventricle and the cardiovascular region adjacent the first portion includes at least an aorta.

20. calculating a first plurality of gradients from the subset of the first time series of pressure values, the first plurality of gradients including the first gradient; calculating a second plurality of gradients from the subset of the second time series of pressure values, the second plurality of gradients including the second gradient; and determining a slope angle for each slope of the first plurality of slopes and the second plurality of slopes, wherein the step of determining a reflux index comprises: determining a first statistical measure from the slope angles for each slope of the first plurality of slopes; determining a second statistical measure from the slope angles for each slope of the second plurality of slopes; calculating a combined statistical measure from the first statistical measure and the second statistical measure; and assigning the combined statistical measure as the reflux index.

21. 21. The method of claim 20, wherein the step of calculating the combined statistical measure further comprises at least one of adding or subtracting the first statistical measure and the second statistical measure.

22. determining a first slope angle for the first slope; and determining a second slope angle for the second slope, the step of determining a reflux index comprising: calculating a combined slope angle from the first slope angle and the second slope angle; and assigning the combined slope angle as the reflux index.

23. 23. The method of claim 22, wherein calculating the combined slope angle further comprises at least one of adding, subtracting, multiplying, or dividing the first slope angle and the second slope angle.

24. The step of calculating the second gradient comprises: determining an initial gradient from the subset of the second time series of pressure values; determining a correction factor from the second time series of pressure values; calculating a corrected diastolic slope from the initial slope, the step of calculating the corrected diastolic slope further comprising applying the correction factor to the initial slope; and assigning the corrected diastolic slope to the second slope.

25. The step of determining the correction factor comprises: calculating at least one of an augmentation index or a pressure augmentation from said second time series of pressure values; and identifying the correction factor based at least in part on one of the augmentation index or the pressure increase.

26. 1. A system comprising: a non-transitory computer storage medium configured to store at least computer-executable instructions; one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions comprising at least determining, prior to a cardiac procedure, a first set of time-series pressure values ​​from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; calculating a first time constant from the first set of time series pressure values; determining, after the cardiac procedure, a second set of time-series pressure values ​​from (i) the first pressure sensor positioned at the first portion of the heart and (ii) the second pressure sensor positioned in the cardiovascular region adjacent the first portion of the heart; calculating a second time constant from the second set of time series pressure values; determining a time constant difference value based at least in part on the first time constant and the second time constant; and one or more hardware processors that cause presentation of the time constant difference value in a user interface.

27. 27. The system of claim 26, wherein the first portion of the heart includes at least a left ventricle and the cardiovascular region adjacent the first portion includes at least an aorta.

28. The step of calculating the first time constant from the first set of time series pressure values ​​comprises substantially [0010] It includes a decision relation τ such as Area (P-R) １２ is the area between (i) a first time series of pressure values ​​from the first portion of the heart and (ii) a second time series of pressure values ​​from the cardiovascular region adjacent the first portion of the heart, and between a first time and a second time; P １ is a first pressure value from the first time series of pressure values ​​at the first time, R １ is a first pressure value from the second time series of pressure values ​​at the first time, P ２ is a second pressure value from the first time series of pressure values ​​at the second time, R ２ 28. The system of claim 26 or 27, wherein: x is a second pressure value from the second time series of pressure values ​​at the second time.

29. 30. The system of claim 28, wherein the first time and the second time are within a diastolic phase.

30. 1. A system comprising: a non-transitory computer storage medium configured to store at least computer-executable instructions; one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions comprising at least determining a set of time series pressure values ​​from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; Calculating a time constant from said set of time series pressure values, said calculating said time constant comprising substantially [0025] and further including a decision relation τ such that Area (P-R) １２ is the area between (i) a first time series of pressure values ​​from the first portion of the heart and (ii) a second time series of pressure values ​​from the cardiovascular region adjacent the first portion of the heart, and between a first time and a second time; P １ is a first pressure value from the first time series of pressure values ​​at the first time, R １ is a first pressure value from the second time series of pressure values ​​at the first time, P ２ is a second pressure value from the first time series of pressure values ​​at the second time, R ２ is a second pressure value from the second time series of pressure values ​​at the second time, and one or more hardware processors that cause presentation of the time constants in a user interface.

31. 31. The system of claim 30, wherein the first time and the second time are within a diastolic phase.

32. 1. A system comprising: a non-transitory computer storage medium configured to store at least computer-executable instructions; one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions comprising at least determining a first time series of pressure values ​​from a pressure sensor positioned in a portion of the heart prior to the cardiac procedure; calculating a first time constant from the first time series of pressure values; determining a second time series of pressure values ​​from the pressure sensor positioned at the portion of the heart after the cardiac procedure; calculating a second time constant from the second time series of pressure values; determining a time constant difference value based at least in part on the first time constant and the second time constant; and one or more hardware processors that cause presentation of the time constant difference value in a user interface.

33. 33. The system of claim 32, wherein the portion of the heart includes a left ventricle or an aorta.

34. The step of calculating the first time constant from the first time series of pressure values ​​substantially comprises: [0030] It includes a decision relation τ such as Area (P) １２ is the area under the first time series of pressure values ​​between a first time and a second time, P １ is a first pressure value from the first time series of pressure values ​​at the first time, P ２ 34. The system of claim 32 or 33, wherein: x is a second pressure value from the first time series of pressure values ​​at the second time.

35. 35. The system of claim 34, wherein the first time and the second time are within a diastolic phase.

36. 1. A system comprising: a non-transitory computer storage medium configured to store at least computer-executable instructions; one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions comprising at least determining a first time series of pressure values ​​from a first pressure sensor positioned in a first portion of the heart; determining a second time series of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; identifying a first heart beat and a second heart beat from the first time series and the second time series; Associating the first heart beat with a first category based at least in part on a first characteristic of the first heart beat, the first category indicating that the first heart beat is rejected; Associating the second heartbeat with a second category based at least in part on a second characteristic of the second heartbeat, the second category indicating that the second heartbeat is accepted; determining a reflux index, said determining the reflux index rejecting the first heart beat based at least in part on the first category and the rejected first heart beat; including the second heart beat based at least in part on the second category and the accepted second heart beat; calculating the regurgitation index based at least in part on (i) a first portion of the first time series associated with the second heartbeat and (ii) a second portion of the second time series associated with the second heartbeat; and one or more hardware processors that cause presentation of the reflux index in a user interface.

37. The first feature of the first heart beat corresponds to an elapsed time of the first heart beat, and associating the first heart beat with the first category based at least in part on the first feature includes:

37. The system of claim 36, further comprising determining that the elapsed time of the first heart beat is outside a threshold range.

38. The first feature of the first heart beat corresponds to a duration of a diastolic phase of the first heart beat, and associating the first heart beat with the first category based at least in part on the first feature comprises:

37. The system of claim 36, further comprising determining that the elapsed time of the diastolic phase of the first heart beat exceeds a threshold time.

39. The first characteristic of the first heart beat corresponds to a pressure from a systolic phase of the first heart beat, and associating the first heart beat with the first category based at least in part on the first characteristic includes:

37. The system of claim 36, further comprising determining that the pressure from a systolic phase of the first heart beat exceeds a threshold value.

40. 40. The system of any one of claims 36 to 39, wherein the first portion of the heart includes the aorta or the left ventricle.

41. 1. A system comprising: a non-transitory computer storage medium configured to store at least computer-executable instructions; one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions comprising at least receiving a first set of time-series pressure values ​​during a first time period from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; calculating a first reflux index from said first set of time series pressure values; receiving a second set of time series pressure values ​​during a second time period from (i) the first pressure sensor positioned in the first portion of the heart and (ii) the second pressure sensor positioned in the cardiovascular region adjacent the first portion of the heart; calculating a second reflux index from said second set of time series pressure values; Into the user interface a first set of graphs for said first set of time series pressure values; a first visual representation of the first reflux index on the first set of graphs; a second set of graphs for the second set of time series pressure values; and and one or more hardware processors that cause presentation of a second visual representation of the second reflux index on the second set of graphs.

42. 1. A system comprising: a non-transitory computer storage medium configured to store at least computer-executable instructions; one or more hardware processors in communication with the non-transitory computer storage medium, the one or more hardware processors configured to execute the computer-executable instructions, the computer-executable instructions comprising at least receiving a first set of time-series pressure values ​​during a first time period from (i) a first pressure sensor positioned in a first portion of the heart and (ii) a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; calculating a first hemodynamic parameter from said first set of time series pressure values; receiving a second set of time series pressure values ​​during a second time period from (i) the first pressure sensor positioned in the first portion of the heart and (ii) the second pressure sensor positioned in the cardiovascular region adjacent the first portion of the heart; calculating a second hemodynamic parameter from said second set of time series pressure values; Into the user interface a first set of graphs for said first set of time series pressure values; a first visual representation of the first hemodynamic parameter; a second set of graphs for the second set of time series pressure values; and and one or more hardware processors that cause presentation of a second visual representation of the second hemodynamic parameter.

43. 43. The system of claim 41 or 42, wherein the first time period corresponds to before a cardiac procedure and the second time period corresponds to after the cardiac procedure.

44. 44. The system of claim 43, wherein the cardiac procedure comprises a balloon aortic valvuloplasty (BAV) procedure or a prosthesis insertion procedure.

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