Pressure-based structural heart evaluation system and method

Abstract

To provide a heart valve evaluation system.SOLUTION: The heart valve evaluation system described herein advantageously provides an instruction of a heart valve state such as a pressure gradient or an index of a valve backflow. The heart valve evaluation system can provide the instruction of the heart valve state during heart treatment. The pressure gradient instructs severity or measurement of valve narrowing (or stenosis) due to an increase in pressure behind the valve. The index of the valve backflow instructs valve leakage measurement.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] [Incorporation by reference to priority application] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 849,768, entitled "Pressure Sensing Guidewires, Systems and Methods for Structural Heart Procedures," filed May 17, 2019, U.S. Provisional Patent Application No. 62 / 849,806, entitled "Heart Valve Assessment Systems and User Interfaces," filed May 17, 2019, and U.S. Provisional Patent Application No. 62 / 849,798, entitled "Pressure Based Structural Heart Assessment Systems and Methods," filed May 17, 2019, each of which is hereby incorporated by reference in its entirety.

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

[0003] Guidewires are known for delivering catheters to many vascular sites in the body. Access to the vascular sites is facilitated by a combination of mechanical properties such as flexibility, pushability, and torqueability. It is known that coronary procedures include pressure sensors to allow measurement of blood flow through a static occlusion to help cardiologists decide whether to treat a patient.

[0004] Although pressure sensing around static obstructions in coronary vessels is known, such concepts have not been applied to structural heart procedures, such as for repairing heart valves and for improving the pumping function of the heart. Pumping function 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 fitted with percutaneous heart valves and through which such valves are delivered. Summary of the Invention [Means for solving the problem]

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

[0006] According to an embodiment, a method for determining a cardiac valve status during deployment of a replacement cardiac valve is disclosed, the method including the steps of calibrating a second pressure sensor against a first pressure sensor while both the first pressure sensor and the second pressure sensor are in the heart, determining a first plurality of pressure values ​​from the 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 cardiac vascular region adjacent to the first portion of the heart, adjusting the second plurality of pressure values ​​based at least in part on the calibration, detecting a first characteristic at the first plurality of pressure values, detecting a second characteristic at the adjusted plurality of pressure values, determining a cardiac valve status based at least in part on the first characteristic and the second characteristic, and displaying the cardiac valve status on a user interface.

[0007] According to one aspect, calibrating the second pressure sensor relative to the first pressure sensor may further include receiving a first calibration pressure value corresponding to a first calibration signal received from the first pressure sensor measuring the first cardiovascular region; receiving a second calibration pressure value corresponding to a second calibration signal received from the second pressure sensor measuring the first cardiovascular region; and calculating a calibration parameter based at least in part on the first calibration pressure value and the second calibration pressure value, where adjusting the second plurality of pressure values ​​further includes applying the calibration parameter to the second plurality of pressure values.

[0008] According to another aspect, receiving the first calibrated pressure value may further include receiving a first plurality of calibrated pressure values, where the first plurality of calibrated pressure values ​​may include the first calibrated pressure values ​​and the first plurality of calibrated pressure values ​​may correspond to a first vector, receiving the second calibrated pressure value may further include receiving a second plurality of calibrated pressure values, where the second plurality of calibrated pressure values ​​may include the second calibrated pressure values ​​and the second plurality of calibrated pressure values ​​may correspond to a second vector, and calculating the calibration parameters may further include determining a linear fit between the first vector and the second vector.

[0009] According to yet another aspect, the first vector can correspond to [P1], the second vector can correspond to [P2], the calibration parameters can include K and b, and the step of determining a linear fit can include determining a relationship substantially as [P1]=K·[P2]+b.

[0010] According to yet another aspect, the first characteristic may include at least one of a first systole or a first diastole at a first plurality of pressure values.

[0011] According to yet another aspect, detecting at least one of the first systole or the first diastole may further include detecting a first dicrotic notch feature at the first plurality of pressure values ​​and identifying at least one of the first systole or the first diastole according to the first dicrotic notch feature.

[0012] According to yet another aspect, detecting the first dicrotic notch feature may further include calculating a plurality of second derivative values ​​from the first plurality of pressure values ​​and identifying a zero-crossing point based at least in part on the plurality of second derivative values, the zero-crossing point corresponding to the first dicrotic notch feature.

[0013] According to yet another aspect, detecting the first dicrotic notch feature may further include calculating a first angle for the first point from the first plurality of pressure values ​​based at least in part on the first preceding point and the first following point, calculating a second angle for the second point from the first plurality of pressure values ​​based at least in part on the second preceding point and the second following point, determining that the second angle is less than the first angle, and identifying the second point as the first dicrotic notch feature.

[0014] According to yet another aspect, the second characteristic may include at least one of a second systole or a second diastole at the adjusted plurality of pressure values.

[0015] According to yet another aspect, the cardiac valve status may include an indication of regurgitation, and determining the cardiac valve status may further include calculating the indication of regurgitation based at least in part on a first subset of the first plurality of pressure values ​​responsive to at least one of the first systole or the first diastole and a second subset of the adjusted plurality of pressure values ​​responsive to at least one of the second systole or the second diastole.

[0016] According to yet another aspect, the cardiac valve state may include a gradient value, and determining the cardiac valve state may further include calculating the gradient value based at least in part on a difference between a first subset of the first plurality of pressure values ​​during the first systole and a second subset of the adjusted plurality of pressure values ​​during the second systole.

[0017] According to yet another aspect, detecting at least one of the first systole or the first diastole may further include identifying a first subset of ascending pressure values ​​from the first plurality of pressure values; identifying a locally minimum pressure value from the first plurality of pressure values; determining a tangent from the first subset; identifying a horizontal line that intersects the locally minimum pressure value; identifying a first intersection between the tangent and the horizontal line; and identifying a first point from the first plurality of pressure values ​​as an end of the first diastole or a start of the first systole based at least in part on the first intersection.

[0018] According to yet another aspect, identifying the first point may further include adjusting the first intersection by a predetermined period of time.

[0019] According to yet another aspect, the predetermined period of time may comprise approximately 60 milliseconds.

[0020] According to yet another aspect, the predetermined period of time may include between approximately 40 milliseconds and approximately 100 milliseconds.

[0021] According to yet another aspect, identifying the first point may further include adjusting the first intersection by a percentage of a cardiac cycle.

[0022] According to yet another embodiment, the percentage may include between approximately 8 percent and 12 percent of the cardiac cycle.

[0023] According to yet another embodiment, the percentage may include between approximately 5 percent and 8 percent of the cardiac cycle.

[0024] According to yet another aspect, the step of calibrating the second pressure sensor relative to the first pressure sensor may be performed while (i) the first pressure sensor is positioned in a first portion of the heart and (ii) the second pressure sensor is positioned in a cardiovascular region adjacent to the first portion of the heart.

[0025] According to yet another aspect, the step of calibrating the second pressure sensor relative to the first pressure sensor may further include the steps of determining a third plurality of pressure values ​​from the first pressure sensor positioned in the first portion of the heart, determining a fourth plurality of pressure values ​​from the second pressure sensor in a cardiovascular region adjacent the first portion of the heart, detecting a value at a substantial start of systole at the third plurality of pressure values, and calculating a time adjustment to the fourth plurality of pressure values ​​such that a value from the fourth plurality of pressure values ​​corresponds to a value at a substantial start of systole at the third plurality of pressure values, wherein adjusting the second plurality of pressure values ​​further includes applying the time adjustment to the second plurality of pressure values.

[0026] According to yet another aspect, calibrating the second pressure sensor relative to the first pressure sensor may further include detecting a dicrotic notch feature at a third plurality of pressure values; identifying a timestamp corresponding to the dicrotic notch feature; determining a first value at the timestamp from the third plurality of pressure values; determining a second value at the timestamp from the fourth plurality of pressure values; and calculating a gain adjustment based at least in part on the first value and the second value, where adjusting the second plurality of pressure values ​​further includes applying the gain adjustment to the second plurality of pressure values.

[0027] According to yet another aspect, the step of calibrating the second pressure sensor relative to the first pressure sensor includes determining a third plurality of pressure values ​​from the first pressure sensor positioned in the first portion of the heart, determining a fourth plurality of pressure values ​​from the second pressure sensor in a cardiovascular region adjacent the first portion of the heart, detecting a value at a substantial start of systole at the third plurality of pressure values, calculating a time adjustment to the fourth plurality of pressure values ​​such that a value from the fourth plurality of pressure values ​​corresponds to a value at a substantial start of systole at the third plurality of pressure values, and calculating a time adjustment to the fourth plurality of pressure values ​​from the third plurality of pressure values. The method may further include detecting a dicrotic notch feature in the pressure values; identifying a timestamp corresponding to the dicrotic notch feature; determining a first value at the timestamp from the third plurality of pressure values; determining a second value at the timestamp from the fourth plurality of pressure values ​​and a time adjustment; and calculating a gain adjustment based at least in part on the first value and the second value, where adjusting the second plurality of pressure values ​​further includes applying the time adjustment and the gain adjustment to the second plurality of pressure values.

[0028] According to yet another aspect, calibrating the second pressure sensor relative to the first pressure sensor may further include identifying a substantial start of systole within a percentage of a cardiac cycle before or after an end of diastole at the third plurality of pressure values. According to yet another aspect, the percentage may include between approximately 0 percent and 1 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 2 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 5 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 10 percent of the cardiac cycle.

[0029] According to yet another aspect, identifying a timestamp corresponding to a dicrotic notch feature may further include identifying a timestamp within a percentage of a cardiac cycle before or after the dicrotic notch at the third plurality of pressure values. According to yet another aspect, the percentage may include between approximately 0 percent and 1 percent of a cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 2 percent of a cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 5 percent of a cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 10 percent of a cardiac cycle.

[0030] According to yet another aspect, the first value can correspond to V1, the second value can correspond to V2, and the gain adjustment can correspond to g, and the step of calculating the gain adjustment can be substantially

[0031]

number

[0032] It may further include as:

[0033] According to an 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 processing devices in communication with the non-transitory computer storage medium, the one or more hardware processing devices configured to execute the computer-executable instructions to at least determine a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart, determine a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent to the first portion of the heart, detect a first feature at the first plurality of pressure values, detect a second feature at the second plurality of pressure values, determine a cardiac valve status based at least in part on the first feature and the second feature, and display the cardiac valve status in a user interface.

[0034] According to an embodiment, the one or more hardware processing devices may be further configured to calibrate the second pressure sensor relative to the first pressure sensor while both the first pressure sensor and the second pressure sensor are positioned in the heart.

[0035] According to another aspect, calibrating the second pressure sensor relative to the first pressure sensor may further include receiving a first calibration pressure value corresponding to a first calibration signal received from the first pressure sensor measuring the first cardiovascular area, receiving a second calibration pressure value corresponding to a second calibration signal received from the second pressure sensor measuring the first cardiovascular area, and calculating a calibration parameter based at least in part on the first calibration pressure value and the second calibration pressure value, where determining the second plurality of pressure values ​​further includes applying the calibration parameter to the initial plurality of pressure values.

[0036] According to yet another aspect, causing to receive the first calibrated pressure values ​​may further include receiving a first plurality of calibrated pressure values, the first plurality of calibrated pressure values ​​including the first calibrated pressure values, the first plurality of calibrated pressure values ​​corresponding to a first vector, causing to receive the second calibrated pressure values ​​further include receiving a second plurality of calibrated pressure values, the second plurality of calibrated pressure values ​​including the second calibrated pressure values, the second plurality of calibrated pressure values ​​corresponding to a second vector, and attempting to calculate the calibration parameters further includes determining a linear fit between the first vector and the second vector.

[0037] According to yet another aspect, calibrating the second pressure sensor relative to the first pressure sensor may be performed while (i) the first pressure sensor is positioned in a first portion of the heart and (ii) the second pressure sensor is positioned in a cardiovascular region adjacent to the first portion of the heart.

[0038] According to yet another aspect, calibrating the second pressure sensor relative to the first pressure sensor may further include determining a third plurality of pressure values ​​from the first pressure sensor positioned in a first portion of the heart, determining a fourth plurality of pressure values ​​from the second pressure sensor in a cardiovascular region adjacent the first portion of the heart, detecting a value at a substantial start of systole in the third plurality of pressure values, and calculating a time adjustment to the fourth plurality of pressure values ​​such that a value from the fourth plurality of pressure values ​​corresponds to a value at a substantial start of systole in the third plurality of pressure values, wherein determining the second plurality of pressure values ​​further includes applying the time adjustment to the earlier plurality of pressure values.

[0039] According to yet another aspect, calibrating the second pressure sensor relative to the first pressure sensor may further include detecting a dicrotic notch feature at a third plurality of pressure values, identifying a timestamp corresponding to the dicrotic notch feature, determining a first value at the timestamp from the third plurality of pressure values, determining a second value at the timestamp from the fourth plurality of pressure values, and calculating a gain adjustment based at least in part on the first value and the second value, where determining the second plurality of pressure values ​​further includes applying the gain adjustment to the initial plurality of pressure values.

[0040] According to yet another aspect, calibrating the second pressure sensor relative to the first pressure sensor includes determining a third plurality of pressure values ​​from the first pressure sensor positioned in the first portion of the heart, determining a fourth plurality of pressure values ​​from the second pressure sensor in a cardiovascular region adjacent the first portion of the heart, detecting a value at a substantial start of systole at the third plurality of pressure values, calculating a time adjustment to the fourth plurality of pressure values ​​such that a value from the fourth plurality of pressure values ​​corresponds to a value at a substantial start of systole at the third plurality of pressure values, and calculating a time adjustment to the fourth plurality of pressure values ​​from the third plurality of pressure values. the first plurality of pressure values; determining a first value at the timestamp from the third plurality of pressure values; determining a second value at the timestamp from the fourth plurality of pressure values ​​and a time adjustment; and calculating a gain adjustment based at least in part on the first value and the second value, where determining the second plurality of pressure values ​​further includes applying the time adjustment and the gain adjustment to the initial plurality of pressure values.

[0041] According to yet another aspect, calibrating the second pressure sensor relative to the first pressure sensor may further include identifying a substantial start of systole within a percentage of a cardiac cycle before or after an end of diastole at the third plurality of pressure values. According to yet another aspect, the percentage may include between approximately 0 percent and 1 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 2 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 5 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 10 percent of the cardiac cycle.

[0042] According to yet another aspect, determining a timestamp corresponding to a dicrotic notch feature may further include determining a timestamp within a percentage of a cardiac cycle before or after the dicrotic notch at the third plurality of pressure values. According to yet another aspect, the percentage may include between approximately 0 percent and 1 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 2 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 5 percent of the cardiac cycle. According to yet another aspect, the percentage may include between approximately 0 percent and 10 percent of the cardiac cycle.

[0043] According to yet another aspect, the first value can correspond to V1, the second value can correspond to V2, and the gain adjustment can include g, and calculating the gain adjustment can include:

[0044]

number

[0045] It may further include as:

[0046] According to yet another aspect, the first characteristic may include at least one of a first systole or a first diastole at a first plurality of pressure values.

[0047] According to yet another aspect, detecting at least one of a first systole or a first diastole may further include detecting a first dicrotic notch feature at the first plurality of pressure values ​​and identifying at least one of the first systole or the first diastole as a function of the first dicrotic notch feature.

[0048] According to yet another aspect, detecting the first dicrotic notch feature may further include calculating a plurality of second derivative values ​​from the first plurality of pressure values ​​and identifying a zero-crossing point based at least in part on the plurality of second derivative values, the zero-crossing point corresponding to the first dicrotic notch feature.

[0049] According to yet another aspect, detecting the first dicrotic notch feature may further include calculating a first angle for the first point based at least in part on the first preceding point and the first following point from the first plurality of pressure values, calculating a second angle for the second point based at least in part on the second preceding point and the second following point from the first plurality of pressure values, determining that the second angle is less than the first angle, and identifying the second point as the first dicrotic notch feature.

[0050] According to yet another aspect, the second characteristic may include at least one of a second systole or a second diastole at the adjusted plurality of pressure values.

[0051] According to yet another aspect, the cardiac valve status may include an indication of regurgitation, and determining the cardiac valve status may further include calculating the indication of regurgitation based at least in part on a first subset of the first plurality of pressure values ​​responsive to at least one of the first systole or the first diastole and a second subset of the adjusted plurality of pressure values ​​responsive to at least one of the second systole or the second diastole.

[0052] According to yet another aspect, the cardiac valve state may include a gradient value, and determining the cardiac valve state may further include calculating the gradient value based at least in part on a difference between a first subset of the first plurality of pressure values ​​during the first systole and a second subset of the adjusted plurality of pressure values ​​during the second systole.

[0053] According to yet another aspect, detecting at least one of the first systole or the first diastole may further include identifying a first subset of ascending pressure values ​​from the first plurality of pressure values, identifying a locally minimum pressure value from the first plurality of pressure values, determining a tangent from the first subset, identifying a horizontal line that intersects the locally minimum pressure value, identifying a first intersection between the tangent and the horizontal line, and identifying a first point from the first plurality of pressure values ​​as an end of the first diastole or a start of the first systole based at least in part on the first intersection.

[0054] According to yet another aspect, determining the first point may further include adjusting the first intersection by a predetermined time period. According to yet another aspect, the predetermined time period may include approximately 60 milliseconds. According to yet another aspect, the predetermined time period may include between approximately 40 milliseconds and approximately 100 milliseconds.

[0055] According to yet another aspect, determining the first point may further include adjusting the first intersection by a percentage of a cardiac cycle. According to yet another aspect, the percentage may include between approximately 8 percent and 12 percent of a cardiac cycle. According to yet another aspect, the percentage may include between approximately 5 percent and 8 percent of a cardiac cycle.

[0056] According to yet another embodiment, a system is disclosed that includes a pressure guidewire configured to be positioned in a first cardiac vascular region, a second pressure sensing device configured to be positioned in a second cardiac vascular region adjacent the first cardiac vascular region, and one or more hardware processing devices configured to at least determine a first plurality of pressure values ​​from the pressure guidewire, determine a second plurality of pressure values ​​from the second pressure sensing device, detect a first feature at the first plurality of pressure values, detect a second feature at the second plurality of pressure values, determine a cardiac valve status based at least in part on the first feature and the second feature, and display the cardiac valve status on a user interface.

[0057] According to certain embodiments, the one or more hardware processing devices are further configured to calibrate one of the pressure guidewire or the second pressure sensing device to the other of the pressure guidewire or the second pressure sensing device while both are positioned in the same cardiovascular region.

[0058] According to another aspect, calibrating one of the pressure guidewire or the second pressure sensing device may further include receiving a first calibration pressure value corresponding to a first calibration signal received from the pressure guidewire measuring the first cardiovascular region, receiving a second calibration pressure value corresponding to a second calibration signal received from a second pressure sensing device measuring the first cardiovascular region, and calculating a calibration parameter based at least in part on the first calibration pressure value and the second calibration pressure value, where determining the second plurality of pressure values ​​further includes applying the calibration parameter to the second plurality of pressure values.

[0059] According to yet another aspect, causing to receive the first calibrated pressure values ​​may further include receiving a first plurality of calibrated pressure values, the first plurality of calibrated pressure values ​​including the first calibrated pressure values, the first plurality of calibrated pressure values ​​corresponding to a first vector, causing to receive the second calibrated pressure values ​​further include receiving a second plurality of calibrated pressure values, the second plurality of calibrated pressure values ​​including the second calibrated pressure values, the second plurality of calibrated pressure values ​​corresponding to a second vector, and attempting to calculate the calibration parameters may further include determining a linear fit between the first vector and the second vector.

[0060] According to yet another embodiment, a method for determining a cardiac valve status during deployment of a replacement cardiac valve is disclosed, the method including: detecting a first characteristic from a first plurality of pressure values ​​in response to measurements by a first pressure sensor positioned in a first portion of the heart; detecting a second characteristic from a second plurality of pressure values ​​in response to measurements by a second sensor positioned in a cardiac vascular region adjacent the first portion of the heart; determining a cardiac valve status based at least in part on the first and second characteristics; and displaying the cardiac valve status on a user interface.

[0061] According to yet other embodiments, a method is disclosed for calibrating a pressure waveform used to determine a heart valve status during deployment of a replacement heart valve, comprising the steps of receiving a first calibrated pressure value corresponding to a first calibrated signal received from a first pressure sensor measuring a first cardiovascular region, receiving a second calibrated pressure value corresponding to a second calibrated signal received from a second pressure sensor measuring the same first cardiovascular region, calculating a calibration parameter based at least in part on the first calibrated pressure value and the second calibrated pressure value, 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, adjusting the second plurality of pressure values ​​based at least in part on the calculated calibration parameter, and determining the heart valve status using the adjusted second plurality of pressure values.

[0062] According to an embodiment, determining the heart valve status may further include using the first plurality of pressure values.

[0063] According to another aspect, the heart valve condition may include an indication of the severity of valvular stenosis.

[0064] According to another aspect, the heart valve status may include an indication of corrected aortic regurgitation.

[0065] According to an embodiment, a method includes the steps of receiving a first plurality of pressure values, each pressure value from the first plurality of pressure values ​​corresponding to a first signal received from a first pressure sensor measuring a first portion of the heart; receiving a second plurality of pressure values, each pressure value from the second plurality of pressure values ​​corresponding to a second signal received from a second pressure sensor measuring a cardiovascular region adjacent the first portion of the heart; and presenting a first user interface for the first gradient type, the first user interface visually presenting a first graph based at least in part on the first plurality of pressure values, a second graph based at least in part on the second plurality of pressure values, and an area between the first graph and the second graph. A method is disclosed for presenting an interactive graphical user interface of a patient monitoring device during deployment of a replacement heart valve, the method comprising: receiving a user selection of a second gradient type via the first user interface, the second gradient type including a first gradient representation, the area of ​​which indicates a pressure difference between a first portion of the heart and a second portion of the heart and a first gradient of the valve; presenting a second user interface for the second gradient type in place of the first user interface, the second user interface including a first graph and a second graph and a second gradient representation visually presenting a gradient measurement between a first peak in the first graph and a second peak in the second graph.

[0066] According to one embodiment, the first user interface may further include a numerical value indicating the amount of regurgitation of the valve.

[0067] According to another aspect, the first user interface may further include a regurgitation representation that visually presents a measurement of regurgitation between a first point on the first graph and a second point on the second graph, the measurement of regurgitation indicating quantitative regurgitation of the valve.

[0068] According to yet another aspect, the first user interface may further include a numerical value for the first slope of the valve as a function of the statistical measurement.

[0069] According to yet another aspect, the method may further include receiving a second user selection of a third slope type via the second user interface and presenting a third user interface for the third slope type in place of the second user interface, the third user interface including the first graph and the second graph and a third slope depiction visually presenting a second slope measurement between a first point on the first graph and a second point on the second graph.

[0070] According to yet another aspect, the first user interface may further include a first numerical value for the first slope and a second numerical value for the second slope.

[0071] According to yet another aspect, the first value and the second value are presented on a display device including a first graph and a second graph.

[0072] According to yet another aspect, the method may further include presenting a third user interface including an electrocardiogram graph.

[0073] According to yet another aspect, the method may further include detecting high-frequency pacing from at least one of the first plurality of pressure values ​​or the second plurality of pressure values ​​and presenting a high-frequency pacing warning on a user interface.

[0074] According to yet another aspect, the first user interface may further include a first numerical value for the first slope, and the method may further include receiving a user heart rate selection and calculating the first numerical value based at least in part on the user heart rate selection.

[0075] According to yet another aspect, the user heart rate selection may further include a number of heart rates, and calculating the first numerical value may further include determining the first numerical value as a function of a statistical measurement of the number of heart rates.

[0076] According to yet another aspect, user heart rate selection may include selection of a specific heart rate.

[0077] According to yet another aspect, calculating the first numerical value may further include determining the first numerical value for a particular heart beat.

[0078] According to yet another aspect, calculating the first numerical value may further include determining the first numerical value for one or more other heart beats except for the particular heart beat.

[0079] 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 processing devices in communication with the non-transitory computer storage medium, the one or more hardware processing devices configured to execute the computer-executable instructions to: determine at least a first plurality of pressure values ​​from a first pressure sensor positioned in a first portion of the heart; determine a second plurality of pressure values ​​from a second pressure sensor positioned in a cardiovascular region adjacent the first portion of the heart; and present a first user interface for a first gradient type, the first user interface including a first graph based at least in part on the first plurality of pressure values, a second graph based at least in part on the second plurality of pressure values, and a first gradient depiction visually presenting a first gradient measurement between a first peak in the first graph and a second peak in the second graph.

[0080] According to an aspect, the one or more hardware processing devices may be further configured to receive a user selection of a second gradient type via the first user interface; and to present a second user interface for the second gradient type in place of the first user interface, the second user interface including the first graph and the second graph and a second gradient representation visually presenting an area between the first graph and the second graph, the area indicating a pressure difference between the first portion of the heart and the second portion of the heart and a second gradient of the valve.

[0081] According to another aspect, the one or more hardware processing devices may be further configured to receive a user selection of a second gradient type via the first user interface, and to present a second user interface for the second gradient type in place of the first user interface, the second user interface including the first graph and the second graph, and a second gradient depiction visually presenting a second gradient measurement between a first point on the first graph and a second point on the second graph.

[0082] According to yet another aspect, the first user interface may further include a numerical value indicating the amount of backflow of the valve.

[0083] According to yet another aspect, the first user interface may further include a regurgitation representation that visually presents a measurement of regurgitation between a first point on the first graph and a second point on the second graph, the measurement of regurgitation indicating quantitative regurgitation of the valve.

[0084] According to yet another aspect, the first user interface may further include a numerical value for the first slope of the valve as a function of the statistical measurement.

[0085] According to yet another aspect, the first user interface may further include a first numerical value for the first slope and a second numerical value for the second slope.

[0086] According to yet another aspect, the first and second values ​​may be presented on a display device including a first graph and a second graph.

[0087] According to yet another aspect, the one or more hardware processing devices may be further configured to present a third user interface including an electrocardiogram graph.

[0088] According to yet another aspect, the one or more hardware processing devices may be further configured to detect high-frequency pacing from at least one of the first plurality of pressure values ​​or the second plurality of pressure values ​​and present a high-frequency pacing warning on a user interface.

[0089] According to yet another aspect, the first user interface may further include a first numerical value for the first slope, and the one or more hardware processing devices may be further configured to receive a user heart rate selection and to calculate the first numerical value based at least in part on the user heart rate selection.

[0090] According to yet another embodiment, a system is disclosed comprising a pressure guidewire configured to be positioned in a first cardiac vascular region, a second pressure sensing device configured to be positioned in a second cardiac vascular region adjacent the first cardiac vascular region, and one or more hardware processing devices configured to determine at least a first plurality of pressure values ​​from the pressure guidewire, determine a second plurality of pressure values ​​from the second pressure sensing device, and present a first user interface for a first gradient type, the first user interface including a first graph based at least in part on the first plurality of pressure values, a second graph based at least in part on the second plurality of pressure values, and a first numerical value for a first gradient of the valve.

[0091] According to an aspect, the first user interface may further include a first gradient depiction that visually presents a first gradient measurement between a first point in the first graph and a second point in the second graph.

[0092] According to another aspect, the one or more hardware processing devices may be further configured to receive a user selection of a second gradient type via the first user interface; and to present a second user interface for the second gradient type in place of the first user interface, the second user interface including the first graph and the second graph and a second gradient representation visually presenting an area between the first graph and the second graph, the area indicating a pressure difference between the first portion of the heart and the second portion of the heart and a second gradient of the valve.

[0093] According to yet another aspect, the one or more hardware processing devices may be further configured to receive a user selection of a second slope type via the first user interface; and to present a second user interface for the second slope type in place of the first user interface, the second user interface including the first graph and the second graph, and a second slope depiction visually presenting a second slope measurement between a first peak in the first graph and a second peak in the second graph.

[0094] According to yet another aspect, the first user interface may further include a second numerical value indicating an amount of regurgitation of the valve.

[0095] According to yet another aspect, the first user interface may further include a regurgitation representation that visually presents a measurement of regurgitation between a first point on the first graph and a second point on the second graph, the measurement of regurgitation indicating quantitative regurgitation of the valve.

[0096] According to yet another aspect, the first user interface may further include a second numerical value for the first slope of the valve responsive to the statistical measurement.

[0097] According to yet another aspect, the first user interface may further include a second numerical value for the second slope.

[0098] According to yet another aspect, the first value and the second value are presented on a display device including a first graph and a second graph.

[0099] According to yet another aspect, the one or more hardware processing devices may be further configured to present a second user interface including an electrocardiogram graph.

[0100] Although pressure measuring coronary guidewires have been described and commercially available for many years, structural cardiac guidewires have not been developed and are therefore needed to enable cardiologists to improve structural heart procedures.

[0101] During structural heart procedures, the downstream and upstream pressure curves can be used to determine the state of the heart valve and the conditions of blood flow through the heart valve, and in some cases, can be used to determine when and how to treat the patient. Depending on the valve being treated and the procedure, in some practices, the downstream pressure curve can be provided by a pressure sensor in the guide catheter, a pressure guidewire, or other device capable of sensing pressure. The upstream pressure curve can be provided by a pressure guidewire, or other device capable of sensing pressure upstream of the downstream pressure measurement. In other practices, the upstream pressure curve can be provided by a guide catheter pressure sensor, a pressure guidewire, or other device capable of sensing pressure. The downstream pressure curve can be provided by a pressure guidewire, or other device capable of sensing pressure downstream of the upstream pressure measurement.

[0102] For example, some methods for evaluating a heart valve include accessing a blood flow passageway of a patient at an access location. The access location may be the femoral artery, radial artery, femoral vein, radial vein, left ventricular apex, or other location. A pressure guidewire may be advanced through the access location to a location adjacent to a treatment site of the patient, such as the heart valve to be evaluated, treated, or replaced. A pressure sensing device separate from the pressure guidewire may be advanced to the opposite side of the treatment site, such as to the opposite side of the heart valve, with the pressure sensing device positioned toward the distal tip of the pressure guidewire. The pressure sensing device may comprise or be located on an aortic pigtail catheter, a guide catheter, a pressure guidewire, or other device capable of sensing pressure. A treatment device, such as a balloon or a replacement heart valve, may be advanced over the pressure guidewire. In some implementations, the pressure sensing device can sense pressure on a first side of the heart valve, such as in the aorta or atrium, and the pressure guidewire can sense pressure on a second side of the heart valve, such as in the left or right ventricle. In some implementations, the pressure sensing device can sense pressure in a heart chamber, and the pressure guidewire can sense pressure in the opposite blood flow passage of the heart valve, such as in the second heart chamber or the aorta. A specific example includes positioning a pressure sensing device in the left ventricle to sense pressure in the left ventricle, and positioning a pressure guidewire in the aorta to sense pressure in the aorta to assess the aortic valve from a transapical heart access procedure. Another specific example includes positioning a pressure sensing device in the left ventricle to sense pressure in the left ventricle, and positioning a pressure guidewire in the left atrium to sense pressure in the left atrium to assess the mitral valve from a transapical heart access procedure. Pressure measurements can be used to measure the state of valve health, such as pressure gradients across a heart valve and / or valve regurgitation.

[0103] The methods described herein may include the step of equalizing pressure measurements between a pressure sensing device and a pressure guidewire. Pressure equalization may occur anywhere, such as the aorta or left ventricle. Equalizing pressure measurements may include automatically or manually adjusting a phase lag between a pressure curve generated from the pressure sensing device and a pressure curve generated from the pressure guidewire.

[0104] Some methods described herein are directed to addressing and / or treating cardiac and / or cardiovascular conditions. In some cases, the methods include treating structural heart conditions. For example, the methods may include accessing a patient's blood flow passageway at an access location, advancing an access catheter through the access location to a location in the heart, advancing a pressure guidewire through the access catheter, and / or sensing pressure using the pressure guidewire. The methods may also include inducing high-frequency pacing through the pressure guidewire. For example, an electric current may be sent from a proximal section of the pressure guidewire through a core wire of the pressure guidewire to a distal section of the pressure guidewire. The access catheter or other delivery catheter may insulate the patient from the electric current in the high-frequency pacing pressure guidewire. In some configurations, the pressure guidewire may include insulation along at least a portion of the pressure guidewire, for example, a polymer layer such as a PTFE layer may insulate the patient from the high-frequency pacing pressure guidewire when application of electric current is not desired. By combining pressure sensing with the capability of high frequency pacing, these methods eliminate the need for a separate pacing device and / or the need for replacement of such devices in order to apply these capabilities continuously.

[0105] Various pressure guidewire configurations are suitable for the pressure sensing methods described herein. These pressure guidewires can guide other catheters that are advanced over them. The distal section of the catheter may include a curve to provide an atraumatic tip. The pressure guidewire may include a distal tip to encircle the distal end of the pressure guidewire, for example, to prevent the flow of fluids or the passage of structures through the distal end of the pressure guidewire.

[0106] Some of the pressure guidewires described herein may include an outer tube having a lumen extending therethrough. At least a portion of the outer tube includes a coil portion and / or a connector tube. The pressure guidewire may also include a core wire extending through at least a portion of the lumen of the outer tube. In some configurations, the core wire may extend substantially the entire length or the entire length of the lumen of the outer tube. The core wire may include a reduced diameter portion, such as a tapered portion. The pressure guidewire may also include a pressure sensor assembly having a pressure sensor and one or more pressure wire leads extending from the pressure sensor toward the proximal end of the pressure guidewire. For example, the pressure sensor may be an optical sensor, an electrical sensor, a MEMS sensor, or a membrane-based sensor, and the pressure wire leads may be optical fibers or electrical wires. The pressure sensor may be positioned radially between the reduced diameter portion of the core wire and the coil portion of the outer tube. The pressure sensor may be disposed in a sensor housing, or the outer tube itself may provide the sensor housing. The pressure sensor may be exposed to or in pressure communication with the blood flow outside the pressure guidewire through a space in the coil portion and / or through one or more openings in the sensor housing.

[0107] At least a portion of at least one pressure wire lead may not be concentric with the outer tube. For example, a first section of the pressure wire lead may be concentric with the outer tube and a second section of the pressure wire lead may be non-coaxial with respect to the longitudinal axis of the outer tube. The second section may be positioned radially outward of the core wire. For example, in a distal region of the pressure guidewire where the core wire has a reduced diameter, there may be a space between the core wire and the outer tube to allow the pressure sensor to be positioned non-coaxial with respect to the longitudinal axis of the outer tube. When the pressure sensor is positioned in the distal region of the pressure guidewire, the pressure guidewire may measure pressure at a more centrally located location in the heart cavity, while the core wire maintains structural integrity in the distal region. However, it may be beneficial for at least a portion of the pressure wire lead to be concentric with the outer tube to facilitate connection to an optical connector or other connector at the proximal end of the pressure guidewire.

[0108] The outer tube may include an opening configured to allow at least one pressure wire lead to transition from a first section that is concentric with the outer tube to a second section that is not concentric with the outer tube. The opening may be a partial thickness cut away or may extend through the entire thickness of the outer tube. If the opening extends through the entire thickness of the outer tube, it may be sealed, for example using an adhesive, to prevent fluid from flowing through the opening to the pressure guide wire.

[0109] In some implementations, current can be delivered through the core wire to the outer conductive surface of the guidewire to induce high frequency pacing. When the core wire extends substantially the entire or entire working length of the pressure guidewire, the current generator can deliver current directly to the core wire or to an exposed conductor in direct or indirect contact with a proximal portion of the core wire. Additionally or alternatively, current may be delivered to a conductive tube and / or coil and then directly or indirectly conducted to the core wire, for example through another conductive connector. In some configurations, the outer tube of the pressure guidewire may include insulation, for example a polymer layer such as PTFE, along at least a portion of the pressure guidewire to insulate the patient from the core wire.

[0110] Some of the pressure guidewires described herein include a connector tube, a core wire, a coil portion, and / or a pressure sensor assembly. The connector tube may extend from a proximal end of the pressure guidewire such that a current generator may be coupled to the connector tube. The core wire may extend, for example, through the distal end of the connector tube, distal to the distal end of the connector tube, or may extend distal to the distal end of the connector tube. The core wire may include a reduced diameter section, such as a tapered section. In some implementations, current may be delivered directly or indirectly from the connector tube to the core wire for high frequency pacing. For example, current may be delivered from the connector tube to the core wire through a connector separate from the connector for optical coupling when using optical sensing.

[0111] The coil portion may be positioned distal to the distal end of the connector tube and may surround at least a portion of the core wire. The coil portion may include a sensor housing section, e.g., a tube or weld, that is more rigid than other sections or the remainder of the coil portion. A pressure sensor of the pressure sensor assembly may be disposed within the sensor housing section of the coil portion. In this configuration, the sensor housing section of the coil portion may include one or more openings to allow blood, or other fluid in pressure communication with the blood, to reach the pressure sensor.

[0112] The pressure sensor assembly may include a pressure sensor and one or more pressure wire leads extending from the pressure sensor toward the proximal end of the pressure guidewire. For example, the pressure sensor may be an optical sensor, an electrical sensor, a MEMS sensor, or a membrane-based sensor. The pressure sensor may be positioned radially between the reduced diameter portion of the core wire and the coil portion such that fluid can flow through a space in the coil portion to the pressure sensor. In some configurations, the pressure sensor assembly may include a separate pressure housing disposed over the pressure sensor.

[0113] The pressure wire leads can be optical fibers or electrical wires. A first section of at least one pressure wire lead can be concentric with the connector tube and a second section of the pressure wire lead can be non-coaxial with respect to the longitudinal axis of the connector tube. The second section of the pressure wire lead can be positioned radially outward of the core wire. The tube wall of the connector tube can include an opening to allow the pressure wire lead to transition from the first section concentric with the connector tube to the second section non-coaxial with respect to the longitudinal axis of the connector tube. The opening can be a partial thickness cut out or can extend through the entire thickness of the connector tube. If the opening extends through the entire thickness of the outer tube, it can be sealed to prevent fluid from flowing through the opening to the pressure guide wire. In other configurations, the pressure guide wire can include another connector with an opening to allow the pressure wire lead to transition from the first section concentric with the connector tube to the second section non-coaxial with respect to the longitudinal axis of the connector tube.

[0114] Some of the pressure guidewires discussed herein include an outer tube, a connector tube positioned radially inward of the outer tube, a pressure sensor assembly, and / or a distal tip at the distal end of the outer tube. The outer tube may have a uniform or substantially uniform diameter. A core wire may be positioned distal to the connector tube. The core wire may have a reduced diameter portion, such as a tapered portion. The pressure sensor assembly may include a pressure sensor positioned distal to the connector tube, e.g., radially between the coil portion of the outer tube and the core wire. The pressure sensor assembly may also include one or more pressure wire leads extending from the pressure sensor through the lumen of the connector tube.

[0115] The pressure guidewire may include a sensor housing, for example, in the outer tube or over the pressure sensor but within the outer tube. The sensor housing may include at least one opening to allow blood or other fluids to flow to the pressure sensor. In this configuration, the pressure guidewire may include a second coil portion extending proximally from the sensor housing toward the proximal end of the pressure guidewire. The coil portion of the outer tube may extend along a majority of the working length of the pressure guidewire or along substantially the entire working length of the pressure guidewire. The proximal end of the connector tube may be exposed from the proximal end of the second coil portion to facilitate high frequency pacing. For example, less than 10 percent or less than 5 percent of the length of the connector tube may be exposed from the proximal end of the second coil portion.

[0116] 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 processing devices configured to execute the program instructions to itself perform operations that include one or more aspects of the above and / or below embodiments (including one or more aspects of the appended claims).

[0117] In various embodiments, computer-implemented methods are disclosed that practice and / or perform one or more of the above and / or below embodiments (including one or more aspects of the appended claims) by one or more processing devices executing program instructions.

[0118] In various embodiments, a computer program product is disclosed that comprises a computer-readable storage medium having program instructions embodied therein that are executable by one or more processing devices to cause the one or more processing devices 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).

[0119] 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. Furthermore, various features of different disclosed embodiments may be combined to form additional embodiments, which are part of this disclosure. In the drawings, like reference numerals refer to corresponding features consistently throughout like embodiments. Below is a brief description of each of the drawings. [Brief description of the drawings]

[0120] [Figure 1A] FIG. 2 is a schematic diagram of a pressure guidewire deployed in the heart. [Figure 1B] FIG. 2 is a schematic diagram of a pressure guidewire deployed in the heart. [Figure 1C] FIG. 2 is a schematic diagram of a pressure guidewire deployed in the heart. [Figure 1D] FIG. 2 is a schematic diagram of a pressure guidewire deployed in the heart. [Figure 1E] FIG. 2 is a schematic diagram of a pressure guidewire deployed in the heart. [Figure 1F] FIG. 2 is a schematic diagram of a pressure guidewire deployed in the heart. [Figure 2A] FIG. 1 is a schematic diagram of a system including a console and guidewire adapted to facilitate delivery of a structural heart device. [Figure 2B] FIG. 3 is a plan view of a coiled distal tip of a pressure sensing guidewire that can be incorporated into the system of FIG. 2. [Figure 2C] FIG. 1 is a transverse cross-sectional view of a system including an aortic pigtail catheter and a guide catheter for a TAVR delivery system. [Figure 2D] FIG. 1 is a transverse cross-sectional view of a system including a guide catheter for a TMVR delivery system. [Diagram 3] 2C is a schematic diagram of one of the variations of the pressure sensing guidewire shown in FIG. 2B. [Figure 4] 2C is a cross-sectional view of another one of the pressure sensing guidewire variations shown in FIG. 2B. [Diagram 5] FIG. 2C is a schematic diagram of another of the variations of the pressure sensing guidewire shown in FIG. 2B. [Figure 6] 2C is a cross-sectional view of another one of the pressure sensing guidewire variations shown in FIG. 2B. [Figure 7] FIG. 2C is a schematic diagram of another of the variations of the pressure sensing guidewire shown in FIG. 2B. [Figure 8] FIG. 2C is a schematic diagram of another of the variations of the pressure sensing guidewire shown in FIG. 2B. [Figure 9] 2C is a cross-sectional view of another one of the pressure sensing guidewire variations shown in FIG. 2B. [Figure 10A] FIG. 1 is a diagram of a user interface for the heart valve evaluation system. [Figure 10B] FIG. 1 is a diagram of a user interface for the heart valve evaluation system. [Figure 10C] FIG. 1 is a diagram of a user interface for the heart valve evaluation system. [Figure 10D] FIG. 1 is a diagram of a user interface for the heart valve evaluation system. [Figure 10E]FIG. 1 is a diagram of a user interface for the heart valve evaluation system. [Figure 11A] 13A-13C are diagrams of additional user interfaces for the heart valve evaluation system. [Figure 11B] 13A-13C are diagrams of additional user interfaces for the heart valve evaluation system. [Figure 11C] 13A-13C are diagrams of additional user interfaces for the heart valve evaluation system. [Figure 12] FIG. 1 is a diagram of a configuration user interface for the heart valve evaluation system. [Figure 13] 1 is a flow diagram 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 diagram of a heart valve evaluation process. [Figure 16] 1 is a flow diagram of a calibration process. [Figure 17] FIG. 13 is an example waveform analysis. [Figure 18] FIG. 13 is a diagram of an additional example waveform analysis. [Figure 19] 1 is a flow diagram of a calibration process. [Figure 20] FIG. 13 is a diagram of an additional example waveform analysis. [Figure 21] FIG. 13 is a diagram of an additional example waveform analysis. [Figure 22] FIG. 13 is a diagram of an additional example waveform analysis. [Figure 23] FIG. 13 is a diagram of an additional example waveform analysis. [Figure 24] FIG. 13 is a diagram of an additional example waveform analysis. [Diagram 25] FIG. 13 is a diagram of an additional example waveform analysis. [Figure 26] FIG. 13 is a diagram of an additional example waveform analysis. [Figure 27] 11 is a flow diagram of another calibration process. [Figure 28] FIG. 2 is another diagram of a heart valve assessment system in which the various methods and systems discussed herein may be practiced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0121] The present application is directed to systems and methods for providing pressure curves during surgical heart procedures including valvuloplasty procedures, transcatheter aortic valve replacement (TAVR) procedures, sometimes referred to as transcatheter aortic valve implantation (TAVI) procedures, and transcatheter mitral valve replacement (TAMR) procedures. The systems and methods can be used to assist cardiologists in completing critical aspects of structural heart procedures. The embodiments herein can be used to communicate, for example graphically, via user interface output, 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 other heart valve. The embodiments herein can be used to communicate the nature of blood flow through a heart valve before, during, and / or immediately after the deployment of a structural heart device, such as an aortic valve, mitral valve, or other heart valve. The novel display provides an intuitive and / or immediate sense of a patient's condition to simplify procedures, facilitate procedures, and increase the success of procedures. Further discussion of user interface output can be found in Section III of this application.

[0122] Pressure measurements obtained from the systems and methods described herein can be used to calculate heart valve or blood flow indices, such as an index of valve regurgitation or a pressure gradient across a native heart valve, a previously placed replacement heart valve, or a currently implanted replacement heart valve. The index of valve regurgitation and the pressure gradient can allow a cardiologist to properly evaluate the heart valve. A larger pressure gradient across the aortic valve (or a lower pressure in the aorta) during heart systole can indicate greater valve calcification. A smaller index of regurgitation at the end of heart diastole can indicate greater regurgitation. Further discussion of such calculations can be found in Sections III and IV of this application.

[0123] I. Example Methodology 1A-1F show various methods of accessing the heart during a structural heart procedure. Either the pressure guidewire 30 or the pressure sensing device (e.g., pigtail catheter 10 or access catheter 20) can be used to calculate an upstream pressure curve (with respect to flow), and the other of the pressure guidewire 30 or the pressure sensing device can be used to calculate a downstream pressure curve (with respect to flow). Although specific methods are described below with respect to specific heart valves and accessing techniques, similar systems may be used to evaluate other valves, such as the tricuspid or pulmonary valves.

[0124] 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 native diseased valve accessed in a later procedure or a previously implanted replacement heart valve. As illustrated, a pigtail catheter 10 may be positioned downstream of the treatment site, e.g., downstream of the aortic valve in the aorta A, to provide a downstream pressure curve. The pigtail catheter 10 may 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 another delivery catheter replaced with the access catheter 20, may be used to advance a valve inflation balloon, a replacement valve, and / or other devices to the treatment site. A pressure guidewire 30 may extend through the access catheter 20 to a location upstream of the treatment site, e.g., in the left ventricle LV, to provide an upstream pressure curve. The pressure guidewire 30 may include a pressure sensor 40 anywhere along the distal section of the pressure guidewire 30, for example, in the atraumatic bend, at the transition to the atraumatic bend, or proximal to the atraumatic bend (see FIG. 2B). Prior to entering the heart, access is provided using an arterial approach, such as a femoral or radial approach. FIG. 1B shows a similar configuration to FIG. 1A, except that one or both of the pigtail catheter 10 and / or the access catheter 20 may be used to provide a pressure reading using external pressure sensing. The catheter 20 may allow for measurement of downstream pressure as well as pressure read by the pressure guidewire 30. This configuration may be used to equate an external pressure sensor to the pressure guidewire. Alternatively, any other delivery catheter that replaces 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 the pigtail catheter 10 and the access catheter 20.

[0125] It may be important to equalize pressure readings between the downstream and upstream pressure sensing devices. Equalization may be done in the sense of pressure accuracy (gain and offset), but also in the sense of phase lag between the two pressure curves. For example, pressure readings may be taken from the downstream and upstream pressure sensing devices in the same general anatomical region, and the pressure measurements may be adjusted manually or automatically for phase lag between the two pressure curves. As shown in FIG. 1B, pressure measurements for equalization may be taken 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 (the distal end of the fluid column in the catheter 20) is advanced adjacent to the sensing feature of the pressure guidewire 30. The sensing feature of the access catheter 20 and the sensing feature of the pressure guidewire 30 may be secured to be positioned in the left ventricle LV. The sensing features of the access catheter 20 and the pressure guidewire 30 may be secured to similar locations in the left ventricle LV.

[0126] 1C shows a pressure sensor 40 positioned proximal to the atraumatic bend of the pressure guidewire 30. For example, the sensing feature of the pigtail catheter 10 (the distal end of the fluid column in the catheter 10) is advanced adjacent to the sensing feature of the pressure guidewire 30. The sensing feature of the pigtail catheter 10 and the sensing feature of the pressure guidewire 30 can be secured to be positioned in the aorta A. In this configuration, pressure equalization can be performed in the aorta A. After pressure equalization, the pressure guidewire 30 can be 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.

[0127] In FIG. 1D, the pigtail catheter 10 may be positioned in the aorta A to provide a downstream pressure curve. The pressure guidewire 30 extends through the pigtail catheter 10 in this embodiment to provide an upstream pressure curve. In this configuration, pressure equalization may be performed in the aorta A. For example, the sensing feature of the pressure guidewire 30 may be advanced to the end of the fluid column in the pigtail catheter 10, or just distal to that end. The signals from the sensing feature of the pressure guidewire 30 and the fluid column may be compared to equalize them (discussed further below in Section IV). After pressure equalization, the pressure guidewire 30 may be withdrawn from the aortic pigtail and inserted into the left ventricle via an access catheter, as is normally done, while the pigtail catheter 10 remains in the aorta A to provide a downstream pressure curve.

[0128] The systems described herein may be used to measure the performance of an existing or replacement mitral valve. For example, as shown in FIG. 1E, an access catheter 20 may be advanced through the venous vasculature, e.g., from a femoral approach, e.g., through the inferior or superior vena cava VC, into 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 patient's foramen ovale, or to track a guidewire or device that provided such access. The access catheter 20, or a separate delivery catheter exchanged for the access catheter 20, may be used to advance a valve inflation balloon, a replacement valve, and / or other device to the treatment site. A pressure guidewire 30 may extend through the access catheter 20 into the left ventricle LV. The access catheter 20 may provide a pressure signal that may be used to generate an upstream pressure curve, while the pressure guidewire 30 provides a pressure signal that may be used to generate a downstream pressure curve. Alternatively, any other delivery catheter that replaces the access catheter may be used to provide the upstream pressure curve.

[0129] A similar system may be used in an apical approach for aortic or mitral valve treatment. For example, as shown in FIG. 1F, an access catheter 20 may access the left ventricle LV through the apex P of the heart. Another device (not shown) may be used to open a passage through the apex P. The access catheter 20 may be advanced through the device, etc. The access catheter 20, or another delivery catheter replaced with the access catheter 20, may be used to advance a valve expansion balloon, a replacement valve, and / or other device to the treatment site. A pressure guidewire 30 may extend through the access catheter 20 into the aorta A in aortic valve treatment. The access catheter 20 may provide a pressure signal that may be used to calculate an upstream pressure curve, while the pressure guidewire 30 may provide a signal that may be used to calculate a downstream pressure curve. Alternatively, any other delivery catheter replaced with the access catheter may be used to provide an upstream pressure curve.

[0130] 1F illustrates assessment or treatment of the aortic valve via the cusp 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 (from a flow perspective, the proximal or upstream pressure curve). The access catheter 20 can generate a pressure signal that can be used to calculate the left ventricular pressure curve (from a flow perspective, the distal or downstream pressure curve).

[0131] During a valve expansion procedure, sometimes referred to as a valvuloplasty or valve implantation procedure, the native circulation through the heart valve may be impeded by a valvuloplasty balloon, valve replacement delivery system, or other therapeutic device. However, when the heart is pumping, pressure from the left ventricle LV or compression of the myocardium may drive the therapeutic device back into the aorta A, making it difficult to properly position the therapeutic device. High-frequency 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 on the myocardium, allowing the clinician to complete the procedure. Conventional high-frequency pacing may involve introducing a temporary pacemaker into the heart, which typically requires another access location, such as a venous access location. The temporary pacemaker may also burn the heart and cause other complications. Alternatively, a pressure guidewire 30 may be used to perform high-frequency pacing. As previously described, the pressure guidewire 30 may be introduced through the same access location as the access catheter 20 or other delivery catheter, which reduces the overall number of access locations. Current may be delivered to the proximal section of the pressure guidewire and transmitted through the connector tube and / or core wire to the distal section of the pressure guidewire, as described in more detail below. The access catheter 20 or other delivery catheter may insulate at least the intermediate section of the high frequency pacing pressure guidewire 30 from the patient to prevent burns. Alternatively or additionally, the pressure guidewire 30 may include an insulating portion to isolate the pressure guidewire 30. As shown in FIG. 2B, the distal section of the pressure guidewire may include curves that allow the current to contact the ventricular wall at multiple locations.

[0132] II. Overview of Pressure Wire Systems and Their Use 2A illustrates a diagnostic system 200 that may be used in a patient's vasculature. Diagnostic system 200 is configured to determine whether the degree of valve damage is significant enough to indicate that balloon dilatation (e.g., valvuloplasty), valve replacement, or other catheter intervention should be performed.

[0133] The diagnostic system 200 may include a monitoring assembly 204 configured to be coupled to a pressure guidewire 208. The diagnostic system 200 may include a connection (indicated by dashed line A) that facilitates coupling of the monitoring assembly 204 to the pressure guidewire 208 and decoupling of the pressure guidewire 208 from the monitoring assembly 204. Coupling and decoupling to and from the monitoring assembly 204 is useful when allowing a clinician to initially use the pressure guidewire 208 to assess the effects of heart valve injury. The pressure guidewire 208 may be used to deliver a therapeutic device, such as a balloon catheter or a valve delivery system.

[0134] A fiber optic interface cable 202 may be used to couple the pressure guidewire 208 to the monitoring assembly 204 using 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 the access catheter 20, or a pressure-sensing distal tip on 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, such as in the aorta, is 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.

[0135] The pressure guidewire 208 can take any suitable form. For example, the pressure guidewire 208 can include a proximal section having a proximal end positioned outside the patient and a distal end that can be advanced through the access catheter 20 into the vasculature. The pressure guidewire 208 can be configured to be flexible 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 for structural integrity, while the distal section of the pressure guidewire 208 can be formed with an atraumatic curve 250, such as the coiled end shown in FIG. 2B, to provide greater 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.

[0136] Any sensing modality can be used. For example, an optical sensor can be configured to sense pressure when exposed to blood. The optical sensor can be disposed within an interior space of the pressure guidewire 208 in fluid communication with the exterior of the pressure guidewire 208. The sensor can be an optical or electrical pressure sensor. The sensor can be selectively placed in communication with the monitoring assembly 204 by a pressure wire lead disposed between the sensor and the proximal end of the pressure guidewire 208. The pressure wire lead can be an optical fiber or an electrical wire.

[0137] 2B, the pressure sensor may be located 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 guidewire's curved portion 250 at location 206C, at the transition to the guidewire's curved portion 250 at location 206B, or proximal to the guidewire's curved portion 250 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 anywhere in the curved distal region of the pressure guidewire from the straight region of the pressure guidewire, such as, for example, between about 0 degrees and about 90 degrees, between about 90 degrees and about 180 degrees, between about 180 degrees and about 270 degrees, between about 270 degrees and about 360 degrees, between about 360 degrees and about 450 degrees, or between about 450 degrees and about 540 degrees.

[0138] 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 in the heart chamber, e.g., the left ventricle LV, and offset from the chamber 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 made closer to the heart valve, and it is possible to perform equalization in the aorta A while maintaining the distal tip of the pressure guidewire 208 in the left ventricle LV. In some procedures, performing equalization in the aorta A requires less manipulation of the pigtail catheter or other pressure sensing device is required. For example, during an aortic valve procedure, the pigtail catheter is already positioned 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.

[0139] FIG. 2C shows a cross-section of a TAVR system in a patient's descending aorta, with anatomy removed for clarity. The TAVR system may be used in conjunction with a monitor and display device 204. For example, a pressure guidewire 208 extends through an access catheter 210. The same access catheter 210 may be used to advance a delivery system 212 over the pressure guidewire 208. The delivery system 212 may be used to advance a valve replacement or other therapeutic device. Other configurations are possible. For example, a catheter for the access catheter 210 may 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 the blood in the aorta is an aortic pigtail catheter 214, delivered separately from the access catheter 210, although possible from the same access location.

[0140] In other configurations, the access catheter 210 or delivery system 212 may be used to obtain a pressure signal for the pressure of blood in the aorta and thus may be a pressure sensing device for the aortic pressure. As shown in FIG. 2D, for a mitral valve replacement, the access catheter 211 may be the pressure sensing device. A pressure guidewire 208 may extend through the access catheter 211 and a delivery system 213 may be advanced over the pressure guidewire 208. The delivery system 213 may be used to deliver a mitral valve or other replacement or treatment device.

[0141] a. Wire-based pressure guidewire 3 and 4 show different pressure guidewires 308, 408 that may be used in any of the methods previously described. The numbers used to identify features of pressure guidewire 308 have been incremented by the number one hundred (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.

[0142] Generally, 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 comprise a distal tip that 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 or entire 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 entire working length except for the distal tip 432 or the atraumatic 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 atraumatic 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.

[0143] FIG. 3 is a schematic diagram of one variation of a pressure sensing guidewire 308. As shown, 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 round 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. When a substantial length of the coiled outer tube 310 is coiled, the coil portion 312 provides flexibility and softness to avoid any trauma (e.g., puncture and / or dissection) during use. The coil portion 312 also promotes safety in the event of failure of the distal tip. The coil portion 312 may also ensure electrical contact with the heart during high frequency pacing.

[0144] 3, at least a proximal portion 328 of the core wire 316 can be concentric with the outer tube 310 and can extend through at least a portion of the lumen of the outer tube 310. For example, the core wire 316 can 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 sufficient stiffness to the pressure guidewire 308 for pushability and to prevent tangling. The core wire 316 also provides stiffness to support the delivery catheter during implementation of the valve.

[0145] At least a portion of the core wire 316 may include a reduced diameter section 326 to provide space in the lumen of the outer tube 310 for the pressure sensor 322. For example, as shown in FIG. 3, the reduced diameter section 326 may be tapered toward the distal end of the pressure guidewire 308. A 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 the entire atraumatic curve 250 at the distal section of the pressure guidewire 308 (shown in FIG. 2B) to facilitate a flexible transition to the atraumatic curve 250 of the pressure guidewire 308. The core wire 316 continues to extend through at least a portion of the atraumatic curve 250. This flexible transition acts as a force absorber and ensures that kinks do not form in the proximal section of the atraumatic curve 250 of the pressure guidewire 308. Tangling can complicate procedures, such as advancing another catheter over the guidewire 308 or atraumatically removing the guidewire 308 from the patient.

[0146] The proximal portion 328 of the core wire 316 may include an outer diameter of up to 0.03 inches, for example, between 0.015 inches and 0.03 inches. The reduced diameter portion 326 of the 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 the core wire 316. For example, the reduced diameter portion 326 of the core wire 316 may include an outer diameter of less than 0.01 inches or less than 0.0075 inches.

[0147] The core wire 316 may comprise a conductive material such as stainless steel to provide a conductive path for electrical current applied to the guidewire 308 in connection with high-frequency 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 and display device 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 high-frequency pacing.

[0148] 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 sensor, an electrical sensor, a membrane-based sensor, a MEMS sensor, or other device capable of generating a signal in response to a pressure level or pressure fluctuation. 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 in the coil portion 312.

[0149] The pressure sensor assembly 318 may be radially disposed between the core wire 316 and the outer tube 310, with the pressure sensor 322 radially disposed between the reduced diameter section 326 of the core wire 316 and the coiled portion 312 of the outer tube 310. At least a portion of the pressure sensor assembly 318 may be non-coaxial with respect to the longitudinal axis L of the pressure guidewire 308. In some configurations, the entire pressure sensor assembly 318 may be non-coaxial with respect to the longitudinal axis L of the pressure guidewire 308.

[0150] The pressure sensor 322 may be exposed to blood or other fluids through a gap or gap 314 in the coil portion 312. In other variations, the outer tube 310 may include a sensor housing section with one or more openings to expose the pressure sensor 322 to blood or other fluids. The sensor housing section may be more rigid 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 mounted 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 create a stiffened section.

[0151] At least a portion of the pressure guidewire 308 may be covered by a lubricious insulator, for example a polymer layer such as PTFE. The insulator may secure one or more pressure wire leads 320 in place. The insulator may also electrically isolate the core wire 316 from the patient along its length when high frequency pacing is induced through the core wire 316. The insulator may replace the need for a separate catheter to electrically isolate the pressure guidewire 308.

[0152] FIG. 4 illustrates another variation of a pressure guidewire 408. The pressure guidewire 408 may include any of the features described with respect to the pressure guidewire 308. In this variation, a distal portion of the outer tube 410 may be formed by a coil portion 412. A proximal portion of the outer tube 410 may be formed by a connector tube 430. The connector tube 430 may include a conductive material to facilitate high frequency pacing. For example, the connector tube 430 may be formed of a metallic construction, such as a stainless steel tube. The connector tube 430 is not covered with a coating or other insulation to allow high frequency pacing. In some configurations, current may additionally or alternatively flow through one or more pressure wire leads 420. The connector tube 430 may be directly or indirectly coupled to the coil portion 412 and / or the distal tip 432. For example, the coil portion 412 may be indirectly coupled to the connector tube 430 by an insulated portion. The insulated portion may provide a length that is insulated from the patient and thus may be the insulated portion 434 in some embodiments. The insulating portion 434 can insulate the patient from the core wire 416. In some configurations, the insulating portion 434 can comprise a polymer layer, such as PTFE.

[0153] At least a non-reduced diameter portion of the core wire 416 can be concentric with the outer tube 410. The core wire 416 can extend through at least the coil portion 412, but may also extend through at least a portion of the insulated portion 434 of the outer tube 410 and / or the connector tube 430. For example, the proximal end of the core wire 416 may be sealed to the distal end of the connector tube 430, e.g., with an adhesive 436, and extend distally from the distal end of the connector tube 430.

[0154] 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. The 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.

[0155] The pressure sensor assembly 418 may be radially disposed 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 non-coaxial 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 non-coaxial with respect to the longitudinal axis of the outer tube 410. The outer tube 410 may include an opening 440 to allow 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 non-coaxial with respect to the longitudinal axis of the outer tube 410. The aperture 440 may be a partial thickness cut away or may extend through the entire thickness of the outer tube 410. If the aperture 440 extends through the entire thickness of the outer tube 410, the aperture 440 may be sealed, for example with adhesive 436, to prevent blood or other fluids from flowing through the aperture 440 to the pressure guidewire. As shown in FIG. 4, the aperture 440 is located in the connector tube 430. However, in other configurations, the aperture 440 may be located in the insulating portion 434.

[0156] 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 non-coaxial with respect to the longitudinal axis of the outer tube 410. The core wire 416 may have a groove on one side configured to accommodate the expansion of the pressure wire lead 420 to allow the lead to transition from the first section 438a to the second section 438b.

[0157] The pressure guidewire 408 may include a rounded distal tip 432 to form an atraumatic tip. For example, the distal tip 432 may have a hemispherical shape. The tip 432 may also be reduced or flattened to prevent unwanted ingress of foreign matter through the distal end of the pressure guidewire 408.

[0158] In some configurations, the distal tip 432 is a separate component that is adhered, welded, and / or otherwise bonded to the coil portion 412 and / or core wire 416. The distal tip may be bonded to the inner surface of the coil portion 412 and / or to 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 straighten the adhesive bond to the distal tip 432. In other configurations, the distal tip 432 may be an enlarged distal end of the core wire 416 that is distal to the reduced diameter portion 426. The distal end of the core wire 416 may be adhered, welded, and / or otherwise bonded to the inner surface and / or to the distal-most edge of the coil portion 412. In one method, the distal tip 432 is formed by transforming an enlarged section of the core wire 416 into a hemispherical member. The enlarged section may be melted to form the hemispherical member. The hemispherical member may be bonded to a distal portion of the coil portion 412. In any of these configurations, the atraumatic portion of the distal tip 432 may be formed from the core wire 416, adhesives, and / or welds.

[0159] b. Tube-Based Pressure Guidewire 5-9 show further variations of pressure guidewires that may be used in any of the methods previously described. The pressure guidewires described below may include any of the features of the pressure guidewires 308, 408 previously described. Generally, 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 or entire 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 abraded bend. The pressure guidewire may include an outer diameter of up to 0.035 inches, e.g., between 0.018 inches and 0.035 inches. In some configurations, the distal portion of the pressure guidewire may be formed into an atraumatic bend 250 as shown in FIG. 2B. In other configurations, the distal portion of the pressure guidewire may remain straight.

[0160] The connector tube may include an inner diameter that is less than one-third or 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 of 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. 6). In a non-uniform configuration, a reduced diameter portion of the connector tube may have an outer diameter of about 0.027 inches or less. The connector tube may extend along most 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.

[0161] The connector tube may be constructed from 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 and / or display device and / or to a current generator. Thus, at least the proximal end of the connector tube may be uncoated.

[0162] The pressure guidewire may comprise a core wire distal to the connector tube. In venous or transapical aortic valve applications, the portion with the core wire may be disposed in the bloodstream downstream of the portion with the connector tube. In arterial or transapical mitral valve applications, the portion with the core wire may be disposed in the bloodstream upstream of the portion 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 reduced diameter portion 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 reduced diameter portion 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., along less than 20 percent, less than 10 percent, or less than 5 percent of the working length of the pressure guidewire.

[0163] FIG. 5 is a schematic diagram of another variation of the pressure sensing guidewire 508. As shown, 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 round coil. As shown in FIG. 5, the coiled portion may comprise two coiled sections 512a, 512b separated from one another by a sensor housing 542. Together, the coiled sections 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, together, the coiled sections 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 coiled, the coiled sections 512a, 512b provide sufficient flexibility to navigate a tortuous vasculature. The distal coil portion 512a also promotes safety in the event of a failure along the coiled portion, such as failure of the distal tip. When used for high frequency pacing, the distal coil portion 512a may also ensure electrical contact with the inner wall of the patient's heart, such as the inner wall of the left ventricle.

[0164] As shown in FIG. 5 , at least a proximal portion 528 of the core wire 516 can be concentric with the outer tube 510 and can 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 can be the same as the outermost diameter of the connector tube 530. At least a portion of the core wire 516 can include a reduced diameter section 526, such as a tapered section tapered toward the distal end of the pressure guidewire 508. A transition between the proximal portion 528 and the reduced diameter section 526 of the core wire 516 can be positioned proximal to the atraumatic curve 250 at the distal section of the pressure guidewire 508 to facilitate a flexible transition to the atraumatic curve 250 of the pressure guidewire 508. This flexible transition acts as a force absorber and ensures that kinks do not form in the proximal section of the atraumatic curve 250 of the pressure guidewire 508. Tangling can complicate procedures, such as advancing another catheter over the guidewire 508 or traumatically removing the guidewire 508 from the patient. The core wire 516 can include a conductive material, such as stainless steel, to provide high frequency pacing, as previously described.

[0165] The pressure sensor assembly 518 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 sensor, an electrical sensor, a membrane-based sensor, or others. The pressure wire leads 520 may be optical fibers or electrical wires. The pressure wire leads 520 may extend 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 the connector tube 530 and in some cases may be sealed to the connector tube 530, for example, with an adhesive. In some cases, the adhesive provides a seal to prevent fluid from flowing proximally through the connector tube 530. An adhesive may be used at the proximal end of the connector tube 530 to concentrically secure the optical fiber 520 to the connector tube 530.

[0166] 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 shown, the sensor housing 542 may be a metal tube that joins the two coil portions 512a, 512b, although in other variations, the sensor housing 542 may be formed by welding several coils together to form a weld that joins the coil portions 512a, 512b.

[0167] The sensor housing 542 and pressure sensor 522 may be positioned proximal to the atraumatic curve 250 shown in FIG. 2B, such as at location 206A. However, as previously described, the pressure sensor may be positioned anywhere along the curve 250 in the distal section of the pressure guidewire 508.

[0168] At least a portion of the pressure guidewire 508 may be covered by a lubricious insulator, for example a polymer layer such as PTFE. The insulator may electrically isolate a portion of the pressure guidewire 508 when high frequency pacing is induced through the connector tube 530 and / or the core wire 516. The insulator can replace the requirement for a separate catheter body to electrically isolate the pressure guidewire 508.

[0169] FIG. 6 is a cross-sectional view of another variation of pressure sensing guidewire 608. Pressure sensing guidewire 608 is similar to pressure sensing guidewire 508, except as described below as different. The disclosure in connection with FIG. 6 may be seen as supplemental to the disclosure of FIG. 5. Pressure sensing guidewire 608 includes a distal tip 632. Distal tip 632 is similar to distal tip 432, except as described below as different. Distal tip 632 provides atraumatic interaction with blood vessels, valves, and heart wall chambers. Tip 632 can reduce or prevent ingress of foreign matter, e.g., components or fluids, through the distal end of pressure guidewire 608. Distal tip 632 can have a hemispherical shape.

[0170] In some configurations, distal tip 632 is a separate component that is attached, welded, and / or otherwise bonded to coil portion 612a and / or core wire 616. Distal tip 632 may be bonded to the inner surface of coil portion 612a and / or to the distal-most edge of coil portion 612a. Core wire 616 may be bent up to 180 degrees within outer tube 610 to straighten the adhesive bond to distal tip 632. In other configurations, distal tip 632 may be an enlarged distal end of core wire 616 that is distal to reduced diameter portion 626. The distal end of core wire 616 may be attached, welded, and / or otherwise bonded to the inner surface and / or the distal-most edge of coil portion 612a. In any of these configurations, the atraumatic portion of distal tip 632 may be formed from core wire 616, such as by melting or reforming the enlarged section of core wire 616 to create the desired shape.

[0171] 7 is a schematic diagram of another variation of a pressure sensing guidewire 708. 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 to the distal curve 250 of the pressure guidewire 708, such as at locations 206B or 206C shown in FIG. 2B. However, as previously discussed, it may be beneficial to reduce the diameter of the inner core wire to promote flexibility at the transition to the distal curve 250. Thus, the sensor housing 742 and pressure sensor 722 may be positioned in the region where the connector tube 730 and / or core wire 716 transition to a reduced 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 can be smaller than the outermost diameter of the connector tube 730, such as at the distal end or region of the connector tube 730. In this configuration, the outer diameter of the sensor housing 742 can be reduced as compared to the sensor housing 542.

[0172] FIG. 8 is a schematic diagram of another variation of a pressure sensing guidewire 808. The pressure sensing guidewire 808 is similar to the pressure sensing guidewire 708, except that the sensor housing 842 and pressure sensor 822 may be positioned more distally to the distal curve 250 of the pressure guidewire 808, such as at location 206D shown in FIG. 2B. However, as previously discussed, it may be beneficial to reduce the diameter of the inner core wire to promote flexibility at the transition to the distal curve 250. Thus, in the region of 206D at the distal curve 250, the reduced diameter section 826 of the core wire 816 may have a sufficiently reduced diameter to allow positioning of the sensor 822 radially between the distal coil portion 812a and the reduced diameter section 826 of the core wire 816. As shown in FIG. 8, the sensor 822 may have a separate sensor housing 842 positioned about the sensor 822.

[0173] Instead of a sensor housing along the outer tube 810, the pressure guidewire 808 includes a connector 848 that extends between the coil portions 812a, 812b. The connector 848 may include an opening 852 to allow the at least one pressure wire lead 820 to transition from a first section 838a, which is concentric with the outer tube 810 and in the connector tube 830, to a second section 838b, which is non-coaxial with respect to the longitudinal axis L of the outer tube 810. The opening 852 may be a partial thickness cut away 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 840 may be sealed, for example with an adhesive, to prevent fluid from flowing through the opening 840 to the pressure guidewire.

[0174] 9 is a cross-sectional view of another variation of a pressure sensing guidewire 908. Pressure sensing guidewire 908 is similar to pressure sensing guidewire 808, except that FIG. 9 includes a distal tip 932. Distal tip 932 may include any of the features of distal tip 632 shown in FIG.

[0175] The outer tube 910 includes an insulating portion 934 and a coil portion 912 joined by a connector 948. The insulating portion 934 surrounds at least a portion of the connector tube 930. The insulating portion 934 may include a polymer layer, such as PTFE, to electrically isolate the connector tube 930 from the patient during high frequency pacing. A proximal end 956 of the connector tube 930 may be exposed from the proximal end of the insulating portion 934 for connection to a monitor and / or display device and / or to a current generator. Thus, at least the proximal end of the connector tube 930 may be uncoated.

[0176] As shown, the connector 948 may be a metal tube connecting the insulating portion 934 and the coil portion 912, although in other variations, the connector 948 may be a welded portion joining the insulating portion 934 and the coil portion 912.

[0177] One or more pressure wire leads 920 may be sealed to the inner lumen of the connector tube 930, for example with an adhesive, to prevent proximal fluid flow and ensure concentricity of the optical fibers for signal transmission.

[0178] The pressure sensor 922 may be exposed to blood or other fluids through a gap or gap in the coil portion 912. The outer tube 910 may also include a sensor housing section 924. The sensor housing section may be more rigid than the remainder of the coil portion 912. For example, the sensor housing section 924 may be a metal tube that divides the coil portion 912 into two sections. The sensor housing section 924 may be mounted on a distal portion of a first coil section of the coil portion 912 and on a proximal portion of a second coil section of the coil portion 912. The sensor housing section 924 may include one or more openings to expose the pressure sensor 922 to blood or other fluids. As another example, the coil portion 912 may include two coils welded together to create a reinforced section that acts as the sensor housing section 924.

[0179] III. Heart valve evaluation user interface system Existing user interfaces may be unable or incomplete in indicating a heart valve status 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 indications of a heart valve status, such as an indication of valve regurgitation or a pressure gradient. Additionally, existing user interfaces for structural heart procedures may have limited user interaction capabilities, such as a lack of options to allow a user to customize one or more user interfaces. Existing patient monitoring and / or display devices may have limited visual space for presenting indications, such as heart valve status, diagnoses, physiological parameters, or other data.

[0180] Thus, the user interface of the heart valve evaluation system disclosed herein can be improved over existing user interfaces. During a structural heart procedure, one or more indications of a heart valve status can be provided to a clinician via a user interface. The user interface can be constructed to provide information in an efficient manner. A particular graphical depiction or indication can be presented or selected by a user, which can provide a heart valve clinician with quick access to a condition or problem. The systems and techniques described herein can allow a clinician to access data more quickly, perform an analysis more quickly, and / or interact with one or more user interfaces more quickly than existing graphical user interface systems (such as by reducing the number of clicks or selections by a user). The user interfaces described herein can be improved over existing user interfaces by providing a more efficient use of limited visual space in small monitoring devices or display devices. For example, visual indications, graphical depictions, and / or combinations thereof can provide information to a user related to a heart valve status in an efficient manner configured for a monitoring device or display device with limited space. Thus, the systems and techniques described herein can be improved over conventional user interfaces.

[0181] As used herein, in addition to its ordinary meaning, "cardiovascular region" may broadly refer to the region with or surrounding the left ventricle, right ventricle, aorta, left atrium, right atrium, vena cava, and / or blood flow passageways (blood flow chambers, blood vessels, pulmonary arteries, etc.) adjacent to a portion of the heart.

[0182] The heart valve assessment system described herein can advantageously provide an indication of heart valve status, such as a pressure gradient or an index of valve regurgitation. 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. Example gradients, such as peak-to-peak gradient, area gradient, or instantaneous gradient, are provided herein. A peak-to-peak gradient can indicate the difference in pressure between a maximum or locally maximum systolic pressure of a first cardiovascular region (such as the left ventricle LV) and a maximum or locally maximum systolic pressure of a second cardiovascular region (such as the aorta Ao). An area gradient can indicate the area between two graphs, such as pressure curves. An instantaneous gradient can indicate the maximum or locally maximum pressure between a first cardiovascular region and a second cardiovascular region in a cardiac cycle. As used herein, in addition to its ordinary meaning, an "indicator of valve regurgitation," "indicator of regurgitation," or "regurgitation" can refer to a measurement of valve leakage. The regurgitant flow calculation may include the difference in pressure at the end of the diastolic cycle divided or normalized by the systolic pressure. The aortic regurgitant flow calculation may correspond to the following formula: Aortic Regurgitant Flow Index=(Aortic Diastolic Pressure-Left Ventricular Diastolic Pressure) / Aortic Systolic Pressure. Other cardiac valve conditions may include high frequency pacing of the heart. The systems, techniques, and / or graphical user interfaces described herein may provide the clinician with additional data on which to base a treatment / action decision. For example, the cardiac valve condition and / or associated user interface may provide the clinician with additional information to address valve disease, to modify a replacement valve during a procedure, and / or to make recommendations following a valve procedure.

[0183] Regurgitation can occur when blood leaks back through a valve, which can be caused by disease of the valve or, in the case of prosthetic replacements, by poor fit of the replacement valve against the native valve.

[0184] a. Example User Interface 10A-10E, 11A-11C, and 12 depict example heart valve evaluation user interfaces. The heart valve evaluation system may be the same as or similar to the diagnostic system 200 previously described in FIG. 2A, or may include similar components as the diagnostic system 200. For convenience, the user interface is described as being presented by the diagnostic system 200 or the monitoring device 204, although other computer systems may present the user interface. The user interface may be presented by the monitoring device 204 previously described, 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.

[0185] 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 from those shown and described below, and / or specific aspects may or may not be included. Additionally, the illustrated user interfaces may be combined or divided into other user interfaces such that similar or the same functionality may be provided. The user interfaces of FIGS. 10A-10E, such as user interfaces 1000, 1020, 1040, 1060, and / or 1080, may have similar user interface elements and / or capabilities. 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., a finger or pen), or a keyboard input, among other user interface input options.

[0186] 10A-10E depict example user interfaces that may be presented by the monitoring device 204 described above. In FIG. 10A, the user interface 1000 may be presented before, during, and / or immediately after 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 example graphs 1002, 1004, 1006, 1008 may include or be pressure waves. The graphs 1002, 1004, 1006, 1008 may present pressure values ​​corresponding to measurements from a cardiovascular region. The pressure values ​​may include a series of pressure values ​​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 real-time or near real-time as pressure measurements are obtained from the patient.

[0187] As shown, the user interface 1000 may 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 may correspond to statistical measurements of pressure values ​​from the cardiovascular regions, such as average or arithmetic mean pressure values ​​for the aorta Ao or the left ventricle LV. The statistical measurements may be user selectable and based on configuration parameters that indicate a statistical measurement period, such as a number of heartbeats or a period of time for which to calculate the statistical measurements. In some embodiments, one or more of the graphs 1002, 1004, 1006, 1008 may have an indication to indicate the corresponding cardiovascular region for the graph (e.g., the aorta Ao graphs 1002, 1004 may be colored red and the left ventricle LV graphs 1006, 1008 may be colored blue).

[0188] As shown, the user interface 1000 may 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 may include systolic blood pressure, diastolic blood pressure, and / or statistical measures of blood pressure, such as mean or arithmetic mean systolic or diastolic blood pressure, or some combination thereof for a specific cardiovascular region. The statistical measures of the physiological parameters may correspond to additional graphs 1004, 1008.

[0189] 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 ​​related to a procedure. The clinician may then play back the recorded data. In some embodiments, cardiac valve status may be presented to the user during the playback mode, such as, but not limited to, an indication of gradient or regurgitation.

[0190] 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 allows the user to stop recording of the patient data. In some embodiments, once stopped, the user may enter a playback mode to view heart valve status, such as, but not limited to, gradient or regurgitation indicators.

[0191] 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 graph and second graph 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.

[0192] The user interface 1040 may include a first number 1046 corresponding to a slope type, such as a peak-to-peak slope type. The first number 1046 may correspond to a pressure difference between a maximum or locally maximum systolic pressure of a first cardiovascular region (such as the left ventricle LV) and a maximum or locally maximum systolic pressure of a second cardiovascular region (such as the aorta Ao). In some embodiments, the first number 1046 may include a statistical measurement, such as an arithmetic mean or average of the pressure difference between the maximum or locally maximum systolic pressures for multiple cardiac cycles. As shown, the first number 1046 (here 28) may be a statistical measurement of the peak-to-peak measurement for multiple cardiac cycles, which corresponds to the peak-to-peak measurements 1042a, 1042b, 1042c of the three graphs.

[0193] The user interface 1040 can present one or more backflow representations 1044a, 1044b, 1044c. As shown, the one or more backflow representations 1044a, 1044b, 1044c can visually present a measurement of backflow between a first point in the first graph 1002 and a second point in the second graph 1006. The one or more backflow representations 1044a, 1044b, 1044c can correspond to a calculation of the difference in pressure at the end of the diastolic cycle (here, aortic A end-diastolic pressure minus left ventricular LV end-diastolic pressure) divided or normalized by the systolic pressure (here, aortic systolic pressure).

[0194] The user interface 1040 may include a second number 1048 corresponding to an indication of reflux. The second number 1048 may include a difference in pressure at the end of the diastolic cycle divided or normalized by the systolic pressure. In some embodiments, the second number 1048 may include a statistical measurement, such as an arithmetic mean or average reflux, for multiple cardiac cycles. As shown, the second number 1048 (here 22) may be a statistical measurement of the calculation of reflux for multiple cardiac cycles corresponding to the three reflux depictions 1044a, 1044b, 1044c.

[0195] The user interface 1040 may include an electrocardiogram graph 1050. The electrocardiogram graph 1050 may be disabled or enabled by the user. Additionally, the electrocardiogram graph 1050 may be removed or omitted from the user interface 1040. Although not shown, in some embodiments, when the electrocardiogram graph 1050 is removed or omitted, the pressure graph display portion 1051 may increase in size in the user interface 1040.

[0196] The user interface 1040 can include a playback control 1052 and a gradient type selector 1056. As shown, the playback control 1052 can present a time (here, 0:01:18) and a current playback position 1054. In some embodiments, a user can interact with the playback control 1052 to fast forward or rewind the playback of one or more graphs and corresponding indications of heart valve status. A user can change the gradient type of the user interface 1040 by selecting the gradient type selector 1056, which can cause an updated user interface to be presented in place of the current user interface 1040.

[0197] 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 1060 may include a first graph 1002 and a second graph 1006 similar to the first graph and second graph 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 selection portion 1056 of FIG. 10C.

[0198] The one or more gradient representations 1062a, 1062b, 1062c can correspond to a gradient type, such as an instantaneous gradient type. The instantaneous gradient representations 1062a, 1062b, 1062c can indicate a maximum or locally maximum pressure difference between a first cardiovascular region and a second cardiovascular region in a cardiac cycle. The user interface 1060 can include a numerical value 1064 (here 64) corresponding to a gradient type, such as an instantaneous gradient type. The numerical value 1064 can indicate a maximum or locally maximum 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 can include a statistical measure, such as an arithmetic mean or average maximum or locally maximum pressure difference over multiple cardiac cycles. As shown, the value 1064 may be a statistical measurement of the instantaneous slope for multiple heartbeats corresponding to the instantaneous measurements 1062a, 1062b, 1062c of the three graphs.

[0199] 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 graph and the second graph 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 1080 may be presented in response to a user selection, such as one or more user selections of the gradient type selection portion 1056 of FIG. 10C.

[0200] One or more of the gradient representations 1082a, 1082b, 1082c can correspond to a gradient type, such as an area gradient type. The area gradient representations 1082a, 1082b, 1082c can indicate a pressure difference between a first cardiovascular region and a second cardiovascular region. The user interface 1080 can include a numerical value 1084 (here 56) corresponding to a gradient type, such as an area gradient type. The numerical value 1084 can 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 can include a statistical measurement, such as an arithmetic mean or average area between the two graphs or pressure curves over multiple cardiac cycles. As illustrated, the numerical value 1084 can be a statistical measurement of the area gradient for multiple cardiac beats corresponding to the instantaneous measurements 1082a, 1082b, 1082c of the three graphs.

[0201] 11A-11C depict additional example user interfaces that may be presented by the monitoring device 204 described above. 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 depictions to the gradient depictions of the user interfaces 1040, 1060, 1080 of FIGS. 10C, 10D, 10E, respectively. Additionally, the user interfaces 1100, 1120, 1140 of FIGS. 11A, 11B, 11C may depict user interfaces presenting heart valve status for the mitral valve.

[0202] In FIG. 11A, the user interface 1100 may include a gradient representation 1102. The gradient representation 1102 may be of a peak-to-peak gradient type that may be similar to the peak-to-peak gradient type of FIG. 10C. However, instead of a visualization of the measurement 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 allows the clinician to quickly review the relative peak-to-peak pressure changes over time, which may include past and current measurements.

[0203] The regurgitant flow representation 1104 of Figure 11A can be similar to the regurgitant flow representations 1044a, 1044b, 1044c of Figure 10C. However, similar to the gradient representation 1102, the regurgitant flow representation 1104 can depict one or more pressure values ​​corresponding to valve regurgitation in graphical form, instead of a visualization of a measurement between two points.

[0204] 11B, the user interface 1120 may include another slope representation 1122. The slope representation 1122 may be of an instantaneous slope type that may be similar to the instantaneous slope type of FIG. 10D. However, instead of a visualization of a measurement between two points, the slope representation 1122 may depict one or more pressure values ​​corresponding to a peak-to-peak slope in a graph format. Similar to the slope representation 1102 of FIG. 11A, an advantage of the slope representation 1122 of FIG. 11B is that it allows the clinician to quickly review relative instantaneous pressure changes over time, which may include past and current measurements.

[0205] 11C, the user interface 1140 may include another gradient representation 1142. The gradient representation 1142 may be of an area gradient type that may be similar to the area gradient type of FIG. 10E. However, instead of or in addition to depicting the area between the two graphs as the exclusive visualization, the gradient representation 1142 may depict one or more pressure values ​​that correspond to the area gradient in graph form. Similar to the gradient representation 1102 of FIG. 11A, an advantage of the gradient representation 1142 of FIG. 11C is that it allows the clinician to quickly review relative pressure changes over time, which may include past and current measurements.

[0206] 12 depicts a configuration user interface 1200 for a cardiac valve evaluation system. A clinician can use the configuration user interface 1200 to configure one or more user interfaces. The configuration user interface 1200 can allow a clinician to select a treatment 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 measurement period selection portion 1202 that can allow a user to select the number of heart beats for calculation of statistical measurements.

[0207] b. User interface generation process Turning now to FIG. 13, an example user interface generation process 1300 is shown. The process 1300 is described in the context of 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 this disclosure. The process 1300 may be performed by various components of the system of FIG. 2A as discussed herein, including the monitoring device 204, or the system 1400 of FIG. 14 described below. 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 that shown. Other embodiments of the process 1300 may include fewer blocks than those shown or the blocks may be performed in a different order than that shown.

[0208] Beginning at block 1302, pressure values ​​may be received. Specifically, the monitoring device 204 may receive the pressure values. The monitoring device 204 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 passageway adjacent to the first portion of the heart. Thus, the monitoring device 204 may determine the first and second sets of pressure values ​​from the first and second sensors, respectively. As previously described in Sections I and / or II, the pressure sensor may be included in a pressure guidewire, an access catheter, a pigtail catheter, or a treatment device, such as a heart valve inflation balloon or 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 with respect to blocks 1502 and / or 1504 of process 1500.

[0209] At block 1304, configuration parameters may be received. In particular, the monitoring device 204 may receive the configuration parameters. Example configuration parameters may include the number of heart beats or the default slope type to present in the user interface. Additional details regarding the configuration parameters are described in more detail above in connection with FIG. 12.

[0210] At block 1306, a user selection may be received. An example user selection may include a change in slope type. A user may select the slope type selector 1056 of FIG. 10C to change between slope types, such as the instantaneous slope type of FIG. 10D or the area slope type of FIG. 10E. Additional user selections may include changes to configuration parameters of the configuration user interface 1200 described above in FIG. 12. For example, a user selection may include a user heart rate selection. The user heart rate selection may specify the number of heart beats that may be used for statistical measurements (e.g., 2, 3, or 4 heart beats, etc.). The user heart rate selection may also include a selection of one or more specific heart beats. For example, a user may interact with a user interface described herein to select a portion of a graph that corresponds to a specific heart beat and / or may select an identifier for a specific heart beat.

[0211] At block 1308, a heart valve status may be determined. As described herein, example heart valve status may include an index of regurgitation or a gradient pressure. The monitoring device 204 may determine the heart valve status based on the data from the previous blocks 1302, 1304, 1306. For example, the monitoring device 204 may calculate a particular heart valve status from the received pressure values ​​depending on configuration parameters or user selections that may specify a particular gradient type, number of beats for calculation, and / or particular beats to use or exclude. As described herein, the number of beats may be used to calculate a statistical measurement for a particular heart valve status, such as an index of regurgitation or a gradient. The monitoring device 204 may detect high frequency 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 of time. Additional details regarding determining a heart valve status are described later in Section IV, such as with respect to process 1500 of FIG. 15. Some of the blocks of process 1500 of FIG. 15 may further describe determining heart valve status, such as blocks 1504, 1506, 1508, 1510.

[0212] At block 1310, a user interface may be presented. The monitoring device 204 may present a user interface. Example user interfaces are described above in connection with 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 include a depiction of a slope indicative of the slope of the valve, such as a peak-to-peak slope, an instantaneous slope, and / or an area slope. For example, the first gradient representation may visually represent 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 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 include a regurgitation representation (such as regurgitation representations 1044a, 1044b, 1044c in FIG. 10C) visually presenting a measurement of regurgitation between a first point in the first graph and a second point in the second graph. Thus, the measurement of regurgitation may indicate the quantitative regurgitation of the valve. The first user interface may also include a numerical value for the first gradient of the valve by statistical measurement (first numerical value 1084 in FIG. 10E, which may be an average or arithmetic mean gradient value). The first user interface may also include an electrocardiogram graph, described in more detail above in connection with FIG 10C. In some embodiments, the first user interface may present a high-rate pacing warning if high-rate pacing is detected.

[0213] In some embodiments, the first user interface may include multiple values ​​for different slope types in the same graphical display, for example, two or more values ​​may be selected from a peak-to-peak slope value, an instantaneous slope value, and / or an area slope value and presented simultaneously in the same graphical display.

[0214] As shown, after presenting block 1310 executes, the previous block may be revisited to receive additional pressure value data, user selections, and / or update configuration parameters that cause one or more user interfaces to be updated. For example, the monitoring device 204 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 monitoring device 204 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 the first graph, the second graph, and a second slope depiction (such as slope depictions 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.

[0215] The user may make any number of changes to the user interface. For example, a selection of another user interface may be received for a third slope type (such as an instantaneous slope type). Thus, the monitoring device 204 may present a third user interface for the third slope type (such as an instantaneous slope type) instead of the second user interface. The third user interface may include a first graph, a second graph, and a third slope representation (such as slope representations 1062a, 1062b, 1062c of FIG. 10D) that visually presents a second slope measurement between a first point on the first graph and a second point on the second graph. Although a specific order of slope type changes is described herein, any order of slope type changes may be accepted by the cardiac valve evaluation system.

[0216] IV. CARDIAC VALVE ASSESSMENT SYSTEMS AND METHODS The systems and methods described herein can evaluate heart valves. Pressure valves can be used to evaluate valves. Valves can be diagnosed using various signal processing methods involving pressure gradients across the valve. The pressure gradient across the valve during systole can indicate the pressure loss caused by blood flowing through the valve, which can indicate limitations in blood flow. For example, the pressure gradient at the end of diastole after the valve is closed can indicate the amount of blood leaking through the valve while 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, including, but not limited to, calibrating pressure sensors, adjusting waveforms, detecting features, and / or generating valve states.

[0217] a. Overview of Heart Valve Assessment Systems and Methods 14, a block diagram of a heart valve system 1400 is depicted. 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 example waveform may include time-continuous data, such as a series of respective pressure and timestamp paired values. The heart valve evaluation system 1400 may be similar to the monitoring device 204, may be embodied in the monitoring device 204, and / or components of the heart valve evaluation system 1400 may be embodied in the monitoring device 204. The pressure signal 1406 may 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.

[0218] 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 systole, diastole, a dicrotic notch, the end of diastole, and / or the start 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 an index of valvular regurgitation. The slope calculator 1418 may generate a pressure gradient and / or a statistical measurement of the pressure gradient. The generated output data 1406, such as valve status, valve diagnostic indices, and / or waveforms, may be provided to a user interface as described herein or may be provided to other devices or systems.

[0219] Turning to FIG. 15, an example valve evaluation process 1500 is shown. Although the process 1500 is described in the context of a heart valve evaluation system, such as the system 200 of FIG. 2A or the system 1400 of FIG. 14, any system configured to perform the process in any order is within the scope of this disclosure. The process 1500 may be performed by various components of the system of FIG. 2A or the system 1400 of FIG. 14 as discussed herein, including the monitoring device 204. 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 that shown. Other embodiments of the process 1500 may include fewer blocks than those shown or the blocks may be performed in a different order than that shown.

[0220] Beginning at block 1502, a pressure value or signal may be received or determined. Specifically, 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 previously described in Sections I and / or II, the pressure sensor may be included in the pressure guidewire or other pressure sensing device. In some embodiments, the first pressure sensor and the second pressure sensor may be located in the same or different cardiovascular regions, such as where the calibration is performed. In such a case, the process may proceed to block 1504.

[0221] At block 1504, a calibration may be performed. The calibration service 1408 may perform the calibration. A 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 be both calibrated together. The pressure value determined from the second sensor may be adjusted based on the calibration. The calibration of the first sensor and the second sensor may result in the generation of one or more calibration parameters. 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 the 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.

[0222] The process can return to block 1502. Once the calibration is completed, one or more pressure sensors can be moved to a different cardiovascular region and additional pressure signals can be received in block 1502. Pressure signals can be received from two or more pressure sensors located in different cardiovascular regions. Examples of different cardiovascular regions can include adjacent blood passages, such as, but not limited to, both sides of a heart valve, the left ventricle and the aorta, the left ventricle and the left atrium, the right ventricle and the pulmonary artery, the right atrium and the right ventricle, the vena cava and the right atrium, etc. The heart valve evaluation system 1400 can determine a first and a second set of pressure values ​​from the pressure signals, such as by applying the determined calibration parameters.

[0223] 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 during the cardiac cycle may be used, it may be important to adjust one or more pressure waveforms to generally synchronize or align two or more pressure waveforms. The waveform adjustments may accommodate a time shift in one or more of the waveforms such that corresponding features of the waveforms 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.

[0224] The waveform adjustment service 1410 can adjust the phase between one or both pressure waveforms by adding a delay to one or both of the pressure waveforms during installation, maintenance, or use with a particular patient. This technique can take a set-up process during installation or maintenance representative of a set-up process during a procedure such as TAVI. For example, a time delay in the aortic pressure signal can represent a delay in the aortic pressure line induced in a TAVI procedure. The waveform adjustment service 1410 can adjust the phase for each particular patient.

[0225] The waveform adjustment service 1410 may include or be in communication with an automatic phase lag recognition system that can advise an operator to match and adjust the phase lag between both pressure signals. The waveform adjustment service 1410 can match such time lags while an equalization is requested or while an equalization is being performed, such as when both pressure signals have the same origin (e.g., are located in the same place to experience similar pressures) or when the pressure signals are from different locations.

[0226] The waveform conditioning service 1410 can detect the phase lag based on a time delay between one or more pressure waveform features. The pressure waveform features can include one or more of the relative position of the systolic pressure, the relative position of the dicrotic notch, or the relative position of the end of diastole. The waveform conditioning service 1410 can use the feature of the relative position of the maximum slope of the ascending boundary of systole, which can be a reliable feature.

[0227] Additionally or alternatively, the waveform adjustment service 1410 can systematically adjust the time delay when pressure equalization is required. Similar to techniques for detecting phase lag, 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 recognition of the pressure waveform features. The waveform adjustment service 1410 can use cross-correlation between both signals, that is, by calculating the correlation of one signal to the other while shifted in time. The time shift can result in an increase in the correlation value between both signals, which can correspond to a time shift that can be added to the pressure signal or other, or can even result in maximizing the correlation value.

[0228] Feature detection may be performed at block 1508. The feature detection service 1412 may perform the feature detection. Example features that may be detected from the pressure waveform may include systole, diastole, a dicrotic notch, the end of diastole, and / or the start of systole. Additional details regarding feature detection are described in more detail below in connection with process 1900 of FIG. 19.

[0229] At block 1510, a heart valve status may be determined. The valve status determination service 1414 may determine the valve status. In particular, the index calculator 1416 may generate an index, such as an index of valve regurgitation, and the gradient calculator 1418 may generate a pressure gradient and / or a statistical measurement of the pressure gradient. The index calculator 1416 and / or the gradient calculator 1418 may use the calibrated or adjusted waveform or detected features of the previous block to generate the valve status. The index calculator 1416 may calculate an index of regurgitation based at least in part on a first subset of the first set of pressure values ​​according to systole or diastole and a second subset of the adjusted pressure values ​​according to systole or diastole. For example, the index calculator 1416 may calculate the index of regurgitation according to the following formula: index of aortic regurgitation=(aortic diastolic pressure-left ventricular diastolic pressure) / aortic systolic pressure. The gradient calculator 1418 may calculate a gradient value based at least in part on a difference between a first subset of pressure values ​​during systole and a second subset of adjusted pressure values ​​during systole (such as area gradient values, peak-to-peak gradient values, and / or instantaneous gradient values, as described in further detail above in Section III). Additional details regarding valve state determination are described in further detail above in Section III.

[0230] In block 1512, the cardiac valve status may be presented in a user interface. The cardiac valve evaluation system 1400 and / or the monitoring device 204 may present the cardiac 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 FIG. 10A-10E and FIG. 11A-11C.

[0231] b. Pressure sensor calibration As described herein, a first sensor can be calibrated against a second sensor to determine a more accurate pressure measurement, which can also be referred to as equalization. For example, a pressure guidewire can be at or near the valve location along with another pressure device. The other pressure device can be a catheter, pigtail, or other device with a lumen used to deliver the valve and connected to a pressure transducer. The pressure device can be another pressure guidewire or a catheter with a pressure sensor at its tip. The pressure guidewire and pressure device are positioned to measure the same pressure. The pressure sensor can be positioned in the same cardiovascular region, such as the aorta, in the ventricle, in the atrium, or in some other location. It can 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 between the aortic pressure Pa and the distal pressure Pd). Thus, once at the same location, one pressure line can be calibrated against the other pressure sensor.

[0232] The systems and methods described herein for calibration of pressure sensors can improve the accuracy of pressure instruments. For example, as described above, even if two pressure instruments are located in the same cardiovascular region, there may be differences in pressure based on the proximal or distal location of each pressure instrument. Furthermore, differences in pressure may result from other factors, such as different device types between multiple pressure instruments. Thus, the systems and methods described herein for calibration can improve the technology of pressure instruments by providing more accurate pressure readings.

[0233] Turning to FIG. 16, an example calibration process 1600 is shown. Although the process 1600 is described in the context of a heart valve evaluation system, such as the system 200 of FIG. 2A or the system 1400 of FIG. 14, 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 of FIG. 2A or the system 1400 of FIG. 14 as discussed herein, including the monitoring device 204. 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 that shown. Other embodiments of the process 1600 may include fewer blocks than those shown or the blocks may be performed in a different order than that shown.

[0234] Beginning at block 1602, one or more calibrated pressure values ​​may be determined from one or more pressure sensors. A calibration service 1600 may determine the one or more calibrated pressure values ​​from the one or more pressure sensors. The calibration service 1600 may receive a first calibrated pressure value corresponding to a first calibrated signal received from a first pressure sensor measuring a cardiovascular region and a second calibrated pressure value corresponding to a second calibrated signal received from a second pressure sensor measuring the same cardiovascular region. The calibration service 1600 may receive a first set of calibrated pressure values ​​determined from the first pressure sensor and a second set of calibrated pressure values ​​determined from the second pressure sensor.

[0235] At block 1604, calibration parameters may be calculated. The calibration service 1600 may calculate one or more calibration parameters. The calibration service 1600 may use one or more techniques to calculate the calibration parameters, such as an offset or gain (G). The calibration service 1600 may determine the offset or gain (G). The calibration service 1600 may use the following offset formula to calculate the offset: P1=P2+offset, 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 use the following gain formula to calculate the gain (G): P1=G*P2, where P1 may be Pd and P2 may be Pa.

[0236] The calibration service 1600 can use a linear fit to determine the calibration parameters. 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 use the following offset formula to calculate the offset: [P1]=K*[P2]+b. The calibration service 1600 can apply a linear fit between multiple pressure measurements of one pressure sensor relative to the other pressure sensor to determine the calibration parameters K and b. A linear fit calibration can be desirable when equating both pressure measurements when positioned in a heart chamber, such as the ventricle. In contrast to aortic pressure, ventricular pressure (and atrial pressure) vary over a wide range of pressures, from mostly venous pressure to aortic systolic pressure (and even higher to account for pressure losses across the aortic valve), so 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 only systolic pressure measurements, diastolic pressure measurements, or other parts of the cardiac cycle.

[0237] At block 1606, calibration parameters may be applied. 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.

[0238] c. Feature detection The cardiac valve evaluation system 1400 may rely on determining the phase of the cardiac cycle to determine valve status, such as an indication of regurgitation. Thus, the cardiac valve evaluation system 1400 may detect one or more features, such as, but not limited to, systole, diastole, dicrotic notch, end of diastole, and / or start of systole. The dicrotic notch is a feature that may indicate a phase change from diastole to systole. End of diastole or start of systole is another feature that may be detected. End of diastole may be identified using an electrocardiogram (ECG). In some embodiments, it may be desirable to identify end of diastole using pressure, since an ECG signal may not be available or since ECG signals often may not be sufficiently complete. The transition from diastole to systole is often not clearly distinguishable, since it may be completely rounded and / or the transition may also include various pressure features that may result in improper localization. The cardiac valve evaluation system 1400 may rely on features such as areas of elevated systolic pressure. The cardiac valve evaluation system 1400 can identify the location of the maximum or locally maximum slope of the systolic pressure increase that may be more reliable than other features. In particular, the cardiac valve evaluation system 1400 can identify the location of the maximum slope of the conditioned pressure signal.

[0239] Turning 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 evaluation system 1400 can analyze the data points in the environment 1700 to detect dicrotic notch features. The cardiac valve evaluation system 1400 can detect dicrotic notch features by calculating and identifying the data point with the smallest angle formed with nearby data points. An example of angle calculation is shown in FIG. 17. For the first set 1702 of data points, the cardiac valve evaluation system 1400 can obtain an angle α(i) by calculating the angle formed by a first line extending from a center point P(i) and a preceding point P(i-1) and a second line extending from the same center point P(i) and a subsequent point P(i+1). For the first set 1702 and the second set 1704 of data points, the angle α(i+1) about the point P(i+1) may be smaller than the angle α(i) about P(i). Thus, the heart valve evaluation system 1400 may identify a dicrotic notch feature at the 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 more than n data points (e.g., more than two or three data points) for the calculation of the line forming part of the angle. Depending on the embodiment, the signal for the data point may or may not be preconditioned.

[0240] Turning to FIG. 18, another waveform analysis environment 1800 is depicted. The cardiac valve evaluation 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 slope 1802 extending from a position of a maximum or locally maximum slope of the ascending portion of the cardiac systole 1801 is shown in FIG. 18. The cardiac valve evaluation system 1400 can track a horizontal line 1804 that intersects with a minimum or locally minimum pressure value 1803. The intersection 1805 between the slope 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 location of the end of diastole is obtained by moving the location by a time period 1807, which can be predetermined. The end of diastole 1807 is obtained by shifting the crossing 1805 by 40-100 ms. In some embodiments, a 60 ms shift in location can provide a good estimate of the end of diastole. The cardiac valve evaluation system 1400 can use other techniques, such as shifting the crossing by a percentage of the cardiac cycle, such as between 8%-12% or 5%-8%.

[0241] The techniques described herein may be adapted to identify the end of diastole when using aortic pressure. The techniques may be adapted when the pressure being processed is ventricular pressure. Ventricular pressure may result in a more accurate determination of the end of diastole since the location of the intersection 1805 does not need to be moved. Once the location of the first intersection 1805 is determined, a more accurate determination of the end of diastole may include changing the slope extending from the location of the maximum slope to a new slope extending from a location located between the location of the maximum slope and the first intersection 1805. Specifically, the determination of the end of diastole may include changing the slope extending from the location of the maximum slope to a new slope extending from a location closer to the first intersection 1805. The new slope extending from a location closer to the first intersection 1805 may then be extended to intersect with the horizontal line. The new intersection may be found and used as the end of diastole.

[0242] Turning to Figure 19, a feature detection process 1900 is shown. The process 1900 is described in the context of a heart valve evaluation system, such as the system 200 of Figure 2A or the system 1400 of Figure 14, but any system configured to perform the process in any order is within the scope of this disclosure. The process 1900 may be performed by various components of the system of Figure 2A or the system 1400 of Figure 14 as discussed herein, including the monitoring device 204. 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 that shown. Other embodiments of the process 1900 may include fewer blocks than those shown or the blocks may be performed in a different order than that shown.

[0243] Beginning at block 1902, the signal may be conditioned. The cardiac valve evaluation system 1400 may condition the signal. The cardiac valve evaluation system 1400 may filter the pressure signal, such as by convolving the signal with a window. The window may be square or of other shape and the period may be two or more samples. Conditioning the signal may be preferable in certain situations, such as finding the location of maximum slope, as there may be oscillatory features caused by air bubbles or other factors.

[0244] In block 1904, the dicrotic notch feature may be detected. The feature detection service 1412 may detect the dicrotic notch feature. Various techniques may be used to determine the dicrotic notch 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 identify a point of zero crossing based at least in part on the second derivative value, the point of zero crossing corresponding to the first dicrotic notch feature. These techniques may enable localization of the dicrotic notch feature in the absence of a distinct notch, i.e., in the absence of a notch visible in the graphical depiction of the pressure waveform itself. When a distinct notch is present, i.e., the notch includes a feature of a short returning pressure signal that is visible in the graphical depiction of the pressure waveform, the feature detection service 1412 may look for a nearby first derivative zero crossing. These techniques may be performed on unconditioned pressure signals, but may also be performed on conditioned pressure signals.

[0245] The feature detection service 1412 can detect a dicrotic notch feature by calculating and identifying a data point with a minimum angle formed with nearby data points. The feature detection service 1412 can calculate a first angle for a first point based at least in part on a first predecessor point and a first successor point from the set of pressure values. The feature detection service 1412 can calculate a second angle for a second point based at least in part on a second predecessor point and a 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 can identify the second point as a first dicrotic notch feature. Additional details regarding detecting dicrotic notch features are described above in connection with FIG. 17.

[0246] At block 1906, a feature of the end of diastole or the start of systole may be detected. The feature detection service 1412 may detect a feature of the end of diastole or the start of systole. 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 locally minimum pressure value from the first plurality of pressure values. The feature detection service 1412 may determine a tangent from the first subset. The feature detection service 1412 may then identify a horizontal line that intersects with the locally minimum pressure value and may identify a first intersection between the tangent 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 diastole or as a start of a first systole based at least in part on the first intersection. Identifying the first point may further include adjusting the first intersection by a predetermined time period. The predetermined time period may be or may include approximately 60 milliseconds. The predetermined time period may include between approximately 40 milliseconds and approximately 100 milliseconds. Identifying the first point may further include aligning the first intersection with a percentage of a cardiac cycle. The percentage may include or may be between approximately 8 percent and 12 percent of a cardiac cycle. The percentage may include or may be between approximately 8 percent and 12 percent of a cardiac cycle. The percentage may include or may be between 5 percent and 8 percent of a cardiac cycle. Additional details regarding detecting the end of cardiac diastole or the start of cardiac systole characteristics are described above in connection with FIG. 18.

[0247] In block 1908, systole or diastole can be determined. The feature detection service 1412 can detect diastolic or systolic features. The feature detection service 1412 can use a dicrotic notch feature to identify the phase change from diastolic to systolic. The end of diastole or the start of systole are other features that can be detected.

[0248] d. Additional valve states The cardiac valve evaluation system 1400 can determine additional valve conditions. Additional example valve conditions can include, but are not limited to, a transvenous dysfunction diagnosis, an indication of the severity of valve stenosis, an indication of aortic regurgitation, and / or an indication of corrected aortic regurgitation.

[0249] i. Indicators of severity of valve stenosis Although the aortic valve is used to illustrate a particular embodiment, the techniques described herein may be applied to other valves, such as the mitral valve, the pulmonary valve, or the tricuspid valve. 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, an aortic stenosis may be present. The aortic stenosis may impede the passage of blood through the valve, which may cause a loss or reduction in pressure. The pressure loss may occur during cardiac contraction. In fact, the 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 defined by the point where the left ventricular pressure crosses the aortic pressure.

[0250] In normal healthy subjects, the left ventricular pressure and the aortic pressure should be equal during the ejection period. However, in the presence of aortic stenosis, the left ventricular pressure may be higher than the aortic pressure. The pressure loss may increase with the severity of the aortic stenosis. A technique for assessing the severity of aortic stenosis (AS) may include calculating the pressure gradient between the LVP and the AOP during the entire ejection period. Specifically, the severity of aortic stenosis (AS) may be determined by the gradient between the mean LVP and the mean AOP during the ejection period ( <lvsp> - <asp>) as described below. <lvsp>is the mean left ventricular systolic pressure during the ejection period, <asp>can be the mean aortic systolic pressure during the ejection period. An improved technique can involve excluding the edge portions of the ejection period and calculating the pressure gradient in regions where the instantaneous pressure gradient is more constant. This can be 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 also possible, such as 30%, 40%, 60%, 70%, or 80%.

[0251] 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, as indicated by the following formula:

[0252]

number

[0253] <lvsp>is the mean left ventricular systolic pressure during the ejection period, <asp>can be taken as the mean aortic systolic pressure during the ejection period.

[0254] At rest, it can be assumed that the total volume of blood supply is adequate, i.e., the aortic pressure during the ejection period allows for adequate total perfusion. In the absence of aortic stenosis, it can be reasonable to assume that the left ventricular pressure during the ejection period is equal to the aortic pressure in the presence of aortic stenosis. Total vascular resistance in either the presence or absence of aortic stenosis may not change.

[0255]

number

[0256] The value of corresponds to the loss of available perfusion caused by the presence of aortic stenosis. In normal healthy subjects without aortic stenosis,

[0257]

number

[0258] is equal to 0. The equivalent of fractional flow reserve (FFR) is

[0259]

number

[0260] Like

[0261]

number

[0262] In this case, the purpose is to change the indicators of

[0263]

number

[0264] may represent the percentage of available perfusion of a stenotic valve relative to a normal valve.

[0265]

number

[0266] and

[0267]

number

[0268] can be calculated by taking the average pressure over the entire ejection period, or the pressure can be calculated by taking a fraction of the ejection period. Another index consists of taking the maximum instantaneous slope between LVSP and ASP during the ejection period.

[0269] ii. Indicators of aortic regurgitation Regurgitation can occur when blood leaks back through the valve. Regurgitation can be caused by valve disease or, in the case of prosthetic replacement, by incomplete fit of the replacement valve to the native valve. Patient procedural outcomes following valve replacement can be adversely affected by valvular regurgitation. Therefore, diagnosing post-TAVI valvular regurgitation and possible pre-TAVI regurgitation for valve adjustment can be important.

[0270] Figure 21 shows a pressure waveform in a normal healthy subject. Figure 22 shows a similar pressure waveform with aortic regurgitation. Blood flowing through the valve and flowing backwards in the left ventricle can increase left ventricular diastolic pressure. This can also decrease aortic diastolic pressure as a result of the volume of blood lost through the closed aortic valve. Systolic pressure can increase to compensate for the loss of available blood perfusion.

[0271] The aortic regurgitation index (AR) may consist of calculating the slope 2220 between the ventricular pressure at end of diastole (LVEDP) and the aortic pressure at end of diastole (AEDP), normalized by the aortic systolic pressure (ASP), as shown in the following formula:

[0272]

number

[0273] Another index that may provide better stability and reproducibility consists of calculating the slope 2221 between the mean left ventricular diastolic pressure (LVDP) and the mean aortic diastolic pressure (ADP) divided by the aortic systolic pressure (ASP). Another index consists of calculating the same slope over a portion of diastole, for example calculating the slope over the period when the left ventricular pressure is below a certain value 2222, more specifically over the period when the LVDP is in a relatively flat region. A predetermined portion of diastole may be used to calculate the index of retrograde flow, for example taking 75% of the left portion of diastole.

[0274] iii. Corrected aortic regurgitation index Arterial stiffening, which may be common for patients with valve replacement, affects the pressure waveform in a manner similar to aortic regurgitation. In these cases, the above indicators of aortic regurgitation may result in a false positive regurgitation determination, which may further result in unnecessary valve adjustments. More specifically, arterial stiffening has the effect of increasing systolic pressure. In FIG. 23, this pressure increase 2330 may be caused by a reflected pressure wave from the stiffened vasculature, which occurs more easily than in normal vasculature. In normal vasculature, the reflected wave occurs later during cardiac diastole, so there may be an increase in diastolic pressure earlier.

[0275] The pressure during cardiac diastole can be withstood by the compliance of the vascular system. The distensibility of the arteries, mainly the aorta, retracts back towards the spontaneous state, thus maintaining the pressure within the vascular system. Stiffened arteries do not have the same degree of compliance, and therefore the arteries do not have the ability to withstand the expanded pressure during cardiac diastole. As the diastolic pressure falls more rapidly, the aortic end diastolic pressure (AEDP) also falls more rapidly, resulting in less aortic backflow.

[0276] Diastolic pressure can be represented by a two-component model that includes vascular compliance (C) and total vascular resistance (R). Diastolic pressure relaxes as expressed by the following equation for relaxation:

[0277]

number

[0278] If the compliance is known, a formula allows to calculate the total vascular resistance (R). The aortic end-diastolic pressure can be recalculated using the general normal compliance together with the previously calculated total vascular resistance.

[0279] Compliance can be described as the gain in arterial volume caused by a given pressure change, as indicated by the following formula:

[0280]

number

[0281] ΔV is obtained by measuring the relative change in arterial diameter. ΔV is more easily measured by measuring the left ventricular cardiac output, which is obtained from the difference in angiographic left ventricular contour measurements between systole and diastole. ΔP is the slope of the aortic systole to diastole.

[0282] Arterial stiffness may be well correlated with augmentation pressure (AP) 2330, or conversely, compliance may be well correlated with the inverse of augmentation pressure. It is preferred to use augmentation pressure to correct aortic backflow, as it may be easier to implement in a clinical setting. Augmentation pressure is accompanied by a visible change in the ascending part of the cardiac contraction 2331, allowing for the estimation of augmentation pressure. Another method is to inject nitroglycerin into the patient, as this relaxes the arterial system and reduces the augmentation pressure. The change in aortic systolic pressure caused by nitroglycerin may give the augmentation pressure. Compliance may be estimated with a relationship in the form of the compliance equation below, or with any relationship of f(AP) adjusting the assumed general normal compliance Cn with augmentation pressure: C=f(AP)=C n -k·AP

[0283] R can be calculated by applying C from the above equation to the diastolic equation using the diastolic aortic pressure measurement. Corrected aortic diastolic pressure (CADP) is calculated by using the calculated R and Cn into the compliance equation. Corrected aortic regurgitation is calculated by replacing aortic diastolic pressure (ADP) by corrected aortic diastolic pressure (CADP) as shown in the following equation:

[0284]

number

[0285] Another method consists in replacing the measured aortic systolic pressure by a corrected aortic systolic pressure, i.e. removing the contribution of the augmentation pressure from the ASP. The corrected aortic retrograde flow can use the calculation of the mean diastole as described above, rather than using only the pressure value at the end of diastole.

[0286] Elevated left ventricular diastolic pressure caused by abnormal venous pressure may also result in an erroneously calculated indication of aortic regurgitation. Another improved method consists of subtracting the contribution of the venous or atrial pressure from the left ventricular diastolic pressure component, as shown in the following formula:

[0287]

number

[0288] e. Additional pressure sensor calibration As described herein, a first sensor can be calibrated against a second sensor to determine a more accurate pressure measurement, which can also be referred to as equalization. For example, a pressure guidewire can be at or near the valve along with other pressure devices. The other pressure devices can be catheters, pigtails, or other devices with lumens used to deliver the valve and connected to a pressure transducer. The pressure devices can be other pressure guidewires or catheters with a tip pressure sensor. The additional pressure devices can include piezoelectric and / or optical sensors. Example pressure devices that can be equalized can be selected from, but are not limited to, pressure guidewires, catheters, pigtails, tip pressure sensors, piezoelectric sensors, and / or optical sensors. Thus, example combinations of pressure devices that can be equalized can 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 positioned in the same cardiac vascular region for calibration purposes, other calibration techniques described herein may be performed while the pressure devices are positioned in different cardiac vascular regions, such as a first device positioned in the left ventricle and a second device positioned in the aorta. As described herein, calibration of the pressure devices while the devices are positioned 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 to the pressure waveform for equalization purposes.

[0289] 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 previously described, calibration can be performed when the 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 for calibrating with time and / or gain adjustments from waveform features can advantageously be performed while the pressure devices are in different locations as required by a cardiac procedure. As such, the systems and methods described herein for calibration while pressure devices are in different locations can improve the technology of pressure devices by providing more accurate pressure readings without adding additional steps to a cardiac procedure.

[0290] The aortic pressure waveform may differ from the ventricular pressure waveform. For example, with reference to FIG. 20 described above, the aortic pressure may begin to increase at the beginning of systole, as shown by aortic pressure waveform 2011. Specifically, the aortic pressure may begin to increase when the aortic valve opens at the beginning of aortic valve opening time period 2012. The aortic pressure waveform 2011 increases at least until it reaches a local maximum in time period 2012, which is the systolic pressure, and then drops sharply until it reaches a dicrotic notch at the end of time period 2012. The dicrotic notch represents the moment the aortic valve closes. These two moments of aortic valve opening and closing may be useful for equating, as they may represent the only points at which ventricular pressure and aortic pressure can be equal. These two moments of aortic valve opening and closing may generally correspond to the beginning and end of time period 2012, respectively. The left ventricular pressure waveform 2010 may intersect with the aortic pressure waveform 2011 at the beginning and end of a time period 2012 .

[0291] In FIG. 24, pressure waveforms that may include a phase lag are depicted. Specifically, 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. Specifically, in FIG. 24, the left ventricular pressure waveform 2402 does not intersect with the aortic pressure waveform 2404 at the valve opening 2406 or at the dicrotic notch 2408. The calibration techniques described herein may be applied to the pressure waveforms of FIG. 24. Specifically, a time adjustment may be applied to the pressure waveforms of FIG. 24.

[0292] In FIG. 25, pressure waveforms that may include gain errors are depicted. Specifically, a left ventricular pressure waveform 2502 and an aortic pressure waveform 2504 are depicted. In the pressure waveforms of FIG. 25, there may be gain errors that may cause amplitude changes. For example, the left ventricular pressure waveform 2502 may include a gain error of approximately 1.3, which may cause a widening of the point where the left ventricular pressure waveform 2502 crosses the aortic pressure waveform 2504. Specifically, 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 notch feature of the aortic pressure waveform 2504. In another example, if the gain is less than 1, the crossing points will approach one another (not shown). The calibration techniques described herein may be applied to the pressure waveforms 2502, 2504 of FIG. 25. Specifically, a gain adjustment may be applied to the pressure waveforms of FIG. 25.

[0293] In Figure 26, pressure waveforms that may include phase lag and gain error are depicted. Specifically, 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. Specifically, time adjustments and / or gain adjustments may be applied to the pressure waveforms of Figure 26.

[0294] In Fig. 27, another example calibration process 2700 is shown. The process 2700 is described in the context of a heart valve evaluation system such as the system 200 of Fig. 2A or the system 1400 of Fig. 14, but any system configured to perform the process in any order is within the scope of this disclosure. The process 2700 may be performed by various components of the system of Fig. 2A or the system 1400 of Fig. 14 as discussed herein, including the monitoring device 204. 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 shown. Other embodiments of the process 2700 may include fewer blocks than shown or the blocks may be performed in a different order than shown.

[0295] In some embodiments, one set of pressure values ​​can be from a pressure sensor (such as a pressure liquid-filled line) positioned in the left ventricle, and another set of pressure values ​​can 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 can adjust the pressure values ​​for the left ventricle based on the output of the calibration process 2700. In some cases, the pressure liquid-filled line has a relatively larger delay compared to the pressure guidewire due to pressure propagation time in the fluid-filled line. Therefore, it may be advantageous to adjust the pressure of the left ventricle instead of the pressure of the aorta. As described herein, multiple options are possible. For example, in addition or alternatively, the heart valve evaluation system 1400 can adjust the pressure values ​​for the aorta based on the output of the calibration process 2700.

[0296] Beginning at block 2702, pressure devices may be zeroed. Specifically, 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, in the system 1400 may be nulled. The system 1400 may zero one or more pressure devices to eliminate other pressure signals other than the actual pressure from the patient. Zeroing may provide more accurate data on which to base treatment / action decisions.

[0297] At block 2704, a pressure value or signal may be received or determined. Specifically, 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, 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 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 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. This 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.

[0298] Feature detection may be performed in block 2706. The feature detection service 1412 may perform feature detection. Example features that may be detected from a pressure waveform may include systole, diastole, dicrotic notch, end of diastole, and / or start of systole. The feature detection service 1412 may identify features in the example pressure waveforms of FIGS. 24-26. Specifically, the feature detection service 1412 may determine a substantial start of systole in the set of pressure values. As another example, the feature detection service 1412 may determine a dicrotic notch feature in the set of pressure values. Additional details regarding feature detection are described in more detail above in connection with process 1900 of FIG. 19. This block 2706 for performing feature detection may be similar to block 1508 of FIG. 15 for performing feature detection.

[0299] In some embodiments, the feature detection service 1412 may perform feature detection by applying one or more thresholds. In some pressure waveforms, the point of crossing that opens the valve may not be completely at the start of cardiac systole, but slightly later or earlier. For example, the pressure required to open a heavily calcified valve leaflet may delay pressure transmission in the aorta, resulting in a flatter aortic pressure curve, which may change the point of crossing. For example, the feature detection service 1412 may identify the substantial start of systole within a percentage of the cardiac cycle before or after the end of diastole in a set of pressure values. As another example, the feature detection service 1412 may identify a timestamp corresponding to a dicrotic notch feature, where the timestamp may be within a percentage of the cardiac cycle before or after the dicrotic notch in a set of pressure values. Example threshold percentages may be between approximately 0 percent and 1 percent of the cardiac cycle, between approximately 0 percent and 2 percent, between approximately 0 percent and 5 percent, and between approximately 0 percent and 10 percent.

[0300] At block 2708, a time adjustment may be calculated. Specifically, 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 intersect with the basis set of pressure values ​​at the substantial start of systole 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 intersect with the aortic pressure waveform 2404 at the substantial start of systole / valve opening 2406. An example 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. Specifically, 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 the substantial start of systole in the basis set of pressure values.

[0301] At block 2712, a gain adjustment may be calculated. Specifically, the calibration service 1408 may calculate the gain adjustment. The calibration service 1408 may measure a pressure difference at the location of the dicrotic notch and calculate the required gain correction. Specifically, the calibration service 1408 may use the detected dicrotic notch feature in a basis set of pressure values. The calibration service 1408 may identify a timestamp corresponding to the dicrotic notch feature and may determine a first value at the timestamp from the basis set of pressure values. The calibration service 1408 may further determine a second value at the timestamp from another set of pressure values. The first value may correspond to V1 and the second value may correspond to V2, the gain adjustment may include g, and an example formula for calculating the gain adjustment may include a relationship determination substantially as follows:

[0302]

number

[0303] 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 ).

[0304] At block 2714, a gain adjustment may be applied. Specifically, the calibration service 1408 may apply a gain adjustment to the set of pressure values ​​to achieve the gain correction. In some embodiments, the calibration service 1408 may multiply each value by a gain adjustment to form a set of pressure values ​​to vary the amplitude of the pressure values.

[0305] 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 example exit condition may include determining whether a point of intersection for a set of pressure values ​​is within a threshold of a base set of pressure values ​​at one or more detected features. For example, the calibration service 1408 may determine that an intersection from a left ventricular pressure waveform is within a threshold from a substantial start of systole at an aortic pressure value. As another example, the calibration service 1408 may determine that an intersection from a left ventricular pressure waveform is within a threshold from a dicrotic notch feature at an 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 crossing of the pressure waveform coincides with the opening of a valve as dictated by a feature in the pressure waveform. If an exit condition is met, the process continues to block 2718.

[0306] The determined calibration parameters may be stored and / or used at block 2718. In particular, the calibration service 1408 may store and / or use the time adjustments and / or gain adjustments. For example, the calibration service 1408 may apply time adjustments and / or gain adjustments to a set of pressure values ​​and / or signals received from the pressure device after a calibration is completed.

[0307] Implementation mechanism Fig. 28 is a block diagram illustrating components of an example cardiac valve evaluation system 1400. Although the cardiac valve evaluation system 1400 of Fig. 28 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, etc. The cardiac valve evaluation system 1400 may include any number of devices operating as a distributed computing resource providing services such as storage, computation, networking, etc.

[0308] The cardiac valve evaluation system 1400 may include a hardware processing unit 2802, a data storage unit 2804, a memory unit 2806, a bus 2808, a display unit 2812, and one or more input / output devices 2814. The processing unit 2802 may be implemented as a combination of computing devices, such as 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 processing unit 2802 may be configured to process data or execute instructions to perform one or more functions, among others. The data storage unit 2804 may include a magnetic disk, an optical disk, a flash device, or the like, and may be provided and coupled to the bus 2808 for storing information and instructions. The memory 2806 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 2808 to a display device 2812, 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 2808 to one or more input / output devices 2814. The input devices 2814 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 eye, hand, head, or body tracking data and / or positioning), a game pad, an accelerometer, or a gyroscope.

[0309] The cardiac valve evaluation system 1400 may include one or more software engines (or services) for implementing the processes and functions described herein. The software engines may include program instructions for implementing the processes as detailed herein (and as illustrated in the flow diagrams) for detecting input conditions, such as pressure signals, and generating output conditions, such as cardiac valve conditions. The engines may be executed by one or more hardware processing units 2802. The program instructions may be stored in a data storage unit 2804 and / or loaded into a memory 2806. The program 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 processing units in application specific circuits, such as ASICs and FPGAs. Some aspects of the functionality of the cardiac valve evaluation system 1400 may be executed remotely in a server (not shown) over a network. Additionally, some aspects of the functionality of the cardiac valve evaluation system 1400 may be executed in one or more sensors or external devices.

[0310] The heart valve evaluation system 1400 may be in communication with one or more sensor devices 2816 described herein, such as the pressure guidewire 208, the pressure sensing access catheter 20, or the pressure sensing pigtail catheter 10.

[0311] term As used herein, relative terms such as "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.

[0312] As used herein, the relative terms "upstream" and "downstream" are defined in terms of blood flow, thus downstream refers to the direction toward the aorta relative to the left ventricle.

[0313] Conditional language such as "can," "could," "might," or "may," unless expressly stated otherwise or understood within the context as used, is generally intended to convey that certain embodiments include certain features, elements, and / or steps, but not other embodiments. As such, conditional language is generally not intended to imply that the features, elements, and / or steps are in any way required for one or more embodiments.

[0314] Terms such as "comprising," "including," "having," and the like are synonymous and are used in an open-ended, inclusive manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or," when used to join a list of elements, for example, is used in its inclusive sense (and not its exclusive sense) to mean one, some, or all of the elements in the list.

[0315] As used herein, the terms "approximately," "about," "generally," and "substantially" refer to an amount close to a stated amount that still performs a desired function or achieves a desired result. For example, the terms "approximately," "about," "generally," and "substantially" can refer to an amount that is within less than 5% of a stated amount, as the context may dictate.

[0316] Ranges disclosed herein encompass any and all overlapping, subranges, and combinations thereof. Words such as "up to," "at least," "greater than," "less than," "between" and "and" are inclusive of the number stated. Numbers preceded by terms such as "about" or "approximately" are inclusive of the number stated. For example, "about 4" includes "4."

[0317] Any methods disclosed herein need not be performed in the order suggested. Methods disclosed herein include specific actions taken by a practitioner, but may also include any third-party command of those actions, either explicitly or implicitly. For example, an action such as "distally move a locking element" includes "commanding distal movement of the locking element."

[0318] While specific embodiments and examples are described herein, it will be understood by those skilled in the art that many aspects of the humeral assembly shown and described in this disclosure can be differently combined and / or modified to form still further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of the present disclosure. A wide variety of designs and approaches are possible. No feature, structure, or step disclosed herein is essential or essential.

[0319] Some embodiments are described in conjunction with the accompanying drawings. However, it should be understood that the figures are not drawn to scale. Distances, angles, and the like are merely exemplary and do not necessarily bear a precise relationship to the actual dimensions and arrangement of the illustrated devices. Components may be added, removed, and / or rearranged. Furthermore, any specific features, aspects, methods, properties, characteristics, qualities, attributes, elements, etc. disclosed herein in connection with various embodiments can be used in all other embodiments described herein. It is also recognized that any method described herein can be performed using any device suitable for performing the proposed steps.

[0320] For the purpose of this disclosure, certain aspects, advantages, and novel features are described herein. It is understood that not all such advantages may be achieved according to any particular embodiment. Thus, for example, those skilled in the art will recognize that the present disclosure may be embodied or carried out in a manner that achieves one advantage or group of advantages as taught herein, without necessarily achieving other advantages as may be taught or suggested herein.

[0321] Furthermore, although exemplary embodiments are described herein, the scope of any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., combinations of aspects across various embodiments), adaptations, and / or modifications will be understood by those skilled in the art in the art based on this disclosure. Any limitations in the claims are to be interpreted broadly based on the words used in the claims and are not limited to the examples described herein or during prosecution of this application, which examples are to be interpreted as non-exclusive. Furthermore, the acts of the disclosed processes and methods may be modified in any manner, including reordering acts, inserting additional acts, and / or deleting acts. As such, it is intended that the specification and examples be considered as exemplary only, with the true scope and spirit being indicated by the claims and their full scope of equivalents. [Explanation of symbols]

[0322] 10 Pigtail Catheter 20 Access Catheter 30 Pressure Guide Wire 40 Pressure Sensor 200 Diagnostic System 202 Fiber Optic Interface Cable 204 Monitoring assembly, monitoring display device 207 Handle 206A, 206B, 206C, 206D Locations on Pressure Guide Wire 208 208 Pressure Guide Wire 210 Access Catheter 211 Access Catheter 212 Delivery Systems 213 Delivery Systems 214 Aortic Pigtail Catheter 250 Atraumatic Curvature 308 Pressure Guide Wire 310 Outer tube 312 Coil part 314 Spacing, Gap 316 core wire 318 Pressure Sensor Assembly 320 Pressure Wire Lead 322 Pressure Sensor 324 Sensor housing 326 Reduced diameter part 328 Proximal part 408 Pressure Guide Wire 410 Outer tube 412 Coil part 416 core wire 418 Pressure Sensor Assembly 420 Pressure Wire Lead 422 Pressure Sensor 426 Reduced Diameter Part 428 Unreduced diameter part 430 Connector pipe 432 Distal tip 434 Insulation Part 436 Adhesive 438a First Area 438b Second Area 440 Aperture 508 Pressure Sensing Guidewire 510 Outer tube 512a, 512b Coiled section, coil portion 516 core wire 518 Pressure Sensor Assembly 520 Pressure Wire Lead 522 Pressure Sensor 526 Reduced Diameter Part 528 Proximal part 530 Connector tube 542 Pressure Sensor Housing 544 Aperture 608 Pressure Sensing Guidewire 612a Coil part 616 core wire 626 Reduced Diameter Part 632 Distal tip 708 Pressure Sensing Guidewire 716 core wire 722 Pressure Sensor 730 Connector pipe 742 Sensor housing 746 Reduced Diameter Area 754 Tapered section 808 Pressure Sensing Guidewire 810 Outer tube 812a, 812b Coil parts 816 core wire 820 Pressure Wire Lead 822 Pressure Sensor 826 Reduced diameter part 830 Connector pipe 838a First Area 838b Second Area 842 Sensor housing 848 Connector 852 Aperture 908 Pressure Sensing Guidewire 910 Outer tube 912 Coil part 920 Pressure Wire Lead 922 Pressure Sensor 924 Sensor Housing Area 930 Connector pipe 932 Distal tip 934 Insulation part 948 Connector 956 Proximal end 1000, 1020, 1040, 1060, 1080 User Interface 1002, 1004, 1006, 1008 graphs 1010, 1012 Physiological parameters 1014 Recording Options 1042a, 1042b, 1042c Gradient depiction 1044a, 1044b, 1044c Backflow depiction 1046 First Number 1048 Second Number 1050 Electrocardiogram Recording Graph 1051 Pressure graph display 1052 Playback control section 1054 current playback position 1056 Gradient Type Selection 1062a, 1062b, 1062c Gradient depiction 1064 Number 1082a, 1082b, 1082c Gradient depiction 1084 Number 1100, 1120, 1140 User Interface 1102, 1122, 1142 Gradient depiction 1104 Backflow Description 1200 Configuration User Interface 1202 Statistical measurement period selection unit 1400 Heart Valve Assessment System 1402 Heart valve evaluation environment 1404 Input section 1406 Output section 1408 Calibration Services 1410 Waveform Adjustment Service 1412 Feature Detection Service 1414 Valve Status Determination Service 1416 Indicator calculation section 1418 Gradient Calculation Unit 1700 waveform analysis environment 1702 First set of pressure data points 1704 Second set of pressure data points 1800 waveform analysis environment 1801 Cardiac contraction 1802 Incline 1806 waveform 1803 Minimum or locally minimum pressure value 1804 horizontal line 1805 Crossing 1807 time period, end of diastole 2010 Left ventricular pressure waveform 2011 Aortic pressure waveform 2012 Ejection period, time period 2013 area 2220 Gradient between end-diastolic ventricular pressure and end-diastolic aortic force 2221 Gradient between mean left ventricular diastolic pressure and mean aortic diastolic pressure 2222 Specific Value 2330 Pressure Increase 2331 Cardiac contraction 2402 Left ventricular pressure waveform 2404 Aortic pressure waveform 2406 When the valve opens 2408 Dicrotic Notch 2502 Left ventricular pressure waveform 2504 Aortic pressure waveform 2506 Pressure value of aortic pressure waveform 2508 Pressure value of left ventricular pressure waveform 2602 Left ventricular pressure waveform 2604 Aortic pressure waveform 2802 Hardware Processing Unit 2804 Data storage device 2806 Memory Device 2808 Bus 2812 Display device 2814 Input / Output Device A. Aorta L longitudinal axis of pressure guidewire LA Left atrium LV left ventricle M Mitral valve P cusp RA right atrium RV right ventricle VC Inferior vena cava, superior vena cava< / asp> < / lvsp> < / asp> < / lvsp> < / asp> < / lvsp>

Claims

1. A non-temporary computer storage medium configured to store at least computer executable instructions, One or more hardware processing devices communicating with the aforementioned non-temporary computer storage medium, wherein at least, Calibrating the second pressure sensor relative to the first pressure sensor while both the first and second pressure sensors are positioned in the heart, wherein the calibration of the second pressure sensor is Determining a first set of pressure values ​​from the first pressure sensor located in a first part of the heart, Determining a second set of pressure values ​​from the second pressure sensor located in the cardiovascular region adjacent to the first portion of the heart, To detect the value at the start of systole in the first plurality of pressure values, and Calculating time adjustments to the second set of pressure values ​​such that the second set of pressure values ​​intersects with the values ​​at the start of the systolic phase in the first set of pressure values, Calibrate the second pressure sensor, including To determine a third set of pressure values ​​from the first pressure sensor located in the first part of the heart, Determining a fourth plurality of pressure values ​​from the second pressure sensor located in the cardiovascular region adjacent to the first portion of the heart, wherein determining the fourth plurality of pressure values ​​is To determine a fourth set of pressure values, which includes applying the aforementioned time adjustment to a set of initial pressure values, To detect the first characteristic at the third set of pressure values, To detect the second characteristic at the fourth set of pressure values, The condition of the heart valves is determined based at least partially on the first and second features, To display the aforementioned heart valve status on the user interface, One or more hardware processing units configured to execute the aforementioned computer executable instructions A system equipped with these features.

2. Calibrating the second pressure sensor with respect to the first pressure sensor is, To detect dicrotic notch features at the aforementioned first set of pressure values, Identifying the timestamp corresponding to the aforementioned dichroic notch feature, From the aforementioned first plurality of pressure values, determine the first value in the timestamp, From the fourth set of pressure values ​​and the time adjustment, determine the second value in the timestamp, and The method further includes calculating the gain adjustment based at least partially on the first and second values, Determining the fourth set of pressure values ​​means The system according to claim 1, further comprising applying the gain adjustment to a set of pressure values.

3. Identifying the timestamp corresponding to the aforementioned dicrotic notch feature is, The system according to claim 2, further comprising specifying the timestamp within a range of percentages of heart cycles before or after the dicrotic notch feature in the first plurality of pressure values.

4. The first value is V １ Corresponding to the above, the second value is V ２ Corresponding to this, the gain adjustment includes g, and calculating the gain adjustment is related to determining the relationship. [Math 1] The system according to claim 2, further comprising:

5. The one or more hardware processing devices are The system according to claim 1, further configured to identify the start of systole within a range of percentages of the heart cycle before or after the end of diastole in the first plurality of pressure values.

6. The first feature is the system according to claim 1, wherein at least one of a first systolic period or a first diastolic period is provided for the third plurality of pressure values.

7. Detecting at least one of the first systolic phase or the first diastolic phase is: The method involves detecting a first dicrotic notch feature at the third set of pressure values, Calculating multiple second derivative values ​​from the first multiple pressure values, and Identifying the zero-crossing point corresponding to the first dichroic notch feature based at least partially on the plurality of second derivative values. To detect a first dichroic notch feature, Depending on the first dichroic notch feature, at least one of the first systole or the first diastolic phase is identified. The system according to claim 6, further comprising:

8. A non-temporary computer storage medium configured to store at least computer executable instructions, One or more hardware processing devices communicating with the aforementioned non-temporary computer storage medium, wherein at least, Calibrating the second pressure sensor relative to the first pressure sensor while both the first and second pressure sensors are positioned in the heart, wherein the calibration of the second pressure sensor is Determining a first set of pressure values ​​from the first pressure sensor located in a first part of the heart, Determining a second set of pressure values ​​from the second pressure sensor located in the cardiovascular region adjacent to the first portion of the heart, To identify the value at the start of systole in the first plurality of pressure values, and The time adjustment to the second set of pressure values ​​is calculated so that the second set of pressure values ​​intersects with the value at the start of the systolic phase in the first set of pressure values. Calibrate the second pressure sensor, including To determine a third set of pressure values ​​from the first pressure sensor located in the first part of the heart, Determining a fourth plurality of pressure values ​​from the second pressure sensor located in the cardiovascular region adjacent to the first portion of the heart, wherein determining the fourth plurality of pressure values ​​is To determine a fourth set of pressure values, which includes applying the aforementioned time adjustment to a set of initial pressure values, To present a first user interface including a first graph based at least partially on the third plurality of pressure values ​​and a second graph based at least partially on the fourth plurality of pressure values, One or more hardware processing units configured to execute the aforementioned computer executable instructions A system equipped with these features.

9. Calibrating the second pressure sensor with respect to the first pressure sensor is, To detect dicrotic notch features at the aforementioned first set of pressure values, Identifying the timestamp corresponding to the aforementioned dichroic notch feature, From the aforementioned first plurality of pressure values, determine the first value in the timestamp, From the fourth set of pressure values ​​and the time adjustment, determine the second value in the timestamp, and The method further includes calculating the gain adjustment based at least partially on the first and second values, Determining the fourth set of pressure values ​​means The system according to claim 8, further comprising applying the gain adjustment to a set of pressure values.

10. Identifying the timestamp corresponding to the aforementioned dicrotic notch feature is, The system according to claim 9, further comprising specifying the timestamp within a range of percentages of heart cycles before or after the dicrotic notch feature in the first plurality of pressure values.

11. The first value is V １ Corresponding to the above, the second value is V ２ Corresponding to this, the gain adjustment includes g, and calculating the gain adjustment is related to determining the relationship. [Math 2] The system according to claim 9, further comprising:

12. The one or more hardware processing devices are The system according to claim 8, further configured to identify the start of systole within a range of percentages of the heart cycle before or after the end of diastole in the first plurality of pressure values.

13. The system according to claim 8, wherein the first user interface comprises a first gradient drawing that visually presents a first gradient measurement between a first peak in the first graph and a second peak in the second graph.

14. The one or more hardware processing devices are To receive user selection for a second gradient type via the first user interface, and It is further configured to present a second user interface for a second gradient type instead of the first user interface, The second user interface described above is: The first graph and the second graph, and, A second gradient diagram visually presents the region between the first graph and the second graph, wherein the region indicates the pressure difference between the first part of the heart and the second part of the heart, and the second gradient of the valve. The system according to claim 13, comprising:

15. The first user interface further comprises a first numerical value for the first gradient drawing, The one or more hardware processing devices are To receive user heart rate selection, and, The system according to claim 13, further configured to calculate the first value based at least in part on the user heart rate selection.

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