CN113558592B

CN113558592B - Method and system for tracking cardiac circulatory events using blood pressure

Info

Publication number: CN113558592B
Application number: CN202111017292.6A
Authority: CN
Inventors: 林佳燕; 郑欲晓; 邵小虎; 宋亮; 陈丽丽
Original assignee: Insight Lifetech Co Ltd
Current assignee: Insight Lifetech Co Ltd
Priority date: 2020-05-08
Filing date: 2020-05-08
Publication date: 2023-06-13
Anticipated expiration: 2040-05-08
Also published as: CN111466900B; CN113576439A; CN113558592A; CN113576439B; CN111466900A

Abstract

The present disclosure relates to a method of tracking a cardiac circulatory event using blood pressure, comprising receiving a first pressure signal and a second pressure signal, the first pressure signal being an intravascular proximal pressure signal and the second pressure signal being an intravascular distal pressure signal; the method comprises the steps of distinguishing each cardiac cycle according to a first pressure signal and a second pressure signal, synchronizing the first pressure signal and the second pressure signal, calculating the ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal according to the first pressure signal and the second pressure signal to obtain a target pressure waveform, obtaining the derivative value of the pressure ratio relative to time according to the target pressure waveform to obtain a target derivative waveform, determining a target period in any cardiac cycle according to the target derivative waveform, and obtaining the average value of the corresponding target pressure waveform in the target period.

Description

Method and system for tracking cardiac circulatory events using blood pressure

The present application is a divisional application of patent application with application number 2020103834392, application number 05 and 08, and patent application entitled system and method for tracking cardiac circulatory events using blood pressure.

Technical Field

The present disclosure relates specifically to methods and systems for tracking cardiac circulatory events using blood pressure.

Background

Coronary artery disease is one of the leading causes of death worldwide, and the ability to better diagnose, monitor and treat coronary artery disease can save lives. Coronary angiography is a technique conventionally used to evaluate stenotic lesions of coronary arteries, but it does not reflect the reality of coronary vascular function, so it is basically unclear whether or not a stenotic lesion coronary artery is associated with myocardial ischemia, symptoms of a patient. Currently, a method for clinically judging stenosis of coronary arteries mainly uses a blood flow reserve fraction (Fractional Flow Reserve, abbreviated as FFR) technique obtained by pressure guide wire examination.

However, the following drawbacks exist in obtaining FFR: the need to inject a maximum hyperemia inducing drug (e.g., adenosine triphosphate ATP) into the coronary arteries prior to FFR measurement, to place the coronary arteries in a maximum hyperemic state, increases clinical procedure time, adds significant medical costs while providing patient with an indication, and also causes the patient to develop an allergic response.

Disclosure of Invention

The present disclosure has been made in view of the above-described circumstances, and an object thereof is to provide a system and method capable of tracking cardiac circulatory events using blood pressure without the need for injection of a maximum congestion-inducing drug.

To this end, a first aspect of the present disclosure provides a system for tracking cardiac circulatory events using blood pressure, comprising: a pressure measurement device configured to measure a pressure in the blood vessel near the proximal side at a sampling rate to generate a first pressure signal and measure a pressure in the blood vessel far the proximal side to generate a second pressure signal; and a host connected to the pressure measuring device and receiving the first pressure signal and the second pressure signal, the host distinguishing each cardiac cycle based on the first pressure signal and the second pressure signal and calculating a ratio of a pressure value of the second pressure signal to a pressure value of the first pressure signal corresponding to a pressure value of the second pressure signal to obtain a pressure ratio value and generate a target pressure waveform, the host obtaining a derivative value of the pressure ratio value with respect to time based on the target pressure waveform to obtain a target derivative waveform, the host determining a target period in any cardiac cycle based on the target derivative waveform to obtain an average value of the corresponding pressure ratio value in the target period, the target period being a period in which a derivative value of the target derivative waveform in the cardiac cycle varies within a preset numerical range.

In the present disclosure, the pressure measurement device is configured to measure pressure within the blood vessel near the proximal side at a sampling rate to generate a first pressure signal and measure pressure within the blood vessel far from the proximal side to generate a second pressure signal, and the host may be coupled to the pressure measurement device and receive the first pressure signal and the second pressure signal. The host obtains a pressure ratio value based on a ratio of a pressure value of the second pressure signal to a pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal based on the first pressure signal and the second pressure signal, and generates a target pressure waveform, the host obtains a derivative value of the pressure ratio value with respect to time based on the target pressure waveform, thereby obtaining a target derivative waveform, and determines a target period in any cardiac cycle based on the target derivative waveform, thereby obtaining an average value of the corresponding pressure ratio value in the target period, the target period being a period in which the derivative value of the target derivative waveform in the cardiac cycle varies within a preset value range. In this case, the present disclosure can determine the pathological condition of the blood vessel of the patient without the need to inject the maximum congestion inducing drug.

In the system for tracking cardiac cycle events using blood pressure according to the first aspect of the present disclosure, optionally, the host computer obtains a first pressure waveform including at least one complete cardiac cycle based on the first pressure signal, the host computer obtains a second pressure waveform including at least one complete cardiac cycle based on the second pressure signal, and the host computer distinguishes each cardiac cycle based on the first pressure waveform and/or the second pressure waveform. Thereby a first pressure waveform and a second pressure waveform can be obtained, and the host computer can distinguish between individual cardiac cycles based on the first pressure waveform and/or the second pressure waveform.

In the system for tracking cardiac cycle events using blood pressure related to the first aspect of the present disclosure, optionally, the host computer is configured to synchronize the first pressure waveform and the second pressure waveform such that a time at which the first pressure waveform peaks is the same as a time at which the second pressure waveform peaks within the cardiac cycle. Therefore, the first pressure waveform and the second pressure waveform can be synchronized, and accurate pressure ratio can be obtained conveniently.

In the system for tracking cardiac cycle events using blood pressure according to the first aspect of the present disclosure, optionally, the host computer obtains a target period corresponding to each of a plurality of cardiac cycles based on the target pressure waveform, and calculates an average value of the corresponding pressure ratios in the target period of each cardiac cycle, so as to average the obtained plurality of average values to obtain a target average value. Thereby enabling a target average value to be obtained.

In the system for tracking cardiac cycle events using blood pressure related to the first aspect of the present disclosure, optionally, the cardiac cycle includes a systolic phase of systole and a diastolic phase of diastole, the target phase being located in the diastolic phase. Thereby a target period located in diastole can be obtained.

In the system for tracking cardiac cycle events using blood pressure according to the first aspect of the present disclosure, optionally, the host computer pre-processes the first pressure signal and the second pressure signal, rejects invalid signals in the first pressure signal and the second pressure signal, and filters the first pressure signal and the second pressure signal. Thereby facilitating a more accurate target period to be obtained later.

In the system for tracking cardiac cycle events using blood pressure according to the first aspect of the present disclosure, optionally, the invalid signal includes a portion signal exceeding a preset numerical range in pressure values corresponding to the first pressure signal and the second pressure signal, a portion signal exceeding a preset frequency range in occurrence frequency of a cardiac cycle within the first pressure signal and the second pressure signal, and a portion signal exceeding a preset peak range in peak values of pressure values of respective cardiac cycles corresponding to the first pressure signal and the second pressure signal. Thus, invalid signals in the first pressure signal and the second pressure signal can be eliminated.

In the system for tracking cardiac cycle events using blood pressure related to the first aspect of the present disclosure, optionally, the target period is continuous and the length of time of the target period is greater than a preset time value. Thereby enabling a more efficient target period to be obtained.

A second aspect of the present disclosure provides a method of tracking cardiac circulatory events using blood pressure, characterized by: comprising the following steps: measuring the pressure in the blood vessel near the proximal side at a certain sampling rate to obtain a first pressure signal, and simultaneously measuring the pressure in the blood vessel far from the proximal side to obtain a second pressure signal; and according to the first pressure signal and the second pressure signal, the pressure ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal is calculated to obtain a target pressure waveform, the derivative value of the pressure ratio relative to time is obtained according to the target pressure waveform, a target period in any cardiac cycle is determined according to the target derivative waveform, and thus the average value of the corresponding pressure ratio in the target period is obtained, the target period is a period in which the derivative value of the target derivative waveform in the cardiac cycle changes in a preset numerical range, wherein the target period comprises a period in which the derivative value of the pressure value of the first pressure signal in the first cardiac cycle exceeds the preset numerical range, a period in which the derivative value of the pressure value of the second pressure signal exceeds the corresponding pressure value of the second pressure signal in the first cardiac cycle, and a portion of the cardiac cycle which the pressure value of the pressure signal exceeds the preset numerical range.

In the present disclosure, a first pressure signal is obtained by measuring the pressure in the blood vessel near the proximal side at a certain sampling rate, and a second pressure signal is obtained by measuring the pressure in the blood vessel far from the proximal side. And distinguishing each cardiac cycle according to the first pressure signal and the second pressure signal, synchronizing the first pressure signal and the second pressure signal, removing invalid signals in the first pressure signal and the second pressure signal, calculating the ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal according to the first pressure signal and the second pressure signal to obtain a target pressure waveform, obtaining the derivative value of the pressure ratio relative to time according to the target pressure waveform to obtain a target derivative waveform, determining a target period in any cardiac cycle according to the target derivative waveform, wherein the target period is a period in which the derivative value of the target derivative waveform in the cardiac cycle changes within a preset numerical range, and obtaining the average value of the corresponding pressure ratios in the target period. In this case, the present disclosure can determine the pathological condition of the blood vessel of the patient without the need to inject the maximum congestion inducing drug.

In the method for tracking cardiac cycle events using blood pressure according to the second aspect of the present disclosure, optionally, the cardiac cycle includes a systolic phase of systole and a diastolic phase of diastole, the target phases are continuous and located in the diastolic phase, and a time length of the target phases is greater than a preset time value, the target phases corresponding to each of the plurality of cardiac cycles are obtained from the target pressure waveform, and an average value of the corresponding pressure ratios in the target phases of each cardiac cycle is calculated, so that the obtained plurality of average values are averaged to obtain a target average value. In this case, a more effective target period can be obtained, and a more effective target period can be obtained.

In accordance with the present invention, a system and method for tracking cardiac circulatory events using blood pressure without the need for injection of a maximum hyperemia inducing drug can be provided.

Drawings

Fig. 1 is a block diagram illustrating a system for tracking cardiac circulatory events using blood pressure in accordance with an example of the present disclosure.

Fig. 2 is a schematic diagram illustrating a system related to tracking cardiac circulatory events using blood pressure in accordance with examples of the present disclosure.

Fig. 3 is a schematic diagram illustrating an interventional human body of a system for tracking cardiac circulatory events using blood pressure in accordance with examples of the present disclosure.

Fig. 4 is a blood vessel image showing a preset site to which examples of the present disclosure relate.

Fig. 5 is a cross-sectional view illustrating a system application in a blood vessel to which examples of the present disclosure relate.

Fig. 6 is a pressure waveform diagram illustrating a plurality of cardiac cycles involved in an example of the present disclosure.

Fig. 7 is a pressure waveform diagram illustrating a plurality of cardiac cycles to which examples of the present disclosure relate.

Fig. 8 is a pressure waveform diagram illustrating a plurality of cardiac cycles involved in another example of the present disclosure.

Fig. 9 is a flow diagram illustrating a method of tracking cardiac circulatory events using blood pressure in accordance with an example of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same members are denoted by the same reference numerals, and overlapping description thereof is omitted. In addition, the drawings are schematic, and the ratio of the sizes of the components to each other, the shapes of the components, and the like may be different from actual ones.

In addition, headings and the like referred to in the following description of the disclosure are not intended to limit the disclosure or scope thereof, but rather are merely indicative of reading. Such subtitles are not to be understood as being used for segmenting the content of the article, nor should the content under the subtitle be limited only to the scope of the subtitle.

The present disclosure provides a system and method for tracking cardiac circulatory events using blood pressure, in which the condition of a patient's blood vessel can be determined without the need to inject a maximum congestion-inducing drug.

Fig. 1 is a block diagram illustrating a system 1 related to tracking cardiac circulatory events using blood pressure in accordance with an example of the present disclosure. Fig. 2 is a schematic diagram illustrating a system 1 related to tracking cardiac circulatory events using blood pressure in accordance with examples of the present disclosure. Fig. 3 is a schematic diagram illustrating an interventional human body of the system 1 for tracking cardiac circulatory events using blood pressure in accordance with examples of the present disclosure.

In some examples, as shown in fig. 1 and 2, a system 1 (referred to as "system 1") for tracking cardiac circulatory events using blood pressure may include a pressure measurement device 10 and a host 20. The pressure measurement device 10 may be coupled to a host 20. The pressure measurement device 10 may measure the pressure within the blood vessel (also referred to as "intravascular pressure") and generate a pressure signal, which may then be transmitted to the host 20 for processing.

In some examples, as shown in fig. 1 and 2, a side closer to the host 20 (described later) may be a proximal side 20a and a side farther from the host 20 may be a distal side 20b.

The system 1 for tracking cardiac circulatory events using blood pressure in accordance with the present disclosure may utilize interventional catheter techniques to measure pressure intravascularly for determining a condition of a patient's blood vessel, such as stenosis 421 (see fig. 5). The system 1 may be used to measure the pressure within a patient's blood vessel and process it (e.g., to obtain a pressure ratio as described later, and thus an average of the corresponding pressure ratios over a target period), thereby enabling a determination of a pathological condition of the patient's blood vessel without the need to inject a maximum congestion inducing drug.

In some examples, the pressure measurement device 10 may measure pressure within a blood vessel and generate a pressure signal.

In some examples, as shown in fig. 2, the pressure measurement device 10 may include a first pressure measurement device and a second pressure measurement device. In some examples, the first pressure measurement device may have a first pressure sensor that may measure pressure within the blood vessel and generate a pressure waveform (e.g., a first pressure signal described later). In some examples, the second pressure measurement device may have a second pressure sensor that may measure pressure within the blood vessel and generate a pressure waveform (e.g., a second pressure signal described later). Examples of the present disclosure are not limited thereto, and in other examples, the pressure measurement device may include a third pressure measurement device, which may have two pressure sensors that may simultaneously measure pressure within a blood vessel and generate pressure signals (e.g., first and second pressure signals, etc., described later) respectively.

In some examples, the first pressure measurement device may measure pressure within the blood vessel and generate a pressure waveform. In some examples, as shown in fig. 2, the first pressure measurement device may be a guide catheter 110, and the guide catheter 110 may have a pressure sensor 112 for measuring intravascular pressure. In some examples, the guide catheter 120 may measure the pressure within the blood vessel (e.g., the pressure within the blood vessel near the proximal side 20 a) and generate a pressure signal via the pressure sensor 112. The example of the present disclosure is not limited thereto and the first pressure measuring device may be other devices capable of measuring pressure in a blood vessel.

In some examples, as shown in fig. 2, the first pressure measurement device may be a guide catheter 110, the guide catheter 110 may be elongate tubular, and the guide catheter 110 may have an internal cavity 111. In some examples, guide catheter 110 has a proximal side 110a proximal to host 20 and a distal side 110b distal to host 20.

In some examples, guide catheter 110 is provided with a pressure sensor 112. In some examples, as shown in fig. 2, pressure sensor 112 may be an invasive blood pressure sensor that may be directly connected to a port on proximal side 110a of guide catheter 110 to be disposed on guide catheter 110. For example, pressure sensor 112 may be provided with a circular interface that mates with the tubular structure of guide catheter 110 for connection to guide catheter 110. This allows for a better fit between guide catheter 110 and pressure sensor 112, and for a better measurement of intravascular pressure. In some examples, pressure sensor 112 may sense the pressure generated by the flow of liquid from distal side 110b into interior lumen 111 of guide catheter 110.

Specifically, guide catheter 110 may be placed within a blood vessel of a human body and the port of distal side 110b of guide catheter 110 is placed at a first preset location within the blood vessel (e.g., the side of the blood vessel proximal to proximal side 20 a), pressure sensor 112 may be disposed outside the body and connected to the port of proximal side 110a of guide catheter 110, blood at the location of the proximal side within the blood vessel may flow into guide catheter 110 and may flow from distal side 110b of guide catheter 110 to proximal side 110a of guide catheter 110 to be sensed by pressure sensor 112, whereby pressure sensor 122 is able to obtain the pressure within interior cavity 121 of guide catheter 120, i.e., the pressure at the first preset location within the blood vessel.

However, examples of the present disclosure are not limited thereto, and in other examples, pressure sensor 112 may be a capacitive pressure sensor, a resistive pressure sensor, a fiber optic pressure sensor, etc., pressure sensor 112 may be disposed on distal side 110b of guide catheter 110, e.g., pressure sensor 112 may be disposed on an outer wall of guide catheter 110 proximate distal side 110 b. For example, in operation of system 1, guide catheter 110 may be placed within a blood vessel of a human body and pressure sensor 112 may be placed at a first preset location within the blood vessel. In this case, the pressure sensor 112 may directly sense the pressure at the first preset location within the blood vessel.

In some examples, the first preset location may be a side of the blood vessel proximal to proximal side 20a, whereby guide catheter 110 may acquire a cardiac cycle-dependent pressure of the blood vessel proximal to proximal side 20a and generate a pressure waveform at a sampling rate via pressure sensor 112.

In some examples, a first pressure measurement device may be coupled to host 20 and a pressure signal obtained by the first measurement device may be transmitted to host 20. For example, as shown in fig. 2, guide catheter 110 may be connected to host 20 by a transmission wire, in which case the pressure signal measured by pressure sensor 112 is transmitted to host 20 via the transmission wire.

In some examples, the second pressure measurement device may measure pressure within the blood vessel and generate a pressure waveform. In some examples, as shown in fig. 2, the second pressure measurement device may be a blood pressure measurement catheter 120, and the blood pressure measurement catheter 120 may have a pressure sensor 122 for measuring pressure within the blood vessel. In some examples, the blood pressure measurement catheter 120 measures intravascular pressure (e.g., intravascular pressure distal the proximal side 20 a) via the pressure sensor 122 and generates a pressure signal. The first pressure measuring device may be, but is not limited to, other devices for measuring pressure within a blood vessel, such as a medical guidewire with a pressure sensor.

In some examples, as shown in fig. 2, the second pressure measurement device may be a blood pressure measurement catheter 120, and the blood pressure measurement catheter 120 may be elongate tubular. In some examples, the blood pressure measurement catheter 120 may have a proximal side 120a proximal to the host 20 and a distal side 120b distal to the host 20, and the blood pressure measurement catheter 120 may have an internal cavity 121.

In some examples, the blood pressure measurement catheter 120 is provided with a pressure sensor 121, and a pressure sensor 122 may be provided at the distal side 120b of the blood pressure measurement catheter 120. In some examples, the pressure sensor 122 may be disposed on an outer wall of the blood pressure measurement catheter 120, and in some examples, the pressure sensor 122 may also be disposed within an interior cavity 121 of the blood pressure measurement catheter 120, the interior cavity 121 may have a window with the pressure sensor 122. In some examples, in operation of the system 1, the blood pressure measurement catheter 120 may be placed within a blood vessel of a human body and the pressure sensor 122 may be placed at a second preset location within the blood vessel. In this case, the pressure sensor 122 may measure the pressure at a second preset location within the vessel.

In some examples, the second preset location may be the side of the blood vessel distal to the proximal side 20a, whereby the blood pressure measurement catheter 120 may acquire the pressure of the blood vessel distal to the proximal side 20a at a sampling rate by the pressure sensor 122 and generate a pressure waveform as a function of the cardiac cycle.

In some examples, the second pressure measurement device may be coupled to the host 20. For example, as shown in FIG. 2, a blood pressure measurement catheter 120 may be coupled to the host 20. The blood pressure measurement catheter 120 may be provided with a signal path 123, the signal path 123 may be disposed within the internal cavity 121 of the blood pressure measurement catheter 120, and the signal path 123 may connect the pressure sensor 122 and the host 20. In this case, the pressure signal obtained by measurement of the pressure sensor 122 is transmitted to the host 20 via the signal path 123.

In some examples, pressure sensor 122 may be a capacitive pressure sensor, a resistive pressure sensor, or the like. The pressure sensor 122 may be a MEMS pressure sensor. For example, the pressure sensor 122 may measure in a range of about-50 mmHg to about +300 mmHg. Depending on the type of pressure sensor 122, the signal path 123 may be a conductive medium such as an electrical lead. Further, in some embodiments, the signal path 123 may also be a wireless communication line, an infrared communication line, or an ultrasonic communication line.

In some examples, as shown in fig. 2, if the first pressure measurement device is a guide catheter 110 and the second pressure measurement device is a blood pressure measurement catheter 120, the diameter of the interior cavity 111 of the guide catheter 110 may be greater than the outer diameter of the blood pressure measurement catheter 120. In some examples, the blood pressure measurement catheter 120 may enter the internal cavity 111 from the proximal side 110a of the guide catheter 110 (see fig. 2 and 3). In this case, the blood pressure measurement catheter 120 can be disposed within the internal cavity 111 and facilitate movement of the blood pressure measurement catheter 120 relative to the guide catheter 110, which guide catheter 110 can remain stationary, during operation of the system 1.

In some examples, guide catheter 110 and blood pressure measurement catheter 120 may enter or exit the patient as separate devices, respectively. In this case, the healthcare worker can independently control the blood pressure measurement catheter 120 and the guide catheter 110. For example, during operation of the system 1, a healthcare worker may control movement of the blood pressure measurement catheter 120 relative to the guide catheter 110 (e.g., advancement or retraction deep into a blood vessel within a patient), and the guide catheter 120 may remain stationary.

In some examples, the second pressure measurement device may be deeper into the patient (see fig. 5) than the first pressure measurement device, and the second pressure sensor (e.g., pressure sensor 122) may measure intravascular pressure deeper into the human body (e.g., the side of the vessel distal from proximal side 20 a) than the first pressure sensor (e.g., pressure sensor 112).

Specifically, as shown in fig. 2 and 3, if the first pressure measuring device is a guide catheter 110 and the second pressure measuring device is a blood pressure measuring catheter 120, during the interventional procedure, an operator such as a medical staff first advances a guide wire from a certain portion (e.g., a femoral artery) of a patient (or patient) along a blood vessel to a certain position (e.g., a first preset position) in the blood vessel, then advances the guide catheter 110 along the guide wire to the first preset position in the blood vessel, enables the guide catheter 110 to measure the pressure at the first preset position, then withdraws the guide wire, and further advances a medical guide wire (not shown) along the guide catheter 110 to a second preset position in the blood vessel by, for example, contrast agent. In this case, the blood pressure measurement catheter 120 is along the medical guidewire such that the catheter lumen 121 can be slid over the medical guidewire and the pressure sensor 122 can also be moved along the blood pressure measurement catheter 120 by manipulating (e.g., pushing and/or pulling) the proximal side 120a of the blood pressure measurement catheter 120 (or an operating device (not shown) connected to the proximal side 120a of the blood pressure measurement catheter 120) external to the patient until the pressure sensor 122 is in a preset position (e.g., a second preset position).

In some examples, pressure sensor 112 and pressure sensor 122 may measure pressure within the blood vessel simultaneously, e.g., pressure sensor 112 may measure a pressure-generating pressure signal at a first preset location while pressure sensor 122 may measure a pressure-generating pressure signal at a second preset location.

In some examples, the pressure measurement device 10 may be provided with an X-ray opaque visualization ring, thereby enabling the pressure measurement device 10 to measure pressure to obtain preset locations (e.g., a first preset location and a second preset location) within the blood vessel. In some examples, the pressure measurement device 10 employs different types of devices for intravascular pressure measurement, and the location of the imaging ring placement may also be different. For example, if the first pressure measuring device is a guide catheter 110 and the pressure sensor 112 is an invasive blood pressure sensor, the developing ring should be disposed at the port of the distal end side 110b of the guide catheter 110, and if the pressure sensor 112 is a capacitive pressure sensor or the like, the developing ring should be disposed on the guide catheter 110 on the side of the pressure sensor 112, or the pressure sensor 112 is directly disposed on the developing ring. In some examples, if the second pressure measurement device is a blood pressure measurement catheter 120, the visualization ring should be disposed on the blood pressure measurement catheter 120 on one side of the pressure sensor 122, or the pressure sensor 122 may be disposed directly on the visualization ring. In this case, the healthcare worker may operate the pressure measurement device 10 in conjunction with an X-ray machine (not shown), thereby enabling the pressure measurement device 10 to obtain intravascular pressure at a preset location (e.g., a first preset location and a second preset location).

In some examples, the side of the interior vessel proximal to proximal side 20a may be the side of the coronary artery proximal to the aortic port (i.e., proximal coronary artery side), and the side of the interior vessel distal to proximal side 20a may be the side of the coronary artery distal to the aortic port (i.e., distal coronary artery side). Thus, the pressure in the blood vessels on both sides of the coronary artery can be obtained, and the lesion condition of the coronary artery can be judged. Examples of the present disclosure are not limited thereto and, in some examples, the vessel (also referred to as a "target vessel") measured by pressure measurement device 10 may be determined by a healthcare worker.

Fig. 4 is a blood vessel image showing a preset site to which examples of the present disclosure relate. Among other things, FIG. 4 (a) shows vessel 410, vessel 420, vessel 430, vessel 440, vessel 450, and other small vessels. In the example of the present disclosure, the treatment manner of the other small blood vessels may be the same as the treatment manner of the blood vessel 410, the blood vessel 420, the blood vessel 430, the blood vessel 440, the blood vessel 450, and for convenience of representation, fig. 4 (b) shows the blood vessel excluding the preset portion of the other small blood vessels. Where the points A, B, C, D, E, F are the respective locations in the respective blood vessels. For example, vessel 410 may be the aorta, vessel 420 may be the right coronary, vessel 430 may be the left trunk, vessel 440 may be the anterior descending branch, and vessel 450 may be the circumflex branch. Fig. 5 is a cross-sectional view illustrating an application of the system 1 according to an example of the present disclosure in a blood vessel. The corresponding vessel in fig. 5 is vessel 420 in fig. 4.

In some examples, the vessel image of the pre-set site may be obtained by contrast with a contrast agent.

In some examples, a healthcare worker may take intravascular pressure measurements of multiple blood vessels in a preset site, thereby enabling determination of an overall condition of the preset site. In some examples, a healthcare worker may take intravascular pressure measurements of a single blood vessel in a preset site, thereby being able to determine the condition of the blood vessel.

In this embodiment, the pressure measurement device 10 may be configured to measure the pressure within the blood vessel near the proximal side 20a at a sampling rate to generate a first pressure signal and measure the pressure within the blood vessel far from the proximal side 20a to generate a second pressure signal.

In some examples, the specific location of the target vessel, i.e., the first preset location and the second preset location, measured by the pressure measurement device 10 may be determined by the healthcare worker.

In some examples, as shown in fig. 5, taking the vessel 420 as an example, a point E in the vessel 420 may be a first preset location (i.e., a side of the vessel that is proximal to the proximal side 20 a), and a point F in the vessel 420 may be a second preset location (i.e., a side of the vessel that is distal to the proximal side 20 a). Thus, the pressure measurement device 10 may be configured to measure the pressure at point E in the blood vessel 420 at a sampling rate to generate a first pressure signal and measure the pressure at point F in the blood vessel 420 to generate a second pressure signal. In some examples, the healthcare worker may select other blood vessels to take measurements, e.g., blood vessel 440, point B in blood vessel 440 may be a first preset location, and point C in blood vessel 440 may be a second preset location; for example, the vessel 450 may be at a point a in the vessel 450 as a first preset location and a point C in the vessel 450 as a second preset location.

In some examples, the sampling rate of the pressure measurement device 10 ranges from about 30Hz to 1.5KHz. For example, pressure sensor 122 may measure intravascular pressure with pressure sensor 112 at a sampling rate of 30Hz, 50Hz, 100Hz, 200Hz, 250Hz, 300Hz, 400Hz, 500Hz, 600Hz, 700Hz, 1000Hz, 1100Hz, 1200Hz, 1300Hz, 1400Hz, 1500 Hz. Thereby enabling more accurate measurement of the pressure within the blood vessel.

In some examples, the pressure measurement device 10 may measure pressure at different locations within the blood vessel simultaneously and generate multiple pressure signals. For example, the pressure measurement device 10 may include a first pressure measurement device that may measure a pressure-generating pressure signal at a first preset location and a second pressure measurement device that may measure a pressure-generating pressure signal at a second preset location. Or the pressure measurement device 10 may include a third pressure measurement device. The third pressure measuring device may comprise a plurality of pressure sensors located at different locations, whereby the pressure measuring device 10 is capable of measuring pressure at different locations within the blood vessel simultaneously to obtain a plurality of pressure signals.

In some examples, the first pressure signal and the second pressure signal may be obtained by simultaneous measurement by the pressure measurement device 10. For example, a first pressure measurement device may measure the pressure within the blood vessel near the proximal side 20a to generate a first pressure signal and a second pressure measurement device may measure the pressure within the blood vessel near the proximal side 20a to generate a second pressure signal.

In some examples, the pressure signal measured by the pressure measurement device 10 may vary with the cardiac cycle, which may include the diastolic phase of diastole and the systolic phase of systole.

In some examples, the pressure measurement device 10 may be configured to measure the pressure within the blood vessel near the proximal side 20a to generate a first pressure signal and measure the pressure within the blood vessel far from the proximal side 20a to generate a second pressure signal. For example, the pressure measurement device 10 may include a first pressure measurement device that may measure pressure within the blood vessel near the proximal side 20a (i.e., a first preset location) to generate a first pressure signal and a second pressure measurement device that may measure pressure within the blood vessel far from the proximal side 20a (i.e., a second preset location) to generate a second pressure signal, and the host 20 may receive the first pressure signal and the second pressure signal.

In some examples, the correction may be performed by having the second pressure sensor measure the pressure at the first preset position before the second pressure sensor measures the pressure at the second preset position to obtain the second pressure signal, i.e. by measuring the pressure at the first preset position simultaneously with the first pressure sensor to generate the pressure signal. Specifically, the pressure sensor may be calibrated before the second pressure sensor measures the pressure at a second preset location (e.g., at point F of vessel 420). The second pressure sensor may be placed at a first preset position (e.g. at point E of the vessel 420), i.e. the second pressure sensor may measure the intravascular pressure at the first preset position, in which case the first pressure sensor and the second pressure sensor simultaneously measure the intravascular pressure generating pressure signals at the first preset position, from which the second pressure sensor may be verified. In some examples, the pressure signals obtained by the first pressure sensor and the second pressure sensor may be transmitted to the host 20, and the host 20 may correct the second pressure sensor or the first pressure sensor (adjust the second pressure sensor or the first pressure sensor) based on the received pressure signals until there is no significant difference between the pressure signals obtained by the second pressure sensor and the pressure signals obtained by the first pressure sensor. In some examples, host 20 may display the received pressure signal in the form of a waveform (described later) on, for example, a display screen, and the healthcare worker may correct the second pressure sensor or the first pressure sensor based on the obtained waveform until there is no significant difference in the pressure signals obtained by the first pressure sensor and the second pressure sensor, i.e., the corresponding two change curves displayed on host 20 overlap.

In some examples, after further calibration of the pressure sensor, the healthcare worker may move the second pressure sensor by operating the second pressure measurement device (e.g., pushing the proximal side 120a of the blood pressure measurement catheter 120 external to the patient) or other apparatus to enable the second pressure sensor to measure the pressure at the second preset location, in which case the first pressure sensor may measure the pressure at the first preset location to generate the first pressure signal and the second pressure sensor may measure the pressure at the second preset location to generate the second pressure signal.

In some examples, after the second pressure sensor measures the second pressure signal, the second pressure sensor is moved to be able to measure the pressure at the first preset location, thereby verifying the second pressure sensor. Specifically, after the second pressure signal is obtained by the measurement of the second pressure sensor, the medical staff may move the second pressure sensor by operating the second pressure measuring device (e.g. pulling the proximal side 120a of the blood pressure measuring catheter 120 outside the patient) or other means, so that the second pressure sensor can measure the pressure at the first preset position, in which case the first pressure sensor and the second pressure sensor simultaneously measure the intravascular pressure at the first preset position to generate the pressure signal, the second pressure sensor may be verified according to the obtained pressure signal, and the accuracy of the second pressure signal obtained by the second pressure sensor is determined, e.g. the second pressure sensor may drift during the movement, resulting in errors in the second pressure signal obtained by the measurement of the second pressure sensor.

In some examples, at the time of verification, the pressure signals obtained by the first pressure sensor and the second pressure sensor may be transmitted to the host 20, and the host 20 may verify the second pressure sensor based on the received pressure signals. For example, in the verification, if there is no obvious difference between the pressure signals obtained by the first pressure sensor and the second pressure sensor, it may be determined that the second pressure signal obtained before the second pressure sensor can be used normally; if the pressure signals obtained by the first pressure sensor and the second pressure sensor have obvious differences, it can be judged that the second pressure signal obtained by the second pressure sensor cannot be used normally, and the accuracy of the first blood pressure value cannot be determined. In some examples, during verification, the pressure signals obtained by the first pressure sensor and the second pressure sensor may be transmitted to the host 20, the host 20 may display the received pressure signals in the form of waveforms (described later) on, for example, a display screen, and the medical staff may verify the second pressure sensor according to the obtained waveforms, and determine whether there is a significant difference in the pressure signals obtained by the first pressure sensor and the second pressure sensor, that is, determine whether the two corresponding change curves displayed on the host 20 overlap. Therefore, the second pressure signal obtained by the second pressure sensor can be more accurate and can be matched with the first pressure signal, and the pathological change condition of the blood vessel to be detected can be conveniently and better judged later.

Fig. 6 is a pressure waveform diagram illustrating a plurality of cardiac cycles involved in an example of the present disclosure. In fig. 6, a curve a is a first pressure waveform, that is, a curve of a pressure value corresponding to a first pressure signal changing with time, a curve B is a second pressure waveform, that is, a curve of a pressure value corresponding to a second pressure signal changing with time, and a section a and a section B are each a cardiac cycle. The vertical axis may be the magnitude of pressure (i.e., pressure value), and the horizontal axis may be the time axis.

Fig. 7 is a pressure waveform diagram illustrating a plurality of cardiac cycles in fig. 6 in accordance with an example of the present disclosure. In fig. 7, curve C is a target pressure waveform, curve D is a target derivative waveform, curve C shows a pressure ratio that is hundreds of times of an actually calculated pressure ratio, and curve D is a curve formed by a derivative of curve C with respect to time. The ordinate corresponding to the curve C is the left ordinate axis in fig. 7, and the ordinate corresponding to the curve D is the right ordinate axis in fig. 7. The pressure ratio may be a ratio of a pressure value of the second pressure signal (see fig. 6) to a pressure value of the first pressure signal (see fig. 6) corresponding to the pressure value of the second pressure signal, the interval a, the interval b being one cardiac cycle, the interval c being a target period in the interval a, the interval d being a target period in the interval b.

Fig. 8 is a pressure waveform diagram illustrating a plurality of cardiac cycles in fig. 6 in accordance with another example of the present disclosure. Curve a in fig. 8 is a first pressure waveform, that is, a curve of a pressure value corresponding to the first pressure signal changing with time, curve B is a second pressure waveform, that is, a curve of a pressure value corresponding to the second pressure signal changing with time, curve C is a target pressure waveform, the target pressure waveform is a curve of a pressure ratio value changing with time (wherein the curve C shows a pressure ratio that is hundreds of times the actually calculated pressure ratio), the pressure ratio may be a ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal, interval a, interval B are one cardiac cycle, interval m is a target period in interval a (described later), and interval n is a target period in interval B. The vertical axis may be the magnitude of the pressure value or the numerical value, and the horizontal axis may be the time axis.

In some examples, when the system 1 is in operation, the pressure measuring device 10 measures the pressure in the blood vessel and generates a pressure signal, which is then transmitted to the host 20, and the host 20 may display the received pressure signal in the form of a waveform on, for example, a display screen, that is, a change curve of the pressure corresponding to the pressure signal with time (see fig. 6 to 8).

In some examples, host 20 may process the received pressure signal.

In some examples, host 20 may filter the received pressure signal.

In some examples, the pressure waveform received by the host 20 includes at least one complete cardiac cycle. In some examples, host 20 may distinguish between individual cardiac cycles in the pressure waveform based on the obtained pressure waveform.

In some examples, host 20 may receive a first pressure signal and a second pressure signal, host 20 may obtain a first pressure waveform based on the first pressure signal (e.g., curve a in fig. 6), and host 20 may obtain a second pressure waveform based on the second pressure signal (e.g., curve B in fig. 6). In some examples, the first pressure waveform includes at least one complete cardiac cycle. In some examples, the second pressure waveform includes at least one complete cardiac cycle. In some examples, host 20 may differentiate between individual cardiac cycles based on the first pressure waveform and/or the second pressure waveform. Thereby enabling a first pressure waveform and a second pressure waveform, and the host 20 is able to distinguish between individual cardiac cycles based on the first pressure waveform and/or the second pressure waveform.

In some examples, the host 20 may be configured to synchronize the received pressure signals (e.g., the pressure signals transmitted by the first and second pressure measurement devices) such that the times at which the respective pressure waveforms received by the host 20 peak during the corresponding same cardiac cycle are the same. For example, upon further calibration and verification of the second pressure sensor, the host 20 may synchronize the received pressure signals measured by the first and second pressure sensors.

In some examples, the host 20 may be configured to synchronize the first pressure waveform and the second pressure waveform such that the moment in time at which the first pressure waveform peaks is the same as the moment in time at which the second pressure waveform peaks during the cardiac cycle. Therefore, the first pressure waveform and the second pressure waveform can be synchronized, and accurate pressure ratio can be obtained conveniently. In some examples, host 20 may determine whether the first pressure signal and the second pressure signal are synchronized by determining a degree of dissimilarity of the trend of the first pressure waveform and the second pressure waveform using covariance. In some examples, the host 20 may synchronize the first pressure waveform and the second pressure waveform by utilizing covariance and a cross-correlation function.

In some examples, host 20 may pre-process the received pressure signal and may reject the invalid portion of the pressure signal. In some examples, host 20 may pre-process the pressure signal based on the received pressure signal and the reference index. In some examples, the reference index may include a preset range of values for the pressure signal, or a preset range of frequencies for the corresponding cardiac cycle, or a preset peak range for each cardiac cycle for the pressure signal, or the like.

In some examples, host 20 may pre-process the first pressure signal and the second pressure signal, and may reject invalid ones of the first pressure signal and the second pressure signal. Thereby, a more efficient pressure signal can be obtained. In some examples, host 20 may compare the first and second pressure signals to a reference indicator based on the first and second pressure signals, thereby preprocessing the first and second pressure signals. In some examples, the invalid signal may include a portion of the pressure values corresponding to the first pressure signal and the second pressure signal that exceeds a preset numerical range, a portion of the pressure values corresponding to the first pressure signal and the second pressure signal that exceeds a preset peak range, and a portion of the pressure values corresponding to the first pressure signal and the second pressure signal that exceeds a preset frequency range. Thus, invalid signals in the first pressure signal and the second pressure signal can be eliminated.

In some examples, the intervals of the invalid signals rejected by the host 20 may also be different depending on the reference index. In some examples, the minimum unit of the nullification signal that the host 20 rejects may be one cardiac cycle.

In some examples, the reference index may include a preset range of values for the pressure signal. In some examples, if the value in the pressure signal does not appear in the preset range of values, the entirety of the cardiac cycle corresponding to the portion may be eliminated. For example, the predetermined range of values may be 30-200 mmHg, i.e., the reference indicator may include values of both the first pressure signal and the second pressure signal within 30-200 mmHg. Thereby, the portion of the first pressure signal and the second pressure signal having a value not in the range of 30 mmHg to 200mmHg can be removed. In some examples, the host 20 may reject the entirety of the cardiac cycle in which the portion of the first and second pressure signals having values other than between 30 and 200mmHg is located,

in some examples, the reference indicator may include a preset peak range of peaks of values corresponding to the pressure signal. In some examples, if the peak value in the pressure signal exceeds the preset peak value range, the whole cardiac cycle in which the peak value is located may be eliminated. For example, the predetermined peak range may be that a first percentage of the peak value of the first pressure signal should be greater than the peak value of the second pressure signal, the first percentage may range from 105% to 130%, for example, the first percentage may be 105%, 110%, 115%, 120%, 125%, or 130%. That is, the reference indicator may include that the first percentage of peaks of the first pressure signal should be greater than the peaks of the second pressure signal. Therefore, the first percentage of the peak value of the first pressure signal in the first pressure signal and the peak value of the second pressure signal are not smaller than the peak value of the second pressure signal, and the whole cardiac cycle corresponding to the peak value can be eliminated, for example, the peak value of the second pressure signal in the first pressure signal and the second pressure signal is larger than 110% of the peak value of the first pressure signal, and the whole cardiac cycle corresponding to the peak value can be eliminated.

In some examples, the reference index may include a frequency range of the cardiac cycle to which the pressure signal corresponds per unit time. In some examples, if the number of occurrences (i.e., frequency) of the corresponding cardiac cycle in a unit of time of the pressure signal is not within the frequency range, the unit-time signal is culled. For example, the reference index may include that the frequency of the cardiac cycle corresponding to the first pressure signal and the second pressure signal should be between 40 and 120 per minute, thereby enabling the rejection of the signal for the period of time when the cardiac cycle corresponding to each minute in the first pressure signal and the second pressure signal is not between 40 and 120.

In some examples, the host 20 receives a plurality of corresponding pressure signals (e.g., a first pressure signal and a second pressure signal), if there is an unsatisfied reference index in any of the pressure signals, the host 20 may reject an unsatisfied portion of the pressure signals (e.g., a cardiac cycle corresponding to the unsatisfied portion), and the host 20 may reject a portion of the other pressure signals corresponding to the rejected portion of the pressure signals. For example, if there is an unsatisfied reference index in the first pressure signal, the host 20 may reject the unsatisfied portion (e.g., the cardiac cycle corresponding to the unsatisfied portion), and the host 20 may reject a portion of the second pressure signal corresponding to the reject portion of the first pressure signal.

In some examples, the host 20 may reject portions of the pressure signal that do not meet the reference indicator, other portions of the pressure signal may be used normally, and the host 20 may treat the cardiac cycle before and after the reject portion as consecutive cardiac cycles when selecting a plurality of consecutive cardiac cycles. In some examples, the host 20 may cull out the unsatisfied portions of the pressure signal, forming other portions into a continuous waveform. For example, if there are 2 nd and 6 th cardiac cycles in the pressure signal that do not meet the reference index, the host 20 may reject the 2 nd and 6 th cardiac cycles in the pressure signal, the host 20 may form other portions of the pressure signal into a continuous waveform, and the host 20 may select the 1 st and 3 rd cardiac cycles as continuous when selecting a plurality of continuous cardiac cycles.

However, examples of the present disclosure are not limited thereto, and in some examples, the host 20 may reject a portion of the pressure signal that does not meet the reference indicator, and when the host 20 selects a plurality of consecutive cardiac cycles, if a portion that does not meet the reference indicator is encountered, the host 20 may reselect a plurality of consecutive cardiac cycles from a cardiac cycle subsequent to the portion, or may reselect from other portions of the signal.

In this embodiment, the lesion condition of a blood vessel (e.g., coronary artery) can be estimated by the ratio of the minimum constant trans-myocardial resistance measured at normal times of the target region of the blood vessel to the minimum constant trans-myocardial resistance measured if there is a stenosis in the target region of the blood vessel. Specifically, according to the hydrodynamic formula, the blood flow Q, the pressure difference Δp, and the blood flow resistance R within a blood vessel (for example, the blood vessel may be a coronary artery) may satisfy:

the blood flow of the blood vessel can be obtained based on the formula (1), which satisfies: />

Wherein P is _a Represented as the pressure within the vessel near the proximal side 20a, P _d Represented as pressure within the vessel at the distal proximal side 20a, P _v Expressed as central venous pressure, R _a Expressed as vascular resistance, R _b Expressed as the resistance to microcirculation. Under physiological conditions, the central venous pressure is equal to or almost equal to 0, which can be obtained based on formula (2):

it follows that the condition of the blood vessel can be estimated by the ratio of the pressure in the blood vessel at the distal end side 20a to the pressure in the blood vessel at the proximal end side 20 a.

In some examples, the host 20 may process the received first and second pressure signals, and the host 20 may obtain a pressure ratio based on the first and second pressure signals, where the ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal. In some examples, host 20 may generate a target pressure waveform based on the obtained pressure ratio (see curve C in fig. 7).

In some examples, the host 20 may obtain a target derivative waveform based on the target pressure waveform (see curve D in fig. 7). Specifically, the host 20 may obtain a derivative value of the pressure ratio with respect to time based on the target pressure waveform, thereby obtaining a target derivative waveform in which the derivative value varies with time.

In the present embodiment, P can be found by the target pressure waveform _d /P _a The plateau of the signal may also be d (P _d /P _a ) A period approaching 0 in/dt, whereby a period in which blood flow resistance is lowest and most constant (i.e., a target period described later) can be obtained. That is, the target period may be a period in which the target pressure waveform changes smoothly (i.e., a plateau) in the cardiac cycle, i.e., the target pressure waveform has a small change in amplitude in the period.

In some examples, the host 20 may determine a target period for any cardiac cycle from the target derivative waveform, wherein the target period may be a period in which the derivative value of the target derivative waveform varies within a preset range of values for that cardiac cycle. That is, the host 20 may determine, from any one cardiac cycle, a period in which the derivative value of the target derivative waveform in that cardiac cycle changes within a preset numerical range as the target period. Examples of the present disclosure are not limited thereto, however, and in other examples, the target period of any cardiac cycle (described in detail later) may also be determined from a target pressure waveform.

In some examples, the target period may be continuous. In some examples, the target period may be a period in which the derivative value of the target derivative waveform in the cardiac cycle varies within a preset range of values, that is, the derivative value of the cardiac cycle in the target period may be within the preset range of values.

In some examples, the host 20 may obtain a period in which the derivative value approaches 0 from the target derivative waveform as the target period. In some examples, the target time period may be a time period in which the derivative value in the target derivative waveform is within a preset numerical range (see interval c and interval d in fig. 7). In some examples, the preset value range may be set by the healthcare worker itself. In the example according to the present embodiment, the unit of the time axis is adjusted to ms, and the preset value range may be-0.2/ms to 0.2/ms (see fig. 7), but the example of the present disclosure is not limited thereto, and the preset value range may be-0.01/ms to 0.01/ms, -0.02/ms to 0.02/ms, -0.03/ms to 0.03/ms, -0.04/ms to 0.04/ms, -0.05/ms to 0.05/ms, -0.06/ms to 0.06/ms, -0.07/ms to 0.07/ms, -0.08/ms to 0.08/ms, -0.09/ms to 0.09/ms, -0.10/ms to 0.10/ms, -0.12/ms to 0.12/ms, -0.15/ms, -0.16/ms to 0.16/ms, or-0.18/ms to 0.18/ms, or the like.

In some examples, the length of time that the target period is continuous may be greater than a preset time value, e.g., the derivative value of the target derivative waveform over the length of time corresponding to the target period may be within a preset range of values (e.g., -0.2/ms to 0.2/ms). In some examples, the preset time value may be selected from a range of 0.1 to 0.5S, for example, the target period may be continuous for a length of time greater than 0.1S, 0.2S, 0.25S, 0.3S, 0.4S, 0.5S, or the like. Thereby enabling a more efficient target period to be obtained.

In some examples, the target period is located in a diastole phase of a corresponding cardiac cycle. Thereby a target period located in diastole can be obtained.

In some examples, host 20 may also filter the target derivative waveform. That is, the host 20 may filter the target derivative waveform before determining the target period. Thereby enabling a more accurate target period to be obtained.

In other examples, the target time period may be a time period in which the target pressure waveform of the cardiac cycle varies in magnitude less than a preset percentage (e.g., 10%) over the target time period, that is, the difference between the maximum and minimum values of the target pressure waveform of the cardiac cycle may be less than a preset percentage (e.g., 10%) of the minimum value, or the difference between the maximum and minimum values of the target pressure waveform of the cardiac cycle may be less than a preset percentage (e.g., 10%) of the maximum value.

In some examples, the target period may be a period during which the target pressure waveform of the cardiac cycle varies overall by less than a preset percentage (see interval m or interval n in fig. 8), which may be set by the healthcare worker, which may be one of a range of 0-20%, for example, which may be 1%, 2%, 2.5%, 2.6%, 3%, 4%, 5%, 5.5%, 6%, 7%, 7.5%, 8%, 9%, 10%, 11%, 11.5%, 12%, 13%, 14%, 15%, 15.5%, 16%, 17%, 18%, 18.5%, 19% or 20%, etc.

In some examples, the length of time that the target period is continuous may be greater than a preset time value, e.g., the overall amplitude variation of the pressure ratio value may be less than a preset percentage (e.g., 10%) for the length of time that the target pressure waveform corresponds to the target period. In some examples, the preset time value may be selected from a range of 0.1 to 0.5S, for example, the target period may be continuous for a length of time greater than 0.1S, 0.2S, 0.25S, 0.3S, 0.4S, 0.5S, or the like. Thereby enabling a more efficient target period to be obtained.

In some examples, host 20 may also filter a target pressure waveform obtained based on the first pressure signal and the second pressure signal. That is, the host 20 may filter the target pressure waveform before determining the target period. Thereby enabling a more accurate target period to be obtained.

In some examples, the plateau in the target pressure waveform may be affected by filtering, e.g., the strength of the filtering varies, and the overall change in the target pressure waveform will also vary. In this case, the preset value range or the preset percentage will be affected by the filtering, and the preset value range or the preset percentage can be appropriately adjusted by the medical staff according to the actual filtering condition. For example, if the target derivative waveform is filtered based on a 40 th order FIR filter, the preset value range may be-0.2/ms to 0.2/ms (see FIG. 7).

In some examples, host 20 may calculate an average of the corresponding pressure ratios over the target period of the cardiac cycle. In some examples, host 20 or a healthcare worker may compare the obtained average value to a preset threshold to determine a condition of the patient's blood vessel, thereby enabling a determination of a condition of the patient's blood vessel without the need to inject a maximum congestion-inducing drug.

In some examples, the preset threshold may be obtained by intravascular pressure acquisition and processing of non-diseased personnel. In some examples, the preset threshold may also be derived from past experience, set by the healthcare worker itself.

In some examples, the host 20 may obtain a target time period for each of the plurality of cardiac cycles based on the target derivative waveform or the target pressure waveform and calculate an average of the corresponding pressure ratios over the target time period for each cardiac cycle, thereby averaging the obtained plurality of averages to obtain a target average. Thereby enabling a target average value to be obtained. In some examples, the plurality of cardiac cycles may be consecutive, e.g., the host 20 may obtain a respective target period for consecutive 5 cardiac cycles based on the target derivative waveform or the target pressure waveform.

In some examples, host computer 20 or a healthcare worker may compare the obtained target average value to a preset threshold to determine a condition of the patient's blood vessel, thereby enabling a determination of a condition of the patient's blood vessel without the need to inject a maximum congestion-inducing drug.

In the example according to the present embodiment, the pressure measurement device 10 may be configured to measure the pressure in the blood vessel near the proximal end side at a certain sampling rate to generate a first pressure signal, and may also measure the pressure in the blood vessel far from the proximal end side to generate a second pressure signal, and the host 20 may be connected to the pressure measurement device and receive the first pressure signal and the second pressure signal. The host 20 may obtain a pressure ratio value based on the first pressure signal and the second pressure signal, and a ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal, and generate a target pressure waveform, the host 20 may obtain a derivative value of the pressure ratio value with respect to time based on the target pressure waveform, thereby obtaining a target derivative waveform, may determine a target period in any cardiac cycle based on the target derivative waveform, may obtain an average value of the corresponding pressure ratio values in the target period, and the target period may be a period in which the derivative value of the target derivative waveform in the cardiac cycle varies within a preset value range. In this case, the present embodiment can determine the pathological condition of the blood vessel of the patient without injecting the maximum congestion-inducing drug.

In this embodiment, as shown in fig. 9, a method for tracking a cardiac circulatory event using blood pressure may include the steps of: measuring the pressure in the blood vessel near the proximal side at a sampling rate to obtain a first pressure signal, and measuring the pressure in the blood vessel far from the proximal side to obtain a second pressure signal (step S10); distinguishing each cardiac cycle based on the first pressure signal and the second pressure signal (step S20); synchronizing the first pressure signal and the second pressure signal so that the moment when the peak value of the first pressure signal appears is the same as the moment when the peak value of the second pressure signal appears in the heart cycle, and rejecting invalid signals in the first pressure signal and the second pressure signal (step S30); calculating a ratio of a pressure value of the second pressure signal to a pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal according to the first pressure signal and the second pressure signal to obtain a target pressure waveform, and obtaining a derivative value of the pressure ratio with respect to time according to the target pressure waveform to obtain a target derivative waveform (step S40); determining a target period in any cardiac cycle according to the target derivative waveform, wherein the target period is a period in which the derivative value of the target derivative waveform in the cardiac cycle changes within a preset numerical range (step S50); an average value of the corresponding pressure ratios in the target period is obtained (step S60).

In the example related to the embodiment, the pressure in the blood vessel near the proximal side may be measured at a sampling rate to obtain a first pressure signal, and the pressure in the blood vessel far the proximal side may be measured to obtain a second pressure signal. The method comprises the steps of dividing each cardiac cycle according to a first pressure signal and a second pressure signal, synchronizing the first pressure signal and the second pressure signal, eliminating invalid signals in the first pressure signal and the second pressure signal, calculating a pressure ratio of a pressure value of the second pressure signal to a pressure value of the first pressure signal corresponding to a pressure value of the second pressure signal according to the first pressure signal and the second pressure signal to obtain a target pressure waveform, obtaining a derivative value of the pressure ratio relative to time according to the target pressure waveform to obtain a target derivative waveform, determining a target period in any cardiac cycle according to the target derivative waveform, wherein the target period can be a period in which the derivative value of the target derivative waveform in the cardiac cycle changes within a preset numerical range, and obtaining an average value of the corresponding pressure ratio in the target period. In this case, the present embodiment can determine the pathological condition of the blood vessel of the patient without injecting the maximum congestion-inducing drug.

In this embodiment, the processing and obtaining of the first pressure signal, the second pressure signal, the target pressure waveform, the target derivative waveform, and the target period in the method may refer to the first pressure signal, the second pressure signal, the target pressure waveform, the target derivative waveform, and the target period. In some examples, step S10 may be processed using an interventional catheter technique, such as pressure measurement device 10. In some examples, steps S20-S60 may be processed with host 20.

In step S10, as described above, the pressure in the blood vessel near the proximal side may be measured at a certain sampling rate to obtain a first pressure signal, and the pressure in the blood vessel far from the proximal side may be measured to obtain a second pressure signal.

In some examples, the first and second pressure signals may be generated using an interventional catheter technique, such as the pressure measurement device 10, to measure pressure within the blood vessel near the proximal side 20a and within the blood vessel far from the proximal side 20a, respectively, at a sampling rate. In some examples, the first pressure signal and the second pressure signal may be obtained by simultaneous measurement by the pressure measurement device 10.

In some examples, the side of the interior vessel proximal to proximal side 20a may be the side of the coronary artery proximal to the aortic port and the side of the interior vessel distal to proximal side 20a may be the side of the coronary artery distal to the aortic port. Thus, the pressure in the blood vessels on both sides of the coronary artery can be obtained, and the lesion condition of the coronary artery can be judged.

In some examples, if the pressure measurement device 10 includes a first pressure measurement device and a second pressure measurement device, the second pressure sensor may be calibrated and verified.

In some examples, the sampling rate ranges from about 30Hz to 1.5KHz. For example, the first pressure sensor may measure intravascular pressure with the second pressure sensor at a sampling rate of 30Hz, 50Hz, 100Hz, 200Hz, 250Hz, 300Hz, 400Hz, 500Hz, 600Hz, 700Hz, 1000Hz, 1100Hz, 1200Hz, 1300Hz, 1400Hz, 1500 Hz. Thereby enabling more accurate measurement of the pressure within the blood vessel.

In step S20, the respective cardiac cycle may be distinguished from the first pressure signal and the second pressure signal, as described above.

In some examples, the first pressure signal and the second pressure signal may be received by the host 20, and the host 20 may distinguish between individual cardiac cycles based on the first pressure signal and the second pressure signal (see related description above for specific procedures).

In step S30, as described above, the first pressure signal and the second pressure signal may be synchronized such that the timing at which the peak occurs in the first pressure signal is the same as the timing at which the peak occurs in the second pressure signal in the cardiac cycle, and invalid signals in the first pressure signal and the second pressure signal are eliminated.

In some examples, the first pressure signal and the second pressure signal may be processed to some degree. In some examples, the first pressure signal and the second pressure signal may be filtered, thereby facilitating subsequent acquisition of a more accurate target pressure waveform.

In some examples, the first pressure signal and the second pressure signal may be synchronized such that a time at which the first pressure signal peaks is the same as a time at which the second pressure signal peaks during the cardiac cycle. Therefore, the first pressure signal and the second pressure signal can be synchronized, and accurate pressure ratio can be obtained conveniently. In some examples, host 20 may determine whether the first pressure signal and the second pressure signal are synchronized by determining a degree of dissimilarity of the trend of the first pressure waveform and the second pressure waveform using covariance. In some examples, the host 20 may synchronize the first pressure waveform and the second pressure waveform by utilizing covariance and a cross-correlation function.

In some examples, invalid ones of the first pressure signal and the second pressure signal may be rejected. Thereby, a more efficient pressure signal can be obtained. In some examples, the invalid signal may include a portion of the pressure values corresponding to the first pressure signal and the second pressure signal that exceeds a preset numerical range, a portion of the pressure values corresponding to the first pressure signal and the second pressure signal that exceeds a preset peak range, and a portion of the pressure values corresponding to the first pressure signal and the second pressure signal that exceeds a preset frequency range. Thus, invalid signals in the first pressure signal and the second pressure signal can be eliminated.

In step S40, as described above, a pressure ratio may be calculated from the first pressure signal and the second pressure signal to a pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal to obtain a target pressure waveform, and a derivative value of the pressure ratio with respect to time may be obtained from the target pressure waveform to obtain a target derivative waveform.

In some examples, host 20 may calculate a pressure ratio from the first pressure signal and the second pressure signal, where the pressure ratio is obtained from a ratio of a pressure value of the second pressure signal to a pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal. In some examples, host 20 may obtain a target pressure waveform from the obtained pressure ratio. In some examples, the host 20 may obtain the target derivative waveform from the target pressure waveform. Specifically, the host 20 may obtain a derivative value of the pressure ratio with respect to time from the target pressure waveform, thereby obtaining a target derivative waveform in which the derivative value varies with time.

In step S50, as described above, a target period in any cardiac cycle may be determined from the target derivative waveform, and the target period may be a period in which the derivative value of the target derivative waveform in the cardiac cycle varies within a preset numerical range.

In some examples, the host 20 may determine a target period for any cardiac cycle from the target derivative waveform, wherein the target period may be a period in which the derivative value of the target derivative waveform in the cardiac cycle varies within a preset range of values (e.g., -0.2/ms to 0.2 ms) (see interval c in fig. 7). That is, the host 20 may determine, from any one cardiac cycle, a period in which the derivative value of the target derivative waveform in that cardiac cycle changes within a preset numerical range as the target period.

In some examples, the target derivative waveform may be filtered. Thereby enabling a more accurate target period to be obtained later.

However, examples of the present disclosure are not limited thereto, and in other examples, the host 20 may determine a target period for any one of the cardiac cycles based on the target pressure waveform, wherein the target period may be a period in which the target pressure waveform varies by less than a preset percentage (e.g., 10%) in the cardiac cycle (see interval m or interval n in fig. 8). That is, the host 20 may determine, from any one cardiac cycle, a period in which the target pressure waveform corresponding to that cardiac cycle continuously changes by less than a preset percentage (e.g., 10%) as the target period.

In some examples, the target period may be continuous. In some examples, the length of time the target period is continuous may be greater than a preset time value, e.g., the length of time the target period is continuous may be greater than 0.2s. In some examples, the selection range of the preset time value may be 0.1-0.5S. Thereby enabling a more efficient target period to be obtained.

In some examples, the cardiac cycle may include a systolic phase of systole and a diastolic phase of diastole, and the target period may be located in the diastolic phase of the corresponding cardiac cycle. Thereby a target period lying in diastole can be obtained.

In step S60, as described above, an average value of the corresponding pressure ratios in the target period may be obtained.

In some examples, host 20 may calculate an average of the corresponding pressure ratios over the target period of the cardiac cycle. In some examples, a target time period for a plurality of cardiac cycles may be obtained, an average of corresponding pressure ratios for each of the plurality of target time periods may be obtained, and the plurality of averages may be averaged to obtain a target average. In some examples, host computer 20 or a healthcare worker may compare the obtained average or target average to a preset threshold to determine the condition of the patient's blood vessel, thereby enabling the determination of the condition of the patient's blood vessel without the need to inject a maximum congestion-inducing drug.

While the disclosure has been described in detail in connection with the drawings and embodiments, it should be understood that the foregoing description is not intended to limit the disclosure in any way. Modifications and variations of the present disclosure may be made as desired by those skilled in the art without departing from the true spirit and scope of the disclosure, and such modifications and variations fall within the scope of the disclosure.

Claims

1. A method for tracking cardiac circulatory events using blood pressure, comprising: receiving a first pressure signal and a second pressure signal, wherein the first pressure signal is a pressure signal in the blood vessel near the proximal end side, and the second pressure signal is a pressure signal in the blood vessel far from the proximal end side; and according to the first pressure signal and the second pressure signal, distinguishing each cardiac cycle, synchronizing the first pressure signal and the second pressure signal so that the time when the peak value of the first pressure signal appears in the cardiac cycle is the same as the time when the peak value of the second pressure signal appears in the cardiac cycle, calculating the ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal according to the first pressure signal and the second pressure signal to obtain a target pressure waveform, obtaining the derivative value of the pressure ratio relative to time according to the target pressure waveform to obtain a target derivative waveform, determining a target period in any cardiac cycle according to the target derivative waveform to obtain the average value of the corresponding target pressure waveform in the target period, wherein the target period is a period in which the derivative value of the target derivative waveform changes within a preset numerical range.

2. The method according to claim 1, characterized in that:

and preprocessing the first pressure signal and the second pressure signal to eliminate invalid signals in the first pressure signal and the second pressure signal, wherein the invalid signals comprise partial signals exceeding a preset numerical range in pressure values corresponding to the first pressure signal and the second pressure signal, partial signals exceeding a preset frequency range in occurrence frequencies of cardiac cycles in the first pressure signal and the second pressure signal and partial signals exceeding a preset peak range in peak values of pressure values of each cardiac cycle corresponding to the first pressure signal and the second pressure signal.

3. The method according to claim 2, characterized in that:

in the first pressure signal and the second pressure signal, if there is an invalid signal, a plurality of consecutive cardiac cycles are reselected from after the invalid signal.

4. The method according to claim 1, characterized in that:

a first pressure waveform comprising at least one complete cardiac cycle is obtained based on the first pressure signal, a second pressure waveform comprising at least one complete cardiac cycle is obtained based on the second pressure signal, each cardiac cycle is distinguished based on the first pressure waveform and/or the second pressure waveform, and the first pressure waveform and the second pressure waveform are synchronized such that a moment at which the first pressure waveform peaks during the cardiac cycle is the same as a moment at which the second pressure waveform peaks.

5. The method according to claim 4, wherein:

determining whether the first pressure signal and the second pressure signal are synchronized by determining a degree of dissimilarity of the trend of variation of the first pressure waveform and the second pressure waveform using covariance.

6. The method according to claim 1, characterized in that:

the continuous time length of the target period is greater than a preset time value, and the preset time value is 0.1S-0.5S.

7. The method according to claim 2, characterized in that:

and if any one of the first pressure signal and the second pressure signal has an invalid signal, rejecting the part corresponding to the invalid signal in other pressure signals, and forming a continuous waveform from the part which is not rejected.

8. The method according to claim 1, characterized in that:

the cardiac cycle includes a systolic phase of systole and a diastolic phase of diastole, the target period being located in the diastolic phase.

9. A system for tracking cardiac circulatory events using blood pressure, comprising: a pressure measurement device configured to receive a first pressure signal and a second pressure signal, the first pressure signal being an intravascular pressure signal near a proximal side and the second pressure signal being an intravascular pressure signal far from the proximal side; the host computer is configured to distinguish each cardiac cycle according to the first pressure signal and the second pressure signal, synchronize the first pressure signal and the second pressure signal so that the time when the peak value of the first pressure signal appears in the cardiac cycle is the same as the time when the peak value of the second pressure signal appears in the cardiac cycle, calculate the ratio of the pressure value of the second pressure signal to the pressure value of the first pressure signal corresponding to the pressure value of the second pressure signal according to the first pressure signal and the second pressure signal to obtain a target pressure waveform, and determine a target period in any cardiac cycle based on the target pressure waveform to obtain the corresponding pressure ratio in the target period, wherein the target period is a period in which the change of the target pressure waveform in the cardiac cycle is gentle.

10. The system according to claim 9, wherein:

the host computer calculates an average value of the corresponding pressure ratios in the target period of each cardiac cycle and/or averages the obtained plurality of average values to obtain a target average value.