CN111466900A

CN111466900A - System and method for tracking cardiac cycle events using blood pressure

Info

Publication number: CN111466900A
Application number: CN202010383439.2A
Authority: CN
Inventors: 林佳燕; 郑欲晓; 邵小虎; 李连波; 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: 2020-07-31
Anticipated expiration: 2040-05-08
Also published as: CN113558592A; CN113558592B; CN113576439A; CN113576439B; CN111466900B

Abstract

The present disclosure relates to a system for tracking cardiac cycle events using blood pressure, comprising: a pressure measurement device configured to measure pressure within the blood vessel proximal side and within the blood vessel distal side, respectively, and generate a first pressure signal and a second pressure signal; and the host is connected with the pressure measuring device and receives the first pressure signal and the second pressure signal, the host distinguishes each cardiac cycle based on the first pressure signal and the second pressure signal, calculates 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 to obtain a pressure ratio and generates a target pressure waveform, the host obtains a target derivative waveform based on the target pressure waveform, and determines a target period in any cardiac cycle based on the target derivative waveform to obtain an average value of the pressure ratio corresponding to the target period, wherein the target period is a period in the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range.

Description

System and method for tracking cardiac cycle events using blood pressure

Technical Field

The present disclosure relates specifically to systems and methods for tracking cardiac cycle 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 for evaluating stenosis of coronary arteries with the aid of frequently used coil of size, but coronary angiography cannot reflect the actual function of coronary vessels, so whether the stenosed coronary arteries are associated with myocardial ischemia and symptoms of patients cannot be basically determined. At present, the method for clinically judging stenosis of coronary artery mainly applies the technique of Fractional Flow Reserve (FFR) obtained by pressure guide wire examination.

However, the following drawbacks exist in obtaining FFR: the need to inject a maximal hyperemic inducing drug (e.g., adenosine triphosphate ATP) into the coronary arteries to place the coronary arteries in a maximal hyperemic state prior to FFR measurement can increase the clinical procedure time, cause discomfort to the patient, greatly increase the medical costs, and also cause allergic reactions in the patient.

Disclosure of Invention

The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a system and a method for tracking a cardiac cycle event using blood pressure without injecting a maximum hyperemia-inducing drug.

To this end, a first aspect of the present disclosure provides a system for tracking cardiac cycle events using blood pressure, comprising: a pressure measurement device configured to measure a pressure within the blood vessel proximal to the proximal side at a sampling rate to generate a first pressure signal and to measure a pressure within the blood vessel distal to the proximal side to generate a second pressure signal; and a host connected to the pressure measurement device and receiving the first pressure signal and receiving the second pressure signal, the host machine distinguishes each cardiac cycle based on the first pressure signal and the second pressure signal and calculates 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 to obtain a pressure ratio value and generate a target pressure waveform, the host computer 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 computer determining a target period in any cardiac cycle based on the target derivative waveform, thereby obtaining an average value of the corresponding pressure ratio values in the target period, wherein the target period is a period in the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range.

In the present disclosure, the pressure measurement device is configured to measure a pressure within the blood vessel near the proximal side at a sampling rate to generate a first pressure signal and to measure a pressure within the blood vessel away from the proximal side to generate a second pressure signal, and the host computer may be connected to the pressure measurement device and receive the first pressure signal and the second pressure signal. The host machine obtains a pressure ratio value based on the first pressure signal and the second pressure signal and 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, obtains a derivative value of the pressure ratio value relative to time based on the target pressure waveform, obtains a target derivative waveform, and determines a target period in any cardiac cycle based on the target derivative waveform, so as to obtain an average value of the corresponding pressure ratio value in the target period, 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 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 maximal hyperemia-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 obtains a first pressure waveform including at least one complete cardiac cycle based on the first pressure signal, the host obtains a second pressure waveform including at least one complete cardiac cycle based on the second pressure signal, and the host distinguishes between cardiac cycles 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 machine can distinguish individual cardiac cycles based on the first pressure waveform and/or the second pressure waveform.

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

In the system for tracking cardiac cycle events using blood pressure according to the first aspect of the present disclosure, optionally, the host 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 pressure ratio values corresponding to the target period of each cardiac cycle, so as to average the obtained plurality of average values to obtain a target average value. Thereby, a target average value can be obtained.

In a system for tracking cardiac cycle events using blood pressure as referred to in the first aspect of the disclosure, optionally the cardiac cycle comprises a systolic phase in which the heart contracts and a diastolic phase in which the target period is located. Thereby, a target period in diastole can be obtained.

In the system for tracking a cardiac cycle event using blood pressure according to the first aspect of the present disclosure, optionally, the host preprocesses the first pressure signal and the second pressure signal, eliminates invalid signals in the first pressure signal and the second pressure signal, and filters the first pressure signal and the second pressure signal. Therefore, more accurate target periods can be obtained conveniently.

In the system for tracking a cardiac cycle event using blood pressure according to the first aspect of the present disclosure, optionally, the invalid signals include a portion of the pressure values corresponding to the first pressure signal and the second pressure signal, which is beyond a preset value range, a portion of the first pressure signal and the second pressure signal, which is beyond a preset frequency range, in the cardiac cycle, and a portion of the peak values of the pressure values of each cardiac cycle, which is beyond a preset peak range, in the first pressure signal and the second pressure signal. This makes it possible to eliminate an invalid signal from the first pressure signal and the second pressure signal.

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

A second aspect of the present disclosure provides a method of tracking cardiac cycle events using blood pressure, characterized by: the method comprises the following steps: measuring the pressure in the blood vessel close to the near-end side at a certain sampling rate to obtain a first pressure signal, and simultaneously measuring the pressure in the blood vessel far away from the near-end side to obtain a second pressure signal; 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 so that the time when the first pressure signal has a peak value is the same as the time when the second pressure signal has a peak value in the cardiac cycle, eliminating 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 pressure ratio value so as to obtain a target pressure waveform, obtaining a derivative value of the pressure ratio value relative to time according to the target pressure waveform so as to obtain a target derivative waveform, and determining a target period in any cardiac cycle according to the target derivative waveform, and obtaining an average value of the corresponding pressure ratio values in the target period, where the target period is a period in which the derivative value of the target derivative waveform changes within a preset value range in the cardiac cycle, where the invalid signals include a part of the pressure values corresponding to the first pressure signal and the second pressure signal, which is out of the preset value range, a part of the first pressure signal and the second pressure signal, which is out of the preset frequency range, and a part of the first pressure signal and the second pressure signal, which is out of the preset peak range, of the peak values of the pressure values of each cardiac cycle corresponding to the first pressure signal and the second pressure signal.

In the present disclosure, a first pressure signal is obtained by measuring a pressure within the blood vessel near the proximal side at a sampling rate, and a second pressure signal is obtained by measuring a pressure within the blood vessel far from the proximal side. 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, eliminating invalid signals in the first pressure signal and the second pressure signal, calculating the 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 pressure ratio value so as to obtain a target pressure waveform, obtaining a derivative value of the pressure ratio value relative to time according to the target pressure waveform so as 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 the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range, and obtaining an average value of the pressure ratio value corresponding to 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 maximal hyperemia-inducing drug.

In the method for tracking a cardiac cycle event using blood pressure according to the second aspect of the present disclosure, optionally, the cardiac cycle includes a systolic phase and a diastolic phase, the target period is continuous and located in the diastolic phase, and a time length of the target period is greater than a preset time value, a target period corresponding to each of a plurality of cardiac cycles is obtained according to the target pressure waveform, and an average value of corresponding pressure ratios in the target period 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 using blood pressure to track cardiac circulatory events without the need for injecting maximal hyperemia-inducing drugs can be provided.

Drawings

Fig. 1 is a block diagram illustrating the architecture of a system that uses blood pressure to track cardiac cycle events in accordance with an example of the present disclosure.

Fig. 2 is a schematic diagram illustrating a system in accordance with an example of the present disclosure that uses blood pressure to track cardiac cycle events.

Fig. 3 is a schematic diagram of an interventional body showing a system for tracking cardiac cycle events using blood pressure in accordance with an example of the present disclosure.

Fig. 4 is a blood vessel image showing a preset portion to which an example of the present disclosure relates.

Fig. 5 is a cross-sectional view showing an application of a system according to an example of the present disclosure in a blood vessel.

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

Fig. 7 is a pressure waveform diagram illustrating a plurality of cardiac cycles in accordance with an example of the present disclosure.

Fig. 8 is a pressure waveform diagram showing a plurality of cardiac cycles in accordance with another example of the present disclosure.

Fig. 9 is a flow diagram illustrating a method of tracking cardiac cycle 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 components are denoted by the same reference numerals, and redundant description thereof is omitted. The drawings are schematic and the ratio of the dimensions of the components and the shapes of the components may be different from the actual ones.

In addition, the headings and the like referred to in the following description of the present disclosure are not intended to limit the content or scope of the present disclosure, but merely serve as a reminder for reading. Such a subtitle should neither be understood as a content for segmenting an article, nor should the content under the subtitle be limited to only the scope of the subtitle.

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

Fig. 1 is a block diagram illustrating the structure of a system 1 for tracking cardiac cycle events using blood pressure in accordance with an example of the present disclosure. Fig. 2 is a schematic diagram illustrating a system 1 in accordance with an example of the present disclosure relating to tracking cardiac cycle events using blood pressure. Fig. 3 is a schematic diagram illustrating an interventional body of a system 1 for tracking cardiac cycle 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 for tracking cardiac cycle events using blood pressure (referred to simply as "system 1") may include a pressure measurement device 10 and a host 20. Pressure measurement device 10 may be connected to a host 20. The pressure measurement device 10 may measure the intravascular pressure (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 close to the host 20 (described later) may be a proximal side 20a and a side far from the host 20 may be a distal side 20 b.

The system 1 for tracking cardiac cycle events using blood pressure according to the present disclosure can measure pressure intravascularly using interventional catheter technology to determine a lesion condition of a patient's blood vessel, such as stenotic lesion 421 (see fig. 5). The system 1 may be used to measure and process the pressure in the patient's blood vessel (e.g., to obtain a pressure ratio value as described later, and to obtain an average of the corresponding pressure ratio values over a target time period), thereby enabling a determination of the lesion status of the patient's blood vessel without the need for injection of a maximum hyperemia-inducing drug.

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

In some examples, as shown in fig. 2, pressure measurement device 10 may include a first pressure measurement device and a second pressure measurement device. In some examples, a first pressure measurement device may have a first pressure sensor that may measure pressure within a vessel and generate a pressure waveform (e.g., a first pressure signal described subsequently). In some examples, a second pressure measurement device may have a second pressure sensor, may measure the intravascular pressure and generate a pressure waveform (e.g., a second pressure signal described subsequently). 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 the pressure in the blood vessel and respectively generate pressure signals (e.g., a first pressure signal and a second pressure signal, etc., described later).

In some examples, a first pressure measurement device may measure pressure within a vessel and generate a pressure waveform. In some examples, as shown in fig. 2, the first pressure measuring 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 guiding catheter 120 may measure the pressure within the blood vessel (e.g., the pressure within the blood vessel near the proximal side 20a) via the pressure sensor 112 and generate a pressure signal. However, examples of the present disclosure are not limited thereto, and the first pressure measuring device may be other devices capable of measuring the pressure in the 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 in the form of an elongated tube, and the guide catheter 110 may have an internal lumen 111. In some examples, guide catheter 110 has a proximal side 110a proximal host 20 and a distal side 110b distal 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 the proximal side 110a of guide catheter 110 so as to be disposed on guide catheter 110. For example, pressure sensor 112 may be provided with a circular port that mates with the tubular structure of guide catheter 110 for connection to guide catheter 110. This allows for better matching of the guide catheter 110 and the pressure sensor 112, and better measurement of intravascular pressure. In some examples, pressure sensor 112 may sense the pressure resulting from the flow of liquid from distal side 110b into interior cavity 111 of guide catheter 110.

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

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

In some examples, the first preset position may be a side of the blood vessel near the proximal side 20a, whereby the guiding catheter 110 may acquire a cardiac-cycle-dependent pressure near the proximal side 20a at a sampling rate and generate a pressure waveform via the 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, the guide catheter 110 may be connected to the host computer 20 via a transmission wire, in which case a pressure signal measured by the pressure sensor 112 is transmitted to the host computer 20 via the transmission wire.

In some examples, the second pressure measurement device may measure pressure within the 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 to the proximal side 20a) via the pressure sensor 122 and generates a pressure signal. The examples of the present disclosure are not limited thereto, and the first pressure measurement device may also be other devices for measuring pressure in a blood vessel, for example, 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 in the form of an elongated tube. In some examples, the blood pressure measurement catheter 120 may have a proximal side 120a proximal to the host computer 20 and a distal side 120b distal to the host computer 20, and the blood pressure measurement catheter 120 may have an internal cavity 121.

In some examples, the blood pressure measuring 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 measuring 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 the internal cavity 121 of the blood pressure measurement catheter 120, the internal cavity 121 may have a window with the pressure sensor 122. In some examples, in operation of the system 1, the blood pressure measuring catheter 120 may be placed within a blood vessel of a human body and the pressure sensor 122 may be placed at a second predetermined location within the blood vessel. In this case, pressure sensor 122 may measure the pressure at a second predetermined location within the vessel.

In some examples, the second preset position may be a side of the blood vessel distal from the proximal side 20a, whereby the blood pressure measurement catheter 120 may acquire a cardiac-cycle-dependent pressure distal from the proximal side 20a at a sampling rate via the pressure sensor 122 and generate a pressure waveform.

In some examples, a second pressure measurement device may be connected with host 20. For example, as shown in FIG. 2, a blood pressure measuring catheter 120 may be connected 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 measured by pressure sensor 122 is transmitted to host 20 via signal path 123.

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

In some examples, as shown in fig. 2, if the first pressure measurement device is the guide catheter 110 and the second pressure measurement device is the blood pressure measurement catheter 120, the diameter of the inner lumen 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 measuring catheter 120 can be disposed within the internal cavity 111 during operation of the system 1 and facilitates movement of the blood pressure measuring catheter 120 relative to the guide catheter 110, and the guide catheter 110 can remain stationary.

In some examples, the guide catheter 110 and the blood pressure measurement catheter 120 may enter or exit the patient as separate devices, respectively. In this case, the medical staff can control the blood pressure measuring catheter 120 and the guide catheter 110 independently. For example, while system 1 is in operation, a healthcare worker may control blood pressure measurement catheter 120 to move relative to guide catheter 110 (e.g., to advance or retract deep into a blood vessel within a patient), and guide catheter 120 may remain stationary.

In some examples, the second pressure-measuring device may be deeper into the patient's body relative to the first pressure-measuring device (see fig. 5), and the second pressure sensor (e.g., pressure sensor 122) may measure intravascular pressure deeper into the body (e.g., the side of the blood vessel distal from proximal side 20a) relative to 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 therapy, an operator such as a medical staff firstly advances a guide wire from a certain part (for example, a femoral artery) on a patient (or a patient) to a certain position (for example, a first preset position) in a blood vessel along the blood vessel, then advances the guide catheter 110 to the first preset position in the blood vessel along the guide wire, so that the guide catheter 110 can measure the pressure at the first preset position, then withdraws the guide wire, and further advances a medical guide wire (not shown) to a second preset position in the blood vessel along the guide catheter 110 by contrast of, for example, a contrast medium. In this case, the blood pressure measuring catheter 120 is guided along the medical guide wire such that the catheter lumen 121 can slide over the medical guide wire and by operating (e.g. pushing and/or pulling) the proximal side 120a of the blood pressure measuring catheter 120 outside the patient (or an operating means (not shown) connected to the proximal side 120a of the blood pressure measuring catheter 120) to move the blood pressure measuring catheter 120, the pressure sensor 122 can also follow the blood pressure measuring catheter 120 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 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 a visualization ring that is opaque to X-rays, thereby enabling the pressure measurement device 10 to measure the pressure at predetermined locations (e.g., a first predetermined location and a second predetermined 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 at which the visualization ring is disposed may also vary. For example, if the first pressure measuring device is the guide catheter 110 and the pressure sensor 112 is an invasive blood pressure sensor, the visualization ring should be provided 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 visualization ring should be provided on the guide catheter 110 and on the side of the pressure sensor 112, or the pressure sensor 112 should be provided directly on the visualization ring. In some examples, if the second pressure measurement device is a blood pressure measurement catheter 120, a visualization ring should be disposed on the blood pressure measurement catheter 120 and 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 medical staff may operate the pressure measurement device 10 in cooperation with an X-ray machine (not shown) to thereby enable the pressure measurement device 10 to obtain the intravascular pressure at the preset positions (e.g., the first preset position and the second preset position).

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

Fig. 4 is a blood vessel image showing a preset portion to which an example of the present disclosure relates. Fig. 4(a) shows, among others, a blood vessel 410, a blood vessel 420, a blood vessel 430, a blood vessel 440, a blood vessel 450, and other small blood vessels. In the example of the present disclosure, the other small blood vessels may be treated in the same manner as the

blood vessels

410, 420, 430, 440, and 450, and fig. 4(b) shows the blood vessels of the predetermined portion not including the other small blood vessels for convenience of representation. Where points A, B, C, D, E, F are the corresponding locations in the corresponding blood vessels, respectively. For example, vessel 410 may be the aorta, vessel 420 may be the right coronary artery, vessel 430 may be the left main trunk, vessel 440 may be the anterior descending branch, and vessel 450 may be the circumflex branch. Fig. 5 is a cross-sectional view showing the 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 predetermined site may be obtained by contrast with a contrast agent.

In some examples, a medical practitioner may take intravascular pressure measurements of multiple blood vessels in a predetermined site, thereby enabling assessment of the overall lesion at the predetermined site. In some examples, a health care provider may take intravascular pressure measurements of a single blood vessel in a predetermined location, thereby enabling a determination of the presence of a lesion in that blood vessel.

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

In some examples, the pressure measurement device 10 measures the specific location of the target blood vessel, i.e., the first preset location and the second preset location, may be determined by the medical personnel at their own discretion.

In some examples, as shown in fig. 5, taking blood vessel 420 as an example, point E in blood vessel 420 may be taken as a first preset location (i.e., the side of the blood vessel closer to proximal side 20a), and point F in blood vessel 420 may be taken as a second preset location (i.e., the side of the blood vessel farther from 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 to 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 measure, such as blood vessel 440, where point B in blood vessel 440 may be the first preset location and point C in blood vessel 440 may be the second preset location; for example, the blood vessel 450, the point a in the blood vessel 450 may be a first preset position, and the point C in the blood vessel 450 may be a second preset position.

In some examples, the sampling rate of the pressure measurement device 10 ranges from about 30Hz to 1.5 KHz. 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. This enables the intravascular pressure to be measured more accurately.

In some examples, the pressure measurement device 10 may simultaneously measure pressures at different locations within the vessel and generate a plurality of 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 predetermined location and a second pressure measurement device that may measure a pressure generating pressure signal at a second predetermined location. Or the pressure measurement device 10 may comprise a third pressure measurement device. The third pressure measurement device may comprise a plurality of pressure sensors at different locations, whereby the pressure measurement device 10 is capable of simultaneously measuring pressures at different locations in the blood vessel to obtain a plurality of pressure signals.

In some examples, the first pressure signal and the second pressure signal may be measured simultaneously by the pressure measurement device 10. For example, a first pressure measurement device may measure pressure within the blood vessel near the proximal side 20a to generate a first pressure signal, and a second pressure measurement device may measure 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 diastolic phases during diastole and systolic phases during systole.

In some examples, the pressure measurement device 10 may be configured to measure pressure within the blood vessel proximal to the proximal side 20a to generate a first pressure signal and to measure pressure within the blood vessel distal to 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 proximate the proximal side 20a (i.e., a first predetermined location) to generate a first pressure signal and a second pressure measurement device that may measure pressure within the blood vessel distal the proximal side 20a (i.e., a second predetermined location) to generate a second pressure signal, the first and second pressure signals being receivable by the host computer 20.

In some examples, before the second pressure sensor measures the pressure at the second preset position to obtain the second pressure signal, the second pressure sensor may be caused to measure the pressure at the first preset position, that is, the pressure signal generated by measuring the pressure at the first preset position simultaneously with the first pressure sensor is corrected. In particular, the pressure sensor may be calibrated before the second pressure sensor measures the pressure at the second predetermined location (e.g., at point F of the blood vessel 420). The second pressure sensor may be placed at the first predetermined location (for example, at point E of the blood vessel 420), that is, the second pressure sensor may measure the intravascular pressure at the first predetermined location, in which case, the first pressure sensor and the second pressure sensor simultaneously measure the intravascular pressure at the first predetermined location to generate a pressure signal, and the second pressure sensor may be verified according to the obtained pressure signal. In some examples, the pressure signals obtained by the first and second pressure sensors may be transmitted to the host 20, and the host 20 may correct (adjust) the second or first pressure sensor based on the received pressure signals until there is no significant difference between the pressure signals obtained by the second and first pressure sensors. In some examples, the host 20 may display the received pressure signal in the form of a waveform (described later) on, for example, a display screen, and the medical staff may correct the second pressure sensor or the first pressure sensor according to the obtained waveform until the pressure signals obtained by the first pressure sensor and the second pressure sensor are not significantly different, that is, the two corresponding variation curves displayed on the host 20 coincide.

In some examples, after the pressure sensor is calibrated, the healthcare worker may move the second pressure sensor by operating a second pressure measuring device (e.g., pushing the proximal side 120a of the blood pressure measuring catheter 120 outside the patient) or other device to enable the second pressure sensor to measure the pressure at the second predetermined location, in which case the first pressure sensor may measure the pressure at the first predetermined location to generate the first pressure signal and the second pressure sensor may measure the pressure at the second predetermined 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 measure the pressure at the first predetermined location, and the second pressure sensor is verified. Specifically, after the second pressure sensor measures the second pressure signal, the medical staff may operate the second pressure measuring device (e.g., pull the proximal end 120a of the blood pressure measuring catheter 120 outside the patient) or other device to move the second pressure sensor, so that the second pressure sensor can measure the pressure at the first predetermined position, in which case, the first pressure sensor and the second pressure sensor simultaneously measure the intravascular pressure at the first predetermined position to generate the pressure signal, and the second pressure sensor can be verified according to the obtained pressure signal to determine the accuracy of the second pressure signal obtained by the second pressure sensor, for example, the second pressure sensor may drift during the moving process, resulting in an error in the second pressure signal obtained by the second pressure sensor.

In some examples, at the time of verification, the pressure signals obtained by the first and second pressure sensors may be transmitted to host 20, and host 20 may verify the second pressure sensor based on the received pressure signals. For example, during 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 are obviously different, it can be judged that the second pressure signal obtained by the second pressure sensor cannot be normally used, and the accuracy of the first blood pressure value cannot be determined. In some examples, when verifying, 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 a waveform (described later) on, for example, a display screen, and the medical staff may verify the second pressure sensor according to the obtained waveform, determine whether there is a significant difference between the pressure signals obtained by the first pressure sensor and the second pressure sensor, that is, determine whether the two corresponding variation curves displayed on the host 20 coincide. 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 subsequently.

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

Fig. 7 is a pressure waveform diagram illustrating multiple cardiac cycles in fig. 6 in accordance with an example of the present disclosure. In fig. 7, a curve C is a target pressure waveform, a curve D is a target derivative waveform, a pressure ratio shown by the curve C is a hundred times of an actually calculated pressure ratio, and the curve D is a curve formed by a derivative of the curve C with respect to time. The ordinate corresponding to the curve C is the ordinate on the left side in fig. 7, and the ordinate corresponding to the curve D is the ordinate on the right side 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, where the interval a and the interval b are one cardiac cycle, the interval c is a target period in the interval a, and the interval d is a target period in the interval b.

Fig. 8 is a pressure waveform diagram illustrating multiple cardiac cycles in fig. 6 according to another example of the present disclosure. In fig. 8, a curve a is a first pressure waveform, that is, a curve of pressure values corresponding to the first pressure signal over time, a curve B is a second pressure waveform, that is, a curve of pressure values corresponding to the second pressure signal over time, a curve C is a target pressure waveform, the target pressure waveform is a curve of pressure values over time (where the curve C shows a pressure ratio that is a hundred times of an actually calculated pressure ratio), the pressure ratio may be a ratio of the pressure values of the second pressure signal to the pressure values of the first pressure signal corresponding to the pressure values of the second pressure signal, an interval a and an interval B are one cardiac cycle, an interval m is a target period (described later) in an interval a, and an interval n is a target period in an 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, and then transmits the pressure signal 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 variation curve of 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 host 20 includes at least one complete cardiac cycle. In some examples, host 20 may distinguish individual cardiac cycles in the pressure waveform based on the obtained pressure waveform.

In some examples, the host 20 may receive a first pressure signal and a second pressure signal, the host 20 may obtain a first pressure waveform (e.g., curve a in fig. 6) based on the first pressure signal, and the host 20 may obtain a second pressure waveform (e.g., curve B in fig. 6) based on the second pressure signal. 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 distinguish between individual cardiac cycles 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 20 can distinguish 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 time at which peaks occur in the respective pressure waveforms received by the host 20 within the same corresponding cardiac cycle are the same. For example, when the second pressure sensor is calibrated and verified, the host 20 may synchronize the received pressure signals measured by the first pressure sensor and the second pressure sensor.

In some examples, host 20 may be configured to synchronize the first pressure waveform and the second pressure waveform such that the first pressure waveform peaks at the same time as the second pressure waveform peaks during the cardiac cycle. Therefore, the first pressure waveform and the second pressure waveform can be synchronized, and the accurate pressure ratio can be conveniently obtained subsequently. In some examples, the host 20 may determine whether the first pressure signal and the second pressure signal are synchronized by using the covariance to determine how different the trends of the first pressure waveform and the second pressure waveform are. In some examples, the host 20 may synchronize the first pressure waveform and the second pressure waveform by utilizing covariance and cross-correlation functions.

In some examples, host 20 may pre-process the received pressure signal and may reject invalid portions of the pressure signal. In some examples, host 20 may pre-process the pressure signal based on the received pressure signal and the reference indicator. In some examples, the reference indicator may include a preset value range corresponding to the pressure signal, or a preset frequency range corresponding to the cardiac cycle, or a preset peak range corresponding to each cardiac cycle of the pressure signal, and the like.

In some examples, the host 20 may pre-process the first and second pressure signals and may reject invalid ones of the first and second pressure signals. Thereby, a more effective pressure signal can be obtained. In some examples, host 20 may pre-process the first and second pressure signals based on a comparison of the first and second pressure signals and a reference indicator. In some examples, the invalid signals may include a portion of the pressure values corresponding to the first and second pressure signals that exceeds a preset value range, a portion of the first and second pressure signals in which the frequency of occurrence of the cardiac cycle exceeds a preset frequency range, and a signal of the first and second pressure signals that exceeds a preset peak range in the peak values of the pressure values of the respective cardiac cycles. This makes it possible to eliminate an invalid signal from the first pressure signal and the second pressure signal.

In some examples, the intervals of invalid signals rejected by the host 20 may be different according to different reference indexes. In some examples, the minimum unit of invalid signal that host 20 rejects may be one cardiac cycle.

In some examples, the reference indicator may include a preset range of values corresponding to the pressure signal. In some examples, if the value in the pressure signal is not present in the preset range of values, the portion of the corresponding cardiac cycle may be eliminated in its entirety. For example, the predetermined value range may be 30 to 200mmHg, i.e., the reference index may include the values of the first pressure signal and the second pressure signal within 30 to 200 mmHg. Therefore, the parts of the first pressure signal and the second pressure signal, the numerical values of which are not between 30 and 200mmHg, can be eliminated. In some examples, host 20 may reject the entirety of the cardiac cycle in which the portion of the first pressure signal and the second pressure signal that does not have a value between 30 mmHg and 200mmHg is located,

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

In some examples, the reference indicator may include a frequency range of a 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 of the pressure signal in a unit time is not within the frequency range, the signal in the unit time is rejected. For example, the reference index may include that the frequency of the corresponding cardiac cycles of the first pressure signal and the second pressure signal should be 40-120/min, so that the corresponding cardiac cycles per minute in the first pressure signal and the second pressure signal can be excluded from being 40-120, and the signals in the time period can be eliminated.

In some examples, the host 20 receives a plurality of corresponding pressure signals (e.g., a first pressure signal and a second pressure signal), and if there is any pressure signal that does not satisfy the reference indicator, the host 20 may reject an unsatisfied portion of the pressure signal (e.g., a cardiac cycle corresponding to the unsatisfied portion), and the host 20 may also reject corresponding portions of other pressure signals that correspond to the rejected portion of the pressure signal. For example, if there is a portion of the first pressure signal that does not satisfy the reference indicator, the host 20 may reject the portion that does not satisfy (e.g., the cardiac cycle corresponding to the portion that does not satisfy), or the host 20 may reject a portion of the second pressure signal that corresponds to the rejected portion of the first pressure signal.

In some examples, host 20 may reject portions of the pressure signal that do not meet the reference criteria, other portions of the pressure signal may be used normally, and host 20 may treat the cardiac cycles before and after the rejected portions as consecutive cardiac cycles when selecting a plurality of consecutive cardiac cycles. In some examples, host 20 may cull the non-satisfied portions of the pressure signal and form other portions into a continuous waveform. For example, if the 2 nd and 6 th cardiac cycles in the pressure signal do not satisfy the reference index, the host 20 may eliminate 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 original 1 st cardiac cycle and 3 rd cardiac cycle as continuous when selecting a plurality of continuous cardiac cycles.

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

In this embodiment, the pathological condition of a blood vessel (e.g., a coronary artery) can be assessed by the ratio of the minimum constant trans-myocardial resistance measured when the target region of the blood vessel is normal to the minimum constant trans-myocardial resistance measured when the target region of the blood vessel is stenotic. Specifically, according to the fluid mechanics formula, the blood flow Q, the pressure difference Δ p, and the blood flow resistance R within a blood vessel (e.g., the blood vessel may be a coronary artery) may satisfy:

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

wherein, P_aExpressed as the pressure, P, in the blood vessel near the proximal side 20a_dExpressed as the pressure, P, in the blood vessel at the side 20a remote from the proximal end_vIs shown asCardiac venous pressure, R_aExpressed as vascular resistance, R_bExpressed as microcirculation resistance. Under physiological conditions, the central venous pressure is equal or almost equal to 0, which can be obtained based on equation (2):

it follows that the lesion status of the blood vessel can be assessed by the ratio of the pressure in the blood vessel distal to the proximal side 20a and the pressure in the blood vessel proximal to the proximal 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 value based on the first and second pressure signals by obtaining 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 generate a target pressure waveform based on the obtained pressure ratio value (see curve C in fig. 7).

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

In this embodiment, P can be found from the target pressure waveform_d/P_aThe stationary phase of the signal, may also be d (P)_d/P_a) A period approaching 0 in/dt, whereby a period in which the blood flow resistance is the lowest and most constant (i.e., a target period described later) can be obtained. That is, the target period may be a period during which the target pressure waveform changes gently (i.e., a plateau) in the cardiac cycle, i.e., the amplitude of the target pressure waveform changes less during this period.

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

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

In some examples, host 20 may obtain, as the target period, a period in which the derivative value approaches 0 from the target derivative waveform. In some examples, the target period may be a period in which the derivative value in the target derivative waveform is within a preset value range (see intervals c and d in fig. 7). In some examples, the preset value range may be set by the medical staff himself. In the example according to the present embodiment, the time axis unit is adjusted to ms, and the predetermined numerical range may be-0.2/ms to 0.2/ms (see fig. 7), but the present disclosure is not limited thereto, and the predetermined numerical 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 to 0.15/ms, -0.16/ms to 0.16/ms or-0.18/ms to 0.18/ms, etc.

In some examples, the time duration over which the target time period continues may be greater than a preset time value, e.g., the derivative value of the target derivative waveform over the time duration corresponding to the target time period may be within a preset range of values (e.g., -0.2/ms to 0.2/ms). In some examples, the predetermined time value may be selected to be in a range of 0.1-0.5S, for example, the target period may be continuous for a time period longer than 0.1S, 0.2S, 0.25S, 0.3S, 0.4S, 0.5S, etc. Whereby a more efficient target period can be obtained.

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

In some examples, host 20 may also perform a filtering process on the target derivative waveform. That is, the host 20 may filter the target derivative waveform prior to determining the target time period. Whereby a more accurate target period can be obtained.

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

In some examples, the target period may be a period in which the target pressure waveform of the cardiac cycle varies less than a preset percentage (see interval m or interval n in fig. 8) over the target period as a whole, the preset percentage may be set by the medical staff at will, and the preset percentage may be one of the ranges of 0-20%, for example, the preset percentage 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%, 20%, or the like.

In some examples, the target time period may continue for a length of time greater than a preset time value, e.g., the overall amplitude variation of the pressure ratio value within the target pressure waveform over the target time period may be less than a preset percentage (e.g., 10%). In some examples, the predetermined time value may be selected to be in a range of 0.1-0.5S, for example, the target period may be continuous for a time period longer than 0.1S, 0.2S, 0.25S, 0.3S, 0.4S, 0.5S, etc. Whereby a more efficient target period can be obtained.

In some examples, host 20 may also filter a target pressure waveform obtained based on the first and second pressure signals. That is, the host 20 may filter the target pressure waveform prior to determining the target time period. Whereby a more accurate target period can be obtained.

In some examples, the plateau in the target pressure waveform may be affected by filtering, e.g., the strength of the filtering is different, and the overall change in the target pressure waveform will also be different. 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 properly 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 from-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 with a preset threshold value to determine the lesion of the blood vessel of the patient, thereby determining the lesion of the blood vessel of the patient without injecting the maximum hyperemia inducing drug.

In some examples, the preset threshold may be obtained by collecting and processing pressure within a blood vessel of a person who is not suffering from a disease. In some examples, the preset threshold may also be derived from past experience and set by the healthcare worker.

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

In some examples, host 20 or a health care provider may compare the obtained target average to a preset threshold to determine a lesion in a blood vessel of the patient, thereby enabling determination of a lesion in a blood vessel of the patient without the need to inject a maximal hyperemia-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 side at a certain sampling rate to generate a first pressure signal, or may measure the pressure in the blood vessel far from the proximal 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 obtain 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, 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, so as to obtain 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 the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range. In this case, the present embodiment can determine the lesion condition of the blood vessel of the patient without injecting the maximum hyperemia-inducing drug.

In this embodiment, as shown in fig. 9, the method for tracking cardiac cycle events using blood pressure may include the steps of: measuring the pressure in the blood vessel near the proximal side at a certain 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 individual cardiac cycles based on the first pressure signal and the second pressure signal (step S20); synchronizing the first pressure signal and the second pressure signal such that a peak of the first pressure signal occurs at the same time as a peak of the second pressure signal during the cardiac cycle, and rejecting invalid signals of 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 pressure ratio value so as to obtain a target pressure waveform, and obtaining a derivative value of the pressure ratio value with respect to time according to the target pressure waveform so as to obtain a target derivative waveform (step S40); determining a target period in any one cardiac cycle according to the target derivative waveform, wherein the target period is a period in the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range (step S50); the average value of the corresponding pressure ratio values in the target period is obtained (step S60).

In an example of an embodiment, a first pressure signal may be obtained by measuring a pressure within the blood vessel near the proximal side and a second pressure signal may be obtained by measuring a pressure within the blood vessel far from the proximal side at a sampling rate. The individual cardiac cycles may be differentiated based on the first pressure signal and the second pressure signal, the first pressure signal and the second pressure signal may be synchronized, and invalid ones of the first pressure signal and the second pressure signal may be eliminated, a pressure ratio may be obtained by 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 from the first pressure signal and the second pressure signal to obtain a target pressure waveform, 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, a target period in any cardiac cycle may be determined according to the target derivative waveform, and the target period may be a period in the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range, and may obtain an average value of corresponding pressure ratio values in the target period. In this case, the present embodiment can determine the lesion condition of the blood vessel of the patient without injecting the maximum hyperemia-inducing drug.

In this embodiment, the processing and acquisition of the first pressure signal, the second pressure signal, the target pressure waveform, the target derivative waveform, and the target time period in the method may be referred to above for the first pressure signal, the second pressure signal, the target pressure waveform, the target derivative waveform, and the target time period. In some examples, step S10 may be processed using interventional catheter technology, such as the pressure measurement device 10. In some examples, steps S20 through S60 may be processed by the host 20.

In step S10, a first pressure signal may be obtained by measuring the pressure within the blood vessel near the proximal side and a second pressure signal may be obtained by measuring the pressure within the blood vessel far from the proximal side at a sampling rate, as described above.

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 vessel proximal side 20a and within the vessel distal side 20a, respectively, at a sampling rate. In some examples, the first pressure signal and the second pressure signal may be measured simultaneously by the pressure measurement device 10.

In some examples, the side of the blood vessel proximal to the proximal side 20a may be the side of a coronary artery proximal to the aortic port, and the side of the blood vessel distal to the proximal side 20a may be the side of a coronary artery distal to the aortic port. Therefore, the pressure in the blood vessels at two sides of the coronary artery can be obtained, and the pathological change condition of the coronary artery can be further judged.

In some examples, if the pressure measurement device 10 includes a first pressure measurement device and a second pressure measurement device, calibration and verification of the second pressure sensor may be performed.

In some examples, the sampling rate ranges from about 30Hz to 1.5 KHz. 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. This enables the intravascular pressure to be measured more accurately.

In step S20, the individual cardiac cycles may be distinguished based on the first pressure signal and the second pressure signal, as described above.

In some examples, the host 20 may be utilized to receive the first pressure signal and the second pressure signal, and the host 20 may distinguish the individual cardiac cycles according to the first pressure signal and the second pressure signal (see the above description for a specific procedure).

In step S30, as described above, the first pressure signal and the second pressure signal may be synchronized such that the first pressure signal peaks at the same time as the second pressure signal peaks during the cardiac cycle, and invalid ones of the first pressure signal and the second pressure signal are rejected.

In some examples, certain processing may be performed on the first pressure signal and the second pressure signal. 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 the first pressure signal peaks at the same time as the second pressure signal peaks during the cardiac cycle. Therefore, the first pressure signal and the second pressure signal can be synchronized, and the accurate pressure ratio can be obtained conveniently. In some examples, the host 20 may determine whether the first pressure signal and the second pressure signal are synchronized by using the covariance to determine how different the trends of the first pressure waveform and the second pressure waveform are. In some examples, the host 20 may synchronize the first pressure waveform and the second pressure waveform by utilizing covariance and cross-correlation functions.

In some examples, invalid ones of the first and second pressure signals may be rejected. Thereby, a more effective pressure signal can be obtained. In some examples, the invalid signals may include a portion of the pressure values corresponding to the first and second pressure signals that exceeds a preset value range, a portion of the first and second pressure signals in which the frequency of occurrence of the cardiac cycle exceeds a preset frequency range, and a signal of the first and second pressure signals that exceeds a preset peak range in the peak values of the pressure values of the respective cardiac cycles. This makes it possible to eliminate an invalid signal from the first pressure signal and the second pressure signal.

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

In some examples, the host 20 may calculate 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 the pressure ratio. In some examples, host 20 may obtain a target pressure waveform from the obtained pressure ratio. In some examples, host 20 may obtain a target derivative waveform from a target pressure waveform. Specifically, host 20 may obtain a derivative value of the pressure ratio with respect to time based on the target pressure waveform to obtain 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 the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range.

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

In some examples, the target derivative waveform may be subjected to a filtering process. Thereby facilitating subsequent acquisition of a more accurate target period.

However, examples of the present disclosure are not limited thereto, and in other examples, host 20 may determine a target time period of any cardiac cycle based on the target pressure waveform, where the target time period may be a time 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, as the target period, a period in which the target pressure waveform corresponding to any cardiac cycle continuously changes by less than a preset percentage (e.g., 10%) from the target period.

In some examples, the target time period may be continuous. In some examples, the length of time that the target period continues may be greater than a preset time value, for example, the length of time that the target period continues may be greater than 0.2 s. In some examples, the predetermined time value may be selected to be in a range of 0.1S to 0.5S. Whereby a more efficient target period can 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 within the diastolic period can be obtained.

In step S60, as described above, the average of the corresponding pressure ratios over 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 ratio values 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 20 or a healthcare worker may compare the obtained or target average to a preset threshold to determine a lesion in a blood vessel of the patient, thereby enabling determination of a lesion in a blood vessel of the patient without the need to inject a maximum hyperemia-inducing drug.

While the present disclosure has been described in detail in connection with the drawings and examples, it should be understood that the above description is not intended to limit the disclosure in any way. Those skilled in the art can make modifications and variations to the present disclosure as needed without departing from the true spirit and scope of the disclosure, which fall within the scope of the disclosure.

Claims

1. A system for tracking cardiac cycle events using blood pressure,

the method comprises the following steps:

a pressure measurement device configured to measure a pressure within the blood vessel proximal to the proximal side at a sampling rate to generate a first pressure signal and to measure a pressure within the blood vessel distal to the proximal side to generate a second pressure signal; and

a host connected to the pressure measurement device and receiving the first pressure signal and receiving the second pressure signal, the host machine distinguishes each cardiac cycle based on the first pressure signal and the second pressure signal and calculates 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 to obtain a pressure ratio value and generate a target pressure waveform, the host computer 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 computer determining a target period in any cardiac cycle based on the target derivative waveform, thereby obtaining an average value of the corresponding pressure ratio values in the target period, wherein the target period is a period in the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range.

2. The system for tracking cardiac cycle events using blood pressure as recited in claim 1, wherein:

the host obtains a first pressure waveform comprising at least one complete cardiac cycle based on the first pressure signal, the host obtains a second pressure waveform comprising at least one complete cardiac cycle based on the second pressure signal, and the host distinguishes between cardiac cycles based on the first pressure waveform and/or the second pressure waveform.

3. The system for tracking cardiac cycle events using blood pressure as recited in claim 2, wherein:

the host 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.

4. The system for tracking cardiac cycle events using blood pressure as recited in claim 1, wherein:

the host computer obtains a target period corresponding to each of the plurality of cardiac cycles based on the target pressure waveform, and calculates an average value of pressure ratio values corresponding to the target period of each cardiac cycle, so as to average the obtained plurality of average values to obtain a target average value.

5. The system for tracking cardiac cycle events using blood pressure as recited in claim 1, wherein:

the cardiac cycle includes a systolic phase in which the heart contracts and a diastolic phase in which the heart relaxes, the target period being in the diastolic phase.

6. The system for tracking cardiac cycle events using blood pressure as recited in claim 1, wherein:

the host computer preprocesses the first pressure signal and the second pressure signal, eliminates invalid signals in the first pressure signal and the second pressure signal, and filters the first pressure signal and the second pressure signal.

7. The system for tracking cardiac cycle events using blood pressure as recited in claim 6, wherein:

the invalid signals comprise a partial signal which exceeds a preset numerical range in pressure values corresponding to the first pressure signal and the second pressure signal, a partial signal which exceeds a preset frequency range in the occurrence frequency of the cardiac cycle in the first pressure signal and the second pressure signal, and a partial signal which exceeds a preset peak value range in the peak value of the pressure value of each cardiac cycle corresponding to the first pressure signal and the second pressure signal.

8. The system for tracking cardiac cycle events using blood pressure as recited in claim 1, wherein:

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

9. A method of tracking cardiac cycle events using blood pressure, characterized by:

the method comprises the following steps:

measuring the pressure in the blood vessel close to the near-end side at a certain sampling rate to obtain a first pressure signal, and simultaneously measuring the pressure in the blood vessel far away from the near-end side to obtain a second pressure signal;

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 so that the time when the first pressure signal has a peak value is the same as the time when the second pressure signal has a peak value in the cardiac cycle, eliminating 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 pressure ratio value so as to obtain a target pressure waveform, obtaining a derivative value of the pressure ratio value relative to time according to the target pressure waveform so as to obtain a target derivative waveform, and determining a target period in any cardiac cycle according to the target derivative waveform, thereby obtaining an average value of corresponding pressure ratio values in the target period, wherein the target period is a period in the cardiac cycle in which the derivative value of the target derivative waveform changes within a preset value range,

the invalid signals comprise a partial signal which exceeds a preset value range in pressure values corresponding to the first pressure signal and the second pressure signal, a partial signal which exceeds a preset frequency range in the occurrence frequency of the cardiac cycle in the first pressure signal and the second pressure signal, and a partial signal which exceeds a preset peak value range in the peak value of the pressure value of each cardiac cycle corresponding to the first pressure signal and the second pressure signal.

10. The method of using blood pressure to track cardiac cycle events of claim 9, wherein:

the cardiac cycle comprises a systolic phase and a diastolic phase, the target periods are continuous and located in the diastolic phase, the time length of the target periods is larger than a preset time value, the target periods corresponding to the multiple cardiac cycles are obtained according to the target pressure waveforms, the average value of the pressure ratio corresponding to the target periods of the cardiac cycles is calculated, and therefore the average value of the obtained multiple average values is obtained to obtain the target average value.