阅读说明：本技术 一种跨心动周期的图像数据采集设备 (Image data acquisition equipment crossing cardiac cycle ) 是由 刘桂英 李宁 杨曦 李佳 赵蕾 马晓海 徐磊 于 2020-06-17 设计创作，主要内容包括：本发明公开了一种跨心动周期的图像数据采集设备,其中设备包括：比较装置,确定实际心率与心率阈值的比较结果,基于比较结果确定进行图像数据采集时的周期系数；周期确定装置,基于周期系数确定进行图像数据采集时的每个采集周期所包括的心动周期的数量,并基于实际心率确定进行图像数据采集时的每个心动周期的时间长度；延迟确定装置,根据实际心率、调整因子和反转时间确定脉冲准备时间,基于反转时间和脉冲准备时间确定触发延迟时间；时刻确定装置,根据采集周期的周期起始时刻和触发延迟时间确定在采集周期中进行图像数据采集的采集起始时刻；以及采集装置,基于采集起始时刻和持续时间以跨心动周期的方式在心率波形中进行图像数据采集。(The invention discloses an image data acquisition device across a cardiac cycle, wherein the device comprises: the comparison device is used for determining a comparison result of the actual heart rate and the heart rate threshold value and determining a cycle coefficient when image data are acquired based on the comparison result; a cycle determination device that determines the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed, based on the cycle coefficient, and determines the time length of each cardiac cycle when image data acquisition is performed, based on the actual heart rate; the delay determining device is used for determining the pulse preparation time according to the actual heart rate, the adjusting factor and the inversion time and determining the trigger delay time based on the inversion time and the pulse preparation time; the time determining device is used for determining the acquisition starting time for acquiring the image data in the acquisition cycle according to the cycle starting time and the trigger delay time of the acquisition cycle; and an acquisition device that performs image data acquisition in the heart rate waveform in a manner spanning the cardiac cycle based on an acquisition start time and duration.)

1. A method of image data acquisition across a cardiac cycle, the method comprising:

acquiring an actual heart rate determined by a heart rate detection instrument, determining a comparison result of the actual heart rate and a heart rate threshold value, and determining a cycle coefficient when image data is acquired based on the comparison result;

determining the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient, and determining the time length of each cardiac cycle when image data acquisition is performed based on the actual heart rate;

acquiring predetermined reversal time, determining pulse preparation time according to the actual heart rate, the adjustment factor and the reversal time, and determining trigger delay time based on the reversal time and the pulse preparation time;

determining the acquisition starting time for acquiring the image data in the acquisition period according to the period starting time of the acquisition period and the trigger delay time; and

the duration of time for which image data acquisition is performed is determined, and image data acquisition is performed in a heart rate waveform map across a cardiac cycle based on the acquisition start time and duration.

2. The method of claim 1, the heart rate detection instrument to detect a heart rate value of a target subject.

3. The method of claim 2, the heart rate detection instrument performing a plurality of detections on a target subject to obtain a plurality of heart rate values;

determining any one of a plurality of heart rate values as an actual heart rate of the target subject;

alternatively, the first and second electrodes may be,

an average of the plurality of heart rate values is determined as the actual heart rate of the target subject.

4. The method of claim 1, wherein determining a periodicity coefficient at which to perform image data acquisition based on the comparison comprises:

and when the comparison result shows that the actual heart rate is greater than the heart rate threshold value, setting the cycle coefficient when image data acquisition is carried out to be 2.

5. The method of claim 1 or 4, determining the number of cardiac cycles included per acquisition cycle at which image data acquisition is performed based on the cycle coefficient comprises:

the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed is set equal to the cycle coefficient.

6. An image data acquisition device spanning a cardiac cycle, the device comprising:

the comparison device is used for acquiring the actual heart rate determined by the heart rate detection instrument, determining the comparison result of the actual heart rate and the heart rate threshold value, and determining the cycle coefficient during image data acquisition based on the comparison result;

a cycle determination device that determines the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient, and determines the time length of each cardiac cycle when image data acquisition is performed based on the actual heart rate;

the delay determining device is used for acquiring the predetermined reversal time, determining the pulse preparation time according to the actual heart rate, the adjustment factor and the reversal time, and determining the trigger delay time based on the reversal time and the pulse preparation time;

the time determining device is used for determining the acquisition starting time for acquiring the image data in the acquisition cycle according to the cycle starting time of the acquisition cycle and the trigger delay time; and

an acquisition device determines a duration of time for performing image data acquisition and performs image data acquisition in a heart rate waveform across a cardiac cycle based on an acquisition start time and duration.

7. The apparatus of claim 6, the heart rate detection instrument to detect a heart rate value of a target subject.

8. The apparatus of claim 7, the heart rate detection instrument to perform a plurality of detections on a target subject to obtain a plurality of heart rate values;

determining any one of a plurality of heart rate values as an actual heart rate of the target subject;

alternatively, the first and second electrodes may be,

an average of the plurality of heart rate values is determined as the actual heart rate of the target subject.

9. The apparatus of claim 6, wherein the comparing means determining the periodicity coefficient at the time of image data acquisition based on the comparison result comprises:

and when the comparison result determined by the comparison device is that the actual heart rate is greater than the heart rate threshold value, the comparison device sets the cycle coefficient during image data acquisition to be 2.

10. The apparatus according to claim 6 or 9, wherein the cycle determining means determines the number of cardiac cycles included per acquisition cycle when image data acquisition is performed based on the cycle coefficient includes:

the cycle determining means sets the number of cardiac cycles included in each acquisition cycle at the time of image data acquisition equal to the cycle coefficient.

Technical Field

The present invention relates to the field of image data acquisition technology, and more particularly to an image data acquisition device spanning a cardiac cycle.

Background

Neonatal cardiomyopathy includes primarily inflammatory cardiomyopathy and cardiomyopathy (e.g., hypertrophic cardiomyopathy). Clinical studies found that 53.1% of the neonates with non-structural heart disease were discharged from the hospital after active treatment, cardiac troponin I (cTnI) was higher than normal, and the cTnI level was progressively increased in 36.7% of the neonates, while no significant abnormalities were seen in both echocardiograms and electrocardiograms. In addition, previous studies found that myocardial thickening was detectable in 11.5% of newborns within 2 weeks after birth in the Hypertrophic CardioMyopathy (HCM) pedigree with mutations in the sarcomere gene. According to related studies, HCM in the neonatal period mostly dies within 1 year of age. Therefore, more accurately evaluating the myocardial lesion condition of the infant patient, and making a better treatment decision is one of the problems to be solved in clinic.

The role of Cardiac Magnetic Resonance imaging (CMR) techniques in assessing myocardial pathologies is undoubted. Currently, CMR technology has become more widely used in the assessment and diagnosis of various myocardial diseases. Quantitative evaluation and qualitative evaluation are carried out on myocardial lesions from a histological level through a plurality of sequence combinations, and changes such as myocardial edema, myocardial fibrosis and the like can be visually observed. CMR technology is the "gold standard" for the diagnosis of myocardial disease, particularly cardiomyopathy, and is currently a difficult alternative to any other non-invasive examination.

During a scan of a conventional CMR examination, the patient is required to hold his or her breath, limit thoracic motion, and require a relatively low heart rate (e.g., below 90 beats/minute) to achieve a relatively good signal-to-noise ratio, thereby reducing artifacts to obtain a sharp image. However, these requirements are difficult to accomplish for infants (e.g., infants under 3 years of age) or newborns. The infant or the newborn cannot hold breath, and especially the heart rate of the newborn can be as high as 120-160 times/min and almost 2 times of the required heart rate in the conventional detection, so the detection or scanning requirements of the conventional CMR technology are difficult to meet.

At present, in adults and children with a fast heart rate, when a cardiac magnetic resonance examination is performed, the heart rate is reduced to about 90 times/min mainly by a drug (e.g., metoprolol) or deep anesthesia, so that scanning can be performed. In general, the normal heart rate of a newborn is between 120 and 160 times/min, and if the heart rate is reduced to 90 times/min, the blood perfusion of organs in the whole body is affected, and the organs are damaged. Therefore, the neonate cannot scan by lowering the heart rate.

Disclosure of Invention

In order to solve the problems, the invention breaks through the inherent thinking mode that the data acquisition can only be carried out in a single cardiac cycle in the prior art. The prior art can not finish the magnetic resonance scanning of the heart of the newborn or the infant, and can not acquire effective images, but the magnetic resonance scanning of the heart of the newborn can be finished by using the image data acquisition method with multiple cardiac cycles or across cardiac cycles, and high-quality images can be obtained.

According to an aspect of the invention, there is provided a method of image data acquisition across a cardiac cycle, the method comprising:

acquiring an actual heart rate determined by a heart rate detection instrument, determining a comparison result of the actual heart rate and a heart rate threshold value, and determining a cycle coefficient when image data is acquired based on the comparison result;

determining the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient, and determining the time length of each cardiac cycle when image data acquisition is performed based on the actual heart rate;

acquiring predetermined reversal time, determining pulse preparation time according to the actual heart rate, the adjustment factor and the reversal time, and determining trigger delay time based on the reversal time and the pulse preparation time;

determining the acquisition starting time for acquiring the image data in the acquisition period according to the period starting time of the acquisition period and the trigger delay time; and

the duration of time for which image data acquisition is performed is determined, and image data acquisition is performed in a heart rate waveform map across a cardiac cycle based on the acquisition start time and duration.

The heart rate detection instrument is used for detecting a heart rate value of a target object.

The heart rate detection instrument detects a target object for a plurality of times to obtain a plurality of heart rate values;

determining any one of a plurality of heart rate values as an actual heart rate of the target subject; alternatively, the first and second electrodes may be,

an average of the plurality of heart rate values is determined as the actual heart rate of the target subject.

Wherein determining a periodicity coefficient at the time of image data acquisition based on the comparison result comprises:

and when the comparison result shows that the actual heart rate is greater than the heart rate threshold value, setting the cycle coefficient when image data acquisition is carried out to be 2.

Determining the number of cardiac cycles included per acquisition cycle when image data acquisition is performed based on the cycle coefficient includes:

the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed is set equal to the cycle coefficient.

Determining a length of time for each cardiac cycle at which image data acquisition is performed based on the actual heart rate comprises:

the ratio of the unit time to the actual heart rate is taken as the length of time for each cardiac cycle when the image data acquisition is performed.

The determining a pulse preparation time from the actual heart rate, the adjustment factor, and the reversal time includes:

the unit time T is determined and the pulse preparation time P is calculated according to the following formula:

wherein T is unit time, R is actual heart rate, alpha is an adjusting factor, and TI is reversal time.

The determining a trigger delay time based on the inversion time and the pulse preparation time comprises:

and taking the sum of the inversion time and the pulse preparation time as a trigger delay time.

The determining the acquisition starting time for acquiring the image data in the acquisition period according to the period starting time of the acquisition period and the trigger delay time comprises:

in the heart rate waveform, taking the period starting time of a first heart period of the acquisition period as a first time, and taking a second time which is in a second heart period and starts from the first time after the triggering delay time as the acquisition starting time for acquiring image data;

wherein the period start time of the acquisition period is the same as the period start time of the first cardiac cycle.

The acquiring image data in a heart rate waveform across a cardiac cycle based on an acquisition start time and duration comprises:

image data is acquired in a heart rate waveform across a cardiac cycle, starting at an acquisition start time that is located in a second cardiac cycle of the acquisition cycle, but not the first cardiac cycle, for a length of time of duration.

According to an aspect of the invention, there is provided an image data acquisition apparatus across a cardiac cycle, the apparatus comprising:

the comparison device is used for acquiring the actual heart rate determined by the heart rate detection instrument, determining the comparison result of the actual heart rate and the heart rate threshold value, and determining the cycle coefficient during image data acquisition based on the comparison result;

a cycle determination device that determines the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient, and determines the time length of each cardiac cycle when image data acquisition is performed based on the actual heart rate;

the delay determining device is used for acquiring the predetermined reversal time, determining the pulse preparation time according to the actual heart rate, the adjustment factor and the reversal time, and determining the trigger delay time based on the reversal time and the pulse preparation time;

the time determining device is used for determining the acquisition starting time for acquiring the image data in the acquisition cycle according to the cycle starting time of the acquisition cycle and the trigger delay time; and

an acquisition device determines a duration of time for performing image data acquisition and performs image data acquisition in a heart rate waveform across a cardiac cycle based on an acquisition start time and duration.

The heart rate detection instrument is used for detecting a heart rate value of a target object.

The heart rate detection instrument detects a target object for a plurality of times to obtain a plurality of heart rate values;

determining any one of a plurality of heart rate values as an actual heart rate of the target subject;

alternatively, the first and second electrodes may be,

an average of the plurality of heart rate values is determined as the actual heart rate of the target subject.

Wherein the comparing means determines the cycle coefficient at the time of image data acquisition based on the comparison result includes:

and when the comparison result determined by the comparison device is that the actual heart rate is greater than the heart rate threshold value, the comparison device sets the cycle coefficient during image data acquisition to be 2.

Wherein the cycle determining means determines the number of cardiac cycles included in each acquisition cycle at the time of image data acquisition based on the cycle coefficient includes:

the cycle determining means sets the number of cardiac cycles included in each acquisition cycle at the time of image data acquisition equal to the cycle coefficient.

The cycle determination means determining the time length of each cardiac cycle at which image data acquisition is performed based on the actual heart rate includes:

the cycle determining means takes a ratio of the unit time to the actual heart rate as a time length of each cardiac cycle when the image data acquisition is performed.

The delay determining means determining the pulse preparation time based on the actual heart rate, the adjustment factor and the inversion time comprises:

the delay determining means determines a unit time T and calculates a pulse preparation time P according to the following formula:

wherein T is unit time, R is actual heart rate, alpha is an adjusting factor, and TI is reversal time.

The delay determining means determining the trigger delay time based on the inversion time and the pulse preparation time includes:

the delay determining means takes the sum of the inversion time and the pulse preparation time as a trigger delay time.

The time determining device determines the acquisition starting time of image data acquisition in the acquisition cycle according to the cycle starting time of the acquisition cycle and the trigger delay time, and comprises the following steps:

in the heart rate waveform, the time determination device takes the period starting time of the first heart period of the acquisition period as the first time, and takes the second time which is in the second heart period and starts from the first time after the triggering delay time as the acquisition starting time for acquiring the image data;

wherein the period start time of the acquisition period is the same as the period start time of the first cardiac cycle.

The acquisition device acquiring image data in a heart rate waveform across a cardiac cycle based on an acquisition start time and duration comprises:

the acquisition device acquires image data for a length of time of duration in a heart rate waveform across a cardiac cycle, starting at an acquisition start time that is located in a second cardiac cycle of the acquisition cycle rather than the first cardiac cycle.

According to an aspect of the present invention, there is provided a method of image data acquisition in a cross-cycle manner, the method comprising:

acquiring dynamic frequency determined by a detection instrument, determining a comparison result of the dynamic frequency and a frequency threshold, and determining a period coefficient when image data is acquired based on the comparison result;

determining the number of waveform periods included in each acquisition period when image data is acquired based on the period coefficient, and determining the time length of each waveform period when image data is acquired based on the dynamic frequency;

acquiring predetermined reversal time, determining pulse preparation time according to the dynamic frequency, the adjustment factor and the reversal time, and determining trigger delay time based on the reversal time and the pulse preparation time;

determining the acquisition starting time for acquiring the image data in the acquisition period according to the period starting time of the acquisition period and the trigger delay time; and

a duration of time for image data acquisition is determined, and image data acquisition is performed in the target waveform in a cycle-spanning manner based on the acquisition start time and duration.

The detection instrument is used for detecting the frequency value of the target waveform.

The detection instrument detects a target waveform for multiple times to obtain multiple frequency values;

determining any one of the plurality of frequency values as a dynamic frequency of the target waveform; alternatively, the first and second electrodes may be,

an average of the plurality of frequency values is determined as the dynamic frequency of the target waveform.

Wherein determining a periodicity coefficient at the time of image data acquisition based on the comparison result comprises:

and when the comparison result shows that the dynamic frequency is greater than the frequency threshold, setting the cycle coefficient when image data acquisition is carried out to be 2.

Determining the number of waveform cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient includes:

the number of waveform cycles included in each acquisition cycle when image data acquisition is performed is set equal to the cycle coefficient.

Determining a time length of each waveform period when image data acquisition is performed based on the dynamic frequency includes:

the ratio of the unit time to the dynamic frequency is taken as the time length of each waveform period when image data acquisition is performed.

The determining a pulse preparation time based on the dynamic frequency, the adjustment factor, and the inversion time comprises:

the unit time T is determined and the pulse preparation time P is calculated according to the following formula:

wherein T is unit time, R is dynamic frequency, alpha is adjustment factor, and TI is reversal time.

The determining a trigger delay time based on the inversion time and the pulse preparation time comprises:

and taking the sum of the inversion time and the pulse preparation time as a trigger delay time.

The determining the acquisition starting time for acquiring the image data in the acquisition period according to the period starting time of the acquisition period and the trigger delay time comprises:

in the target waveform, taking the period starting time of the first waveform period of the acquisition period as a first time, and taking a second time which is in the second waveform period and starts from the first time after the triggering delay time as the acquisition starting time for acquiring the image data;

wherein the period start time of the acquisition period is the same as the period start time of the first waveform period.

The acquiring of image data in a target waveform in a manner of spanning a waveform period based on an acquisition start time and a duration includes:

acquiring image data within a time length of a duration from an acquisition start time located in a second waveform period of the acquisition period instead of the first waveform period in a manner spanning the waveform period in the target waveform.

According to an aspect of the present invention, there is provided an apparatus for image data acquisition in a cross-cycle manner, the apparatus comprising:

the comparison device is used for acquiring the dynamic frequency determined by the detection instrument, determining the comparison result of the dynamic frequency and the frequency threshold value, and determining the cycle coefficient when image data are acquired based on the comparison result;

a cycle determining device that determines the number of waveform cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient, and determines the time length of each waveform cycle when image data acquisition is performed based on the dynamic frequency;

the delay determining device is used for acquiring predetermined reversal time, determining pulse preparation time according to the dynamic frequency, the adjusting factor and the reversal time, and determining trigger delay time based on the reversal time and the pulse preparation time;

the time determining device is used for determining the acquisition starting time for acquiring the image data in the acquisition cycle according to the cycle starting time of the acquisition cycle and the trigger delay time; and

and an acquisition device which determines the duration of image data acquisition and acquires image data in the target waveform in a cycle-crossing manner based on the acquisition start time and the duration.

The detection instrument is used for detecting the frequency value of the target waveform.

The detection instrument detects a target waveform for multiple times to obtain multiple frequency values;

determining any one of the plurality of frequency values as a dynamic frequency of the target waveform;

alternatively, the first and second electrodes may be,

an average of the plurality of frequency values is determined as the dynamic frequency of the target waveform.

Wherein the comparing means determines the cycle coefficient at the time of image data acquisition based on the comparison result includes:

and when the comparison result of the comparison device is that the dynamic frequency is greater than the frequency threshold, setting the cycle coefficient when image data acquisition is carried out to be 2.

Wherein the cycle determining means determines the number of waveform cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient includes:

the cycle determining means sets the number of waveform cycles included in each acquisition cycle when image data acquisition is performed to be equal to the cycle coefficient.

Wherein the period determining means determines the time length of each waveform period at the time of image data acquisition based on the dynamic frequency includes:

the period determining means takes a ratio of the unit time to the dynamic frequency as a time length of each waveform period when the image data is acquired.

The delay determining means determining the pulse preparation time based on the dynamic frequency, the adjustment factor, and the inversion time comprises:

the unit time T is determined and the pulse preparation time P is calculated according to the following formula:

wherein T is unit time, R is dynamic frequency, alpha is adjustment factor, and TI is reversal time.

The delay determining means determining the trigger delay time based on the inversion time and the pulse preparation time includes:

the delay determining means takes the sum of the inversion time and the pulse preparation time as a trigger delay time.

The time determining device determines the acquisition starting time of image data acquisition in the acquisition cycle according to the cycle starting time of the acquisition cycle and the trigger delay time, and comprises the following steps:

in the target waveform, the time determination device takes the period starting time of the first waveform period of the acquisition period as the first time, and takes the second time which is in the second waveform period and starts from the first time after the triggering delay time as the acquisition starting time for acquiring the image data;

wherein the period start time of the acquisition period is the same as the period start time of the first waveform period.

The acquisition device acquires image data in a target waveform in a mode of crossing waveform cycles based on an acquisition starting time and a duration, and comprises the following steps:

the acquisition device acquires the image data within the time length of the duration from the acquisition starting time of a second waveform period, which is positioned in the acquisition period, but not the first waveform period, in a mode of crossing waveform periods in the target waveform.

The data acquisition technology of multi-cardiac cycle provided by the invention does not reduce the heart rate of the neonate or the infant, and the examination is carried out under the normal heartbeat state of the neonate or the infant, so that the risk of other organ injury caused by low heart rate is avoided. In addition, the data acquisition technology with multiple cardiac cycles provided by the invention can be used for scanning newborns or infants without deep anesthesia on the newborns or infants, so that the risk and adverse consequences of the deep anesthesia of the infants are greatly reduced.

Drawings

A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:

FIG. 1 is a schematic illustration of image data acquisition according to a single cardiac cycle;

FIG. 2 is a flow chart of a method of image data acquisition across a cardiac cycle in accordance with the present invention;

FIG. 3 is a schematic diagram of image data acquisition across a cardiac cycle in accordance with the present invention;

FIG. 4 is a schematic structural diagram of an image data acquisition device spanning a cardiac cycle in accordance with the present invention;

FIG. 5 is a flow chart of a method of image data acquisition in a cross-cycle manner in accordance with the present invention; and

fig. 6 is a schematic structural diagram of an apparatus for image data acquisition in a cross-cycle manner according to the present invention.

Detailed Description

The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.

Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

Fig. 1 is a schematic illustration of image data acquisition according to a single cardiac cycle. Typically, CMR detection or scanning employs a single cardiac cycle acquisition modality, i.e., triggering of a pulse by an upward R wave in the QRS (the entire process of depolarization of the ventricles) complex of each cardiac cycle by prospective cardiac gating, and acquiring images in subsequent graphs. Due to technical limitations, there is a length of time for pulse preparation after the R-wave trigger pulse to the time at which scanning starts. In addition, the CMR detection or scanning needs to keep the inversion time ti (inversion time) for the detection of the corresponding data or content. Within the time length of the inversion time TI, the CMR may, for example, perform other conventional detections or scans. Generally, the TI value is within the interval of 250-300ms, the acquired image data provides the best contrast effect between the diseased myocardium and the non-diseased myocardium. The time between the R-wave trigger pulse and the moment when the image acquisition is started is the trigger delay (trigger delay), i.e. the time length of the trigger delay is equal to the sum of the time length of the pulse preparation (e.g. greater than or equal to 15ms) and the inversion time TI. For adults or adolescents with heart rates between 60-90 beats/minute, a clear image can be acquired with good fit (as shown in fig. 1) due to the long enough R-R interval. In fig. 1, for example, the heart rate of the target subject is 90 times/min, and the R-R period is 666 ms. The duration of the image acquisition is generally optimal within the interval of 300-400 ms. Furthermore, the trigger delay (trigger delay) is 285ms, the pulse preparation is 15ms, the TI is 270ms and the acquisition time or duration is 100 ms.

Fig. 2 is a flow chart of a method 200 of image data acquisition across a cardiac cycle in accordance with the present invention. The method 200 adopts a multi-cardiac cycle data acquisition technology, can acquire image data in a natural or conventional or normal heartbeat state of a target object under the condition of not reducing an actual heart rate larger than a heart rate threshold value, and avoids the risk of other organ injury caused by artificial heart rate reduction.

The method 200 begins at step 201. In step 201, an actual heart rate determined by a heart rate detecting instrument is acquired, a comparison result of the actual heart rate and a heart rate threshold value is determined, and a periodicity coefficient when image data acquisition is performed is determined based on the comparison result.

Wherein the heart rate detection instrument is used for detecting the heart rate value of the target object in a mode of not intervening in a human body or not generating trauma. Wherein the heart rate value refers to the number of beats per minute in a resting state of a normal person. The heart rate detection instrument may be any instrument capable of detecting the heart rate or heart rate value of a target subject in a non-invasive or non-invasive manner. Heart rate or heart rate value is in units of times/minute.

The heart rate detection instrument detects a target object a plurality of times to obtain a plurality of heart rate values. For example, a heart rate detection instrument detects a target object multiple times at fixed intervals (e.g., 2 minutes, 3 minutes, or 5 minutes). Wherein the time of each detection is any reasonable value such as 2 minutes, 1 minute, 30 seconds or 20 seconds. In this way, the heart rate detection instrument can obtain a plurality of heart rate values through detection.

In this application, the heart rate detection instrument may determine any one of a plurality of heart rate values as the actual heart rate of the target subject. For example, the heart rate detection instrument may determine a maximum or minimum of the plurality of heart rate values as the actual heart rate of the target subject. Alternatively, the heart rate detection instrument may determine a heart rate value closest to the median value among the plurality of heart rate values as the actual heart rate of the target subject. Alternatively, the heart rate detection instrument may determine a randomly selected one of the plurality of heart rate values as the actual heart rate of the target subject.

Further, the heart rate detection instrument determines an average of the plurality of heart rate values as an actual heart rate of the target subject. Preferably, an integer value obtained by rounding the average up or rounding down may be determined as the actual heart rate of the target subject. Alternatively, for example, the heart rate detection instrument obtains a plurality of heart rate values H by detection₁、H₂、H₃、……、H_nThe actual heart rate H can then be determined in the following manner_act：

Wherein t is the interval time between each detection and t is a natural number greater than 2 when the target object is detected by the heart rate detection instrument for multiple times, and the unit is minutes;

H_maxfor a plurality of heart rate values H₁、H₂、H₃、……、H_nMaximum heart rate value of (1);

H_minfor a plurality of heart rate values H₁、H₂、H₃、……、H_nA minimum heart rate value of;

μ is the adjusted heart rate value

H_iFor a plurality of heart rate values H₁、H₂、H₃、……、H_nThe ith heart rate value of

n is a plurality of heart rate values H₁、H₂、H₃、……、H_nThe number of (2);

for a plurality of heart rate values H₁、H₂、H₃、……、H_nAverage value of (a).

The heart rate threshold may be pre-set and may be dynamically adjusted based on actual operation or actual detection. For example, the heart rate threshold is 105/min, 110/min, 115/min, 120/min, 125/min, 130/min, or 135/min.

Wherein determining the periodicity coefficient at the time of image data acquisition based on the comparison result comprises: and when the comparison result shows that the actual heart rate is larger than the heart rate threshold value, setting the cycle coefficient when image data acquisition is carried out to be 2. That is, when actual detection is performed, 2 cardiac cycles are made up into one acquisition cycle, so that better image data can be acquired with delayed triggering. It should be appreciated that the periodicity coefficient may be any reasonable value, such as 3, 4, 5, etc.

Further, when the actual heart rate is less than or equal to the heart rate threshold value as a result of the comparison, the cycle coefficient at the time of image data acquisition is set to 1. That is, in actual examination, 1 cardiac cycle is made one acquisition cycle as shown in fig. 1.

In step 202, the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed is determined based on the cycle coefficient, and the time length of each cardiac cycle when image data acquisition is performed is determined based on the actual heart rate. Determining the number of cardiac cycles included per acquisition cycle when acquiring image data based on the cycle coefficient includes: the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed is set equal to the cycle coefficient. For example, when the cycle coefficient is 2, the number of cardiac cycles included per acquisition cycle when image data acquisition is performed is set to 2. I.e. each acquisition cycle comprises two cardiac cycles.

Determining a length of time for each cardiac cycle at which image data acquisition is performed based on the actual heart rate includes: the ratio of the unit time to the actual heart rate is taken as the length of time for each cardiac cycle when the image data acquisition is performed. In the present application, the unit time may be set to 1 minute, and may be equal to 60000 milliseconds (ms), i.e., 6 × 10⁴ms. It should be appreciated that the unit time can be any reasonable value, such as 2 minutes, 30 seconds, or 20 seconds, etc. For example, when the actual heart rate of the target subject is 150 times/min, the time length of each cardiac cycle is 6 × 10⁴And ms/150 equals 400 ms. Then, since each acquisition cycle includes two cardiac cycles, each acquisition cycle is 400ms × 2 — 800 ms.

In step 203, a predetermined inversion time is obtained, a pulse preparation time is determined from the actual heart rate, the adjustment factor and the inversion time, and a trigger delay time is determined based on the inversion time and the pulse preparation time. Generally, the inversion time of an inversion recovery sequence of cardiac magnetic resonance imaging may be preset. Cardiac magnetic resonance imaging is a multi-modality imaging technique that can assess a variety of parameters including cardiovascular anatomy and function. Selecting the proper TI time during the scanning or imaging process can improve the signal-to-noise ratio of the image and reduce breathing artifacts. Indeed, during the TI time, the cardiac magnetic resonance imaging device needs to perform other scanning or imaging actions on the heart rate waveform. For this, the TI time may be preferably set to 250 to 300 ms. It should be appreciated that in the present application, the initial TI time may be dynamically modified to achieve better signal-to-noise ratio depending on the actual operating conditions, e.g., depending on whether the requirements for imaging or scanning in the case of the initial TI time are met.

Wherein determining the pulse preparation time from the actual heart rate, the adjustment factor, and the reversal time comprises: the pulse preparation time is calculated by T as unit time, R as actual heart rate, α as adjustment factor and TI as inversion time. And (3) determining a unit time T and calculating a pulse preparation time P according to the following formula:

wherein T is unit time, R is actual heart rate, alpha is an adjusting factor, and TI is reversal time. The unit time is, for example, 1 minute, 2 minutes, 30 seconds, 20 seconds, or the like. The unit of the actual heart rate is times/minute. Alpha is a regulating factor and the value of alpha is preferably 0.375 to 0.5. The inversion time TI is preferably 250ms to 300 ms.

Wherein determining the trigger delay time based on the inversion time and the pulse preparation time comprises: the sum of the inversion time and the pulse preparation time is taken as the trigger delay time. As above, the trigger delay time may be P + TI. Preferably, the trigger delay time may also be linearly proportional to the sum of the inversion time and the pulse preparation time. For example, the trigger delay time may be (P + TI) × β.

In step 204, an acquisition start time for image data acquisition in the acquisition cycle is determined based on the cycle start time and the trigger delay time of the acquisition cycle. Wherein determining the acquisition start time for acquiring the image data in the acquisition period according to the period start time and the trigger delay time of the acquisition period comprises: in the heart rate waveform, the period start time of the first heart cycle of the acquisition period is used as the first time, and the second time in the second heart cycle after the trigger delay time from the first time is used as the acquisition start time for acquiring the image data. Wherein the cycle start time of the acquisition cycle is the same as the cycle start time of the first cardiac cycle.

It should be appreciated that in the heart rate waveform, there are multiple QRS complexes. The application determines a cardiac cycle with an upward wave R wave trigger in the current QRS complex as the starting point and an upward wave R wave trigger in the next QRS complex as the ending point. As shown in fig. 3, between the two R-waves is one cardiac cycle, i.e., the waveform associated with one complete beat of the heart. As described above, according to the technical solution of the present application, in the heart rate waveform of the target to be measured, the time at which the R-wave peak point of the first cardiac cycle of the current acquisition cycle is located is taken as the first time, and the second time (between the time at which the R-wave peak point of the second cardiac cycle is located at the second time and the time at which the R-wave peak point of the third cardiac cycle is located at the second time) in the second cardiac cycle after the trigger delay time (P + TI) from the first time is taken as the acquisition start time for acquiring the image data. Wherein the period starting time of the acquisition period is the time of the R wave peak point of the first cardiac cycle.

In step 205, the duration of time for which image data acquisition is performed is determined, and image data acquisition is performed in a heart rate waveform map across the cardiac cycle based on the acquisition start time and duration. Wherein acquiring image data in a heart rate waveform map across a cardiac cycle based on an acquisition start time and duration comprises: image data for a time length of duration is acquired in a heart rate waveform in a manner spanning a cardiac cycle from an acquisition start time located in a second cardiac cycle of the acquisition cycle rather than the first cardiac cycle (the acquisition start time is located between a time at which an R-wave peak point of the second cardiac cycle is located and a time at which an R-wave peak point of the third cardiac cycle is located). Since according to the solution of the present application the acquisition cycle starts from the first cardiac cycle, but the acquisition of the image data is performed within the second cardiac cycle (or the cardiac cycle after the first cardiac cycle, in particular the third cardiac cycle), the present application provides a solution for the acquisition of the image data in a manner spanning the cardiac cycles.

Fig. 3 is a schematic diagram of image data acquisition across a cardiac cycle in accordance with the present invention. Conventional single cardiac cycle acquisition modalities of magnetic resonance imaging or scanning acquire images for too short a time or fail to acquire valid images, and thus the present application provides a multi-cardiac cycle or cross-cardiac cycle acquisition modality.

As shown in fig. 3, the multi-cardiac cycle or cross-cardiac cycle acquisition mode is to set an adjusted R-R interval according to the actual heart rate (e.g. 150 beats/min for the actual heart rate of the subject to be measured, the instrument sets the heart rate to be half of the actual heart rate, i.e. 75 beats/min, so that two R-R intervals constitute the acquisition cycle). For this reason, the R-wave trigger is determined by the set heart rate of the instrument, i.e. after adjusting the set heart rate, one scan is triggered every 2 cardiac cycles. By setting the pulse preparation time, image data in the second cardiac cycle is acquired after R-wave triggering, and thus a sharp image is obtained with sufficient data acquisition time.

Wherein the setting of the main parameters in the data acquisition of multiple cardiac cycles or across cardiac cycles comprises: setting 1/2 the instrument heart rate to the actual heart rate, and determining therefrom the pulse delay time sets the formula: (6X 10)⁴ms/actual heart rate) + (6 × 10⁴ms/actual heart rate x α) -TI values. Wherein the TI value is any value from 250 to 300 ms. Preferably, the TI value may take any reasonable value. α is a tuning factor and the value of α preferably ranges from 0.375 to 0.5. It should be appreciated that the range of values for α can be any reasonable range.

Fig. 3 illustrates an actual heart rate of 150 beats/minute. When the actual heart rate is 150 beats/minute, the instrument sets the heart rate to 75 beats and a single actual R-R interval (i.e., cardiac cycle) to 400 ms. Since the instrument set the heart rate to 75 times, the instrument calculated an R-R interval (i.e., 2 cardiac cycles) of 800 ms. The optimal collection time phase is 150-300ms after R1 and R2. Since the optimal acquisition phase time after R1 is too short or unavailable, (the time length of) the pulse preparation time is set to 285ms and TI time is set to 270 ms. After the trigger pulse by R1, image data in the optimal acquisition phase after R2 is acquired with an acquisition time or duration of 70-80 ms. The acquisition time or duration is shown by the downward-directed arrow in fig. 3.

Thus, based on the concept of multi-cardiac cycle or cross-cardiac cycle data acquisition, a multi-cardiac cycle or cross-cardiac cycle acquisition sequence for an infant or neonate is determined. This application can carry out automatic adjustment under the condition of TI time of monitoring rhythm of the heart and constantly changing, makes data acquisition time, acceleration technique, hold back the breath time many-sided reach ideal balance to thereby adjust to different rhythm of the heart and set for the phase change extension R-R interval, with the data of second or third heart cycle after gathering R ripples and triggering. Compared with the traditional single cardiac cycle acquisition technology and the rapid scanning technology, the method and the device compare the success rate and the image quality of image acquisition of each technology, and provide a new method for myocardial scanning of infants or newborns.

Fig. 4 is a schematic diagram of the structure of an image data acquisition device 400 across a cardiac cycle in accordance with the present invention. The apparatus 400 comprises: a comparison means 401, a period determination means 402, a delay determination means 403, a delay determination means 404 and an acquisition means 405. The device 400 employs a multi-cardiac cycle data acquisition technique, and can acquire image data in a natural or conventional or normal heartbeat state of the target object without reducing the actual heart rate greater than the heart rate threshold, thereby avoiding the risk of other organ damage caused by artificially reducing the heart rate.

The actual heart rate determined by the heart rate detecting instrument is acquired, the comparing device 401 determines the comparison result of the actual heart rate and the heart rate threshold value, and the cycle coefficient when image data acquisition is performed is determined based on the comparison result.

Wherein the heart rate detection instrument is used for detecting the heart rate value of the target object in a mode of not intervening in a human body or not generating trauma. Wherein the heart rate value refers to the number of beats per minute in a resting state of a normal person. The heart rate detection instrument may be any instrument capable of detecting the heart rate or heart rate value of a target subject in a non-invasive or non-invasive manner. Heart rate or heart rate value is in units of times/minute.

The heart rate detection instrument detects a target object a plurality of times to obtain a plurality of heart rate values. For example, a heart rate detection instrument detects a target object multiple times at fixed intervals (e.g., 2 minutes, 3 minutes, or 5 minutes). Wherein the time of each detection is any reasonable value such as 2 minutes, 1 minute, 30 seconds or 20 seconds. In this way, the heart rate detection instrument can obtain a plurality of heart rate values through detection.

In this application, the heart rate detection instrument may determine any one of a plurality of heart rate values as the actual heart rate of the target subject. For example, the heart rate detection instrument may determine a maximum or minimum of the plurality of heart rate values as the actual heart rate of the target subject. Alternatively, the heart rate detection instrument may determine a heart rate value closest to the median value among the plurality of heart rate values as the actual heart rate of the target subject. Alternatively, the heart rate detection instrument may determine a randomly selected one of the plurality of heart rate values as the actual heart rate of the target subject.

Further, the heart rate detection instrument determines an average of the plurality of heart rate values as an actual heart rate of the target subject. Preferably, an integer value obtained by rounding the average up or rounding down may be determined as the actual heart rate of the target subject. Alternatively, for example, the heart rate detection instrument obtains a plurality of heart rate values H by detection₁、H₂、H₃、……、H_nThe actual heart rate H can then be determined in the following manner_act：

Wherein t is the interval time between each detection and t is a natural number greater than 2 when the target object is detected by the heart rate detection instrument for multiple times, and the unit is minutes;

H_maxfor a plurality of heart rate values H₁、H₂、H₃、……、H_nMaximum heart rate value of (1);

H_minfor a plurality of heart rate values H₁、H₂、H₃、……、H_nA minimum heart rate value of;

μ is the adjusted heart rate value

H_iFor a plurality of heart rate values H₁、H₂、H₃、……、H_nThe ith heart rate value of

n is a plurality of heart rate values H₁、H₂、H₃、……、H_nThe number of (2);

for a plurality of heart rate values H₁、H₂、H₃、……、H_nAverage value of (a).

The heart rate threshold may be pre-set and may be dynamically adjusted based on actual operation or actual detection. For example, the heart rate threshold is 105/min, 110/min, 115/min, 120/min, 125/min, 130/min, or 135/min.

Wherein determining the periodicity coefficient at the time of image data acquisition based on the comparison result comprises: and when the comparison result shows that the actual heart rate is larger than the heart rate threshold value, setting the cycle coefficient when image data acquisition is carried out to be 2. That is, when actual detection is performed, 2 cardiac cycles are made up into one acquisition cycle, so that better image data can be acquired with delayed triggering. It should be appreciated that the periodicity coefficient may be any reasonable value, such as 3, 4, 5, etc.

Further, when the actual heart rate is less than or equal to the heart rate threshold value as a result of the comparison, the cycle coefficient at the time of image data acquisition is set to 1. That is, in actual examination, 1 cardiac cycle is made one acquisition cycle as shown in fig. 1.

The cycle determining means 402 determines the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient, and determines the time length of each cardiac cycle when image data acquisition is performed based on the actual heart rate. Determining the number of cardiac cycles included per acquisition cycle when acquiring image data based on the cycle coefficient includes: the number of cardiac cycles included in each acquisition cycle when image data acquisition is performed is set equal to the cycle coefficient. For example, when the cycle coefficient is 2, the number of cardiac cycles included per acquisition cycle when image data acquisition is performed is set to 2. I.e. each acquisition cycle comprises two cardiac cycles.

Based on realityHeart rate determination the length of time of each cardiac cycle at which image data acquisition is performed includes: the ratio of the unit time to the actual heart rate is taken as the length of time for each cardiac cycle when the image data acquisition is performed. In the present application, the unit time may be set to 1 minute, and may be equal to 60000 milliseconds (ms), i.e., 6 × 10⁴ms. It should be appreciated that the unit time can be any reasonable value, such as 2 minutes, 30 seconds, or 20 seconds, etc. For example, when the actual heart rate of the target subject is 150 times/min, the time length of each cardiac cycle is 6 × 10⁴And ms/150 equals 400 ms. Then, since each acquisition cycle includes two cardiac cycles, each acquisition cycle is 400ms × 2 — 800 ms.

The delay determination device 403 acquires a predetermined inversion time, determines a pulse preparation time according to the actual heart rate, the adjustment factor, and the inversion time, and determines a trigger delay time based on the inversion time and the pulse preparation time. Generally, the inversion time of an inversion recovery sequence of cardiac magnetic resonance imaging may be preset. Cardiac magnetic resonance imaging is a multi-modality imaging technique that can assess a variety of parameters including cardiovascular anatomy and function. Selecting the proper TI time during the scanning or imaging process can improve the signal-to-noise ratio of the image and reduce breathing artifacts. Indeed, during the TI time, the cardiac magnetic resonance imaging device needs to perform other scanning or imaging actions on the heart rate waveform. For this, the TI time may be preferably set to 250 to 300 ms. It should be appreciated that in the present application, the initial TI time may be dynamically modified to achieve better signal-to-noise ratio depending on the actual operating conditions, e.g., depending on whether the requirements for imaging or scanning in the case of the initial TI time are met.

Wherein determining the pulse preparation time from the actual heart rate, the adjustment factor, and the reversal time comprises: the pulse preparation time is calculated by T as unit time, R as actual heart rate, α as adjustment factor and TI as inversion time. And (3) determining a unit time T and calculating a pulse preparation time P according to the following formula:

wherein T is unit time, R is actual heart rate, alpha is an adjusting factor, and TI is reversal time. The unit time is, for example, 1 minute, 2 minutes, 30 seconds, 20 seconds, or the like. The unit of the actual heart rate is times/minute. Alpha is a regulating factor and the value of alpha is preferably 0.375 to 0.5. The inversion time TI is preferably 250ms to 300 ms.

Wherein determining the trigger delay time based on the inversion time and the pulse preparation time comprises: the sum of the inversion time and the pulse preparation time is taken as the trigger delay time. As above, the trigger delay time may be P + TI. Preferably, the trigger delay time may also be linearly proportional to the sum of the inversion time and the pulse preparation time. For example, the trigger delay time may be (P + TI) × β.

The time determination device 404 determines the acquisition start time of image data acquisition in the acquisition cycle according to the cycle start time and the trigger delay time of the acquisition cycle. Wherein determining the acquisition start time for acquiring the image data in the acquisition period according to the period start time and the trigger delay time of the acquisition period comprises: in the heart rate waveform, the period start time of the first heart cycle of the acquisition period is used as the first time, and the second time in the second heart cycle after the trigger delay time from the first time is used as the acquisition start time for acquiring the image data. Wherein the cycle start time of the acquisition cycle is the same as the cycle start time of the first cardiac cycle.

It should be appreciated that in the heart rate waveform, there are multiple QRS complexes. The application determines a cardiac cycle with an upward wave R wave trigger in the current QRS complex as the starting point and an upward wave R wave trigger in the next QRS complex as the ending point. As shown in fig. 3, between the two R-waves is one cardiac cycle, i.e., the waveform associated with one complete beat of the heart. As described above, according to the technical solution of the present application, in the heart rate waveform of the target to be measured, the time at which the R-wave peak point of the first cardiac cycle of the current acquisition cycle is located is taken as the first time, and the second time (between the time at which the R-wave peak point of the second cardiac cycle is located at the second time and the time at which the R-wave peak point of the third cardiac cycle is located at the second time) in the second cardiac cycle after the trigger delay time (P + TI) from the first time is taken as the acquisition start time for acquiring the image data. Wherein the period starting time of the acquisition period is the time of the R wave peak point of the first cardiac cycle.

An acquisition device 405 determines a duration of time for performing image data acquisition and performs image data acquisition in a heart rate waveform map across a cardiac cycle based on an acquisition start time and duration. Wherein acquiring image data in a heart rate waveform map across a cardiac cycle based on an acquisition start time and duration comprises: image data for a time length of duration is acquired in a heart rate waveform in a manner spanning a cardiac cycle from an acquisition start time located in a second cardiac cycle of the acquisition cycle rather than the first cardiac cycle (the acquisition start time is located between a time at which an R-wave peak point of the second cardiac cycle is located and a time at which an R-wave peak point of the third cardiac cycle is located). Since according to the solution of the present application the acquisition cycle starts from the first cardiac cycle, but the acquisition of the image data is performed within the second cardiac cycle (or the cardiac cycle after the first cardiac cycle, in particular the third cardiac cycle), the present application provides a solution for the acquisition of the image data in a manner spanning the cardiac cycles.

It should be appreciated that the aspects of the present invention are not limited to image data acquisition of heart rate waveforms, but may be used to image data acquisition of other waveforms. Other waveforms are, for example, vibration waveforms, detection waveforms, voltage waveforms, current waveforms, pulse waveforms, and the like, as appropriate.

FIG. 5 is a flow chart of a method of image data acquisition in a cross-cycle manner in accordance with the present invention. The method 500 employs a multi-cycle or cross-cycle data acquisition technique, which can acquire image data under conditions of higher frequency or shorter waveform period of the waveform to be detected or the target waveform. The method 500 begins at step 501. In step 501, the dynamic frequency determined by the detection instrument is obtained, a comparison result of the dynamic frequency and a frequency threshold is determined, and a periodicity coefficient when image data acquisition is performed is determined based on the comparison result.

The detection instrument is used for detecting the frequency value of the target waveform or the waveform to be detected. Wherein the frequency value is the number of repetitions per unit time of each waveform element of the waveform to be measured or the target waveform. The detection instrument may be any instrument capable of detecting the frequency or frequency value of the waveform to be measured or the target waveform. The frequency or frequency value is in units of times/minute, times/second, times/millisecond, etc.

The detection instrument detects the waveform to be detected or the target waveform for multiple times to obtain multiple frequency values. For example, the detection instrument performs multiple detections of the waveform to be detected or the target waveform at fixed intervals (e.g., 2 minutes, 3 minutes, or 5 minutes). Wherein the time of each detection is any reasonable value such as 2 minutes, 1 minute, 30 seconds or 20 seconds. In this way, the detection instrument can obtain a plurality of frequency values by detection.

In this application, the detection instrument may determine any one of the plurality of frequency values as the dynamic frequency of the waveform to be detected or the target waveform. For example, the detection instrument may determine the maximum or minimum of the plurality of frequency values as the dynamic frequency of the waveform to be measured or the target waveform. Alternatively, the detection instrument may determine a frequency value closest to the median value among the plurality of frequency values as the dynamic frequency of the waveform to be detected or the target waveform. Alternatively, the detection instrument may determine a randomly selected one of the plurality of frequency values as the dynamic frequency of the waveform to be measured or the target waveform.

In addition, the detection instrument determines the average value of the plurality of frequency values as the dynamic frequency of the waveform to be detected or the target waveform. Preferably, an integer value obtained by rounding up or rounding down the average value may be determined as the dynamic frequency of the waveform to be measured or the target waveform. Alternatively, for example, the detection instrument obtains a plurality of frequency values H by detection₁、H₂、H₃、……、H_nThe dynamic frequency H may then be determined in the following manner_act：

Wherein t is the interval time between each detection and t is a natural number greater than 2 when the detection instrument detects the waveform to be detected or the target waveform for multiple times, and the unit is minutes;

H_maxfor a plurality of frequency values H₁、H₂、H₃、……、H_nMaximum frequency value of (1);

H_minfor a plurality of frequency values H₁、H₂、H₃、……、H_nMinimum frequency value of;

mu is the adjusted frequency value

H_iFor a plurality of frequency values H₁、H₂、H₃、……、H_nThe ith frequency value of

n is a plurality of frequency values H₁、H₂、H₃、……、H_nThe number of (2);

for a plurality of frequency values H₁、H₂、H₃、……、H_nAverage value of (a).

The frequency threshold may be pre-set and may be dynamically adjusted based on actual operation or actual detection. For example, the frequency threshold is 105 times/min, 110 times/min, 115 times/min, 120 times/min, 125 times/min, 130 times/min, or 135 times/min.

Wherein determining the periodicity coefficient at the time of image data acquisition based on the comparison result comprises: and when the comparison result shows that the dynamic frequency is greater than the frequency threshold, setting the cycle coefficient when image data acquisition is carried out to be 2. That is, when actual detection is performed, 2 cardiac cycles are made up into one acquisition cycle, so that better image data can be acquired with delayed triggering. It should be appreciated that the periodicity coefficient may be any reasonable value, such as 3, 4, 5, etc.

Further, when the dynamic frequency is less than or equal to the frequency threshold as a result of the comparison, the cycle coefficient at the time of image data acquisition is set to 1. That is, in actual examination, 1 cardiac cycle is made one acquisition cycle as shown in fig. 1.

In step 502, the number of waveform cycles included in each acquisition cycle when image data acquisition is performed is determined based on the cycle coefficient, and the time length of each waveform cycle when image data acquisition is performed is determined based on the dynamic frequency. Determining the number of waveform cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient includes: the number of waveform periods included in each acquisition period when image data acquisition is performed is set equal to a period coefficient. For example, when the cycle coefficient is 2, the number of waveform cycles included in each acquisition cycle when image data acquisition is performed is set to 2. I.e. each acquisition period comprises two waveform periods.

Determining a time length of each waveform period when image data acquisition is performed based on the dynamic frequency includes: the ratio of the unit time to the dynamic frequency is taken as the time length of each waveform period when image data acquisition is performed. In the present application, the unit time may be set to 1 minute, and may be equal to 60000 milliseconds (ms), i.e., 6 × 10⁴ms. It should be appreciated that the unit time can be any reasonable value, such as 2 minutes, 30 seconds, or 20 seconds, etc. For example, when the dynamic frequency of the target waveform is 150 times/minute, the time length of each waveform period is 6 × 10⁴And ms/150 equals 400 ms. Then, since each acquisition period includes two waveform periods, each acquisition period is 400ms × 2 — 800 ms.

In step 503, a predetermined inversion time is obtained, a pulse preparation time is determined according to the dynamic frequency, the adjustment factor, and the inversion time, and a trigger delay time is determined based on the inversion time and the pulse preparation time. In general, the inversion time TI may be set in advance. In fact, during TI time, the imaging device needs to perform other scanning or imaging actions with respect to the frequency waveform. For this, the TI time may be preferably set to 250 to 300 ms. It should be appreciated that in the present application, the initial TI time may be dynamically modified to achieve better signal-to-noise ratio depending on the actual operating conditions, e.g., depending on whether the requirements for imaging or scanning in the case of the initial TI time are met.

Wherein determining the pulse preparation time based on the dynamic frequency, the adjustment factor, and the inversion time comprises: the pulse preparation time is calculated by T as unit time, R as dynamic frequency, α as adjustment factor and TI as inversion time. And (3) determining a unit time T and calculating a pulse preparation time P according to the following formula:

wherein T is unit time, R is dynamic frequency, alpha is adjustment factor, and TI is reversal time. The unit time is, for example, 1 minute, 2 minutes, 30 seconds, 20 seconds, or the like. The dynamic frequency is given in units of times/minute. Alpha is a regulating factor and the value of alpha is preferably 0.375 to 0.5. The inversion time TI is preferably 250ms to 300 ms.

Wherein determining the trigger delay time based on the inversion time and the pulse preparation time comprises: the sum of the inversion time and the pulse preparation time is taken as the trigger delay time. As above, the trigger delay time may be P + TI. Preferably, the trigger delay time may also be linearly proportional to the sum of the inversion time and the pulse preparation time. For example, the trigger delay time may be (P + TI) × β.

In step 504, an acquisition start time for image data acquisition in the acquisition cycle is determined based on the cycle start time and the trigger delay time of the acquisition cycle. Wherein determining the acquisition start time for acquiring the image data in the acquisition period according to the period start time and the trigger delay time of the acquisition period comprises: in the target waveform, the period starting time of a first waveform period of an acquisition period is used as a first time, and a second time which is in a second waveform period and starts from the first time after a trigger delay time is used as the acquisition starting time for acquiring image data. Wherein the period start time of the acquisition period is the same as the period start time of the first waveform period.

It should be appreciated that in a frequency waveform, there may be peaks and valleys. The method and the device determine a waveform period by taking a peak or a trough in the current waveform period as a starting point and taking the peak or the trough in the next waveform period as an end point. As shown in fig. 3, there is one waveform period between two peaks or troughs. As described above, according to the technical solution of the present application, in the waveform to be measured or the target waveform, the time at which the peak or the trough of the first waveform period of the current acquisition period is located is used as the first time, and the second time (between the time at which the peak or the trough of the second waveform period is located and the time at which the peak or the trough of the third waveform period is located) located in the second waveform period after the trigger delay time (P + TI) from the first time is used as the acquisition start time for acquiring the image data. Wherein the period start time of the acquisition period is the time at which the peak or trough of the first waveform period is located.

In step 505, a duration for performing image data acquisition is determined, and image data acquisition is performed in a frequency waveform map or target waveform in a manner spanning a waveform period based on an acquisition start time and duration. Wherein acquiring image data in a frequency oscillogram or a target waveform in a manner spanning a waveform period based on an acquisition start time and a duration comprises: in the frequency waveform diagram or the target waveform, image data within the time length of the duration is acquired from the acquisition start time (the acquisition start time is between the time of the peak or the trough of the second waveform period and the time of the peak or the trough of the third waveform period) of the second waveform period rather than the first waveform period in a mode of crossing the waveform period. Since according to the technical solution of the present application, the acquisition cycle starts from the first waveform cycle, but the acquisition of the image data is performed within the second waveform cycle (or a waveform cycle subsequent to the first waveform cycle, in a specific case, within the third waveform cycle), the present application provides a technical solution for performing the image data acquisition in a manner of spanning the waveform cycles.

Fig. 6 is a schematic structural diagram of an apparatus 600 for image data acquisition in a cross-cycle manner according to the present invention. The apparatus 600 comprises: a comparison means 601, a period determination means 602, a delay determination means 603, a delay determination means 604 and an acquisition means 605. The device 600 employs a multi-cycle or cross-cycle data acquisition technique, which enables image data acquisition to be performed at higher frequencies or shorter periods of the waveform to be measured or the target waveform.

The dynamic frequency determined by the detection instrument is acquired, the comparison device 601 determines the comparison result of the dynamic frequency and the frequency threshold, and the cycle coefficient when image data acquisition is performed is determined based on the comparison result.

The detection instrument is used for detecting the frequency value of the target waveform or the waveform to be detected. Wherein the frequency value is the number of repetitions per unit time of each waveform element of the waveform to be measured or the target waveform. The detection instrument may be any instrument capable of detecting the frequency or frequency value of the waveform to be measured or the target waveform. The frequency or frequency value is in units of times/minute, times/second, times/millisecond, etc.

The detection instrument detects the waveform to be detected or the target waveform for multiple times to obtain multiple frequency values. For example, the detection instrument performs multiple detections of the waveform to be detected or the target waveform at fixed intervals (e.g., 2 minutes, 3 minutes, or 5 minutes). Wherein the time of each detection is any reasonable value such as 2 minutes, 1 minute, 30 seconds or 20 seconds. In this way, the detection instrument can obtain a plurality of frequency values by detection.

In this application, the detection instrument may determine any one of the plurality of frequency values as the dynamic frequency of the waveform to be detected or the target waveform. For example, the detection instrument may determine the maximum or minimum of the plurality of frequency values as the dynamic frequency of the waveform to be measured or the target waveform. Alternatively, the detection instrument may determine a frequency value closest to the median value among the plurality of frequency values as the dynamic frequency of the waveform to be detected or the target waveform. Alternatively, the detection instrument may determine a randomly selected one of the plurality of frequency values as the dynamic frequency of the waveform to be measured or the target waveform.

In addition, the detection instrument determines the average value of the plurality of frequency values as the dynamic frequency of the waveform to be detected or the target waveform. Preferably, an integer value obtained by rounding up or rounding down the average value may be determined as the dynamic frequency of the waveform to be measured or the target waveform. Alternatively, for example, the detection instrument obtains a plurality of frequency values H by detection₁、H₂、H₃、……、H_nThe dynamic frequency H may then be determined in the following manner_act：

Wherein t is the interval time between each detection and t is a natural number greater than 2 when the detection instrument detects the waveform to be detected or the target waveform for multiple times, and the unit is minutes;

H_maxfor a plurality of frequency values H₁、H₂、H₃、……、H_nMaximum frequency value of (1);

H_minfor a plurality of frequency values H₁、H₂、H₃、……、H_nMinimum frequency value of;

mu is the adjusted frequency value

H_iFor a plurality of frequency values H₁、H₂、H₃、……、H_nThe ith frequency value of

n is a plurality of frequency values H₁、H₂、H₃、……、H_nThe number of (2);

for a plurality of frequency values H₁、H₂、H₃、……、H_nAverage value of (a).

The frequency threshold may be pre-set and may be dynamically adjusted based on actual operation or actual detection. For example, the frequency threshold is 105 times/min, 110 times/min, 115 times/min, 120 times/min, 125 times/min, 130 times/min, or 135 times/min.

Wherein determining the periodicity coefficient at the time of image data acquisition based on the comparison result comprises: and when the comparison result shows that the dynamic frequency is greater than the frequency threshold, setting the cycle coefficient when image data acquisition is carried out to be 2. That is, when actual detection is performed, 2 cardiac cycles are made up into one acquisition cycle, so that better image data can be acquired with delayed triggering. It should be appreciated that the periodicity coefficient may be any reasonable value, such as 3, 4, 5, etc.

Further, when the dynamic frequency is less than or equal to the frequency threshold as a result of the comparison, the cycle coefficient at the time of image data acquisition is set to 1. That is, in actual examination, 1 cardiac cycle is made one acquisition cycle as shown in fig. 1.

The period determination means 602 determines the number of waveform periods included in each acquisition period when image data acquisition is performed based on the period coefficient, and determines the time length of each waveform period when image data acquisition is performed based on the dynamic frequency. Determining the number of waveform cycles included in each acquisition cycle when image data acquisition is performed based on the cycle coefficient includes: the number of waveform periods included in each acquisition period when image data acquisition is performed is set equal to a period coefficient. For example, when the cycle coefficient is 2, the number of waveform cycles included in each acquisition cycle when image data acquisition is performed is set to 2. I.e. each acquisition period comprises two waveform periods.

Determining a time length of each waveform period when image data acquisition is performed based on the dynamic frequency includes: using the ratio of unit time to dynamic frequency as image data acquisitionThe time length of each waveform period of the set time. In the present application, the unit time may be set to 1 minute, and may be equal to 60000 milliseconds (ms), i.e., 6 × 10⁴ms. It should be appreciated that the unit time can be any reasonable value, such as 2 minutes, 30 seconds, or 20 seconds, etc. For example, when the dynamic frequency of the target waveform is 150 times/minute, the time length of each waveform period is 6 × 10⁴And ms/150 equals 400 ms. Then, since each acquisition period includes two waveform periods, each acquisition period is 400ms × 2 — 800 ms.

The delay determining means 603 acquires a predetermined inversion time, determines a pulse preparation time from the dynamic frequency, the adjustment factor, and the inversion time, and determines a trigger delay time based on the inversion time and the pulse preparation time. In general, the inversion time TI may be set in advance. In fact, during TI time, the imaging device needs to perform other scanning or imaging actions with respect to the frequency waveform. For this, the TI time may be preferably set to 250 to 300 ms. It should be appreciated that in the present application, the initial TI time may be dynamically modified to achieve better signal-to-noise ratio depending on the actual operating conditions, e.g., depending on whether the requirements for imaging or scanning in the case of the initial TI time are met.

Wherein determining the pulse preparation time based on the dynamic frequency, the adjustment factor, and the inversion time comprises: the pulse preparation time is calculated by T as unit time, R as dynamic frequency, α as adjustment factor and TI as inversion time. And (3) determining a unit time T and calculating a pulse preparation time P according to the following formula:

wherein T is unit time, R is dynamic frequency, alpha is adjustment factor, and TI is reversal time. The unit time is, for example, 1 minute, 2 minutes, 30 seconds, 20 seconds, or the like. The dynamic frequency is given in units of times/minute. Alpha is a regulating factor and the value of alpha is preferably 0.375 to 0.5. The inversion time TI is preferably 250ms to 300 ms.

Wherein determining the trigger delay time based on the inversion time and the pulse preparation time comprises: the sum of the inversion time and the pulse preparation time is taken as the trigger delay time. As above, the trigger delay time may be P + TI. Preferably, the trigger delay time may also be linearly proportional to the sum of the inversion time and the pulse preparation time. For example, the trigger delay time may be (P + TI) × β.

The delay determining device 604 determines the acquisition start time of image data acquisition in the acquisition cycle according to the cycle start time and the trigger delay time of the acquisition cycle. Wherein determining the acquisition start time for acquiring the image data in the acquisition period according to the period start time and the trigger delay time of the acquisition period comprises: in the target waveform, the period starting time of a first waveform period of an acquisition period is used as a first time, and a second time which is in a second waveform period and starts from the first time after a trigger delay time is used as the acquisition starting time for acquiring image data. Wherein the period start time of the acquisition period is the same as the period start time of the first waveform period.

It should be appreciated that in a frequency waveform, there may be peaks and valleys. The method and the device determine a waveform period by taking a peak or a trough in the current waveform period as a starting point and taking the peak or the trough in the next waveform period as an end point. As shown in fig. 3, there is one waveform period between two peaks or troughs. As described above, according to the technical solution of the present application, in the waveform to be measured or the target waveform, the time at which the peak or the trough of the first waveform period of the current acquisition period is located is used as the first time, and the second time (between the time at which the peak or the trough of the second waveform period is located and the time at which the peak or the trough of the third waveform period is located) located in the second waveform period after the trigger delay time (P + TI) from the first time is used as the acquisition start time for acquiring the image data. Wherein the period start time of the acquisition period is the time at which the peak or trough of the first waveform period is located.

And an acquisition device 605 which determines the duration of image data acquisition and acquires image data in the frequency waveform diagram or the target waveform in a manner of crossing waveform cycles based on the acquisition start time and the duration. Wherein acquiring image data in a frequency oscillogram or a target waveform in a manner spanning a waveform period based on an acquisition start time and a duration comprises: in the frequency waveform diagram or the target waveform, image data within the time length of the duration is acquired from the acquisition start time (the acquisition start time is between the time at which the peak or the trough of the second waveform period is located and the time at which the peak or the trough of the third waveform period is located) of the second waveform period rather than the first waveform period in a manner of spanning the waveform period. Since according to the technical solution of the present application, the acquisition cycle starts from the first waveform cycle, but the acquisition of the image data is performed within the second waveform cycle (or a waveform cycle subsequent to the first waveform cycle, in a specific case, within the third waveform cycle), the present application provides a technical solution for performing the image data acquisition in a manner of spanning the waveform cycles.

The invention has been described with reference to a few embodiments. However, other embodiments of the invention than the one disclosed above are equally possible within the scope of the invention, as would be apparent to a person skilled in the art from the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a// the [ device, component, etc ]" are to be interpreted openly as at least one instance of a device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.