CN110269618B

Movatterモバイル変換

Info

Publication number: CN110269618B
Application number: CN201910563235.4A
Authority: CN
Inventors: 高军峰; 张家琦; 党鑫; 田洪君; 邓春平; 荣凡稳; 陈军波; 张崇; 张绪
Original assignee: South Central University for Nationalities
Current assignee: South Central Minzu University
Priority date: 2019-06-26
Filing date: 2019-06-26
Publication date: 2020-09-25
Anticipated expiration: 2039-06-26
Also published as: CN110269618A

Abstract

The invention relates to wearable equipment and a magnetic resonance electrocardio-gating system based on the wearable equipment, wherein the wearable equipment comprises a PPG (photoplethysmography) signal acquisition unit, an R wave pulse construction unit of electrocardiosignals and a communication unit; the PPG signal acquisition unit acquires a PPG signal of a tester and sends the PPG signal to the R wave pulse construction unit of the electrocardiosignal; the R wave pulse construction unit of the electrocardiosignal delays the PPG signal according to the set delay time length and then generates the R wave pulse of the electrocardiosignal; the communication unit sends the R wave pulse of the electrocardiosignal to a corresponding upper computer of the magnetic resonance electrocardio gate control system. Collect the R ripples pulse of tester's PPG signal through the time delay after getting ECG (electrocardiograph), this wearable equipment simple structure, low price and easy operation, the tester need not to keep the state of sticking to the electrode in front of the chest in the testing process.

Description

Wearable device and magnetic resonance electrocardiogram gate control system based on wearable device

Technical Field

The invention relates to the field of magnetic resonance systems, in particular to wearable equipment and a magnetic resonance electrocardio-gating system based on the wearable equipment.

Background

In the scanning process of a scanner of a magnetic resonance system, in order to reconstruct a clear image, the scanner repeatedly transmits a series of radio frequency pulse sequences within a long scanning time, and then reconstructs an image in an overlapping manner, and an imaging object is required to be kept in a static state all the time in the scanning process. When imaging the heart, the radio frequency pulse sequences of each scan randomly appear at different times in the cardiac cycle, and the resulting signals also come from different times in the cardiac process, which finally results in severe motion artifacts in the heart images obtained by multiple non-synchronized signal superposition. A widely used effective method of excluding image motion artifacts is to synchronize both the transmission of the radio frequency pulse sequence and the acquisition of the signal to the motion of the heart. This is the basic working principle of the cardiac gating system of the magnetic resonance system.

The magnetic resonance electrocardiographic gating technology is generally divided into two modes of prospective (prospective) acquisition technology and retrospective (retrospective) acquisition technology, wherein R waves of electrocardiographic signals are used as trigger identification, and data acquisition is started after a certain time.

No matter what way is adopted, accurate acquisition of electrocardiosignals is the primary condition for realizing the electrocardio-gating, and in the current magnetic resonance system, the collection mode of the chest electrode for collecting the electrocardiosignals of the electrocardio-gating is relatively complicated, has certain limitation on the operation process, and needs to pay attention to the installation and arrangement positions of a plurality of lead wires. And the manufacturing cost is relatively high, and the total manufacturing cost of the magnetic resonance system is increased.

Disclosure of Invention

The invention provides wearable equipment and a magnetic resonance electrocardio-gating system based on the wearable equipment, aiming at the technical problems in the prior art.

The technical scheme for solving the technical problems is as follows: a wearable device, comprising: the device comprises a PPG signal acquisition unit, an R wave pulse construction unit of electrocardiosignals and a communication unit;

the PPG signal acquisition unit acquires a PPG signal of a tester and sends the PPG signal to the R wave pulse construction unit of the electrocardiosignal;

the R wave pulse construction unit of the electrocardiosignal delays the PPG signal according to the set delay time length and then generates R wave pulse of the electrocardiosignal;

and the communication unit sends the R wave pulse of the electrocardiosignal to a corresponding upper computer of the magnetic resonance electrocardio-gating system.

A magnetic resonance electrocardio gate control system based on wearable equipment comprises the wearable equipment and an upper computer; and the wearable device sends the generated R wave pulse of the electrocardiosignal to the upper computer.

The invention has the beneficial effects that: the wearable device is used for acquiring the PPG signal of a tester through the wearable device, obtaining the R wave pulse of the ECG signal after time delay and sending the R wave pulse to the corresponding magnetic resonance electrocardio gating system to meet the requirement of the magnetic resonance electrocardio gating system on acquisition of trigger time.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, the PPG signal acquisition unit comprises a sensor module, an amplification filter circuit and an ADC acquisition module, and acquires and converts the PPG signal of the tester.

The set time delay duration in the R wave pulse construction unit of the electrocardiosignals is adjustable.

The delay time length T_delayReal-time adjustment is carried out according to PPG signals and ECG signals which are synchronously acquired in real time before the magnetic resonance examination of the tester:

T_delay＝T1-PWTT；

wherein T1 is the period of the PPG signal of the tester acquired in real time, and PWTT is the trigger delay time of the peak of the PPG signal of the tester acquired in real time and the R wave of the ECG signal.

The wearable device also comprises an ECG signal acquisition unit and a delay time calculation storage unit;

the ECG signal acquisition unit and the PPG signal acquisition unit respectively synchronously acquire PPG signals and ECG signals of the testee before magnetic resonance examination;

the delay time calculation storage unit calculates the delay time of the tester and stores the delay time;

and the R wave pulse construction unit of the electrocardiosignals constructs the R wave pulse of the electrocardiosignals according to the time delay time length stored by the time delay time length calculation storage unit.

The wearable device is a wearable bracelet;

the ECG signal acquisition unit and the PPG signal acquisition unit are respectively and synchronously acquire PPG signals and ECG signals before the magnetic resonance examination is carried out by the tester, the wrist of one hand of the tester is worn on the wearable bracelet, and the finger of the other hand is pressed on the ECG signal acquisition unit on the wearable bracelet.

The wearable device is a wearable bracelet;

The communication unit includes a first photoelectric conversion module;

the first photoelectric conversion module converts the electric signal of the R wave pulse of the electrocardiosignal generated by the R wave pulse construction unit into an optical signal and sends the optical signal to the corresponding upper computer of the magnetic resonance electrocardio-gating system.

When the communication unit of the wearable device comprises a first photoelectric conversion module, the magnetic resonance electrocardio-gating system further comprises a second photoelectric conversion module connected with the first photoelectric conversion module through an optical fiber;

the first photoelectric conversion module converts an electrical signal of an R wave pulse of an electrocardiosignal into an optical signal and then sends the optical signal to the second photoelectric conversion module through an optical fiber, and the second photoelectric conversion module converts the optical signal of the R wave pulse of the electrocardiosignal into an electrical signal and sends the electrical signal to the upper computer.

The wearable device is provided with the ECG signal acquisition unit, the PPG signal and the ECG signal are synchronously acquired by the wearable device before the magnetic resonance examination is carried out on a tester, the accurate delay time is obtained through calculation and stored, and the delay time is provided for the R wave pulse construction unit of the electrocardiosignals in the magnetic resonance examination process of the tester, so that the problem of different delay times caused by individuality and different time is prevented, the precision of the R wave pulse of the constructed electrocardiosignals is ensured, and the quality of the reconstructed images in the magnetic resonance examination process is further ensured.

The wearable device and the electrocardio-gating system are respectively provided with a photoelectric conversion module, R wave pulses of the constructed electrocardiosignals are converted into optical signals, then the optical signals are transmitted to the outside of the magnetic resonance chamber through optical fibers, and the optical signals are restored to electric signals outside the magnetic resonance chamber, so that the signals are not interfered by the magnetic field of the magnetic resonance system.

Drawings

Fig. 1 is a block diagram of a wearable device according to the present invention;

FIG. 2 is a graph of ECG signal versus PPG signal;

FIG. 3 is a schematic diagram of a portion of a circuit of a delay time calculation memory unit according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a first photoelectric conversion module according to an embodiment of the present invention;

fig. 5 is a block diagram of a magnetic resonance electrocardiographic gating system based on a wearable device according to an embodiment of the present invention;

FIG. 6 is a flowchart of the construction of an ECG R-wave pulse signal according to an embodiment of the present invention;

fig. 7 is a schematic circuit diagram of a second photoelectric conversion module according to an embodiment of the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1. wearable equipment, 11, PPG signal acquisition unit, 12, electrocardiosignal's R wave pulse construction unit, 13, communication unit, 131, first photoelectric conversion module, 14, ECG signal acquisition unit, 15, time delay duration calculation memory cell, 2, host computer, 3, second photoelectric conversion module.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

The invention provides a wearable device, as shown in fig. 1, which is a structural block diagram of the wearable device provided by the invention, and as shown in fig. 1, thewearable device 1 includes a PPGsignal acquisition unit 11, an R-wavepulse construction unit 12 of an electrocardiograph signal, and acommunication unit 13.

The PPGsignal acquisition unit 11 acquires a PPG signal of the subject and sends the PPG signal to the R-wavepulse construction unit 12 of the cardiac signal.

The R-wavepulse constructing unit 12 of the electrocardiographic signal delays the PPG signal according to a set delay duration and then generates an R-wave pulse of the electrocardiographic signal.

Thecommunication unit 13 sends the R-wave pulse of the electrocardiographic signal to the upper computer of the corresponding magnetic resonance electrocardiographic gating system.

As shown in fig. 2, which is a graph of the relationship between the ECG signal and the PPG signal, it can be seen from fig. 2 that the period T1 of the PPG signal is equal to the period T2 of the ECG signal, the peak of the pulse signal and the trigger delay time of the R wave of the ECG signal are defined as PWTT, and then the peak pulse of the PPG signal is T-pulsed_delayIs delayed to obtain the next upcoming R-wave pulse of the ECG signal, where T is_delay＝T1-PWTT。

The wearable device provided by the embodiment of the invention is applied to a magnetic resonance electrocardio-gating system, and utilizes the natural characteristics that the periods of a PPG signal and an ECG signal are equal, and the wave crest of the R wave pulse of the ECG signal and the wave crest of the PPG signal are delayed, the wearable device acquires the PPG signal of a tester to obtain the R wave pulse of the ECG signal after time delay, and the R wave pulse is sent to the corresponding magnetic resonance electrocardio-gating system to meet the requirement of the magnetic resonance electrocardio-gating system on acquiring trigger time.

Example 1

Embodiment 1 provided by the present invention is an embodiment of a wearable device provided by the present invention, thewearable device 1 may be configured as a common bracelet shape, and is worn on a wrist part of a test person, or may be configured as another shape, and corresponds to another part that can acquire a PPG signal and is worn on the test person.

Thewearable device 1 includes a PPGsignal acquisition unit 11, an R-wavepulse construction unit 12 of electrocardiographic signals, and acommunication unit 13.

Specifically, considering that the peak of the PPG signal and the delay duration of the R-wave pulse of the ECG signal have individual differences, the set delay duration in the R-wavepulse constructing unit 12 of the ECG signal is adjustable.

Further, the delay time period T is set so as to improve the accuracy of the R-wave pulse of the electrocardiographic signal generated by the R-wavepulse constructing unit 12 of the electrocardiographic signal_delayCan be adjusted in real time according to PPG signals and ECG signals synchronously acquired in real time before the magnetic resonance examination of a tester is carried out, T_delayT1-PWTT, where T1 is the period of the PPG signal of the subject acquired in real time and PWTT is the trigger delay time of the peak of the PPG signal of the subject acquired in real time and the R-wave of the ECG signal.

Furthermore, thewearable device 1 is a wearable bracelet, the wearable bracelet further comprises an ECGsignal acquisition unit 14 and a time delaycalculation storage unit 15, during a specific test process, PPG signals and ECG signals before a tester enters a magnetic resonance chamber are synchronously acquired, the wearable bracelet is worn on the wrist of one hand of the tester, the ECGsignal acquisition unit 14 on the wearable bracelet needs to be pressed by the finger of the other hand, and the electrocardiosignals are acquired by adopting a current international universal wrist electrocardio acquisition mode; and the sensor module is used for synchronously acquiring the PPG signals.

The PPGsignal acquisition unit 11 and the ECGsignal acquisition unit 14 respectively include a sensor module, an amplification filter circuit and an ADC acquisition module, and acquire and convert the PPG signal and the ECG signal of the tester, respectively.

FIG. 3 shows an embodiment of the present inventionAs can be seen from fig. 3, the delay timecalculation storage unit 15 synchronously acquires PPG signals and ECG signals at the analog front end RT1025 by using ECG/PPG measurement for low power consumption electrocardiographic monitoring, and in the specific calculation process, an average value method can be adopted to acquire T1 in a plurality of cycles and then perform average calculation to obtain an average value of T1 and PWTT, and then calculate T1 and PWTT according to the average value of T1 and PWTT_delayAnd stored.

The delay timecalculation storage unit 15 is connected to the R-wavepulse construction unit 12 of the electrocardiographic signal, and provides a basis for the delay time of the R-wavepulse construction unit 12 of the electrocardiographic signal for performing delay, so that a tester only needs to collect PPG signals when entering a magnetic resonance room for magnetic resonance examination, and the tester only needs to wear the wearable bracelet device provided by the embodiment of the invention to lie down during examination, and can obtain the R-wave pulse signals of the ECG signal without collecting ECG signals.

Preferably, the wearable device provided by the embodiment of the present invention converts the electrical signal of the R-wave pulse of the electrocardiograph signal generated by the R-wavepulse constructing unit 12 of the electrocardiograph signal into an optical signal and then transmits the optical signal to the upper computer of the corresponding magnetic resonance electrocardiograph gating system, so as to prevent the magnetic field in the magnetic resonance system from interfering with the transmission of the electrical signal.

Specifically, thecommunication unit 13 includes a firstphotoelectric conversion module 131, as shown in fig. 4, which is a schematic circuit diagram of the first photoelectric conversion module provided in the embodiment of the present invention, and the firstphotoelectric conversion module 131 converts the electrical signal of the R-wave pulse of the electrocardiographic signal generated by the R-wavepulse constructing unit 12 into an optical signal and sends the optical signal to the upper computer of the corresponding magnetic resonance electrocardiographic gating system.

Example 2

Theembodiment 2 provided by the invention is an embodiment of a magnetic resonance electrocardiographic gating system based on wearable equipment, and the magnetic resonance electrocardiographic gating system comprises thewearable equipment 1 provided by the embodiment of the invention and anupper computer 2. Thewearable device 1 transmits the generated R-wave pulse of the electrocardiographic signal to theupper computer 2.

Preferably, as shown in fig. 5, a block diagram of a magnetic resonance electrocardiographic gating system based on a wearable device according to an embodiment of the present invention is shown, as shown in fig. 6, a flowchart of constructing an electrocardiographic R-wave pulse signal according to an embodiment of the present invention is shown, and as shown in fig. 5 and 6, when thecommunication unit 13 of thewearable device 1 includes the firstphotoelectric conversion module 131, the system further includes the secondphotoelectric conversion module 3 connected to the firstphotoelectric conversion module 131 through an optical fiber.

As shown in fig. 7, which is a schematic circuit diagram of the second photoelectric conversion module according to the embodiment of the present invention, the firstphotoelectric conversion module 131 converts an electrical signal of an R-wave pulse of an electrocardiographic signal into an optical signal and transmits the optical signal to the secondphotoelectric conversion module 3 through an optical fiber, and the secondphotoelectric conversion module 3 converts the optical signal of the R-wave pulse of the electrocardiographic signal into an electrical signal and transmits the electrical signal to theupper computer 2.

Theupper computer 2 communicates with a magnetic resonance scanning system, and completes scanning and image reconstruction processes according to the provided R wave pulse of the electrocardiosignal.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A wearable device, comprising: the device comprises a PPG signal acquisition unit, an R wave pulse construction unit of electrocardiosignals and a communication unit;

the communication unit sends the R wave pulse of the electrocardiosignal to a corresponding upper computer of the magnetic resonance electrocardio gate control system;

the above-mentionedTime delay duration T_delayReal-time adjustment is carried out according to PPG signals and ECG signals which are synchronously acquired in real time before the magnetic resonance examination of the tester:

T_delay＝T1-PWTT；

wherein, T1 is the PPG signal cycle of the tester acquired in real time, and PWTT is the trigger delay time of the PPG signal peak and the ECG signal R wave of the tester acquired in real time;

the wearable device is a wearable bracelet;

2. The wearable device according to claim 1, wherein the delay time set in the R-wave pulse constructing unit of the electrocardiographic signal is adjustable.

3. The wearable device according to claim 1, further comprising an ECG signal acquisition unit and a delay time duration calculation storage unit;

the ECG signal acquisition unit and the PPG signal acquisition unit respectively synchronously acquire a PPG signal and an ECG signal of the tester before magnetic resonance examination;

4. The wearable device of claim 3, wherein the delay time duration calculation storage unit collects T1 and PWTT over a plurality of periods and then performs average calculation to obtain an average value of T1 and PWTT, and the average value is calculated according to the T1 and the PWTTCalculating the average value of the PWTT to obtain the delay time T_delayAnd stored.

5. The wearable device of claim 1, wherein the communication unit comprises a first photoelectric conversion module;

6. A wearable device-based magnetic resonance electrocardiographic gating system, wherein the magnetic resonance electrocardiographic gating system comprises the wearable device according to any one of claims 1-5, and further comprises an upper computer;

and the wearable device sends the generated R wave pulse of the electrocardiosignal to the upper computer.

7. The magnetic resonance cardiac gating system of claim 6, wherein when the communication unit of the wearable device comprises a first photoelectric conversion module, the magnetic resonance cardiac gating system further comprises a second photoelectric conversion module connected to the first photoelectric conversion module by an optical fiber;