Implementation method of heart gating

Abstract

The invention discloses a heart gating implementation method. The heart gating implementation method comprises the steps that artery pulse mechanical vibration signals synchronous with the heartbeat cycle of a human body are collected based on wearable equipment; carrying out filtering and common-mode interference suppression processing on the collected arterial pulse mechanical vibration signal to obtain an effective vibration signal; establishing a time mapping relation between the effective vibration signal and the electrocardiosignal; the trigger point location of the effective vibration signal is converted into an equivalent electrocardio gating trigger point location and transmitted to CT equipment, and heart gating adjustment is carried out; acquiring imaging data in real time, and transmitting the imaging data to the terminal according to a set mode; arterial vibration signals are acquired at multiple points, weak electric signals of 1-2 mV do not need to be acquired, and the precision and anti-interference requirements of a signal acquisition and processing circuit are reduced.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a method for implementing cardiac gating. Background Technology

[0002] ECG gating is a type of cardiac gating, the fundamental purpose of which is to "freeze" the heart's movement to obtain a clear image.

[0003] The heart is constantly beating. If its motion is not controlled during scanning, motion artifacts (blurring, ghosting) will occur in the resulting images, making it impossible to assess structures such as the coronary arteries (small, tortuous blood vessels). ECG gating technology uses electrocardiogram (ECG) signals as a time reference to "synchronize" CT data acquisition with specific phases of the heartbeat, thereby selecting moments when the heart is relatively still for imaging.

[0004] Traditional ECG gating technology has the following drawbacks: 1. This technology relies on the weak electrical signals generated by the heart's contraction and relaxation. The original signal is often only 1-2mV in size, which requires high precision and anti-interference capabilities from the signal acquisition and processing circuit. 2. The amplitude of the electrocardiogram signal and the waveform of the electrocardiogram vary greatly from person to person. In particular, some patients have heart disease and their electrocardiograms are irregular and the R wave is not obvious. Therefore, the subsequent signal processing circuit and software are relatively complex. 3. The usual method for obtaining ECG signals is to have the patient's upper body naked, prepare the skin of relevant points on the trunk, and then attach special shadowless electrodes. Then, the shadowless lead connector is connected to the electrodes. During the entire scanning cycle, the patient's arms generally need to be raised above their head and placed on the bed. The whole process is complicated and the patient's comfort and experience are low. 4. Since the ECG signal is a weak signal, movement can cause signal disturbance. The patient needs to remain still throughout the scanning cycle, which is not very friendly to patients with poor self-control. 5. The connection between the lead wire connector and the electrode can be affected by the scanning bed movement, which may lead to poor contact; 6. Electrodes are disposable consumables, especially shadowless electrodes used in CT scans, which are expensive and increase the financial burden on hospitals and patients. Summary of the Invention

[0005] To address at least one of the aforementioned technical problems, this invention proposes a method for implementing cardiac gating.

[0006] The first aspect of this invention provides a method for implementing cardiac gating, comprising: Based on the acquisition of arterial pulse mechanical vibration signals synchronized with the human heartbeat cycle using wearable devices; The collected arterial pulse mechanical vibration signal was filtered and common-mode interference suppressed to obtain an effective vibration signal; Establish the time mapping relationship between the effective vibration signal and the electrocardiogram signal; The effective vibration signal trigger point is converted into an equivalent ECG gating trigger point and transmitted to the CT equipment for cardiac gating adjustment; Real-time acquisition of imaging data, and transmission of the imaging data to the terminal according to the set method.

[0007] In a preferred embodiment of the present invention, the wearable device uses a flexible circuit board as its core carrier. Several vibration sensors are equidistantly mounted on the front of the flexible circuit board, and protrusions are mirror-image arranged on the back of the board corresponding to the vibration sensors. The protrusions are used to closely fit the skin of the arterial area of ​​the human epidermis to improve the transmission efficiency of pulse vibration signals.

[0008] In a preferred embodiment of the present invention, the vibration sensor is an accelerometer, and the front side of the flexible circuit board also integrates a power supply module, a microprocessor, and a data transmission module; the power supply module includes a miniature button battery and / or an external power interface, the data transmission module includes a wireless transmission module and / or a wired interface, and the microprocessor is used to process the signals collected by the vibration sensor and control the data transmission process.

[0009] In a preferred embodiment of the present invention, the wireless transmission module is a Bluetooth module or a WiFi module, and the wired interface is a USB interface, which has the dual functions of data transmission and external power supply.

[0010] In a preferred embodiment of the present invention, the protrusion is a surface mount stud on a circuit board.

[0011] In a preferred embodiment of the present invention, the flexible circuit board is encapsulated in medical-grade soft plastic, forming an adjustable wristband, ankle, or neck strap structure after encapsulation.

[0012] In a preferred embodiment of the present invention, the common-mode interference suppression processing adopts any one of the following methods: Method 1: Select the sensor data with the smallest output value among all vibration sensors as the common mode component, subtract the common mode component from the output amplitude of each vibration sensor, and take the maximum difference as the effective gating signal; Method 2: An additional vibration sensor is attached to the patient's skin where there is no arterial pulse. The output data is used as the common mode component. The output amplitude of each vibration sensor is subtracted from the common mode component, and the maximum difference is taken as the effective gating signal. Method 3: Configure a calibration sensor for each vibration sensor used for data acquisition. The output data of each calibration sensor is used as the common mode component of the corresponding acquisition sensor. Subtract the output amplitude of each acquisition sensor from the data of the corresponding calibration sensor, and take the maximum difference as the effective gating signal.

[0013] In a preferred embodiment of the present invention, the filtering process employs a low-pass filtering algorithm to filter out high-frequency electromagnetic interference and noise signals generated by human muscle tremors.

[0014] The technical solution of the present invention has the following advantages compared with the prior art: 1. By acquiring arterial vibration signals at multiple points, it is not necessary to acquire weak electrical signals of 1-2mV, thus reducing the precision and anti-interference requirements of the signal acquisition and processing circuit. 2. By applying pressure to the arteries near the skin with raised dots, individual differences in ECG signals are ignored, and patients with severe heart disease can also be tested normally; 3. The entire structure is similar to a wristband or bracelet, eliminating the need to remove clothing for electrode installation, protecting patient privacy, and improving the comfort and efficiency of cardiac gating. 4. The cardiac gating device is a wearable and reusable device, which reduces the cost of scanning and diagnosis. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, some of the drawings in the following description are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the hardware structure of an embodiment of the present invention; Figure 2 This is a cross-sectional view of the flexible circuit board according to an embodiment of the present invention; Figure 3 This is a graph of sensor output data corresponding to the protrusion closest to the arterial pulse under ideal conditions in an embodiment of the present invention; Figure 4 This is a graph of sensor output data corresponding to a protrusion located far from the arterial pulse under ideal conditions in an embodiment of the present invention; Figure 5 This is a graph of sensor output data corresponding to the protrusion furthest from the arterial pulse under ideal conditions in an embodiment of the present invention; Figure 6 This is a schematic diagram of pulse vibration heart gating and electrocardiogram gating delay in an embodiment of the present invention. Detailed Implementation

[0017] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0019] Example 1 See Figures 1-6 As shown, this invention proposes a method for implementing cardiac gating, comprising: Based on the acquisition of arterial pulse mechanical vibration signals synchronized with the human heartbeat cycle using wearable devices; The collected arterial pulse mechanical vibration signal was filtered and common-mode interference suppressed to obtain an effective vibration signal; Establish a time mapping relationship between effective vibration signals and electrocardiogram signals; The effective vibration signal trigger point is converted into an equivalent ECG gating trigger point and transmitted to the CT equipment for cardiac gating adjustment; Real-time acquisition of imaging data, and transmission of the imaging data to the terminal according to the set method.

[0020] Specifically, vibration sensors are placed close to the skin of the human arteries (wrist, ankle, neck, etc.) to detect mechanical vibration signals of the pulse that are consistent with the heartbeat. After selecting the optimal sensor location, filtering, removing common-mode interference, and other processing, the signals are sent to the CT scanner to achieve the effect of cardiac gating.

[0021] According to an embodiment of the present invention, the wearable device uses a flexible circuit board as the core carrier. Several vibration sensors are equidistantly mounted on the front of the flexible circuit board, and protrusions are mirror-image arranged on the back of the board corresponding to the vibration sensors. The protrusions are used to fit tightly against the skin of the arterial area of ​​the human epidermis to improve the transmission efficiency of pulse vibration signals.

[0022] like Figure 2 As shown, several vibration sensors, which can be accelerometers, are equidistantly mounted on the front of the flexible circuit board for pulse vibration detection. The battery can be a miniature button cell battery to power the entire circuit board. An external power supply can be used when there is no battery. The microprocessor processes the pulse vibration data detected by the vibration sensors and sends it to the CT scanner via a wireless data transmission module. The wireless data transmission module can be a Bluetooth or WiFi module, which receives instructions sent by the CT scanner and transmits data sent by the microcontroller to the CT scanner. The wired interface has the same function as the wireless module and also has an external power supply function, which can replace the external power supply port. It can be a USB interface.

[0023] There are no electrical components on the back of the circuit board, but there are structural components, which are solderable protrusions. Each front vibration sensor has a protrusion soldered to its mirror back for contact with the skin and to transmit the mechanical vibration of the pulse. This protrusion can be a surface mount stud on the circuit board.

[0024] like Figure 1 As shown in the embodiment of the present invention, the vibration sensor adopts an accelerometer, and the front side of the flexible circuit board also integrates a power supply module, a microprocessor, and a data transmission module; the power supply module includes a miniature button battery and / or an external power interface, the data transmission module includes a wireless transmission module and / or a wired interface, and the microprocessor is used to process the signals collected by the vibration sensor and control the data transmission process.

[0025] According to an embodiment of the present invention, the wireless transmission module is a Bluetooth module or a WiFi module, and the wired interface is a USB interface, which has the dual functions of data transmission and external power supply.

[0026] According to an embodiment of the present invention, the protrusion is a surface mount stud on the circuit board.

[0027] Because the distance between the protrusion and the arterial pulse varies, the corresponding sensor output amplitude also varies. The closer the distance, the larger the amplitude. Ideally, the output amplitude at the furthest distance from the arterial pulse might be an approximate straight line, such as... Figure 5 As shown.

[0028] According to an embodiment of the present invention, the flexible circuit board is encapsulated in medical-grade soft plastic, and after encapsulation, it forms a wristband, ankle, or neck-type structure with adjustable tightness.

[0029] It should be noted that the circuit boards are designed with different lengths and numbers of sensors. The circuit boards are encapsulated using soft plastic or equivalent materials, exposing the interfaces and protrusions. Different lengths of encapsulated circuit boards are selected depending on the winding location to ensure that the protrusions fit snugly against the skin.

[0030] Ideally, the sensor output data corresponding to the protrusions closest to and furthest from the arterial pulse are converted into curves as shown in the figure. Figures 3-4 As shown.

[0031] It should be noted that the largest amplitude of the vibration sensor indicates that the protrusion corresponding to the sensor is closest to the artery. Sensors slightly farther away from the artery have slightly smaller vibration amplitudes, and the farthest sensor has almost no vibration and the smallest amplitude. At this point, the vibration sensed by the sensor can be considered as environmental vibration, such as human body shaking or bed board vibration. Therefore, it can be used as the common mode component in Method 1. Subtracting the value of this sensor from the values ​​of other sensors gives the pure arterial vibration amplitude. Since all vibration sensors detect the same human body, vibration detection is a comparison between sensors on the same human body. The nearest, farthest, and farthest distances are distinguished by the sensor amplitude from large to small, without any other fixed standards.

[0032] According to embodiments of the present invention, the common-mode interference suppression processing adopts any of the following methods: Method 1: Select the sensor data with the smallest output value among all vibration sensors as the common mode component, subtract the common mode component from the output amplitude of each vibration sensor, and take the maximum difference as the effective gating signal; Method 2: An additional vibration sensor is attached to the patient's skin where there is no arterial pulse. The output data is used as the common mode component. The output amplitude of each vibration sensor is subtracted from the common mode component, and the maximum difference is taken as the effective gating signal. Method 3: Configure a calibration sensor for each vibration sensor used for data acquisition. The output data of each calibration sensor is used as the common mode component of the corresponding acquisition sensor. Subtract the output amplitude of each acquisition sensor from the data of the corresponding calibration sensor, and take the maximum difference as the effective gating signal.

[0033] It should be noted that, ideally, the sensor output data (y) corresponding to the protrusion closest to the arterial pulse can be selected. near Using time (t) as a functional variable and as the basis for cardiac gating, the following formula is established: y near =f(t); In practice, to eliminate the effects of patient movement and scanning bed movement, the following filtering and common-mode interference removal methods can be used: ① Output data (y) from the sensor with the smallest value (usually the sensor furthest from the arterial pulse). far As the common-mode component of all sensor data y, it reflects the effects of external interference and motion, and represents the amplitude y of all sensors. n respectively with y far Subtract the values, and select the maximum sensor value after subtraction as the basis for cardiac gating, i.e.: y=max(y1-y far y2-y far , ..., y n -y far ); This value is typically the sensor output data corresponding to the protrusion closest to the artery pulse, and is related to y. far The difference; ②Use an additional vibration sensor, attached to normal skin (without arterial pulse), to output data (y extra As the common-mode component of all sensor data y, it reflects the effects of external disturbances and motion, and represents the amplitude of all sensor data y.n respectively with y extra Subtract the values, and select the maximum sensor value after subtraction as the basis for cardiac gating, i.e.: y=max(y1-y extra y2-y extra , ..., y n -y extra ); This value is typically the sensor output data corresponding to the protrusion closest to the artery pulse, and is related to y. extra The difference; ③ Place a calibration sensor next to each sensor to output data (y calin As the common-mode component of its corresponding sensor data y, it reflects the effects of external interference and movement, and represents the amplitude y of each sensor. n respectively with y calin Subtract the values, and select the maximum sensor value after subtraction as the basis for cardiac gating, i.e.: y=max(y1-y cali1 y2-y cali2 , ..., y n -y calin ); This value is typically the sensor output data corresponding to the bulge closest to the artery pulse and its corresponding calibration sensor y. calix The difference; Furthermore, since the original pulse vibration waveform does not strictly correspond to the electrocardiogram waveform, a time mapping relationship between the two can be established by collecting a sufficient number of human samples, such as... Figure 6 As shown.

[0034] Therefore, the ECG gating trigger point t ECG , and the pulse vibration gating trigger point t PULSE The mapping relationship is as follows: t ECG =t PULSE +△t;

[0035] Where Δt represents the delay between the two within the same period, it can be positive or negative, and Δt < heartbeat period T. In practical use, t can be used. ECG As a trigger point, it simulates ECG gating.

[0036] According to an embodiment of the present invention, the filtering process employs a low-pass filtering algorithm to filter out high-frequency electromagnetic interference and noise signals generated by human muscle tremors.

[0037] In summary, by acquiring arterial vibration signals at multiple points, it eliminates the need to acquire weak electrical signals of 1-2mV, reducing the precision and anti-interference requirements of the signal acquisition and processing circuitry. Using raised points to press on the arteries near the skin ignores individual differences in ECG signals, allowing for normal testing even for patients with severe heart disease. The entire structure resembles a wristband or bracelet, eliminating the need for undressing to install electrodes, protecting patient privacy, and improving the comfort and diagnostic efficiency of cardiac gating. Furthermore, the cardiac gating device is wearable and reusable, reducing scanning and diagnostic costs.

[0038] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to the above embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0040] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for implementing cardiac gating, characterized in that, include: Based on the acquisition of arterial pulse mechanical vibration signals synchronized with the human heartbeat cycle using wearable devices; The collected arterial pulse mechanical vibration signal was filtered and common-mode interference suppressed to obtain an effective vibration signal; Establish the time mapping relationship between the effective vibration signal and the electrocardiogram signal; The effective vibration signal trigger point is converted into an equivalent ECG gating trigger point and transmitted to the CT equipment for cardiac gating adjustment; Real-time acquisition of imaging data, and transmission of the imaging data to the terminal according to the set method.

2. The method for implementing cardiac gating according to claim 1, characterized in that, The wearable device uses a flexible circuit board as its core carrier. Several vibration sensors are equidistantly mounted on the front of the flexible circuit board, and protrusions are mirrored on the back of the board corresponding to the vibration sensors. The protrusions are used to fit tightly against the skin of the arterial area of ​​the human epidermis to improve the transmission efficiency of pulse vibration signals.

3. The method for implementing cardiac gating according to claim 2, characterized in that, The vibration sensor is an accelerometer. The flexible circuit board also integrates a power supply module, a microprocessor, and a data transmission module on its front side. The power supply module includes a miniature button battery and / or an external power interface. The data transmission module includes a wireless transmission module and / or a wired interface. The microprocessor is used to process the signals collected by the vibration sensor and control the data transmission process.

4. The method for implementing cardiac gating according to claim 3, characterized in that, The wireless transmission module is a Bluetooth module or a WiFi module, and the wired interface is a USB interface, which has the dual functions of data transmission and external power supply.

5. The method for implementing cardiac gating according to claim 2, characterized in that, The protrusion is a surface mount stud on the circuit board.

6. The method for implementing cardiac gating according to claim 2, characterized in that, The flexible circuit board is encapsulated in medical-grade soft plastic, forming an adjustable wristband, ankle, or neck strap structure.

7. The method for implementing cardiac gating according to claim 1, characterized in that, The common-mode interference suppression process adopts any of the following methods: Method 1: Select the sensor data with the smallest output value among all vibration sensors as the common mode component, subtract the common mode component from the output amplitude of each vibration sensor, and take the maximum difference as the effective gating signal; Method 2: An additional vibration sensor is attached to the patient's skin where there is no arterial pulse. The output data is used as the common mode component. The output amplitude of each vibration sensor is subtracted from the common mode component, and the maximum difference is taken as the effective gating signal. Method 3: Configure a calibration sensor for each vibration sensor used for data acquisition. The output data of each calibration sensor is used as the common mode component of the corresponding acquisition sensor. Subtract the output amplitude of each acquisition sensor from the data of the corresponding calibration sensor, and take the maximum difference as the effective gating signal.

8. The method for implementing cardiac gating according to claim 1, characterized in that, The filtering process employs a low-pass filtering algorithm to remove high-frequency electromagnetic interference and noise signals generated by human muscle tremors.

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