CN117323585A - Cardiac target area positioning, guiding and controlling method and gating system for assisting fat heart SBRT treatment - Google Patents

Abstract

The invention discloses a heart target area positioning and guiding control method and system for assisting fat heart SBRT treatment, wherein the method comprises the following steps: collecting respiratory signals and electrocardiosignals of a patient, and synchronizing and preprocessing the signals; the method comprises the steps of correspondingly extracting a respiratory beam candidate working window and an electrocardio beam candidate working window in real time according to an obtained respiratory signal and an electrocardio signal respectively; and determining the beam-out starting moment of the linear accelerator for radiation therapy based on the obtained respiratory beam candidate working window and the electrocardio beam candidate working window and comprehensively considering the delay influence. The method and the system fill the blank of the double-gating technology in the field of heart SBRT treatment, assist in realizing a brand new heart ablation treatment mode of 'noninvasive, accurate and safe', and can effectively change the situations of large trauma and high risk of the current fat heart treatment.

Description

Cardiac target area positioning, guiding and controlling method and gating system for assisting fat heart SBRT treatment

Technical Field

The invention belongs to the field of automatic control of medical equipment, relates to a heart target area positioning guide control method and a gating system for assisting fat heart SBRT treatment, and particularly relates to a respiration/electrocardio gating system and a control method for guiding a linear accelerator to accurately output beams by acquiring and synchronizing heart and lung motion rhythms of a human body.

Background

Stereotactic Body Radiation Therapy (SBRT) is a non-invasive ablation technique that focuses a low dose ionizing radiation beam at a target volume. Based on the characteristics of accuracy, noninvasive property and safety, the application of the SBRT technology to the ablation of the obstructive fat heart becomes a treatment means with great application prospect. However, cardiac ablation is different from ablation treatment of solid tumors, and cardiac SBRT treatment suffers from problems of cardiopulmonary exercise calibration, target area positioning tracking, peripheral tissue protection and the like due to the influence of factors such as heartbeat respiration, complex structures and the like. The gating technology can effectively improve the ablation accuracy and reduce the damage to surrounding tissues by acquiring physiological signals such as respiration, electrocardio and the like of a patient and selecting a relatively safe time period to control the accelerator to output beams.

There are two main problems with door control devices that are common in the marketplace:

1. the function is single, and the respiratory door control equipment and related technologies account for the market main body; an active respiratory control system (Active Breathing Control, ABC) such as alekta; RPM (Real-time Position Management) System from Varian, inc. of Varian; application number 201410680557.4, entitled "respiratory gating system and control method based on stereoscopic vision"; patent application number 202210037161.2 entitled "a respiratory gating monitoring apparatus, method, and computer readable storage medium", etc. The above technology only realizes respiratory gating, and the device is complex and has high cost. The equipment related to the electrocardiographic gating is Micro CT equipment of perennial company, and the equipment is only aimed at small animals; patent application number 201580004703.4 entitled "collection and processing of reliable ECG signals and gating of pulses in a magnetic resonance environment" and the like. However, there are a smaller number of devices that compromise both electrocardiographic and respiratory gating.

2. The application scene is single; most of the existing gating devices and technologies are directed to medical imaging devices, wherein MRI devices are in most cases, compared with few gating devices dedicated to linacs, gating systems for medical imaging devices cannot be directly applied to linacs due to differences in communication protocols. In addition, error tolerance for reducing MRI image artifacts using respiratory gating is typically on the order of seconds, while the error required for cardiopulmonary ablation procedures is on the order of milliseconds, with higher demands on gating calibration and communication delays. There is no solution on the market for double gating assisted cardiac ablation surgery.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a heart target area positioning and guiding control method and a gating system for assisting fat heart SBRT treatment, fills the application blank of breathing/electrocardio double gating control in the field of SBRT treatment, and solves the problems of heart-lung movement calibration, heart target area positioning and guiding, communication control of an SBRT system and the like faced by fat heart SBRT ablation.

In a first aspect, an embodiment of the present invention provides a method for positioning, guiding and controlling a target region of a heart for assisting fat heart SBRT therapy, including the following steps:

collecting respiratory signals and electrocardiosignals of a patient, and synchronizing and preprocessing the signals;

the method comprises the steps of correspondingly extracting a respiratory beam candidate working window and an electrocardio beam candidate working window in real time according to an obtained respiratory signal and an electrocardio signal respectively;

and determining the beam-out starting moment of the linear accelerator for radiation therapy based on the obtained respiratory beam candidate working window and the electrocardio beam candidate working window and comprehensively considering the delay influence.

In the above technical scheme, further, a method based on a body surface marker is adopted to place or adsorb the target on the body surface of the patient, a fixed camera acquires a picture containing the target in real time, and an image processing method is adopted to acquire the frame of the target in each frame so as to calculate the two-dimensional coordinates of the center point of the target, thereby obtaining a motion curve of the target along with the fluctuation of the body surface of the patient, and obtaining a respiratory signal.

Further, the electrocardiographic data of the patient are acquired in real time, and an electrocardiographic QRS waveform is obtained and used as an electrocardiographic signal.

Further, the candidate working window of the respiratory beam current is extracted by combining a peak-valley automatic detection algorithm, specifically: for a respiratory signal curve, the first n points of the current point p are stored, when the current n points continuously rise, the p points are used as peak candidate points, if the last n points continuously fall, the p points are determined to be peaks, wherein the value of n is obtained through dynamic real-time calculation of the respiratory period and the frame rate, and the detection method of the trough is similar; the detection of the wave crests and the wave troughs is in a mutual exclusion state, namely the detection of the wave crests and the wave troughs needs to be alternately performed, and the wave crests and the wave troughs cannot be continuously detected; the threshold is set according to a specific percentage of the peak-to-valley value, which is typically set to 20%, and the trough segment of the respiratory signal curve waveform below the threshold is set as the respiratory beam candidate operating window.

Further, two parameters are preset: beam current working starting time percentage point P _start And beam on duration percentage P _last Both parameters are referenced to a real-time heartbeat cycle duration; r wave in electrocardiosignal curve is detected in real time, and the two most are detectedThe adjacent R wave time points are respectively marked as T _R′ ,T _R On the premise of monitoring that the heart rate of the patient is stable, according to the detected R wave and two preset parameters P _start And P _last Calculating to obtain real-time effective working time window of beam current, and calculating real-time heartbeat period (T) _RR ＝T _R -T _R ' according to formula T _ecg-start ＝T _R +P _start ×T _RR And T _ecg-end ＝T _ecg-start +P _last ×T _RR And obtaining a real-time electrocardio beam candidate working window.

Further, taking the intersection of the candidate work window of the respiratory beam and the candidate work window of the electrocardio beam as an ideal beam work window, taking the delay influence of all aspects into consideration, delaying for a certain time after the ideal beam time point, discharging the beam again, and setting the current respiratory cycle as T _res The electrocardio period is T _ecg An ideal working window starting point is T _{start_init} The delay time of the accelerator signal is T _delav The starting point T of the formal working window _start ＝T _{start_init} +(I _res /T _ecg )*T _ecg -T _delay 。

In a second aspect, an embodiment of the present invention provides a cardiac target positioning, guiding and gating system for assisting fat heart SBRT therapy, including: the server monitoring module is used for collecting real-time electrocardiographic data and respiratory data of a patient and transmitting the data to the client;

the client is provided with a gating management module which is used for determining a comprehensive gating signal according to electrocardiograph data and respiratory data, is connected with an accelerator control module of the linear accelerator through a USB interface, and is used for transmitting control commands by adopting a USB protocol and reading response data of the linear accelerator control module; the accelerator control module is connected with the accelerator execution module through optical fibers.

In a third aspect, an embodiment of the present invention provides a computer apparatus, including:

one or more processors;

a memory for storing one or more programs;

the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the control method as described in any of the embodiments.

In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a control method as described in any of the embodiments.

The beneficial effects of the invention are as follows:

the method and the system fill the blank of the double-gating technology in the field of heart SBRT treatment, assist in realizing a brand new heart ablation treatment mode of 'noninvasive, accurate and safe', and can effectively change the situations of large trauma and high risk of the current fat heart treatment.

Drawings

FIG. 1 is a workflow diagram of server-side data collection, synchronization and presentation in accordance with the present invention

FIG. 2 is a workflow diagram of client-generated gating, display, and accelerator control of the present invention

FIG. 3 is an overall workflow diagram of the present invention

FIG. 4 is a diagram of a server software interface

FIG. 5 is a diagram of a client software interface

FIG. 6 is a software interface diagram of an accelerator control module

FIG. 7 is a schematic diagram of a respiratory beam candidate working window generation

FIG. 8 is a schematic diagram of an electrocardio beam candidate working window generation

FIG. 9 is a schematic diagram of an ideal beam formal work window generation

Detailed description of the preferred embodiments

The technical scheme of the invention is further described in detail below with reference to the attached drawings and specific embodiments.

The invention provides a heart target area positioning, guiding and controlling method for assisting fat heart SBRT treatment, which comprises the following steps:

collecting respiratory signals and electrocardiosignals of a patient, and synchronizing and preprocessing the signals;

the method comprises the steps of correspondingly extracting a respiratory beam candidate working window and an electrocardio beam candidate working window in real time according to an obtained respiratory signal and an electrocardio signal respectively;

and determining the beam-out starting moment of the linear accelerator for radiation therapy based on the obtained respiratory beam candidate working window and the electrocardio beam candidate working window and comprehensively considering the delay influence.

The embodiment of the invention provides an electrocardio/respiration gating system capable of controlling a linear accelerator, which mainly comprises a server and a client, wherein the server and the client realize data transmission through a TCP/IP protocol. The server side is responsible for acquiring the electrocardio and respiratory data in real time, displaying the electrocardio and respiratory data in an image mode and transmitting the electrocardio and respiratory data to the client side; the client is responsible for analyzing and processing data, generating a gating signal, and realizing stable communication and real-time control of the linear accelerator through a USB protocol. The specific technical scheme is as follows:

1. the server side:

(1) Acquiring a respiratory signal: in view of the discomfort caused by the respiratory flow monitoring method and the barometric pressure monitoring method, in this example, a method based on body surface markers is adopted, and only one digital camera with a common frame rate, one target and one computer are needed in terms of hardware, wherein the target can be any object which is easy to place or adsorb on the body surface of the patient, and is characterized in that the color and the background (the background in the view frame picture of the camera) are greatly different. The software obtains the frame of each frame of target by a color-based image processing method to calculate the two-dimensional coordinates of the center point of the target, thereby obtaining the motion curve of the target along with the fluctuation of the body surface of the patient.

(2) Acquiring electrocardiosignals: in the embodiment, the electrocardiosignal is obtained by adopting a five-lead mode, the obtaining equipment is a BeneVision N1 patient monitor of Mairui company, the voltage analog signal obtained by the equipment is connected to an analog-to-digital converter through an MP1 interface, the analog-to-digital converter is a VK-701H data acquisition card of Shenzhen micro-fine electronic limited company, and the acquisition card carries out analog-to-digital conversion and signal amplification and then transmits the signal to a computer for further processing through a USB protocol.

The server collects and synchronizes respiratory/electrocardiosignals through the method so as to solve the cardiopulmonary exercise calibration problem faced by fat heart SBRT ablation, and the software of the upper computer is compiled by Python, and can display an electrocardio/respiratory curve and a real-time patient monitoring picture, and meanwhile, the requirements of filtering degree, dynamic balance accuracy and real-time performance can be manually adjusted. And finally, synchronously packaging the processed data and transmitting the processed data to the client through a TCP/IP protocol. The specific workflow may be as shown in fig. 1.

2. Client side:

(1) Generating respiratory signal gating: in this embodiment, a compensation calibration scheme in a free breathing state is adopted, that is, under the condition of not interfering with the breathing behavior of a patient, a stable breathing time period is automatically detected in each breathing period and a beam current working candidate signal is generated, the stable breathing time period specifically refers to a period when a breathing curve is in a valley, and a threshold is dynamically adjusted according to actual conditions.

(2) Generating electrocardiosignal gating: and the client side is required to process the acquired electrocardio data at high speed and high performance, and automatically detects a heart level stable time period in each electrocardio period, wherein the time period is required to construct an effective working time window according to the heart beating full-period image displayed by the heart super-display of the patient, an initial starting point and duration are defined firstly, and then parameters are dynamically adjusted according to actual conditions.

(3) Generating a comprehensive gating signal: since displacement of the cardiac target is affected by both respiration and electrocardiography, it is necessary to synchronize the beam working candidates of both to produce the ideal gating signal that controls the actuation and suspension of the accelerator by high and low levels. Due to the cooling characteristics of the accelerator itself, a cold start in a short time can create a delay of a few seconds, so that the final beam-out time is not within the designed ideal gating signal. To address this problem, the present example devised a gating signal generation algorithm that takes into account machine latency.

(4) An accelerator control module: the accelerator control module can be manually connected, turned on and off, or can be automatically controlled by a gating signal generated before.

(5) Other functions: in addition to the above-mentioned main functions, the client software interface in this example also has the functions of timing, respiration/electrocardiographic gating counting, real-time heart rate calculation, real-time respiration cycle calculation, accelerator machine delay real-time calculation, prompt information, and the like.

The client generates a comprehensive gating signal in real time through calculation, controls the accelerator to output beams at stable time through the accelerator control module, solves the problem of positioning and guiding the heart target area, and the specific working flow is shown in figure 2.

The server side of the invention collects real-time electrocardio/respiratory data of a patient through the monitoring modules and transmits the data to the client side, the two monitoring modules internally comprise an Ethernet communication sub-module, the two monitoring modules are connected with the client side equipment through a network cable, and the data is transmitted stably at a high speed in real time by adopting an Ethernet protocol. And the gating management module internally comprises a US B communication sub-module which is connected with the control module of the accelerator through a USB interface, and a control command is sent by adopting a USB protocol and response data of the control module of the accelerator are read. The accelerator control module is connected with the accelerator execution module through optical fibers. The workflow is shown in fig. 3, and is specific:

the actual operational procedure of the present invention is further described with reference to the drawings and examples below:

1. preoperative preparation

(1) Preparing an instrument: two computers with Ethernet interfaces, an electrocardiograph monitor, a target, a camera, a network cable, a USB cable and a plurality of electrode plates.

(2) Time synchronization is carried out on two computers, and delay errors are reduced

(3) The server computer is provided with a driver of a VK701H acquisition card, is connected with the camera and the acquisition card, and is connected with the client computer through a network cable

(4) Acquiring PID (product identification code) and VID (vendor ID) of accelerator equipment, enabling a client computer to be connected with an accelerator console through a USB interface, starting software to wait for being connected with a server 2. Acquiring respiratory/electrocardiosignals

The five-lead electrode plate is fixed on a patient according to a specified position, and the patient monitor acquires electrocardiosignals in real time and is connected with one of four channels of the digital acquisition card through an MP1 interface. Sampling and analog-to-digital conversion are carried out at a sampling rate set by a digital acquisition cartoon process sequence, and digital signals are transmitted to an electrocardiosignal processing module through a USB2.0 protocol; the target is fixed on the chest or abdomen of the patient, the camera is placed at a proper position on the same axis as the patient (the specific position is adjusted according to the actual scene), and the spatial amplitude of the camera is adjusted to enable the target to be placed at the center of the visual field. The vision measurement unit processes the images acquired by the camera frame by frame, acquires a real-time two-dimensional coordinate sequence and transmits the real-time two-dimensional coordinate sequence to the respiratory signal processing module. Referring to fig. 4, two paths of signals processed by the algorithm are displayed through a server software interface, and the software has the following operation steps:

(1) Clicking the "start" button can obtain a real-time picture (upper right corner of the software) shot by the camera, so as to adjust the position of the camera and check whether the target can be stably identified.

(2) After the picture is stable, clicking a 'Detect' button, and displaying an electrocardiosignal in real time by using a red curve at the upper left corner and displaying an original respiratory signal in real time by using a yellow curve at the lower left corner by software, wherein the curve coordinates are synchronously processed.

(3) Clicking the "stop" button may pause acquisition of the signal.

(4) The respiratory curve frame simultaneously displays the filtered smooth respiratory signal by using a green curve, and the degree of filtering is adjusted by changing the numerical values of the window and the window. The smoothness of the breathing curve and the accuracy of detecting critical points are in direct proportion to the time delay, namely, the higher the filtering level is, the smoother the curve is, the more accurate the peak-valley value is detected, the lower the instantaneity is, and the dynamic adjustment is required according to specific display conditions.

(5) When the curve satisfies the condition, clicking the "send" button transfers the data to the client.

3. The client receives the processing signal

Fig. 5 is a client software interface, the left half of the interface being a signal display area: (1) displaying electrocardiosignals, (2) displaying respiratory signals, and (3) displaying gating signals. The right half is the information display and control area: (4) a real-time picture may be displayed. (5) Displaying important parameters such as respiratory cycle, machine delay, operation time and beam times, etc., (6) placing software control buttons, (7) containing prompt boxes and heart rate information. The specific operation flow is as follows:

(1) Clicking the connect button, the software waits to connect with the server, and the prompt box displays the corresponding information

(2) When a signal transmitted by the server is received, the left half part of the interface displays the transmitted signal (the breathing curve only displays the filtered signal), the connect key is converted into the stop key to provide a pause function, and the prompt box displays that the connection is successful.

(3) At this time, the software automatically detects the peak valley value and calculates the respiratory cycle. The breathing cycle can be set manually through a text box of 'window', at the moment, the software automatically calculates the failure of the function, and the function is fixed as manually set parameters, so that the influence caused by the disturbance of the breathing curve is prevented. At the same time, the software will automatically calculate that the real-time heart rate is displayed in the lower right corner.

(4) Clicking the "config" key opens the accelerator control module, sets the electrocardiographic gating in percentage form at the start time and duration of each electrocardiographic cycle, and clicks the "Run" key to initiate gating calculations.

(5) At the moment, software starts to calculate a respiratory beam candidate working window (green) and an electrocardiograph beam candidate working window (red), and an algorithm calculates a beam formal working window (yellow) by combining signal acquisition delay, signal transmission delay, accelerator control delay and the like, and generates a gating signal to control the opening and closing of the accelerator through high and low levels.

4. Communication and control of accelerators

FIG. 6 is an accelerator control module, with the upper half being the electrocardiographic gating parameter setting and the lower half being the accelerator communication module. Data can be transmitted to the accelerator by manually clicking the start and stop buttons before the experiment to verify the control capability of the software on the accelerator, and the software can obtain initiative after the experiment starts and automatically control according to the gating signals obtained before.

The key processes and algorithms involved in the above processes are specifically as follows:

1. respiratory data preprocessing:

1) The camera obtains pictures containing markers at a rate of 30 frames per second.

2) The first frame is determined and the following operations are performed:

A. reading real-time camera pictures using cv library

B. The picture is resized (640, 480)

C. Gaussian blur of pictures

D. Converting the color of a picture from rgb to hsv

E. ERode method (Corrosion) using cv library to reduce noise and glitch of pictures

F. Designating the color of the marker, removing the background outside the designated color

G. Converting pictures into binarized images

H. Detecting the outline of an object in a binarized image, detecting only the outline of the outside

I. Selecting a contour set with the largest area from the detected contours

J. Computing minimum bounding rectangle in contour set

K. And calculating coordinates of a central point of the rectangle.

3) Taking the y coordinate value of the rectangular center coordinate of the first frame as a reference y0, and subtracting the y coordinate value and the y0 of each frame as relative displacement to be used as a point of the breathing curve.

4) The real-time y obtained is saved by an array with fixed length, and the data stream is smoothly denoised by a Savitzky-Golay filter when the array is filled. Then, every time a point comes in, the forefront point is deleted, the length of the array is maintained, and the denoising operation is performed.

5) And obtaining an array after denoising, and solving the peak value and the valley value in the current array.

2. Electrocardiogram data preprocessing

Two threads are required to be started, one thread reads electrocardiograph data from the acquisition card in real time, and the other thread processes the obtained electrocardiograph data in real time

1) Acquiring data of an acquisition card of the VK701H at a sampling rate of 500hz, and simultaneously giving a time stamp to each sampling point;

2) The electrocardio data is also stored by an array with fixed length, and old data is deleted every time new data comes in;

3) Wavelet transformation is carried out on the electrocardiograph data to obtain qrs points, and a time stamp is also given to each R point;

4) And calculating the electrocardio gating time according to the qrs point.

3. Time-space calibration of cardiac target area

(1) Respiratory beam candidate work window

The effective window of respiration gate control is selected as a trough, the threshold value parameter is set to be 20% of the peak-to-trough value, and the range of waveform below the threshold value is set as a candidate working window of respiration beam current. During radiation therapy, the beam current operation candidate signal is pulled high when the characterization value of the patient's respiratory motion is detected to be within the threshold range, and is set low when not within the threshold range, as shown in fig. 7. The automatic detection algorithm dynamically obtains threshold points by detecting peaks and troughs, the specific method is that the first n points of the current point p are stored (the value of n is obtained through dynamic calculation of a respiratory period and a frame rate), when the current n points continuously rise, the p points are used as peak candidate points, if the last n points continuously fall, the p points are determined to be peaks, and the detection method of the troughs is similar. It should be noted that the detection of the wave crest and the wave trough needs to be in a mutually exclusive state, that is, the detection of the wave crest and the wave trough must be alternately performed, and the detection cannot be continuously detected as the wave crest or the wave trough, and the operation is realized by using one signal quantity.

(2) Electrocardiogram beam candidate working window

The effective working time window of the beam current suitable for the patient is defined by two parameters, namely a, the starting time percentage point P of the beam current with the duration of one heartbeat cycle as a reference _start Beam on duration percentage P _last . During radiotherapy, the patient will be connected with the electrocardiograph monitoring module through the three-lead/five-lead ECG to monitor the real-time electrocardiograph signal of the patient, and R waves are detected in real time based on the real-time data (the two nearest adjacent R wave time points are respectively marked as T _R ′，T _R ) On the premise of monitoring that the heart rate of the patient is stable, according to the detected R wave and two preset parameters P _start And P _last Calculating to obtain real-time effective working time window of beam current, and simultaneously calculating R-R real-time value (i.e. T _RR ＝T _R -T _R ') and corrected in time. According to formula T _ecg-start ＝T _R +P _start ×T _RR And T _ecg-end ＝T _ecg-start +P _last ×T _RR Obtaining a real-time beam current working candidate waveform based on electrocardio, namely obtaining a rectangular wave which is T in each heartbeat period _ecg-start Time pull up signal, T _ecg-end The time signal is set low as shown in FIG. 8

4. SBRT system delay calibration

The operating window period represents the accelerator out-of-beam period. The ideal beam formal work window takes the intersection of the respiratory beam candidate work window and the electrocardiographic beam candidate work window, and as shown in fig. 9, the electrocardiographic window in the respiratory window can be considered as the formal work window. But is affected by delays in various aspects of the system, requiring a corresponding time delay after the ideal beam time point to re-beam. The delay time is calculated as follows: let the breathing cycle be T _res The electrocardio period is T _ecg An ideal working window starting point is T _{start_init} The machine delay time is T _delav The starting point T of the formal working window _start ＝T _{start_init} +(T _res /T _ecg )*T _ecg -T _delay Then a delay (T) _start -T _{start_init} ) Wherein T is _delav Will vary from accelerator to accelerator.

5. Communication control

The communication between the server and the client is realized through the Ethernet, and certain treatment is carried out on the packet loss and repetition of the data in the process of synchronizing and transmitting the electrocardio-respiratory data; the communication between the server and the accelerator is realized through a USB protocol, and the functions of connection, starting and stopping are mainly realized.

The animal experiment is carried out in the radiology department of the Hospital Shao Yifu by adopting the method, the experimental object is an experimental pig with heart rate and respiratory frequency close to those of human beings, and the pig is anesthetized before the experiment to ensure that the physiological state of the pig is stable.

The specific steps are as follows:

1. the pig is fixed on the lying platform of the accelerator equipment, a marker is bound on the abdomen of the pig, and a camera is placed on the periphery of the pig to acquire a breathing curve. The marker and camera positions are adjusted to obtain the best signal. Further, electrode plates are attached to the four limbs and the heart, and the positions are adjusted to display the optimal electrocardiogram on the electrocardiograph monitor. After the above operation is completed, the marker and the region where the electrode plate is located are drawn by a marker pen for subsequent experiments.

2. And adjusting the filtering degree of the breathing curve on the server software to obtain a smooth curve, and requesting connection with the client after the breathing electrocardiograph curve is stable. All ready to leave the accelerator chamber.

3. The client and the accelerator console are connected by a usb wire in the control room, and the client and the server are connected by a network wire. The doctor sets the required dose for the experiment, the client obtains the control right of the accelerator after configuration, and meanwhile, the client establishes connection with the server to acquire data.

4. The client processes the data and generates a gating signal to control the starting and closing of the accelerator.

The experiment proves that the system can acquire the physiological signals to be tested in real time and successfully control the operation of the accelerator, and the time delay can be controlled in a reasonable range.

The method and the system can fill the blank of the double-gating technology in the field of heart SBRT treatment, and assist in realizing a brand new heart ablation treatment mode of noninvasive, accurate and safe, and compared with the traditional technology, the technology of the embodiment has the following advantages: 1. the operation is simple and flexible, and is friendly to patients. 2. The professional patient monitor and the high-speed acquisition card are adopted, so that the reliability and the instantaneity of signal acquisition are ensured. 3. Visual respiration and electrocardio waveforms are output in real time, so that on-site debugging and monitoring of a tested person are facilitated.

Claims (9)

1. The heart target area positioning, guiding and controlling method for assisting fat heart SBRT treatment is characterized by comprising the following steps of:

collecting respiratory signals and electrocardiosignals of a patient, and synchronizing and preprocessing the signals;

the method comprises the steps of correspondingly extracting a respiratory beam candidate working window and an electrocardio beam candidate working window in real time according to an obtained respiratory signal and an electrocardio signal respectively;

and determining the beam-out starting moment of the linear accelerator for radiation therapy based on the obtained respiratory beam candidate working window and the electrocardio beam candidate working window and comprehensively considering the delay influence.

2. The method for positioning and guiding the heart target area for assisting fat heart SBRT treatment according to claim 1, wherein a method based on a body surface marker is adopted, a target is placed or adsorbed on the body surface of a patient, a fixed camera acquires a picture containing the target in real time, and an image processing method is adopted to acquire the frame of the target in each frame so as to calculate the two-dimensional coordinates of the center point of the target, so that a motion curve of the target along with the fluctuation of the body surface of the patient is obtained, and a respiratory signal is obtained.

3. The method for positioning and guiding a target region of a heart for assisting fat heart SBRT treatment according to claim 1, wherein electrocardiographic data of a patient is acquired in real time and an electrocardiographic QRS waveform is obtained as an electrocardiographic signal.

4. The method for positioning and guiding the heart target area for assisting fat heart SBRT treatment according to claim 1, wherein the method for extracting the candidate working window of respiratory beam current by combining peak-valley automatic detection algorithm is specifically as follows: for a respiratory signal curve, the first n points of the current point p are stored, when the current n points continuously rise, the p points are used as peak candidate points, if the last n points continuously fall, the p points are determined to be peaks, wherein the value of n is obtained through dynamic real-time calculation of the respiratory period and the frame rate, and the detection method of the trough is similar; the detection of the wave crests and the wave troughs is in a mutual exclusion state, namely the detection of the wave crests and the wave troughs is required to be alternately carried out; and setting a threshold according to a specific percentage example of the peak-valley value, and setting the valley section of the respiratory signal curve waveform lower than the threshold as a respiratory beam candidate working window.

5. The method for cardiac target positioning guidance control for assisting fat heart SBRT treatment according to claim 1, wherein two parameters are set in advance: beam current working starting time percentage point P _start And beam on duration percentage P _last Both parameters are referenced to a real-time heartbeat cycle duration; r waves in an electrocardiosignal curve are detected in real time, and two nearest adjacent R wave time points are respectively marked as T _R′ ，T _R On the premise of monitoring that the heart rate of the patient is stable, according to the detected R wave and two preset parameters P _start And P _last Calculating to obtain real-time effective working time window of beam current, and calculating real-time heartbeat period (T) _RR ＝T _R -T _R′ According to formula T _ecg-start ＝T _R +P _start ×T _RR And T _ecg-end ＝T _ecg-start +P _last ×T _RR And obtaining a real-time electrocardio beam candidate working window.

6. The method for positioning and guiding a cardiac target for assisting fat heart SBRT therapy according to claim 1, wherein an intersection of a candidate work window of respiratory beam current and a candidate work window of cardiac beam current is taken as an ideal work window of beam current, delay effects in all aspects are considered, beam is discharged after a certain time delay after a beam time point is conceivable, and a current respiratory cycle is set as T _res The electrocardio period is T _ecg An ideal working window starting point is T _{start_init} The delay time of the accelerator signal is T _delav The starting point T of the formal working window _start ＝T _{start_init} +(T _res /T _ecg )*T _ecg -T _delay 。

7. A cardiac target positioning guidance gating system for assisting fat heart SBRT therapy, comprising: the server monitoring module is used for collecting real-time electrocardiographic data and respiratory data of a patient and transmitting the data to the client;

the client is provided with a gating management module which is used for determining a comprehensive gating signal according to electrocardiograph data and respiratory data by adopting the method as set forth in any one of claims 1-6, and is connected with an accelerator control module of the linear accelerator through a USB interface, and a control command is sent by adopting a USB protocol and reads response data of the linear accelerator control module; the accelerator control module is connected with the accelerator execution module through optical fibers.

8. A computer device, the computer device comprising:

one or more processors;

a memory for storing one or more programs;

when executed by the one or more processors, causes the one or more processors to implement the control method of any of claims 1-6.

9. A computer-readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the control method as claimed in any one of claims 1-6.