Intracardiac ultrasound catheter magnetic positioning system and using method thereof

Abstract

The invention provides a magnetic positioning system for an intracardiac ultrasound catheter, which is characterized by comprising a puncture needle positioned at the tail end of a mechanical arm; the ultrasonic catheter is an independent tubular device, and an ultrasonic device and a magnetic device are embedded in a far-end catheter body of the ultrasonic catheter; and a robot arm. The mechanical arm is provided with three modules: a signal acquisition module comprising an in-vitro sensing device; the position calculation module comprises a processor and a memory in which a target positioning algorithm is stored; and the catheter tracking module comprises a PID control chip. The magnetic device is arranged in the ultrasonic catheter, and the sensing device is arranged at the tail end of the mechanical arm, so that the system structure is simpler, and the positioning precision can be better guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to an intracardiac ultrasonic catheter magnetic positioning system and a use method thereof. Background Art

[0002] In minimally invasive cardiac surgery, the treatment of pericardial effusion requires interventional drainage with the aid of a puncture needle. Due to the complex anatomical structure around the heart, if the puncture positioning accuracy is insufficient, myocardial tissue or adjacent blood vessels may be accidentally injured, which will not only lead to treatment failure, but may also cause serious complications such as pericardial tamponade and arrhythmia, directly threatening the patient's life.

[0003] Traditional operations rely on manual positioning with the assistance of a puncture stand, that is, the doctor manually adjusts the puncture angle and depth based on subjective experience. This method has significant defects: first, the quality of the operation is highly dependent on the doctor's spatial perception ability and operational proficiency, which requires long-term training to master, and there are significant individual operational differences; second, there is a lack of real-time navigation and correction mechanism during manual advancement, which is easily disturbed by factors such as slight hand tremors and tissue deformation, resulting in an increased risk of puncture path deviation, which is particularly prominent during dynamic cardiac contraction or abnormal distribution of effusion.

[0004] Patent CN118383804A proposes a puncture positioning method based on magnetic navigation technology, the core of which is to achieve magnetic positioning by magnetizing the puncture needle and integrating multiple magnetic sensors inside the probe of the catheter. This technology uses magnetic sensors to collect the magnetic field information of the puncture needle, and then calculates the spatial position of the puncture needle in real time to guide the puncture needle to perform puncture. However, there are dual technical challenges in actual applications: on the one hand, the miniaturization design requirements of medical probes conflict with the spatial layout requirements of multiple sensors. The limited inner cavity space not only restricts the configuration density of magnetic sensors, but also increases the complexity of the structural design of the probe; on the other hand, the physical properties of the puncture needle magnetization process directly affect the positioning accuracy. Insufficient material magnetization uniformity will cause magnetic field characteristic distortion, which will then cause spatial positioning errors. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an intracardiac ultrasonic catheter magnetic positioning system and a method for using the same.

[0006] An intracardiac ultrasonic catheter magnetic positioning system, on which a puncture needle, an ultrasonic catheter and a mechanical arm are arranged;

[0007] The puncture needle is located at the end of the mechanical arm;

[0008] The ultrasonic catheter is an independent tubular device, and an ultrasonic device and a magnetic device are embedded in the distal end of the catheter;

[0009] The following three modules are arranged on the robot arm:

[0010] A signal acquisition module, including an in-vitro sensing device, is used to acquire the positioning signal of the magnetic device of the ultrasonic catheter;

[0011] A position calculation module, including a processor and a memory storing a target positioning algorithm, is used to calculate the real-time moving position of the ultrasonic catheter by the processor through the target positioning algorithm according to the positioning signal. The position calculation module is signal-connected to the signal acquisition module;

[0012] A catheter tracking module, including a PID control chip, is used to control the robotic arm to track the ultrasonic catheter in real time according to the real-time moving position until the ultrasonic catheter reaches the target position to be punctured. The catheter tracking module is signal-connected to the position calculation module.

[0013] Preferably, the puncture needle is a titanium alloy puncture needle with a diameter of 2.4 mm and a length of 60 mm.

[0014] Preferably, the in-vitro sensing device is located at the end of the robotic arm, the puncture needle is installed in the center of the in-vitro sensing device, and the puncture needle and the in-vitro sensing device are rigidly connected.

[0015] Preferably, the in-vitro sensing device is a magnetic sensor array with an adjacent sensor spacing of 40 mm and the number of sensors is not less than 5.

[0016] Preferably, the ultrasonic device is an ultrasonic transducer for detecting the target position to be punctured.

[0017] Preferably, the magnetic device is a permanent magnet for marking the real-time position of the ultrasonic catheter.

[0018] Preferably, the signal connection is to transmit data through shielded twisted pair or coaxial cable.

[0019] A usage method of an intracardiac ultrasonic catheter magnetic positioning system includes the steps of:

[0020] A doctor uses the ultrasonic catheter and the ultrasonic device to find the target position to be punctured;

[0021] The in-vitro sensing device of the robotic arm acquires the positioning signal of the magnetic device of the ultrasonic catheter;

[0022] According to the positioning signal, the processor calculates the real-time moving position of the ultrasonic catheter through the target positioning algorithm;

[0023] Based on the real-time moving position, the PID controller controls the robotic arm to track the ultrasonic catheter in vitro in real time until the ultrasonic catheter reaches the target position to be punctured;

[0024] The doctor performs the puncture work according to the target position.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention embeds the magnetic device in the ultrasonic catheter and arranges the sensor device at the end of the mechanical arm. The magnetic device is set as a permanent magnet and the sensor device is set as a magnetic sensor array. Compared with magnetizing the puncture needle and embedding the sensor in the ultrasonic catheter, the system structure is simpler, and the permanent magnet can provide a more stable magnetic field signal. The sensor array can arrange more sensors, and the positioning accuracy can be better guaranteed.

[0027] 2. During the positioning process, the present invention utilizes the real-time position of the robotic arm and the current position of the ultrasonic catheter to perform real-time navigation and correction. Compared with relying solely on manual judgment, it can reduce the risk of deviation and further improve the positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following is an introduction to the drawings of the relevant technical solution of the embodiment of the present invention. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solution of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 Schematic diagram of the structure of the intracardiac ultrasound catheter magnetic positioning system provided in an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of the positional relationship between the ultrasound catheter and the sensor array provided in an embodiment of the present invention;

[0031] Figure 3 It is a flow chart of the method of using the intracardiac ultrasound catheter magnetic positioning system provided in an embodiment of the present invention.

[0032] Explanation of the reference numerals: 1 - ultrasonic catheter; 2 - puncture needle; 3 - magnetic sensor array; 4 - robotic arm; 5 - ultrasonic device; 6 - magnetic device. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0034] In the description of the implementation of the present invention, unless otherwise clearly defined, terms such as "setting", "installation", "connection", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0035] An intracardiac ultrasound catheter magnetic positioning system is provided in an embodiment of the present invention. The structural composition of the positioning system is as Figure 1 shown, including: a robotic arm 4, a puncture needle 2, and an ultrasound catheter 1. Among them, the puncture needle 2 is located at the end of the robotic arm 4. There is also a magnetic sensor array 3 at the end of the robotic arm 4. The puncture needle 2 is installed in the center of the magnetic sensor array 3, and the puncture needle 2 and the magnetic sensor array 3 are rigidly fixed.

[0036] In an embodiment of the present invention, the ultrasound catheter 1 includes an ultrasound device 5 and a magnetic device 6. The ultrasound device 5 is used to detect the target position to be punctured, and the magnetic device 6 is used to mark the real-time position of the ultrasound catheter 1. The magnetic sensor array 3 performs positioning by collecting the magnetic data of the magnetic device 6. The positional relationship between the ultrasound catheter 1 and the sensor array 3 is as Figure 2 shown.

[0037] In an embodiment of the present invention, the robotic arm 4 is provided with the following three modules: a signal acquisition module, including an extracorporeal sensing device, for acquiring the positioning signal of the ultrasound catheter; a position calculation module, including a processor and a memory storing a target positioning algorithm, for calculating the real-time position of the ultrasound catheter according to the positioning signal, and the processor calculates the real-time position of the ultrasound catheter through the target positioning algorithm. The position calculation module is signal-connected to the signal acquisition module; a catheter tracking module, including a PID control chip, for controlling the robotic arm to track the ultrasound catheter in real time according to the real-time position until the ultrasound catheter reaches the target position to be punctured. The catheter tracking module is signal-connected to the position calculation module.

[0038] Specifically, the magnetic sensor array 3 is distributed in a 5*5 array, with a total of 25 three-axis magnetic sensors. The size of each sensor is 2mm×2mm×1mm, and the distance between the sensors is 40mm. A puncture needle 2 with a diameter of 2.4mm and a length of 60mm is installed in the center of the magnetic sensor array 3. The puncture needle 2 is fixed to the center of the magnetic sensor array 3 through a rigid connecting piece, perpendicular to the array plane. The connecting piece is made of non-magnetic titanium alloy material to avoid magnetic field interference. The complex of the magnetic sensor array 3 and the puncture needle 2 is installed at the end of the four-axis controlled robotic arm 4, and the mechanical and electrical connections are realized through a customized fixture.

[0039] On this basis, the doctor uses the ultrasound catheter 1 to find the position to be punctured in real time. During this process, the magnetic sensor array 3 identifies the magnetic signal of the magnetic device 6, and the real-time moving position of the ultrasound catheter 1 can be obtained by using the target positioning algorithm.

[0040] In the embodiments of the present invention, the target positioning algorithm adopts the Levenberg-Marquardt algorithm. The magnetic field strength decays with the cube of the distance, resulting in a highly non-linear relationship between the target position and the sensor data. The Levenberg-Marquardt algorithm adaptively switches between the gradient descent method and the Gauss-Newton method by dynamically adjusting the damping factor, effectively solving the non-linear least squares problem and achieving sub-millimeter positioning accuracy. By setting the initial damping factor and the maximum number of iterations, on the premise of ensuring accuracy, the Levenberg-Marquardt algorithm can converge to the target position within 15 to 20 iterations on average, and the single solution time is <2 ms, meeting the real-time tracking requirements of the robotic arm.

[0041] In other embodiments, the target positioning algorithm can also introduce the Unscented Kalman Filter (UKF) while retaining the Levenberg-Marquardt algorithm, adopting the LM+UKF hybrid architecture. The LM+UKF hybrid architecture synergistically combines non-linear filtering and non-linear optimization, uses the robotic arm motion model and historical data to predict the magnetic source position, solves the tracking delay problem caused by movement, performs local optimization based on the UKF prediction value, eliminates the model linearization error, improves the sub-millimeter positioning accuracy, and realizes high-precision positioning and tracking of magnetic targets in a dynamic environment. The LM+UKF hybrid architecture achieves a good balance among dynamic accuracy, anti-noise ability, and computational efficiency by integrating the advantages of non-linear filtering and optimization algorithms, and the accuracy is improved by 30% to 50% compared with pure LM.

[0042] Furthermore, the control of the robotic arm 4 adopts a dual-loop PID strategy. When the processor calculates the real-time moving position of the ultrasonic catheter according to the target positioning algorithm, the outer-loop PID immediately converts the deviation of the real-time moving position into joint torque commands, and these torque commands are then transmitted to the inner-loop PID. The inner-loop PID directly drives the motor, precisely adjusts the width and frequency of the voltage pulse by high-frequency sampling of the motor current, and ensures that the torque output by the motor conforms to the outer-loop command. This process repeats continuously. The outer loop updates the pose correction amount every 2 ms, and the inner loop fine-tunes the current at 5 times the speed. In this way, the robotic arm can track the ultrasonic catheter in real time until the ultrasonic catheter reaches the target position. The dual-loop PID can achieve the rapid response of the robotic arm and the high-precision tracking of the ultrasonic catheter through the coordination of the inner and outer loops.

[0043] In the embodiments of the present invention, the signal transmission mode between an intracardiac ultrasound catheter magnetic positioning system mainly takes wired connection as the core and wireless connection as the auxiliary. For the signal transmission mode between the signal acquisition module, the position calculation module and the catheter tracking module, shielded twisted pair or coaxial cable is used to transmit data. In this way, the transmission has strong anti-electromagnetic interference ability and low latency, ensuring the real-time performance of data during the positioning process. For the monitoring of the state of the robotic arm, such as vibration, etc., low-power Bluetooth is used, which can remotely monitor the state of the robotic arm and avoid the impact of the unstable state of the robotic arm on puncture.

[0044] The embodiments of the present invention also provide a usage method of an intracardiac ultrasound catheter magnetic positioning system. The method flow is as Figure 3 shown and includes:

[0045] The doctor uses the ultrasound catheter and the ultrasound device to find the target position that needs to be punctured;

[0046] The extracorporeal sensing device of the robotic arm acquires the positioning signal of the magnetic device of the ultrasound catheter;

[0047] According to the positioning signal, the processor calculates the real-time moving position of the ultrasound catheter through the target positioning algorithm;

[0048] Based on the real-time moving position, the PID controller controls the robotic arm to track the ultrasound catheter in vitro in real time until the ultrasound catheter reaches the target position that needs to be punctured;

[0049] The doctor performs the puncture work according to the target position.

[0050] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to the embodiments of the present invention without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An intracardiac ultrasound catheter magnetic positioning system, characterized in that: Includes puncture needle, ultrasound catheter and robotic arm; The puncture needle is located at the end of the mechanical arm; The ultrasonic catheter is an independent tubular device, and an ultrasonic device and a magnetic device are embedded in the distal end of the catheter; The following three modules are arranged on the robot arm: A signal acquisition module, including an in vitro sensing device, for acquiring positioning signals of the ultrasonic catheter magnetic device; A position calculation module, comprising a processor and a memory storing a target positioning algorithm, for calculating the real-time moving position of the ultrasonic catheter by the processor through the target positioning algorithm according to the positioning signal, and the position calculation module is signal-connected to the signal acquisition module; The catheter tracking module includes a PID control chip, which is used to control the mechanical arm to track the ultrasonic catheter in real time outside the body according to the real-time moving position until the ultrasonic catheter reaches the target position where puncture is required. The catheter tracking module is connected to the position calculation module by signal.

2. The intracardiac ultrasound catheter magnetic positioning system according to claim 1, characterized in that: The puncture needle is a titanium alloy puncture needle with a diameter of 2.4 mm and a length of 60 mm.

3. The intracardiac ultrasound catheter magnetic positioning system according to claim 1, characterized in that: The in vitro sensing device is located at the end of the mechanical arm, the puncture needle is installed in the center of the in vitro sensing device, and the puncture needle and the in vitro sensing device are rigidly connected.

4. The intracardiac ultrasound catheter magnetic positioning system according to claim 3, characterized in that: The in vitro sensing device is a magnetic sensor array, the distance between adjacent sensors is 40 mm, and the number of sensors is not less than 5.

5. The intracardiac ultrasound catheter magnetic positioning system according to claim 1, characterized in that: The ultrasonic device is an ultrasonic transducer used to detect the target position that needs to be punctured.

6. The intracardiac ultrasound catheter magnetic positioning system according to claim 1, characterized in that: The magnetic device is a permanent magnet, which is used to mark the real-time position of the ultrasonic catheter.

7. The intracardiac ultrasound catheter magnetic positioning system according to claim 1, characterized in that: The signal connection is a shielded twisted pair or a coaxial cable to transmit data.

8. A method for using the intracardiac ultrasound catheter magnetic positioning system according to any one of claims 1 to 7, characterized in that: include: Doctors use ultrasound catheters and ultrasound devices to find the target location that needs puncture; The in vitro sensor device of the robotic arm collects the positioning signal of the magnetic device of the ultrasonic catheter; According to the positioning signal, the processor calculates the real-time moving position of the ultrasound catheter through a target positioning algorithm; Based on the real-time moving position, the PID controller controls the robotic arm to track the ultrasound catheter in real time outside the body until the ultrasound catheter reaches the target position where puncture is required; The doctor performs puncture according to the target location.

Images