Real-time positioning method and system for tail end of PICC (peripherally inserted central catheter)

Abstract

The invention relates to the technical field of catheter tail end positioning, in particular to a PICC catheter tail end real-time positioning system and method. According to the invention, through mutual cooperation of the detection module and the external module, the effect of judging whether the tail end of the PICC enters the positioning target range is realized, and the positioning effect of the tail end of the PICC can be realized by eliminating in-vivo tissue interference based on the mapping relation between the magnetic field intensity gradient and the spatial position and also by utilizing the electromagnetic induction principle.

Description

Technical Field

[0001] The present invention relates to the technical field of catheter end positioning, and in particular to a real-time positioning system and method for a PICC catheter end. Background Art

[0002] Peripherally Inserted Central Catheter (PICC) is an important channel for enteral and parenteral nutrition for patients, and plays an important role in the treatment of critically ill newborns. The PICC catheter is an important route for parenteral nutrition. PICC catheterization is a catheterization technique in which the catheter tip is placed in the central vein through the peripheral vein. It is mainly used as a lifeline for patients who require medium- to long-term intravenous infusion and infusion of irritating drugs. After completing the PICC catheterization, it is necessary to determine whether the catheter tip is in the upper or lower cavity before it can be used safely, that is, the end of the PICC catheter must be positioned before it can be used safely.

[0003] Existing PICC catheter positioning methods include:

[0004] 1. X-ray localization: This method utilizes the penetrating properties of X-rays to image the human body and visualize the position of central venous catheters within the body. It is relatively simple to perform and can visually display the approximate position of the catheter within the body, making it a commonly used localization method in clinical practice. However, it lacks clarity regarding subtle positional changes or the relationship between the catheter and surrounding tissue, and cannot be observed in real time. Furthermore, X-rays are radioactive, increasing the risk of radiation exposure, especially for newborns undergoing repeated X-rays.

[0005] 2. Ultrasound positioning method: its principle is that the ultrasonic waves emitted by the ultrasound probe will produce reflection and scattering when encountering different tissue interfaces, forming an ultrasonic image, so that the position of blood vessels and catheters can be observed.

[0006] However, ultrasound machines are expensive and require high technical skills and experience from the operator. Professional training is required to accurately operate and judge ultrasound images.

[0007] 3. The electrocardiogram (ECG) method for assessing PICC position is based on the principle that, under normal circumstances, as the PICC catheter tip approaches the superior vena cava or inferior vena cava-right atrium junction (CAJ), corresponding changes in intracardiac electrophysiological activity occur. By acquiring intracardiac potential changes over an intracatheter guidewire or a dedicated guidewire and synchronously monitoring and comparing these changes with the surface ECG, the influence of the catheter tip, which may lead to inaccurate positioning, can be accurately determined.

[0008] For example, the patient's fat tissue may affect the conduction of ECG signals, making ECG changes less obvious; when the patient has heart disease or arrhythmia, it will also interfere with the judgment of normal electrical signals, thereby affecting the accurate assessment of the catheter position. This equipment and technology have high requirements and require special equipment and professional technicians to operate and judge, which to a certain extent increases the cost and limits its widespread application in primary medical institutions. In addition, due to the influence of physiological anatomy, this technology is relatively accurate for PICC positioning inserted in the upper limbs, but less accurate for PICC positioning in the lower limbs.

[0009] Although it has a certain degree of real-time performance compared to X-ray positioning, in actual operation, it may still require multiple attempts and repeated monitoring of ECG changes to determine whether the catheter is in the correct position. ECG positioning may produce false positive or false negative results, leading to misjudgment of the catheter position. For example, when the patient has electrolyte disorders, myocardial ischemia, etc., the ECG P wave itself may be abnormal, which can easily be confused with the P wave changes caused by abnormal catheter position, thereby affecting the accurate judgment of the catheter position. There are requirements for the patient's basic ECG: This method is mainly suitable for patients with obvious P waves on the basic ECG. If the patient's basic ECG P wave is not obvious or there are other abnormalities, it will be difficult to accurately assess the position through this method.

[0010] PICC catheters are widely used for long-term infusion, chemotherapy, and nutritional support. Their distal end must be precisely positioned at the junction of the superior vena cava and right atrium (CAJ). Traditional methods rely on X-ray or ultrasound guidance, which poses problems such as radiation exposure, complex operation, and inability to monitor in real time. Existing technologies (such as CN202310664045.8) achieve some functions through monitoring guidewires, but do not address the problem of dynamic positioning of the catheter distal end. Summary of the Invention

[0011] The purpose of the present invention is to solve the problems existing in the prior art and provide a method and system for real-time positioning of the end of a PICC catheter.

[0012] In order to solve the problems existing in the prior art, the present invention adopts the following technical solutions:

[0013] A method for real-time positioning of a PICC catheter end comprises the following steps:

[0014] Insert the guidewire with the detection module at the end into the PICC catheter so that the end of the guidewire and the end of the PICC catheter correspond to each other, and extend the PICC catheter into the human body so that the end of the PICC catheter is close to the target range;

[0015] The detection component cooperates with the external device to obtain real-time position information of the PICC catheter end. When the detection module enters or exceeds the target range, the external device sends a reminder signal to determine whether the position of the PICC catheter end is within the target range.

[0016] As an improvement to the technical solution of the real-time positioning method for the PICC catheter end of the present invention, the detection module is a detection module made of magnetic material, and the external device includes an induction coil wound around the human body and an ammeter connected to the induction coil;

[0017] When the detection module enters the target range, the detection module cuts the magnetic flux lines, and the pointer of the ammeter deflects.

[0018] As an improvement to the technical solution of the real-time positioning method for the PICC catheter end of the present invention, the target range includes a first limit and a second limit, and a first coil and a second coil are wound around the first limit and the second limit respectively, and the target range is enclosed between the first coil and the second coil;

[0019] When the medical staff inserts the PICC catheter with the guide wire into the human body, when the detection module corresponding to the end of the PICC catheter passes the first limit, the ammeter pointer deflects, and at this time the end of the PICC catheter enters the target range;

[0020] When the PICC catheter is further extended and the detection module corresponding to the end of the PICC catheter reaches the second limit, the ammeter pointer deflects. At this time, the end of the PICC catheter exceeds the target range. The medical staff retracts the end of the PICC catheter into the target range, and then pulls out the guide wire to use the PICC catheter normally.

[0021] As an improvement to the technical solution of the real-time positioning method for the PICC catheter end of the present invention, the detection module is a Hall sensor, and the external device is a magnetic field generator;

[0022] The magnetic field generator is placed above a corresponding target range outside the human body. When the medical staff extends the detection module corresponding to the end of the PICC catheter into the human body and does not enter the target range, the Hall sensor obtains a first magnetic field strength value; under the action of the magnetic field generator, when the detection module corresponding to the end of the PICC catheter enters the target range, the Hall sensor obtains a second magnetic field strength value;

[0023] When the difference between the first magnetic field strength value and the second magnetic field strength value gradually increases, the PICC catheter end approaches the target range; when the difference between the first magnetic field strength value and the second magnetic field strength value gradually decreases, the PICC catheter end moves away from the target range, and whether the PICC catheter end enters the target range is determined based on the difference between the second magnetic field strength value and the first magnetic field strength value.

[0024] When the end of the PICC catheter enters the target range, the medical staff can pull out the guide wire and use the PICC catheter normally.

[0025] As an improvement to the technical solution of the real-time positioning method for the PICC catheter end of the present invention, the detection module is a three-axis Hall sensor, and the three-axis Hall sensor is connected to the data processing module;

[0026] A coordinate system is established within the target range, and the x-axis, y-axis, and z-axis information of the PICC catheter end position is obtained through the three-axis Hall sensor to determine whether the PICC catheter end enters the target range.

[0027] A PICC catheter end real-time positioning system is used in the above-mentioned PICC catheter end real-time positioning method, and the PICC catheter end positioning system includes:

[0028] A PICC catheter comprises a hollow catheter body and a guide wire inserted into the catheter body, wherein the end of the guide wire corresponds to the position of the end of the PICC catheter;

[0029] a detection module, which is arranged at the end of the guidewire and extends into the human body along with the guidewire and the catheter body;

[0030] The external device is connected to the detection module and cooperates with the detection module to obtain whether the real-time position of the end of the PICC catheter enters the target range.

[0031] As an improvement to the technical solution of the real-time positioning system for the PICC catheter end of the present invention, the detection module is a magnetic detection module, and the external device includes an induction coil wound around the human body and an ammeter connected to the induction coil;

[0032] The guide wire is a non-magnetic guide wire, and the detection module is provided at the end of the guide wire. When the detection module passes the position of the induction collar, the pointer of the ammeter is deflected.

[0033] As an improvement to the technical solution of the real-time positioning system for the PICC catheter end of the present invention, the guidewire is a non-magnetic guidewire made of Ag999 material; the detection module is a detection module made of holmium metal or iron-based nano-gold material.

[0034] As an improvement to the technical solution of the real-time positioning system for the PICC catheter end of the present invention, the detection module is a Hall sensor, the external device is a magnetic field generator, and wires connected to the Hall sensor and a power source are passed through the PICC catheter.

[0035] According to whether the position of the PICC catheter end enters the target range, and under the action of the magnetic field generator, the Hall sensor obtains a first magnetic field strength value and a second magnetic field strength value respectively, and determines whether the PICC catheter end enters the target range according to the difference between the second magnetic field strength value and the first magnetic field strength value.

[0036] As an improvement to the technical solution of the real-time positioning system for the PICC catheter end of the present invention, the detection module is a three-axis Hall sensor, wires connected to the Hall sensor and a power supply are passed through the PICC catheter, and the three-axis Hall sensor is also connected to a data processing terminal;

[0037] The three-axis Hall sensor is used to obtain real-time position information of the PICC catheter end; a coordinate system is established within the target range, and the x-axis, y-axis and z-axis of the PICC catheter end position are obtained through the three-axis Hall sensor to determine whether the PICC catheter end enters the target range.

[0038] Beneficial effects of the present invention:

[0039] 1. The present invention's real-time PICC catheter tip location system and method lacks X-ray radiation but possesses real-time location capabilities not available from X-rays. Compared to methods for assessing PICC location using ultrasound or electrocardiography, the system and method are less technically challenging and simpler to perform. Furthermore, the system is more accurate than electrocardiography and less susceptible to external or internal influences.

[0040] 2. The present invention is used for PICC terminal positioning, which is simpler and more convenient than existing positioning technologies, and has high safety and accuracy. It greatly reduces the risk of X-ray exposure and is therefore easier to promote and apply in clinical work;

[0041] 3. In the present invention, the detection module and the external device cooperate with each other to realize the effect of whether the end of the PICC catheter enters the positioning target range. The interference of the tissue in the body can be eliminated based on the mapping relationship between the magnetic field intensity gradient and the spatial position. The electromagnetic induction principle can also be used to realize the positioning effect of the end of the PICC catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flow chart of the real-time positioning method for a PICC catheter of the present invention;

[0043] Figure 2 This is a positioning diagram of Example 2-1 of the real-time positioning system for a PICC catheter of the present invention;

[0044] Figure 3 This is a structural connection diagram of Example 2-2 of the PICC catheter real-time positioning system of the present invention;

[0045] Figure 4 This is a positioning diagram of Embodiment 2-3 of the PICC catheter real-time positioning system of the present invention.

[0046] Explanation of reference numerals: 1-PICC catheter; 2-detection module; 3-coil; 4-ammeter; 5-power supply; 6-guidewire; 7-electrical wire; 8-target range. DETAILED DESCRIPTION

[0047] In order to make the purpose of the invention, technical solutions and beneficial effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0048] Example 1

[0049] like Figures 1 to 4 As shown, the present invention provides a real-time positioning method for a PICC catheter 1, comprising the following steps:

[0050] Insert the guidewire 6 with the detection module 2 at the end into the PICC catheter 1 so that the end of the guidewire 6 corresponds to the end of the PICC catheter 1, and extend the PICC catheter 1 into the human body so that the end of the PICC catheter 1 is close to the target range 8;

[0051] By cooperating with the detection component and the external device, the real-time position information of the end of the PICC catheter 1 is obtained. When the detection module 2 enters or exceeds the target range 8, the external device sends a reminder signal to determine whether the position of the end of the PICC catheter 1 is within the target range 8.

[0052] In the present invention, a guide wire 6 is inserted into the PICC catheter 1, and the end of the guide wire 6 is connected to the detection module 2. The PICC catheter 1 drives the guide wire 6 and the detection module 2 into the human body, so that the end of the PICC catheter 1 and the detection module 2 are close to the target range 8;

[0053] Through the cooperation of the detection module 2 and the external device, the position information of the end of the PICC catheter 1 is obtained to determine whether the end of the PICC catheter 1 has entered the target range 8.

[0054] The present invention forms a precise closed-loop positioning feedback mechanism through the cooperation of the detection module 2 and the external equipment, which can avoid the errors of traditional blind insertion or imaging positioning, improve the accuracy of catheterization, and reduce the risk of complications such as vascular damage and ectopic position caused by position deviation. At the same time, it does not need to rely on imaging equipment to reduce radiation exposure and medical costs. It can also continuously monitor the displacement after catheterization, adapt to the dynamic environment of the human body, and the standardized operation process is easy to promote, providing an efficient and safe PICC catheter 1 positioning method for clinical use. Through magnetic field sensing and dynamic data processing, a PICC catheter 1 positioning system with both accuracy, safety and economy is constructed, breaking through the limitations of traditional catheterization technology and providing a more efficient solution for clinical vascular access establishment.

[0055] Example 1-1

[0056] The detection module 2 is a detection module 2 made of magnetic material, and the external device includes an induction coil 3 wound around the human body and an ammeter 4 connected to the induction coil 3;

[0057] When the detection module 2 enters the target range 8 , the detection module 2 cuts the magnetic flux lines, and the pointer of the ammeter 4 deflects.

[0058] In this embodiment, based on the principle of electromagnetic induction, the real-time magnetic field induction monitoring of the terminal position of the PICC catheter 1 is realized through the cooperation of the magnetic detection module 2 and the induction coil 3. When the detection module 2 enters the target range 8 and cuts the magnetic flux lines, the pointer deflection of the ammeter 4 provides an intuitive position reminder, assists in precise positioning, and avoids catheterization deviation or complications caused by blind operation.

[0059] Furthermore, the target range 8 includes a first limit and a second limit, and the first coil 3 and the second coil 3 are wound around the first limit and the second limit respectively, and the target range 8 is enclosed between the first coil 3 and the second coil 3;

[0060] When the medical staff inserts the PICC catheter 1 with the guide wire 6 into the human body, when the detection module 2 at the end of the PICC catheter 1 passes the first limit, the pointer of the ammeter 4 deflects, and the end of the PICC catheter 1 enters the target range 8;

[0061] When the PICC catheter 1 is further extended, when the detection module 2 corresponding to the end of the PICC catheter 1 reaches the second limit, the pointer of the ammeter 4 deflects. At this time, the end of the PICC catheter 1 exceeds the target range 8. The medical staff retracts the end of the PICC catheter 1 to the target range 8, and then pulls out the guide wire 6 to use the PICC catheter 1 normally.

[0062] In detail, in this embodiment, taking the PICC catheterization of the lower limbs of children or newborns as an example, T8-T10 is the target range, and the T8 position and the T10 position are the first limit and the second limit of the target range 8 respectively. The first induction coil 3 and the second induction coil 3 are correspondingly set at the first limit and the second limit, and the target range 8 is enclosed between the first induction coil 3 and the second induction coil 3.

[0063] When the medical staff inserts the PICC catheter 1 with the guide wire 6 into the human body, when the detection module 2 at the end of the PICC catheter 1 passes the T10 position, the pointer of the ammeter 4 deflects, and the end of the PICC catheter 1 enters the target range 8;

[0064] When the PICC catheter 1 is further extended and the detection module 2 corresponding to the end of the PICC catheter 1 reaches the T8 position, the pointer of the ammeter 4 deflects. At this time, the end of the PICC catheter 1 exceeds the target range 8. The medical staff retracts the end of the PICC catheter 1 to the target range 8, and then pulls out the guide wire 6 to use the PICC catheter 1 normally.

[0065] Specifically, when the distal end of PICC catheter 1 moves, it drives the magnetic detection component at the distal end past coil 3, cutting the magnetic flux lines and generating a current. External ammeter 4 detects the change in current to determine whether the distal end of PICC catheter 1 enters or exceeds target range 8. Detection module 2 is highly magnetic, and coil 3 is highly magnetically sensitive.

[0066] It should be noted here that when PICC is placed in the lower limbs, taking pediatrics and neonates as an example, the end of the lower limb PICC is located in the inferior vena cava above the level of the diaphragm, and does not enter the right atrium, which is roughly equivalent to the position between T8 and T10. Generally, a chest X-ray is required after placement to check and determine the position of the catheter end. T8 and T10 are used to describe the position of the catheter end relative to the thoracic spine on the chest X-ray. T8 is the level of the 8th thoracic vertebra, and T10 is the level of the 10th thoracic vertebra. Since the position of the catheter end is too deep (such as entering the heart) may cause danger, and the position is too shallow (such as in the upper part of the superior vena cava), it may slip during use. Therefore, accurately judging the position of the catheter end is crucial to ensuring the safety and effectiveness of PICC placement.

[0067] Preferably, the guidewire 6 is a non-magnetic guidewire made of Ag999, and the detection module 2 is made of holmium metal or iron-based nano-gold. The highly sensitive induction coil 3 in the electromagnetic reaction is made of Permalloy, which has extremely high magnetic permeability, allowing magnetic lines of force to gather and pass efficiently.

[0068] In a weak magnetic field, Permalloy can generate a strong magnetic induction intensity and can keenly sense small changes in magnetic lines of force. In the actual operation of this embodiment, it has been verified through COMSOL simulation calculations and experimental data has been obtained to achieve the effect of real-time positioning of the end of the PICC catheter 1.

[0069] In more detail, when the distal end of the PICC catheter 1 enters the T10 position range from the lower limb blood vessel, the pointer of the ammeter 4 will deflect for the first time, indicating that it has entered the second limit position (T10).

[0070] The PICC catheter 1 continues to be inserted, and when the pointer of the ammeter 4 deflects for the second time, it indicates that it has entered the first limit (T8). The PICC insertion depth is then adjusted according to clinical needs to achieve the effect of positioning the end of the PICC catheter 1, solving the clinical problem.

[0071] It is important to ensure that the winding directions of the two induction coils 3 are opposite so that the direction of deflection of the ammeter 4 can be distinguished in the subsequent operation. The medical staff uses a puncture needle to puncture the peripheral vein of the lower limb where the PICC is to be placed, such as the great saphenous vein, small saphenous vein, popliteal vein, etc.

[0072] For example, when the lower limbs are used as puncture points, two high-magnetic sensitivity induction coils 3 are wrapped around the neonate's body at positions T10 and T8, respectively. The area between T10 and T8 is the ideal and safe infusion location for the end of the indwelling PICC catheter 1. The two induction coils 3 are connected to an ammeter 4.

[0073] Insert the PICC with the built-in guide wire 6 into the blood vessel and advance it gradually. When the pointer of the ammeter 4 deflects to one side, it indicates that the tip of the PICC has entered the T10 position (the lowest position of the first limit). Continue to insert the PICC slowly, and the pointer of the ammeter 4 will gradually return to zero. Continue to insert the PICC slowly, and the pointer of the ammeter 4 will deflect to the other side, indicating that the tip of the PICC has reached the T8 position (the highest position of the second limit). At this time, the PICC can be pulled out an appropriate distance until the pointer of the ammeter 4 returns to zero, but at this time, care must be taken to avoid the third deflection of the ammeter 4 to prevent the end of the PICC from reaching the lowest position T10. At this time, it can be judged that the end of the PICC is between T8-T10, and this position is the conventional safe infusion position for the tip of the PICC.

[0074] If the upper limb is used as the puncture point, two high magnetic sensitivity induction coils 3 are respectively wrapped around the T4 and T6 positions on the body surface. When the PICC terminal is located between T4-T6, it is equivalent to the PICC terminal being located in the lower 1 / 3 of the superior vena cava, close to the junction of the superior vena cava and the right atrium, and not entering the right atrium. The judgment principle is the same as that of lower limb PICC catheterization.

[0075] In this embodiment, the magnetic body of the guide wire 6 cuts the magnetic flux lines when moving in the magnetic field of the induction coil 3 to generate current, so that the pointer of the external ammeter 4 deflects twice in sequence when the catheter approaches the target position, thereby accurately defining the first limit and the second limit, and limiting the target position between the two, forming a visual interval positioning reference, avoiding the error of single threshold positioning, and improving the accuracy of the catheter placement; the design of the end of the high magnetic guide wire 6 can ensure that the two deflection signals correspond to the critical states of the end of the guide wire 6 entering and leaving the induction coil 3, respectively, making the current change characteristics more significant and easy to identify, so that the operator can intuitively judge the relative position of the catheter end; there is no need to rely on imaging equipment such as X-rays, only By monitoring the changes in the 4 pointers of the ammeter, the changes in the magnetic field intensity during the movement of the catheter tip can be monitored in real time, achieving non-invasive, radiation-free dynamic positioning, reducing the risk of radiation exposure for patients and medical staff, while reducing dependence on expensive imaging equipment, reducing medical costs and improving the feasibility of bedside catheterization; the dual-limit interval positioning mechanism provides a safe movement boundary for the catheter tip, which can effectively avoid complications such as vascular damage and catheter dislocation caused by over-insertion or under-insertion. Combined with real-time current detection feedback, the operator can adjust the catheter position in time during the catheterization process, shortening the operation time and improving the efficiency and safety of catheterization. It has a simple structure and is easy to operate, making it suitable for promotion and application in primary medical scenarios.

[0076] Example 1-2

[0077] The detection module 2 is a Hall sensor, and the external device is a magnetic field generator;

[0078] Still taking lower limb PICC catheterization as an example, the magnetic field generator is placed above the corresponding target range 8 outside the human body (i.e., the upper and middle segments of the inferior vena cava (IVC)). When the medical staff inserts the detection module 2 corresponding to the end of the PICC catheter 1 into the human body and does not enter the target range 8, the Hall sensor obtains a first magnetic field strength value. Under the action of the magnetic field generator, when the detection module 2 corresponding to the end of the PICC catheter 1 enters the target range 8, the Hall sensor obtains a second magnetic field strength value.

[0079] When the difference between the first magnetic field strength value and the second magnetic field strength value gradually increases, the end of the PICC catheter 1 is close to the target range 8; when the difference between the first magnetic field strength value and the second magnetic field strength value gradually decreases, the end of the PICC catheter 1 is away from the target range 8, and the difference between the second magnetic field strength value and the first magnetic field strength value changes to determine whether the end of the PICC catheter 1 enters the target range 8;

[0080] When the distal end of the PICC catheter 1 enters the target range 8 , the medical staff can pull out the guide wire 6 and use the PICC catheter 1 normally.

[0081] In detail, this embodiment is based on the mapping relationship between the magnetic field intensity gradient and the spatial position. Since the Hall sensor can obtain the magnitude of the magnetic field intensity at its location, and since the magnetic field generator is arranged above the target range 8, when the distance between the Hall sensor and the target range 8 is smaller, the magnetic field intensity will change significantly, and the magnetic field intensity value obtained by the Hall sensor arranged at the end of the guide wire 6 (the end of the PICC catheter 1) will be larger. When the end of the PICC catheter 1 does not enter the target range 8, the magnetic field intensity change will not change significantly.

[0082] That is, before entering the target range 8, the first magnetic field strength value is close to the original magnetic field strength value, that is, the first magnetic field strength value does not change much relative to the original magnetic field strength value; when the end of the PICC catheter 1 enters the target range 8, the magnetic field strength value obtained by the Hall sensor set at the end of the guide wire 6 (the end of the PICC catheter 1) is the second magnetic field strength value. At this time, the difference between the second magnetic field strength value and the original magnetic field strength value becomes significantly larger. At this time, medical personnel can determine whether the Hall sensor set at the end of the guide wire 6 (the end of the PICC catheter 1) has reached the target range 8 based on the magnitude of the change in magnetic field strength.

[0083] Alternatively, when the distal end of the PICC catheter 1 does not enter the target range 8, the Hall sensor obtains the first magnetic field strength value, and since the distance between the Hall sensor and the magnetic field generator is relatively far, the magnetic field strength does not change significantly.

[0084] When the distal end of the PICC catheter 1 gradually enters the target range 8 , the distance between the Hall sensor and the magnetic field generator gradually decreases, and the magnetic field intensity value obtained by the Hall sensor gradually increases.

[0085] As the distal end of the PICC catheter 1 continues to extend into the human body, after the magnetic field strength reaches a certain value, the magnetic field strength value will gradually decrease due to the gradual increase in the distance between the Hall sensor and the magnetic field generator.

[0086] That is, as the distal end of the PICC catheter 1 is inserted into the human body and under the action of the magnetic field generator, the magnetic field strength value obtained by the Hall sensor will gradually increase. When the distance between the Hall sensor and the magnetic field generator is the smallest, the magnetic field strength value obtained by the Hall sensor is the largest.

[0087] When the end of the PICC catheter 1 does not enter the target range 8, the Hall sensor obtains a first magnetic field strength value. As the end of the PICC catheter 1 is extended into the human body, the Hall sensor obtains a second magnetic field strength value in real time. When the difference between the first magnetic field strength value and the second magnetic field strength value gradually increases, the end of the PICC catheter 1 is close to the target range 8; when the difference between the first magnetic field strength value and the second magnetic field strength value gradually decreases, the end of the PICC catheter 1 is away from the target range 8. The difference between the second magnetic field strength value and the first magnetic field strength value changes to determine whether the end of the PICC catheter 1 has entered the target range 8.

[0088] When the distal end of the PICC catheter 1 enters the target range 8 , the medical staff can pull out the guide wire 6 and use the PICC catheter 1 normally.

[0089] As a specific example of this embodiment, the external device is a wearable magnetic field generator, which is worn on the chest wall of the human body.

[0090] Preferably, the Hall sensor is the Melexis MLX90288 magnetic Hall sensor. The Melexis MLX90288 magnetic Hall sensor is small in size and manufactured using advanced CMOS technology. It has 4 metal layers, a feature size of only 350nm, and a die size of 2.08mm x 1.50mm. It is not only compact in size, but also has exquisite manufacturing technology, excellent performance and stability, and is suitable for newborns.

[0091] Preferably, the frequency of the gradient magnetic field generated by the magnetic field generator is a medium frequency, which is 1-10kHz. As a specific example of this embodiment, the wearable magnetic field generator is worn on the patient's chest wall, and the frequency of the gradient magnetic field it generates is 1-10kHz and the intensity is 0.1-1mT. Since 1-10kHz belongs to the medium frequency range, (low-frequency magnetic fields (<1kHz) have weak penetration and mainly act on the surface; high-frequency (>100kHz) penetrates deeper but can easily cause tissue overheating), the magnetic field it generates can penetrate the skin, muscles and superficial tissues, penetrate 2-5cm deep into the subcutaneous tissue (depending on the frequency and medium), and can directly act on deep nerves, blood vessels or lesions. The magnetic field intensity of 0.1-1mT is within the safety threshold (international safety standards recommend long-term exposure of no more than 0.3μT, i.e. 0.3mT), which can avoid the risk of cell damage or gene mutation. The medium-frequency magnetic field does not produce the muscle contraction or tingling sensation common in low-frequency electrotherapy, and the patient has high tolerance and is suitable for long-term wear. Furthermore, magnetic fields with specific frequencies and waveforms can regulate the release of neurotransmitters (such as dopamine and serotonin), improving anxiety, insomnia, or chronic pain. Medium-frequency magnetic field generators do not require complex cooling systems and can be integrated into lightweight wearable devices (such as vests and chest straps).

[0092] During positioning, the PICC catheter 1, with a guidewire 6 inserted, is inserted into the human body, bringing the end of the PICC catheter 1 close to the target location. A Hall sensor located at the end of the guidewire 6 (the end of the PICC catheter 1) detects changes in the magnetic field intensity at the end of the PICC catheter 1 in real time. A controllable gradient magnetic field is generated by an external device, and a magnetic field calibration module automatically compensates for the geomagnetic field or environmental interference to adjust the gradient magnetic field intensity signal. This signal is then transmitted back to the data processing terminal via a wireless communication module. The data processing terminal processes the gradient intensity signal to obtain the coordinates of the end of the PICC catheter 1. These coordinates are then compared with the coordinates of the target location. If they match, positioning is complete; if not, the gradient magnetic field intensity signal is further adjusted.

[0093] The data processing terminal includes a function for displaying the magnetic field strength at the end of the PICC catheter 1. When the magnetic field strength changes, the processor sends an over-limit alarm signal.

[0094] In some embodiments of the present invention, the real-time positioning system for the end of the PICC catheter 1 also includes a data processing terminal, which includes a processor for displaying the coordinate value or magnetic field strength of the end of the PICC catheter 1. A coordinate area of ​​the target range 8 is preset in the processor. When the preset coordinate area is exceeded or when the magnetic field strength changes, the processor issues an over-limit alarm signal.

[0095] In some embodiments of the present invention, the wireless communication component may be a Bluetooth module or a Zigbee module. The principle is the same as that in the prior art and will not be described in detail here.

[0096] Examples 1-3

[0097] The detection module 2 is a three-axis Hall sensor, which is located at the end of the guidewire 6 inserted into the PICC catheter 1. The Hall sensor is connected to the data processing module through a wireless communication module, and a coordinate system is established within the target range 8. The x-axis, y-axis and z-axis of the end position of the PICC catheter 1 are obtained through the Hall sensor to determine whether the end of the PICC catheter 1 enters the target range 8.

[0098] The data processing terminal includes a function for displaying the coordinate value of the end of the PICC catheter 1. A coordinate area of ​​a target range 8 is preset in the processor. When the preset coordinate area is exceeded, the processor sends an over-limit alarm signal.

[0099] The three-axis Hall sensor can be used to synchronously obtain the magnetic field strength data and position information of the catheter end in three-dimensional space (x-axis, y-axis, and z-axis), realize three-dimensional perception of the spatial position of the catheter end, accurately capture tiny displacements in any direction, and avoid the limitations of two-dimensional positioning; the controllable gradient magnetic field generated by the magnetic field generator can actively act on the catheter end, guide it to move to the target position through the magnetic field force, change passive adjustment to active control, shorten position calibration time, and improve operational efficiency; the controllability of the gradient magnetic field enables the system to dynamically calculate the second position information of the catheter end according to the real-time magnetic field intensity change data, and combine the data processing module to compare and judge the position coordinate range. Automated feedback of the current positioning process reduces errors caused by human intervention; the combination of three-dimensional detection and active magnetic field control can accurately navigate the catheter in complex vascular structures to bypass branches or curved paths, improving the success rate of deep or variant blood vessel catheterization. At the same time, non-contact magnetic field force adjustment can avoid mechanical vascular damage and reduce the risk of complications; the entire system does not require the assistance of traditional imaging equipment. While reducing radiation exposure, the standardized three-dimensional data processing process makes the positioning results more objective and reliable, adapting to the needs of rapid bedside catheterization and dynamic monitoring of long-term indwelling catheters, providing clinical practice with a PICC catheter positioning solution that is both accurate, safe and intelligent.

[0100] Example 2

[0101] Another aspect of the present invention provides a real-time positioning system for the end of a PICC catheter 1, which is used in the real-time positioning method for the end of a PICC catheter 1 as described above. The PICC catheter 1 end positioning system includes a PICC catheter 1, a detection module 2, and an external device; wherein the PICC catheter 1 includes a hollow catheter body and a guidewire 6 inserted into the catheter body, and the end of the guidewire 6 corresponds to the position of the end of the PICC catheter 1; the detection module 2 is arranged at the end of the guidewire 6 and extends into the human body along with the guidewire 6 and the catheter body; the external device is connected to the detection module 2 and cooperates with the detection module 2 to obtain whether the real-time position of the end of the PICC catheter 1 enters the target range 8.

[0102] Through the cooperation of detection module 2 and external equipment, the real-time and accurate monitoring of the terminal position of PICC catheter 1 is achieved, providing dynamic feedback for the catheterization process, avoiding problems such as catheter misplacement, excessive depth or shallowness, and improving catheterization safety and operational efficiency.

[0103] Example 2-1

[0104] The detection module 2 is a magnetic detection module 2, and the external device includes an induction coil 3 wound around the human body and an ammeter 4 connected to the induction coil 3;

[0105] The guide wire 6 is non-magnetic, and a detection module 2 is provided at the end of the guide wire 6. When the detection module 2 passes through the position of the induction collar, the pointer of the ammeter 4 is deflected.

[0106] Preferably, the guide wire 6 is a non-magnetic guide wire 6 made of Ag999 material; the detection module 2 is a detection module 2 made of holmium metal or iron-based nano-gold material.

[0107] The effect of this embodiment is consistent with that of embodiment 1-1.

[0108] Example 2-2

[0109] The detection module 2 is a Hall sensor, the external device is a magnetic field generator, and a wire 7 connected to the Hall sensor and the power supply 5 is passed through the PICC catheter 1;

[0110] Depending on whether the position of the end of the PICC catheter 1 enters the target range 8, and under the action of the magnetic field generator, the Hall sensor obtains a first magnetic field strength value and a second magnetic field strength value respectively, and determines whether the end of the PICC catheter 1 enters the target range 8 according to the difference between the second magnetic field strength value and the first magnetic field strength value.

[0111] The effects of this embodiment are consistent with those of Embodiments 1-2.

[0112] Example 2-3

[0113] The detection module 2 is a three-axis Hall sensor. Wires 7 connected to the Hall sensor and the power supply 5 are provided in the PICC catheter 1. The three-axis Hall sensor is also connected to a data processing terminal.

[0114] The real-time position information of the end of the PICC catheter 1 is obtained through a three-axis Hall sensor; a coordinate system is established within the target range 8, and the x-axis, y-axis and z-axis of the position of the end of the PICC catheter 1 are obtained through the three-axis Hall sensor to determine whether the end of the PICC catheter 1 enters the target range 8.

[0115] The effects of this embodiment are consistent with those of embodiments 1-3.

[0116] In Example 2-2 and Example 2-3, the real-time positioning system for the end of the PICC catheter 1 also includes a data processing terminal, which includes a processor for displaying the coordinate value or magnetic field strength of the end of the PICC catheter 1. A coordinate area of ​​the target range 8 is preset in the processor. When the preset coordinate area is exceeded or when the magnetic field strength changes significantly, the processor issues an over-limit alarm signal.

[0117] The significant change mentioned above refers to the situation where the second magnetic field strength change value obtained after the Hall sensor set at the end of the guidewire 6 (the end of the PICC catheter 1) enters the target range 8 has a larger difference in magnetic field strength than the original magnetic field strength value.

[0118] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. A real-time positioning method for the end of a PICC catheter, characterized in that: The following steps are included: Insert the guidewire with the detection module at the end into the PICC catheter so that the end of the guidewire and the end of the PICC catheter correspond to each other, and extend the PICC catheter into the human body so that the end of the PICC catheter is close to the target range; The detection component cooperates with the external device to obtain real-time position information of the PICC catheter end. When the detection module enters or exceeds the target range, the external device sends a reminder signal to determine whether the position of the PICC catheter end is within the target range.

2. The real-time positioning method for the PICC catheter tip according to claim 1, characterized in that: The detection module is a detection module made of magnetic material, and the external device includes an induction coil wound around the human body and an ammeter connected to the induction coil; When the detection module enters the target range, the detection module cuts the magnetic flux lines, and the pointer of the ammeter deflects.

3. The real-time positioning method for the PICC catheter tip according to claim 2, characterized in that: The target range includes a first limit and a second limit, the first limit and the second limit are respectively wound with a first coil and a second coil, and the first coil and the second coil form the target range; When the medical staff inserts the PICC catheter with the guide wire into the human body, when the detection module corresponding to the end of the PICC catheter passes the first limit, the ammeter pointer deflects, and at this time the end of the PICC catheter enters the target range; When the PICC catheter is further extended and the detection module corresponding to the end of the PICC catheter reaches the second limit, the ammeter pointer deflects. At this time, the end of the PICC catheter exceeds the target range. The medical staff retracts the end of the PICC catheter into the target range, and then pulls out the guide wire to use the PICC catheter normally.

4. The real-time positioning method for the PICC catheter tip according to claim 1, characterized in that: The detection module is a Hall sensor, and the external device is a magnetic field generator; The magnetic field generator is placed above a corresponding target range outside the human body. When the medical staff extends the detection module corresponding to the end of the PICC catheter into the human body and does not enter the target range, the Hall sensor obtains a first magnetic field strength value; under the action of the magnetic field generator, when the detection module corresponding to the end of the PICC catheter enters the target range, the Hall sensor obtains a second magnetic field strength value; When the difference between the first magnetic field strength value and the second magnetic field strength value gradually increases, the PICC catheter end approaches the target range; when the difference between the first magnetic field strength value and the second magnetic field strength value gradually decreases, the PICC catheter end moves away from the target range, and whether the PICC catheter end enters the target range is determined based on the difference between the second magnetic field strength value and the first magnetic field strength value. When the end of the PICC catheter enters the target range, the medical staff can pull out the guide wire and use the PICC catheter normally.

5. The real-time positioning method for the PICC catheter tip according to claim 1, wherein the detection module is a three-axis Hall sensor connected to the data processing module; A coordinate system is established within the target range, and the x-axis, y-axis, and z-axis information of the PICC catheter end position is obtained through the three-axis Hall sensor to determine whether the PICC catheter end enters the target range.

6. A real-time positioning system for the end of a PICC catheter, characterized in that: Used in the real-time positioning method for the PICC catheter end according to any one of claims 1 to 5, the PICC catheter end positioning system comprises: A PICC catheter comprises a hollow catheter body and a guide wire inserted into the catheter body, wherein the end of the guide wire corresponds to the position of the end of the PICC catheter; a detection module, which is arranged at the end of the guidewire and extends into the human body along with the guidewire and the catheter body; The external device is connected to the detection module and cooperates with the detection module to obtain whether the real-time position of the end of the PICC catheter enters the target range.

7. The PICC catheter tip real-time positioning system according to claim 6, characterized in that: The detection module is a magnetic detection module, and the external device includes an induction coil wound around the human body and an ammeter connected to the induction coil; The guidewire includes a guidewire body and a guidewire end, the guidewire end being tightly connected to the guidewire body and integrally formed. The guidewire body is a non-magnetic guidewire, and the end of the guidewire is provided with the detection module. When the detection module passes the position of the induction collar, the pointer of the ammeter is deflected.

8. The PICC catheter tip real-time positioning system according to claim 7, characterized in that: The guide wire is a non-magnetic guide wire made of Ag999 material; the detection module is a detection module made of holmium metal or iron-based nano-gold material.

9. The PICC catheter tip real-time positioning system according to claim 6, characterized in that: The detection module is a Hall sensor, the external device is a magnetic field generator, and wires connected to the Hall sensor and a power source are passed through the PICC catheter. According to whether the position of the PICC catheter end enters the target range, and under the action of the magnetic field generator, the Hall sensor obtains a first magnetic field strength value and a second magnetic field strength value respectively, and determines whether the PICC catheter end enters the target range according to the difference between the second magnetic field strength value and the first magnetic field strength value.

10. The PICC catheter tip real-time positioning system according to claim 6, characterized in that: The detection module is a three-axis Hall sensor, and wires connected to the Hall sensor and a power supply are passed through the PICC catheter, and the three-axis Hall sensor is also connected to a data processing terminal; The three-axis Hall sensor is used to obtain real-time position information of the PICC catheter end; a coordinate system is established within the target range, and the x-axis, y-axis and z-axis of the PICC catheter end position are obtained through the three-axis Hall sensor to determine whether the PICC catheter end enters the target range.

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