Anti-acupuncture trocar for internal fistula puncture and system thereof
By designing a spring-loaded needle core mechanism and a probe isolation sleeve to prevent needle puncture, the risks of internal needle exposure and instability of ultrasound-guided operation during arteriovenous fistula puncture were solved. This achieved automatic isolation of the internal needle and simplification of aseptic operation, improving the safety and efficiency of puncture.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGZHOU HOSPITAL OF TRADITIONAL CHINESE MEDICINE
- Filing Date
- 2026-04-10
- Publication Date
- 2026-05-12
AI Technical Summary
In current arteriovenous fistula puncture procedures, the retraction of the internal needle relies on manual operation, resulting in prolonged needle tip exposure and a high risk of needle puncture injury. Furthermore, the probe isolation method during ultrasound-guided puncture is unstable, the operation is cumbersome, and it is difficult to balance aseptic requirements with efficiency.
A needle-proof cannula for arteriovenous fistula puncture was designed, comprising a spring-loaded needle core mechanism and a probe isolation sleeve. The inner needle is automatically retracted and isolated by rotating the long tube body. The probe isolation sleeve, composed of a thin film sleeve and a snap tie, ensures aseptic isolation and simplifies the operation.
It achieves instantaneous isolation of the inner needle, avoids the risk of needle puncture, simplifies the operation process, improves the safety and efficiency of puncture, and meets the aseptic requirements.
Smart Images
Figure CN122005028A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of medical device technology, specifically to an anti-needle-puncture cannula and its system for arteriovenous fistula puncture. Background Technology
[0002] Hemodialysis is a crucial long-term and recurring treatment for patients with end-stage renal disease. Arteriovenous fistulas (AVFs) are the most commonly used and safest vascular access method for hemodialysis, and their puncture is performed almost throughout the entire dialysis cycle. In clinical practice, AVF punctures typically need to be performed multiple times per week over a long period, placing high demands on puncture safety, stability, and occupational protection for healthcare workers.
[0003] Currently, arteriovenous fistula (AVF) puncture is generally performed using a cannula structure, where an inner and outer needle work together to puncture the blood vessel. After successful puncture, the inner needle is withdrawn, leaving only the outer needle for establishing blood access. However, most commonly used cannulas still rely on manual removal of the inner needle. This process inevitably leaves the inner needle exposed for a short period after successful puncture, especially in a hemodialysis environment where medical staff operate frequently and at a fast pace. This increases the risk of accidental needle tip injury due to factors such as hand slippage, involuntary patient limb movements, or limited operating angles.
[0004] Needlestick injuries not only cause immediate skin damage but also pose a risk of occupational exposure to bloodborne pathogens such as hepatitis B virus, hepatitis C virus, and human immunodeficiency virus, making them one of the major occupational safety hazards that dialysis unit medical staff have long faced. Although some medical institutions have reduced the risk by strengthening operational training or standardizing waste needle disposal procedures, the risk of needlestick injuries still objectively exists and cannot be fundamentally eliminated without changes to the structure of the instruments themselves.
[0005] To improve the success rate of arteriovenous fistula (AVF) puncture and reduce complications, ultrasound-guided AVF puncture has been increasingly adopted in clinical practice in recent years. Real-time ultrasound imaging guidance allows for more accurate assessment of the vessel's course, depth, and patency, making it particularly suitable for patients with poor vascular conditions or those who have experienced multiple failed punctures. However, during ultrasound-guided puncture, the ultrasound probe needs to directly contact the patient's skin and is often performed simultaneously with the puncture procedure, which places higher demands on the aseptic isolation of the probe.
[0006] Existing isolation sleeves for ultrasound probes mostly use thin film bags or disposable sleeve structures, which usually require the use of tape, rubber bands, or simple cable ties for fixation. This not only makes the installation process cumbersome, but also easily leads to problems such as insecure fixation, slippage, or local wrinkles during actual operation, affecting ultrasound imaging quality and even increasing the risk of cross-infection. In addition, frequent replacement of probe isolation sleeves increases the workload of medical staff and is not conducive to the efficient and orderly operation of the dialysis room.
[0007] In summary, existing arteriovenous fistula puncture-related instruments and systems still have at least the following shortcomings: First, the retraction of the internal needle after successful puncture depends on manual operation, resulting in long needle tip exposure time and a high risk of needlestick injury; second, there is a lack of reliable mechanism design that can automatically and quickly achieve internal needle isolation after puncture; third, the probe isolation method during ultrasound-guided puncture is not stable enough, the operation procedure is cumbersome, and it is difficult to balance aseptic requirements and operational efficiency.
[0008] To address these issues, the present invention provides an anti-needle-puncture cannula and its system for arteriovenous fistula puncture. Summary of the Invention
[0009] The purpose of this invention is to address the problems of the prior art mentioned in the background section by providing an anti-needle-puncture cannula and its system for arteriovenous fistula puncture.
[0010] To achieve the above objectives, the present invention provides the following technical solution:
[0011] A needle-proof cannula for arteriovenous fistula puncture includes a spring-loaded needle core, which consists of a short tube body, a long tube body, an inner needle, and a spring. The short tube body has a connector at its head and is connected to a retention needle, and a positioning groove is formed at its tail edge. The long tube body is rotatably connected to the tail of the short tube body, and two symmetrically arranged limiting blocks are fixed inside it. The inner needle passes through the short tube body and the long tube body, and a circular block is fixed in its middle. A positioning block is fixed on the circular surface of the circular block near the short tube body. The positioning block is inserted into the positioning groove. The circular surfaces on both sides of the circular block contact the tail of the short tube body and the limiting block, respectively. Two symmetrical release grooves are formed on the side of the circular block. The two release grooves are staggered from the two limiting blocks. The spring is sleeved on the inner needle and is located between the inner head of the short tube body and the circular block and is always in a compressed state.
[0012] Furthermore, a pair of cylinders are fixed to the outer side of the tail of the short tube, the head of the long tube is fitted onto the tail of the short tube, and a pair of circumferential guide grooves are opened on the side of the head of the long tube, with the two cylinders respectively set in the two guide grooves.
[0013] Furthermore, the length of the guide groove is greater than one-quarter of the circumference of the long tube cross-section and less than one-half of the circumference of the long tube cross-section.
[0014] Furthermore, the short tube and the long tube are connected by a plurality of conical connecting columns arranged in a ring array.
[0015] Furthermore, the retention needle consists of a first needle seat and an outer needle. The first needle seat is connected to the connector at the head of the short tube, and the outer needle is fixed on the first needle seat and is sleeved outside the inner needle.
[0016] Furthermore, the inner needle's front end protrudes from the outer needle's front end, and its rear end protrudes from the tail of the long tube and is fixed with a second needle seat.
[0017] Furthermore, the limiting block and the release groove are distributed at a 90° angle with the inner needle as the axis, and the limiting block can pass through the release groove.
[0018] The present invention also provides an arteriovenous fistula puncture system, which includes an anti-needle-puncture cannula for arteriovenous fistula puncture, and an ultrasound machine, wherein an ultrasound probe is connected to the ultrasound machine, and the head of the ultrasound probe is covered with a replaceable probe isolation sleeve.
[0019] Furthermore, the probe isolation sleeve consists of a thin film sleeve, thin straps, and a slipknot cable tie. The thin film sleeve is fitted over the head of the ultrasonic probe, and multiple evenly distributed thin straps are provided on the outer side of its opening. Both ends of each thin strap are fixed to the thin film sleeve to form perforations. The slipknot cable tie passes through these perforations and is fastened to the handle of the ultrasonic probe.
[0020] Furthermore, the outer side of the long tube is provided with an anti-accidental touch operation area and a non-operation area along the axial direction. The anti-accidental touch operation area is made of anti-slip elastic material and the non-operation area has a smooth surface structure. The long tube can only rotate relative to the short tube when the operator applies a rotational force to the anti-accidental touch operation area, thereby triggering the alignment of the limiting block and the release groove and causing the inner needle to retract, so as to avoid premature rebound of the inner needle due to accidental touch during puncture advancement or needle holding.
[0021] Compared with the prior art, the anti-needle-puncture cannula and system for arteriovenous fistula puncture provided by the present invention have the following beneficial effects:
[0022] 1. The anti-needle-puncture cannula for fistula puncture of the present invention, through a spring-loaded needle core mechanism composed of a short tube body, a long tube body, an inner needle, a spring, a circular block, a positioning block, a positioning groove, a limiting block and a release groove, allows the limiting block to align with the release groove simply by rotating the long tube body after successful puncture. The compressed spring then automatically drives the inner needle to quickly and completely retract into the short tube body, achieving instantaneous isolation of the inner needle and fundamentally avoiding the risk of needle puncture accidents during the needle withdrawal stage after puncture.
[0023] 2. The anti-needle-puncture cannula for arteriovenous fistula puncture uses multiple conical connecting posts arranged in a ring array between the short and long tubes to fix the long tube and prevent it from rotating accidentally during use. The conical design of the connecting posts makes it easy for the user to unscrew them so that the long tube can be rotated when needed.
[0024] 3. The anti-puncture cannula and its system for arteriovenous fistula puncture, by setting a probe isolation sleeve consisting of a thin film sleeve, a thin band and a slipknot ties on the ultrasound probe, and by passing the slipknot ties through the perforation of the thin band and tightening them, can quickly and securely achieve aseptic isolation and replacement of the probe, which significantly simplifies the preparation work before ultrasound-guided puncture. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the overall structure of the cannula needle of the present invention;
[0026] Figure 2 This is a magnified view of point A in the present invention;
[0027] Figure 3 This is a schematic diagram of the internal structure of the tube body in the extended state of the inner needle of the present invention;
[0028] Figure 4 This is a magnified view of point B in the present invention;
[0029] Figure 5 This is a schematic diagram of the short tube structure of the present invention;
[0030] Figure 6 This is a schematic diagram of the circular block structure of the present invention;
[0031] Figure 7 This is a schematic diagram of the internal structure of the tube body in the retracted state of the inner needle according to the present invention;
[0032] Figure 8 This is a schematic diagram of the overall structure of the fistula puncture system of the present invention.
[0033] Reference numerals: 1. Short tube body; 2. Long tube body; 3. Inner needle; 4. Spring; 5. Positioning groove; 6. Limiting block; 7. Circular block; 8. Positioning block; 9. Release groove; 10. Cylinder; 11. Guide groove; 12. Conical connecting column; 13. First needle seat; 14. Outer needle; 15. Second needle seat; 16. Ultrasonic probe; 17. Membrane sleeve; 18. Thin strap; 19. Loose-knot cable tie. Detailed Implementation
[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0035] Example 1: Please refer to Figures 1-8As shown, the anti-puncture cannula for arteriovenous fistula puncture includes a retaining needle and a spring-loaded needle core. The retaining needle consists of a first needle seat 13 and an outer needle 14, with the outer needle 14 fixed to the first needle seat 13. The spring-loaded needle core consists of a short tube body 1, a long tube body 2, an inner needle 3, and a spring 4. The head of the short tube body 1 has a connector, and the first needle seat 13 of the retaining needle is tightly inserted into the connector at the head of the short tube body 1. A positioning groove 5 is provided at the edge of the tail of the short tube body 1. The long tube body 2 is rotatably connected to... At the tail of the short tube 1, two symmetrically arranged limiting blocks 6 are fixed inside. The inner needle 3 penetrates the short tube 1 and the long tube 2, with its front end protruding from the front end of the outer needle 14 and its rear end protruding from the tail of the long tube 2 and fixed with a second needle seat 15. A circular block 7 is fixed in the middle of the inner tube 1, and a positioning block 8 is fixed on the circular surface of the circular block 7 near the side of the short tube 1. The positioning block 8 is inserted into the positioning groove 5. The cooperation between the positioning block 8 and the positioning groove 5 can limit the movement of the circular block 7 and the inner needle 3. Rotation and radial movement: The circular surfaces on both sides of the circular block 7 contact the tail of the short tube 1 and the limiting block 6 respectively, which are used to limit the axial movement of the circular block 7 and the inner needle 3, thereby ensuring the stability of the inner needle 3. Two symmetrical release grooves 9 are opened on the side of the circular block 7. The two release grooves 9 are staggered from the two limiting blocks 6. The spring 4 is sleeved on the inner needle 3. It is located between the inner head of the short tube 1 and the circular block 7 and is always in a compressed state. A pair of cylinders 10 are fixed on the outer side of the tail of the short tube 1. The head of the long tube 2 is sleeved on the tail of the short tube 1. A pair of circumferential guide grooves 11 are opened on the side of the head of the long tube 2. The two cylinders 10 are respectively set in the two guide grooves 11. The length of the guide groove 11 is greater than one-quarter of the circumference of the cross section of the long tube 2 and less than one-half of the circumference of the cross section of the long tube 2. This design allows the long tube 2 to rotate relative to the short tube 1 in a range of greater than 90° and less than 180°.
[0036] Example 2: To prevent the long tube 2 from rotating unexpectedly during the use of the cannula, causing the inner needle 3 to retract, multiple conical connecting posts 12 arranged in a ring array are connected between the short tube 1 and the long tube 2. The design of the conical connecting posts 12 can fix the long tube 2, preventing it from rotating unexpectedly under vibration, transportation, or other conditions. By forcefully rotating the long tube 2, the conical connecting posts 12 break, allowing the long tube 2 to rotate smoothly. The size of the release groove 9 allows the limiting block 6 to pass through smoothly. The limiting block 6 and the release groove 9 are arranged at a 90° angle with the inner needle 3 as the axis, so that after the long tube 2 rotates 90°, the limiting block 6 can pass through the release groove 9 smoothly, thereby releasing the restriction on the circular block 7. At this time, the spring 4 quickly extends, pushing the circular block 7 to the tail of the inner cavity of the long tube 2 through elastic force, thereby quickly retracting the tip of the inner needle 3 into the short tube 1.
[0037] Example 3: The anti-puncture cannula for arteriovenous fistula puncture is included in an arteriovenous fistula puncture system. This system also includes an ultrasound machine with an ultrasound probe 16 connected to it. The head of the ultrasound probe 16 is fitted with a replaceable probe isolation sleeve, which consists of a thin film sleeve 17, thin straps 18, and a slipknotted strap 19. The thin film sleeve 17 is made of medical-grade TPU material and is fitted onto the head of the ultrasound probe 16. Multiple evenly distributed thin straps 18 are provided on the outer side of the sleeve opening. Both ends of each thin strap 18 are fixed to the thin film sleeve 17 to form perforations. The slipknotted strap 19 passes through these perforations and is tightened on the handle of the ultrasound probe 16, thereby achieving quick and secure installation of the thin film sleeve 17, ensuring aseptic isolation of the probe during puncture, and allowing for easy replacement for different patients. This system combines an anti-puncture cannula with aseptic ultrasound guidance, improving the safety and operational efficiency of arteriovenous fistula puncture.
[0038] Example 4: When using this fistula puncture system, before operation, first put the film sleeve 17 on the head of the ultrasound probe 16, and use the slipknot cable ties 19 to pass through the holes of each thin strap 18 and tie them tightly to the handle to complete the assembly of the probe isolation sleeve. After using the B-ultrasound to guide and locate the puncture point, hold the cannula needle to perform the puncture. In the initial state, the positioning block 8 of the cannula needle is stuck in the positioning groove 5, the circular block 7 is held by the limiting block 6, and the spring 4 is in a compressed and stored state. During puncture, hold the cannula needle to make the inner needle 3 and the outer needle 14 puncture together. After successful puncture and the outer needle 14 enters the blood vessel, rotate the long tube body 2. The cylinder 10 slides along the guide groove 11, and the long tube body 2 drives the limiting block 6 on its inner side. Rotate synchronously by about 90 degrees until the limiting block 6 aligns with the release groove 9 on the circular block 7. At this point, the elastic force of the compressed spring 4 is released, pushing the circular block 7 to move towards the tail of the long tube 2. The positioning block 8 disengages from the positioning groove 5 of the short tube 1. Under the action of the spring 4, the inner needle 3 quickly retracts backward, and its needle tip is completely retracted into the short tube 1, thereby completing the automatic anti-needle puncture retraction and realizing anti-needle puncture protection to prevent the needle tip of the inner needle 3 from puncturing medical personnel. Afterward, leave the first needle seat 13 and the outer needle 14 in place, separate and properly dispose of the rebound needle core part after rebound. After each puncture, untie the slipknot 19 and replace the new film sleeve 17 to ensure aseptic operation.
[0039] Example 5: In this example, based on the anti-needle-puncture cannula and its system for arteriovenous fistula puncture described in Examples 1 to 4, the outer surface structure and operation prompting method of the long tube body 2 are further optimized to reduce the risk of accidental rotation triggering rebound during clinical use, while enhancing the operator's intuitive perception of the rebound state.
[0040] Specifically, the outer circumferential surface of the long tube 2 is provided with at least one anti-slip operating area along the axial direction. The anti-slip operating area is made of medical-grade elastic silicone or thermoplastic elastomer material and has a uniformly distributed anti-slip texture on its surface, which is used for the operator to rotate the tube after puncture. The outer surface of the non-anti-slip operating area is formed with a smooth structure, so that it is clearly distinguished from the anti-slip operating area in terms of touch, so that the operator can hold and rotate the long tube 2 only consciously, avoiding the long tube 2 from rotating due to hand slippage or accidental touch during the puncture advancement.
[0041] Meanwhile, at corresponding positions on the outer surfaces of the short tube 1 and the long tube 2, a first status marking area and a second status marking area are respectively set. The first status marking area is used to indicate the working state of "inner needle extended, not rebounding", and the second status marking area is used to indicate the safety state of "inner needle retracted, anti-needle puncture completed". The status marking areas can be distinguished by color, for example, the first status marking area is marked in red and the second status marking area is marked in green, or by tactile structures such as raised dots, grooves, and engraving lines.
[0042] In the initial state, the first state indicator area is visible from the outside, indicating that the inner needle 3 is in the extended state. When the operator rotates the long tube 2 to align the limiting block 6 with the release groove 9 and trigger the spring 4 to release and the inner needle 3 to retract, the long tube 2 changes angle relative to the short tube 1, making the second state indicator area visible to the outside, thereby providing the operator with clear and intuitive visual or tactile feedback, indicating that the anti-needle-puncture action has been completed.
[0043] In clinical practice, after the operator completes the arteriovenous fistula puncture under ultrasound guidance and confirms that the external needle 14 has successfully entered the blood vessel, the operator can automatically retract the internal needle 3 by rotating the long tube 2 while holding the anti-slip operation area. Subsequently, the operator can confirm whether the internal needle has been completely retracted by observing or touching the status indicator area. There is no need to check the needle tip position again or perform a secondary confirmation operation, thereby reducing operation steps and improving the efficiency of post-puncture treatment.
[0044] This embodiment, through comprehensive design of the operating area, anti-accidental touch structure, and status indication method, further improves the safety, operability, and human-centeredness of the cannula in real clinical environments without changing the original core structure and working principle of the spring-loaded needle core. It is particularly suitable for application scenarios with high-frequency punctures and high-intensity work, such as hemodialysis centers.
[0045] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A needle-proof cannula for arteriovenous fistula puncture, comprising a spring-loaded needle core, characterized in that, The spring-loaded needle core consists of a short tube (1), a long tube (2), an inner needle (3), and a spring (4). The head of the short tube (1) is provided with a connector and connected to a retaining needle. A positioning groove (5) is opened at the edge of its tail. The long tube (2) is rotatably connected to the tail of the short tube (1). Two symmetrically arranged limiting blocks (6) are fixed inside the long tube (2). The inner needle (3) passes through the short tube (1) and the long tube (2). A circular block (7) is fixed in the middle of the inner tube. The circular block (7) is close to the short tube (1). 1) A positioning block (8) is fixed on one side of the circular surface. The positioning block (8) is inserted into the positioning groove (5). The circular surfaces on both sides of the circular block (7) are in contact with the tail of the short tube (1) and the limiting block (6) respectively. Two symmetrical release grooves (9) are opened on the side of the circular block (7). The two release grooves (9) are staggered from the two limiting blocks (6). The spring (4) is sleeved on the inner needle (3). It is located between the head of the inner cavity of the short tube (1) and the circular block (7) and is always in a compressed state.
2. The anti-needle-puncture cannula for arteriovenous fistula puncture according to claim 1, characterized in that, A pair of cylinders (10) are fixed on the outer side of the tail of the short tube (1), and the head of the long tube (2) is fitted onto the tail of the short tube (1). A pair of circumferential guide grooves (11) are opened on the side of the head of the long tube (2), and the two cylinders (10) are respectively set in the two guide grooves (11).
3. The anti-needle-puncture cannula for arteriovenous fistula puncture according to claim 2, characterized in that, The length of the guide groove (11) is greater than one-quarter of the circumference of the cross section of the long tube (2) and less than one-half of the circumference of the cross section of the long tube (2).
4. The anti-needle-puncture cannula for arteriovenous fistula puncture according to claim 1, characterized in that, The short tube (1) and the long tube (2) are connected by a plurality of conical connecting columns (12) arranged in a ring array.
5. The anti-needle-puncture cannula for arteriovenous fistula puncture according to claim 1, characterized in that, The retention needle consists of a first needle seat (13) and an outer needle (14). The first needle seat (13) is connected to the connector at the head of the short tube (1), and the outer needle (14) is fixed on the first needle seat (13) and is sleeved outside the inner needle (3).
6. The anti-needle-puncture cannula for arteriovenous fistula puncture according to claim 5, characterized in that, The inner needle (3) protrudes from the front end of the outer needle (14), and its rear end protrudes from the tail of the long tube (2) and is fixed with a second needle seat (15).
7. The anti-needle-puncture cannula for arteriovenous fistula puncture according to claim 1, characterized in that, The limiting block (6) and the release groove (9) are distributed at a 90° angle with the inner needle (3) as the axis, and the limiting block (6) can pass through the release groove (9).
8. The anti-needle-puncture cannula for arteriovenous fistula puncture according to claim 1, characterized in that, The outer side of the long tube (2) is provided with an anti-accidental touch operation area and a non-operation area along the axial direction. The anti-accidental touch operation area is made of anti-slip elastic material and the non-operation area has a smooth surface structure. The long tube (2) can only rotate relative to the short tube (1) when the operator applies a rotational force to the anti-accidental touch operation area, thereby triggering the alignment of the limiting block (6) and the release groove (9) and causing the inner needle (3) to retract, so as to avoid premature rebound of the inner needle (3) due to accidental touch during puncture advancement or needle holding.
9. An arteriovenous fistula puncture system, comprising an anti-needle-puncture cannula for arteriovenous fistula puncture as described in any one of claims 1-7, further comprising an ultrasound device, characterized in that, The ultrasound machine is connected to an ultrasound probe (16), and the head of the ultrasound probe (16) is covered with a replaceable probe isolation sleeve.
10. The arteriovenous fistula puncture system according to claim 9, characterized in that, The probe isolation sleeve consists of a thin film sleeve (17), thin strips (18) and a slipknot cable tie (19). The thin film sleeve (17) is fitted over the head of the ultrasonic probe (16). Multiple thin strips (18) are evenly distributed on the outside of the sleeve opening. Both ends of each thin strip (18) are fixed to the thin film sleeve (17) to form perforations. The slipknot cable tie (19) passes through these perforations and is tied tightly to the handle of the ultrasonic probe (16).