Needle inserting auxiliary device suitable for arteriovenous puncture and using method
By combining a needle insertion assist device with color Doppler ultrasound measurement technology, rapid and accurate arterial and venous puncture operations have been achieved, solving the problem of inaccurate needle positioning, reducing patient pain, and improving the success rate of puncture.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-10
- Publication Date
- 2026-04-14
AI Technical Summary
During arteriovenous puncture procedures, it is difficult to accurately determine the depth of the puncture needle, especially for obese patients. The slow puncture speed leads to increased pain, and current technology makes it difficult to achieve fast and accurate puncture.
The device employs a needle insertion aid, including a puncture needle, an insertion tube, and an ejector assembly. The puncture depth and angle are measured using a portable color Doppler ultrasound machine. The movable push rod and limiting sleeve of the ejector assembly work together to ensure that the puncture needle enters the center of the vein or artery quickly and accurately. The support frame provides a fixed needle insertion angle.
It enables rapid and accurate insertion of the puncture needle, reduces patient pain response, improves puncture success rate, and alleviates local pain.
Smart Images
Figure CN121845705A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of medical device technology, specifically relating to a needle insertion auxiliary device and its usage method suitable for arterial and venous puncture. Background Technology
[0002] Arterial and venous puncture are commonly used invasive procedures in clinical practice, divided into arterial puncture (such as radial artery and femoral artery) and venous puncture (such as peripheral veins and central veins). The core objectives of the procedure include blood collection, hemodynamic monitoring, infusion, or catheter placement. Strict adherence to aseptic principles and precise positioning are required to reduce the risk of complications.
[0003] Clinically, arteries and veins are not easily visible on the skin, making it difficult to determine the depth of insertion. The needle needs to be inserted slowly to confirm the location of the vessel. However, the slow speed at which the needle enters the vessel can cause significant pain for the patient. At the same time, because arteries are located deeper than veins, they are difficult to visualize on the skin at the puncture site. For obese patients, the process of inserting the needle into the artery is even slower, requiring them to endure the pain of needle insertion for a longer period of time. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a needle insertion auxiliary device and its usage method that allows for fast puncture speed and is suitable for arterial and venous puncture.
[0005] The present invention adopts the following technical solution: A needle insertion aid device suitable for arterial and venous puncture includes a puncture needle, an installation tube, and an ejection assembly; A puncture needle includes a needle body, a cannula sleeved outside the needle body, a fixing wing on the needle body, and a connecting tube on one side of the cannula. The mounting tube includes a receiving cylinder, a positioning part disposed at the front end of the receiving cylinder, and a rear cover disposed at the rear end of the receiving cylinder. The rear cover is detachably connected to the receiving cylinder by threads. The ejector assembly includes a movable push rod movably mounted on the mounting tube, a limiting sleeve movably mounted on the movable push rod that abuts against the rear cover, and an elastic limiting member disposed between the movable push rod and the receiving tube. The puncture needle is detachably mounted at the end of the movable push rod.
[0006] Furthermore, the positioning part includes a first limiting groove and a second limiting groove extending inward from its end and a first extension section extending outward from its end. The first limiting groove allows the fixed needle wing to pass through, and the second limiting groove allows the connecting tube to pass through.
[0007] Furthermore, the movable push rod includes a main body section, a fixing part disposed at the front end of the main body section, and a fixing part disposed at the rear end of the main body section and cooperating with the limiting sleeve.
[0008] Furthermore, the fixing part includes a mounting groove extending vertically downward from its top surface to form a mounting groove for mounting a puncture needle, and a plurality of rubber protrusions arranged at intervals along the length of the mounting groove within the mounting groove.
[0009] Furthermore, the elastic limiting member includes a reset spring sleeved on the outer periphery of the fixed section and located inside the receiving cylinder, a first positioning block disposed on the main body section, and an elastic pressing rod rotatably disposed on the receiving cylinder. The top surface of the receiving cylinder has a positioning groove opposite to the first positioning block. When the elastic pressing rod abuts against the first positioning block, the reset spring is squeezed and deformed by the main body section.
[0010] Furthermore, the top of the receiving cylinder is formed with a relief seat communicating with the interior of the receiving cylinder. The elastic pressing rod includes a rotating section rotatably disposed in the relief seat, a second positioning block disposed at the lower end of the rotating section, a pressing block disposed at the upper end of the rotating section, and a V-shaped spring sheet disposed at the top of the receiving cylinder located in the relief seat. One side of the V-shaped spring sheet is connected to the side of the rotating section, and the other side is connected to the top of the receiving cylinder. When the rotating section rotates downward to press the V-shaped spring sheet, the second positioning block moves away from the first positioning block.
[0011] Furthermore, the elastic limiting component also includes a limiting pin and a limiting silicone ring. The limiting pin is movably disposed on the relief seat and can be located in the V-shaped spring, thereby limiting the downward rotation of the rotating segment. The limiting silicone ring is disposed on one side of the relief seat, and one end of the limiting pin can be embedded in the limiting silicone ring.
[0012] Furthermore, the fixing section includes a first threaded portion disposed on its outer periphery that engages with the threaded portion of the limiting sleeve and a spherical handle detachably disposed at its end, and a fixing bolt is disposed on one side of the limiting sleeve that can abut against the fixing section.
[0013] Furthermore, the installation tube also includes a support frame detachably mounted on the installation tube. The support frame includes a guide platform that can contact the epidermis of the patient's puncture site, an inclined platform mounted on the guide platform, and a fixing ring mounted at one end of the inclined platform and extending outward along the length of the inclined platform. The fixing ring can be sleeved on the outside of the receiving tube.
[0014] Furthermore, a rubber layer is provided on the inner circumference of the fixing ring, and when the fixing ring is sleeved on the outside of the receiving cylinder, the end of the extension section is located on the same plane as the lowest point of the inclined platform.
[0015] A method of using a needle insertion assist device suitable for arterial and venous puncture includes the following steps: Step 1: First, use a portable color Doppler ultrasound machine (c) to measure the vein or artery at the puncture site, and measure the vertical depth (d) between the epidermis at the puncture site and the center of the relative vein or artery. Then, define the puncture depth as (a) and the tilt angle of the inclined table as (b). Using the trigonometric function formula, we know that a = d / sinb. Here, the calculation formula can be set on the corresponding machine; simply input d and b into the machine to obtain a. Step 2: Set the pop-out distance of the movable push rod. First, pull the movable push rod outward, and then adjust the position of the limiting sleeve. The pop-out distance of the movable push rod is equal to the adjustment distance between the limiting sleeve and the rear cover of the installation tube. The adjustment distance = the insertion depth of the puncture needle + the length of the first extension section. Step 3: Puncture the vein or artery. First, place the insertion tube on the skin at the puncture site. Then, release the movable push rod through the elastic limiting element so that the puncture needle on the movable push rod is inserted into the center of the vein or artery, avoiding puncture of the vein or artery.
[0016] As can be seen from the above description of the present invention, compared with the prior art, the beneficial effects of the present invention are: the present application, through the cooperation between the puncture needle, the installation tube and the ejection assembly, and defining the specific structure of the ejection assembly, allows medical personnel to first determine the insertion depth of the puncture needle from the center position of the relative vein or artery based on the color Doppler ultrasound of the vein or artery at the puncture site of different patients, and then adjust the position of the limiting sleeve on the movable push rod so that the ejection distance of the movable push rod can be just inserted into the relative vein or artery, thereby realizing the rapid and accurate insertion of the puncture needle into the relative vein or artery, which can reduce the patient's pain response and improve the puncture success rate of medical personnel; By setting up a support frame, the insertion angle between the puncture needle and the skin at the puncture site is fixed and at the optimal insertion angle, making it easier to puncture the skin and blood vessels and reducing local pain; By the mutual cooperation between the fixing bolts on the limiting sleeve and the first threaded part on the fixed section, the limiting sleeve can be fixed in a suitable position on the fixed section, achieving a double fixing effect and preventing the limiting sleeve from rotating on the fixed section. Attached Figure Description
[0017] Figure 1 Schematic diagram of the needle insertion device Figure 1 .
[0018] Figure 2 Schematic diagram of the needle insertion device Figure 2 .
[0019] Figure 3 This is an exploded view of the needle insertion device.
[0020] Figure 4This is an exploded view of the installation pipe body.
[0021] Figure 5 This is a diagram showing the exploded structure of the pop-up component.
[0022] Figure 6 for Figure 1 Internal schematic diagram of part of the structure.
[0023] Figure 7 for Figure 2 Internal schematic diagram of part of the structure.
[0024] Figure 8 This is a partial structural diagram of the needle insertion device.
[0025] Figure 9 This is a schematic diagram showing the usage of the needle insertion device.
[0026] In the diagram: 1. Puncture needle; 11. Needle body; 12. Cannula; 13. Fixed needle wing; 14. Connecting tube; 2. Mounting tube body; 21. Receiving cylinder; 211. Positioning groove; 212. Leaving seat; 22. Positioning part; 221. First limiting groove; 222. Second limiting groove; 223. First extension section; 23. Rear cover; 24. Support frame; 25. Guide platform; 26. Inclined platform; 27. Fixing ring; 3. Pop-out assembly; 31. Movable push rod; 311. Main body section; 312. Fixing part; 313. Fixing section; 314. Mounting groove; 3 15. Rubber protrusion; 316. First threaded part; 317. Spherical handle; 32. Restricting sleeve; 321. Fixing bolt; 33. Elastic limiting component; 331. Limiting pin; 332. Limiting silicone ring; 34. Return spring; 35. First positioning block; 36. Elastic pressing rod; 361. Rotating section; 362. Second positioning block; 363. Pressing block; 364. V-shaped spring; 37. Distance sensor; 38. Display screen; a. Penetration depth; b. Tilt angle; c. Portable color ultrasound machine; d. Vertical depth; e. Projection indicator light. Detailed Implementation
[0027] The present invention will be further described below through specific embodiments.
[0028] like Figures 1 to 9 As shown, this embodiment provides a needle insertion auxiliary device suitable for arterial and venous puncture, including a puncture needle 1, an installation tube 2, and an ejection assembly 3.
[0029] The puncture needle 1 includes a needle body 11, a cannula 12 sleeved outside the needle body 11, a fixing wing 13 disposed on the needle body 11, and a connecting tube 14 disposed on one side of the cannula 12. In use, the fixing wing 13 can drive the needle body 11 to detach, and one end of the cannula 12 is placed in a vein or artery.
[0030] The mounting tube 2 includes a receiving cylinder 21, a positioning part 22 disposed at the front end of the receiving cylinder 21, a rear cover 23 disposed at the rear end of the receiving cylinder 21, and a support frame 24 detachably disposed on the mounting tube 2. The rear cover 23 is detachably connected to the receiving cylinder 21 by threads. Specifically, the positioning part 22 includes a first limiting groove 221 and a second limiting groove 222 extending inward from its end, and a first extension section 223 extending outward from its end. The first limiting groove 221 allows the fixed needle wing 13 to pass through, and the second limiting groove 222 allows... The connecting tube 14 is inserted through the tube; by setting the first limiting groove 221 and the second limiting groove 222, the relative position of the needle body 11 and the cannula 12 is limited to prevent the puncture needle 1 from rotating during ejection; further, the included angle between the first limiting groove 221 and the second limiting groove 222 is set at 90°; further, the support frame 24 includes a guide platform 25 that can contact the epidermis of the patient's puncture site, an inclined platform 26 set on the guide platform 25, and a fixed part set at one end of the inclined platform 26 and extending outward along the length of the inclined platform 26. The fixed ring 27 can be sleeved on the outside of the receiving cylinder 21; furthermore, multiple support frames 24 are provided, and the angles of the inclined platform 26 of the multiple support frames 24 are different, respectively set to various specifications such as 45°, 51°-60°, etc., so as to achieve different needle insertion angles; furthermore, a rubber layer is provided on the inner circumference of the fixed ring 27, and when the fixed ring 27 is sleeved on the outside of the receiving cylinder 21, the end of the first extension section 223 is on the same plane as the lowest point of the inclined platform 26; by providing a rubber layer, the distance between the fixed ring 27 and the receiving cylinder 21 is increased. The friction between the two makes it difficult for the fixing ring 27 to move on the receiving cylinder 21, thereby temporarily fixing the receiving cylinder 21 on the support frame 24. Furthermore, in use, the fixing ring 27 is fixedly sleeved on the outer periphery of the receiving cylinder 21, the positioning part 22 is parallel to the inclined table 26, the guide platform 25 is placed on the puncture site, and the first extension section 223 abuts against the epidermis. At this time, the needle insertion angle between the installation tube 2 and the epidermis is fixed, so that the puncture needle 1 is at the optimal needle insertion angle, making it easier to puncture the skin and blood vessels and reduce local pain.
[0031] The pop-out component 3 includes a movable push rod 31 movably mounted on the mounting tube 2, a limiting sleeve 32 movably mounted on the movable push rod 31 that abuts against the rear cover 23, and an elastic limiting member 33 disposed between the movable push rod 31 and the receiving tube 21. The puncture needle 1 is detachably mounted at the end of the movable push rod 31. Through the cooperation between the movable push rod 31, the limiting sleeve 32, and the elastic limiting member 33, the puncture needle 1 can be quickly and accurately inserted into the corresponding vein or artery, which can reduce the patient's pain response and improve the puncture success rate of medical staff. Specifically, the movable push rod 31 includes a main body section 311, a fixing part 312 disposed at the front end of the main body section 311, and a fixing part 313 disposed at the rear end of the main body section 311 that cooperates with the limiting sleeve 32. Further, the fixing part 312 includes a vertically downward extending part from its top surface to form a... The mounting groove 314 for mounting the puncture needle 1 and a plurality of rubber protrusions 315 arranged at intervals along the length of the mounting groove 314 are provided in the mounting groove 314. In use, the fixing wing 13 is embedded in the mounting groove 314, and its outer periphery abuts against the plurality of rubber protrusions 315, making it difficult to fall off. Furthermore, the fixing section 313 includes a first threaded portion 316 that is threadedly engaged with the limiting sleeve 32 on its outer periphery and a detachable ball handle 317 at its end. A fixing bolt 321 that abuts against the fixing section 313 is provided on one side of the limiting sleeve 32. By providing the first threaded portion 316 and the fixing bolt 321, the limiting sleeve 32 can be fixed in a suitable position on the fixing section 313, achieving a double fixing effect and preventing the limiting sleeve 32 from rotating on the fixing section 313. Furthermore, the fixing section 313 is provided with scale lines.
[0032] There are two specific ways to set up pop-up component 3 in this application, see below. Figure 1 As shown, this is a first embodiment of the pop-out component of this application, which includes a movable push rod 31, a limiting sleeve 32, and an elastic limiting member 33.
[0033] Reference Figure 8 As shown, this is a second embodiment of the pop-up component of this application. The difference from the first embodiment is that the pop-up component 3 further includes a distance sensor 37 and a display screen 38 connected to the distance sensor 37. The distance sensor 37 is disposed on the spherical handle 317 opposite to the limiting sleeve 32. The display screen 38 is disposed on the top of the spherical handle 317 and is used to display the distance between the limiting sleeve 32 and the spherical handle 317 measured by the distance sensor 37. The distance between the limiting sleeve 32 and the rear cover 23 can be calculated by the value measured by the distance sensor 37.
[0034] The elastic limiting member 33 includes a return spring 34 sleeved around the outer periphery of the fixed section 313 and located inside the receiving cylinder 21, a first positioning block 35 disposed on the main body section 311, and an elastic pressing rod 36 rotatably disposed on the receiving cylinder 21. A positioning groove 211 is formed on the inner top surface of the receiving cylinder 21, opposite to the first positioning block 35. When the elastic pressing rod 36 abuts against the first positioning block 35, the return spring 34 is deformed by the main body section 311. When the elastic pressing rod 36 disengages from the first positioning block 35, the return spring 34 returns to its original position, causing the limiting sleeve 32 and the movable push rod 31 to move in the piercing direction. When the limiting sleeve 32 abuts against the rear cover 23, the elastic pressing rod 36... The puncture needle 1 enters the relative vein or artery; specifically, the top of the receiving cylinder 21 is formed with a relief seat 212 communicating with the interior of the receiving cylinder 21, and the elastic pressing rod 36 includes a rotating section 361 rotatably disposed in the relief seat 212, a second positioning block 362 disposed at the lower end of the rotating section 361, a pressing block 363 disposed at the upper end of the rotating section 361, and a V-shaped spring piece 364 disposed at the top of the receiving cylinder 21 located in the relief seat 212; furthermore, one side of the V-shaped spring piece 364 is connected to the side of the rotating section 361, and the other side is connected to the top of the receiving cylinder 21. When the rotating section 361 rotates downward to squeeze the V-shaped spring piece 364, the second positioning block 362 moves away from the first positioning block 35.
[0035] There are two specific ways to set the flexible limiting component 33 in this application, such as Figure 1 As shown, this is a first embodiment of the elastic limiting member of this application, which includes a reset spring 34, a first positioning block 35 and an elastic pressing rod 36.
[0036] Reference Figure 8 The image shows a second embodiment of the elastic limiting member 33 of this application. The difference from the first embodiment is that the elastic limiting member 33 further includes a limiting pin 331 and a limiting silicone ring 332. The limiting pin 331 is movably disposed on the relief seat 212 and can be located within the V-shaped spring 364, thereby restricting the downward rotation of the rotating section 361. The limiting silicone ring 332 is disposed on one side of the relief seat 212, and one end of the limiting pin 331 can be embedded within the limiting silicone ring 332. The inner wall of the limiting silicone ring 332 can press against the outer wall of the limiting pin 331, making it difficult for the limiting pin 331 to detach from the relief seat 212. During use, medical personnel need to first remove the limiting pin 331 before pressing the rotating section 361, improving the safety of medical personnel during operation.
[0037] This application discloses a method for using a needle insertion assist device suitable for arterial and venous puncture. The method of using the needle insertion assist device described above involves the following steps: Step one: First, use a portable color Doppler ultrasound machine c to measure the vein or artery at the patient's puncture site, measuring the vertical depth d between the epidermis of the puncture site and the center of the relative vein or artery. Simultaneously, a projection indicator light e can be installed on the portable color Doppler ultrasound machine c. When the portable color Doppler ultrasound machine c is placed on the patient's skin at the puncture site, the projection indicator light e can display a horizontal reference line opposite to the vein or artery and multiple vertical reference lines spaced along the horizontal reference line on the patient's epidermis, facilitating the positioning of the needle insertion device. Then, define the insertion depth of the puncture needle 1 as a, and the tilt angle of the inclined table as b. Using trigonometric formulas, we know that a = d / sinb. Here, a can be obtained by setting a calculation formula on the corresponding machine; simply input d and b into the machine.
[0038] Step 2: Set the pop-out distance of the movable push rod 31. First, pull the movable push rod 31 outward through the ball handle 317 so that the first positioning block 35 and the second positioning block 362 abut against each other. Then, adjust the position of the limiting sleeve 32 on the fixed section 313. The pop-out distance of the movable push rod 31 is equal to the adjustment distance between the limiting sleeve 32 and the rear cover 23 of the mounting tube 2. The adjustment distance = the insertion depth of the puncture needle 1 + the length of the first extension section 223.
[0039] Step 3: Puncture the vein or artery. At this time, the support frame 24 is installed on the installation tube 2 and placed on the skin of the puncture site. The puncture needle 1 is aligned with the intersection of the horizontal reference line and one of the vertical reference lines. By pressing the elastic pressing rod 36, the movable push rod 31 is released, so that the puncture needle 1 on the movable push rod 31 is inserted into the center of the vein or artery, avoiding puncturing the vein or artery.
[0040] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.
Claims
1. A needle insertion auxiliary device suitable for arterial and venous puncture, characterized in that: Includes a puncture needle, an installation tube, and an ejection assembly; A puncture needle includes a needle body, a cannula sleeved outside the needle body, a fixing wing on the needle body, and a connecting tube on one side of the cannula. The mounting tube includes a receiving cylinder, a positioning part disposed at the front end of the receiving cylinder, and a rear cover disposed at the rear end of the receiving cylinder. The rear cover is detachably connected to the receiving cylinder by threads. The pop-out component includes a movable push rod movably mounted on the mounting tube, a limiting sleeve movably mounted on the movable push rod that can abut against the rear cover, and an elastic limiting member disposed between the movable push rod and the receiving tube. The puncture needle is detachably mounted at the end of the movable push rod. The installation tube also includes a support frame that can be detachably mounted on the installation tube. The support frame includes a guide platform that can contact the epidermis of the patient's puncture site, an inclined platform mounted on the guide platform, and a fixing ring that is mounted at one end of the inclined platform and extends outward along the length of the inclined platform. The fixing ring can be sleeved on the outside of the receiving tube. The positioning part includes a first limiting groove and a second limiting groove extending inward from its end and a first extension section extending outward from its end. The first limiting groove allows a fixed pin wing to pass through, and the second limiting groove allows a connecting tube to pass through.
2. The needle insertion auxiliary device for arterial and venous puncture according to claim 1, characterized in that: The movable push rod includes a main body section, a fixed part located at the front end of the main body section, and a fixed part located at the rear end of the main body section that cooperates with the limiting sleeve.
3. The needle insertion auxiliary device suitable for arterial and venous puncture according to claim 2, characterized in that: The fixing part includes a mounting groove extending vertically downward from its top surface to form a mounting groove for mounting a puncture needle, and a plurality of rubber protrusions arranged at intervals along the length of the mounting groove within the mounting groove.
4. The needle insertion auxiliary device for arterial and venous puncture according to claim 2, characterized in that: The elastic limiting component includes a reset spring sleeved on the outer periphery of the fixed section and located inside the receiving cylinder, a first positioning block disposed on the main body section, and an elastic pressing rod rotatably disposed on the receiving cylinder. The top surface of the receiving cylinder has a positioning groove opposite to the first positioning block. When the elastic pressing rod abuts against the first positioning block, the reset spring is squeezed and deformed by the main body section.
5. A needle insertion auxiliary device suitable for arterial and venous puncture according to claim 4, characterized in that: The top of the receiving cylinder has a relief seat that communicates with the inside of the receiving cylinder. The elastic pressing rod includes a rotating section that is rotatably disposed in the relief seat, a second positioning block disposed at the lower end of the rotating section, a pressing block disposed at the upper end of the rotating section, and a V-shaped spring sheet disposed at the top of the receiving cylinder and located in the relief seat. One side of the V-shaped spring sheet is connected to the side of the rotating section, and the other side is connected to the top of the receiving cylinder. When the rotating section rotates downward to press the V-shaped spring sheet, the second positioning block moves away from the first positioning block.
6. A needle insertion auxiliary device suitable for arterial and venous puncture according to claim 5, characterized in that: The elastic limiting component also includes a limiting pin and a limiting silicone ring. The limiting pin is movably disposed on the relief seat and can be located in the V-shaped spring, thereby limiting the downward rotation of the rotating section. The limiting silicone ring is disposed on one side of the relief seat, and one end of the limiting pin can be embedded in the limiting silicone ring.
7. A needle insertion auxiliary device suitable for arterial and venous puncture according to claim 2, characterized in that: The fixed section includes a first threaded portion disposed on its outer periphery that engages with the threaded portion of the limiting sleeve and a spherical handle disposed at its end. A fixing bolt is disposed on one side of the limiting sleeve that can abut against the fixed section.
8. A needle insertion auxiliary device suitable for arterial and venous puncture according to claim 1, characterized in that: The inner circumference of the fixing ring is provided with a rubber layer. When the fixing ring is sleeved on the outside of the receiving cylinder, the end of the extension section is located on the same plane as the lowest point of the inclined platform.
9. A method of using a needle insertion auxiliary device suitable for arterial and venous puncture, characterized in that: The method of using the acupuncture device as described in any one of claims 1-8 includes the following steps: Step 1: First, use a portable color Doppler ultrasound machine (c) to measure the vein or artery at the puncture site, and measure the vertical depth (d) between the epidermis at the puncture site and the center of the relative vein or artery. Then, define the puncture depth as (a) and the tilt angle of the inclined table as (b). Using the trigonometric function formula, we know that a = d / sinb. Here, the calculation formula can be set on the corresponding machine; simply input d and b into the machine to obtain a. Step 2: Set the pop-out distance of the movable push rod. First, pull the movable push rod outward, and then adjust the position of the limiting sleeve. The pop-out distance of the movable push rod is equal to the adjustment distance between the limiting sleeve and the rear cover of the installation tube. The adjustment distance = the insertion depth of the puncture needle + the length of the first extension section. Step 3: Puncture the vein or artery. First, place the insertion tube on the skin at the puncture site. Then, release the movable push rod through the elastic limiting element so that the puncture needle on the movable push rod is inserted into the center of the vein or artery, avoiding puncture of the vein or artery.