Blood sampling pen with needle withdrawing function

Abstract

The invention relates to the technical field of medical instruments, in particular to a blood sampling pen with a needle withdrawing function, which comprises a pen container, a pen point and a pen cap, an inner sleeve is movably connected in the pen container, an ejection device for ejecting a blood sampling needle is arranged in the inner sleeve, and a needle withdrawing channel is arranged in the ejection device. A needle withdrawing assembly is mounted in the needle withdrawing channel; the pen point is detachably connected to the inner sleeve, and an adjusting thread is arranged on the peripheral face of the pen point. One end face of the pen cap is provided with a needle outlet used for popping out a blood taking needle, a plurality of frosted protruding particles are distributed around the periphery of the needle outlet, and the frosted protruding particles are used for making contact with the skin of the human body and transferring pain. By arranging the needle withdrawing assembly, the needle head can be ejected out through pressing after blood sampling to finish needle withdrawing, the situation that a user pulls out the blood sampling needle manually and contaminates blood on the needle head is effectively avoided, the risk of cross infection is reduced, and the danger of manual needle pulling is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a blood collection pen with needle withdrawal function. Background Technology

[0002] A lancing pen is a pen-shaped blood collection device used in conjunction with a disposable sterile lancet to collect peripheral blood samples. It's a manual, ejector-type auxiliary blood collection device. The lancing pen is reusable, while the lancet is for single use only to prevent cross-infection. A traditional lancing pen is cylindrical and consists of three main parts: a depth adjustment mechanism, an ejection mechanism, and a pen barrel. Its operation is as follows: unscrew the pen cap, insert the lancet, tighten the cap, adjust the appropriate puncture depth, pull the cap at the end of the pen to load the needle, press the top of the pen cap against the finger, and press the release button to collect blood. After collection, unscrew the cap and remove the lancet. However, this type of lancing pen requires manual removal of the lancet after collection, posing a certain risk and increasing the risk of cross-infection.

[0003] Currently, some existing blood collection pens also have a needle withdrawal function. For example, patent CN216060524U discloses a blood collection pen with a needle withdrawal function, which mainly adds a needle withdrawal rod at the needle cap position to facilitate needle withdrawal after blood collection. The structure is simple and practical, reducing the risk of needle removal. However, when drawing blood from patients, due to the use of a catapult launch method, the vibration is large when the elastic rod ejects the needle, which can easily cause strong pain to the patient. After the needle withdrawal is completed, the needle withdrawal rod inside the blood collection pen still needs to be manually reset, which is inefficient. Summary of the Invention

[0004] In order to address the technical deficiencies mentioned in the background art, the purpose of this invention is to provide a blood collection pen with a needle withdrawal function. This blood collection pen can alleviate or reduce pain during blood collection, thereby relieving discomfort for the person being punctured. At the same time, it effectively avoids the user manually pulling out the blood collection needle and getting blood on the needle tip, reducing the risk of cross-infection and lowering the danger of manually pulling out the needle.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A lancing pen with needle retraction function, including

[0007] A pen holder, wherein an inner sleeve is movably connected inside the pen holder, and an ejection device for ejecting blood collection needles is provided inside the inner sleeve. The ejection device has a built-in needle withdrawal channel, and a needle withdrawal assembly is installed in the needle withdrawal channel.

[0008] The pen tip is detachably connected to the inner sleeve, and an adjustment thread is provided on the outer circumferential surface of the pen tip;

[0009] The pen cap is threaded onto the pen tip. One end of the pen cap has a needle outlet hole for ejecting the blood collection needle. Multiple frosted bumps are distributed around the circumference of the needle outlet hole. The frosted bumps are used to contact human skin and transfer pain.

[0010] The needle withdrawal assembly includes a needle withdrawal rod, a return spring, and a needle removal cap. The needle withdrawal rod is installed in the elastic channel, with one end abutting against the blood collection needle and the other end extending outward beyond the cap and connecting to the needle removal cap. The return spring is sleeved on the outside of the needle withdrawal rod, with one end abutting against the elastic launching device and the other end connecting to the needle removal cap. Pressing the needle removal cap drives the needle withdrawal rod to slide along the needle withdrawal channel and push out the blood collection needle.

[0011] Preferably, the ejection device includes an ejection cylinder for mounting the blood collection needle, a guide plate, an ejection arm, and an elastic rod. The ejection cylinder, guide plate, ejection arm, and elastic rod are integrally formed. The ejection cylinder has an ejection cavity for mounting the blood collection needle. The guide plate is connected between the ejection cylinder and the elastic rod. One end of the ejection arm is fixedly connected to the guide plate, and there is a certain angle between the ejection arm and the guide plate. The elastic rod is composed of multiple clamping plates, and an elastic stop is integrally formed at the end of the elastic rod.

[0012] Preferably, the pen holder is further provided with a retaining ring, which is connected to the pen holder by an interference fit, and the retaining ring has a first opening that allows the elastic rod to pass through, and a limiting spring is sleeved on the outer side of one end of the elastic rod extending out of the retaining ring.

[0013] Preferably, an elastic pressing part is provided on the outer circumferential surface of the pen holder at the position corresponding to the ejector arm, and the elastic pressing part is circumferentially hollowed out; a guide rib is provided on the inner circumferential surface of the pen holder, and the guide rib is slidably connected to the inner sleeve so that the inner sleeve can move back and forth in a straight line along the pen holder.

[0014] Preferably, the inner sleeve is a columnar structure with an opening on one side, and a second opening is provided on the closed end face of the inner sleeve to allow the elastic rod 54 to pass through. Both the first opening and the second opening are straight-line structures.

[0015] Preferably, the outer surface of the inner sleeve is provided with a limiting protrusion ring for limiting the return position. The diameter of the limiting protrusion ring is larger than the diameter of the inner sleeve, and the limiting protrusion ring is adapted to the pen holder.

[0016] Preferably, the inner sleeve is provided with a positioning groove on the left side surface of the limiting protrusion ring. The positioning groove is slidably connected with the ejector arm so that the inner sleeve is accurately guided by the guide rib. The inner sleeve is provided with a retaining groove on the right side surface of the limiting protrusion ring. The retaining groove is an L-shaped structure and is circumferentially distributed along the outer circumference of the inner sleeve.

[0017] Preferably, the inner sleeve has multiple guide grooves distributed circumferentially on its inner and outer circumferential surfaces. The guide grooves on the outer circumferential surface are connected to the guide ribs. The guide grooves on the inner circumferential surface are engaged with the guide plates. When the inner sleeve is pulled to move along the pen holder axis, the ejection device can be prepared to load along the guide grooves.

[0018] Preferably, a first locking block adapted to the slot is provided on the inner circumferential surface of the pen tip, and the first locking block and the slot are fixedly connected by rotation and engagement.

[0019] Preferably, the outer peripheral wall of the pen cap is provided with multiple position markings along the circumferential direction of the pen cap, each position marking corresponding to a different puncture depth, and the outer side of the pen tip is provided with an indicator marking that cooperates with the position markings; the inner peripheral wall of the pen cap is provided with a second locking block that cooperates with the adjusting thread, so that different positions can be adjusted by rotating the pen cap.

[0020] In summary, the beneficial effects of the present invention are as follows:

[0021] This invention features multiple frosted bumps around the needle outlet of the pen cap. These bumps contact the skin, reducing or alleviating pain during blood collection and thus alleviating discomfort for the person being pierced. Simultaneously, a needle retraction component allows the needle to be pushed out after blood collection by pressing, effectively preventing the user from manually removing the needle and contaminating it with blood, reducing the risk of cross-infection, and minimizing the danger of manual needle removal. Furthermore, the precise coordination of all components within the lancing pen ensures stable and accurate operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the blood collection pen with needle withdrawal function of the present invention;

[0023] Figure 2 This is an exploded view of the blood collection pen with needle withdrawal function of the present invention;

[0024] Figure 3 This is a front view of the blood collection pen with needle withdrawal function of the present invention;

[0025] Figure 4 yes Figure 3 A cross-sectional view of the AA plane;

[0026] Figure 5This is a schematic diagram of the pen holder structure in this invention;

[0027] Figure 6 This is a schematic diagram of the pen tip structure in this invention;

[0028] Figure 7 This is a schematic diagram of the pen cap structure in this invention;

[0029] Figure 8 This is a schematic diagram of the other side of the pen cap in this invention;

[0030] Figure 9 This is a schematic diagram of the inner sleeve in this invention;

[0031] Figure 10 This is a schematic diagram of the ejection device in this invention;

[0032] Figure 11 This is a schematic diagram of the needle retraction assembly in this invention;

[0033] Figure 12 This is a schematic diagram of the fixing ring structure in this invention.

[0034] Explanation of the reference numerals in the figure:

[0035] 1. Pen holder; 11. Elastic pressing part; 12. Guide rib; 2. Pen tip; 21. Adjusting thread; 22. First locking block; 23. Indicator mark; 3. Pen cap; 31. Needle outlet hole; 32. Frosted protrusion; 33. Stop mark; 34. Second locking block; 4. Inner sleeve; 41. Second opening; 42. Limiting protrusion; 43. Positioning groove; 44. Locking groove; 45. Guide groove; 5. Ejection device; 51. Ejection tube; 511. Ejection cavity; 52. Guide plate; 53. Ejection arm; 54. Elastic rod; 541. Elastic stop block; 6. Needle retraction assembly; 61. Needle retraction rod; 62. Return spring; 63. Needle removal cap; 7. Fixing ring; 71. First opening; 8. Limiting spring. Detailed Implementation

[0036] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0037] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0038] In the description of this invention, the use of terms such as "a number" means one or more, with "more than" meaning two or more. Terms like "greater than," "less than," and "exceeding" are understood to exclude the stated number, while terms like "above," "below," and "within" are understood to include the stated number. The use of terms like "first," "second," and "third" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, the number of indicated technical features, or the sequential relationship between indicated technical features.

[0039] The following is combined with Figure 1-12 The following is a more detailed description of an embodiment of the blood collection pen with needle withdrawal function of the present invention.

[0040] A lancing pen with needle retraction function, such as Figure 1 , 2 As shown in Figures 10 and 11, the device includes a pen holder 1, an inner sleeve 4 is movably connected inside the pen holder 1, an ejection device 5 for ejecting blood collection needles is provided inside the inner sleeve 4, the ejection device 5 has a built-in needle withdrawal channel, and a needle withdrawal assembly 6 is installed in the needle withdrawal channel.

[0041] The pen tip 2 is detachably connected to the inner sleeve 4, and the outer circumferential surface of the pen tip 2 is provided with an adjustment thread 21.

[0042] The pen cap 3 is threaded onto the pen tip 2. One end face of the pen cap 3 has a needle outlet hole 31 for ejecting the blood collection needle. Multiple frosted protrusions 32 are distributed around the needle outlet hole 31. The frosted protrusions 32 are used to contact human skin and transfer pain.

[0043] The needle withdrawal assembly 6 includes a needle withdrawal rod 61, a return spring 62, and a needle removal cap 63. The needle withdrawal rod 61 is installed in the elastic channel, with one end abutting against the blood collection needle and the other end extending outward beyond the pen cap 3 and connecting to the needle removal cap 63. The return spring 62 is sleeved on the outside of the needle withdrawal rod 61, with one end abutting against the elastic launching device and the other end connecting to the needle removal cap 63. By pressing the needle removal cap 63, the needle withdrawal rod 61 is driven to slide along the needle withdrawal channel and push out the blood collection needle.

[0044] Specifically, when using this lancing pen with a needle withdrawal function, preparation work is first performed. The lancing needle is installed in the ejector device 5, and the desired puncture depth is adjusted by rotating the pen cap 3. Then, the end of the pen cap 3 with the frosted protrusions 32 is pressed against the finger or other blood collection site. The frosted protrusions 32 on the pen cap 3 contact the skin, dispersing the local pressure on the skin and stimulating other nerve endings in the skin to some extent divert pain and alleviate discomfort for the person having their blood drawn. During blood collection, the ejector device 5 is controlled to eject the lancing needle, allowing it to quickly pierce the body and complete the blood collection operation in conjunction with other blood collection instruments. After blood collection, the needle removal cap 63 on the outside of the pen cap 3 is pressed. The needle removal cap 63 drives the needle withdrawal rod 61 to slide along the needle withdrawal channel. One end of the needle withdrawal rod 61 abuts against the lancing needle and pushes it out. During this process, the return spring 62 is compressed. After releasing the needle removal cap 63, the return spring 62 uses its own elasticity to return to its original shape, releasing elastic potential energy and pushing the needle withdrawal rod 61 back to its original position for next use. This design avoids the need for users to manually remove the lancet, preventing blood from getting on the needle tip and greatly reducing the risk of cross-infection. It also reduces the dangers of needlestick injuries that may result from manual needle removal. Through the coordinated operation of its various components, the entire lancet provides a safe, comfortable, and convenient user experience from pre-collection preparation and the collection process to post-collection needle removal.

[0045] It is worth noting that the frosted bumps 32 have one or more of the following structures: hemispherical, columnar, or conical.

[0046] In this embodiment, as Figure 10 As shown, the ejection device 5 includes an ejection cylinder 51 for mounting blood collection needles, a guide plate 52, an ejection arm 53, and an elastic rod 54. The ejection cylinder 51, guide plate 52, ejection arm 53, and elastic rod 54 are integrally formed. The ejection cylinder 51 has an ejection cavity 511 for mounting blood collection needles. The guide plate 52 is connected between the ejection cylinder 51 and the elastic rod 54. One end of the ejection arm 53 is fixedly connected to the guide plate 52, and there is a certain angle between the ejection arm 53 and the guide plate 52. The elastic rod 54 is composed of multiple clamping plates, and an elastic stop 541 is integrally formed at the end of the elastic rod 54.

[0047] Specifically, during the preparation stage of the lancing device, the lancing needle is inserted into the ejection cavity 511 of the ejection tube 51. At this time, the clamping plate of the elastic rod 54 will exert a certain clamping force on the lancing needle, making it securely installed in the ejection cavity 511. When blood collection is required, the elastic pressing part 11 on the pen tube 1 is pressed, and the elastic pressing part 11 will transmit the force to the ejection arm 53. Since there is a certain angle between the ejection arm 53 and the guide plate 52, the ejection arm 53 will undergo elastic deformation when subjected to force, which will drive the guide plate 52 and the elastic rod 54 to move. During the deformation process of the elastic rod 54, the elastic stop 541 at its end will accumulate elastic potential energy. When the elastic potential energy reaches a certain level, the elastic rod 54 will quickly return to its original shape, using the elastic potential energy to eject the lancing needle from the ejection cavity 511, and pierce the human skin through the needle outlet 31 of the pen cap 3 to collect blood. Based on the principles of elastic deformation and elastic potential energy release, the ejector arm 53 undergoes elastic deformation when subjected to external force. According to Hooke's Law, within the elastic limit, its deformation is proportional to the applied external force, at which point the ejector arm 53 stores elastic potential energy. The guide plate 52 connects and transmits the force, transferring the force from the ejector arm 53 to the elastic rod 54. The elastic rod 54 consists of multiple clamping plates, possessing excellent elastic deformation capabilities. Under stress, the spacing between the clamping plates changes, further accumulating elastic potential energy. When the external force reaches a certain threshold, the elastic potential energy accumulated in the elastic rod 54 is released instantaneously, converting into the kinetic energy of the blood collection needle, causing the needle to eject rapidly. This design utilizes the elastic properties of materials and achieves the ejection function of the blood collection needle through ingenious structural design.

[0048] It is worth noting that the one-piece molding structure reduces the number of connection points between components, lowering the risk of failure due to loose connections or wear, and improving the overall stability and reliability of the ejection device 5. During long-term use, components are less likely to detach or shift, ensuring the normal operation of the lancing pen. Furthermore, the one-piece molding process, achieved through mold processing or precision machining, allows for precise control of the size and shape of each component, ensuring that the performance of each ejection device 5 is essentially consistent. This helps improve the production quality and standardization of the lancing pen, ensuring stable ejection performance and consistent puncture results for each pen. It also allows the elastic rod 54 and ejection arm 53 to effectively accumulate and release elastic potential energy, ensuring that the lancing needle ejects at a stable and appropriate speed, improving the success rate and accuracy of blood collection, and reducing blood collection failures or poor punctures caused by unstable ejection force.

[0049] In this embodiment, as Figure 4 and Figure 12 As shown, a retaining ring 7 is also provided inside the pen holder 1. The retaining ring 7 is connected to the pen holder 1 by an interference fit, and a first opening 71 is provided on the retaining ring 7 to allow the elastic rod 54 to pass through. A limiting spring 8 is sleeved on the outer side of one end of the elastic rod 54 extending out of the retaining ring 7.

[0050] Specifically, during the process of installing the ejector device 5 into the inner sleeve 4 and inserting the inner sleeve 4 into the pen holder 1, the elastic rod 54 passes through the first opening 71 of the retaining ring 7. When the inner sleeve 4 is pulled to prepare for loading, the elastic rod 54 slides within the first opening 71, and the limiting spring 8 is compressed. When ejecting the blood collection needle, the elastic rod 54 is subjected to the force of the ejector device 5, further compressing the limiting spring 8. After blood collection is completed, the elastic rod 54 tends to return to its original position under the elastic force of the limiting spring 8. The limiting spring 8 plays a role in buffering and assisting in the return, allowing the elastic rod 54 to smoothly return to its initial position or close to its initial position. The first opening 71 provides a movement channel for the elastic rod 54, ensuring that the elastic rod 54 can move smoothly in a straight line within the pen holder 1. The limiting spring 8 utilizes the elastic properties of the spring to provide resistance and return force during the movement of the elastic rod 54. When the elastic rod 54 is compressed by an external force, the limiting spring 8 stores elastic potential energy; when the external force disappears or decreases, the limiting spring 8 releases the elastic potential energy, pushing the elastic rod 54 to reset, thus stabilizing the movement of the elastic rod 54 and assisting in its reset.

[0051] The retaining ring 7 and the pen holder 1 are connected by an interference fit, ensuring the retaining ring 7 is firmly fixed inside the pen holder 1 and is not prone to loosening or displacement. This provides a stable support structure for the movement of the elastic rod 54, ensuring the positional accuracy of the ejection device 5 within the pen holder 1 and improving the overall stability and reliability of the lancing pen. Simultaneously, the first opening 71 provides precise guidance for the elastic rod 54, restricting its movement direction to a straight line, preventing deviation or wobbling during movement, thus ensuring the accuracy and stability of the lancing needle ejection. Furthermore, the limiting spring 8 provides a buffering effect during the movement of the elastic rod 54, reducing the impact force and protecting the internal structure of the lancing pen from damage. After ejection, the limiting spring 8 assists the elastic rod 54 in resetting, allowing the lancing pen to quickly return to its initial state for easy reuse.

[0052] In this embodiment, as Figure 5 As shown, an elastic pressing part 11 is provided on the outer circumferential surface of the pen holder 1 at the position corresponding to the ejector arm 53. The elastic pressing part 11 is circumferentially hollowed out. A guide rib 12 is provided on the inner circumferential surface of the pen holder 1. The guide rib 12 is slidably connected to the inner sleeve 4 so that the inner sleeve 4 can move back and forth in a straight line along the pen holder 1.

[0053] Specifically, when the blood collection needle needs to be ejected, the elastic pressing part 11 on the outer circumference of the pen holder 1 is pressed with a finger. Due to its hollow structure, the elastic pressing part 11 has a certain degree of elasticity and will deform under force, transmitting the force to the ejection arm 53 and triggering the ejection device 5. During the process of pulling the inner sleeve 4 to prepare for loading or the inner sleeve 4 resetting after ejection, the guide groove 45 on the outer circumference of the inner sleeve 4 cooperates with the guide rib 12 on the inner circumference of the pen holder 1, and the inner sleeve 4 makes a linear reciprocating motion along the guide rib 12. The guide rib 12 restricts the movement trajectory of the inner sleeve 4, so that it can only make axial linear movements within the pen holder 1, ensuring the stability and accuracy of the movement of the inner sleeve 4.

[0054] The elastic design of the elastic pressing part 11 makes the pressing operation more comfortable, allowing the fingers to feel appropriate feedback force when pressing, and reducing hand fatigue caused by excessive pressing. At the same time, the design of the elastic pressing part 11 also makes the operation more sensitive, accurately triggering the ejection device 5. The cooperation between the guide rib 12 and the guide groove 45 of the inner sleeve 4 effectively improves the stability of the inner sleeve 4's movement within the pen holder 1, reducing the shaking and offset of the inner sleeve 4 during movement, ensuring the relative positional accuracy of the ejection device 5 and other internal components, and contributing to improving the overall performance and reliability of the lancing pen.

[0055] It is worth mentioning that the design of the elastic pressing part 11 and the guide rib 12 achieves the functions of operation triggering and motion guidance without increasing the structural complexity. Compared with the button-type structure commonly used in the prior art, it not only makes the structure of the lancing pen more compact and the functions more complete, but also improves the practicality and user experience of the lancing pen.

[0056] In this embodiment, as Figure 9 As shown, the inner sleeve 4 is a columnar structure with an opening on one side, and a second opening 41 is provided on the closed end face of the inner sleeve 4 to allow the elastic rod 54 to pass through. Both the first opening 71 and the second opening 41 are straight structures.

[0057] Specifically, the opening on one side of the inner sleeve 4 facilitates the installation and disassembly of the ejection device 5, improving the ease of assembly and maintenance of the blood collection pen. The second opening 41 provides a passage for the elastic rod 54, ensuring that the elastic rod 54 can move linearly within the inner sleeve 4.

[0058] In this embodiment, as Figure 9As shown, the outer surface of the inner sleeve 4 is provided with a limiting protrusion ring for restricting the return position. The diameter of the limiting protrusion ring is larger than the diameter of the inner sleeve 4, and the limiting protrusion ring is adapted to the pen holder 1. Utilizing its larger size than the main body of the inner sleeve 4, the limiting protrusion ring cooperates with the inner wall of the pen holder 1 to restrict the return position of the inner sleeve 4, ensuring that the ejection device 5 reaches the accurate position each time it is loaded, thereby ensuring the consistency and accuracy of the blood collection needle ejection.

[0059] In this embodiment, the inner sleeve 4 is provided with a positioning groove 43 on the left side surface of the limiting protrusion ring. The positioning groove 43 is slidably connected with the ejector arm 53 so that the inner sleeve 4 is accurately guided under the action of the guide ribs 12. The inner sleeve 4 is provided with a slot 44 on the right side surface of the limiting protrusion ring. The slot 44 is an L-shaped structure and is circumferentially distributed along the outer circumference of the inner sleeve 4.

[0060] Specifically, the sliding fit between the positioning groove 43 and the ejector arm 53, as well as the fit between the guide groove 45 and the guide rib 12 of the pen holder 1 and the guide piece 52 of the ejector device 5, are all based on the guiding and positioning principles in mechanical motion. They provide precise guidance and positioning for the movement of the inner sleeve 4 and the ejector device 5, ensuring the relative position accuracy and motion coordination between the components.

[0061] In this embodiment, as Figure 9 As shown, the inner sleeve 4 has multiple guide grooves 45 distributed circumferentially on its inner and outer circumferential surfaces. The guide grooves 45 on the outer circumferential surface are connected to the guide ribs 12. The guide grooves 45 on the inner circumferential surface are engaged with the guide plate 52. When the inner sleeve 4 is pulled to move along the axial direction of the pen holder 1, the ejection device 5 can be prepared to load along the guide grooves 45.

[0062] Specifically, when installing the ejector device 5, it is inserted from the opening on one side of the inner sleeve 4, allowing the elastic rod 54 to pass through the second opening 41 on one closed end face of the inner sleeve 4. When the inner sleeve 4 is pulled to prepare for loading, it moves linearly along the guide rib 12 on the inner circumferential surface of the pen holder 1. At this time, the ejector arm 53 slides within the positioning groove 43 of the inner sleeve 4. The guide groove 45 on the outer circumferential surface of the inner sleeve 4 engages with the guide rib 12 of the pen holder 1, ensuring the accuracy of the inner sleeve 4's movement. The limiting protrusion ring restricts the return position when the inner sleeve 4 is pulled. When the inner sleeve 4 reaches a certain position, the limiting protrusion ring contacts the inner wall of the pen holder 1, preventing further movement and ensuring the ejector device 5 reaches the appropriate loading position. When rotating to install the pen tip 2, the first locking block 22 on the inner circumferential surface of the pen tip 2 and the locking groove 44 on the outer circumferential surface of the inner sleeve 4 are fixedly connected by rotation, achieving a stable connection between the pen tip 2 and the inner sleeve 4.

[0063] In this embodiment, as Figure 6As shown, a first locking block 22 is provided on the inner circumferential surface of the pen tip 2, which is adapted to the slot 44. The first locking block 22 and the slot 44 are fixedly connected by rotational engagement. The rotational engagement connection between the slot 44 and the first locking block 22 utilizes the snap-fit ​​principle in mechanical connections, achieving a quick and stable connection through rotation.

[0064] In this embodiment, as Figure 7 , 8 As shown, multiple position markings 33 are provided on the outer peripheral wall of the pen cap 3 along the circumferential direction of the pen cap 3. Each position marking 33 corresponds to a different puncture depth. An indicator marking 23 is provided on the outer side of the pen tip 2 to cooperate with the position marking 33. A second locking block 34 is provided on the inner peripheral wall of the pen cap 3 to cooperate with the adjusting thread 21, so that different positions can be adjusted by rotating the pen cap 3.

[0065] Specifically, the position indicator 33 is in the form of scale lines, and the indicator 23 is in the form of arrows. The position indicator 33 and the indicator 23 work together to indicate the puncture depth of the blood collection needle, so as to intuitively understand the puncture depth of the blood collection needle and make a more appropriate choice based on the user's own bleeding situation. In addition, the position indicator 33 and the indicator 23 can also be in the form of numbers, scale lines, dots, or a combination of the above forms.

[0066] Working principle of the invention:

[0067] In use, first, open the pen tip 2 and install the lancet into the ejection chamber 511 of the ejection device 5; then rotate the pen cap 3, and adjust it to the appropriate puncture depth by engaging the second locking block 34 on the inner circumferential wall of the pen cap 3 with the adjusting thread 21 on the pen tip 2, according to the position marking 33 on the pen cap 3 and the indicator marking 23 on the pen tip 2; next, pull the inner sleeve 4 to move it axially along the pen cylinder 1, the guide groove 45 on the outer circumferential surface of the inner sleeve 4 engages with the guide rib 12 on the pen cylinder 1, and the guide groove 45 on the inner circumferential surface of the inner sleeve 4 engages with the guide plate 52 of the ejection device 5, so that the ejection device 5 is ready to load along the guide groove 45. The ejector arm 53 slides within the positioning groove 43 of the inner sleeve 4, and the limiting protrusion ring restricts the return position of the inner sleeve 4. Finally, the frosted protrusion 32 on the top of the pen cap 3 is pressed against the finger area, and the elastic pressing part 11 of the pen tube 1 is pressed. The elastic pressing part 11 causes the ejector arm 53 to be under force, and the ejector device 5 is activated. The blood collection needle is ejected from the needle outlet 31 of the pen cap 3 through the elastic rod 54 to collect blood. After blood collection is completed, the needle removal cap 63 of the needle removal assembly 6 is pressed, and the needle removal rod 61 slides along the needle removal channel to push out the blood collection needle, completing the needle removal. After releasing the needle removal cap 63, the return spring 62 resets the needle removal rod 61.

[0068] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A lancing pen with a needle withdrawal function, characterized in that, include A pen holder, wherein an inner sleeve is movably connected inside the pen holder, and an ejection device for ejecting blood collection needles is provided inside the inner sleeve. The ejection device has a built-in needle withdrawal channel, and a needle withdrawal assembly is installed in the needle withdrawal channel. The pen tip is detachably connected to the inner sleeve, and an adjustment thread is provided on the outer circumferential surface of the pen tip; The pen cap is threaded onto the pen tip. One end of the pen cap has a needle outlet hole for ejecting the blood collection needle. Multiple frosted bumps are distributed around the circumference of the needle outlet hole. The frosted bumps are used to contact human skin and transfer pain. The needle withdrawal assembly includes a needle withdrawal rod, a return spring, and a needle removal cap. The needle withdrawal rod is installed in the elastic channel, with one end abutting against the blood collection needle and the other end extending outward beyond the cap and connecting to the needle removal cap. The return spring is sleeved on the outside of the needle withdrawal rod, with one end abutting against the elastic launching device and the other end connecting to the needle removal cap. Pressing the needle removal cap drives the needle withdrawal rod to slide along the needle withdrawal channel and push out the blood collection needle.

2. The blood collection pen with needle withdrawal function according to claim 1, characterized in that, The ejection device includes an ejection cylinder for mounting the blood collection needle, a guide plate, an ejection arm, and an elastic rod. The ejection cylinder, guide plate, ejection arm, and elastic rod are integrally formed. The ejection cylinder has an ejection cavity for mounting the blood collection needle. The guide plate is connected between the ejection cylinder and the elastic rod. One end of the ejection arm is fixedly connected to the guide plate, and there is a certain angle between the ejection arm and the guide plate. The elastic rod is composed of multiple clamping plates, and an elastic stop is integrally formed at the end of the elastic rod.

3. The blood collection pen with needle withdrawal function according to claim 2, characterized in that, The pen holder is also provided with a retaining ring, which is connected to the pen holder by an interference fit. The retaining ring has a first opening that allows the elastic rod to pass through, and a limiting spring is sleeved on the outer side of the end of the elastic rod that extends out of the retaining ring.

4. The blood collection pen with needle withdrawal function according to claim 3, characterized in that, An elastic pressing part is provided on the outer circumferential surface of the pen holder at the position corresponding to the ejector arm, and the elastic pressing part is circumferentially hollowed out; a guide rib is provided on the inner circumferential surface of the pen holder, and the guide rib is slidably connected to the inner sleeve so that the inner sleeve can move back and forth in a straight line along the pen holder.

5. The blood collection pen with needle withdrawal function according to claim 4, characterized in that, The inner sleeve is a columnar structure with an opening on one side, and a second opening is provided on the closed end face of the inner sleeve to allow the elastic rod 54 to pass through. Both the first opening and the second opening are straight structures.

6. The lancing pen with needle withdrawal function according to claim 5, characterized in that, The outer surface of the inner sleeve is provided with a limiting protrusion ring for limiting the return position. The diameter of the limiting protrusion ring is larger than the diameter of the inner sleeve, and the limiting protrusion ring is adapted to the pen holder.

7. The lancing pen with needle withdrawal function according to claim 6, characterized in that, The inner sleeve is provided with a positioning groove on the left side surface of the limiting protrusion ring. The positioning groove is slidably connected with the ejector arm so that the inner sleeve is accurately guided by the guide rib. The inner sleeve is provided with a retaining groove on the right side surface of the limiting protrusion ring. The retaining groove is L-shaped and is distributed circumferentially along the outer circumference of the inner sleeve.

8. The lancing pen with needle withdrawal function according to claim 7, characterized in that, The inner sleeve has multiple guide grooves distributed circumferentially on its inner and outer circumferential surfaces. The guide grooves on the outer circumferential surface are connected to the guide ribs. The guide grooves on the inner circumferential surface are engaged with the guide plates. When the inner sleeve is pulled to move along the pen holder axis, the ejection device can be prepared to load along the guide grooves.

9. The lancing pen with needle withdrawal function according to claim 7, characterized in that, The inner circumferential surface of the pen tip is provided with a first locking block that is adapted to the card slot, and the first locking block and the card slot are fixedly connected by rotation and locking.

10. The lancing pen with needle withdrawal function according to claim 1, characterized in that, The outer peripheral wall of the pen cap has multiple position markings along the circumferential direction of the pen cap, each position marking corresponding to a different puncture depth. The outer side of the pen tip has an indicator marking that matches the position markings. The inner peripheral wall of the pen cap has a second locking block that engages with the adjusting thread, so that different positions can be adjusted by rotating the pen cap.

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