A blunt needle for precise site aspiration and injection

Abstract

The present invention discloses a blunt needle for precise part aspiration and injection, which includes a needle base hermetically sleeved on the liquid discharge head of an injection cylinder, and also includes an eccentric needle head. The tail end of the eccentric needle head is fitted and installed in the needle base and is hermetically communicated with the liquid discharge port of the liquid discharge head through the needle base. The needle base includes a connecting seat, an outer casing and a rotary telescopic mechanism. The tail end of the connecting seat is hermetically sleeved on the liquid discharge head, and a transition channel communicating with the liquid discharge head is axially opened in the middle of the front end of the connecting seat. The structure of the present invention is unique and convenient to use. It can not only automatically avoid blood vessels during the needle insertion process, effectively solving the problem that the existing blunt needles are prone to puncture blood vessels in tissues during use, but also can complete large-area injection or extraction with a single needle insertion during use, thus effectively solving the problem that the existing blunt needles need multiple needle insertions to complete large-area extraction or injection during use.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical aesthetics, and particularly relates to a blunt needle for precise site aspiration and injection. Background Art

[0002] Medical plastic surgery and beauty plastic surgery are inseparable from common items such as puncture and injection, such as clinical intravenous puncture, autologous fat transplantation in plastic surgery, hyaluronic acid injection, and wrinkle removal; different needles and devices for extraction and injection have different damages to cells and drugs; traditional sharp needles for extraction and injection are extremely likely to cause damage to cells, blood vessels, nerves, and fibrous structures, and are likely to cause postoperative bruising and swelling. In addition, the sharp needle has a short length and a limited injection range, and cannot inject deeper parts, which brings limitations in technology; while the blunt needle is relatively longer than the sharp needle, up to 5 - 10 cm, and can reach deeper positions for injection or extraction, and the layer control is relatively simple, and the operation requirements for medical staff are not so strict, and it has been widely recognized in the medical and beauty industries in recent years.

[0003] However, during use, although the fat in the tissue is soft and the tip of the blunt needle is blunt and round, it can move smoothly in the tissue. However, since blood vessels are like a net in the human body and are everywhere, and blood vessels have a certain rigidity, when the tip of the blunt needle touches a blood vessel, if the needle is still forced to be inserted inward, the tip of the needle will pierce the blood vessel, causing internal bleeding in the tissue and bruising and swelling in the puncture area. Even some fillers will enter the blood vessel and cause embolism, affecting health; and there is a liquid outlet at the tip of the existing blunt needle. When performing aspiration or injection, the single - extraction or injection volume is small, and multiple needle insertions are required to complete large - area extraction or injection, which further aggravates the postoperative trauma of the patient. Summary of the Invention

[0004] Aiming at the defects and problems of the existing blunt needle, the present invention provides a blunt needle for precise site aspiration and injection. The structure of the blunt needle is unique and easy to use. It can not only automatically avoid blood vessels during the needle - insertion process, effectively solving the problem that the existing blunt needle is likely to pierce blood vessels in the tissue during use; but also can complete large - area injection or extraction with a single needle insertion during use, thus effectively solving the problem that the existing blunt needle requires multiple needle insertions to complete large - area extraction or injection during use.

[0005] The solution adopted by the present invention to solve its technical problems is as follows: A blunt needle for precise part aspiration and injection includes a needle base hermetically sleeved on the liquid discharge head of an injection cylinder, and further includes an eccentric needle head. The tail end of the eccentric needle head is fitted and installed in the needle base and is hermetically communicated with the liquid discharge port of the liquid discharge head through the needle base. The needle base includes a connecting seat, an outer shell, and a rotary telescopic mechanism. The tail end of the connecting seat is fitted and sleeved on the liquid discharge head, and a transition channel communicating with the liquid discharge head is axially opened in the middle of the front end of the connecting seat. The outer shell is fixedly sleeved on the connecting seat, and a columnar cavity is coaxially arranged in the outer shell on the front side of the connecting seat, and the columnar cavity is communicated with the internal channel of the connecting seat. A needle passing hole communicating with the outside is axially opened in the middle of the front cavity wall of the columnar cavity. The rotary telescopic mechanism includes a rotary sleeve, a limiting ring, and a return spring. The rotary sleeve is fitted and sleeved in the columnar cavity, and a spiral chute is axially opened on the inner ring wall of the rotary sleeve. The tail end of the eccentric needle head is fitted and sleeved in the needle passing hole, and the tail end of the eccentric needle head passes through the rotary sleeve and is hermetically inserted into the transition channel of the connecting seat, and can rotate and slide along the inner wall of the transition channel. The limiting ring is fixedly sleeved on the eccentric needle head in the rotary sleeve, and a spherical slider slidingly embedded in the chute is connected to one side of the rotary sleeve. The return spring is fitted and sleeved on the eccentric needle head between the limiting ring and the connecting seat, and in the natural state, the return spring will push the limiting ring to drive the spherical slider to rotate and slide forward along the chute.

[0006] Further, when the eccentric needle head penetrates into the fat, the resistance received by the eccentric needle head is greater than the minimum working load of the return spring.

[0007] Further, a fixing groove adapted to the liquid discharge head is axially opened at the tail end of the connecting seat, and is hermetically nested on the liquid discharge head in a matching manner.

[0008] Further, an annular groove is circumferentially opened on the inner ring arm of the fixing groove, and a sealing ring is fitted and installed. After the connecting seat is nested on the liquid discharge head in a matching manner, the sealing ring in the fixing groove will be deformed by the extrusion of the connecting seat and the liquid discharge head.

[0009] Further, a circular chamfer is provided at the rear end notch of the fixing groove.

[0010] Further, the eccentric needle head includes a needle stem. The tail end of the needle stem is fitted and sleeved in the needle passing hole, and the tail end of the needle stem passes through the rotary sleeve and is hermetically inserted into the transition channel of the connecting seat. A spherical needle tip is provided at the top end of the needle stem in a sealing manner. Liquid discharge ports communicating with the inside are radially opened on the circumferential side wall of the needle stem behind the spherical needle tip, and the spherical needle tip and the needle stem are eccentrically arranged.

[0011] Further, three liquid discharge ports are circumferentially spaced apart on the circumferential side wall of the needle stem behind the spherical needle tip, and all three liquid discharge ports are radially arranged and communicated with the internal channel of the needle stem.

[0012] Further, a threaded section is axially provided on the outer cylindrical wall of the connecting seat. The outer sleeve is fitted over the threaded section of the connecting seat, and the outer shell is threadedly connected to the connecting seat.

[0013] Further, a plurality of strip-shaped bosses are circumferentially spaced along the outer circumferential surface at the tail end of the connecting outer shell, and the strip-shaped bosses are axially arranged.

[0014] Further, a seal is fitted inside the front end of the transition channel of the connecting seat. The tail end of the eccentric needle passes through the seal and is inserted into the fixed channel in a matching manner. The seal can enhance the sealing strength between the outer circumferential surface of the eccentric needle and the inner circumferential wall of the transition channel on the premise of not affecting the rotation and sliding of the tail end of the eccentric needle in the transition channel.

[0015] Beneficial effects of the present invention: A blunt needle for precise part aspiration and injection provided by the present invention has a unique structure, including a needle seat hermetically sleeved on the liquid discharge head of the syringe. An eccentric needle is installed on the needle seat. The needle seat adopts a split assembly design and includes a connecting seat, an outer sleeve and a rotary telescopic mechanism, which is convenient for processing and production. The eccentric needle includes a needle stem. The tail end of the needle stem is fitted over the needle-passing hole in a matching manner, and the tail end of the needle stem passes through the rotary sleeve and is hermetically inserted into the transition channel of the connecting seat. The top end of the needle stem is blocked with a spherical tip. A liquid discharge port communicating with the inside is radially opened on the circumferential side wall of the needle stem behind the spherical tip, and the spherical tip and the needle stem are eccentrically arranged.

[0016] During use, by holding the syringe by hand, the depth of the eccentric needle into the tissue can be controlled for aspiration operation. And during the penetration process, since the tip at the top of the eccentric needle is spherical, the eccentric needle can smoothly shuttle through the tissue. When the spherical tip at the top of the eccentric needle contacts the blood vessel in the tissue during the penetration process, continuously pushing the eccentric needle into the tissue through the syringe will cause the extrusion force on the return spring in the rotary telescopic mechanism to increase. As a result, the return spring will be further compressed due to the extrusion, causing the needle stem part to retract into the needle seat. During this process, the needle stem will drive the tip to rotate. And because the spherical tip of the eccentric needle and the needle stem are eccentrically arranged, when the needle stem retracts and rotates, the spherical tip in contact with the blood vessel in the tissue will follow the needle stem and rotate around the central axis of the needle stem, separating from the contacted blood vessel and automatically avoiding the blood vessel. Therefore, when the eccentric needle penetrates into the tissue, it will automatically avoid the blood vessels in the tissue and will not pierce the blood vessels in the tissue, which is convenient to use and effectively solves the problem that the existing blunt needles are prone to piercing the blood vessels in the tissue during use.

[0017] And since the resistance on the eccentric needle is greater than the minimum working load of the return spring when the eccentric needle penetrates deep into the fat of the tissue, when injecting the injectate into the tissue or extracting fat outwards, by slightly pulling the syringe barrel outwards, the pressure on the return spring of the rotary telescopic mechanism is reduced, causing it to automatically extend. During the extension process of the return spring, the limit ring is driven to drive the needle shank to rotate. When the needle shank rotates, the needle shank located in the tissue will rotate synchronously, enabling injection or extraction of the surgical site in all directions, thereby increasing the area of injection or extraction and effectively solving the problem that existing blunt needles require multiple needle insertions to complete large-area extraction or injection during use.

[0018] The present invention provides a blunt needle for precise site aspiration and injection. This blunt needle has a unique structure and is convenient to use. It can not only automatically avoid blood vessels during the needle insertion process, effectively solving the problem that existing blunt needles are prone to puncturing blood vessels in the tissue during use; but also can complete large-area injection or extraction with a single needle insertion during use, thus effectively solving the problem that existing blunt needles require multiple needle insertions to complete large-area extraction or injection during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of the present invention.

[0020] Figure 2 is Figure 1 an enlarged schematic diagram of the structure at A in

[0021] Figure 3 is a schematic structural diagram of the needle holder of the present invention.

[0022] Figure 4 is a schematic structural diagram of the connecting seat of the present invention.

[0023] Figure 5 is one of the three-dimensional structural schematic diagrams of the rotary sleeve of the present invention.

[0024] Figure 6 is one of the internal structural schematic diagrams of the rotary sleeve of the present invention.

[0025] Figure 7 is a schematic diagram of the connection relationship between the spherical slider and the sliding sleeve of the present invention.

[0026] Figure 8 is a schematic diagram of the position where the chamfer of the connecting seat of the present invention is opened.

[0027] Figure 9 is a schematic diagram of the position where the strip-shaped boss of the present invention is provided.

[0028] Figure 10 is a schematic diagram of the arrangement position of the three liquid outlets of the eccentric needle of the present invention.

[0029] Figure 11It is a schematic structural diagram of the needle stem sliding adjustment component of the present invention.

[0030] Figure 12 is Figure 11 An enlarged schematic diagram of the structure at position B in

[0031] Figure 13 It is the second schematic three-dimensional structure diagram of the rotary sleeve of the present invention.

[0032] Figure 14 It is a schematic diagram of the double slideway structure inside the rotary sleeve of the present invention.

[0033] Figure 15 It is a schematic structural diagram of the extrusion component of the present invention.

[0034] Figure 16 It is a schematic diagram of the structure of the extrusion component of the present invention from another perspective.

[0035] Reference numerals in the figure: 1 is a syringe barrel, 11 is a liquid discharge head, 2 is a needle seat, 21 is a connecting seat, 211 is a transition channel, 212 is a fixing groove, 213 is a circular chamfer, 22 is an outer shell, 221 is a columnar cavity, 2211 is a needle passing hole, 222 is a strip-shaped boss, 223 is an extrusion cavity, 3 is an eccentric needle, 31 is a needle stem, 32 is a spherical needle tip, 33 is a liquid outlet, 4 is a rotary telescopic mechanism, 41 is a rotary sleeve, 411 is a sliding groove, 42 is a limiting ring, 43 is a return spring, 44 is a spherical slider, 51 is a sliding sleeve, 511 is an extrusion seam, 52 is a locking sleeve, 53 is a threaded sleeve, 54 is a guiding block, 55 is a guiding ring. 6 is an extrusion component, 61 is an extrusion block, 62 is a tightening bolt. Detailed implementation mode

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] Embodiment 1

[0038] During the use of existing blunt needles, although the fat in human tissues is relatively soft and the blunt needle can smoothly advance in the tissue due to the blunt round tip of the blunt needle, since blood vessels are like a network in the human body and are everywhere, and blood vessels have a certain rigidity, when the tip of the blunt needle encounters a blood vessel and still tries to push the needle inward forcefully, the tip of the needle will pierce the blood vessel, causing internal bleeding in the tissue, resulting in bruising and swelling in the puncture area, and even some fillers may enter the blood vessel and cause embolism, affecting health; and there is a liquid outlet at the tip of the existing blunt needle. When performing aspiration or injection, the single aspiration or injection volume is small, and multiple needle insertions are required to complete large-area aspiration or injection, which further aggravates the postoperative trauma of the patient.

[0039] In view of the above problems, this embodiment provides a blunt needle for precise site aspiration and injection, such as Figure 1-7As shown in the figure, it includes a needle seat 2 hermetically sleeved on the liquid discharge head 11 of the syringe barrel 1, and also includes an eccentric needle head 3. The eccentric needle head 3 includes a needle stem 31 fitted and installed in the needle seat. The top end of the needle stem 31 is sealed with a spherical needle tip 32. A liquid outlet 33 communicating with the inside is radially opened on the circumferential side wall of the needle stem 31 behind the spherical needle tip 32, and the spherical needle tip 32 and the needle stem 31 are eccentrically arranged; the needle stem 31 is hermetically communicated with the liquid discharge port of the injection head through the needle seat 2. Thus, when the piston in the syringe barrel 1 is pushed, the injection substance in the syringe barrel will enter the needle stem through the needle head seat 2 and be discharged from the liquid outlet; since the needle tip at the top of the eccentric needle head is spherical, the eccentric needle head can smoothly shuttle in the tissue.

[0040] The needle seat 2 includes a connecting seat 21, an outer shell 22 and a rotary telescopic mechanism. The tail end of the connecting seat 21 is fitted and sleeved on the liquid discharge head 11, and a transition channel 211 communicating with the liquid discharge port of the liquid discharge head 11 in a sealed manner is axially opened in the middle of the front end of the connecting seat 21. When the piston in the syringe barrel is pushed forward, the piston will squeeze the injection substance in the syringe barrel forward, and the injection substance will be discharged into the transition channel 211 of the connecting seat through the liquid discharge head 11; when the piston in the syringe barrel 1 is pulled backward, negative pressure will be synchronously generated in the transition channel of the connecting seat; there are various connection methods between the connecting seat 21 and the liquid discharge head 11. For example: a fixing groove 212 adapted to the liquid discharge head is axially opened at the tail end of the connecting seat and is hermetically nested on the liquid discharge head. Further, an annular groove is circumferentially opened on the inner ring wall of the fixing groove, and a sealing ring is fitted and installed. After the connecting seat 21 is hermetically nested on the liquid discharge head, the sealing ring in the fixing groove will be deformed by the extrusion of the connecting seat and the liquid discharge head, so as to tightly contact the inner wall of the annular groove and the outer ring wall of the liquid discharge head 11, further enhancing the sealing performance between the connecting seat and the liquid discharge head.

[0041] The outer shell 22 is fixedly sleeved on the connecting seat 21, and a columnar cavity 221 is coaxially arranged in the outer shell 22 in front of the connecting seat 21. The tail end of the columnar cavity 221 communicates with the transition channel 211 in the connecting seat 21; a needle passing hole 2211 communicating with the outside is axially opened in the middle of the front cavity wall of the columnar cavity 221, and the eccentric needle head 32 is inserted into the needle seat through the needle passing hole 2211.

[0042] The rotary telescopic mechanism includes a rotary sleeve 41, a limit ring 42 and a return spring 43. The rotary sleeve 41 is fitted and sleeved in a columnar cavity. The front and rear ends of the rotary sleeve 41 are respectively in contact with the front cavity wall of the columnar cavity and the front end face of the connecting seat. A spiral chute 411 is axially formed on the inner ring wall of the rotary sleeve 41. The tail end of the needle stem 31 of the eccentric needle head 3 is hermetically and slidably sleeved in the needle-passing hole, and the tail end of the needle stem passes through the rotary sleeve and is hermetically inserted into the transition channel of the connecting seat, and can rotate and slide along the inner wall of the transition channel. The limit ring is fixedly sleeved on the needle stem 31 inside the rotary sleeve, and a spherical slider slidably embedded in the chute is connected to one side of the rotary sleeve. When the needle stem slides axially, it will drive the spherical slider 44 in the chute 411 to slide along the chute 411 through the limit ring, so as to drive the needle stem to rotate synchronously along the chute in the rotary sleeve 41 when sliding axially.

[0043] The return spring 43 is fitted and sleeved on the needle stem 31 between the limit ring 42 and the connecting seat 21, and the two ends of the return spring 43 are respectively in contact with the adjacent limit ring and the connecting seat. In the natural state, the return spring will push the limit ring to drive the spherical slider to rotate and slide forward along the chute, so that the limit ring is in contact with the front cavity wall of the columnar cavity. And when the eccentric needle head penetrates into the fat, the resistance received by the eccentric needle head is greater than the minimum working load of the return spring. Therefore, when the eccentric needle head penetrates into the fat, the eccentric needle head will squeeze the return spring 42 through the limit ring to generate a retraction deformation. When the piston in the syringe barrel is pushed forward, the injection liquid discharged from the liquid discharge head 11 will enter the needle stem through the transition channel 211 and be discharged from the liquid outlet at the front end of the needle stem.

[0044] Furthermore, a seal is preferably provided inside the front end of the transition channel of the connecting seat 21. Without affecting the rotation and sliding of the needle stem in the transition channel, the seal enhances the sealing strength between the outer ring surface of the eccentric needle head and the inner ring wall of the transition channel. There are various structural forms of the seal. For example, the seal includes a sealing ring. A circular mounting groove is formed along the circumference on the inner ring wall at the front end of the transition channel. The sealing ring is fitted and mounted in the mounting groove in the transition channel and protrudes out of the mounting groove. The tail end of the needle stem passes through the sealing ring in the transition channel and extends into the transition channel, and the sealing ring in the transition channel will be deformed by the inserted needle stem, so as to enhance the sealing strength between the needle stem and the transition channel without affecting the movement of the needle stem in the transition channel.

[0045] The blunt needle for precise part aspiration and injection provided in this embodiment has a unique structure and adopts a split assembly design, which is convenient for processing and production. During assembly, first, the rotary sleeve of the rotary telescopic mechanism is fitted and installed in the columnar cavity of the outer sleeve 22. Then, the tail end of the needle stem 31 of the eccentric needle 3 is inserted into the outer sleeve through the needle hole 2211 at the top of the outer sleeve 22, so that the position of the needle stem installation limit ring 42 extends from the other end of the outer sleeve. Then, the limit ring is fitted and sleeved on the needle stem. When the eccentric needle 3 is rotated and pulled forward, the needle stem will drive the limit ring into the outer sleeve. During the process of the spherical slider on the limit ring rotating with the needle stem, it will enter the sliding groove from the port of the sliding groove. Then, the return spring is sleeved on the needle stem from the outer end of the outer sleeve. Next, the connecting seat 21 is fitted and sleeved into the outer sleeve from the tail end of the outer sleeve 22. During this process, the tail end of the needle stem will be inserted into the transition channel of the connecting seat. When the connecting seat is installed in place, the return spring will automatically push the limit ring to drive the spherical slider to rotate and slide forward along the sliding groove, so that the limit ring touches the front cavity wall of the columnar cavity. At this time, the blunt needle provided in this embodiment is assembled. After disinfection, it can be packaged. When in use, the assembled blunt needle is fitted and installed on the liquid discharge head of the syringe 1 and can be directly used.

[0046] During use, by holding the syringe barrel by hand, the eccentric needle can be controlled to penetrate into the tissue for aspiration operation. During the penetration process, since the tip of the eccentric needle is spherical, the eccentric needle can smoothly shuttle through the tissue. When the spherical tip of the eccentric needle contacts the blood vessel in the tissue during the penetration process, continuously pushing the eccentric needle into the tissue through the syringe barrel will cause the extrusion force on the return spring in the rotary telescopic mechanism to increase. As a result, the return spring will be further compressed due to the extrusion, causing the needle stem part to retract into the needle base 2. During this process, the needle stem in the rotary telescopic mechanism 4 will drive the spherical slider to slide backward along the chute 411 through the limiting ring 42, driving the needle stem 31 to rotate synchronously. Since the spherical tip 32 of the eccentric needle 3 is eccentrically arranged with the needle stem 31, when the needle stem 31 retracts and rotates, the spherical tip in contact with the blood vessel in the tissue will follow the needle stem 31 to rotate around the central axis of the needle stem 31, separating from the contacted blood vessel and automatically avoiding the blood vessel. Therefore, when the eccentric needle penetrates into the tissue, it will automatically avoid the blood vessels in the tissue and will not pierce the blood vessels in the tissue, which is convenient to use and effectively solves the problem that the existing blunt needles are prone to piercing the blood vessels in the tissue during use. And since when the eccentric needle penetrates into the fat of the tissue, the resistance received by the eccentric needle is greater than the minimum working load of the return spring, when injecting the injectate into the tissue or extracting fat outward, by slightly pulling the syringe barrel outward, the pressure on the return spring of the rotary telescopic mechanism is reduced, causing it to automatically extend. And during the extension process of the return spring, it will drive the limiting ring to drive the needle stem to rotate. When the needle stem rotates, the needle stem located in the tissue will rotate synchronously, enabling injection or extraction of the surgical site in all directions, thereby increasing the area of injection or extraction and effectively solving the problem that the existing blunt needles need to be inserted multiple times to complete large-area extraction or injection during use.

[0047] Example 2

[0048] The difference between Example 2 and Example 1 is that, as Figure 8 shown, a circular chamfer 213 is provided at the rear slot opening of the fixing groove 212. When the connecting seat 21 is rearwardly and matingly installed on the front end of the liquid discharge head 11, the circular chamfer 213 has a guiding effect, facilitating the rearward insertion and sleeving of the connecting seat 21 on the liquid discharge head 11.

[0049] Example 3

[0050] The difference between Example 3 and Example 2 is that the connection relationship between the outer shell 22 and the connecting seat is different, as Figure 9As shown, a threaded section is axially provided on the outer cylindrical wall of the connecting seat. The outer sleeve is fitted over the threaded section of the connecting seat, and the outer shell is threadedly connected to the connecting seat. Further, a plurality of strip-shaped protrusions 222 are circumferentially spaced on the outer circumferential surface at the tail end of the connecting outer shell 22, and the strip-shaped protrusions 22 are axially arranged. When the outer sleeve 22 is tightened, the strip-shaped protrusions 222 can increase the friction between the finger and the connecting outer shell.

[0051] Embodiment 4

[0052] The difference between Embodiment 4 and Embodiment 3 is that, as Figure 10 shown, three liquid outlets are circumferentially spaced on the circumferential side wall of the needle shank behind the spherical needle tip, and the three liquid outlets are all radially arranged and communicated with the internal channel of the needle shank. Compared with Embodiment 3, the three liquid outlets 33 on the eccentric needle head in this embodiment are evenly arranged in a circle, and can be injected in multiple directions of 360 degrees, increasing the skin activation area. When in use, a single needle insertion can complete large-area injection, reducing the number of needle insertion points and avoiding postoperative trauma. At the same time, when performing cell, such as fat cell aspiration and injection, the number of cells or fat particles that can be aspirated or injected can be increased. When injecting, through the backflow at the top of the eccentric needle head, the cells can be slowly and evenly injected into the surgical site in all directions without causing any impact and pressure on the cells, improving the cell survival rate.

[0053] Embodiment 5

[0054] The difference between Embodiment 5 and Embodiment 4 is that a needle shank sliding adjustment component is provided on the needle shank outside the needle seat.

[0055] As Figure 11 and Figure 12As shown, a sliding adjustment component for the needle stem is provided on the needle stem. The sliding adjustment component for the needle stem includes a sliding sleeve 51, a locking sleeve 52, and a threaded sleeve 53. The sliding sleeve is sleeved on the needle stem at the front side of the needle base 2 in a matching manner, and the tail end of the sliding sleeve abuts against the front end of the outer shell of the needle base. A plurality of extrusion slits 511 are arranged at intervals along the circumference of the front end face. The extrusion slits are arranged radially and penetrate through the sliding sleeve. A trapezoidal guiding block 54 is fixed on the sliding sleeve between every two extrusion slits. The trapezoidal guiding blocks are arranged along the circumference, and the inclined surfaces of the trapezoidal guiding blocks face forward. The locking sleeve is coaxially sleeved outside the sliding sleeve. The extrusion blocks arranged along the circumference on the sliding sleeve are all located inside the locking sleeve. A conical guiding ring 55 is fixed inside the locking sleeve in front of the extrusion block. The inclined surface of the guiding ring faces the extrusion block and is in contact with the inclined surface of the extrusion block. An external thread is provided in a matching manner on the outer ring surface of the front section of the outer shell. The threaded sleeve is sleeved on the external thread at the front end of the outer shell and can rotate and slide back and forth along the thread. The front end of the threaded sleeve extends forward out of the outer shell 22 and is connected to the tail end of the locking sleeve. When the locking sleeve is driven to approach the needle base 2 along the outer ring surface of the sliding sleeve by rotating the threaded sleeve, the guiding ring inside the locking sleeve will squeeze the guiding block in contact with it to squeeze the sliding sleeve inward along the inclined surface of the guiding ring, thereby adjusting the friction force between the sliding sleeve and the needle stem. Compared with Embodiment 4, when the blunt needle provided in this embodiment is in use, the friction force between the sliding sleeve and the needle stem can be adjusted through the sliding adjustment component of the needle stem according to requirements, so as to adjust the degree of compression of the return spring when the eccentric needle head penetrates into the tissue, enabling the blunt needle to have the function of adjusting its rotation and telescoping under what kind of pressure, and increasing the applicability of the blunt needle.

[0056] Embodiment 6

[0057] The difference between Embodiment 6 and Embodiment 5 is that, as Figure 13 shown, the columnar cavity is a hexagonal columnar cavity, and the outer end face of the rotary sleeve 41 is a hexagonal columnar shape adapted to the columnar cavity. Thus, when the rotary sleeve 41 is matched and installed in the columnar cavity, due to the special shape of the rotary sleeve 41, the rotary sleeve 41 cannot rotate freely in the columnar cavity, so there is no need to independently fix the rotary sleeve 41.

[0058] Embodiment 7

[0059] The difference between Embodiment 7 and Embodiment 6 is that, as Figure 14As shown, two spiral chutes 411 are axially formed on the inner ring wall of the rotary sleeve 41. The pitches and number of turns of the two chutes are the same, and the ports of the two chutes 411 are oppositely arranged. Spherical sliders are symmetrically arranged at the left and right ends of the limiting ring 41 on the inner needle stem of the rotary sleeve. The two spherical sliders are axially spaced apart, and the spherical sliders at the left and right ends of the limiting ring 41 are respectively slidably inserted into the corresponding chutes 411. When the limiting ring 41 axially slides within the rotary sleeve, the limiting ring 41 will drive the spherical sliders on both sides to slide within the corresponding chutes, thereby driving the needle stem to rotate while the limiting ring axially slides. Compared with Embodiment 6, in this embodiment, by providing double chutes and double spherical sliders, both ends of the limiting ring are supported, so that the movement of the limiting ring can be more stable.

[0060] Embodiment 8

[0061] The difference between Embodiment 8 and Embodiment 5 is that the rotary sleeve is rotatably sleeved in the columnar cavity 221, and an extrusion cavity 223 communicating with the columnar cavity is provided on the outer shell on one side of the columnar cavity, and an extrusion member is provided in the extrusion cavity.

[0062] As Figure 15 and Figure 16 shown, the rotary sleeve is rotatably sleeved in the columnar cavity 221, and an extrusion cavity 223 communicating with the columnar cavity is provided on the outer shell on one side of the columnar cavity, and an extrusion member is provided in the extrusion cavity. There are various ways to sleeve the rotary sleeve 41. For example: shaft sleeves are sleeved at both the front and rear ends of the rotary sleeve 41, and the rotary sleeve is rotatably sleeved in the columnar cavity through the shaft sleeves; the extrusion member includes an extrusion block 61 and a tightening bolt 62. The extrusion block 61 is fitted and sleeved in the extrusion cavity 223 on the right side of the columnar cavity, and one end of the extrusion block 51 facing the columnar cavity is a soft concave arc surface adapted to the outer ring surface of the rotary sleeve 41. The tightening bolt is rotatably installed on the end surface of the extrusion block 61 away from the columnar cavity, and extends outward through the outer shell to the outside of the outer shell, and the contact part between the tightening bolt 62 is threadedly connected. When the tightening bolt is rotated, the tightening bolt will drive the pressing block 61 to slide along the wall of the extrusion cavity closer to or away from the rotary sleeve. In use, when the tightening bolt 62 is tightened to drive the concave arc surface of the extrusion block to penetrate into the columnar cavity 221 and tightly contact the outer ring surface of the rotary sleeve, the rotary sleeve 41 will be fixed, so that the rotary sleeve loses its rotation function. At this time, when the eccentric needle punctures and contacts the blood vessel, continuously pushing the eccentric needle into the tissue through the syringe will cause the extrusion force on the return spring in the rotary telescopic mechanism to increase, so that the return spring will be further compressed due to the extrusion, and the needle stem part will retract into the needle seat 2. During this process, the needle stem in the rotary telescopic mechanism 4 will drive the spherical slider to slide backward along the chute 411 through the limiting ring 42, driving the needle stem 31 to rotate synchronously, so as to avoid the blood vessel;

[0063] When the tightening bolt 62 is loosened to drive the concave arc surface of the extrusion block to separate from the outer ring surface of the rotary sleeve, the rotary sleeve will resume its rotation function. At this time, when the eccentric needle punctures and contacts the blood vessel, continuously pushing the eccentric needle into the tissue through the syringe will cause the extrusion force on the return spring in the rotary telescopic mechanism to increase. The needle stem will slide along the chute 411 in the rotary sleeve 41 through the spherical slider on the limit ring, driving the rotary sleeve to rotate in the cylindrical cavity, so as to make the needle stem rotate and retract. Compared with the situation where only the resistance received by the eccentric needle penetrating into the tissue drives the limit ring 42 to drive the eccentric needle to rotate and retract along the chute in the rotary sleeve, the rotary sleeve 41 in the rotating state can reduce the friction between the spherical slider 44 and the chute more effectively, making its retraction smooth. Moreover, by adjusting the position of the extrusion block 61 through the tightening bolt, the friction of the rotation of the rotary sleeve 41 can be adjusted according to requirements.

[0064] The basic principle, main features and advantages of the present invention have been described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, there will be various changes and improvements to the present invention. For example, increasing the number of chutes in the rotary sleeve and the number of spherical sliders. These changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A blunt needle for precise site aspiration and injection, comprising a needle seat hermetically sleeved on the liquid discharge head of a syringe, characterized in that, It further includes an eccentric needle head. The tail end of the eccentric needle head is fitted and installed in the needle holder, and is hermetically communicated with the liquid discharge port of the liquid discharge head through the needle holder. The needle holder includes a connecting seat, an outer casing and a rotary telescopic mechanism. The tail end of the connecting seat is fitted and sleeved on the liquid discharge head, and a transition channel communicating with the liquid discharge head is axially opened in the middle of the front end of the connecting seat. The outer casing is fixedly sleeved on the connecting seat, and a columnar cavity is coaxially arranged in the outer casing on the front side of the connecting seat, and the columnar cavity is communicated with the internal channel of the connecting seat. A needle passing hole communicating with the outside is axially opened in the middle of the front cavity wall of the columnar cavity. The rotary telescopic mechanism includes a rotary sleeve, a limiting ring and a return spring. The rotary sleeve is fitted and sleeved in the columnar cavity, and a spiral chute is axially opened on the inner ring wall of the rotary sleeve. The tail end of the eccentric needle head is fitted and sleeved in the needle passing hole, and the tail end of the eccentric needle head passes through the rotary sleeve and is hermetically inserted into the transition channel of the connecting seat, and can rotate and slide along the inner wall of the transition channel. The limiting ring is fixedly sleeved on the eccentric needle head in the rotary sleeve, and a spherical slider slidably embedded in the chute is connected to one side of the rotary sleeve. The return spring is fitted and sleeved on the eccentric needle head between the limiting ring and the connecting seat, and the return spring will push the limiting ring to drive the spherical slider to rotate and slide forward along the chute in the natural state. The eccentric needle head includes a needle stem. The tail end of the needle stem is fitted and sleeved in the needle passing hole, and the tail end of the needle stem passes through the rotary sleeve and is hermetically inserted into the transition channel of the connecting seat. A spherical needle tip is provided at the top end of the needle stem in a sealing manner. A liquid discharge port communicating with the inside is radially opened on the circumferential side wall of the needle stem behind the spherical needle tip, and the spherical needle tip and the needle stem are eccentrically arranged. The resistance received by the eccentric needle head is greater than the minimum working load of the return spring, and the return spring will drive the needle stem to rotate during the stretching process.

2. The blunt needle for precise local aspiration and injection according to claim 1, characterized in that, When the eccentric needle head penetrates into the fat, the resistance received by the eccentric needle head is greater than the minimum working load of the return spring.

3. The blunt needle for precise site aspiration and injection according to claim 1, wherein The tail end of the connecting seat is axially provided with a fixing groove adapted to the liquid discharge head, and is hermetically nested on the liquid discharge head in a matching manner.

4. The blunt needle for precise part aspiration and injection according to claim 3, characterized in that, An annular groove is circumferentially opened on the inner ring arm of the fixing groove, and a sealing ring is fitted and installed. After the connecting seat is nested on the liquid discharge head in a matching manner, the sealing ring in the fixing groove will be deformed by the extrusion of the connecting seat and the liquid discharge head.

5. The blunt needle for precise site aspiration and injection according to claim 3, wherein A circular chamfer is provided at the rear end notch of the fixing groove.

6. The blunt needle for precise local aspiration and injection according to claim 1, wherein Three liquid discharge ports are circumferentially spaced on the circumferential side wall of the needle stem behind the spherical needle tip, and the three liquid discharge ports are all radially arranged and communicated with the internal channel of the needle stem.

7. The blunt needle for precise site aspiration and injection according to claim 1, characterized in that, A threaded section is axially arranged on the outer cylindrical wall of the connecting seat. The outer casing is fitted and sleeved on the threaded section of the connecting seat, and the outer casing is threadedly connected to the connecting seat.

8. The blunt needle for precise site aspiration and injection according to claim 1, characterized in that, A plurality of strip-shaped protrusions are circumferentially spaced on the outer ring surface at the tail end of the outer casing, and the strip-shaped protrusions are axially arranged.

9. The blunt needle for precise local aspiration and injection according to claim 1, characterized in that, A sealing member is fitted in the front end of the transition channel of the connecting seat. The tail end of the eccentric needle head passes through the sealing member and is inserted into the fixing channel in a matching manner, and the sealing member can enhance the sealing strength between the outer ring surface of the eccentric needle head and the inner ring arm of the transition channel on the premise of not affecting the rotation and sliding of the tail end of the eccentric needle head in the transition channel.

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