Subendometrial injection device

Abstract

A subendometrial injection device comprises a supporting sleeve, an injection sheath and an injection needle. The injection sheath is inserted into the supporting sleeve in a sliding mode, a positioning disc with the outer diameter larger than that of a cervix uteri outer opening is fixed to the outer wall of the supporting sleeve, the supporting sleeve is divided into an insertion section with the outer diameter smaller than the inner diameter of a cervix uteri tube and the length larger than that of the cervix uteri tube and a positioning section outside the cervix uteri, and the end, inserted into the supporting sleeve, of the injection sheath is an in-vivo section; and the other end extends out of the positioning section of the supporting sleeve to form an in-vitro section. An external thread section is arranged on the in-vitro section of the injection sheath, a first positioning nut used for positioning the insertion depth of the injection sheath is connected to the external thread section, an injection needle is movably inserted into the injection sheath, a first scale and a second scale which display the insertion depth of the injection sheath and the injection needle are arranged outside the injection sheath and the injection needle respectively, and the injection sheath is provided with a channel for injection of the bottom and the side wall of a uterine cavity. By adopting the device, multi-site subendometrial injection can be completed, the operation process is simple, the trauma is small, the risk is low, the injection depth can be accurately controlled, and clinical development is facilitated.

Description

Technical Field

[0001] This utility model relates to a subendothelial injection device. Background Technology

[0002] In clinical practice of assisted reproductive technology, infertile patients with intrauterine adhesions, thin endometrium, or recurrent implantation failure after IVF treatment often require local endometrial drug administration to promote endometrial repair and / or improve endometrial receptivity, increasing the probability of natural pregnancy or improving the clinical pregnancy rate of IVF embryo transfer. However, the uterus is an internal cavity organ, making direct injection of drugs through the body surface impossible. Currently, the main clinical approach is intrauterine infusion, where drugs are injected into the uterine cavity via vaginal-cervical cannulation. The drugs are absorbed directly through contact with the endometrium. However, drugs are prone to leakage through the cervix or into the pelvic cavity via the fallopian tubes, resulting in short drug retention time and limited contact time with the endometrium, thus affecting treatment efficacy. It is now believed that endometrial repair is mainly carried out by stem cells in the basal layer of the endometrium, which are responsible for renewing and repairing damaged endometrium. Therefore, subendoscopic drug injection is more conducive to slow absorption of drugs and direct action on the basal layer of the endometrium, which is more beneficial for endometrial regeneration and repair.

[0003] Currently, there is no specialized subendothelial puncture and injection device available in clinical practice to complement the above-mentioned treatment methods. Existing techniques include transvaginal ultrasound-guided transvaginal fornix puncture, inserting the needle through the uterine serosa and penetrating the myometrium for injection. However, this method has three problems: First, it is high-risk because it requires penetrating the entire myometrium, resulting in significant trauma and a high risk of bleeding, infection, and damage to pelvic organs such as the intestines and blood vessels. Second, it is more painful for patients, sometimes requiring anesthesia, which increases costs and also increases the risks associated with anesthesia. Third, because the boundary between the myometrium and the endometrium is unclear, and due to limitations imposed by the needle insertion direction and the myometrium, only single-point injections or repeated punctures of the myometrium are possible, making it difficult to control the injection depth and precisely target the intended target. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a device that is minimally invasive, low-risk, and capable of precisely controlling injection depth and enabling multi-directional subendothelial injection.

[0005] To achieve the above objectives, this utility model first proposes a subendothelial injection device, including a support cannula, an injection sheath, and an injection needle. The injection sheath is slidably inserted into the support cannula. A positioning disc with an outer diameter larger than the external os of the cervix is ​​fixed on the outer wall of the support cannula. The positioning disc divides the support cannula into an insertion section with an outer diameter smaller than the inner diameter of the cervical canal and a length smaller than the length of the cervical canal, and a positioning section placed outside the body. One end of the injection sheath inserted into the support cannula is the internal section, and the other end extends out from the positioning section of the support cannula to form the external section. The external section of the injection sheath is provided with an external thread section, and a first positioning nut for positioning the insertion depth of the injection sheath is threaded onto the external thread section. The injection sheath is provided with a first scale indicating its insertion depth. An injection needle is movably inserted into the injection sheath, and the injection needle is provided with a second scale indicating its injection depth.

[0006] In this embodiment, the first positioning nut is provided with a threaded through hole along the radial direction, and a first locking bolt is connected to the threaded through hole. The first locking bolt achieves axial positioning of the first positioning nut on the outer section of the injection sheath through friction.

[0007] In this embodiment, the first scale is set on the outer section of the injection sheath, and the first scale is used to display the length between the first positioning nut and the end of the inner section of the injection sheath.

[0008] In this embodiment, the injection sheath is provided with a plurality of independent through holes along the axial direction, each with an inner diameter larger than the outer diameter of the injection needle.

[0009] In this embodiment, the injection sheath has three independent through holes along the axial direction, each with an inner diameter larger than the outer diameter of the injection needle. The three through holes form a first needle insertion channel, a second needle insertion channel, and a third needle insertion channel, respectively. The inlets of the first, second, and third needle insertion channels are all located on the end face of the outer section of the injection sheath. The outlets of the first and third needle insertion channels are located on the outer side wall near the inner section of the injection sheath, and the outlet of the second needle insertion channel is located on the end face of the inner section of the injection sheath. The first and third needle insertion channels are used for injection needles with bent needle tips to enter, and the second needle insertion channel is used for injection needles with straight needle tips to enter.

[0010] In this embodiment, the wall thickness of the first needle insertion channel facing the first outlet inside the injection sheath is less than the wall thickness of the third needle insertion channel facing the third outlet, such that the length of the first needle exit channel formed between the first needle insertion channel and the first outlet is less than the length of the third needle exit channel formed between the third needle insertion channel and the third outlet.

[0011] In this embodiment, the positioning disc is threaded onto the support sleeve, and the length of the inner segment can be adjusted according to the length of the cervical canal of different patients. The positioning disc is adjusted to ensure that the top of the inner segment of the support sleeve exceeds the internal os of the cervix.

[0012] In this embodiment, one end of the injection needle is inserted into the injection sheath as the needle tip, and the other end extends out of the injection sheath to form a holding section. The holding section of the injection needle is provided with an external thread section, and a second positioning nut for positioning the insertion depth of the injection needle is threaded onto the external thread section.

[0013] In this embodiment, the second positioning nut is provided with a threaded through hole along the radial direction, and a second locking bolt is internally threaded into the threaded through hole. The second locking bolt achieves axial positioning of the second positioning nut on the injection needle holding section through friction.

[0014] In this embodiment, the second scale on the injection needle is set on the holding section of the injection needle, and the second scale is used to display the length between the second positioning nut and the tip of the injection needle.

[0015] With the above structure, this utility model has the following advantages:

[0016] 1. This device is inserted through natural cavities, passing through the vagina, cervical canal, and uterine cavity, and directly injecting into the subendometrium. The needle insertion process does not need to pass through the myometrium, resulting in low risks of bleeding and infection, high safety, minimal trauma, and less patient discomfort.

[0017] 2. This device, through the engagement of the first positioning nut connected to the external thread of the injection sheath with the first and second scales on the injection sheath and injection needle, can accurately confirm and understand the depth of needle insertion. This ensures that the length of the needle tip extending from the injection sheath matches the depth of subendothelial puncture, thus guaranteeing the accuracy of the injection and preventing damage to the uterine cavity or cervical canal when the needle enters through the injection sheath.

[0018] 3. This device also has a second positioning nut threadedly connected to the holding section of the injection needle. After the injection sheath enters the uterine cavity through the vagina, cervix, and cervical canal, the axial depth of the injection sheath insertion is positioned by the first locking bolt. While the position of the injection sheath moves, the insertion depth of the injection sheath is read and recorded by the first scale on the outside of the injection sheath. The second positioning nut is used to adjust the second scale so that the insertion depth of the injection needle is only slightly more than the needle tip's set puncture length compared to the insertion depth of the injection sheath. Then, the injection needle is inserted through the injection sheath. Under the limitation of the second positioning nut, it is ensured that the length of the injection needle tip extending from the inner part of the injection sheath is exactly matched with the depth of the subendothelial puncture, thereby achieving precise control of the injection depth.

[0019] 4. Through the coordination of multiple needle channels within the injection sheath and the rotation of the injection sheath, injections can be performed in multiple directions with a single puncture. This ensures that the medication is injected at the designated location while achieving multi-site injection under the endometrium, greatly increasing the efficacy of the medication and reducing the patient's pain.

[0020] 5. Because the four walls of the uterine cavity are attached to each other by the endometrium when the cavity is filled with water, they are approximately an inverted triangle. Therefore, a straight needle cannot be used to inject into the lateral walls of the uterine cavity. A bent needle is required to inject into the lateral walls of the uterine cavity. This device controls the depth of lateral wall injection by setting different wall thicknesses for the two lateral wall injection channels and controlling the length of the bent needle extending out of the injection sheath. This simple method achieves adjustment of the lateral wall injection depth.

[0021] In summary, this device allows for simple intrauterine manipulation to achieve subendothelial injections into the uterine cavity floor and lateral walls, which are currently difficult to perform clinically. The procedure is simple, minimally invasive, low-risk, and allows for precise control of injection depth and direction, making it suitable for clinical application. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model.

[0023] Figure 2 This is a cross-sectional view of the injection sheath of this utility model at the first outlet and the third outlet.

[0024] Figure 3 This is a diagram showing the state when the first and third outlets of this utility model are equipped with bent needles.

[0025] Figure 4 This is a schematic diagram of the structure of the outer end face of the injection sheath of this utility model.

[0026] Figure 5 This is a schematic diagram of the internal structure of the injection sheath of this utility model.

[0027] Figure 6 This is a diagram showing the working state of the straight needle head of this utility model during use.

[0028] Figure 7 This diagram shows the working state of the bent needle of this utility model during use.

[0029] In the attached diagram, 1. Support sleeve; 11. Positioning plate; 2. Injection sheath; 21. First positioning nut; 22. First locking bolt; 23. First needle inlet channel; 231. First outlet; 24. Second needle inlet channel; 241. Second outlet; 25. Third needle inlet channel; 251. Third outlet; 3. Injection needle; 31. Second positioning nut; 32. Second locking bolt; 33. Straight needle; 34. Bent needle; 4. Uterine cavity. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] like Figures 1 to 6 As shown, a subendothelial injection device includes a support cannula 1, an injection sheath 2, and an injection needle 3. The inner diameter of the support cannula 1 is larger than the outer diameter of the injection sheath 2. The injection sheath 2 is slidably inserted into the support cannula 1. A positioning disc 11 with an outer diameter larger than the external os of the cervix is ​​fixed or threaded onto the outer wall of the support cannula 1. The positioning disc 11 divides the support cannula 1 into an insertion section with an outer diameter smaller than the inner diameter of the cervical canal and a positioning section placed outside the body. The length of the insertion section of the support cannula 1 is slightly larger than the length of the cervical canal. When the positioning disc 11 is threaded, the length of the insertion section can be adjusted to ensure that the support cannula can exceed the internal os of the cervix and be fixed in position, thereby adapting to different patients.

[0032] The injection sheath 2 is inserted into the support sleeve 1 at one end, forming the inner section, and the other end extends from the positioning section of the support sleeve 1, forming the outer section. The outer section of the injection sheath 2 has an external thread section, on which a first positioning nut 21 is threadedly connected. The outer diameter of the first positioning nut 21 is larger than the inner diameter of the support sleeve 1. The first positioning nut 21 has a radially threaded through hole, on which a first locking bolt 22 is threadedly connected. The first locking bolt 22 achieves axial positioning of the first positioning nut 21 on the outer section of the injection sheath 2 through friction with the outer wall of the injection sheath 2. The length of the needle 3 is greater than that of the injection sheath 2. One end of the injection needle 3 is inserted into the injection sheath 2 as the needle tip, and the other end extends out of the injection sheath 2 to form a holding section. The holding section of the injection needle 3 is provided with an external thread section. A second positioning nut 31 is threadedly connected to the external thread section. The outer diameter of the second positioning nut 31 is greater than the inner diameter of the injection sheath 2. The second positioning nut 31 is provided with a threaded through hole along the radial direction. A second locking bolt 32 is threadedly connected to the threaded through hole. The second locking bolt 32 achieves axial positioning of the second positioning nut 31 on the holding section of the injection needle 3 through friction with the outer wall of the injection needle 3.

[0033] Furthermore, the inner section of the injection sheath 2 is a flexible tube with a certain degree of toughness and plasticity, and the hardness of the outer section can be greater than that of the inner section. For example, the injection sheath 2 is made of polyvinyl chloride.

[0034] Both the injection sheath 2 and the injection needle 3 are provided with scales to display their lengths; furthermore, the first scale on the injection sheath 2 is set on the outer section of the injection sheath 2, and the first scale is used to display the length between the first positioning nut 21 and the end of the inner section of the injection sheath 2; the second scale on the injection needle 3 is set on the holding section of the injection needle 3, and the second scale is used to display the length between the second positioning nut 31 and the tip of the injection needle 3.

[0035] like Figure 2 , 3 As shown in Figure 4, the injection sheath 2 has three independent through holes along the axial direction, each with an inner diameter larger than the outer diameter of the injection needle 3. The three through holes form a first needle insertion channel 23, a second needle insertion channel 24, and a third needle insertion channel 25, respectively. The inlets of the first needle insertion channel 23, the second needle insertion channel 24, and the third needle insertion channel 25 are all located on the end face of the outer section of the injection sheath 2. The first outlet 231 of the first needle insertion channel 23 and the third outlet 251 of the third needle insertion channel 25 are located on the outer side wall near the inner section of the injection sheath 2. The second outlet 241 of the second needle insertion channel 24 is located on the end face of the inner section of the injection sheath 2, so that the first needle insertion channel 23 and the third needle insertion channel 25 form a side wall injection channel, and the second needle insertion channel 24 forms an end injection channel. In this device, the first needle inlet channel 23 and the third needle inlet channel 25 are matched with the size of the injection needle 3 of the bent needle 34 for the injection needle 3 of the bent needle 34 to enter, while the second needle inlet channel 24 is matched with the size of the injection needle 3 of the straight needle 33 for the injection needle 3 of the straight needle 33 to enter. The injection needle 3 can enter from any one of the needle inlet channels of the injection sheath 2 as needed to achieve injection. The injection sheath 2 can prevent damage to the uterine cavity 4 or cervical canal when the injection needle 3 enters.

[0036] Furthermore, such as Figure 2 , 3 As shown, the wall thickness of the first needle inlet channel 23 facing the first outlet 231 inside the injection sheath 2 is less than the wall thickness of the third needle inlet channel 25 facing the third outlet 251. This results in the length of the first needle outlet channel formed between the first needle inlet channel 23 and the first outlet 231 being less than the length of the third needle outlet channel formed between the third needle inlet channel 25 and the third outlet 251. Therefore, the depth of sidewall injection is controlled by controlling the length of the bent needle 34 extending from the sidewall of the injection sheath 2. Furthermore, the outer wall of the injection sheath 2 has a plane connecting the first outlet 231 and the third outlet 251, facilitating precise control of the length of the bent needle 34 extending from the first outlet 231 and the third outlet 251. Figure 3As shown, the length of the bent needle 34 extending from the first outlet 231 to the side wall of the injection sheath 2 differs from the length extending from the third outlet 251 to the side wall of the injection sheath 2 by a height difference H. By entering from different needle channels, this height difference H can be used to control different injection depths.

[0037] The specific usage process of this device is as follows:

[0038] After the vagina is opened and the cervix is ​​exposed using a standard vaginal speculum, the insertion segment of the support cannula 1 is first inserted through the external os of the cervix until it extends beyond the internal os. The positioning disc 11 then supports the cervix, limiting the insertion depth of the support cannula 1 and stabilizing the position of the external segment. Under abdominal ultrasound guidance, the injection sheath 2 is inserted into the support cannula 1. The injection sheath 2 passes through the vagina, cervical os, and cervical canal into the uterine cavity 4, ensuring the internal segment of the injection sheath 2 is close to the uterine wall. Then, it is rotated... The first positioning nut 21 contacts the end of the positioning section of the support sleeve 1. The position of the first positioning nut 21 is locked by the first locking bolt 22, thereby positioning the axial depth of the injection sheath 2 insertion and preventing the position of the injection sheath 2 from moving when the injection needle 3 is inserted. At the same time, the insertion depth of the injection sheath 2 is read and recorded by the first scale on the outside of the injection sheath 2. Then, according to the axial insertion length shown on the first scale of the injection sheath 2, the second positioning nut 31 is rotated and adjusted on the second scale.

[0039] Then, depending on the type of needle, the insertion depth of the injection needle 3 into the injection sheath 2 is adjusted by adjusting the position of the second positioning nut 31. If it is a straight needle, after adjustment, the insertion depth of the injection needle 3 is only more than the set insertion length of the injection needle 3 compared to the insertion depth of the injection sheath 2. Under the limit of the second positioning nut 31, it is ensured that the length of the injection needle 3 extending from the body section of the injection sheath 2 is exactly matched with the depth of the subendothelial puncture.

[0040] If it is a bent needle, after adjustment, the insertion depth of the injection needle 3 is the same as the insertion depth of the injection sheath 2. The injection depth of the bent needle is controlled by controlling the length of the bent needle 34 extending out of the side wall of the injection sheath 2. In this embodiment, the wall thickness of the first needle insertion channel and the third needle insertion channel are different, so the injection depth of the bent needle can be controlled by selecting different needle insertion channels.

[0041] Finally, the bent needle is inserted into the injection sheath 2 through the first and third needle insertion channels, while the straight needle is inserted into the injection sheath 2 through the second needle insertion channel. After puncture, a targeted injection is performed. This ensures the accuracy of the injection and avoids damage to the uterine cavity 4 or cervical canal when the injection needle 3 enters.

[0042] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A subendometrial injection device, characterized by: The device includes a support sleeve (1), an injection sheath (2), and an injection needle (3). The injection sheath (2) is slidably inserted into the support sleeve (1). A positioning disc (11) with an outer diameter larger than the external os of the cervix is ​​installed on the outer wall of the support sleeve (1). The positioning disc (11) divides the support sleeve (1) into an insertion section with an outer diameter smaller than the inner diameter of the cervical canal and a positioning section placed outside the external os of the cervix. One end of the injection sheath (2) inserted into the support sleeve (1) is the internal section, and the other end extends out from the positioning section of the support sleeve (1) to form the external section. The external section of the injection sheath (2) is provided with an external thread section, and a first positioning nut (21) for positioning the insertion depth of the injection sheath (2) is threaded onto the external thread section. The injection sheath (2) is provided with a first scale indicating its insertion depth. An injection needle (3) is movably inserted into the injection sheath (2), and the injection needle (3) is provided with a second scale indicating its injection depth.

2. The subendometrial injection device of claim 1, wherein: The first positioning nut (21) has a threaded through hole along the radial direction. The threaded through hole is connected to a first locking bolt (22). The first locking bolt (22) achieves axial positioning of the first positioning nut (21) on the outer section of the injection sheath (2) through friction.

3. The subendometrial injection device of claim 1, wherein: The first scale is set on the outer section of the injection sheath (2) and is used to show the length between the first positioning nut (21) and the end of the inner section of the injection sheath (2).

4. The subendometrial injection device of claim 1, wherein: The injection sheath (2) has multiple independent through holes along the axial direction, each with an inner diameter larger than the outer diameter of the injection needle (3).

5. The subendometrial injection device of claim 4, wherein: The injection sheath (2) has three independent through holes along the axial direction. The three through holes form a first needle insertion channel (23), a second needle insertion channel (24), and a third needle insertion channel (25), respectively. The inlets of the first needle insertion channel (23), the second needle insertion channel (24), and the third needle insertion channel (25) are all located on the end face of the outer section of the injection sheath (2). The first outlet (231) of the first needle insertion channel (23) and the third outlet (251) of the third needle insertion channel (25) are located on the outer side wall near the inner section of the injection sheath (2). The second outlet (241) of the second needle insertion channel (24) is located on the end face of the inner section of the injection sheath (2). The first needle insertion channel (23) and the third needle insertion channel (25) are used for the injection needle (3) with a bent needle tip (34) to enter. The second needle insertion channel (24) is used for the injection needle (3) with a straight needle tip (33) to enter.

6. The subendometrial injection device of claim 5, wherein: The wall thickness of the first needle inlet channel (23) facing the first outlet (231) inside the injection sheath (2) is less than the wall thickness of the third needle inlet channel (25) facing the third outlet (251), so that the length of the first needle outlet channel formed between the first needle inlet channel (23) and the first outlet (231) is less than the length of the third needle outlet channel formed between the third needle inlet channel (25) and the third outlet (251).

7. The subendometrial injection device of claim 1, wherein: The positioning disc (11) is threaded onto the support sleeve (1).

8. The subendometrial injection device according to any one of claims 1 to 7, characterized in that: One end of the injection needle (3) is inserted into the injection sheath (2) as the needle tip, and the other end extends out of the injection sheath (2) to form a holding section. The holding section of the injection needle (3) is provided with an external thread section, and a second positioning nut (31) for positioning the insertion depth of the injection needle (3) is threaded onto the external thread section.

9. The subendometrial injection device of claim 8, wherein: The second positioning nut (31) has a threaded through hole along the radial direction. The threaded through hole is internally threaded with a second locking bolt (32). The second locking bolt (32) achieves axial positioning of the second positioning nut (31) on the holding section of the injection needle (3) through friction.

10. The subendometrial injection device of claim 8, wherein: The second scale on the injection needle (3) is set on the holding section of the injection needle (3), and the second scale is used to show the length between the second positioning nut (31) and the tip of the injection needle (3).

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