A trocar cannula assembly

Abstract

The present application provides a trocar cannula assembly, which relates to the technical field of trocars. The trocar cannula assembly includes a cannula, a sealing film and a holding member. The sealing film is disposed inside the cannula. The holding member is partially disposed inside the cannula. The holding member is connected to the top of the cannula and abuts against the sealing film. The holding member is used to hold an external instrument so that the instrument is at the center of the cannula. The trocar cannula assembly can reduce the damage to the sealing film.

Description

Technical Field

[0001] The present application relates to the technical field of trocars, and more particularly, to a trocar cannula assembly. Background Art

[0002] With the continuous popularization of laparoscopic minimally invasive surgery, the trocar, which is essential in minimally invasive surgery, has become increasingly familiar and commonly used by doctors. Doctors establish pneumoperitoneum in laparoscopic minimally invasive surgery and use the trocar to establish a surgical channel, enabling various instruments (such as ultrasonic scalpels, staplers, etc.) to enter the abdominal cavity for surgical operations.

[0003] During the use of existing trocars, external instruments are inserted into the trocar, which easily damages the sealing film. As a result, the sealing film cannot wrap the instrument in real time, leading to air leakage. Summary of the Invention

[0004] The objectives of the present application include, for example, providing a trocar cannula assembly that can reduce damage to the sealing film.

[0005] The embodiments of the present application can be implemented as follows:

[0006] The embodiments of the present application provide a trocar cannula assembly, which includes a cannula, a sealing film, and a holding member. The sealing film is disposed inside the cannula. The holding member is partially disposed inside the cannula, is connected to the top of the cannula, and abuts against the sealing film. The holding member is used to hold an external instrument so that the instrument is located at the center of the cannula.

[0007] Optionally, the holding member includes a fixed cover, a sleeve, and a plurality of elastic structures arranged circumferentially along the sleeve. The fixed cover and the sleeve are connected. The fixed cover is connected to the top of the cannula. The plurality of elastic structures are used to cooperate to hold an external instrument together.

[0008] Optionally, the elastic structure includes an integrally formed first connecting section and a second connecting section. One end of the first connecting section away from the second connecting section is connected to the sleeve. One end of the second connecting section away from the first connecting section is a free end. The first connecting section extends towards the inside of the sleeve, and the second connecting section extends towards the outside of the sleeve.

[0009] Optionally, an arc surface is provided at the connection between the first connecting section and the second connecting section. The arc surfaces of the plurality of elastic structures are located on the same circumference.

[0010] Optionally, a first limiting ring is provided on the sealing film. The bottom end of the sleeve is matched with the first limiting ring so that the central axis of the sleeve coincides with that of the sealing film.

[0011] Optionally, the surface of the sealing film is arc-shaped, and the thickness of the sealing film gradually decreases in the direction away from the holding member.

[0012] Optionally, a first opening for the instrument to enter is provided on the fixed cover. The fixed cover is provided with a second limiting ring and a third limiting ring. The top end of the sleeve extends between the second limiting ring and the third limiting ring, wherein the diameter of the third limiting ring is greater than that of the second limiting ring.

[0013] Optionally, a limiting bayonet is provided on the third limiting ring, and a limiting portion is provided on the sleeve. The limiting portion is snapped into the limiting bayonet.

[0014] Optionally, the fixed cover and the sleeve are integrally formed.

[0015] Optionally, the trocar cannula assembly further includes a gas blocking valve. The gas blocking valve is disposed inside the cannula, and a part of the sealing film extends into the gas blocking valve.

[0016] Optionally, the gas blocking valve includes an integrally formed mounting portion and a gas blocking portion. An annular protrusion is provided inside the cannula, an annular groove is provided on the mounting portion, the annular protrusion is matched with the annular groove, and a second opening is provided on the gas blocking portion.

[0017] Optionally, the outer surface of the gas blocking portion is arc-shaped.

[0018] The beneficial effects of the trocar cannula assembly provided by the embodiments of the present application include, for example: in order to reduce the damage to the sealing film, a trocar cannula assembly is designed. The trocar cannula assembly includes a cannula, a sealing film and a holding member. The sealing film is disposed inside the cannula, and a part of the holding member is disposed inside the cannula. The holding member is connected to the top of the cannula and abuts against the sealing film. The holding member is used to hold an external instrument so that the instrument is at the center of the cannula. By providing a holding member at the front end of the sealing film, when the external instrument enters the cannula, the holding member can hold the instrument so that the instrument is at the center of the cannula. At this time, the instrument is not likely to damage the sealing film. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic diagram of the trocar cannula assembly in the embodiments of the present application;

[0021] Figure 2 It is a partial cross-sectional view of the trocar cannula assembly in the embodiment of the present application;

[0022] Figure 3 It is a schematic diagram of the first perspective of the first holding member in the embodiment of the present application;

[0023] Figure 4 It is a schematic diagram of the second perspective of the first holding member in the embodiment of the present application;

[0024] Figure 5 It is a schematic diagram of the sealing film in the embodiment of the present application;

[0025] Figure 6 It is a schematic diagram of the fixing cover in the embodiment of the present application;

[0026] Figure 7 It is a partial structural schematic diagram of the cannula in the embodiment of the present application;

[0027] Figure 8 It is a schematic diagram of the second holding member in the embodiment of the present application;

[0028] Figure 9 It is a schematic diagram of the air blocking valve in the embodiment of the present application.

[0029] Icon: 100 - cannula; 110 - fixing column; 120 - annular protrusion; 130 - extension tube; 131 - Luer channel; 132 - mounting hole; 200 - sealing film; 210 - first limiting ring; 220 - second reinforcing rib; 300 - holding member; 310 - sleeve; 311 - rectangular through hole; 312 - third reinforcing rib; 320 - elastic structure; 321 - first connecting section; 322 - second connecting section; 323 - arc surface; 324 - first reinforcing rib; 330 - limiting part; 400 - fixing cover; 410 - first opening; 420 - second limiting ring; 430 - third limiting ring; 431 - limiting bayonet; 440 - fixing hole; 450 - guiding arc surface; 460 - buckle; 500 - air blocking valve; 510 - mounting part; 511 - annular groove; 520 - air blocking part; 521 - second opening; 600 - gas injection valve. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0031] Accordingly, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts fall within the scope of protection of the present application.

[0032] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the present application, it should be noted that if terms such as "upper", "lower", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is usually placed during use. This is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0034] In addition, if terms such as "first", "second", etc. are used only for distinguishing descriptions, they cannot be understood as indicating or implying relative importance.

[0035] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0036] As disclosed in the background art section, during the use of an existing trocar, external instruments are inserted into the trocar. Once the instrument is in an inclined state or not located at the center of the cannula, the instrument is likely to damage the sealing film, resulting in the sealing film being unable to wrap the instrument in real time and causing air leakage. Embodiments of the present application provide a trocar cannula assembly for at least solving the above technical problems.

[0037] Please refer to Figure 1 、 Figure 2 , the trocar cannula assembly provided by the embodiments of the present application includes a cannula 100, a sealing film 200, and a holding member 300. The sealing film 200 is disposed inside the cannula 100. The holding member 300 is partially disposed inside the cannula 100. The holding member 300 is connected to the top of the cannula 100 and abuts against the sealing film 200. The holding member 300 is used to hold an external instrument so that the instrument is located at the center of the cannula 100.

[0038] An installation cavity is provided inside the cannula 100. Both the sealing film 200 and a part of the holding member 300 are disposed in the installation cavity. When the holding member 300 is connected to the top of the cannula 100, the holding member 300 presses and fixes the sealing film 200 in the installation cavity.

[0039] By providing a holding member 300 at the front end of the sealing film 200, when an external instrument enters the cannula 100, the holding member 300 can hold the instrument so that the instrument is centered within the cannula 100, and at this time, the instrument is less likely to damage the sealing film 200.

[0040] Please refer to Figure 3 、 Figure 4 , in this embodiment, the holding member 300 includes a fixed cover 400, a sleeve 310, and a plurality of elastic structures 320 arranged circumferentially along the sleeve 310. The fixed cover 400 is connected to the sleeve 310, and the fixed cover 400 is connected to the top of the cannula 100. The plurality of elastic structures 320 are used to cooperate to hold an external instrument together.

[0041] The elastic structure 320 has a certain elasticity. When an external instrument enters the sleeve 310, the plurality of elastic structures 320 cooperate to hold the instrument together so that the instrument is centered within the cannula 100.

[0042] , in this embodiment, the elastic structure 320 includes an integrally formed first connecting section 321 and a second connecting section 322. One end of the first connecting section 321 away from the second connecting section 322 is connected to the sleeve 310. One end of the second connecting section 322 away from the first connecting section 321 is a free end. The first connecting section 321 extends toward the inside of the sleeve 310, and the second connecting section 322 extends toward the outside of the sleeve 310.

[0043] The sleeve 310 is provided with a plurality of rectangular through holes 311 along the circumference. The plurality of rectangular through holes 311 correspond to the plurality of elastic structures 320 one by one. One end of the first connecting section 321 away from the second connecting section 322 is connected to the inner top wall of the rectangular through hole 311. The first connecting section 321 extends toward the inside of the sleeve 310, and the surface of the first connecting section 321 is an inclined downward conical surface. The second connecting section 322 extends toward the outside of the sleeve 310, and the surface of the second connecting section 322 is an arc surface. The first connecting section 321 and the second connecting section 322 together form an elastic structure 320 protruding toward the inside of the sleeve 310 to hold the instrument.

[0044] Furthermore, an arc surface 323 is provided at the connection between the first connecting section 321 and the second connecting section 322. The arc surfaces 323 of the plurality of elastic structures 320 are located on the same circumference.

[0045] In a cross-section parallel to the top surface of the sleeve 310, the arc surfaces 323 of the plurality of elastic structures 320 are located on the same circumference. The plurality of arc surfaces 323 cooperate to hold the instrument together so that the instrument is located at the center of the sleeve 310.

[0046] It should be noted that the diameter of the circumference should match the diameter of the largest instrument allowed to pass through, and the size of the circumference can be scaled and adjusted for different types of trocars. For example, when an instrument with a maximum diameter of 10 mm is allowed to enter, the diameter of the circumference formed by the arc surfaces 323 of the plurality of elastic structures 320 is 9 - 10 mm at this time, so that excessive force will not be applied when holding the instrument, which affects the operation.

[0047] In addition, a first reinforcing rib 324 is provided between the first connecting section 321 and the second connecting section 322.

[0048] By providing the first reinforcing rib 324 between the first connecting section 321 and the second connecting section 322, the holding force of the elastic structure 320 on the instrument can be increased, so that the instrument can be better held at the center of the cannula 100.

[0049] Please refer to Figure 5 , in this embodiment, a first limiting ring 210 is provided on the sealing film 200, and the bottom end of the sleeve 310 is matched with the first limiting ring 210 so that the central axis of the sleeve 310 coincides with that of the sealing film 200.

[0050] The first limiting ring 210 protrudes upward from the top of the sealing film 200. The bottom end of the sleeve 310 extends into the inner side of the first limiting ring 210 and fits with the first limiting ring 210, so that the central axis of the sleeve 310 coincides with that of the sealing film 200, avoiding damage to the sealing film 200 caused by the misalignment of the sleeve 310 and the sealing film 200.

[0051] In this embodiment, the surface of the sealing film 200 is arc-shaped, and along the direction away from the holding member 300, the thickness of the sealing film 200 gradually decreases.

[0052] The sealing film 200 is provided with a central hole for the instrument to pass through. The inner and outer surfaces of the main body of the sealing film 200 are both arc-shaped, and the part of the sealing film 200 closer to the central hole is thinner. When the instrument enters the sealing film 200, it only receives the pulling force of the part of the sealing film 200 closer to the central hole, so that the instrument can move more smoothly. When the instrument exits, because the part of the sealing film 200 closer to the central hole is thinner, even if the part of the sealing film 200 closer to the central hole is folded, due to the thicker part of the sealing film 200 away from the central hole, the part of the sealing film 200 closer to the central hole will be pulled by the part of the sealing film 200 away from the central hole and restored to its original state.

[0053] The holding effect of the holding member 300 on the instrument maximally avoids the biased pulling of the central hole of the sealing film 200 during the use of the instrument, preventing the sealing film 200 from being ruptured due to long-term pulling during the operation.

[0054] In addition, a second reinforcing rib 220 is provided on the outer surface of the sealing film 200.

[0055] A plurality of second reinforcing ribs 220 are provided along the outer surface of the main body of the sealing film 200, which can enhance the strength of the sealing film 200 and also enable the portion of the sealing film 200 near the central hole to quickly return to its original position after being folded.

[0056] Please refer to Figure 6 , in some embodiments, the fixed cover 400 and the sleeve 310 are of a split structure. A first opening 410 for the instrument to enter is provided on the fixed cover 400, and the first opening 410 communicates with the sleeve 310; a second limiting ring 420 and a third limiting ring 430 are provided on the fixed cover 400, and the top end of the sleeve 310 extends into the space between the second limiting ring 420 and the third limiting ring 430, wherein the diameter of the third limiting ring 430 is greater than the diameter of the second limiting ring 420.

[0057] Both the second limiting ring 420 and the third limiting ring 430 extend towards the inside of the sleeve 100. The second limiting ring 420 and the third limiting ring 430 are coaxially arranged. The top end of the sleeve 310 extends into the space between the second limiting ring 420 and the third limiting ring 430. The second limiting ring 420 and the third limiting ring 430 cooperate together to limit the sleeve 310, so that the first opening 410 coincides with the central axis of the sleeve 310.

[0058] Furthermore, a limiting bayonet 431 is provided on the third limiting ring 430, and a limiting portion 330 is provided on the sleeve 310, and the limiting portion 330 is snapped into the limiting bayonet 431.

[0059] By snapping the limiting portion 330 into the limiting bayonet 431, the fixed cover 400 can prevent the sleeve 310 from rotating, so as to prevent the sleeve 310 from rotating when the instrument enters and exits.

[0060] Optionally, two limiting bayonets 431 are oppositely arranged on the third limiting ring 430. Correspondingly, two limiting portions 330 are oppositely arranged on the sleeve 310, and the two limiting portions 330 are respectively snapped into the two limiting bayonets 431. The limiting portion 330 protrudes from the outer surface of the sleeve 310, and the limiting portion 330 can be a limiting piece or a limiting post. Combined with Figure 7 , in some embodiments, a plurality of fixing holes 440 are provided on the fixed cover 400 along the circumferential direction, and a plurality of fixing posts 110 are provided on the top of the sleeve 100, and the plurality of fixing posts 110 cooperate with the plurality of fixing holes 440 one by one.

[0061] The plurality of fixing holes 440 are all arranged on the surface of the fixed cover 400 facing the inside of the sleeve 100. The plurality of fixing posts 110 are inserted into the plurality of fixing holes 440 one by one. An interference fit can be selected between the fixing post 110 and the fixing hole 440 to relatively fix the fixed cover 400 and the sleeve 100.

[0062] In some other embodiments, please refer to Figure 8 , the fixed cover 400 is integrally formed with the sleeve 310, and the fixed cover 400 is connected to the top of the sleeve 100 through a buckle 460. A third reinforcing rib 312 is circumferentially provided on the outer surface of the sleeve 310.

[0063] When the fixed cover 400 is integrally formed with the sleeve 310, the holding position is shifted upward as a whole. The first reinforcing rib 324 provided between the first connecting section 321 and the second connecting section 322 can be cancelled. By providing the third reinforcing rib 312 on the sleeve 310, the overall strength of the holding member 300 can be ensured.

[0064] Combined with Figure 1 , in this embodiment, the fixed cover 400 is provided with a guiding arc surface 450 at the first opening 410.

[0065] The guiding arc surface 450 serves to guide the instrument into the sleeve 100. When the instrument contacts the guiding arc surface 450, the guiding arc surface 450 can guide the instrument into the first opening 410.

[0066] The height of the second limiting ring 420 is greater than the height of the third limiting ring 430. The second limiting ring 420 can contact the instrument. After the instrument enters the first opening 410 along the guiding arc surface 450, the instrument will bump against the second limiting ring 420, causing the instrument to naturally deviate and coincide with the central axis of the sleeve 100 during continuous advancement. The instrument can be realigned when it first enters the sleeve 100, thereby restricting the angle when the instrument enters and preventing the instrument from being stuck in the rectangular through hole 311 corresponding to the elastic structure 320.

[0067] Please refer to Figure 9 , in this embodiment, the trocar sleeve assembly further includes an air blocking valve 500. The air blocking valve 500 is arranged inside the sleeve 100, and a part of the sealing film 200 extends into the air blocking valve 500.

[0068] The air blocking valve 500 can maintain the seal inside the sleeve 100 when no instrument passes through, and the sealing film 200 can maintain the seal inside the sleeve 100 when the instrument passes through. The air blocking valve 500 and the sealing film 200 form a double-sealing structure.

[0069] Further, the air blocking valve 500 includes an integrally formed mounting portion 510 and an air blocking portion 520. An annular protrusion 120 is provided inside the sleeve 100. An annular groove 511 is provided on the mounting portion 510. The annular protrusion 120 cooperates with the annular groove 511, and a second opening 521 is provided on the air blocking portion 520.

[0070] An annular protrusion 120 facing the fixed cover 400 is provided in the mounting cavity of the sleeve 100. The annular protrusion 120 cooperates with the annular groove 511, so that the air blocking valve 500 is located at the center of the sleeve 100.

[0071] When the fixed cover 400 is fixed to the top of the cannula 100, the fixed cover 400 presses against the holder 300, the holder 300 presses against the sealing film 200, the sealing film 200 presses against the air-blocking valve 500, and the annular groove 511 on the air-blocking valve 500 fits tightly with the annular protrusion 120 on the cannula 100, so that seals are formed between the fixed cover 400 and the holder 300, between the holder 300 and the sealing film 200, between the sealing film 200 and the air-blocking valve 500, and between the air-blocking valve 500 and the cannula 100.

[0072] In this embodiment, the outer surface of the air-blocking portion 520 is arc-shaped.

[0073] The second opening 521 on the air-blocking portion 520 is cross-shaped. When the instrument enters, the second opening 521 is pushed open, and when the instrument exits, the second opening 521 returns to its original state. Designing the outer surface of the air-blocking portion 520 to be arc-shaped is beneficial for the second opening 521 to automatically close and return to its original state when the instrument exits. After the second opening 521 is stretched for a long time, it may reach the tolerance limit of the material itself and cannot fully recover. However, due to the arc-shaped design, the second opening 521 can receive more material volume recovery effect without being able to increase the material tolerance limit, extending the time that the second opening 521 can be stretched by the instrument.

[0074] In this embodiment, the trocar cannula assembly further includes an air injection valve 600, and the air injection valve 600 is disposed on the cannula 100.

[0075] An extension tube 130 is provided on one side of the cannula 100. A Luer channel 131 is provided in the extension tube 130. An installation hole 132 perpendicular to the axis of the Luer channel 131 is provided on the extension tube 130. The air injection valve 600 is installed in the installation hole 132. By rotating the air injection valve 600, the opening and closing of the Luer channel 131 can be controlled, so as to deliver additional gas or release the pneumoperitoneum according to the needs of the operation.

[0076] The installation process of the trocar cannula assembly provided by the embodiment of the present application is as follows: Place the fixed cover 400 upside down, and sequentially assemble the holder 300, the sealing film 200, and the air-blocking valve 500 upside down. Finally, place the cannula 100 upside down over the holder 300, the sealing film 200, and the air-blocking valve 500, and perform a preliminary pre-pressing. At this time, the trocar cannula assembly can be placed upright on the tooling for complete tight-fitting pressing to complete the assembly of the trocar cannula assembly.

[0077] The beneficial effects of the trocar cannula assembly provided by the embodiments of the present application at least include: The holding member 300 has a certain holding effect on the instrument through a plurality of elastic structures 320, making the instrument and the entire trocar cannula assembly an integral whole, and maintaining the instrument at the central position of the cannula 100. In this way, the biased pulling of the central hole of the sealing film 200 by the instrument is avoided to the greatest extent, preventing the sealing film 200 from rupturing due to long-term pulling during the operation; Since the holding member 300 is provided between the sealing film 200 and the fixing cover 400, the distance between the sealing film 200 and the fixing cover 400 is increased. When the instrument enters and reaches the sealing film 200, even if the instrument is still slightly skewed, the front end of the instrument can basically align with the central hole of the sealing film 200, thus preventing the instrument from puncturing the sealing film 200.

[0078] In summary, the embodiments of the present application provide a trocar cannula assembly, which includes a cannula 100, a sealing film 200, a holding member 300 and a fixing cover 400. The holding member 300 is disposed between the fixing cover 400 and the sealing film 200, increasing the distance between the fixing cover 400 and the sealing film 200. When an external instrument enters the cannula 100, the holding member 300 can hold the instrument so that the instrument is at the center of the cannula 100. At this time, the instrument is not likely to damage the sealing film 200.

[0079] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A trocar cannula assembly, characterized in that, It includes a sleeve (100), a sealing film (200) and a holding member (300). The sealing film (200) is arranged inside the sleeve (100). The holding member (300) is partially arranged inside the sleeve (100). The holding member (300) is connected to the top of the sleeve (100) and abuts against the sealing film (200). The holding member (300) is used to hold an external instrument so that the instrument is at the center of the sleeve (100). The holding member (300) includes a fixed cover (400), a sleeve (310) and a plurality of elastic structures (320) arranged circumferentially along the sleeve (310). The fixed cover (400) and the sleeve (310) are connected. The fixed cover (400) is connected to the top of the sleeve (100). The plurality of elastic structures (320) are used to cooperate to hold an external instrument together. The elastic structure (320) includes an integrally formed first connecting section (321) and a second connecting section (322). One end of the first connecting section (321) away from the second connecting section (322) is connected to the sleeve (310). One end of the second connecting section (322) away from the first connecting section (321) is a free end. The first connecting section (321) extends towards the inside of the sleeve (310). The second connecting section (322) extends towards the outside of the sleeve (310). An arc surface (323) is arranged at the connection between the first connecting section (321) and the second connecting section (322). In a cross-section parallel to the top surface of the sleeve (310), the arc surfaces (323) of the plurality of elastic structures (320) are located on the same circumference. The plurality of arc surfaces (323) cooperate to hold the instrument together so that the instrument is at the center of the sleeve (310). The central axis of the sleeve (310) coincides with that of the sealing film (200). The sleeve (310) is provided with a plurality of rectangular through holes (311) along the circumferential direction. The plurality of rectangular through holes (311) correspond to the plurality of elastic structures (320) one by one. One end of the first connecting section (321) away from the second connecting section (322) is connected to the inner top wall of the rectangular through hole (311).

2. The trocar cannula assembly according to claim 1, characterized in that A first limiting ring (210) is arranged on the sealing film (200). The bottom end of the sleeve (310) cooperates with the first limiting ring (210) so that the central axis of the sleeve (310) coincides with that of the sealing film (200).

3. The trocar cannula assembly according to claim 1, wherein The surface of the sealing film (200) is arc-shaped. Along the direction away from the holding member (300), the thickness of the sealing film (200) gradually decreases.

4. The trocar cannula assembly according to claim 1, wherein, The fixed cover (400) is provided with a first opening (410) for the instrument to enter. The fixed cover (400) is provided with a second limiting ring (420) and a third limiting ring (430). The top end of the sleeve (310) extends between the second limiting ring (420) and the third limiting ring (430). Among them, the diameter of the third limiting ring (430) is larger than that of the second limiting ring (420).

5. The trocar cannula assembly according to claim 4, wherein The third limiting ring (430) is provided with a limiting bayonet (431). The sleeve (310) is provided with a limiting part (330). The limiting part (330) is snapped into the limiting bayonet (431).

6. The trocar cannula assembly according to claim 1, characterized in that, The fixed cover (400) and the sleeve (310) are integrally formed.

7. The trocar cannula assembly according to claim 1, characterized in that, The trocar cannula assembly further includes an air blocking valve (500). The air blocking valve (500) is arranged inside the cannula (100). The sealing film (200) partially extends into the air blocking valve (500).

8. The trocar cannula assembly according to claim 7, wherein, The air blocking valve (500) includes an integrally formed installation part (510) and an air blocking part (520). An annular protrusion (120) is provided inside the cannula (100). The installation part (510) is provided with an annular groove (511). The annular protrusion (120) is matched with the annular groove (511). The air blocking part (520) is provided with a second opening (521).

9. The trocar cannula assembly according to claim 8, wherein, The outer surface of the air blocking part (520) is arc-shaped.

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