A self-sealing sheath device for PICC placement

Abstract

This utility model discloses a self-sealing outer sheath device for PICC insertion, relating to the field of medical device technology. It includes an outer sheath with a sealing plate at its proximal end; an inner dilator slidably inserted within the outer sheath; a liquid-sealed cavity formed in the proximal inner cavity of the outer sheath, located distal to the sealing plate; and a reservoir cavity divided into a liquid chamber and a pressure-regulating chamber by a separator, the liquid chamber being in fluid communication with the liquid-sealed cavity and containing liquid. The inner dilator has a first relative position inserted within the liquid-sealed cavity and a second relative position relative to the outer sheath after proximal withdrawal. During the withdrawal of the inner dilator from the first relative position to the second relative position, liquid from the liquid chamber enters the liquid-sealed cavity, filling at least a portion of the space released by the inner dilator's withdrawal. The separator moves or deforms in response to a decrease in the volume of the liquid chamber to compensate for the volume change. This device helps reduce the risk of air entering the sheath during PICC insertion.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a self-sealing outer sheath device for PICC insertion. Background Technology

[0002] Peripherally inserted central catheter (PICC) placement is an important clinical method widely used for medium- to long-term intravenous infusion, chemotherapy, and parenteral nutrition. During PICC placement, a modified Seldinger technique is typically used to complete the steps of puncture, guidewire insertion, sheath insertion, and catheter insertion. Specifically, after successful puncture, a peelable outer sheath with an inner dilator is first inserted into the blood vessel along the guidewire. Then, the guidewire and inner sheath dilator are withdrawn, leaving only the outer sheath inside the vessel. The PICC catheter is then inserted into the vessel through the outer sheath, and finally, the outer sheath is peeled off and withdrawn.

[0003] In the above procedure, after the guidewire and inner sheath dilator are withdrawn, the proximal main channel of the outer sheath is completely open, making it easy for blood to flow out from the proximal end of the outer sheath, causing intraoperative blood loss. Current clinical procedures often rely on medical staff to press on the blood vessel with their fingers on the skin surface in front of the puncture site or to block the sheath opening with their fingers to temporarily stop blood flow. However, this method requires a high level of skill and coordination from the operator, has poor consistency in operation, and may also affect the continuity and convenience of catheter insertion.

[0004] Some manufacturers have already integrated hemostatic valves into removable sheaths. Simple hemostatic valves are typically elastic sealing discs that rely on the material's elasticity to conform to the outer wall of the inner dilator to achieve a seal. Generally, when no instruments are being inserted or removed, or when the instruments are stationary, the sealing disc can maintain a basic seal. However, during the dynamic process of dilator withdrawal or catheter insertion / removal, it is necessary to simultaneously allow instrument movement and maintain a tight seal. These two aspects are difficult to balance, and there is a risk of air entering the sheath through the gap between the sealing disc and the outer wall of the instrument.

[0005] To improve sealing performance, some products in the industry employ multi-layer sealing plates or more complex sealing valves. Improving the sealing valve structure can effectively enhance the seal and more effectively prevent air ingress or blood backflow, but it may also increase frictional resistance during subsequent PICC catheter insertion, affecting the ease of catheter advancement. For tearable outer sheaths, the proximal sealing structure also needs to accommodate subsequent tearing and removal operations; if the sealing component is too thick, too rigid, or too complex to integrate with the outer sheath, it may affect the ease of removal of the outer sheath along the tear line. Utility Model Content

[0006] In order to solve at least one of the problems existing in the prior art, the present invention provides a self-sealing outer sheath device for PICC insertion, which takes into account both sealing reliability and smooth instrument delivery, while reducing the impact on the peelability of the sheath.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a self-sealing outer sheath device for PICC insertion, comprising an outer sheath tube with a sealing plate at its proximal end; an inner expander slidably inserted into the outer sheath tube; a liquid sealing cavity formed in the inner cavity at the proximal end of the outer sheath tube and located on the distal side of the sealing plate; and a liquid storage cavity with a movable or deformable partition inside. The separator divides the reservoir into a liquid chamber and a pressure regulating chamber, the liquid chamber being in fluid communication with the liquid seal chamber and containing liquid; the inner expander has a first relative position extending through the liquid seal chamber and a second relative position after being withdrawn proximally relative to the outer sheath; as the inner expander withdraws from the first relative position to the second relative position, liquid in the liquid chamber enters the liquid seal chamber to fill at least a portion of the space released by the withdrawal of the inner expander, and the separator moves or deforms in response to a decrease in the volume of the liquid chamber to compensate for the volume change of the liquid chamber.

[0008] Preferably, the outer sheath is made of a tearable material and has a tear line along the axial direction, and the sealing piece is fixed to the proximal opening of the outer sheath.

[0009] Preferably, the separator is a piston that slides and seals with the inner wall of the liquid storage chamber; Alternatively, the separator is a flexible isolation membrane, the periphery of which is sealed to the inner wall of the liquid storage cavity, and its membrane surface area is larger than the cross-sectional area of ​​the liquid storage cavity it covers. Alternatively, the liquid chamber may be defined by a deformable bladder disposed within the liquid storage chamber, the bladder wall of which constitutes the separator.

[0010] Preferably, the pressure regulating chamber is provided with a balance hole that communicates with the atmosphere.

[0011] Preferably, the pressure regulating chamber is provided with an elastic element, which is used to drive the separator to move or deform, thereby reducing the volume of the liquid chamber. When the separator is a flexible isolation membrane or the wall of a deformable bladder, the elastic element acts on the separator through a pushing element.

[0012] Preferably, the liquid chamber is connected to the liquid seal cavity via a connecting channel, the connecting channel having a liquid outlet facing the liquid seal cavity, the liquid outlet being located on the distal side of the sealing sheet.

[0013] Preferably, at the first relative position, the outer wall of the inner expander covers or blocks the liquid outlet; as the inner expander moves to the second relative position, the flow cross-sectional area at the liquid outlet increases as the outer wall of the inner expander moves away.

[0014] Preferably, the liquid seal cavity includes a tapered cavity segment that gradually expands toward the sealing sheet. During the retraction of the inner expander, a liquid supply gap is formed between the inner expander and the inner wall of the tapered cavity segment, communicating with the liquid outlet.

[0015] Preferably, the sealing sheet is a single-layer elastic sealing sheet. The liquid is physiological saline or medical lubricant.

[0016] First, this invention supplies liquid to the liquid-sealed cavity on the distal side of the sealing plate through the liquid chamber, so that the liquid fills at least part of the space released during the withdrawal of the inner expander, thereby forming a liquid-sealed area on the distal side of the sealing plate and reducing the risk of air entering the outer sheath.

[0017] Second, the separator moves or deforms in response to the decrease in the volume of the liquid chamber, thereby compensating for the volume of the liquid chamber, reducing the negative pressure obstruction generated when the liquid flows out, and enabling the liquid to enter the liquid seal cavity more promptly.

[0018] Third, since the liquid seal area can assist the sealing plate in achieving dynamic sealing, the sealing plate does not need to be excessively tight or have a complex multi-layer valve plate structure. This helps to reduce the resistance when the PICC catheter passes through the sealing plate and reduce the impact of the sealing structure on the removal of the outer sheath. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of one embodiment of the self-sealing outer sheath device of this utility model when it is in the first relative position; Figure 2 This is a schematic diagram of one embodiment of the self-sealing outer sheath device of this utility model when it is in the second relative position; Figure 3 This is a partial structural diagram of the liquid storage chamber and separator in this utility model when a piston structure is used. Figure 4 This is a partial structural diagram of the separator in this utility model when a flexible isolation membrane is used; Figure 5 This is a partial structural diagram of the liquid chamber in this utility model when it is defined by a deformable bladder; Figure 6 This is a partial structural diagram of the pressure regulating chamber of this utility model when an elastic element is provided; Figure 7 This is a partial structural diagram illustrating the fit between the liquid outlet and the conical cavity section in this utility model; Figure 8 This is a partial structural diagram of the liquid outlet and the conical cavity section in this utility model, which together form a liquid supply gap.

[0021] Marked in the image: 1. Outer sheath; 11. Sheath body; 12. Outer sheath seat; 13. Sheath wing; 14. Tear line; 2. Internal expander; 21. Constant diameter section; 22. Transition section; 3. Sealing sheet; 4. Liquid-sealed cavity; 41. Conical cavity segment; 5. Liquid storage chamber; 51. Liquid chamber; 52. Pressure regulating chamber; 53. Divider; 54. Balance hole; 55. Elastic element; 56. Limiting structure; 57. Slide rod; 6. Conduit; 61. Connecting channel; 62. Liquid outlet; 63. Liquid supply gap; Detailed Implementation

[0022] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] In Example 1, in this application, the end closer to the operator is called the proximal end, and the end entering the patient's blood vessel is called the distal end. For example... Figure 1 and Figure 2 As shown, this embodiment provides a self-sealing outer sheath device for PICC insertion, including an outer sheath tube 1, an inner dilator 2, a sealing plate 3, a liquid-sealed cavity 4, and a reservoir 5. During PICC insertion, the self-sealing outer sheath device is used to establish a temporary working channel between the external body and the blood vessel.

[0024] The outer sheath 1 is made of a tearable material and includes a sheath body 11, an outer sheath seat 12, and sheath wings 13. A tear line 14 is provided axially on the outer sheath 1 on the sheath body 11 and / or the outer sheath seat 12. The tear line 14 can be one or two oppositely arranged lines. After the PICC catheter is inserted, the operator can pinch the sheath wings 13 and apply force to both sides to tear the sheath body 11 and the outer sheath seat 12 along the tear line 14, allowing for removal from the outside of the PICC catheter.

[0025] The internal dilator 2 is slidably inserted into the outer sheath 1. The internal dilator 2 has an inner lumen for the guidewire to pass through. Unless otherwise specified, its basic structure can adopt the dilator structure commonly used in PICC placement. When the internal dilator 2 is engaged with the outer sheath, its distal end can extend beyond the distal end of the outer sheath 1, forming a smooth transition with the distal end of the outer sheath 1, so that the outer sheath 1 can enter the blood vessel along the guidewire with the internal dilator 2.

[0026] The sealing strip 3 is disposed at the proximal end of the outer sheath 1, located at the proximal opening of the outer sheath seat 12. In this embodiment, the sealing strip 3 is a single-layer elastic sealing strip with an incision. The incision can be a straight incision, a cross incision, or other incision form suitable for instrument passage and capable of elastic closure. When no instrument passes through, the sealing strip 3 can close the incision due to its own elasticity; when the internal dilator 2 or PICC catheter passes through, the sealing strip 3 elastically deforms around the outer wall of the corresponding instrument.

[0027] The liquid-sealed cavity 4 is formed in the proximal inner cavity of the outer sheath 1, located on the distal side of the sealing plate 3, and is defined by the inner wall of the outer sheath seat 12 and the distal end face of the sealing plate 3. When the inner expander 2 is inserted into the outer sheath 1, the liquid-sealed cavity 4 is at least partially occupied by the inner expander 2; during the withdrawal of the inner expander 2, the liquid-sealed cavity 4 is used to receive liquid from the liquid storage cavity 5 and form a liquid-sealed area on the distal side of the sealing plate 3.

[0028] The liquid storage chamber 5 is in fluid communication with the liquid-sealed chamber 4. The liquid storage chamber 5 is provided with a movable or deformable partition 53, which divides the liquid storage chamber 5 into a liquid chamber 51 and a pressure-regulating chamber 52, and liquid-tightly isolates the liquid chamber 51 from the pressure-regulating chamber 52. The liquid chamber 51 is used to store liquid, which may be physiological saline, medical lubricant, or other sterile liquid suitable for medical use.

[0029] In this embodiment, the reservoir 5 is located outside the outer sheath 1 and communicates with the side wall of the outer sheath 1 via a conduit 6. The connection point of the conduit 6 is located circumferentially outside the tear line 14. This ensures that at least a portion of the reservoir 5 avoids the tear path of the outer sheath 1, thereby reducing the impact on the tearing of the outer sheath 1 along the tear line 14 and preventing the connection point of the conduit 6 from obstructing the tearing action when the outer sheath 1 is torn. The conduit 6 has a communicating channel 61, one end of which communicates with the liquid chamber 51, and the other end of which communicates with the liquid seal chamber 4. Liquid in the liquid chamber 51 enters the liquid seal chamber 4 through the communicating channel 61.

[0030] The self-sealing outer sheath device of this embodiment has a first relative position and a second relative position.

[0031] like Figure 1As shown, the first relative position refers to the position where the inner expander 2 passes through the outer sheath 1 and the liquid seal cavity 4. In the first relative position, the inner expander 2 occupies at least part of the space in the liquid seal cavity 4, the sealing sheet 3 is attached to the outer wall of the inner expander 2, and the liquid chamber 51 stores liquid.

[0032] like Figure 2 As shown, the second relative position refers to the position of the inner expander 2 after it has retracted proximally relative to the outer sheath 1. During the retraction of the inner expander 2 from the first relative position to the second relative position, the space originally occupied by the inner expander 2 is gradually released, forming a space to be filled within the liquid seal cavity 4. Since the liquid chamber 51 is in fluid communication with the liquid seal cavity 4, the liquid in the liquid chamber 51 enters the liquid seal cavity 4 and fills at least a portion of the space released during the retraction of the inner expander 2.

[0033] During the process of liquid entering the liquid seal chamber 4 from the liquid chamber 51, the volume of the liquid chamber 51 decreases. The separator 53 moves or deforms in response to the decrease in the volume of the liquid chamber 51 to compensate for the volume change of the liquid chamber 51, reduce the negative pressure resistance caused by the liquid outflow in the liquid chamber 51, and enable the liquid to enter the liquid seal chamber 4 in a timely manner.

[0034] After the liquid enters the liquid-sealed cavity 4, a liquid-sealed area is formed on the distal side of the sealing plate 3. This liquid-sealed area acts as a liquid barrier in the air entry path, thereby reducing the risk of air entering the outer sheath 1 during the withdrawal of the inner expander 2. Since the liquid-sealed area can assist the sealing plate 3 in achieving dynamic sealing, the sealing plate 3 does not need to adopt an excessively tight or multi-layered complex valve plate structure, which helps to reduce the resistance when the PICC catheter subsequently passes through the sealing plate 3 and improves the smoothness of subsequent catheter push.

[0035] Example 2, please refer to Figures 3 to 6 This embodiment further explains the partition 53 and the pressure regulating chamber 52 based on the first embodiment.

[0036] The pressure regulating chamber 52 is provided with a balance hole 54 that communicates with the atmosphere. When the liquid in the liquid chamber 51 is introduced into the liquid seal chamber 4, the volume of the liquid chamber 51 decreases. The outside atmosphere acts on the separator 53 through the balance hole 54, causing the separator 53 to move or deform to one side of the liquid chamber 51, thereby compensating for the pressure in the liquid chamber 51 and allowing the liquid in the liquid chamber 51 to enter the liquid seal chamber 4 more smoothly.

[0037] Please see Figure 3 In one embodiment, the separator 53 is a piston, and the separator 53 and the inner wall of the liquid storage chamber 5 are in a sliding seal fit, so that the liquid in the liquid chamber 51 is not easy to enter the pressure regulating chamber 52. At the same time, the separator 53 can move in the liquid storage chamber 5 as the volume of the liquid chamber 51 changes.

[0038] Please see Figure 4 In another embodiment, the separator 53 is a flexible isolation membrane. The periphery of the flexible isolation membrane is sealed to the inner wall of the liquid storage chamber 5. The flexible isolation membrane can be a non-elastic or low-elastic flexible film, with a membrane surface area larger than the cross-sectional area of ​​the liquid storage chamber 5 it covers. The excess area allows the flexible isolation membrane to fold or wrinkle in its natural state. When the volume of the liquid chamber 51 decreases, the flexible isolation membrane unfolds accordingly, transmitting the pressure from the pressure regulating chamber 52 side to the liquid chamber 51.

[0039] Please see Figure 5 In another alternative embodiment, the separator 53 is a deformable capsule disposed within the liquid storage chamber 5, with its opening periphery sealed to the inner wall of the liquid storage chamber 5. The capsule wall of the deformable capsule has annular pleats. When the liquid chamber 51 is filled with liquid, the annular pleats are compressed into a closed state; when liquid is discharged from the liquid chamber 51, the annular pleats unfold, allowing the deformable capsule to fill the volume of the liquid chamber 51 reduced due to liquid outflow.

[0040] Please see Figure 6 In another embodiment, the pressure regulating chamber 52 is provided with an elastic element 55. The elastic element 55 releases energy when the inner expander 2 retracts, driving the separator 53 to move or deform towards the liquid chamber 51, reducing the volume of the liquid chamber 51, thereby facilitating the more timely entry of liquid into the liquid seal chamber 4. The elastic element 55 can be a compression spring, an elastic rubber component, or other elastic structure capable of providing thrust.

[0041] When the separator 53 is a piston, the elastic element 55 can act directly on the piston; when the separator 53 is a flexible separating membrane or the wall of a deformable bladder, the elastic element 55 can act on the separator 53 through a pushing element. The pushing element can be a pressure plate, pressure sheet, pressure block, or other structure that can distribute the thrust of the elastic element 55 to the flexible separator.

[0042] Preferably, when the separator 53 is a piston, a limiting structure 56 may also be provided in the liquid storage chamber 5. The limiting structure 56 is used to limit the movement stroke of the separator 53. When the separator 53 moves to abut against the limiting structure 56, the separator 53 stops moving, the volume of the liquid chamber 51 no longer continues to decrease, and the resistance that the liquid needs to overcome to continue flowing out increases, thereby limiting the amount of liquid output from the liquid chamber 51 to the liquid seal chamber 4, reducing the risk that excessive liquid will enter the distal end of the outer sheath 1 and enter the blood vessel after filling the liquid seal chamber 4.

[0043] In one embodiment, the limiting structure 56 is a blocking part disposed on the inner wall of the liquid storage cavity 5, and the separator 53 abuts against the blocking part when it moves to a preset position. In another embodiment, the limiting structure 56 includes a sliding rod 57, which extends along the moving direction of the separator 53 and passes through the separator 53. The separator 53 and the sliding rod 57 are slidably engaged. The sliding rod 57 is provided with a blocking part, and the separator 53 abuts against the blocking part when it moves to the preset position to limit its displacement.

[0044] Example 3, please refer to Figure 7 and Figure 8 This embodiment further defines the structure of the liquid-sealed cavity 4 based on the aforementioned embodiments.

[0045] The liquid chamber 51 is connected to the liquid-sealed cavity 4 via a connecting channel 61. One end of the connecting channel 61 is connected to the liquid chamber 51, and the other end is connected to the liquid outlet 62 facing the liquid-sealed cavity 4. The liquid outlet 62 is located on the distal side of the sealing plate 3.

[0046] In the first relative position, the inner expander 2 is inserted into the liquid seal cavity 4, and the outer wall of the inner expander 2 blocks the liquid outlet 62 to restrict the liquid from entering the liquid seal cavity 4 from the liquid chamber 51. As the inner expander 2 moves from the first relative position to the second relative position, the outer wall of the inner expander 2 gradually moves away from the liquid outlet 62, increasing the flow cross-sectional area at the liquid outlet 62, allowing the liquid to enter the liquid seal cavity 4 through the liquid outlet 62.

[0047] Preferably, the liquid-sealing cavity 4 includes a tapered cavity section 41 that gradually expands toward the sealing plate 3. The tapered cavity section 41 has a larger inner diameter at the end closer to the sealing plate 3 and a smaller inner diameter at the end farther from the sealing plate 3. The inner wall profile of the tapered cavity section 41 can mate with the outer wall of the inner expander 2 to form a liquid supply gap 63 during the withdrawal of the inner expander 2; Specifically, the internal expander 2 includes a constant diameter section 21 and a transition section 22 located proximal to the constant diameter section 21. The constant diameter section 21 is the main tube section of the internal expander 2, used to mate with the sheath tube body. The transition section 22 is used to connect the constant diameter section 21 to a handle or connecting seat proximal to the expander. The outer diameter of the transition section 22 is larger than the outer diameter of the constant diameter section 21, or the outer diameter of the transition section 22 gradually increases along the proximal direction.

[0048] In the first relative position, at least a portion of the transition section 22 is located within the conical cavity section 41 and cooperates with the conical cavity section 41 to block at least a portion of the outlet 62. When the inner expander 2 moves to the second relative position, the transition section 22 moves proximally with the inner expander 2 and gradually moves away from the outlet 62, and the smaller outer diameter equal-diameter section 21 enters or corresponds to the conical cavity section 41. At this time, a liquid supply gap 63 communicating with the outlet 62 is formed between the inner expander 2 and the inner wall of the conical cavity section 41, and the liquid in the liquid chamber 51 can enter the liquid seal chamber 4 through the outlet 62 and the liquid supply gap 63.

[0049] Preferably, when the liquid supply gap 63 is formed, the inner expander 2 is still inserted within the sealing sheet 3. Liquid can enter the distal side of the sealing sheet 3 before the inner expander 2 completely leaves the sealing sheet 3, thus forming a liquid seal area in advance. When the inner expander 2 continues to withdraw and a dynamic gap appears between the sealing sheet 3 and the outer wall of the inner expander 2, a liquid barrier already exists on the distal side of this dynamic gap, thereby reducing the risk of air ingress.

[0050] Preferably, there can be one or more outlets 62. Multiple outlets 62 can be spaced apart circumferentially along the outer sheath 1. Alternatively, the outlets 62 can also be annular outlet slits extending circumferentially around the inner cavity of the outer sheath 1, so that the liquid forms a circumferentially continuous or substantially continuous liquid seal area on the distal side of the sealing plate 3.

[0051] The self-sealing outer sheath device of this utility model can be used in conjunction with the conventional PICC insertion procedure, as detailed below: After successful puncture and guidewire insertion, the internal dilator 2 is in the first relative position, passing through the outer sheath 1 and the liquid-sealed cavity 4. The sealing plate 3 elastically deforms around the outer wall of the internal dilator 2, and the liquid chamber 51 stores liquid. The operator then inserts the outer sheath 1 and the internal dilator 2 along the guidewire into the patient's blood vessel.

[0052] After the outer sheath 1 reaches the predetermined position, the operator withdraws the inner expander 2 proximally. The inner expander 2 moves from the first relative position to the second relative position, and the space occupied by the inner expander 2 in the liquid seal cavity 4 is gradually released. Since the liquid chamber 51 is connected to the liquid seal cavity 4, the liquid in the liquid chamber 51 enters the liquid seal cavity 4 and fills at least part of the space that the inner expander 2 has exited.

[0053] As the liquid enters the liquid-sealed cavity 4, the volume of the liquid chamber 51 decreases. The separator 53 moves or deforms as the volume of the liquid chamber 51 decreases to compensate for the volume change of the liquid chamber 51, reduce the negative pressure resistance caused by the liquid outflow in the liquid chamber 51, and allow the liquid to enter the liquid-sealed cavity 4 more smoothly.

[0054] After the liquid enters the liquid-sealed cavity 4, a liquid-sealed area is formed on the distal side of the sealing plate 3. This liquid-sealed area preferentially occupies the space released after the inner expander 2 is withdrawn, making it difficult for air to enter the interior of the outer sheath tube 1 through the sealing plate 3.

[0055] In the preferred structure employing the conical cavity section 41, when the inner expander 2 retracts, the transition section 22 gradually moves away from the outlet 62, and the equal-diameter section 21 enters or corresponds to the conical cavity section 41, forming a supply gap 63 between the inner expander 2 and the inner wall of the conical cavity section 41. Liquid in the liquid chamber 51 enters the liquid seal chamber 4 through the outlet 62 and the supply gap 63. Preferably, when the supply gap 63 is formed, the inner expander 2 remains inserted in the sealing plate 3, allowing liquid to enter the distal side of the sealing plate 3 before the inner expander 2 completely leaves the sealing plate 3.

[0056] After the internal dilator 2 is withdrawn to the second relative position, a liquid-sealed area is formed on the distal side of the sealing strip 3. Subsequently, the PICC catheter is inserted into the blood vessel through the sealing strip 3 and the outer sheath 1. Because the liquid-sealed area can assist the sealing strip 3 in achieving a seal, the sealing strip 3 does not need to be excessively tight or have a multi-layered complex valve structure. Therefore, the PICC catheter experiences less resistance when passing through the sealing strip 3, and the insertion is relatively smooth.

[0057] After the PICC catheter is inserted, the operator can pinch the sheath wings 13 and apply force to both sides to tear the sheath body 11 and the outer sheath seat 12 along the tear line 14, so as to peel the outer sheath 1 from the outside of the PICC catheter and remove it.

[0058] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A self-sealing sheath device for PICC placement, characterized by, include: The outer sheath has a sealing plate at its proximal end; An internal expander is slidably inserted inside the outer sheath. The liquid seal cavity is formed in the inner cavity of the proximal end of the outer sheath and is located on the distal side of the sealing strip; The liquid storage chamber is equipped with movable or deformable partitions. The separator divides the liquid storage chamber into a liquid chamber and a pressure regulating chamber. The liquid chamber is in fluid communication with the liquid-sealed chamber, and the liquid chamber contains liquid; The internal expander has a first relative position inserted into the liquid-sealed cavity, and a second relative position after being withdrawn proximally relative to the outer sheath. During the process of the inner expander retracting from the first relative position to the second relative position, the liquid in the liquid chamber enters the liquid seal chamber to fill at least a portion of the space released by the retraction of the inner expander. The separator moves or deforms in response to a decrease in the volume of the liquid chamber to compensate for the change in the volume of the liquid chamber.

2. The self-sealing sheath device for PICC placement of claim 1, wherein, The outer sheath is made of a tearable material and has a tear line along the axial direction. The sealing piece is fixed to the proximal opening of the outer sheath.

3. The self-sealing sheath device for PICC placement of claim 1, wherein, The pressure regulating chamber has a balance hole that communicates with the atmosphere.

4. The self-sealing sheath device for PICC placement of claim 3, wherein, The separator is a piston that slides and seals with the inner wall of the liquid storage chamber; Alternatively, the separator may be a flexible isolation membrane, the periphery of which is sealed to the inner wall of the liquid storage chamber; Alternatively, the liquid chamber may include a deformable bladder disposed within the liquid storage chamber, the bladder wall of which constitutes the separator.

5. The self-sealing sheath device for PICC placement of claim 1, wherein, The pressure regulating chamber is equipped with an elastic element that drives the separator to move or deform, thereby reducing the volume of the liquid chamber.

6. The self-sealing sheath device for PICC placement of claim 5, wherein, When the separator is a flexible isolation membrane or a deformable bladder, the elastic element acts on the separator through the pushing element.

7. The self-sealing sheath device for PICC placement of claim 1, wherein, The liquid storage chamber is located outside the outer sheath and is connected to the proximal side wall of the outer sheath via a conduit. The conduit has a communication channel connecting the liquid chamber and the liquid seal chamber.

8. The self-sealing sheath device for PICC placement of claim 1, wherein, The liquid chamber is connected to the liquid seal cavity via a connecting channel, the connecting channel having a liquid outlet facing the liquid seal cavity, the liquid outlet being located on the distal side of the sealing sheet.

9. The self-sealing outer sheath device for PICC insertion according to claim 8, characterized in that, In the first relative position, the outer wall of the inner expander covers or blocks at least a portion of the liquid outlet to restrict liquid from entering the liquid seal chamber from the liquid chamber.

10. The self-sealing sheath device for PICC placement of claim 8, wherein, The liquid-sealed cavity includes a tapered cavity segment that gradually expands toward the sealing sheet; In the first relative position, the internal expander is at least partially located within the conical cavity and cooperates with the conical cavity to block at least a portion of the liquid outlet; During the movement of the internal expander from the first relative position to the second relative position, a liquid supply gap is formed between the internal expander and the inner wall of the conical cavity section, which communicates with the liquid outlet.

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