Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
SELF-LOCKING SYRINGE

2. APPLICANT:
Meril Life Sciences Pvt. Ltd., an Indian company, of the address Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi-Gujarat 396191

3. The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF INVENTION
[001] The present invention relates to a medical device. More specifically, the invention relates to a self-locking syringe.
BACKGROUND OF INVENTION
[002] In the medical field, syringes are used to administer medications to patients, remove fluids and tissue from them, and/or administer or aspirate fluids in association with other types of equipment, such as when preparing the balloon of a dilatation catheter. Although the causes of vacuum are very different, in the majority of these applications, whether the syringe is being used for injecting or aspirating, a vacuum is created in the barrel of the syringe.
[003] When the syringe is used for injecting, the barrel of the syringe is partially filled with a medicinal fluid and a needle is fixed to the distal end of the barrel. Further, the needle is inserted in a patient’s vein. It is possible that the point of the needle does not enter the vein instead enters the tissue and at the same time, the plunger is pushed leading to injecting the fluid in a wrong location.
[004] When the syringe is used for aspirating or injecting a fluid with the help of a balloon of a dilation catheter, the syringe is attached to the catheter. In order to withdraw the fluid from the balloon of the catheter, the plunger of the syringe is withdrawn. This action leads to withdrawal of the fluid from the balloon of the dilation catheter. Meanwhile, a relatively strong vacuum is created within the barrel of the syringe which leads to exertion of a force on the plunger of the syringe. The plunger of the syringe could pull the syringe back into the barrel unless the plunger is restrained by holding it at a place.
[005] Most of the syringes used in practice, employ certain locking devices where the plunger can be locked at a position as soon as the vacuum is created. Such syringe needs rotation of the plunger to lock or unlock. Further, required orientation of the plunger and the barrel of the syringe is to be maintained. The aforesaid requirements lead to restrictions in the usability of the syringe.
[006] Therefore, there is a need of an improved locking mechanism for a syringe.
SUMMARY OF INVENTION
[007] The present disclosure relates to a syringe. The syringe includes a barrel having a proximal end and a distal end. The barrel includes a flange at the proximal end of the barrel. The syringe further includes a piston, and a locking mechanism. The piston of the syringe having a proximal end and a distal end, is operatively coupled to the barrel. The piston includes a plurality of wings. Each wing of the plurality of wings has a plurality of grooves. Each groove of the plurality of grooves includes a straight edge and a tapered edge. The tapering in the tapered edge increases from the proximal end of the piston to the distal end of the piston. The locking mechanism of the syringe is operatively coupled to the piston for configuring the piston in one of a locked state and an unlocked state. The locking mechanism includes a casing, a slider, and a resiling element. The casing of the locking mechanism has a top face and a bottom face and includes a plurality of clamps. The plurality of clamps is disposed at the bottom face of the casing. Each clamp of the plurality of clamps includes a plurality of slots for receiving the flange such that the flange is fixedly locked with the plurality of clamps. The slider of the locking mechanism includes a first end and a second end. The slider is slidably coupled to the casing. Further, the slider is configured to contact one of an outer edge of at least one wing of the plurality of wings, a straight edge of at least one groove of the plurality of grooves, and a tapered edge of the at least one groove. The resiling element of the locking mechanism can be in a compressed state or an expanded state. The resiling element is operatively coupled to the slider such that in response to the slider contacting the straight edge of the at least one groove, the resiling element is configured to be in the expanded state. This causes the slider to slide out of the casing at least partially, which results in configuring the piston in the locked state. Further, in response to the slider contacting at least one of the outer edge of the at least one wing or the tapered edge of the at least one groove, the slider is configured to slide in the casing at least partially. This causes the resiling element to be the compressed state, which results in configuring the piston to be in the unlocked state.
[008] The foregoing features and other features as well as the advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
[009] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended figures. For the purpose of illustrating the present disclosure, various exemplary embodiments are shown in the figures. However, the disclosure is not limited to the description and figures disclosed herein. Moreover, those familiar with the art will understand that the figures are not to scale. Wherever possible, like elements have been indicated by identical numbers.
[0010] FIG. 1 depicts a syringe 100 in accordance with an embodiment of the present disclosure.
[0011] FIG. 2 depicts a barrel 101 of the syringe 100 in accordance with an embodiment of the present disclosure.
[0012] FIG. 2a depicts a side view of the syringe 100 with a pressure gauge 102 in accordance with an embodiment of the present disclosure.
[0013] FIG. 2b and 2c depict isomeric views of the syringe 100 with the pressure gauge 102 in accordance with an embodiment of the present disclosure.
[0014] FIG. 2d depicts the pressure gauge 102 in accordance with an embodiment of the present disclosure.
[0015] FIG. 3 illustrates a piston 103 of the syringe 100 in accordance with an embodiment of the present disclosure.
[0016] FIG. 3a illustrates a plurality of wings 103b of the syringe 100 in accordance with an embodiment of the present disclosure.
[0017] FIGS. 4-4e depict a lock mechanism 10 of the syringe 100 and parts thereof in accordance with an embodiment of the present disclosure.
[0018] FIG. 5a shows an internal view of the lock mechanism 10 in a compressed state in accordance with an embodiment of the present disclosure.
[0019] FIG. 5b shows an internal view of the lock mechanism 10 in an expanded state in accordance with an embodiment of the present disclosure.
[0020] FIG. 6-6c depict a resilient member 109 of the syringe 100 and parts thereof in accordance with an embodiment of the present disclosure.
[0021] FIG 6d – 6e depict the resilient member 109 of the syringe 100 and parts thereof, in accordance with an embodiment of the present disclosure.
[0022] FIG. 7 illustrates a flowchart for a method 600 of pulling the piston 103 in a proximal direction, in accordance with an embodiment of the present disclosure.
[0023] FIG. 7a illustrates a flowchart for a method 600a of pushing the piston 103 in in a distal direction in accordance with an embodiment of the present disclosure.
[0024] FIG. 7b illustrates a method 600b for assembling the syringe 100 in accordance with an embodiment of the present disclosure.
[0025] FIG. 8 illustrates a dismantled position of the syringe 100 in accordance with an embodiment of the present disclosure.
[0026] FIG. 8a illustrates a mean position of the syringe 100 in accordance with an embodiment of the present disclosure.
[0027] FIG. 8b illustrates an intermediate position of the syringe 100 in accordance with an embodiment of the present disclosure.
[0028] FIG. 8c illustrates an extreme position of the syringe 100 in accordance with an embodiment of the present disclosure.
[0029] FIGS. 9 - 9e depict positions of various components of the syringe 100 at different positions while pulling the piston 103 in the proximal direction in accordance with an embodiment of the present disclosure.
[0030] FIG. 10 depicts a position of various components of the syringe 100 while pushing the piston 103 in the distal direction in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF ACCOMPANYING DRAWINGS
[0031] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like; Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[0032] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[0033] Although the operations of exemplary embodiments of the disclosed device/apparatus or method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[0034] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[0035] The present invention discloses a self-locking and self-adjustable syringe. In an embodiment, the syringe includes a barrel and a piston with a plurality of grooves. Further, the syringe includes a multi-stage locking mechanism mounted on barrel. In an embodiment, a flange of the barrel acts as an anchor for the multi-stage locking mechanism, where the flange slides through a casing of the multi-stage locking mechanism and locks with the casing. Thus, the multi-stage locking mechanism is fixedly coupled to the barrel. Further, the piston is locked in a desired position by pulling the piston out from the barrel (i.e., pulling the piston in the proximal direction) until the locking mechanism contacts with the plurality of grooves at the desired position. The volume for aspirating the blood clot from the vasculature can be adjusted based on a user’s requirement by locking the piston at a suitable intermediate position and thus, overcomes the problem of collapsing of a blood vessel while aspirating the clot from the vessel. For example, if the clot size is small, then the piston can be adjusted by the user to an intermediate position corresponding to a smaller volume. The mentioned approach allows less blood loss from the vessel. If the clot size is large, the user can adjust the piston to an intermediate position corresponding to a larger volume. The syringe of the present disclosure also overcomes the problem of collapsing the vessel due to improper vacuum pressure generation during injecting or aspirating a fluid and/or blood clots from the body of patient. The syringe of the present disclosure includes a plurality of grooves provided on the stem of the piston. A groove of the piston is self-locked to the locking mechanism whence the groove comes in contact with the locking mechanism while the piston is being pulled outside the barrel. The groove of the syringe is locked with the locking mechanism such that even if the piston is twisted, the syringe can be easily used. The user need not fix the position of piston every time, during loading of the piston in the barrel. The syringe can be smoothly pulled by the user and the piston can be operated without any restriction. Since, the syringe is compact and can be self-locked, no external mechanism or a button is needed to lock the piston during initial loading of the fluid.
[0036] During operation of the syringe (for example, to aspire thrombus from the vasculature), the syringe can be engaged with a tubing of an external device (such as a catheter) at a proximal end of the external device, when the piston is in a mean position. The tubing may have an in-line closure element, such as a clamp, a valve, a stop cock, etc. The user closes the in-line closure element and then pulls the piston in the proximal direction. As the piston reaches a first groove at a proximal end of the piston, the locking mechanism ensures that the piston is locked and corresponding vacuum is generated. If needed, the user can unlock the piston by continuing to pull the piston. Once the piston reaches a next groove in the distal direction, the piston is locked again by the locking mechanism. Thus, the user can generate the desired vacuum by simply pulling the piston until the piston reaches the desired groove and the piston locks automatically (via the locking mechanism) at the desired groove. To infuse a fluid into a vessel or release the aspired thrombus, the user pushes a slider of the syringe to unlock the piston. The user may need to remove the syringe from the tubing of the external device and then push the piston in the distal direction.
[0037] As an exemplary application, the syringe disclosed in this disclosure is used as a device for thrombus management. Alternately, the syringe can be used to inject or aspirate fluids, infuse contrast media in vascular vessels, etc. Now referring to figures, FIG. 1 shows a syringe 100 that includes a barrel 101, a piston 103, a slider 105, a casing 107 and a resilient member 109 (shown in detail in FIGS. 4-4e, FIGS. 6-6e). The syringe 100 also includes a proximal end and a distal end. In an exemplary embodiment, the syringe 100 is a self-locking, self-adjustable device with a multi-stage locking mechanism.
[0038] The barrel 101 may be made of, but not limited to, a polymer such as polypropylene, glass, etc. In an embodiment, the barrel 101 is made of a clear polycarbonate. In an embodiment, the barrel 101 includes a plurality of markings on its outer surface. For example, the plurality of markings on the barrel 101 range from 0 to 60ml.
[0039] The barrel 101 (shown in FIG. 2) of the syringe 100 includes a proximal end ‘A’, a distal end ‘B’ and a plurality of sections – a proximal section, a distal section and a middle section. The proximal end ‘A’ includes a flange 101a. The flange 101a at acts as an anchor for the locking mechanism. As an exemplary embodiment, the flange 101a is a flat extension with an orifice at the proximal end ‘A’ of the barrel 101.
[0040] The middle section of the barrel 101 includes a tubular portion with a lumen to which the piston 103 is operatively coupled. The distal end ‘B’ of the barrel 101 includes a transition portion 101e coupled to an extension 101b, a first sealing member 101c and a bore 101d at the distal end ‘B’.
[0041] The extension 101b is a tubular structure. The extension 101b includes a press fit type slot that may be used to connect the syringe 100 with a catheter tubing with a diameter narrower than the transition portion 101e and provides support to the syringe 100 for holding the syringe 100 to an external device, say, a catheter (not shown) with a ON/OFF valve located at the proximal side and/or for locking the syringe 100 with an extension end of a catheter, a sheath, etc (not shown).
[0042] The first sealing member 101c is mounted on the extension 101b and is used to achieve a leak proof connection between the barrel 101 and a device (for example, a catheter, a vascular system, etc.) to which the barrel 101 is coupled. As an example, the first sealing member 101c creates a leak proof seal once the syringe 100 is attached to the catheter (not shown). The first sealing member 101c may be removably mounted on the extension 101b. In an embodiment, the first sealing member 101c is an O-ring seal.
[0043] The bore 101d includes a press fit type slot for locking the syringe 100 to a connector element. The inner diameter of bore 101d may range from 5 mm to 10 mm. In an embodiment, the inner diameter of bore 101d is 7 mm. The bore 101d can be used for infusion of fluids in the vascular system with the help of a balloon of a dilation catheter, when the syringe 100 is attached to the dilation catheter. The bore 101d can also be used for extraction of relatively large thrombus from the vascular system without any blockage or any restriction during aspiration procedure.
[0044] In an embodiment, barrel 101 may also include a pressure gauge 102. FIG. 2a illustrate a side view and FIG. 2b illustrates an isometric view of the barrel 101 having the pressure gauge 102. The pressure gauge 102 may be coupled to the barrel 101 through the transition portion 101e as shown in FIG. 2b. In an embodiment, the pressure gauge 102 may be attached to the extension 101b as an additional element (as shown in FIG. 2c). The pressure gauge 102 can be attached to the distal end of the barrel 101 through a tubular body 102a. The tubular body 102a is hollow with open distal and proximal end. The proximal end of tubular body 102a can be attached to the extension 101b through the sealing member 101c and fixes at the bore 101d.The distal end of the tubular body 102a can be used for aspirating the blood clot from the vasculature. In an embodiment, the pressure gauge 102 may include an indicator 102b (as shown in FIG. 2d). The indicator 102b may have a plurality of markings, first markings 102b1 and second markings 102b2. The second markings 102b2indicate a positive pressure and the first markings 102b1 indicate a negative pressure. The pressure gauge 102 can measure the negative pressure in the range of 0 to 15 psi (pound per square inch) and the positive pressure in the range of 0 to 180 psi (pound per square inch) according to an embodiment.
[0045] The piston 103 is operatively coupled to the lumen of the barrel 101. The piston 103 includes a proximal end ‘A1’, a distal end ‘B1’ and a stem ‘C1’ extending therebetween (as shown in FIG. 3).
[0046] The proximal end ‘A1’ of the piston 103 includes a grip 103a. The grip 103a can be used for providing a hold to the user for pushing the piston 103 into the barrel 101 or pulling the same from the barrel 101. The grip 103a of the piston 103 includes a plurality of supports 103a’. In an embodiment, the grip 103a includes two supports 103a’ and are used to position the user’s finger for pulling the piston 103 from the barrel 101, pushing the piston 103 into the barrel 101, etc.
[0047] The grip 103a can be made of polypropylene (PP), Acrylonitrile Butadiene Styrene (ABS), polyethylene (PE), etc. In an embodiment, the grip 103a is made of ABS.
[0048] The distal end ‘B1’ of the piston 103 includes a second sealing member 103c for maintaining a tight seal between the edges of the second sealing member 103c and the inner surface of the lumen of the barrel 101. The second sealing member 103c thus acts as a barrier and prevents a fluid from being transferred from the distal end ‘B’ of the barrel 101 to the proximal end ‘A’ of the barrel 101 of the syringe 100. Further, the second sealing member 103c helps to optimize the movement of the piston 103 and at same time smoothly controls accurate positioning of the piston 103, based on requirement of user (not shown). In an embodiment, the second sealing member 103c is an O ring seal.
[0049] The second sealing member 103c can be made of various materials such as, but not limited to, natural rubber, nitrile rubber, ethylene propylene (EPDM Rubber), neoprene, silicone, fluorocarbon (Viton), and PTFE (Teflon), FKM (Viton), EPDM, neoprene, nitrile, hypalon, polyisoprene. In an embodiment, the second sealing member 103c is made of silicone. The second sealing member 103c can have varying diameters. For example, an outer diameter of the second sealing member 103c is between 25 mm and 30 mm, an inner diameter of the second sealing member 103c is between 18 mm and 22 mm and a cross-sectional diameter of the second sealing member 103c is between 2 mm and 5 mm. In an embodiment, the second sealing member 103c has the outer diameter of 27.40 mm, the inner diameter of 20.20 mm and the cross-sectional diameter of 3.6 mm.
[0050] The stem ‘C1’ is a solid longitudinal structure having multiple edges that extend as wings 103b. Each wing 103b includes a plurality of grooves 103d. In an exemplary embodiment, the stem ‘C1’ includes four wings 103b (as shown in FIG. 3a) and each wing 103b includes three grooves 103d. It should be understood that the stem ‘C1’ can have two or more wings 103b. Also, it should be understood that depending upon the application of the syringe 100, each wing 103b may have any suitable number of grooves 103d. The grooves 103d are equally spaced on each wing 103b facilitating multi-stage locking as explained in detail below.
[0051] The stem ‘C1’ can be made of polypropylene (PP), Acrylonitrile Butadiene Styrene (ABS), polyethylene (PE), etc. In an embodiment, the stem ‘C1’ is made of ABS.
[0052] In an exemplary embodiment, the grooves 103d of the wings 103b can be notched equally in the downward direction, towards the distal end ‘B1’ of the piston 103. In an embodiment, a groove 103d is formed between a straight edge of at least one groove 103d of the plurality of grooves 103d and a tapered edge of the at least one groove 103d of the plurality of grooves 103d. The tapered edge has an increasing taper from its proximal end to its distal end. The tapered edge of the groove 103d enables a user to smoothly pull and operate the piston 103 from its locked position without any restriction. This is so as the pulling force at the proximal end A1 pulls the wing 103b at the groove 103d along the taper and hence, exerts a uniform force on the resilient member 109 for unlocking the piston 103 and providing unhindered movement. The tapered edge of the groove 103d enables a user to smoothly pull the piston 103 even if the piston 103 is rotated at any angle along the central axis of rotation. The tapered edge of the groove 103d also eliminates the use of the slider 105 for unlocking the piston 103 by pulling the piston 103 and sliding the piston 103 from a proximal end to a distal end of the grooves 103d. For example, if the piston 103 is locked on a groove 103d at the proximal end ‘A1’ of the piston 103, the piston 103 cannot move into the barrel 101. The piston 103 can be shifted to a next groove 103d in the distal direction from the first groove 103d by pulling the piston 103 through the tapered edge of the groove 103d. The tapered edge of the groove 103d unlocks the piston 103 and allows the slider 105 to be pushed, exerting a compression force on the resilient member 109 and disengages the piston 103 from the groove 103d. Various embodiments include several numbers of grooves 103d with the same or different depths and tapering angles as per the requirement.
[0053] The groove 103d can be distributed along the stem ‘C1’ at even or uneven intervals. Alternately, the grooves 103d may be provided on the basis of markings on the barrel 101. In an embodiment, distribution of the grooves 103d on the piston 103 is based on difference of 20ml marked on the barrel 101. Further, the grooves 103d may be provided at the same height of the stem ‘C1’ on the respective wings 103b.
[0054] The lock mechanism 10 (FIG. 4) includes the slider 105, a casing 107 and a resilient member 109, according to an embodiment of the present disclosure.
[0055] The slider 105 (FIG. 4a) may be a plate-like structure having a slider hole 105e, an arc 105c at one end and downwardly extending edges at its periphery. For instance, the plate-like structure may be rectangular in shape with a first end ‘x’ acting as a button for receiving a user’s inputs while the second end ‘y’ may be in the form of the arc 105c for exerting pressure on the resilient member 109 when the button is pressed. In an embodiment, a separate button (not shown) may be provided at the first end ‘x’.
[0056] The slider hole 105e is provided towards the second end ‘y’ through which the piston 103 passes. The slider hole 105e may be shaped to correspond to the shape of the slider 105, as in, the slider hole 105e may be bounded by a slider arc 105d on one side and rectangular edges 105d1 on other three sides, roughly resembling a U-structure. The slider arc 105d of the slider 105 comes in contact with a groove (such as, a groove 103d) for locking the piston 103 when the piston 103 is pulled. However, on unlocking, a gap fills between the slider arc 105d of the slider 105 and the groove 103d.
[0057] The area of the slider hole 105e is substantially larger than the cross-sectional area of the stem ‘C1’. While the slider 105 is described as including the aforesaid shapes, other shapes are within the scope and teachings of the present disclosure.
[0058] The slider 105 includes a top surface ‘A2’ and a bottom surface ‘B2’. The edges at the periphery extend from the top surface ‘A2’ to the bottom surface ‘B2’ of the slider 105. The bottom surface ‘B2’ of the slider 105 includes a fillet 105b. The fillet 105b enables the slider 105 to slide freely when the piston 103 is pulled, as in the piston 103 moves in the proximal direction.
[0059] The first end ‘x’ includes a gripper 105a. In an embodiment, the gripper 105a includes a plurality of slits 105a’. The plurality of slits 105a’ can be in vertical, horizontal, or tapered direction. In an embodiment, the plurality of slits 105a’ may include between one to twenty slits 105a’. The slits 105a’ provide a surface to the user for pushing the button over the casing 107. According to one embodiment, the gripper 105a may not include slits 105a’. In an embodiment, the gripper 105a is configured to be pushed by the user.
[0060] The slider 105 can be made of polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC). In an embodiment, the slider 105 is made of acrylonitrile butadiene styrene (ABS).
[0061] The top view of the casing 107 is illustrated in FIG. 4b while the perspective bottom view is illustrated in FIG. 4c. As can be seen from the two figures, the casing 107 is in the form of a hollow box having three edges, a top face ‘A3’ and a bottom face ‘B3’. The top face ‘A3’ includes a casing hole 107a. The casing hole 107a is used to pass the piston 103 therethrough at the time of assembly of the syringe 100. The casing hole 107a has a diameter at least corresponding to the diameter of the piston 103. The range of the diameter of the casing hole 107a varies from 24mm to 28mm.
[0062] The bottom face ‘B3’ includes an arc shaped edge culminating into two clamps 107c. The hollow space between the clamps 107c facilitates the passage of the piston 103 through the casing 107 while the space enclosed between the upper and bottom faces seats the slider 105. In an embodiment, each clamp 107c includes a guiding slot 107b’ and a plurality of slots 107b. The guiding slot 107b’ can be used for guiding the slider 105 to slide, at least partially, inside and/or outside the casing 107. The plurality of slots 107b can be used for attaching the flange 101a with the casing 107 (as shown in FIG. 4b1). The casing 107 may include two guiding slots 107b’ (one with each clamp 107c), opposite to each other at the bottom face ‘B3’ of the casing 107.
[0063] In an embodiment, the clamps 107c (shown in FIG. 4c) are structured in such a way that the clamps 107c form a press fit structure. The press fit structure allows the slider 105 to fix to the clamps 107c and form the lock mechanism 10. For example, the flange 101a of the barrel 101 can slide through the plurality of slots 107b such that the casing 107 mounts on the top of the flange 101a and locks the flange 101a with the casing 107. Further, the slider 105 can slides through the guiding slots 107b’ on a top face of the flange 101a.
[0064] In an embodiment, the resilient member 109 includes a resiling element. The resiling element may have a compressed state and an expanded state, and provides resilient force when changing from the compressed state to the expanded state. The resilient force of the resiling element ensures that the slider 105 (for example, via the slider arc 105d) remains in contact with the stem ‘C1’ of the piston 103. In an embodiment, the resiling element is operatively coupled to the slider 105 such that when a pressure is applied on the slider 105, the resiling element is configured to be in the compressed state, and when the resiling element is in the expanded state the resiling element applies the resilient force on the slider 105 to slide, at least partially, out of the casing 107. In an example implementation, the resiling element is operatively coupled to the arc 105c of the slider 105. The operative coupling between the resiling element and the slider 105 enables the lock mechanism 10 to lock the piston 103 to a locked state or unlock the piston 103 to an unlocked state (as will be explained later).
[0065] According to one embodiment, the resiling element includes a plurality of torsion springs 109a (as shown in FIG. 4d). In the example shown in FIG. 4d, the resiling element includes two torsion springs 109a. Each torsion spring 109a includes a radially movable leg 109b and a rigid leg 109c. The radially movable legs 109b are operatively coupled to the arc 105c of the slider 105 (FIG. 4e). The rigid legs 109c are attached to the casing 107. In an embodiment, the torsion springs 109a are mounted on respective support rods (not shown) within the casing 107.
[0066] The torsion spring 109a can be made of music wire (steel with manganese, silicon, and a high content of carbon), stainless steel, chrome silicon, phospher bronze, hard-drawn steel material, etc. In an embodiment, the torsion spring 109a is made of stainless steel. The pitch of the torsion spring 109a varies from 0.5 to 1 mm. In an embodiment, a tight pitch torsion spring 109a is used.
[0067] FIGS. 5a and 5b depict the compressed state and the expanded state, respectively of the torsion spring 109a. When the piston 103 is pulled away from the barrel 101, an outer edge (i.e., the edge farthest from the central axis of the piston 103) of at least one wing 103b of the plurality of wings 103b comes in contact with the slider 105 (e.g., at the slider arc 105d). Consequently, the slider 105 applies a force on the torsion springs 109a (through for example, the arc 105c), thereby, configuring the torsion springs 109a in the compressed state. When the slider 105 (e.g., via the slider arc 105d) contacts the straight edge of the groove 103d, the torsion springs 109a moves to the expanded state (as shown in FIG. 5b) and exerts the resilient force on the slider 105 (e.g., on the arc 105c). As a result, the slider 105 slides, at least partially, out of the casing 107. Thus, the slider 105 locks the piston 103 in the grooves 103d. When the slider 105 (e.g., via the slider arc 105d) contacts and traverses the tapered edge of grooves 103d, the slider 105 starts to exert force on the torsion spring 109a and the torsion springs 109a begin to move to the compressed state. The force exerted by the slider 105 (for example, by pressing the button) allows the arc 105c compress the radially movable legs 109b of the torsion springs 109a (as depicted in FIG. 5a) such that the torsion springs 109a move to the compressed state. However, upon releasing the force of the slider 105 (e.g., upon releasing the button) or when the piston 103 reaches any of the plurality of the grooves 103, the torsion springs 109a expand and regain their original state and push the slider 105 outwards (as depicted in FIG. 5b).
[0068] In an embodiment, the resiling element may be an elastic element 109a’’ (for example, a rubber, silicon, elastin, nylon, latex, etc.) as shown in FIGS 6 – 6c. A metal support 109a’ may be provided at the ends of the elastic element 109a’’. The metal support 109a’ is rigidly fixed within the slots 107b of the casing 107. As shown, the elastic element 109a’’ is operatively coupled with the slider 105 (for example, by connecting with the arc 105c of the slider 105). In the expanded state, the elastic element 109a’’ applies the resilient force on the slider 105. When a force is applied by the slider 105, the elastic element 109a’’ moves to the compressed state. Thus, the operative coupling of the elastic element 109a’’ with the slider 105 enables the piston 103 to be locked and unlocked.
[0069] In another embodiment, the resiling element may be a pre-curved metallic strip element 109a1, as shown in FIG. 6c – 6e. A flat support 109a2 is provided at the ends of the metallic strip element 109a1. The metallic strip element 109a1 can be made of, without limitation, stainless steel, nickel, tantalum, cobalt, titanium, copper, brass etc. The metallic strip element 109a1 is operatively coupled to the slider 105 (for example, by connecting with the arc 105c of the slide 105). The flat support 109a2 can be fixed rigidly inside the slots 107b of the casing 107. In the expanded state, the metallic strip element 109a1 applies the resilient force on the slider 105. When a force is applied by the slider 105, the metallic strip element 109a1 moves to the compressed state. Thus, the operative coupling of the metallic strip element 109a1 with the slider 105 enables the piston 103 to be locked and unlocked.
[0070] It should be appreciated that the present disclosure is not limited to specific embodiments disclosed for the resiling element. Any other suitable resiling element (operatively coupled to the slider 105) providing a resilient force on the slider 105 when in the expanded state and transitioning to the compressed state upon force exerted by the slider 105 can be used without deviating from the scope of the present disclosure.
[0071] FIGS. 7 and 7a illustrate operation of the syringe 100. The description below is explained with the torsion springs 109a being the resiling element. It should be appreciated though that the syringe 100 operates similarly, with other resiling element. FIG. 7 shows a flowchart 600 illustrating operation of the syringe 100 when the piston 103 is pulled in a proximal direction. The piston 103 is in a mean position (step 602) (as shown in FIGS. 8a and 9). The syringe 100 may be engaged with a tubing having a valve at a proximal end of a catheter (not shown). The valve may be in a closed position. As shown in FIG. 9, in the mean position, the slider arc 105d of the slider 105 is in contact with an outer edge 103f of at least one wing 103b of the plurality of wings 103b. The slider 105 exerts force on the torsion springs 109a such that the torsion springs 109a are in the compressed state. The user begins to pull out the piston 103 in the proximal direction (step 604), for example, by applying force on the grip 103a. As the slider 105 is still in the contact with the outer edge 103f of the at least one wing 103b, at this stage the torsion springs 109a are in the compressed state (step 606). As the user continues to pull the piston 103, the slider arc 105d of the slider 105 comes in contact with a straight edge of at least one groove 103d of the plurality of grooves 103d (shown in FIG. 9a). As a result, the torsion springs 109a move to the expanded state and exert the resilient force on the slider 105 (for example, via the arc 105c), thereby sliding the slider 105 at least partially out of the casing 107 (as shown in FIG. 9a). Thus, the piston 103 is locked (i.e., the locked state) at the plurality of grooves 103d (step 608). As the piston 103 is pulled further, the slider arc 105d of the slider 105 traverses the tapered edge of the at least one groove 103d, and the slider 105 exerts force on the torsion springs 109a. As a result, the torsion springs 109a start to move to the compressed state from the expanded state and the piston 103 is in the unlocked state. Once the slider arc 105d touches the outer edge 103f of the at least one wing 103b, the torsion springs 109a are fully in the compressed state as shown in FIG. 9b (step 610). As the user continues to pull the piston 103 in the proximal direction, the piston 103 proceeds to the next groove 103d where the torsion spring 109a again becomes expanded as shown in FIG. 9c). As explained earlier, the piston 103 becomes in the locked state (step 612). Locking of the piston 103 at intermediate grooves 103d may be denoted as an intermediate position (as shown in FIG. 8b). The process of unlocking (shown in FIG. 9d) and locking the piston 103 continues as the user continues to pull the piston 103. Eventually, the piston 103 is locked at the final groove 103d as shown in FIG. 9e (step 614). Thus, the piston 103 is at an extreme position (also shown in FIG. 8c).
[0072] Further in FIG. 7a, the flowchart 600a shows an operation of the syringe 100 when the piston 103 is pushed from the extreme position to the mean position. In step 622, the button of the slider 105 is pressed. The slider 105 then exerts the force on the torsion springs 109, thereby moving the torsion springs 109a to the compressed state (step 624). Consequently, the piston 103 is released from the groove 103d (Step 626), i.e., the piston 103 moves to the unlocked state. The piston 103 can then be pushed in the barrel 101 in the distal direction (step 628). The user can continue to push the piston 103 to the mean position (step 630) as shown in FIG. 10. The button of the slider 105 button is released (step 632).
[0073] FIG. 7b, illustrates a flowchart 600b of a method for assembling the syringe 100. Various parts (a dismantled view shown in FIG. 8) are assembled to form the syringe 100. For this, the resiling element (such as the torsion springs 109a) is inserted inside the casing 107 (step 702). The flange 101a is inserted into the casing 107 from the side opening of the casing 107 such that the casing hole 107a coincides with the lumen of the barrel 101(step 704). Thereafter, the slider 105 is inserted inside the casing 107 from the side opening such that the slider hole 105e of the slider 105 coincides with the casing hole 107a and the lumen of the barrel 101, thereby aligning all the three holes (the lumen of the barrel 101, the casing hole 107a and the slider hole 105e) with each other (step 706). Further, the second sealing member 103c is inserted into the distal end of the piston 103 (step 708). The button of the slider 105 is then pressed (step 710). The piston 103 is then inserted in the lumen of the barrel 101 from the aligned holes (step 712). Lastly, the piston 103 is pushed until the piston 103 reaches the mean position (step 714) and the button of the slider 105 is released. The assembled syringe 100 where the piston 103 is in the mean position is illustrated in FIG. 8a.
[0074] The scope of the disclosure is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present disclosure is/are used. , Claims:WE CLAIM
1. A syringe (100) comprising:
a barrel (101) having a proximal end (A) and a distal end (B), the barrel (101) comprising a flange (101a) at the proximal end (A) of the barrel (101);
a piston (103), operatively coupled to the barrel (101) and having a proximal end (A1) and a distal end (B1), the piston (103) comprising:
a plurality of wings (103b), wherein each wing (103b) comprises a plurality of grooves (103d), each groove (103d) comprising a straight edge and a tapered edge having an increasing taper from the proximal end (A1) of the piston (103) to the distal end (B1) of the piston (103); and
a lock mechanism (10), operatively coupled to the piston (103) to configure the piston (103) in one of a locked state and an unlocked state, the lock mechanism (10) comprising:
a casing (107), having a top face (A3) and a bottom face (B3), the casing (107) comprising a plurality of clamps (107c) at the bottom face (B3) of the casing (107), each clamp (107c) comprising a plurality of slots (107b) configured to receive the flange (101a) such that the flange (101a) is fixedly locked with the plurality of clamps (107c);
a slider (105), having a first end (x) and a second end (y), slidably coupled to the casing (107), wherein the slider (105) is configured to contact one of an outer edge (103f) of at least one wing (103b) of the plurality of wings (103b), a straight edge of at least one groove (103d) of the plurality of grooves (103d) and a tapered edge of the at least one groove (103d) of the plurality of grooves (103d); and
a resiling element (109a, 109a’’, 109a1) having a compressed state and an expanded state, wherein the resiling element (109a, 109a’’, 109a1) is operatively coupled to the slider (105) such that:
in response to the slider (105) contacting the straight edge of the at least one groove (103d), the resiling element (109a, 109a’’, 109a1) is configured to be in the expanded state causing the slider (105) to, at least partially, slide out of the casing (107), thereby configuring the piston (103) in the locked state; and
in response to the slider (105) contacting at least one of the outer edge (103f) of the at least one wing (103b) or the tapered edge of the at least one groove (103d), the slider (105) is configured to, at least partially, slide in the casing (107) causing the resiling element (109a, 109a’’, 109a1) to be in the compressed state, thereby configuring the piston (103) into the unlocked state.
2. The syringe (100) as claimed in claim 1, wherein the slider (105) comprises a slider hole (105e) having a slider arc (105d) configured to contact one of the outer edge (103f) of the at least one wing (103b), the straight edge of the at least one groove (103d) and the tapered edge of the at least one groove (103d).
3. The syringe (100) as claimed in claim 1, wherein the slider (105) comprises an arc (105c) at the second end (y) operatively coupled with the resiling element (109a, 109a’’, 109a1) and configured to:
a. exert force on the resiling element (109a, 109a’’, 109a1) when the slider (105) contacts one of the tapered edge of the at least one groove (103d) or the outer edge (103f) of the at least one wing (103b) causing the resiling element (109a, 109a’’, 109a1) to be in the compressed state; and
b. receive resilient force from the resiling element (109a, 109a’’, 109a1) in the expanded state when the slider (105) contacts the straight edge of the at least one groove (103d) causing the slider (105) to, at least partially, slide out of the casing (107).
4. The syringe (100) as claimed in claim 1, wherein the slider (105) is configured to be pushed by a user, wherein when the slider (105) is pushed by the user, the slider (105) is further configured to slide, at least partially, into the casing (107) and exert force on the resiling element (109a, 109a’’, 109a1) causing the resiling element (109a, 109a’’, 109a1) to be in the compressed state, thereby configuring the piston (103) into the unlocked state.
5. The syringe (100) as claimed in claim 1, wherein the slider (105) comprises a button at the first end (x) configured to be pressed by a user, wherein the slider (105) is configured to slide, at least partially, in the casing (107) when the button is pressed by the user.
6. The syringe (100) as claimed in claim 1, wherein the slider (105) comprises a gripper (105a) at the first end (x) configured to be pressed by a user, wherein the slider (105) is configured to slide, at least partially, in the casing (107) when the gripper (105a) is pressed by the user.
7. The syringe (100) as claimed in claim 1, wherein the barrel (101) comprises a bore (101d) at the distal end (B) of the barrel (101).
8. The syringe (100) as claimed in claim 1, wherein the distal end (B) of the barrel (101) comprises a transition portion (101e) coupled to an extension (101b) and a first sealing member (101c) mounted on the extension (101b).
9. The syringe (100) as claimed in claim 8, wherein the first sealing member (101c) is an O-ring seal.
10. The syringe (100) as claimed in claim 1, wherein the distal end (B1) of the piston (103) comprises a second sealing member (103c) configured to seal edges of the second sealing member (103c) and an inner edge of a lumen of the barrel (101).
11. The syringe (100) as claimed in claim 10, wherein the second sealing member (103c) is an O-ring seal.
12. The syringe (100) as claimed in claim 1, wherein the barrel (101) comprises a pressure gauge (102) coupled to an extension (101b) of the barrel (101) via a tubular body (102a).
13. The syringe (100) as claimed in claim 1, wherein the barrel (101) comprises a pressure gauge (102) coupled to a transition portion (101e) of the barrel (101).
14. The syringe (100) as claimed in claim 1, wherein each of the plurality of clamps (107c) comprises a guiding slot (107b’), wherein the slider (105) is configured to slide within the guiding slot (107b’).
15. The syringe (100) as claimed in claim 1, wherein the resiling element (109a, 109a’’, 109a1) comprises one of a plurality of torsion springs (109a), an elastic element (109a’’) or a pre-curved metallic strip element (109a1).