Patent Application
20230133890
The present disclosure relates generally to medical devices. In some instances, the present disclosure relates to a lubrication-free syringe used to deliver fluid to or withdraw fluid from a patient. In some embodiments, the present disclosure relates to a syringe plunger having a tip seal configured to permit axial translation of a plunger within a lubrication-free syringe barrel.
The embodiments disclosed herein will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. These drawings depict only typical embodiments, which will be described with additional specificity and detail through use of the accompanying drawings in which:
A syringe may be used to deliver fluids to or withdraw fluids from a patient. In certain instances, some components of the syringe (e.g., barrel, plunger tip) are coated with a lubricant, such as silicone oil, to facilitate or ease axial translation of a plunger within the barrel. However, silicone oil or other lubricants can negatively react with certain medicaments disposed within the barrel. For example, particles comprising poly vinyl alcohol agglomerate when interacting with silicone oil, sodium tetradecyl sulfate foam is defoamed when interacting with silicone oil, and silicone oil has a negative effect when injected into the eye.
Embodiments herein describe embodiments of syringes free of a lubricant, such as silicone oil. In some embodiments within the scope of this disclosure, the syringe includes a barrel defining a reservoir, a syringe plunger, and a Luer lock fitting. The syringe plunger includes an integrally formed handle and a plunger tip disposed at a distal end of the handle. The plunger tip includes a wiper portion having two seals, a pressure seal and a vacuum seal, configured to sealingly engage with an internal surface of the barrel. A flexing hinge couples the wiper portion to a central portion of the plunger tip. The flexing hinge allows the wiper portion to be proximally deflected as the syringe plunger is inserted into the reservoir. The flexing hinge also allows the wiper portion to rock from a pressure state where the pressure seal seals against the internal surface of the barrel when the reservoir is pressurized by distal movement of the syringe plunger and a vacuum state where the vacuum seal seals against the internal surface of the barrel when a vacuum or negative pressure is formed in the reservoir by proximal movement of the syringe plunger.
The syringe plunger may be formed from a material having a low co-efficient of friction to allow the seals to slide against the internal surface of the barrel without adding a lubricant to the seals and/or the internal surface. For example, the syringe plunger may be formed from high density polyethylene (HDPE), polypropylene, nylon, low density polyethylene (LDPE), or polyoxy methylene (POM). Other materials are contemplated. In some embodiments, a syringe plunger formed from HDPE is gamma irradiated to reduce the co-efficient of friction relative to a non-irradiated syringe plunger. The syringe plunger may be formed using an injection molding process. In some such embodiments, a cavity of a mold used to form the syringe plunger has parting lines along a length of the handle and circumferentially at a proximal end of the plunger tip such that a parting line does not cross the seals to prevent mold flashing from forming across the seals. If the mold flashing were to cross the seals, the mold flashing may cause fluid leakage at the plunger tip adjacent the mold flashing.
The barrel may include detents formed at a proximal end following insertion of the syringe plunger. The barrel may also include a zero draft internal diameter where the internal diameter is equivalent at a proximal end and a distal end of the barrel. Furthermore, in some embodiments, the barrel is formed of a clear, rigid thermoplastic material, such as polycarbonate (PC), polypropylene, polystyrene, polypropylene, cyclo-olefin polymer (COP), cyclo-olefin copolymer (COC), amorphous nylon or glass.
Embodiments may be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood by one of ordinary skill in the art having the benefit of this disclosure that the components of the embodiments, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.
As illustrated in
As illustrated in
The handle 130 of the depicted embodiment includes a thumb pad 131 disposed at a proximal end of the handle 130. The thumb pad 131 may be used to manipulate the syringe plunger 110 relative to the syringe barrel 150 to inject a fluid, such as a medicament, from the syringe barrel 150 or to draw the fluid into the syringe barrel 150. A proximal surface of the thumb pad 131 can include features to enhance a user's interaction with the thumb pad 131. The features may include ribs, grooves, bumps, divots, surface texturing, etc. In other embodiments, the thumb pad 131 may be a ring configured to receive a user's digit, such as a thumb.
In some embodiments, a plurality of ribs 132 are disposed between the thumb pad 131 and the plunger tip 120. The number of ribs 132 may be three, four, five, six, or more. In another embodiment, the handle 130 may include an elongate cylinder disposed between the thumb pad 130 and the plunger tip 120. A width of the handle 130 transversely across the ribs 132 may be smaller than a diameter of a bore 157 of the syringe barrel 150 such that the ribs 132 help to maintain co-axial alignment of the plunger tip 120 with the bore 157 of the syringe barrel 150. For example, the width of the handle may be from about 0.10 millimeter to about 0.25 millimeter smaller than the diameter of the bore 157. This configuration may be configured to help to ensure substantial equal circumferential sealing of the plunger tip seals 123, 124 with an internal surface 156 of the syringe barrel 150.
A proximal alignment disk 133 and a distal alignment disk 134 can be disposed at a distal portion of the handle 130 adjacent or near the plunger tip 120. The disks 133, 134 may be longitudinally spaced apart and have a diameter substantially equivalent to the diameter of the handle 130, such that the disks 133, 134 help to maintain co-axial alignment of the plunger tip 120 with the bore 157 of the syringe barrel 150. This configuration helps to ensure substantial equal circumferential sealing of the plunger tip seals 123, 124 with an internal surface 156 of the syringe barrel 150.
In the illustrated embodiment, as shown in
The wiper 121 extends radially outward from the hinge 122. The wiper 121 includes a circumferential distal seal 123, a circumferential proximal seal 124, and a circumferential recess 125 disposed between the distal seal 123 and the proximal seal 124. A distal surface 128 of the wiper 121 includes an angle α ranging from about 30 degrees to about 80 degrees relative to the longitudinal axis of the syringe plunger 110 as shown in
As depicted in the embodiment of
As depicted, the body 151 includes an internal detent 154 disposed adjacent the proximal end to retain the syringe plunger 110 within the bore 157. The number of detents 154 may be one, two, three, four, or more that are spaced equidistantly around a circumference of the body 151. A height of the detent 154 may range from about 2.0 millimeters to about 2.5 millimeters from the internal surface 156. In other words, the proximal disk 133 has a diameter larger than a transverse distance between the detents 154 such that the proximal disk 133 can engage the detents 154 when the syringe plunger 110 is displaced proximally to prevent the syringe plunger 110 from inadvertently being removed from the syringe barrel 150. The detent 154 can include a rectangular, circular, or dome shape. Other shapes are contemplated. The detent 154 may be formed in the body 151 following insertion of the plunger tip 120 into the bore 157 using pressure and/or heat applied by a detent forming tool.
A plunger tip portion 208 of the cavity 205 may be disposed within the slide portion 204. The plunger tip portion 208 includes a negative shape of the plunger tip 120 of the syringe plunger 110. A vertical parting line 205 divides the slide portion 204 from the upper and lower mold portions 201, 202. Thus, the plunger tip portion 208 may be configured such that the vertical parting line 205 does not cross into the plunger tip portion 208 of the cavity 206.
In use, molten material is injected into the cavity 206 to form the syringe plunger 110. Following cooling of the molten material, the upper mold portion 201 is separated from the lower mold portion 202 along the parting line 203 releasing the handle 130 of the syringe plunger 110 from the handle portion 207 of the cavity 206, as indicated by the arrows. The upper and lower mold portions 201, 202 are also moved along the vertical parting line 205 to expose a proximal surface of the plunger tip 120 of the syringe plunger 110. The slide portion 204 is moved away from the upper mold portion 201 and the lower mold portion 202, as indicated by the arrow. The plunger tip 120 is ejected from the plunger tip portion 208. The formed plunger tip 120 is free of mold flashing across the seals 123, 124 because the vertical parting line 205 did not cross the seals 123, 124. This design may be configured to prevent leakage around the plunger tip 120. Mold flashing crossing the seals 123, 124 may prevent the plunger tip 120 from sealing with the internal surface 156 of the syringe barrel 150. In other words, mold flashing on the seals 123, 124 may allow fluid to leak around the plunger tip 120. Thus, embodiments wherein the seals 123, 124 are free of mold flashing may be configured to facilitate sealing.
Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified. For example, a method of manufacturing a syringe plunger may include one or more of the following steps: injecting a molten material into a cavity of the mold; wherein the cavity comprises a syringe plunger shaped void comprising: a plunger tip portion comprising a first seal portion and a second seal portion, and a plunger handle portion, a longitudinal parting line extending proximally of a plunger tip portion of the cavity, and a circumferential parting line disposed proximally of the plunger tip portion; parting the mold along the longitudinal parting line; and ejecting a plunger tip of a molded syringe plunger from the plunger tip portion of the cavity, wherein the plunger tip is free of molding flashing extending longitudinally across a first seal and a second seal of the plunger tip. Other steps are also contemplated.
In the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim requires more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment.
It will be appreciated that various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. Many of these features may be used alone and/or in combination with one another.
The phrases “coupled to” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be coupled to or in communication with each other even though they are not in direct contact with each other. For example, two components may be coupled to or in communication with each other through an intermediate component.
The directional terms “distal” and “proximal” are given their ordinary meaning in the art. That is, the distal end of a medical device means the end of the device furthest from the practitioner during use. The proximal end refers to the opposite end, or the end nearest to the practitioner during use.
“Fluid” is used in its broadest sense, to refer to any fluid, including both liquids and gases as well as solutions, compounds, suspensions, body fluids, etc., which generally behave as fluids.
References to approximations are made throughout this specification, such as by use of the term “substantially.” For each such reference, it is to be understood that, in some embodiments, the value, feature, or characteristic may be specified without approximation. For example, where qualifiers such as “about” and “substantially” are used, these terms include within their scope the qualified words in the absence of their qualifiers. For example, where the term “substantially equivalent” is recited with respect to a feature, it is understood that in further embodiments, the feature can have a precisely equivalent configuration.
The terms “a” and “an” can be described as one, but not limited to one. For example, although the disclosure may recite a housing having “a stopper,” the disclosure also contemplates that the housing can have two or more stoppers.
Unless otherwise stated, all ranges include both endpoints and all numbers between the endpoints.
Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element.
The claims following this written disclosure are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Moreover, additional embodiments capable of derivation from the independent and dependent claims that follow are also expressly incorporated into the present written description.
Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the invention to its fullest extent. The claims and embodiments disclosed herein are to be construed as merely illustrative and exemplary, and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having ordinary skill in the art, with the aid of the present disclosure, that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended claims. Moreover, the order of the steps or actions of the methods disclosed herein may be changed by those skilled in the art without departing from the scope of the present disclosure. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order or use of specific steps or actions may be modified. The scope of the invention is therefore defined by the following claims and their equivalents.
This application claims priority to U.S. Provisional Application No. 63/275,183, filed on Nov. 3, 2021 and titled, “Living Hinge Seal for Silicone-Free Syringe Barrel,” which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63275183 | Nov 2021 | US |
