Precision low-dose, low-waste syringes and ergonomic attachments therefor
Syringe attachments and syringes have particular suitability to the precision dispensing of small amounts of high viscosity materials, such as dermal fillers. An attachment may include a main body having an assist feature that includes a wheel and pinion gears on each side of the wheel which engage respective racks on the syringe body. A mechanical advantage may be provided to the user as the wheel is rotated relative to the syringe body and racks. Syringes and attachments may include precision position indicators viewed from multiple positions to enable a user to determine plunger position and the amount of dispensed contents with precision. An alternative configuration attachment may be slidably secured to a syringe to permit a user to operation the syringe from a lateral position using sliding movement of the thumb and fingers of one hand, for example. This configuration may be particularly suitable for self-administered insulin injections.
1 . An attachment for a syringe, the syringe comprising a syringe body, the syringe body including an axially extending flat upper surface and a plunger having a plunger thumb pad, the attachment comprising:
a main body having a plunger engaging end adapted to engage the plunger, the plunger engaging end including a receptacle adapted to receive the plunger thumb pad and the main body including a guide end adapted to guide the main body along the syringe body;
a pair of opposed retaining edges formed in the guide end and adapted to engage respective opposing sides of the flat upper surface of the syringe body to keep the attachment aligned with the syringe body; and
the main body further comprising a thumb actuated portion positioned on the main body of the attachment such that when the attachment is installed on the syringe body and a user grasps the syringe body with the user's fingers, the thumb actuated portion is positioned to be engaged by the user's thumb, the main body further comprising a pair of guiding projections located beneath the thumb actuated portion and arranged to slidingly engage opposing sides of the flat upper surface of the syringe body.
2 . The attachment of claim 1 , further comprising a viewing window disposed near the guide end.
3 . The attachment of claim 1 , wherein the thumb actuated portion comprises a projection adapted to be engaged by a user's thumb.
4 . The attachment of claim 1 , wherein the plunger engaging end includes a snap fitting for engaging the plunger.
5 . A system for operating a syringe, the syringe comprising:
a syringe body, including a syringe barrel having a lumen, and a plunger adapted to be received within the lumen, the plunger having a plunger thumb pad, the syringe barrel having a flat surface extending in an axial direction; and
an attachment, adapted to be moved relative to the syringe body, the attachment comprising a main body having a plunger engaging end adapted to engage the plunger, the plunger engaging end including a receptacle adapted to receive the plunger thumb pad and the main body including a guide end including a pair of opposed retaining edges formed in the guide end, the opposed retaining edges being adapted to engage respective opposing sides of the flat surface of the syringe barrel, the retaining edges operating to guide the attachment and keep the attachment aligned with the syringe barrel as the attachment moves relative to the syringe barrel,
the main body further comprising a thumb actuated portion positioned on the main body of the attachment such that when the attachment is installed on the syringe body and a user grasps the syringe body with the user's fingers, the thumb actuated portion is positioned to be engaged by the user's thumb, the main body further comprising a pair of guiding projections located beneath the thumb actuated portion and arranged to slidingly engage opposing sides of the flat surface of the syringe body.
6 . The system of claim 5 , further comprising a tactile indicator configured to generate a tactile event to a user as the attachment moves relative to the syringe body.
7 . The system of claim 5 , wherein the attachment main body guide end includes a U-shaped extension for receiving the syringe body.
8 . The system of claim 5 , wherein the thumb actuated portion comprises a projection adapted to be engaged by a user's thumb.
9 . A system comprising:
a syringe comprising a syringe body and a plunger, the plunger having a plunger thumb pad, the syringe body having a syringe barrel, including a flat surface, the syringe having an internal lumen with a diameter and length that provides a total syringe volume of about 0.50 ml, wherein the syringe has 50 gradations on the syringe barrel;
an attachment comprising a main body having a plunger engaging end adapted to engage the plunger, the main body including a guide end adapted to guide the attachment along the syringe body and a pair of opposed retaining edges formed in the guide end and adapted to engage respective opposing sides of the flat surface of the syringe barrel to keep the attachment aligned with the syringe barrel, the main body further comprising a receptacle adapted to receive the plunger thumb pad, the main body further comprising a thumb actuated portion positioned on the main body of the attachment such that when the attachment is installed on the syringe body and a user grasps the syringe body with the user's fingers, the thumb actuated portion is positioned to be engaged by the user's thumb, the main body further comprising a pair of guiding projections located beneath the thumb actuated portion and arranged to slidingly engage opposing sides of the flat surface of the syringe body.
10 . The system of claim 9 , wherein the syringe has a length of about 4 inches with a 0.50 ml volume and 50 gradations, wherein the attachment is adapted to allow a user to operate the syringe to dispense an incremental 0.01 ml dose.
11 . The system of claim 10 , wherein the syringe volume and internal lumen are configured such that dispensing the incremental 0.01 ml dose results from a controlled a plunger movement of 0.08 inches.
12 . The system of claim 9 , wherein the thumb actuated portion comprises a projection adapted to be engaged by a user's thumb.