Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1999-12-02
2001-05-15
Kennedy, Sharon (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
Reexamination Certificate
active
06231550
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a one-handed, finger-gripped, thumb activated syringe that can be used in both injection and aspiration modes, and more particularly one which can be operated in either mode from a single finger gripping position and which is activated in either mode by a single thumb action where the thumb is advanced towards the fingers.
Background of the Invention
There are various one-handed finger-gripped injection and aspiration syringes, which predominantly fall into two types. U.S. Pat. Nos. 3,990,446; 4,639,248; 5,135,511; and 5,582,595 teach one type, where changing the mode of operation requires repositioning the fingers which grip the syringe. This requirement complicates control and operation of the syringe when it is to be used in both modes. The second type, taught in U.S. Pat. Nos. 3,758,006 and 5,902,278, requires pushing and pulling of a plunger stem with the thumb to change modes. The action of pulling using the thumb is contrary to the normal grasping action of the hand, which makes control of the syringe in the aspiration mode difficult. Thus, there is a need for a finger gripped injecting and aspirating syringe where the finger grip remains unchanged as the mode is changed, and where the thumb is advanced towards the fingers in both modes to provide better control of the syringe.
SUMMARY OF THE INVENTION
The present invention is a syringe which can readily be used in an injection mode or an aspiration mode while being held in one hand. The syringe is operated in either mode with a single gripping position of the user's fingers, and in both modes is activated by advancement of the user's thumb toward the fingers which grip the syringe. The invention is particularly well suited for use as a hypodermic syringe, but may also be employed for other types of syringes, such as irrigation syringes and suction syringes. The syringe has a barrel having a central passage and a longitudinal axis. The barrel terminates in a distal end region and a proximal end region, and has a pair of finger-engageable wings attached to the proximal end region of the barrel, which are preferably symmetrically disposed about the barrel. The finger-engageable wings assist the user in stabilizing the barrel in the hand of the user by providing finger grips which are engaged by the fingers with the same gripping action when operating the syringe in both the injection mode and the aspiration mode, thus allowing the user to change modes without altering the finger position.
The syringe has a plunger assembly having a plunger stem. The plunger stem terminates in a plunger head region and a plunger stem free end. The plunger head region has a plunger head configured to slidably and sealably engage the central passage of the barrel. The plunger stem is axially aligned with the longitudinal axis of the barrel and preferably of sufficient length that the plunger stem free end extends beyond the proximal end region of the barrel when the plunger head resides in the distal end region of the barrel. It is also preferred that the plunger stem free end is provided with a plunger thumb pad for the comfort of the user by distributing pressure on the thumb when depressing the plunger stem when operating the syringe in the injection mode.
A barrel attachment is provided, which engages the barrel and has an associated attachment stem. The attachment stem has an attachment stem distal end region and an attachment stem proximal end region terminating in an attachment stem free end. In one preferred embodiment, the barrel attachment is affixed to the barrel and the attachment stem slidably engages the barrel attachment. It is further preferred that one of the wings have an attachment stem passage therethrough, and that the barrel attachment be so positioned that the attachment stem passes through the attachment stem passage.
In other embodiments, the barrel attachment slidably engages the barrel and the attachment stem has the attachment stem distal end region affixed to the barrel attachment or made integral therewith. The attachment stem is preferably of sufficient length that the attachment stem free end extends beyond the proximal end region of the barrel when the barrel attachment resides at the distal end region of the barrel. In one such embodiment, the slidable barrel attachment is a clip which engages the barrel. In another embodiment, a sleeve which encircles the barrel is employed as the slidable barrel attachment.
For all embodiments, it is preferred for the attachment stem free end to be fitted with an attachment stem thumb pad which distributes the pressure on the thumb when depressing the attachment stem. When thumb pads are attached to the plunger stem free end and the attachment stem free end, they should be configured such that, when mounted on their respective stems, they can freely pass by each other as the stems are raised and lowered. It is further preferred that the thumb pads be so positioned that they can be readily independently actuated by the thumb of the user by pivotal action of the thumb relative to the fingers, which remain fixably engaged with respect to the barrel and the wings.
For the convenience and comfort of the user and to further stabilize the syringe during aspiration, it is further preferred that the pivotable action of the thumb move the thumb in the direction of the palm when moving from the injection mode to the aspiration mode.
Means for inducing diametrically opposed movement of the plunger stem and the attachment stem are provided. These means provide a mechanism for raising the plunger stem by depressing the attachment stem, allowing the syringe to operate in the aspiration mode.
A flexible filament terminating in a first filament end and a second filament end offers one preferred means for inducing diametrically opposed movement of the plunger stem with respect to the attachment stem. As used herein, the term “flexible filament” includes monofilaments, stranded filaments, and similar flexible elongated elements. The first filament end is attached to the plunger head region of the plunger stem and affixed with respect to the plunger stem such that it does not interfere with the seal between the central passage and the plunger head. The flexible filament passes along the central passage of the barrel, over the proximal end region, and down the barrel to where the second filament end is affixed with respect to the attachment stem distal end region. The second filament end is either directly connected to the attachment stem distal end region or, when the barrel attachment is a clip or sleeve attached to the attachment stem, the second filament end can be attached to the attachment stem distal end region by attaching to the barrel attachment.
Preferably, the flexible filament is positioned such that it will traverse a path which is substantially parallel to the longitudinal axis of the barrel. It is further preferred that a reference plane containing the longitudinal axis of the central passage of the barrel and the flexible filament intersects the attachment thumb pad and that the flexible filament reside substantially within the footprint of the attachment stem thumb pad.
An alternative to employing a flexible filament as the means for inducing diametrically opposed movement of the plunger stem and the attachment stem is to employ a rack and pinion mechanism to provide such means. In such an embodiment, a pinion gear is mounted in the proximal end region of the barrel so as to rotate about an axis which is perpendicular to a radius of the barrel intersecting the pinion gear. The pinion gear extends into the central passage and extends beyond the barrel. The plunger stem is fitted with a plunger stem rack which engages the pinion gear inside of the central passage, while the attachment stem has an attachment stem rack which engages the pinion gear outside the central passage. In combination, the pinion gear, the plunger stem rack, and the attachment stem rack couple the motion of the two stems to reverse the dire
Kennedy Sharon
Sempreban Jeffrey S.
Serke Catherine
Weins Michael J.
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