Reciprocating syringes

The present invention provides a syringe device comprising: a first syringe comprising: a first syringe barrel including a first opening at a distal end thereof through which fluid may be forced or aspirated; and a first syringe plunger sliding within the first syringe barrel for forcing fluid through the first syringe barrel opening, the first syringe plunger including a stopper at a distal end thereof which sealingly and slidably engages the first syringe barrel; a reciprocating member which moves along a track parallel to the axial direction of the first syringe; and a reciprocating device connecting the first syringe plunger to the reciprocating member so that when one member of the group consisting of the first syringe plunger and the reciprocating member moves distally, the other member of the group is forced to move proximally. The present invention also provides a syringe device where one member of the group consisting of the first syringe plunger and the reciprocating member moves proximally, the other member of the group is forced to move distally.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to single-handed syringe.

2. Description of the Prior Art

Syringes are an essential element in the day-to-day practice of medicine and nursing, but are also essential in industry, laboratory science, research, and animal husbandry. Syringes are used to inject medications, aspirate body fluids, provide vacuum, and transfer fluids. The syringe design most commonly used in medicine consists of a barrel made of plastic and an internal plunger which is moved into or out of the barrel, resulting in pressure or a vacuum, respectively. The difference in pressure between the volume in the syringe and the outside environment is produced by movement of the plunger, resulting in movement of fluid into (aspiration) or out (injection) of the syringe. This difference in pressure creates the desired effect of a syringe, that is, aspiration or injection.

Injection with a standard syringe is simple, and uses powerful flexor muscles of the hand and forearm. Injection with a standard syringe can usually be easily accomplished with one hand, freeing up the other hand for other necessary tasks or procedures. In this technique the 2nd (index) and 3rd fingers (middle finger) are placed on a finger flange of the syringe and the thumb is placed on a thumb rest of the plunger. The digits are brought together resulting in a powerful injection due to contraction of powerful flexor muscles of the hand and forearm. The ability to use a syringe with one hand and use the other hand for other tasks is important in many complicated procedures.

Aspiration with a standard syringe usually requires the use of two hands in order to generate the necessary power and maintain fine control. Generally, this is done by using one hand to control the barrel and the other hand to pull on the thumb rest of the plunger. The two-handed technique uses muscular strength of both the hands and the arm. Thus, very powerful vacuums with rapid movement of fluid into the syringe can be obtained. This is currently the technique of choice when either fine control of the syringe is required or considerable power is necessary. This is also the technique used by most physicians and nurses.

Single-handed aspiration with a standard syringe is possible, but is difficult and awkward. Generally, two techniques may be used. In the first method, the thumb rest of the plunger is grasped by the 2nd and 3rd digits (index finger and middle finger) and the thumb is placed on the finger flange of the syringe. The fingers are forcefully flexed, while the thumb remains extended. This results in the plunger being pulled out, resulting in an effective aspiration. There are several problems with this method including: 1) fine control of the syringe is effectively lost (which is important when there is a sharp needle in delicate living tissues); 2) the entire syringe tends to rotate, further degrading control; 3) due to the size of the syringe components relative to the dimensions and strength of the human hand this method is extremely difficult with syringes larger than 10 cc (i.e. 20 cc or 60 cc); and 4) the force of aspiration is generated by weak intrinsic flexors of the hand, without using powerful flexors of the thumb and forearm, resulting in a weaker aspiration. Thus, this single-handed method is unsatisfactory.

Single-handed aspiration may also be accomplished by an alternative thumb method. In this method, the syringe barrel is grasped by the four fingers, and the thumb is placed under the thumb rest of the plunger. With the syringe firmly grasped by the digits the thumb is extended, resulting in aspiration. Unfortunately, variations of this method are best demonstrated by drug addicts who inject themselves with drugs. The alternative thumb method has several disadvantages: 1) although a degree of control is maintained, it is not the fine control of the fingers, but the more coarse control of the forearm musculature; 2) power of the aspiration is weak, because it is accomplished by the extensors of the thumb; 3) full aspiration is difficult to achieve without changing the handgrip; 4) the syringe is generally pointing toward an operator which is the opposite direction required in a medical procedure (except for a person injecting themselves with drugs); and 5) when the thumb is extended the hypothenar tissues are compressed under the syringe, resulting in an unpredictable deviation of the needle side of the syringe with some loss of control.

Single-handed aspiration with a standard syringe is difficult and awkward, resulting in loss of fine control and power during aspiration. With loss of control, there is a higher rate of procedure failure and contamination. With loss of power, speed of aspiration is impaired, especially for viscous fluids. Because of the loss of strength and control with single-handed aspiration, procedures that demand either fine control of the syringe during aspiration or the generation of a powerful vacuum, are difficult if not impossible to accomplish with a conventional single-handed syringe.

Various attempts have been made to design a syringe which will allow for easier single-handed aspiration. Several of these designs have involved the use of a an external apparatus which is integral with the syringe and allows the plunger to be advanced or retracted using squeezing motions of digits on one hand rather than pulling motion using two hands, see for example U.S. Pat. No. 3,990,446; to Taylor et al. Other patents, such as U.S. Pat. No. 5,582,295; to Haber et al., have described essentially the same device, and some patents have described an adapter which can be fitted on a conventional syringe, see U.S. Pat. No. 5,135,511; to Houghton.

Several U.S. patents have described a syringe with an external slide which attaches to the plunger, permitting single-handed operation, see U.S. Pat. No. 4,484,915; to Tartaglia and U.S. Pat. No. 4,639,248; to Schweblin.

However, in all of the above-described designs, the position of the index and middle fingers as well as the thumb, must be moved on the syringes when switching from aspiration to injection mode, resulting in intraoperative instability. In addition, during single-handed aspiration using these devices, the barrel and needle advance beyond the index and ring finger, an unstable situation, creating major difficulties in control and localization of the needle and resulting in instability and unpredictability during procedures.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a syringe that permits both injection and aspiration with one hand, yet maintains fine motor control and the strength necessary to generate high pressures and vacuums.

It is another object of the present invention to provide a stable platform for both injection and aspiration with the index and middle fingers in a fixed position, with the only required movement being a lateral movement of the thumb to a reciprocating plunger.

A first aspect of the present invention provides a syringe device comprising: a first syringe barrel including a first opening at a distal end thereof through which fluid may be forced or aspirated; and a first syringe plunger sliding within the first syringe barrel for forcing fluid through the first syringe barrel opening, the first syringe plunger including a stopper at a distal end thereof which sealingly and slidably engages the first syringe barrel; a reciprocating member which moves along a track parallel to the axial direction of the first syringe; and a reciprocating device connecting the first syringe plunger to the reciprocating member so that when one member of the group consisting of the first syringe plunger and the reciprocating member moves distally, the other member of the group is forced to move proximally.

A second aspect of the present invention provides a syringe device comprising: a first syringe comprising: a first syringe barrel including an opening at a distal end thereof through which fluid may be forced or aspirated; and a first syringe plunger sliding within the first syringe barrel for forcing fluid through the first syringe barrel opening, the first syringe plunger including a stopper at a distal end thereof which sealingly and slidably engages the first syringe; a reciprocating member which moves along a track parallel to the axial direction of the first syringe; and a reciprocating device connecting the first syringe plunger to the reciprocating member so that when one member of the group consisting of the first syringe plunger and the reciprocating member moves proximally, the other member of the group is forced to move distally.

Other objects and features of the present invention will be apparent from the following detailed description of the preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Definitions

For the purposes of the present invention, the term “axial direction of a syringe” refers to the line along a center axis of a syringe from its distal end to its proximal end or from its proximal end to its distal end.

For the purposes of the present invention, the term “proximal” refers to a direction towards a user of a syringe. For the purposes of the present invention, the term “distal” refers to a direction away from the user of the syringe.

For the purposes of the present invention, the term “reciprocating member” refers to plungers, sliders, thumb rest mounted on a belt, plunger with teeth on one side, etc., which is connected to a syringe plunger by a reciprocating device and moves in a direction opposite a direction of motion of the syringe plunger to which the reciprocating member is connected.

For the purposes of the present invention, a “reciprocating device” refers to a device which combines the functions of connecting a syringe plunger to a reciprocating member and causing the directions of motion of the syringe plunger and reciprocating member to be in opposite directions. Examples of a reciprocating device include: a connecting cord running over a round smooth edge of a syringe wall; a connecting cord which runs through a pulley mounted on a pulley post; a notched connecting cord running through a geared pulley, a gear mounted on a support and teeth mounted on a syringe plunger and reciprocating member which engages the gear; a U-tube filled with a liquid; etc.

For the purposes of the present invention, the term “track” refers to any means which constrains the motion of a reciprocating member such as a hollow syringe barrel in which a reciprocating member slides; a post on which a reciprocating member slides; a combination of retaining band, a gear mounted on a support, and teeth mounting on the reciprocating member which engages the gear, etc.

Description

Although two compartment and double plunger syringes have been described before in prior patents, these syringes have usually been based on a single barrel and are intended to mix or administer two different substances, see U.S. Pat. No. 3,685,514; to Cheney and U.S. Pat. No. 5,186,616; to Nadal. Other patents have also described double piston devices, either mechanically or hydraulically driven, for aspirating fluids or administering medications, see U.S. Pat. No. 4,036,232; to Genese and U.S. Pat. No. 4,437,859; to Whitehouse. However, none of these patents have described a device similar to the present invention that utilizes a reciprocating, thumb-operated, double-plunger syringe device intended for both aspiration and injection.

The present invention provides a syringe that permits injection and aspiration of fluids or gas using one hand with applications to health care, research, animal husbandry, and industry. The present invention utilizes fundamental changes in syringe design. In one embodiment, the syringe of the present invention includes an internal or external accessory plunger, with or without an accessory barrel, which is mechanically associated with the plunger of the functional syringe, resulting in a set of reciprocating plungers. Thus, when one plunger is depressed with the thumb, the syringe injects and when the accessory plunger is depressed with the same thumb, the syringe aspirates. This arrangement permits the index and middle fingers to stay in one position during aspiration and injection, while the thumb only need move laterally to the alternative plunger in order to change the direction of flow, i.e. aspiration or injection.

The resulting syringe is highly stable since only thumb position changes, and very powerful vacuums or pressures may be developed since powerful flexors of fingers, thumb, and forearm are used for both aspiration and injection. The syringe of the present invention is designed to be used with one hand, but may be used in all cases where standard syringes are used. This syringe may have particular uses in medical procedures when single-handed injection/aspiration is required, such as cardiac catheterization, emergency procedures, certain types of surgery, pediatric, and veterinary procedures, and in those handicapped individuals who can only use one hand. The applicability of these new syringe designs is expected to be large.

FIG. 1illustrates a syringe device100of one preferred embodiment of the present invention. Syringe device100ofFIG. 1includes a modified conventional syringe102made of plastic, glass, or other material. On syringe102there is mounted a needle or cannula104having a hub106. Hypodermic needle or cannula104is held on syringe102by a conventional needle or cannula fitting108such as a luer, Luer-Lok, etc. Syringe102includes a syringe barrel110with a finger flange112. A syringe plunger114, inserted into syringe barrel110, includes a stopper116, made from rubber or another flexible or tight-sealing material, and a thumb rest118. Mounted on one side of syringe102is an accessory barrel120having a finger flange122. Finger flange122is effectively joined to syringe barrel110by accessory barrel120. Accessory barrel120provides a track for movement of a reciprocating accessory plunger124having a thumb rest126and a stopper128which may be similar or different from stopper116. Barrels110and120maybe integrated together by bonding, retaining bands, simultaneous extrusion, casting, gluing, or any other method of integrating components. Accessory barrel120has an opening130at a distal end132to permit movement of gas in or out of accessory barrel120. Barrel120, unlike syringe barrel110, is meant only to confine movement of accessory plunger124and not to transfer fluid or gas. There may be more than one opening for gas release and accessory barrel120may also include one or more openings on a side of the accessory barrel120. Plungers114and124or stoppers116and128are mechanically attached by a connector134which may be a cord, line, string, wire, strap, band, chain, etc., which reaches from one plunger/stopper to the other by going over the sides of both barrels110and120. In the embodiment shown inFIG. 1, stoppers116and128are connected by connector134. Pulley structure136, where the mechanical attachment as defined above contacts the junction of the two barrels functions as a pulley device which may take on a number of configurations as shown in other embodiments of the present invention, described below. In the embodiment shown inFIG. 1, pulley structure136is merely an edge of a wall that is preferably smooth and rounded to provide for easy sliding movement of connector134. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

Syringe barrel and accessory barrel of the embodiment ofFIG. 1need not be the same size. Also, accessory, barrel can be much smaller in diameter and have portions removed to save material and still function as a guide for the reciprocating accessory plunger. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that can be operated with one hand and effects both aspiration and injection. The accessory barrel may be external to the syringe barrel, as shown inFIG. 1, or internal to the syringe barrel (not shown).

FIGS. 2A and 2Billustrate a syringe device200of another preferred embodiment of the present invention. Syringe device200ofFIGS. 2A and 2Bincludes a modified conventional syringe202made of plastic, glass, or other suitable material. On syringe202there is mounted a needle or cannula204having a hub206. Hypodermic needle or cannula204is held on syringe202by a conventional needle or cannula fitting208such as a Luer, Luer-Lok, etc. Syringe202includes a syringe barrel210with a finger flange212. A syringe plunger214inserted into syringe barrel210includes a stopper216, made from rubber or another flexible or tight-sealing material, and a thumb rest218. Conventional syringe202modified by addition of two guide supports220and222. A finger flange224is mounted on upper guide support222. Supports220and222provide a track for movement of a reciprocating accessory plunger226having a thumb rest228. Guide supports220and222function similarly to the accessory barrel of the embodiment shown in FIG.1. On a distal end of accessory plunger226there is a connector support230to which is connected a connector232and is also connected to syringe stopper216. The connector may be a cord, line, string, wire, strap, band, chain, etc. which contacts pulley device234mounted on syringe barrel210, creating a pulleyFIG. 2Bshows an opening236between guide supports220and syringe barrel210through which connector232may travel. A similar opening exists between upper guide support222and syringe barrel210. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

The guide supports of the embodiment ofFIGS. 2A and 2Bmay be external to the syringe barrel, as shown inFIGS. 2A and 2Bor located inside the syringe barrel (not shown).

FIG. 3illustrates a syringe device300of another preferred embodiment of the present invention. Syringe device300ofFIG. 3includes a modified conventional syringe302made of plastic, glass, or other suitable material. On syringe302there is mounted a needle or cannula304having a hub306. Hypodermic needle or cannula304is held on syringe302by a conventional needle or cannula fitting308such as a luer, Luer-Lok, etc. Syringe302includes a syringe barrel310with a finger flange312. A syringe plunger314inserted into syringe barrel310and includes a stopper316, made from rubber or another flexible or tight-sealing material, and a thumb rest318. Mounted on one side of syringe302is an accessory barrel320having a finger flange322. Finger flange322is effectively joined to syringe barrel310by accessory barrel320. Accessory barrel320provides for the movement of a reciprocating accessory plunger324having a thumb rest326and a stopper328which may be similar or different from stopper316. Barrels310and320may be integrated together by bonding, retaining bands, simultaneous extrusion, casting, gluing, or any other method of integrating components. Accessory barrel has an opening330at a distal end332to permit movement of gas in or out of accessory barrel320. Barrel320, unlike syringe barrel310, is meant only to confine the movement of accessory plunger324and not to transfer fluid or gas. Syringe plunger thumb rest318and accessory plunger thumb rest326are mechanically connected by a connector334, which may be a cord, line, string, wire, strap, band, chain, etc. A central pulley post336including extends proximally from where syringe barrel310and accessory barrel320join. Connector332extends over pulley post336and contacts pulley post336at a pulley device338, which may have a number of configurations as described below. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that can be operated with one hand and effects both aspiration and injection.

The syringe barrel and accessory barrel need not be the same size. Also, the accessory barrel may be much smaller in diameter and have portions removed to save material and still function as a guide for the reciprocating accessory plunger. The accessory barrel may be external to the syringe barrel, as shown inFIG. 3, or internal to the syringe barrel (not shown).

FIGS. 4A and 4Billustrate a syringe device400of another preferred embodiment of the present invention. Syringe device400ofFIGS. 4A and 4Bincludes a modified conventional syringe402made of plastic, glass, or other suitable material. On syringe402there is mounted a needle or cannula404having a hub406. Hypodermic needle or cannula404is held on syringe402by a conventional needle or cannula fitting408such as a luer, Luer-Lok, etc. Syringe402includes a syringe barrel410with a finger flange412. A syringe plunger414inserted into syringe barrel410includes a stopper416, made from rubber or another flexible or tight-sealing material, and a thumb rest418. Conventional syringe402modified by the addition of two guide supports420and422. A finger flange424is mounted on upper guide support422. Supports420and422provide a track for the movement of a reciprocating accessory plunger426having a thumb rest428. Guide supports420and422function similarly to the guide supports of the embodiment shown in FIG.2. On a distal end of accessory plunger426there is a sliding support430which slides along the outside of syringe barrel410. A connector432connects thumb rests418and428. Connector432may be a cord, line, string, wire, strap, band, chain, etc. A pulley post434extends proximally from where syringe barrel410and upper guide support422are joined. Connector432extends over pulley post434and contacts pulley post434at a pulley device436, which can have a number of configurations as described below.FIG. 4Bshows an opening438between guide supports420and syringe barrel410through which connector432may travel. A similar opening exists between upper guide support422and syringe barrel410. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

The guide supports of the embodiment ofFIGS. 4A and 4Bmay be external to the syringe barrel, as shown inFIGS. 4A and 4B, or located inside the syringe barrel (not shown).

FIGS. 5A and 5Billustrate a syringe device500of another preferred embodiment of the present invention. Syringe device500ofFIGS. 5A and 5Bincludes a modified conventional syringe502made of plastic, glass, or other suitable material. On syringe502there is mounted a needle or cannula504having a hub506. Hypodermic needle or cannula504is held on syringe502by a conventional needle or cannula fitting508such as a Luer, Luer-Lok, etc. Syringe502includes a syringe barrel510with two finger flanges512and514. A syringe plunger516inserted into syringe barrel510includes a stopper518, made from rubber or another flexible or tight-sealing material, and a thumb rest520. Adjacent to finger flange514is a pulley post522extending proximally from syringe502. A slider524has a thumb rest526and opening528, shown inFIG. 5B, which allows slider524to slide up and down pulley post522. A connector530connects syringe thumb rest520and slider thumb rest526. Connector530may be a cord, line, string, wire, strap, band, chain, etc. Connector530extends over pulley post522and contacts pulley post522at a pulley device532, which may have a number of configurations as described below. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

FIG. 6illustrates a syringe device600of another preferred embodiment of the present invention. Syringe device600ofFIG. 6includes a modified conventional syringe602made of plastic, glass, or other suitable material. On syringe602there is mounted a needle or cannula604having a hub606. Hypodermic needle or cannula604is held on syringe602by a conventional needle or cannula fitting608such as a luer, Luer-Lok, etc. Syringe602includes a syringe barrel610with two finger flanges612and614. A syringe plunger616inserted into syringe barrel610includes a stopper618, made from rubber or another flexible or tight-sealing material, and a thumb rest620. Mounted on one side of syringe barrel610between two finger flanges612and614is a pulley post622. Mounted on pulley post622are a distal pulley624and a proximal pulley626. Thumb rest620includes a neck portion (not shown inFIG. 6) which extends thumb rest620out of the plane of syringe barrel610, so that thumb rest620is in substantially the same plane as pulleys624and626. A belt connector628travels over both pulleys624and626. Syringe plunger thumb rest620and a reciprocating thumb rest630are both mechanically attached to belt connector630on parallel strands632and634of belt connector630by conventional means such as glue, interlocking notches on belt connector630and thumb rests620and630, and other known means. Reciprocating thumb rest630is substantially in the same plane as the syringe plunger thumb rest620and pulleys624and626. The engagement between the pulleys and the belt connector may take a number of forms as described below. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

FIGS. 7A through 7Fillustrate some of the configurations the pulley devices of the present invention may have.FIG. 7Aillustrates a pulley device702of the present invention which is a round smooth edge of the side of a syringe barrel (not shown) or a pulley post (not shown) over which a connector704slides.FIG. 7Billustrates a pulley device712of the present invention which is a smooth or groove tip of plastic, metal or other low-friction material mounted on a flat surface of a support714.FIG. 7Cillustrates a pulley device722of the present invention which is a hole or grommet, drilled or inserted in a post724. Hole or grommet may be made of plastic, metal, or other low-friction materials. Hole or grommet may either be straight (shown) or curved (not shown).FIG. 7Dillustrates a pulley device732of the present invention which is a tip cover, grooved or curved-columnar and made of plastic, metal, or low friction material, mounted on a curved support734.FIG. 7Eillustrates a pulley device742of the present invention which is a rotating pulley with a central pin or axle744which engages a connector746that may be a cord, belt, chain, etc.FIG. 7Fillustrates a pulley device752of the present invention which is a rotating gear pulley that rotates on a central pin or axle754and engages a connector756that may be chain, notched cord, etc.

FIG. 8illustrates a syringe device800of another preferred embodiment of the present invention. Syringe device800ofFIG. 8includes a modified conventional syringe802made of plastic, glass, or other suitable material. On syringe802there is mounted a needle or cannula804having a hub806. Hypodermic needle or cannula804is held on syringe802by a conventional needle or cannula fitting808such as a luer, Luer-Lok, etc syringe802includes a syringe barrel810with two finger flanges812and814. A syringe plunger816inserted into syringe barrel810includes a stopper818, made from rubber or another flexible or tight-sealing material, and a thumb rest820. Syringe plunger includes teeth or notches822on one side. An reciprocating accessory plunger824is located on the outside of syringe barrel810and includes teeth or notches826on one side and a thumb rest828at the proximal end of accessory plunger824. A gear pulley post830is mounted on and extends proximally from syringe barrel810. Mounted on gear pulley post830is a gear pulley832, which engages teeth822and826on syringe plunger816and accessory plunger824, respectively. A proximal retaining band834is fixed to pulley post830or syringe barrel810and surrounds syringe plunger816and accessory plunger824permitting plungers816and824to move along defined tracks and keeping teeth822and826of plungers816and824, respectively in contact with gear pulley832. A distal retaining band836is fixed to accessory plunger824and surrounds syringe barrel810, and further defines the track of accessory plunger824. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

FIGS. 9A and 9Billustrate another syringe device900of a preferred embodiment of the present invention. Syringe device900ofFIGS. 9A and 9Bincludes a modified conventional syringe902made of plastic, glass, or other suitable material. On syringe902there is mounted a needle or cannula904having a hub906. Hypodermic needle or cannula904is held on syringe902by a conventional needle or cannula fitting908such as a luer, Luer-Lok, etc. Syringe902includes a syringe barrel910with two finger flanges912and914. A syringe plunger916inserted into syringe barrel910includes a stopper918, made from rubber or another flexible or tight-sealing material. Mounted on one side of syringe barrel910is a gear pulley920, which is free to rotate. A supplementary plunger922having a thumb rest924is attached to one side of syringe plunger916by a neck piece926, shown inFIG. 9B, so that supplementary plunger922is aligned with gear pulley920. Functionally, thumb rest924of supplementary plunger922acts as the thumb rest for syringe plunger916. Supplementary plunger922includes teeth or notches928on one side which engage teeth930of gear pulley920. An accessory plunger932located outside of syringe barrel910includes teeth934on one side which engage teeth930of gear pulley920. Accessory plunger932also includes a thumb rest936. A proximal retaining band938is fixed to syringe barrel910and surrounds plungers922and932permitting plungers922and932to move along defined tracks and keeping teeth928and934of plungers922and932, respectively in contact with gear pulley920. A distal retaining band940is fixed to accessory plunger932and surrounds syringe barrel910and further defines the track of accessory plunger932. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

FIGS. 10A and 10Billustrate another syringe device1000of a preferred embodiment of the present invention. Syringe device1000ofFIGS. 10A and 10Bincludes a modified conventional syringe1002made of plastic, glass, or other suitable material. On syringe1002there is mounted a needle or cannula1004having a hub1006. Hypodermic needle or cannula1004is held on syringe1002by a conventional needle or cannula fitting1008such as a luer, Luer-Lok, etc. Syringe1002includes a syringe barrel1010with two finger flanges1012and1014. A syringe plunger1016inserted into syringe barrel1010includes a stopper1018, made from rubber or another flexible or tight-sealing material. A U-tube1020having arms1022and1024is mounted on one side of syringe barrel1010. A supplementary plunger1026having a thumb rest1028is attached to one side of syringe plunger1016by a neck piece1030, shown inFIG. 10B, so that supplementary plunger1026is aligned with U-tube1020and so that supplementary plunger1026may travel in arm1022of U-tube1020. Functionally, thumb rest1028of supplementary plunger1026acts as the thumb rest for syringe plunger1016. An accessory plunger1032having a thumb rest1034travels in other arm1024of U-tube1020. Supplementary plunger1026and accessory plunger1032each include an end piece or stopper1036and1038, respectively, which may be made of a flexible material such as rubber. Between two end pieces1036and1038there is a connector material1040which causes one of plungers1026or1028to move proximally when the other plunger moves distally. In syringe device1000shown, connector material1040is a hydraulic fluid. However, connector material may also be a spring cable or other stiff, but flexible solid material which extends between the end pieces or is connected at each end to each of the end pieces of the syringe device. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that can be operated with one hand and effects both aspiration and injection.

FIG. 11illustrates another syringe device1100of a preferred embodiment of the present invention. Syringe device1100ofFIG. 11includes a modified conventional syringe1102made of plastic, glass, or other suitable material. On syringe1102there is mounted a needle or cannula1104having a hub1106. Hypodermic needle or cannula1104is held on syringe1102by a conventional needle or cannula fitting1108such as a luer, Luer-Lok, etc. Syringe1102includes a syringe barrel1110with a finger flange1112. A syringe plunger1116inserted into syringe barrel1110and includes a stopper1118, made from rubber or another flexible or tight-sealing material as well as a thumb rest1120. Mounted on one side of syringe barrel1110are a supplementary hydraulic chamber1122and an accessory hydraulic chamber1124filled with a hydraulic fluid1126. Supplementary hydraulic chamber1122is in hydraulic communication with accessory hydraulic chamber1124by means of an opening1128. A second finger flange1130for syringe device1100is mounted on accessory hydraulic chamber1124and is effectively mounted on syringe barrel1110by means of accessory hydraulic chamber1124and supplementary hydraulic chamber1122. A supplementary plunger1132is connected to syringe plunger1116by a neck1134and extends substantially parallel to syringe plunger1116. Supplementary plunger1132travels within supplementary hydraulic chamber1122and includes a stopper1136made of a flexible material such as rubber. An accessory plunger1138travels within accessory hydraulic chamber1124and includes a stopper1140made of a flexible material and a thumb rest1142. Pushing down on supplementary plunger1116forces hydraulic fluid1126from accessory hydraulic chamber1122into supplementary hydraulic chamber1122, thereby exerting pressure on distal face of supplementary stopper1138. This in turn forces supplementary stopper1136and attached supplementary plunger1132upwards so that a medication or other fluid1140may be aspirated into syringe barrel1110. Pushing down on syringe plunger1116when supplementary hydraulic 0chamber1122is full of hydraulic fluid1126forces fluid1142out of syringe barrel1110and, simultaneously, forces hydraulic fluid1126in supplementary hydraulic chamber1122into accessory hydraulic chamber1124. Although the syringe barrel, supplementary hydraulic chamber, and accessory hydraulic chamber are shown as being part of the same housing in the syringe device shown inFIG. 11, they may also be formed as separate units and attached together. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

FIG. 12illustrates another syringe device1200of a preferred embodiment of the present invention. Syringe device1200ofFIG. 12includes a modified conventional syringe1202made of plastic, glass, or other suitable material. On syringe1202there is mounted a needle or cannula1204having a hub1206. Hypodermic needle or cannula1204is held on syringe1202by a conventional needle or cannula fitting1208such as a luer, Luer-Lok, etc. Syringe1202includes a syringe barrel1210with a finger flange1212. A syringe plunger1216inserted into syringe barrel1210includes a lower stopper1218, made from rubber or another flexible or tight-sealing material, and a thumb rest1220. Mounted in syringe barrel1210is a barrel divider1222which divides syringe barrel1210into a lower chamber1224and an upper chamber1226. Syringe plunger1216extends through an opening (not shown) in barrel divider1222and lower stopper1218abuts against a bottom surface of the barrel divider1222when syringe plunger1216is fully retracted, as shown in FIG.12. An upper stopper1228is also mounted on syringe plunger1216and slides within and acts as a movable upper seal for upper chamber1226. Upper stopper1228is preferably made of a flexible material similar to that of lower stopper1218. Upper chamber1226is connected by a passageway1230to an accessory hydraulic chamber1232. A second finger flange1234for syringe device1200is mounted on accessory hydraulic chamber1232and is effectively mounted on syringe barrel1210by means of accessory hydraulic chamber1232. An accessory plunger1236travels within accessory hydraulic chamber1230and includes a stopper1238made of a flexible material and a thumb rest1240. A hydraulic fluid1240fills upper chamber1228, passageway1230, and accessory hydraulic chamber1232. Pushing down on accessory plunger1236forces hydraulic fluid1240from accessory hydraulic chamber1232into upper chamber1224, thereby exerting pressure on a distal surface1242of upper stopper1228. This in turn forces stopper1228and attached syringe plunger1216upwards so that a fluid or medication1242may be aspirated into lower chamber1224. Pushing down on syringe plunger1216when upper chamber1226is full of hydraulic fluid1240as shown inFIG. 12forces fluid1242out of lower chamber1224and, simultaneously, forces hydraulic fluid1240in upper chamber1236and into accessory hydraulic chamber1232. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

Although the accessory chamber and syringe barrel are shown as being separated in the syringe device ofFIG. 12, the accessory chamber may also be mounted directly on the syringe barrel.

FIG. 13illustrates another syringe device1300of a preferred embodiment of the present invention. Syringe device1300ofFIG. 13includes a modified conventional first syringe1302made of plastic, glass, or other suitable material. On first syringe1302there is mounted a first needle or cannula1304having a first hub1306. Hypodermic first needle or cannula1304is held on first syringe1302by a conventional first needle or cannula fitting1308such as a luer, Luer-Lok, etc. First syringe1302includes a first syringe barrel1310with a first finger flange1312. A first syringe plunger1314inserted into first syringe barrel1310includes a first stopper1316, made from rubber or another flexible or tight-sealing material, and a thumb rest1316. First syringe stopper1316divides syringe barrel1310into a first lower chamber1320and a first upper chamber1322which each changing in size as first syringe plunger1314moves within syringe barrel1310. A fluid tight seal1324seals a top of first upper chamber1322and includes an opening (not shown) through which first syringe plunger1314extends. Mounted on a side of first syringe1302is a second syringe1332. On second syringe1332there is mounted a second needle or cannula1334having a second hub1336. Second hypodermic needle or cannula1334is held on second syringe1332by a conventional second needle or cannula fitting1338such as a luer, Luer-Lok, etc. Second syringe1332includes a second syringe barrel1340with a second finger flange1342. A second syringe plunger1344inserted into second syringe barrel1340includes a second stopper1346, made from rubber or another flexible or tight-sealing material, and a thumb rest1348. Second syringe stopper1342divides second syringe barrel1330into a second lower chamber1350and a second upper chamber1352which each change in size as second syringe plunger1336moves within second syringe barrel1330. At a top of second upper chamber1352is a fluid tight seal1354which seals the top of second upper chamber1352and includes an opening (not shown) through which second syringe plunger1336extends. First upper chamber1322and second upper chamber1352are in fluid communication by means of an opening1356between chambers1322and1352. Chambers1322and1352are filled with a hydraulic fluid1358. Pulling up on first plunger1314aspirates a first medication or fluid1360into first lower chamber1320and, simultaneously, forces hydraulic fluid1358from first upper chamber1322into second upper chamber1352. Thus, pressure is exerted on a proximal surface1362of second stopper1346, forcing second stopper1346and attached second syringe plunger1344downwards so that a second medication or fluid1364is forced from second lower chamber1350. Pulling up on second plunger1336aspirates additional second fluid1364into second lower chamber1350and, simultaneously, forces hydraulic fluid1358from second upper chamber1352into first upper chamber1322. Thus, pressure is exerted on a proximal surface1366of first stopper1316, forcing first stopper1316and attached first syringe plunger1314downwards so that the medication or fluid1360is forced from first lower chamber1320. The above-described mechanical arrangement results in a reciprocating, thumb-operated, double-plunger syringe device that may be operated with one hand and effects both aspiration and injection.

Although the syringe device ofFIG. 13includes two syringes, one or the other of the two syringes may act as an accessory barrel and have a lower chamber which only contains air. In this situation, it may be desirable to provide a larger opening in the lower chamber of the accessory barrel so that the air in the lower chamber is free to escape.

The presence of two plungers in the syringe device of the present invention and the resulting movement of a user's thumb between the two plungers may result in temporary instability of the syringe. One option to minimize this is the use of a handle as shown inFIGS. 14A and 14B.FIGS. 14A and 14Billustrates another syringe device1400of the present invention having a syringe1402and accessory chamber1404on which are mounted a gun-like handle1406and finger ring1408for a user's index finger that allow syringe device1402to be gripped more securely. Although finger flanges are shown in the syringe device shown inFIGS. 14A and 14B, it is not necessary to include such finger flanges in this embodiment, the finger ring functions similar to the finger flanges in the previously described embodiments of the present invention. Another option is the development of finger flanges with greater stability as shown inFIGS. 15A,15B, and15C. The most simple technique for stability is to exaggerate the size and surface area of the finger flange.FIGS. 15A,15B, and15C illustrate various types of finger flanges which may be used with syringe devices of the present invention.FIG. 15Aillustrates a syringe device1500having circular finger flanges1502FIG. 15Billustrates a syringe device1510having half-ring finger flanges1512.FIG. 15Cillustrates a syringe device1520having curvilinear flanges1522.

FIGS. 16A,16B,16C, and16D illustrate the use of another syringe device1600of the present invention. Syringe device1600includes a Syringe1602having two finger flanges1604and1606, a syringe plunger1608, a thumb rest1610, a reciprocating plunger1612, a thumb rest1614, a guide piece1616, an opening1618in finger flange1606through which reciprocating plunger1612extends, and a track1620on a side of syringe1602along which guide piece1616and attached reciprocating plunger1612moves. To aspirate, a user's fingers are placed on finger flanges1604and1606and the user's thumb is placed on thumb rest1614of reciprocating plunger1612as shown in FIG.16A. Thumb rest1614of reciprocating plunger1612is then squeezed between the fingers and thumb resulting in an effective aspiration and the generation of a powerful vacuum as shown in FIG.16B. The power result from use of forceful flexion of not only intrinsic muscles of the hand, but also powerful flexors of the forearm. Since the motion is smooth and in one direction, there is no rotation, twist, or other loss of control, resulting in a smooth aspiration with excellent control. For aspiration procedures in which a syringe must be held still during the procedure, the syringe of the present invention has special advantages as the barrel of the syringe does not advance beyond the plane of the digits of the hand. Thus, creating an extremely stable platform. Injection with the syringe of the present invention is identical to that of a standard syringe, using powerful flexor muscles of the hand and forearm. Injection with this aspiration syringe may be easily accomplished with one hand, freeing up the other hand for other necessary tasks or procedures. In this technique, the 2nd (index) and 3rd fingers (middle finger) remain on finger flange1604of syringe1602and the thumb is moved laterally from thumb rest1614of reciprocating plunger1612to thumb rest1610of syringe plunger1608, as shown in FIG.16C. Flange1604and thumb rest1614are brought together due to contraction of the powerful flexor muscles of the hand and forearm resulting in an effective injection with all the power of a conventional syringe as shown in FIG.16D.

Any of the above-described reciprocating syringes of the present invention may be used as a pump by the addition of an external or integrated valve system consisting of two one-way valves as shown inFIGS. 17A and 17B.FIG. 17Ashows a syringe device1700of the present invention having a double one-way valve1702attached. Arrows1704show the direction of flow through the valve.FIG. 17Bshows a syringe device1710of the present invention having two, one-way valves1712and1714mounted on a syringe barrel1716. Value1714is mounted over and in communication with an opening1718at a distal end of syringe barrel1716. Valve1714is mounted over and in communication with an opening1720in a side wall1724of syringe barrel1716. Arrows1724show direction of flow. The direction of the one-way valves determines whether the syringe functions as an infusion or aspiration pump. An integrated valve system transforms the syringe into a dedicated pump. The valves themselves may be dedicated uni-directional, or may be adjustable: on-bi-directional, on-aspiration, on-infusion, or off, creating greater flexibility of the syringe pump device. These devices may also be used as a vacuum or pressure device for procedures, particularly if a distal pressure or vacuum chamber is added and the syringe is then used as a topping device.

Any of the previously described reciprocating devices: line driven, line-driven-pulley post, gear-driven, U-tube-driven, or hydraulic-driven, etc. may be used to drive a reciprocating, thumb-operated, double plunger syringe of the present invention having double functional barrels. Examples of double functional barrels are shown inFIGS. 18A and 18B, although the double functional barrel designs of the present invention also encompass using the reciprocating devices discussed previously for the single barrel designs of the present invention.

FIG. 18Ashows a double functional barrel syringe device1800having a line drive reciprocating device andFIG. 18Bshows a double functional barrel syringe device1810having a pulley post line drive reciprocating device. The double functional barrel syringe devices of the present invention may be used identically to the single functional barrel versions of the reciprocating syringes, both as an aspiration-injection syringe or as a pump. However, with two functional barrels, this design has special applications and efficiency as a pump. This results from the fact that the double functional barrel design permits twice the amount of volume to be transferred with a complete stroke cycle compared to the single functional barrel designs.

To function as a pump, the barrels may be fitted with unidirectional valves. The direction of the one-way valves determines whether the syringe functions as an infusion, aspiration, or irrigation pump. When the direction of the valve systems are opposite in the two barrels, an irrigation pump is created.FIG. 18Cshows a syringe device1820of the present invention having two double one-way valves1822and1824mounted on syringe device1820. Valves1822and1824operate in opposite directions shown by arrows1826, causing the syringe device1820to function as an irrigation pump.FIG. 18Dshows a syringe device1830comprising two syringes1832and1834. Syringe1832has a one-way valve1836mounted over and communication with an opening1838at a distal end of syringe1832and a one-way valve1840mounted over and communication with an opening1842in a wall of syringe1832. Syringe1834, which is mounted on syringe1832, has a one-way valve1844mounted over and in communication with an opening1846at a distal end of syringe1834and a one-way valve1848mounted over and in communication with an opening1850in a wall of syringe1834. Valves1836and1840of syringe1832operate in opposite direction to valves1844and1840of syringe1834, as shown by arrows1852, causing syringe device1830to function as a dedicated irrigation pump.

When the direction of the valve systems are in the same direction, either an aspiration or infusion pump is created, depending on the direction of the valves. An integrated valve system transforms the syringe into a dedicated pump. The valves themselves may be dedicated uni-directional, or may be adjustable: on-bi-directional, on-aspiration, on-infusion, or off, creating greater flexibility of the individual syringe pump device.

FIG. 18Eshows a syringe device1860of the present invention having two one-way valves1862and1864in which valves1862,1864operate in the same directions as shown by arrows1866. This causes syringe device1860to function as an aspiration pump.FIG. 18Fshows a syringe device1870comprising two syringes1872and1874. Syringe1872has a one-way valve1876mounted over and in communication with an opening1878at a distal end of syringe1862and a one-way valve1880mounted over and in communication with an opening1882in a wall of syringe1872. Syringe1874, which is mounted on syringe1872, has a one-way valve1884mounted over and in communication with an opening1886at a distal end of syringe1874and a one-way valve1888mounted over and in communication with an opening1890in a wall of syringe1874. Valves1876and1880of syringe1872operate in the same direction as valves1884and1888of syringe1874, as shown by arrows1892, thus, causing syringe device1860to function as a dedicated aspiration pump. These devices may also be used as a vacuum or pressure device for procedures, particularly if a distal pressure or vacuum chamber is added and the syringe is then used as a topping device.

The reciprocating syringe device of the present invention has the following advantages over conventional syringes: 1) single-handed aspiration may be accomplished easily; 2) injection is performed identically to aspiration with only a change in the thumb position while the index and middle fingers do not change position; 3) the other hand is freed and may be used for other tasks; 4) the power of the aspiration is maximized by the use of hand and forearm flexors rather than weak extensors of the thumb; 5) exquisite control of the syringe is maintained because it is gripped by fingers and not the palm; 6) there is no rotational twist during forceful movement of the plunger resulting in markedly improved performance over other single-handed aspiration techniques; 7) the same hand grip position may be used throughout the aspiration/injection cycles unlike other single-hand techniques; 8) for procedures that require constant aspiration with one hand, this syringe is ideal because it may be held in an aspiration position with or without a locking device; 9) both single functional barrel and double functional barrel versions may be converted into single-hand-held pumps by the addition of unidirectional valves; and 10) reciprocating, thumb-operated, double-plunger syringe for single-handed use of all sizes: 1, 3, 5, 10, 20, 60 cc; may be constructed with the same effectiveness. For the above reasons, syringes of the present invention are clearly superior to other single-handed devices currently in use.

Although the above-described embodiments of the present invention are manually operated, syringes of the present invention may also be mechanically, motor, electrically, or computer-driven or controlled devices. For example, in a syringe device of the present invention having two barrels and one or more valves associated with each barrel, the reciprocal motion of the plungers for each of the barrels may be controlled with a crankshaft-like device which pushes one plunger down as it pulls the other plunger up. Such a crankshaft-like device may be powered in a variety of ways and such a crankshaft device may be used to operate all of the plungers in syringe device of the present invention having multiple barrels. In embodiments of the present invention which are not manually operated, finger flanges shown in the above-described manually operated embodiments may be eliminated and syringe barrel, barrels, guide tracks, etc,. may be held in place relative to the plunger, plungers, reciprocating members, etc., by other means, such as mounting the syringe barrel in place.

Although in the above-described embodiments of the syringe device have been primarily described as being used as a medical device, this device may also be used in other applications such as industrial applications, automotive applications, etc.

Finally, the present invention has been fully described in conjunction with the preferred embodiment thereof with reference to the accompanying drawings, it is to be understood that various changes and modifications may be apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom.