Abstract:
A syringe includes a barrel defining a liquid chamber, an aperture and two or more contents indicators; a plunger movable within said barrel whereby movement of the plunger in a first direction causes the liquid chamber to fill with a fluid and movement by the plunger in a second direction causes fluid to be expelled from the liquid chamber through the aperture; and a selecting mechanism disposed on the barrel that is actuated to select only one of the contents indicators.

Description:
FIELD OF INVENTION 
       [0001]    This invention relates to syringes and more particularly to syringes provided with selectable indicia of contents. 
       BACKGROUND OF THE INVENTION 
       [0002]    Syringes are used in various medical procedures for introducing fluids into vessels, cavities or medical devices, e.g. catheters or other access devices. Virtually any liquid can be introduced via a syringe, including a large selection of liquids introduced into a patient for therapeutic purposes, e.g. liquid medications. 
         [0003]    Once a liquid is contained within the barrel of a syringe, it can be difficult to determine accurately and quickly the identity of the liquid. Many liquids introduced via syringe are weak solutions containing primarily water, and are thus visually indistinguishable from each other. In addition, it is usually of critical importance to know what liquid is being introduced and to avoid the introduction of other liquids. The amount of a particular liquid to be introduced is also usually critical. The possibility of confusion coupled with the adverse consequences that could result for the administration of the wrong medicine requires the proper identification of a fluid to be introduced into a patient. 
         [0004]    U.S. Patent Application Publication No. 2004/0186437 discloses a syringe structure for identifying the contents of the syringe by printing on the barrel or plunger of the syringe. Similarly, U.S. Pat. No. 6,315,760 discloses a coating applied to the outer surface of the syringe barrel, where the coating may be inscribed with contents identification using a pen or marker. 
         [0005]    Accordingly, there is a need for simple, convenient, inexpensive structure and method of identifying the contents of a syringe without having to choose a particular barrel or plunger beforehand or requiring the recording of contents using a pen. 
       SUMMARY OF THE INVENTION 
       [0006]    A syringe according to an exemplary embodiment of the invention includes a barrel defining a liquid chamber, an aperture and two or more contents indicators; a plunger movable within said barrel whereby movement of the plunger in a first direction causes the liquid chamber to fill with a fluid and movement by the plunger in a second direction causes fluid to be expelled from the liquid chamber through the aperture; and a selecting mechanism disposed on the barrel that is actuated to select only one of the contents indicators. 
         [0007]    In a preferred embodiment, the syringe has a selecting mechanism comprising a collar that is attached axially around the barrel. The collar in this preferred embodiment may further comprise a window portion through which a portion of the barrel may be viewed, and wherein the portion of the barrel viewed has associated therewith a selected one of the contents indicators. One or more unselected contents indicators associated with the barrel of the syringe may be obscured by the collar. 
         [0008]    In another preferred embodiment, a proximal flange is disposed adjacent a proximal end of the barrel, the proximal flange having an aperture extending therethrough. The selecting mechanism includes a collar attached axially around the barrel and a proximally extending tab; and wherein the proximally extending tab extends into the aperture of the proximal flange and engages the proximal flange. The engagement of the proximally extending tab and the proximal flange acts to retain the collar in rotational engagement with the barrel. 
         [0009]    The syringe may also be provided with a pair of finger flanges extending radially from a proximal flange disposed adjacent a proximal end of the barrel. 
         [0010]    The syringe, may also include a supplemental identification portion associated with the selecting mechanism. This supplemental identification portion may be marked on with pen or may receive stickers or other information conveying indicia. 
         [0011]    In an alternative embodiment, the syringe comprises a plunger; a barrel including a bore and a distal end having an aperture therethrough, the barrel having associated therewith two or more contents indicators, the barrel having further associated therewith a selecting mechanism that may be actuated such that the selecting mechanism identifies one of the contents indicators; and the barrel further comprising a locking tab capable of engaging a locking portion on the selecting mechanism, whereby the selecting mechanism may be locked in place after the appropriate contents indicator is identified. 
         [0012]    In a further alternative embodiment, the syringe comprises a barrel including a bore and a distal end having an aperture therethrough, a plunger comprising two or more contents indicators printed on the proximal end of the plunger stem, the proximal end of the plunger having further associated therewith a selecting mechanism that may be actuated such that the selecting mechanism identifies one of the contents indicators. 
         [0013]    These and other features of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of this invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Various exemplary embodiments of this invention will be described in detail, with reference to the following figures, wherein: 
           [0015]      FIG. 1  is a partially transparent perspective view showing the plunger and internal features of a syringe barrel according to an exemplary embodiment of the present invention; 
           [0016]      FIG. 2  is a partially transparent perspective view of the syringe of  FIG. 1  showing the plunger inserted fully into the barrel; 
           [0017]      FIG. 3  is a bottom perspective view of the syringe of  FIG. 1 ; 
           [0018]      FIG. 4  is an exploded partially transparent perspective view of a syringe according to an exemplary embodiment of the present invention; 
           [0019]      FIG. 5  is a perspective view showing of a syringe according to another exemplary embodiment of the present invention; 
           [0020]      FIG. 6  is a perspective view showing the bottom of the syringe of  FIG. 5 ; 
           [0021]      FIG. 7  is a perspective view of the syringe of  FIG. 5  with the collar locked in place; 
           [0022]      FIG. 8  is an exploded partially transparent perspective view of the syringe of  FIG. 5 ; 
           [0023]      FIG. 8A  is a cross sectional view of contents indicator sleeve  60  taken along line A-A; 
           [0024]      FIG. 8B  is a cross sectional view of contents indicator sleeve  60  taken along line B-B; 
           [0025]      FIG. 9  is a perspective view showing a syringe according to another exemplary embodiment of the present invention; 
           [0026]      FIG. 10  is a perspective view of the syringe of  FIG. 9  with the contents indicator collar locked in place; 
           [0027]      FIG. 11  is a perspective view of a syringe according to another exemplary embodiment of the present invention with the contents indicator structure removed from the syringe barrel; 
           [0028]      FIG. 12  is a perspective view of the syringe of  FIG. 11  with the contents indicator collar disposed over the syringe barrel; and 
           [0029]      FIG. 13  is a perspective view of a syringe according to another exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0030]      FIG. 1  is a partially transparent perspective view of a syringe  10  according to an exemplary embodiment of the invention. The three basic components of syringe  10  are barrel  12 , plunger  14  and contents indicator collar  24 . Although portions of plunger  14  and internal features of barrel  12  are visible in  FIG. 1 , this does not necessarily mean that they would be visible in a physical embodiment of the syringe, i.e. structures of syringe  10  may be of a transparent material or of an opaque material. 
         [0031]    Plunger  14  fits in the central bore  13  of barrel  12 . A sealing element  16  is attached to the distal end portion  18  of plunger  14 . Sealing element  16  comes into sliding/sealing contact with the cylindrical inner wall of barrel  12 . The distal end of barrel  12 , the cylindrical inner wall of barrel  12 , and the sealing element  16  of plunger  14  define the portion of central bore  13  capable of containing a liquid to be delivered by the syringe  10 . The size of the liquid containing portion of central bore  13  may be varied by the sliding displacement of plunger  14  relative to barrel  12 . Thus, the liquid containing portion of central bore  13  can be varied in size from nearly the entire volume of central bore  13  to zero or nearly zero volume. 
         [0032]    Syringe  10  may contain a great variety of liquids. With the distal end portion  16  of plunger  14  in contact with the distal end of barrel  12  or nearly so, the liquid port  32  may be put into contact with a liquid source; withdrawal of the plunger by way of handle  30  will cause a vacuum in central bore  13 , thus causing liquid to fill the liquid containing portion of central bore  13  through liquid port  32 . Liquid is prevented from entering the non-liquid containing portion of central bore  13 , i.e. proximal of distal end portion  18 , by the sealing contact between sealing element  16  of plunger  14  and the inner wall of barrel  12 . 
         [0033]    When it is desired to deliver the liquid contained in the liquid containing portion of syringe  10 , handle  30  is compressed distally, causing plunger  14  to move distally and reduce the size of the liquid containing portion of central bore  13  thus creating a pressure that causes the liquid to exit liquid port  32 . Finger wings  22  are provided at the end of barrel  12  to allow a practitioner to accomplish this compression of handle  30  with a thumb and two fingers disposed distally of wings  22  in the standard syringe manner. 
         [0034]    The identity of the liquid contained in syringe  10  is often difficult or impossible to determine accurately using sensory perception. This being the case, the present invention provides a simple and accurate method of identifying the syringe contents. This identifying structure is both simple to use and requires a specific intent to change, such that alteration of this identification in an accidental manner is less likely. 
         [0035]    Contents indicator collar  24 , seen in  FIGS. 1-4 , includes a collar window  26 . Collar  24  may be rotated circumferentially about barrel  12  but is prevented from axial displacement by interaction between retention tab  42  and barrel flange  20 . As most clearly seen in  FIG. 4 , multiple contents indicator designations  28  may be printed on the external surface of barrel  12 . Each of these contents indicator designations  28  is sized to be easily readable through collar window  26 . 
         [0036]    Circumferential rotation of collar  24  results in displacement of collar window  26  and registration thereof with a different contents indicator designation  28 . Thus, a practitioner may fill the liquid containing portion of central bore  13  with a particular liquid, as described previously, and identify the contents of syringe  10  by rotating collar  28  such that collar window  26  is in registration with the appropriate contents indicator designation  28 . Alternatively, a practitioner may identify the contents of syringe  10  by rotating collar  28  such that collar window  26  is in registration with the appropriate contents indicator designation  28  and then fill the liquid containing portion of central bore  13  with the designated liquid. 
         [0037]    Selection tab  34  extends proximally from the proximal end of collar  24 . Selection tab  34  extends into selection slot  36  which is formed in barrel flange  20  which extends axially from the proximal end of barrel  12 . Selection slot  36  has disposed therein one or more selection cams  44 . Selection cams  44  prevent circumferential movement of selection tab  34  in selection slot  36  absent a significant rotational force exerted on collar  24 . In the absence of a significant rotational force, selection tab  34  will not displace relative to selection slot  36 . As a result of the restraining action of the selection cams  44 , collar  24  and collar window  26  cannot be easily accidentally displaced with respect to barrel  12 . When a significant rotational force is exerted on collar  24 , selection tab  34  may be caused to deflect and slide over a selection cam  44 . Once selection tab  34  has passed over a selection cam  44  it resiliently deflects back to its original shape, again preventing collar  24  from circumferential rotation without significant rotational force being exerted. Placement of the selection cams  44  and the terminal ends of slot  36  are chosen such that an unstressed selection tab  34  position corresponds to collar window  26  being in registration with a single contents indicator designation  28 . 
         [0038]    Retention tab  42 , as best seen in  FIGS. 3 and 4 , performs a dual role. The first role of retention tab  42  is to prevent axial displacement of contents indicator collar  24 , as discussed previously. The barrel flange  20  and plunger  14  may also be configured such that retention tab  42  prevents plunger  14  from being displaced proximally. Retention tab  42  engages plunger flange  46  when retention tab  42  is aligned with cut-out  48  in barrel flange  20 , as shown in  FIG. 3 . 
         [0039]    The retention tab  42 , plunger flange  46 , barrel flange  20 , and cut-out  48  structures may be used as a reminder to the practitioner to use the indicia mechanism of the present invention. Thus, examples of an appropriate contents indicator designation  28  when retention tab  42  is aligned with cut-out  48  include no designation, i.e. contents indicator designation  28  is left blank, or the words “Choose Syringe Contents” or the like are used. Only upon rotation of collar  24  and selection of a contents indicator designation will barrel flange  20  deflect retention tab  42  such that retention tab  42  no longer engages plunger flange  46 . Thus, collar  24  must be rotated before plunger  14  may be displaced proximally to fill syringe  10  with liquid. This requirement will increase the likelihood of the person filling the syringe first utilizing the contents indicia feature of the syringe of the present invention. 
         [0040]    In an alternative embodiment of the present invention, one contents indicator designation  28  may read “Turn Over” or similar language. The contents identification area  40  is an area on the contents indicator collar  24  capable of receiving written or other indicia of syringe  10  contents. Contents identification area  40  may be capable of receiving ink from a pen or marker, or may be capable of having a sticker attached thereto. Contents identification area  40  may be used as a ‘miscellaneous’ indicator of syringe contents, i.e. where the syringe contents in not one of the available contents indicator designations  28 . Contents identification area  40  may also be utilized in combination with an available contents indicator designation  28  to record, for example, the concentration of the solution contained in the syringe or the identity of the person who filled the syringe or the time when the syringe was filled. The use of stickers, preprinted or color coded, in conjunction with the contents identification area  40  is an alternative to written information especially where the use of a pen is difficult or inadvisable. 
         [0041]    An alternative embodiment of the present invention is shown in  FIGS. 5-8 . This alternative embodiment seeks more positive and permanent locking of the contents indicator collar  24  once a contents indicator designation  28  has been chosen. 
         [0042]      FIG. 5  illustrates the position of the contents indicator collar  24  when supplied to the medical professional, i.e. the collar  24  is disposed distally of the contents indicator designations  28 . The practitioner chooses a contents indicator designation  28  utilizing the collar index notch  27 . Once a contents indicator designation  28  is chosen, collar  24  may be slid axially along the barrel  12  of syringe  10  in the proximal direction. Once the collar  24  abuts the finger wings  22  and barrel flange  20 , as seen in  FIGS. 7 , the collar  24  is locked in place and the appropriate contents indicator designation  28  appears in collar window  26 . 
         [0043]    In this alternative embodiment, collar  24  may not be moved, either axially or rotationally, once it is locked in place. This prevents inadvertent alteration of the contents indicator designation  28 . In addition, collar  24  must be locked in place prior to filling the syringe  10 . These functions are accomplished utilizing specialized structures associated with the contents indicator sleeve  60 . A plurality of tab engagement grooves  74  are provided on the inside surface of collar  24 . Each tab engagement groove  74  is indexed to a contents indicator designation  28 . As will be further discussed below, locking tab  72  enters into the tab engagement groove  74  indexed to the contents indicator designation  28  chosen by the person filling the syringe  10 . 
         [0044]    Contents indicator sleeve  60  is disclosed in  FIG. 8  and in two cross sections in  FIGS. 8A and 8B . Contents indicator sleeve  60  fits over barrel  12  and is retained on barrel  12  through any standard engagement method such as adhesive, welding, interference fit or the like. Tabs  82  and holes  78  are utilized to assure proper alignment of indicator sleeve  60  and to assist in retention thereof on barrel  12 . 
         [0045]    Contents indicator sleeve  60  also has an arm  64 . Arm  64  has several tabs along its length. At the extreme proximal end of arm  64  is plunger flange engagement tab  66 , which extends through barrel flange notch  80  and engages plunger flange  46  and prevents withdrawal of plunger  14  from barrel  12 . That is, plunger flange engagement tab  66  in its unstressed position, shown in  FIG. 8 , prevents filling of syringe  10  by engaging with plunger flange  46  and preventing movement of plunger  14 . 
         [0046]    Adjacent the distal end of contents indicator sleeve  60  on the arm  64  is retention tab  70 . Retention tab  70  retains collar  24  on contents indicator sleeve  60 , i.e. retention tab  70  prevents collar  24  from movement distally of the distal end of contents indicator sleeve  60 . Retention tab  70  retains collar  24  by engaging a portion of tab engagement grooves  74  disposed on the inside surface of collar  24 . Between plunger flange engagement tab  66  and retention tab  70  on the arm  64  is locking tab  72 . Locking tab  72  locks collar  24  in place when the appropriate contents indicator designation has been chosen and the collar  24  has been moved proximally from the position shown in  FIG. 5  to the position shown in  FIG. 7 , as discussed previously. Locking tab  72  interacts with tab engagement groove  74  on the inner surface of collar  24 . The engagement between locking tab  72  and tab engagement groove  74  prevents any relative movement between collar  24  and contents indicator sleeve  60 , whether axial or rotational. Thus, collar  24  is permanently locked into position once locking tab  72  engages tab engagement groove  74 . 
         [0047]    Another function of locking tab  72  and tab engagement groove  74  is to cause the disengagement of plunger flange engagement tab  66  from plunger flange  46  and, thus, allow operation of the syringe  10 . As seen in  FIGS. 6 and 8 , locking tab  72  is located between the ends of arm  64 . Before the appropriate contents indicator designation  28  is chosen and collar  24  is slid proximally along indicator sleeve  60 , plunger flange engagement tab prevents withdrawal of plunger  14  though blocking plunger flange  46 . However, when collar  24  is moved proximally with respect to contents indicator sleeve  60 , locking tab  72  enters one of several available tab engagement grooves  74 , as shown in  FIG. 6 . Each tab engagement groove  74  is dimensioned such that a radial force is exerted on locking tab  72  as collar  24  is slid radially. The force on locking tab  72  and engagement of cantilever element  68  with the barrel  12  causes plunger flange engagement tab  66  to flex away from the plunger. This flexing of plunger flange engagement tab  66  causes it to cease blocking plunger flange  46 , thus allowing displacement of plunger  14  with respect to barrel  12 . Tab engagement groove  74  is dimensioned such that, even after locking tab  72  has locked collar  24  in position, a force remains on locking tab  72  such that plunger flange engagement tab  66  remains flexed away from plunger  14  such that it does not block plunger flange  46 . 
         [0048]      FIGS. 9 and 10  shown another exemplary embodiment of the present invention, in which collar  24  may be supplied with contents indicator designations  28  on the surface thereof. A contrasting background  90  may be printed on the barrel  12  or on the contents indicator sleeve  60 . In this embodiment, collar  24  must be at least partially transparent. When the appropriate contents indicator designation  28  is indexed with the contrasting background  90 , taking the place of the contents indicator window  26 , the chosen contents indicator designation  28  is shown in a contrasting relationship to the non-chosen contents indicators. 
         [0049]    Another exemplary embodiment of the present invention is disclosed in  FIGS. 11 and 12 . In this embodiment, instead of providing multiple contents indicator designations  28  associated with the barrel or contents indicator sleeve, a selection of preprinted contents indicator collars  100  is provided. Each preprinted collar  100  has an opening  102  allowing the preprinted collar  100  to be snapped over barrel  12 . This embodiment may be used with either specialized syringes  10  or with generic syringes. Different sizes of preprinted collars, each size capable of being preprinted with a large assortment of contents indicators, may be sold to accommodate most syringe sizes. 
         [0050]    Another feature that may be utilized with any of the contents indicator syringes-described herein is the ability to provide guidewire access. As most completely disclosed in  FIGS. 4 and 8 , a bore  33  may be formed along the entire length of plunger  14 . This bore  33  extents from an entrance point  31 , through the entire length of the plunger  31 , and then through distal end portion  18  and sliding element  16  of plunger  14 . This bore  33  may be used to feed a guidewire through the syringe  10 ; syringe  10  provides access to the patient for a guidewire (not shown). 
         [0051]      FIG. 13  discloses an alternative structure for syringe  10 . Collar  24  may also circumferentially engage plunger  14 . In this alternative embodiment, contents indicator designations  28  are associated with the cylindrical surface adjacent the proximal end of plunger  14 . Collar  24  engages plunger  14  in such a way that window  26  may be rotated to overlie one of contents indicator designations  28 . Selection slot  36  is located in handle  30  of plunger  14 . Selection tab  34  extends from the proximal end of collar  24  and engages selection cams  44  in selection slot  36 . These elements operate in the same manner as discussed previously. 
         [0052]    In its most general structure, the contents indicator takes the form of any actuatable structural element that may be actuated from one position to another in order to select one of a plurality of contents indicator designations. Examples have been provided above but are not limiting. Other non-limiting examples include: (i) an axially sliding contents indicator that can be actuated to select one of a plurality of contents indicator designations; (ii) an arrow like contents indicator that can be actuated to select one of a plurality of contents indicator designations; and (iii) a set of actuatable shutters that can be actuated to obscure the non-selected contents indicator designations, leaving only the selected one of the plurality of contents indicators viewable. 
         [0053]    Now that the preferred embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be construed broadly and limited only by the appended claims, and not by the foregoing specification.