Abstract:
Disclosed is a safety catheter that automatically sheaths the needle upon withdrawal of the needle from a patient. The catheter can include a plunger for drawing a vacuum to draw blood or alternatively may delete the plunger and use nearly identical components with the addition of a blocking plug. The catheter also includes a cap/re-cap device that provides additional sheathing of the needle during assembly, shipping, and use of the needle. It also includes raised indicia that serves as a trademark as well as a friction gripping surface. The catheter includes improved catheter hub mounting structure as well as strengthened ribbed areas for grasping during use of the catheter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation of application Ser. No. 09/477,213, filed Jan. 4, 2000, now U.S. Pat. No. 6,156,015, which is a continuation of application Ser. No. 09/102,467, filed Jun. 22, 1998, now U.S. Pat. No. 6,010,487, which is a continuation of application Ser. No. 08/823,830, filed Mar. 25, 1997, now U.S. Pat. No. 5,769,827, which is a continuation of application Ser. No. 08/296,329, filed Aug. 25, 1994 now abandoned. Each application identified above is incorporated here by reference in its entirety. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    NOT APPLICABLE  
         BACKGROUND OF THE INVENTION  
         [0003]    This invention relates to safety needles of the type used to puncture the skin of patients. More particularly, this invention relates to intravenous catheters that protect the needle both before use and upon withdrawal from a patient.  
           [0004]    Safety needles and catheters are old in the art. For example, safety catheters are disclosed in: (1) U.S. Pat. No. 4,834,718 (“the &#39;718 patent”) issued on May 30, 1989, to Michael McDonald; and (2) U.S. Pat. No. 4,944,725 (“the &#39;725 patent”), issued on Jul. 31, 1990, to Michael McDonald. Mr. McDonald is one of the inventors of the present invention in this application.  
           [0005]    The catheter in the &#39;718 patent was the first catheter to provide convenient, reliable, economical, and automatic sheathing of the needle upon withdrawal of the needle from the patient. The &#39;725 patent discloses improvements to Mr. McDonald&#39;s first patented structure in the &#39;718 patent. The applicants hereby incorporate by reference the complete disclosures of the &#39;718 and &#39;725 patents.  
           [0006]    The structures shown in the &#39;718 and &#39;725 patents were significant advances in the art. They included “flash back” chambers to determine, by relatively small sliding movement of an outer housing away from the catheter, whether the vein had been punctured sufficiently so that blood would flow through the catheter and needle into the flash back chamber where the blood could be seen at the back of the housing.  
           [0007]    These prior structures, however, were not as effective in drawing blood into the flash back chamber when used on trauma patients with very low blood pressure. For these types of patients, the blood pressure of the patient can be too low to force blood through the catheter and needle into the flash back chamber in the housing. These prior art devices did not provide any way to draw a substantial vacuum in the housing in order to draw blood from the trauma patient into the flash back chamber when the needle and associated catheter penetrate the vein of the patient.  
           [0008]    Other safety needles in the art have employed plungers penetrating the back of the needle housing to draw a vacuum in the housing. None of these prior art structures, however, have provided such a vacuum plunger for the McDonald safety needles shown in the &#39;718 and &#39;725 patents.  
           [0009]    Another problem with the prior art safety catheters and needles is the lack of capping structure for complete capping of the entire needle and catheter during assembly, shipping, and pre-use handling. Thus, the prior art catheters and needles such as shown in the &#39;718 and &#39;725 patents provided an exposed needle during needle assembly and shipping. The needles are also exposed when removed from their packaging and prior to actual alignment for injection into the patient. This brings about risk of inadvertent needle sticks to manufacturers and needle operators, and subsequent inappropriate use of the same needles on patients. Accidental needle sticks can have dire consequences and have long been recognized as a great problem in the industry and, indeed, in society in general.  
           [0010]    Needles such those shown in the &#39;718 patent and &#39;725 patent do sheath the needle upon withdrawal from the patient. This provides the great advantage of automatic sheathing and protection against needle sticks upon withdrawal, but it leaves the operator without the comfort of having taken any action on his or her own to cover the needle. Existing paramedics, nurses, and doctors in the field are often accustomed to the prior art devices that do not automatically sheath the needle upon withdrawal from the patient. These types of operators are often most comfortable with capping of the needle whether it is necessary or not. The prior safety catheters of the &#39;718 and &#39;725 patents, and other safety catheters in the prior art, did not provide any such additional capping feature, probably because it appears to be unnecessary. It is often necessary, in fact, however, since such a cap can put certain types of operators at ease and reduce their reluctance to use a safety needle such as that shown in the &#39;718 and &#39;725 patents.  
           [0011]    The prior McDonald safety catheters of the &#39;718 and &#39;725 patents incorporated needle hub design that had a reduced and thin neck (shown as number  36  in FIG. 1 of the &#39;718 patent). This neck is easy for the operator to grasp and hold in place with one hand while simultaneously, with the other hand, pulling back on the outer housing and thus automatically sheathing the needle within the needle housing. The reduced diameter neck is relatively weak, however, and may be subject to breakage when in use out in the field.  
           [0012]    Finally, the prior McDonald safety catheter employed a cylindrical outer housing with a smooth, transparent plastic surface. The operator grasps and pushes and pulls on the this smooth surface when using the device out in the field. Although this cylindrical transparent design is particularly effective and reliable for a number of reasons, the operator&#39;s fingers can slip on the smooth surface, particularly when wet, and risk puncturing the patient incorrectly or at least not as accurately as desired. An incorrectly positioned needle puncture, which misses the vein or goes through it, can be painful and cause bleeding.  
         OBJECTS OF THE INVENTION  
         [0013]    It is therefore an object of the present invention to develop a safety catheter and needle that develops a vacuum to draw blood into the flash back chamber when the needle is used on trauma patients having low blood pressure.  
           [0014]    It is yet another object of the present invention to develop such a safety catheter and needle that provides protection against accidental needle sticks during needle and catheter assembly and shipping.  
           [0015]    A further object is to provide a needle that also protects against accidental sticks upon opening of the needle package, removal of the needle from the package, and pre-use manipulation of the needle and catheter.  
           [0016]    Another object is to provide a catheter and needle that also provides recapping structure to allow the operator to place an otherwise separate cap over the needle after its withdrawal from the patient.  
           [0017]    Yet another object is to provide a single cap structure that provides both pre-use capping and post-withdrawal capping of the needle.  
           [0018]    A still further object of the invention is to provide a catheter and needle housing that is less subject to slipping in the hands of a user while still being predominantly transparent and generally cylindrical for easy use and grasping.  
           [0019]    Another object is to provide a safety catheter that is stronger, and less subject to accidental breakage in use, than prior catheters and needles.  
           [0020]    An additional object is to provide a safety catheter that meets the prior objects while providing a safety catheter that is convenient, easy and economical to manufacture, assemble, and ship, slim yet sturdy, and easy to use and dispose of properly and safely.  
           [0021]    There are other objects that will become apparent as the specification proceeds.  
         SUMMARY OF THE INVENTION  
         [0022]    The foregoing objects and advantages are attained by our invention of an improved safety needle, preferably a catheter needle, that has an outer housing and an inner needle housing slidably mounted in the outer housing. The inner needle housing includes a catheter mounting end opposite the junction of the needle housing and the outer housing. Preferably, a removable cap, which is preferably frusto-conical, has one end mountable about the catheter mounting end and another end mountable on the outer housing. The cap can be mounted on the inner needle housing to protect against needle sticks during shipping of the inner needle housing and assembly of the catheter on the needle and the inner housing within the outer housing. The cap can then be reversed and mounted on the outer housing to protect against needle sticks during packaging, shipment, and pre-insertion manipulation of the catheter. Preferably, after withdrawal of the needle, the cap can be remounted on the outer housing to provide protection against accidental sticks after use of the needle and during disposal.  
           [0023]    The outer housing may include a plunger penetrating the outer housing on the side of the outer housing opposite the needle. The plunger is slidably mounted in the outer housing to draw a vacuum within the outer housing. Alternatively, the plunger may be omitted and the plunger passage blocked with a plug.  
           [0024]    The outer housing may also include a gripping friction surface which preferably results from embossing a trademark or suitable indicia on the outer surface of the outer housing. The inner needle housing may also include ribs or columns on the periphery of the needle housing to strengthen it while minimizing material use and providing grasping surfaces on the needle housing. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    The preferred embodiments of the applicants&#39; invention are depicted in the following drawings in which:  
         [0026]    [0026]FIG. 1 is an exploded isometric view of the major components of the preferred catheter embodiment having a plunger, a separable needle cap, and an embossed trademark/friction surface on the outer housing;  
         [0027]    [0027]FIG. 2 is a partial plan view of the catheter needle of FIG. 1 after assembly and showing the plunger in partial cutaway within the housing;  
         [0028]    [0028]FIG. 3 is a partial cross-sectional view through section line  3 - 3  of FIG. 2, showing the indicia embossing of the outer wall of the outer housing;  
         [0029]    [0029]FIG. 4 is a cross-sectional view of the preferred plunger catheter showing the narrow end of the cap mounted on the inner needle housing to cover the needle during shipment and assembly;  
         [0030]    [0030]FIG. 5 is a cross-sectional view of the preferred plunger catheter showing the cap being removed from the inner needle housing after assembly of the inner needle housing within the outer housing of the catheter;  
         [0031]    [0031]FIG. 6 is a cross-sectional view of the preferred plunger catheter showing the cap inverted from the orientation of FIG. 5 and mounted on the outer housing to cover the catheter and needle during packaging, shipment, removal from the packaging by the user, and pre-use manipulation of the catheter;  
         [0032]    [0032]FIG. 7 is a cross-sectional view of the preferred plunger catheter showing removal of the cap from the outer housing prior to insertion of the needle and catheter into the patient;  
         [0033]    [0033]FIG. 8 is a cross-sectional view of the preferred plunger catheter showing the withdrawal of the needle from the patient and automatic sheathing of the needle within the inner needle housing;  
         [0034]    [0034]FIG. 9 is a cross-sectional view of the preferred plunger catheter showing the cap mounted once again on the outer housing to further protect the inner housing and needle within the inner housing; and  
         [0035]    [0035]FIG. 10 is a cross-section view of the preferred catheter without the plunger and with a flash back plug abutting and thus blocking the plunger passage in the back of the outer housing. 
     
    
       [0036]    This description of the preferred embodiment utilizes spacial orienting terms such as “back” and “outer.” It is to be understood that these terms are used for convenience of description and not themselves limiting or requiring a particular location in space.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0037]    Referring now to FIG. 1, the applicant&#39;s preferred plunger safety needle, generally  10 , has a plunger rod  12  and plunger  14 , a needle mounting cylinder  16 , a needle  18 , a catheter  20 , an inner needle housing  22 , an outer handle housing  24 , and a cap  26 . The plunger rod  12  consists of an “X” shaped plunger beam  28  extending perpendicularly from a planar plunger end cap  30 . The plunger beam  28  slidably penetrates the open end  31  of a cylindrical flash back chamber  32  on the interior of the needle mounting cylinder  16 ; and the needle  18  is mounted on the end of the needle mounting cylinder  16  opposite the open end  31  of the flash back chamber  32 .  
         [0038]    The needle mounting cylinder  16  slidably penetrates an open passage  34  in the needle housing  22 . In turn, the needle housing  22 , the needle mounting cylinder  16 , plunger rod  12 , and plunger  14  are mounted within the generally cylindrical interior wall  36  of the outer handle housing  24 . The plunger beam  28  of the plunger rod  12  slidably penetrates and abuts the “X” shaped plunger passage  38  cooperatively provided by the mating upper  40  and lower  42  halves of the handle housing  24  when sonically welded together with the needle housing  22  and the associated structure assembled within the handle housing  24 .  
         [0039]    The plunger rod  12  is thus slidably mounted in the plunger passage  38  to slidably penetrate the cylindrical flash back chamber  32  within the needle mounting cylinder  16 . In turn, the substantially cylindrical needle housing  22  slidably penetrates a housing passage  44  provided within the interior wall  36  of the handle housing  24 .  
         [0040]    The catheter  20  has a skin penetration tube  46  coaxially extending from an expanded catheter hub  48 . The catheter hub  48  mounts on the catheter mount  50  extending from the needle housing  22 , and the cap  26  is mountable on the needle housing  22  or the handle housing  24  as explained below.  
         [0041]    Referring now to FIG. 2, the plunger beam  28  has a resilient plunger  14  mounted within and slidably abutting the interior wall  52  of the needle mounting cylinder  16 . Thus, when the plunger cap  30  is drawn away from the handle housing  24  and air cannot enter through the needle  18  (not shown in FIG. 2) into the interior vacuum space  54  within the needle mounting cylinder  16 , the plunger  14  slides within the mounting cylinder  16  in the same direction and simultaneously draws a vacuum in the interior vacuum space  54 . If the needle  18  has penetrated the vein of a patient (not shown) when the vacuum is drawn in the interior vacuum space  54 , blood is urged to flow from the vein, through the needle, and into the vacuum space  54 .  
         [0042]    The outer surface of the handle housing  24  includes trademark indicia  56 . With reference to FIG. 3, the indicia  56  projects from the outer surface of the housing  24 . The raised indicia  56  not only can identify the product and convey information about the product  10  but also can provide a surface that is more likely to cause greater friction in the hands of a user and less likely to result in slippage when in use. This is particularly helpful in an emergency, when sweaty palms and other fluids, including blood, etc., may otherwise render the outer surface of the handle housing  24  quite slippery. The preferred indicia  56  are cut into the molds for the needle housing  24  so that the indicia  24  are included into the transparent housing  24  automatically when molded. Other surface alteration or scoring may also be utilized.  
         [0043]    Referring now to FIG. 4, the cap  26  is frusto-conical and thus has a larger somewhat cylindrical end  58  opposite a narrower somewhat cylindrical end  60 . The cap is made out of resilient material, and its narrower end  60  is mountable on the narrowed cap mounting hub  62  on the needle housing  22 . The cap mounting hub  62  is intermediate the wider needle mounting housing central body  64  and the narrower raised column guard hub  66 . When mounted on the hub  62 , the cap  26  thus provides a protective shield around the needle  18  extending from the needle housing  22  when the needle mounting cylinder  16  is placed within the needle housing  22  as shown in FIG. 1. In this manner, the partial needle assembly  99  (consisting of the needle housing  22 , needle mounting cylinder  16 , needle  18 , and cap  26 ) can be shipped or moved from one assembling or manufacturing area to another with significantly reduced risk of any accidental needle stick to an assemblers, handlers, etc.  
         [0044]    With reference now to FIG. 5, the cap  26  is readily removed by an operator. The partial needle assembly  99  can then be further assembled into the handle housing  24  as shown in FIG. 1.  
         [0045]    With the cap  26  removed, the next manufacturer can install the catheter  20  by sliding it over the needle  18  so that the catheter hub  48  mounts on the catheter mount  50 . The catheter mount  50  has a cylindrical mounting body  71  with diametrically opposed catheter hub engaging arms  72 ,  74  extending radially outwardly from the mounting body  71 . The catheter hub  48  has a radially extending detent or undercut  76  penetrating the cylindrical interior wall  78  of the catheter hub  48 .  
         [0046]    Referring now to FIG. 6, the catheter hub  48  mounts on the catheter mount  50  and is retained in place on the mount  50  by the radially extending arms  72 ,  74 , which penetrate the radially extending undercut  76  in the catheter hub  48 . The catheter hub  48  is made of resilient material and is held in place by the arms  72 ,  74  until the operator forces the catheter  20  off of the mount  50  until it is fully separated from the needle housing  22 .  
         [0047]    Still referring to FIG. 6, the larger end  58  of the cap  26  has an internal radial rib or lip  68 . The handle housing  24  has a mating radial detent  70  on the needle end  61  of the handle housing  24  opposite the plunger end cap  30  (not shown in FIG. 6). The larger end  58  of the cap  26  is mounted on the needle end  61  so that the cap&#39;s internal rib  68  abuts the radial detent  70  in the housing  24 . In this manner, the protective cap  26  is mounted on the handle housing  24  to extend from the housing  24  and surround the needle  18  and catheter  20 . The protective cap  26  once again provides a protective sheath around the needle  18  and catheter  20  to minimize accidental needle sticks during (i) further packaging, shipment, and handling of the packaging, (ii) opening of the packaging, and (iii) pre-use manipulation of the catheter  10  prior to actual use to puncture the skin of a patient.  
         [0048]    Referring now to FIG. 7, when the operator is ready to use the needle  18  and catheter  20 , the cap  26  may be pulled off of the handle housing  24  (not shown). The operator may now insert the needle  18  and catheter  20  into the patient as described in the &#39;718 and &#39;725 patents.  
         [0049]    Referring back to FIG. 5, the raised column guard hub  66 , which is exposed upon removal of the cap  26 , provides significant strength with minimum material between the cap mounting hub  62  and catheter mounting hub  50  on the needle housing  22 . The operator can readily grasp this area  66  of the needle housing to hold the housing  22  when withdrawing the needle  18  from the patient (not shown). In this operation, the handle housing (not shown in FIG. 5) can be drawn away from the patient with one hand while grasping the guard hub  66  and holding it in place as (i) the needle  18  is drawn out of the patient, (ii) the mounting hub  50  separates from the catheter hub  48  as shown in FIG. 7, (iii) the needle  18  slides out of the catheter  20  as also shown in FIG. 7, and (iv) the needle  18  is drawn into the needle housing  22  as shown in FIG. 8. This operation is described in greater detail in the &#39;718 and &#39;725 patents.  
         [0050]    Now that the operator has completed use of the needle  18 , the operator can, as shown in FIG. 9, slide the large end  58  of the cap  26  over the needle housing  22  to yet again engage the radial detent  70  and secure the cap  26  on the handle housing  24 . The same cap  26  thus provides yet another level of protection against subsequent needle sticks. This cap-remounting procedure also provides the clinician, particularly one who is accustomed to manual capping of needles after use, with a greater level of comfort and security in using the safety needle  10 . It also reduces the likelihood that the cap  26  will be left behind on the street or any other accident or trauma location.  
         [0051]    Referring now to FIG. 10, the cap  26 , indicia  56 , (FIG. 1) on the housing  24 , mounting hub  50 , and catheter hub  48  described above may also be used on a safety needle not having a plunger at all. This type of catheter is preferably for use with patients having sufficient blood pressure. This non-plunger needle  100  has a resilient plug  102  mounted within the mounting cylinder  16  to extend therefrom and abut the generally planar interior end  104  of the needle housing  24 . The plug  102  thus abuts the “X” shaped plunger passage  38  and prevents the flow of blood from the flash back chamber  32  through the plunger passage  38 .  
         [0052]    The protective cap  26 , plunger rod  12  and catheter hub  48  are preferably made from polypropylene. The plug  102  is made from rubber, and the handle housing  24  and needle mount  16  are made from high impact polystyrene. The needle is made of steel. The catheter  20  is made from radiopaque Teflon, and the needle housing  22  is made from ploycarbonate.  
         [0053]    It can thus be seen that the applicants have invented a safety catheter and needle that is safer than prior art catheters and needles and yet convenient, economical, and easy to assemble and manufacture. It provides numerous significant advantages over the prior art, and it does so at minimal cost.  
         [0054]    While in the foregoing the applicants have described their preferred embodiments, it is to be understood that the scope of the invention is to be determined by reference to the following claims.