Patent Application
20080021392
Turning now to a more detailed description of the various embodiments of the present invention illustrated in the attached drawings, of which:
As illustrated in
For introducing fluid into or withdrawing fluid from the flow path, the illustrated IV set 10 includes one or more access devices 18 in accordance with the present invention. The fluid access device 18 (or additional such devices) may be provided at any convenient location along the length of the tubing 12, and
Other shapes and forms of the access device may also be used. For example,
In the illustrated access device, the aperture 26 is closed by a gland 28 that is preferably made of resilient/elastomeric material, such as rubber, silicone or latex. The gland normally closes and seals the aperture 26 when it is not being accessed. As used herein, “gland” is intended to have a broad and generic meaning directed to any member or members for normally closing or sealing the access site and which, in cooperation with an accessing member, allows for entry or access into the access site for introduction or withdrawal of medical fluid therethrough.
The gland 28 may be mounted or carried on or in the housing in a variety of ways that are known in the medical field. For example, as noted earlier, the gland may be a solid rubber, silicone or latex septum that spans the aperture and is pierceable by a needle, or the gland may include a pre-formed aperture or slit, which is adapted to receive or be opened by a blunt cannula, such as a male luer or specially designed cannula, for introducing or withdrawing fluid, or the gland may be moveable between the normally closed position and an open position, such as a “luer activated valve” or “luer access device” (LAD), for introduction or withdrawal of medical fluid. This is not an exclusive listing, but merely an indication of the wide variety of gland constructions that may be employed in an access site employing the present invention.
For purposes of illustration,
It will be appreciated that a fluid access device of the type described herein is, in normal usage, exposed to various contaminants or pathogens, such as airborne microorganisms, or by human contact by medical staff or patients. This may cause the surface of the access device to become contaminated with microbes such as bacteria or other harmful microorganisms. To reduce the risk of introducing such microorganisms or other pathogens into the subject, potentially resulting in infection, sickness, or even worse, good medical practice dictates that the clinician clean the access device with an antiseptic agent to kill or reduce the number of pathogens on the access site before administering fluid into or withdrawing fluid through the access site.
In accordance with the present invention, the access device 18 includes an indicator 32 that provides a visual indication when the access device has been exposed to an antiseptic agent. The indicator (or absence of a visual indication) serves as a deterrent to a clinician who might otherwise fail to observe proper aseptic techniques before introducing or withdrawing fluid through the access device.
As shown in
As illustrated in
Referring to
A visual indication in the form of a color change may also serve as an indication to the clinician of the quality and thoroughness of the antiseptic treatment, such as proper swabbing surface coverage, proper swabbing force and/or pressure to the surface. For example, if aggressive antiseptic treating has taken place, the color change of the indicator may be of greater difference or intensity. More specifically, for example, if the indicator changes to green upon exposure to an antiseptic agent, the vividness or shade of the green color could indicate the extent of exposure. Dark or bright green could indicate that the access site has been aggressively treated with antiseptic agent or contacted with antiseptic agent over an extended period of time. A lighter or paler green might indicate a less aggressive treatment and signal the nurse or other clinician that further swabbing or wiping is necessary or would be useful.
It will be appreciated that the effectiveness of the antiseptic agent is only temporary, as the access device may become re-contaminated from exposure to the air or from human contact. As such, it is preferable that the visual indication, such as a color change, be temporary and of limited time duration, and that the access site return to its original or another color at some time after disinfecting—for example, several minutes, such as 3-10 or 5-10 minutes or such other time as may be desired after disinfecting. By reverting to the original condition or color, the indicator serves to remind the clinician to re-swab the access device with antiseptic agent before it is used again.
As seen in
With the above arrangement, if the indicator rings are, for example, red before the access device is swabbed with antiseptic agent, and the reference ring were green, the access device would have red, green and red rings around the gland prior to swabbing, thereby alerting the user to the need to disinfect the access site. After swabbing with an antiseptic agent, the red rings would turn green and the visual indication would appear as generally a single, wide green ring around the gland—until such time as the indicator rings 32 returned to their original red color or other non-green color.
The visual indicator of the present invention may also include a feature or aspect that facilitates visual indication to a clinicial who is color-blind or otherwise color-sight impaired. For example, if the visual indicator is a change of color, the change of color may have associated with it a pattern or arrangement that is visible to a color-impaired clinician. For example, the color change may be from a solid color to a color of having a pattern discernible to the impaired clinician, or vice versa. Alternatively, colors may be specially selected such that the color change employed by the indicator are detectable even by a person who is color-sight impaired.
The indicator of the present invention may be made in a number of different ways. In an optimal configuration, the indicator would actually be sensitive or reactive to presence of micro-organisms or other contaminants and would generate a visual indication when the surface of the gland and surrounding housing are substantially free of contaminants or microbes.
Alternatively, as indicated earlier, the indicator can be of a material that generates the visual indication in response to contact with an antiseptic agent, such as isopropyl alcohol. The indicator could, for example, include a solvatochromic dye that reacts to the polarity of the antiseptic solution. Such a dye could be coated on the access device or impregnated into the material of the access device. For a coating application to polycarbonate substrates, for example, the use of polyacrylic acid (hydrogel) with Nile red dye has yielded a blue to pink color shift in the presence of a polar solvent such as isopropanol. Alternatively, the dye could be incorporated into a film that is bonded to the access device.
Potential variants of this approach include the use of agents in the indicator that detect a pH shift or chemical change from the swab antiseptic agent. For stability, the active agent in the indicator, such as a dye or other agent, could be coated with another material or could be encapsulated in a hydrogel material or chemically cross-liked to other materials. Other variations may include cross-linked density hydrogels, placing the dye in an acrylic polymer such as HEMA, using thermal cure types of emulsion carriers for the dye, or employing lacquer carriers for the dye or employing substrates (such as silicone) to hold the dye in the substrate matrix. The dye could potentially also be suspended in a matrix of adhesive or epoxy or secured by two-shot molding of film to a polycarbonate substrate of the access device.
The indicator of the present invention could also include a liquid crystal material that changes color upon a temperature change from contact with the antiseptic agent. The liquid crystal material may be suspended between layers of film, such as polyester film, to capture the material. Such material may be present in the form of mirco-capsules. The film may then be attached to the access device housing, which may be of polycarbonate material, by cyanoacrylate adhesive or other bonding agent or method. Alternatively, the liquid crystal material may be suspended in an impregnated substrate or contained in a coating applied to the access device. An alternative to liquid crystal materials are thermochromic dyes, which change color due to a temperature change. Such dyes could be employed as described above. Such an indicator allows for quick color change which is also reversible back to the original color in minutes.
Yet a further variation of the indicator is the use of a pressure-sensitive material, such as liquid crystal microcapsules, which change color as a result of pressure exerted by the clinician during swabbing. Such microcapsules may exhibit a single color change and may not be reversible. Accordingly if reversibility of the color change is desired, other pressure sensitive materials or mechanisms may be employed.
In another embodiment, the visual indication may comprise a change in transparency. For example, an indicator may be disposed on a portion of the housing, the gland, or both, and undergo a change in transparency upon exposure to an antiseptic agent. For example, dry (air filled) microporous structures appear white to the observer even when the strands comprising the microporous structures are transparent. The reason this is so is the mismatch between the refractive index of the solid strand and the air. If the air is replaced by another fluid with a refractive index identical to or very close to that of the strand, the structure will appear transparent to the observer. It is desired that the fluid penetrate the structure if it is to wet all strands. One can use this phenomenon as a visual signal of good wetting by a known fluid. For example ePTFE and 70% IPA have almost identical refractive indices. Other membranes may include PTFE, PCTFE, PVDF, and ETFE membranes
Thus, when a microporous structure such as an ePTFE membrane which is white or opaque to the eye when dry, is wetted by swabbing with a 70% IPA, the membrane becomes transparent, and the underlying color or predetermined visual signal, such as printed message, will be visually discernible. If the user tries to swab with a fluid which does not provide effective swabbing, which by way of example may be water, the ePTFE membrane will not wet, and will remain white. This signaling procedure is purely physical in nature and does not rely on incorporated dyes or pigments and is not subject to extractables of any kind. In an example, the swabbing fluid may include 70% isopropyl alcohol. Chlorhexidine Gluconate with 70% IPA may also used be used as the swabbing agent as the 70% IPA matches the refractive index of such membranes.
Such a microporous structure may be carried or mounted on the gland or housing or both in any desired manner. If provided as a separate member, the microporous structure could be in the form of a membrane or other structure, with an adhesive backing that may be attached to the housing or gland using ultrasound, heat or other techniques.
The change in transparency may itself be a visual indication to the user, or the microporous structure may be used in combination with a visual signal source. When in a substantially non-transparent state, the microporous structure may serve to obscure the visual signal source, such as a source that is situated therebelow. Such a visual signal source may be, for example, a particular color, a text message, a bar code or other computer readable image, an icon, or other visual indicator that, when revealed, would provide an indication to the clinician that the access device has been exposed to antiseptic agent. Conversely, when the visual signal source is obscured by the non-transparent state of the indicator, the clinician will be alerted to the fact that the surface of the access device has not been treated with antiseptic agent. Accordingly, as the microporous structure dries, it returns to a non-transparent state, alerting the clinician to swab the access device before using it again. The reading of the visual signal source by a reader may then produce a signal which is fed into a medical information system or database to verify and produce a historical record of the swabbing before administration.
In a further embodiment the degree of transparency exhibited may be controlled such that the desired degree of transparency only occurs upon a desired level of swabbing. By way of example, a visual indicator such as a bar code may not be visible with a required degree of readability without the membrane being sufficiently wetted or swabbed, this required degree being imposed by the bar code reader. One method of achieving this control is to provide two or more layers of the membrane which require the desired swabbing before the needed transparency is achieved.
The accompanying drawings show other types of access sites in which the present invention also may be employed.
The access device of
In this regard,
It should be understood that the indicator may include a protective coating which is permeable to the swabbing fluid. Such a coating would not hinder the indication of proper swabbing from being verifiable but would act as a controller of proper IPA absorption relative to the quality of the swabbing conducted. In an example the coating would be a clear porous material.
Finally, it should be noted that the access device of the present invention does not need to be a separate device, and the access device housing may also be formed as part of another structure, such as in the form of the neck end of a medical fluid vial, a port on a stopcock or any other structure that defines an access opening into a container, a fluid flow system or other structure for the introduction or withdrawal of medical fluid therethrough. For example, the present invention may be particularly useful on medical vials. Such vials are commonly glass or plastic containers with an open top or neck defining an opening or access site that is sealed by an elastomeric gland such as a rubber or silicone stopper or septum. The visual indicator of the present invention may be employed on the gland, or on a surrounding portion of the vial or closure structure, or both, so as to indicate to the user when the stopper or septum has been properly swabbed with disinfectant before the stopper or septum is punctured or otherwise accessed for withdrawal of contents from or introduction of fluid into the vial.
While the present invention has been described in terms of certain preferred and alternative embodiments for purposes of illustration, it is not limited to the precise embodiments shown or to the particular features, shapes or sizes illustrated. A variety of changes may be made without departing from the present invention as defined by the appended claims.
