MXPA97006932A - Self-scattered seal for use on medi devices - Google Patents

Abstract

The present invention relates to a medical device comprising: a housing defining an inner portion and a distal recess and a proximal recess axially spaced apart from each other, a distal disc placed in the distal recess, a proximal disc; a viscous fluid material placed inside the inner portion between the distant disk and the proximal disk

Description

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SELF-HEALING STAMP FOR USE IN MEDICAL DEVICES BACKGROUND 1. Field of the Invention The present invention relates to a seal that is used in medical equipment that is "self healing". More particularly, the present invention relates to a seal which is designed to be punctured by a catheter, needle, or similar object, but which retains the ability to seal spontaneously and completely upon removal of the penetrating object. 2. Technical Background In various medical devices it is necessary to provide seals that are substantially impervious to liquids, but that also allow penetration to hypodermic needles and other similar penetrating instruments when necessary. Devices of this type include catheter assemblies, respiratory devices and blood collection systems. It will be appreciated that the construction of this type of seal presents a number of unique technical problems. Specific devices that require this type of seal include several catheters and cannulas (hereafter "catheters"). These devices are usually placed in the communication of flows with a specific part of a patient's body. For example, catheters are frequently used to give access to the vascular system. When this is the case, an introducer needle is generally used to place the catheter within the desired vein or artery. Once the catheter is properly placed, the needle that was inserted is removed from the blood vessel and finally it is also detached from the catheter device. It will be appreciated that it is necessary to maintain a tight seal of liquid inside the device even after removing the needle. In this way the device must include means to close the hole that was left while the needle of the device is detached. Various types of valves or seals have been used in medical devices of this type. For example, it is conventional to use single leaf valves in many medical devices in order to provide selective opening and closing of an access port. In other configurations, a safety mechanism is placed at the point where the needle and another penetrating instrument is separated from the device. Once the instrument has been removed, a safety cap is simply placed over the hole. This type of device has a number of obvious limitations. When a device filled with liquids is being used, often under significant pressure, a drip may occur between the time the needle separates and the time when the cap or other closure means is placed in position. This increases the likelihood of contamination of the catheter system as well as contamination of the surrounding work environment by blood and other body fluids. Another alternative is to place a relatively rigid elastomeric plug on the end of the device through which the penetration instrument passes. Generally the stopper is made of a relatively rigid rubber material. These devices were designed in such a way that they are automatically sealed when the needle or other instrument is removed. A problem that arises with this type of device is the friction between the needle and the rubber stopper. In order to provide an adequate seal, it is necessary to compress the plug. This makes the movement of the needle through the stopper more difficult. In addition, the need to exert pressure on the plug limits the option of using materials to make a suitable housing. The result is that often these devices are not particularly compatible with the skin of the patient, particularly when it is necessary to have the device next to the skin for a long period of time. This can cause irritation, possible infection and related problems. Therefore, there is a need for an alternative stamp to be used in the aforementioned contexts. In this regard, it will be an improvement in the art to provide an improved barrier or seal that is capable of closing the hole left by needles and other similar instruments. It will also be an improvement in the art to provide this type of device that could be manufactured from a wide variety of materials, including materials that are more compatible with patients' skin than those materials used in the present. In addition, it will be an improvement in the art to provide a seal that is adaptable to use in a variety of different devices and that is highly effective. This type of apparatus is disclosed and claimed in the present.

BRIEF COMPENDIUM AND OBJECTIVES OF THE INVENTION The present invention relates to a self-healing seal for use in various medical devices, particularly in devices such as catheter assemblies where it is important to maintain a fluid or fluid seal when a series of handling steps are carried out. The seal of the present invention includes a retention housing so as to shape the exterior of the device. The shape retention housing defines an interior chamber. Placed inside the chamber is a bolus of viscous flow material. In general, sufficient viscous flow material will be placed inside the inner chamber of the housing, so that the chamber is completely filled.

The seal is configured in a specific manner such that if a penetrating instrument, such as a hypodermic needle is inserted and the object is subsequently removed, the viscous flow material flows to fill the space previously occupied by the penetrating object. At the same time the housing is elastic enough to keep the viscous material inside the inner chamber once it is removed from the needle. In this way a seal impervious to the liquid is provided.

A significant feature of the present invention is that the housing can be manufactured from a wide variety of materials. Due to the fact that the housing does not need to exert a high level of pressure on the interior material, it is possible to select it from a wide variety of materials. Among the possible candidate materials are those that are compatible with the skin of the patient. Accordingly, it is possible to design the devices in such a way that they do not irritate the patient. Examples of materials that can be used include rubbers and synthetic elastomers such as latex, polyisoprene, silicon and polyurethanes. Various viscous flow materials can also be used. For example gels, such as silicon gels are suitable and are within the scope of the present invention. Gels can be selected that increase viscosity and solidification upon contact with oxygen, water or other substances to ensure a complete seal. The present invention also has advantages in that it is possible to decrease the friction on the needle while it is removed from the device. In existing systems, high levels of friction on the needle often have drawbacks, and may result in the cap or seal inadvertently dislodging or moving. Thus, the present invention provides a significant advantage in that the needle can slide smoothly through the seal. These and other advantages of the invention will become apparent upon reading the following detailed description and the appended claims, as well as with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the invention, a more particular description of the invention will be offered by reference to specific embodiments illustrated in the attached drawings. On the understanding that these drawings describe only the typical embodiments of the invention and therefore are not considered to be limiting of their scope; The invention will be described and explained with specificity and additional details through the use of the accompanying drawings, wherein: Figure 1 is a cross-sectional view of a catheter assembly that is employed in the present invention. Figure 2 is a perspective view of the present invention that specifically illustrates the shape retention housing. Figure 3 illustrates the manner in which an embodiment of the present invention is fabricated with a needle in place and penetrating the housing. Figure 4 is a cross-sectional view of an alternative to the disc shape embodiment generally of the present invention. Figure 5 is a cross-sectional view of a further alternative embodiment wherein the body of the catheter forms a portion of the seal.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention can be better understood by reference to the drawings in which the parts are designated with the same number. A portion of a typical catheter assembly is designated generally as 10 in Figure 1. Arranged within frame 12 of catheter assembly 10 is a representative embodiment of the self-healing seal 14 of the present invention. In the present embodiment, a catheter (not shown) provides an access to the vein or artery such that the blood can be drawn from a patient or in such a manner that the necessary fluids can be provided to the patient. In either case, the liquids flow through a Y-shaped section 18 into an inlet 20. the inlet 20 in turn connects to a tube 22 through which the intravenous fluids are proportional to the patient or to the patient. through which the patient's blood is drawn. As mentioned before, catheters of this type are typically placed by an insertion needle 24. The insertion needle 24 is used to locate and penetrate the desired vein or artery. Once the introducer needle is in place, the catheter is placed in the same vein or artery. After the catheter is in the desired position, the insertion needle 24 is removed from the vein or artery and finally is also removed from the catheter assembly 10. In the embodiment of the invention as illustrated in Figure 1, when it is separated to the introduction needle, it is removed and removed by means of the self-sealing stamp 14. • As illustrated in Figure 1, the seal 14 includes a shape retention housing 26. As mentioned above, the housing 26 can be manufactured from a wide variety of materials. Examples of this type of material include latex, polyisoprene, silicon and various polyurethanes. The housing 26 is configured in such a way that it fits securely within the structure of the catheter 12 and thus forms an inner chamber 28. The inner chamber 28 in turn is completely filled with the viscous flow material 30 as it is a gel. Silicon gel is a preferred material herein.

It will be appreciated that when the insertion needle 24 is pulled out of the catheter assembly 10, it will tend to leave a hole in the seal 14 because it is held in a deformed state by the presence of a penetrating object and is stored beforehand. to be used for up to five years, the material composes a "compression set". However, due to the design of the present invention, the hole that would otherwise remain self-sealing. That is, the nature of the elastomeric shape retaining housing 26 causes it to close completely. At the same time, the viscous material 30 is fluid enough to fill the gap left by the insertion needle but sufficiently viscous so that the viscous material 30 can not flow through the orifice.

Figure 2 illustrates the self-healing seal 14 as illustrated in Figure 1. As illustrated in Figure 2, the insertion needle has been removed from the seal 14. However, the viscous material remains inside the housing 26 due to the elastic nature of the housing 26. Inside the seal 14, the visco material (not shown) will have flowed enough to fill the path of the needle and finish the seal. As illustrated in Figure 2, the seal 14 usually has a cylindrical shape. However, the seal can be adapted to other shapes, sizes and configurations.

Figure 3 illustrates a method of forming a self-healing seal 14 of the present invention. As illustrated in Figure 3, the insertion needle 24 is initially inserted through the housing 26. Once this has been achieved, a second needle 32 is inserted through the wall of the housing 26 and into the interior chamber 28. The inner chamber 28 of the housing 26 is then completely filled with the viscous flow material 30., like a gel. Once the introduction of the gel 30 into the interior chamber 28 is completed, the needle 32 is withdrawn. Due to the self-healing properties of the seal 14, the gel remains in place even after the gel has been removed. needle 32. Once the insertion needle 24 has been placed inside the seal 14, and the seal 14 is inflated from the gel 30, the device is ready to be used. As previously described with reference to Figure 1, the device can then be placed within a catheter structure 12. While the insertion needle 24 could be inserted into the device after it was inflated with gel 30 and placed inside the device. of the structure of catheter 12, this is usually not preferred. The above-described procedures are generally preferred in order to ensure that the insertion needle 24 is not clogged with the gel before use. Figure 4 illustrates a further embodiment of the device of the present invention. The self-healing seal 50 that is illustrated in Figure 4 has somehow more disk shape than the seal 14 that ant * is described. Seal 50 is illustrated positioned within a catheter 52. A penetrating object 54, such as a needle, is illustrated by passing through seal 50. As to the above-described embodiment, seal 50 is illustrated in FIG. 4. it comprises a shape retention housing 56 that defines an interior volume 58. A gel 60 is placed inside the inner chamber 58 or other liquid material. Referring now to Figure 5, a further embodiment of the present invention is illustrated and designated generally. In this embodiment of the device the wall 72 of the catheter forms a portion of the seal. As illustrated in Figure 5, a pair of disks 75 are placed within the slits 78 with the inner wall 72 of the catheter 74. The disks together contain a gel 75. As discussed above with respect to the modalities previously described, one or both discs 76 are formed of a generally elastomeric material that closes completely after the penetrating object is removed, such as a needle 80. If only one of the discs 76 is elastomeric in nature, the other disc will likely be made of a material rigid that has a near free space for the object of penetration. In any case, those skilled in the art will appreciate that different combinations of materials can be employed to achieve the objectives of this particular embodiment of the invention. As in the embodiments described above, the interior of the space defined by the wall 72 and the pair of disks 76 can be filled with the gel material. Thus, in this embodiment of the invention it is possible to achieve the advantages of a self-healing seal without the need for a complete housing for the gel in which the catheter 74 provides a portion of the required housing. Thus, the present invention achieves the objectives identified above. The device of the present invention provides a seal that self-heals when a penetrating object is removed through the seal. The device is capable of decreasing the friction that would otherwise occur when removing the penetrating object through the seal. The seal is also effective. The seal self-seals in such a way that medical personnel do not need to worry about closing the seal once the penetrating object is removed. This allows the use of catheters and other similar devices to be easier and safer. The invention can be carried out in other specific forms without departing from the spirit or essential characteristics. The described modalities should be considered only in all aspects of illustration and not of restriction. Accordingly, the scope of the invention will be better indicated by way of the appended claims than by the foregoing descriptions. All changes that arise with the meaning and field of equivalence of the claims should be encompassed within its scope.

Claims (5)

1. A medical device comprising: a housing defining an inner portion and a distal slot and a proximal slot axially spaced from one another; a distant disk placed in the distant slit; a nearby disc placed in the proximal slot; and a viscous fluid material placed within the inner portion between the distal disk and the proximal disk.

2. The medical device of claim 1, wherein one of the distant discs or proximal discs is formed of a rubber material.

3. A medical device of claim 1, wherein one of the distal or proximal disks is formed of a polymeric elastomeric material.

4. The device of claim 1, wherein the viscous fluid material is gel.

5. A medical device of claim 4, wherein the gel is a silicon gel.