MXPA98000181A - A member of reinforcement to increase the deflated flow within a med device - Google Patents

Abstract

The present invention relates to a reinforcing member that is a stylet that helps to increase the area of fluid flow within a catheter, in a preferred embodiment, the stylet is made in a single piece of rectangular flat material that can be wound to provide the same stiffness in all directions, a cross-section of the stool reveals that the substantially flat rectangular shape of the stylet allows maximum fluid flow between the stylet and the catheter, this results in easier handling and removal of the catheter stylet; In view of the fact that the preferred embodiment of the stylet comprises a single element, it is easier to manufacture and would result in lower manufacturing costs, on the other hand, the use of the present invention would also result in lower total costs of salt services.

Description

A GIIE REINFORCEMENT PULF INCREASE FLUID OF FLUID WITHIN A MEDICAL DEVICE FIELD OF THE INVENTION In general terms, the present invention relates to medical devices. In particular, this invention pertains to a stylet that helps increase the stiffness of a medical device, particularly when the medical device is inserted.

BACKGROUND OF THE INVENTION Many types of catheters are well known in the prior art; for example, peripherally inserted central catheters (PICCs) are commonly used in the prior art. Peripherally inserted central catheters are used to access the vascular system.

In particular, PICCs are used when vascular access is required for a long period (for example, more than two weeks of residence time in a patient) to avoid multiple injections to the patient. A PICC is a large catheter that is frequently inserted into the patient. the middle part on the arm of a patient, and the end of the catheter is often placed in the superior vena cava of the heart. Frequently, PICCs provide access to a patient's vascular system for chemotherapy or other types of intravenous medication. Because the P1CC frequently must travel through many natural obstacles in the venous / vascular system, the catheter must be soft and foldable for ease of navigation and to avoid trauma to a blood vessel. In addition, the catheter must also be made of biocornpatible materials so that it does not irritate a patient's veins during the prolonged residence time of the catheter. Unfortunately, the PICC lines made of a soft biocornpatible material are very difficult to insert into a patient because their soft or foldable construction causes the PICC to collapse and fold frequently before entering the patient's veins. more rapidly and preferably a PICC, a flexible metal stylus (or guidewire) or reinforcing member is used within the catheter during insertion.After the catheter is placed inside the patient, the guide wire is removed. However, the guidewires cause several problems.There is an increased friction between the guidewire and the inner wall of the catheter, since the catheter often makes many turns and rolls up before reaching its final destination.As a result, it is often difficult to manipulate and then remove the guide wire.Second-, the use of the guide wire introduces -also the possibility that the guidewire could perforate a catheter when it is forced against the catheter. One solution to these problems is to flood the catheter before use, during the insertion procedure to aid in the manipulation of the guidewire, and / or after the insertion procedure to help remove the guidewire. These flood solutions frequently contain heparma and saline solution. The need for a flood system and a reinforcing member such as a stylet becomes even more significant as the catheters decrease in diameter. A smaller catheter is often more beneficial for patients with small or fragile veins, since a smaller catheter causes less trauma to the patient's veins. The use of smaller catheters also requires that the guidewire or stylet be smaller. However, the stilettos have not decreased in tarnafío to the necessary degree. Consequently, the fluid flow area of the flood solution decreases at the same time as the need for the flood solution and a larger fluid flow area increases. This is counterproductive. Referring to Figure 1, a cross section of a prior art guide wire 102 is shown in a small catheter 100 with minimal space for the fluid flow area 104. In an exemplary catheter with a diameter of 0.09 cm, a cross-sectional area of the guide wire 102 occupies approximately 70% of the transverse area of the LOO catheter lumen. Consequently, only about 30% of the transverse area of the catheter lumen-100 is available as a fluid flow area 104. Another prior art embodiment of a guide wire 200 is shown in Figure 2A. The guide wire 200 is made of three elements: a flat belt of material 207, adjacent to a core 209, both of which are disposed within a coiled helical coil 205. The resulting fluid flow area 203 between the guide wire 200 and catheter 201 is minimal. In Figure 2B a side view of the guide wire 200 of Figure 2A is shown. The helical spiral 205 is welded on both ends of the tape 207 at 211a and 211b. The twists of the splint 205 are not normally visible to the naked eye, but for the sake of clarity, the space between each of the turns in the spiral 205 in FIG. 2B has been exaggerated. Spiral 205 frequently bends as it coils and rotates with catheter 201. This allows part of the fluid to flow between coils 205 and around core 209, which provides stiffness, and flat tape 207. In addition, core 209 also it can be welded to the flat belt 207. Figure 3 illustrates a cross section of another prior art embodiment in which the guide wire 301 is made of three separate wires 301a-c, which are braided together. Each wire can have a diameter of approximately 0.02 crn, while the internal diameter of catheter 300 can be 0.08 crn. Figure 3 illustrates a disadvantage of prior art systems. The length of the guidewire can not be changed without altering- or compromising the structural integrity of the guidewire. For example, the guidewire 301 (Figure 3) can not be cut without compromising or destroying the structural integrity of the guidewire 301, since its three wires 301 ac unravel and separate.The same is true for the guidewire 200 of Figure 2 and its three components 205, 207 and 209. As is evident from Figures 1, 2 and 3, the area of fluid flow (104, 203, 303) around each respective guide wire (102, 200, 301). ) is severely restricted as the diameter of the guide wire approaches the internal diameter of the catheter Many guidewires of the prior art are made of rne + al, so that the guidewire can not be cut when the length of the guidewire is desired. As a result, in these prior art modalities, the guidewire is adjusted by first removing the guidewire from the proximal end of the catheter and then cutting the catheter.Therefore, these catheters require extrinsic manipulations. s before you can use them. The smaller flow of fluid due to the diminished area between the guide wire (or stylet) and the internal wall of the catheter is inconvenient. An adequate amount of the flood solution is needed to assist in the insertion and removal of the guidewire (or stylet) in the catheter. In addition, unimpeded fluid flow helps prevent friction in the guidewire (or stylet). ) and the internal wall of the catheter. In this way, it is convenient for a guide wire (or stylet) to serve as a reinforcing member in a medical device such as a PICC catheter, for example, during the insertion of the medical device. It is also convenient that the shape of the reinforcement member helps to increase the flow of fluid around the guidewire (or stylet) disposed within the medical device.

BRIEF DESCRIPTION OF THE INVENTION The present invention describes a reinforcing member that allows an increase in the area of fluid flow within a medical device such as a catheter. In one embodiment, the reinforcing member is a substantially rectangular elongate stylet that is disposed within the catheter. , so that the stylet can occupy less than half the lumen area of the catheter. As a result, adequate fluid flow is allowed between the stylet and the inner wall of the catheter *. This increases the comfort for the patient. In a preferred embodiment, the stylet is made of substantially planar material, so that in the transverse section, the larger dimension of the stylet closely approximates the internal diameter of the catheter or is slightly smaller. Furthermore, in the preferred embodiment, the flat material is rolled over the length of the stylet to achieve equal stiffness or flexibility over the entire length of the stylet on any axis. Different gauges (ie, number twists or turns per 2.5 crn) can be used to obtain stilettos with different degrees of stiffness. In addition, the caliber can be varied within a single stylet to create multiple degrees of stiffness within a single stylet. For example, the close end of a stylet may have a larger gauge than the far end to create a softer, closer extrusion. This is beneficial since the near end is first inserted into the patient. The substantially rectangular elongated stylet comprises most of the transverse area of the substantially rectangular reinforcing member. Substantially rectangular, as defined, may also include a cross-sectional area of a single element that is configured as different versions of a beam I, a dog bone, an ellipse, an oval and a rectangle. The transverse section of the rectangular substi- tial stylet has a first long axis and a second short axis that is not aligned with the first axis. However, the first and second axis are coupled together and are parts of a single-element stylet. The cross-sectional area of the reinforcing member is usually such that one dimension (the "long" dimension) is at least two times, or rnuy preferably eight times the length of the other dimension (the "short" dimension); in this way, the reinforcing member is substantially rectangular at least in cross-sectional view. This allows the flood fluid to flow through at least half of the lumen area within the catheter, and preferably through approximately 80% of the catheter lumen area. In or to modality, a cross-sectional area of the alar stylet. -adored is a percentage of up to 65% of the transverse area of the lumen of the catheter. The area of available fluid flow is the area not occupied by the elongated stylet within the lumen of the catheter. The cross-sectional area of the elongated stylet is substantially formed by a single reinforcing member. In another aspect of the present invention, a coating may be placed around the single reinforcing member. The coating does not substantially decrease the flow of fluid around the stylet. In addition, the screening can be selected from a group consisting of a hydrogel, or Teflon ™, which is applied to a fluorocarbon polymer of tetrafluoroethylene and a fluorinated styrene-propylene resin.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which similar references indicate similar elements. Also, for purposes of clarity, certain elements in a figure may appear large and are not drawn to scale. Figure 1 illustrates a guide wire (or stylet) of the prior art. Figure 2 is a guide wire with the previous technique made of three components. 2D is an exaggerated side view of Figure 2A. Figure 3 illustrates another guide wire of the prior art which is made of three braided wires. Figure 4 illustrates the placement of a PICC catheter. Figure 5A illustrates a cross section of one embodiment of the present invention, Figure 5B illustrates a cross section of a large embodiment of Figure 5A, Figure 5C illustrates a cross section of a still larger embodiment of Figure 5A. Figure 6A illustrates a cross section of a dog bone or dumbbell embodiment of the present invention, Figure 6B illustrates a cross section of another embodiment in the form of dog bone or dumbbell of the present invention. invention »Figure 6C illustrates a cross-section of another embodiment in dog bone or dumbbell of the present invention Figure 7A illustrates another view of reinforcement member 502 in Figure 5A Figure 7B illustrates a side view of another embodiment of the present invention Figure 8 illustrates a cross-section of another embodiment (ie the present invention) Figure 9A illustrates a cross-section of a beam mode I of the present invention. Figure 9B illustrates a cross-section of another beam embodiment I of the present invention. The figure <3C illustrates a cross section of another beam embodiment I of the present invention. Figure LO illustrates a cross section of another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION An apparatus for increasing the flow of fluid within a medical device such as a catheter is disclosed. In the following description, numerous specific details are indicated to provide a complete understanding of the present invention. However, it will be apparent to the person skilled in the art that the present invention can be practiced without these specific details. In other cases, well-known structures for clarity of the present invention may not be shown. In other cases, specific examples are described and shown to fully describe the invention. It should be appreciated that these specific examples are for the purpose of explanation and that alternative modalities will be understood by experts in the field. The present invention provides several advantages over the prior art. The present invention increases the flow of fluid within a catheter without sacrificing the mechanical stiffness provided by the stylet. This is especially important in floodable guide wire systems where the unobstructed flow of a flood solution is essential. The flood solution helps reduce friction between the guidewire (or stylet) and the inner wall of the catheter while the catheter is wound and rotated through the blood vessel. In addition, the flood solution aids in the handling and final removal of the stylet. This reduces the possibility that the guidewire may become stuck in the catheter and requires removal of the patient's catheter. It is also helpful in infusing fluid through the catheter while also advancing the catheter through the patient. This is because the fluid dilates the blood vessel and makes the catheter move more easily, particularly if there is an obstruction in the vessel. In this way, by increasing the area available for fluid flow between the stylet and the inner wall of the catheter, many of these problems are avoided. In addition, the increased fluid flow within the catheter also increases comfort for the patient. On the other hand, for catheters with small internal diameters, the present invention allows maximum effectiveness of the stylet while retaining full flooding capabilities at the same time. The stylet of the present invention can also be easily cut to adjust the length of the catheter without compromising or destroying the structural integrity of the stylet. For example, the structural integrity of two guide wires of the prior art 200 and 301 of Figures 2 and 3 is lost if the guide wires 200 and 301 are cut, since the components (205, 207, 209 and 301a-c) , respectively) unravel and separate. This should also result in significant time savings, since unlike the prior art, the stylet of the present invention does not require being-removed before cutting the catheter. In addition, the stylet does not need to be previously digested to adjust the exact length of the catheter. Because a physician or nurse can not usually determine with absolute accuracy the length of the catheter needed for a particular patient, the present invention provides additional time flexibility and efficiency for the busy medical practitioner. Finally, the present stylet is much easier to manufacture than the examples of the prior art, since it is a single element. For example, the guide wires of the prior art illustrated in Figure 3 and Figure 2A comprise three elements. In this way, the present invention should decrease manufacturing costs and also decrease the overall costs of health services. One embodiment of the present invention is particularly useful in peripherally inserted central catheters (PICCs), one of which is illustrated in Figure 4. A PTCC 402 is used when long-term vascular access is required, eg, more than two weeks, to avoid traumatizing the patient with multiple injections »As shown in figure 4, a PICC is a long-line catheter that is frequently inserted in the middle part on the br-azo of a patient 400 and the end of the catheter - is frequently placed in the superior vena cava of the heart 401. A PICC must frequently be moved in any part from 15.2 to 50.8 crn, depending on the size of the patient, before its distant end (the farthest end of the original entry point) reaches its final point of residence. As a result, a stylet is often used to help reinforce the catheter, which is often made of a soft biocompatible material. The smooth construction of a catheter-often causes the PICC to flatten and / or bend before entering a patient's veins. In this way, a flexible metal stylet allows a PICC to be inserted quickly and efficiently »Since the PICC 402, and therefore the stylet, must travel through many natural barriers and a fairly long distance through the patient's body , maximum flow of fluid between the stylet and the catheter is necessary to increase patient comfort and decrease trauma incidents in the patient's veins. Referring to Figure 5A, a cross-section of a modali of the present invention is illustrated. A single reinforcing member 502 substantially rectangular elongate denti or a catheter 500 is shown.

Substantially rectangular means that in cross section, a first dimension or first axis 508 of the reinforcement member 502 is at least twice the length of a second dimension or second axis 506 that is perpendicular to the first dimension. In particular, the first axis 508 is eight times the length of the second axis 506. For example, if the internal diameter of the catheter 500 is 0.09 crn and the first axis 508 is about 0.08 crn and the second ee 506 is 0.01 crn , then the reinforcement member (in transverse section) occupies approximately 16.8% of the cross-sectional area of the lumen of the catheter-500. In this manner, a cross section of the reinforcing member 502 originates a substantially rectangular shape. It is appreciated that other dimensions may be used for the first axis 508 and the second ee 506 within the scope of the present invention. For example, the first axis 508 (or long) may be six times larger than the second ee 506 (or short) ). In addition, the first shaft 508 provides the greater part of the flexural stiffness of the stretched r-force member 502. The flexural stiffness is the force required to bend an object. For example, steel has a higher flexural stiffness than rubber. A fluid flow area 502 is shown through at least more than half of the internal area or lumen of the catheter 500. The fluid flow area 504 is much larger than the fluid flow areas of the prior art (FIG. 104, 203 and 303) -.lust adas in Figures 1, 2A and 3, respectively. Although the reinforcing member 502 can operate as a stylet providing resistance as a column to the catheter 500 to aid insertion of the catheter, its substantially rectangular shape (as seen in cross section) does not significantly reduce fluid flow like the wires guide of the prior art. In an exemplary embodiment, the stylet has a transverse area that is substantially defined by the cross sectional area of the substantially rectangular elongated rfing member 502. It will be appreciated that additional treatment, such as a coating (e.g. a Teflon ™ or Teflon ™ type material) around the reinforcement member 502 »The term Teflon ™ is applied to fluorocarbon polymers of tetrafluoroethylene and fluoro-propylene ethylene reams. The coating should not substantially increase the diameter or transverse area of the reinforcing member 502. Thus, the coating should not dramatically decrease the fluid flow area 504. In FIG. 5A, a cross section of the planar section is shown. of reinforcement member 502 which is smaller than the internal diameter of catheter 500. It is seen that the flat section of reinforcing member 502, as shown in cross section, can also closely approximate the internal diameter of catheter 500 in another modality. The reinforcing member 502 can be made of metal or plastic. It will be apparent to the person skilled in the art that the reinforcing member 502 can be made of any biocornpatible material that provides strength as a column to the caterpillar 500, with minimal irritation to the patient's blood vessel. It will also be apparent to the person skilled in the art that the present invention can also be used in other catheters such as a midline catheter and is not restricted to PICCs. In FIG. 5B a cross-section of another embodiment of a reinforcing member is shown. The riving member 510 is disposed within the lumen of the catheter 500 with a fluid flow arc 511. In this particular embodiment, the length of the long axis or first axis of the stiffening member 510 is approximately four times greater than the length of its short axis or second axis. For example, if the reinforcement member 510 has a first axis of 0.08 cm, a second axis of approximately 0.02 cm and the internal diameter of the catheter is 0.09 cm., then the cross-sectional area of the reinforcing member 510 is about 27% of the lumen cross-sectional area to the catheter 500. This means that there is a fluid flow area 511 of about 73% in a modality with these dimens. In Figure 5C, the cross-section of a still larger modality (ie a reinforcing member configured similiarly) is illustrated.The reinforcing member 512 is disposed within the catheter lumen 500. The area of fluid fLuido 503 of the figure 5C is smaller than the fluid flow area 511 of Figure 5B because the size of the reinforcing member has increased For example, if the internal diameter of the catheter 500 is 0.09 cm, the long axis or first axis of the member of reinforcement 512 is 0.08 crn and the short axis or second axis of reinforcement member 512 is 0-04 crn, then reinforcement member 512 occupies about 48% of lumen area of catheter 500 in cross section. Figure 5C illustrates a modality in which the long axis is approximately twice the length of the short axis, This causes a fluid flow of approximately 52% of the transverse area of the lumen of the catheter 500. The ratio of long axis to axis short in the secc Transverse ion of the different reinforcing members shown in Figures 5A-C, means that it is illustrative and not limiting. Figures 5A-C illustrate a cross section of a series of different modalities in dog bone form or dumbbell for a reinforcing member. In the three figures, Figures 6A-C, it is assumed that the internal diameter of catheter 600 is 0.09 crn for an exemplary catheter. In addition, it is also assumed for illustrative purposes that the long axis (defined as 508 of Figure 5A) of the reinforcement element. 602, 604 and 608 of each respective figure (6A-C), is 0.08 crn. In Figure 6A, for example, the thin middle portion of the reinforcing member 002 can have a thickness of approximately 0.01 crn and the two thicker end portions of the reinforcing member 602 (which are contiguous with the middle portion) can be approximately 0.02 an in an exemplary mode. If the thickness of the end portions is considered as a "short axis", in this case 0.02 crn, then the "long axis" of 0.00 crn is four times greater than the short axis. In this exemplary embodiment, the reinforcement member 602, in cross section, occupies approximately 16.8% of the cross-sectional area of the catheter lumen 600. Thus, the fluid flow area 603 in this embodiment is approximately 83.2%, which is a significant increase over the prior art. Referring to Figure 6B, the middle portion of the reinforcing member 604 is wider than the middle portion of Figure 6A, so that the cross sectional area of the reinforcing member 604 increases to approximately 27% of the transverse area of the catheter lumen. 600. The short axis (defined by the thickness of the two end portions), however, is slightly smaller than the short axis of Figure 6A. Consequently, the fluid luxury area 605 has therefore decreased to approximately 73% of the transverse area of the lumen of the cat ter 600. In another mode, as illustrated in FIG. 6C, the middle portion and the two portions of FIG. end of reinforcing member 608 are increased in size. For example, the middle portion may be about 0.03 crn and the two end portions ("ee short") may be about 0.03 crn, which means that the long ee of 0.08 crn is about 2.67 times greater than the short axis in this modality. In accordance with these exemplary dimensions, the reinforcing member 608 occupies approximately 38.6% cross sectional area of the catheter lumen 600 in cross section. Thus, the fluid flow area 609 is approximately 61.4% of the cross sectional area of the catheter lumen 600. Thus, FIGS. 6A-C illustrate how changing the size of the substantially rectangular modality in the form of a dumbbell or dog bone of the reinforcing member affects the resulting fluid flow area. It is noted that the fluid flow area is still larger than the fluid flow area available in Figure 1 of the prior art, which has a fluid flow area of about 30%. Another view of the present invention is illustrated in Figure 7A. In a preferred embodiment, the stiffening member or stylet 700 is made of substantially flat rectangular material that can be rolled to provide equal rigidity or flexibility in all directions. Substantially flat, in this case, it is defined as without any major curve that changes the substantial rec angular cross-section of the reinforcing member 700. It will be apparent to the person skilled in the art that the gauge (i.e., twists or turns per each 2.5 crn) can vary to change the rigidity of the stylet. Furthermore, the tip 701 shown in Figure 7A is reduced but still maintains the same caliber as the rest of the reinforcing member 700. It is appreciated that the tip 701 of the reinforcing member or stylet 700 may have different shapes, for example a tip in a flat shape or a rounded tip. It will also be apparent to the person skilled in the art that both ends of the stylet may have, for example, a flat shaped tip or a rounded tip rotatably stamped. The condition shown in Figure 7A is illustrative and not limiting. In FIG. 7B a side view of another embodiment of the present invention is shown. Illustrated is a reinforcing member 702 having three different gauges. The near portion 703 of the reinforcing member 702 has the largest caliper and thus is the smooth portion of the reinforcing member 702. The distal portion 706 has the caliber rn small and consequentlyis the stiffer portion of the stiffening member 702. The middle section 704 has a caliper between the caliper of the near portion 703 and the distal portion 706. In this manner, the middle section 704 is more rigid than the near portion 703, but softer than the remote portion 706. It is appreciated that any number of different calibers can be obtained within a single reinforcing member 702. Referring to Figure 8, a cross section of another embodiment of the present invention is illustrated. A single elongate rectangular reinforcing member 004 is shown within an 800 catheter. In this embodiment, the substantially rectangular shaped member is an elliptical member 804 that can be wound, in one embodiment, to provide equal stiffness to the other. long of any axis. The elliptical shape is included within "substantially rectangular", as defined above. A cross section of the elliptical reinforcement member 804 has a first axis that is larger than a second axis, which is perpendicular to the first axis. In other words, in cross section, the first ee is the "long" dimension and the second axis is the "short" dimension of the substantially rectangular reinforcing member 804. The portion of the reinforcing member 804 that is aligned along the first Shaft provides most of the mechanical strength. The diameter of the cross section of the first axis can approximate very closely to the diameter of the catheter or be smaller than this. In addition, the elliptical reinforcement member 804 can be formed in such a way that more than half of the lumen area of the catheter 800 is available. for fluid flow 802. A cross section of the reinforcing member 804 can also substantially define the cross-sectional area of the stylet. It will be appreciated that an additional treatment, such as a coating (eg, a hydrogel or Teflon ™) can be placed around the reinforcing member 804. The coating does not substantially increase the diameter or cross-sectional area of the reinforcing member 804. In other words, the The liner should not dramatically decrease the area of fluid flow 802. The gauge of the r-force member 804 can be varied elliptically to change the stiffness of the stylet. For example, the stiffening member 804 can be wound to a gauge on its near end and to another gauge at its distal end to produce different degrees of stiffness within a single stiffening member 804. In addition, one end or both ends of the shape member 804 elliptical can have many different shapes. For example, one end or both ends can be reduced to form a point. The tip may have different configurations, for example, a tip in a flat form or a rounded tip which can be obtained by a rotary stamp. In this way, Figure 8 is illustrative and not limiting. Figures 9A-C illustrate how the present invention can be defined by a cross-sectional area of a stylet that is a certain percentage of the cross-sectional area of the lumen of the catheter. More specifically, FIGS. 9A-C illustrate a cross-section of a beam embodiment I of the present invention in relation to the cross section of the lumen of the catheter in which the beam-I embodiment is disposed. For example, the internal diameter of the beam catheter 900 may be 0.09 crn, and the axis along the length of the two ends may be increased from about 0.03 crn in Fig. 9A, to about 0.06 crn in Fig. 9B, and then to about 0.076 crn in Figure 9C. It is appreciated that other variations of a beam I are also covered by the present invention. Figures 9A-C illustrate how the area of fluid flow decreases as the cross-sectional area of the reinforcing member of Figures 9A-C increases. In Figure 9A, the reinforcing member 9Q2 has a cross-sectional area that is approximately 18% of the lumen cross-sectional area of the catheter 900. As a result, there is a fluid flow area 903 which is approximately 82% of the lumen cross-sectional area of the catheter 900. In contrast, in Figure 9B, the reinforcement member 904 is larger and its cross-section occupies approximately 27.2% of the transverse area of catheter lumen 900. In this way, fluid flow area 905 is approximately 72.8% of the lumen cross-sectional area of catheter 900. In Figure 9C, beam ends I have been increased in such a way that the transverse area of reinforcement member 906 has been increased to approximately 38.6% of the cross-sectional area of the catheter lumen 900. As a result, the fluid flow area 907 is approximately 62.4% of the transverse area of the catheter lumen-900, which is still better than the fluid flow area of the single element guide wire in the prior art shown in Figure i. It will be apparent to the expert in the art that the percentages given for Figures 9A-C are illustrative and does not mean that they are limiting.

It will also be appreciated that an additional treatment such as a coating (e.g., a hydrogel or a Teflon ™, or a Teflon ™ type material) can also be placed around each of the reinforcing members (902,904,906) illustrated in the drawings. Figures 9A-C, respectively. This coating should not substantially increase the cross-sectional area of the reinforcing member, nor decrease dramatically the area of fluid flow. It will also be appreciated that each of the reinforcing members (902,904,906) shown in Figures 9 -C can be rolled and can have different gauges within a single reinforcing member. Furthermore, although not shown, a reinforcing member formed as a circular or ellipsoidal ring 0 would also fall within the scope of the present invention. In FIG. 10, a cross section of an "X-shaped" or "cross-shaped" embodiment of the present invention is illustrated. A "X-shaped" reinforcing member 1004 formed of two substantially rectangular elongate members is disposed within a catheter 100 with fluid flow area 1005. A substantially rectangular elongate member has a long axis L003 that is at least twice as long. the length of its short axis 1006. Furthermore, the second substantially elongated rectangular member + e also has a long axis 1001 which is at least twice the length of its short axis 1002. It is seen that the long ee 1001 and the long axis L003, and each of their respective short axes (1002, 1006) do not have to be equivalent as shown in Figure 10. For example, the long axis 1001 can be shorter than the long axis 1003 and the short axis 1002 it may be wider than the short axis 1006. It is noted that the reinforcing member 1004 may be wound in a different caliber or several different calibers over its entire length. In addition, it is also appreciated that an additional treatment such as a coating (eg, a hydrogel or a Teflon ™, or a Teflon ™ type material) can be placed around the reinforcing member 1004. The coating should not substantially increase the diameter or the cross-sectional area of the reinforcing member 1004. Thus, the coating should not decrease the fluid flow area 1005. The foregoing description provides an example of a reinforcing member, such as a stylet, disposed within a medical device such as a PICC. It will be apparent to the person skilled in the art that the medical device may be for example a fixator, a cannula, an extension or any other device that uses a stylet or a guidewire. It will be appreciated that numerous modifications may be made in the practice of the present invention without departing from the spirit and scope of the invention, which is defined by the following claims.

Claims (21)

V NOVELTY OF THE INVENTION CLAIMS

1. - A reinforcement member for aiding the insertion of a medical device, comprising: an elongate member that is disposed within the medical device, characterized in that said elongated member has a cross section that is substantially rectangular.

2. The reinforcement member according to claim 1, characterized in that the elongated member is wound.

3. The reinforcing device according to claim 2, characterized in that the medical device 15 has a lumen area and the substantially elongated rectangular member occupies less than half the lumen area of the medical device.

4. The reinforcement member according to claim 1, characterized in that the cross section 20 of the elongated member is selected from a group of shapes consisting of an oval, a rectangle, an ellipse, a beam I and a dog bone.

5. The reinforcement member according to claim 2, characterized in that the elongate member is 25 winding the reinforcement member provides equal stiffness in all directions.

6. - The reinforcement member according to claim 1, characterized in that the cross section of the elongated member includes a first axis and a second axis.

7. The reinforcement member according to claim 6, characterized in that the first axis is longer than the second axis.

8. The reinforcement member according to claim 7, characterized in that the first axis provides the greater part of the flexural stiffness of the elongate member.

9. The reinforcing member according to claim 1, characterized in that the elongate member has a first end having a flat shaped tip.

10. The reinforcement member according to claim 1, characterized in that the elongated member 15 has a first end that is rounded.

11. The reinforcement member according to claim 7, characterized in that the first and second axes in cross section are directed to fit within an internal wall of the medical device.

12. The reinforcement member according to claim 2, characterized in that the elongated member can have different calibers along its length. 3.

A vascular access device-comprising: a catheter that has a Lumen; and an elongated stiletto arranged 25 inside the lumen, characterized in that the stylet allows the flow of a fluid through ace of the half of the lumen around the stylet.

14. The vascular access device according to claim 13, characterized in that a transverse section of the elongated stylet has a rectangular shape 5 sub tancialinen e flat.

15. The vascular access device according to claim 13, characterized in that the elongate stylet is wound.

16. The vascular access device according to claim 15, characterized in that the elongated stylet is wound, so that the stylet provides equal stiffness in all di ections.

17. The vascular access device according to claim 15, characterized in that a gauge (twists per 2.5 crn) can be varied between a stylet.

18. The vascular access device according to claim 15, characterized in that a gauge can be varied inside the elongated stylet.

19. The vascular access device according to claim 15, characterized in that the elongated stylet comprises a material selected from a group consisting of metal and plastic.

20. The vascular access device according to claim 13, characterized in that a cross section of a flat section of the elongate stylet closely approximates an internal diameter of the catheter.

21. - The vascular access device according to claim 13, characterized in that a cross section of a flat section of the elongated stylet is smaller than an internal diameter of the catheter- »22» - The vascular access device according to claim 13 , characterized in that the elongated stylet has a reduced tip. 23. - The vascular access device according to claim 13, characterized in that the elongated stylet has a rounded tip "24.- The vascular access device according to claim 13, characterized in that the elongated stylet includes a coating around of a reinforcing member, wherein the reinforcing member comprises most of the cross section of the elongated stylet, and wherein the coating does not substantially decrease the flow of fluid around the stylet. 25. The vascular access device according to claim 24, characterized in that the coating is selected from a group consisting of a hydrogel, a fluorocarbon polymer of tetrafluoroethylene and a fluoropolyethylene ethylene resin. 26.- The vascular access device - comprising: a catheter having a lumen; and an elongated stylet disposed within the lurnum, wherein a transverse area of the elongated stylet is a percentage of up to 65% of a transverse area of the lumen, and the cross sectional area of the elongated stylet is substantially formed by a single reinforcing member. 27. The vascular access device according to claim 26, characterized in that the transverse area of the percentage of the elongate stylet is in the range of approximately 16% to approximately 50% of the lumen cross-sectional area. 28. The vascular access device according to claim 26, characterized in that the elongate stylet is wound. 29. The vascular access device according to claim 28, characterized in that a gauge can be varied inside the elongated stylet. 30. The vascular access device according to claim 26, characterized in that a cross section of a fluid flow area between the cross-section of the elongated stylet and the cross section of the lumen, results in a cross-sectional area of fluid flow of at least 35% of the cross section of the lumen. 31. The vascular access device according to claim 26, characterized in that the elongate stylet can be cut to a predetermined length.