MXPA97000436A - A probe that has a lumen in the form of gear to prevent the elimination of the flux of fluid in the mi - Google Patents

Abstract

The present invention relates to a probe having evidence or non-obstruction properties comprising a tube having a proximal end, a distal end and a length therebetween, said tube defining a fluid path having a central axis, an outer wall and an inner wall, said inner wall having a plurality of protrusions arranged longitudinally on the internal wall in a direction parallel with the central axis of said tube, each of the protuberances having a tip, a root extending at length of the inner wall, and a pair of straight side walls extending between the tip and the root, each of the roots of the plurality of protuberances is spaced a distance from another of the roots of another of said protuberances along the the inner wall, so that one of said pair of straight side walls of each of the protuberances is oriented in opposite relation to a of the side walls of another of said protuberances, and wherein in response to a force exerted during the normal use of said probe, the distance between the roots of the plurality of protuberances prevents the opposite straight side walls from coming into total contact with one another. the other in order to prevent the occlusion of the fluid path, wherein at least one of the protuberances further comprises a radiopaque strip between the outer wall of the tube and the tip of the protuberance.

Description

./* * "A PROBE THAT HAS A LUMEN IN THE FORM OF GEAR TO PREVENT THE ELIMINATION OF THE FLUX OF FLUID IN THE SAME" I. FIELD OF THE INVENTION This invention relates to a probe having improved patency or evidence characteristics, and more particularly, to a probe having a lumen in the form of a gear to prevent removal of fluid flow through the probe when subjected to Bending or torsional forces and which is adaptable for use with a medical adapter and normal delivery instruments and accessories.

II. BACKGROUND "* In recent years, there has been a notable increase in the use of probes by physicians who carry out medical procedures and especially procedures surgical. The probes are typically elongated tubes formed of medical grade plastic made of polyethylene, polyimide or even nylon, which define fluid carrying conduits for transporting a medicament from a delivery instrument to the body tissue. HE typically enter the body cavity through the lumen of a needle or an insertion device that has already penetrated the body. Then, the needle or introducer is removed screwed around the probe without moving the probe from the position inside the body. A use of a probe is found to provide continuous regional anesthesia, and is exemplified, for example, by the use of epidural probes to deliver anesthesia to a patient's epidural space. The probes are also used for analgesic purposes to provide pain relief sustained after a surgical procedure. Here, the probe remains in place after the procedure and the analgesic drugs administered intermittently according to the needs of the patient. The nature of uses for the above mentioned probes regulate that the dimensions, materials and other characteristics are selected in order to promote their effective use with trauma or minimal intrusion reaction for the patient. For example, the outer dimensions of the probe are normally reduced to the smallest possible diameter to minimize the intrusion effects of the probe into the body tissue. Attention should also be given to the type of material used to build the body of the probe. Generally, probes such as those intended for epidural anesthesia may be formed of a rigid material such as nylon or a soft material, such as polyurethane. Both types of materials present certain advantages and certain inconveniences. In a study carried out by M. Jdhr, 5 F. A. Hess, S. Balogh and H. Gerber. "The choice of the epidural catheter: stiff or soft?" (Regional Anesthesia, Volume 17, Number 3S, Supplement May-June 1992), the "rigid" versus "soft" probes were compared against "*" a number of parameters including difficulty of insertion, the sufficiency of the blockade that is provided by the probe, the problems of blood aspiration and paraesthesia. It was generally found that a stiffer probe could be preferred in view of its easier insertion into the body but that these probes' provided greater instances of complications including paraesthesia and blood aspiration. Similar conclusions were reached by S. Rolbin, E. Hew, and G. Ogilvie in "A comparison of two types of epidural catheters," Can. J. Anesth, 1987, 34: 5 pages 459-61. The difficulties mentioned in last term Such as paraesthesia frequently leads practitioners to prefer probes made of a softer material in order to minimize trauma to the body. Due to the selection considerations of diameter and material, probes for example, epidural probes often experience difficulties of patency or evidence during use. Depending on the forces exerted on the probe, the fluid-carrying conduit defined by a probe can occlude particularly at points subject to external pressures such as when a probe is fixed at an injection orifice site (P. of Long and P. Kansen, "A Comparison of Epidural Catheters With or Without Subcutaneous Injection Ports for Treatment of Cancer Pain", Anesth. Analg. 1994, 78: 94-100). The result is the arrest of fluid flow through the probe. For example, one area of the probe particularly prone to occlusion difficulties is the proximal end. Here, the probe is typically secured to a standard medical connector, such as a Tuohy-Borst adapter, to match a medical delivery device such as a syringe. As is well known, the Tuohy-Borst adapter includes a packing portion that applies pressure around the circumference of the probe. Pressure exerted at or near the proximal end can cause the walls of the probe to flatten on itself to restrict if not eliminate the flow of a medicament from the medical delivery device through the probe.

The probes may also experience patency or evidence difficulties depending on the torsional or bending forces exerted normally on the probe while in use. For example, any torsional or bending action imparted to the probe during insertion into a patient's body could cause the walls of the probe to collapse on itself, thus restricting or eliminating fluid flow through the patient. the probe. Likewise, when the probe is used for analgesic purposes, any of the movements by the patient can cause the probe to twist or flex possibly eliminating fluid flow. Another concern is the practitioner's ability to discern the flow of fluid through the probe.

The probes are typically formed of materials that are translucent. Certain attempts in the prior art have attempted to reinforce the anti-crush probe for example by incorporating metal components, for example such as spiral windings along the length of the probe. The presence of a largely opaque metal component along the length of the probe can impede the physician's easy visualization of fluid flow, decreasing the ability of the physician to quickly discern certain difficulties such as aspiration of the blood. In view of the demands of the operating environment, the need to provide the patient with epidural blockage as quickly and efficiently as possible, the restrictions of the operating room facilities and the like, such problems can cause major difficulties for both the patient as for the medical staff and deserve to be focused. There is a need, therefore, for a probe that has improved patency or evidence to prevent the elimination of fluid flow, which retains the resistance of the probe as well as the integrity of the probe in the body, which it provides to the physician. an easy visualization of the fluids that flow through the probe and that together focus the problems experienced through previous access routes.

COMPENDIUM OF THE INVENTION These and other concerns are addressed by a probe in accordance with the present invention. Although the principles of the present invention are described with specific reference to a probe, it will be readily apparent and will be fully appreciated by an artisan skilled in the art that the principles discussed herein can easily be applied to any tube or similar device subject to patency or difficulties. evidence. The probe is preferably formed of a tube having a proximal end, a distal end and length between them. The inner wall of a probe has a plurality of protuberances placed along the length of the probe in a manner parallel to the central axis of the tube. The protuberances have a tip, a root that extends along the inner wall of a probe and a pair of side walls that extend between the tip and the root of the protrusion. The roots of the adjacent protuberances are spaced apart from each other along the inner wall such that each set of opposite side walls of adjacent protuberances are separated by a portion of the inner wall. When viewed in cross section then the lumen of the probe gives the appearance of having a profile in the form of a gear. A fluid path is established between the inner wall of the tube and each set of opposite side walls of adjacent protuberances. The tip can ensure a variety of shapes, such as flat, blunt, rounded or pointed as needed or desired. In one configuration, the side walls are essentially straight. When bending or twisting forces are exerted on the probe, the spacing between the roots of adjacent protuberances prevents the opposite side walls of the adjacent protuberances from coming into full contact with each other, thus avoiding the occlusion of the fluid path. If desired, the protrusions may be formed with a tip that is narrower than the root such that the opposite side walls are bent one with respect to the other. The tilting of the side walls coupled with the separation of the roots, contributes to the conservation of the fluid path. In another configuration, at least one of the opposite side walls of a protuberance may have a non-linear portion along its length. For example, the non-linear portion can be formed as a curved surface defined along the length of the side wall. Preferably, both opposite side walls of the adjacent protuberances have a non-linear portion along their length. The non-linear portion that is provided in at least one of the opposite side walls aided by the spacing between the roots, prevents the side walls from coming into full contact with each other, thus protecting the fluid path from occlusion. The probe may have a distant end that is either open or closed, as needed or desired. One or more of the holes may be incorporated adjacent a closed remote end to facilitate the supply of fluid to the body. In a preferred embodiment, three side holes are provided. In order to further strengthen the proximal end of the restriction probe by the forces exerted by a medical adapter, such as a Tuohy-Borst adapter, one or more elements of tube-like supports can be incorporated in the proximal end of the probe. In another embodiment, the support elements are placed with the inner wall of the probe adjacent to the proximal end. Preferably, the tubes that can be formed of metal or plastic cannula sections or spiral wound sections are separated from one another inside the inner wall of the probe. By this arrangement, the proximal end of the probe retains its ability to flex, preventing the proximal end from being trapped at the curved distant end of an epidural needle through which the probe has been screwed. The probe can be formed from a variety of materials. Preferably, the selection of the material is translucent, allowing the physician to discern the flow of fluid through the probe. A selection of material is nylon. Alternatively, a mild material such as polyurethane can be employed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail with reference to the following drawings in which: Figure 1 illustrates a longitudinal view of a , x. probe according to the present invention; Figure 2 is a longitudinal cross-sectional view taken along line 2-2 of Figure 1; Figure 3a illustrates a way to form the protrusions, as will be seen in cross section along the line 3a-3a of Figure 1; Figure 3b illustrates a second way to form the protuberances as seen in cross section along the line 3b-3b of Figure 1; Figure 4 is a cross-sectional view of the proximal end of a prior art probe 20 subject to restriction by an external force; Figure 5 is a cross-sectional view of the proximal end of a probe in accordance with the present invention, incorporating one or more support elements at the proximal end to prevent restriction by an external force; Figure 5a illustrates the support elements that can be incorporated in the proximal end of the probe as seen in cross section along the line 5a-5a of Figure 1; Figure 5b illustrates, in cross section, protrusions that act to preserve the fluid path as the probe is subjected to forces normally experienced during use; "" * Figure 6 is a cross-sectional view of a probe in accordance with the present invention that is introduced into the body of a patient by an insertion device such as an epidural needle; and Figure 7 is a cross-sectional view of a probe in accordance with the present invention, in where an introducer device such as an epidural needle is being withdrawn around the probe once the probe is finally placed in the body.

DETAILED DESCRIPTION OF THE INVENTION 20 Turning now to the drawings, wherein like numbers represent like components, a mode of a probe 10 in accordance with the present invention is illustrated in Figures 1 and 2. The probe 10, which can be extruded in a tube-like manner from a material such as polyurethane or nylon, includes one end 12, a distant end 14 and a length or section between them. The probe 10 also includes an external wall 16, an internal wall 17 and a fluid carrying lumen 19 inside the probe characterized by a central "X" axis. One or more signs or marks 80 deep (Figure 6) may be printed or otherwise provided on the external wall 16 to assist the physician in assessing the relative insertion of the probe 10 into the body cavity. As illustrated herein, the distal end 14 is closed with one or more side holes 18 that are provided between the outer and inner walls of the probe, adjacent the distal end to allow fluid flow between the probe 10 and a cavity. of the body. In a preferred construction, three side holes 18 are provided but one skilled in the art will appreciate that the probe 10 can be configured to incorporate any number of side holes 18. It will also be understood by an expert that the probe 10 can be constructed such that the remote end 14 is open. An inconvenience of certain probes of the prior art is their loss of patency or evidence due to the occlusion of the fluid conduit when twisting or bending forces are applied to the probe during normal use. A particularity of the probe 10 according to the present invention is to incorporate a structure that maintains the flow of fluid through the probe in spite of the torsional or bending forces experienced during normal use of the probe. For example, as can be seen in Figures 2 and 3a, the probe 10 can be constructed in such a way that the fluid carrying lumen 19, when viewed in cross section (Figure 3a) appears in the form of a gear. The probe 10 has one or more protuberances 20 formed or otherwise provided along the internal wall 17. The protrusions 10 are preferably oriented longitudinally along the probe 10 parallel to the central axis "X" of the lumen 19. Here, it will be seen that seven protuberances are provided, but a skilled artisan will appreciate that any number of protuberances can be provided. protuberances that is appropriate to the size and application of the probe. The protuberances 20 each exit a root 22 positioned along the inner wall 17 and extend to a point 24. A pair of side walls 26 extend between the tip and the root of each protuberance 20. The lumen 19 carrier of fluid is characterized by a main fluid channel 29 and one or more fluid paths 28. Both the main fluid channel 29 and each of the fluid paths 28 extend along the length of the probe 10. As seen in Figure 3a, the lumen 19 includes a main "Z" diameter as measured on the inner wall 17. If a circle "C" is drawn connecting one of the tips 24, the lumen 19 also defines a "Y" of small diameter. The area of the probe 10 placed inside the circle "C" establishes the main fluid channel 29 of the lumen. Referring again to Figure 3a, it will be seen that each of the roots 22 of the adjacent protuberances 20 are separated from one another by a respective section 23 of the internal wall 17. Accordingly, a fluid path 28 is established outside the area of the circle "C" between the inner wall 17 and each pair of opposite side walls 26 of the adjacent protuberances. The total appearance of lumen 19 when seen in cross section is similar to that of an internal gear. The configuration of the protuberances 20 preserves the patency or evidence of the probe 10 in case the main fluid channel 29 is occluded by torsional or bending forces normally experienced during use. Referring to Figure 5b, if the probe 10 is subjected to torsion or bending forces normally experienced during use, the spacing between the roots 22 of the adjacent protrusions prevents the opposing side walls 26 from coming into full surface contact with one another. other. Accordingly, the fluid path 28 between the inner wall 17 and each pair of opposite side walls 26 is prevented from total occlusion, thus allowing the flow of fluid through the probe 10 even when the main fluid channel 29 is occluded by those forces. Figure 3a illustrates that the side walls 26 can be formed essentially from straight sides. Here, it is likewise illustrated that the root 22 is wider than the tip 24 of a given protuberance 20. In this way, the side walls 26 are bent between the tip and the root, such that the fluid path 28 is wider when measured in the "C" circle than when measured in the internal wall 17. The tilting of the side walls 26 coupled with the spacing provided between the roots 22 of the adjacent protuberances, helps to prevent the opposite side walls 26 from coming into full surface contact with each other under the torsional or bending forces. However, it will be appreciated by an expert that if desired, the side walls 26 need not be edged, the roots 22 and the tips 24 can take the same width, the spacing between the roots 22 of the adjacent protuberances acting only to prevent contact total surface between the opposite side walls 26. Figure 3b illustrates an alternative way to configure the lumen 19 ', in accordance with the present invention. Here, instead of the straight side walls 26, each of the protuberances 20 'has side walls 26' which exhibit at least a non-linear portion along the length of the side wall. In a configuration such as that illustrated in Figure 3b, the non-linear portion may comprise forming the side walls 26 'with a curved portion 27'. As above, each of the protuberances 20 'is separated from one another by a respective section 23' of the inner wall 17 '. In this way, the curved portion 27 ', coupled with the spacing provided between the roots 22' of the adjacent protuberances, helps to prevent the total surface contact between the opposite side walls 26 'thus preserving the trajectory 28' of fluid. Also, as described above, the side walls 26 'can be set between the roots 22' which are wider than the tips 24 ', further contributing to preserve the patency or evidence of the probe. Many of the features of the probe 10 can be modified by a user as necessary or desired. For example, even when Figures 3a and 3b illustrate that the protuberances 20 (20 ') are equally spaced along the inner wall, a skilled artisan will appreciate that, if desired, the spacing may be uneven. Also, even when the spacing between the adjacent protuberances 20 (20 ') is illustrated as sections 23 (23') of the circumferential length of the circular internal wall 17, it will be understood that the probe can be formed in such a way that the sections 23 (23 ') adopt other configurations, either linear or non-linear. While the tips 24 (24 ') are shown as flat, they can take any configuration such as pointed or rounded and can be sharp or blunt as desired. In addition, even when the probe 10 can be extruded from a single material, it will be apparent that the probe can also be co-extruded from different materials. For example, the protuberances 20 (20 ') may encompass a material that differs from the material used for the remainder of the probe 10. In the same manner, Figures 1, 3a and 3b illustrate that one or more radiopaque strips 70 may be incorporated in the probe 10 by extruding an appropriate material into the body of the probe. For example, one or more of the radiopaque strips 70 may conveniently be extruded in the probe 10 between the external wall 16 and one or more of the tips 24 (24 ') of the protuberances.

As described above, an area of a probe particularly prone to occlusion difficulties is the proximal end. This is particularly the case if the probe is formed of a relatively smooth material such as polyurethane. As illustrated in Figure 4, in the prior art, a probe 30 is subject to torsion and / or oppression "F" forces exerted by a medical adapter such as the Tuohy-Borst adapter, which is fixed to the proximal end. The "F" forces can restrict the fluid carrying lumen 39 of the prior art probe contributing to patency or evidence difficulties. To further improve the patency characteristics of a probe in accordance with the present invention, if desired, one or more elements 40 of tube-like supports can be inserted in surface contact with the inner wall 17 of the probe 10 adjacent to the proximal end. (see Figures 5 and 5a). The support elements, for example, may be formed of sections of metal or plastic cannulas or may encompass sections of spiral windings. The number or placement of the support elements 40 at the proximal end of the probe 10 can be selected per user according to the length of the probe 10 subjected to the "F" forces. Here, it will be seen that three support elements 40 are provided. It will also be understood by a skilled artisan that the support elements 40 may be incorporated around the external wall 16 of the probe 10. Preferably each of the support elements 40 are separated from one another by a distance 5"A". As illustrated in Figure 6, the probe 10 is normally inserted into a cavity of the patient's body through a lumen 52 of an insertion device such as an epidural needle. After * "" "" the probe is placed within the desired area of the The body cavity is fixed with tapes or otherwise held in place against the patient, and the epidural needle is removed from the body with the probe passing through lumen 52 (see Figure 7). Most epidural needles 50 include curved distant ends 54.

By separating the support elements 40 from one another, the proximal end 12 of the probe 10 remains flexible "" preventing the proximal end from being retained within the curved distant end of the epidural needle during withdrawal. Therefore it will be seen that the probe in accordance with the present invention addresses many of the inconveniences exemplified by the prior art. The probe exhibits improved patency properties essentially along its entire length all without obscure the physician's view during use and allowing the probe to be formed of a relatively soft material with a closed-ended construction in order to minimize the traumatic effects for the patient. The construction also contributes to the overall strength and integrity of the probe along its entire length. It will be appreciated and understood by those skilled in the art that additional forms of the invention may be devised without departing from the spirit and scope of the appended claims, the invention not being limited to the specific embodiments shown.

Claims (10)

CLAIMS:

1. A probe having patency properties comprising: a tube having a proximal end, a distal end and a length therebetween, the tube having a central axis, an outer wall and an inner wall, the inner wall having a plurality of protrusions placed longitudinally on the inner wall in a direction parallel to the central axis of the tube, each of the protuberances has a tip, a root extending along the inner wall and a pair of side walls extending between the tip and the root, each of the roots of plurality of protuberances is separated from one another along the inner wall, one of the side walls of a protuberance is oriented in opposite relation to one of the side walls of an adnt protuberance , wherein a fluid path coaxial with the central axis of the tube is defined between the inner wall of the tube and the opposite side walls of the adnt protuberances s, wherein in response to a force experienced during the normal use of the probe, the spacing between the roots of the plurality of protuberances prevents the opposite side walls from coming into full contact with each other to avoid occlusion of the path of the probe. fluid defined between the opposite side walls and the inner wall.

2. The probe according to claim 1, wherein the side walls are straight.

The probe according to claim 1, wherein at least one of the opposite side walls of the adnt protuberances defines a non-linear portion.

The probe according to claim 3, wherein the non-linear portion of one of the opposite side walls comprises a curved surface.

The probe according to claim 3, wherein each of the opposite side walls defines a non-linear portion between the tip and the root.

6. The probe in accordance with the claim 5, wherein the non-linear portion defined by each of the opposite side walls comprises a curved surface.

The probe according to claim 3, wherein the separation between the roots cooperates with the non-linear portion of one of the opposite side walls to prevent the opposite side walls from coming into total contact with each other in order to avoid the occlusion of the fluid path defined between the opposite side walls.

8. The probe according to claim 1, wherein the root is of the plurality of protuberances are equally spaced apart from one another.

9. The probe according to claim 1, wherein a radiopaque strip is placed in the tube. The probe according to claim 1, wherein the distal end is closed and further comprises a plurality of lateral holes positioned adnt the distal end of the probe. SUMMARY OF THE INVENTION A probe designed for improved patency characteristics under forces that are normally exerted on the probe during use. The probe has an internal wall having one or more protuberances running longitudinally in a manner parallel to the central axis of the probe. The protuberances include a tip, a root defined along the inner wall and a pair of side walls that extend between the tip and the root. The roots of the adnt protuberances are separated one from the other. A fluid path is established between the inner wall and the opposite side walls of the adnt protuberances. The opposite side walls can be straight. Alternatively, at least one of the opposite side walls includes a non-linear portion along its length. In response to a force normally exerted on the probe during use, the spacing between the adnt roots and, if the non-linear portion of the opposite side wall is provided, prevents the opposite side walls from coming into full contact with each other, thus avoiding occlusion of the fluid path. If desired, to reinforce the occlusion probe by a medical adapter attached to the proximal end, one or more of the support elements may be incorporated in the proximal end of the inner wall.