INTERLOCKING LOW PROFILE GRIPPING DEVICE

Abstract

A low profile gripping device having a locking assembly attached to a base, wherein the locking assembly comprises a locking strap with pairs of fins disposed for insertion into an aperture of a buckle. The locking assembly comprises an anchor block having opposing sides, the locking strap attached to one side, and the buckle attached to the opposing side. The interface between the locking strap and the anchor block forms a creased groove for seating a flexible polymer tube or polymer coated cable. The locking strap is inserted through the aperture to secure the tube or cable in the creased groove, and the fins retain the locking strap in fixed relation to the buckle.

Claims

1. A gripping device for securing flexible polymer tubing or polymer coated cables to the skin of a medical patient, the gripping device comprising: an elongated base having a bottom and a top, the bottom comprising an interface member, and the top having a sloped apron surrounding a central table; one or more locking assemblies, each locking assembly attached to the base, and each of the locking assemblies comprising: an anchor block having a first side and a second side, the first side having a recess; a locking strap having a root, a spine, a tip, and a plurality of fins, the root anchored in the recess of the first side of the anchor block such that a creased groove is defined by an interface between the first side and the locking strap, the fins disposed in pairs symmetrically about the spine, each fin having a trailing edge disposed substantially perpendicular to the spine, and a leading edge disposed at about a 40° angle in relation to the trailing edge; and a buckle having a root and a distal end, the root attached to the second side of the anchor block, and the root having a yoke such that an aperture is defined by the second side of the anchor block and the yoke.

2. The gripping device of claim 1, wherein anchor blocks are attached to the top of the base at a skewed orientation in relation to the table of the base.

3. The gripping device of claim 1, wherein the locking strap comprises a visual indicator corresponding to a diameter of a tubing member.

4. The gripping device of claim 1, wherein the interface member comprises a plurality of cleats disposed in a dovetail orientation.

5. The gripping device of claim 1, wherein the interface member comprises an irregular surface feature.

6. The gripping device of claim 1, wherein the root of the locking straps further comprise an elbow having an outside and an inside, the outside curving away from the base, and the inside having a cutout groove.

7. The gripping device of claim 1, wherein the pairs of fins attached to the locking strap are disposed such that a notch is defined between adjacent fin pairs, and the buckles have a thickness sized to snugly seat in the notch.

8. The gripping device of claim 2, wherein the locking strap comprises a visual indicator corresponding to a diameter of a tubing member.

9. The gripping device of claim 2, wherein the interface member comprises a plurality of cleats disposed in a dovetail orientation.

10. The gripping device of claim 2, wherein the interface member comprises an irregular surface feature.

11. The gripping device of claim 2, wherein the root of the locking straps further comprise an elbow having an outside and an inside, the outside curving away from the base, and the inside having a cutout groove.

12. The gripping device of claim 2, wherein the pairs of fins attached to the locking strap are disposed such that a notch is defined between adjacent fin pairs, and the buckles have a thickness sized to snugly seat in the notch.

13. The gripping device of claim 8, wherein the root of the locking straps further comprise an elbow having an outside and an inside, the outside curving away from the base, and the inside having a cutout groove.

14. The gripping device of claim 8, wherein the pairs of fins attached to the locking strap are disposed such that a notch is defined between adjacent fin pairs, and the buckles have a thickness sized to snugly seat in the notch.

15. The gripping device of claim 9, wherein the root of the locking straps further comprise an elbow having an outside and an inside, the outside curving away from the base, and the inside having a cutout groove.

16. The gripping device of claim 9, wherein the pairs of fins attached to the locking strap are disposed such that a notch is defined between adjacent fin pairs, and the buckles have a thickness sized to snugly seat in the notch.

17. The gripping device of claim 13, wherein the interface member comprises a plurality of cleats disposed in a dovetail orientation.

18. The gripping device of claim 14, wherein the interface member comprises a plurality of cleats disposed in a dovetail orientation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a perspective view of one embodiment of a gripping device in its undeformed shape.

[0016] FIG. 2 is a top view of one embodiment of a gripping device in its undeformed shape.

[0017] FIG. 3 is an isometric view of one embodiment of a gripping device in its undeformed shape.

[0018] FIG. 4 is a side view of one embodiment of a gripping device.

[0019] FIG. 5 is a bottom perspective view of one embodiment of a gripping device.

[0020] FIG. 6 is a bottom view of one embodiment of a gripping device.

[0021] FIG. 7 is a side view of one embodiment of a gripping device, showing a locking strap inserted through the aperture of the buckle.

[0022] FIG. 8 is a perspective view showing a tubing member securely retained by one embodiment of a gripping device.

[0023] FIG. 9 is a perspective view showing a tubing member having a service loop securely retained by one embodiment of a gripping device.

[0024] FIG. 10 is a top view of one embodiment of a gripping device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] With reference to the drawings, the gripping device will now be described with regard for the best mode and the preferred embodiments. In general, the device disclosed herein is a gripping device for securing polymer tubing and polymer coated cables to a medical patient's body. The embodiments disclosed herein are meant for illustration and not for limitation of the inventive scope. An ordinary practitioner will appreciate that it is possible to create many variations of the following embodiments without undue experimentation.

[0026] One aspect of the present gripping device 1 is to secure flexible polymer tubing or flexible polymer coated cables, collectively referred to herein as “tubing members.” These tubing members 5 are typically attached to medical equipment that provides direct therapy or monitoring of a patient, or introduces or removes fluids to or from the patient's body. The gripping device 1 is adapted for direct attachment to the surface of a patient's epidermis. This securement is accomplished by the assembly of the present catheter gripping device to a specially formulated hydrocolloid patch 11, which is manufactured in various sizes and shapes.

[0027] Referring to FIGS. 1-4, in one embodiment, the gripping device 1 comprises one or more locking assemblies 25 attached to a base 10. The base 10 is intended to secure the locking assemblies 25 to an adhesive patch 11, such as a hydrocolloid patch, which is adapted to removably attach to the skin of a medical patient. The base 10 is an elongate member with rounded ends 12, and the base 10 has a top 13 and a bottom 14 (See FIGS. 5 & 6). The top 13 of the base 10 has a central table 15 surrounded by a sloping apron 16. The table 15 is oriented in substantial alignment with a longitudinal axis 17 of the base 10. It is preferable, but not required, that the base 10 is substantially symmetric about its longitudinal axis 17.

[0028] In one embodiment, the base 10 is secured to the patch 11 by an adhesive. Referring to FIGS. 5 and 6, the bottom 14 of the base 10 comprises one or more interface members 18 to assist mechanical bonding between the base 10 and the adhesive. Examples of interface members 18 could be cleats 19 disposed in a dovetail orientation, a roughened surface 20, or some other equivalent interface feature capable of forming a mechanical bond with the cured adhesive disposed between the bottom 14 of the base 10 and the patch 11.

[0029] Referring again to FIGS. 1-4, each locking assembly 25 comprises an anchor block 26, a locking strap 27, and a buckle 28. The anchor block 26 is secured to the base 10, and the anchor block 26 has a length disposed substantially parallel to the longitudinal axis 17 of the base 10. The anchor block 26 has a first side 29, a second side 30, the first side 29 and second side 30 being separated by a crown 31. The first side 29 of the anchor block 26 has a recess 32 for receiving the locking strap 27, as described below. In one embodiment, the anchor block 26 is attached to the base 10 at a location offset from the longitudinal axis 17. In this configuration, the anchor block 26 is attached to the table 15 and to the apron 16 on one side of the longitudinal axis 17. However, in this configuration the anchor block 26 does not attach to the apron 16 on both sides of the longitudinal axis 17.

[0030] Each locking strap 27 comprises a root 33, a spine 34, a tip 35, and a plurality of locking members 36, such as or fins, tabs, or the like. Each of the fins 36 has a trailing edge 37 and a leading edge 38. The trailing edge 37 is disposed at an orientation that is about perpendicular to the spine 34 when the gripping device 1 is in its undeformed shape. The leading edge 38 is disposed at an angle of about 40° in relation to the trailing edge 37 (see FIG. 10). The fins 36 are disposed in pairs symmetrically about the spine 34. The pairs of fins 36 are spaced at intervals along the spine 34 such that the space between the pairs of fins 36 defines a notch 39.

[0031] The root 33 of the locking strap 27 is anchored in, or attached within, the recess 32 of the first side 29 of the anchor block 26. The root 33 comprises an elbow 21 having a cutout groove 22 on the inside of the elbow 21 to promote flexibility. The elbow 21 of the root 33 biases the orientation of the locking strap 27 such that in its undeformed shape, the locking strap 27 is oriented in a plane that is substantially parallel to the plane of the table 15 of the base 10. At least a portion of the first side 29 of the anchor block 26 is curved toward the crown 31, which is the direction opposite that of the curvature of the outside of the elbow 21. Thus, the interface between the elbow 21 and the first side 29 defines a creased groove 23.

[0032] FIG. 4 illustrates an angle located at the creased groove 23 in which a small French size tubing member 5 may be placed, as described above. The angle of the creased groove 23 is preferably about 80°. This angle minimizes or eliminates the possible mechanical occluding of tubing members 5 enclosed by the gripping device 1 post threading of the locking strap 27 into the aperture 43.

[0033] Referring again to FIGS. 1-4, each buckle 28 comprises a root 40 and a distal end 41. The root 40 is attached to the second side 30 of the anchor block 26. The root 40 comprises a Y-shaped or a U-shaped structure, such as a yoke 42. The open end of the yoke 42 is placed against the second side 30 of the anchor block 26 such that an aperture 43 is defined by the second side 30 and the yoke 42. The width of the aperture 43 is slightly larger than the width of the spine 34 of the locking strap 27, but smaller than the tip to tip width of a pair of fins 36. In one embodiment, the tip to tip width of the fins is about 2 mm larger than the width of the aperture 43. The buckle 28 has a thickness sized to snugly seat in a notch 39 between pairs of fins 36. In another embodiment, the aperture 43 is disposed within the buckle 28, and the second side 30 does not form a part of the aperture 43.

[0034] Referring to FIGS. 7-8, the gripping device 1 is capable of releasably securing tubing members 5 of various sizes. For a large diameter tubing member 5, one of a relatively large French size, the tubing member 5 is first placed in the creased groove 23 between the first side 29 of the anchor block 26 and the root 33 of the locking strap 27 attached to the anchor block 26. The locking strap 27 is then looped over the tubing member 5, and the tip 35 of the locking strap 27 is inserted through the aperture 43 of the buckle 28. The tip 35 is then pulled such that the locking strap 27 continues to pass through the aperture 43, thereby forcing one or more pairs of fins 36 through the aperture 43. As the fins 36 pass through the aperture 43, the fins 36 deform in shape, bending toward the trailing edge 37 to enable passage of the relatively wide fins 36 through the relatively narrow aperture 43. The angled orientation of the leading edge 38 of the fins 36 promotes passage of the pairs of fins 36 through the aperture 43. Optionally, the throat 44 of the aperture 43 can comprise angled walls 45 to further promote passage of the fins 36. The orientation of the angled walls 45 can approximate that of the leading edges 38, thus oriented at about 40° with respect to the trailing edges 37.

[0035] The locking strap 27 is pulled through the aperture 43 until the locking strap 27 snugly wraps around the tubing member 5, thereby seating the tubing member 5 firmly into the creased groove 23. The locking strap 27 is thus held in place, securing the tubing member 5, because the trailing edge 37 of the fins 36 abut against the root 40 of the buckle 28 in proximity to the aperture 43. In other words, due to the configuration of the fins 36, the retraction force needed to retract the locking strap 27 from the aperture 43 is larger than the insertion force required to insert the locking strap 27 into and through the aperture 43.

[0036] For tubing members 5 of a smaller diameter, or smaller French size, such tubing members 5 are secured in a manner similar to that described above. In fact, tubing members 5 of any French size can be seated in the creased groove 23 to minimize mechanical occluding of the fully secured tubing member 5. In an alternative orientation, the tubing members 5 can be placed on the crown 31 rather than seated in the creased groove 23. However, this orientation may increase the risk of mechanical occluding of the tubing member 5.

[0037] In one embodiment, the gripping device 1 is made from an amorphous thermoplastic elastomer polymer, herein referred to as “TPE,” which is extremely elastic (reaching 870% elongation) with a very high tear strength value (19.3 kN/m). TPE materials exhibit the properties of both plastics and rubbers. Additionally the natural tribological or frictional nature of the TPE allows for superior gripping to other polymeric materials, which is a characteristic not present in prior art gripping devices. The designed surface area of the interfacing surface of the present gripping device 1 establishes a large tangential contact area to the polymer tubing members 5.

[0038] Thermoplastic elastomers are generally low modulus, flexible materials that exhibit substantial elastic deformation. These materials may be subjected to temporary shape changes that are normally self-reversing after a force is removed, thus enabling an object made from this material to return to its original shape. Elastic deformation is a change in the shape of a material at low stress, and this deformation is recoverable after the stress is removed. This type of deformation involves stretching of the bonds of the TPE material, but the atoms do not slip past each other.

[0039] The tribological aspect of the material chosen for the gripping device 1 can be defined as the contact behavior of the interface, in that it depends not only on the morphology of solids, but the elasticity, viscoelasticity, and surface hardness of the contact surfaces of the polymers that will come in contact with the surface of the gripping device 1. The unique design features of the gripping device, coupled with the tribological aspects of the TPE, increase the run-in friction of the interface of the gripping device 1 and the tubing members 5. Run-in friction is an unsteady state friction. It refers to a friction state where the frictional coefficient varies as the sliding time (sliding distance) during the beginnings of relative motion. For example, if a polymeric sphere slides across a relatively clean, smooth, and hard surface, the majority of resulting frictional forces arise from the interfacial adhesion. Therefore if polymeric surfaces slide over relatively clean, smooth, hard surfaces, such as normally stiff PVC tubing used for LVAD drivelines, most frictional forces are resulted from the interfacial adhesion created by the contacting surfaces.

[0040] The effect of this phenomenon is that the use of this TPE material with these polymeric characteristics increases the mutual attraction of the polymeric substances used in the construction of flexible polymer tubing and polymer coated cables. This increases the coefficient of friction between the contacting polymeric surfaces of the tubing members 5 and the gripping device 1, thus minimizing or eliminating chance occurrence of the tubing members 5 slipping or sliding relative to the gripping device 1. The mechanical design features of the gripping device 1 coupled with this TPE material allow for maximum surface contact between the gripping device 1 and the tubing members 5.

[0041] In one exemplary embodiment, shown in FIGS. 1-3, a multi-strap design has two or more locking assemblies 25 that are flexible, extremely elastic (about 870% elongation), and attached to the base 10 adjacent to each other. These locking assemblies 25 may be molded onto the base 10 or attached by an adhesive or other suitable attachment material. The locking straps 27 of each locking assembly 25 can be manufactured in various lengths that can accommodate very small (3 Fr) to very large (47 Fr) sized tubing members 5.

[0042] In one embodiment, shown in FIG. 9, the distance between the adjacent locking assemblies 25, as measured along the length of the base 10, is calculated to allow for a service loop 46 in the tubing member 5. The distance should be large enough such that the service loop 46 does not kink or otherwise mechanically occlude the tubing member 5. In many types of tubing members 5, approximately 30 mm length service loops 46 may be desirable.

[0043] In another embodiment of the gripping device 1, shown in FIG. 10, the gripping device 1 has a single locking assembly 25, which is located at about the midpoint along the length of the base 10.

[0044] In another embodiment of the locking assembly 25, shown in FIGS. 1-3, and 10, each of the locking straps 27 further comprises a visual indicator 47 corresponding to the approximate diameter of tubing member 5 to be secured. For example, the visual indicator 47 could be a series of numerical references to approximate French size of the tubing member 5 to be secured. The locking straps 27 are threaded into the aperture 43 of the buckle 28, as described above. The locking straps 27 are inserted through the buckle 43 to an extent corresponding to the visual indicator's 47 designation of the French size of the tubing member 5. Use of this type of visual indicator 47 ensures that each tubing member 5 is securely retained by the gripping device 1 without unnecessary over tightening, which can cause mechanical occlusion of the tubing member 5.

[0045] In one embodiment, the height of the base is about 2 mm. In this embodiment, the overall height of the undeformed gripping device 1 is about 7.5 mm.

[0046] The low profile of the base 10 enables other dimensions of the gripping device 1 to be fabricated in a manner such that there is little or no loss in the mechanical strength or elastic properties of the gripping device 1. The low profile of the gripping device 1 is beneficial to minimize or eliminate the tubing member 5 from snagging, catching, entangling, or otherwise interfering with other patient monitoring or therapeutic devices or lines.

[0047] The foregoing embodiments are merely representative of the gripping device and not meant for limitation of the invention. For example, persons skilled in the art would readily appreciate that there are several embodiments and configurations of locking assembly features and other components will not substantially alter the nature of the gripping device. Likewise, elements and features of the disclosed embodiments could be substituted or interchanged with elements and features of other embodiments, as will be appreciated by an ordinary practitioner. Consequently, it is understood that equivalents and substitutions for certain elements and components set forth above are part of the gripping device described herein, and the true scope of the invention is set forth in the claims below.