Abstract:
A popoid connector for use with other medical devices such as tracheal tubes, intubation tubes and aspiration and ventilation systems comprises a plurality of saucer shaped members each having a first portion and a second portion to form a corrugated portion along the connector. On side of each of the saucer shaped members is provide with at least one circumscribing reinforcing rib to provide additional structural support for the popoid connector. The reinforcing ribs are integrally formed with the popoid connector. The reinforcing ribs inhibit transverse collapsing of the popoid connector add rigidity to the popoid connector when the popoid connector is in a bent position.

Description:
BACKGROUND 
     1. Field of the Invention 
     This invention relates generally to connectors for various tubular medical devices, and, more specifically, to a popoid type connector that is capable of being bent relative to a longitudinal axis thereof and is configured to maintain the bent position. 
     2. Background of the Invention 
     Popoids are typically formed into plastic tubing to allow bending of the plastic tubing without causing the plastic tubing to kink. A popoid is generally comprised of a plurality of saw tooth sections that are circumferentially formed into the wall of the tubing. When collapsed, each saw tooth section abuts against and fits slightly within the adjacent saw tooth section effectively shortening the length of tubing from which the popoid is formed. In an expanded position, the popoid is capable of bending in any direction (i.e., 360 degrees) relative to the longitudinal axis of the tubing in which the popoid is formed and will generally hold its bent position when released. 
     Popoid devices are used in many applications both inside and outside the medical industry. For example, plastic drinking straws have been available for many years that include a popoid section proximate the drinking end thereof to allow the straw to bend along the popoid section and thus maintain its bent shape when released. In the medical industry, popoid devices have been developed for use where typically more rigid tubing devices require bending or flexing without causing the tubing to become kinked. For example, endotracheal tubes are typically formed from a sufficiently rigid plastic material to maintain an open airway through the trachea of a patient. The proximal end of such an endotracheal tube is often connected to other sections of tubing outside the patients body. In order to place less stress on the endotracheal tube as it exits the patient and thus increase patient comfort, connectors have been developed that utilize a popoid section to join the endotracheal tube with another external section of tubing. These popoid connectors allow an abrupt bend to be made in the tubing connected to the endotracheal tube proximate the end of the endotracheal tube exiting the patent that places the least amount of force on the proximal end of the endotracheal tube. Such popoid connectors are also advantageous for use in conjunction with other medical devices such as those used for intubation applications as well as in various breathing circuits for aspiration and/or ventilation. 
     Tubular popoid connectors are typically formed from extruded sections of plastic tubing. Often, shortly after extrusion, the sections of plastic tubing are placed within a mold. Because the sections of plastic tubing are placed within the mold shortly after extrusion, the sections of tubing are still in a pliable state and have thus not yet complete solidified. As such, the sections of tubing are amenable to being molded. The molds include recesses formed therein that are configured to define the popoid connector Such molds are generally formed from two matching half molds, each of which define a plurality of semicircular recesses as well as the other desired features of the popoid connector. When mated, the two matching half molds form the complete desired shape of the popoid connector. 
     As each section of tubing is placed within the mold, the tubing is forced into the recesses of the mold to cause the tubing to form to the inside of the mold. Such force is usually applied by using suction on the external surfaces of the tubing to draw the tubing into the recesses of the mold, or by pressurizing the inside of the section of tubing to cause the tubing to expand into the internal recesses of the mold. Because the section of tubing is often comprised of a relatively thin walled, plastic material, the section of tubing rapidly cools to rigidly maintain the shape of the mold upon its release from the mold. 
     FIGS. 1 and 2 illustrate a popoid connector, generally indicated at  10 , known in the art. The popoid connector  10  is comprised of a generally elongate tubular member having a distal end  12  and a proximal end  14 . A first connection end  16  is provided at the distal end  12  and includes various features  18 ,  20 ,  22  and  24  for connecting to another device, such as an endotracheal tube (not shown). Likewise, the proximal end  14  has a similarly configured second connection end  26  that includes features  28 ,  30 ,  32 , and  34  for attachment to another medical device. 
     Interposed between the first and second connecting ends  16  and  26 , respectively, is a popoid section, generally indicated at  38 . The popoid section  38  is comprised of a plurality of corrugations  40 - 47  that have a configuration which allows the popoid section  38  to bend and retain its bent orientation when released. Each corrugation  40 - 47  is comprised of a pair of oppositely facing frustoconical sections, such as the frustoconical sections  48  and  50  of corrugation  41 . While the largest and smallest diameters of the frustoconical sections  48  and  50  are the same, the longitudinal length of each frustoconical section  48  and  50  is different. In this example, the frustoconical portions  48  nearest the distal end  12  of each corrugation  40 - 47  have a greater longitudinal length than the longitudinal length of the frustoconical sections  50  nearer the proximal end  14 . When the distal end  12  is forced toward the proximal end  14  along the longitudinal axis of the connector  10 , the frustoconical portions  48  substantially maintain their shape, while the frustoconical portions  50  become inverted to fit within the associated frustoconical portions  48 . Thus, the popoid section  38  will collapse upon itself to shorten the length of the connector  10 . A similar condition occurs when the popoid section  38  is bent in a direction relative to the longitudinal axis of the connector  10 . As the popoid section  38  is bent, the sides of the frustoconical portions  48  and  50  on the side of the popoid section that are in the direction of the bend will fold upon themselves to shorten the length of the popoid along that side. Conversely, the frustoconical portions  48  and  50  that are on the opposite side to the direction of the bend maintain their pre-bent arrangement such that the length of the popoid section  38  along this side of the popoid section  38  maintains its length. 
     In order for the popoid to function properly, the frustoconical sections  50  must be able to flex relative to the frustoconical sections  48  to be able to invert when the popoid section  38  is bent or collapsed and maintain their position when released. Thus, the frustoconical sections  48  are configured with an angle between their outer surface and the longitudinal axis of the connector  10  that is less than the angle between the longitudinal axis and the outer surface of the frustoconical sections  50 . As such, the frustoconical sections  48  are more difficult to collapse than the frustoconical sections  50 . 
     One problem with such prior art popoids, however, has been their generally flexible nature even when placed in a bent position. Because each portion of the popoid is formed from the same length and strength of plastic tubing, even the frustoconical portions that are less likely to flex when the popoid is bent, as previously discussed, are somewhat easy to flex themselves and thus do not create as rigid a structure as may otherwise be desirable. Thus, it would be advantageous to provide a popoid connector that is substantially more rigid than popoid connectors known in the art. It would also be advantageous to provide such a popoid connector without increasing the wall thickness of the tubing from which the popoid connector is formed. It would be a further advantage to provide a popoid connector that is substantially more rigid than popoid connectors known in the art that can be manufactured in a manner that is simple and relatively inexpensive compared to manufacturing techniques utilized for manufacturing popoid connectors known in the art. 
     SUMMARY OF THE INVENTION 
     Accordingly, a flexible connector, commonly referred to as a popoid connector, for interconnecting a pair of medical devices is provided in accordance with the principles of the present invention. The popoid connector is comprised of an elongate section of tubing having distal and proximal ends for connection to other medical devices. The tubing, while being generally cylindrical in overall shape, is provided with a corrugated portion comprised of a first set of frustoconical members and a second set of frustoconical members. The first set of frustoconical members alternate with and face in an opposite direction to the second set of frustoconical members to form corrugations in the tubing. 
     In a preferred embodiment, each corrugation is provided with at least one reinforcing rib circumscribing the corrugation. The reinforcing rib is preferably formed into the first set of frustoconical members. The first set of frustoconical members are preferably the set that substantially maintain their relative orientation with the popoid connector is bent or longitudinally collapsed. 
     Each of the frustoconical members has a slope defined by its outer surface. Preferably, the slope, relative to a longitudinal axis of the tubing, defined by the outer surface of the second set of frustoconical members is greater than the slope defined by the outer surface of the first set of frustoconical members. This variation of slope determines which portions of the popoid collapse when the popoid is bent or longitudinally compressed. That is, the portions that have the least amount of slope have greater structural strength against longitudinal forces applied to the popoid connector and will thus resist collapsing. 
     In yet another preferred embodiment, the frustoconical members of the popoid connector define an outer diameter and an inner diameter wherein the outer diameter is approximately equal to a diameter of the tubing. 
     In still another preferred embodiment, the inner diameter of the frustoconical members is substantially equal to a diameter the tubing. 
     In still another preferred embodiment, the reinforcing rib comprises a ring integral with and circumscribing an outer surface of an associated frustoconical member. 
     In yet another preferred embodiment, each pair of said frustoconical members defines an apex. The reinforcing rib is preferably positioned proximate to the apex. 
     In another preferred embodiment, the reinforcing rib comprises a first reinforcing rib positioned proximate to the apex of the frustoconical members and a second reinforcing rib is positioned proximate to the first reinforcing rib. 
     In yet another preferred embodiment, a third reinforcing rib is positioned proximate to the second reinforcing rib. 
     In still another preferred embodiment, the reinforcing rib is integrally formed with the apex of the frustoconical members. 
     In accordance with another aspect of the invention, the reinforcing rib has a width that is substantially greater than its height. 
     In accordance with yet another aspect of the invention, the reinforcing rib has a width that is substantially equal to its height. 
     In still another preferred embodiment, the reinforcing rib is formed on the inside of the first set of frustoconical members. 
     In yet another preferred embodiment, the reinforcing rib is formed into the second set of frustoconical members. 
     In another preferred embodiment, the reinforcing rib is positioned proximate to a base of the frustoconical member. 
     In another preferred embodiment, the popoid connector includes a plurality of saucer shaped members integral with and forming a corrugated section along a length of an tubular member. Each of the saucer shaped members define at least one circumscribing rib integrally formed therewith and protruding therefrom. 
     The circumscribing ribs may be formed on any outer or inner surface of the saucer shaped members depending upon the desired structural rigidity of the resulting popoid connector. Preferably, however, a pair of circumscribing ribs are provided on the exterior surface of each of the saucer sections on the side of the saucer section that resists longitudinal collapsing when the popoid connector is bent or longitudinally collapsed. 
     Other objects and advantages of the present invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a prior art popoid connector. 
     FIG. 2 is an end elevational view of the prior art popoid connector illustrated in FIG.  1 . 
     FIG. 3 is a side elevational view of a first preferred embodiment of a popoid connector in accordance with the principles of the present invention; 
     FIG. 4 is an end view of the popoid connector illustrated in FIG. 3 
     FIG. 5 is a partial side elevational view of the popoid connector illustrated in FIG. 3; 
     FIG. 6 is a partial cross-sectional side view of a second preferred embodiment of a popoid connector in accordance with the principles of the present invention; 
     FIG. 7 is a partial elevational side view of a third preferred embodiment of a popoid connector in accordance with the principles of the present invention; 
     FIG. 8 is a partial cross-sectional side view of a fourth preferred embodiment of a popoid connector in accordance with the principles of the present invention; 
     FIG. 9 is a partial cross-sectional side view of a fifth preferred embodiment of a popoid connector in accordance with the principles of the present invention; 
     FIG. 10 is a partial cross-sectional side view of a sixth preferred embodiment of a popoid connector in accordance with the principles of the present invention; 
     FIG. 11A and 11B are partial elevational side views of a seventh preferred embodiment of a popoid connector in accordance with the principles of the present invention; and 
     FIG. 12 is a partial elevational side view of an eighth preferred embodiment of a popoid connector in accordance with the principles of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference is now made to the drawings wherein like parts are designated with like numerals throughout. FIGS. 3 and 4 illustrate a flex or popoid connector, generally indicated at  100 , in accordance with the principles of the present invention. The popoid connector  100  is similar in configuration as the prior art popoid connector and is thus comprised of an elongate section or member of tubing  102  that has a distal end  104  and a proximal end  106 . 
     Preferably, the popoid connector  100  is formed from an extruded section of plastic, such as polypropylene. The polypropylene may be combined with other materials to modify the properties of the polypropylene. For example, an ethylene alpha-olefin copolymer, like ENGAGE® Polyolefin Elastomer, or an equivalent known in the art, may be added to the polypropylene to increase its flexibility. In addition, various lubricants such as an unsaturated fatty monoamide, e.g., KEMAMIDE® Ultra Fatty Amide (erucamide), or an equivalent thereof, may be added to the polypropylene to give the polypropylene a more lubricious feel when the popoid connector  100  is attached to another device. Other substances may be added to the polypropylene to increase or decrease its stiffness as desired. 
     A first connection end  108  of the popoid connector  100  is provided at the distal end  104  and includes various features  110  and  112  for connecting to another device, such as an endotracheal tube (not shown). The proximal end  106  has a similarly configured second connection end  114  that includes features  116  and  118  for attachment to another medical device. 
     Interposed between the first and second connecting ends  108  and  114 , respectively, is a popoid section, generally indicated at  120 . The popoid section  120  is comprised of a plurality of saucer shaped members or corrugations  121 - 129  that have a configuration which allows the popoid section  120  to bend and retain its bent orientation when released. Each corrugation  121 - 129  is comprised of a pair of oppositely facing frustoconical sections, such as the frustoconical sections  130  and  132  of corrugation  122 . While the largest and smallest diameters of each frustoconical section  130  and  132  are the same, the longitudinal length of the frustoconical sections  130  and  132  are different. In this example, the frustoconical portion  132  nearest the proximal end  106  of the corrugation  122  has a greater longitudinal length than the longitudinal length of the frustoconical section  130  nearer the distal end  104 . When the distal end  104  is forced toward the proximal end  106  along the longitudinal axis of the connector  100 , the frustoconical portion  132  substantially maintains its shape, while the frustoconical portion  130  inverts to fit within the associated frustoconical portion  132 . Thus, the popoid section  120  will collapse upon itself to shorten the length of the connector  100 . A similar condition occurs when the popoid section  120  is bent in a direction relative to the longitudinal axis of the connector  100 . As the popoid section  120  is bent, the sides of the frustoconical portions  130  and  132  on the side of the popoid section that are in the direction of the bend will fold upon themselves to shorten the length of the popoid  120  along that side. Conversely, the frustoconical portions  130  and  132  that are on the opposite side to the direction of the bend maintain their pre-bent arrangement such that the length of the popoid section  120  along this side of the popoid section  120  maintains its length. 
     In order for the popoid to function, the frustoconical section  130  must be able to flex relative to the frustoconical section  132  to be able to invert when the popoid section  120  is bent or collapsed and maintain this inverted position when released. Because it would be difficult to form the popoid  120  from a tubular material that has varying thicknesses to provide additional material and thus additional rigidity to the frustoconical sections  130 , the frustoconical sections  130  are configured with a slope or angle between their outer surface and the longitudinal axis of the connector  100  that is less than the angle between the longitudinal axis and the outer surface of the frustoconical sections  132 . As such, the frustoconical sections  132  have greater longitudinal strength than the frustoconical sections  130 . 
     Referring now to FIG. 5, the saucer shaped members, such as members  123  and  124 , are defined by frustoconical members  134 ,  135 ,  136  and  137 , respectively. The frustoconical members  134  and  136  face in opposite directions to and alternate with the frustoconical members  135  and  137 , respectively. As such, the pair  134  and  135  of frustoconical members define apex  139  and the pair  136  and  137  of frustoconical members define apex  141 . The apexes  123  and  124  define an outer diameter of the popoid section  120  which is preferably approximately equal to the diameter of the ends  104  and  106  of the connector  100 . By narrowing the outer diameter of the popoid section  120 , the popoid section becomes inherently stronger since the material forming the popoid section  120  is expanded to a lesser degree than would be the case if the popoid were configured similar to the popoid connector of FIG.  1 . 
     Each frustoconical member  134 ,  135 ,  136  and  137  defines a base which further defines the smallest diameter of the popoid section  120 . Those skilled in the art after understanding the principles of the present invention will appreciate the popoid section  120  may be configured similar to that illustrated in FIG. 1 such that the inner diameter defined by that base of the frustoconical sections  134 ,  135 ,  136 , and.  137 , as well as others, is approximately equal to the diameter of the ends  104  and  106  of the popoid connector  100 . 
     Each of the frustoconical members  135  and  137  that resists inversion when the popoid section  120  is longitudinally collapsed is provided with circumscribing reinforcing ribs  140  and  142  that are integrally formed therewith. With reference to apex  139 , the rib  140  is configured to have a width that is similar to its height and is positioned adjacent to the apex  139 . The second rib  142  has a smaller diameter depending on its location and is spaced from but proximate to the first rib  140 . The ribs  140  and  142  provide structural support for the frustoconical portion  135  so that the popoid section  120  will more rigidly hold its position when bent to a position that causes one or more frustoconical portions, such as portion  134  to invert. Thus, the ribs  140  and  142  stop compression of the frustoconical portion  135  perpendicular to the longitudinal axis of the popoid connector. 
     As illustrated in FIG. 6, the saucer section  150  and  151  may include different numbers of ribs  152 ,  154 , and  156  as desired. With specific reference to saucer section  150 , because of its shortened frustoconical portion  158 , only one reinforcing rib  152  is provided. Preferably, however, each of the other saucer sections, such as saucer section  152  are provided with equal numbers of ribs along a substantial portion of the length of the popoid section to provide equal rigidity throughout. 
     FIG. 7 illustrates yet another preferred embodiment of a portion of a popoid section, generally indicated at  200 , in accordance with the principles of the present invention. As with other embodiments herein described, the popoid section  200  is comprised of a plurality of oppositely facing frustoconical portions  201 - 204 . The frustoconical portions  202  and  204  each include three circumferential ribs  205 - 205 ,  206 , and  207  that circumscribe an outer surface and are integrally formed with the outer surface of the frustoconical portions  202  and  204 . The ribs  205 ,  206 , and  207  are preferably molded into the outer surface of the popoid section  200  and are formed from the same material as the rest of the popoid connector. Thus, the ribs  205 ,  206  and  207  do not add any extra material to the popoid connector while adding strength to the frustoconical portions  202  and  204 . 
     As illustrated in FIG. 8, reinforcing rings  220  and  222  may be provided on frustoconical portions  224  and  226 , respectively, in addition to ribs  228  and  230  that are similar to those previously described. As such, the reinforcing rings  220  and  222  provide structural support for the frustoconical portions  224  and  226  that will invert when the popoid is bent to a certain degree. As further illustrated, the rings  220  and  222  are positioned proximate the base  232  and  234  of the frustoconical portions  224  and  226 , respectively to add structural support to the frustoconical portions  224  and  226  at this location to help maintain the frustoconical portions  224  and  226  in an inverted position. 
     In accordance with the principles of the present invention, as illustrated in FIG. 9, reinforcing ribs  250  and  252  are provided an the inside surface  254  of the popoid section, generally indicated at  260 . The ribs  250  and  252  are formed by indentations or recesses in the outer surface  253  of the popoid  260 . As such, protrusions, rather than recesses, may be formed in a popoid mold (not shown) to form the internal ribs  250  and  252 . It is further illustrated that the ribs  250  and  252  are positioned near the base  262  of each saucer section  264  an  266  to cause minimal interference with the collapsing process as the saucer sections  264  and  266  fold relative to one another. Those skilled in the art, after understanding the principles of the present invention that any of the other popoids described herein may be provided with internal stiffening ribs or a combination of internal and external stiffening ribs. 
     Referring now to FIG. 10, a saucer shaped member, generally indicated at  300 , a plurality of which would form a popoid, includes a first reinforcing bead or ring  302  which circumscribes the saucer shaped member  300  immediately adjacent the apex  304  of the saucer shaped member  300 . The ring  302  may be positioned on either side  308  and  310  of the saucer shaped member  300 . An additional circumscribing, reinforcing rib  312  is positioned proximate the ring  304  around the side  308  of the saucer shaped member  300 . 
     As shown in FIGS. 11A and 11B, the reinforcing ribs  400  and  402  have a width W that is larger than its height H. As such, after understanding the principles of the present invention, the reinforcing ribs in accordance with the present invention may have may different sizes and configurations. In addition, as illustrated in FIG. 12, the various reinforcing ribs, such as ribs  500  and  502 , discussed and described herein may be combined in a single popoid section, generally indicated at  504  depending on the desired characteristics of the popoid section  504 . 
     It will be appreciated that the various embodiments specifically described of the present invention are capable of being incorporated in the form of a variety of embodiments, only a few of which have been illustrated and described above. The invention may be embodied in other forms without departing from its spirit or essential characteristics. For example, the reinforcing or stiffening ribs described in conjunction with the illustrated embodiments have generally been shown as having a semicircular or rounded cross-sectional shape. It is understood, however, that the geometric cross-sectional configuration of such ribs, whether external or internal, may include, but is not limited to, rectangular, square, triangular, pointed, and/or any combination thereof and such rib configurations are intended to come within the scope of the appended claims. Thus, the described embodiments are to be considered in all respects only as illustrative and not restrictive, and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.