Abstract:
A multi-lumen catheter, for insertion into and draining a body cavity, that mitigates the risk of obstruction of the drainage ports and drainage lumen of the catheter, reduces the detrimental effects caused by the suction forces of the drainage ports on the body cavity being drained, and reduces the risk of infection of the body cavity being drained by decreasing the residual volume of fluid retained in the body cavity being drained. These advantages are achieved by the novel approach of disposing a perforated filter membrane over a segmented retention element and also over the drainage ports of the drainage lumen of the catheter thereby creating internal interstitial drainage channels and internal interstitial drainage cavities.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Nos. 61/820,532, filed May 7, 2013, and 61/826,869, filed May 23, 2013, which are both incorporated herein by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates generally to medical devices and, in particular, to retention drainage catheters. 
       BACKGROUND OF THE INVENTION 
       [0003]    In the medical field, catheters are generally used to drain fluids from a body cavity. In the urology field, a Foley retention drainage catheter, which may be interchangeably referred to as a Foley catheter or drainage catheter, is commonly used to drain a human bladder. There are many medical conditions that necessitate the use of a Foley catheter. The collection of urine and other fluids after a surgical procedure is such a condition. For the past seventy to eighty years the Foley retention drainage catheter, as depicted in  FIG. 18  and labeled “PRIOR ART,” has been the preferred option to drain and collect urine and other fluids from the bladder. The basic design of a Foley catheter comprises an elongated cylindrical element containing a central drainage lumen running the length of the elongated cylindrical element, having one or more drainage ports in series at or near the distal end, and an expandable retention element, located proximal to the drainage ports, for securing the catheter within the bladder. The retention element is expanded with fluid via an inflation lumen running from the inflation valve located on the proximal end of the elongated cylindrical element to the retention element. The design of the Foley catheter has not undergone significant changes other than changes to the base materials and attempts to give the materials antibacterial properties. Despite its continued use in the health care industry without significant design changes the Foley catheter does have some acknowledged weaknesses. 
         [0004]    Firstly, the Foley catheter is susceptible to obstruction of the drainage ports and the drainage lumen of the catheter due to plugging and/or buildup of debris (debris is defined as loose tissue, sediments, clotted blood, redundant bladder mucosa, and any other materials or viscous fluids in the clinical setting). The drainage ports are generally at least twice the cross sectional area of the drainage lumen. This can result in a funneling effect with debris draining into smaller and smaller spaces, thus, resulting in plugs and blockages causing catheter obstruction. Further, due to the drainage ports being in series, if the most proximal drainage port becomes obstructed by debris that extend from the port into the drainage lumen, thus obstructing the drainage lumen, any remaining unobstructed drainage ports are rendered ineffective as they are upstream of the obstruction. Incomplete emptying/drainage of the bladder caused by obstructions in the catheter are significant causes of catheter associated urinary tract infections (UTIs). 
         [0005]    Secondly, the drainage ports in the catheter, being limited in number and limited in cumulative cross sectional area as related to the cross sectional area of the drainage lumen, create a suction effect so that when the force of the suction is projected on the bladder mucosa the suction can cause a disruption in the mucosal integrity. This can result in increased risk of pain, bladder spasms, discomfort, and catheter associated UTIs. 
         [0006]    Thirdly, yet another problem is the inability of the Foley catheter to completely drain the bladder, even when the drainage system is completely free of obstruction. Due to the aforementioned drainage port locations, when the bladder is actively drained during catheterization, and the bladder wall closes around the retention element, the bladder retains a residual volume of fluid that is not able to reach the drainage ports. This volume of stagnant fluid can contain urine, blood, bacteria, and/or other pathogens that, when not regularly flushed out of the bladder, can set up an infection in the surrounding tissues, form blood clots in the bladder, and/or other conditions detrimental to the patient. It should be understood that catheter associated UTIs are now the most expensive hospital acquired infection according to the Centers for Disease Control and Prevention. 
       SUMMARY OF THE INVENTION 
       [0007]    The aforementioned problems are solved and a technical advance is achieved in an illustrative novel multi-lumen filter membrane internal interstitial drainage channel catheter (also referred to herein as a FMID catheter) for insertion into and draining a body cavity, that mitigates the risk of obstruction of the drainage ports and drainage lumen of the catheter and also reduces the detrimental effects caused by the suction forces of the drainage ports on the body cavity being drained, and reduces the risk of infection of the body cavity being drained by decreasing the residual volume of fluid retained in the body cavity being drained. These advantages and more are achieved by the novel approach of disposing a perforated filter membrane over a segmented retention element, the proximal drainage ports, and the distal drainage ports of the drainage lumen of the catheter. 
         [0008]    When the segmented retention element and filter membrane are in their expanded state, expandable cavities (henceforth referred to as internal interstitial drainage cavities) are created between the filter membrane and the elongated cylindrical element and expand as the filter membrane is pushed away from elongated cylindrical element. Also, when the segmented retention element and filter membrane are in their expanded state, other expandable cavities (henceforth referred to as internal interstitial drainage channels) are created between the substantially spherical wedges of the retention element and the filter membrane. The internal interstitial drainage channels are disposed from the distal end of the segmented retention element to the proximal end of the segmented retention element and expand proportionally as the expanded state of the segmented retention element and the filter membrane is reached. The drainage ports communicate with the internal interstitial drainage cavities. The internal interstitial drainage cavities communicate with the internal interstitial drainage channels. The internal interstitial drainage cavities and/or the internal interstitial drainage channels communicate with the body cavity being drained through the filter membrane. 
         [0009]    And also when the segmented retention element and filter membrane are in their expanded state, the individual perforations in the filter membrane have a smaller cross sectional area than that of the drainage ports and the drainage lumen so that debris smaller than the perforations can pass through the filter membrane, the drainage ports, and the drainage lumen without obstructing either. Debris larger than the perforations is stopped by the filter membrane while still leaving a plurality of perforations in the filter membrane unblocked, thus creating a drainage system in parallel rather than in series. Due to there being a plurality of perforations in the filter membrane, the suction force produced by the drainage ports is distributed amongst all the perforations, thus mitigating the detrimental effects of suction force on the tissues of the body cavity being drained. This FMID catheter is particularly advantageous when patients require an indwelling catheter and/or are at risk of having a catheter obstruction. Because the presently disclosed device improves the basic function of current Foley catheters without changing the way it is implemented by the health care professional, it is expected to replace the current Foley catheters as the standard of care. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings which form a portion of the disclosure and wherein: 
           [0011]      FIG. 1  depicts a pictorial view of an embodiment of a FMID catheter in a collapsed state. 
           [0012]      FIG. 2  depicts a pictorial view of an embodiment of a FMID catheter in an expanded state. 
           [0013]      FIG. 3  depicts an enlarged sectioned view of the distal portion of the FMID catheter shown in  FIG. 2  taken along LINE  1 - 1 . 
           [0014]      FIG. 4  depicts an enlarged sectioned view of the distal portion of the FMID catheter shown in  FIG. 2  taken along LINE  2 - 2 . 
           [0015]      FIG. 5  depicts an embodiment of a FMID catheter in an expanded state positioned in a body cavity of a patient. 
           [0016]      FIG. 6  depicts a pictorial view of an embodiment of a FMID catheter in a collapsed state with irrigation port and irrigation opening connector. 
           [0017]      FIG. 7  depicts a pictorial view of an embodiment of a FMID catheter in an expanded state with irrigation port and irrigation opening connector. 
           [0018]      FIG. 8  depicts a pictorial view of an embodiment of a FMID catheter in a collapsed state with perforated sleeve. 
           [0019]      FIG. 9  depicts a pictorial view of an embodiment of a FMID catheter in an expanded state with perforated sleeve. 
           [0020]      FIG. 10  depicts an enlarged sectioned view of the distal portion of the FMID catheter shown in  FIG. 9  taken along LINE  4 - 4 . 
           [0021]      FIG. 11  depicts a pictorial view of an embodiment of a FMID catheter in a collapsed state with wire guide. 
           [0022]      FIG. 12  depicts a pictorial view of an embodiment of a FMID catheter in a collapsed state with encapsulated distal end. 
           [0023]      FIG. 13  depicts a pictorial view of an embodiment of a FMID catheter in an expanded state with encapsulated distal end. 
           [0024]      FIG. 14  depicts an enlarged sectioned view of the distal portion of the FMID catheter shown in  FIG. 13  taken along LINE  3 - 3 . 
           [0025]      FIG. 15  depicts an enlarged sectioned view of an embodiment of a FMID catheter in an expanded state. 
           [0026]      FIG. 16  depicts an enlarged sectioned view of an embodiment of a FMID catheter in an expanded state. 
           [0027]      FIGS. 17A , B, and C depict enlarged sectioned views of the elongated cylindrical element of embodiments of a FMID catheter. 
           [0028]      FIG. 18  depicts an exemplary PRIOR ART Foley retention drainage catheter. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    The following detailed description is presented to enable any person skilled in the art to make and use the invention. For purposes of explanation, specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the invention. Descriptions of specific applications are provided only as representative examples. Various modifications to the preferred embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. The present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein. 
         [0030]    For the purposes of this disclosure a Foley retention drainage catheter, which may be interchangeably referred to as a Foley catheter or drainage catheter, and is commonly used to drain a human bladder, is discussed. However it should be understood that the same inventive features described in this disclosure can be applied to other types of catheters used in other parts of the bodies of both animals and humans in need thereof. Referring to the drawings for a better understanding of the function and structure of the invention,  FIGS. 1 and 2  present an exemplary embodiment of the multi-lumen filter membrane internal interstitial drainage channel catheter  20 , referred to also as a FMID catheter  20 . As shown in  FIG. 1 , the FMID catheter  20  is an improvement over the existing Foley catheter design. Like the existing Foley catheter, the FMID catheter  20 , is designed to be inserted into a body cavity  21  of a patient in need thereof, which may include a human being or another animal. Once inserted, the FMID catheter  20  can be used to drain fluids from, remove small debris from, and/or infuse fluids into of the body cavity  21 . In an exemplary embodiment, the FMID catheter  20  is an indwelling catheter that is inserted through the urethral canal  58 , and in some cases the suprapubic tract, and then into the bladder  59 . It should be understood that the dimensions of the FMID catheter  20  and its components can vary both as to length and diameter as needed or appropriate for a given procedure on a patient in need of draining a body cavity  21 . 
         [0031]      FIG. 3  depicts an enlarged sectioned view of the distal portion  72  of the embodiment of a FMID catheter  20  shown in  FIG. 2  along LINE  1 - 1 .  FIG. 4  depicts an enlarged sectioned view of the distal portion  72  of the embodiment of a FMID catheter  20  shown in  FIG. 2  along LINE  2 - 2 .  FIG. 5  depicts an exemplary embodiment of a FMID catheter  20  positioned in a body cavity  21  (the bladder  59 , as shown) of a patient. Once the FMID catheter  20  is in position, the segmented retention element  39  surrounding a portion of the distal end  28  of the FMID catheter  20  is expandable for inflation to the expanded state  40  and retains the FMID catheter  20  against the neck  78  of the bladder  59  until the segmented retention element  39  is deflated for removal (the distal end  28  being the end of the catheter inserted into the body cavity  21  and the proximal end  29  being the end that remains outside of the body). Although segmented retention elements are preferred in many embodiments, it should be understood that some embodiments may include non-segmented expandable retention element  39 . Unless specifically stated otherwise, it should be understood that the discussed embodiments could include either a segmented or non-segmented retention element  39 . When included, the segmented retention element  39  can have an unlimited number of segments and/or as few as one segment. Preferred embodiments contain four symmetrical segments. The distal end  28  of a flexible elongated cylindrical element  31  can be of hemispherical shape and/or other shapes as required per conditions specific to its intended use by a medical professional. Pluralities of lumina (drainage lumen  23 , inflation lumen  46 , and irrigation lumen  48 ) provide for functions comprising, but not limited to, separate drainage, inflation, and irrigation, respectively. Preferred embodiments of the FMID catheter  20  will have at least two lumina (drainage lumen  23  and inflation lumen  46 ). In addition to the aforementioned characteristics, the FMID catheter  20  provides for a perforated filter membrane  24  encapsulating the retention element  39 . In some embodiments, however, the filter membrane  24  may be configured to not encapsulate any of the segmented retention element  39 . The perforated filter membrane  24  is also disposed over the proximal drainage ports  22   b  and over the distal drainage ports  22   a  of the drainage lumen  23  of the FMID catheter  20 . When in an expanded state  40  the filter membrane  24  mitigates the chance of the drainage ports  22 , drainage lumen  23 , and drainage connector  51  of the FMID catheter  20  being obstructed by debris  73 . 
         [0032]    To retain the FMID catheter  20  in a body cavity  21  of a patient in need thereof, a segmented retention element  39  comprising one or more substantially spherical wedges  41  is disposed near the distal end  28  but proximal to the distal drainage ports  22   a  and distal to the proximal drainage ports  22   b . For example, see  FIG. 3 . One or more inflation ports  44  are disposed on the flexible elongated cylindrical element  31  underneath the segmented retention element  39 . An inflation lumen  46  is disposed within the elongated cylindrical element  31  from the inflation ports  44  to the proximal end  29  of the elongated cylindrical element  31 . In preferred embodiments, the inflation lumen  46  is positioned adjacent to the drainage lumen  23  and extending longitudinally within the elongated cylindrical element  31 . One or more inflation valves  45  are disposed at or near the proximal end  29 . The valve(s)  45  can be of various forms known in the art. The segmented retention element  39  is in fluid communication with the inflation ports  44 . The inflation ports  44  communicate with the inflation lumen  46 . The inflation lumen  46  communicates with the inflation valve  45 . A removable syringe (not shown) communicating with the inflation valve  45  can be used to exert a positive pressure force on the segmented retention element  39 , thereby causing inflation to an expanded state  40  of the segmented retention element  39 . Similarly, a removable syringe (not shown) communicating with the inflation valve  45  can be used to exert a negative pressure force on the segmented retention element  39 , thereby causing deflation to a collapsed state  42  of the segmented retention element  39 . Inflation of the segmented retention element  39  can be carried out by injecting air, gel, fluid, or other substance known in the art. Preferably, a biocompatible fluid, such as saline, water, and/or contrast media, is used to inflate the segmented retention element  39 . Alternatively, the segmented retention element  39  and/or the filter membrane  24  of the FMID catheter  20  can be mechanically expandable. 
         [0033]    To drain the body cavity  21  of the patient, the FMID catheter  20  includes a drainage lumen  23  extends longitudinally within the flexible elongated cylindrical element  31  and having a drainage connector  51  at the proximal end  29  of the elongated cylindrical element. Preferably, the drainage lumen  23  is disposed centrally within the elongated cylindrical element  31 . The drainage ports  22  can be of any size and/or shape and disposed anywhere along the elongated cylindrical element  31 . Preferably, the drainage lumen  23  may have one or a plurality of drainage ports  22  disposed at least near the distal end  74  of the retention element  39  in fluid communication with the exterior, (e.g., the body cavity  21  to be drained) of the FMID catheter  20 . In embodiments having a double-cone configuration, these preferably also have one or a plurality of drainage ports  22  disposed at least near the proximal end  68  of the retention element  39  in fluid communication with the exterior, (e.g., the body cavity  21  to be drained) of the FMID catheter  20 . 
         [0034]    To mitigate the risk of obstruction to the drainage lumen  23  and the drainage ports  22 , a filter membrane  24  is included with its proximal end  36  affixed on the outer surface  67  of the flexible elongated cylindrical element  31  near the proximal end  68  of the retention element  39  and disposed proximal to the proximal drainage ports  22   b  (referred to as the proximal membrane affixing point  70 ). The distal end  69  of the filter membrane  24  is affixed on the outer surface  67  of the elongated cylindrical element  31  near the distal end  28  and disposed distal to the distal drainage ports  22   a  (referred to as the distal membrane affixing point  71 ). The retention element  39  is preferably made of a soft and resilient material capable of expansion and deflation, such as silicone, latex rubber, synthetic latex, silicone-based composite materials, latex-based composite materials, and/or combinations of these. Such materials will stretch or expand to the expanded state of the device and then retract to the collapsed state of the device. It should be understood that the retention element  39  may be made of any acceptable material known in the art or later discovered to be acceptable for constructing similar balloon catheters. 
         [0035]    When the retention element  39  and the filter membrane  24  are in a collapsed state  42 , the retention element  39  and the filter membrane  24  lay substantially flat against the flexible elongated cylindrical element  31  encapsulating but not affixed to the remaining portion of the retention element  39  or the elongated cylindrical element  31  between the proximal membrane affixing point  70  and distal membrane affixing points  71 . Some embodiments of the FMID catheter  20  may include a portion of the elongated cylindrical element  31 , for example, but not intended to be limiting in any way, from one end of the retention element  39  to the distal membrane affixing points  71  (i.e., substantially all of the portion inserted into the body cavity  21 ), that is made of a firm and resilient material, such as biocompatible plastics or other materials known in the art. The firm and resilient material can be disposed continuously or in a series of rings within the aforementioned portion. It is understood that any other material and configuration of material that increases the stiffness of the catheter  20  at the aforementioned portion is contemplated. Thus, the FMID catheter  20  is to be inserted into a body cavity  21  when in the collapsed state  42 . 
         [0036]    When the retention element  39  is in the expanded state  40 , the filter membrane  24  is expanded into a substantially double conical shape being largest in diameter near the retention element  39 , and smallest in diameter at proximal membrane affixing point  70  and distal membrane affixing points  71 . This configuration causes the filer membrane  24  to be held apart from the flexible elongated cylindrical element  31  to form internal interstitial drainage cavities  27 , one disposed near the proximal end  68  of the retention element  39  ( 27   a ) and one disposed near the distal end  28  of the elongated cylindrical element  31  ( 27   b ), between the filter membrane  24  and the elongated cylindrical element  31 . The proximal  27   a  and distal  27   b  internal interstitial drainage cavities  27  are in fluid communication with the proximal  22   b  and distal drainage ports  22   a , respectively, to allow for fluids and/or debris to flow into the drainage ports  22 . The internal interstitial drainage cavities  27  can be formed by masses, elements, and/or processes different from those relating to the retention element  39  and/or the filter membrane  24 . 
         [0037]    The filter membrane  24  has a plurality of perforations  47  that are individually smaller in cross sectional area than the most constricted portion of the drainage lumen  23  and the drainage ports  22  whereby preventing debris  73  larger than the most constricted portion of the drainage lumen  23  and the drainage ports  22  from entering an internal interstitial drainage cavities  27 . When the retention element  39  and the filter membrane  24  are in the expanded state  40  a plurality of sizes and shapes of perforations  47  may result. Debris  73  smaller in cross sectional area than the cross sectional area of an individual perforation  47 , and thus smaller than the most constricted portion of the drainage lumen  23  and the drainage ports  22 , can pass freely through the filter membrane  24 , drainage ports  22 , and then through the drainage lumen  23  without causing obstruction. As the plurality of perforations  47  in the filter membrane  24  provide a significantly greater total cross sectional drainage area than the total cross sectional drainage area of the drainage ports  22  and the drainage lumen  23  so that when debris  73  larger than the perforations lodges in and/or over more than one perforation  47 , the rate of drainage is not substantially diminished or obstructed due to the availability of a plurality of perforations  47 . In the event that debris  73  does cover the filter membrane  24 , a removable syringe (not shown) can be connected to the drainage connector  51 . A negative pressure force can be applied, by use of the removable syringe, to the perforations  47  to aspirate debris  73  through the perforations  47 , through the internal interstitial drainage cavities  27 , through the internal interstitial drainage channels  26 , through the drainage ports  22 , and through the drainage lumen  23 . A positive pressure force can be applied, by use of the removable syringe, to the perforations  47  to flush debris  73  out of and/or away from the perforations  47 . 
         [0038]    The filter membrane  24  may include perforations  47  that are round in shape and/or any other shape and may be of varying size. In addition to or in the alternative to a plurality of perforations  47 , some embodiments of the FMID catheter  20  may include a filter membrane  24  comprising a material with passive diffusion characteristics that would allow the free flow of fluids and dissolved materials through the membrane while blocking debris  73 . Other embodiments may include a filter membrane  24  having a configuration and/or construction that does not possess the qualities and/or characteristics of a membrane, such as, but not intended to be limiting, open cell foam and/or sponge materials could be utilized. The distal end  69  of the filter membrane  24  can be non-perforated. The filter membrane  24  may additionally have ribs (not shown) extending from the proximal membrane affixing point  70  to the distal membrane affixing point  71  to provide structural support for the filter membrane  24  while in the expanded state  40 . 
         [0039]    Due to there being a plurality of perforations  47  in the filter membrane  24 , the suction force produced by the drainage ports  22  is dispersed amongst all the perforations  47 , thus resulting in a greatly reduced rate of fluid flowing through any individual perforation  47  as compared to the rate of fluid flowing through any individual drainage port  22 . Thus, a significant suction force is not created by individual perforations  47 . This characteristic causes debris  73  to not be readily drawn to the filter membrane  24 , as it would be drawn to an unfiltered drainage port, which reduces the chance of debris buildup on the filter membrane  24 . This characteristic also reduces the detrimental effects of focal suction force projected on the tissues of the body cavity  21  being drained, particularly the bladder mucosa  32 , the irritation of which can cause an increased risk of catheter associated UTIs and/or other damage to the mucosa. Catheter associated UTIs are now the most expensive hospital acquired infection according to the Centers for Disease Control and Prevention (CDC). 
         [0040]    To provide for enhanced drainage when the segmented retention element  39  and filter membrane  24  are in their expanded state  40 , expandable internal interstitial drainage cavities  27  are created between the filter membrane  24  and the flexible elongated cylindrical element  31 , which expand as the filter membrane is pushed away from the elongated cylindrical element  31 . Also, when the segmented retention element  39  and filter membrane  24  are in their expanded state  40 , expandable internal interstitial drainage channels  26  are created between the spherical wedges  41  of the retention element  39  and the filter membrane  24 . The internal interstitial drainage channels  26  are disposed from the distal end  74  of the segmented retention element  39  to the proximal end  68  of the segmented retention element  39  and expand proportionally as the expanded state of the segmented retention element  39  and the filter membrane  24  is reached. The internal interstitial drainage channels  26  can be formed by masses, elements, and/or processes different from those relating to the retention element  39  and/or the filter membrane  24 . As stated above, the drainage ports  22  are in fluid communication with the internal interstitial drainage cavities  27 . The internal interstitial drainage cavities  27  are in fluid communication with the internal interstitial drainage channels  26 . The internal interstitial drainage cavities  27  and/or the internal interstitial drainage channels  26  are in fluid communication with the body cavity  21  being drained through the filter membrane  24 . The internal interstitial drainage channels  26  advantageously allow for more surface area of the distal portion  72  of the FMID catheter  20  to drain the body cavity  21 , as well as fluid communication between the internal interstitial drainage cavities  27 . This configuration also advantageously allows for continued drainage through one drainage port  22  in the event that the other becomes obstructed. 
         [0041]    Some embodiments of the FMID catheter  20  may have an irrigation lumen  48  disposed in the flexible elongated cylindrical element  31  and extending longitudinally within the elongated cylindrical element  31 , having an irrigation opening connector  50  at the proximal end  29  of the elongated cylindrical element  31 . The irrigation lumen  48  may have one or more irrigation ports  49  disposed along the elongated cylindrical element  31 . The irrigation port(s)  49  can be of any size and/or shape and disposed anywhere along the elongated cylindrical element  31 . Preferably, the irrigation port(s)  49  at and/or near the distal end  28 , in fluid communication with the exterior  66  of the FMID catheter  20 , and located distal to the filter membrane  24  for delivering an irrigating solution to the body cavity  21  being drained.  FIGS. 6 and 7  depict a pictorial view of illustrative embodiment of a FMID catheter  20  having an irrigation lumen  48 . A normal saline and/or sterile water irrigating fluid may be delivered to the body cavity  21  in order to prevent postoperative and/or spontaneous blood clot retention. The irrigating fluid may also be delivered to the body cavity  21  being drained to cleanse and/or administer medicines for treating conditions, such as bacteriuria. 
         [0042]    Other embodiments of FMID catheter  20  may have a plurality of separate sub-retention elements  75  in the segmented retention element  39  that are formed by disposing a perforated sleeve  52  around the collapsed retention element  39 . When being put into an expanded state, the retention element  39  expands through the perforations in the perforated sleeve  52  creating one and or more sub-retention elements  75 .  FIGS. 8 and 9  depict a pictorial view of a FMID catheter  20  having a perforated sleeve  52  and sub-retention elements  75 .  FIG. 10  depicts an enlarged sectioned view of the distal portion  72  of the embodiment of a FMID catheter  20  shown in  FIG. 9  along LINE  4 - 4 . The separate sub-retention elements  75  in the segmented retention element  39  due to the perforated sleeve  52  may create larger interstitial drainage channels  26 . 
         [0043]    Some embodiments of the FMID catheter  20  may have at least one drainage port  22   c  disposed at the distal end  28  of the flexible elongated cylindrical element  31 . This configuration permits the catheter  20  to be inserted over a guidewire  57  through the drainage lumen  23  and the aforementioned drainage port  22   c  disposed on the distal end  28 . This configuration is especially useful in various surgical procedures, such as those needing cystoscopic access to the bladder  32  or body cavity  21  with subsequent need for leaving a catheter in situ. A guidewire  57  is placed under direct vision using a cystoscope. The cystoscope is removed leaving the guidewire  57  in place within the bladder  32  or body cavity  21 , on which the catheter, such as FMID catheter  20 , may be guided. 
         [0044]    In addition, endoscopic instruments and other medical devices, for example, but not limited to cystoscopes, ureteroscopes, temperature probes, microwave thermotherapy probes, radiofrequency ablation probes, urodynamic catheters, etc. can likewise be inserted through the FMID catheter  20  using drainage lumen  23  (with or without the aid of guidewire  57 ) for access to the bladder  32  or body cavity  21 .  FIG. 11  depicts a pictorial view of a FMID catheter  20  as described in this embodiment. 
         [0045]    Further embodiments of the FMID catheter  20  may include a distal membrane affixing point  71  of the filter membrane  24  disposed at the distal end  28  of the flexible elongated cylindrical element  31  such that the distal membrane affixing point  71  seats into and encapsulates the distal end  28 . The distal membrane affixing point  71  of the filter membrane  24  may and/or may not be perforated.  FIGS. 12 and 13  depict a pictorial view of a FMID catheter  20  as described in this embodiment. Furthermore, some embodiments may include a filter membrane  24  configured to encapsulate only a portion of the segmented retention element  39 .  FIG. 14  depicts an enlarged sectioned view of the distal portion of a FMID catheter with a partially encapsulating filter membrane. Thus, in some embodiments, the proximal membrane affixing point  70  may be on the proximal end  68  of the retention element  39 . Note that no proximal drainage port  22   b  is necessary in this embodiment. Nevertheless, a segmented retention element  39  may be used to create internal interstitial drainage channels  26  and more surface area for drainage through the plurality of perforations  47 . 
         [0046]    Still further embodiments of the FMID catheter  20  may include a perforated retention element  64  of which the perforations  47  are configured as drainage lumina  62 . The perforated retention element  64  can be comprised of multiple layers. Disposed between the multiple layers of the perforated retention element  64  are inflation cavities  77  which are in fluid communication with the inflation port  44  and inflation lumen  46 . The flexible elongated cylindrical element  31  (internal to the perforated retention element  64 ) may have one or more drainage ports  65  in fluid communication with the drainage lumen  23 . Internal  53  to the perforated retention element  64  are drainage cavities  61  which are in fluid communication with the body cavity  21  being drained and the drainage port  65  and drainage lumen  23 . It is also envisioned that the perforated retention element  64  can be comprised of a single layer that would be mechanically and/or by means other than inflation cavities deployed to an expanded state  40 . The perforated retention element  64  would perform the job of both the segmented retention element  39  and the filter membrane  24  thus reducing the size of the unit so less patient discomfort is experienced. It could also reduce the cost and increase production efficiency.  FIG. 15  depicts an enlarged sectioned view of a FMID catheter  20  having a perforated retention element  64 . 
         [0047]    Still further embodiments of the FMID catheter  20  may include the retention element  39  comprised of one and or a plurality of individually inflated sub-retention elements  75 . The sub-retention elements  75  can be disposed on the flexible elongated cylindrical element  31  radially, non-radially, and/or otherwise. In some embodiments, the sub-retention elements  75  can be inflated individually by separate inflation lumen  46 .  FIG. 16  depicts an enlarged sectioned view of the distal portion of a FMID catheter  20  having retention element  39  comprised four individually inflated sub-retention elements  75 . 
         [0048]    It is to be understood that various embodiments of the FMID catheter  20  described above may also include one and or more of the following characteristics: The flexible elongated cylindrical element  31  of the FMID catheter  20  may take a shape other than cylindrical as required per conditions such as, but not limited to, trabeculated bladders, bladder diverticula, neobladders, and bladders with large prostate median lobes protruding into the bladder.  FIGS. 17A-C  depicts multiple sectional views of an elongated cylindrical element  31  having various internal structural shapes. 
         [0049]    The invention further provides methods of manufacturing the FMID catheter  20  such as would be apparent to one of skill in the art given the disclosure and objectives of this disclosure. The FMID catheter  20  can be configured into any number of catheter designs comprising but not limited to, straight Foley, Coude&#39; tip Foley, Council tip Foley, 3-way Foley, Whistle tip, spanning tandem balloon, Malecot catheters, subsumed tip, and any other catheter design presently existing or developed in the future. The FMID catheter  20  being of a material comprising at least one from a group of any biologically inert, biologically non-inert, naturally occurring, synthetic, non-biodegradable, biodegradable, and bioresorbable materials now known or later discovered in the future that are acceptable within the art for manufacturing catheter components, comprising but not limited to elastomeric materials, polymers, copolymers, metals and metal alloys. Exemplary materials are elastomeric, latex, and silicone. The retention element  39  and filter membrane  24  components are preferably made of an expandable silicone, latex rubber, silicone-based material, latex-based material, and/or combinations thereof. In some embodiments, especially where the filter membrane  24  possesses membrane properties, elastomeric material having micro-pores for filtering fluids and/or dissolved materials may be utilized. Thermo-sensitive materials, which change resiliency and or size at different temperatures, are contemplated to be within the scope of the disclosure. The filter membrane  24  and/or the retention element  39 / 64  may be affixed by any known method, including by adhesive, heat/chemical welding, mechanical fasteners, and/or combinations thereof. Preferably, a biocompatible latex or silicone adhesive is used. 
         [0050]    The FMID catheter  20  can be coated or impregnated with therapeutic agents, such as but not limited to, antibiotics, antiseptics, blood clotting factors, growth factors, steroids, or any other materials and substances now known or later discovered in the future. The FMID catheter  20  can be coated or impregnated with fluorescent or radiopaque materials for radiological imaging. Applicants intend to encompass any structure presently existing or developed in the future that performs the same function. 
         [0051]    The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention. 
         [0052]    The FMID catheter  20  and methods have been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. It will be apparent to one of ordinary skill in the art that methods, devices, device elements, materials, procedures and techniques other than those specifically described herein can be applied to the practice of the invention as broadly disclosed herein without resort to undue experimentation. All art-known functional equivalents of methods, devices, device elements, materials, procedures and techniques described herein are intended to be encompassed by this invention. 
         [0053]    While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. This invention is not to be limited by the embodiments disclosed, including any shown in the drawings or exemplified in the specification, which are given by way of example and not of limitation. Accordingly, the scope of the invention should be limited only by the attached claims.