Patent Description:
Body fluids may need to be withdrawn from a patient in the course of medical treatment. Two common medical procedures requiring fluid removal are thoracentesis and paracentesis.

In paracentesis, peritoneal fluid is aspirated from the abdomen. Typical patients have tense ascites resulting from liver disease and portal hypertension, which may cause discomfort, respiratory distress, and the formation and rupture of umbilical hernias. Paracentesis has been observed to provide quick and effective relief with few adverse side effects. Other treatment options, such as the use of diuretics, are available, but may not provide as effective relief as paracentesis. Additionally, many patients with ascites have renal impairment and cannot use the high doses of diuretics necessary to effectively treat the ascites. See "<NPL>. Relatively large volumes of fluid, such as five liters, may be withdrawn from a patient during one paracentesis procedure.

Many existing devices are capable of performing paracentesis. At its simplest, a paracentesis device need only include a hollow needle with one end inserted into the patient and the other end attached to a negative pressure device, such as a syringe or vacuum bottle. However, more specialized devices have been developed to allow safer, more comfortable, and more sanitary paracentesis. These devices may allow for body fluid to be dispensed into at least two containers, so that one container may be filled with fluid for diagnostic purposes and the other container may be filled with waste fluid. Another development has been the use of Kuss or Verres type needle assemblies, where a blunt drainage needle is attached to a retractile sharp introducer needle. This reduces the likelihood of the sharp needle damaging internal tissue during paracentesis. A further development is to drain body fluid through a blunt-tipped catheter introduced by a sharp introducing needle, which allows the sharp needle to be removed from the patient after a relatively quick introduction process and avoids the prolonged presence of a sharp needle in the body of the patient.

Problems may arise when drainage is diverted from one container to another if the drainage system is not airtight. Air could contaminate a sample or enter the body of the patient and cause injury. Known devices that are meant to be airtight have tubes and multiple containers attached to the devices which make the devices cumbersome and somewhat difficult to insert into the patient. Also, known devices require manipulation of a manual valve, such as a stopcock to work effectively. If the stopcock is not set at the proper setting, the device may admit air into the patient or otherwise malfunction. Problems also may arise in devices which allow a needle assembly to be withdrawn. Air must be prevented from entering the patient when the fluid is withdrawn. Also, body fluid must be prevented from leaking out of the device through the space formerly occupied by the needle assembly.

Thoracentesis is a procedure similar to paracentesis, except that effusion fluid is withdrawn from the pleural region instead of the abdomen. Normally, the pleural space contains approximately <NUM> to <NUM> of fluid. The fluid is the result of the hydrostatic-oncotic pressure of the capillaries of the parietal pleura. The turnover of the fluid in the pleural space is normally quite rapid, so that approximately <NUM> to <NUM> liters (e.g., <NUM> to <NUM> liters) of fluid move through the pleural space each day. A disruption in the balance between the movement of fluid into the pleural space and the movement of fluid out of the pleural space may produce excessive fluid accumulation in the pleural space. Pleural effusion is particularly common in patients with disseminated breast cancer, lung cancer or lymphatic cancer and patients with congestive heart failure, but also occurs in patients with many other forms of malignancy.

Pleural effusion may cause dyspnea, coughing, and chest pain, which diminish a patient's quality of life. Although pleural effusion typically occurs toward the end of terminal malignancies, such as breast cancer, it occurs earlier in other diseases. Therefore, relieving the clinical manifestations of pleural effusion is for real and extended advantage to the patient. For example, non-breast cancer patients with pleural effusion have been known to survive for years. See "<NPL>.

There are several treatments for pleural effusion. If the patient is asymptomatic and the effusion is known to be malignant or paramalignant, no treatment may be required. Pleurectomy and pleural abrasion are generally effective in obliterating the pleural space, thus controlling the malignant pleural effusion. However, pleurectomy is a major surgical procedure associated with substantial morbidity and some mortality. Chemotherapy is generally disappointing; however, it may produce good responses for patients with lymphoma, breast cancer, or small-cell carcinoma. Another approach is to surgically implant a chest tube. However, such a tube is painful to the patient, both when it is inserted and during the time that it remains in the pleural space. Improvements on the traditional chest tube are described in <CIT>.

Despite other treatment options, thoracentesis remains the most common approach to removing pleural fluid. However, thoracentesis poses the danger of causing pneumothorax, a collapsed lung. Pneumothorax can be caused directly by puncturing a lung with a needle assembly or catheter tip or indirectly by allowing air to enter the pleural space. Normally, the pleural space is at negative pressure relative to the atmosphere, which helps keep the lungs expanded. If the atmosphere is allowed to communicate with the pleural space, the pleural space may no longer be at negative pressure and pneumothorax may result.

Thoracentesis devices have been developed to reduce the risk of pneumothorax and other similar problems that may result from the procedure. In general, these devices incorporate similar protections as do paracentesis devices. For example,
<CIT>discloses a thoracentesis device with a catheter introduced by a removable needle assembly, with a valve that closes upon removal of the needle assembly. The purpose of the valve is to prevent air from entering the body of the patient. <CIT>, <CIT>, <CIT>, and <CIT>disclose similar devices with a manual valve that may be closed after withdrawal of the needle assembly. However, none of the previous devices allow for a truly fail-safe operation, as various valves must be properly set by the operator when changing from one drain port to another or when withdrawing the introducing needle assembly from the patient. Also, care must be taken to avoid accidental withdrawal of the introducing needle assembly, as in the disclosed devices where the needle assembly is not firmly attached to the remainder of the device. Further, the disclosed valves that allow for catheter drainage after removal of an introducing needle assembly rely on a single contact point. Due to the possibly dire consequences of a valve failure, such valves may not produce acceptably safe thoracentesis.

A Verres-type needle assembly that may be used for thoracentesis is disclosed in <CIT>. While this reduces the risk of pneumothorax due to lung puncture, the Turkel device does not improve the safety of thoracentesis when the introducing needle assembly is withdrawn or solve the problems associated with multiple drainage ports. Thus there is a need for a safer and more reliable device that may be used for paracentesis and thoracentesis. Another device is described in <CIT>.

Other difficulties with existing systems relate to manufacturing, storing and using the vacuum element. Syringes are sometimes used to generate the vacuum, but syringes are somewhat complicated to manufacture and use. An alternative vacuum source is a vacuum bottle. In that approach, a vacuum is created in an air-tight bottle at the manufacturing stage, and then the bottle is sealed. The bottle is then tapped at the time of use so that the vacuum can be applied to a drainage line to remove the undesired body fluids.

This is quite elegant in concept but somewhat difficult to implement perfectly in every individual unit. There is always some risk that the vacuum will be lost in transit before use, either by leaks, fractures or just air permeating through a plastic wall. Moreover, the loss of vacuum is not necessarily apparent to the user; a bottle with a perfect vacuum inside looks no different than a bottle of air, but the drainage efficacy of the unit may be diminished upon loss of vacuum before use or during use where the vacuum is wasted on pulling in air rather than exerting drainage effectively from the patient. Another problem is in tapping the bottle. This requires a system that pierces a vacuum seal but does not allow air to enter the bottle, except through the draw line. One such system is described in commonly owned <CIT>.

In known systems utilizing a vacuum bottle, a cap may be provided that acts as an interface between the bottle and a drainage line. In practice, it is typical for the junction of the cap and the bottle to be assembled with the use of an adhesive, such as a silicone adhesive gel. The silicone gel may act both to secure the cap to the bottle and to create a fluid seal at the junction.

Systems using a silicone adhesive have achieved positive results. However, silicone gel adhesive typically is expensive and manufacturing expenses associated with applying a silicone gel remain high. Further, it can be difficult to apply a precise amount of adhesive during the assembly process to achieve consistent securing and sealing that will patently maintain desired vacuum throughout the device live and usage. Silicone adhesives also typically can only dry and set one time, shortly after application, and therefore the system is generally shipped fully assembled, and it may be difficult to interchange the vacuum bottles at the medical facility. Further, the use of an suitable amount of adhesive to form an adequate seal may secure the cap the bottle to a degree such that is difficult to remove by a user, thus making it difficult for user the to remove the cap prior to disposing medical waste collected within the bottle.

In light of this background, it would be advantageous to provide an improved system utilizing a container, such as a vacuum bottle, connected to a drainage line that achieves sufficient securing and sealing between the container and cap without the need for the use of an adhesive, that can be removed by a user without undue force for purposes of waste disposal. <CIT> describes a drainage system, the drainage system comprising a container having an interior and a mouth, the mouth comprising an outer surface and an opening, a frangible seal covering the opening, a cap secured to the mouth and in fluid communication with a drainage line, the cap having an inner surface configured to engage with the outer surface of the mouth an O-ring located at least partially between the outer surface of the mouth and the inner surface of the cap and configured to form a fluid seal between a space defined by the cap and the space located externally of the drainage system, and a retaining ring circumferentially engaging the cap. <CIT> describes a container made from a vial-like mass produced glass bottle with a plastic neck mounted securely thereon, and a simple method for securely mounting the plastic neck to the glass bottle. The open end of the bottle has a neck with a flange forming an annular shoulder. A plastic neck insert is provided that has a threaded neck opposite a resilient sleeve. The resilient sleeve is adapted to expand to receive the flange in a snap fit type engagement. An aluminium ferrule is press fit over the resilient sleeve of the plastic neck insert to lock the plastic neck insert onto the flange. The ferrule has an upwardly directed edge that engages a downwardly directed edge of the sleeve in interference fit to lock the ferrule onto the sleeve. An elastic seal is provided between the plastic neck insert and the glass bottle to ensure that the connection of the two components is airtight. <CIT> describes an assembly for securing and sealing a dispenser, such as a pump or valve, to a flanged container. The assembly comprises a mounting cup having a generally cylindrical skirt around its periphery and a sealing collar including a sleeve having a diameter sized to receive the sidewall of the flange and sized to be encased by the mounting cup. The end portion of the sleeve, such as a plurality of spaced tabs, is in the path of movement of the mounting cup and is deformed radially inwardly beneath the flange ledge thereby to secure the collar to the flange. The present invention relates to a drainage system and to a method as defined in the claims. Embodiments that do not fall within the scope of the claims are to be interpreted as examples useful for understanding the invention. The present disclosure provides a drainage system according to claim <NUM> and a method according to claim <NUM>. Further details are provided in dependent claims <NUM>-<NUM> and <NUM>-<NUM> respectively.

Various embodiments are described below with reference to the drawings in which like elements generally are referred to by like numerals. The relationship and functioning of the various elements of the embodiments may better be understood by reference to the following detailed description. However, embodiments are not limited to those illustrated in the drawings. It should be understood that the drawings are not necessarily to scale, and in certain instances details may have been omitted that are not necessary for an understanding of embodiments disclosed herein, such as - for example - conventional fabrication and assembly.

The invention is defined by the claims, may be embodied in many different forms, and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey enabling disclosure to those skilled in the art. As used in this specification and the claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Reference herein to any industry standards (e.g., ASTM, ANSI, IEEE standards) is defined as complying with the currently published standards as of the original filing date of this disclosure concerning the units, measurements, and testing criteria communicated by those standards unless expressly otherwise defined herein. The terms "proximal" and "distal" are used herein in the common usage sense where they refer respectively to a handle/doctor-end of a device or related object and a tool/patient-end of a device or related object. The terms "about," "substantially," "generally," and other terms of degree, when used with reference to any volume, dimension, proportion, or other quantitative or qualitative value, are intended to communicate a definite and identifiable value within the standard parameters that would be understood by one of skill in the art (equivalent to a medical device engineer with experience in this field), and should be interpreted to include at least any legal equivalents, minor but functionally-insignificant variants, standard manufacturing tolerances, and including at least mathematically significant figures (although not required to be as broad as the largest range thereof).

<FIG> is an illustration showing a front cut-out schematic of one embodiment of a drainage system <NUM>. Referring to <FIG>, the drainage system <NUM> may include a container <NUM>, which may be a bottle or a vacuum bottle (or other suitable container). The container <NUM> may have a mouth <NUM> with an outer surface <NUM> and an opening <NUM> at its proximal end <NUM>. The opening <NUM> may lead to an interior <NUM> of the container <NUM>. During a drainage procedure, a cap <NUM> may cover the opening <NUM> of the mouth <NUM> and may lead to a drainage line <NUM>. The cap <NUM> may have a sleeve <NUM> at its upper (distal) end and a widened body <NUM> at its lower (proximal) end. The sleeve <NUM> of the cap <NUM> may receive a spike <NUM> in a manner such that a substantially air-tight seal is formed between the exterior surface of spike <NUM> and a lumen <NUM> of sleeve <NUM>.

The lower end of spike <NUM> may terminate at a point <NUM>. The upper end of spike <NUM> may receive the drainage line <NUM>. Like the connection between spike <NUM> and the sleeve <NUM> of the elastomeric cap <NUM>, the connection between spike <NUM> and drainage line <NUM> is preferably substantially air-tight. The spike <NUM> may also include a circumferential flange <NUM> to assist in manipulating the spike <NUM> in relation to container <NUM> in the manner described below. A lumen <NUM> may extend through spike <NUM> such that a lumen <NUM> of the drainage line <NUM> can communicate with the container <NUM> during a drainage procedure.

A frangible seal <NUM> may cover the opening <NUM> of the mouth <NUM> prior to initiation of the drainage procedure. Prior to being pierced, the frangible seal <NUM> may seal the interior <NUM> of the container <NUM> from the external environment <NUM>. More particularly, the frangible seal <NUM> may be constructed of foil, mylar, or other substantially air-tight material to prevent air or other fluid from leaking into the interior <NUM> of the container <NUM> to spoil a pressure differential (e.g., a relative vacuum) between the interior <NUM> and the external environment. In some embodiments, the pressure differential may be at least <NUM> kPa (<NUM> psi), such as <NUM> kPa (<NUM> psi), but other pressure differentials are also contemplated. The frangible seal <NUM> may be attached to the mouth <NUM> via heat-sealing (as in, for example, direct heat, induction heat or vibration generated heating processes), by gluing or using another adhesive, and/or by any other suitable method.

The drainage system <NUM> may be packaged and shipped as an assembly that includes the container <NUM> with the interior <NUM> sealed by the frangible seal <NUM>. When packaged and shipped (or otherwise transported), the interior <NUM> of the container <NUM> is preferably pre-loaded with a vacuum (and herein, a "vacuum" may refer to an environment with relatively low pressure with respect to an external environment, but "vacuum" does not necessarily require the space to be entirely devoid of matter). It is also contemplated that the vacuum may be loaded by the patient (e.g., by hooking the container <NUM> to a vacuum pump).

To perform a drainage procedure, the distal end (not shown) of the drainage line <NUM> may be attached to a collection device that is at least partially placed into a target space in the body of a patient. For example, the collection device (not shown) may include a catheter that can be placed in the pleural space of the patient to remove excess pleural fluid via a needle within the body of the patient. Once the drainage line <NUM> is appropriately coupled to the collection device, the spike <NUM> may be pushed towards the container <NUM> by applying a downward (distal-facing) force to the flange <NUM>. This force
may deform the cap <NUM>, and particularly the widened body <NUM> of the cap <NUM> in the depicted embodiment, such that the spike <NUM> moves distally and such that the point <NUM> of the spike <NUM> pierces the frangible seal <NUM>. When the frangible seal <NUM> is pierced, the vacuum loaded within the interior <NUM> of the container <NUM> may communicate with the drainage line <NUM> to draw fluid (including gasses and liquids) from the target space of the patient body and/or the collection device, through the drainage line <NUM>, and ultimately into the interior <NUM> of the container <NUM>.

It may be important to be able to verify at a glance that the vacuum in the interior <NUM> of the container <NUM> is intact to ensure suitable operation. In some embodiments, this can be accomplished through recognition of deformation of the cap <NUM> (which, as stated above, may be formed of an elastomeric material). In its default position (i.e., when not exposed to the vacuum), the cap <NUM> may appear substantially different than it may appear when exposed to the vacuum of the interior <NUM>. For example, when exposed to the vacuum, the widened body <NUM> of the cap <NUM> may at least partially collapse. This partial collapse will thus be apparent to the user and will verify the existence of the vacuum. The state of the cap <NUM> may further indicate the state of the vacuum as the drainage procedure continues, and the cap <NUM> may indicate that the vacuum has been exhausted when it returns fully to its default state.

Optionally, the cap <NUM> may be secured to the container <NUM> via a silicone adhesive, and/or an O-ring may be located between the cap <NUM> and the underlying mouth <NUM> of the container <NUM> to ensure a suitable seal. Embodiments utilizing an adhesive and embodiments with an O-ring are described in detail in <CIT>, and published Jan. <NUM>, <NUM>. Additionally or alternatively, retention ring <NUM> (which may also be referred to as a retaining ring) may be included to facilitate securement of the cap <NUM> to the container <NUM>. The retention ring <NUM> may be formed integrally (e.g., by injection molding, 3D printing, or another suitable method), and may be formed of any suitable material. In certain non-limiting exemplary embodiments, the retention ring <NUM> may be formed of a polypropylene material or a nylon.

<FIG> is an illustration showing a side perspective view of a portion of the drainage system <NUM>. As shown, the retention ring <NUM> may have a collar <NUM> that circumferentially engages an outer surface <NUM> of the cap <NUM>, thereby squeezing or otherwise providing a constricting force to retain the cap <NUM> in engagement with the mouth <NUM> of the container <NUM>. This constriction provided by the retention ring <NUM> may compress the elastomeric material of the cap <NUM> against the mouth <NUM> of the container <NUM>, thus providing a seal. The retention ring <NUM> may be installed (i.e., manipulated into its position around the cap <NUM> and mouth <NUM> as shown in <FIG>) by a user prior to a drainage procedure when attaching the cap <NUM> to the container <NUM>, or the retention ring <NUM> may be installed prior to packaging and shipping of the drainage system <NUM>.

<FIG> shows a side section view of a portion of the drainage system <NUM> of <FIG> about line <NUM>-<NUM>, and <FIG> shows a magnified view of a portion of <FIG>. As shown in <FIG>, and as described above, the collar <NUM> of the retention ring <NUM> may circumferentially engage the cap <NUM>. The collar <NUM> of the retention ring <NUM> may be sized such that it provides a constriction force on the outer surface <NUM> of the cap <NUM> when the cap <NUM> is located over the mouth <NUM> of the container <NUM>. For example, the retention ring <NUM> may include the collar <NUM> with an inner diameter that is slightly larger than an outer diameter defined by the outer surface <NUM> of the mouth <NUM>. The cap <NUM> may have a default thickness <NUM> (e.g., a thickness when not deformed by the retention ring <NUM>). In one non-limiting exemplary embodiment, the default thickness may be about <NUM> (<NUM> inches) in at least some locations, but other suitable dimensions are also contemplated (e.g., the default thickness may be between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), such as between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches)). Adjacent to where the retention ring <NUM> engages the cap <NUM> during a drainage procedure, the cap <NUM> may be compressed such that the thickness at the area where the retention ring <NUM> engages the cap <NUM> is smaller than the cap's default thickness. The compression between the outer surface <NUM> of the mouth <NUM> and the collar <NUM> of the retention ring <NUM> may create or enhance a seal between the cap <NUM> and the mouth <NUM>. This seal may retain the above-described pressure differential between the interior <NUM> of the container <NUM> and the external environment <NUM> and also may prevent leakage of fluid during drainage.

As depicted in <FIG>, the retention ring <NUM> may include a bead <NUM> located on an inner surface <NUM> of the collar <NUM> of the retention ring <NUM>, where the inner surface <NUM> defines the inner diameter of the collar <NUM>. While only one bead <NUM> is shown in the present figure, more than one bead may be included. The bead <NUM> may have an apex <NUM>, which may be closer to an axis <NUM> through the center of the collar <NUM> of the retention ring <NUM> relative to adjacent areas of the inner surface <NUM>. While any suitable dimensions are contemplated, the bead <NUM> may be an arc with a diameter of about <NUM> (<NUM> inches), and the apex <NUM> may be about <NUM> (<NUM> inches) from the center of the collar <NUM> at its closest point. The apex <NUM> of the bead <NUM> may be formed integrally with the remainder of the retention ring <NUM> (e.g., through a common injection molding process, 3D printing process, or other suitable process), or it may be installed after formation of the remainder of the retention ring <NUM>. The apex <NUM> may be advantageous for concentrating the above-described constriction force on a relatively small area of the cap <NUM> when the retention ring <NUM> is engaged with the cap <NUM> around the mouth <NUM> of the container <NUM>, as shown in <FIG>. The resulting deformation of the relatively small area receiving a high proportion of the constricting force may provide an enhanced seal between the mouth <NUM> and the cap <NUM> with respect to other embodiments. In exemplary embodiments, the constriction force may provide at least <NUM> kPa (<NUM> psi) of contact pressure between the cap <NUM> and the mouth <NUM> adjacent to the apex <NUM> around the entirety of the mouth <NUM>, and the contact pressure may be significantly higher in certain locations. Further, the concentration of the contraction force may provide enhanced ability to retain the seal between the mouth <NUM> and the cap <NUM> over relatively long period of time (e.g., <NUM> years or more), which is advantageous for supply-chain efficiency due to the ability to store the system for a relatively long time period prior to use.

Optionally, as shown <FIG>, the mouth <NUM> of the container <NUM> may include a protrusion <NUM> around the outer diameter defined by the outer surface <NUM> of the mouth <NUM>. The protrusion <NUM> may have dimensions similar to the bead <NUM> with respect to the outer surface <NUM> of the mouth <NUM>, but this is not required. The protrusion <NUM> may be located just proximal (above) the bead <NUM> of the retention ring <NUM> when the retention ring <NUM> is installed, but other locations are also contemplated. Like the bead <NUM>, the protrusion <NUM> may be advantageous for
concentrating compression at a relatively small area of the cap <NUM> to provide an enhanced seal. Additionally or alternatively, the protrusion <NUM> may retain the retention ring <NUM> in place by preventing distal-to-proximal movement of the retention ring <NUM> relative to the mouth <NUM> when the retention ring <NUM> is installed around the cap <NUM> and mouth <NUM>. In some embodiments, the cap <NUM> may also (or alternatively) include a protrusion <NUM> and/or a channel for receiving the bead <NUM> to facilitate suitable positioning of the retention ring <NUM> with respect to the cap <NUM>.

The protrusion <NUM> and/or the bead <NUM> may be rounded or otherwise shaped such that, when a force is applied to the retention ring <NUM> to install the retention ring <NUM> around the mouth <NUM> or remove the retention ring <NUM>, at least one of the mouth <NUM> and the retention ring <NUM> slightly deforms to allow passage of the bead <NUM> beyond the protrusion. In exemplary embodiments, the retention ring <NUM> may be more easily deformed than the mouth <NUM>. As shown in <FIG>, the protrusion <NUM> and/or the bead <NUM> may be positioned on their respective elements such that, when installed, the retention ring <NUM> is forced into a position such that it contacts a shoulder <NUM> of the container <NUM> and/or a lip <NUM> of the cap <NUM>. As a result, the retention ring <NUM> may be substantially fixed in place with respect to the mouth <NUM> and cap <NUM> when installed (absent a removal force).

<FIG> are figures showing a portion of the drainage system <NUM> to further illustrate the respective fits of the cap <NUM> around the mouth <NUM> and the retention ring <NUM> around the cap <NUM>. <FIG> shows the cap <NUM> as it may appear relative to the mouth <NUM> and the retention ring <NUM> when the cap <NUM> is not deformed. As shown, the protrusion <NUM> and the bead <NUM> may extend into the default path of the cap <NUM>. As a result of this feature, the cap <NUM> may be forced to deform when the cap <NUM> is installed around the mouth <NUM> and/or the retention ring <NUM> is installed around the cap <NUM> as shown in <FIG>. A bead gap, which may be defined as the shortest distance between the protrusion <NUM> and the bead <NUM> in the horizontal direction of <FIG>, may be approximately <NUM> (<NUM> inches). As described above (with reference to <FIG>), the dimensions and orientation of the protrusion <NUM>, the bead <NUM>, and the remainders of the mouth <NUM> and retention ring <NUM> may cause the material of the cap <NUM> to compress, thereby enhancing the seal. In other words, the above-described bead gap may be smaller
than the default thickness of the cap <NUM> (see <FIG>). In some embodiments, the cap <NUM> may compress to about <NUM>% to about <NUM>% of its default thickness (e.g., about <NUM>%) when the retention ring <NUM> is engaged. <FIG> is similar to <FIG>, but shows the above-described elements as they may appear when the interior of the cap <NUM> is exposed to the vacuum provided by the interior <NUM> of the container <NUM>. The cap <NUM> may be formed of a material that is relatively compliant or otherwise compressible. In some non-limiting examples, the cap <NUM> may be substantially formed by Mediprene™ <NUM>-<NUM> supplied by HEXPOL TPE or Santoprene™ <NUM>-65MED supplied by ExxonMobile.

<FIG> is an illustration showing a side section view of the retention ring <NUM>, where the retention ring is deformed due to a force provided on a tab <NUM> of the retention ring <NUM>. The tab <NUM> may be integrally formed (e.g., injection molded) with the remainder of the retention ring <NUM>. The tab <NUM> may include a surface <NUM> facing approximately distally, where the surface <NUM> is configured to receive a removal force provided by a user (e.g., through contact and pressure with a finger on the surface <NUM>, for example). As shown, the surface <NUM> may optionally include grip elements <NUM> for suitable friction/grip with a finger or hand of a user. Optionally, the tab <NUM> may include an extension <NUM> that is configured to abut the shoulder <NUM> of the container <NUM> when the retention ring <NUM> is installed. In some embodiments, the shoulder <NUM> may be spaced from the extension <NUM> unless a downward force is provided on the tab <NUM>, thus engaging the extension <NUM> with the shoulder <NUM>. Advantageously, when a downward force is provided (e.g., inadvertently), the extension <NUM> may transfer the force to the shoulder <NUM> to prevent the retention ring <NUM> from deforming to a degree such that it is inadvertently removed from its engaged state.

As depicted, when a sufficient force (such as the depicted removal force <NUM>) is provided, the retention ring <NUM> may deform. As described in more detail below (with reference to <FIG>), a rim portion of the retention ring <NUM> may be more easily deformed than other portions of the retention ring <NUM> such that the retention ring <NUM> deforms in a particular manner such that it manipulates itself out of engagement with the mouth <NUM> when the removal force <NUM> is provided. Optionally, the retention ring <NUM> may include a lip <NUM> on the proximal side of the collar <NUM>. In some embodiments, the lip <NUM> may taper outwards such that it is not snug with the mouth <NUM>. In other embodiments, the lip <NUM> may be flush with the mouth <NUM>. Additionally or alternatively, the lip <NUM> may be configured to engage with a proximal end <NUM> of the mouth <NUM> (e.g., through the thickness of the cap <NUM>) when the removal force <NUM> is applied such that the lip <NUM> pivot around the mouth <NUM> and presses into the cap <NUM>. The partial collapse of the cap <NUM> due to this pressure may enhance the ability of the retention ring <NUM> to remove the cap <NUM> and/or may reduce the minimum remove force <NUM> sufficient for cap removal. The pivot of the lip <NUM> may additionally or alternatively cause the lip <NUM> to press distally against the proximal end <NUM> of the mouth <NUM> (e.g., through the compliant material of the cap <NUM>), thereby facilitating proximal removal of the retention ring <NUM> from the mouth <NUM>. In other words, a lever-like effect of the lip <NUM> pressing against the mouth <NUM> and/or the outer surface <NUM> of the cap <NUM> may assist in deforming the retention ring <NUM> such that the bead <NUM> can pass the protrusion <NUM> of the mouth <NUM> of the container <NUM>. In some exemplary embodiments, a removal force of between about <NUM> N (<NUM> pounds) and <NUM> N (<NUM> pounds) may be sufficient to remove the retention ring <NUM>, such as about <NUM> N (<NUM> pounds) at nominal conditions. This force required for removal may vary depending on the specific dimensions of the cap <NUM>, retention ring <NUM>, and mouth <NUM>, as well as the materials forming these elements and the friction coefficient between said elements. The retention ring <NUM> may be designed such that different removal forces are adequate in other embodiments, and it is contemplated that the minimum force for removing the retention ring <NUM> may change as the drainage system ages.

Only one tab <NUM> is depicted in <FIG>, but more than one tab <NUM> may be included. For example, it may be advantageous to provide a tab <NUM> on opposite sides of the collar <NUM> of the retention ring <NUM> such that a user can provide removal forces on the respective opposite sides of the collar <NUM>. It is further contemplated that the tab <NUM> may include a surface on its proximal side and related elements (e.g., elements to provide a lever-like effect) configured to receive an installation force by a user or other person when installing the retention ring <NUM> around the mouth <NUM> and/or cap <NUM>.

Referring to <FIG>, which is an illustration showing a perspective view of the retention ring <NUM>, the proximal side of the tab <NUM> may optionally include structural ribs <NUM> and/or other structural features such that the tab <NUM> is relatively stiff (at least when compared to portions of the collar <NUM>). The ribs <NUM> may in particular provide stiffness to the tab <NUM> such that when the tab <NUM> receives a force, the force is primarily transferred through the ribs <NUM> to the collar <NUM> of the retention ring <NUM> without substantially deforming the tab <NUM> and thus enhancing the ability of the retention ring <NUM> to focus the deformation of the retention ring <NUM> at a certain location of the collar <NUM>. The ribs <NUM> may include gussets <NUM> extending to the lip <NUM> of the collar <NUM> to further transfer the force in a desired manner and to increase the force required to initiate undesirable buckling of the tab <NUM>. In certain non-limiting exemplary embodiments, the ribs <NUM> may be approximately <NUM> (<NUM> inches) in thickness, which may be an optimal thickness for providing adequate strength without unduly increasing component cost or decreasing manufacturing efficiency.

<FIG> is an illustration showing a side view of the retention ring <NUM>. As shown in <FIG>, the collar <NUM> of the retention ring <NUM> may include one or more bendable collar portions <NUM> that are relatively deformable with respect to other portions of the retention ring <NUM>, such as the remainder of the collar <NUM>, the tab <NUM>, etc. The bendable collar portions <NUM> may have relatively small cross-sectional dimensions with respect to the remainder of the collar <NUM> such that, when subjected to a force, the collar <NUM> tends to deform primarily at the bendable collar portions <NUM>. While any suitable dimensions are contemplated, in some embodiments, the bendable collar portions <NUM> may include a cutout <NUM> located at least in the lip <NUM> and that is shaped as an arc with a radius of approximately <NUM> (<NUM> inch). If the cutout <NUM> is in the shape of an arc, the edges of the bead <NUM> (shown in <FIG>) may optionally be approximately tangent to the arc of the cutout <NUM>. These dimensions may be optimal for certain applications by maximizing the flexibility of the collar <NUM> at the bendable collar portions <NUM> without interrupting the function(s) of the bead <NUM>. The cutout <NUM> may reduce the bending moment of inertia during removal of the collar <NUM> to thereby reduce the load required to remove the retention ring <NUM>.

Referring to <FIG>, the retention ring <NUM> may include a prong <NUM>. The prong <NUM> may be configured to open the frangible seal <NUM> by piercing the frangible seal <NUM> (see <FIG>) with a spike or point <NUM>. As described above, the frangible seal <NUM> may initially be pierced by a spike <NUM> (shown in <FIG>) during a drainage procedure. However, when it is desirable to drain the container <NUM> after the drainage
procedure, the piercing of the frangible seal <NUM> may not have a sufficient opening for efficient removal of fluid or solid medical waste from the container <NUM> after a drainage procedure. Further, in embodiments where it is advantageous to add a solidifier to fluid waste within the container <NUM> prior to disposal, a relatively large opening (e.g., larger than used during drainage) may be advantageous for simplifying the deployment of the solidifier without the use of a funnel, for example. Thus, the present embodiments may be advantageous because after the drainage procedure, a user (e.g., a patient) may remove the retention ring <NUM> from the mouth <NUM> (as described above) and then use the prong <NUM> of the retention ring <NUM> to further open the frangible seal <NUM> such that its opening is sufficient for drainage. Thus, at least the point <NUM> of the prong <NUM> may be sized, shaped, and/or otherwise configured to increase the size of the opening in the frangible seal <NUM> through manipulation of an edge <NUM> of the prong <NUM> through the frangible seal <NUM> by a user. The prong <NUM> may be relatively rigid when compared to the frangible seal <NUM>. <FIG> shows the prong <NUM> when used to increase the opening of a frangible seal at the mouth <NUM> of the container <NUM>.

As shown in <FIG>, the drainage system <NUM> may include a safety clip <NUM> that fits around the cap <NUM>. When the drainage system <NUM> is initially assembled, the safety clip <NUM> engaged with the cap <NUM> such that it is located around the cap <NUM> and between the flange <NUM> of the spike <NUM> and the container <NUM>. The safety clip <NUM>, when engaged, may prevent the spike <NUM> from moving distally and puncturing the frangible seal <NUM> prematurely. As shown in <FIG>, the safety clip <NUM> may include a groove <NUM> that is configured (e.g., sized and shaped) to fit around at least a portion of the collar <NUM> of the retention ring <NUM>. The engagement between the groove <NUM> and the retention ring <NUM> may retain the safety clip <NUM> in place by preventing its motion in the distal and/or proximal direction. Further, when groove <NUM> is sized and shaped to fit around at least one of the relatively narrow rim portions <NUM> (which may incorporate a curve, as described above), the size of the groove <NUM> with respect to the curve of the rim portions <NUM> may prevent rotation of the safety clip <NUM>. The safety clip <NUM> may be removed by a user by pulling on a handle <NUM>, and the drainage procedure may be initiated through movement of the spike <NUM> when the safety clip <NUM> is removed (e.g., to pierce a frangible seal as described above). While not shown, it is contemplated that the safety clip <NUM> may have a prong similar or identical to the prong <NUM> of the retention ring <NUM> (e.g., as an alternative to including the prong <NUM> of the retention ring <NUM>). In some embodiments, the extension holding the groove <NUM> (or another extension) may be configured (sized and shaped) such that it can be used to engage the retention ring <NUM> when the retention ring <NUM> is being removed, thereby providing a user with a tool to assist in removal of the retention ring <NUM> from its engaged state. Additionally or alternatively, the safety clip <NUM> may include a visual indicator (e.g., a molded arrow) depicting the direction that a user must pull to remove the safety clip <NUM> from the cap <NUM>, thus providing instructions to a user for initiation of a drainage procedure.

Claim 1:
A drainage system (<NUM>), the drainage system (<NUM>) comprising:
a container (<NUM>) having an interior (<NUM>) and a mouth (<NUM>), the mouth (<NUM>) having an outer surface (<NUM>) and an opening (<NUM>);
a frangible seal (<NUM>) covering the opening (<NUM>);
a cap (<NUM>) secured to the mouth (<NUM>) and configured to be in fluid communication with a drainage line (<NUM>), the cap (<NUM>) having an inner surface for engaging the outer surface (<NUM>) of the mouth (<NUM>); and
a retention ring (<NUM>) with a collar (<NUM>) having an inner surface configured to engage an outer surface (<NUM>) of the cap (<NUM>), the collar (<NUM>) terminating at opposite sides,
wherein the cap (<NUM>) is formed from a compressible material, and the retention ring (<NUM>) includes a bead (<NUM>) at least partially spaced from both the opposite sides of the collar (<NUM>), the bead (<NUM>) at least partially concentrating a restriction force provided by the retention ring (<NUM>) on an adjacent area of the outer surface (<NUM>) of the cap (<NUM>), the restriction force concentrated by the bead (<NUM>) compressing a thickness of the cap (<NUM>) at the bead (<NUM>) to a compressed portion having a compressed thickness less than a default thickness.