Patent Publication Number: US-2020276385-A1

Title: Devices and methods for delivering a beneficial agent to a user

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 14/863,312, filed Sep. 23, 2015, which claims priority to U.S. Provisional Patent Application No. 62/054,146, filed Sep. 23, 2014, all of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     Field of the Disclosed Subject Matter 
     The disclosed subject matter relates to devices, systems and methods for controlling and delivering fluids, for example for delivery of a beneficial agent to a user. 
     Description of Related Art 
     The disclosed subject matter is generally related to devices, systems and methods for controlling and delivering fluids, for example for delivery of a beneficial agent to a user. 
     A variety of fluid transport devices and systems have been developed for controlling and delivering beneficial agents in fluid form. Such fluid flow systems can include 1) volumetric-based aspiration flow systems using positive displacement pumps, and 2) vacuum-based aspiration systems using a vacuum source. For example, volumetric aspiration systems include peristaltic pumps for the delivery of therapeutic agents to a user. Various forms of peristaltic pumps are known, such as using rotating rollers to press against a flexible tubing to induce flow therethrough. Cassette systems or other drug delivery reservoir configurations can be coupled with the pump device to provide a source of beneficial agent fluid via the flexible tubing. 
     Such devices and systems are particularly beneficial as portable infusion pumps capable of being worn or carried by the user. However, there remains a need for improvement of such devices and systems. For example, it is desirable to deliver a generally uniform concentration of beneficial agent throughout the delivery process. However, it is possible the concentration of beneficial agent is not or will not remain uniform throughout the fluid reservoir. As such, there is a need and desire for a drug delivery reservoir capable of providing more uniform delivery of the beneficial agent throughout the delivery process. 
     SUMMARY 
     The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings. 
     To achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter includes a drug delivery reservoir for delivery of a beneficial agent to a user. The drug delivery reservoir generally includes a drug delivery reservoir housing, a dip tube and an adaptor. The drug delivery reservoir housing has a fluid reservoir defined therein and a drug delivery reservoir base region. The dip tube extends inside the fluid reservoir and includes a tubular wall defining a flow lumen. The tubular wall has at least one aperture defined therein and spaced proximally from a distal end of the tubular wall in fluid communication with the fluid reservoir. The adaptor is disposed external to the drug delivery reservoir housing and coupled to a proximal end of the dip tube. 
     Additionally, and as embodied herein, the fluid reservoir can be a flexible bag disposed within the housing. In some embodiments, the dip tube can be disposed diagonally across an interior region of the fluid reservoir. Additionally or alternatively, the dip tube can be disposed along a perimeter of the fluid reservoir, or at least a portion of the dip tube can be disposed proximate a center region. 
     Furthermore, and as embodied herein, the tubular wall can have a plurality of apertures spaced apart along a length of the tubular wall. One of the plurality of apertures nearest the outlet end can spaced from the outlet end a distance of at least 15% of the length of the tubular wall. In some embodiments, one of the plurality of apertures nearest the outlet end is spaced from the outlet end a distance of about 20% of the length of the tubular wall. 
     In addition, and as embodied herein, the plurality of apertures can be configured to provide a generally uniform distribution of flow through the plurality of apertures along the length of the tubular member. The plurality of apertures can vary in spacing between adjacent apertures along the length of the tubular wall. In some embodiments, the plurality of apertures can decrease in spacing toward the distal end of the tubular wall. Additionally or alternatively, the plurality of apertures can vary in cross dimension along the length of the tubular wall. In some embodiments, the plurality of apertures can increase in cross dimension along the length of the tubular wall. For example, and as embodied herein, a size of the plurality of apertures can increase along the tubular wall from the outlet end toward the distal end. 
     Additionally, and as embodied herein, the plurality of apertures can have a slotted shape. Alternatively, the plurality of apertures can have a circular shape. At least two of the plurality of apertures can be aligned axially along the length of the tubular wall and spaced circumferentially about the tubular wall. Additionally or alternatively, at least three of the plurality of apertures are aligned axially along the length of the tubular wall and spaced circumferentially about the tubular wall. 
     Furthermore, and as embodied herein, the drug delivery reservoir can include fluid beneficial agent in the reservoir. The concentration of the beneficial agent may be generally uniform throughout the reservoir, or may be non-uniform. For example, the fluid beneficial agent can have a volume and a concentration increasing from a region proximate the outlet end to a region proximate the distal end. The dip tube can be configured to deliver the volume of the fluid beneficial agent at a substantially uniform concentration. 
     In some embodiments, the drug delivery reservoir can include a junction with a first dip tube section and a second dip tube section each extending from an outlet thereof. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the disclosed subject matter claimed. 
     The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the disclosed subject matter. Together with the description, the drawings serve to explain the principles of the disclosed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded plan view of an exemplary device for delivering a beneficial agent according to the disclosed subject matter. 
         FIG. 2  is a perspective view of the device of  FIG. 1 . 
         FIG. 3  is a plan view of an exemplary fluid reservoir and delivery tube assembly of the disclosed subject matter. 
         FIG. 4  is a plan view of another embodiment of a fluid reservoir and delivery tube assembly of the disclosed subject matter. 
         FIG. 5A  is a schematic view of another embodiment of a fluid reservoir and delivery tube assembly of the disclosed subject matter. 
         FIG. 5B  is a schematic view of another embodiment of a fluid reservoir and delivery tube assembly of the disclosed subject matter. 
         FIG. 5C  is a schematic view of an exemplary fluid reservoir of the disclosed subject matter. 
         FIG. 5D  is a plan view of yet another embodiment of fluid reservoir and delivery tube assembly of the disclosed subject matter. 
         FIG. 5E  is a schematic view of yet another embodiment of fluid reservoir and delivery tube assembly of the disclosed subject matter. 
         FIGS. 6A-6B  are top-left perspective and rear-right perspective views, respectively, of an exemplary drug delivery reservoir of the device of  FIG. 1 . 
         FIG. 7  is a perspective view of another exemplary device for delivering a beneficial agent according to the disclosed subject matter, with the cassette separated from the pump. 
         FIGS. 8-11  each sequentially shows the cassette and pump of  FIG. 7  being joined, with a latch in an open position. 
         FIG. 12  shows the cassette and pump of  FIG. 7  joined with the latch in a closed position. 
         FIGS. 13A-13C  together illustrate an exemplary embodiment of an aperture configuration, which can be used with any of the dip tubes according to the disclosed subject matter. 
         FIGS. 14A-14D  together illustrate another exemplary embodiment of an aperture configuration, which can be used with any of the dip tubes according to the disclosed subject matter. 
         FIG. 15  illustrates another exemplary embodiment of an aperture configuration, which can be used with any of the dip tubes according to the disclosed subject matter. 
         FIGS. 16A-16D  together illustrate yet another exemplary embodiment of an aperture configuration, which can be used with any of the dip tubes according to the disclosed subject matter. 
         FIG. 17  is a diagram illustrating additional details of an exemplary peristaltic tubing according to the disclosed subject matter. 
         FIG. 18A  is a left side view of an exemplary junction fitting according to the disclosed subject matter. 
         FIG. 18B  is cross-sectional side view taken along line A-A of  FIG. 18A . 
         FIG. 18C  is an enlarged cross-sectional view of region C of  FIG. 18B . 
         FIG. 18D  is a plan view of the junction fitting of  FIG. 18A . 
         FIG. 19  is a diagram illustrating exemplary beneficial agent concentration per dispensed volume for drug delivery reservoirs using exemplary dip tube configurations according to the disclosed subject matter compared to cassettes using no dip tube. 
         FIG. 20  is a diagram illustrating exemplary beneficial agent concentration per dispensed volume for drug delivery reservoirs using exemplary dip tube configurations according to the disclosed subject matter. 
         FIG. 21  is a diagram illustrating exemplary beneficial agent concentration per dispensed volume for drug delivery reservoirs using exemplary dip tube configurations according to the disclosed subject matter. 
         FIG. 22  is a diagram illustrating exemplary beneficial agent concentration per dispensed volume for drug delivery reservoirs using exemplary dip tube configurations according to the disclosed subject matter. 
         FIG. 23  is a diagram illustrating an exemplary beneficial agent concentration for a plurality of regions of a fluid according to the disclosed subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the exemplary embodiments of the disclosed subject matter, examples of which are illustrated in the accompanying drawings. The methods of the disclosed subject matter will be described in conjunction with the detailed description of the system. The devices and methods presented herein can be used for delivering a beneficial agent to a user. 
     The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the disclosed subject matter. 
     The apparatus and methods presented herein can be used for administering any of a variety of suitable therapeutic agents or substances, such as a drug or biologic agent, to a patient. For example, and as embodied herein, a drug delivery reservoir is provided for use with a pump or the like to deliver a beneficial agent to a user. The drug delivery reservoir includes a housing having a fluid reservoir defined therein. The housing can be in the form of a cassette or similar rigid body. The fluid reservoir containing a fluid substance can be joined to a delivery tube system. In operation, the pump can operate on the drug delivery reservoir to deliver the fluid substance through the tubing system. In this manner, the device is capable of administering a dosage of the fluid substance, such as a therapeutic agent, including a formulation in a liquid or gel form, through the delivery tube system and to a patient. In some embodiments, the fluid therapeutic agent can include one or more pharmaceutical or biologic agents. 
     In accordance with the disclosed subject matter, a drug delivery reservoir for delivery of a beneficial agent to a user is provided. The drug delivery reservoir generally includes a drug delivery reservoir housing having a fluid reservoir defined therein. The drug delivery reservoir housing includes a drug delivery reservoir base region. The drug delivery reservoir includes a dip tube extending inside the fluid reservoir. The dip tube includes a tubular wall defining a flow lumen. The tubular wall can include at least one aperture defined therein and spaced proximally from a distal end of the tubular wall in fluid communication with the fluid reservoir. The drug delivery reservoir further includes an adaptor coupled to a proximal end of the dip tube. The adaptor can be disposed external to the drug delivery reservoir housing. 
     For the purpose of explanation and illustration, and not limitation, an exemplary embodiment of the device in accordance with the disclosed subject matter is shown in  FIGS. 1-2  and is designated generally by reference character  100 . As embodied herein, for purpose of illustration and not limitation, the device  100  is provided in the form of a cassette  10 . The cassette  10  has a cassette housing  11  and a fluid reservoir  12  defined within the cassette housing  11 . The cassette housing  11  can include a cassette base region  83  to join with the pump mechanism  30  having a pump housing  31 , as discussed further herein. As shown in  FIGS. 1 and 2 , the device can also include a delivery tube  20 , as discussed further herein. In some embodiments, the delivery tube  20  can have a first portion  21  disposed within the cassette housing  11  and second portion  22  disposed outside the cassette housing  11 . In this manner, the housing  11  is a rigid member. Alternatively, the housing itself can be in the form of a flexible pouch or the like to define the fluid reservoir  12 . 
     In accordance with the disclosed subject matter, the fluid reservoir  12  can be defined by the interior surface of the cassette housing  11 . Alternatively, as depicted here, the fluid reservoir  12  can be defined by a separate member disposed inside the cassette housing  11 . For example, the fluid reservoir  12 , shown in the various embodiments of  FIGS. 3, 4, and 5A -C, respectively, for the purpose of illustration and not limitation, can be configured as a flexible pouch. The fluid reservoir  12  of each embodiment can also have a textured inner surface as described further below. Opposing sides of the pouch can be secured about a perimeter (such as denoted by “Perimeter B” in  FIG. 5A ) to form the fluid reservoir  12 , for example by thermal or radio frequency (RF) welding or the like. The fluid reservoir  12  can have a “rounded square shape.” As shown for example in  FIGS. 3-5E , and as embodied herein, the fluid reservoir  12  can be generally square-shaped with rounded corners. The rounded corners can allow the bag to fit more easily into the cassette housing  11 , allow the bag to fill more evenly with a fluid beneficial agent, and inhibit or prevent the fluid beneficial agent from becoming trapped or otherwise unable to be removed from the fluid reservoir during normal operation of the cassette and pump. Additionally or alternatively, ridges can be formed on the surface of the fluid reservoir  12 . The ridges can allow the fluid beneficial agent to be more easily drawn into the tube. 
     The fluid reservoir  12  can be formed from a flexible material having low oxygen permeability. For purpose of illustration and not limitation, the fluid reservoir  12  can be made of EVA/EVOH/EVA, TOTM Plasticized PVC, combinations thereof, or other suitable materials, and as embodied herein, can be made of Renolit Solmed® Medipak UVO 9002. For purpose of illustration and not limitation, as embodied herein, the fluid reservoir  12  can have a thickness of about 12 mil. Additionally, for purpose of illustration and not limitation, the fluid reservoir  12  can be formed using an adhesive, by RF welding, or any other suitable technique. 
     As described herein, and in accordance with the disclosed subject matter, a dip tube  13  is disposed inside the fluid reservoir  12 . The dip tube  13  includes a tubular wall  13   a  defining a flow lumen. The tubular wall  13   a  of the dip tube  13  disclosed herein can have at least one aperture  14  defined therein and be spaced proximally from a distal end of the tubular wall  13   a . The aperture  14  is in fluid communication with the reservoir  12  to receive a beneficial agent contained within the reservoir  12 . Furthermore, the inner surface of the fluid reservoir  12  can have a textured, ribbed or grooved configuration to further enhance fluid flow by preventing unintended occlusion of the apertures  14 . For example, and as embodied herein, fluid reservoir  12  can include a plurality of horizontal grooves formed therein, as shown in  FIG. 5D . 
     In accordance with an additional aspect of the disclosed subject matter, dip tube  13  can include a plurality of apertures  14 , as shown for example in  FIG. 5A . For example, and as embodied herein, the plurality of apertures  14  each can be the same or similar size with the same or similar spacing therebetween. In accordance with the disclosed subject matter, the plurality of apertures can be configured to provide generally uniform flow distribution through the apertures along a length of the tubular wall of the dip tube. For example, and as described further below, the plurality of apertures  14  can have different sizes and/or have uneven distribution along the length of the dip tube  13 . Various combinations of variations in aperture size, shape and/or spacing along the tubular wall are described below for purpose of illustration and not limitation. For purpose of illustration, and not limitation, as embodied herein, apertures can be formed by machining, laser perforation or any other suitable techniques. 
     Generally, the dip tube is configured to bridge or otherwise extend at least through the area expected to have the highest concentration of beneficial agent within the fluid reservoir. For purpose of illustration and not limitation, and as embodied herein, the dip tube  13  can be arranged in any of a number of suitable configurations within the fluid reservoir  12 . For example, and as shown in  FIG. 3 , the dip tube  13  can extend along the perimeter of the fluid reservoir  12 . Additionally or alternatively, the dip tube  13  can be coiled within a central region of the fluid reservoir  12 , as depicted in  FIG. 4 . In addition, or as a further alternative, the dip tube  13  can form a serpentine configuration within all or a portion of the fluid reservoir  12 . In accordance with yet another embodiment, as shown in  FIG. 5A , the dip tube  13  can extend diagonally across the fluid reservoir  12  from one extreme end or corner to another. In accordance with yet another embodiment, as shown in  FIG. 5B , the dip tube  13 , can extend diagonally across the fluid reservoir  12  from one extreme end or corner to another, and having a bend to define an arcuate shape therebetween. 
     In accordance with yet another embodiment, as shown in  FIG. 5E , the dip tube  13  can extend to a junction  99  disposed within the reservoir  12  with dip tube sections  98   a ,  98   b  extending from the junction  99 . For purpose of illustration and not limitation, and as embodied herein, dip tube  13  can be free of apertures between the outlet end  33  and the junction  99 . Alternatively, dip tube  13  can include one or more apertures between the outlet end  33  and the junction  99  in any configuration described herein. Sections  98   a ,  98   b  can extend from the junction  99 , for example and as embodied herein, with a first section  98   a  extending toward an upper region of the reservoir  12  and a second section  98   b  extending toward a lower region of the reservoir  12  relative the outlet. As embodied herein, sections  98   a ,  98   b  each can include one or more apertures in any configuration described herein. For example and as embodied herein, sections  98   a ,  98   b  can include similar aperture configurations. Alternatively, sections  98   a ,  98   b  each can include varied aperture configurations. For purpose of illustration and not limitation, as embodied herein, the upper and lower regions can have different concentrations of a beneficial agent, and as such, having a dip tube  13  with sections  98   a ,  98   b  disposed in the upper and lower regions can be configured to allow different concentrations of a beneficial agent to be drawn from the reservoir through the different apertures  14  at substantially the same time for an overall more uniform concentration of beneficial agent delivered from the device during the delivery process. 
     In operation, the perforated dip tube  13  of each embodiment according to the disclosed subject matter allows fluid to be drawn from the fluid reservoir  12  regardless of the orientation of the reservoir  12 . For example, and with reference to  FIG. 3 , the dip tube  13  can be disposed generally along the perimeter of the reservoir  12 , which can include placing the dip tube  13  proximate the “corners” of the reservoir  12 , if provided. Additionally or alternatively, for example as shown in  FIG. 4 , the dip tube  13  can have one or more portions disposed proximate the center of the reservoir  12 . In this manner, if liquid becomes trapped in the center of the reservoir  12 , for example if the reservoir  12  becomes oriented horizontally, the dip tube  13  can receive the fluid from the center of the reservoir  12 . 
     Referring now to  FIGS. 5A and 5B , for illustration and not limitation, the dip tube  13  embodied herein for use within a fluid reservoir as shown can be configured using SUNLITE VYSUN 102-80-26 (Non-DEHP PVC) tube material, resin material such as Dupont Elvax 3182-2 EVA or silicone tube material, for example Saint-Gobain&#39;s Biosil Precision silicone tubing. As embodied herein, for a fluid reservoir  12  having a height of approximately 80 inches and a width of approximately 74 inches, the dip tube  13  can have a length of approximately 105 mm, and the tubular wall  13   a  can have a plurality of approximately 2 mm diameter apertures (denoted as “Holes C” in  FIG. 5A ) disposed therein. As shown for example in  FIG. 5A , apertures C can be disposed along the tubular wall  13   a  of the dip tube  13  starting from a location 8.5 mm from the tube interior or distal end (denoted as “End A 1 ” in  FIG. 5A ). The distal end of the dip tube  13  can have any suitable size or shape. The distal end of the dip tube  13  can be closed to ensure all fluid flow is through the apertures  14 . For example and without limitation, the distal end of the dip tube  13  can be flattened, tapered, or flared. As embodied herein, each aperture C can be spaced apart 8 mm along the length of the tubular wall  13   a  of dip tube  13  and rotated  90  degrees about the tubular wall  13   a  of dip tube  13  relative to adjacent apertures C. Representative dimensions of exemplary fluid reservoir and dip tube assemblies, for purpose of illustration and not limitation, are set forth below. 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Exemplary 
               
               
                   
                 FIG. 5A 
                 Dimensions (mm) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 w 1, 1   
                 58 
               
               
                   
                 w 1, 2   
                 7.165 
               
               
                   
                 w 1, 3   
                 1.6 
               
               
                   
                 w 1, 4   
                 80.2 
               
               
                   
                 h 1, 1   
                 74.2 
               
               
                   
                 h 1, 2   
                 1.5 
               
               
                   
                 h 1, 3   
                 4.78 
               
               
                   
                 h 1, 4   
                 9.9 
               
               
                   
                 h 1, 5   
                 12 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 FIG.  
                 Exemplary 
               
               
                   
                 5B &amp; 5E 
                 Dimensions (mm) 
               
               
                   
                   
               
             
            
               
                   
                 w 2, 1   
                 63.34 ± 1.60 
               
               
                   
                 w 2, 2   
                  5.6 ± 0.4 
               
               
                   
                 w 2, 3   
                  0.8 ± 0.4 
               
               
                   
                 w 2, 4   
                 74.6 
               
               
                   
                 h 2, 1   
                 70.6 
               
               
                   
                 h 2, 2   
                  1.5 
               
               
                   
                 h 2, 3   
                  4.8 
               
               
                   
                 h 2, 4   
                 11.9 
               
               
                   
                 h 2, 5   
                 14   
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Exemplary 
               
               
                   
                 FIG. 5C 
                 Dimensions (mm) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 w 3, 1   
                 4.6 
               
               
                   
                 w 3, 2   
                 5.6 
               
               
                   
                 w 3, 3   
                 0.8 
               
               
                   
                 w 3, 4   
                 74.6 
               
               
                   
                 h 3, 1   
                 70.6 
               
               
                   
                 h 3, 2   
                 4.8 
               
               
                   
                 h 3, 3   
                 11.9 
               
               
                   
                   
               
            
           
         
       
     
     Furthermore, and as embodied herein, the dip tube  13  can have an inside diameter of 3 mm and an outside diameter of 4.6 mm. In some embodiments, the dip tube  13  can have a thickness of at least about 1.5 mm; in some embodiments, the dip tube  13  can have a thickness of at least about 1.6 mm. As shown for example in  FIG. 5A , the dip tube  13  can be disposed diagonally across the interior of the fluid reservoir  12  (i.e., bisecting fluid reservoir  12 ). In accordance with yet another embodiment, as shown in  FIG. 5B , the dip tube  14 , can extend diagonally across the fluid reservoir  12  from one corner or end to another, having a bend to define an arcuate shape therebetween. The dip tube  13  can be joined to the reservoir  12  at a reservoir entry port (denoted as “End A 2 ” in  FIG. 5A ) as well as at the opposing end of the tube A 1  inside the reservoir  12 . As such, the dip tube  13  can be inhibited or prevented from movement within the reservoir  12 . 
     The dip tube  13  can extend from the fluid reservoir  12  to serve as a delivery tube if desired or appropriate. Alternatively, and as embodied herein, an adaptor disposed external to the cassette housing  11  can be provided and coupled to a proximal end of the dip tube  13 . In this manner, a separate delivery tube can be coupled to the adaptor for delivery of the beneficial agent from the fluid reservoir  12  to the user due to operation of the pump  30 . Additionally, a peristaltic tube can be provided between or as a part of the dip tube  13  and/or the delivery tube for interaction with the pump  30 . 
     For the purpose of illustration and not limitation, exemplary embodiments of such an adaptor are depicted in  FIGS. 5A-B . As shown, the fluid reservoir  12  includes an adaptor  15  disposed external to the cassette housing  11 . The adaptor  15  of  FIG. 5  is coupled to a proximal end of the dip tube  13 . As embodied herein, a polypropylene-barbed elbow fitting  16  is provided at the proximal end of the dip tube  13 . The elbow fitting  16  can be adhered to the exterior end of the dip tube  13  and oriented in plane with the fluid reservoir  12 . A peristaltic tube  23  can be installed or coupled to an opposing end of the elbow fitting  16 . For example, and as embodied herein, the peristaltic tube  23  can be formed from a section of Saint Gobain Biosil Precision PCS-Silicone tubing material. The peristaltic tube  23  can have an inside diameter of 1.6 mm and an outside diameter of 4.8 mm. A junction fitting  24  is joined to the peristaltic tube  23 , and a delivery tube  20  can be adhered into the junction fitting  24 . As such, the delivery tube  20  can be fluidly coupled with the fluid reservoir  12 . For example and without limitation, the delivery tube  20  can be formed from any suitable polymeric material or combination of materials, and as embodied herein, with an inner diameter of Dupont Elvax 3182-2 EVA and an outer diameter Colorite 8088G-015 Non-DEHP PVC. 
     A device having a fluid reservoir  12  and dip tube  13  as disclosed in  FIGS. 5A-5B  thus ensures delivery of a significant portion of beneficial agent regardless of the orientation of the fluid reservoir  12 . Additionally, the use of a plurality of apertures reduces the risk associated with one or more apertures becoming occluded during delivery. 
     However, it has been determined that certain formulations of beneficial agent may result in non-uniform flow distribution through the apertures, such as when more viscous fluids are used (e.g., oils, gels or the like). As such, and in accordance with another aspect of the disclosed subject matter, dosing accuracy can be further enhanced by modifying the dip tube to increase uniformity of the amount of fluid uptake along the length of the dip tube. That is, in vacuum pump systems or the like, pressure can be lost between the vacuum supply point (e.g., in a peristaltic pump system, the interface between the pump fingers and the tube) and the fluid supply point, causing a change in pressure along the tubing of a vacuum pump system. Such a pressure loss is exacerbated with more viscous fluids, such as oils and gels, due to frictional and shear forces of the fluid through the relatively small tube. The change in pressure along the length of dip tube  13  can cause different amounts of fluid uptake along the length of dip tube  13  due to the plurality of apertures  14  along the length of dip tube  13 . As such, and as disclosed herein, the plurality of apertures can be configured to provide a generally uniform distribution of flow through the plurality of apertures along the length of the tubular member. For example, apertures  14  disposed closer to the reservoir  12  outlet, where vacuum pressure is greatest, can be reduced in size, can be removed, and/or can be spaced further away from the outlet. In some embodiments, a number of apertures  14  spaced closer to the reservoir  12  outlet can be reduced. Additionally or alternatively, apertures  14  spaced further away from the reservoir  12  outlet can be increased in size. As a further alternative, the shape of some or all of the apertures  14  along the length of the tube can be modified, for example to have a slotted shape. 
     Additionally, the spacing between adjacent apertures can be varied along the length of the tubular wall. For purpose of illustration and not limitation, as embodied herein, the plurality of apertures decrease in spacing toward the distal end of the tubular wall. Alternatively, the plurality of apertures can increase in spacing toward the distal end of the tubular wall. 
     Furthermore, and as embodied herein, the plurality of apertures can vary in cross dimension along the length of the tubular wall. For purpose of illustration and not limitation, the size of apertures  14  can increase along the length of the dip tube  13  from the reservoir  12  outlet toward the end of the dip tube. As shown for example in  FIGS. 13A-13C , dip tube  13  can have apertures  12  varying in size along the length of the dip tube, spaced apart from the outlet end  33  of the dip tube  13  by varying distances along the length of the tubular wall  13   a  of the dip tube  13 , and rotated varying degrees about the tubular wall  13   a  of the dip tube  13 . Increasing the size of apertures  14  along the length of the dip tube  13  from the outlet end  33  toward the distal end of the dip tube  13  can compensate for the decreasing vacuum pressure. For example, increasing the size of apertures  14  along the length of the dip tube  13  can result in a more uniform uptake of fluid along the dip tube  13 . 
     Table 1 illustrates an exemplary dip tube aperture configuration. For purpose of illustration, and not limitation, hole number or hole location refers to an axial distance from the outlet end  33  of the dip tube  13 , with the distance increasing as the hole number or location number increases. As embodied herein and illustrated in the following Tables, unless otherwise specified, hole number or location number 1 corresponds to an axial distance 18.18 mm from the outlet end  33  of the dip tube  13 , and each successive hole number represents a distance of about an additional 8 mm from the outlet end  33  of the dip tube  13 . As such, a fractional hole number or location number represents a fraction of the 8 mm spacing. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 New 
                   
                 Concen- 
                 Sampled 
                   
               
               
                 Hole 
                 Diameter  
                 % 
                 tration %  
                 Concen- 
                   
               
               
                 Number 
                 (mm) 
                 flow 
                 Remaining 
                 tration 
               
               
                   
               
               
                  1 
                 0.     
                 11.    % 
                  90% 
                 10.7% 
                   
               
               
                  2 
                 0.     
                 11.    % 
                  90% 
                 10.    % 
                   
               
               
                  3 
                 0.     
                 10.    % 
                  95% 
                 10.    % 
                   
               
               
                  4 
                 0.7     
                 11.    % 
                  99% 
                 11.    % 
                   
               
               
                  5 
                 0.8     
                 10.3% 
                 100% 
                 10.    % 
                   
               
               
                  6 
                 1 
                 10.2% 
                 100% 
                 10.    % 
                   
               
               
                  7 
                 1.     
                 11.0% 
                 100% 
                 11.0% 
                   
               
               
                  8 
                 1.     
                 10.    % 
                 100% 
                 10.    % 
                   
               
               
                  9 
                 1.     
                      % 
                 100% 
                      .1% 
                   
               
               
                 10 
                 2 
                      % 
                 100% 
                      % 
                   
               
               
                 11 
                 2.     
                  2.0% 
                 100% 
                  2.0% 
                   
               
               
                   
                   
                  0.    % 
                 100% 
                  0.    % 
                   
               
               
                   
                   
                   
                   
                 97.0% 
                 Total 
               
               
                   
                   
                   
                   
                   
                 Concentration 
               
               
                   
               
               
                     indicates data missing or illegible when filed 
               
            
           
         
       
     
     Table 2 illustrates another exemplary dip tube aperture configuration. As shown, no apertures were formed in the first two hole locations (e.g., spaced about 18.18 mm and 26.18 mm from the outlet end  33 ). As such, the first aperture was formed in hole location 3, spaced about 34.18 mm from the outlet end  33 , which is about 20% of the length of the dip tube  13 . Apertures were formed at 9 axial locations along the dip tube  13  and have a uniform diameter. For purpose of comparison and confirmation of the disclosed subject matter, as illustrated in Table 3, flow uniformity is improved over dip tube configurations having constant diameter apertures, uniform spacing, and apertures formed closer to the outlet end  33  of the dip tube  13 . In this configuration, the initial aperture can be located in a region of relatively low concentration gradient, which can provide more uniform concentration of beneficial agent delivered during the delivery process. 
     For purpose of comparison with and confirmation of the disclosed subject matter, a representative formulation having a high viscosity and varied concentration was produced for purpose of illustration. For example and without limitation, the representative formulation was formed with Boron Nitride (BN) and a highly viscous gel, as embodied herein at a ratio of 6.77%(w/w) of Boron Nitride to the gel. The composition of the representative formulation is shown in Table A. 
     
       
         
           
               
             
               
                 TABLE A 
               
             
            
               
                   
               
               
                 Representative Formulation Composition 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Lot # 
                 Percent 
                 Theoretical 
                 Actual 
               
               
                 Ingredient 
                 (Vendor) 
                 Weight 
                 Weight (g) 
                 Weight (g) 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Boron Nitride  
                 3-5048-00-21  
                 6.77 
                 241.4 
                 241.6 
               
               
                 Powder 
                 (ZYP Coatings) 
                   
                   
                   
               
               
                 NaCMC 
                 2C1550NEFC 
                 1.58 
                 56.21 
                 56.5 
               
               
                 2000 
                 (Biogrund) 
                   
                   
                   
               
               
                 NaCMC 700 
                 212250NEFA 
                 1.29 
                 45.99 
                 46.1 
               
               
                   
                 (Biogrund) 
                   
                   
                   
               
               
                 DI Water 
                 N/A 
                 90.37 
                 3222.8 
                 3221.4 
               
               
                 Total 
                   
                 100 
                 3566.4 
                 3565.6 
               
               
                   
               
            
           
         
       
     
     Sample fluid reservoirs, for example as illustrated in  FIG. 5A and 5D , were filled with 50 mL of the representative formulation and assembled into a drug delivery reservoir. To further illustrate the effect of varied concentration within the fluid reservoir, the drug delivery reservoirs were installed on a centrifuge, which was operated for a duration of 66 hours to accelerate the BN within the gel to produce a varied concentration of BN throughout the gel. The operating conditions of the centrifuge are shown in Table B. 
     
       
         
           
               
             
               
                 TABLE B 
               
               
                   
               
             
            
               
                 Centrifuge Operating Conditions 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                 Relative 
               
               
                   
                   
                   
                   
                   
                   
                 centri- 
               
               
                   
                   
                   
                   
                   
                   
                 fugal 
               
               
                 Radius 
                 Radius 
                 Frequency 
                 Speed 
                 Speed 
                 Acceleration 
                 force  
               
               
                 (in) 
                 (m) 
                 (Hz) 
                 (RPM) 
                 (rad/s) 
                 (m/s{circumflex over ( )}2) 
                 (G&#39;s) 
               
               
                   
               
               
                 36.5 
                 0.93 
                 2.04 
                 122.4 
                 12.82 
                 152.32 
                 15.53 
               
               
                   
               
            
           
         
       
     
     The drug delivery reservoirs were mounted at a 3 foot radius to reduce or minimize differences in acceleration within the drug delivery reservoir. As a result, a varied concentration of the representative formulation throughout the reservoir was produced, as shown for example in  FIG. 23 . The concentration of the representative formulation after being accelerated for 66 hours is illustrated along the vertical broken line. Each section of the fluid reservoir in the diagram represents one-tenth of the volume of the reservoir from a top section of the reservoir to a bottom section of the reservoir. As shown in  FIG. 23 , after being accelerated for 66 hours, the top section of the fluid reservoir has about 65-70% of the concentration of BN compared to the bottom section. 
     For purpose of comparison with and confirmation of the disclosed subject matter,  FIG. 19  is a diagram illustrating exemplary nominal concentration per dispensed volume for drug delivery reservoirs using a dip tube having a constant hole size and spacing (referred to herein as “Hybrid 1” or “Baseline”) compared to drug delivery reservoirs using no dip tube. The representative formulation with varied concentration as discussed above with respect to  FIG. 23  was utilized, and the fluid was dispensed from the reservoir at a rate of 1 mL/min. With reference to  FIG. 19 , the drug delivery reservoir using a dip tube having constant hole spacing can draw from the top of the bag initially, and then progressively down into the bag as the bag empties and collapses. For bags without dip tubes, fluid draw can be a function of the bag collapse pattern. The results of the concentration dispensed over the volume for the Hybrid 1 establish a baseline for purpose of comparison with modified aperture configurations discussed herein. 
     For purpose of comparison and confirmation of the disclosed subject matter,  FIG. 20  is a diagram illustrating exemplary nominal concentration per dispensed volume for cassettes using a dip tube having a uniform hole size and spacing (Baseline) compared to cassettes using a dip tube having an aperture configuration described in Table 2 (Hybrid 2). The representative formulation with varied concentration as discussed above with respect to  FIG. 23  was utilized, and the fluid was dispensed from the reservoir at a rate of 1 mL/min. As shown in  FIG. 20 , the aperture configuration of Table 2 provides a relatively consistent fluid concentration of the representative formulation over the entire dispensing volume compared to the Baseline. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Hole 
                 Hole Diameter 
                 Hole  
                 flow Rate 
                 %  
                 % 
                   
                   
               
               
                 Number 
                 (mm) 
                 Diameter (in) 
                 (m{circumflex over ( )}3/s) 
                 Flow 
                 Remaining 
                 Concentration 
               
               
                   
               
               
                  1 
                 0 
                 0.0000 
                 0.00E+00 
                  0% 
                  90% 
                  0.0% 
                   
               
               
                  2 
                 0 
                 0.0000 
                 0.00E+00 
                  0% 
                  90% 
                  0.0% 
                   
               
               
                  3 
                 2.15 
                 0.0846 
                 8.32E−09 
                 75% 
                  95% 
                 71.2% 
                   
               
               
                  4 
                 2.15 
                 0.0846 
                 2.09E−09 
                 19% 
                  95% 
                 17.9% 
                   
               
               
                  5 
                 2.15 
                 0.0846 
                 5.24E−10 
                  5% 
                  99% 
                  4.7% 
                   
               
               
                  6 
                 2.15 
                 0.0846 
                 1.31E−10 
                  1% 
                 100% 
                  1.2% 
                   
               
               
                  7 
                 2.15 
                 0.0846 
                 3.32E−11 
                  0% 
                 100% 
                  0.3% 
                   
               
               
                  8 
                 2.15 
                 0.0846 
                 8.22E−12 
                  0% 
                 100% 
                  0.1% 
                   
               
               
                  9 
                 2.15 
                 0.0846 
                 2.17E−12 
                  0% 
                 100% 
                  0.0% 
                   
               
               
                 10 
                 2.15 
                 0.0846 
                 5.61E−13 
                  0% 
                 100% 
                  0.0% 
                   
               
               
                 11 
                 2.15 
                 0.0846 
                 5.61E−13 
                  0% 
                 100% 
                  0.0% 
                   
               
               
                   
                   
                   
                   
                   
                   
                 95.3% 
                 Total Concentration 
               
               
                   
               
            
           
         
       
     
     Table 3 illustrates another exemplary dip tube aperture configuration. Compared to the configuration of Table 1, an additional aperture is added toward the distal end of the dip tube  13 , opposite the outlet end  33 . For purpose of comparison and confirmation of the disclosed subject matter, using a known dip tube with constant aperture sizes and uniform spacing, about 95% of fluid flowed into the dip tube  13  from the first two hole locations during a flow period. The % flow indicates a percentage of fluid taken into the dip tube  13  through the aperture or apertures  14  formed at the corresponding hole location during the flow period. For purpose of comparison and confirmation of the disclosed subject matter, as illustrated in Table 2, flow uniformity is improved over dip tube configurations having constant diameter apertures and uniform spacing. As such, when used with a product having variable concentration, the increased flow uniformity can reduce variations in concentration by drawing fluid at different rates from different locations. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Hole  
                 New Diameter 
                 New  
                 %  
                 Concentration 
                 Sampled 
                   
               
               
                 Number 
                 (mm) 
                 Diameter (in) 
                 flow 
                 % Remaining 
                 Concentrtion 
               
               
                   
               
               
                  1 
                 0.55 
                 0.0217 
                 11.9% 
                  90% 
                 10.7% 
                   
               
               
                  2 
                 0.6 
                 0.0236 
                 11.8% 
                  90% 
                 10.8% 
                   
               
               
                  3 
                 0.65 
                 0.0256 
                 10.9% 
                  95% 
                 10.3% 
                   
               
               
                  4 
                 0.75 
                 0.0295 
                 11.9% 
                  99% 
                 11.8% 
                   
               
               
                  5 
                 0.85 
                 0.0335 
                 10.3% 
                 100% 
                 10.3% 
                   
               
               
                  6 
                 1 
                 0.0394 
                 10.2% 
                 100% 
                 10.2% 
                   
               
               
                  7 
                 1.2 
                 0.0472 
                 11.0% 
                 100% 
                 11.0% 
                   
               
               
                  8 
                 1.5 
                 0.0591 
                 10.2% 
                 100% 
                 10.2% 
                   
               
               
                  9 
                 1.9 
                 0.0748 
                  9.1% 
                 100% 
                  9.1% 
                   
               
               
                 10 
                 2 
                 0.0787 
                  8.8% 
                 100% 
                  8.8% 
                   
               
               
                 11 
                 2.25 
                 0.0888 
                  2..0% 
                 100% 
                  2.0% 
                   
               
               
                 12 
                 2.25 
                 0.0888 
                  0.9% 
                 100% 
                  0.9% 
                   
               
               
                   
                   
                   
                   
                   
                 97.0% 
                 Total Concentration 
               
               
                   
               
            
           
         
       
     
     Table 4 illustrates another exemplary dip tube aperture configuration. As shown, relatively smaller apertures were formed in the first 3 hole locations, and larger apertures were formed in 9 subsequent hole locations. For purpose of comparison and confirmation of the disclosed subject matter, as illustrated in Table 4, flow uniformity is improved for the representative formulation over dip tube configurations having constant diameter apertures and uniform spacing. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Hole  
                 New Diameter 
                 New Diameter 
                 Flow Rate  
                 %  
                 Concentration 
                 Sampled 
                   
               
               
                 Number 
                 (mm) 
                 (in) 
                 (m{circumflex over ( )}3/s) 
                 flow 
                 % Remaining 
                 Concentrtion 
               
               
                   
               
               
                  1 
                 1 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                  90% 
                 
                   
                 
                   
               
               
                  2 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                  90% 
                 
                   
                 
                   
               
               
                  3 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                  95% 
                 
                   
                 
                   
               
               
                  4 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                   
               
               
                  5 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 100% 
                 
                   
                 
                   
               
               
                  6 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 100% 
                 
                   
                 
                   
               
               
                  7 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 0% 
                 100% 
                 
                   
                 
                   
               
               
                  8 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 0% 
                 100% 
                 
                   
                 
                   
               
               
                  9 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 0% 
                 100% 
                  0.0% 
                   
               
               
                 10 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 0% 
                 100% 
                  0.0% 
                   
               
               
                 11 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 0% 
                 100% 
                  0.0% 
                   
               
               
                 12 
                 
                   
                 
                 
                   
                 
                 
                   
                 
                 0% 
                 100% 
                  0.0% 
                   
               
               
                   
                   
                   
                   
                   
                   
                 93.6% 
                 Total Concentration 
               
               
                   
               
               
                     indicates data missing or illegible when filed 
               
            
           
         
       
     
     Table 5-1 illustrates another exemplary dip tube aperture configuration. As shown, no aperture was formed in hole location 1, and a non-uniform aperture spacing is used. In hole positions 2.0, 2.9, 3.8 and 4.8, a single hole is formed in the dip tube at the corresponding axial distance. In the subsequent hole positions, two holes were formed in the dip tube at the corresponding axial distance, for example, by forming a through-hole. Table 5-2 and  FIG. 14  illustrates another exemplary dip tube aperture configuration. As shown, no aperture was formed in hole location 1, and a non-uniform aperture spacing is used. In hole positions 2.0, 2.9 and 3.8, a single hole is formed in the dip tube at the corresponding axial distance. In subsequent hole positions, two holes were formed in the dip tube at the corresponding axial distance, for example, by forming a through-hole. For purpose of comparison and confirmation of the disclosed subject matter, as illustrated in Tables 5-1 and 5-2, flow uniformity is improved for the representative formulation over dip tube configurations having constant diameter apertures, uniform spacing, and apertures formed closer to the outlet end  33  of the dip tube  13 . 
     
       
         
           
               
             
               
                 TABLE 5-1 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Hole Axial Location 
                   
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Axial  
                 Hole Diameter 
                   
                 %  
                 Concentration 
                 Sampled 
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Position 
                 Dimension (mm) 
                 mm 
                 inch 
                   
                 flow 
                 % Remaining 
                 Concentration 
                   
               
               
                   
               
               
                  1.1 
                  18.18 
                 None 
                   
                   
                   
                  90% 
                  0.0% 
                   
               
               
                  2.0 
                  26.2 
                 0.84 
                 0.033 
                 single hole 
                  19% 
                  90% 
                 17.1% 
                   
               
               
                  2.9 
                  33.6 
                 0.84 
                 0.033 
                 single hole 
                  12% 
                  95% 
                 11.8% 
                   
               
               
                  3.8 
                  40.5 
                 0.88 
                 0.033 
                 single hole 
                   8% 
                  99% 
                  8.0% 
                   
               
               
                  4.8 
                  48.8 
                 1.35 
                 0.049 
                 single hole 
                  20% 
                 100% 
                 20.1% 
                   
               
               
                  5.7 
                  55.5 
                 0.84 
                 0.033 
                 two holes 
                   6% 
                 100% 
                  5.8% 
                   
               
               
                  6.7 
                  63.8 
                 1.25 
                 0.049 
                 two holes 
                  13% 
                 100% 
                 12.9% 
                   
               
               
                  7.5 
                  70.5 
                 1.25 
                 0.049 
                 two holes 
                   7% 
                 100% 
                  7.1% 
                   
               
               
                  8.8 
                  79.1 
                 2.03 
                 0.080 
                 two holes 
                  11% 
                 100% 
                 20.5% 
                   
               
               
                  9.6 
                  87.2 
                 2.03 
                 0.080 
                 two holes 
                   3% 
                 100% 
                  2.9% 
                   
               
               
                 10.5 
                  94.4 
                 2.03 
                 0.080 
                 two holes 
                 0.8% 
                 100% 
                  0.9% 
                   
               
               
                 11.4 
                 101.6 
                 2.03 
                 0.080 
                 two holes 
                 0.3% 
                 100% 
                  0.3% 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                 97.4% 
                 Total Concentration 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5-2 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Hole Axial Location 
                 Axial  
                 Hole Diameter 
                   
                 Flown  
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Position 
                 Dimension (mm) 
                 mm 
                 inch 
                   
                 Rate m{circumflex over ( )}3/s 
                 ml/hr 
                 % flow 
               
               
                   
               
               
                  1 
                 18.18   
                 None 
                   
                   
                   
                   
                   
               
               
                  2 
                 26.2 (x 2,1 ) 
                 0.84 (Ø 2,1 ) 
                 0.033 
                 single hole 
                 2.22E−09 
                 8.00E+00  
                 20% 
               
               
                  2.9 
                 33.6 (x 2,2 ) 
                 0.84 (Ø 2,2 ) 
                 0.033 
                 single hole 
                 1.48E−09 
                 5.33E+00  
                 13% 
               
               
                  3.8 
                 40.5 (x 2,3 ) 
                 0.84 (Ø 2,3 ) 
                 0.033 
                 single hole 
                 9.99E−10 
                 3.60E+00  
                  9% 
               
               
                  4.8 
                 48.4 (x 2,4 ) 
                 0.84 (Ø 2,4 ) 
                 0.033 
                 two holes 
                 1.23E−09 
                 4.42E+00  
                 11% 
               
               
                  5.6 
                 55.1 (x 2,5 ) 
                 0.84 (Ø 2,5 ) 
                 0.033 
                 two holes 
                 7.58E−10 
                 2.73E+00  
                  7% 
               
               
                  6.7 
                 63.5 (x 2,6 ) 
                 1.25 (Ø 2,6 ) 
                 0.049 
                 two holes 
                 1.64E−09 
                 5.92E+00  
                 15% 
               
               
                  7.5 
                 70.1 (x 2,7 ) 
                 1.25 (Ø 2,7 ) 
                 0.049 
                 two holes 
                 9.07E−10 
                 3.26E+00  
                  8% 
               
               
                  8.6 
                 78.7 (x 2,8 ) 
                 2.03 (Ø 2,8 ) 
                 0.08 
                 two holes 
                 1.34E−09 
                 4.84E+00  
                 12% 
               
               
                  9.6 
                 86.8 (x 2,9 ) 
                 2.03 (Ø 2,9 ) 
                 0.08 
                 two holes 
                 3.72E−10 
                 1.34E+00  
                  3% 
               
               
                 10.5 
                  94 (x 2,10 ) 
                 2.03 (Ø 2,10 ) 
                 0.08 
                 two holes 
                 1.14E−10 
                 4.09E−01 
                  1% 
               
               
                 11.4 
                 101.2 (x 2,11 )  
                 2.03 (Ø 2,11 ) 
                 0.08 
                 two holes 
                 4.30E−11 
                 1.55E−01 
                  0% 
               
               
                 Total length 
                 168.69 (x 2,12 )   
                   
                   
                   
                   
                 4.00E+01 
               
               
                   
               
            
           
         
       
     
     Table 6 illustrates the exemplary dip tube aperture configuration of  FIGS. 13A-13C . As shown, no aperture was formed in hole location 1, and a non-uniform aperture spacing is used. For purpose of comparison and confirmation of the disclosed subject matter, as illustrated in Table 6, flow uniformity is improved over known dip tube configurations having constant diameter apertures, uniform spacing, and apertures formed closer to the outlet end  33  of the dip tube  13 .  FIG. 21  is a diagram illustrating exemplary nominal concentration per dispensed volume for drug delivery reservoirs using a dip tube having a uniform hole size and spacing (Baseline) compared to drug delivery reservoirs using a dip tube having an aperture configuration described in Table 6 (Config 4). The representative formulation with varied concentration as discussed above with respect to  FIG. 23  was utilized, and the fluid was dispensed from the reservoir at a rate of 1 mL/min. As shown, using the aperture configuration of Table 6, the dispensed concentration was substantially uniform over the entire displacement from the bag, and thus provides about a nine-fold improvement in dose accuracy compared to the uniform hole dip tube for the representative formulation. 
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Hole Axial Location 
                 Axial  
                 Hole Diameter 
                   
                 %  
                 Concentration 
                 Sampled 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Position 
                 Dimension (mm) 
                 mm 
                 inch 
                   
                 flow 
                 % Remaining 
                 Concentration 
               
               
                   
               
               
                  1 
                 18.18 
                 None 
                   
                   
                   
                  90% 
                  0.00% 
               
               
                  2 
                 26.2 (x 1,1 ) 
                 0.51 (Ø 1,1 ) 
                 0.02 
                 four holes 
                 13% 
                  90% 
                 11.30% 
               
               
                  2.9 
                 33.6 (x 1,2 ) 
                 0.51 (Ø 1,2 ) 
                 0.02 
                 four holes 
                  8% 
                  95% 
                  7.80% 
               
               
                  3.8 
                 40.5 (x 1,3 ) 
                 0.84 (Ø 1,3 ) 
                 0.033 
                 two holes 
                 19% 
                  99% 
                 18.40% 
               
               
                  4.8 
                 48.4 (x 1,4 ) 
                 0.84 (Ø 1,4 ) 
                 0.033 
                 two holes 
                 11% 
                 100% 
                 11.20% 
               
               
                  5.6 
                 55.1 (x 1,5 ) 
                 0.84 (Ø 1,5 ) 
                 0.033 
                 three holes 
                 10% 
                 100% 
                 10.10% 
               
               
                  6.7 
                 63.5 (x 1,6 ) 
                 1.24 (Ø 1,6 ) 
                 0.049 
                 two holes 
                 15% 
                 100% 
                 14.60% 
               
               
                  7.5 
                 70.1 (x 1,7 ) 
                 1.24 (Ø 1,7 ) 
                 0.049 
                 two holes 
                  8% 
                 100% 
                  8.10% 
               
               
                  8.6 
                 78.7 (x 1,8 ) 
                 2.03 (Ø 1,8 ) 
                 0.08 
                 two holes 
                 12% 
                 100% 
                 12.00% 
               
               
                  9.6 
                 86.8 (x 1,9 ) 
                 2.03 (Ø 1,9 ) 
                 0.08 
                 two holes 
                  3% 
                 100% 
                  3.30% 
               
               
                 10.5 
                  94 (x 1,10 ) 
                 1.65 (Ø 1,10 ) 
                 0.065 
                 four holes 
                  1% 
                 100% 
                  1.00% 
               
               
                 11.4 
                 101.2 (x 1,11 )  
                 1.65 (Ø 1,11 ) 
                 0.065 
                 four holes 
                  0% 
                 100% 
                  0.40% 
               
               
                 Total length 
                 168.69 (x 1,12 )   
                   
                   
                   
                   
                   
                 98.10% 
               
               
                   
               
            
           
         
       
     
     Table 7 and  FIG. 15  illustrate another exemplary dip tube aperture configuration.  FIG. 15  shows the exemplary dip tube  13  in a flattened configuration, for purpose of illustration of the configuration of apertures  14  of the dip tube  13 . In the configuration of Table 7 and  FIG. 15 , a slotted aperture configuration is used. Additionally, no aperture is formed in hole location 1, and a non-uniform slot length is used. For purpose of comparison and confirmation of the disclosed subject matter, as illustrated in Table 7, flow uniformity is improved over known dip tube configurations having constant diameter apertures, uniform spacing, and apertures formed closer to the outlet end  33  of the dip tube  13 .  FIG. 22  is a diagram illustrating exemplary nominal concentration per dispensed volume for cassettes using a dip tube having a uniform hole size and spacing (Hybrid 1) compared to drug delivery reservoirs using a dip tube having an aperture configuration described in Table 7 (Config 5). The representative formulation with varied concentration as discussed above with respect to  FIG. 23  was utilized, and the fluid was dispensed from the reservoir at a rate of 1 mL/min. As shown, the configuration of Table 7 provides about a 50% improvement in dose accuracy versus the uniform hole dip tube for the representative formulation. Additionally, the configuration of Table 7 can reduce or minimize the effects of manufacturing tolerances by providing a substantially uniform slit width. 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow (Slotted) 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Axial  
                 Total Area 
                    ngth = Area/ 
                   
                 length per slot 
                 Flow Rate 
                   
                 % 
                 Concentration 
                 Sampled 
               
               
                 Location 
                 Dimension (mm) 
                 inch{circumflex over ( )}2 
                 0.01″ inch 
                 no:of slots 
                 inch 
                 m{circumflex over ( )}3/s 
                 ml/hr 
                 flow 
                 % Remaining 
                 Concentration 
               
               
                   
               
               
                  1 
                 None 
                   
                   
                   
                   
                   
                   
                   
                  90% 
                  0.00% 
               
               
                  2 
                 26.2 (x 4,1 ) 
                 0.001 
                 0.126 
                 2 
                 0.0628 (l 4,1 ) 
                 1.39E−09 
                 5.01E+00  
                 13% 
                  90% 
                 11.30% 
               
               
                  3 
                 33.6 (x 4,2 ) 
                 0.001 
                 0.126 
                 2 
                 0.0628 (l 4,2 ) 
                 1.10E−09 
                 3.98E+00  
                 10% 
                  95% 
                  9.50% 
               
               
                  4 
                 40.5 (x 4,3 ) 
                 0.002 
                 0.171 
                 2 
                 0.0855 (l 4,3 ) 
                 1.26E−09 
                 4.55E+00  
                 11% 
                  99% 
                 11.30% 
               
               
                  5 
                 48.4 (x 4,4 ) 
                 0.002 
                 0.171 
                 2 
                 0.0855 (l 4,4 ) 
                 9.09E−10 
                 3.27E+00  
                  8% 
                 100% 
                  8.20% 
               
               
                  6 
                 55.1 (x 4,5 ) 
                 0.003 
                 0.257 
                 4 
                 0.0641 (l 4,5 ) 
                 9.09E−10 
                 3.27E+00  
                  8% 
                 100% 
                  8.20% 
               
               
                  7 
                 63.5 (x 4,6 ) 
                 0.004 
                 0.377 
                 4 
                 0.0943 (l 4,6 ) 
                 9.75E−10 
                 3.51E+00  
                  9% 
                 100% 
                  8.80% 
               
               
                  8 
                 70.1 (x 4,7 ) 
                 0.004 
                 0.377 
                 4 
                 0.0943 (l 4,7 ) 
                 7.11E−10 
                 2.56E+00  
                  6% 
                 100% 
                  6.40% 
               
               
                  9 
                 78.7 (x 4,8 ) 
                 0.01 
                 1.005 
                 6 
                 0.1676 (l 4,8 ) 
                 1.31E−09 
                 4.72E+00  
                 12% 
                 100% 
                 11.80% 
               
               
                 10 
                 86.8 (x 4,9 ) 
                 0.01 
                 1.005 
                 6 
                 0.1676 (l 4,9 ) 
                 9.13E−10 
                 3.29E+00  
                  8% 
                 100% 
                  8.20% 
               
               
                 11 
                    94 (x 4,10 ) 
                 0.013 
                 1.327 
                 8 
                 0.1659 (l 4,10 ) 
                 8.77E−10 
                 3.16E+00  
                  8% 
                 100% 
                  7.90% 
               
               
                 12 
                 101.2 (x 4,11 ) 
                 0.013 
                 1.327 
                 8 
                 0.1659 (l 4,11 ) 
                 7.29E−10 
                 2.63E+00  
                  7% 
                 100% 
                  6.60% 
               
               
                   
                   
                   
                   
                   
                   
                   
                 3.99E+01 
                   
                   
                 98.10% 
               
               
                   
               
               
                     indicates data missing or illegible when filed 
               
            
           
         
       
     
     Table 8 and  FIG. 16A  illustrate another exemplary dip tube aperture configuration.  FIG. 16B  shows the exemplary dip tube  13  rotated 90 degrees with respect to  FIG. 16A .  FIG. 16C  shows the exemplary dip tube  13  joined to an exemplary peristaltic tube.  FIG. 16D  shows the exemplary dip tube  13  in a flattened configuration, for purpose of illustration of the configuration of apertures  14  of the dip tube  13 . In the configuration of Table 8, as embodied herein, each aperture has the same diameter. Additionally, no aperture is formed in hole location 1. Flow distribution can be adjusted by the number of holes at each location and the spacing between holes. For purpose of comparison and confirmation of the disclosed subject matter, as illustrated in Table 8, flow uniformity is improved for the representative formulation over known dip tube configurations having constant diameter apertures, uniform spacing, and apertures formed closer to the outlet end  33  of the dip tube  13 . 
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 Exemplary Dip Tube Aperture Configuration and Flow 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Hole Axial 
                 Hole Diameter 
                   
                 Flow Rate 
                   
                 Concentration 
                 Sampled 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Dimensio   
                 mm 
                 inch 
                 No: of holes 
                 m{circumflex over ( )}3/2 
                 ml/hr 
                 % Remaining 
                 Concentration 
               
               
                   
               
               
                 26.2 (x 3,1 ) 
                 0.86 
                 0.0339 
                 1 (θ 3,1 ) 
                 2.04E−09 
                 7.33E+00  
                  90% 
                 16.50% 
               
               
                 31.2 (x 3,2 ) 
                 0.86 
                 0.0339 
                 1 (θ 3,4 ) 
                 1.53E−09 
                 5.51E+00  
                  95% 
                 13.10% 
               
               
                 40.5 (x 3,3 ) 
                 0.86 
                 0.0339 
                 2 (θ 3,2 , θ 3,6 ) 
                 1.75E−09 
                 6.29E+00  
                  99% 
                 15.60% 
               
               
                 48.4 (x 3,4)   
                 0.86 
                 0.0339 
                 2 (θ 3,1 , θ 3,4 ) 
                 1.05E−09 
                 3.79E+00  
                 100% 
                  9.50% 
               
               
                   55 (x 3,5 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 9.83E−10 
                 3.54E+00  
                 100% 
                  8.80% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   59 (x 3,6 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 7.34E−10 
                 2.64E+00  
                 100% 
                  6.60% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   62 (x 3,7 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 5.84E−10 
                 2.10E+00  
                 100% 
                  5.30% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   65 (x 3,8 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 4.61E−10 
                 1.66E+00  
                 100% 
                  4.10% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   68 (x 3,9 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 3.62E−10 
                 1.30E+00  
                 100% 
                  3.30% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   70 (x 3,10 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 , 
                 3.07E−10 
                 1.11E+00  
                 100% 
                  2.80% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   73 (x 3,11 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 , 
                 2.40E−10 
                 8.64E−01 
                 100% 
                  2.20% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   76 (x 3,12 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 1.86E−10 
                 6.68E−01 
                 100% 
                  1.70% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   78 (x 3,13 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 1.55E−10 
                 5.56E−01 
                 100% 
                  1.40% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   80 (x 3,14 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 1.29E−10 
                 4.64E−01 
                 100% 
                  1.20% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   82 (x 3,15 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 1.08E−10 
                 3.88E−01 
                 100% 
                  1.00% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   84 (x 3,16 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 9.01E−11 
                 3.24E−01 
                 100% 
                  0.80% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   86 (x 3,17 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 7.57E−11 
                 2.72E−01 
                 100% 
                  0.70% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   88 (x 3,18 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 6.37E−11 
                 2.29E−01 
                 100% 
                  0.60% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   90 (x 3,19 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 5.40E−11 
                 1.94E−01 
                 100% 
                  0.50% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   92 (x 3,20 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 4.64E−11 
                 1.67E−01 
                 100% 
                  0.40% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   94 (x 3,21 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 4.02E−11 
                 1.45E−01 
                 100% 
                  0.40% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   96 (x 3,22 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 3.56E−11 
                 1.28E−01 
                 100% 
                  0.30% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                   98 (x 3,23 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 , 
                 3.23E−11 
                 1.16E−01 
                 100% 
                  0.30% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                  100 (x 3,24 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 3.01E−11 
                 1.08E−01 
                 100% 
                  0.30% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                   
                   
                   
               
               
                  102 (x 3,25 ) 
                 0.86 
                 0.0339 
                 3 (θ 3,1 , θ 3,3 ,  
                 2.90E−11 
                 1.04E−01 
                 100% 
                  0.30% 
               
               
                   
                   
                   
                 θ 3,5 ) 
                   
                 4.00E+01 
                   
                 97.30% 
               
               
                   
               
               
                     indicates data missing or illegible when filed 
               
            
           
         
       
     
     As such, and as demonstrated above, the plurality of apertures can be configured to provide a generally uniform distribution of flow through the plurality of apertures along the length of the tubular member. For purpose of illustration and not limitation, and as embodied herein, the plurality of apertures can vary in spacing between adjacent apertures along the length of the tubular wall. For example, and as embodied herein, the plurality of apertures can decrease in spacing toward the distal end of the tubular wall. Additionally, in combination with any or all of the above configurations, or alternatively, the plurality of apertures can vary in cross dimension along the length of the tubular wall. For example, and as embodied herein, the plurality of apertures can increase in cross dimension along the length of the tubular wall. Furthermore, in combination with any or all of the above configurations, or as a further alternative, the plurality of apertures can have one or more shapes, for example and without limitation, a slotted shape, a circular shape, and/or any other suitable shape. In addition, in combination with any or all of the above configurations, or as another alternative, one of the plurality of apertures nearest the outlet end can be spaced from the outlet end a distance of at least 15% of the length of the tubular wall, and as embodied herein, the one of the plurality of apertures nearest the outlet end can be spaced from the outlet a distance of about 20% of the length of the tubular wall. Moreover, in combination with any or all of the above configurations, or as another alternative, at least two of the plurality of apertures can be aligned axially along the length of the tubular wall and spaced circumferentially about the tubular wall. As described herein, in accordance with the disclosed subject matter, a fluid beneficial agent in the reservoir can have a volume and a concentration increasing from a region proximate the outlet end to a region proximate the distal end, and as embodied herein, the dip tube can be configured to deliver the volume of the fluid beneficial agent at a substantially uniform concentration. 
     Furthermore, and as embodied herein, flow accuracy of the peristaltic pump can be improved by controlling the tension of the peristaltic tube  23 . As embodied herein, the tube tension fit can be achieved by controlling the length and diameter of the peristaltic tube  23  to achieve a desired tension. That is, reducing the length of the peristaltic tube  23  increases tension and reduces the overall flow rate. Increasing the length of the peristaltic tube  23  reduces tension and can cause buckling in the peristaltic tube  23  and create issues with installation and repeatability. 
       FIG. 17  is a diagram illustrating the accumulated flow rate (mL/hr) plotted against fitting-to fitting length (in.) for a section of peristaltic tubing with a nominal length of 2.275″ stretched or relaxed by +/1 ⅛″ in 1/32″ steps. The tests were run with 3 samples of each tubing length, sweeping test runs from low length to high length, then back from high to low, to randomize runs and allow for data on all lengths.  FIG. 16  shows that as tension was increased, the flow rate decreased. In contrast, as slacking/buckling increased, flow rate increased. Furthermore,  FIG. 17  illustrates that for a peristaltic tube having a nominal length of 2.275″ and stretched about a 1/32″ there is a tolerance window of +/− 1/16″ such that the flow rate will remain between about 91 ml/hr and 96 ml/hr. 
     For example, and as embodied herein, peristaltic tube  23  can be stretched at least about 0.782 mm (0.031 in). The specific length can be held in place by the cassette housing  11 , along with elbow fitting  16  and junction fitting  24 . Controlling the tension of the peristaltic tube  23  can allow for increased pump flow accuracy and repeatability. 
       FIG. 18  illustrates an exemplary junction fitting  24 . A tubing clamp  25  (illustrated in  FIG. 5B ) can be connected to the delivery tube  20  to allow a user to align and secure the tubing at a desired orientation and position. Additionally, as embodied herein, a connection sub-assembly  26  (illustrated in  FIG. 5B ) can be provided on the end of delivery tube  20  to allow the tubing and reservoir to be joined to a pump device. Representative dimensions of an exemplary junction fitting, for purpose of illustration and not limitation, are set forth below. 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                   
                 Exemplary 
               
               
                   
                 FIG. 18 
                 Dimensions (mm) 
               
               
                   
                   
               
               
                   
                 w 4, 1   
                 2.378 
               
               
                   
                 w 4, 2   
                 4.051 
               
               
                   
                 w 4, 3   
                 5.692 
               
               
                   
                 w 4, 4   
                 4.241 
               
               
                   
                 w 4, 5   
                 1.944 
               
               
                   
                 w 4, 6   
                 3.556 ± 0.051 
               
               
                   
                 w 4, 7   
                 5.56 
               
               
                   
                 w 4, 8   
                 3.378 ± 0.051 
               
               
                   
                 w 4, 9   
                 8.94 
               
               
                   
                 w 4, 10   
                 7.2 
               
               
                   
                 w 4, 11   
                 6.85 
               
               
                   
                 w 4, 12   
                 4.775 ± 0.051 
               
               
                   
                 w 4, 13   
                 3.378 
               
               
                   
                 h 4, 1   
                 5.082 
               
               
                   
                 h 4, 2   
                 2.542 
               
               
                   
                 h 4, 3   
                 3.75 
               
               
                   
                 h 4, 4   
                 4.2 
               
               
                   
                 h 4, 5   
                 9.855 
               
               
                   
                 h 4, 6   
                 7.950 ± 0.051 
               
               
                   
                 h 4, 7   
                 3 
               
               
                   
                 h 4, 8   
                 0.787 ± 0.051 
               
               
                   
                 h 4, 9   
                 0.508 
               
               
                   
                 h 4, 10   
                 4.5 
               
               
                   
                   
               
               
                   
                   
                 Exemplary 
               
               
                   
                 FIG. 18 
                 Dimensions (deg) 
               
               
                   
                   
               
               
                   
                 θ 4, 1   
                  13.1° 
               
               
                   
                 θ 4, 2   
                    74° 
               
               
                   
                 θ 4, 3   
                   1.0° 
               
               
                   
                 θ 4, 4   
                   9.6° 
               
               
                   
                 θ 4, 5   
                 45.000° 
               
               
                   
                   
               
            
           
         
       
     
     If formed separately, the fluid reservoir  12  can be installed into the cassette housing  11 . For example, and as embodied herein, the cassette housing  11  can be configured with two enclosure clamshell portions  17  and  18  (as shown for example in  FIG. 6B ), which can receive and contain the fluid reservoir  12 . The two clamshell portions  17  and  18  can be adhered or otherwise joined together, for example by ultrasonic welding. Furthermore, and as embodied herein, the peristaltic tube portion  23  can be received by a RFID enclosure shell  19  on one side of the cassette housing  11  and by a frictional engagement (for example as denoted by “D” in  FIG. 6A ) or other receiving feature on an opposing side of the cassette housing  11 . As such, the peristaltic tube  23  can be suspended within the housing  11 , which can allow for increased shape or dimensional control of the peristaltic tube  23  inside the pump mechanism, and can reduce the profile of the peristaltic tube  23  within the cassette housing  11 . 
     As previously noted, the cassette  10  disclosed herein can be used with a variety of pumps or similar fluid delivery devices. For purpose of illustration and not limitation, reference is made to the pump  30  of  FIGS. 1, 2 and 7-12 . The pump  30  can include a pump housing  31 . The pump housing  31  can include a pump assembly having a fluid drive component. The pump assembly can be configured, for example, as a peristaltic pump. For example, a peristaltic pump can include, a motor, a cam shaft, and a plurality of finger plates disposed along the length of the cam shaft. The cam shaft can be coupled to the motor for rotation about a longitudinal axis of the cam shaft, and can have at least one radially-outward projection defining a helical engagement portion disposed along a length of the cam shaft. The plurality of finger plates can be disposed along the length of the cam shaft. Each finger plate can be mounted for movement in a transverse direction relative to the longitudinal axis of the cam shaft, and can have an aperture defined therein to receive the cam shaft therethrough. 
     The pump housing  31  can have a receiving region  32  (for example as shown in  FIG. 7 ) to receive the cassette base region  83 . The fluid drive component can be disposed proximate the receiving region. For example, and as embodied herein, the cassette  10  can be joined to the receiving region  32  of the pump  30  with the delivery tube or peristaltic tube, if provided, in alignment with the fluid drive component of the pump  30 . Furthermore, and as embodied herein, the cassette  10  can be received by the pump housing  31  at a 90 degree angle (as shown for example in  FIGS. 7-8 ) and rotated 90 degrees relative the pump housing  31  into an orientation generally parallel with the pump housing  31  (as shown for example in  FIGS. 9-11 ). The cassette  10  can be rotated into engagement with a spring loaded clip  50  (shown in  FIG. 11 ), to thereby retain the cassette  10  within the housing  31 . Furthermore, and as embodied herein, the clip  50  can be retracted to disengage the cassette  10  from the housing  31 . 
     As shown in  FIGS. 7-12 , for the purpose of illustration and not limitation, the device  100  can include a latch  40  coupled to the pump housing  31  and movable between an open position and a closed position.  FIG. 7  shows an exploded view of the cassette  10  and pump  30  separated.  FIGS. 8-11  each sequentially shows the cassette  10  and pump being joined, with latch  40  in the open position.  FIG. 12  shows the latch  40  moved to the closed position. The cassette  10  can be inserted into and removed from the receiving region  32  when the latch  40  is in the open position. When the latch  40  is in the closed position, the cassette  10  can be secured to the pump  30  with the cassette base region  83  disposed within the receiving region. The delivery tube and/or peristaltic tube, if provided, can be in operative engagement with the fluid drive component along the length of the delivery tube. The latch  40  can be configured, for example and as embodied herein, as a spring latch. The latch  40  can be disposed within a recess of the pump body  31 , and as such, when the latch  40  is in the closed position, the latch  40  can be substantially flush with the pump body  31 . 
     Each of the components described herein can be made of any suitable material (e.g., plastic, composites, metal, etc.) and technique for its intended purpose. In addition to the specific embodiments claimed below, the disclosed subject matter is also directed to other embodiments having any other possible combination of the dependent features claimed below and those disclosed above. As such, the particular features disclosed herein can be combined with each other in other manners within the scope of the disclosed subject matter such that the disclosed subject matter should be recognized as also specifically directed to other embodiments having any other possible combinations. Thus, the foregoing description of specific embodiments of the disclosed subject matter has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosed subject matter to those embodiments disclosed. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the method and system of the disclosed subject matter without departing from the spirit or scope of the disclosed subject matter. Thus, it is intended that the disclosed subject matter include modifications and variations that are within the scope of the appended claims and their equivalents.