Abstract:
A fluid delivery system is provided having a disposable fluid reservoir that is integral with, and supported by, a pump housing. A peristaltic pump head is mounted within the pump housing. A length of flexible tubing is operatively engaged by the peristaltic pump, and includes a first end arranged in flow communication with the fluid reservoir and an accessible second end. A central portion of the tube is operatively engaged by the peristaltic pump head so that consecutive portions of the flexible tubing are successively collapsed to thereby propel fluid through the tubing so as to exit the second end. The disposable cartridge is preferably mateable with a recess in a base housing. A transmission system is mounted within the recess of the base housing and arranged to operatively engage the peristaltic pump head. A control module is disposed in control communication with the transmission system for selective operation of the fluid delivery system.

Description:
Field Of The Invention  
         [0001]    The present invention generally relates to fluid delivery systems, and more particularly, to a peristaltic pump-cartridge and reservoir for pumping fluid through a length of tube.  
         BACKGROUND OF THE INVENTION  
         [0002]    There exist many instances where a liquid in a container is to be dispensed repeatedly in the same, pre-measured quantity. One such situation is the dispensing of a liquid to a user in a medical or assisted living environment, e.g., home care, nursing home, hospital, etc. In the foregoing settings, there have typically been two different methods for dispensing exactly-repeated quantities of a liquid to a user. The first method consists of carefully pouring the liquid into a measurement container to obtain the desired amount, then having the person drink. The chief disadvantages of this method are that an additional tool, the measurement container, must be provided and the fluid has to be manually poured into the containers increasing the chances of spillage.  
           [0003]    A second method consists of controlling the outlet of a liquid container by a tap and measuring the dispensed amount of liquid by reading the liquid level on a scale on the liquid container. Since the liquid container has to be held exactly vertically in order to correctly read the level of the liquid, and since at least one hand is needed in order to control the tap, this method is mainly restricted to liquid containers installed at a fixed location and is not convenient for small transportable bottles in a assisted care setting. Moreover, there is no record of refills with this method, and therefore it is often difficult to accurately determine the total consumption of liquid dispensed. Additionally, at least a part of the container needs to be transparent in order to observe the level of liquid. One other prevalent problem associated with such methods is the eventual warming and stagnation of the fluid. This causes the liquid to be less than desirable for ingestion by a person.  
           [0004]    Peristaltic pumps are preferred for certain liquid dispensing applications due to their ability to pump fluids without any contact between the pump&#39;s components and the fluid. Roller-type peristaltic pumps are frequently encountered in laboratory, instrumentation, and light commercial settings. In a typical roller-type peristaltic pump system, one or more lengths of flexible tubing are contacted by a series of rollers that are mounted on a rotor so as to be capable of moving in a circular path, i.e., a circumferential, circular arc, over the tubing. The flexible tube is compressed between rollers and a circular backstop or race. The race has a surface adjacent to, and concentric with, the path of the rollers. As the occluded portion of the tube is advanced, the fluid in front of it is forced to travel through the tube. The rotor may be rotated by a variable-speed motor or other suitable drive. Peristaltic pump systems are known to offer very limited tubing life.  
           [0005]    It would be of great advantage to have a liquid container capable of repeatedly dispensing a controlled, defined volume of liquid without using an additional measurement container or a tap. Additionally, it would be very convenient if dispensing a defined amount of liquid were continuously adjustable, with only minimum manual control of the apparatus necessary to establish the desired volume of liquid. It would be further advantageous if the dispensing of liquid to a person in a medical setting could be repeated until the container is empty, without any need of additional operations to be carried out, and with the rate, volume, and time of dispensing recordable and selectively controllable. Also, recirculation of the liquid through appropriate filters and cooling systems so as to prevent the warming and stagnation of the fluid, would provide a distinct advantage over the prior art.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a fluid delivery system comprising a disposable fluid reservoir that is integral with, and supported by, a pump housing with a peristaltic pump mounted within the pump housing. A length of flexible tubing is operatively engaged by the peristaltic pump, and includes a first end arranged in flow communication with the fluid reservoir and an accessible second end. A central portion of the tube is operatively engaged by the peristaltic pump so that consecutive portions of the flexible tubing are successively collapsed to thereby propel fluid through the tubing so as to exit the second end. The disposable cartridge is preferably mateable with a recess in a base housing. A transmission system is mounted within the recess of the base housing and arranged to operatively engage the peristaltic pump. A control module is disposed in control communication with the transmission system for selective operation of the fluid delivery system. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    These and other features and advantages of the present invention will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiment of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:  
         [0008]    [0008]FIG. 1 is a perspective view of a peristaltic pump-cartridge, base housing and controls for a fluid delivery system formed in accordance with the present invention;  
         [0009]    [0009]FIG. 2 is an exploded perspective view, partially in phantom, of the peristaltic pump cartridge shown in FIG. 1;  
         [0010]    [0010]FIG. 3 is a perspective view, partially broken-away, of a base housing and control module of the present invention;  
         [0011]    [0011]FIG. 4 is a perspective view, partially in phantom, of a peristaltic pump cartridge formed in accordance with the present invention;  
         [0012]    [0012]FIG. 5 is a side elevational view of the peristaltic pump cartridge shown in FIGS. 1 and 2, shown partially in cross-section for clarity of illustration;  
         [0013]    [0013]FIG. 6 is a side elevational view of the peristaltic pump cartridge shown in FIGS. 1 and 2, shown partially in cross-section for clarity of illustration, and illustrating a fluid delivery bag;  
         [0014]    [0014]FIG. 7 is a perspective, partially exploded, view of a pump head assembly and transmission system;  
         [0015]    [0015]FIG. 8 is a cross-sectional view of a central spindle mounted upon a drive shaft;  
         [0016]    [0016]FIG. 9 is a perspective view of a portion of the transmission system shown FIG. 6;  
         [0017]    [0017]FIG. 10 is a perspective view of the pump head assembly and transmission system shown in FIG. 6, with a flexible tube positioned between a plurality of rollers and a race;  
         [0018]    [0018]FIG. 11 is a perspective view of the pump head assembly and transmission system shown in FIG. 9, with the race and tube shown partially in phantom and exploded-away for clarity of illustration;  
         [0019]    [0019]FIG. 12 is a bottom view of a rotor showing the internal features of the central spindle; and  
         [0020]    [0020]FIG. 13 is a side elevational view of an alternative embodiment of peristaltic pump cartridge shown in FIGS. 1 and 2, shown partially in cross-section for clarity of illustration. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. In the claims, means-plus-function clauses are intended to cover the structures described, suggested, or rendered obvious by the written description or drawings for performing the recited function, including not only structural equivalents but also equivalent structures.  
         [0022]    Referring to FIGS. 1-3, a peristaltic pump-cartridge, fluid delivery system  2  formed in accordance with the present invention generally comprises a base  5 , a reservoir cartridge  8 , and a control module  12 . More particularly, base  5  has a generally rectilinear profile including an annular wall  15  that surrounds a central recess  17  (FIGS. 2). Stops  19  are periodically positioned on the interior surface of wall  15  so as to support portions of reservoir cartridge  8 . A slot  20  extends into a top portion of wall  15  at a first end of base  5 , and a plurality of through-bores  22  are defined through a bottom portion of wall  15  at a second end of base  5 , adjacent to control module  12 , to accommodate conventional electrical interconnection (FIG. 3). Base  5  may be formed from one of the well known polymer materials that are suitable for use in structures requiring mechanical strength and integrity, e.g., but without limitation, thermoplastics (crystalline or non-crystalline, cross-linked or non-cross-linked), thermosetting resins, or blends or composites thereof, including polyhalo-olefins, polyamides, polyolefins, polystyrenes, polyvinyls, polyacrylates, polymethacrylates, polyesters, polydienes, polyoxides, polyamides and polysulfides and their blends, co-polymers and substituted derivatives thereof. Of course, other engineering materials suitable for support structures may also be used in connection with the present invention, e.g., metals, ceramics, and composites.  
         [0023]    Referring to FIGS. 1, 2, and  4 - 7 , reservoir cartridge  8  includes a fluid reservoir  25 , a pump housing  27 , a pump head assembly  29 , a flexible tubing or hose  30  and a filtration assembly  32 . Fluid reservoir  25  comprises an open ended receptacle capable of supporting a predetermined quantity of fluid  28 , e.g., water, medication, etc. It is often covered by a removable lid  33 . A fluid bag  31  may also be used by placing it within fluid reservoir  25  and arranged in fluid flow communication with flexible hose  30  (FIG. 6). Pump housing  27  is also formed as an open ended receptacle disposed under fluid reservoir  25 , and includes a race  26 , i.e., a curved, interior wall formed as a course along which a fluid is conveyed within flexible hose  30  (FIGS. 2, 4,  10  and  12 ). Fluid reservoir  25  and pump housing  27  are often integrally formed with one another so that a common wall  37  separates fluid reservoir  25  from pump housing  27 . Common wall  37  includes one or more through-holes  38  (FIG. 4) that allow for fluid communication between interior portions of fluid reservoir  25  and pump housing  27 .  
         [0024]    Referring to FIGS. 6-8 and  10 , pump head assembly  29  comprises a rotor  40  that includes a central spindle  53  having a top flange  55  positioned at one end, and a bottom flange  57  positioned at another end in spaced relation to top flange  55 . Top flange  55  and bottom flange  57  comprise circular disks that each have a plurality of slots  60  defined in their edges and arranged in circumferentially spaced relation to one another, e.g., at 90° intervals around the circumference of each circular flange. A plurality of rollers  63  are positioned between top flange  55  and bottom flange  57 , and include a cylindrical spindle  67  and a pair of spaced apart flanges  68 , one positioned at each end of cylindrical spindle  67 . A pair of axles  70  project outwardly from each end of spindle  67 . Axles  70  are sized, shaped, and arranged on each roller  63  so that they may be rotatably received within a pair of corresponding slots  60  in top flange  55  and bottom flange  57  of rotor  40 . Central spindle  53  includes a blind hole  72  that is defined along the longitudinal axis of rotor  40 . A pair of diametrically opposed teeth  75  project radially inwardly from the surface that defines blind hold  72 . Each tooth  75  includes a chamfered top  76  (FIGS. 8 and 12).  
         [0025]    Referring to FIGS. 6-9, transmission system  50  includes a drive shaft  43  and a motor  47  that are supported on block  51 . Drive shaft  43  includes a body  90 , a gear pin  93 , and a key  96 . Body  90  often comprises a metal cylinder with gear pin  93  projecting outwardly from one end and key  96  projecting outwardly from the other end. Gear pin  93  is typically formed as a shaft that is sized and shaped so as to be operatively connected to a portion of transmission system  50 . For example, a hole  94  may be defined through a portion of gear pin  93  that is sized and shaped to accept a fastener (not shown) so as to lock gear pin  93  in place within transmission system  50 . Key  96  comprises a pair of substantially identical blades  100  that are arranged in back-to-back, off-set relation to one another on the end of body  90 . Each blade  100  includes a downwardly inclined top surface  102  and tooth engagement surface  104 . Top surfaces  102  of each blade intersect so as to form a recessed groove in the top portion of key  96  that provides a “lead-in” chamfer. This construction compensates for the situation where the rotational position of drive shaft  43  orients surfaces  102  so as to be out of axial alignment with teeth  75  upon engagement with the pump-cartridge.  
         [0026]    Pump head assembly  29  is driven by motor  47  that is operatively connected to transmission system  50 . Motor  47  may comprise a servo-motor of the type well known for use in consumer appliances. A motor that has been found to provide adequate results is the one manufactured by Maxon Precision Motors, Inc., of Burlingame, Calif., under the tradename A-Max 22. Transmission system  50  also includes a pair of helical gears  118  and  119  that are operatively engaged with one another. Helical gear  118  is mounted on motor  47  and helical gear  119  is arranged within support block  51  so as to operatively engage gear pin  93  of drive shaft  43 . Motor  47  is arranged in electrical communication with both control module  12  and an appropriate power supply, via through-bores  22  (not shown) of the type well known for providing electrical energy to motors.  
         [0027]    Referring to FIGS. 2, 4,  11  and  12  flexible hose  30  comprises a tube that is often formed from a resilient elastomeric material, and includes a central portion  110 , a head end  112 , and a trail end  114 . Head end  112  is disposed in fluid communication with a portion of filtration assembly  32  and trail end  114  exits pump housing  27  through slot  20 . Central portion  110  is positioned between race  26  and rollers  63  (FIGS. 10-12).  
         [0028]    Referring to FIG. 5, filtration assembly  32  includes a base  125 , a filter medium  127 , and a cover  130 . More particularly, base  125  is often circularly shaped, and includes a central opening  133  that leads to a head opening  136  through a passageway  137 . An interface fitting  139  is positioned at head opening  136  so as to provide for interconnection of head end  112  of flexible hose  30  with filtration assembly  32 . Filter medium  127  often has a closed, hollow cylindrical profile or dome shape with a diameter at an open end that is substantially the same as the diameter of base  125 . For example, the gravity filters manufactured by SafeWater Anywhere of Ashland, Oreg. have been found to provide adequate results when used with the present invention. Such filters often comprise antimicrobial compounds that slowly release silver ions into the filtered fluid. These silver ions act as broad-spectrum antimicrobial agents and are highly effective when eradicating many types of bacteria and mold. Cover  130  has a shape and size that complement the shape and size of filter medium  127 , i.e., a closed, hollow cylindrical profile or dome shape with a diameter at an open end that is substantially the same as the diameter of base  125 . An opening  138  is defined in a top portion of cover  130  to allow filtration assembly  32  to be arranged in flow communication with the interior of fluid reservoir  25 , via through-holes  38  in common wall  37 . Although a separate cover  130  has been found to provide adequate results, it is preferred to form cover  130  integrally with housing  27  (FIG. 13).  
         [0029]    Control module  12  includes an arrangement of known electronic components that together may store and execute instructions for the operation of motor  47  and the recording of rate and time of delivery of fluid. Control system  12  provides for the control and initiation for the priming of fluid delivery system  2 , the basic operation of pump head assembly  29  and transmission system  50 , and the monitoring of fluid output. This monitoring is in ml while in a Normal Mode of operation, or in ml/hr while in Control Mode operation. The Control Mode feature gives the user the option for programming and monitoring set requirements for maximum or minimum ml/hr output of fluid to be allowed for a particular user. If these preselected limits are exceeded by the user, or not met, respectively, both a flashing led and an audible alert located within control module  12  are activated. Additionally, the fluid output amounts are stored in memory until reset, and may be viewed on a display as either ml in Normal Mode, or Total ml/ Elapsed Time, in Control Mode.  
         [0030]    In operation, reservoir cartridge  8  is assembled to base  5  by first positioning reservoir cartridge  8  in confronting relation to central recess  17  of base  5 . In this position, blind hole  72  of central spindle  53  is positioned in coaxially aligned relation to key  96  of drive shaft  43 . From this position, reservoir cartridge  8  is moved toward base  5  such that key  96  enters blind hole  72  of central spindle  53 . Reservoir cartridge  8  continues toward base  5  until it engages stops  19 . It may be necessary to advance drive shaft  43  slightly in order to effect proper seating of key  96 . When reservoir cartridge  8  is fully seated within recess  17  of base  5 , trail end  114  of flexible hose  30  extend outwardly through slot  20  in annular wall  15  of base  5 . At the same time, key  96  of drive shaft  43  is positioned within blind hole  72  of central spindle  53  of rotor  40  (FIG. 8).  
         [0031]    When motor  47  is activated by control module  12 , transmission system  50  operates to rotate drive shaft  43  into engagement with rotor  40 . More particularly, as drive shaft  43  rotates, surfaces  104  of key  96  engage teeth  75  so as to rotate rotor  40  and initiate the priming of fluid delivery system  2 . As transmission system  50  drives rotor  40 , fluid is dispensed according to a preprogrammed scheme which is monitored and recorded by control module  12  in Normal Mode or Control Mode operation.  
         [0032]    It is to be understood that the present invention is by no means limited only to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.