Apparatus for altering the characteristics of a fluid

An apparatus for altering characteristics of a fluid. The apparatus includes a canister having a side wall, a first end wall, and a second end wall defining a chamber therein. A beneficial agent is disposed in the chamber. The end walls define apertures therethrough. The apparatus further includes a tubing portion defining a first end portion constructed for connection to a fluid source and an outlet portion. The tubing portion also defines a canister-receiving portion intermediate the first end portion and the outlet portion. The canister-receiving portion defines a first fluid flow channel fluidly connecting the first end portion and the second outlet portion of said tubing portion. The canister-receiving portion also defines first and second fluid flow orifices therethrough. The canister-receiving portion is constructed to be selectively connectable to the canister such that fluid from the tubing portion can be selectively directed through the canister chamber, thereby causing the beneficial agent to become dispersed in the flowing fluid.

BACKGROUND OF THE INVENTION
 The present invention is directed to an apparatus for altering the
 characteristics of a fluid. In particular, the present invention is
 directed to an apparatus defining a first flow path and a second flow
 path. When the fluid follows the first flow path, it reaches an output of
 the apparatus without an alteration of its characteristics. When the fluid
 follows the second flow path, the fluid passes through a chamber
 containing a beneficial agent such that the beneficial agent becomes
 dispersed in the flowing fluid, thereby altering the fluid's
 characteristics. The apparatus is constructed such that flow through the
 second flow path can be selectively controlled.
 The delivery of enteral and parenteral products to a patient from a fluid
 source is well known. Such fluid products can be provided in hangable
 containers such as bottles and flexible bags having a bottom outlet that
 is fluidly connected to a drip chamber. The drip chamber in turn is
 fluidly connected to a flexible tube which in turn delivers the enteral or
 parenteral product to a patient. For example, an enteral product can be
 delivered to a patient by way of a nasogastric tube or a feeding tube
 inserted through a gastrostomy or a jejunostomy while a parenteral product
 can be delivered by way of a catheter inserted into a patient's vascular
 system. The parenteral or enteral product is delivered from the container
 to the patient through the use of gravity or through the use of an
 infusion pump. Pumps useful in the administration of enteral and
 parenteral products are well known and include, but are not limited to,
 rotary peristaltic pumps, piston pumps, and cassette pumps.
 Although such parenteral and enteral fluid delivery systems have been used
 widely in the medical field for many years, they lack a degree of
 flexibility. That is, in some cases it is desirable to supplement or
 otherwise alter the contents of enteral or parenteral products with an
 additional agent or with additional quantities of an agent already
 contained in the product. Such supplementation or alteration typically
 requires the use of a specialized delivery system. For example, a
 piggy-back delivery system can be used in order to provide a bolus of the
 additional agent to the enteral or parenteral product during
 administration thereof. Other known sets capable of simultaneously
 delivering a plurality of fluids from a plurality of sources can be used.
 However, such systems include additional tubes and ports that can become
 entangled during use. Further, such systems are typically higher in cost
 due to the need for additional lengths of tubing and Y-connectors.
 Some fluid delivery systems provide for supplementation of the liquid
 product in a container by providing a port on the container that can be
 opened, thereby permitting an additional agent, or additional quantities
 of an agent contained in the product, to be added directly thereto.
 However, by allowing such direct access to the product, the sterility of
 the product may be compromised. In the case of parenteral products,
 sterility must be maintained during delivery to a patient, thus making
 direct access unacceptable for parenteral products. The sterility of
 enteral products historically has posed less of a concern to medical
 professionals. However, there is a growing recognition of the desirability
 of providing and delivering enteral nutritional products to patients
 aseptically. Accordingly, it is desirable to provide a method and
 apparatus for modifying the characteristics of enteral and parenteral
 products without exposing the products to contamination.
 Without a system or apparatus for easily supplementing the contents of a
 liquid product prior to delivery thereof from a container to a patient, it
 becomes necessary to provide products having a wider variety of dosages,
 volumes, and combinations of agents. For this reason, delivery systems
 such as those described in U.S. Pat. Nos. 4,511,353; 5,318,558; and
 5,324,280 have been developed. In these systems, an agent to be delivered
 parenterally to a patient is contained in a capsule from which it is
 ejected over time as a result of osmotic infusion. That is, as the capsule
 is subjected to the presence of a fluid, the contents of the capsule are
 released into the fluid. U.S. Pat. No. 5,318,558 discloses the use of such
 a system in the delivery of agents directly into the body by exposing the
 capsule directly to bodily fluids.
 U.S. Pat. No. 5,069,071 describes a formulation chamber in which various
 forms of sustained release mechanism can be employed to release agents
 into a parenteral fluid traversing through the formulation chamber,
 thereby providing for delivery of the supplemental agent to the patient.
 In each of the systems disclosed in the above-referenced patents, it is
 necessary to place the additional, beneficial agent(s) in the flow path of
 a tubing set prior to delivering fluid to a patient through the tubing
 set. Thus, in order to delay the introduction of one or more beneficial
 agents into the flowing fluid, it was necessary to formulate the
 beneficial agents such that they had a delayed release into the fluid,
 thereby increasing the cost of formulating the beneficial agent. It is
 desirable to provide an apparatus that allows for the introduction of
 beneficial agents in varying amounts and at various times without the need
 for formulating the beneficial agents such that their release into the
 flowing fluid is delayed. It also is desirable to provide an apparatus
 that allows an operator to initiate the introduction of one or more
 beneficial agents into the flowing fluid on an as-needed basis without the
 need for opening the apparatus to an external environment thereof.
 SUMMARY OF THE INVENTION
 The present invention provides an apparatus for altering characteristics of
 a fluid flowing therethrough. The apparatus includes a canister having a
 side wall, a first end wall, and a second end wall defining a chamber
 therein. A beneficial agent is disposed in the chamber. The end walls
 define apertures therethrough. The apparatus further includes a tubing
 portion defining a first end portion constructed for connection to a fluid
 source and an outlet portion. The tubing portion also defines a
 canister-receiving portion intermediate the first end portion and the
 outlet portion. The canister-receiving portion defines a first fluid flow
 channel fluidly connecting the first end portion and the second outlet
 portion of said tubing portion. The canister-receiving portion also
 defines first and second fluid flow orifices therethrough. The
 canister-receiving portion is constructed to be selectively connectable to
 the canister such that fluid from the tubing portion can be selectively
 directed through the canister chamber, thereby causing the beneficial
 agent to become dispersed in the flowing fluid.

DETAILED DESCRIPTION
 The present invention is directed to an apparatus for altering the
 characteristics of a fluid. For the purposes of this disclosure, the
 apparatus will be described in the context of an enteral nutritional fluid
 delivery system. However, it will be appreciated that the present
 invention also can be used to alter the characteristics of a parenteral
 fluid as it is delivered to a patient.
 The present invention is described herein with reference to the
 accompanying figures. Terms of reference such as "upper" and "lower" are
 used to facilitate an understanding of the present invention in view of
 the accompanying figures. These terms are not intended to be limiting and
 one of ordinary skill in the art will recognize that the present invention
 can be practiced in a variety of spatial orientations without departing
 from the spirit and scope of the present invention.
 As used herein, the terms "enteral nutritional product" and "enteral
 product" refer to a liquid composition designed to be delivered to a
 patient's gastrointestinal tract. Delivery to the gastrointestinal tract
 can be effected through a nasogastric tube, through a gastrostomy tube,
 and/or through a jejunostomy tube. These liquids typically have a
 viscosity of at least about 3 centipoises.
 A "beneficial agent" is an agent that is, or that is believed to be,
 nutritionally or pharmaceutically important to the patient, or that is
 otherwise medically important as in the case of a probiotic, or that
 serves as a diagnostic agent as in the case of an opaquing agent, an
 imaging agent, or a coloring agent.
 A "probiotic" is understood to be a live microbial food supplement that
 beneficially affects the human host by improving the microbial balance in
 the host's gastrointestinal tract, e.g., Lactobacillus reuteri.
 A "useful amount" of a beneficial agent is an amount that is
 physiologically effective or diagnostically detectable when administered
 to a patient or that is believed to be physiologically effective or
 diagnostically detectable when administered to a patient. That is, an
 amount that is reasonably expected to produce a detectable effect on the
 patient on either a short term or long term basis when delivered to the
 patient or an amount that is detectable in diagnosing a disease state or a
 medical condition.
 "At least one beneficial agent" is meant to refer to the singular as well
 as the plural and is intended to include combinations of ingredients,
 agents, or factors.
 The term "dispersible" as used herein with respect to beneficial agents is
 to be understood to apply to substances that are soluble as well as those
 that are suspendable enough to be taken up readily and carried along by
 the liquid medium as the liquid flows through the chamber containing the
 beneficial agent. Dispersible agents include, but are not limited to,
 agents in controlled release dosage form.
 The term "feeding set" refers to a combination of known elements useful in
 delivering a product from a liquid container to a patient. Such
 combinations include, but are not intended to be limited to, combinations
 comprising one or more of drip chambers, formulation chambers, lengths of
 tubing, flow control clamps, pumps, and other devices commonly found in
 infusion sets.
 The term "infusion" is meant to refer to the enteral or parenteral delivery
 of a liquid to a patient.
 The term "flowing the fluid" is intended to include the utilization of
 gravity to effect flow as well as the utilization of a pump of known
 construction to effect flow.
 An apparatus for altering characteristics of a fluid is generally indicated
 at 10 in FIG. 2. Apparatus 10 includes a tubing portion 12 having a first
 end portion 14 constructed to be connected to a fluid source. As depicted
 in FIG. 1, first end portion 14 is configured as a spike 16 of known
 construction for piercing a membrane seal on a fluid container of the type
 typically used in the medical field. As depicted in FIG. 2, first end
 portion 14 is configured as a male luer member 18 constructed for
 frictional retention within a complementary female luer member provided on
 a fluid source. It will be appreciated that first end portion 14 can have
 any number of other configurations that facilitate connection of first end
 portion 14 to a fluid source. For example, first end portion 14 can be
 constructed for connection to a fluid source by way of a locking luer
 connection or by way of a threaded connection. Further, first end portion
 14 can be constructed to be frictionally connected to a fluid source by
 way of, for example, a snap fitment of known construction. Other known
 mechanisms for connection of tubing portion 12 to a fluid source are
 intended to be within the scope of the present invention.
 Tubing portion 12 further includes an outlet portion 20 which, in the
 embodiment depicted in FIG. 1, is constructed to deliver fluid from tubing
 portion 12 to a separate fluid delivery apparatus, e.g., a length of
 tubing constructed to deliver an enteral or parenteral fluid to a patient.
 In the embodiment of the invention depicted in FIG. 1, outlet portion 20
 has a female luer configuration such that it can be frictionally connected
 to a male luer member, e.g., male luer member 18 of first end portion 14.
 In this way, multiple tubing portions 12 can be interconnected, as
 discussed in greater detail herein. However, it will be appreciated that
 outlet portion 20 can have a variety of known constructions, as
 above-discussed with respect to first end portion 14.
 Tubing portion 12 further includes canister-retaining portion 22, as
 depicted in FIG. 1. Canister-receiving portion 22 is positioned
 intermediate first end portion 14 and outlet portion 20.
 Canister-retaining portion 22, first end portion 14, and outlet portion 20
 define a first fluid flow channel 24 therethrough. It will be appreciated
 that first fluid flow channel 24 provides for fluid communication through
 tubing portion 12 from first end portion 14 to outlet portion 20 such that
 fluid can flow through tubing portion 12. As depicted in the accompanying
 figures, tubing portion 12 is of a unitary construction and is made of a
 material commonly used in the delivery of enteral and parenteral fluids to
 a patient. However, it is to be appreciated that tubing portion 12 can be
 constructed of several distinct pieces without departing from the scope of
 the present invention.
 In the embodiment of the present invention depicted in the FIG. 2,
 canister-receiving portion 22 includes a first segment 26, second segment
 28, and third segment 30. First segment 26 and third segment 30 are
 substantially parallel and define a canister-retention space 32
 therebetween. Canister-retention space 32 is further defined by second
 segment 28 which, in the depicted in embodiment, is substantially
 perpendicular to first segment 26 and third segment 30. It will be
 appreciated that the relative orientations of first segment 26, second
 segment 28, and third segment 30 can be varied without departing from the
 scope of the present invention. First segment 26, second segment 28, and
 third segment 30 can be constructed and oriented to define
 canister-retention spaces 32 having a wide variety of configurations. In
 this way, canister-retention space 32 can be constructed to match the
 configuration of a canister 34 to be placed therein. This construction can
 serve to prevent the insertion of an improper canister 34 into
 canister-retention space 32, thereby ensuring that canisters 34 containing
 improper beneficial agents are not placed into the flow path of a feeding
 set that includes apparatus 10 of the present invention.
 First segment 26 of canister-retaining portion 22 defines one or more first
 fluid flow orifices 36 therethrough. Third segment 30 of
 canister-retaining portion 22 defines one or more second fluid flow
 orifices 38 therethrough. First and second fluid flow orifices 36, 38
 preferably are oriented such that they provide fluid communication between
 first fluid flow channel 22 and canister-retaining space 32.
 Canister 34 includes a side wall 40, a first end wall 42, and a second end
 wall 44. In the embodiment of the present invention depicted herein,
 canister 34 is substantially cylindrical. However, it is to be appreciated
 that canister 34 can have a variety of shapes and sizes without departing
 from the scope of the present invention. For example, canister 34 can be
 substantially spherical in shape. Further, the shape of canister 34 and
 the shape of canister-retaining space 32 can be selected so as to prevent
 certain shapes of canisters 34 from being placed in certain
 canister-retaining spaces 32, thereby limiting the possibility that
 apparatus 10 of the present invention can be used inappropriately.
 First end wall 42 defines one or more apertures 46 therethrough. Second end
 wall 44 defines one or more apertures 48 therethrough. FIGS. 4 and 5
 represent alternative configurations for both first end wall 42 and second
 end wall 44. In one embodiment of the present invention depicted in FIGS.
 4 and 5, first end wall 42 and second end wall 44 include a first,
 substantially imperforate section 50 and a second section 52. In the
 embodiment depicted in FIG. 4, a plurality of apertures 46, 48 are defined
 by second section 52. In the embodiment depicted in FIG. 5, a single
 aperture 46, 48 is defined by second section 52. It will be appreciated
 that the configurations of first end wall 42 and second end wall 44 can be
 varied from those depicted herein, and varied from one another, without
 departing from the scope of the present invention.
 Canister 34 is constructed such that it can be received by
 canister-retention space 32, that is, such that first fluid flow orifice
 36 defined by first segment 26 of canister-retaining portion 22 is in
 fluid communication with aperture 46 defined by first end wall 42 and such
 that second fluid flow orifice 38 defined by third segment 30 of
 canister-retaining portion 22 is in fluid communication with aperture 48
 defined by second end wall 44.
 In a preferred embodiment of the present invention, canister 34 is
 constructed to be received by canister-retention space 32 such that
 canister 34 is rotatable relative to canister-retaining portion 22 of
 tubing portion 12. In a first configuration of the preferred embodiment,
 canister 34 is substantially cylindrical in shape. It will be appreciated
 that the cylindrical shape of canister 34 will facilitate relative
 rotation between canister 34 and canister-retaining portion 22 because
 side wall 40 of canister 34 does not have any corners to impede such
 rotation. In an alternative configuration of the preferred embodiment of
 the present invention, first end wall 42, or a portion thereof, is
 rotatable relative to side wall 40 of canister 34. In this embodiment,
 second end wall 44, or a portion thereof, also is rotatable relative to
 side wall 40 of canister 34.
 In the preferred embodiment of the present invention, canister 34 is
 rotatable between a first position and a second position. In the second
 position, first fluid flow orifice 36 defined by first segment 26 of
 canister-retaining portion 22 is in direct contact with first,
 substantially imperforate section 50 of first end wall 42 and second fluid
 flow orifice 38 defined by third segment 30 of canister-retaining portion
 22 is in direct contact with first, substantially imperforate section 50
 of second end wall 44. Canister 34 and canister-retaining portion 22
 preferably are configured such that substantially no fluid is released
 through first and second fluid flow orifices 36, 38 when canister 34 is in
 the second position. Accordingly, it is preferred that first and second
 end walls 42, 44 be constructed to substantially seal first and second
 fluid flow orifices 36, 38, respectively. For example, first,
 substantially imperforate sections 50 of first and second end walls 42, 44
 can have an elastomeric surface constructed to provide a substantially
 fluid-tight seal of first and second fluid flow orifices 36, 38. It also
 will be appreciated that a relatively tight fit between first end wall 42
 and first segment 26 and between second end wall 44 and third segment 30
 is desirable in order to facilitate the desired sealing of first and
 second fluid flow orifices 36, 38. That is, a length of canister 34 from
 first end wall 42 to second end wall 44 preferably is substantially the
 same as the distance from first segment 26 to third segment 30 across
 canister-retention space 32. When canister 34 is in its first position
 relative to canister-retaining portion 22 of tubing portion 12, a fluid
 introduced into first end portion 14 of tubing portion 12 flows through
 first fluid flow channel 24 to outlet portion 20 of tubing portion 12.
 When canister 34 is in its first position relative to canister-retaining
 portion 22 of tubing portion 12, first and second fluid flow orifices 36,
 38 are in fluid communication with apertures 46, 48 defined through second
 sections 52 of first end wall 42 and second end wall 44, thereby allowing
 fluid to flow from first fluid flow channel 24 through canister 34. Here
 again it will be appreciated that a relatively close fit between canister
 34 and first and third segments 26, 30 is desirable in order to prevent
 the flow of fluid outside of apparatus 10.
 Canister 34 preferably defines chamber 58 therein. At least one beneficial
 agent 60 is positioned within chamber 58. Beneficial agents 60 are
 formulated to be dispersible in a fluid flowing through chamber 58 defined
 by canister 34. Beneficial agents 60 can be in tablet form, powder form,
 liquid form, gel form, or any other known form. Beneficial agents 60 can
 be placed in chamber 58 defined by canister 34 either by a manufacturer or
 by a pharmacist or other individual immediately prior to use of apparatus
 of the present invention.
 Because beneficial agent 60 is selected to be dispersible in a particular
 fluid flowing through chamber 58 during use of apparatus 10 of the present
 invention, beneficial agent 60 will be dispersed in a fluid exiting outlet
 portion 20 of tubing portion 12 when canister 34 is in its first position
 relative to canister-retaining portion 22 of tubing portion 12. It will be
 appreciated that it is desirable that a useful amount of beneficial agent
 60 be present in the fluid exiting outlet portion 20. In this regard,
 apertures 46, 48 defined by first and second end walls 42, 44, and first
 and second fluid flow orifices 36, 38 defined by first and third segments
 26, 30, preferably are dimensioned so as to ensure that an adequate amount
 of fluid flowing through tubing portion 12 flows through chamber 58,
 thereby exposing beneficial agent 60 to an adequate amount of the flowing
 fluid. It will be appreciated that the preferred dimensions of apertures
 46, 48 and fluid flow orifices 36, 38 will be dependent upon a variety of
 factors including, but not limited to, the fluid to be flowed through
 tubing portion 12, the rate at which fluid is to be flowed through tubing
 portion 12, the formulation of the beneficial agent 60, the beneficial
 agent 60, and the desired delivery rate of beneficial agent 60.
 In the above-referenced second configuration of the preferred embodiment of
 the present invention, first and second end walls 42, 44, or portions
 thereof, are rotatable between the first and second positions described
 above with respect to the first configuration of the preferred embodiment
 of the present invention. That is, in the first position, apertures 46, 48
 defined respectively by first end wall 42 and second end wall 44 are in
 fluid communication with first and second fluid flow orifices 36, 38,
 while in the second position, apertures 46, 48 are not in fluid
 communication with first and second fluid flow orifices 36, 38.
 In an alternative embodiment of the present invention depicted in FIG. 8,
 seals 62, 64 are provided. Seals 62, 64 serve to seal fluidly apertures
 46, 48 from first and second fluid flow orifices 36, 38. Seals 62, 64 can
 be mounted on first segment 26 and third segment 30 of canister-retaining
 portion 22, or, as depicted in FIG. 8, on first end wall 42 and second end
 wall 44 of canister 34. Alternatively, seals 62, 64 can be separate
 elements from both canister-retaining portion 22 and canister 34. Seals
 62, 64 are constructed such that they can be selectively deactivated or
 removed in order to provide fluid communication between apertures 46, 48
 and first and second fluid flow orifices 36, 38. For example, seals 62, 64
 can be in the form of a sheet of fluid-impervious material which, when
 used in connection with apparatus 10 of the present invention, prevents
 fluid flow through fluid flow orifices 36, 38.
 In one configuration of the above-discussed embodiment, sealing members 66,
 68 form first end wall 42 and second end wall 44, respectively, of
 canister 34, as depicted generally in FIGS. 6 and 7. Sealing members 66,
 68 are constructed of a known, frangible material that breaks upon the
 application of an external force of a predetermined magnitude, e.g., a
 radially inwardly directed force, in order to provide a flow channel(s)
 therethrough, thus providing fluid communication between apertures 46, 48
 and first and second fluid flow orifices 36, 38 through the newly-formed
 flow channel(s). In the embodiment depicted in FIGS. 6 and 7, sealing
 members 66, 68 are scored, as indicated by reference numeral 72, in order
 to facilitate breaking thereof upon the application of a radially inwardly
 directed force. Upon the application of such a force to the embodiment
 depicted in FIGS. 6 and 7, channels 74 are defined through However, it
 will be appreciated that a variety of other configurations of sealing
 members 66, 68 are possible without departing from the scope of the
 present invention.
 Canister 34 and canister-retaining portion 22 preferably are configured
 such that canister-retaining portion 22 retains canister 34 therein after
 canister 34 has been connected to canister-retaining portion 22, thereby
 preventing leakage of fluid from apparatus 10. In the embodiment depicted
 in the accompanying figures, canister 34 is configured to be frictionally
 retained within canister-retention space 32 by canister-retaining portion
 22. It will be appreciated that a variety of other locking configurations
 are possible for the retention of canister 34 in canister-retention space
 32, including, but not limited to, threaded connections, snap-fit
 connections, and other known locking arrangements.
 Canister 34, first segment 26, and third segment 30 can be configured such
 that canister 34 can only be rotated in one direction relative to
 canister-retaining portion 22. In addition, lever 70 can be provided on
 canister 34 in order to facilitate rotation of canister 34 relative to
 canister-retaining portion 22. In those embodiments of the present
 invention in which first end wall 42 and second end wall 44 are rotatable
 relative to side wall 40, lever 70 can be connected to either side wall 40
 or to first and second end walls 42, 44 in order to facilitate relative
 rotation therebetween.
 Canister 34 and canister-retaining portion 22 also may include indicia 76
 thereon in order to indicate when canister 34 is in its first, activated
 position and when canister 34 is in its second, inactivated position.
 Indicia 76 can have a variety of forms, including raised markings provided
 on an exterior surface of canister 34, as depicted in FIG. 8. Indicia 76
 can have a variety of other forms, including raised markings provided on
 tubing portion 12, colorations provided on canister 34 and/or tubing
 portion 12, and other markings and indicators of known construction.
 In order to use apparatus 10 of the present invention, one or more tubing
 portions 12 are provided. The tubing portions 12 are connected to one
 another by connecting the outlet portion 20 of an upper tubing portion 12
 to a first end portion 14 of a lower tubing portion. For each tubing
 portion 12, a canister 34 preferably is provided. The canisters 34 are
 selected based upon the beneficial agent 60 contained therein, per the
 needs of a patient to whom fluid is to be delivered. The canisters 34 are
 placed in respective canister-retention spaces 32 defined by tubing
 portions 12 such that canisters 34 are in their second, closed position,
 thereby preventing the flow of fluid from first fluid flow channel 24
 through chamber 58. The resulting structure is then ready for placement in
 fluid communication with a feeding set. For example, first end portion 14
 of the uppermost tubing portion 12 can be fluidly connected to a fluid
 source of known construction, e.g., a feeding tube, a flexible container,
 or a rigid container. This fluid connection can be effected in a variety
 of ways, including the use of spike 16 or male luer member 18, dependent
 upon the configuration of the fluid source. The outlet portion 20 of the
 lowermost tubing portion 12 can be connected to a fluid delivery device of
 known construction for delivery of a fluid to a patient.
 After a feeding set including apparatus 10 of the present invention has
 been connected to a fluid source and to a patient, fluid can be directed
 through apparatus 10 of the present invention, i.e., through first fluid
 flow channel 24. At a preselected time, one or more of the canisters 34
 can be moved from their second to their first positions relative to tubing
 portion 12, thereby causing fluid to flow through chambers 58 of the
 "activated" canisters 34. It may be preferable to construct canisters 34
 and tubing portion 12 such that canisters 34 cannot be returned to their
 second positions after they have been "activated", i.e., placed in their
 first position. This feature, in combination with indicia 76, will prevent
 confusion regarding whether or not a particular canister 34 has been
 activated. It will be appreciated that canisters 34 can be activated at
 different times, per the needs of the individual patient to whom fluid is
 being delivered. It further will be appreciated that beneficial agents 60
 contained in chambers 58 of activated canisters 34 will become dispersed
 in the fluid flowing therethrough and thus delivered to the patient.
 Upon completion of a regimen of fluid delivery to a patient, apparatus 10
 of the present invention can be detached from the feeding set and
 discarded, or, in the alternative, sterilized and re-used.
 Although the present invention has been described herein in connection with
 certain preferred embodiments, one of ordinary skill will appreciate that
 various modifications are possible without departing from the intended
 spirit and scope of the invention which is defined by the appended claims.