Abstract:
The present invention relates to an infant feeding warming system useful to repeatedly and precisely warm breastmilk or formula for use in the NICU. The system in one form comprises a bedside unit that is attachable to an IV pole. The system may also comprise a centralized warming station with multiple chambers, wherein one chamber heats a bottle or syringe, and the remaining chambers are used for storage and/or refrigeration. The system will use a non-liquid heating system to heat feedings. A disposable liner may be used inside the chamber. The system may also contain heating algorithms that are based on a user inputting milk parameters such as volume and initial temperature.

Description:
CROSS-CITE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional application of U.S. patent application Ser. No. 12/371,834, filed Feb. 16, 2009, which claims priority to U.S. Provisional Application Ser. No. 61/066,186, filed on Feb. 19, 2008. The disclosures of application Ser. No. 12/371,834 and 61/066,186 are incorporated herein by reference in their entirety for all purposes. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to a warming, as well as cooling, system and apparatus, particularly useful for breastmilk, and most particularly for neonatal care. 
       BACKGROUND 
       [0003]    Most infants in the neonatal intensive care unit (NICU) are not able to breastfeed effectively. Instead, either the infant is bottle fed, or breastmilk or formula is delivered through an orogastric or nasogastric passage to the infant&#39;s stomach. In these situations, breastmilk is expressed from the mother and stored in a freezer or refrigerator until it is desired for use, at which point it is often transferred to bottles or syringes for delivery to the baby. 
         [0004]    Because infants in the NICU have difficulty maintaining their body temperature, the breastmilk or formula is warmed prior to feeding so the chill will not stress the infant. The current practice for warming breastmilk or formula is for nurses to place the bottles in warm water baths. The water in the warm water baths is typically supplied from sink faucets. Depending on the hot water settings, distance of the NICU from the water heater, and other variables, the temperatures of the warm water can vary greatly. The temperatures of the warm water can also vary depending on how long the nurses wait for the water to reach its maximum temperature before filling the baths. The actual water temperature is not measured, and the actual temperature of the milk in the bottle is unknown. 
         [0005]    The breastmilk is typically thawed using one of several methods: thawing for more than 24 hours in a refrigerator at 4° C., setting the liquid out for an undetermined number of hours on a counter at room temperature and then placing it in a refrigerator, or a rapid thaw may be performed in which the protocol used for thawing and warming with water is employed to frozen milk in order to accelerate the thawing rate. This protocol is an uncontrolled method in which the damage that has potentially been done to the milk as a result of the temperature and rate times that are employed is unknown. 
         [0006]    Additionally, the prevention of the spreading of germs is critical in this environment, as infants in the NICU are very fragile and susceptible to infection. The risk of warming a bottle or syringe using water that is not sterile and contains some level of bacteria exists. This water could leak into the bottle or syringe and contaminate the liquid within, aid transfer of germs through handling of the water and containers, and provide a media for further bacterial growth. This is a known potential of contamination within the majority of hospitals. Just using water as a temperature adjustment medium is considered undesirable. 
         [0007]    The fact that water is used to heat the bottles and the bottles are then often carried to the baby&#39;s bed may also result in water damage to bedside charts and computers. 
         [0008]    It is desirable to have an apparatus that can repeatedly warm and thaw breastmilk or formula to an appropriate temperature without detrimentally affecting the breastmilk composition in order to prevent stressing the infant and eliminating the risk of potential contamination sites. Conversely, it would be desirable for the same apparatus to further have a cooling (or refrigeration) aspect as well. 
         [0009]    It is also desirable to perform these tasks as quickly as possible, given the time constraints and workload imposed upon neonatal nurses. Nurses usually state it takes them approximately 15 minutes for the total warming process for breastmilk. Considering that this task is repeated six to eight times a day, it can accumulate to a considerable amount of time and labor cost for a facility. 
         [0010]    It is also desirable to have an apparatus that can handle all manner of devices that may be used to contain the breastmilk, such as syringes, bottles, jars, bags and other containers. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention is an improved apparatus and system for thawing, warming and in a further application cooling, breastmilk. More particularly, the present invention has a principal objective of providing a bottle and syringe warmer system useful to repeatedly and precisely warm breastmilk or formula for use in the NICU, such as to infants in need of milk. It will be understood that while the invention is generally discussed in the particular environment of a bottle or syringe type container, and in the NICU setting, other containers and applications are contemplated and will fall within the scope of the invention. 
         [0012]    The bottle and syringe warmer system in one form comprises a bedside unit that is attachable to an IV pole. By having the unit at a bedside IV pole, the amount of time a nurse is away from a baby due to milk preparation is greatly reduced. Warming and preparation is now done bedside, allowing nurses to spend more time devoted to the care of the patient. Additionally, every time milk is transferred from one area to another, a second nurse is typically required to verify that the right milk is going to the right patient. Enabling bedside preparation reduces the need for identification verification. The foregoing need not be pole-mounted, but could be a desktop unit. 
         [0013]    Alternatively, or in addition, a bottle or syringe warming device may be a multi-port unit in a centralized milk preparation area. This embodiment comprises a centralized heating system that allows for the ability to warm and/or cool multiple containers at the same time while providing patient identification methods to properly identify each individual warming port. This embodiment would also provide all of the benefits of the single, IV-mountable unit: consistency, performance, safety, and reliability while reducing the cycle time spent by nurses, technicians, or other milk preparation staff in the thawing and warming of milk. 
         [0014]    The bottle and syringe warming device is intended in a preferred form to accommodate a variety of sizes, shapes, and containers of various volumes commonly used in the NICU. 
         [0015]    This device will most preferably use a non-liquid heating system to eliminate the risk of infection as well as cleanup associated with using water as a heat transfer means. The device will also preferably accommodate a liner element so as to capture spills and reduce potential contamination. The liner would be intended to be changed out between nurse shifts and patients, but may be changed more frequently as warranted. The liner may comprise a first material with an interior that defines a liquid containing portion and an opening defined by a perimeter. A top section that covers at least part of the opening may be made from a second material; the top section would contain an access port to the interior of the liquid containing portion. 
         [0016]    The device will, in its preferred form, advantageously contain a heating algorithm or like operational feature based on a user inputting milk parameters such as volume and initial temperature. The heating program then provides for a predetermined thawing/warming cycle based upon the input parameters that yields a minimization of time required to heat milk with the least deleterious impact on the milk according to customized heat profiles. The apparatus will advantageously use a control heating and thawing cycle that has been designed, based on research, to not damage the critical composition of breastmilk or formula. For the nurse, mother, or other user, the input required is minimal and the rest is automated. 
         [0017]    The bottle and syringe warming device will in its most preferred form herein use warm air forced convection as the primary mode of heat transfer. The air temperature will be regulated in accordance with the warming algorithm (program or other controller) associated with nurse/clinician input parameters. Temperature hold modes may further maintain desired temperatures until the user is ready to use the bottle or syringe (or other container). 
         [0018]    In yet a further variation, the invention may advantageously further employ a cooling aspect. As discussed herein, for example, a Peltier heating/cooling element is employed, yielding the ability to readily switch between thawing/warming to cooling. A separate refrigeration element is also contemplated as a possibility. 
         [0019]    All in all, a relatively compact apparatus and system is achieved by the invention which is adapted for use with a wide range of types, sizes, shapes and volumes of containers commonly employed in a hospital or other institutional setting for the handling of breastmilk. The foregoing invention is considered to be a highly useful apparatus and system for a NICU setting where a plurality of mothers and their premature babies are treated, and where the invention is easily operated and maintained with a minimum of effort and skill. 
         [0020]    These and other advantages of the invention will be further understood upon consideration of the following detailed description of certain embodiments, taken in conjunction with the drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1A  illustrates a perspective view of a bottle and syringe warmer in accordance with one embodiment of the present invention; 
           [0022]      FIG. 1B  illustrates a top view of a bottle and syringe warmer with an open lid in accordance with one embodiment of the present invention; 
           [0023]      FIG. 2  illustrates a top view of a bottle and syringe warmer with an open cover in accordance with one embodiment of the present invention; 
           [0024]      FIG. 3  illustrates a perspective view of an alternative mechanism for airflow within a bottle and syringe warmer, and  FIG. 3A  is a syringe-receiving element for use with the same; 
           [0025]      FIG. 4  illustrates a liner in accordance with one embodiment of the present invention; 
           [0026]      FIG. 5  illustrates a liner in accordance with one embodiment of the present invention; 
           [0027]      FIGS. 6A and 6B  illustrate a liner in accordance with one embodiment of the present invention; 
           [0028]      FIGS. 7A and 7B  illustrate a liner in accordance with one embodiment of the present invention; 
           [0029]      FIG. 8  illustrates a similar view as in  FIG. 1A , of a prototype of an embodiment of the present invention; 
           [0030]      FIG. 9  illustrates a similar view as in  FIG. 1B , of a prototype of an embodiment of the present invention; 
           [0031]      FIG. 10  illustrates a similar view as in  FIG. 2 , of a prototype of an embodiment of the present invention; 
           [0032]      FIG. 11  illustrates an exemplary control screen according to an embodiment of the present invention; 
           [0033]      FIG. 12  is a perspective view of another embodiment of a bottle and syringe warmer with a liner mounted therein; 
           [0034]      FIG. 13  is a perspective view of an exemplary liner according to one embodiment of the present invention; 
           [0035]      FIG. 14  is a top view of the liner of  FIG. 13 ; 
           [0036]      FIG. 15  is a perspective view of an exemplary bottle and syringe warmer according to one embodiment of the present invention; 
           [0037]      FIG. 16  is a cross-sectional view of the bottle and syringe warmer of  FIG. 15 ; and 
           [0038]      FIG. 17  is a diagram showing the temperature of the air and liquid over time. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]      FIG. 1A  illustrates a perspective view of a bottle and syringe warmer  100  in the closed position in accordance with one embodiment of the present invention. Although bottle and syringe warmer  100  may be used to warm any suitable liquid for a variety of purposes, bottle and syringe warmer  100  is particularly advantageous for warming feedings for premature infants. Likewise, as previously noted, while syringes and small bottles are the most commonly used milk containers in the NICU setting, other containers are contemplated for use with the invention. In a similar vein, while the invention has found particular application in an NICU environment, it can be used or adapted for other breastmilk and related feeding applications. A “feeding” or “infant feed” as used throughout this description refers to an amount of breastmilk or other suitable liquid for infants, where the former may be housed in a variety of containers such as a bottle, a syringe, or a vial, for example. 
         [0040]    To ensure health and proper growth, rapid weight gain is important for a premature infant. One way for a premature infant to gain weight rapidly is to feed the infant breastmilk at the correct temperature. Breastmilk contains important immunoglobulins, nutritional components, and vitamins. If overheated, these elements within the breastmilk will not remain intact; thus it is important to avoid overheating the breastmilk. Feeding a premature infant breastmilk, or related liquid-like formula, at the correct temperature also avoids placing any undue stress on the infant that may be present as a result of the temperature difference between the infant&#39;s body temperature and the temperature of the feeding. Moreover, the manner of feeding the premature infant may be highly circumscribed, such as the need to administer the milk at a very small rate, as through a syringe-type feeder. 
         [0041]    As shown in  FIG. 1A , bottle and syringe warmer  100  includes a heater  110 , a first passage  112 , a second passage  114 , and a housing  116 . A first lid  118  rests on top of first passage  112 , second passage  114 , and housing  116 , effectively forming the closed position in  FIG. 1A . First lid  118  pivots about at least one first hinge  120  to cover or leave open to ambient air first passage  112 , second passage  114 , and a chamber  136 . A second lid  128  may be attached to first lid  118 , and may comprise a knob  129  for manual manipulation. 
         [0042]    In the open lid position, as shown in  FIG. 1B , first lid  118  comprises at least one first hinge  120 , a first compartment  122 , and a second compartment  124 . Access port  126  comprises a hole  130 . Second lid  128  is connected to first lid  118  with second hinge  121 . Second lid  128  is positioned so that when the lid is in the closed position it covers hole  130 . 
         [0043]    First compartment  122  and second compartment  124  are raised portions of lid  118 . There are two openings per compartment, as shown in  FIG. 2 . A first opening  132  in each compartment is located so as to be in fluid communication with either first passage  112  or second passage  114  so that when lid  118  is in the closed position of  FIG. 1A  air flows from first passage  112  into first opening  132  of first compartment  122  and from first opening  132  of second compartment  124  into second passage  114 . A second opening  134  in each compartment is located so that when lid  118  is closed, each second opening  134  allows for air to flow into and out from a chamber  136 .  FIG. 2  shows chambers  136  within housing  116 . 
         [0044]    In a situation in which a larger syringe is used, second lid  128  may be opened, and the larger syringe may be pushed through hole or orifice  130  so that the milk-containing portion of the syringe is in chamber  136 . The plunger handle of the larger syringe extends outside of chamber  136 . Access port  126  may hold the syringe to keep internal and external air flows separated. Hole or orifice  130  may be adjustable to accommodate various syringe sizes. One way to accomplish this would be to use an adjustable material, such as silicone, for access port  126 . 
         [0045]    First passage  112  is in fluid communication with heater  110  and with first compartment  122  of housing  116 . Second passage  114  is in fluid communication with heater  110  and with second compartment  124  of housing  116 . Each of first opening of first compartment  122  and second compartment  124  is in fluid communication with each of first passage  112  and second passage  114 , respectively, and each of second opening  134  of first compartment  122  and second compartment  124  releases the air into chamber  136 . 
         [0046]    Bottle and syringe warmer  100  has the ability to be mounted on an IV pole. If mounted on an IV pole, bottle and syringe warmer  100  will have mechanisms to attach to the pole and to maintain the device in the upright position. This could be a clamp (not shown) affixed to the warmer  100 . Having bottle and syringe warmer  100  attached to an IV pole that is bedside has many advantages. Warming and preparation of the milk may now be done at the bedside, allowing a nurse to spend a greater portion of his or her time near the baby, devoted to the infant&#39;s care. Additionally, every time milk is transferred from one area to another, an additional nurse is typically required to verify that the correct milk is going to the assigned patient. With bottle and syringe warmer  100  attached to the IV pole at a patient&#39;s bedside, this tedious step can be eliminated. Alternatively, bottle and syringe warmer  100  may be placed on a countertop. 
         [0047]      FIG. 3  illustrates an alternative configuration to direct air into and out of chamber  136  through a conduit structure. Bottom pathways  138  are carved out of housing  116  on either side of chamber  136 , and top pathways  140  are carved out of lid  118 , so that when lid  118  is closed and lies flush with housing  116  each bottom pathway and top pathway mate to form a tunnel. First passage  112 , not shown in  FIG. 3 , is within housing  116  and is in fluid communication with a first tunnel formed from a top pathway and a bottom pathway, not shown. Second passage  114  is also within housing  116  and is in fluid communication with a second tunnel, formed from a top pathway and a bottom pathway, not shown. 
         [0048]      FIG. 3A  shows a top or lid  139  that would further close chamber  136 , and provide a flexible surface  141 , with a hole or orifice  130  for receiving the syringe. Top or lid  139  has cut-outs  143  to accommodate pathways  140 . 
         [0049]    Preferably, heater  110  uses warm air forced convection as the primary mode of heat transfer. Alternate versions of heater  110  may employ either natural or forced convection, conduction, or radiation as the primary method to warm the milk. Bottle and syringe warmer  100  uses a non-liquid heating system to eliminate the infection risk and mess associated with using water for heat transfer. 
         [0050]    The airflow within bottle and syringe warmer  100  may be conditioned. Conditioned air may be heated air. Alternatively, conditioned air may be cooled air. The airflow within bottle and syringe warmer  100  comprises a temperature that is altered by conditioning using either heater  110 , a cooling mechanism, or both simultaneously. 
         [0051]    Examples of reasons for cooling infant feed would be for temperature control, refrigeration prior to warming the liquid (storage), and post thawing. The conditioned airflow may be fully recirculating to minimize the power requirements necessary to heat or cool and maintain the air at the desired temperature. When the system is set up so that the air is recirculating, the airflow is substantially a closed or mostly closed system, wherein the air is conditioned to generate the desired heating or cooling effect. Closing the system reduces the power requirements to modify the air temperature. The conditioned airflow may be set up to be a partially recirculating, or a venting system. Airflow in a partially closed or open system would comprise ambient air introduction into the system. Ambient air at the ambient air temperature may be strategically introduced so as to quickly heat or cool the system air as desired, also helping reduce the power requirements to modify the air temperature. 
         [0052]    The airflow temperature may be raised using a heating mechanism until the temperature of the airflow reaches a set temperature. The airflow temperature may then be maintained at the set temperature for a period of time. The length of the period of time may be determined by the user, or may be pre-set. To properly maintain the set temperature for a period of time, a cooling mechanism may be used to function in tandem with the heating mechanism. Both the cooling mechanism and the heating mechanism may operate at the same time. Alternatively, the heating mechanism and the cooling mechanism may alternate, so that only one of the mechanisms is operating at a time. After the designated period of time has elapsed, the temperature of the airflow may be reduced to a temperature that is less than the set temperature, using solely the cooling mechanism. In an alternative embodiment, once the temperature of the airflow achieves the set temperature, the airflow may be immediately cooled using the cooling mechanism to a temperature that is less than the set temperature. 
         [0053]    Bottle and syringe warmer  100  may regulate the air temperature within chamber  136  using heating algorithms based on nurse entered parameters into a control panel  200 , as shown in  FIG. 11 . For example, a nurse may manually enter milk parameters such as a volume of milk within a container parameter  168  or an initial milk temperature parameter  170 . Other milk parameters could also comprise type or brand of container, and weight of the container and the milk inside the container, not shown in  FIG. 11 . Alternate versions may have one or more automated methods or sensors to provide these input variables. Temperature sensors may also be employed to detect the milk and/or container temperatures and thereby regulate and automate the conditioned air. After the nurse has input the desired parameters, the nurse may hit either a thaw button  172  or a warm button  174 . The heating algorithms allow for customized heat profiles to minimize the time required to heat the milk. The heating algorithm may determine a completion time  176 , and show completion time  176  on the control panel. On the control panel, an elapsed time bar  178  may show the time elapsed since the thawing or warming was initiated. Additionally, a thaw complete bar  180  and a warm complete bar  182  may be present on control panel  200 . A stop button  184  may also be included so the nurse can manually stop the thawing or warming process. 
         [0054]    In an exemplary embodiment, four heating profiles may be used based on the possible combinations of warming or thawing and the solid or liquid phases of milk. The first profile may be to warm refrigerated milk, the second profile to warm room temperature milk, the third profile to thaw frozen milk, and the fourth profile to warm frozen milk. An exemplary heating logic algorithm to warm refrigerated milk is shown in the diagram shown in  FIG. 17 . This diagram shows three temperature control zones for the heated air. Zone 1 may be a high heat zone, depicted in the diagram at 60° Celsius. Zone 2 is a low heat zone, depicted at 40° Celsius. Zone 3 is a ready hold zone, where the air is held at a set temperature, in the diagram below at 37° Celsius. The desired temperature for the liquid to be warmed to may be described as the “target” temperature, which in the diagram is 34° Celsius. The heating time calculations may be based on the volume of the liquid. 
         [0055]    Temperature hold modes will maintain desired temperatures until the nurse is ready to use the milk. A maximum temperature may be set to as to not damage the composition of the breastmilk. The temperature limits may be based on University Western Australia research as disclosed in WO 2007/11267 A1 in order to ensure protection of proteins and other milk components by not overheating the milk. Based on this data, the air temperature itself could be held at a higher temperature that is determined to be safe, removing cross-contamination potential from a recirculating airflow. 
         [0056]    Additionally, bottle and syringe warmer  100  may employ a cleaning cycle where the temperature limits are intentionally held or exceeded for a period of time in order to disinfect the device. Alternatively, an inline disinfecting agent, antimicrobial materials, filter, or UV light in the airflow may be used to disable or remove potential contaminants. 
         [0057]    Heater  110  may be covered with a separate housing. Alternatively, housing  116  may cover the entire warming device, including heater  110 . 
         [0058]    Chamber  136  is large enough to accommodate a variety of sizes, shapes, and volumes of containers commonly used in the NICU. For example, chamber  136  may accommodate either a bottle or a syringe. Chamber  136  may comprise an airflow inlet into the interior of the chamber, which is in fluid communication with the conditioned airflow. Chamber  136  may be made to be infrared transparent. In this embodiment, an infrared transparent polymer would be used to manufacture the chamber. 
         [0059]    Bottle and syringe warmer  100  typically includes a liner  146  to capture any spills and reduce potential contamination. Liner  146  is intended to be removed and changed out between patients and nurse shifts, but may be changed even more frequently. Portions of liner  146  may be used to direct airflow effectively around the bottle or syringe to maximize heat transfer. Liner  146  may also incorporate features to center the syringe or bottle in order to ensure effective and repeatable heat transfer and airflow. 
         [0060]    Liner  146  may take on a variety of forms.  FIG. 4  illustrates an exemplary liner  146 . This liner comprises a malleable cup-shaped body  148  that can be inserted into chamber  136  of housing  116 . Once liner  146  is put into place inside chamber  136 , a rigid ring  150  is set on liner  146  to hold the liner in place within chamber  136 . 
         [0061]      FIG. 5  illustrates an exemplary liner configuration. Liner  146  is placed within a rigid ring, such as around chamber  136 . Snap-ring  150  snaps down to secure the liner to the ring. Pass-through  152  is secured to seal a syringe inserted therein. Pass-through  152  may function as a lid for liner  146 . 
         [0062]      FIG. 6A  illustrates another exemplary liner  146 . In this embodiment, liner  146  has a rigid or semi-rigid cup-shaped body  154  that fits within chamber  136  of housing  116 , as well as an attached top  156  via hinge  157 . Attached top  156  comprises a hole or  158  and a slot  160 . Lid  128  of housing  116  may have a hook that is insertable into slot  160  to mechanically attach liner  146  to bottle and syringe warmer  100 . The liners may be stackable as shown in  FIG. 6B . Hole  158  is the syringe pass-through and sealing feature. 
         [0063]      FIGS. 7A and 7B  illustrate perspective and side views of a top  156  that may be placed on a rigid liner  164  that is then inserted into chamber  136 .  FIG. 7B  also shows a separate disk  166  which is flexible and has hole  130  as a syringe pass-through feature. It would be captured in pass-through lid  162 . Pass-through lid  162  would preferably have holes cut in the top to allow airflow into the chamber as in  FIG. 3 . As an alternative, rigid liner  164  may be one piece that incorporates the pass-through lid  162 . 
         [0064]    Bottle and syringe warmer may also comprise a multi-chamber unit. In this embodiment, a plurality of chambers is present in housing  116  instead of merely one chamber. In this embodiment, one chamber is designated for heating and thawing and the other chambers could be storage areas for the refrigeration or freezing of milk. 
         [0065]    In operation, lid  118  of housing  116  is opened to reveal the interior of chamber  136 . Liner  146  may be placed inside chamber  136  using any of the methods previously discussed to attach liner  146  to chamber  136 . Next a bottle is placed inside liner  146 . After the bottle is placed in liner  146 , lid  118  is returned to the closed position, and a nurse may enter information into bottle and syringe warmer  100  describing the previously discussed parameters required for the heating algorithm. Heater  110  then heats air using forced convection. The heated air exits heater  110  and enters into first passage  112 . The heated air then moves through first passage  112  into first compartment  122 , and finally into chamber  136 . While the conditioned air is within the interior of chamber  136 , it is effectively heating the liquid inside the bottle. The air is able to exit chamber  136  via second compartment  124  and then through second passage  114 , and may either exit to ambient air or return to heater  110  for re-circulation. A temperature sensor may provide control of the air temperature and monitor the heating profile. 
         [0066]    If a syringe is to be heated in lieu of a bottle, access port  126  is used. A syringe detection sensor may be used to detect whether a syringe is being used instead of a bottle. After liner  146  has been secured within chamber  136 , lid  118  may be returned to the closed position and lid  128  may be opened, revealing access port  126  and hole  130 . A sensor may be used to determine when lid  118  is closed. The syringe may be inserted into hole  130 , ensuring that the liquid containing portion of the syringe is within chamber  136 . The heating process then begins as described in the example using a bottle. 
         [0067]      FIG. 12  is yet another embodiment of a warming apparatus particularly adapted for syringes and bottles, and very similar to that described with regard to  FIG. 3 . Here, housing  116  has a lid  118  that closes chamber or well  136 . This embodiment uses a modified liner similar to that of  FIG. 6A , having a body  154  and top  156  which is attached via a hinge  157 . Hole or orifice  158  is again provided for use with a syringe or other small diameter container. Top  156  is thus made flexible at least in the area of this hole or orifice  158  for a sealing closure around the syringe. 
         [0068]    The liner top  156  is held in place on housing lid  118 , so as to open and close the liner body  154  as the lid  118  is opened and closed. Shown are a pair of clasps  161  that grip the front edge of top  156  for travel with the lid. Alternative mechanisms can be readily envisioned to keep top  156  in place with the lid. Note that orifice  131  (shown in dotted line) is formed in lid  118  and aligns with hole  158  for access to the chamber for a syringe with lid  118  closed. Lid may be made from an infrared opaque substrate. 
         [0069]    It will be further understood that top  156  may have cut-outs formed therein similar to those of  FIG. 3A  if an air manifold like that of  FIG. 3  was employed. It will be noted, however, that this and other of the liners described herein, could be made with the airflow designed to flow around the liner, rather than through it, e.g., the body of the liner is sized much smaller than the chamber diameter, with air routed between the liner and chamber interior wall. In that event, no openings for airflow need be provided in the body/top. This is not considered the most desirable way to make the invention, however, since heat transfer must then occur through the relative static air thereby maintained inside the liner. 
         [0070]      FIG. 13  illustrates an exemplary liner  200  according to one aspect of the present invention. Liner  200  is intended to be changed out between patients and nurse shifts, but may be changed even more frequently. Portions of liner  200  may be used to direct airflow effectively around a container to maximize heat transfer. Liner  200  may also incorporate features to center the container in order to ensure effective and repeatable heat transfer and airflow. 
         [0071]    In one embodiment, liner  200  comprises a bag or receptacle formed of a first material  210 . First material may be a flexible polyethylene. The bag has an interior  220 , an opening  230 , and a plurality of pressure equalization holes  231 . Pressure equalization holes  231  allow for air to flow between the outside of the bag and the bag interior so that the pressure inside the bag is equalized. Liner  200  may be formed from a first sheet being attached to a second sheet with a first seam, a second seam, and a third seam. The sheets effectively form the sides of liner  200 . 
         [0072]    Opening  230  includes a perimeter  232 . Opening  230  may be sealed shut by attaching the first sheet to the second sheet along a fourth seam. 
         [0073]    Liner  200  also comprises a rim portion  240  formed of a second material  250  and a section  260 . Section  260  comprises a port  262 . 
         [0074]    Interior  220  has the purpose of containing liquid. Rim portion  240  may extend along the entire perimeter  232 . Rim portion  240  may comprise an indented line that allows the rim portion to flex at the line, effectively creating a living hinge, or a hinge  241 . Hinge  241  allows for the rim portion  240  to lie flat during manufacturing or storage of the liner, and then to flex as needed for insertion and use in the warmer. Section  260  may also be formed from second material  250 , and may be integral with rim portion  240 . Top section may cover at least a portion of opening  230 , as shown in  FIG. 13 . The second material  250  used for rim portion  240  and section  260  may be manufactured from a rigid high density polyethylene. Second material  250  may be welded to first material  210 . 
         [0075]    Port  262  may serve as a pass-through for bottles, syringes, and the like. Port  262  may be a sphincter-like member. Port  262  may be flexible to accommodate various syringe sizes. One way to accomplish this would be to use a flexible third material  264 , such as silicone, for port  262 . The third material may be such that when pressure is applied to the material, the material deforms. 
         [0076]    Third material  264  comprising port  262  may be molded so that there are no openings through the port, only frangible sections  263 . Port  262  is then in a sealed state until a container such as a syringe is pressed against the third material  264  and breaks frangible portions  263 , opening port  262 . 
         [0077]      FIG. 14  shows a top view of liner  200 . Alternatively, access port  262  may comprise a hole  266  and a plurality of slits  268 , as shown in  FIG. 14 . Each slit comprises a first end  267  and a second end  269 . First end  267  is located at the perimeter of hole  266 . Each slit extends away from hole  266  such that second end  269  is at a location within port  262 , as shown in  FIG. 14 . When pressure is applied to port  262 , each of the plurality of slits  268  gives way, effectively creating a larger hole  266  through which a container may be pushed through. When a container is pushed through the hole, the plurality of slits  268  conforms to the sides of the container. The container may be a bottle. Alternatively, the container may be a syringe. The container may be any vessel that can house infant feed within. To accommodate a wide range of container diameters or sizes, the slits  268  may have a thin membrane between them that tears for larger containers but stretches for smaller containers to provide for a better hold. 
         [0078]      FIG. 15  illustrates a perspective view of an exemplary liner  200  emplaced within a bottle and syringe warmer  300  in the closed position in accordance with one embodiment of the present invention. The infant feeding warming apparatus  300  in  FIG. 15  comprises a mounting mechanism  302  attached to a housing  316  that may be used to mount infant feeding warming apparatus  300  to an IV pole. A display  360  shows the user settings and current status of the infant feed. A liner present sensor may be present on infant feeding warming apparatus  300  to ensure operation only with the liner installed. 
         [0079]      FIG. 16  shows a cross-sectional view of the bottle and syringe warmer  300  of  FIG. 15 , taken at A-A. Infant feeding warming apparatus  300  comprises at least one heater  310 , a fan  312 , a vent mechanism  314 , a housing  316 , a lid  318 , at least one hinge  320 , an upper duct  330 , a lower duct  340 , a chamber  350 , display  360 , and a power supply  370 . Housing  316  further comprises a housing lip  315 . 
         [0080]    In operation, lid  318  of housing  316  is opened to reveal chamber  350 . Liner  200  may be placed inside chamber  350  by setting rim portion  240  on housing lip  315 , as shown in  FIG. 16 . A container may then be inserted through opening  230  into the liner interior. Lid  318  is returned to the closed position, the closed position being shown in  FIGS. 15 and 16 , covering opening  230  of liner  200 . If a container was not already emplaced in the liner, a container  380  such as a syringe, as shown, can be placed through port  262 , ensuring that the liquid containing portion of the syringe is within chamber  350 . In the alternative, container  380  may not be a syringe but may be a number of other containers used in the field. As an example, container  380  may be a vial. 
         [0081]    The container may have one or more sides, a top and a bottom. Liner  200  is sized to receive the container therein, allowing for the container side or sides to be spaced from the side or sides of liner  200 , such that airflow through liner  200  can pass around the side or sides of the container to thereby provide moving air around the container. 
         [0082]      FIG. 16  also shows the path of air flow with arrows  390 . Fan  312  blows the air through each heater  310 , effectively heating the air. Alternatively, cooling devices may be present that cool the air that is blown by fan  312 . The air then flows through the conduit structure: upper duct  330 , lower duct  340 , and into liner  200 . The air is forced around container  380 , providing moving air around the container. The air then moves up through fan  312 . Air may enter or exit the system through vent mechanism  314 . 
         [0083]    A motion mechanism may be included to vibrate or mix the milk in the bottle or syringe during operation. The benefit of the motion mechanism would be to keep the milk components homogenous as well as aid in heat transfer, speeding up the warming process. This motion may be imparted by a mechanical system such as a shaker or orbital mixer. Additionally the motion may be imparted by the air circulation on the container already in use for the heat transfer. 
         [0084]    Various exemplary embodiments have been described above. Those skilled in the art will understand, however, that changes and modifications may be made to those examples without departing from the scope and spirit of the present invention. And it should be noted that the above overview is meant to be illustrative, not limiting. That is, additional and/or different features may be present in some embodiments of the present invention.