Abstract:
A system and a method are adapted for assessing the patency of a fluid infusion line connected to a patient, a source of medicant, and a pump. The system is configured for injecting a fluid into the fluid pressure line using a syringe, determining whether the syringe exhibits a resistance to fluid being injected into a the fluid line and, if no resistance is exhibited, monitoring the pump to verify whether the pump exhibits an alarm that indicates a check valve has been opened.

Description:
REFERENCE TO PRIORITY DOCUMENT 
       [0001]    This application claims priority to U.S. Provisional Patent Application Ser. No. 61/949,855 filed Mar. 7, 2014 and entitled SYRINGE FLUSH PROTECTION VALVE AND METHOD. Priority of the filing date is claimed and the provisional application is incorporated by reference in its entirety. 
     
    
     FIELD 
       [0002]    Embodiments relate generally to the field of medical infusion therapy. More particularly, embodiments relate to intravenous therapy. 
       BACKGROUND 
       [0003]    In general, intravenous therapy is used to administer substances directly into a vein of a patient. Many tubing systems used in administration of intravenous or parenteral therapy employ a drip chamber. The drip chamber prevents air from entering the blood stream, causing air embolism. The drip chamber also allows for a flow rate of the administered substance to be estimated. Further, the drip chamber offers a means to vent closed containers, such as bottles, thereby permitting filtered air to replace the fluid removed and thus avoiding the formation of a vacuum that would inhibit flow. Some substances that may be infused intravenously include volume expanders, blood-based products, blood substitutes, buffer solutions and medications. 
         [0004]    Typically, the traditional IV infusion setup includes a pre-filled, sterile container (glass bottle, plastic bottle or plastic bag) of fluid(s) with a tubular port that allows the attachment of an IV set&#39;s drip chamber “spike”. The IV set&#39;s drip chamber includes: a drip chamber orifice that allows the fluid to form drops of an approximate volume at slow flow rates, making it easy to see the flow rate (and also to avoid the entrainment of air bubbles in the tubing); a long sterile tube with a variable restriction clamp to regulate or stop the flow of fluids; a connector to attach to the vascular access device (VAD); connectors and a one-way check valve to allow “piggybacking” (Secondary mode infusion setup) of another infusion set onto the same line, e.g., for adding a dose of antibiotics to a continuous fluid drip. Further, the addition of an infusion pump to the IV infusion setup allows for control over the flow rate and total fluid volume delivered to a patient. 
         [0005]    In certain cases, where a change in flow rate and a total volume delivered would not have serious consequences, flow is produced by elevating the container above the patient and employing gravity pressure in concert with manual adjustment of a clamp and visual monitoring of the rate of drop formation in the drip chamber to regulate the flow rate. Limitations exist with regards the administration of multiple substances using such a gravity mode intravenous therapy setup. 
       SUMMARY 
       [0006]    Disclosed is a system and a method are adapted for assessing the patency of a fluid infusion line connected to a patient, a source of medicant, and a pump. The system is configured for injecting a fluid into the fluid pressure line using a syringe, determining whether the syringe exhibits a resistance to fluid being injected into a the fluid line and, if no resistance is exhibited, monitoring the pump to verify whether the pump exhibits an alarm that indicates a check valve has been opened. 
         [0007]    In one aspect, there is disclosed a drug infusion system, comprising: a source of fluid medicant; a pump configured to pump fluid medicant from the source of fluid medicant toward a patient through a fluid line; a sensor coupled to the fluid line, wherein the sensor measures a fluid pressure change in a predetermined location in the fluid line resulting from a fluid being injected into the fluid line; and a microprocessor that determined whether the measured fluid pressure exceeds a threshold, and if the pressure exceeds a threshold, open a check valve to permit fluid to flow through the fluid line in a backflow direction in order to reduce fluid pressure in the fluid line. 
         [0008]    In another aspect, there is disclosed a method of regulating pressure in a fluid infusion line, the infusion line being connected to a patient, a source of medicant, and a pump, the method comprising: detecting a fluid pressure change in the fluid line, the fluid pressure change resulting from a fluid being injected into the fluid line; measuring a fluid pressure at a predetermined location in the fluid line; determining whether the fluid pressure exceeds a threshold; and if the pressure exceeds a threshold, opening a check valve to permit fluid to flow through the fluid line in a predetermined direction in order to reduce fluid pressure in the fluid line. 
         [0009]    In another aspect, there is disclosed a method of regulating pressure in a fluid infusion line, the infusion line being connected to a patient, a source of medicant, and a pump, the method comprising: monitoring a fluid pressure in the fluid infusion line; detecting that the fluid pressure exceeds a threshold; and permitting a check valve to open so that fluid may flow in a backflow direction so as to relieve pressure in the fluid line. 
         [0010]    In another aspect, there is disclosed A method of assessing the patency of a fluid infusion line, the infusion line being connected to a patient, a source of medicant, and a pump, the method comprising: injecting a fluid into the fluid pressure line using a syringe; determining whether the syringe exhibits a resistance to fluid being injected into a the fluid line; and if no resistance is exhibited, monitoring the pump to verify whether the pump exhibits an alarm that indicates a check valve has been opened. 
         [0011]    The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is an example of a traditional Secondary mode infusion setup. 
           [0013]      FIG. 2  shows an example Secondary mode infusion setup, including a drip chamber, in accordance with an embodiment. 
           [0014]      FIG. 3  shows a cross-sectional view of the example drip chamber of  FIG. 2 , in accordance with an embodiment. 
           [0015]      FIG. 4  shows a cross-sectional view of the example drip chamber of  FIG. 2 , in accordance with an embodiment. 
           [0016]      FIG. 5  shows a flow diagram of an example method for managing a flow of fluid within a flow control system, in accordance an embodiment. 
           [0017]      FIG. 6  shows a flow diagram of an example method for manufacturing a drip chamber, in accordance with an embodiment. 
           [0018]      FIG. 7  shows an example flow control system, in accordance with an embodiment. 
           [0019]      FIG. 8A  shows an example device, a tubing clamp coupled with a vacuum activated catch, the tubing clamp being in the closed position, in accordance with an embodiment. 
           [0020]      FIG. 8B  shows an example device, a tubing clamp coupled with a vacuum activated catch, the tubing clamp being in the open position, in accordance with an embodiment. 
           [0021]      FIG. 9  shows an example flow control system, in accordance with an embodiment. 
           [0022]      FIG. 10  shows a flow diagram of an example method for manufacturing a device, in accordance with an embodiment. 
           [0023]      FIG. 11  shows a block diagram of an example flow control system, including an example drip chamber, in accordance with an embodiment. 
       
    
    
       [0024]    The drawings referred to in this description should not be understood as being drawn to scale unless specifically noted. 
       DETAILED DESCRIPTION 
       [0025]    Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. While the subject matter will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the subject matter to these embodiments. On the contrary, the subject matter described herein is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope. Furthermore, in the following description, numerous specific details are set forth in order to provide a thorough understanding of the subject matter. However, some embodiments may be practiced without these specific details. In other instances, well-known structures and components have not been described in detail as not to unnecessarily obscure aspects of the subject matter. 
       Section One 
     Pressure Wave Damping Drip Chamber 
     Overview of Discussion 
       [0026]    Herein, various embodiments of a drip chamber, a fluid control system and methods for controlling the flow of fluid are described. The description begins with a brief general discussion of a traditional flow control system and drip chamber. This general discussion provides a framework of understanding for more particularized descriptions of features and concepts of operation associated with one or more embodiments of the described fluid control technology. 
       Flow Control Systems with Respect to Drip Chambers 
       [0027]    As discussed herein, traditional flow control systems are used to apply intravenous or intravascular (IV) therapy. IV therapy is the administration of substances directly into a vascular system of a patient. Many systems of administration of IV therapy use a “drip chamber”. The drip chamber, in general, prevents air from entering the IV tubing and ultimately the blood stream (causing air embolism) and allows for an estimate of a flow rate of the medication administered. 
         [0028]    Referring now to  FIG. 1 , an example of a traditional Secondary mode infusion setup  100  is shown. Traditional Secondary mode infusion setup  100  includes a Primary container  104  coupled with a Primary drip chamber  108 , and a Secondary container  136  (positioned at a location higher than the Primary container  104 ) coupled with a Secondary drip chamber  132 . The Primary container hangs from the hanger  102 , while the Secondary container  136  hangs from the same line  138  from which the hanger  102  is attached. The Primary drip chamber  108  is coupled with a Primary fluid line  112 , wherein the Primary fluid line  112  runs to a pump  120 . In between the Primary drip chamber  108  and the pump  120 , a check valve  116  is coupled with the Primary fluid line  112 . Further, the Secondary drip chamber  132  is coupled with a Secondary fluid line  128 , wherein the Secondary fluid line  128  also runs to the pump  120 . In between the Secondary drip chamber  132  and the pump  120 , a male luer  126  and needle-free valve connection  124  is coupled with the Secondary fluid line  128 . On the downstream side, or patient-side portion, of the administration set of the pump  120  is a vascular access device (aka catheter, e.g. IV fluid line  122 ) or interconnecting plumbing such as an extension set or a needlefree valve. 
         [0029]    When the Secondary fluid level  135  in the Secondary container  136  is at a level above the Primary fluid level  107 , a hydrostatic pressure differential is created across the check valve  116  causing it to close, thereby preventing flow of the Primary fluid  106  from the Primary container  104  to the pump  120  and significantly, preventing reverse flow of the Secondary fluid  134  into the Primary container  104 . However, when the Secondary fluid level  135  decreases as fluid is withdrawn and/or if the Secondary container  136  is lowered such that the Secondary fluid level  134  is at about the same height as the Primary fluid level  107 , the pressures directed at the inlet  114  and the outlet  118  of the check valve  116  approach equilibrium. Ideally, when the Primary side pressure on the check valve  116  becomes just slightly greater than the Secondary side pressure on the check valve  116 , the pump  120  will draw fluid solely from the Primary container  104 . 
         [0030]    Even if the Secondary fluid level  135  is higher than the Primary fluid level  107 , if the pump flow rate is in the range of 250 to 1000 milliliters per hour, there may be pressure loss through a restriction in the flow path of the Secondary container  136 , such as due to the connection between the male luer  126  and the needle-free valve connection  124 . Flow through a restriction (Of note, there may be multiple restrictive elements such as a vent in the drip chamber which has become wetted, thereby increasing its resistance to flow.) causes a pressure loss, thereby reducing the pressure applied on the check valve  116  from the Secondary side. When there is just a slightly positive pressure across the check valve  116  from the Primary side, the check valve  116  will open, thereby allowing flow from the Primary container  104  to occur intermittently with each pulse of flow aspirated by the pump. Thus, there may be concurrent flow from both the Primary and Secondary containers,  104  and  136 , respectively, in some varying proportion dependent on the flow rate, the restriction and the degree of pulsatility of the pump&#39;s intake flow pattern. 
         [0031]    When the Secondary fluid level  135  has lowered sufficiently in the Secondary container  136 , the pressure of the Primary fluid  106  will remain consistently slightly higher than the pressure of the Secondary fluid  134 . The check valve  116  is continuously open allowing all the fluid to preferentially be drawn from the Primary container  104 , while the Secondary fluid level  135  in the Secondary container  136  will remain fairly constant. Note that at this point, since there is no flow coming from the Secondary container  136 , no pressure pulses are being produced via the Secondary restriction, so the check valve  116  is held open by the differential pressure between the Secondary container  136  and the Primary container  104 , only. 
         [0032]    In the delivery of chemotherapy, clinicians frequently use the traditional Secondary mode infusion setup  100 . This is in part owing to its convenience and safety in the handling and transport of the medication and is in part due to the frequent need to infuse pre and post medication fluids via the same IV catheter. While using the traditional Secondary mode infusion setup  100  within an oncology framework, several issues and problems become apparent. Firstly, larger and taller bags and bottles (containers) are used to hold a large volume of medication. Secondly, much higher flow rates than the traditional Secondary mode infusion setup  100  was originally designed for are used. Thirdly, the use of some needle-less (a.k.a. needle-free) valve connectors may present somewhat higher flow restrictions in the Secondary pathway than the large bore metal needle/rubber port used when the traditional Secondary mode infusion setup  100  was developed. Fourthly, the length of hangers for lowering the Primary container  104  may not be adequate to lower the Primary container sufficiently to assure adequate pressure differential in these demanding applications. 
         [0033]    As the Secondary fluid  134  finishes delivery, the taller Secondary container(s)  136  together with inadequate hanger length means that the elevation of the Secondary fluid  134  relative to the Primary fluid level  107  will be lower than with smaller Secondary container(s). Without an adequate pressure difference of the Secondary side over the Primary side, the Primary fluid  106  can begin flowing prematurely before the Secondary fluid  134  is completely delivered, due to the normal action of the check valve  116 . This may result in delayed delivery completion of the Secondary fluid  134 , since for each drop of the Primary fluid  106  delivered, a drop of Secondary fluid  134  is NOT delivered. Thus, some amount of the Primary fluid  106  replaces some amount of the Secondary fluid  134  as its level lowers, thereby causing the inadvertent delay in the delivery completion of the Secondary fluid  134 . Further, the check valve  116  located along the Primary fluid line  112  may transiently open prior to completion of the delivery of Secondary fluid  134  due to pump-flow-induced transient drops in pressure, thereby producing a condition of concurrent flow in varying proportion from both the Primary and Secondary containers,  104  and  136 , respectively. 
         [0034]    The intake flow from pumps is not entirely steady. In fact, in many pump designs, the pump  120  draws fluid in at several times the mean outflow rate. When these rapid flows occur, they cause a pressure loss through any restriction in the Secondary pathway such as at a needle-free valve connection  124  or a blocked intake air vent  140 . These transient pressure drops allow the check valve  116  to open very briefly, and then close. Thus, even if there was a suitable head height difference between the Secondary fluid level  135  and the Primary fluid level  107 , there may still be inadequate pressure within the Primary fluid line  112  to prevent inadvertent partial flow from the Primary container  104  while fluid remains to be delivered in the Secondary container  136 . (In other words, and briefly, the restriction of the Secondary fluid line  128  is too high and the pulsation of the intake of the pump  120  is too abrupt, causing the inadvertent partial flow from the Primary container  104  while fluid remains to be delivered in the Secondary container  136 .) For oncology and other patients who similarly require a particular volume of medication to be administered within a precisely defined period of time, the delayed delivery completion of the Secondary fluid  134  from the Secondary container  136  may result in complications in scheduling subsequent therapy and other clinical management difficulties for the hospital. 
         [0035]    Embodiments incorporate a check valve placed uniquely within a drip chamber of a Primary delivery set, thereby overcoming many of the problems besetting the traditional infusion setup  100 . In one embodiment, the drip chamber is used with IV therapy. However, while embodiments are described within the context of IV therapy, it should be understood that the concepts described herein may be applied to a device/integration within equipment other than for use in IV therapy. 
         [0036]    Embodiments allow for taller containers, higher flow rates, Secondary path connections having less than ideal low resistance and pumps having less than ideal smooth intake flow to be used during IV therapy, while still preventing flow through the Primary fluid line when the Secondary container is nearly empty (i.e. substantially empty). As noted earlier, when elevations of Primary and Secondary fluids are about equal, the check valve no longer is held closed and thus allows the Primary fluid to flow (intended). In practice, the Secondary level may have to be just a small amount lower than the Primary fluid due to the design of some check valves which requires a so called ‘cracking pressure’ to open. This is typically no more than one inch of water pressure (elevation). Embodiments provide for no flow coming from the Secondary container. If flow did come from the Secondary container, then the reduced Secondary pressure would quickly reopen the check valve, thereby drawing fluid totally from the Primary container. More specifically, embodiments mitigate the effect of pressure pulses that cause the check valve to open intermittently before the Secondary fluid has been completely delivered. 
         [0037]    Moreover, in one embodiment, by having a (one-way) check valve placed above the drip forming orifice and the pocket of air within the drip chamber (along with a controlled restriction in the drip chamber orifice), wherein the walls of the drip chamber provide a certain amount of elasticity, the likelihood that the pressure pulses from the infusion pump would cause an unwanted Primary fluid to replace desired Secondary fluid prior to the delivery of the Secondary fluid is significantly reduced. By placement of a check valve more remote (further upstream) from its typical placement near the connecting port, the inherent elasticity of the Primary tubing together with its own resistance therein to a movement of fluid there through provide an additional source of damping of the effects of the pressure wave of the infusion pump. The walls of the drip chamber itself, along with the fluid resistance and fluid inertance within the drip forming orifice, damp the negative pressure created by the pressure pulses from the infusion pump. By damping the negative pressure pulses created by the infusion pump&#39;s intake flow pattern, the now steady reverse pressure across the check valve prevents the Primary fluid from moving through the check valve. 
         [0038]    In one embodiment, the one-way check valve includes a bypass mechanism. The bypass mechanism allows the one-way check valve, in response to a signal, to open to allow Primary fluid to move through the one-way check valve in a direction that is reverse to the direction of the current fluid flow from the container. This bypass mechanism enables practitioners to expel excess IV fluid from the drip chamber back into the container by inverting the drip chamber and gently squeezing it. This allows adjustment of the amount of fluid in the drip chamber to permit visualization of drops. It should be appreciated that alternate embodiments may include “bypass” mechanisms, other than the bypass mechanism described herein, that enable the release of fluid through a fluid line. For example, but not limited to such, a channel parallel to the check valve may be opened by a deformation of the fluid pathway and/or by an activation of a lever (or similar device). 
         [0039]    Thus, embodiments improve the accuracy of the Secondary Mode delivery of substances by minimizing the unintended flow from a Primary container while the Secondary fluid remains to be delivered. For example, for time-critical Secondary applications, such as chemotherapy, where flows are high (&gt;300 ml/h), pressure loss through the Secondary pathway is exacerbated by the pulsatile intake flow of many pumps. Embodiments markedly minimize the exposure of the check valve to these pulsatile pressures, thereby reducing unintended check valve opening with attendant flow from the Primary container prior to completion of the Secondary fluid administration. 
         [0040]    Additionally, embodiments reduce the cost of the Primary set by integrating components and reducing labor during its manufacture. Currently, one check valve is used in a significant percentage of Primary sets built. Assembly of these check valves into the finished delivery set adds steps and points for possible failure. By integrating the check valve within the drip chamber, manufacturing steps are eliminated, resources are saved and reliability can be improved. 
         [0041]    The following discussion will focus on example structures and example operations, in accordance with embodiments. For clarity and ease of explanation of an example first drip chamber  206 A (of  FIG. 2 ),  FIG. 2  shows a Secondary mode infusion setup  200  (hereinafter, “infusion setup  200 ”), in accordance with an embodiment. The drip chamber  206 B of  FIG. 3  and the drip chamber  206 C of  FIG. 4  are enlarged views of first drip chamber  206 A of  FIG. 2 , in accordance with an embodiment. The infusion setup  200  shows the first container  204  (supported by hanger  202 ) and the second container  230  hanging directly from the line  232 . Further, the first and second containers,  204  and  230 , respectively, in various embodiments, may be used in a device/integration within equipment other than for use in IV therapy. 
         [0042]    In one embodiment, the first container  204  is a Primary container, the first fluid line  214  is a Primary fluid line, the first fluid  234  is a Primary fluid, the second container  230  is a Secondary container, the second drip chamber  228  is a Secondary drip chamber, the second fluid line  224  is a Secondary fluid line, the second fluid  236  is a Secondary fluid, the first fluid flow is a Primary fluid flow, and the second fluid flow is a Secondary fluid flow. Thus, the descriptions herein, with regards to  FIGS. 1-6 , using the terms “first” and “second” may be associated with the delivery of Secondary medications (as is commonly known in the art), in one embodiment. 
         [0043]    The first drip chamber  206 A is coupled with and between the first container  204  and the infusion pump  216 . The first fluid line  214  couples the first drip chamber  206 A with the infusion pump  216 . The first drip chamber  206 A includes a spike  208 , a drip forming orifice  212  (providing a controlled restriction or “fluid resistance”) and a check valve  210  coupled with and between the spike  208  and the drip forming orifice  212 . 
         [0044]    As part of the infusion setup  200 , a second drip chamber  228  is shown coupled with and between the second container  230  and the infusion pump  216 . Of note, the second drip chamber  228  does not include all of the features of the first drip chamber  206 A. The second fluid line  224  couples the second drip chamber  228  with the infusion pump  216 . In one embodiment, attached to the second fluid line  224 , between the second drip chamber  228  and the infusion pump  216 , are a roller clamp  226 , a male luer  222  and a needle-free valve connection  220 . It should be appreciated that the roller clamp  226 , the male luer  222  and the needle-free valve connection  220  may be those that are commonly known in the art. A patient IV fluid line  218  is coupled with the infusion pump  216  and transports the fluid drawn from the first and/or second containers,  204  and  230 , respectively, to the patient. 
         [0045]    The drip chamber  206 B is shown as a block diagram in  FIG. 3 , in accordance with an embodiment. The drip chamber  206 B is an enlargement of the first drip chamber  206 A of  FIG. 2 , the details of which will be discussed herein.  FIG. 4  shows a drip chamber  206 C, a cross-sectional view of the first drip chamber  206 A ( FIG. 2 ) and drip chamber  206 B ( FIG. 3 ), in accordance with an embodiment, the details of which will be discussed herein. 
         [0046]    Referring now to  FIG. 3 , in one embodiment, the drip chamber  206 B includes: a first end  312 ; a second end  314 ; a spike  208 ; a drip forming orifice  212  (providing a controlled restriction to flow); a check valve  210 ; and an enclosing wall  318 . The first end  312  includes an inlet  302 . The second end  314  includes an outlet  316 . The spike  208  is integrally coupled with the first end  312 . More specifically, the spike  208  is coupled with the rest of the body of the drip chamber  206 B such that the outer wall of the spike  208  is included as a portion of the “housing” of the drip chamber  206 B at the first end  312 . 
         [0047]    In different embodiments, portions of the first end  312  include different components, and portions of the second end  314  include different components. For example, but not limited to such, in one embodiment, the first end  312  of the drip chamber  206 B includes the spike  208  and the check valve  210 . However, in another embodiment, the first end  312  includes just the spike  208 . Similarly, the second end  314  of the drip chamber  206 B includes the outlet  316 , the air holding portion  310  (discussed later) and the drip forming orifice  212 , in one embodiment. However, in another embodiment, the second end  314  of the drip chamber  206 B includes the outlet  316 , the air holding portion  310 , the drip forming orifice  212  and the check valve  210 . 
         [0048]    In one embodiment, the drip forming orifice  212  is coupled with the spike  208 , with the check valve  210  disposed there between. An interior flow passage  328  runs through and between the spike  208 , check valve  210  and drip forming orifice  212  (which also, in one embodiment, provides a path that includes a flow restriction). The first end  306  of the interior flow passage  328  is positioned at the inlet  302  of the drip chamber  206 B. The second end  322  of the interior flow passage  328  is positioned at the intake side of the check valve  210 . Connected to the outlet of the check valve  210  is the lower section of the interior flow passage  328 , which also connects to the drip forming orifice  212 . Further, the enclosing wall  318 , which is coupled with the first end  312  and the second end  314 , houses within the spike  208 , the check valve  210  and the drip forming orifice  212 . 
         [0049]    In one embodiment, the check valve  210  is a one-way check valve. Again, of note, the check-valve is typically one-way by design. The one-way check valve allows a fluid to flow in a second direction  304  within the interior flow passage  328 , while stopping a fluid from flowing in a first direction  320  within the interior flow passage  328 . Referring now to  FIGS. 2 and 3 , in one example, the fluid flowing in the second direction  304  is the first fluid  234  from the first container  204 , and the fluid attempting to flow in the first direction  320  is the second fluid  236  from the second container  230 . The fluid flowing in the second direction  304  is flowing in an opposite direction as the fluid attempting to flow in the first direction  320 . Thus, the check valve  210  allows the first fluid  234  to flow down to the first fluid line  214  to the infusion pump  216 , while stopping any fluid from flowing up through the check valve  210  and into the first container  204 . This fluid that is stopped may be the first fluid  234  itself that has already traveled past the drip forming orifice  212 , and/or it may be second fluid  236  having been drawn into the drip chamber  206 B. 
         [0050]    Referring still to  FIGS. 2 and 3 , in one embodiment, the drip chamber  206 B includes a pressure damping elastic component. The pressure damping elastic component includes an air holding portion  310  of the drip chamber  206 B and at least a portion  308  of the enclosing wall  318  that is elastic. It should be appreciated that the at least a portion  308  of the enclosing wall  318  that is elastic may be all of the enclosing wall  318 , or a portion less than an entirety of the enclosing wall  318 . The air holding portion  310  of the drip chamber  206 B holds air. The air holding portion  310  and the at least a portion  308  of the enclosing wall  318  that is elastic include an elasticity that damps a pressure pulse from the infusion pump  216 . The infusion pump  216 , as shown in  FIG. 2 , is fluidly coupled with the drip chamber  206 B. It should be noted that the infusion pump  216  used with embodiments is an infusion pump that is commonly known in the art to be used with IV therapy. 
         [0051]    In one embodiment, the drip forming orifice  212  includes a flow resistance channel  324 . The flow resistance channel  324  provides a hydraulic resistance to a fluid flowing from the outlet  316  to the inlet  302 . The term, “hydraulic resistance”, refers to the resistance to the movement of fluid through an area. For example, the flow resistance channel  324  resists the movement of fluid through the drip forming orifice  212  from the infusion pump  216  side. This hydraulic resistance interacts with the pressure damping elastic component (the air holding portion  310  and the portion  308  of the enclosing wall  318  that is elastic) to form a “damper” which attenuates pressure pulses originating downstream in the second fluid line  224  due to the infusion pump&#39;s  216  intake flow through a restriction in the second fluid line  224 . Thus, the air holding portion  310  and the portion  308  of the enclosing wall  318  that is elastic (i.e., the pressure damping elastic component described herein) contribute additively to the total compliance of the drip chamber. That compliance, in turn, interacts with the flow resistance channel  324  to form what is called the ‘damping’ effect. 
         [0052]    In one embodiment, the drip chamber  206 B includes a pressure damper that shields the check valve  210  from a negative transient pressure. The negative transient pressure is that pressure caused by the pulsating pump, thereby drawing fluid towards the infusion pump  216  through any resistance in the fluid pathway (e.g., Secondary fluid pathway). If the check valve  210  were to receive the full effects of the pressure caused by the infusion pump  216  that is pulsating, the check valve  210  would open transiently, thereby allowing bursts of fluid to rapidly drip through the drip forming orifice  212  and ultimately through the drip chamber  206 B. 
         [0053]    The pressure damper includes the combination of the flow resistance channel  324  and the pressure damping elastic component described herein. The net damping effect, as measured by the highest frequency which is passed without attenuation, is inversely proportional to the product of the resistance and the compliance of the pressure damping elastic component (including the air holding portion  310  and the at least a portion  308  of the enclosing wall  318  having an elasticity). Thus, it is the two aspects working together that result in the effective damping of unwanted pressure waves. Additionally, aggressively increasing at least one of the following serves to attenuate pulses that originate in the infusion pump flow passing through the restriction of the Secondary pathway: the resistance to the movement of fluid through an area; and the compliance of the air holding portion  310  and the enclosing wall  318  having an elasticity. 
         [0054]    Therefore, the damping provided by the flow resistance channel  324  together with the pressure damping elastic component, including elastic elements therein, protects the check valve  210  from exposure to negative—going transient pressure which could cause the check valve  210  to temporarily and prematurely open. This premature and intermittent opening may cause the unintended partial flow of the first fluid  234  while the second fluid  236  remains to be delivered. 
         [0055]    Under some circumstances, there may be excess fluid in a drip chamber. This reduces both the ability of the clinician to visualize drops for monitoring, as well as reduces the elasticity, described above, that is useful in damping unwanted pressure waves. In one embodiment, the check valve  210  of the drip chamber  206 B includes a bypass mechanism  326 . The bypass mechanism  326  opens the check valve  210  in response to receiving an opening trigger, thereby releasing a fluid flowing in the first direction  320  through the check valve  210  from the outlet  316  to the inlet  302 . In one embodiment, the opening trigger is a threshold pressure of the fluid flowing in the first direction  320  from the outlet  316  to the inlet  302 . The threshold pressure refers to that pressure which is needed to cause a portion of the check valve  210  to open to let the fluid flow through. In one embodiment, the threshold pressure needed would be between 4 and 8 psi. For example, the threshold pressure may be provided by the nurse&#39;s fingers squeezing the body of the first drip chamber  206 A to remove excess fluid out of the first drip chamber  206 A and restore the normal amount of air. Of note, the first drip chamber  206 A and bag must be inverted so that when the wall of the first drip chamber  206 A is released from squeezing, it will draw air, and not fluid, from the bag. 
         [0056]    In another embodiment, the opening trigger is a threshold force applied against the check valve  210 , thereby causing the check valve  210  to deform from a first shape to a second shape. For example, a practitioner may deform the housing or activate an attached element that would trigger the bypass mechanism  326  to cause the check valve  210  to open to allow the fluid to flow there through. In one embodiment, the bypass mechanism  326  is a deformation characteristic of a component within the check valve  210  that changes shape, such as the shape of a bell curve that faces one direction to the shape of a bell curve that faces an opposite direction. The shape change leaves an opening within the interior flow passage  328  that allows for fluid to flow there through. 
         [0057]    With reference to  FIG. 4 , an example drip chamber  206 C is shown, including: a check valve  210  coupled with and between a spike  208  and a drip forming orifice  212 . The spike  208  includes at least a portion of the interior flow passage  328  and an air passageway  412 . In another embodiment, the spike  208  includes the interior flow passage  328  without the air passageway  412 . For example, a drip chamber may not have a vent path, such as with bags whose walls collapse as the fluid is withdrawn, thus not requiring a path for replacement air to enter. The inlet  302  is at one end of the interior flow passage  328 . An enlarged view  410  of the check valve  210  is also shown. It can be seen that the fluid flows through the portion of the interior flow passage  328  of the check valve  210 , thereby flowing around an obstruction  408  in the middle of the check valve  210 . It should be noted that a check valve that is known in the art may be used as part of some embodiments described herein. In one embodiment, the check valve includes the bypass mechanism  326 , as described herein. 
         [0058]      FIG. 4  also shows a drip forming orifice  212 , along with a drip  402  of fluid falling from an end of the drip forming orifice  212 . Further, the enclosing wall  318  couples with the first and second end,  312  and  314 , respectively, of the drip chamber  206 C, and houses within the spike  208 , check valve  210  and drip forming orifice  212 . Also shown is the pressure damping elastic component  406  that includes the air holding portion  310  and at least the portion  308  of the enclosing wall  318  that includes an elasticity. The fluid drips into the air holding portion  310  to form a volume of fluid  404 . A portion of that volume of fluid  404  may then continue moving through components (such as the first fluid line  214 , the infusion pump  216  and the patient IV fluid line  218 ) coupled with the drip chamber  206 C to reach the patient. 
         [0059]    With reference now to  FIGS. 3 and 4 , a device for managing fluid flow may be described, according to one embodiment. The device includes: a drip chamber  206 B. The drip chamber  206 B of the device includes, in one embodiment: an inlet  302 ; an outlet  316 ; and a check valve  210  positioned between the inlet  302  and the outlet  316 . The check valve  210  manages fluid flowing between the inlet  302  and the outlet  316 . In one embodiment, the drip chamber  206 B further includes the flow resistance channel  324 . 
         [0060]    The example device further includes, in one embodiment, the enclosing wall  318  that couples the first end  312  with the second end  314 . The enclosing wall  318  houses within at least the spike  208 , the check valve  210  and the drip forming orifice  212 . An additional embodiment of the device includes the pressure damping elastic component described herein. In yet another example embodiment, the device includes the pressure damper described herein. 
         [0061]    In one example device, the check valve is the one-way check valve described herein. Further, in yet another embodiment, the one-way check valve includes the bypass mechanism described herein. 
         [0062]      FIG. 5  is a flow diagram of an example method  500  for managing a flow of fluid within a flow control system, in accordance with embodiments. 
         [0063]    Referring now to  FIGS. 2-5 , at  505  and as described herein, in one embodiment, the method  500  includes receiving  505  a fluid flow, the receiving occurring at a drip forming orifice  212  of a drip chamber  206 C. The fluid flow occurs at a first rate in a first direction  320 . At  510  and as described herein, in one embodiment, the drip forming orifice  212  resists the fluid flow. At  515  and as described herein, in one embodiment, the check valve  210  stops the fluid flow. The check valve  210  is coupled with and positioned between the spike  208  and the drip forming orifice  212 . The spike  208  is integrally coupled with the first end  312  of the drip chamber  206 C. 
         [0064]    At  520  and as described herein, in one embodiment at least a portion  308  of an effect of a pressure pulse formed by the infusion pump  216  is damped. The infusion pump  216  is fluidly coupled with the drip chamber  206 C. The damping  520  includes at least one of: in response to receiving the pressure pulse from the infusion pump  216 , elastically expanding an air holding portion  310  and at least a portion  308  of the enclosing wall  318  of the drip chamber  206 C; and in response to receiving the pressure pulses from the infusion pump  216 , providing a hydraulic resistance to the fluid flow from an outlet of a second end of the drip chamber  206 C to an inlet of a first end of the drip chamber  206 C. Of note and as described herein, in one embodiment, the damping is produced not just by the pressure damping elastic component  406  and not just by the flow resistance channel  324 , but rather by the combined effect of the pressure damping elastic component  406  and the flow resistance channel  324 . 
         [0065]    At  525  and as described herein, in one embodiment at least a portion  308  of an effect of a pressure pulse formed by the infusion pump  216  is damped. The infusion pump  216  is fluidly coupled with the drip chamber  206 C via a tubing. The tubing elastically expands in response to the receiving of the pressure pulse from the infusion pump and provides a resistance within to the movement of the fluid there through. 
         [0066]    At  530  and as described herein, in one embodiment a volume of fluid  404  that is stopped at the check valve  210  is released. The releasing of this volume of fluid  404  includes: receiving a check valve opening trigger; and in response to the receiving of the check valve opening trigger, opening the check valve  210 . In one embodiment, the receiving of the check valve opening trigger includes the receiving of a threshold pressure that is applied by a fluid flowing in a first direction  320 . In another embodiment, the receiving of the check valve opening trigger includes the receiving of a threshold force applied against the check valve  210 , wherein the threshold force applied against the check valve  210  deforms the check valve  210  from a first shape to a second shape. 
         [0067]      FIG. 6  is a flow diagram of a method  600  for manufacturing a drip chamber, such as drip chamber  206 C of  FIG. 4 , in accordance with an embodiment. 
         [0068]    Referring now to  FIGS. 2-4  and  6 , at  605  and as described herein, in one embodiment, the method  600  includes providing  605  a spike  208  integrally coupled with an enclosing wall  318  of the drip chamber  206 C. At  610  and as described herein, in one embodiment, the drip forming orifice  212  is provided. At  615  and as described herein, in one embodiment, the check valve  210  is coupled with and between the spike  208  and the drip forming orifice  212 . In one embodiment and as described herein, the check valve  210  is a one-way check valve. In another embodiment and as described herein, the check valve  210  includes the bypass mechanism  326 . 
         [0069]    Further, and as described herein, in one embodiment, the enclosing wall  318  is integrally coupled with the spike  208 . The enclosing wall  318  includes an inlet  302  and an outlet  316  and encloses at least the spike  208 , the check valve  210 , the drip forming orifice  212  and the interior flow passage  328  (that extends through the spike  208 , the check valve  210  and the drip forming orifice  212  as well as between the inlet  302  and the outlet  316 ). 
         [0070]    At  620  and as described herein, in one embodiment, the pressure damping elastic component  406  is integrally coupled with the enclosing wall  318 . The pressure damping elastic component  406  includes the air holding portion  310  of the drip chamber  206 C and at least a portion of the enclosing wall  318  of the drip chamber  206 C that is elastic, as is described herein. 
         [0071]    At  625  and as described herein, in one embodiment, the check valve  210  is coupled with the pressure damper. The pressure damper shields the check valve  210  from a negative transient pressure. The pressure damper includes: the flow resistance channel  324  and the pressure damping elastic component  406  that is described herein. 
       Section Two 
     Vacuum Activated Catch for Managing a Fluid Flow 
       [0072]    Herein, various embodiments of a device for controlling fluid flow, a flow control system and a method of manufacturing the device are described. The description begins with a continuation of the brief general discussion, in Section One regarding the example Drip Chamber above, of the traditional flow control system and methods for delivery of Secondary medications. This general discussion provides a framework of understanding for more particularized descriptions of features and concepts of operation associated with one or more embodiments of the described device and flow control system. 
       Flow Control Systems with Respect to Managing Fluid Flow 
       [0073]    Referring to  FIG. 1 , traditional methods for delivery of Secondary medications include employing the check valve  116  in the Primary set while lowering the Primary container  104  with a hanger  102  to create a back pressure against the check valve  116 , thus keeping it closed until the Secondary fluid  134  has been delivered. This requires, but does not always achieve, a very low flow resistance in the Secondary pathway. When high flow rates are involved and/or the resistance of the Secondary pathway is not sufficiently low, or when there is insufficient elevation difference between the Primary and Secondary fluids,  106  and  134 , respectively, some Primary fluid  106  will flow when only the Secondary fluid  134  is intended to flow. This condition is referred to as “sympathetic flow”. This results in the delayed completion of the Secondary fluid  134 . In other words, the pressure lost through excess resistance in the Secondary pathway effectively reduces the pressure differential across the check valve  116 . This allows intermittent flow of the Primary fluid  106  to occur even though there may still be significant fluid left in the Secondary container  136 . 
         [0074]    The traditional use of the check valve together with elevation differential has the following inherent weaknesses: it requires the manual lowering of the Primary container  104 ; uncertainty exists for the operator regarding the needed elevation with regards to lowering the Primary container  104 ; the resistance to the flow in the Secondary fluid line  128  may vary from setup to setup and may cause unintended flow from the Primary container  104 , thereby delaying the completion of the delivery of the Secondary fluid  134 ; air may be entrained when the Primary container  104  is lowered below the Primary port entrance; and Primary infusion setups used bear the cost of manufacturing the check valve  116 , even though only a small percentage of the Primary infusion setups are used for Secondary delivery of medication (and thus use the check valve  116 ). 
         [0075]    In accordance with various embodiments, an example flow control system includes a device for controlling fluid flow and a sealable component which automatically stops flow once fluid in the container is depleted (such as, but not limited to, a ball float valve) positioned within a drip chamber. The device includes a tubing clamp coupled with a vacuum activated catch. When the tubing clamp is secured in a closed position by the vacuum activated catch, a Primary fluid line is pinched closed. When the vacuum activated catch releases the tubing clamp to an open position, the first fluid line is also released into an open position. The vacuum activated catch is also coupled with the Secondary container via a Secondary fluid line. In between the Secondary container and the vacuum activated catch is a check valve. This check valve prevents reverse flow into the Secondary container when the tubing clamp is open. 
         [0076]    Further, in embodiments, there is no need for the Primary container to be lowered, which simplifies the work of a caregiver, thus removing a significant source of error. 
         [0077]    The sealable component is coupled with the Secondary container and stops the flow of the Secondary fluid when the Secondary container empties to the drip chamber. When the sealable component seals shut, thereby closing an interior flow passage within the drip chamber, the pump&#39;s intake draws a vacuum in the Secondary fluid pathway. This vacuum deforms a membrane in the vacuum activated catch that is coupled with the Secondary fluid line, which then releases and opens the tubing clamp, thereby opening the Primary fluid line and allowing the Primary fluid flow to commence there through. 
         [0078]    Embodiments eliminate the need for a costly check valve to be placed in every Primary infusion setup. Further, embodiments help to ensure on-time Secondary delivery of fluids. Moreover, the need for a hanger and/or to reposition containers is removed. Additionally, the device may other forms of “vacuum activated” clamps or valves, such as, but not limited to, using a lever arm to minimize the force needed to lock and release the clamping of a Primary fluid line. 
         [0079]    The following discussion will focus on example structures and operations of embodiments. 
         [0080]      FIG. 7  shows a tubing clamp  706  coupled with a vacuum activated catch  710 , within a flow control system  700 , in accordance with an embodiment. In embodiments, the flow control system  700  includes: a tubing clamp  706 ; a vacuum activated catch  710  retainably coupled with the tubing clamp  706  and a second fluid line  714 ; a second drip chamber  724  coupled with and between the second container  726  and the second fluid line  714 ; and an infusion pump  728  coupled with the first and second fluid lines,  704  and  714 , respectively. Additionally, in one embodiment, a one-way check valve  729  is shown in the second tubing pathway. This one-way check valve  729  prevents flow from the first container  702  when the tubing clamp  706  is open. In one embodiment, the one-way check valve  729  is incorporated within the design of the device  800 A/ 800 B (of  FIGS. 8A and 8B , respectively), which includes the tubing clamp  706  and the vacuum activated catch  710 . In another embodiment, the one-way check valve  729  is a conventional component positioned separately from the device  800 A/ 800 B. 
         [0081]    In one embodiment, the first container  702  is a Primary container, the first fluid line  704  is a Primary fluid line, the first fluid  730  is a Primary fluid, the second container  726  is a Secondary container, the second drip chamber  724  is a Secondary drip chamber, the second fluid line  714  is a Secondary fluid line, the second fluid  732  is a Secondary fluid, the first fluid level  734  is a Primary fluid level, the second fluid level  736  is a Secondary fluid level, the first fluid flow is a Primary fluid flow, and the second fluid flow is a Secondary fluid flow. Thus, the descriptions herein, with regards to  FIGS. 7-10 , using the terms “first” and “second” may be associated with the delivery of Secondary medications, in one embodiment. 
         [0082]      FIG. 8A  shows a device  800 A, including a tubing clamp  706  (of  FIG. 2 ) coupled with a vacuum activated catch  710 . Referring to  FIGS. 7 and 8A , in one embodiment, the tubing clamp  706  includes a first arm  816  and a second arm  804  that is coupled with the first arm  816  via a connector  818 . In one embodiment, the connector  818  is flexible. Thus, in one embodiment, the connector  818  and the first arm  816  and second arm  804  to which it is attached are made of one piece. In another embodiment, the combination of the first arm  816  and the second arm  804  to which it is attached is made of at least two pieces that are manufactured to appear to be a single piece. In yet another embodiment, the connector  818  to which the first arm  816  and the second arm  804  is attached is a hinge-like component such that portions of the hinge-like component open and close, thereby opening and closing the first arm  816  and the second arm  804 . In one example, connector  818  is an axle about which first arm  816  and second arm  804  of the tubing clamp  706  pivot. Further, in one embodiment, a spring is used to assure that when the tubing clamp  706  is opened, and the first arm  816  and the second arm  804  swing away. In another embodiment, the wall itself of the tubing clamp  706  provides sufficient force to cause a desired opening of the first arm  816  and the second arm  804 . 
         [0083]    Further, in one embodiment, the second arm  804  is attached to a hooked end  810 . For example, in one embodiment, the second arm  804  and the hooked end  810  are a single piece. However, in another embodiment, the combination of the second arm  804  and the hooked end  810  to which the second arm  804  is attached is made of at least two pieces that are manufactured to appear to be a single piece. Of note, it should be appreciated that the first arm  816 , the clamping mechanism  802 , the second arm  804  and the hooked end  810  may be a single piece or multiple pieces attached to each other, or any combination thereof. 
         [0084]    Moreover, the first arm  816  and the second arm  804 , in one embodiment, are long, slender beams. However, it should be appreciated that the shape and length of the first arm  816  and the second arm  804  may be any shape and length such that the first arm  816  articulates with the holding notch  822  of the vacuum activated catch  710 , thereby holding it in place. 
         [0085]    Additionally and as will be discussed below in more detail, a first attachment portion  812  and a second attachment portion  806  of the vacuum activated catch  710  are coupled with the hook end  810  of the tubing clamp  706  such that a portion of the first arm of the tubing clamp  706  may be held in place by one or more notches (such as but not limited to holding notch  822 ) in the vacuum activated catch  710 . Of note,  FIG. 8A  also shows section AA, an end view of a circular shaped deformable element  824 , which is one example of a vacuum activated catch  710 . As seen, the circular shaped deformable element  824  includes the holding notch  822 . The arrow pointing from the first attachment portion  812  to the circular shaped deformable element  824  shows an attachment point at  826 . This represents where the first attachment portion  812  attaches to the vacuum activated catch  710 . 
         [0086]    Referring still to  FIGS. 7 and 8A , the tubing clamp  706  includes the clamping mechanism  802  that holds closed the first fluid line  704  while a second fluid  732  flows along the second fluid line  714  from the second container  726 . The first fluid line  704  delivers a flow of a first fluid. The direction  712  of the flow of the second fluid  732  is from the second container  726  towards the infusion pump  728 . The tubing clamp  706  is in the closed position, in accordance with an embodiment. 
         [0087]    The second drip chamber  724  includes a sealable component  722  that seals closed an interior flow passage  708  within the second drip chamber  724  when the second container  726  is empty (or nearly empty [i.e. substantially empty]), thereby obstructing the flow of the second fluid  732 . In one embodiment, the sealable component  722  is a ball float valve. The ball float valve includes a ball  720  and a base  716 , wherein when the second container  726  is empty (or nearly empty [i.e. substantially empty]), the ball  720  sets within the base  716 , thereby sealing the interior flow passage  708  within the second drip chamber  724 , such that the ball  720  prevents whatever small amounts of fluid that are left, if any, within the second drip chamber  724  and/or the second container  726  from flowing through to the second fluid line  714 . Of note, there can be some fluid left in the second container  726  since some bags (e.g., second container  726 ) have ‘side lobes’ where fluid may sequester and thus not flow into the spike, the drip orifice, and finally the drip chamber (e.g., second drip chamber  724 ). However, the activation of the ‘sealable’ element occurs when no further fluid is entering the second drip chamber  724  while the pump draws fluid out of it. This is true whether the ‘ball float’ design, the filter, or any other are employed. 
         [0088]    For example and referring to  FIG. 7 , after the spike of the second drip chamber  724  is placed in the second container  726 , fluid flows into the second drip chamber  724 . The ball  720  has buoyancy that causes it to float on the volume of fluid  718  that fills a portion of the second drip chamber  724 . When the second container  726  is emptied (or nearly empty [i.e. substantially empty]) and all (or nearly all) of the fluid has exited the second drip chamber  724  through the interior flow passage  708  into the second fluid line  714 , the ball  720  sets into the base  716 , thus sealing the portion of the interior flow passage  708  within the second drip chamber  724 . 
         [0089]      FIG. 9  shows a tubing clamp  706  coupled with a vacuum activated catch  710 , within a flow control system  900 , in accordance with an embodiment.  FIG. 9  also shows the ball  720  set into the base  716 , as a result of the second container  726  being empty (or nearly empty [i.e. substantially empty]), and/or the infusion pump  728  drawing a vacuum through the second fluid line  714 , thus pulling the ball  720  into the base  716 . 
         [0090]    Of note, the interior flow passage  708  is shown, in both  FIGS. 7 and 9 , as a dotted line from and through the second drip chamber  724  and the second fluid line  714 . When the second container  726  is emptied (or nearly emptied), there is no longer any fluid and/or enough fluid to support a floating ball  720  such that the interior flow passage  708  is kept open. The ball  720  then sets in the base  716 . The infusion pump  728 , in operation, draws a vacuum within the second fluid line  714  and away from the second drip chamber  724 . The displacement of the fluid by the pump creates a negative pressure within the second fluid line  714 , resulting in the deformation of the vacuum activated catch  710 . For example, the vacuum activated catch  710  may pop inwards, releasing the first attachment portion  812 , as shown in  FIGS. 8B and 9 , in response to the negative transient pressure. Since the vacuum activated catch  710  is constructed of a movable element, the vacuum activated catch  710  has the ability to change shapes when receiving a pressure that overcomes the material&#39;s inherent characteristics causing stiffness. The inward deformation will cause a portion of the tubing clamp  706  to be released, as will be explained herein. The movable element may be, but is not limited to, any of the following: a deformable membrane; a piston; a rolling hat seal; and any structure capable of being displaced by the vacuum established by the closure of the second fluid path and continued intake of fluid by the infusion pump  728 . 
         [0091]    In another embodiment, the sealable component  722  is a filter (not shown in the Figures). For example, but not limited to such, in one embodiment the filter has a diameter of 0.22 micron. The filter is placed in the base of the second drip chamber  724 . When air is on one side and fluid is on the other side of the filter, a meniscus, having a bubble point pressure, is created. The bubble point pressure blocks air from flowing through the filter. The bubble point pressure increases in inverse proportion to the filter&#39;s diaphragm diameter. In other words, the filter produces a bubble point pressure that is sufficient to activate the movable element, thereby releasing the vacuum activated catch  710  that is closing the first tubing. 
         [0092]      FIG. 8B  shows a device  800 B, the tubing clamp  706  (of  FIG. 7 ) coupled with the vacuum activated catch  710 . The tubing clamp  706  is in an open position, in accordance with an embodiment. Referring now to  FIGS. 8A and 8B , the vacuum activated catch  710  includes a movable element that is coupled with the tubing clamp  706 . The movable element changes from a first shape  808  to a second shape  820  upon receipt of a deforming vacuum pressure. When the movable element is in the first shape  808 , the vacuum activated catch  710  retains the tubing clamp  706  in a closed position. When the movable element is in the second shape  820 , the vacuum activated catch  710  releases the tubing clamp  706  into an open position, thereby allowing the flow of the first fluid  730  to commence within the first fluid line  704 . 
         [0093]    In one embodiment, and as described herein, a portion of the first arm  816  of the tubing clamp  706  is releasably secured by the holding notch  822  of the vacuum activated catch  710 . (Again, it should be noted that the vacuum activated catch  710  may include more than one holding notch  822 .) For example, in one embodiment, the movable element has a holding notch  822  for holding the first arm  816  of the tubing clamp  706  in place. In one embodiment, the movable element is of a shape that is capable of changing from a first shape  808  to a second shape  820  (of  FIG. 8B ) upon applied vacuum (a positive pressure) and/or force such that the first arm  816  of the tubing clamp  706  is released from the holding notch  822  of the vacuum activated catch  710 , such as, but not limited to, a cup shape, a disk shape, or a combination thereof. 
         [0094]    Referring to  FIG. 8A , it can be seen that in one embodiment, when the movable element of the vacuum activated catch  710  is in a first shape  808 , the vacuum activated catch  710  secures closed the first arm  816  of the tubing clamp  706  such that the first fluid line  704  is pinched closed. 
         [0095]    Referring now to  FIG. 8B , the tubing clamp  706  is in an open position. In one embodiment, the movable element of the vacuum activated catch  710  releases the first arm  816  of the tubing clamp  706  while the movable element is in the second shape  820 , such that the first fluid line  704  opens. It should be appreciated that the second shape  820  of the movable element may be any shape that allows the first arm  816  to be released from its secured position such that the first fluid line  704  is then opened. The second shape  820  may be that shape which is different from the first shape  808 , such that the end of the first arm  816  can no longer be secured in a closed position. For example, but not limited to such, if the first shape is a bell curve, then the second shape  820  may be flat. 
         [0096]    The infusion pump  728  draws a vacuum in the second fluid line  714 , thereby creating the deforming force (the pressure is a negative value) when the second container  726  is substantially empty (i.e. empty or nearly empty). In one embodiment, the deforming pressure is a negative pressure caused by the drawing of the vacuum. More specifically, the infusion pump  728  withdraws fluid from the blocked tubing, thereby drawing or producing a vacuum. In one embodiment, the infusion pump  728  has a pressure sensor. 
         [0097]    Further, as can be seen, once the movable element pops in and releases the first arm  816  of the tubing clamp  706 , thus opening the first fluid line  704 , the first fluid  730  commences flowing in the direction  902  from the first container  702  towards the infusion pump  728 . Since the first fluid level  734  is now higher than fluid in the second container  726 , the one-way check valve  729  is forced closed so that only the fluid from the first container  702  flows only to the infusion pump  728 . 
         [0098]    With reference to  FIGS. 7-9 , an embodiment of a device may be described. In one embodiment, a device includes a tubing clamp  706  and a vacuum activated catch  710 . The tubing clamp  706 , according to one embodiment, holds closed the first fluid line  704  while the second fluid  732  flows along a second fluid line  714  from the second container  726 , wherein the first fluid line  704  delivers a flow of first fluid  730 . The vacuum activated catch  710 , according to one embodiment, is coupled with the second fluid line  714  and is releasably secured as described herein, by the tubing clamp  706 . The term, “releasably secured”, refers to the ability of the tubing clamp  706  to release, as well as hold in place, a portion of the vacuum activated catch  710 . Upon receipt of a deforming force, the catch  710  opens and allows the flow of the first fluid  730  within the first fluid line  704 . In one embodiment, the deforming force is due to a vacuum caused by the infusion pump  728  that is coupled with the second fluid line  714 , wherein the infusion pump  728  draws a vacuum during operation by aspirating fluid from the tubing. 
         [0099]    In one embodiment, the tubing clamp  706  includes the clamping mechanism  802  described herein. In yet another embodiment, the vacuum activated catch  706  includes the movable element described herein. 
         [0100]    A further embodiment of the tubing clamp  706  of the example device includes a first arm  816  and a second arm  804  coupled with the first arm  816  via the connector  818 , wherein the connector  818  is flexible. 
         [0101]      FIG. 10  is a flow diagram of an example method  1000  for manufacturing a device, in accordance with embodiments. 
         [0102]    Referring now to  FIGS. 7-10 , at  1005  and as described herein, in one embodiment, the method  1000  includes providing a tubing clamp  706 , wherein the tubing clamp  706  includes a clamping mechanism  802  configured for holding closed a first fluid line  704  while the second fluid  732  flows along a second fluid line  714  from a second container  726 . The first fluid line  704  delivers a flow of a first fluid  730 . Further, in one embodiment, the providing  1005  of the tubing clamp  706  includes providing a first arm  816  and a second arm  804  of the tubing clamp  706 , and coupling the first arm  816  and the second arm  804  with the connector  818 , wherein the connector  818  is flexible. 
         [0103]    At  1010  and as described herein, in one embodiment the method  1000  includes coupling a vacuum activated catch  710  with the tubing clamp  706 , wherein the vacuum activated catch  710  includes a movable element coupled with the tubing clamp  706  and configured for changing from a first shape  808  to a second shape  820  upon receipt of a deforming force. When the movable element is in the first shape  808 , the vacuum activated catch  710  retains the tubing clamp  706  in a closed position. When the movable element is in the second shape  820 , the vacuum activated catch  710  releases the tubing clamp  706  into an open position, thereby allowing the flow of the first fluid  730  to commence within the first fluid line  704 . Further, in one embodiment, the coupling  1010  of the vacuum activated catch  710  includes coupling a first attachment portion  812  and a second attachment portion  806  of the movable element with a hooked end  810  of the second arm  804  of the tubing clamp  706 . 
         [0104]    At  1015  and as described herein, in one embodiment the method  1000  includes disposing at least one latching element on the movable element, such that the movable element is enabled to secure the tubing clamp  706  in a closed position. For example and with reference to  FIG. 8A , the first shape  808  includes a concave portion that receives an end of the first arm  816 . The fitting together of the concave portion and the end of the first arm  816  shows the function of the at least one latching element of the first shape  808 , that of the concave portion. In other words, areas may be disposed on the movable element that are capable of receiving one or more portions of the first arm  816  such that the movable element secures and retains the first arm  816  in a position that allows the first fluid line  704  to be and remain pinched closed, until released. 
         [0105]    Further, the vacuum activated catch  710  functions in a bi-stable mode. That is, once it ‘switches’ to the released position, it no longer requires vacuum force to remain in that position. Thus, as soon as the clamp opens, the vacuum disappears. One embodiment provides a means for the operator to place the vacuum operated catch  710  back into the latching position. For example, but not limited to such example, a tab is used that enables the vacuum activated catch  710  to be manually pulled out and placed back into the latching position. In another embodiment, a pushing element from within the fluid path is used, the pushing element allowing the vacuum activated catch  710  to be placed back into the latching position. 
       Section Three 
     An Example Drip Chamber Integrated within an Example Flow Control System 
       [0106]    Herein, various embodiments of a flow control system integrated with a drip chamber are described. The description below describes the integration of the example drip chamber discussed in Section One above with the example flow control system discussed in Section Two above. 
         [0107]      FIG. 11  shows a tubing clamp  706  coupled with a vacuum activated catch  710 , within a flow control system  1100 , in accordance with an embodiment. In embodiments, the flow control system  1100  includes: the tubing clamp  706 ; the vacuum activated catch  710  retainably coupled with the tubing clamp  706  and the second fluid line  714 ; the first drip chamber  206 A (of  FIG. 2 ) coupled with and between the second container  726  and the second fluid line  714 ; and the infusion pump  728  coupled with the first and second fluid lines,  704  and  714 , respectively.  FIG. 11  further shows, in accordance with various embodiments: the first container  702   
         [0108]    In one embodiment, the first container  702  is a Primary container, the first fluid line  704  is a Primary fluid line, the first fluid  730  is a Primary fluid, the second container  726  is a Secondary container, the first drip chamber  206 A is a Secondary drip chamber, the second fluid line  714  is a Secondary fluid line, the second fluid  732  is a Secondary fluid, the first fluid level  734  is a Primary fluid level, the second fluid level  736  is a Secondary fluid level, the first fluid flow is a Primary fluid flow, and the second fluid flow is a Secondary fluid flow. Thus, the descriptions herein, with regards to  FIGS. 7-11 , using the terms “first” and “second” may be associated with the delivery of Secondary medications, in one embodiment. 
         [0109]    In one embodiment and as described herein, the tubing clamp  706  includes the clamping mechanism  802  (of  FIGS. 8A and 8B ) that holds closed the first fluid line  704  while the second fluid  732  flows along the second fluid line  714  from the second container  726 . The first fluid line  704  is coupled with the first container  702  and delivers a flow of the first fluid  730 . 
         [0110]    Referring to  FIG. 3 , the example drip chamber  206 B (a cross-sectional view of the example first drip chamber  206 A) includes in one embodiment and as described herein the following: the first end  312  having an inlet  302 ; the second end  314  having an outlet  316 ; a spike  208  integrally coupled with the first end  312 ; a drip forming orifice  212  coupled with the spike  208 ; a check valve  210  disposed between and coupled with the spike  208  and the drip forming orifice  212 ; the enclosing wall  318  coupling the first end  312  and the second end  314 ; and the sealable component  722  (of  FIG. 7 ). 
         [0111]    Referring now to  FIGS. 3 and 11 , in one embodiment and as described herein, the check valve  210  manages the fluid flowing between the inlet  302  and the outlet  316  through the interior flow passage  328  that extends at least through the spike  208 . In one embodiment, the enclosing wall  318  houses within at least the spike  208 , the check valve  210  and the drip forming orifice  212 . In one embodiment and as described herein, the sealable component  722  (including the ball  720  and the base  716  that are intermittently separated by the volume of fluid  718 ; see  FIGS. 7 and 9 ) seals closed the interior flow passage  328  within the drip chamber  206 B when the second container  726  is substantially empty, thereby obstructing the flow of the second fluid  732 . 
         [0112]    The vacuum activated catch  710  includes a movable element coupled with the tubing clamp  706 , according to one embodiment and as described herein. The movable element changes from a first shape (e.g., first shape  808  of  FIG. 8A ) to a second shape (e.g., second shape  820  of  FIG. 8B ) upon receipt of a deforming force, wherein when the movable element is in the first shape, the vacuum activated catch  710  retains the tubing clamp  706  in a closed position. When the movable element is in the second shape, the vacuum activated catch  710  releases the tubing clamp  706  in an open position, thereby allowing the flow of the first fluid  730  to commence within the first fluid line  704 , according to one embodiment. 
         [0113]    In another embodiment and as described herein, the infusion pump  728  draws a vacuum in the second fluid line  714 , thereby creating the deforming force when the second container  726  is substantially empty. 
         [0114]    The check valve  210  incorporated in the Secondary set prevents the reverse flow of the Primary fluid (i.e., first fluid  730 ) into the Secondary container (i.e., the second container  726 ). For example, the hydrostatic pressure of the fluid in the Primary fluid line will be greater than that in the Secondary fluid line at the moment the tubing clamp  706  opens on the Primary fluid line. Additionally, the check valve  210  facilitates keeping the ball  720  from moving away from the base  716  (and thus re-opening), thereby preventing the backward flow of the Primary fluid flow into an empty Secondary container (i.e., second container  726 ). While employing the sealable component  722  (including the ball  720  and base  716 ) and without the check valve&#39;s  210  presence, an amount of Primary fluid would flow backward into the Secondary container through the opened sealable component  722 , while still another amount of Primary fluid would continue to flow to the infusion pump  728 . However, this backflow into the Secondary container wouldn&#39;t be safe in cases such as chemo delivery. It would be unsafe for there to be any fluid in the Secondary container that once contained the chemo. 
         [0115]    Thus, the advantages of integrating the example first drip chamber  206 A (including the check valve  210 ) along the Secondary pathway together with the tubing clamp  706  and the vacuum activated catch  710  include at least saving costs, creating a safer environment and the simplicity of its design that renders significant benefits. 
         [0116]    There is now described a method and system for using a check valve  210  ( FIG. 3 ) pursuant to a syringe flush process that may be performed by a clinician. Pursuant to the method, a clinician (such as a nurse) performs a syringe flush process to assess the patency of the fluid line to the patient. The clinician first infuses an amount of fluid, such as saline, through a port of the fluid line. The clinician may do this using a syringe. If the fluid line is occluded or otherwise non-patent at a location downstream of where the clinician infuses the fluid, then the clinician should feel some resistance in the syringe during injection of the fluid. That is, the clinician may detect some resistance in the syringe as the clinician pressed on a syringe plunger. 
         [0117]    If an occlusion is present in the fluid line, the injection of fluid may result in the occlusion being pushed further down the fluid line and/or it may result in a back pressure being generated within the fluid line if the fluid does not budge. The back pressure would be trapped between the occlusion in the fluid line and the location of the check valve, which is generally upstream of the location where the fluid is being injected. The fluid backpressure may be sufficiently high so as to cause the deformable fluid line (or a portion of a fluid line pump set) to deform in shape, such as to expand, in order to compensate for the elevated pressure. In such a case, the pressure is relieved and the clinician may incorrectly assess the patency of the fluid line because the clinician does not detect any resistance to injection of the fluid. This may also damage any components that are sensitive to elevated pressures. 
         [0118]    In order to avoid such masking of pressure buildup, the check valve may include a pressure release component as described above. The check valve may allow flow in an intended direction, such as toward the patient. However, the check valve may permit back flow in the opposite direction upon satisfaction of the valve opening trigger (i.e., the fluid pressure is greater than a predetermined value) such as when the clinician injects fluid into the fluid line during a syringe flush process. 
         [0119]    The check valve may include at least one sensor  211  ( FIG. 3 ) that monitors fluid pressure, measures fluid pressure, detects a change in fluid pressure, and/or detects when the check valve opens. The sensor(s) may include or may be communicatively coupled to an indicator configured to emit a signal that notifies the clinician when the check valve opened for backflow. If this occurs, then clinician would consider whether an incorrect patency assessment has occurred. The signal emitted by the indicator may be any of a wide variety of signals including an audio signal, a visual signal, or a tactile signal for example. The sensor  211  may further be coupled to a microprocessor that evaluates a pressure measured by the pressure sensor or other appropriate feature and determines whether to emit the signal. 
         [0120]    All statements herein reciting principles, aspects, and embodiments as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. The scope of embodiments, therefore, is not intended to be limited to the embodiments shown and described herein. Rather, the scope and spirit of embodiments are embodied by the appended claims.