Abstract:
An intravenous flow control device includes a rigid casing ( 2 ) defining a flow passage having a fluid entrance ( 211 ) and a fluid exit ( 222 ); and a flow regulator ( 1 ) disposed in the casing ( 2 ) and including a floating member ( 11 ) having a hollow cylinder ( 111 ), an opening ( 112 ) on a bottom of the hollow cylinder ( 111 ), and a lower stepped-diameter chamber ( 113 ) in the hollow cylinder ( 111 ) and communicating with the opening ( 112 ); and a valve member ( 12 ) including a hollow member ( 121 ), a flat member ( 122 ), and a space ( 123 ) open to top. The valve member ( 12 ) is retained in the chamber ( 113 ) through the opening ( 112 ) and together they form a sealed hollow structure. The flow regulator ( 1 ) floats on fluid in the casing ( 2 ) due to the sealed hollow structure.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to intravenous (IV) infusion and more particularly to an intravenous flow control device. 
         [0003]    2. Description of Related Art 
         [0004]    Conventionally, an IV infusion set comprises a flow control device and a manual flow control device together for adjusting IV fluids flowing to a patient or stopping the infusion at the end of IV infusion. Also, they can prevent air from entering the blood stream (i.e., air embolism). 
         [0005]    The conventional flow control device comprises a float buoyed in a casing containing IV fluid, and a suction cup member under the float. However, the float may not function normally and/or the suction cup member may not be capable of blocking an outlet if the flow control device is inclined. 
         [0006]    Thus, the need for improvement still exists. 
       SUMMARY OF THE INVENTION 
       [0007]    It is therefore one object of the invention to provide an intravenous flow control device comprising a flow regulator disposed in a casing and comprising a floating member including a hollow cylinder, an opening on a bottom of the hollow cylinder, and a lower stepped-diameter chamber in the hollow cylinder and communicating with the opening; and a valve member including a hollow member, a flat member, and a space open to top; wherein the valve member is retained in the chamber through the opening and together they form a sealed hollow structure; and wherein the flow regulator floats on fluid in the casing due to the sealed hollow structure. 
         [0008]    The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of an intravenous flow control device according to a first preferred embodiment of the invention; 
           [0010]      FIG. 2  is an exploded view of  FIG. 1 ; 
           [0011]      FIG. 3A  is an enlarged view of a first configuration of a flow regulator of  FIG. 2 ; 
           [0012]      FIG. 3B  is a longitudinal sectional view of the assembled flow regulator of  FIG. 3A ; 
           [0013]      FIG. 4  is a longitudinal sectional view of  FIG. 1  showing fluid dropped into the casing during an IV infusion; 
           [0014]      FIG. 5  is a view similar to  FIG. 4  showing the IV flow completely blocked by the flow regulator at the end of IV infusion; 
           [0015]      FIG. 6A  is an enlarged view of a second configuration of a flow regulator of  FIG. 2 ; 
           [0016]      FIG. 6B  is a longitudinal sectional view of the assembled flow regulator of  FIG. 6A ; 
           [0017]      FIG. 7  is a longitudinal sectional view of  FIG. 1  showing fluid dropped into the casing during an IV infusion in which the flow regulator is the second configuration; 
           [0018]      FIG. 8  is a view similar to  FIG. 7  showing the IV flow completely blocked by the second configuration of the flow regulator at the end of IV infusion; 
           [0019]      FIG. 9  is a perspective view of an IV infusion set incorporating the intravenous flow control device according to the first preferred embodiment of the invention; 
           [0020]      FIG. 10A  is an enlarged view of a first configuration of a flow regulator of an intravenous flow control device according to a second preferred embodiment of the invention; 
           [0021]      FIG. 10B  is a longitudinal sectional view of the assembled flow regulator of  FIG. 10A ; 
           [0022]      FIG. 11A  is an enlarged view of a second configuration of a flow regulator of the intravenous flow control device according to the second preferred embodiment of the invention; 
           [0023]      FIG. 11B  is a longitudinal sectional view of the assembled flow regulator of  FIG. 11A ; 
           [0024]      FIG. 12  is a longitudinal sectional view of  FIG. 1  showing fluid dropped into the casing during an IV infusion in which the flow regulator is the first configuration of the intravenous flow control device according to the second preferred embodiment of the invention; 
           [0025]      FIG. 13  is a longitudinal sectional view of  FIG. 1  showing fluid dropped into the casing during an IV infusion in which the flow regulator is the second configuration of the intravenous flow control device according to the second preferred embodiment of the invention; 
           [0026]      FIG. 14A  is an enlarged view of a flow regulator of an intravenous flow control device according to a third preferred embodiment of the invention; 
           [0027]      FIG. 14B  is a longitudinal sectional view of the assembled flow regulator of  FIG. 14A ; 
           [0028]      FIG. 15  is a longitudinal sectional view of  FIG. 1  showing fluid dropped into the casing during an IV infusion in which the flow regulator is the one shown in  FIGS. 14A and 14B ; and 
           [0029]      FIG. 16  is a view similar to  FIG. 15  showing the IV flow completely blocked by the flow regulator at the end of IV infusion. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    Referring to  FIGS. 1 to 9 , an IV infusion set in accordance with a first preferred embodiment of the invention is shown. The IV fusion set comprises, from upstream to downstream, a drip chamber  4  filled with fluid, a first plastic IV tubing  3 , an flow control device, a second plastic IV tubing  5 , a manual flow control device  7 , and an IV needle  6 . The flow control device as the subject of the invention and its components will be discussed in detail below. 
         [0031]    A flow regulator  1  comprising a floating member  11  and a valve member  12  disposed in a rigid, cylindrical, transparent casing  2 . The casing  2  comprises an upper member  21  and a lower member  22  fastened together. The upper member  21  comprises a projecting inlet  211  on top. The lower member  22  comprises an intermediate annular grooved flange  221  on an outer surface, together with a portion of the lower member  22  above the flange  221 , for fastening a lower portion of the upper member  21  put thereon. The lower member  22  further comprises an inner tubing connector  222  on a bottom and an outer tubing connector  223  in fluid communication with the inner tubing connector  222  and downward projecting out of the bottom. The outer tubing connector  223  is connected to one end of the second plastic IV tubing  5  for allowing fluid communication therewith. 
         [0032]    The floating member  11  is a hollow cylindrical member and comprises a hollow cylinder  111 , a bottom opening  112  on a bottom of the cylinder  111 , a stepped-diameter chamber  113  in a lower portion of the cylinder  111  and communicating with the bottom opening  112 , a plurality of equally spaced longitudinal ridges  114  of rectangular cross-section formed on an outer surface of the cylinder  111 , and a recess  115  on a top of the cylinder  111 . The recess  115  is separated from the chamber  113  by a member. Depth of the recess  115  is about one-fifth of the height of the cylinder  111 . The recess  115  is capable of adjusting buoyancy. 
         [0033]    Outer diameter of the floating member  11  is slightly less than an inner diameter of each of the upper member  21  and the lower member  22 . Thus, the floating member  11  can freely float upward or downward in both the upper member  21  and the lower member  22  (i.e., the casing  2 ). Thus, the ridges  114  may frictionally contact an inner surface of the casing  2  when the casing is inclined. This has the advantage of keeping the flow regulator  1  from upside down and preventing the flow regulator  1  from being malfunctioned. 
         [0034]    As shown in  FIGS. 3A and 3B  specifically, in a first configuration the valve member  12  is bowl-shaped and comprises a downward tapered hollow member  121 , a flat member  122 , and a space  123  open to top. The valve member  12  can be disposed in the chamber  113  through the bottom opening  112 . 
         [0035]    The valve member  12  can be oriented with top being open as that shown in  FIG. 3A  prior to disposing in the chamber  113  through the opening  112 . Thus, the space  123  in the hollow member  121  can communicate with the chamber  113  of the floating member  11 . Therefore the floating member  11  and the valve member  12  having the flat member  122  as a blocking member form a sealed hollow structure. 
         [0036]    As shown in  FIGS. 4 and 5  specifically, fluid can be fed from the drip chamber  4 , the first plastic IV tubing  3 , and the inlet  211  into the casing  2  to accumulate therein. As such, the floating member  11  and the valve member  12  as a unit float in the casing  2 . In  FIG. 4 , it is shown that the recess  115  is filled with fluid and a portion of space of the casing  2  below the flow regulator  1  is filled with fluid. Level of the fluid in the casing  2  may drop due to fluid flow out of the casing  2  via the inner tubing connector  222 , the outer tubing connector  223 , and the second plastic IV tubing  5 . In a position of  FIG. 5 , the inner tubing connector  222  is completely blocked by the flat member  122  of the valve member  12 . As a result, the fluid flow is stopped. 
         [0037]    As shown in  FIGS. 6A and 6B  specifically, in a second configuration the valve member  12  is inverted bowl-shaped and comprises an upward tapered hollow member  121 , a flat member  122 , and a space  123  open to bottom. The valve member  12  can be disposed in the chamber  113  through the bottom opening  112 . 
         [0038]    The valve member  12  can be oriented with bottom being open as that shown in  FIGS. 6A and 6B  prior to disposing in the chamber  113  through the opening  112 . Thus, the flat member  122  separates the space  123  in the hollow member  121  from the chamber  113  of the floating member  11 . Therefore, the chamber  113  of the floating member  11  and the valve member  12  having the flat member  122  disposed on top form a sealed hollow structure. 
         [0039]    The valve member  12  can be disposed with either the flat member  122  on top or the space  123  open to top prior to disposing in the chamber  113  through the opening  112 . Therefore, the chamber  113  of the floating member  11  and the valve member  12  disposed therein form a sealed hollow structure. 
         [0040]    As shown in  FIGS. 7 and 8  specifically, fluid can be fed from the drip chamber  4 , the first plastic IV tubing  3 , and the inlet  211  into the casing  2  to accumulate therein. As such, the floating member  11  and the valve member  12  as a unit float in the casing  2 . In  FIG. 7 , it is shown that the recess  115  is filled with fluid and a portion of space of the casing  2  below the flow regulator  1  is filled with fluid. Level of the fluid in the casing  2  may drop due to fluid flow out of the casing  2  via the inner tubing connector  222 , the outer tubing connector  223 , and the second plastic IV tubing  5 . In a position of  FIG. 8 , the inner tubing connector  222  is completely blocked by the flat member  122  of the valve member  12 . As a result, the fluid flow is stopped. Alternatively, the valve member  12  can be disposed upside down in the chamber  113 . Therefore, the chamber  113  of the floating member  11  and the valve member  12  disposed therein form a sealed hollow structure and together are adapted to float upward or downward in the casing  2 . 
         [0041]    Referring to  FIGS. 10A to 13 , an intravenous flow control device in accordance with a second preferred embodiment of the invention is shown. The characteristics of the second preferred embodiment are substantially the same as that of the first preferred embodiment except the following: 
         [0042]    A flow regulator  1 A comprises a floating member  11 A and a valve member  12 A. The floating member  11 A is shaped an inverted cup and comprises a hollow cylinder  111 A, a smooth top, a bottom opening  112 A on a bottom of the cylinder  111 A, a stepped-diameter chamber  113 A in the cylinder  111 A and communicating with the bottom opening  112 A, a plurality of equally spaced longitudinal ridges  114 A of rectangular cross-section formed on an outer surface of the cylinder  111 A. 
         [0043]    As shown in  FIGS. 10A and 10B  specifically, in a first configuration the valve member  12  is bowl-shaped and comprises a downward tapered hollow member  121 , a flat member  122 , and a space  123  open to top. The valve member  12  can be disposed in a lower portion of the chamber  113 A through the bottom opening  112 A. 
         [0044]    As shown in  FIGS. 11A and 11B  specifically, in a second configuration the valve member  12  is an inverted bowl-shaped member and comprises an upward tapered hollow member  121 , a flat member  122 , and a space  123  open to bottom. The valve member  12  can be disposed in a lower portion of the chamber  113 A through the bottom opening  112 A. 
         [0045]    As shown in  FIGS. 12 and 13  specifically in conjunction with  FIG. 9 , fluid can be fed from the drip chamber  4 , the first plastic IV tubing  3 , and the inlet  211  into the casing  2  to accumulate therein. As such, the floating member  11 A and the valve member  12  as a unit float in the casing  2 . In  FIG. 12 , it is shown that a portion of space of the casing  2  below the flow regulator  1  is filled with fluid. Level of the fluid in the casing  2  may drop due to fluid flow out of the casing  2  via the inner tubing connector  222 , the outer tubing connector  223 , and the second plastic IV tubing  5 . In a position of  FIG. 13 , the inner tubing connector  222  is completely blocked by the flat member  122  of the valve member  12 . As a result, the fluid flow is stopped. 
         [0046]    The valve member  12  can be oriented with opening open to top as that shown in  FIG. 12  or open to bottom as that shown in  FIG. 13  as desired. 
         [0047]    The valve member  12  can be oriented with the space  123  open to top as that shown in  FIGS. 10A and 10B  prior to disposing in the chamber  113  through the opening  112 . Alternatively, the valve member  12  can be oriented with the flat member  122  on top as that shown in  FIGS. 11A and 11B  prior to disposing in the chamber  113  through the opening  112 . Therefore, the chamber  113  of the floating member  11  and the valve member  12  disposed therein form a sealed hollow structure and together are adapted to float upward or downward in the casing  2 . 
         [0048]    Referring to  FIGS. 12 and 13  again, the flow regulator  1 A can float upward or downward in the casing  2  due to the sealed hollow structure formed by the chamber  113 A of the floating member  11 A and the valve member  12  therein. 
         [0049]    Referring to  FIGS. 14A to 16 , an intravenous flow control device in accordance with a third preferred embodiment of the invention is shown. The characteristics of the third preferred embodiment are substantially the same as that of the first preferred embodiment except the following: 
         [0050]    A flow regulator  1 B comprises a floating member  11  and a valve member  12 B. The floating member  11  is a hollow cylindrical member and comprises a hollow cylinder  111 , a bottom opening  112  on a bottom of the cylinder  111 , a chamber  113  in a substantial portion of the cylinder  111  and communicating with the bottom opening  112 , a plurality of equally spaced longitudinal ridges  114  of rectangular cross-section formed on an outer surface of the cylinder  111 , and a recess  115  on a top of the cylinder  111 . The recess  115  is separated from the chamber  113  by a member. 
         [0051]    As shown in  FIGS. 14A and 14B  specifically, the valve member  12 B is inverted cup shaped and comprises a hollow member  121 B, a top  122 B, an externally extended rim  124 B on a bottom, and a space  123 B open to bottom. The valve member  12  can be disposed in a lower portion of the chamber  113 . 
         [0052]    As shown in  FIGS. 15 and 16  specifically in conjunction with  FIG. 9 , fluid can be fed from the drip chamber  4 , the first plastic IV tubing  3 , and the inlet  211  into the casing  2  to accumulate therein. As such, the floating member  11  and the valve member  12 B as a unit float in the casing  2 . In  FIG. 15 , it is shown that the recess  115  is filled with fluid and a portion of space of the casing  2  below the flow regulator  1  is filled with fluid. Level of the fluid in the casing  2  may drop due to fluid flow out of the casing  2  via the inner tubing connector  222 , the outer tubing connector  223 , and the second plastic IV tubing  5 . In a position of  FIG. 16 , the inner tubing connector  222  is completely blocked by the bottom  122 B of the valve member  12 B. As a result, the fluid flow is stopped. 
         [0053]    While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.