Abstract:
The invention provides an apparatus for preparing a fluid for a medical procedure by mixing of at least one medicament in the form of powder with water, the medicament is held in a vessel which defines a bottom, a side wall, and a top opening which is closed by an membrane for sealing the inside of the vessel. The apparatus includes an opener for opening the membrane of the vessel. The opener includes a holder for vertically holding the vessel to downwardly orient the opening; a cutter, provided beneath the opening of the vessel held by the holder, for partially cutting the membrane along the periphery of the opening; a mechanism for vertically moving the holder toward the cutter so that the cutting edge of the cutter pierces to partially separate the membrane from the periphery of the opening whereby the medicament in the vessel falls from the vessel; a receiving member, in the form of a mesh provided beneath the cutter, for receiving all of the medicament from the vessel; and a nozzle for directing water from the source of water in the form of a spray to the medicament received by the receiving member to dissolve the medicament into the water directed to the medicament.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an apparatus for preparing a fluid for a medical procedure, an opener for unsealing a vessel containing a medicament, and a cutter for the opener. 
     2. Description of the Related Art 
     Recently, an apparatus for preparing a fluid for a medical procedure, such as dialysis treatment, has been proposed. The fluids for dialysis treatment includes an acetic acid aqueous solution, which is prepared by diluting an acetic acid stock solution with water, in particular reverse osmosis water (referred to RO water in this specification), and a sodium bicarbonate aqueous solution, which is prepared by dissolving sodium bicarbonate powder in RO water. 
     Japanese Patent Publication (Kokai) No. 5-168678 (JPP &#39;678) describes an apparatus for preparing sodium bicarbona aqueous solution. The apparatus holds an inverted vessel for containing a solid medicament, sodium bicarbona, in the form of a powder or granules, after the vessel is unsealed, so that the contents fall by gravity into a tank which contains water. The tank includes an agitator for promoting the mixing of the medicament with the water. The apparatus of JPP &#39;678 has a problem that the sodium bicarbona, which has been fallen into the tank, cannot be solved quickly in the water within the tank since the dissolid medicament deposits on the bottom of the tank. 
     Japanese Patent Publication (Kokai) No. 4-84967 (JPP &#39;967) also describes an apparatus for preparing sodium bicarbona aqueous solution. The apparatus is configured to dissolve and wash out sodium bicarbonate contained within a vessel by spraying water into the inverted vessel after the vessel is unsealed. However, with the apparatus of JPP &#39;967, dissolving the solid content within the vessel cannot be sufficiently carried out due the small volume available for the dissolving process so that the substantial portion of the sodium bicarbona is wash out of the vessel without dissolving into the water sprayed into the vessel. 
     SUMMARY OF THE INVENTION 
     The invention is directed to solve the prior art problems, and to provide an improved apparatus for preparing a fluid for a medical procedure. 
     Further, the objective of the invention is to provide an opener for unsealing a vessel containing a medicament used for preparing the fluid for a medical procedure 
     Further, the objective of the invention is to provide a cutter for the opener. 
     The invention provides an apparatus for preparing a fluid for a medical procedure by mixing of at least one medicament in the form of powder with water, the medicament is held in a vessel which defines a bottom, a side wall, and a top opening which is closed by an membrane for sealing the inside of the vessel. The apparatus includes a source of water for dissolving the medicament. An opener is provided for opening the membrane of the vessel. The opener includes a holder for vertically holding the vessel to downwardly orient the opening; a cutter, provided beneath the opening of the vessel held by the holder, for partially cutting the membrane along the periphery of the opening; a mechanism for vertically moving the holder toward the cutter so that the cutting edge of the cutter pierces to partially separate the membrane from the periphery of the opening whereby the medicament in the vessel falls from the vessel; a receiving member, in the form of a mesh provided beneath the cutter, for receiving all of the medicament from the vessel; and a nozzle for directing water from the source of water in the form of a spray to the medicament received by the receiving member to dissolve the medicament into the water directed onto the medicament. A tank is provided for receiving and containing the substances dissolved into the sprayed water. 
     According to one feature of the invention, the tank is adapted to receive the water from the water source. The apparatus further includes a circulating system for supplying the water from the tank to the nozzle. 
     According to another feature of the invention, the opener may include a housing for enclosing the cutter and the receiving member. The holder is vertically displaceable relative to the housing; and the nozzle is attached to the housing to direct the water to the medicament received by the receiving member from outside of the housing. 
     According to another feature of the invention, the mechanism includes a feed screw vertically supported for rotation; a motor, connected to one end of the feed screw, for rotating the screw; a nut engaging the feed screw; and a member connected between the nut and the holder. 
     According to another feature of the invention, the cutting edge includes a serrated portion provided along the inclined end. The serrated portion may be partially provided along the inclined end of the cutter body and, in particular, disposed on the proximal half of the inclined end. The serrated portion may be provided all around the inclined end of the cutter body. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       These and other objects and advantages and further description will now be discussed in connection with the drawings in which: 
         FIG. 1  is a vertical section of an embodiment of an opener according the invention; 
         FIG. 2  is a vertical section of the opener along line I—I in  FIG. 1 ; 
         FIG. 3  is a vertical section of a holder according to the embodiment shown in  FIG. 1 ; 
         FIG. 4  is a partially enlarged side view of a vessel according to the embodiment shown in  FIG. 1 ; 
         FIG. 5A  is a side view of a cutter according to the embodiment shown in  FIG. 1 ; 
         FIG. 5B  is another side view of the cutter in the direction VB—VB in  FIG. 5A ; 
         FIG. 5C  is a horizontal section of the cutter along line VC—VC in  FIG. 5A ; 
         FIG. 5D  is a partially enlarged section of the cutting edge of the cutter along line VD—VD in  FIG. 5E ; 
         FIG. 5E  is a partially enlarge side view of the cutting edge of the cutter; 
         FIG. 6  is a perspective view of a cutter according to another embodiment of the invention; 
         FIG. 7  is a cutter support according the embodiment shown in  FIG. 1 ; 
         FIG. 8  is a vertical section of an opener according to another embodiment of the invention; 
         FIG. 9A  is a side view of a cutter according to the embodiment shown in  FIG. 8 ; 
         FIG. 9B  is another side view of the cutter shown in  FIG. 9A ; 
         FIG. 9C  is a plan view of the cutter viewed in the direction of IXC—IXC in  FIG. 1A ; 
         FIG. 10  is an opener according to another embodiment of the invention; and 
         FIG. 11  is an apparatus for preparing a fluid for a medical procedure according to the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 11  shows an example of an apparatus for preparing a fluid for a medical procedure according an embodiment of the invention. The apparatus  300  includes a tank  302  for containing the fluid, first and second openers  100  and  200  for opening bottles or first and second vessels  10  and  30  which contain medicament in the forms of powder and liquid, respectively. A pump  304  is provided for circulation of the liquid within the apparatus  300 . RO water is supplied to the tank  302  from a RO water source  320  through a supply conduit  318 . The RO water contained in the tank  302  is then supplied to the first opener  100  through a main conduit  306  including the pump  304  and a branch conduit  308  connected between the main conduit  306  and the first opener  100 . Likewise, the RO water is supplied to the second opener  200  through the main conduit  306  and a branch conduit  314  connected between the main conduit  306  and the second opener  200 . 
     The first opener  100  opens the seal of the first vessel  10  to remove the medicament in the form of powder from the first vessel  10  and receives it. The medicament received by the first opener  100  is dissolved into the OR water supplied to the first opener  100 . The liquid containing the dissolved medicament flows back to the tank  302  through a return conduit  312 . 
     Likewise, the second opener  200  opens the seal of the second vessel  30  to remove the medicament in the form of liquid from the second vessel  30 . The medicament from the second vessel  30  is mixed with the OR water supplied to the second opener  100 , and the mixture flows back to the tank  302  through a return conduit  316 . 
     With reference to  FIGS. 1–7 , the first opener  100  according to the embodiment of the invention will be described below. 
     The first opener  100  includes a housing defined by upper and lower housings  102  and  104  and a bottom  105  which are connected to each other by a clamp rings  108  and  110 . The upper housing  102  defines an upper open end  102   a  for receiving a holder  106 . The holder  106  is displaceable relative to and within the upper housing  102  in the vertical direction along the central axis “O” of the housing. The bottom  105  has an outlet  105   a  which is adapted for the connection with the conduit  312 . 
     With reference to  FIG. 3 , the holder  106  has a substantially cylindrical side wall  118  defining an upper open end  106   a  for receiving a fist vessel  10 , as described hereinafter, and a neck  114  defining a lower opening end  106   b . The neck  114  further defines a plurality of inwardly extending lugs  116  which are equally disposed at its upper end and an inwardly extending annular stop  114   a  adjacent to its lower end. The side wall  118  may have a plurality of inclined ribs  118   a  for aiding the insertion of the first vessel  10 . 
     The first vessel  10  is adapted to contain solid medicament in the form of power or granular and has a bottom  12 , a side wall  14  and a neck  16  which has a radius smaller than the side wall  14 . The side wall  14  includes a cylindrical portion  14   a  and a truncated cone portion  14   b  which connects the end of the upper cylindrical portion  14   a  opposite to the bottom  12  to one end of the neck  16 . 
     With reference to  FIG. 4  the neck  16  includes a plurality of engagement portions  20  and screw portions  22 . Each of the engagement portions includes a guide portion spirally extending along the outer surface of the neck  16 , a stop portion  20   b  provided upper end of the spirally extending guide portion  20   a  and a protrusion  20   c . The neck  16  further defines an opening  18  which is air-tightly sealed by a seal in the form of a membrane  24 . Though the opening  18 , a solid medicament in the form powder or granules is charged into and removed from the first vessel  10 . 
     The engagement portions  20  are equally disposed on the outer surface of the neck  16  about the axis O2 of the first vessel  10  so that space  16   a  is provided between the stop  20   b  and the end of the guide  20   a  of the adjacent engagement portion  20 . Likewise, the screw portions  22  are disposed on the outer surface of the neck  16  to provide the spaces  16   a  between the adjacent screws  22 . The spaces  16   a  allow the passage of the protrusions  20   c  when the first vessel  10  is attached to the holder  112 . 
       FIGS. 1 and 2  show the first opener  100  with the first vessel  10  mounted thereto. The first opener  100  has a cutter  150  which is provided within the housing opposite to the opening  18  of the first vessel  10 . 
     The upper hosing  102  of the first opener  100  is vertically supported by a stationary frame  112 . The frame  112  has a pair of arms  112   a  which extend horizontally along the outer surface of the side wall upper housing  102  and are secured thereto by a plurality of screws  112   b  ( FIG. 2 ). 
     The first opener  100  further includes a mechanism  120  for vertically moving the holder  106 . The mechanism  120  includes an electric motor  122  attached to the frame  112  by a bracket  122   a , and a vertically extending feed screw  124  supported by bearings  130   a  and  130   b  at the ends of the screw  124 . At the lower end of the feed screw  124  is connected to the shaft  122   b  of the motor  122  by a coupling  126 . A nut  128  which engages the feed screw  124  is mounted to a connection member  140 . The connection member  140  has a pair of arms  140   a  which extend horizontally along the outer surface of the side wall of the cutter support  160  and are secured thereto by a plurality of screws  140   b  ( FIG. 2 ). 
     With reference to  FIGS. 5A to 5E , the configuration of the cutter  150  is described below. 
     The cutter  150  includes a substantially cylindrical cutter body  150  with a lower end defining a threaded portion  154 , a flange  155  provided over the threaded portion  154 , and an inclined upper end  156  defining an cutting edge. The cutter body  152  further includes a plurality of openings  152   a  (four openings  152   a  are shown in this embodiment) which define columns  152   b  supporting the upper portion of the cutter body  152 . 
     The upper end  156  inclines from a plane perpendicular to the axis of the cutter body  152  by an angle α ( FIG. 5B ) of, preferably, 15–30 degrees. From the peak of the inclined end  156 , a slit  158  vertically extends to one of the opening  152   a . The inclined end  156  includes a plain cutting edge portion  156   a  which extend along upper half of the inclined end  156  and a serrated edge portion  156   b  provided on the lower half of the inclined end  156 .  FIG. 5D  shows a portion of the serrated portion  156   b , and  FIG. 5E  shows a partial side section of the serrated portion  156   b  along line VE—VE in  FIG. 5D . The pitch “P” (see  FIG. 5E ), the distance between the peaks of the adjacent teeth of the serrated portion  156   a , may be 1–5 mm, preferably 3 mm, and the depth “D” of the teeth may be 1–5 mm, preferably 3 mm. Further, the attack angle β may be 15–30 degrees, preferably 20 degrees. Further, the serrated portion may be provided all around the inclined end of the cutter body as shown in  FIG. 6 . 
     The cutter  150  is attached to and supported by an inner frame  160  which is clamped between the upper and lower housings  102  and  104 . With reference to  FIG. 7 , the inner frame  160  includes a circular base  162  adapted to be clamped by the housings  102  and  104  with seal rings  162   a  provided therebetween ( FIGS. 1 and 2 ), and a central mount  164  which is connected to the circular base  162  by radial spokes  168 . The central mount  164  has a substantially cylindrical shape with a central bore including a threaded inner surface and a stop  162 . The cutter  150  is attached to the central mount  164  through the engagement between the threaded portion  154  of the cutter  150  and the threaded inner surface of the central mount  164  with O-rings  150   a  and  150   b  clamped therebetween ( FIGS. 1 and 2 ). 
     A receiving member  170 , for receiving the solid medicament falling down from the first vessel  10  when the seal is broken by the first opener  100 , is provided between the lower housing  104  and the bottom  105 . The receiving member  170  includes a screen which can receive the medicament from the first vessel  10 . The size of the powder of granules of sodium bicarbonate of 200 μm is generally used for preparing a fluid for dialysis treatment. Therefore, the mesh size of the screen is of at most 200 μm. On the other hand, a screen having a unnecessarily small mesh size, for example under 20 μm, inhibits the flow of the solution through the mesh, which results in increase in the pressure within the housing above the screen to break the seal of the first opener  100 . The typical mesh size for the screen is of at least 20 μm, preferably 50–150 μm. 
     A water supply nozzle  180  is mounted to the housing of the first opener  100  and connected to the branch conduit  308 . The water supply nozzle  180  is oriented to the receiving member  170  to direct the water in the form of a spray onto the medicament received on the receiving member  170 . 
     The first opener  100  further includes a pair of washing nozzles  182  and  184  connected to a branch conduit  310  which is further connected to the main conduit  306  ( FIG. 11 ). The washing nozzles  182  and  184  are horizontally oppositely oriented to the cutter  150  to direct the liquid from the tank  302  in the form of a spray for the purpose of washing inside of the housing of the first opener  100  and the cutter  150  after an operation of dissolving the medicament received on the receiving member  170  by spraying the RO water from the water supplying nozzle  180 . 
     With reference to  FIGS. 8–9C , the second opener  200  will be described below. 
     The second opener  200  is configured substantially the same as the first opener  100 , except that the second opener  200  is adapted to open the seal of the second vessel  30  for containing a liquid medicament while the first opener  100  is adapted to open the first vessel  10  for containing a solid medicament in the form of power or granular. 
     The second opener  200  includes upper housing  202  and lower housing  204  which are connected to each other by a clamp ring  208  to define the housing of the second opener  200 . The lower housing defines a bottom of the housing and an outlet  204   a  for connection with the return conduit  316  ( FIG. 11 ). 
     The upper housing  202  vertically displaceablly receives a holder  206  for holding the second vessel  30 . A mechanism  220 , which is configured substantially the same as the mechanism  120  of the first opener  100 , is provided for vertically moving the holder  206  relative to the upper housing  202 . 
     A cutter  250  is provided within the housing opposite to the opening of the first vessel  30 . The cutter  250  is formed substantially the same as the cutter  150  of the first opener  100 , except that the cutter  250  of the second opener  200  is formed into one piece while the cutter  150  of the first opener  100  includes two pieces. The cutter  250  includes substantially a cylindrical cutter body  252  and a circular base portion  254 . The cutter body  252  is disposed at the center of the circular base portion  254  and supported by radial spokes  260 . The circular base portion  254  is adapted to be clamped by the housings  202  and  204  with seal rings provided therebetween ( FIGS. 1 and 2 ), 
     The cutter body  252  includes an inclined upper end  256  defining an cutting edge. The upper end  256  inclines from a plane perpendicular to the axis of the cutter body  252 , the same as the cutter of the first opener  100 . 
     From the peak of the inclined end  256 , a slit  258  vertically extends into the cutter body  252 . The inclined end  256  includes an plain cutting edge portion  256   a  which extend along upper half of the inclined end  256  and a serrated edge portion  256   b  provided on the lower half of the inclined end  256 . 
     A water supplying nozzle  262  is attached to the bottom of the lower housing  204 . The water supplying nozzle  262  is oriented substantially to the center of the cutter  250  to direct the water in the form of a spray to the inside of the second vessel  200  through the central bore of the cutter  250  for the purpose of flushing the inside of the second vessel. 
     The functional operation of the apparatus for preparing a fluid for a medical procedure of the invention will be described below. 
     First, the first and second vessels  10  and  30  are mounted to the first and second openers  100  and  200 , respectively. The first and second vessels  10  and  30  are inverted after their caps (not shown) are removed. The necks  16  and  36  of the first and second vessels  10  and  30  are inserted into the bores defined by the necks  114  and  214  of the holders  106  and  206  of the first and second openers  100  and  200 , respectively, so that the lugs  116  and  216  pass through the spaces  16   a  (only the space  16   a  of the first vessel  10  is shown in the drawings) provided on the outer surfaces of the necks  16  and  36 . When the ends of the necks  16  and  36  abut the stops  114   a  and  214   a  of the holders  206  and  306 , the first and second vessels  10  and  30  are rotated to engage the protrusions  20   c  (only the protrusions  20   c  of the first vessel  10  are shown in the drawings) provided on the outer surfaces of the necks  16  and  36  with the lugs  116  and  216 . This secures the first and second vessels  10  and  30  to the holders  106  and  206  of the first and second openers  100  and  200 . 
     After the first and second vessels  10  and  30  are mounted to the first and second openers  100  and  200 , the contents of the first and second vessels  10  and  20  are removed. In the following description, the operation of removing the solid medicament contained within the first vessel will be described. 
     The mechanism  120  may be activated by an operator so that the nut  128 , the connection member  140  and the holder  106  with the first vessel  10  secured to the holder  106  move downwardly. When the tips  156   c  of the cutting edge  156   a  of the cutter  150  contact the membrane  24  closing the opening  18  of the first vessel  10 , the cutter  150  initiates cutting the membrane  24  in the opposite direction along the inner periphery of the opening  18  of the neck  16 . Penetration of the inclined end  156  into the membrane  24  proceeds the cutting operation so that the membrane  24  is cut along the inner periphery of the opening  18 , except for a portion which is located corresponding to the location of the slit  158 . The serrated portion  156   b  aids the cutting performance when the cutting operation is advanced and the tension in the membrane is reduced. 
     Then, the mechanism  120  moves the nut  128 , the connection member  140 , the holder  106  and the holder  106  upwardly from the cutter  150 . Moving the vessel  10  from the cutter  150  makes the solid medicament within the first vessel  10  to fall down onto the receiving member  170 . At this time, the portion of the membrane  24  which has not been cut by the cutter  150  due to the slit  158  keeps the membrane  24  connected to the neck  16 . The water is directed to the solid medicament on the receiving member  170  through nozzle  180  to dissolve the solid medicament into the sprayed water. The solution flows back to the tank  302  through the outlet  105   a  and the conduit  312 . The tank  302  must have a volume at least the volume of the first opener  100  to receive all of the solution at once. 
     After the solid medicament is completely solved, the water supply through the nozzle  180  is ended and the washing nozzles  182  and  184  start to spray water to clean the inside of the housing  102 ,  104  and  105  and the cutter  150 . In particular, the openings  152   a  of the cutter  150  allow the sprayed water to access the inside of the hollow cutter  150  sufficiently. 
     The second opener  200  functions substantially the same as the first opener  100  except that, while the first vessel  10  contains a solid medicament, the second vessel  30  mounted to the second opener  200  contains a liquid medicament so that the dissolving operation of the content of the vessel is not required. Thus, unsealing the membrane attached to the opening of the second vessel  30  removes the liquid medicament from the second vessel  30  so that the liquid medicament flows to the tank  302  through the outlet  204   a  of the second opener  200  without any operation. After completion of the evacuation of the second vessel  30 , the water supplying nozzle  262  sprays water toward the inside of the second vessel through the central bore of the cutter  250  to clean the insides of housing  202  and  204 , the vessel  30  and the cutter  250 . 
     With reference to  FIG. 10 , an opener according to another embodiment of the invention will described below. 
     The opener  400  includes a housing  402  and a holder  404  to which the vessel  10  is mounted, same as the above-described embodiment. Although it is not shown in  FIG. 10 , the opener  400  also includes a mechanism, substantially the same as the mechanisms  120  and  240 . 
     The holder  404  includes a first plain gear wheel  406  attached to the top of the holder  404 . The first gear wheel  406  engages a drive gear wheel  408  attached to a shaft of an electric motor  410 . The electric motor  410  is securely mounted to a frame  430 . The rotation of the drive gear wheel  408  rotates the holder  404  through the engagement between the drive gear wheel  408  and the first gear wheel  406 . 
     The drive gear wheel  408  also engages a second plain gear wheel  412 . The second plain gear wheel  412  is connected to a bevel gear  414  by a shaft  416  to rotate therewith. The bevel gear  414  engages a second bevel gear  418 . A pinion gear  420  is coaxially connected to the second bevel gear  418  to rotate therewith. The pinion gear  420  engages a rack  422  provided on a drive bar  424  which has a stop ring  424   a  at the end opposite to the rack  422 . 
     Provided beneath the drive bar  424  is a driven bar  426  which horizontally extends through the housing  402 . The driven bar  426  is displaceablely supported by a bracket  432  at one end, and the housing  492  at the other end. The bracket  432  is connected to the frame  430 . A piece  428  is secured to the driven bar  428  to move therewith. The piece  428  has an aperture (not shown in  FIG. 10 ) through which the drive bar  424  extends. Provided on the drive bar between the stop ring  424   a  and the piece  428  is a coil spring  434 . Likewise, a coil spring  436  is provided on the driven bar  426  between the piece  428  and the bracket  432 . 
     Provided on the driven bar  426  is a knife  438  which has a cutting edge  438   a  facing the membrane  24  sealingly closing the opening of the first vessel  10 . A receiving member  440  in the form of a basket, which includes a screen or mesh provided in at least the bottom and a portion of the side wall, is provided beneath the knife  438 . A pair of nozzles  442  is attached to direct water to the solid medicament received by the receiving member  440 . 
     The functional operation of the opener  400  will be described below. 
     The first vessel  10  is mounted to the opener  400 , as described above. After the first vessel  10  is mounted to the opener  400 , the mechanism, substantially identical to the mechanism  120  and  220 , may be activated by an operator to move the holder  404  downwardly with the first vessel  10  secured to the holder  404 . The electric motor  410  is activated when the first gear wheel  406  engages the drive gear wheel  408 . The activation of the electric motor  410  rotates the holder  404  through the engagement between the first gear wheel  406  and the drive gear wheel  408 . Further, the activation of the electric motor  410  moves the drive bar  424  to the right in  FIG. 10  through the gear train of the drive gear wheel  408 , the second gear wheel  412 , shaft  416 , bevel gears  414  and  418 , the pinion  420  and the rack  422 . When the cutting edge  438   a  of the knife  438  contacts the membrane  24  closing the opening the first vessel  10 , the cutting edge  438   a  of the knife  438  is substantially at the inside of the opening of the first vessel  10 . The rotation of the holder  404  with the first vessel  10  secured to the holder  404  cuts the membrane  24  along the inner periphery of the opening of the first vessel  10 . 
     The activation of the electric motor  410  is continued until the membrane  24  is cut along the inner periphery of the opening except for a portion to keep the membrane  24  cut by the knife  438  connected to the neck  16  by the portion. 
     When the opening of the first vessel  10  is unsealed, the solid medicament within the first vessel  10  falls down into the receiving member  440 . The water is directed to the solid medicament in the receiving member  440  through nozzles  442  to solve the solid medicament into the sprayed water. The solution flows back to the tank  302  through the outlet  402   a  and the conduit  312 . 
     It will also be understood by those skilled in the art that the forgoing description is a preferred embodiment of the disclosed device and that various changes and modifications may be made without departing from the spirit and scope of the invention.