Abstract:
The fluid pump of the present invention is used in a lavage instrument that is driven by vacuum pressure supplied by an external vacuum source. The vacuum driven fluid pump is well suited for lavage instruments that are already connected to an external vacuum source to provide aspiration functions. The present invention is lightweight, inexpensive, disposable, and is driven by a alternative power source.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is based on and claims priority from provisional patent application Ser. No. 60/512,332 filed on Oct. 17, 2003. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to a fluid pump used in a lavage instrument.  
       BACKGROUND OF INVENTION  
       [0003]     In many medical and surgical procedures, irrigating wounds, and surgical areas with fluids and/or removing various irrigating fluids from the surgical area are often necessary. Lavage instruments are well known in the medical arts. Lavage instruments that are connected to an external vacuum source to additionally provide an aspiration function have been developed. Typically, lavage instruments have been connected to external fluid pumps, which supply irrigation fluids to the lavage instrument from an external fluid source, such as a hanging fluid bag. Heretofore, lavage instruments that include internal fluid pumps have been electrically powered, which increases the size, weight and cost of the lavage instrument.  
         [0004]     Utility Pat. No. 5,542,918 issued to Atkinson discloses a vacuum driven fluid pump for an aspiration/irrigation instrument. However, the present invention makes significant improvements in apparatus components and functional capabilities. First, the present invention is easy to make and is easy to use. Second, functionally, the present invention can provide continuous fluid flow or at least higher frequency pulsatile fluid flow and is capable of simultaneously aspirating fluid and irrigating fluid.  
         [0005]     For these reasons a lavage instrument, which includes an internal fluid pump that is lightweight, inexpensive, disposable and driven by an alternative power source is needed.  
       SUMMARY OF THE INVENTION  
       [0006]     The fluid pump of this invention is used in a lavage instrument that is driven by vacuum pressure supplied by an external vacuum source. The vacuum driven fluid pump is well suited for lavage instruments that are already connected to an external vacuum source to provide aspiration functions.  
         [0007]     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, claims, and accompanying drawings. Therefore, the form of the invention, as set out above, should be considered illustrative and not as limiting the scope of the following claims. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]      FIG. 1A  is a sectional view of the apparatus of the invention showing the chambers, pistons, valves and their connections, switch, and vacuum controllers;  
         [0009]      FIG. 1B  is a sectional view and internal layout of the auto-switch of this invention;  
         [0010]      FIG. 1C  is a sectional view of an alternate embodiment of the apparatus of the invention showing the chambers, pistons, valves and their connections, switch, and vacuum controllers;  
         [0011]      FIG. 2  is a sectional view of an alternate embodiment of this invention showing two chambers/pistons set side by side (parallel);  
         [0012]      FIG. 3  is a sectional view of an alternate embodiment of this invention showing two different vacuum controllers and without the auto-switch;  
         [0013]      FIG. 4  is a sectional view of an alternate embodiment of this invention showing a single chamber with a volume setter (controller);  
         [0014]      FIG. 5  is a perspective view of different probes/pipes for aspiration and fluid delivery connected to the pump of the present invention. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0015]     The preferred embodiment of the present invention represents a vacuum driven pump for a lavage instrument as shown in  FIGS. 1-5 .  
         [0016]     With reference to  FIG. 1A ,  FIG. 1A  depicts the pump body of the present invention. A cylinder casing  1  has two chambers, the first chamber  2  and the second chamber  3 , which are separated by a wall  4  that is lined up end by end. The first and second chambers  2  and  3  each contain a reciprocating piston, the first piston  5  and the second piston  6  respectively. The first and second pistons  5  and  6  are linked by a rod  7 , which goes through a hole  8  on the separating wall  4 . An elastic cushion  8 A is placed around the hole  8  to maintain the disconnection between the first and second chambers  2  and  3 , but also allows the free movement of the rod  7 . Alternatively, two flexible foldable bags  8 B and  8 C (depicted in  FIG. 1C ), one in each of the first and second chambers  2  and  3 , are used to enclose the rod  7  and the link between the wall  4  and the first and second pistons  5  and  6 . The first and second chambers  2  and  3  each have a port, the first port  9  and the second port  10  respectively, preferably near the separating wall  4 , which is connected alternately to the vacuum source or atmosphere. The first and second ports  9  and  10  are located at either side of the first and second pistons  5  and  6 .  
         [0017]     There are two one-way valves  11 ,  12 ,  13 , and  14  at each end of the cylinder  1 . The first and second chambers  2  and  3  each have two valves: the first and second inlet valves  11  and  13  allow fluid to enter the first and second chambers  2  and  3  respectively; the first and second outlet valves  12  and  14  allow fluid to exit the first and second chambers  2  and  3  respectively.  
         [0018]     With further reference to  FIG. 1A , the following is a description of the operation of the pump body of the present invention. When vacuum is applied to the first chamber  2  through the first port  9 , the second port  10  at the second chamber  3  is now open to atmosphere. The first piston  5  is driven to move from one end of the first chamber  2  to the other end of the first chamber  2 . The second piston  6  at the second chamber  3  simultaneously moves. The movement of the first piston  5  in the first chamber  2  with vacuum draws fluid into the first chamber  2  through the first inlet valve  11 , while the movement of the second piston  6  in the second chamber  3  expels fluid out of the second chamber  3  through the second outlet valve  14 .  
         [0019]     When the vacuum switch connects vacuum to the second port  10  in the second chamber  3 , the first and second pistons  5  and  6  move in opposite directions. Now, the first chamber  2  expels fluid via the first outlet valve  12 , while the second chamber  3  draws fluid via the second inlet valve  13 .  
         [0020]     If the first and second outlet valves  12  and  14  are connected to the same delivery tube  15 , and the first and second inlet valves  11  and  13  are connected to the same liquid source  16 , the fluid is able to flow continuously in and out of the cylinder  1 .  
         [0021]     Further, with reference to  FIG. 1A , the following is a description of the vacuum control of the present invention. Two trumpet valves, the top trumpet valve  17  and the bottom trumpet valve  18 , are each cylindrical in structure, and each slide into a housing  17 A. The top trumpet valve  17  has first, second, and third top holes and channels  19 ,  20 ,  21  and the bottom trumpet valve  18  has first and second bottom holes and channels  22  and  23 . The top and bottom holes and channels match the corresponding first, second, and third housing holes  24 ,  25 , and  26  on the sidewalls of the housing  17 A to communicate to one or two sources. The top and bottom trumpet valves  17  and  18  are able to shuttle between two positions, open or closed, powered by springs, the top and bottom springs  27  and  28 .  
         [0022]     In the event that both the top and bottom trumpet valves  17  and  18  are utilized, both the top and bottom trumpet valves  17  and  18  are normally in the closed position, disconnected from the vacuum source. The bottom trumpet valve  18  connects the vacuum source to the aspiration pipet  29  when the bottom trumpet valve is pushed down until hole and channel  22  matches hole  26 . This configuration is for suction purposes only. The top trumpet valve  17  communicates the vacuum source to both the aspiration pipet  29  and the tube  35  (depicted in  FIG. 1B ) of the driving force of the first and second pistons  9  and  10  when the top trumpet valve  17  is pushed down until hole and channel  19  matches hole  24 , and hole and channel  20  matches hole  25 . This configuration is for the purpose of suction and simultaneous sprinkling.  
         [0023]     In another configuration, in the event that a single trumpet value is utilized, for example the combination of the top trumpet valve  17  or the bottom trumpet valve  18  into a single trumpet valve, the one trumpet valve to function as above can be operated at two levels. The first level, the first position, is suction only (connected to the suction pipet). The second level, the second position, is suction and sprinkling (connected to both the pipet and the pump).  
         [0024]     The delivery tube  15  and the aspiration pipet  29  may be located side-by-side or may be nested, with the delivery tube  15  located inside the aspiration pipet  29 , as shown in  FIG. 1A .  
         [0025]     With reference to  FIG. 1B ,  FIG. 1B  depicts the auto-switch of the cylinder  1  of the present invention. The auto-switch  40  is a means that connects the first and second chambers  2  and  3  to either a vacuum source or the atmosphere alternately.  
         [0026]     The following is the order of the change between vacuum and atmosphere in the first chambers  2 : vacuum to atmosphere to vacuum to atmosphere. The following is the corresponding order of the change between vacuum and atmosphere in the second chamber  3 : atmosphere to vacuum to atmosphere to vacuum. Within a chamber, the following occurs: vacuum to atmosphere to vacuum to atmosphere. These switches from the first and second chambers  2  and  3  and between vacuum and atmosphere are carried out automatically.  
         [0027]     The auto-switch  40  is located between the first chamber  2  and the second chamber  3  at the interface of the separating wall  4  and the body cylinder wall. The auto-switch  40  comprises cylindrical tubing  30  that crosses the separating wall  4  with two opening ends, the first and second ports  9  and  10 . A cylindrical body casing  31  longer than the cylindrical tubing  30 , with both ends closed, but has two side holes, the first and second side holes  32  and  33 , at each end. The first and second side holes  32  and  33  open to common opening  34  that is connected to the tube  35  leading to the vacuum source. The cylindrical body casing  31  also has first and second channels  36  and  37  at each end on the other side of the cylindrical body casing  31  to match the side openings  38  and  39  on the wall of the cylinder casing  1 , near the separating wall  4 , to communicate with the atmosphere.  
         [0028]     Alternatively, the auto-switch  40  can be located in the center of the separating wall  4 . In addition, the auto-switch could also be attached to, a part of, or incorporated with the rod  7 .  
         [0029]     The cylindrical body casing  31  slides into the cylindrical tubing  30 . While the fit of the cylindrical body casing  31  inside the cylindrical tubing  30  is air tight, the cylindrical body casing  31  is still capable of shuttling from left to right. When the cylindrical body casing  31  slides completely into the cylindrical tubing  30  and both ends of the cylindrical body casing  31  and the cylindrical tubing  30  are lined up on one side such as the first chamber  2 , on the other side, the second chamber  3 , the other end of the cylindrical body casing  31  protrudes longer than the cylindrical tubing  30  so the cylindrical body casing  31  is exposed in the second chamber  3 . During this configuration, in the first chamber  2 , the first side hole  32  to the vacuum is closed, but the first channel  36  to the atmosphere is open. Also during this configuration, in the second chamber  3 , the second side hole  33  to the vacuum is open to the second chamber  3 , while the second channel  37  to the atmosphere is disconnected. As a result, when the vacuum controlled  17  connects the vacuum source to the auto-switch, the vacuum force will drive the second piston  6  to move toward the separating wall  4  with an accelerated rate. When the second piston  6  comes to the end and against the extended part of the cylindrical body casing  31 , it will push the cylindrical body casing  31  so that now, the second chamber  3  is even and the first chamber  2  has the extended part of the cylindrical body casing  31 . In the event the vacuum is applied to the first chamber  2 , the opposite will result.  
         [0030]     Alternate embodiments of the present invention are illustrated in  FIGS. 2, 3 ,  4 , and  5 . Specifically  FIG. 2  depicts an alternate embodiment of the present invention with the chambers and corresponding pistons set side by side, in parallel.  FIG. 3  depicts an alternate embodiment of the present invention with different vacuum controllers, trumpet valves, and without the auto-switch.  FIG. 4  depicts an alternate embodiment of the present invention with a single chamber and a volume setter (controller).  FIG. 5  depicts various embodiments of probes/pipes for aspiration and fluid delivery connected to the pump of the present invention.  
         [0031]     Thus, the present invention provides a lavage fluid pump that is lightweight, inexpensive, disposable, easy to make, easy to use, and without need of electric power of batteries. The present invention is low-noise, environmentally friendly, and cost-effective.  
         [0032]     As such the method of making and using the device detailed above constitute the inventor&#39;s preferred embodiment and alternate embodiments to the invention. The inventor is aware that numerous configurations of the device as a whole or some of its constituent parts are available which would provide the desired results. While the invention has been described and illustrated with reference to specific embodiments, it is understood that these other embodiments may be resorted to without departing from the invention. Therefore the form of the invention set out above should be considered illustrative.