Valveless pump

Abstract

A valveless, pulsatile, non-contact, positive displacement, finger-pump for pumping one or more fluids is disclosed. The pump can include one or more channels for holding one or more lengths of flexible tubing. The channels can include an adjustment mechanism and/or a resilient backing plate to reduce over compression of the tubing. The pump can utilize a plurality of profiled, pivoting fingers to sequentially occlude a length of tubing causing a pumping action. The fingers can be moved from the first position to the second position by a motor driven camshaft. Cam lobes disposed on the camshaft can be a modified eccentric design to improve tube occlusion and pump efficiency. At least one cam lobe can completely occlude the tubing at all times during operation to prevent backflow. The fingers can alternatively be moved from the first position to the second position by a variety of linear actuators.

1 . A pump system for pumping one or more fluids comprising:
 a housing comprising:
 a first tubing holder for holding a length of flexible tubing; and 
 a first axle disposed in the housing; 
   a plurality of fingers, each finger comprising an axle hole at a distal end of each finger, wherein each finger is pivotally coupled to the first axle; and   a drive system configured to move each of the plurality of fingers sequentially from a first position to a second position;   wherein each of the fingers at least partially occludes a portion of the flexible tubing in the second position.   
     
     
         2 . The pump system of  claim 1 , wherein each of the fingers substantially completely occludes the portion of the flexible tubing in the second position. 
     
     
         3 . The pump system of  claim 1 , wherein the tubing holder comprises a channel and a plane surface; and
 wherein each of the plurality of fingers compresses the flexible tubing between the finger and the plane surface when the finger is in the second position.   
     
     
         4 . The pump system of  claim 3 , wherein the plane surface further comprises a resilient cover to prevent over compression of the flexible tubing in the second position. 
     
     
         5 . The pump system of  claim 1 , wherein the drive system comprises a camshaft comprising a central shaft and a plurality of cam lobes; and
 a motor for driving the camshaft in a rotary motion.   
     
     
         6 . The pump system of  claim 5 , wherein each of the plurality of cam lobes is a modified eccentric design. 
     
     
         7 . The pump system of  claim 5 , wherein the motor drives the camshaft directly. 
     
     
         8 . The pump system of  claim 5 , wherein the motor drives the camshaft with a belt. 
     
     
         9 . The pump system of  claim 5 , wherein the camshaft further comprises a driven gear mounted to the central shaft; and
 wherein the motor comprises a drive gear mounted to the motor and in communication with the driven gear to drive the camshaft in a rotary motion.   
     
     
         10 . The pump system of  claim 9 , wherein the driven gear comprises a drive gear system comprising two or more gears in communication with each other and with the driven gear to drive the camshaft in a rotary motion. 
     
     
         11 . The pump system of  claim 1 , wherein the drive system comprises a plurality of shape memory alloy (SMA) wires;
 wherein each of the plurality of fingers further comprises:
 a first SMA wire coupled to the finger above the axle hole; and 
 a second SMA wire coupled to the finger below the axle hole; and 
   wherein the first and second SMA wires can be individually activated to move the finger back and forth between the first position and the second position.   
     
     
         12 . The pump system of  claim 11 , wherein the first SMA wire moves the finger from the first position to the second position; and
 wherein the second SMA wire moves the finger from the second position to the first position.   
     
     
         13 . The pump system of  claim 1 , wherein at least one of the plurality of fingers is in the second position at any given time to prevent backflow in the flexible tubing. 
     
     
         14 . The system of  claim 1 , further comprising an inlet connector and an outlet connector for connecting the tubes to the length of flexible tubing;
 wherein the inlet connector comprises an inlet port disposed proximate a top portion of the inlet connector; and   wherein the outlet connector comprises an outlet port disposed proximate a bottom portion of the outlet connector.   
     
     
         15 . A system for pumping two or more fluids comprising:
 a housing, with a first side, a middle, and a second side, comprising:
 a first tubing holder for holding a first flexible tube; 
 a second tubing holder for holding a second flexible tube; 
 a first axle disposed on a first side of the housing; and 
 a second axle disposed on the second side of the housing; 
   a first set of two or more fingers, each finger comprising an axle hole located on a distal end of each finger, wherein each finger is pivotally coupled to the first axle;   a second set of two or more fingers, each finger comprising an axle hole, pivotally coupled to the second axle;   a camshaft, comprising a central shaft and a plurality of cam lobes, disposed in the middle of the housing; and   a motor for driving the camshaft in a rotary motion;   wherein the camshaft sequentially moves the first set of fingers and the second set of fingers from a first position to a second position;   wherein each of the first set of fingers at least partially occludes a portion of the first flexible tubing in the second position;   wherein each of the second set of fingers at least partially occludes a portion of the second flexible tubing in the second position; and   wherein the sequential occlusion of the first and second flexible tubes by the fingers pumps fluid through the tubes.   
     
     
         16 . The system of  claim 15 , wherein the first and second tubes each further comprise an inlet connector and an outlet connector for connecting the tubes to external tubing;
 wherein the inlet connector comprises an inlet port disposed proximate a top portion of the inlet connector; and   wherein the outlet connector comprises an outlet port disposed proximate a bottom portion of the outlet connector.   
     
     
         17 . The system of  claim 16 , wherein the inlet connector further comprises a steeper change in cross-sectional area from a first side to a second side than the outlet connector. 
     
     
         18 . The system of  claim 15 , wherein each cam lobe has a duration angle of between approximately 30 degrees and 180 degrees of rotation. 
     
     
         19 . The system of  claim 15 , wherein each of the fingers further comprises a first shoulder on a first side of the axle hole and a second shoulder on the second side of the axle hole to reduce friction. 
     
     
         20 . The system of  claim 15 , further comprising a washer disposed between each of the fingers to reduce friction. 
     
     
         21 . The system of  claim 15 , wherein the motor is an electric motor. 
     
     
         22 . A method of manufacturing a pump comprising:
 providing a housing with a first end, a second end, a first side, a middle, a second side, and one or more tubing holders;   mounting a first set of one or more fingers on a first axle;   mounting the first axle proximate the first side of the housing;   mounting a camshaft, comprising one or more cam lobes, in the middle of the housing proximate the first set of fingers;   mounting a motor proximate the camshaft to rotate the camshaft;   wherein each of the one or more cam lobes is disposed proximate one of the first set of one or more fingers such that, as the camshaft rotates, each cam lobe activates a respective finger; and   wherein activating the respective finger comprises moving the respective finger from a first, open position to a second closed position.   
     
     
         23 . The method of manufacture of  claim 22 , further comprising:
 mounting a second set of one or more fingers on a second axle;   mounting the second axle proximate the second side of the housing;   wherein each of the one or more cam lobes is disposed proximate one of the first set of one or more fingers and one of the second set of one or more fingers such that, as the camshaft rotates, each cam lobes activates a respective finger from the first set and a respective finger from the second set.   
     
     
         24 . The method of manufacture of  claim 23 , wherein the cam lobes are disposed on the camshaft such that the cam lobes activate the first and second sets of one or more fingers sequentially. 
     
     
         25 . The method of manufacture of  claim 22 , wherein the cam lobes are disposed on the camshaft such that the cam lobes activate the first set of one or more fingers sequentially. 
     
     
         26 . The method of manufacture of  claim 22 , further comprising:
 affixing a drive gear to the motor; and   affixing a driven gear to the camshaft;   wherein the drive gear rotates the driven gear.   
     
     
         27 . The method of manufacture of  claim 22 , wherein motor is directly attached to the camshaft. 
     
     
         28 . The method of manufacture of  claim 22 , wherein the motor and the camshaft are coupled using a drive belt. 
     
     
         29 . The method of manufacture of  claim 22 , wherein the housing further comprises a first adjustment means to enable the distance between the tubing holder and the camshaft to be adjusted. 
     
     
         30 . The method of manufacture of  claim 22 , wherein the housing further comprises a second adjustment means to enable the height of the camshaft to be adjusted. 
     
     
         31 . The method of manufacture of  claim 22 , wherein the first and second sides of the housing are coupled to the housing with hinges to enable insertion of tubing in the tubing holders. 
     
     
         32 . The method of manufacture of  claim 31 , wherein the hinges are independently adjustable to enable different sizes of tubing to be inserted in the tubing holders.