Peristaltic pump assembly

Abstract

A peristaltic pump assembly includes a cassette configured to be operatively engaged with a pump housing. A roller assembly is operatively disposed within a cavity formed into the cassette. The roller assembly includes a plurality of rollers that may be arranged in a planetary configuration around a drive shaft. At least one guide element is disposed about the periphery of the roller assembly and in engagement with at least a portion of an outer surface of each of the plurality of rollers. The guide element is configured to guide the plurality of rollers when the plurality of rollers is rotating.

1 . A peristaltic pump assembly, comprising:
 a cassette configured to be operatively engaged with a pump housing, wherein the cassette includes a cavity formed therein;   a roller assembly operatively disposed within the cavity of the cassette, the roller assembly including a plurality of rollers arranged around a drive shaft, wherein each of the plurality of rollers includes an outer surface; and   at least one guide element disposed about at least a portion of a periphery of the roller assembly and in engagement with at least a portion of the outer surface of each of the plurality of rollers.   
   
   
       2 . The assembly as defined in  claim 1  wherein the at least one guide element is a continuous member. 
   
   
       3 . The assembly as defined in  claim 1  wherein the at least one guide element surrounds the entire periphery of the roller assembly. 
   
   
       4 . The assembly as defined in  claim 1  wherein the at least one guide element is one of a ring or a washer. 
   
   
       5 . The assembly as defined in  claim 1  wherein the at least one guide element is fabricated from elastomeric materials. 
   
   
       6 . The assembly as defined in  claim 1 , wherein the at least one guide element is fabricated from an elastomeric material configured to stretch a predetermined amount beyond its relaxed state so as to minimize the normal force created. 
   
   
       7 . The assembly as defined in  claim 6  wherein the predetermined amount is about 5%. 
   
   
       8 . The assembly as defined in  claim 5  wherein the elastomeric materials are polymeric materials selected from silicones, natural or synthetic rubbers, and combinations thereof. 
   
   
       9 . The assembly as defined in  claim 1  wherein the roller assembly rotates as a single unit while the at least one guide element is disposed about the periphery thereof. 
   
   
       10 . The assembly as defined in  claim 1  wherein each of the plurality of rollers includes an axis of rotation such that each roller rotates individually while the at least one guide element is disposed about the periphery of the roller assembly. 
   
   
       11 . The peristaltic pump assembly as defined in  claim 1  wherein the outer surface of each of the plurality of rollers is configured to retain the at least one guide element. 
   
   
       12 . The assembly as defined in  claim 1  wherein the at least one guide element is configured to guide the plurality of rollers when the plurality of rollers is rotating, and wherein the at least one guide element is an O-ring. 
   
   
       13 . The assembly as defined in  claim 1  wherein each of the plurality of rollers has two opposed ends and at least one radial flange protruding outwardly from at least one of the two opposed ends, and wherein the at least one radial flange is configured to retain the at least one guide element. 
   
   
       14 . The assembly as defined in  claim 1  wherein each of the plurality of rollers has two opposed ends and at least one annular notch defined in each of the rollers substantially adjacent at least one of the two opposed ends, and wherein the at least one annular notch is configured to retain the at least one guide element. 
   
   
       15 . A method for guiding a plurality of rollers for a peristaltic pump, the peristaltic pump including a drive shaft, the method comprising:
 arranging the plurality of rollers around the drive shaft, wherein each of the plurality of rollers includes an outer surface;   disposing at least one guide element about a periphery of the arranged plurality of rollers and in engagement with at least a portion of the outer surface of each of the plurality of rollers; and   rotating the drive shaft to impart rotational movement to the roller assembly.   
   
   
       16 . The method as defined in  claim 15 , further comprising configuring the outer surface of each of the plurality of rollers to retain the at least one guide element. 
   
   
       17 . The method as defined in  claim 15 , further comprising guiding the plurality of rollers when the plurality of rollers is rotating, wherein the at least one guide element is an O-ring. 
   
   
       18 . The method as defined in  claim 15 , further comprising maintaining frictional contact between the plurality of rollers and the drive shaft. 
   
   
       19 . The method as defined in  claim 15 , further comprising:
 rotating the roller assembly as a single unit while the at least one guide element is disposed about the periphery thereof; and   rotating the plurality of rollers individually while the at least one guide element is disposed about the periphery of the roller assembly.   
   
   
       20 . The method as defined in  claim 18  wherein frictional contact between the plurality of rollers and the drive shaft is maintained by the guiding of the plurality of rollers.