System for removing undesirable elements from blood using a first wash step and a second wash step

Abstract

A system for removing undesirable elements from blood. The system includes a centrifuge bowl to separate the blood into components according to relative densities of the components, a pump to provide wash solution that washes the blood in the centrifuge bowl, and a controller to wash the blood in the centrifuge bowl in a first wash and remove first undesirable elements and to wash the blood in the centrifuge bowl in a second wash and remove trapped undesirable elements. The controller to further mix the blood and the wash solution in the centrifuge bowl and provide diluted blood, separate the diluted blood into concentrated blood and the wash solution, fill the centrifuge bowl with previously concentrated blood to build a buffy coat, and empty the centrifuge bowl of the concentrated blood and the previously concentrated blood after the buffy coat is reached.

We claim: 
     
         1 . A system for removing undesirable elements from blood, comprising:
 a centrifuge bowl configured to separate the blood into components including the undesirable elements according to relative densities of the components;   a pump to provide a wash solution that washes the blood in the centrifuge bowl; and   a controller operatively connected to the centrifuge bowl and the pump, the controller programmed to control the centrifuge bowl and the pump to:
 fill the centrifuge bowl with the blood and separate the blood into the components according to the relative densities of the components; 
 add a first amount of the wash solution with the pump to wash the blood in the centrifuge bowl in a first wash step to remove a portion of the undesirable elements and to obtain a first concentrated blood component; 
 mix the first concentrated blood component and a remaining amount of the wash solution with the centrifuge bowl to provide a diluted blood component; 
 remove a portion of the diluted blood component from the centrifuge bowl such that the centrifuge bowl is partially full; 
 separate the diluted blood component into a second concentrated blood component and the remaining amount of the wash solution with the centrifuge bowl; 
 fill the centrifuge bowl with a previously concentrated blood component from a container with the pump; and 
 empty the centrifuge bowl of the second concentrated blood component and the previously concentrated blood component from the container with the pump. 
   
     
     
         2 . The system of  claim 1 , wherein the controller further controls the centrifuge bowl and the pump to add a second amount of the wash solution with the pump to wash the blood in the centrifuge bowl in a second wash step prior to emptying the centrifuge bowl of the second concentrated blood component and the previously concentrated blood component. 
     
     
         3 . The system of  claim 2 , wherein the controller controls at least one of the centrifuge bowl and the pump to provide a first wash speed in the first wash step and a second wash speed in the second wash step, such that the second wash speed is greater than the first wash speed. 
     
     
         4 . The system of  claim 1 , wherein the controller further controls the centrifuge bowl and the pump to remove a pre-wash portion of the undesirable elements prior to the first wash step. 
     
     
         5 . The system of  claim 1 , wherein the centrifuge bowl includes a collector that traps trapped undesirable elements under the collector prior to the first wash step. 
     
     
         6 . The system of  claim 1 , wherein the centrifuge bowl includes a central tube such that the central tube is filled with air in the first wash step and the wash solution in the second wash step flows through the central tube. 
     
     
         7 . The system of  claim 1 , wherein the controller stops at least one of the centrifuge bowl from spinning and the pump to mix the first concentrated blood component and the remaining amount of the wash solution in the centrifuge bowl and provide the diluted blood component. 
     
     
         8 . The system of  claim 1 , wherein the controller further controls the pump to remove the portion of the diluted blood component from the centrifuge bowl and restore air balance in the centrifuge prior to separating the diluted blood component. 
     
     
         9 . A system for removing undesirable elements from blood, comprising:
 a centrifuge bowl configured to separate the blood into components including the undesirable elements according to relative densities of the components;   a pump to provide a wash solution that washes the blood in the centrifuge bowl; and   a controller operatively connected to the centrifuge bowl and the pump, the controller programmed to control the centrifuge bowl and the pump to:
 fill the centrifuge bowl with the blood and separate the blood into the components according to the relative densities of the components; 
 add a first amount of the wash solution with the pump to wash the blood in the centrifuge bowl in a first wash step to remove a portion of the undesirable elements and to obtain a first concentrated blood component and a diluted blood component; 
 remove a portion of the diluted blood component from the centrifuge bowl such that the centrifuge bowl is partially full; 
 separate the diluted blood component into a second concentrated blood component and a remaining amount of the wash solution with the centrifuge bowl; 
 fill the centrifuge bowl with a previously concentrated blood component from a container with the pump; and 
 empty the centrifuge bowl of the second concentrated blood component and the previously concentrated blood component from the container with the pump. 
   
     
     
         10 . The system of  claim 9 , wherein the controller further controls the centrifuge bowl and the pump to mix the first concentrated blood component and the remaining amount of the wash solution with the centrifuge bowl to provide the diluted blood component. 
     
     
         11 . The system of  claim 10 , wherein the controller stops at least one of the centrifuge bowl from spinning and the pump to mix the first concentrated blood component and the remaining amount of the wash solution with the centrifuge bowl to provide the diluted blood component. 
     
     
         12 . The system of  claim 9 , wherein the controller further controls the centrifuge bowl and the pump to add a second amount of the wash solution with the pump to wash the blood in the centrifuge bowl in a second wash step prior to emptying the centrifuge bowl of the second concentrated blood component and the previously concentrated blood component. 
     
     
         13 . The system of  claim 12 , wherein the controller controls at least one of the centrifuge bowl and the pump to provide a first wash speed in the first wash step and a second wash speed in the second wash step, such that the second wash speed is greater than the first wash speed. 
     
     
         14 . The system of  claim 9 , wherein the controller further controls the centrifuge bowl and the pump to remove a pre-wash portion of the undesirable elements prior to the first wash step. 
     
     
         15 . A method for removing undesirable elements from blood, comprising:
 filling a centrifuge bowl with the blood;   separating the blood into components according to relative densities of the components using the centrifuge bowl;   adding a first amount of the wash solution to the centrifuge bowl using a pump;   washing the blood in the centrifuge bowl in a first wash step to remove a portion of the undesirable elements and to obtain a first concentrated blood component;   mixing the first concentrated blood component and a remaining amount of the wash solution with the centrifuge bowl to provide a diluted blood component;   removing a portion of the diluted blood component from the centrifuge bowl such that the centrifuge bowl is partially full;
 separating the diluted blood component into a second concentrated blood component and the remaining amount of the wash solution with the centrifuge bowl; 
   filling the centrifuge bowl with a previously concentrated blood component from a container with the pump; and   emptying the centrifuge bowl of the second concentrated blood component and the previously concentrated blood component from the container with the pump.   
     
     
         16 . The method of  claim 15 , further comprising:
 adding a second amount of the wash solution to the centrifuge bowl using the pump prior to emptying the centrifuge bowl of the second concentrated blood component and the previously concentrated blood component; and   washing the blood in the centrifuge bowl in a second wash step prior to emptying the centrifuge bowl of the second concentrated blood component and the previously concentrated blood component.   
     
     
         17 . The method of  claim 16 , further comprising providing a first wash speed in the first wash step and a second wash speed in the second wash step, such that the second wash speed is greater than the first wash speed. 
     
     
         18 . The method of  claim 15 , further comprising removing a pre-wash portion of the undesirable elements prior to the first wash step. 
     
     
         19 . The method of  claim 15 , wherein mixing the first concentrated blood component and a remaining amount of the wash solution comprises stopping at least one of the centrifuge bowl from spinning and the pump to mix the first concentrated blood component and the remaining amount of the wash solution in the centrifuge bowl and provide the diluted blood component. 
     
     
         20 . The method of  claim 15 , further comprising removing the portion of the diluted blood component and restoring air balance in the centrifuge prior to separating the diluted blood component.