Patent ID: 9533088
Date: 2017-01-03
CPC Classifications: A61M,Y10T

Claim:
1. A flow reversing device for performing blood treatment, comprising: a flow reversing actuator that receives and engages a disposable tubing set with multiple tubing branches which form forward and reverse blood flow paths respectively when blood the flow reversing actuator is selectively changed between forward and reverse configurations, the shape of the tubing being such that during forward operation, dead regions of non-flowing blood are defined; said dead regions including portions of said tubing branches of a predefined volume; and a controller, operatively connected to the flow reversing actuator, the controller configured to operate in a forward mode and at first times, for first intervals sufficient at a first frequency to cause said reversing actuator to clear the dead regions by displacing blood of said predefined volume, and at second times for second intervals at a second frequency to test for leaks by reversing the flow of blood for a period of time sufficient to cause air to be drawn into the tubing set and conveyed to an air sensor, thereby to indicate a leak; where the first intervals are shorter than the second, the first frequency is greater than the second frequency.