Wearable Ultrafiltration Devices Methods and Systems

Abstract

A wearable ultrafiltration apparatus is provided. The apparatus can include a first ultrafilter for filtering a patient's blood along a first fluid path and a second ultrafilter for filtering the patient's blood along a second fluid path. The apparatus can also include a valve being positionable in a first position for directing the patient's blood along the first fluid path. The valve can also be positioned in a second position for directing the patient's blood along the second fluid path. When the valve is in the first position, blood can flow along the first fluid path and prevent blood from flowing along the second fluid path. When the valve is in the second position, blood can flow along the second fluid path and prevent blood from flowing along the first fluid path. When the valve is in the first position, the second ultrafilter can be idle and capable of being serviced or replaced and when the valve is in the second position, the first ultrafilter can be idle and capable of being serviced or replaced. Therefore, when a ultrafilter fouls, blood can be directed to the other ultrafilter while the fouled ultrafilter is being serviced or replaced.

What is claimed is: 
     
         1 . A method for maintaining volume homeostasis in a patient comprising:
 providing a wearable ultrafiltration device;   drawing blood from the patient into the wearable ultrafiltration device at a predetermined continuous rate;   filtering the patient's blood using the ultrafiltration device to create filtered blood; and   returning the filtered blood back to the patient.   
     
     
         2 . The method of  claim 1 , further comprising the step of providing a first ultrafilter for filtering the patient's blood along a first fluid path, a second ultrafilter for filtering the patient's blood along a second fluid path, and further comprising the step of directing blood along the second fluid path when the first dialyzer is inoperable to provide uninterrupted filtering of the patient's blood. 
     
     
         3 . The method of  claim 1 , further comprising the step of directing filtrate out of the wearable ultrafiltration device and into a disposable bag. 
     
     
         4 . The method of  claim 1 , further comprising the step of filtering the patient's blood continuously for at least seventy-two hours between in-center dialyses visits. 
     
     
         5 . The method of  claim 1 , further comprising the step of controlling the predetermined rate of filtrate generation using a resistor clamp connected downstream of the first and second ultrafilters. 
     
     
         6 . The method of  claim 1 , further comprising the step of controlling the predetermined rate of blood flow using a pump. 
     
     
         7 . A pump for drawing a patient's blood into a device comprising:
 a first and a second tube containing the patient's blood positioned on opposing sides of the pump;   a blade electrically operated by a motor and positioned between the first and second tubes;   a first pusher plate positioned between the first tube and a first side of the blade; and   a second pusher plate positioned between the second tube and a second side of the blade;   wherein when the blade rotates, the blade contacts the first pusher plate which contacts the first tube to release the patient's blood from the first tube;   wherein when the blade rotates, the blade contacts the second pusher plate which contacts the second tube to release the patient's blood from the second tube.   
     
     
         8 . The pump of  claim 7 , further comprising a plurality of check valves connected to the first and second tubes. 
     
     
         9 . The pump of  claim 7 , wherein the first pusher plate contacts the first tube at the same time as when the second pusher plate contacts the second tube and wherein upon further rotation of the blade, the first pusher plate releases pressure against the first tube and the second pusher plate releases pressure against the second tube and wherein the release of pressure against the first tube and the second tube forms a partial vacuum within the first tube and the second tube which causes more of the patient's blood to be drawn into the first tube and the second tube and wherein upon rotation of the blade, the exertion and release of pressure against the first tube and the second tube causes two pulses of fluid to be pumped for each full rotation of the blade. 
     
     
         10 . A wearable ultrafiltration apparatus, comprising:
 a first ultrafilter for filtering a patient's blood along a first fluid path;   a second ultrafilter for filtering the patient's blood along a second fluid path; and   a valve being positionable in a first position for directing the patient's blood along the first fluid path and being positionable in a second position for directing the patient's blood along the second fluid path;   wherein when the valve is in the first position, blood flows along the first fluid path and is prevented from flowing along the second fluid path and when the valve is in the second position, blood flows along the second fluid path and is prevented from flowing along the first fluid path;   wherein when the valve is in the first position, the second ultrafilter is idle and capable of being serviced or replaced, and when the valve is in the second position, the first ultrafilter is idle and capable of being serviced or replaced; and   wherein the valve includes a first pinch valve for directing blood along the first fluid path and a second pinch valve for directing blood along a second fluid path and wherein the first fluid path and the second fluid path converge at a Y connector before the patient's blood is returned to the patient.   
     
     
         11 . The apparatus of  claim 10 , wherein the first fluid path includes a third pinch valve for directing blood flow to the Y connector and the second fluid path includes a fourth pinch valve for directing blood flow to the Y connector. 
     
     
         12 . The apparatus of  claim 11 , wherein when the valve is in the first position, the first and third pinch valves are in an open position to direct blood flow along the first fluid path and the second and fourth pinch valves are in a closed position to prevent blood flow along the second fluid path and wherein when the valve is in the second position, the second and fourth pinch valves are in an open position for directing blood flow along the second fluid path and the first and third pinch valves are in a closed position for preventing blood flow along the first fluid path.