Methods, systems, and kits for the extracorporeal processing of blood

• US 20010021817A1
• Filed: 05/21/2001
• Published: 09/13/2001
• Est. Priority Date: 02/11/1998
• Status: Abandoned Application

• Current Assignee: Vasca Inc.
• Original Assignee: Vasca Inc.
• Inventors: Brugger, James M., Burbank, Jeffrey H., Finch, Charles David
• Application Number:
  US09/862,207
• Publication Number:
  US 20010021817A1
• Time in Patent Office: Days
• US Class Current: 604/6.11
• CPC Class Codes: A61M 1/3626 Gas bubble detectors
• CPC Class Codes: A61M 1/3663 Flow rate transducers; Flow integrators
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/279 Peristaltic pumps, e.g. roller pumps
• CPC Class Codes: A61M 60/438 the force acting on the blood contacting member being mechanical
• CPC Class Codes: A61M 60/523 using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/546 of blood flow, e.g. by adapting rotor speed

Abstract

Methods, systems, and kits for extracorporeally circulating and processing blood are described. The systems include a pump, a processing unit, and blood drawn return lines for accessing a patient'"'"'s vasculature. Blood flow through the return line is measured and pump speed controlled to maintain a desired blood flow rate. Alarm conditions can be initiated when expected pump performance differs from that needed to maintain the control point flow rate. By using a ultrasonic flow detector, gas bubbles in the blood flow can be detected.

Claims

1. A method for extracorporeally processing blood, said method comprising:

drawing blood from a patient;

pumping the blood with a pump at a predetermined blood flow rate;

measuring an actual blood flow rate delivered by the pump;

comparing the actual blood flow rate with the predetermined blood flow rate; and

adjusting the blood flow rate delivered by the pump.

2. The method of

claim 1

, further comprising the step of signaling an alarm condition if a difference of a predetermined minimum value exists.

3. The method of

claim 1

, wherein the actual blood flow rate is directly measured.

4. The method of

claim 1

, wherein the step of pumping the drawn blood with a pump at a predetermined blood flow rate includes pumping the drawn blood with a pump at a predetermined stroke volume and blood flow rate.

5. The method of

claim 1

, wherein the drawn blood is pumped at a blood flow rate that corresponds to a theoretical pumped blood flow rate.

6. The method of

claim 1

, wherein the pump is a peristaltic pump.

7. The method of

claim 1

, further comprising the step of slowing or stopping pump operation when said difference has said predetermined minimum value.

8. The method of

claim 1

wherein the measuring step comprises ultrasonically measuring the flow rate using a sensor disposed externally to the blood flow.