Patent ID: 7824354
Filing Date: 2010-11-02
Classification: A61M,F04B

Abstract:
1. An apparatus for controlling blood flow in an extracorporeal blood circuit, wherein said extracorporeal blood circuit has at least one blood treatment unit, at least one access branch extending between a blood collection area, where blood is collected from a patient, and the at least one blood treatment unit, at least one peristaltic pump associated for operation with said access branch of the extracorporeal blood circuit, and at least one return branch extending between the at least one blood treatment unit and a blood return area, where the blood is returned to the patient, said equipment comprising: at least a first sensor means for measuring an arterial pressure in a portion of said at least one access branch upstream of the at least one peristaltic pump and for generating a corresponding first output signal proportional to said arterial pressure; at least a second sensor means for measuring an angular velocity of the at least one peristaltic pump and for generating a corresponding second output signal proportional to the angular velocity of said at least one peristaltic pump; a memory means for storing at least one set flow value of a desired blood flow through said access branch, measured values of arterial pressure and angular velocity, and a calibration function in accordance with at least the following variables: v v v at least one control unit, operatively coupled to said first and second sensor means for receiving said first and second output signals and for storing corresponding measured values of arterial pressure and angular velocity in said memory means, said control unit including means for sequentially executing a control procedure, the means for sequentially executing the control procedure comprising: means for calculating an actual flow value by applying said calibration function to the corresponding measured values of arterial pressure and angular velocity; means for comparing said actual flow value with said at least one set flow value; means for comparing the angular velocity with an acceptable maximum angular velocity value which can be imparted to the at least one peristaltic pump; and means for varying the angular velocity of said at least one peristaltic pump if the difference between the actual flow and the desired blood flow lies outside a predetermined range.