Apparatus for extracorporeal blood treatment and a control method therefor
First Claim
1. An apparatus for extracorporeal blood treatment comprising:
- at least a treatment unit having at least a first chamber and at least a second chamber separated from one another by a semipermeable membrane;
at least a blood removal line connected to an inlet port of a first chamber and predisposed to remove blood from a patient;
at least a blood return line connected to an outlet port from the first chamber and predisposed to return treated blood to the patient;
at least an expansion chamber placed at least in one of the blood removal line and the blood return line, the expansion chamber being arranged in use to contain a predetermined quantity of gas in an upper portion and a predetermined quantity of blood at a predetermined level in a lower portion, the blood removal line, the blood return line, the first chamber and the at least an expansion chamber being part of an extracorporeal blood circuit;
at least a blood pump operating at the extracorporeal blood circuit such as to move the blood in the circuit;
at least a pressure sensor associated to the expansion chamber and configured such as to enable determining pressure values internally of the expansion chamber;
at least a fluid evacuation line connected to an outlet port of the second chamber;
a control unit connected to the at least a pressure sensor, with the pump, and configured to;
move the blood pump such as to generate a variable blood flow comprising a constant flow component of a desired blood flow value and a variable flow component having a substantially nil mean value, the variable blood flow generating at least in the expansion chamber a pressure progression that is variable in time comprising a pressure component oscillating about a mean value;
receive from the at least a sensor a plurality of pressure values for a time period comprising a plurality of pressure oscillations about the means value, the pressure values being measured at successive time instants;
calculate, as a function of the pressure values, a control value that is representative of the oscillating pressure component,compare the control value representing the oscillating pressure component with a reference threshold, anddetermine, following the comparison, the occurrence or not of a condition of variation of the blood level in the expansion chamber.
1 Assignment
0 Petitions
Accused Products
Abstract
An apparatus is described for extracorporeal blood treatment (1), comprising a treatment unit (2), an extracorporeal blood circuit (8) and a fluid evacuation line (10). The apparatus comprises a control unit (21) connected with a pressure sensor (13, 14) and with a blood pump (9) and configured to move the blood pump (9), generating a variable flow with a constant component equal to a desired blood flow value and a variable component having a nil mean value; the variable flow generates, in the expansion chamber (11, 12), a progression of the pressure that is variable over time (P(t)) with a pressure component (ΔP) oscillating about a mean value (Pavg). The control unit receives, from the sensor, a plurality of values (Pj) over a period of time (T) comprising a plurality of oscillations of the pressure about the mean value and calculates, according to the pressure values (Pj), a control value that is representative of the oscillating pressure component (ΔP) and then compares the control value with a reference threshold to determine the verification or not of a condition of variation of the blood level in the expansion chamber (11; 12).
-
Citations
18 Claims
-
1. An apparatus for extracorporeal blood treatment comprising:
-
at least a treatment unit having at least a first chamber and at least a second chamber separated from one another by a semipermeable membrane; at least a blood removal line connected to an inlet port of a first chamber and predisposed to remove blood from a patient; at least a blood return line connected to an outlet port from the first chamber and predisposed to return treated blood to the patient; at least an expansion chamber placed at least in one of the blood removal line and the blood return line, the expansion chamber being arranged in use to contain a predetermined quantity of gas in an upper portion and a predetermined quantity of blood at a predetermined level in a lower portion, the blood removal line, the blood return line, the first chamber and the at least an expansion chamber being part of an extracorporeal blood circuit; at least a blood pump operating at the extracorporeal blood circuit such as to move the blood in the circuit; at least a pressure sensor associated to the expansion chamber and configured such as to enable determining pressure values internally of the expansion chamber; at least a fluid evacuation line connected to an outlet port of the second chamber; a control unit connected to the at least a pressure sensor, with the pump, and configured to; move the blood pump such as to generate a variable blood flow comprising a constant flow component of a desired blood flow value and a variable flow component having a substantially nil mean value, the variable blood flow generating at least in the expansion chamber a pressure progression that is variable in time comprising a pressure component oscillating about a mean value; receive from the at least a sensor a plurality of pressure values for a time period comprising a plurality of pressure oscillations about the means value, the pressure values being measured at successive time instants; calculate, as a function of the pressure values, a control value that is representative of the oscillating pressure component, compare the control value representing the oscillating pressure component with a reference threshold, and determine, following the comparison, the occurrence or not of a condition of variation of the blood level in the expansion chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
Specification