摘要:
A method of sensing the detachment of the venous needle (13) from a patient (P) during an extracorporeal blood treatment in a dialysis machine (1) having an extracorporeal blood circuit (2), in which an electric current is made to flow along a closed-loop path (P1) of an electrical circuit (37) formed by an electrical line (21, 22, 23) external to the extracorporeal circuit (2), a portion of extracorporeal circuit (2) directly connected to the venous needle (13), and the patient (P); a signal correlated with the electric current along the electrical line (21, 22, 23) is detected; and the signal is compared with a threshold value by means of a control unit (15).
摘要:
In an extracorporeal blood treatment system, non-treated blood may be withdrawn from a patient through an arterial line connected to a first compartment of a blood treatment apparatus. The blood treatment apparatus also includes a second compartment separated from the first component by a semi-permeable membrane. Treated blood may be returned to the patient through a venous line connected to the second compartment. In order to determine blood recirculation, i.e., a mixture of treated blood and non-treated blood in the arterial line, the ultrafiltration rate of plasma water through the semi permeable membrane of the treatment apparatus may be temporarily increased or decreased, and the resulting variation of the blood concentration, i.e., of the ratio of the volume of the plasma volume to the blood volume, is determined. The extent of the mixture of the treated blood and the non-treated blood in the arterial line may then be calculated as a function of the blood flow rate in the treatment apparatus, of the amplitude of the variation of the ultrafiltration rate, and of at least two values of the blood concentration, determined before and during the variation of the ultrafiltration flow rate, respectively.
摘要:
A device for monitoring the access to the cardiovascular system of a patient undergoing an extracorporeal treatment of blood in a machine (1) comprising a treatment device (4) and an extracorporeal circuit (2), comprises: a voltage generator (16) for generating a potential difference between a part of the machine (1) and a first point (B) of a venous branch (8) of the extracorporeal circuit (2), connecting the patient to the treatment device (4); a detector (17) for detecting the value (dV) of a quantity that correlates with the electric current along at least one section (10a; 10b; 10c) of the venous branch (10) between the first point (B) and a venous needle (13) fitted at the end of the venous branch (8) and inserted in the vascular system of the patient (P); calculating means (15) for comparing the detected value (dV) with a reference range (I).