Abstract: To monitor an extracorporeal blood circuit during extracorporeal blood treatment, the arterial pressure and venous pressure in the arterial branch and venous branch of the extracorporeal circuit are measured by pressure sensors, and the sum Ps and the difference ?P of the arterial pressure and/or venous pressure measured at the same time are calculated. A possible error state is indicated when the sum Ps and/or difference ?P lie outside predetermined limit value windows A and B. To reduce the susceptibility to error, a check is preferably also made to ascertain whether the two above conditions are satisfied for n successive measurements.

Abstract: The present invention relates to a device and a method for monitoring an access to a patient, in particular a vascular access in extracorporeal blood treatment, in which a patient's blood is withdrawn from the patient via an arterial conduit and is returned to the patient via a venous conduit. In the device according to the present invention and in the method according to the present invention, an alternating voltage signal, relative to a common ground potential, is coupled in and out of the arterial and venous conduits, and the blood flowing through the arterial and venous conduits is at ground potential. In this way, disturbances, which can be attributed particularly to movements of the conduits, are reduced.

Abstract: The present invention relates to a device and a method for monitoring a patient access, in particular a vascular access in extracorporeal blood treatment, in which a patient's blood is withdrawn from the patient via an arterial conduit and is returned to the patient via a venous conduit. The blood is conveyed by a blood pump, preferably an occlusive blood pump, such as a roller pump. To monitor the vascular access, the electrical AC voltage and/or the alternating current and/or a derived electrical measured variable that is generated by electrostatic charges during operation of the occlusive peristaltic pump is monitored. If the triboelectric AC voltage generated by the blood pump and/or the alternating current and/or the derived electrical measured variable lies within predetermined limits, this indicates that the vascular access is faulty.

Abstract: The present invention relates to a device and a method for monitoring an access to a patient, in particular a vascular access in extracorporeal blood treatment, in which a patient's blood is withdrawn from the patient via an arterial conduit and is returned to the patient via a venous conduit. In the device according to the present invention and in the method according to the present invention, an alternating voltage signal, relative to a common ground potential, is coupled in and out of the arterial and venous conduits, and the blood flowing through the arterial and venous conduits is at ground potential. In this way, disturbances, which can be attributed particularly to movements of the conduits, are reduced.

Abstract: To monitor an extracorporeal blood circuit during extracorporeal blood treatment, the arterial pressure and venous pressure in the arterial branch and venous branch of the extracorporeal circuit are measured by pressure sensors, and the sum Ps and the difference ?P of the arterial pressure and/or venous pressure measured at the same time are calculated. A possible error state is indicated when the sum Ps and/or difference ?P lie outside predetermined limit value windows A and B. To reduce the susceptibility to error, a check is preferably also made to ascertain whether the two above conditions are satisfied for n successive measurements.

Abstract: The present invention relates to a device for monitoring a patient access, in particular a vascular access in extracorporeal blood treatment. The device is used to establish a substantially parallel connection between the arterial and venous tubes, or the arterial and venous puncture needles. If the venous needle slips out of the vascular access, the arterial cannula is forcibly withdrawn. This incident is reliably detected by the known protection systems which monitor the pressure in the arterial tube and/or an air intake. In addition, the present invention relates to an extracorporeal blood treatment device and to a method for monitoring a patient access, wherein the venous and arterial tubes or the puncture needles are connected to each other.

Abstract: A method and a device for determining the blood flow QF in a vascular access (F) during an extracorporeal blood treatment is described, where the blood enters the blood treatment unit (3) of the blood treatment machine through an arterial branch (19) of an extracorporeal circulation loop (2) which is in fluid connection with the vascular access at an arterial connection. The blood is returned through a venous branch (21) of the extracorporeal circulation, which is in fluid connection with the vascular access at a venous connection (13). The blood flow in the vascular access is determined by measuring the pressure part, pven, in the arterial and/or venous branch of the extracorporeal circulation when the vascular access is open and interrupted, while the extracorporeal blood flow QB is varied. Then the fistula flow QF is determined from the measured values for the arterial and/or venous pressure while the vascular access is open and interrupted.

Abstract: A method and a device for determining the blood flow QF in a vascular access (F) during an extracorporeal blood treatment is described, where the blood enters the blood treatment unit (3) of the blood treatment machine through an arterial branch (19) of an extracorporeal circulation loop (2) which is in fluid connection with the vascular access at an arterial connection. The blood is returned through a venous branch (21) of the extracorporeal circulation, which is in fluid connection with the vascular access at a venous connection (13). The blood flow in the vascular access is determined by measuring the pressure part, pven, in the arterial and/or venous branch of the extracorporeal circulation when the vascular access is open and interrupted, while the extracorporeal blood flow QB is varied. Then the fistula flow QF is determined from the measured values for the arterial and/or venous pressure while the vascular access is open and interrupted.

Abstract: A method and a device for determining the blood flow QF in a vascular access (F) during an extracorporeal blood treatment is described, where the blood enters the blood treatment unit (3) of the blood treatment machine through an arterial branch (19) of an extracorporeal circulation loop (2) which is in fluid connection with the vascular access at an arterial connection. The blood is returned through a venous branch (21) of the extracorporeal circulation, which is in fluid connection with the vascular access at a venous connection (13). The blood flow in the vascular access is determined by measuring the pressure Part, Pven, in the arterial and/or venous branch of the extracorporeal circulation when the vascular access is open and interrupted, while the extracorporeal blood flow QB is varied. Then the fistula flow QF is determined from the measured values for the arterial and/or venous pressure while the vascular access is open and interrupted.

Abstract: A method and device for monitoring a vascular access during a dialysis treatment in which the pressures in both the arterial and venous branches of the extracorporeal blood system are monitored by pressure sensors. Characteristic values for the condition of the vascular access are calculated in a computer unit from the pressures in the arterial and venous branches of the extracorporeal system, and these values are analyzed in an analyzer unit to detect a defective vascular access.

Abstract: A method and device for monitoring a vascular access during a dialysis treatment in which the pressures in both the arterial and venous branches of the extracorporeal blood system are monitored by pressure sensors. Characteristic values for the condition of the vascular access are calculated in a computer unit from the pressures in the arterial and venous branches of the extracorporeal system, and these values are analyzed in an analyzer unit to detect a defective vascular access.

Abstract: A method and device for monitoring a vascular access during a dialysis treatment in which the pressures in both the arterial and venous branches of the extracorporeal blood system are monitored by pressure sensors. Characteristic values for the condition of the vascular access are calculated in a computer unit from the pressures in the arterial and venous branches of the extracorporeal system, and these values are analyzed in an analyzer unit to detect a defective vascular access.