Abstract:
A method of checking and/or monitoring the correct operation of an adding device of a medical apparatus includes detecting a characteristic signal course being generated by the adding device. The medical apparatus includes an extracorporeal circuit with which the adding device is connected such that an agent can be introduced into the extracorporeal circuit via the adding device. The pressure loss in the extracorporeal circuit is measured and evaluated for checking and/or monitoring the correct operation of the adding device. The adding device for this purpose generates an oscillating pressure course.
Abstract:
The present invention relates to a method and a device for monitoring a blood treatment unit, subdivided by a semipermeable membrane into a blood chamber and a dialysis liquid chamber, of an extra-corporeal blood treatment device, which comprises an extra-corporeal blood circuit having an arterial branch leading to the blood chamber of the blood treatment unit, a venous branch, which extends away from the blood chamber, and a dialysis fluid system, in which the dialysis liquid chamber is arranged. The method according to the present invention and the device according to the present invention are based on the idea that the change of the flow resistance of the dialysis machine is determined based on two measurements, wherein an oscillating pressure signal in the extra-corporeal blood circuit or in the dialysis fluid system is measured before and after the change of the substitution rate and/or ultrafiltration rate, with which the substitute is applied to, or ultrafiltrate is removed from, the blood flowing in the blood circulation system. Preferably, the supply of substitute is interrupted temporarily.
Abstract:
A device for the extracorporal blood treatment in a single-needle operating mode includes means for delivering blood into, and means for delivering blood out of means for collecting blood, and a controller for setting the respective delivery rates of the means for the delivery of blood. The operating mode of the means for delivering blood is continually switched between an arterial and a venous phase by the controller, wherein during the arterial phase the delivery rate Qb of the means for delivering blood is greater than the delivery rate Qsn of the means for delivering blood such that blood may be withdrawn from the patient during the arterial phase, and during the venous phase the delivery rate Qb is smaller than the delivery rate Qsn such that blood may be administered to the patient during the venous phase.
Abstract:
The present invention relates to a device and a method for detecting the direction of the fluid flow through a dialyzer, as well as an extracorporeal blood treatment apparatus which comprises a device for detecting the direction of the fluid flow through the dialyzer. The devices and methods according to the present invention are based on the change in a physical and/or chemical property, for example the substance concentration or the temperature, of a fluid flowing into the one chamber of the dialyzer and the measurement of the change in the physical and/or chemical property of the fluid flowing out of the one chamber of the dialyzer.
Abstract:
The present invention relates to a method and to a device for detecting the entry of air in a fluid system, in particular in an extracorporeal blood circuit of a blood treatment device comprising an arterial branch leading to the blood treatment unit and a venous branch leading from said blood treatment unit. Periodic fluctuations in the fluid system, in particular in the arterial tube, are measured upstream of the blood pump arranged in said arterial tube. The measured periodic pressure signal is analyzed spectrally in a system of functions, in particular a system of orthogonal functions, for example sine and cosine functions and the entry of air is deduced if at least one of the coefficients of the functions exceeds or falls below predefined threshold values.
Abstract:
The present invention relates to devices and methods for inspecting filters for extracorporeal blood treatment devices, e.g., filters for filtering dialysis fluid. The inspection of the filter according to the present invention is based on the measurement of the flow potential before and after changing the fluid flow of an electrolytic fluid between a transversal flow through the semi-permeable membrane of the filter and a longitudinal flow along the semi-permeable membrane of the filter, or vice versa. Changing the flow direction of the electrolytic fluid results in a change to the conductivity proceeding from a base value P to a higher value P2 or a lower value P1, wherein the conductivity readjusts to the base value P after a certain time interval T1, T2. An improper state of the filter is determined on the basis of the change in conductivity after changing the flow direction of the electrolytic fluid.
Abstract:
The invention relates to a method and to a device for operating an electric peristaltic hose pump, in particular a hose pump for transporting fluids in medical-technical devices, in particular extracorporeal blood treatment devices. In order to monitor the regular operation of a hose pump, the power consumption of the pump or a physical variable in correlation with the power consumption, in particular the pump flow, is monitored. The pump flow includes a periodically non-altering direct component which is superimposed on a periodically altering alternating component. In order to monitor the regular operation of the hose pump, the alternating component of the power consumption in relation to the direct component of the power consumption is monitored as whether it increases and/or decreases during blood treatment.
Abstract:
The invention relates to a method and a device for monitoring a vascular access during an extracorporeal blood treatment. The method and the device according to the invention are based on the monitoring of the difference between the venous pressure measured by a venous pressure sensor and the arterial pressure measured by an arterial pressure sensor (in the extracorporeal blood circuit. According to the method and the device according to the invention, a test function describing disturbances in the extracorporeal blood circuit is determined. Said test function is used to determine a noise-free differential pressure from the measured venous and arterial pressure, said differential pressure being evaluated in an arithmetic and evaluation unit to identify a defective vascular access.
Abstract:
The present invention relates to a method and a device for monitoring a blood treatment unit, subdivided by a semipermeable membrane into a blood chamber and a dialysis liquid chamber, of an extra-corporeal blood treatment device, which comprises an extra-corporeal blood circuit having an arterial branch leading to the blood chamber of the blood treatment unit, a venous branch, which extends away from the blood chamber, and a dialysis fluid system, in which the dialysis liquid chamber is arranged. The method according to the present invention and the device according to the present invention are based on the idea that the change of the flow resistance of the dialysis machine is determined based on two measurements, wherein an oscillating pressure signal in the extra-corporeal blood circuit or in the dialysis fluid system is measured before and after the change of the substitution rate and/or ultrafiltration rate, with which the substitute is applied to, or ultrafiltrate is removed from, the blood flowing in the blood circulation system. Preferably, the supply of substitute is interrupted temporarily.
Abstract:
The present invention relates to a method and to a device for detecting the entry of air in a fluid system, in particular in an extracorporeal blood circuit of a blood treatment device comprising an arterial branch leading to the blood treatment unit and a venous branch leading from said blood treatment unit. Periodic fluctuations in the fluid system, in particular in the arterial tube, are measured upstream of the blood pump arranged in said arterial tube. The measured periodic pressure signal is analyzed spectrally in a system of functions, in particular a system of orthogonal functions, for example sine and cosine functions and the entry of air is deduced if at least one of the coefficients of the functions exceeds or falls below predefined threshold values.