Abstract:
The invention relates to a device and to a method for monitoring access to vessels during extracorporeal blood treatment. The invention forms a loop in the arterial and/or venous line and provides device for fixing a section of the line in a loop. When the line is stressed under tension, the loop contracts and the line finally kinks. The modification of the diameter of the line and the formation of a kink in the line leads to a rise of pressure in the line, which is monitored by a pressure monitoring device. If the pressure exceeds a predetermined threshold value, the aspirating cannula is in danger of slipping out of the vessel access or has partially or completely slipped out, thus allowing the threshold value to be determined for alarms.
Abstract:
A method and device that identify impairments of the blood flow in an extra-corporeal blood circuit during extracorporeal treatment of the blood using an extracorporeal haemodialysis device, where the phase angle of at least one harmonic oscillation of an oscillating pressure signal that propagates in the extracorporeal blood circuit is determined. Impairments of the blood flow are detected in the extracorporeal blood circuit based on a characteristic modification of the phase angle of at least one harmonic oscillation of the pressure signal. A temporal modification of the phase angle may be compared with a predefined threshold value and an impairment is detected if the value of the modification of the phase angle is greater than the predefined threshold value. The method and device permit an early identification of a coagulation of the blood that flows through the haemodialysis unit, so that countermeasures can be initiated promptly.
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:
A method of monitoring a treatment of a patient, preferably for monitoring hemodialysis, hemodiafiltration and/or peritoneal dialysis, that includes the steps of irradiating a sample of a dialysis liquid used in the treatment with irradiation light of at least a first irradiation wavelength, detecting light emitted by the irradiated sample in at least a first detection wavelength, the detection wavelength being different from the first irradiation wavelength, and determining the presence and/or concentration of at least one analyte in the sample on the basis of the detected light.
Abstract:
The invention relates to a process for monitoring the supply of substitution fluid upstream or downstream of a dialyser or filter arranged in an extracorporeal blood stream. One embodiment provides, for the detection of predilution or postdilution, for measuring the pressure in the blood stream downstream of the dialyser or filter, predilution or postdilution being recognized on the basis of the change in pressure following the shutting off and/or starting up of the substituate pump provided for conveying the substitution fluid. Another embodiment provides for recognizing predilution or postdilution on the basis of the comparison of the oscillating pressure signal attributable to the substituate pump to a characteristic reference signal. The characteristic reference signal to which the pressure signal of the substituate pump is compared is preferably the oscillating pressure signal of a blood pump arranged in the blood stream for conveying the blood upstream of the dialyser or filter. In addition, the invention relates to an extracorporeal blood treatment device with a facility for detecting predilution or postdilution, which device operates according to the processes detailed above.
Abstract:
The present invention relates to a method for regulating supply of substituate in an extracorporeal blood treatment with an extracorporeal blood treatment apparatus comprising a dialyzer divided by a semipermeable membrane into a blood chamber and a dialyzing fluid chamber and a device for supplying substituate. Moreover, the present invention relates to an extracorporeal blood treatment apparatus having a device for regulating supply of substituate. Regulation of supply of substituate in the extracorporeal blood treatment takes place as a function of the rheological loading of the dialyzer. To regulate supply of substituate during extracorporeal blood treatment, rheological loading of the dialyzer is determined from transmembrane pressure on the dialyzer and flow resistance of the dialyzer and substituate rate is increased or reduced according to the loading. The selection of dialyzer parameters or blood parameters is therefore no longer necessary and the distinction between pre-dilution and post-dilution is also made obsolete.
Abstract:
The invention relates to a method and a hemodialysis machine for at least partial emptying of an extracorporeal blood circulation after the blood of a patient in the extracorporeal blood circulation has been returned to the patient with the help of an infusion liquid which displaces the blood and after the patient has been separated from the extracorporeal blood circulation. The object of the invention is to empty at least the blood chamber of a hemodialyzer (1) that is subdivided by a semipermeable membrane (2) into a blood chamber (3) and a dialysis fluid chamber (4) without additionally connecting the arterial blood line (5) and the venous blood line (7) of the extracorporeal blood circulation to one another. To do so, the arterial blood line (5) is actively or passively aerated at a first point (50) and/or the venous blood line (7) is actively or passively aerated at a second point (40) and the liquid is emptied through the semipermeable membrane (2) into the dialysis fluid chamber (4) and a dialysis fluid discharge line (21) leaving this chamber. The inventive method can take place here through a control program that runs automatically in the control unit (30) of a hemodialysis machine without requiring special operating steps by the operating person after activation of the program.
Abstract:
This invention relates to a method for clearing a wetted hydrophobic filter, in which in a first step the air permeability of the hydrophobic filter is monitored and in which in a second step the hydrophobic filter is cleared by means of a connected air pump, if it is detected that the hydrophobic filter is clogged. Furthermore, the invention relates to an apparatus for performing this method.
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:
A method for clearing a wetted hydrophobic filter includes a first step in which the air permeability of the hydrophobic filter is monitored, and a second step in which the hydrophobic filter is cleared by means of a connected air pump, if it is detected that the hydrophobic filter is clogged. An apparatus for performing this method includes a pressure sensor and an air pump connected to an air separation chamber via a conduit, and a control and monitoring unit configured to actuate the air pump in order to clear the hydrophobic filter.