PROCESS AND DEVICE FOR MONITORING THE SUPPLY OF SUBSTITUTION FLUID DURING AN EXTRACORPOREAL TREATMENT OF BLOOD

摘要

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.

主权项

1. A method of determining fistula recirculation for a device for the extracorporeal treatment of blood, wherein the device for the extracorporeal treatment of blood comprises an extracorporeal blood circuit including a first chamber of a dialyser or a filter, and a fluid system including a second chamber of the dialyser or the filter, wherein the dialyser or the filter is divided by a semipermeable membrane into the first chamber and the second chamber, and wherein substitution fluid is supplied to the extracorporeal blood circuit upstream or downstream of the dialyser or the filter by means of a substituate pump, the method comprising:
at least one of starting up the substituate pump which has been previously shut off, or shutting off the substituate pump which has been previously started up; measuring a pressure in the extracorporeal blood circuit upstream of the dialyser or the filter and downstream of the dialyser or the filter after the at least one of starting up the sub stituate pump which has been previously shut off, or shutting off the substituate pump which has been previously started up; and determining fistula recirculation by calculating the ratio between the integral of the pressure measured upstream of the dialyser or the filter in a predetermined time interval in which a repeating positive and/or negative pressure pulse occurs, and the integral of the pressure measured downstream of the dialyser or the filter in a predetermined time interval in which a repeating positive and/or negative pressure pulse occurs.