The invention relates to a method and to a device for determining an optimum dialysate flow Q.sub.dopt for an extracorporeal blood treatment and to a blood treatment device comprising a device 18 for determining an optimum dialysate flow Qd.sub.opt. The optimum dialysate flow Qd.sub.opt is determined on the basis of a relationship describing the dependence of the clearance K on the dialysate flow Q.sub.d. The device according to the invention comprises a measurement device 18B for measuring at least one value which is characteristic of the clearance K, a calculation and/or evaluation unit 18A of the device according to the invention being configured in such a way that the clearance K is determined on the basis of the at least one value which is characteristic of the clearance. The calculation and/or evaluation unit 18A is configured in such a way that the optimum dialysate flow Q.sub.dopt is determined from the relationship describing the dependence of the clearance K on the dialysate rate Q.sub.d on the basis of the measured clearance K, or the optimum dialysate flow Q.sub.dopt is determined from the measured clearance K.

A dialysis system includes a dialysis instrument including a blood pump, a dialysate inlet pump, a dialysate outlet pump, and at least one fluid velocity sensor, each sensor including an emitter and a receiver, a dialyzer arranged (i) to receive blood pumped by the blood pump, (ii) to receive fresh dialysate pumped by the dialysate inlet pump and (iii) such that used dialysate is pumped from the dialyzer by the dialysate outlet pump, and a disposable cassette including a to-dialyzer dialysate pathway carrying dialysate pumped by the dialysate inlet pump and a from-dialyzer dialysate pathway carrying used dialysate pumped by the dialysate outlet pump, wherein at least one of the to-dialyzer dialysate pathway or the from-dialyzer dialysate pathway includes at least one sensing area so positioned and arranged such that when the disposable cassette is mounted to the instrument, the sensing area is coupled operably with both the emitter and the receiver of the at least one fluid velocity sensor.

Disclosed herein are methods, systems and devices to monitor vascular volume status utilizing at least one oximetry/photoplethysmography sensor. The methods, systems and devices provide an alternative to conventional vascular volume monitoring methods while enabling reliable, non-invasive, and automatic monitoring of vascular volume to avert patient hypotension. The methods, systems and devices may be employed in the context of both inpatient and outpatient facilities and may also be incorporated into conventional monitoring devices, techniques and equipment.

A dialysis machine includes a dialyzer (1), a dialysate feed system (5) having a feed line (52), and a discharge system (6) having a discharge line (62). The machine further includes ultrafiltration control elements (UF) and back-filtration control elements (RF). The feed line is provided with a constriction (520) and with elements for measuring the pressure difference (523, 524) across the terminals of the constriction. The feed system further includes a ventricle bag (50), and pressurizer elements (70) for putting the ventricle bag (50) under pressure. The machine further includes an open/close system (C5, C5′) for opening/closing the discharge line (62) and the back-filtration control elements cause the discharge line (62) to close, and control the pressure applied to the ventricle bag (50), as a function of the pressure difference measured across the terminals of the constriction (520), so as to obtain a given flow rate of dialysate.

A blood treatment system comprising at least one first device and at least one second device, wherein the first device is a membrane filter for the removal of toxic mediators from blood and the second device is suitable for the removal of granulocytes and monocytes from blood. The first device has a first blood flow path a first blood flow path for conducting blood through and the second device has a second blood flow path. The first and second devices are serially connected in succession in such a way that the first blood flow path is in fluid communication with the second blood flow path.

The membrane has an interior filter space in its housing and a semipermeable membrane arranged in the interior filter space, which membrane divides the interior filter space into a retentate chamber and permeate chamber. The housing has a blood inlet device and a blood outlet device that are in fluid communication with the retentate chamber, as well as a permeate outlet for diverting permeate from the permeate chamber. The blood inlet device, the retentate chamber and the blood outlet device form the first blood flow path. The membrane filter has a separation characteristic such that the sieve coefficient for albumin, SK.sub.Alb, is within the range from 0.015 to 0.35.

The present specification describes a modular, portable hemofiltration system, for providing improved clearance levels of blood toxins, which includes at least one roller pump that is designed and operated to generate a rapidly varying pressure profile of fluid within at least a blood circuit of the hemofiltration system.

Systems and methods are provided for determining an estimated risk of arrhythmia during or after dialysis based on changes in serum potassium concentration of a patient and an amount of fluid removed from the patient during dialysis. The systems and methods allow for a determination of a risk that arrhythmia will occur due to the changes in potassium and fluid volume of a patient during dialysis, and for optimizing a dialysis prescription in order to minimize the risk of arrhythmia.

A system with container volume tracking includes a pump receiving a line connected to a tracked container, an air sensor to detect air in the line, and a controller coupled to pump and sensor. The controller is configured to monitor pump operation, and determine a volume removed from the container based thereon. If the volume removed is less than a first percentage of a target volume and there is air, continue operation after an air purge. If the volume removed is more than the first percentage and less than a second percentage and if there is air, prompt the user for an input, and continue operation after an air purge if a first input is received or end operation if a second input is received. If the volume removed is more than the second percentage and if there is air, end operation.

Methods and systems are presented for analyzing the blood of a living being. Equations are presented for volume-aware extension of the concept of Hematocrit. A method for calculating these volume-aware measures and using said measures to evaluate and guide possible treatments is described. A system comprising an automated analyzer and a processor and other components is described which can carry out said calculations. Methods of treatment for volume abnormalities are described which are guided by the volume-aware Hct measures. In one exemplary embodiment, a method of treatment for plasma volume excess using ultrafiltration is described. In another exemplary embodiment, a method of treatment for red cell volume excess using erythrocytapheresis is described.

According to some embodiments, a system may treat blood outside the body of a patient. The system may include one or more pumps configured to draw blood from a patient into a fluid flow path at a rate, for example, of 5-7 liters per minute. The system may include one or more heat exchangers coupled to the fluid flow path and configured to heat the blood, for example, to a temperature above 42 degrees Celsius and below 43.2 degrees Celsius.