Technique for extracorporeal treatment of blood

A method for treating blood from a patient extracorporeally by a treatment which transfers matter to or from the blood through a semipermeable membrane, the semipermeable membrane being part of a filtration unit of an apparatus and dividing the filtration unit into a primary chamber and a secondary chamber, the primary chamber receiving the blood and the matter transferred across the semipermeable membrane into the blood, the secondary chamber receiving the matter to be transferred into the blood and the matter transferred across the semipermeable membrane from the blood, said method comprising the steps of:

• establishing an extracorporeal blood flow primary circuit from the patient through the primary chamber and back to the patient;
• controlling the flow of blood through the primary circuit;
• selectively supplying a replacement fluid to the blood in the primary circuit prior to returning the blood to the patient;
• controlling the amount of the replacement fluid supplied to the blood in the primary circuit;
• establishing a secondary circuit for the flow of fluid through the secondary chamber;
• selectively supplying a one of a secondary fluid containing matter which is to be transferred across the semipermeable membrane into the blood or a secondary fluid to remove matter from the secondary chamber which has been transferred across the semipermeable membrane from the blood to the secondary chamber;
• controlling the amount of secondary fluid supplied to the secondary chamber;
• collecting fluid exiting from the secondary chamber;
• controlling the amount of fluid collected from the secondary chamber;
• selecting one of a plurality of different extracorporeal blood treatments to be performed by the apparatus from the group consisting of UF, HD, HF, and HDF;
• storing predefined information defining which of the ones of the replacement fluid and the secondary fluid are to be supplied and defining the flow rates in the primary and secondary circuits for each of the plurality of different extracorporeal blood treatments,
• accumulating and storing flow rate information about an individual patient being treated with a selected treatment throughout the course of continuous and interrupted treatment;
• and
• automatically adjusting and controlling the rate of flow of fluid through the primary circuit, the rate of flow of replacement fluid into the primary circuit, the rate of flow of secondary fluid into the secondary chamber and the rate of flow of fluid collected from the secondary chamber according to the extracorporeal blood treatment selected and the stored predefined information relating to the type of treatment selected.

Method for controlling and monitoring the circulation of body fluids and medical fluids through a circuit for a plurality of different blood extracorporeal treatments, said circuit having a memory operatively associated therewith in which is stored (a) a plurality of sets of predefined flow rates with at least one of said sets associated with each said different treatment, and (b) priming information about said different treatments, said circuit comprising:

• a filtration unit having a primary and a secondary chamber separated by a semipermeable membrane, each chamber having an inlet and an outlet;
• a primary circuit comprising a blood access line connected to the inlet of the primary chamber and a blood return line connected to the outlet of the primary chamber;
• a secondary circuit comprising a secondary fluid line connected to the inlet of the secondary chamber and a collection fluid line connected to the outlet of the secondary chamber;
• a replacement fluid line connected to the primary circuit;
• and
• an anticoagulant fluid line connected to the blood access line;
• the method comprising the steps of:
• selecting a specific treatment from a group of different extracorporeal blood treatments consisting of UF, HD, HF, and HDF, said specific treatment having a set of predefined flow rates which is one of the plurality of sets stored in the memory operatively associated with the circuit;
• automatically priming the primary circuit and at least one part of the secondary circuit in accordance with the selected treatment and the priming information about the selected treatment stored in the memory;
• connecting the primary circuit to a vascular system of a patient;
• circulating blood, anticoagulant fluid, replacement fluid, secondary fluid and collection fluid in the circuit for multiple blood extracorporeal treatments according to the corresponding flow rates previously defined;
• monitoring a pressure in at least one of the blood access line, the blood return line and the collection fluid line;
• monitoring a flow rate of liquid in at least one of the primary circuit, the anticoagulant fluid line, the replacement fluid line, the secondary fluid line and the collection fluid line;
• and
• stopping the circulation of at least one circulating fluid in the circuit for multiple extracorporeal blood treatments when predetermined alarm conditions occur.