Apparatus for extracorporeal treatment of blood

A process of controlling an apparatus for extracorporeal treatment of blood, the apparatus being of the type comprising:

• a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;
• a blood withdrawal line connected to an inlet of the primary chamber connected to an outlet of the primary chamber said blood lines being designed to be connected to a patient cardiovascular system;
• a blood pump for controlling the flow of blood through the blood lines;
• an effluent fluid line connected to an outlet of the secondary chamber;
• an ultrafiltration actuator connected to the effluent fluid line and configured to cause a transfer of fluid from the primary (3) to the secondary chamber, wherein the process comprises:
• controlling the ultrafiltration actuator based on a set value for patient fluid removal rate, said set value being a desired value for the rate of fluid removal from the patient,
• determining when the ultrafiltration actuator is operated and/or when the ultrafiltration actuator is not operated,
• executing at check points during patient treatment a control procedure comprising:
• receiving one check information selected in the group of:
• an effective time portion, of said time period preceding a check point, during which said ultrafiltration actuator is operated, a down time portion, of said time period preceding a check point, during which said ultrafiltration actuator is not operated,
• calculating an updated value for said fluid removal rate as a function of said set value for a fluid removal rate and of said check information.

A process of controlling an apparatus for extracorporeal treatment of blood, the apparatus being of the type comprising:

• a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;
• a blood withdrawal line connected to an inlet of the primary chamber, and a blood return line connected to an outlet of the primary chamber said blood lines being designed to be connected to a patient cardiovascular system;
• a blood pump for controlling the flow of blood through the blood lines;
• an effluent fluid line connected to an outlet of the secondary chamber;
• an ultrafiltration actuator connected to the effluent fluid line and configured to cause a transfer of fluid from the primary to the secondary chamber, wherein the process comprises:
• controlling the ultrafiltration actuator based on a set value for patient fluid removal rate, said set value being a desired value for the rate of fluid removal from the patient,
• executing at check points during patient treatment a control procedure comprising:
• receiving one check information selected in the group of:
• an effective time portion, of a time period preceding a check point, during which said ultrafiltration actuator is operated,
• a down time portion, of a time period preceding a check point, during which said ultrafiltration actuator is not operated;
• calculating an updated value for said fluid removal rate as a function of said set value for a fluid removal rate and of said check information;
• after calculating said updated value, controlling the ultrafiltration actuator after the check point as a function of said updated value for the fluid removal rate.

A process of controlling an apparatus for extracorporeal treatment of blood, the apparatus being of the type comprising:

• a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;
• a blood withdrawal line connected to an inlet of the primary chamber, and a blood return line connected to an outlet of the primary chamber said blood lines being designed to be connected to a patient cardiovascular system;
• a blood pump for controlling the flow of blood through the blood lines;
• an effluent fluid line connected to an outlet of the secondary chamber;
• an ultrafiltration actuator connected to the effluent fluid line and configured to cause a transfer of fluid from the primary to the secondary chamber, wherein the process comprises:
• controlling the ultrafiltration actuator based on a set value for patient fluid removal rate, said set value being a desired value for the rate of fluid removal from the patient,
• executing at check points during patient treatment a control procedure comprising:
• receiving one check information selected in the group of:
• a value of fluid removed from the patient over a time period preceding a check point,
• an effective time portion, of a time period preceding a check point, during which said ultrafiltration actuator is operated,
• a down time portion, of a time period preceding a check point, during which said ultrafiltration actuator is not operated;
• determining an effective portion of a time period following the check point, during which it is forecasted that the ultrafiltration actuator will be actually pulling fluid from the primary chamber into the secondary chamber;
• calculating an updated value for said fluid removal rate as a function of:
• said set value for a fluid removal rate,
• said effective portion of the time period following the check point, and
• said check information;
• after calculating said updated value, controlling the ultrafiltration actuator after the check point as a function of said updated value for the fluid removal rate.