Ultrafiltration control in extracorporeal blood processing

An extracorporeal blood processing apparatus comprising:

• a pumping arrangement operable to draw blood from an individual and pump the blood through a blood filter arrangement and back to the individual while removing fluid from the blood in the blood filter arrangement at an ultrafiltration rate;
• and
• a control system comprising:
• one or more processors and a computer-readable medium including computer logic which, when executed by the one or more processors during a treatment session, controls the pumping arrangement to draw blood from the individual and pump the blood through the blood filter arrangement and back to the individual while removing fluid from the blood in the blood filter arrangement in accordance with a set value for the ultrafiltration rate, and to input sensor data representing one or more physiological parameters of the individual,
• wherein the computer logic is further configured to perform, intermittently during the treatment session, an optimization procedure to generate the set value based on the sensor data, the optimization procedure comprising:
• evaluating the sensor data for detection of a limiting physiological status (LPS) of the individual,
• sequentially controlling the pumping arrangement to achieve a respective ultrafiltration rate in a sequence of distinct ultrafiltration rates, until the evaluating detects the limiting physiological status (LPS) for a current ultrafiltration rate, and
• updating the set value based on the current ultrafiltration rate for use in continuing the treatment session subsequent to the optimization procedure,
• wherein the evaluating comprises obtaining the sensor data for the respective ultrafiltration rate, wherein the obtaining is temporally separated by a stabilization period (Δt) from initiation of the respective ultrafiltration rate at the extracorporeal blood processing apparatus, and wherein the sequence of distinct ultrafiltration rates is ordered by increasing magnitude from a minimum value (UFRM), wherein the control system is configured to perform at least two optimization procedures during the treatment session, and wherein the minimum value (UFRM) is equal in the at least two optimization procedures, and
• wherein after the at least two optimization procedures are performed, additional optimization procedures are performed where the ultrafiltration rate is increased.

A method of operating a control system for an extracorporeal blood processing apparatus during a treatment session which is performed via instructions stored on a computer-readable medium, wherein the instructions are executed by one or more processors, the method comprising:

• controlling, in the treatment session, the extracorporeal blood processing apparatus to draw blood from an individual through a blood filter arrangement and pump the blood back to the individual, while removing fluid from the blood in the blood filter arrangement in accordance with a set value for an ultrafiltration rate;
• obtaining sensor data representing one or more physiological parameters of the individual;
• and
• performing, intermittently during the treatment session, an optimization procedure to generate the set value based on the sensor data;
• wherein the optimization procedure comprises:
• evaluating the sensor data for detection of a limiting physiological status of the individual;
• sequentially controlling the extracorporeal blood processing apparatus to achieve a respective ultrafiltration rate in a sequence of distinct ultrafiltration rates, until the evaluating detects the limiting physiological status for a current ultrafiltration rate;
• and
• updating the set value based on the current ultrafiltration rate for use in continuing the treatment session subsequent to the optimization procedure,
• wherein the evaluating comprises obtaining the sensor data for the respective ultrafiltration rate, wherein the obtaining is temporally separated by a stabilization period (Δt) from initiation of the respective ultrafiltration rate at the extracorporeal blood processing apparatus, and wherein the sequence of distinct ultrafiltration rates is ordered by increasing magnitude from a minimum value (UFRM), wherein the control system is configured to perform at least two optimization procedures during the treatment session, and wherein the minimum value (UFRM) is equal in the at least two optimization procedures, and
• wherein after the at least two optimization procedures are performed, additional optimization procedures are performed where the ultrafiltration rate is increased.