Systems and methods for monitoring introduction of a processing fluid during a fluid processing procedure

A blood processing system comprising

• a blood processing circuit including a device operating to separate blood into component parts,
• an auxiliary line operating to convey a processing fluid into the blood processing circuit,
• a replenishable source coupled to the auxiliary line, the source containing a volume of a processing fluid having a known density,
• a weigh sensor coupled to the source and operating to sense weight of the source that is proportional to volume of processing fluid present in the source, and
• a processor coupled to the weigh sensor and operating in response to commands to sequentially pause and resume a processing period using the blood processing circuit, the processor including a counting function that operates in processing steps to (i) record a current weight value of the source at commencement of the processing period;(ii) register a first subsequent weight value (Wt1) of the source upon pause in the processing period;
• (iii) register a second subsequent weight value (Wt2) of the source upon resumption of the processing period after the pause;
• (iv) generate an updated current weight value upon resumption of the processing period by adding to the current weight value the difference between Wt2 and Wt1;
• (v) register a final weight value of the source at termination of the processing period;
• and (vi) generate a total volume value of processing fluid dispensed from the source during the processing period, which takes into account replenishment of the processing fluid when the processing period is paused, by subtracting the final weight value from the updated current weight value.

A method for monitoring volume of processing fluid introduced into a fluid processing system comprising the steps of

• establishing a replenishable source containing a volume of a processing fluid having a known density,
• dispensing the processing fluid from the source during a processing period,
• sensing weight of the source that is proportional to volume of processing fluid present in the source,
• recording a current weight value of the source at commencement of the processing period,
• registering a first subsequent weight value (Wt1) of the source upon a pause in the processing period,
• registering a second subsequent weight value (Wt2) of the source upon a resumption of the processing period after the pause,
• generating an updated current weight value upon resumption of the processing period by adding to the current weight value the difference between Wt2 and Wt1,
• registering a final weight value of the source at termination of the processing period, and
• generating a total volume value of processing fluid dispensed from the source during the processing period, which takes into account replenishment of the processing fluid when the processing period is paused, by subtracting the final weight value from the updated current weight value.

A blood processing method comprising the steps of

• establishing a blood processing circuit,
• establishing a replenishable source containing a volume of a processing fluid having a known density,
• dispensing the processing fluid from the source into the blood processing circuit during a processing period,
• sensing weight of the source that is proportional to volume of processing fluid present in the source,
• recording a current weight value of the source at commencement of the processing period,
• registering a first subsequent weight value (Wt1) of the source upon a pause in the processing period,
• registering a second subsequent weight value (Wt2) of the source upon a resumption of the processing period after the pause,
• generating an updated current weight value upon resumption of the processing period by adding to the current weight value the difference between Wt2 and Wt1,
• registering a final weight value of the source at termination of the processing period, and
• generating a total volume value of processing fluid dispensed from the source during the processing period, which takes into account replenishment of the processing fluid when the processing period is paused, by subtracting the final weight value from the updated current weight value.