Blood collection systems and methods which derive instantaneous blood component yield information during blood processing

A system for separating platelets from blood comprising

• a separation device operative for separating blood into plasma and platelets,
• an inlet to the separation device arranged to convey anticoagulated blood containing plasma and platelets from a donor into the separation device for separating into a plasma yield and a platelet yield,
• a processing element coupled to the separation device including a first element that is operative to derive, at least partly while separation occurs in the separation device, the yield of platelets by a method comprising the steps of:
• determining an incremental cleared volume comprising an incremental volume of blood from which all platelets have been collected during a succession of incremental time periods during the separation,
• estimating a current count of platelets available from the donor during each incremental time period by applying a platelet depletion factor that takes into account both removal of platelets by the separation device and replacement of platelets by the donor through splenic mobilization,
• multiplying the determined incremental cleared volume for each incremental time period by the estimated current count of platelets for each incremental time period, to derive an incremental platelet yield for each incremental time period, and
• summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• the processing element including a second element that generates output based, at least in part, upon the derived yield of platelets.

A system for separating platelets from blood comprising

• a separation device operative for separating blood into plasma and platelets,
• an inlet to the separation device arranged to convey anticoagulated blood containing plasma and platelets from a donor into the separation device for separating into a plasma yield and a platelet yield, and
• a processor coupled to the separation device including
• means for determining an incremental blood volume processed during a succession of incremental time periods during the separation,
• means for estimating a separation efficiency for the separation device during each incremental time period,
• means for estimating a current count of platelets available from the donor during each incremental time period by applying a platelet depletion factor that takes into account both removal of platelets by the separation device and replacement of platelets by the donor through splenic mobilization,
• means for multiplying the determined incremental blood volume for each incremental time period by the estimated current count of platelets for each incremental time period by the estimated separation efficiency for each incremental time period, to derive an incremental platelet yield for each incremental time period,
• means for summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• means for generating an output based, at least in part, upon the derived yield of platelets.

A system for separating platelets from blood comprising

• a separation device operative for separating blood into plasma and platelets,
• an inlet to the separation device arranged to convey anticoagulated blood containing plasma and platelets from a donor into the separation device for separating into a plasma yield and a platelet yield, and
• a processor coupled to the separation device including
• means for determining an incremental cleared volume comprising an incremental volume of blood from which all platelets have been collected during a succession of incremental time periods during the separation,
• means for estimating a current count of platelets available from the donor during each incremental time period by applying a platelet depletion factor that takes into account both removal of platelets by the separation device and replacement of platelets by the donor through splenic mobilization,
• means for multiplying the determined incremental cleared volume for each incremental time period by the estimated current count of platelets for each incremental time period, to derive an incremental platelet yield for each incremental time period,
• means for summing the incremental platelet yields over the succession of incremental time periods to obtain a derived yield of platelets, and
• means for generating an output taking into account, at least in part, the derived yield of platelets.

A method for separating platelets from blood comprising the steps of

• continuously conveying anticoagulated blood containing plasma and platelets from a donor into a separation chamber, while
• substantially continuously separating the blood into a yield of plasma and a yield of platelets,
• deriving, at least partly while the separation step is occurring, the yield of platelets by
• determining an incremental blood volume processed during a succession of incremental time periods during the separation step,
• estimating a separation efficiency for the separation device during each incremental time period,
• estimating a current count of platelets available from the donor during each incremental time period by applying a platelet depletion factor that takes into account both removal of platelets by the separation device and replacement of platelets by the donor through splenic mobilization,
• multiplying the determined incremental blood volume for each incremental time period by the estimated current count of platelets for each incremental time period by the estimated separation efficiency for each incremental time period, to derive an incremental platelet yield for each incremental time period, and
• continuously summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• generating an output taking into account, at least in part, the derived yield of platelets.

A method for separating platelets from blood comprising the steps of

• continuously conveying anticoagulated blood containing plasma and platelets from a donor into a separation chamber, while
• substantially continuously separating the blood into a yield of plasma and a yield of platelets,
• deriving, at least partly while the separation step is occurring, the yield of platelets by
• determining an incremental cleared volume comprising an incremental volume of blood from which all platelets have been collected during a succession of incremental time periods during the separation step,
• estimating a current count of platelets available from the donor during each incremental time period by applying a platelet depletion factor that takes into account both removal of platelets by the separation device and replacement of platelets by the donor through splenic mobilization,
• multiplying the determined incremental cleared volume for each incremental time period by the estimated current count of platelets for each incremental time period, to derive an incremental platelet yield for each incremental time period, and
• continuously summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• generating an output taking into account, at least in part, the derived yield of platelets.

A system for separating platelets from blood comprising

• a separation device operative for continuously separating blood into plasma and platelets over a succession of incremental time periods,
• an inlet to the separation device arranged to convey anticoagulated blood containing plasma and platelets from a donor into the separation device for separating into a plasma yield and a platelet yield, and
• a processing element coupled to the separation device including a first element operative to derive platelet yields during the incremental time periods, by a method which includes the step of estimating a count of platelets available from the donor during each incremental time period by applying a platelet depletion factor that takes into account both removal of platelets by the separation device and replacement of platelets by the donor through splenic mobilization, and
• the processing element further including a second element that generates output based, at least in part, upon the derived platelet yields.

A method for separating platelets from blood comprising the steps of

• conveying anticoagulated blood containing plasma and platelets from a donor into a separation chamber,
• separating the blood into a yield of plasma and a yield of platelets,
• deriving, during a succession of incremental time periods while the separation step is occurring, the yield of platelets, at least in part, by estimating a count of platelets available from the donor during the incremental time periods by the application of a platelet depletion factor that takes into account both removal of platelets by the separation device and replacement of platelets by the donor through splenic mobilization, and
• generating an output taking into account, at least in part, the derived yield of platelets.

A method for separating platelets from blood comprising the steps of

• continuously conveying anticoagulated blood containing plasma and platelets from a donor into a separation chamber, while
• substantially continuously separating the blood into a yield of plasma and a yield of platelets,
• deriving, at least partly while the separation step is occurring, the yield of platelets by
• determining an incremental blood volume processed during a succession of incremental time periods during the separation step,
• estimating a separation efficiency for the separation device during each incremental time period,
• estimating a current count of platelets (Plt.sub.CIRC) available from the donor during each incremental time period including estimating a platelet depletion factor (Depletion) as follows:
• ##EQU35## where:
• Yld is the derived yield of platelets (k/.mu.l) at the time Depletion is estimated,
• DonVol is the total volume of donor blood (ml), and
• Spleen is a splenic mobilization factor (Spleen),
• multiplying the determined incremental blood volume for each incremental time period by the estimated current count of platelets for each incremental time period by the estimated separation efficiency for each incremental time period, to derive an incremental platelet yield for each incremental time period, and
• continuously summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• generating an output taking into account, at least in part, the derived yield of platelets.

A method for separating platelets from blood comprising the steps of

• continuously conveying anticoagulated blood containing plasma and platelets from a donor into a separation chamber, while
• substantially continuously separating the blood into a yield of plasma and a yield of platelets,
• deriving, at least partly while the separation step is occurring, the yield of platelets by
• determining an incremental cleared volume comprising an incremental volume of blood from which all platelets have been collected during a succession of incremental time periods during the separation step,
• estimating a current count of platelets available from the donor during each incremental time period including estimating a platelet depletion factor (Depletion) as follows:
• ##EQU36## where:
• Yld is the derived yield of platelets (k/.mu.l) at the time Depletion is estimated,
• DonVol is the total volume of donor blood (ml), and
• Spleen is a splenic mobilization factor (Spleen),
• multiplying the determined incremental cleared volume for each incremental time period by the estimated current count of platelets for each incremental time period, to derive an incremental platelet yield for each incremental time period, and
• continuously summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• generating an output taking into account, at least in part, the derived yield of platelets.

A method for separating platelets from blood comprising the steps of

• continuously conveying anticoagulated blood containing plasma and platelets from a donor into a separation chamber, while
• substantially continuously separating the blood into a yield of plasma and a yield of platelets,
• deriving, at least partly while the separation step is occurring, the yield of platelets by
• determining an incremental blood volume processed during a succession of incremental time periods during the separation step,
• estimating a separation efficiency for the separation device during each incremental time period,
• estimating a current count of platelets (Plt.sub.Circ) available from the donor during each incremental time period by taking into account a measurement of the donor's platelet count before the conveying step (Plt.sub.pre), an estimation of a dilution factor caused by addition of anticoagulant (Dilution), and an estimation of a depletion factor (Depletion) caused by removal of available platelets by the separation step, according to the following expression:
• Plt.sub.Circ =›(Dilution).times.Plt.sub.pre !-(Depletion)
• and wherein the dilution factor (Dilution) is estimated based upon the following expression:
• ##EQU37## where:
• Prime is a priming fluid volume (ml),
• PPP is volume of plasma yield that is not returned to the donor(ml),
• Kid is an empirically determined constant representing kidney function,
• DonVol (ml) is the total volume of donor blood,
• multiplying the determined incremental blood volume for each incremental time period by the estimated current count of platelets for each incremental time period by the estimated separation efficiency for each incremental time period, to derive an incremental platelet yield for each incremental time period, and
• continuously summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• generating an output taking into account, at least in part, the derived yield of platelets.

A method for separating platelets from blood comprising the steps of

• continuously conveying anticoagulated blood containing plasma and platelets from a donor into a separation chamber, while
• substantially continuously separating the blood into a yield of plasma and a yield of platelets,
• deriving, at least partly while the separation step is occurring, the yield of platelets by
• determining an incremental cleared volume comprising an incremental volume of blood from which all platelets have been collected during a succession of incremental time periods during the separation step,
• estimating a current count of platelets (Plt.sub.Circ) available from the donor during each incremental time period by taking into account a measurement of the donor's platelet count before the conveying step (Plt.sub.pre), an estimation of a dilution factor caused by addition of anticoagulant (Dilution), and an estimation of a depletion factor (Depletion) caused by removal of available platelets by the separation step, according to the following expression:
• Plt.sub.Circ =›(Dilution).times.Plt.sub.pre !-(Depletion)
• and wherein the dilution factor (Dilution) is estimated based upon the following expression:
• ##EQU38## where:
• Prime is a priming fluid volume (ml),
• PPP is volume of plasma yield that is not returned to the donor(ml),
• Kid is an empirically determined constant representing kidney function,
• DonVol (ml) is the total volume of donor blood,
• multiplying the determined incremental cleared volume for each incremental time period by the estimated current count of platelets for each incremental time period, to derive an incremental platelet yield for each incremental time period, and
• continuously summing the incremental platelet yields over the succession of incremental time periods to obtain the derived yield of platelets, and
• generating an output taking into account, at least in part, the derived yield of platelets.