Systems and methods for predicting blood processing parameters

• US 5,681,273 A
• Filed: 06/07/1995
• Issued: 10/28/1997
• Est. Priority Date: 12/23/1991
• Status: Expired due to Fees

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Brown, Richard I.
• Primary Examiner(s): Bahr, Jennifer
• Assistant Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US08/483,483
• Time in Patent Office: 874 Days
• Field of Search: 604/4, 604/5, 604/6, 364/413.07
• US Class Current: 604/6.07
• CPC Class Codes: A61M 1/0209 Multiple bag systems for separating or storing blood components
• CPC Class Codes: A61M 1/0218 with filters
• CPC Class Codes: A61M 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/302 having a reservoir for withdrawn untreated blood
• CPC Class Codes: A61M 1/303 having a reservoir for treated blood to be returned
• CPC Class Codes: A61M 1/308 Volume control, e.g. with open or flexible containers, by counting the number of pump revolutions, weighing
• CPC Class Codes: A61M 1/3603 in the same direction
• CPC Class Codes: A61M 1/3624 Level detectors; Level control
• CPC Class Codes: A61M 1/3672 Means preventing coagulation
• CPC Class Codes: A61M 1/3693 using separation based on different densities of components, e.g. centrifuging
• CPC Class Codes: A61M 1/3696 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: A61M 1/385 taking into account of the patient characteristics
• CPC Class Codes: A61M 2202/0071 product to be retained or harvested, e.g. by pheresis
• CPC Class Codes: A61M 2202/0427 Platelets; Thrombocytes
• CPC Class Codes: A61M 2205/3344 Measuring or controlling pressure at the body treatment site
• CPC Class Codes: A61M 2205/3351 Controlling upstream pump pressure
• CPC Class Codes: A61M 2205/3355 Controlling downstream pump pressure
• CPC Class Codes: B01D 17/0217 by centrifugal force
• CPC Class Codes: B01D 21/2405 Feed mechanisms for settling tanks
• CPC Class Codes: B01D 21/245 Discharge mechanisms for the sediments
• CPC Class Codes: B01D 21/26 : Separation of sediment aided by centrifugal force or centripetal forcecentrifuges B04B; cyclones B04C
• CPC Class Codes: B01D 21/262 : by using a centrifuge
• CPC Class Codes: B01D 21/302 : Active control mechanisms with external energy, e.g. with solenoid valve
• CPC Class Codes: B01D 21/34 : Controlling the feed distribution; Controlling the liquid level ; Control of process parameters
• CPC Class Codes: B01D 2221/10 : Separation devices for use in medical, pharmaceutical or laboratory applications, e.g. separating amalgam from dental treatment residues
• CPC Class Codes: B04B 13/00 : Control arrangements specially designed for centrifuges; Programme control of centrifuges control arrangements for feed, charge, or discharge B04B11/00
• CPC Class Codes: B04B 5/0442 : with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: B04B 7/08 : Rotary bowls centrifugal casting machines B22D

Abstract

Systems and methods predict a whole blood processing volume required to achieve a desired platelet yield based upon inputs of selected processing parameters.

Claims

1. A blood processing system comprising:

a separation device for separating whole blood into red blood cells and a plasma constituent,

an inlet path including a pump for conveying whole blood from an individual donor into the separation device at a blood flow rate, Q_b,

a second path for adding an anticoagulant including a citrate concentration to the whole blood,

an input to receive selected processing parameters including;

a selected procedure time, t,

a selected anticoagulant hematocrit for whole blood to be processed, H_b,

the blood flow rate Q_b,

a desired plasma collection volume, PPP_GOAL,

a system variable WB_RES reflecting a residual volume of whole blood drawn but not processed,

a processor coupled to the input that generates a whole blood processing volume, WBVol, as follows;

##EQU32## an output coupled to the processor for outputting WBVol, and a controller coupled to the inlet path pump to control Q_b (in ml/min or equivalent) based upon a citrate equivalent blood flow rate EqQb_CIR, where;

##EQU33## where;

CIR is a nominal a-symptomatic citrate infusion rate (in mg/kg/min or equivalent), empirically selected based upon citrate reactions in a population of different donors,

AC is a selected anticoagulant ratio,

Wgt is the individual donor'"'"'s weight (in kg or equivalent), and

CitrateConc is the citrate concentration in the anticoagulant (in mg/ml or equivalent).

2. A device according to claim 1 wherein CIR≈

1.25 mg/kg/min.

3. A device according to claim 1 wherein t is an estimated procedure time required to collect a desired yield of platelets.

4. A blood processing method for achieving a desired platelet yield comprising the steps of:

inputting processing parameters including;

a selected procedure time, t,

a selected anticoagulated hematocrit for whole blood to be processed, H_b,

a selected blood flow rate Q_b,

desired plasma collection volume, PPP_GOAL,

a system variable WB_RES reflecting a residual volume of whole blood retained after processing and not collected or returned,

deriving a whole blood processing volume, WBVol, to achieve the desired platelet yield, based upon the selected processing parameters as follows;

##EQU34## outputting WBVol, conveying a volume of whole blood, taking into account WBVol, at the rate Q_b from an individual donor into a separation device for separation into red blood cells and a plasma constituent,

adding anticoagulant including a concentration of citrate to the whole blood, and

controlling Qb (in ml/min or equivalent) based upon a citrate equivalent blood flow rate EqQB_CIR, where;

##EQU35## where;

CIR is a nominal a-symptomatic citrate infusion rate (in mq/kg/min or equivalent), empirically selected based upon citrate reactions in a population of different donors,

AC is a selected anticoagulant ratio,

Wgt is the individual donor'"'"'s weight (in kg or equivalent), and

CitrateConc is the citrate concentration in the anticoagulant (in mg/ml or equivalent).

5. A method according to claim 4 wherein CIR≈

1.25 mg/kg/min.

6. A method according to claim 4, wherein t is an estimated procedure time required to collect a desired yield of platelets.