FIELD OF THE DISCLOSURE

The present disclosure relates generally to systems and methods for processing biological fluid and, in particular to systems and methods for using frequency analysis to monitor flow rates during a biological fluid procedure.

BACKGROUND

A variety of available blood processing systems allows for the collection and processing of particular blood components, rather than whole blood, from donors or patients. In the case of a blood donor, whole blood is drawn from the donor, a desired blood constituent isolated and collected, and the remaining blood components returned to the donor. By removing only particular constituents rather than whole blood, it takes the donor's body a shorter time period to recover to normal blood levels, thereby increasing the frequency with which the donor may donate blood. It is beneficial to increase in this manner the overall supply of blood constituents made available for health care, such as red blood cells (RBCs), leukocytes, plasma, and/or platelets, etc.

The separation phase of blood components from whole blood may be achieved through a spinning membrane or centrifugation, in which whole blood is passed through a centrifuge or membrane after it is withdrawn from the patient. To avoid contamination and possible infection of the patient, the blood is preferably contained within a sealed, sterile fluid flow system during the entire separation process. Typical blood processing systems thus may include a permanent, reusable hardware assembly containing the hardware (drive system, pumps, valve actuators, programmable controller, and the like) that pumps the blood, and a disposable, sealed and sterile fluid circuit that is mounted in cooperation on the hardware. In the case of separation via centrifugation, the hardware assembly includes a centrifuge that may engage and spin a separation chamber of the disposable fluid circuit during a blood separation step. The blood, however, may make actual contact only with the fluid circuit, which assembly may be used only once and then discarded. In the case of separation via a spinning membrane, a disposable single-use spinning membrane may be used in cooperation with the hardware assembly and disposable fluid circuit.

In the case of separation via centrifugation, as the whole blood is spun by the centrifuge, the heavier (greater specific gravity) components, such as red blood cells, move radially outwardly away from the center of rotation toward the outer or “high-G” wall of the separation chamber of the fluid circuit. The lighter (lower specific gravity) components, such as plasma, migrate toward the inner or “low-G” wall of the separation chamber. Various ones of these components can be selectively removed from the whole blood by forming appropriately located channeling seals and outlet ports in the separation chamber of the fluid circuit.

In the case of separation via a spinning membrane, whole blood may be spun within a disposable spinning membrane, rather than within a separation chamber of a fluid circuit. Larger molecules, such as red blood cells, may be retained within one side of the membrane, while the smaller molecules, such as plasma, may escape through the pores of the membrane to the other side of the membrane. Various ones of these components can be selectively removed from the whole blood by forming appropriately located outlet ports in the housing of the membrane column. Various types of columns with different pore sizes may be used, depending on the components to be separated.

It is common for two or more medical solutions and/or fluids to be flowing simultaneously during blood processing procedures. Flow of various fluids may be controlled and directed by pumps, e.g., peristaltic pumps. For example, saline solution, anti-coagulant solution, additive solutions, replacement fluids, RBCs, WBCs, platelets, plasma, etc. may be in flow throughout a blood processing procedure along fluid pathways, some of which may be disposed along one or more pumps. Regulating and monitoring flow and pump rates through the various fluid pathways may be desirable for conducting consistent and successful blood processing procedures.

SUMMARY

According to an exemplary embodiment, the present disclosure is directed to a system for monitoring and controlling a fluid procedure. The system comprises a reusable separation apparatus controlled by a microprocessing controller. The reusable separation apparatus comprises a pressure sensor in communication with the controller. The system also comprises a sterile circuit configured to associate with the reusable separation apparatus and provide a first fluid flow path in association with the pressure sensor and a first pump configured to transmit pulsatile pressure signals to the pressure sensor during operation in association with the first fluid flow path. The reusable apparatus and the controller are configured to receive from the pressure sensor one or more pressure signals comprising the pulsatile pressure signals transmitted by the first pump, perform a frequency analysis of the one or more pressure signals received by the pressure sensor over a time duration, derive a first rotation rate of the first pump or a first fluid flow rate at the first pump from the frequency analysis, and provide at least one response action based on the first rotation rate or the first fluid flow rate.

According to an exemplary embodiment, the present disclosure is directed to a computer-implemented method for monitoring fluid flow rates during a fluid procedure. The method comprises providing a first pump configured to transmit pulsatile signals during operation in association with a first fluid flow path, providing a sensor in communication with the first fluid flow path and configured to receive the pulsatile signals from the first pump, providing a controller in communication with the sensor and the first pump, performing via the controller a frequency analysis on one or more signals received by the sensor over a time duration, calculating a first rotation rate of the first pump or a first fluid flow rate at the first pump from the frequency analysis, and providing at least one response action based on the first rotation rate or the first fluid flow rate.

According to an exemplary embodiment, the present disclosure is directed to a system for monitoring and controlling a fluid procedure. The system comprises a reusable separation apparatus controlled by a microprocessing controller and a pressure sensor in communication with the controller. The system also comprises a sterile circuit configured to associate with the reusable separation apparatus and configured to provide a first fluid flow path in association with a first pump and the pressure sensor and a second fluid flow path in association with a second pump. The first pump is configured to transmit pulsatile pressure signals to the pressure sensor during operation in association with the first fluid flow path and the second pump is also configured to transmit pulsatile pressure signals to the pressure sensor during operation in association with the second fluid flow path. A resilient element is in communication with the first and second fluid flow paths. The resilient element comprises a material reactive to pressure changes originating from one or both of the first and second fluid flow paths. The reusable apparatus and the controller are configured to receive from the pressure sensor one or more pressure signals comprising pulsatile pressure signals from the first and second pumps, perform a fast Fourier transform of the one or more pressure signals received by the pressure sensor over a time duration, derive a first rotation rate of the first pump or a first fluid flow rate at the first pump from the frequency analysis, derive a second rotation rate of the second pump or a second fluid flow rate at the second pump from the frequency analysis, and provide at least one response action based on a) the first rotation rate or the first fluid flow rate and b) the second rotation rate or the second fluid flow rate.

