Abstract: A system for reducing pathogens in a biological fluid such as whole blood or blood-derived products includes a pump configured to propagate the fluid through a serpentine-shaped flow path while exposing the fluid to UV irradiation. Extensive mixing of flow is accomplished by a pump control system programmed to cause the pump to vary the flow of fluid. In embodiments, the pump may be automatically operated to periodically switch the flow back and forth between a high flow rate and a slow flow rate. Alternatively, the pump may be periodically stopped or even cause the flow to reverse direction for short periods of time.

Abstract: A system and method for reducing pathogens in a biological fluid such as whole blood or blood-derived products includes a pump configured to propagate the fluid through a serpentine-shaped flow path while exposing the fluid to UV irradiation. Extensive mixing of flow is accomplished by causing the pump to vary the flow of fluid. In embodiments, the pump may be operated to periodically switch the flow back and forth between a high flow rate and a slow flow rate. Alternatively, the pump may be periodically stopped or even cause the flow to reverse direction for short periods of time.

Abstract: An exposure chamber for reducing pathogens in a biological fluid such as whole blood or blood-derived products includes a serpentine-shaped UV-transparent flow path and closely positioned ultraviolet light emitting diodes configured for emanating UV irradiation towards the biological fluid at peak wavelength of 250 nm to 270 nm. The control system is provided to energize UV LEDs using various novel modes of modulating pulse width and current amplitude for LEDs so as to deliver higher UV intensity to the biological fluid but without overheating thereof or the LEDs.

Abstract: A system and method for reducing pathogens in a biological fluid such as whole blood or blood-derived products includes a pump configured to propagate the fluid through a serpentine-shaped flow path while exposing the fluid to UV irradiation. Extensive mixing of flow is accomplished by causing the pump to vary the flow of fluid. In embodiments, the pump may be operated to periodically switch the flow back and forth between a high flow rate and a slow flow rate. Alternatively, the pump may be periodically stopped or even cause the flow to reverse direction for short periods of time.