Selective extracorporeal blood disinfection systems and related methods are disclosed. The systems comprise an input tube forming a flowpath for the flow of infected blood. The systems further comprise a disinfection unit comprising a microbicidal light emitting device configured to emit visible light within the range of about 380-425 nm and/or about 500-700 nm, and a treatment flowpath in communication with the input tube that is substantially transparent to the emitted light of the microbicidal light emitting device for receiving at least a portion of the flow of the infected blood therethrough. The microbicidal light emitting device effectuates a dose of the emitted light to the infected blood flowing through the treatment flowpath to disinfect the blood. The systems also comprise an output tube in fluid communication with the treatment flowpath forming a flowpath for the flow of the disinfected blood from the disinfection unit.

An optimizing device for freely switching RBC removal and plasma exchange are provided, which is used to solve the problems in the prior art that the treatment effect is poor, the consumption of consumables is excessive, and the application range is narrow. According to the device, an additional hanging hook is added, a plasma exchange output pipeline is modified to be separated from the plasma collection pump and to be installed to the additional hanging hook. Then, the RBC recirculation tube is clamped through a freely movable cassette, so that the flow rate control of a plasma collection pump is released. Thereafter, HCT data is adjusted, and liquid is compensated, so that the RBC removal or replacement, lymphoplasma exchange and plasma exchange can be freely switched, which can meet the clinical treatment needs, optimize the process and reduce the cost. Therefore, the application range of a pipeline is greatly increased.