Abstract: In a plasma filtration process including a treatment with a primary filter for separating blood into blood cells and plasma and a treatment with a secondary filter for removing harmful macromolecules from the separated plasma for purification, the secondary filter is washed by passing a washing liquid through an inner chamber of the filter, an outer chamber thereof or both the chambers in an amount corresponding to 5 to 50% of the priming volume of the filter every time the filtration pressure has reached 70 to 100% of the withstanding pressure of the secondary filter. This washing procedure reduces the time required for the filtration of plasma to about 60 to 70% of the time conventionally needed, shortens the patient restraining time, and decreases the amount of washing liquid to be used to consequently diminish the disposal loss of plasma from the system.

Abstract: In a process for filtering plasma by separating blood into blood cells and plasma by a primary filter and filtering the separated plasma by a secondary filter to remove macromolecules from the plasma as harmful components, the loss of plasma to be discarded from the system by a procedure for eliminating plugging of the secondary filter can be diminished by opening an inner chamber of the secondary filter to the atmosphere to thereby lower the internal pressure of the chamber every time increase of the pressure to an upper limit value due to an increasing plugging tendency of the secondary filter is detected, and washing the interior of the secondary filter from the inner and outer chamber sides after the internal pressure has lowered.

Abstract: In a process for filtering plasma by separating blood into blood cells and plasma by a primary filter and filtering the separated plasma by a secondary filter to remove macromolecules from the plasma as harmful components, the loss of plasma to be discarded from the system by a procedure for eliminating plugging of the secondary filter can be diminished by opening an inner chamber of the secondary filter to the atmosphere to thereby lower the internal pressure of the chamber every time increase of the pressure to an upper limit value due to an increasing plugging tendency of the secondary filter is detected, and washing the interior of the secondary filter from the inner and outer chamber sides after the internal pressure has lowered.

Abstract: A surgical nozzle apparatus used for removing an undesired tissue with a jet of pressurized fluid. A handpiece including a fluid injecting nozzle piece and a valve assembly capable of cutting off the supply of the pressurized fluid to the nozzle piece, further includes a suction nozzle opening at a position downstream of the nozzle piece. The suction nozzle is connected to external suction means so that the waste fluid and the separated tissue at a surgically treated part are simultaneously sucked and discharged during the operation.