초록 ▼

A monitoring system for monitoring trans-membrane pressure in plasmapheresis apparatus utilizing a microporous membrane type filter includes first and second pressure-to-frequency transducer circuits for developing signals frequency-indicative of the inlet and outlet pressures of the filter. The sig

A monitoring system for monitoring trans-membrane pressure in plasmapheresis apparatus utilizing a microporous membrane type filter includes first and second pressure-to-frequency transducer circuits for developing signals frequency-indicative of the inlet and outlet pressures of the filter. The signals are digitally compared in a pulse subtraction circuit to produce an output signal frequency-indicative of trans-membrane pressure. The output signal is applied to a periodically reset display counter to develop a digital readout of trans-membrane pressure. Porous filter elements in the flow system and in the inlet port of each transducer isolate bacteria within the flow system, prevent contamination of the transducers, and provide a time constant for each transducer which prevents transient flow variations in the system from causing erroneous trans-membrane pressure readings.

대표청구항 ▼

A trans-membrane pressure monitoring system for use in conjunction with a fluid fractionation system of the type having a microporous membrane filter device including an inlet for whole fluid and an outlet for separated fluid component, comprising: a first electrical transducer having an inlet port

A trans-membrane pressure monitoring system for use in conjunction with a fluid fractionation system of the type having a microporous membrane filter device including an inlet for whole fluid and an outlet for separated fluid component, comprising: a first electrical transducer having an inlet port responsive to an applied pressure for producing a first pressure-indicative signal; first pressure coupling means for establishing a pressure communication channel between said inlet port of said first electrical transducer and one side of said filter device; a second electrical transducer having an inlet port responsive to an applied pressure for producing a second pressure-indicative signal; second pressure coupling means for establishing a pressure communication channel between said inlet port of said second electrical transducer and the other side of said filter device; each of said pressure coupling means including a first conduit portion integral with the associated side of said filter device, and a second conduit portion disconnectable from said first portion and integral with respective one of said transducers; each of said coupling means further including in said first portion of a microporous barrier plug means for providing a determined integration constant in the associated one of said channels; differential pressure derivation means responsive to said first and second pressure signals for producing an output signal indicative of the differential pressure across the membrane; and display means responsive to said output signal for displaying said differential pressure in operator readable format.