Method and apparatus for treating whole blood

Apparatus for separating whole blood into a plasma fraction and an enriched, plasma-depleted blood fraction which comprises at least two contiguous membrane units, each unit consisting of a first membrane layer, a second membrane layer, a first spacer layer positioned on a first surface of the first membrane layer, and a second spacer layer positioned between a second surface of said first membrane layer and a first surface of said second membrane layer,

• each of said membrane layers and said spacer layers being bonded over their entire mating surfaces,
• said first spacer layer having a plurality of channels extending through the thickness of said first spacer layer, each of said channels being between about 0.02 and 0.2 mm in height, between 1 and 10 cm in length, cumulatively between about 20 and 100 cm in width, and individually between about 0.05 and 0.5 cm in width, inlet means for introducing whole blood into said channels, blood outlet means for removing blood depleted of plasma from said channel,
• said second spacer including means connected to a plasma outlet adapted to collect plasma from said whole blood,
• sealing means associated with each of said first and second spacers for preventing whole blood or plasma-depleted blood from passing into said plasma outlet,
• and means for separately collecting plasma and plasma-depleted whole blood from said membrane units and for introducing whole blood into said membrane units.

The process for treating whole blood to effect material transfer from or into the whole blood which comprises:

• continuously introducing whole blood into first channels of a first spacer of a membrane unit, said first channels each between about 0.02 and 0.2 mm in height and extending through the thickness of said first spacer layer,
• each of said membrane layers and said spacer layers being bonded over their entire mating surfaces,
• said membrane unit consisting of a first membrane layer, a second membrane layer, said first spacer layer positioned on a first surface of the first membrane layer, and a second spacer layer positioned between a second surface of said first membrane layer as a first surface of said second layer,
• continuously removing treated blood from said first channels,
• effecting material transfer between said whole blood, through said membrane layers and from or into second channels in said second spacer,
• removing material from said second channels through an outlet connected with said second channels,
• and providing sealing means with each of said first and second spacers to prevent whole blood from being admixed with material introduced into said whole blood without first passing said material through a membrane layer or for preventing whole blood from being admixed with blood from which a blood fraction has been removed.