is also provided as illustrated input line 22 and output line 28 are operatively connected to appropriate arterial venous fistulas 30 32 implanted into the forearm of a patient line 22 thereby being coupled to the radial artery of the patient whereas line 28 is coupled to the forearm vein of course other arterial venous connections to the patient could be fashioned depending upon the discretion of the treating physician the device 10 further includes a bathing fluid reservoir 34 with a solution input line 36 connected thereto and coupled to input 18 a conventional pump 38 is interposed within line 36 for purposes of circulating fluid through assembly 12 a solution output line 40 is operatively coupled between output 20 and a waste reservoir 42 as illustrated attention is next directed to fig2 4 which illustrate a modified membrane assembly broadly denoted with the numeral 44 it is to be understood in this respect that the assembly 44 could be used in the overall system 10 and in that event would function as the schematically depicted assembly 12 in any event the assembly 44 comprises three banks 46 47 and 48 each containing five upright tube and shell hollow capillary cartridges 50 each of these cartridges is identical and includes a large number of hollow fiber capillaries therewithin the preferred cartridges are amicon u00ae units having a 30 000 dalton exclusion limit the assembly 44 further includes a trifurcated input header 52 having a common blood input line 54 and branch lines 56 57 and 58 respectively operatively coupled to and feeding.