The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 23, 2002
Filed:
Sep. 07, 2000
Michel Thomas, Serezin-Du-Rhone, FR;
Pierre Valette, Lyon, FR;
Hospal Industrie, Meyzieu, FR;
Abstract
A method for preventing activation of the contact phase of blood or plasma which comes into contact with a semi-permeable membrane based on polyacrylonitrile bearing fixed negative charges, which is fitted in apparatus for the treatment of blood or plasma, by extra-corporal circulation, said method comprising contacting blood or plasma with said semi-permeable membrane, wherein: a neutral or cationic polymer is combined with said semi-permeable membrane before or after formation of the membrane, and before sterilization of the membrane; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is negative; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is, as an absolute value, not more than 10% less than the overall ionic capacity of the same semi-permeable membrane without a neutral or cationic polymer, at least one of said polymer being present at the surface of the membrane; the semi-permeable membrane based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer complies, before sterilization, with the following two electrical characteristic: the electrokinetic index “I” is less than or equal to 0.8, “I” being equal to the logarithm, in base 10, of the ratio |Z|/R, where “Z” is the Zeta potential, as an absolute value, expressed in microvolts, of the surface of the membrane intended to come into contact with blood or plasma, and where “R” is the electrical resistivity of the membrane, expressed in ohm.centimeters, and the Zeta potential “Z” is negative.