title: Impedance spectral measurements made through a membrane infection barrier.
abstract: Impedance spectra of superficial tissues can be used to detect pre-malignant changes in the cervix but require electrical contact to be made between a probe and the tissue. Using a membrane which is permeable to ions but forms a barrier to agents of infection should enable impedance spectra to be measured without causing an infection risk to the patient. The properties required of such a membrane are considered and measurements on two suitable membranes are presented. It is shown that impedance spectra can be measured through a thin natural cellulose based membrane (Cuprophan) and that these are not significantly different from directly measured spectra. The ability of the membranes to block a virus is tested using expired polio virus vaccine.
authors.affiliation: Medical Physics and Clinical Engineering, University of Sheffield, Royal Hallamshire Hospital, Sheffield S102JF, UK. b.h.brown@sheffield.ac.uk
authors.forename: Brian H
authors.initials: BH
authors.lastname: Brown
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Gonzalez-Correa
authors.forename: John
authors.initials: J
authors.lastname: Bremner
authors.forename: John A
authors.initials: JA
authors.lastname: Tidy
mesh_terms: D001672:Biocompatible Materials; D002482:Cellulose / Q000031:analogs & derivatives; D018553:Cucumis sativus; D017097:Electric Impedance; D005260:Female; D006801:Humans; D017053:Infection Control / Q000379:methods*; D008567:Membranes, Artificial; D008954:Models, Biological; D023321:Poliovirus Vaccines; D012367:RNA, Viral / Q000032:analysis; D012462:Saline Solution, Hypertonic; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis*
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D023321:Poliovirus Vaccines; D012367:RNA, Viral; D012462:Saline Solution, Hypertonic; D002482:Cellulose; C009865:cuprammonium cellulose