Volume 26, Issue 6 (November 1998)
Evaluation of Three Methodologies for Testing Disposable ENT Endoscope Sheaths as Viral Barriers
Three methods to determine the barrier function of ENT endoscope sheaths were evaluated: (1) the air deflation test, a candidate quality assurance test, compared differences in pressure between a test sheath and an intact one; (2) a virus barrier test challenged with bacteriophage ΦX174 outside the sheath, with barrier penetration determined by rinsing inside and assaying for penetrated virus; (3) another virus barrier test challenged from inside, with virus penetration determined by assaying a collection/submersion solution. Sheaths with laser-drilled holes or tears generated by acupuncture needles were tested. Five-µm holes and larger were detected by air deflation or inside virus challenge. Outside virus challenge could reliably detect only 30-µm holes. Tears of 35-µm length were detected by inside virus challenge, while all three tests detected 85-µm tears. In addition, air bubbles during submersion detected and located 5-µm holes and larger, suggesting another quality assurance test.