title: Thickness measurement of soft tissue biomaterials: a comparison of five methods.
abstract: Thickness measurement in soft connective tissues is a continuing problem due to the apparent compression of the tissue by micrometer-type gauges. We have compared five methods for the measurement of thickness: (1) a Mitutoyo non-rotating thickness gauge; (2) a custom-built, instrumented thickness gauge which was strain-gauged to measure contact force; (3) a commercial Hall effect probe (Panametrics Magna-Mike); (4) a custom-built electrical resistance probe; and (5) measurement of fresh frozen histological sections under polarized light. Using bovine pericardium as a test material, all the methods examined were adequate to assess sample-to-sample and location-to-location differences in thickness. The resistance gauge gave significantly greater thicknesses than did the other methods, with little or no compression; indeed, extrapolation to zero load of thickness readings from the instrumented gauge yielded identical thickness. Thicknesses measured by frozen sections were indistinguishable from those measured with the non-rotating gauge, the instrumented gauge under 0.5-1.2 g compressive load, or the Hall effect probe. With the correct technique, the simple and inexpensive non-rotating gauge remains a pragmatic choice for thickness measurement in planar soft tissue.
authors.affiliation: Centre for Biomaterials, University of Toronto, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: Lee
authors.forename: S E
authors.initials: SE
authors.lastname: Langdon
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials; D002417:Cattle; D003238:Connective Tissue / Q000033:anatomy & histology; D017097:Electric Impedance; D005615:Freezing; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods; D008859:Microscopy, Polarization; D010496:Pericardium / Q000033:anatomy & histology*; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials