title: Measurements of tortuosity in stereolithographical bone replicas using audiofrequency pulses.
abstract: The tortuosity of five air-filled stereolithographical cancellous bone replicas has been obtained from measurements using audiofrequency pulses in a rectangular waveguide. The data obtained from the replicas yields information about anisotropy with respect to orthogonal axes of the passages that would be marrow filled in vivo. A strong relationship has been found between the acoustically measured tortuosity and the independently measured porosity. Use of stereolithographical bone replicas has the potential to simulate perforation and thinning of cancellous bone and hence evaluate the dependence of acoustic properties on cancellous bone microstructure. As an "extreme" illustration of such use, "inverses" of the original replicas have been manufactured and acoustic measurements have been made on them. The data reveal significantly greater tortuosity of the passages that are geometrically equivalent to the original solid bone structures.
authors.affiliation: Department of Engineering, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom.
authors.forename: Keith
authors.initials: K
authors.lastname: Attenborough
authors.forename: Ho-Chul
authors.initials: HC
authors.lastname: Shin
authors.forename: Qin
authors.initials: Q
authors.lastname: Qin
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Fagan
authors.forename: Christian M
authors.initials: CM
authors.lastname: Langton
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics / Q000295:instrumentation*; D016880:Anisotropy; D001844:Bone Conduction / Q000502:physiology*; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000502:physiology*; D008953:Models, Anatomic; D008954:Models, Biological