title: A time-dependent model for improved biogalvanic tissue characterisation.
abstract: Measurement of the passive electrical resistance of biological tissues through biogalvanic characterisation has been proposed as a simple means of distinguishing healthy from diseased tissue. This method has the potential to provide valuable real-time information when integrated into surgical tools. Characterised tissue resistance values have been shown to be particularly sensitive to external load switching direction and rate, bringing into question the stability and efficacy of the technique. These errors are due to transient variations observed in measurement data that are not accounted for in current electrical models. The presented research proposes the addition of a time-dependent element to the characterisation model to account for losses associated with this transient behaviour. Influence of switching rate has been examined, with the inclusion of transient elements improving the repeatability of the characterised tissue resistance. Application of this model to repeat biogalvanic measurements on a single ex vivo human colon tissue sample with healthy and cancerous (adenocarcinoma) regions showed a statistically significant difference (p < 0.05) between tissue types. In contrast, an insignificant difference (p > 0.05) between tissue types was found when measurements were subjected to the current model, suggesting that the proposed model may allow for improved biogalvanic tissue characterisation.
authors: School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom. Electronic address: mn07jhc@leeds.ac.uk.
authors: J H
authors: JH
authors: Chandler
authors: School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom.
authors: P R
authors: PR
authors: Culmer
authors: Leeds Academic Surgical Unit, St. James's University Hospital, Leeds, United Kingdom.
authors: D G
authors: DG
authors: Jayne
authors: School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom.
authors: A
authors: A
authors: Neville
mesh_terms: D000230:Adenocarcinoma / Q000503:physiopathology; D000818:Animals; D003106:Colon / Q000502:physiology / Q000503:physiopathology; D003110:Colonic Neoplasms / Q000503:physiopathology; D017097:Electric Impedance; D055664:Electrochemical Techniques; D006801:Humans; D008954:Models, Biological; D013552:Swine; D013995:Time
keywords: Biogalvanic; Electrochemical transients; Galvanic cell; Surgical sensing; Time-dependent model; Tissue resistance; Tissue sensing