Technological assessment of the biogalvanic method for tissue characterization.

Biogalvanic cells have the potential to be used in characterizing biological tissue properties and ultimately tissue health. A biogalvanic cell is established by placing two differing metal electrodes across a target tissue allowing an electrical tissue-specific internal resistance to be determined. A novel data analysis method using least-squares fitting has been developed to more effectively determine the parameters of the biogalvanic system model proposed in the literature. The validity of the method has been examined through characterization of electrical models, ex vivo porcine tissue, and in vivo porcine tissue. Strong agreement between test results and the proposed characterization model has been shown. However, determined internal resistances are influenced by mechanical strain, current modulation direction and tissue thickness, indicating complexities at the electrode–tissue interface. These complexities undermine some assumptions upon which the biogalvanic model is based. Ultimately this technique could offer potential for use in minimally invasive surgery for discriminating tissue health but requires improved understanding and control of testing conditions.