title: Characterization of high capacitance electrodes for the application of direct current electrical nerve block.
abstract: Direct current (DC) can briefly produce a reversible nerve conduction block in acute experiments. However, irreversible reactions at the electrode-tissue interface have prevented its use in both acute and chronic settings. A high capacitance material (platinum black) using a charge-balanced waveform was evaluated to determine whether brief DC block (13 s) could be achieved repeatedly (>100 cycles) without causing acute irreversible reduction in nerve conduction. Electrochemical techniques were used to characterize the electrodes to determine appropriate waveform parameters. In vivo experiments on DC motor conduction block of the rat sciatic nerve were performed to characterize the acute neural response to this novel nerve block system. Complete nerve motor conduction block of the rat sciatic nerve was possible in all experiments, with the block threshold ranging from -0.15 to -3.0 mA. DC pulses were applied for 100 cycles with no nerve conduction reduction in four of the six platinum black electrodes tested. However, two of the six electrodes exhibited irreversible conduction degradation despite charge delivery that was within the initial Q (capacitance) value of the electrode. Degradation of material properties occurred in all experiments, pointing to a possible cause of the reduction in nerve conduction in some platinum black experiments .
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA. tlv@case.edu.
authors.forename: Tina
authors.initials: T
authors.lastname: Vrabec
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA. nxb26@case.edu.
authors.forename: Niloy
authors.initials: N
authors.lastname: Bhadra
authors.affiliation: Department of Chemical Engineering, Case Western Reserve University, Cleveland, OH, USA. jsw7@case.edu.
authors.forename: Jesse
authors.initials: J
authors.lastname: Wainright
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA. narendra.bhadra@case.edu.
authors.forename: Narendra
authors.initials: N
authors.lastname: Bhadra
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA. Manfred.Franke@gmail.com.
authors.forename: Manfred
authors.initials: M
authors.lastname: Franke
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA. klk4@case.edu.|MetroHealth Medical Center, Cleveland, OH, USA. klk4@case.edu.|Louis Stokes Cleveland Department, Veterans Affairs Medical Center, Cleveland, OH, USA. klk4@case.edu.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kilgore
mesh_terms: D004566:Electrodes; D006801:Humans; D009407:Nerve Block / Q000379:methods*
keywords: Direct current; Electrode; Nerve block; Nerve damage; Platinum black