title: Simulation of injury potential compensation by direct current stimulation in rat spinal cord.
abstract: Injury potential, a significant index of spinal cord injury (SCI), is generated by the movement of extracellular ions. It can be compensated through applied direct current (DC) stimulation, which prevents the influx of the free calcium, and eventually reduces the development of secondary injury. Therefore, the compensation of injury potential is beneficial to the repairing of the function of spinal cord. The compensation effect can be evaluated by whether the magnitudes of longitudinal electric fields (EFs) are compensated to zero. However, there have been no established criteria to determine the distribution and shape of stimulating electrodes. In this study, in order to optimize the stimulating electrodes, a finite element model (FEM) of rat spinal cord was developed, and the EFs changes induced by electrodes of different sizes, shapes and locations after SCI were calculated. All the designed configurations of electrodes were able to compensate injury potential, but the resultant compensation effects vary. Pin and disc electrodes produced uneven EFs, while ring electrodes produced uniformly distributed EFs. Moreover, large ring electrodes can compensate the longitudinal EFs almost to zero with relatively low current density (0.55 μA/mm(2)) applied. These results provide a basis for the determination of electrical stimulation parameters in the compensation of injury potential.
authors.affiliation: Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, No. 6 Beiertiao, Zhongguancun, Haidian district, Beijing 100190, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, No. 6 Beiertiao, Zhongguancun, Haidian district, Beijing 100190, China.
authors.forename: Guanghao
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, No. 6 Beiertiao, Zhongguancun, Haidian district, Beijing 100190, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, No. 6 Beiertiao, Zhongguancun, Haidian district, Beijing 100190, China.
authors.forename: Changzhe
authors.initials: C
authors.lastname: Wu
authors.affiliation: Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, No. 6 Beiertiao, Zhongguancun, Haidian district, Beijing 100190, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.affiliation: Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, No. 6 Beiertiao, Zhongguancun, Haidian district, Beijing 100190, China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Huo
mesh_terms: D000818:Animals; D020013:Calcium Signaling; D003198:Computer Simulation; D017076:Computer-Aided Design; D004567:Electrodes, Implanted; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D008959:Models, Neurological; D051381:Rats; D013116:Spinal Cord / Q000503:physiopathology*; D013119:Spinal Cord Injuries / Q000503:physiopathology* / Q000628:therapy*; D062187:Spinal Cord Stimulation / Q000295:instrumentation* / Q000379:methods; D015599:Trauma Severity Indices; D016896:Treatment Outcome
keywords: Direct current stimulation; electric fields; finite element model; spinal cord injury