Silicon microelectrode-based simulation of brain tissue micromotion-induced injury(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2018年第1期
- Page:
- 120-124
- Research Field:
- 脑科学与神经物理
- Publishing date:
Info
- Title:
- Silicon microelectrode-based simulation of brain tissue micromotion-induced injury
- Author(s):
- ZHANG Bingshu; SUI Li
- School of Medical Instrumentation and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
- Keywords:
- ; Keywords: silicon electrode; finite element; micromotion; tissue injury
- PACS:
- R318
- DOI:
- DOI:10.3969/j.issn.1005-202X.2018.01.022
- Abstract:
- Abstract: Objective To predict the injuries induced by brain tissue micromotions and improve the long-term stability of brain implanted electrode by developing finite element models of brain tissues based on silicon microelectrode and conducting a series of numerical simulations of the neural probe-finite element model. Methods The material of brain tissue was described by a hyper-viscoelastic constitutive equation. Strain fields around the electrode were analyzed in varying micromotion models (longitudinal and transverse) and different degrees of physical coupling between the electrode and the brain tissues. Results The analysis of longitudinal loading showed that the maximum von Mises strain around the electrode decreased with increasing friction coefficients, and that strain peaked at the electrode tip, which indicated that physical coupling degree between the electrode and the brain tissues had significant effects on the injuries induced by brain tissue micromotions. Enhancing the attachment between the electrode and the brain tissues was proved to effectively decrease brain tissue injury. The design of the electrode tip also greatly affected the strain of the brain tissues. The analysis of transverse loading revealed that the brain injury region due to the X-axis direction micromotions was approximately 60 ?m. Given this result, when a multi-probe array was implanted into the brain, the strains induced by individual probes may overlap if the distance between probes was shorter than the affected range (60 ?m). Those findings were of great significant for deciding an ideal spacing between electrodes and preventing excess cellular sheath formation due to overlapping strain. Conclusion The established numerical model can provide references for the parameters of the electrode-brain tissue interface and the design of neural probe, which will be helpful to reduce tissue injuries and improve the working life of implanted electrode, achieving the long-term clinical application.
Last Update: 2018-01-25