title: Design, simulation and experimental validation of a novel flexible neural probe for deep brain stimulation and multichannel recording.
abstract: An implantable micromachined neural probe with multichannel electrode arrays for both neural signal recording and electrical stimulation was designed, simulated and experimentally validated for deep brain stimulation (DBS) applications. The developed probe has a rough three-dimensional microstructure on the electrode surface to maximize the electrode-tissue contact area. The flexible, polyimide-based microelectrode arrays were each composed of a long shaft (14.9 mm in length) and 16 electrodes (5 µm thick and with a diameter of 16 µm). The ability of these arrays to record and stimulate specific areas in a rat brain was evaluated. Moreover, we have developed a finite element model (FEM) applied to an electric field to evaluate the volume of tissue activated (VTA) by DBS as a function of the stimulation parameters. The signal-to-noise ratio ranged from 4.4 to 5 over a 50 day recording period, indicating that the laboratory-designed neural probe is reliable and may be used successfully for long-term recordings. The somatosensory evoked potential (SSEP) obtained by thalamic stimulations and in vivo electrode-electrolyte interface impedance measurements was stable for 50 days and demonstrated that the neural probe is feasible for long-term stimulation. A strongly linear (positive correlation) relationship was observed among the simulated VTA, the absolute value of the SSEP during the 200 ms post-stimulus period (ΣSSEP) and c-Fos expression, indicating that the simulated VTA has perfect sensitivity to predict the evoked responses (c-Fos expression). This laboratory-designed neural probe and its FEM simulation represent a simple, functionally effective technique for studying DBS and neural recordings in animal models.
authors.affiliation: Department of Electrical Engineering, National Chiao Tung University, No 1001, Ta-Hsueh Rd, Hsinchu 300, Taiwan, Republic of China. irradiance@so-net.net.tw
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Lai
authors.forename: Lun-De
authors.initials: LD
authors.lastname: Liao
authors.forename: Chin-Teng
authors.initials: CT
authors.lastname: Lin
authors.forename: Jui-Hsiang
authors.initials: JH
authors.lastname: Hsu
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.forename: You-Yin
authors.initials: YY
authors.lastname: Chen
authors.forename: Jyh-Yeong
authors.initials: JY
authors.lastname: Chang
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Chen
authors.forename: Siny
authors.initials: S
authors.lastname: Tsang
authors.forename: Yen-Yu I
authors.initials: YY
authors.lastname: Shih
mesh_terms: D000818:Animals; D001931:Brain Mapping; D046690:Deep Brain Stimulation / Q000295:instrumentation*; D017097:Electric Impedance; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004573:Electrolytes / Q000737:chemistry; D004574:Electromagnetic Fields; D004867:Equipment Design; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D020342:Finite Element Analysis; D007150:Immunohistochemistry; D008297:Male; D008839:Microelectrodes; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D013238:Stereotaxic Techniques; D013788:Thalamus / Q000502:physiology
chemical_list: D004573:Electrolytes; D016760:Proto-Oncogene Proteins c-fos