In Vivo Electrical Impedance Spectroscopy of Tissue Reaction to Microelectrode Arrays

The goal of this experiment was to determine the electrical properties of the tissue reaction to implanted microelectrode arrays. We describe a new method of analyzing electrical impedance spectroscopy data to determine the complex impedance of the tissue reaction as a function of postimplantation time. A model is used to extract electrical model parameters of the electrode-tissue interface, and is used to isolate the impedance of the tissue immediately surrounding the microelectrode. The microelectrode arrays consist of microfabricated polyimide probes, incorporating four 50-mum-diameter platinum microelectrodes. The devices were implanted in the primary motor cortex of adult rats, and measurements were performed for 12 weeks. Histology was performed on implants at three time points in one month. Results demonstrate that the tissue reaction causes a rapid increase in bioimpedance over the first 20 days, and then stabilizes. This result is supported by histological data.

[1]  M Pelizzone,et al.  Subretinal electrode implantation in the P23H rat for chronic stimulations , 2006, British Journal of Ophthalmology.

[2]  W. Grill,et al.  Electrical properties of implant encapsulation tissue , 2006, Annals of Biomedical Engineering.

[3]  C. McIntyre,et al.  Sources and effects of electrode impedance during deep brain stimulation , 2006, Clinical Neurophysiology.

[4]  Jeffrey H Kordower,et al.  Deep brain stimulation for treatment of obesity in rats. , 2007, Journal of neurosurgery.

[5]  Andrew B Schwartz,et al.  Cortical neural prosthetics. , 2004, Annual review of neuroscience.

[6]  A. Covalin,et al.  Deep Brain Stimulation for Obesity Control: Analyzing Stimulation Parameters to Modulate Energy Expenditure , 2005, Conference Proceedings. 2nd International IEEE EMBS Conference on Neural Engineering, 2005..

[7]  P. Renaud,et al.  Demonstration of cortical recording using novel flexible polymer neural probes , 2008 .

[8]  Thomas Stieglitz,et al.  ELECTRODE MATERIALS FOR RECORDING AND STIMULATION , 2004 .

[9]  D. Szarowski,et al.  Cerebral Astrocyte Response to Micromachined Silicon Implants , 1999, Experimental Neurology.

[10]  D. Szarowski,et al.  Brain responses to micro-machined silicon devices , 2003, Brain Research.

[11]  A. Lozano,et al.  Deep Brain Stimulation for Treatment-Resistant Depression , 2005, Neuron.

[12]  P. Renaud,et al.  Technology developments to initiate a next generation of Cochlear Implants , 2007, 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[13]  Daniel R Merrill,et al.  Impedance characterization of microarray recording electrodes in vitro , 2005, IEEE Trans. Biomed. Eng..

[14]  E. McAdams,et al.  The linear and non-linear electrical properties of the electrode-electrolyte interface , 1995 .

[15]  David C. Martin,et al.  Chronic neural recordings using silicon microelectrode arrays electrochemically deposited with a poly(3,4-ethylenedioxythiophene) (PEDOT) film , 2006, Journal of neural engineering.

[16]  G. Paxinos,et al.  The Rat Brain in Stereotaxic Coordinates , 1983 .

[17]  W. Kenan,et al.  Impedance Spectroscopy: Emphasizing Solid Materials and Systems , 1987 .

[18]  R. Shepherd,et al.  Electrical stimulation of the auditory nerve: direct current measurement in vivo , 1999, IEEE Transactions on Biomedical Engineering.

[19]  J. Muthuswamy,et al.  Brain micromotion around implants in the rodent somatosensory cortex , 2006, Journal of neural engineering.

[20]  L. Geddes,et al.  The specific resistance of biological material—A compendium of data for the biomedical engineer and physiologist , 1967, Medical and biological engineering.

[21]  C. McIntyre,et al.  Tissue and electrode capacitance reduce neural activation volumes during deep brain stimulation , 2005, Clinical Neurophysiology.

[22]  J Jossinet,et al.  Tissue impedance: a historical overview. , 1995, Physiological measurement.

[23]  V. Pollak,et al.  An equivalent diagram for the interface impedance of metal needle electrodes , 1974, Medical and biological engineering.

[24]  J. Newman.  Resistance for Flow of Current to a Disk , 1966 .

[25]  O. Wolfbeis,et al.  Capacitive monitoring of protein immobilization and antigen-antibody reactions on monomolecular alkylthiol films on gold electrodes. , 1997, Biosensors & bioelectronics.

[26]  Daryl R Kipke,et al.  Complex impedance spectroscopy for monitoring tissue responses to inserted neural implants , 2007, Journal of neural engineering.

[27]  A. Benabid.  Deep brain stimulation for Parkinson’s disease , 2003, Current Opinion in Neurobiology.

[28]  R. D. Levie,et al.  On the impedance of electrodes with rough interfaces , 1989 .

[29]  W. Reichert,et al.  Polyimides as biomaterials: preliminary biocompatibility testing. , 1993, Biomaterials.

[30]  James D. Weiland,et al.  Chronic neural stimulation with thin-film, iridium oxide electrodes , 2000, IEEE Trans. Biomed. Eng..

[31]  P. Renaud,et al.  Flexible polyimide probes with microelectrodes and embedded microfluidic channels for simultaneous drug delivery and multi-channel monitoring of bioelectric activity. , 2004, Biosensors & bioelectronics.

[32]  G M Clark,et al.  A study of intra-cochlear electrodes and tissue interface by electrochemical impedance methods in vivo. , 2004, Biomaterials.

[33]  Andreas Hierlemann,et al.  Impedance characterization and modeling of electrodes for biomedical applications , 2005, IEEE Transactions on Biomedical Engineering.

[34]  Richard S. C. Cobbold,et al.  Transducers for biomedical measurements: principles and applications , 1974 .

[35]  R. Bellamkonda,et al.  Biomechanical analysis of silicon microelectrode-induced strain in the brain , 2005, Journal of neural engineering.

[36]  D. Djajaputra.  Electrical Impedance Tomography: Methods, History and Applications , 2005 .

[37]  G. Abadal,et al.  Electrochemical platinum coatings for improving performance of implantable microelectrode arrays. , 2002, Biomaterials.

[38]  Daniel Palanker,et al.  Design of a high-resolution optoelectronic retinal prosthesis , 2005, Journal of neural engineering.

[39]  David C. Martin,et al.  In vivo studies of polypyrrole/peptide coated neural probes. , 2003, Biomaterials.