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ref: Schmidt-1993.11 tags: Normann utah array histology silicon electrode array cats date: 02-23-2017 22:03 gmt revision:4 [3] [2] [1] [0] [head]

PMID-8263001[0] Biocompatibility of silicon-based electrode arrays implanted in feline cortical tissue.

  • Tried two different times:
    • one day before euthanasia
    • 6 month implant.
  • Tried three different implants:
    • Uncoated silicon,
    • polymide coating
    • polymide coating with SiO2 adhesion layer / primer.
  • The last was the worst in terms of histopathological response.
  • Chronic implants showed relatively restrained immune response,
    • Gliosis was found around all tracks, 20-40um.
  • Encapsulation was less than 9um.
  • Edema and hemorrhage was minor but present on a subset of all implants.
  • Acute (24h) hemorrhage was more severe -- ~ 60%; edema ~ 20%.
  • Chronic histology revealed considerable macrophages w/ hemosiderin (a complex including ferritin)
  • See also [1]

____References____

[0] Schmidt S, Horch K, Normann R, Biocompatibility of silicon-based electrode arrays implanted in feline cortical tissue.J Biomed Mater Res 27:11, 1393-9 (1993 Nov)
[1] Jones KE, Campbell PK, Normann RA, A glass/silicon composite intracortical electrode array.Ann Biomed Eng 20:4, 423-37 (1992)

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ref: -0 tags: RF microstimulation cats threshold date: 09-04-2014 18:43 gmt revision:1 [0] [head]

PMID-13539663 Subcortical threshold voltages as a function of sine wave frequencies Brown and Brackett

  • 22 GA insulated stainless steel electrodes, both bipolar and monopolar.
    • This happens to be near spike recording passband, unfortunately.
  • Square wave stimulation (8) Mihailovic and Delgado 1956 "Electrical stimulation of monkey brain with various frequencies and pulse durations".
  • Hines (6)(1940) , stimulating the monkey cortex with [a] sine wave, reported jerky uncompleted movements from 1260 Hz to 1440 Hz.
    • Monopolar surface stimulation, though.