{1407} revision 0 modified: 06-02-2018 00:03 gmt

PMID-21896383 Effect of Insertion Speed on Tissue Response and Insertion Mechanics of a Chronically Implanted Silicon-Based Neural Probe

  • Two speeds, 10um/sec and 100um/sec, monitored out to 6 weeks.
  • Once the probes were fully advanced into the brain, we observed a decline in the compression force over time.
    • However, the compression force never decreased to zero.
    • This may indicate that chronically implanted probes experience a constant compression force when inserted in the brain, which may push the probe out of the brain over time if there is nothing to keep it in a fixed position.
      • Yet ... the Utah probe seems fine, up to many months in humans.
    • This may be a drawback for flexible probes [24], [25]. The approach to reduce tissue damage by reducing micromotion by not tethering the probe to the skull can also have this disadvantage [26]. Furthermore, the upward movement may lead to the inability of the contacts to record signals from the same neurons over long periods of time.
  • We did not observe a difference in initial insertion force, amount of dimpling, or the rest force after a 3-min rest period, but the force at the end of the insertion was significantly higher when inserting at 100 μm/s compared to 10 μm/s.
  • No significant difference in histological response observed between the two speeds.