matrix electrodes  (World Precision Instruments)

Journal: PLOS ONE

Article Title: Using camera-guided electrode microdrive navigation for precise 3D targeting of macaque brain sites

doi: 10.1371/journal.pone.0301849

Figure Lengend Snippet: This setup allows movements in 3 translational and 3 rotational axes during online position tracking with IR-cameras. (A) The arch that is holding the microdrive is mounted on two vertical and parallel aluminum beams which allows to change its height. The arch can be rotated along the horizontal line connecting the vertical beams. A set of three linear micromanipulators is mounted on the arch and can be moved along the arch to rotate around the center point of the arch, where the target is placed. The linear micromanipulators can be used to adjust the 3 translational axes and to finally drive the tip of the guide tube down into the tissue. Lastly, the microdrive is connected to the linear micromanipulators on a table that is rotatable 360 degrees. (B) Layout of the CortEXplore System interacting with the TREC Microdrive. The CortEXplore Navigation PC is connected to IR-cameras that are tracking the monkey’s head as well as the microdrive’s position relative to each other. A recording trajectory is defined based on an experimental planning file that utilizes CT and MR imaging. The rotational and translational offsets of the realtime electrode trajectory are then displayed by the CortEXplore system, and the micromanipulators set accordingly to minimize the positioning error. Once the positioning error is minimized on all axes (excluding the penetration axis of the electrode), the TREC Matrix computer advances the electrode out of the guide tube along that axis to the desired target depth (adapted Figure, originally provided by CortEXplore GmbH). (C) Photograph of the setup with a monkey head plastic. Physical objects (red) and their representations in digital 3D space (yellow) are encircled. After co-registration, the stiff connection between the reference geometry A and the monkeys head B, allows positioning of the TREC Mini Matrix C relative to the monkey’s anatomy.

Article Snippet: The Mini Matrix electrode microdrive (Thomas RECORDING GmbH (TREC), Giessen, Germany; customized for cortEXplore compatibility) and the monkeys head are continuously tracked by cortEXplore’s infrared camera system that allows precise evaluation of electrode positions relative to the target volume while advancing recording electrodes.

Techniques: Imaging

Journal: PLOS ONE

Article Title: Using camera-guided electrode microdrive navigation for precise 3D targeting of macaque brain sites

doi: 10.1371/journal.pone.0301849

Figure Lengend Snippet: The rotational offset of each axis is displayed on top of each axis section with the planned trajectory (blue) and realtime trajectory (red). The red dot along the realtime trajectory equals the guide tube tip of the MiniMatrix. The upper blue dot along the planned trajectory is the planned guide tube tip position, and the lower dot shows the electrode target position. The figure shows the realtime trajectory and positioning errors before the fine adjustment. Rotational offsets, displayed at the top of each window, are minimized first by adjusting the respective micromanipulators (rotational errors in this figure: coronal: 6.74°, sagittal: 7.44°, axial: 74.65°). Afterwards, the translational offset of the realtime trajectory to the target location is minimized using the translational micromanipulators. Once the distance depicted in ‘Tool axis to target’ (here 8.35 mm) in the lower right corner is minimized (close to 0 mm), the microdrive is advanced into the tissue along the tool axis which is matching the guide tube.

Article Snippet: The Mini Matrix electrode microdrive (Thomas RECORDING GmbH (TREC), Giessen, Germany; customized for cortEXplore compatibility) and the monkeys head are continuously tracked by cortEXplore’s infrared camera system that allows precise evaluation of electrode positions relative to the target volume while advancing recording electrodes.

Techniques: