Fig. 6: Localization of the SCEAs.

a–d An example showing postoperative SCEA localization. a A postoperative T1-weighted MRI image of a beagle dog brain implanted with a 20 mm × 10 mm 256-channel Ni-SCEA. b 3D reconstruction of the brain and Ni-SCEA according to serial MRI images using MIPAV software (http://www.mipav.cit.nih.gov). The Ni-SCEA is schematically shown by the red rectangle. The red arrows in (a, b) point to the Ni-SCEA. c Three MRI images sectioned along the cortical surface of the brain from the reconstructed 3D MRI image. The portion of the Ni-SCEA sectioned in each plane (1–3) was located in the optical image acquired during surgery, where the semitransparency of the beagle dog dura enabled direct visualization of the Ni-SCEA. The solid red line indicates one edge of the Ni-SCEA, which has a length of 20 mm. ‘A’ indicates anterior, ‘P’ indicates posterior. d Localization of the Ni-SCEA relative to anatomical cortical structures by registering the T1 population template to the subject’s T1 native space. e, f An example showing intraoperative localization of the SCEA using the Brainsight neuronavigation (Vet Robot) system. A 20 mm × 15 mm 64-channel SCEA was implanted subdurally into the brain of a beagle dog. e Overlay of CT images onto MRI images to create a 3D reconstructed image of the skull and brain. f Localization of the SCEA using the Brainsight^TM neuronavigation (Vet Robot) system. By defining the positions of three points marked by 1–3 around the interconnection lines at the dura slit exit, the locations of the recording contacts, which are marked with red dots, relative to the anatomical structures of the brain could be determined according to the layout of the electrode design. KP coronalis posterior, QA ectolateralis anterior, QP ectolateralis posterior, SSM suprasylvian gyrus, MP marginal gyrus, BP entolateral gyrus, EM ectosylvian gyrus. The population template in panels d and f are adapted from ref. ⁴⁵.