MINDZ-- Minimally Invasive Approach Pilot Study

Inclusion Criteria: * Age ≥18 and ≤75 years at the time of enrolment. * Patients diagnosed with a brain tumour or epilepsy who require neurosurgical intervention. This includes patients undergoing craniotomy for brain surgery without the need for intracranial electrode monitoring, as well as patients undergoing neurosurgery with intraoperative neurophysiological monitoring using subdural electrodes. Specifically, this includes patients for whom subdural strip electrodes are indicated and planned to be implanted through standard-size burr holes (e.g., for phase-reversal evaluation) * Participants capable and willing to provide informed consent for participation in the trial. Exclusion Criteria: * History of significant psychiatric impairments which, in the opinion of the investigator, will interfere with the proper administration or completion of the protocol. * Any medical condition that contradicts neurosurgical intervention (i.e., acute or ongoing untreated infections, anticoagulant medication that cannot be discontinued, factor XIII deficiency or any other hematological disease). * Participation in another clinical study. * Known intolerances to the materials used in the soft device (medical grade silicone or platinum). * Vulnerable subject groups (e.g., pregnancy or lactation, prisoners, etc.). * Any other significant disease or disorder which, in the opinion of the investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial.