Carson took two days after finals to sleep and binge watch anime before he had the mental capacity to get back to work on the electrode issue. Ivy brought the machine in her backpack on the first day of graduation practice and since that was only a few hours long he spent the rest of the day tinkering with it.
He could easily attach or detach more electrodes as needed but he couldn't test anything without her being here. He almost couldn't believe how close they were to fixing her problem. They had come a long way since her radius first expanded and he proposed his crazy idea.
She had seemed a lot less worn out in the few weeks before AP testing and that was from having a reduced number of voices only part of the time. Then she rejoined the ranks of the undead alongside everyone else but that was beside the point. The machine worked even in its partially completed state.