What is the fine-grained topic of the following text: As director of cerebrovascular and neuroendovascular research at the UC Irvine School of Medicine's Department of Neurological Surgery, Lin’s goal is to improve and develop novel endovascular devices and techniques to help UCI Health patients with cerebrovascular disorders. Only return the topic.
Lin's role and goals in improving treatments for cerebrovascular disorders at UC Irvine School of Medicine's Department of Neurological Surgery