The aim of the study was to assess changes in subarachnoid space width (sas-TQ). the marker of intracranial pressure (ICP). pial artery pulsation (cc-TQ) and cardiac contribution to blood pressure (BP). cerebral blood flow velocity (CBFV) and cc-TQ oscillations throughout the maximal breath hold in elite apnoea divers. https://seisukeknifes.shop/product-category/cutting-board/