Using artificial dead space to correct hypocapnia or induce hypercapnia is of particular significance for diagnosing and treating specific neurocritical diseases. At present, the above purpose is mainly achieved by adding an extension tube between the Y-type connector of the ventilator and the artificial airway in clinical practice. However, its volume is often fixed and cannot adapt to the individualized diagnosis and treatment in different clinical scenarios. The research group led by Professor Zhou Jianxin from the department of critical care medicine of Beijing Tiantan Hospital, Capital Medical University, has designed an artificial dead cavity with adjustable volume based on years of research in the respiratory field and has been granted a national utility model patent (patent number: ZL 2020 2 0496413.4). The artificial dead chamber is simple in structure, composed of a barrel body, a piston head, and a push-pull rod. By freely adjusting the size of the artificial dead chamber volume, it can accurately regulate the target carbon dioxide, correct the spontaneous hyperventilation, terminate intractable hiccup, and shorten the operation time of asphyxia test in clinical diagnosis of brain death while correcting hypocapnia or inducing hypercapnia. It has the advantages of solid reliability, convenient operation, and low production cost, which significantly facilitates scientific research and clinical diagnosis and treatment.