Method and apparatus for noninvasive absolute (mean) intracranial pressure (A-ICP) measurement and/or monitoring

A non-invasive method for measuring an intracranial pressure (ICP) of a person, comprising:

• using at least one probe configured to be positioned so as to emit energy at pulsating tissue or cavities in the brain of the person and to receive reflected signals;
• deriving from the signals or from images associated with the signals, using a processor, an ICP waveform;
• applying an external pressure, and then incrementally increasing the external pressure, to the person's skull using a pressure mechanism in communication with the processor, the pressure mechanism including a pressure applying component having at least one surface and a manometer and configured to apply the external pressures including the incrementally increased external pressures, to the person's skull when the at least one surface contacts the person's skull;
• detecting, using the processor, a decrease in amplitude of the ICP waveform, the decrease beginning at an initial value A1 of the amplitude, and a final value A2,
• detecting, using the processor, an intracranial reserve space (ICRS) intermediate period and detecting such decrease in amplitude of the ICP waveform that occurs after the ICRS intermediate period is completed;
• and
• determining, using the processor, the ICP of the person as a function of values of the applied external pressures applied beginning on or after a time of the initial value A1 and ending by a time of the final value A2 or earlier,
• wherein the values of the applied external pressures include the values of the applied incrementally increased external pressures.