The present invention relates to a method and a device for determining the hydro-dynamic properties of the
fluid system surrounding the brain and the
spinal cord, the so called
cerebrospinal fluid system, whereby the method comprises continuous
pressure measurement through a fluid contact passage and active infusion of
artificial cerebrospinal fluid through another fluid contact passage to a number of pressure-flow levels, and analysis of the connections between the measured pressures and flows. The method uses an adaptive way of procedure which on each pressure-flow level takes account for the measure time and the patient's fluctuations in physiologic signals for calculating in real time when the relation between the measure time and measure accuracy in pressure and flow on the actual pressure-flow level is sufficient and at an optimum, whereupon the investigation or examination is automatically proceeding to the next level according to a predetermined protocol. In this way, the method gives rise to an investigation with measurements having sufficient pressure and flow information on each level, which forms a base for determination in a correct manner, with an
uncertainty estimate, of the patient's hydrodynamic parameters. The device comprises a hose pump (1) for infusion of
artificial cerebrospinal fluid in a
bottle or bag (2), a standardized hose set including a pump hose (3) and pressure transducers (4) for continuous registration of the
intracranial pressure, an invasive contact object (5) for creating fluid contact with the
cerebrospinal fluid system and consisting of needles or a
catheter, as well as a computer (12) with
software for computerized collection and analysis as well as control of pump speed. The device uses a computerized implementation of the above-mentioned
adaptive method in order to systematically and safely carry through a standardized protocol which generates pressure and flow information which the
software of the measure
system then uses for determining in real time and with an
uncertainty estimate, the hydrodynamic parameters of the system.