Brain biomechanics: monitoring the biomechanical properties of the human craniospinal system

The existing methods of assessing the biomechanical properties of the human craniospinal system are reduced to the study of the dynamics of changes in intracranial pressure with a dosed increase in intracranial volume by introducing a certain volume of fluid into the cranial space. These studies are discrete, traumatic. In different neurosurgical clinics, retrospective analysis of 1732 studies of biomechanical properties of the human craniospinal system (compliance, pressure-volume ratio, elasticity) in the period 1988-2014 were conducted. In order to establish a diagnosis or clarify the tactics of surgical treatment, a relationship between the amplitude of the intracranial pressure oscillation at the pulse rate, intracranial pressure and the compliance of the craniospinal system was established. In a single classical test with the introduction of a bolus of a small volume of fluid, and the indicators of biomechanical properties of the human craniospinal system are numerically evaluated. It is assumed that between two pulse waves (in the second range), these indicators do not change significantly, that is, in fact, we are talking about monitoring biomechanical properties of the human craniospinal system. A mathematical model is proposed that formalizes the relationship between biomechanical properties of the human craniospinal system and the dynamics of intracranial pressure oscillations at the pulse rate. Comparison of the results of the assessment of the main biomechanical indicators by the classical method and the proposed method established their high correlation. On the basis of this, an algorithm is proposed that can be used to create the original biomechanical properties of the human craniospinal system and intracranial pressure monitor.