Patent ID: 8784332
Filing Date: 2014-07-22
Classification: A61B

Abstract:
1. A method of determining an intracranial fluid pressure of an intracranial fluid comprising the steps of: providing a cylindrical crystal oscillator probe having a transducer crystal and a reference crystal, wherein the transducer crystal is in contact with the intracranial fluid; providing at least one driver circuit within the cylindrical crystal oscillator probe connected to the transducer crystal and the reference crystal; exposing the reference crystal to a reference pressure; exposing the transducer crystal to the intracranial fluid pressure; exciting the transducer crystal to provide a first radio frequency energy absorption; exciting the reference crystal to produce a second radio frequency energy absorption; measuring the first radio frequency energy absorption; measuring the second radio frequency energy absorption; comparing the first radio frequency energy absorption and the second radio frequency energy absorption to determine a difference; determining the intracranial fluid pressure from the difference and the reference pressure; determining a first resonance frequency from the first radio frequency absorption; determining a second resonance frequency from the second radio frequency absorption; determining a calibration slope linearly relating a set of absorption frequencies to a set of pressures; wherein the step of determining the intracranial fluid pressure includes application of the formula:  P=the intracranial fluid pressure;  P  m=the calibration slope;  f  f