Patent ID: 6328694
Filing Date: 2001-12-11
Classification: A61B

Abstract:
A method for monitoring intra cranial pressure at a selected site in a brain of a human patient, comprising the steps of:placing an ultrasound probe on a forehead of a patient;transmitting an ultrasound pulse from the ultrasound probe into the forehead of the patent;receiving a reflected signal from said ultrasound pulse;processing said reflected signal to generate a digital echo encephalogram signal;selecting a portion of said echo encephalogram signal;integrating the echo encephalogram signal over the selected portion to generate an echo pulsograph signalcalculating the intra cranial pressure from said echo pulsogram signal in accordance with the formula:intra cranial pressure=.rho.(t/T)*[t/T]-.beta.wherein T is the time period between cardiac systoles, t is the time from the beginning of brain pulsatility to the peak following a venous notch (point ""B""), .beta. is a constant having a value of 9 mm H.sub.2 O, and .rho.(t/T) is a variable function greater than 0 and less than 1, which is characteristic of brain tissue at a site in the brain of the patient corresponding to the selected portion of the echo encephalogram.