Patent Number: 6,309,354

Title: Non-Invasive in vivo pressure measurement

Abstract: Apparatus and methods are disclosed for non-invasive measurement of bloodvelocity in otherwise inaccessible body regions, and for correlating suchmeasurements with externally applied pressure to detect and/or assessdiseases or physiological abnormalities. The blood velocity measurementscan be based on the Doppler shift that occurs when an ultrasonic wave isscattered by moving particles within the blood. Since blood vessels haveelastic walls, the geometry of the walls, and therefore the flow dynamics,will change in response to elevated in vivo pressure. The change inresistance to blood flow resulting from these pressure induced changes tothe blood vessel wall geometry can provide a measure of intracranialpressure, ophthalmic pressure or various other body conditions that affectblood perfusion. Since the blood vessel wall geometry changes rapidly inresponse to such changes in pressure, the invention can be used to detecthydrocephalus, retinopathy, papilledema and other physiologicalabnormalities manifested by pressure changes.

Inventors: Madsen; Joseph R. (Newton, MA), Taylor; George A. (Wellesley, MA)


International Classification:

Expiration Date: 10/32013