Method and apparatus for assessment of changes in intracranial pressure

US6413227B1 · kind B1 · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• William T. Yost · Newport News, US
• John H. Cantrell · Williamsburg, US

Key dates

• Filing date: Dec 2, 1999
• Grant date: Jul 2, 2002
• Expiry date: Dec 2, 2019

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B5/031
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A non-invasive method and apparatus for monitoring changes in intracranial pressure which removes extracranial effects from the measurements. The method and apparatus can include the supplying of a fixed frequency electrical output to a transducer coupled to the patient's head, thereby generating an acoustical tone burst in the patient's head which generates a first echo and a second echo, the first echo reflecting from a first interface in the side of the patient's head coupled to the transducer, and the second echo reflecting from a second interface at the opposite side of the patient's head. The first and second echoes are received by the transducer which can generate a first electrical signal and a second electrical signal, wherein the first and second electrical signals vary in accordance with the corresponding first and second echoes. The counterbalancing phase shifts required to bring about quadrature between each of the first and second electrical signals and the fixed frequency electrical output can be measured, and values for the change in intracranial distance based on the changes in the counterbalancing phase shifts can be obtained.