Patent ID: 8216140

Claim:
A method for measuring internal pressure of a body comprising: aligning with the body a longitudinal axis of a light collecting and delivering device having a wall and an axially extending lumen; illuminating the body by way of the light collecting and delivering device and applying thereto a pneumatic pulse capable of substantially flattening the body, the illuminating light beam and the pneumatic pulse passing axially through the lumen, guiding by total internal reflection through the wall of the light collecting and delivering device light reflected from the body to a detector when the body is in a non-flattened configuration, at least a portion of the light when the body is in a flattened configuration being reflected into the lumen and prevented from reaching the detector; and matching a time-related feature associated with said changes in the light intensity of light reflected to the detector with a given pressure value related to mechanical disturbance, wherein said time related-feature is at least one of: a time length of said pneumatic pulse, a time interval in which said changes of said light intensity measured are detected, and a slope of said changes of said light intensity measured.