Patent ID: 7688677

Claim:
A method for determining the distance of a transceiver located within a lumen from the center of the lumen and for determining the radius of the lumen, the lumen cross-section being substantially circular at the transceiver location, the method applied on data received from a transceiver placed at a position within the lumen that is distance (r) from the center, the method comprising: transmitting a signal of known velocity (v); receiving two echo signals, the first signal related to a near section of the lumen and the second signal related to an outermost section of the lumen; timing a first time difference between the transmission time of the transmitted signal and reception time of the first echo signal (t 1 ) and a second time difference between the transmission time of the transmitted signal and the reception time of the second echo signal (t 2 ); calculating the distance of the transceiver from the center of the lumen r using the equation r=(t 1 −t 2 )v/4; and calculating the radius of the lumen R using the equation R=(t 1 +t 2 )v/4.