TY - GEN
T1 - Precise calibration for biological acoustic impedance microscope
AU - Hozumi, N.
AU - Nakano, A.
AU - Terauchi, S.
AU - Nagao, M.
AU - Yoshida, S.
AU - Kobayashi, K.
AU - Yamamoto, S.
AU - Saijo, Y.
PY - 2007
Y1 - 2007
N2 - This report deals with the scanning acoustic microscope for imaging cross sectional acoustic impedance of biological soft tissues. A focused acoustic beam with a wide frequency range up to about 100 MHz was transmitted to the tissue object in contact with the "rear surface" of plastic substrate. The reflected signals from the target and reference are interpreted into local acoustic impedance. Two-dimensional profile is obtained by scanning the transducer. As the incidence is not vertical, not only longitudinal wave but also transversal wave is generated in the substrate. The error in estimated acoustic impedance assuming vertical incidence was discussed. The error is not negligible if the angle of focusing is large, or the acoustic impedance of the reference material is far different from the target. However it can be compensated, if the beam pattern and acoustic parameters of coupling medium and substrate were known. The improvement of precision brought by the compensation was ensured by using a droplet of saline solution of which acoustic impedance was known. Finally, a cerebellum tissue of rat was observed with a good precision.
AB - This report deals with the scanning acoustic microscope for imaging cross sectional acoustic impedance of biological soft tissues. A focused acoustic beam with a wide frequency range up to about 100 MHz was transmitted to the tissue object in contact with the "rear surface" of plastic substrate. The reflected signals from the target and reference are interpreted into local acoustic impedance. Two-dimensional profile is obtained by scanning the transducer. As the incidence is not vertical, not only longitudinal wave but also transversal wave is generated in the substrate. The error in estimated acoustic impedance assuming vertical incidence was discussed. The error is not negligible if the angle of focusing is large, or the acoustic impedance of the reference material is far different from the target. However it can be compensated, if the beam pattern and acoustic parameters of coupling medium and substrate were known. The improvement of precision brought by the compensation was ensured by using a droplet of saline solution of which acoustic impedance was known. Finally, a cerebellum tissue of rat was observed with a good precision.
KW - Acoustic impedanc
KW - Biological tissue
KW - Micro-scale imaging
UR - http://www.scopus.com/inward/record.url?scp=48149099584&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=48149099584&partnerID=8YFLogxK
U2 - 10.1109/ULTSYM.2007.205
DO - 10.1109/ULTSYM.2007.205
M3 - Conference contribution
AN - SCOPUS:48149099584
SN - 1424413834
SN - 9781424413836
T3 - Proceedings - IEEE Ultrasonics Symposium
SP - 801
EP - 804
BT - 2007 IEEE Ultrasonics Symposium Proceedings, IUS
T2 - 2007 IEEE Ultrasonics Symposium, IUS
Y2 - 28 October 2007 through 31 October 2007
ER -