A two-beam acoustic system for tissue analysis.
A two-beam acoustic system for tissue analysis.
复制标题
用于组织分析的双光束声学系统。
DOI：
10.1088/0031-9155/22/2/012
复制
发表时间：
1977
影响因子：
3.5
通讯作者：
C. D. Janney
中科院分区：
文献类型：
--
作者：
T. Sachs;C. D. Janney
In the 'thermo-acoustic sensing technique' (TAST), a burst of sound, called the 'thermometer' beam is passed through tissue and its transit time is measured. A focused sound field, called the heating field, then warms a small volume in the path of the therometer beam, in proportion to the absorption. Finally, the therometer beam burst is repeated and its transit time subtracted from that of the initial thermometer burst. This difference measures the velocity perturbation in the tissue produced by the heating field. The transit time difference is td = K integral of infinity-infinity IP dchi where K is the instrument constant, I the heating field intensity, and P a perturbation factor which characterizes the tissues. The integration is carried out along the path of the thermometer beam. The perturbation factor is P = (formula: see text) where C is the specific heat, rho the denisty, V the velocity of sound, (formula: see text) the temperature coefficient of velocity and alpha the heating field absorption coefficient which is apparently sensitive to tissue structure and condition. Experiments on a fixed human brain showed an ability to distinguish between various tissue types combined with a spatial resolution of better than 3 mm. Should predictions based on the data and theory prove correct, TAST may become a non-invasive alternative to biopsy.
