USE OF SONOMICROMETRY AND MULTIDIMENSIONAL-SCALING TO DETERMINE THE 3-DIMENSIONAL COORDINATES OF MULTIPLE CARDIAC LOCATIONS - FEASIBILITY AND INITIAL IMPLEMENTATION
Mb. Ratcliffe et al., USE OF SONOMICROMETRY AND MULTIDIMENSIONAL-SCALING TO DETERMINE THE 3-DIMENSIONAL COORDINATES OF MULTIPLE CARDIAC LOCATIONS - FEASIBILITY AND INITIAL IMPLEMENTATION, IEEE transactions on biomedical engineering, 42(6), 1995, pp. 587-598
We describe a new method which uses sonomicrometry and the statistical
technique of multidimensional scaling (MDS) to measure the three-dime
nsional (3-D) coordinates of multiple cardiac locations, We refer to t
his new method as sonomicrometry array localization (SAL). The new met
hod differs from standard sonomicrometry in that each piezoelectric tr
ansducer element is used as both transmitter and receiver and the set
of intertransducer element distances is measured, MDS calculates the 3
-D coordinates of each sonomicrometry transducer element from the set
of intertransducer element distances, The feasibility of this new meth
od was tested with mathematical simulations which demonstrated the abi
lity of MDS to compensate for signal error and missing intertransducer
element distances, We describe the design elements of a modified digi
tally controlled sonomicrometer in which a single transducer element c
an sequentially broadcast to as many as eight receiver elements, That
design is used to validate SAL in a water bath and in ex vivo and livi
ng hearts, Correlation with caliper measurement in the water bath (y i
nt. = 3.91 +/- 3.36 mm, slope = 1.04 +/- 0.05, r(2) = 0.969 +/- 0.027)
and with radiography in ex vivo (y int. = -0.87 +/- 0.92 mm, slope =
0.97 +/- 0.02, r(2) = 0.960 +/- 0.023) and in vivo hearts (y int. = 2.
98 +/- 2.59 mm, slope = 1.01 +/- 0.06, r(2) = 0.953 +/- 0.031) was exc
ellent. Sonomicrometry array localization is able to accurately measur
e the 3-D coordinates of multiple cardiac locations. it can potentiall
y measure myocardial deformation and remodeling after ischemic or valv
ular injury.