Sonomicrometer method Pressure-volume loop experiments

assortment of sonomicrometer crystals

ventricular volume computed directly (either in micro-liters or milli-liters) combining axial length measurements in standard spherical or ellipsoidal volume equations:

v
o
l
u
m
e
=


4
3


×
π
×

r

3




{\displaystyle volume={\frac {4}{3}}\times \pi \times r^{3}}

(for single-axis measurement)

v
o
l
u
m
e
=


π
6


×

l

1


×

l

2


2




{\displaystyle volume={\frac {\pi }{6}}\times l_{1}\times l_{2}^{2}}

(for two-axis measurement, l1 length of long axis)

v
o
l
u
m
e
=


π
6


×

l

1


×

l

2


×

l

3




{\displaystyle volume={\frac {\pi }{6}}\times l_{1}\times l_{2}\times l_{3}}

(for three-axis measurement)

when axial measurements acquired in terms of millimeters, volume units in these equations in terms of milliliters.