Biomedical Engineering Reference
In-Depth Information
0.14
0.11
0.10
0.08
0.07
0.05
0.04
0.02
0.01
-
0.01
-
0.02
-
0.04
-
0.05
-
0.07
-
0.08
-
0.09
-
0.11
-
0.12
-
0.14
-
3.0
-
1.8
-
0.6
0.6
1.8
3.0
0.14
-
3.0
-
1.8
-
0.6
0.6
1.8
0.14
0
0
-
0.14
-
2.4
-
1.2
-
0.14
-
2.4
-
1.2
3.0
0
0
1.2
1.2
2.4
2.4
Y
Axis (mm)
(a)
Y
Axis (mm)
(b)
FIGuRE 16.2 (See color insert.)
. Wavefront. change. ater. AO. compensation.. he. sample. is. a. mouse. heart,.
as. described. in.
Section. 16.3.4
.
and. imaged. at. 20. μm. depth.. (a). Distorted. wavefront. without. the. compensation..
(b) Wavefront.ater.AO.compensation.
(a)
(b)
-
0.0120
0.0005
-
0.0047
-
0.0012
-
0.0072
Astigmatism at 0
°
-
0.0411
0.0198
0.0051
-
0.0087
-
0.0048
Astigmatism at 0
°
Astigmatism at 45
°
Coma at 0
°
Astigmatism at 45
°
Coma at 0
°
Coma at 90
°
Coma at 90
°
ird-order spherical aberration
ird-order spherical aberration
0.02
0.02
0.00
0.00
-
0.02
-
0.02
-
0.04
-
0.04
4
5
6
7
8
4
5
6
7
8
µ
m
µ
m
ird-order aberrations
(Zernike coe
�
cients)
ird-order aberrations
(Zernike coe
�
cients)
FIGuRE 16.3
hird-order.aberration.coeicient.change.ater.AO.compensation..(a).Uncompensated.coeicients.
corresponding.to.Figure.16.2a..he.
x-
axis.represents.Zernike.coeicients;.4.is.
Z
2,2
,.5.is.
Z
2,−2
,.6.is.
Z
3,1
,.7.is.
Z
3,−1
,.and.8.
is.
Z
4,0
..he.error.of.the.wavefront.measurement.is.<2.nm..(b).Compensated.coeicients.
16.3 experiment and results
A.series.of.experiments.using.artiicial.and.biological.specimens.were.devised.to.quantify.the.perfor-
mance. of. our. AO. system.. To. this. end,. two. artiicial. specimens. with. large. aberrations. were. prepared.
and.used.to.evaluate.our.AO.system.in.terms.of.minimizing.the.signal.loss.and.optimizing.the.image-
resolution.loss..Also,.the.performance.of.this.AO.system.was.evaluated.in.three.typical.biological.tissue.
specimens:.mouse.tongue.muscle,.heart.muscle,.and.brain.slice.
16.3.1 Signal Loss Due to Aberrations as a Function of imaging Depth
his.experiment.was.designed.to.measure.the.signal.loss.due.to.aberration.as.a.function.of.the.imag-
ing.depth.and.the.compensatory.performance.of.the.AO.system..A.20x.dry.objective.lens.(Fluar,.0.75.
