Biomedical Engineering Reference
In-Depth Information
PSF FWHM at lateral plane
0.6
PSF FWHM with AO
0.5
0.4
0.3
0.2
0.1
PSF FWHM without AO
Diffraction limited PSF
FWHM
0
0
1
2 3
Measurement
4
5
4
PSF FWHM at axial plane
4
PSF FWHM with AO
3
PSF FWHM without AO
Diffraction limited PSF
FWHM
2
1
0
0
1
2
3
4
5
Measurement
FIGuRE 12.11
Point.spread.function.full.width.at.half.maximum..Top:.the.ive.measurements.of.the.PSF.FWHM.
with.AO.on/of.at.lateral.plane..Bottom:.the.ive.measurements.of.the.PSF.FWHM.with.AO.on/of.at.axial.plane.
12.5.2 Mouse Bone-Marrow imaging with Adaptive optics
To.be.able.to.use.AO.to.correct.the.tissue.aberration.in.mouse.skull.bone.imaging,.light.needs.to.travel.
to.the.bone.structure.below.the.skull.surface.and.generate.enough.lorescence.signal.for.AO.feedback.
and.imaging.purposes..Generally,.this.is.a.light-starving.environment,.and.the.signal.gets.weaker.with.
deeper.imaging.depth..he.biggest.challenge.is.to.ind.a.strong.signal.source.in.the.mouse.model.for.
the.feedback.metric..he.chosen.samples.are.genetically.modiied.mice.whose.osteoblasts.express.GFP,.
developed.by.Dr..David.Rowe.from.the.University.of.Connecticut.and.maintained.by.Dr..Cristina.Lo.
Celso.from.Massachusetts.General.Hospital.
he.test.mouse.is.anesthetized.by.an.injection.of.80.mg/kg.ketamine.+.12.mg/kg.xylazine..he.hair.on.
the.dorsal.scalp.is.removed.by.applying.a.small.quantity.of.hair.remover.cream,.letting.it.work.for.10-15.
minutes,.followed.by.gently.wiping.of.the.area.with.a.cotton.swab..he.area.is.then.cleansed.with.ster-
ile.phosphate-bufered.saline,.disinfected.by.Betadine.solution,.followed.by.an.excision.of.some.of.the.
skin.covering.the.area..he.imaging.gel.(Methocel.2%).is.applied.to.the.exposed.area.and.covered.by.a.
class-1.cover.glass.(Fisher.Scientiic,.PA)..All.protocols.were.approved.by.the.Subcommittee.on.Research.
Animal.Care.Application.from.Massachusetts.General.Hospital.and.performed.by.the.researcher.from.
the.Wellman.Center.for.Photomedicine.
Figures.12.12.
and
.
12.13
.show.the.AO.correction.results.at.145.and.184.μm.below.the.surface..To.avoid.
the.focus.shit.caused.by.the.defocus.term.created.on.the.DM,.the.focus.term.(Zernike.term.no..4).is.not.
adjusted.during.the.closed-loop.SPGD.correction..he.images.with.AO.on.at.both.locations.clearly.show.
brighter.features.and.sharper.contrast.
Figure. 12.14
.
shows. a. plot. of. the. average. intensity. over. the. whole. image. frame. measured. every.
.micrometer.over.a.200.μm.imaging.depth.in.the.skull.bone..he.three.data.sets.correspond.to.conditions.
when.the.DM.was.held.in.its.initial.lat.shape,.when.the.DM.was.corrected.using.AO.at.an.imaging.depth.
of.145.μm,.and.when.the.DM.was.corrected.using.AO.at.an.imaging.depth.of.184.μm..he.intensity.plot.
shows.the.improvements.of.intensity.at.the.optimized.locations.as.well.as.the.neighboring.depth..For.
example,.the.intensity.for.the.data.set.corrected.at.145.μm.depth.is.larger.at.145.μm.depth.than.the.other.
