Strategies for the compensation of specimen‐induced spherical aberration in confocal microscopy of skin

Abstract

SummaryWe consider various strategies for confocal imaging of human skin which seek to reduce the effects of the specimen-induced aberrations. We calculate the spherical aberration introduced by the stratified structure of skin and show how the confocal signal is affected when attempting to image at various depths within the dermis. Using simple methods it is shown how images might be improved by compensating for the induced aberration. The methods include the use of an iris to reduce the pupil area, changing the refractive index of the immersion medium and using a lens with variable coverglass correction.

Adaptive aberration correction in a confocal microscope

“…Despite the practical limitations they have presented, specimen-induced aberrations have long been recognized as a problem, but there have been relatively few attempts to overcome their deleterious effects. Some static aberration correction methods have been proposed (7)(8)(9)(10), but these can provide only a partial solution, because each specimen introduces different aberrations into the optical system. Alternatively, one could use image deconvolution methods that take account of variations in specimen-induced aberrations, although these techniques can be computationally very intensive (11).…”

Direct visualization of the arterial wall water permeability barrier using CARS microscopy

“…Note that the immersion medium must be prevented from mixing with the solution during calibration and experiments when using long working-distance (WD) objectives. This is because small differences between the water and D 2 O refractive indexes [0.004 and 0.003 at 780 nm and 1,040 nm, respectively (48)] result in significant spherical aberrations over long WDs (49). These aberrations (i) degrade the pump and Stokes PSF, (ii) induce a significant focal shift between them, and therefore (iii) degrade the CARS signal independently of the probe concentration within the focal volume.…”

Design of an Endoscopic Microscope Objective Composed of GRIN(Gradient-Index) Lens with Scanning Devices

“…하지만, 아쉽게도 이런 연구는 주로 미국, 일본, 독 일과 같은 선진국을 중심으로 진행되고 있고 국내의 연구 [1] 는 미미한 실정이다. 독일의 막스플랑크 연구소 [2] , 미국의 벨 연구소 [3] , 미국의 코넬 [4] , 스텐퍼드 [5] , 하버드 대학 [6][7] , 영국의 옥스포드 대학 [8] 등 에서 발표한 GRIN 렌즈를 사용한 이광 자 혹은 다광자 in-vivo 실시간 내시현미경은 살아있는 생쥐 의 뇌세포, 뉴런, 혈액세포의 동역학 등을 영상화하고 있다. 참고로 미국의 애리조나 대학의 광과학연구소에서 직경과 길이가 각각 7 mm와 20 mm인 전통적인 형식의 소형 대물 렌즈를 발표한 바 있지만 큰 관심을 끌지는 못했다.…”