Model based Control design of adaptive optics for confocal microscope with biological specimen

Staff Mentor: M. Verhaegen (Michel)

Other Mentor(s):

Ir. Hans Yoo


Imaging and adaptive optics; Robust and fault-tolerant control; System identification and estimation


During the past few decades, the optical microscopy techniques have achieved significant improvements in terms of spatial resolutions. For the most biological samples, however, even the diffraction limited resolution is hardly obtained due to various aberrations in the specimen preparation as well as specimen itself. To reduce these aberrations, adaptive optics (AO) has been attracted much attention to actively compensate the aberrations and to improve the image quality.

The goal of this master thesis project is to develop a model based closed loop controller of an AO system for confocal microscopy. First of all, the closed loop controller for spherical aberration compensation using actuated coverslip correction ring in the objective. The both direct and indirect wavefront sensing methods are used to measure the aberrations, which is developed and verified in a previous master project. The main challenge will be a closed loop controller design for deformable mirror with a wavefront sensor based on the aberration model. The control strategy such as model predictive controller will be investigated. The benefits of the developed controllers are verified with the image of biological specimen, which is provided by the academic partner.

The asset for this MSc student is that he gets acquainted with a multidisciplinary research of various fields such as optics, biology and (bio)photonics, while designing a cutting edge MIMO controller for AO systems. Biophotonics particularly plays an important role in medical and life sciences to gain “full” understanding of the life activity and mechanisms of diseases in molecular level to (a) prevent diseases and/or (b) to diagnose them early and precisely, followed by (c) patient specified treatments.

The image of mouse embryonic fibroblasts (MEFs) with spherical aberrations and corrected image. Aberration correction results in the smallest PSF, the highest intensity, and a sharp lateral as well as axial resolution of the confocal microscope.

© Copyright Delft Center for Systems and Control, Delft University of Technology, 2017.