Design a laser-based medical imaging device model using modeling and simulation

Abstract

Optical Coherence Tomography (OCT) is one of the most advanced medical imaging techniques, as it uses a low-power laser as a light source to produce high-resolution cross-sectional images of living tissues.

The technique is based on the principle of optical interferometry, where the laser beam is divided into two beams: one directed towards the sample to be examined, and the other towards a reference mirror. After the two beams are reflected, they are combined to form an interference pattern that allows for measuring differences in propagation time, and thus determining the depth and optical reflectivity of each layer within the tissue.

The lasers used in OCT are characterized by their time- and space-coherent nature, and are often superluminescent diode (SLD) or pulsed lasers to provide a wide spectral bandwidth, enabling axial resolution down to a few micrometers.

The wavelength is controlled within the 800–1300 nm range to achieve adequate optical penetration into living tissue without causing thermal damage.

OCT technology is widely used in ophthalmology for imaging the retina and optic nerve, in cardiology for diagnosing atherosclerosis, and in dermatology for the early detection of histological changes.

Advanced forms such as Spectral-Domain OCT and Swept-Source OCT have also been developed to increase acquisition speed and spatial resolution, while integrating AI-powered signal processing techniques to improve image quality and automatically extract pathological features.

In this context, the laser is a crucial element because it precisely determines the depth of penetration, time resolution, and scanning speed.

Image quality depends on laser properties such as optical power, coherence, wavelength stability, and signal-to-noise ratio. Optical control systems are used to minimize dispersion within tissues, while spectral filters help improve the signal-to-noise ratio (SNR).