Publication Details
Overview
 
 
 

Thesis

Abstract 

Surgical interventions play a vital role in modern healthcare, but their success heavily relies on the surgeon’s ability to accurately resect diseased tissues while sparing healthy ones. Traditional imaging techniques have limitations in distinguishing subtle variations between tissues. To address this challenge, fluorescence lifetime guided surgery (FLGS) has emerged. In vivo dyes, such as indocyanine green, exhibit short fluorescence lifetimes, which can pose challenges in FLGS. Furthermore, excitation with near-infrared (NIR) light is necessary. This dissertation presents the development of a specialized image sensor called the Current-Assisted Photonic Sampler (CAPS), capable of capturing the weak fluorescence signals emitted by the short-lived NIR dyes. The CAPS detectors utilize the current- assistance principle to achieve (sub-)nanosecond time-gating capabilities. By applying drift fields, photo-generated electrons from a large detection volume can be collected and time-gated. Four generations of CAPS sensors have been developed. The first two featured a resolution of 64 x 64 pixels and focused on improving the instrument response function. The third generation improved the resolution to 128 x 128 pixels while also addressing power consumption concerns. The latest generation introduces a novel pixel design that enables QQVGA (120 x 160) and QVGA (240 x 320) resolutions. In addition to the increased resolution, significant enhancements have been made to sensitivity, gating speed, gating width uniformity, and the instrument response function. The current research has also integrated these CAPS sensors into the tauCAM sub-nanosecond time-gated camera, which includes the design and implementation of the required driving and interfacing electronics. The tauCAM system aims to overcome existing limitations in (pre-)clinical FLGS applications, providing surgeons with the necessary tools to make informed decisions during surgical interventions.

Reference