A high resolution bladder wall map: Feasibility study

Abstract

The aim of this work is to provide the surgeon-urologist with a system for automatic 2D and 3D-reconstruction of the bladder wall to help him within the treatment of bladder cancer as well as planning and documentation of the interventions. Within this small pilot-framework a fast feasibility study was made to clear if it is generally possible to build a bladder wall model using a special endoscope with an embedded laser-based distance measurement, an optical navigation system and modern image stitching techniques. Some experiments with a realistic bladder phantom have shown that this initial concept is generally acceptable and can be used with some extensions to build a system which can provide an automatic bladder wall reconstruction in real time to be used within a surgical intervention.

Construction of Extended 3D Field of Views of the Internal Bladder Wall Surface: A Proof of Concept

“…Shevchenko et al proposed a structuredlight approach for obtaining extended 3D bladder surfaces [27]. The prototype in [27] consists of an external navigation system (which localizes the endoscope position in the examination room) coupled with an endoscopic system projecting a grid of points on the inspected surface. The 3D surface was built by computing a 2D mosaic from the CCD camera images, and exploiting the information provided by the external system.…”

“…In the present 3D bladder mosaicing feasibility study, an active vision solution is chosen. As compared to [27], our goal is to show that a 3D mosaicing algorithm guided by image registration is useful for retriev- The i-th "projector ray" is shown in green. The corresponding "camera ray" is the black line originating from point P i,k 3D of the surface (intersection of the projector and camera rays) and passing through the optical center Oc k of the camera.…”

“…Indeed, a ToF camera uses infrared signals that do not interfere with the visible light of a color camera. Shevchenko et al proposed a structuredlight approach for obtaining extended 3D bladder surfaces [27]. The prototype in [27] consists of an external navigation system (which localizes the endoscope position in the examination room) coupled with an endoscopic system projecting a grid of points on the inspected surface.…”

Flexible calibration of structured-light systems projecting point patterns

“…We show that our SLS prototype makes it possible to reconstruct a 3D large FOV surface of the internal bladder wall including textures from a video acquisition. Moreover, this SLS can be implemented on an endoscope [22], and the surface representation facilitates bladder cancer detection [23].…”

Optimization and characterization of the endogenous production of protoporphyrin IX in a yeast model

“…22,23 The objective of this study was to develop a model producing endogenous levels of PpIX comparable to those observed in the abovementioned clinical applications. Such a model is of high interest to optimize or study basic mechanisms involved in PDT and PDD, such as the influence of agents or environmental factors on the modulation of the PpIX biosynthetic pathway; 23,24 the study of steady-state and time-resolved spectroscopy of PpIX produced endogenously, in particular, its dependence on environmental factors [temperature and oxygen partial pressure (pO 2 )]; 12,13,25 the development of optical phantoms mimicking the PpIX fluorescence spectroscopy and intensity observed in tumors, 26,27 the study of agents modulating the production of ROS, including singlet oxygen, to optimize and/or monitor PDT. 28 Thus, the determination of the conditions reproducibly leading to the maximal PpIX fluorescence intensity produced by Saccharomyces cerevisiae was studied and is reported in this paper.…”