Minimally invasive technique (MIS) revolutionized the field of surgery for its shorter hospitalization
time, lower complication rates, and ultimately reduced morbidity and mortality.
However, one of the critical challenges that prevent it from reaching the full potentials is
the restricted visualization from the traditional monocular camera systems at the presence
of tissue deformations.
This dissertation aims to design a new approach which can provide the surgeons with
real time 3D visualization of complete organ deformations during the MIS operation. This
new approach even allows the surgeon to see through the wall of an organ rather than just
looking at its surface. The proposed design consists of two stages. The first training stage
identified the deformation subspaces from a training data set in the transformed spherical
harmonic domain, such that each surface can be sparsely represented in the structured
dictionary with low dimensionality. This novel idea is based on our experimental discovery
that the spherical harmonic coefficients of any organ surface lie in specific low dimensional
subspaces. The second reconstruction stage reconstructs the complete deformations in realtime
using surface samples obtained with an optical device from a limited field of view while
applying the structured dictionary.
The sparse surface representation algorithm is also applied to ultrasound image enhancement
and efficient surgical simulation. The former is achieved by fusing ultrasound samples
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with optical data under proper weighting strategies. The high speed of surgical simulation
is obtained by decreasing the computational cost based on the high compactness of the
surface representation algorithm.
In order to verify the proposed approaches, we first use the computer models to demonstrate
that the proposed approach matches the accuracy of complex mathematical modeling
techniques. Then ex-vivo experiments are conducted on freshly excised porcine kidneys utilizing
a 3D MRI machine, a 3D optical device and an ultrasound machine to further test the feasibility under practical settings. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/ETD-UT-2012-05-4996 |
| Date | 11 July 2012 |
| Creators | Wang, Dan |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | thesis |
| Format | application/pdf |
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