16,770 research outputs found
Nonrigid reconstruction of 3D breast surfaces with a low-cost RGBD camera for surgical planning and aesthetic evaluation
Accounting for 26% of all new cancer cases worldwide, breast cancer remains
the most common form of cancer in women. Although early breast cancer has a
favourable long-term prognosis, roughly a third of patients suffer from a
suboptimal aesthetic outcome despite breast conserving cancer treatment.
Clinical-quality 3D modelling of the breast surface therefore assumes an
increasingly important role in advancing treatment planning, prediction and
evaluation of breast cosmesis. Yet, existing 3D torso scanners are expensive
and either infrastructure-heavy or subject to motion artefacts. In this paper
we employ a single consumer-grade RGBD camera with an ICP-based registration
approach to jointly align all points from a sequence of depth images
non-rigidly. Subtle body deformation due to postural sway and respiration is
successfully mitigated leading to a higher geometric accuracy through
regularised locally affine transformations. We present results from 6 clinical
cases where our method compares well with the gold standard and outperforms a
previous approach. We show that our method produces better reconstructions
qualitatively by visual assessment and quantitatively by consistently obtaining
lower landmark error scores and yielding more accurate breast volume estimates
Nonparametric joint shape learning for customized shape modeling
We present a shape optimization approach to compute patient-specific models in customized prototyping applications. We design a coupled shape prior to model the transformation between a related pair of surfaces, using a nonparametric joint probability density estimation. The coupled shape prior forces with the help of application-specific data forces and smoothness forces drive a surface deformation
towards a desired output surface. We demonstrate the usefulness of the method for generating customized shape models in applications of hearing aid design and pre-operative to intra-operative anatomic surface estimation
Computer-aided position planning of miniplates to treat facial bone defects
In this contribution, a software system for computer-aided position planning
of miniplates to treat facial bone defects is proposed. The intra-operatively
used bone plates have to be passively adapted on the underlying bone contours
for adequate bone fragment stabilization. However, this procedure can lead to
frequent intra-operatively performed material readjustments especially in
complex surgical cases. Our approach is able to fit a selection of common
implant models on the surgeon's desired position in a 3D computer model. This
happens with respect to the surrounding anatomical structures, always including
the possibility of adjusting both the direction and the position of the used
osteosynthesis material. By using the proposed software, surgeons are able to
pre-plan the out coming implant in its form and morphology with the aid of a
computer-visualized model within a few minutes. Further, the resulting model
can be stored in STL file format, the commonly used format for 3D printing.
Using this technology, surgeons are able to print the virtual generated
implant, or create an individually designed bending tool. This method leads to
adapted osteosynthesis materials according to the surrounding anatomy and
requires further a minimum amount of money and time.Comment: 19 pages, 13 Figures, 2 Table
Optical techniques for 3D surface reconstruction in computer-assisted laparoscopic surgery
One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-opera- tive morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilites by observ- ing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted in- struments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This paper reviews the state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery and discusses the technical challenges and future perspectives towards clinical translation. With the recent paradigm shift of surgical practice towards MIS and new developments in 3D opti- cal imaging, this is a timely discussion about technologies that could facilitate complex CAS procedures in dynamic and deformable anatomical regions
Improving Surgical Training Phantoms by Hyperrealism: Deep Unpaired Image-to-Image Translation from Real Surgeries
Current `dry lab' surgical phantom simulators are a valuable tool for
surgeons which allows them to improve their dexterity and skill with surgical
instruments. These phantoms mimic the haptic and shape of organs of interest,
but lack a realistic visual appearance. In this work, we present an innovative
application in which representations learned from real intraoperative
endoscopic sequences are transferred to a surgical phantom scenario. The term
hyperrealism is introduced in this field, which we regard as a novel subform of
surgical augmented reality for approaches that involve real-time object
transfigurations. For related tasks in the computer vision community, unpaired
cycle-consistent Generative Adversarial Networks (GANs) have shown excellent
results on still RGB images. Though, application of this approach to continuous
video frames can result in flickering, which turned out to be especially
prominent for this application. Therefore, we propose an extension of
cycle-consistent GANs, named tempCycleGAN, to improve temporal consistency.The
novel method is evaluated on captures of a silicone phantom for training
endoscopic reconstructive mitral valve procedures. Synthesized videos show
highly realistic results with regard to 1) replacement of the silicone
appearance of the phantom valve by intraoperative tissue texture, while 2)
explicitly keeping crucial features in the scene, such as instruments, sutures
and prostheses. Compared to the original CycleGAN approach, tempCycleGAN
efficiently removes flickering between frames. The overall approach is expected
to change the future design of surgical training simulators since the generated
sequences clearly demonstrate the feasibility to enable a considerably more
realistic training experience for minimally-invasive procedures.Comment: 8 pages, accepted at MICCAI 2018, supplemental material at
https://youtu.be/qugAYpK-Z4
Soft tissue structure modelling for use in orthopaedic applications and musculoskeletal biomechanics
We present our methodology for the three-dimensional anatomical and geometrical description of soft tissues, relevant for orthopaedic surgical applications and musculoskeletal biomechanics. The technique involves the segmentation and geometrical description of muscles and neurovascular structures from high-resolution computer tomography scanning for the reconstruction of generic anatomical models. These models can be used for quantitative interpretation of anatomical and biomechanical aspects of different soft tissue structures. This approach should allow the use of these data in other application fields, such as musculoskeletal modelling, simulations for radiation therapy, and databases for use in minimally invasive, navigated and robotic surgery
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