Abstract: The purpose of our project is to develop an image guided system for the medialization laryngoplasty. One of the fundamental chal
lenges in our system is to accurately register the preoperative 3D CT data to the intraoperative 3D surfaces of the patient. In this paper, we
will present a combined surface and fiducial based registration method to register the preoperative 3D CT data to the intraoperative surface of larynx. To accurately model the exposed surface area, an active illumination based stereo vision technique is used for the surface econstruction. To register the point clouds from the intraoperative stage to the preoperative 3D CT data, a shape priori based ICP method is proposed to quickly register the two surfaces. The proposed approach is capable of tracking the fiducial markers and reconstructing the surface of larynx with no damage to the anatomical structure. Although, the proposed method is specifically designed for the image guided laryngoplasty, it can be applied to other image guided surgical areas. We used off-the-shelf digital cameras, LCD projector and rapid 3D prototyper to develop our experimental system. The final RMS error in the registration is less than 1mm.

Abstract: Most character motion capture data does not contain secondary motions like detailed hand motion, therefore the resultant animation looks unnatural due to the stiffness of hand motion. In this paper, we analyzed the pose space distance from the character’s motion capture data and used stepwise searching algorithm to find the key poses for hand motion synthesis. We adaptively changed the contrast of the local distance map to capture the small motions. If an appropriate hand motion data available, temporal alignment with speed matching and spatial warping of motion data can produce realistic hand motion. If there is no motion capture data available, key frame with cubic or gaussian based interpolation can be used for generating in between frames.

Abstract: The number of persons who suffer a speech production impairment following neurologic damage is extremely high. The evidence base for the efficacy of articulation remediation in neurogenic speech disorders is insufficient. Traditional techniques for re-training speech rely primarily on the adequacy of auditory feedback to shape articulatory movements of the tongue, lips, jaw, and soft palate. Failure of such techniques to generalize or to be maintained may be the result of neurological damage that impairs the ability to accurately utilize auditory feedback to shape articulator movements during speech re-learning. Visual (bio)feedback of lingual movement of one’s own speech and/or that of others might therefore be effective in establishing and promoting more accurate speech. However, one of the most difficult aspects of speech to convey visually is lingual movement in the oral cavity. The latest electromagnetic articulography system (AG500) can track articulatory movement in 3-dimensions. The purpose of this preliminary study was to demonstrate that lingual movement signals acquired by the AG500 can be translated into visual representations of lingual movement that subjects could use as biofeedback during speech (re)learning. We will discuss the development of the translation programs and demonstrate the preliminary data collected from models and from several non-impaired speakers.

Abstract: Surgical simulators have been developed especially in the past few years for enhancing the training of physicians, reducing the number of animals and cadavers, flexibility of training scenarios and for preoperative planning. Despite their potential benefits, and the fact that they have precedence in flight simulators, there are very few simulators in current use. This is primarily due to the lack of understanding of fundamentally what is required for them to be useful, and the fact that the problem is interdisciplinary. This interdisciplinary nature has lead to difficulties in forming a productive team. In this paper, we discuss the technical and practical issues in developing useful surgical simulators. Two case studies representative of the strengths of weaknesses of the technology is presented, including simulation of procedures in the Cryotherapy of the prostate and interventional radiology.

Abstract: In this paper, we explored the problem of creating a high resolution video from a series of still photographs. Instead of enhancing the resolution from the video stream, we consider the problem of generating a high resolution video as an image synthesis problem. Using the continuous shot in the digital camera, we can get a series of still photographs at 2 to 3 frames pre second. The main challenge in our approach is to synthesize the in between frames from two consecutive still images. The image synthesis approach varies based on the scene motion and image characteristics. We have applied optical flow, image segmentation, image filtering and skeleton based image warping techniques to generate high resolution video.

Abstract: Cryotherapy is a treatment modality that uses a technique to selectively freeze tissue and thereby cause controlled tissue destruction. The procedure involves placement of multiple small diameter probes through the perineum into the prostate tissue at selected spatial intervals. Transrectal ultrasound is used to properly position the cylindrical probes before activation of the liquid Argon cooling element, which lowers the tissue temperature below -40 degrees Centigrade. Tissue effect is monitored by transrectal ultrasound changes as well as thermocouples placed in the tissue. The computer-based cryotherapy simulation system mimics the major surgical steps involved in the procedure. The simulated real-time ultrasound display is generated from 3-D ultrasound datasets where the interaction of the ultrasound with the instruments as well as the frozen tissue is simulated by image processing. The thermal and mechanical simulations of the tissue are done using a modified finite-difference/finite-element method optimized for real-time performance. The simulator developed is a part of a comprehensive training program, including a computer-based learning system and hands-on training program with a proctor, designed to familiarize the physician with the technique and equipment involved.