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In order to optimize the position of oral implants and make the best possible use of the available bone volume in the oral implant therapy, a computer-aided oral implantology system including the framework, modeling, preoperative 3D planning, registration method, optical tracking systems and real-time navigation is introduced in this study. With the support of this system, the precision achieved in...
Non-rigid-body registration techniques, that constrain the set of possible soft tissue deformations to be consistent with the basic laws of physics, offer a means of providing realistic and accurate estimates of breast movement under mammographic compression. Such constraints can be imposed by the use of anatomically accurate finite element models that predict soft tissue deformations. The overarching...
The primary goal in this study was to investigate 3-D dose distribution, near the areas of tissue inhomogeneities, in Gamma Knife radiosurgery with the gel dosimetry. The spherical glass balloon of a diameter of 16 cm filled with the gel forms the homogeneous phantom; and an identical balloon with two corks placed on each side to represent the air cavities forms the inhomogeneous phantom. Dose calibration...
This paper presents the design and initial experimental results of a flexure-based parallel manipulator that is actuated by three piezoelectric stacks. The manipulator is for an active handheld tremor canceling device for microsurgery. By using flexures to approximate pin and ball joints, errors due to friction, backlash, and imperfect assemblies have been eliminated. The results show that the manipulator...
The per presents a new telementoring system incorporating audio-video communication and remote robotic control. The system was developed around an off the shelf ISDN video conferencing system enhanced with video annotation and remote robot control features. The user can remotely control a robot to perform needle alignment and insertion in a percutaneous access procedure. Particular attention was devoted...
Venox is a propriety venous oximetry system, capable of measuring peripheral venous oximetry. In this ongoing study, Venox is being compared against mixed central venous oximetry during human cardiac surgery, with fibre optic reflectance spectrophotometry being used as the gold standard, placed in the pulmonary artery. A background review of the pulse oximetry, current venous oximetry techniques and...
A robot-assisted orthopedic telesurgery system, named HIT-RAOTS, has been developed according to Chinese conventional operation method. Its main function includes obtaining images with information of position and orientation of fracture, providing fracture information for doctors, assisting the doctors to complete the reposition of fracture and locking operation of intramedullary nail. In this system,...
High-level upper-limb amputations result in prostheses with many degrees-of-freedom to be controlled, with very few control signals. A novel method for the control of myoelectric upper limb prostheses has been developed. By transferring the residual nerves to spare muscles in or near the residual limb, additional myoelectric control signals are created that allow the simultaneous control of multiple...
There is a novel method for creating a 2-d parameterized finite element model of the human femur with matching artificial hip joint based on X-ray image before the hip joint replacement surgery. It can help us to evaluate the selected appropriate hip joint prosthesis
Recent advances in tissue-engineered cartilage open the door to new clinical treatments of joint lesions. Common to all therapies with in-vitro engineered autografts is the need for optimal fit of the construct, to allow screwless implantation and optimal integration into the live joint. Computer assisted surgery techniques are prime candidates to ensure the required accuracy while at the same time...
This document describes the design and preliminary testing of a cable-driven robot for the purpose of traveling on the surface of the beating heart to administer therapy. This methodology obviates mechanical stabilization and lung deflation, which are typically required during minimally invasive cardiac surgery. Previous versions of the robot have been remotely actuated through push-pull wires, while...
This paper presents the identification and the study of the impact of a real-time MRI-based propulsion and tracking system constraints on the step response using a discrete PID controller. A simplified model for such a system accounts for these constraints such as the time delay, the sampling period, and the blood velocity. This application is intended for minimally invasive operations within the...
Anatomical structure morphing is the process of estimating the patient-specific 3D shape of a given anatomy from a few digitized surface points. This provides an appropriate intra-operative 3D visualization without pre or intra-operative imaging. Our method fits a statistical deformable model to the digitized landmarks and bone surface points which are usually sparse. The statistical deformable model...
A new approach of registration in multimodal imaging has been developed. Modalities involved are digital subtracted angiography (DSA, 2D) and magnetic resonance angiography (MRA, 3D). Our approach is an hybrid one, mixing feature and intensity based approaches. This approach is based on the extraction of a anatomical referential common to both MRA and DSA. The results obtained prove the methods efficiency...
Calibration and registration of an endoscope are important steps while using the endoscope for any augmented reality applications or for the recovery of 3D information from it during surgical procedures. Traditionally calibration and registration are done simultaneously just before surgery. In this paper we present a novel registration technique, following offline calibration, which is simple, fast...
Brain atlases are valuable tools that assist neurosurgeons during the planning of an intervention. Since current printed and digitalized brain atlas have several disadvantages, including lack of physical descriptions of brain structures and incompatibility with finite element analysis, we have developed a meshed brain atlas for finite element analysis of surgical procedures. Our meshed atlas is a...
A method is presented for data-driven calibration of the magnetometer in an active handheld microsurgical instrument in the presence of a surgical microscope. The instrument is designed to provide tremor compensation during vitreoretinal microsurgery. An adaptive-network-based fuzzy inference system is used to generate a calibration based on data points collected at random locations throughout the...
This work presents the application of a quantitative magnetic resonance imaging (MRI) technique in stereotactic deep-brain neurosurgery planning procedures. The high spatial resolution T1 and T2 maps acquired using this imaging method have been normalized to the standard CJH-27 brain coordinate system and integrated into a neurosurgical visualization and navigation system to improve the accuracy...
Automated identification, pose and size estimation, and contour extraction of diaphyseal bone fragments can greatly improve the usability of a computer-assisted fluoroscopy-based navigation system for long bone fracture reduction. In this paper, a two step solution is proposed. The pose and size of a diaphyseal fragment are estimated through 3D morphable object fitting using a parametric cylinder...
This paper describes problems in traditional transanal endoscopic microsurgery (TEM), and proposes a mechatronics approach in new design. As one of several actuation mechanisms to expose rectal cavity, a compression coil spring made of shape memory alloy (SMA) has been studied. A custom SMA spring actuator was designed to displace 12 mm with 45 N driving force. This actuator was embedded with our...
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