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Needle insertion procedures are commonly used for diagnostic and therapeutic purposes. In this paper, an image-guided control system is developed to robotically steer flexible needles with an asymmetric tip. Knowledge about needle deflection is required for accurate steering. Two different models to predict needle deflection are presented. The first is a(More)
A position and orientation sensing system is developed for the feedback control of endoscopic instruments in advanced flexible endoscopes. The images that are taken by the endoscopic camera are used to match a kinematic model to the observed instrument. Using the pseudo-inverse of the Jacobian of the forward kinematics, the estimated state of the model is(More)
Purpose Endoscopic images can be used to allow accurate flexible endoscopic instrument control. This can be implemented using a pose estimation algorithm, which estimates the actual instrument pose from the endoscopic images. Methods In this paper, two pose estimation algorithms are compared: a marker-less and a marker-based method. The marker-based method(More)
Manually steering the tip of a flexible endoscope to navigate through an endoluminal path relies on the physician's dexterity and experience. In this paper we present the realization of a robotic flexible endoscope steering system that uses the endoscopic images to control the tip orientation towards the direction of the lumen. Two image-based control(More)
BACKGROUND Steering the tip of a flexible endoscope relies on the physician's dexterity and experience. For complex flexible endoscopes, conventional controls may be inadequate. METHODS A steering method based on a multi-degree-of-freedom haptic device is presented. Haptic cues are generated based on the endoscopic images. The method is compared against(More)
Colonoscopy is performed in the screening for colorectal cancer to obtain a diagnosis and to perform small interventions in the large bowel. The manual control of flexible endoscopes is impractical and not very intuitive. The current research aims at computer assisted colonoscopic navigation in the human bowel. An interesting option then is to use the(More)
In current video-assisted thoracic surgery, the endoscopic camera is operated by an assistant of the surgeon, which has several disadvantages. This paper describes a system which enables the surgeon to control the endoscopic camera without the help of an assistant. The system is controlled using head movements, so the surgeon can use his/her hands to(More)
In this paper a structure will be given which in a remarkably simple way offers a solution to the implementation of different telemanipulation schemes for discrete time varying delays by preserving passivity and allowing the highest transparency possible. This is achieved by splitting the communication channel in two separate ones, one for the energy(More)
A system is developed that can reconstruct the pose of flexible endoscopic instruments that are used in advanced flexible endoscopes using solely the endoscopic images. Four markers are placed on the instrument, whose positions are measured in the image. These measurements are compared to a three-dimensional rendered model of the instrument. The(More)
BACKGROUND Advanced flexible endoscopes and instruments with multiple degrees of freedom enable physicians to perform challenging procedures such as the removal of large sections of mucosal tissue. However, these advanced endoscopes are difficult to control and require several physicians to cooperate. METHODS In this article, we present a robotic system(More)