Probe-based confocal laser endomicroscopy provides real-time microscopic images of tissues contacted by a small probe that can be inserted in vivo through a minimally invasive access. Mosaicking consists in sweeping the probe in contact with a tissue to be imaged while collecting the video stream, and process the images to assemble them in a large mosaic. While most of the literature in this field has focused on image processing, little attention has been paid so far to the way the probe motion can be controlled. This is a crucial issue since the precision of the probe trajectory control drastically influences the quality of the final mosaic. Robotically controlled motion has the potential of providing enough precision to perform mosaicking. In this paper, we emphasize the difficulties of implementing such an approach. First, probe-tissue contacts generate deformations that prevent from properly controlling the image trajectory. Second, in the context of minimally invasive procedures targeted by our research, robotic devices are likely to exhibit limited quality of the distal probe motion control at the microscopic scale. To cope with these problems visual servoing from real-time endomicroscopic images is proposed in this paper. It is implemented on two different devices (a high-accuracy industrial robot and a prototype minimally invasive device). Experiments on different kinds of environments (printed paper and ex vivo tissues) show that the quality of the visually servoed probe motion is sufficient to build mosaics with minimal distortion in spite of disturbances.

This article presents distributed impedance as a new approach for multiple robot system control. In this approach, each cooperating manipulator is controlled by an independent impedance controller. In addition, along selected degrees of freedom, force control is achieved through an external loop, to improve control of the object's internal loading. Extensive stability analysis is performed, based on a realistic model that includes robot impedance and object dynamics. Experiments are performed using two cooperating industrial robots holding an object through point contacts. Force and position control actions are suitably dispatched to achieve both internal loading control and object position control. Individual impedance parameters are specified according to the theoritical stability criterion. The performance of the system is demonstrated for transportation and contact tasks.

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Confocal microlaparoscopy is a promising approach in minimally invasive surgery for replacing conventional biopsies that involve physical tissue sampling. However, the typical images acquired with this technique cover a very small area limited by the field of view of the probe. This paper presents the mechanical design of a distal scanner, the conic-spiraleur, to perform automated spiral scan with the probe in order to construct a mosaic-image. The design of the conic-spiraleur is based on using a conic structure with a particularly curved surface. The pieces of the design are simple to manufacture and easy to assemble with conventional methods to form a device that can be inserted through a conventional 5-mm diameter trocar. We present the pieces, assembly, control, and precision test of the system. The system is tested in vivo in an experimental pig operation. We present the first in vivo, large fieldof-view (3 mm 2 ) and high resolution (1.4-μm lateral and 10-μm axial) images in confocal microscopy.

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This paper concerns eye-in-hand robotic applications that involve large relative displacements between the camera and the target object. A major concern for this type of task is to achieve simultaneously two different objectives. Firstly, the robot has to reach its desired final location relative to the target. Secondly, it must be guaranteed that the target stays in the camera's field of view during the whole motion. This paper introduces a new vision based controller that guarantees a convergence towards the final location while keeping the whole target in the camera's field of view.