Nicolas Andreff

Institut FEMTO-ST | FEMTO ST · Department of Automatic Control and Micro-Mechatronic Systems (AS2M)

This article formulates a generic representation of a path-following controller operating under contained motion, which was developed in the context of surgical robotics. It reports two types of constrained motion: i) Bilateral Constrained Motion, also called Remote Center Motion (RCM), and ii) Unilaterally Constrained Motion (UCM). In the first ca...

This letter formulates a generic representation of a path-following controller operating under contained motion, which was developed in the context of surgical robotics. It reports two types of constrained motion: i) Bilateral Constrained Motion, also called Remote Centre Motion (RCM), and ii) Unilaterally Constrained Motion (UCM). To deal with the...

In this paper, we address the calibration of a family of magnetic manipulation systems composed of several coils that are moved around by serial robot manipulators. We show in this paper that the calibration of the whole system ultimately results in calibrating the manipulator and coil separately up to an unknown rigid transformation. For calibrati...

In this paper, we propose a new type of continuum robot, referred to as a magnetic concentric tube robot (M-CTR), for performing minimally invasive surgery in narrow and difficult-to-access areas. The robot combines concentric tubes and magnetic actuation to benefit from the ‘follow the leader’ behaviour, the dexterity and stability of existing rob...

In this study, we present a new approach to improving vocal fold access to perform phonomicrosurgery. It is done by shooting the laser through a mirror to reach the vocal fold hidden parts. A geometrical study of laser shooting path was conducted for vocal fold anatomical constraints, followed by devising a laser-shooting system conceptual design....

Laser microsurgery is the current gold standard surgical technique for the treatment of selected diseases in delicate organs such as the larynx. However, the operations require large surgical expertise and dexterity, and face significant limitations imposed by available technology, such as the requirement for direct line of sight to the surgical fi...

Tensegrity-based mechanisms draw attention in particular for their deployability and compliance. However, task-based design and control of such systems are still open topics. In a previous work, a tensegrity-based manipulator was designed to respect the remote center of motion constraint. Only the workspace was then analyzed. Here, we develop the k...

Laser microsurgery is the current gold standard surgical technique for the treatment of selected diseases in delicate organs such as the larynx. However, the operations require large surgical expertise and dexterity, and face significant limitations imposed by available technology, such as the requirement for direct line of sight to the surgical fi...

Concentric tube robots (CTRs) have a great potential for use in medical applications. Coupled with a follow-the-leader (FTL) deployment, they allow navigation in constrained environments. However, they are subject to instabilities if one makes use of high curvatures for the tubes, long overlapping lengths of their curved sections, or long transmiss...

The use of untethered miniature swimmers is a promising trend, especially in biomedical applications. These swimmers are often operated remotely using a magnetic field commonly generated using fixed coils that can suffer from a lack of compactness and heating issues. The analysis of the swimming capabilities is still an ongoing topic of research. I...

Tensegrity mechanisms are self-stressed and deployable mechanisms which provide interesting properties such as high resistance-to-mass ratio and compliance. Despite a growing interest for these mechanisms in robotics, the actuation selection of such mechanisms is still poorly discussed. In this paper, the influence of the actuation type and positio...

Constrained motion is essential for varying robotics tasks, especially in surgical robotics, for instance, the case of minimally invasive interventions. This article proposes generic formulations of the classical bilateral constrained motion (i.e., when the incision hole has almost the same diameter as that of the tool) as well as unilaterally cons...

This article deals with the development of a vision-based control law to achieve high-accuracy automatic six degrees of freedom (DoF) positioning tasks. The objective of this work is to be able to replace a biological sample under an optical device for a non-invasive depth examination at any given time (i.e., performing repetitive and accurate opti...

For the last two decades, the development of conducting polymers (CP) as artificial muscles, by materials researchers and chemists, has made establishing a reliable and repeatable synthesis of such materials possible. CP-based milli-robots were mostly unknown in soft robotics, however, today, they play a vital role in robotics and smart materials f...

Constrained motion is essential for varying robotics tasks, especially in surgical robotics, for instance, the case of minimally invasive interventions. This article proposes generic formulations of the classical bilateral constrained motion (i.e., when the incision hole has almost the same diameter as that of the tool) as well as unilaterally cons...

This paper deals with the modeling and vision-based control of large-dimension cable-driven parallel robots. Inverse kinematics and instantaneous inverse kinematics models are derived from the elastic catenary cable modeling. These models turn out to be dependent on the pose of the mobile platform (end-effector), on the cable tangent directions and...

Optical Coherence Tomography (OCT) is an emerging tomography imaging technology. It is well suited to various medical applications requiring tissue imaging with micrometer resolution and millimeter penetration depth. Despite its numerous advantages, OCT has a long acquisition time for high-resolution images or volumes. This paper deals with the dev...

This paper focuses on the design of a 6 degrees-of-freedom (DoF) visual servoing control law. Instead of use of geometric visual features in standard vision-based approaches, the proposed controller makes use of wavelet coefficients as control signal inputs. It uses the multiple resolution coefficients representing the wavelet transform of an image...

Concentric tube robot (CTR) is a promising class of continuum robots for medical interventions given their compactness and dexterity. Their dexterity is in particular being used to achieve so called Follow-the-Leader (FTL) deployments, where the tip path draws the shape of the robot. During this kind of deployment they can however be subject to ela...

Concentric tube robots are based on the deformation of elastic pre-curved tubes mounted in a telescopic manner. Their kinematic model consists in a boundary value problem which must be solved during analysis and design. When arbitrary properties and number of the tubes are considered, this model must be solved numerically. We consider in this paper...

In this paper, the mobility matrix of helical microswimmers is investigated to compute the magnetic torque as a function of the angular velocities of the helical robot to achieve a 3D path following in closed-loop. Thus, the helical swimmer kinematics are expressed in the Serret–Frenet frame considering the weight of the robot and lateral disturban...

In the growing field of origami engineering, self-folding is of a high regard. The latter is regularly used by nature as an efficient approach for autonomous growing and reorganizing. In this work, we present a self-folding approach based on Electro-Active Polymer (EAP), especially Conductive Polymers (CP). This approach proposes lightweight, compa...

After reviewing the various motion generation strategies (waypoint sequence, trajectory tracking and path following), this paper suggests that path following is probably the best strategy at small scales. This is illustrated by three examples coming from biomedical applications: endoscopic laser steering, magnetic manipulation of microswimmers and...

This paper deals with a generic modeling and vision-based control approach for a broad class of parallel mechanisms. First, a generic architecture representing several families is proposed. Second, inspired by the geometry of lines, a generic differential inverse kinematic model according to the proposed generic structure is introduced. Finally, ba...

This paper discusses the development of a mosaicking algorithm for building large and high resolution confocal images. Due to the nature of optics and vision systems in general, there is still a dilemma between choosing a wide field-of-view (FOV) and high-resolution. The most accepted solution is to opt for a high-resolution optics and expand the F...

Magnetic continuum robots (m-CR) have grown interest in several applicative contexts that take benefits from their high flexibility and remote control. When submitted to external magnetic fields, m-CR exhibit large elastic deformations, which may lead to a highly nonlinear and complex behavior that is yet difficult to analyze. This letter aims to p...

This paper deals with the development of an Optical Coherence Tomography (OCT) based visual servoing. The proposed control law uses the wavelet coefficients of the OCT images as the signal control inputs instead of the conventional geometric visual features (points, lines, moments, etc.). An important contribution is the determination of the intera...

Inspecting the olfactory cleft can be of high interest, as it is an open access to neurons, and thus an opportunity to collect in situ related data in a non-invasive way. Also, recent studies show a strong link between olfactory deficiency and neurodegenerative diseases such as Alzheimer and Parkinson diseases. However, no inspection of this area i...

Dexterity of robots is highly required when it comes to integration for medical applications. Major efforts have been conducted to increase the dexterity at the distal parts of medical robots. This paper reports on developments toward integrating biocompatible conducting polymers (CP) into inherently dexterous concentric tube robot paradigm. In the...

A visual servoing scheme consists of a closed-loop control approach which uses visual information feedback to control the motion of a robotic system. Probably the most popular visual servoing method is image-based visual servoing (IBVS). This kind of method uses geometric visual features extracted from the image to design the control law. However,...

Otologic surgical procedures tend over time to become minimally invasive due to the development of medicine, micro-techniques and robotics. This trend is expected to reduce the patient's recovery time and to improve the accuracy in diagnosis and treatment. One of the most challenging difficulties that face such techniques are precise control of the...

This paper deals with the development of vision-based controller for a continuum robot architecture. More precisely, the controlled robotic structure is based on three concentric tube robot (CTR), an emerging paradigm to design accurate, miniaturized, and flexible endoscopic robots. This approach has grown considerably in the recent years finding a...

This paper introduces a novel kinematic structure based on the concentric tube robot (CTR) paradigm, augmented with embedded soft micro-actuation. The latter allows to replace troublesome R-joints in CTR with 3 tubes by active tube curvatures (Cu-joints). First, the forward kinematic model is derived. Furthermore, the inverse kinematic problem is p...

This paper presents a magnetic manipulation system composed of three mobile electromagnets. This system is used to control the position and the orientation of a capsule embedding a small permanent magnet in the horizontal plane. The kinematico-magnetic redundancy of the system is dealt with byimposing the planar \(3R\underline{P}R\) parallel kinema...

The Remote Centre of Motion (RCM) is an essential movement done by the surgeon during a minimally invasive surgery. By applying the RCM, the surgical tool should be always superposed upon the centre point of incision hole in order to prevent patient harm. This chapter presents a geometric modelling of such constrained motion in task-space (i.e., op...

This paper deals with the development of a vision-based control scheme for three-dimensional (3-D) laser steering. It proposes to incorporate a simplified trifocal constraint inside a path following scheme in order to ensure intuitively a 3-D control of laser spot displacements in unknown environment (target). The described controller is obtained w...

Optical Coherence Tomography (OCT) is an established medical imaging technique which allows the acquisition of cross-sections in a non-destructive and contactless manner. The use of OCT is recently expanded in numerous medical applications such as ophthalmology and dermatology. OCT is also called optical biopsy, in opposition to the conventional su...

A Helmholtz resonator is a passive acoustic device that enables noise reduction at a given frequency. This frequency is directly related to the volume of the resonator and to the size of the neck that couples the resonator to the acoustic domain. In other words, controlling the volume of the cavity allows a real time tunability of the device, which...

This paper addresses the design of a partitioned vision-guided scheme for repetitive optical biopsies. More precisely , our approach uses two image modalities to perform 6 degrees of freedom (DOF) positioning task. The development aims to partition the control into 3 DOF controlled by the B-scan images acquired with an optical coherence tomography...

This paper deals with the development of a vision-based controller for robot-assisted medical applications. It concerns the use of shearlet coefficients in case of ultrasounds (US) images as visual signal inputs and the design of the associated interaction matrix. The proposed controller was validated in both simulation and on an experimental test...

A novel structure of a 2 DoF telescopic soft robot using a tri-layer Polypyrrole (PPy) soft micro-actuator with deployment is presented in this paper. The kinematic model is introduced and the Position Based Visual Servo (PBVS) control with path-planning and obstacle avoidance algorithms is developed. A prototype is presented and the control scheme...

This paper deals with the development of a fast and smart acquisition technique of Optical Coherence Tomography (OCT) data that has the capability to reconstruct missing data of OCT image. The main objective is to reduce the acquisition time (i.e., increase the frame rate) of an OCT-scan system by choosing a trajectory that covers entirely the imag...

The remote center of motion (RCM) is an essential issue during minimal invasive surgery where the surgeon manipulates a medical instrument inside the human body. It is important to assure that the tool should not apply forces on the incision wall in order to prevent patient harm. The paper shows a geometric method computing the intended robot veloc...

This paper reports the synthesis of an electroactive polymer actuator in polypyrrole (PPy) on a polyvinylidene difluoride (PVDF) substrate. The technological development is detailed. This study reports our investigation on a tri-layer PPy actuator for large deformations and comparison with literature modeling. We also investigate their use towards...

This paper deals with multimodal imaging in the surgical robotics context. On the first hand, it addresses numerical registration of a preoperative image obtained by fluorescence with an intraoperative image grabbed by a conventional white-light endoscope. This registration involves displacement and rotation in the image plane as well as a scale fa...

Helical microswimmers capable of propulsion at low Reynolds numbers have been proposed for numerous applications, ranging from in vitro tasks on lab-on-a-chip to in vivo applications for minimally invasive medicine. Several magnetically actuated helical swimmers with different geometry parameters have been proposed in prior works. However, the infl...

Abstract Continuum robots have shown astounding abilities to assist surgeons reaching confined spaces in the human body. Thus, accurate control of these manipulators, and particularly concentric tube robots, is required in order to achieve intracorporeal microrobotic interventions. We present hereby an improvement of this kinematic structure based...

L’ultime but des sciences, des technologies et de l’innovation est d’être au service de l’humanité. La médecine se démarque alors comme étant celle qui se propose, de façon plus concrète que les autres sciences, d’aider l’être humain. « Guérir parfois, soulager souvent, écouter toujours » disait Louis Pasteur. Mais derrière la médecine pure, un ars...

This topical review discusses recent development and trends on scanning micromirrors for biomedical applications. This also includes a biomedical micro robot for precise manipulations in a limited volume. The characteristics of medical scanning micromirror are explained in general with the fundamental of microelectromechanical systems (MEMS) for fa...

This paper deals with the design, modeling, and control of a compact endoscopic tip for laser steering. It consists of a two-degree-of-freedom microrobotic device based on two linear piezoelectric motors associated with a deformable microfabricated silicon mirror. The proposed device is integrated into an endoscopic tip for microrobot-assisted voca...

This paper focuses on the development of a weakly calibrated three-view-based visual servoing control law applied to the laser steering process. It proposes to revisit the conventional trifocal constraints governing a three-view geometry for a more suitable use in the design of an efficient trifocal vision-based control. Thereby, an explicit contro...

This paper deals with mutual information-based numerical and physical registration of white light images vs. fluorescence images for microrobotic laser microphonosurgery of the vocal folds. More precisely, it presents two techniques: a numerical registration of multimodal images and a vision feedback control for positioning an endoscope with regard...

This paper presents the design of a mesoscale robot for laser phonosurgery. The proposed design is situated between conventional mechanism and MEMS technology. A combination of compliant structures and innovative micro motors enables to achieve two decoupled tilting angle, a high range (up to 45°) and a precise positioning of a laser beam. The desi...

Laser surgery requires accurate following of a path defined by the surgeon, while the velocity on this path is dependent on the laser--tissue interaction. Therefore, path following and velocity profile control must be decoupled. In this paper, nonholonomic control of the unicycle model is used to implement velocity-independent visual path following...

Helical microswimmers that are capable of propulsion at low Reynolds numbers have great potential for numerous applications. Several kinds of artificial magnetic-actuated helical microswimmers have been designed by researchers. However, they are primarily open-loop controlled. This paper aims to investigate methods of closed-loop control of a magne...

Helical microswimmers capable of propulsion at low Reynolds numbers have great potential for numerous applications.Several kinds of artificial magnetic actuated helical microswimmers have been designed by researchers. However, they are primarily open-loop controlled. This paper aims to investigate methods of closed-loop control of a magnetic actuat...

This paper deals with the study of a weakly calibrated multiview visual servoing control law for microrobotic laser phonomicrosurgery of the vocal folds. It consists of the development of an endoluminal surgery system for laser ablation and resection of cancerous tissues. More specifically, this paper focuses on the part concerning the control of t...

Helical microswimmers capable of propulsion at low Reynolds numbers have been proposed for many applications. However, closed-loop controlled helical swimmers are still challenging because of the limits of optical tracking, and a lack of control parameters lying on the swimming characteristics of both linear propulsion and steering. Although the li...

This paper presents a design of electrostatic actuators for 3-DOF micromanipulators in robot-assisted laser phonomicrosurgery. By integrating three sets of electrostatic actuators in a vertical configuration, scanning micro-mirror can be used as a manipulator for laser source. Key enable technology for these miniaturized actuators is microfabricati...

In this paper, we present a dynamic modeling method for parallel kinematic manipulators. This method is built upon the postures (i.e., 3D orientation vectors, lengths and self rotations) of the kinematic elements which form the kinematic chains of the robot. Regarding the structure of the above method, computer vision emerges as a good option to ob...

Purpose: Introducing computational methods to laser surgery are an emerging field. Focusing on endoscopic laser interventions, a novel approach is presented to enhance intraoperative incision planning and laser focusing by means of tissue surface information obtained by stereoscopic vision. Methods: Tissue surface is estimated with stereo-based...

An active micro-endoscope based on concentric tubes, an emerging class of continuum robots, is presented hereby. It is designed to reach the digestive tube and the stomach for early cancer detection and intervention. The manipulator is constructed from three flexible, telescopic, and actuated tubes. The actuators are based on Electro-Active Polymer...

A promising long-term evolution of surgery relies on intracorporeal microrobotics. This book reviews the physical and methodological principles, and the scientific challenges to be tackled to design and control such robots. Three orders of magnitude will be considered, justified by the class of problems encountered and solutions implemented to mani...

Intracorporeal millirobots are at the boundary of conventional surgical robots that are installed in the operating room (OR) along the table or on the patient. They still work in the macroworld, where volumic forces and torques (such as weight) dominate. The chapter presents the principles of three classes of devices: partially intracorporeal devic...

The manipulation and characterization of biological nano-objects and the assembly of nanocomponents for biological applications are still a challenge. The applicative challenges include in vitro applications, nanoassembly for biomedical applications and in vivo applications. The chapter also discusses scientific challenges namely, removing frontier...

This chapter delivers an overview of the ongoing research on intracorporeal robotics at microscale. It first presents the main concepts ruling the microworld, then discusses the methodology required for robotics to enter the human body at microscale, and finally presents a set of representative devices or prototypes such as . In the microworld, the...

This chapter deals with the robotic tools developed to perform operation on biological cells whose size is mostly less than 100 ?m and is usually around 5-10 ?m. It presents original solutions enabling the robotic manipulation of single cells for in vitro applications. The chapter also deals with the physical principles used in non-contact manipula...

This paper presents a linear method for kinematic and dynamic modeling of parallel kinematic manipulators. This method is simple, compact and clear. One can write all the equations from the beginning till the end with pen and paper. It is thus well suited to mechanical understanding and computer implementation. We can apply it to many parallel robo...

To control dynamics of a parallel robot, we should measure the state feedback accurately and fast. In this paper, we show how to estimate positions and velocities simultaneously (i.e., the state feedback) at a reasonable accuracy and speed. We did this using only the sequential visual contours of the legs. A single-iteration virtual visual servoing...

It has been demonstrated that magnetic fields are relevant for manipulating an untethered magnet, either using fixed coils or mobile permanent magnets. This paper shows however, that any magnetic manipulation method is prone to singular configurations and that the simple numerical analysis of the rank of the “manipulation matrix” is not enough to d...