Modular soft robot arms (MSRAs) are composed of multiple modules connected in a sequence, and they can bend at different angles in various directions. This capability allows MSRAs to perform more intricate tasks than single-module robots. However, the modular structure also induces challenges in accurate planning and control. Nonlinearity and hysteresis complicate the physical model, while the modular structure and increased DOFs further lead to cumulative errors along the sequence. To address these challenges, we propose a versatile configuration space planning and control strategy for MSRAs, named$S2C2A$(State to Configuration to Action). Our approach formulates an optimization problem,$S2C$(State to Configuration planning), which integrates various loss functions and a forward model based on biLSTM to generate configuration trajectories based on target states. A configuration controller$C2A$(Configuration to Action control) based on biLSTM is implemented to follow the planned configuration trajectories, leveraging only inaccurate internal sensing feedback. We validate our strategy using a cable-driven MSRA, demonstrating its ability to perform diverse offline tasks such as position and orientation control and obstacle avoidance. Furthermore, our strategy endows MSRA with online interaction capability with targets and obstacles. Future work focuses on addressing MSRA challenges, such as more accurate physical models.

Endovascular intervention is a minimally invasive method for treating cardiovascular diseases. Although fluoroscopy, known for real-time catheter visualization, is commonly used, it exposes patients and physicians to ionizing radiation and lacks depth perception due to its 2D nature. To address these limitations, a study was conducted using teleoperation and 3D visualization techniques. This in-vitro study involved the use of a robotic catheter system and aimed to evaluate user performance through both subjective and objective measures. The focus was on determining the most effective modes of interaction. Three interactive modes for guiding robotic catheters were compared in the study: 1) Mode GM, using a gamepad for control and a standard 2D monitor for visual feedback; 2) Mode GH, with a gamepad for control and HoloLens providing 3D visualization; and 3) Mode HH, where HoloLens serves as both control input and visualization device. Mode GH outperformed other modalities in subjective metrics, except for mental demand. It exhibited a median tracking error of 4.72 mm, a median targeting error of 1.01 mm, a median duration of 82.34 s, and a median natural logarithm of dimensionless squared jerk of 40.38 in the in-vitro study. Mode GH showed 8.5%, 4.7%, 6.5%, and 3.9% improvements over Mode GM and 1.5%, 33.6%, 34.9%, and 8.1% over Mode HH for tracking error, targeting error, duration, and dimensionless squared jerk, respectively. To sum up, the user study emphasizes the potential benefits of employing HoloLens for enhanced 3D visualization in catheterization. The user study also illustrates the advantages of using a gamepad for catheter teleoperation, including user-friendliness and passive haptic feedback, compared to HoloLens. To further gauge the potential of using a more traditional joystick as a control input device, an additional study utilizing the Haption Virtuose robot was conducted. It reveals the potential for achieving smoother trajectories, with a 38.9% reduction in total path length compared to a gamepad, potentially due to its larger range of motion and single-handed control.

As a permanent solution for patients who cannot contract their urinary bladder, an artificial detrusor muscle appears a higher outcome approach compared to current sacral neurostimulators featured by severe long-term side effects. In this paper, a novel soft robotic detrusor is presented to overcome the limitations of the state-of-the-art solutions. It is based on two identical origami-based hydraulic actuators, which completely surround the bladder and contract upon water aspiration. Design, manufacturing, and experimental characterization both in terms of contraction capabilities and voiding efficiency on ex vivo swine bladders are reported for two different origami geometries, as well as a proof-of-concept implementation of an autonomous driving circuit as control unit. Results from assisted urination tests outlined very good performances proving an active voiding efficiency of the hydraulic soft robotic detrusor equal to 84.8%$\pm 7.4\%$in simulated environment.

In this article, a deep learning method for the shape sensing of continuum robots based on multicore fiber bragg grating (FBG) fiber is introduced. The proposed method, based on an artificial neural network (ANN), differs from traditional approaches, where accurate shape reconstruction requires a tedious characterization of many characteristic parameters. A further limitation of traditional approaches is that they require either multiple fibers, whose location relative to the centerline must be precisely known (calibrated), or a single multicore fiber whose position typically coincides with the neutral line. The proposed method addresses this limitation and, thus, allows shape sensing based on a single multicore fiber placed off-center. This helps in miniaturizing and leaves the central channel available for other purposes. The proposed approach was compared to a recent state-of-the-art model-based shape sensing approach. A two-degree-of-freedom benchtop fluidics-driven catheter system was built to validate the proposed ANN. The proposed ANN-based shape sensing approach was evaluated on a 40-mm-long steerable continuum robot in both 3-D free-space and 2-D constrained environments, yielding an average shape sensing error of 0.24 and 0.49 mm, respectively. With these results, the superiority of the proposed approach compared to the recent model-based shape sensing method was demonstrated.

Increased demand for less invasive procedures has accelerated the adoption of Intraluminal Procedures (IP) and Endovascular Interventions (EI) performed through body lumens and vessels. As navigation through lumens and vessels is quite complex, interest grows to establish autonomous navigation techniques for IP and EI for reaching the target area. Current research efforts are directed toward increasing the Level of Autonomy (LoA) during the navigation phase. One key ingredient for autonomous navigation is Motion Planning (MP) techniques. This paper provides an overview of MP techniques categorizing them based on LoA. Our analysis investigates advances for the different clinical scenarios. Through a systematic literature analysis using the PRISMA method, the study summarizes relevant works and investigates the clinical aim, LoA, adopted MP techniques, and validation types. We identify the limitations of the corresponding MP methods and provide directions to improve the robustness of the algorithms in dynamic intraluminal environments. MP for IP and EI can be classified into four subgroups: node, sampling, optimization, and learning-based techniques, with a notable rise in learning-based approaches in recent years. One of the review's contributions is the identification of the limiting factors in IP and EI robotic systems hindering higher levels of autonomous navigation. In the future, navigation is bound to become more autonomous, placing the clinician in a supervisory position to improve control precision and reduce workload.

Aortic valve surgery is the preferred procedure for replacing a damaged valve with an artificial one. The ValveTech robotic platform comprises a flexible articulated manipulator and surgical interface supporting the effective delivery of an artificial valve by teleoperation and endoscopic vision. This article presents our recent work on force-perceptive, safe, semiautonomous navigation of the ValveTech platform prior to valve implantation. First, we present a force observer that transfers forces from the manipulator body and tip to a haptic interface. Second, we demonstrate how hybrid forward/inverse mechanics, together with endoscopic visual servoing, lead to autonomous valve positioning. Benchtop experiments and an artificial phantom quantify the performance of the developed robot controller and navigator. Valves can be autonomously delivered with a 2.0±0.5 mm position error and a minimal misalignment of 3.4±0.9°. The hybrid force/shape observer (FSO) algorithm was able to predict distributed external forces on the articulated manipulator body with an average error of 0.09 N. FSO can also estimate loads on the tip with an average accuracy of 3.3%. The presented system can lead to better patient care, delivery outcome, and surgeon comfort during aortic valve surgery, without requiring sensorization of the robot tip, and therefore obviating miniaturization constraints.

Flexible Endoscopes (FEs) for colonoscopy present several limitations due to their inherent complexity, resulting in patient discomfort and lack of intuitiveness for clinicians. Robotic FEs with autonomous control represent a viable solution to reduce the workload of endoscopists and the training time while improving the procedure outcome. Prior works on autonomous endoscope FE control use heuristic policies that limit their generalisation to the unstructured and highly deformable colon environment and require frequent human intervention. This work proposes an image-based FE control using Deep Reinforcement Learning, called Deep Visuomotor Control (DVC), to exhibit adaptive behaviour in convoluted sections of the colon. DVC learns a mapping between the images and the FE control signal. A first user study of 20 expert gastrointestinal endoscopists was carried out to compare their navigation performance with DVC using a realistic virtual simulator. The results indicate that DVC shows equivalent performance on several assessment parameters, being more safer. Moreover, a second user study with 20 novice users was performed to demonstrate easier human supervision compared to a state-of-the-art heuristic control policy. Seamless supervision of colonoscopy procedures would enable endoscopists to focus on the medical decision rather than on the control of FE.

Since the emergence of soft robotics around two decades ago, research interest in the field has escalated at a pace. It is fuelled by the industry’s appreciation of the wide range of soft materials available that can be used to create highly dexterous robots with adaptability characteristics far beyond that which can be achieved with rigid component devices. The ability, inherent in soft robots, to compliantly adapt to the environment, has significantly sparked interest from the surgical robotics community. This article provides an in-depth overview of recent progress and outlines the remaining challenges in the development of soft robotics for minimally invasive surgery.

Ever since their first introduction in the late 1980s[1],[2], surgical robots have played an increasingly prominent role in medical practice[3],[4]. For example, a recent study[5]found that over 15% of all general surgery procedures in 2020 were performed robotically, compared to only 1.8% in 2012. The current worldwide robotic surgery market is estimated to be$\$ $5.3 billion and is expected to reach$\$ $19 billion by 2027, with a compound annual growth rate over 21%[6].

Microrobots (MRs) have attracted growing interest for their potentialities in diagnosis and noninvasive intervention in hard-to-reach body areas. The safe operation of biomedical MRs requires fine control capabilities, which strongly depend on precise and robust feedback about their position over time. Ultrasound acoustic phase analysis (US-APA) may allow for a reliable feedback strategy for MR imaging and tracking in tissue. In this article, we combine task-specific magnetic actuation and related US-APA motion tracking to achieve closed-loop navigation of a magnetic MR, rolling on the boundary of a lumen in a tissue-mimicking phantom. A C-arm system attached to a robotic platform is used to precisely position the magnetic actuation source and US-APA detection unit within the workspace, thus enabling MR visual-servoing. In the first place, the proposed approach allows to perform supervised localization of the MR without anya-prioriknowledge of its position. After localization, a robust real-time tracking enables closed-loop MR teleoperation in the phantom lumina over a travel distance of 80 mm (145 body lengths), both in static and counter flow, thus achieving an average position tracking error of 368 micron (0.67 body lengths). For the first time, our results validate US-APA as a reliable feedback strategy for visual-servoing control of MRs in simulated in-body environment.

Minimally invasive wireless devices, allowing the sampling of gut’s bacteria, are needed for a longitudinal understanding of the role of the microbiota on the human health. Herein, we present a novel magnetic actuation system fitting inside a 11.5 × 30.5 mm wireless ingestible capsule. Lacking any electronic components, the capsule robot is designed for the collection of microbiota’s samples through mechanical brushing. Wireless activation and in situ sampling are enabled by an external permanent magnetic source. This component, when approaching the capsule, progressively allows: (1) the adhesion of the device to the mucosa, (2 the exposure of the brushes, and (3) the sampling by multiple rotations. Numerical and analytical models were developed for dimensioning the system, and were validated by benchtop experiments.

Learning manipulation skills from open surgery provides more flexible access to the organ targets in the abdomen cavity and this could make the surgical robot working in a highly intelligent and friendly manner. Teaching by demonstration (TbD) is capable of transferring the manipulation skills from human to humanoid robots by employing active learning of multiple demonstrated tasks. This work aims to transfer motion skills from multiple human demonstrations in open surgery to robot manipulators in robot-assisted minimally invasive surgery (RA-MIS) by using TbD. However, the kinematic constraint should be respected during the performing of the learned skills by using a robot for minimally invasive surgery. In this article, we propose a novel methodology by integrating the cognitive learning techniques and the developed control techniques, allowing the robot to be highly intelligent to learn senior surgeons' skills and to perform the learned surgical operations in semiautonomous surgery in the future. Finally, experiments are performed to verify the efficiency of the proposed strategy, and the results demonstrate the ability of the system to transfer human manipulation skills to a robot in RA-MIS and also shows that the remote center of motion (RCM) constraint can be guaranteed simultaneously. Note to Practitioners-This article is inspired by limited access to the manipulation of laparoscopic surgery under a kinematic constraint at the point of incision. Current commercial surgical robots are mostly operated by teleoperation, which is representing less autonomy on surgery. Assisting and enhancing the surgeon's performance by increasing the autonomy of surgical robots has fundamental importance. The technique of teaching by demonstration (TbD) is capable of transferring the manipulation skills from human to humanoid robots by employing active learning of multiple demonstrated tasks. With the improved ability to interact with humans, such as flexibility and compliance, the new generation of serial robots becomes more and more popular in nonclinical research. Thus, advanced control strategies are required by integrating cognitive functions and learning techniques into the processes of surgical operation between robots, surgeon, and minimally invasive surgery (MIS). In this article, we propose a novel methodology to model the manipulation skill from multiple demonstrations and execute the learned operations in robot-assisted minimally invasive surgery (RA-MIS) by using a decoupled controller to respect the remote center of motion (RCM) constraint exploiting the redundancy of the robot. The developed control scheme has the following functionalities: 1) it enables the 3-D manipulation skill modeling after multiple demonstrations of the surgical tasks in open surgery by integrating dynamic time warping (DTW) and Gaussian mixture model (GMM)-based dynamic movement primitive (DMP) and 2) it maintains the RCM constraint in a smaller safe area while performing the learned operation in RA-MIS. The developed control strategy can also be potentially used in other industrial applications with a similar scenario.

The high deformability and compliance of soft robots allow safer interaction with the environment. On the other hand, these advantages bring along controllability and predictability challenges which result in loss of force and stiffness output. Such challenges should be addressed in order to improve the overall functional performance and to meet the requirements of real-scenario applications. In this paper, we present a bidirectional in-plane manipulator which consists of two unidirectional fiber-reinforced actuators (FRAs) and a hybrid soft-rigid stiffness control structure (SCS), all of them controlled by air pressure. Both controllability and predictability of the manipulator are enhanced by the hybrid soft-rigid structure. While the FRAs provide positioning and position dependent stiffness, the SCS increases the stiffness of the manipulator without position dependency. The SCS is able to increase the manipulator stiffness by 35%, 30%, and 18%, when one FRA is pressurized at 150 kPa, 75 kPa, and 0 kPa, respectively. Experiments are carried out to present the feasibility of the proposed manipulator.

Robot-Assisted systems for Minimally Invasive Surgery enhance the surgeon capability, however, direct control over both the surgical tools and the endoscope results in an increased workload that leads to longer operation times. This work investigates the introduction of SCAN (System for Camera Autonomous Navigation) to overcome this limitation. An experimental study involving 12 participants was carried out with the da Vinci Research Kit. Each user tested two novel camera control modalities, autonomous and semi-autonomous, as well as the current manual control of the camera, while carrying out a dry-lab task. Among the camera control modalities, the autonomous navigation achieved better objective performances and the highest user confidence. Moreover, the autonomous control (along with the semi-autonomous one) was able to optimize some metrics related to the robotic surgery workflow.

Untethered magnetic microrobots hold the potential to penetrate hard-to-reach areas of the human body and to perform therapy in a controlled way. In the past decade, impressive advancements have been made in this field but the clinical adoption of magnetoresponsive microrobots is still hampered by safety issues. A tool appointed for magnetic microrobots retrieval within body fluids could enable a real paradigm change, fostering their clinical translation.By starting from the general problem to retrieve magnetic microrobots injected into the bloodstream, the authors introduce a magnetic capture model that allows to design retrieval tools for magnetic cores of different diameters (down to 10 nm) and in different environmental conditions (fluid speed up to 7 cms-1). The model robustness is demonstrated by the design and testing of a retrieval catheter. In its optimal configuration, the catheter includes 27 magnets and fits a 12 F catheter. The model provides a good prediction of capture efficiency for 250 nm magnetic particles (experimental data: 77.6%, model prediction: 65%) and a very good prediction for 500 nm particles (experimental data: 93.6%, model prediction: 94%). The results support the proposed model-based design approach, which can be extended to retrieve other magnetoresponsive agents from body compartments.

This paper proposes the design of a vision-guided control law for microrobotic-assisted biomedical applications. More precisely, the developed control law is to servo an optical coherence tomography (OCT) system in real-time to carry out repetitive optical biopsy tasks. The OCT images are simultaneously used to perform the optical biopsy and to control the sample holder (microrobotic work-flow). Instead of extracting visual features from the OCT images, the vision-based controller uses the concept of frequency domain information to compute relative motion between two successive OCT B-scan (cross-section) images. Therefore, the visual controller is designed to minimize the error between current and desired images by controlling the microrobotic platform. The proposed approach was experimentally validated, demonstrating more than satisfactory results especially in terms of accuracy, convergence, and robustness.

This paper presents the concept design of a modular soft manipulator for minimally invasive surgery. Unlike traditional surgical manipulators based on metallic steerable needles, tendon-driven mechanisms, or articulated motorized links, we combine flexible fluidic actuators to obtain multidirectional bending and elongation with a variable stiffness mechanism based on granular jamming. The idea is to develop a manipulator based on a series of modules, each consisting of a silicone matrix with pneumatic chambers for 3-D motion, and one central channel for the integration of granular-jamming-based stiffening mechanism. A bellows-shaped braided structure is used to contain the lateral expansion of the flexible fluidic actuator and to increase its motion range. In this paper, the design and experimental characterization of a single module composed of such a manipulator is presented. Possible applications of the manipulator in the surgical field are discussed.

Minimally invasive surgery (MIS) is one of the most challenging techniques for robot designers due to the limited size of access points, the high miniaturization level, and the dexterity needed for performing surgical tasks. Conversely, only a few microfabrication technologies are currently available for developing such small-sized systems, which allow safe operations in human bodies. In order to match these challenges in MIS, both design and integration of actuation systems should proceed in parallel with an identification of most effective transmission mechanisms and kinematics. In this paper, an origami parallel module that generates two rotations and one translation is integrated with a twisting module and a compliant gripper to form a novel four-degree-of-freedom grasper. The rotational motion leads to the pitch and yaw motion of the gripper, while the translational motion is converted to a roll motion of the gripper via the twisting module that is stacked on top of the parallel module. In light of plane-symmetric properties of the origami structure in the parallel module, both inverse and forward kinematics are resolved with a geometric approach, revealing a unique joint space and a kinematic mapping of the parallel module, leading to the design of two sets of on-board actuation systems. During the analysis, bending motion of a central spring and static properties of the compliant gripper are modeled using finite-element methods. The structure of the twisting module for motion transmission of the grasper is designed and fabricated using origami folding techniques. Gripping forces of the compliant gripper are evaluated in experimental tests. Further analyses of the system performance are addressed in accordance with the scaling ratio of miniaturization and the scalability of the system is demonstrated by a millimeter-sized origami parallel module produced by the smart composite microstructure fabrication process.

MRI compatibility, which often is a requirement for the new medical soft robot projects, greatly reduces available actuation methods and sensors. An example of such project is STIFF-FLOP, which aims to develop a soft silicone manipulator actuated by pressure. The current arm construction and method of actuation cause several undesirable effects, which pose problems for actuation and sensing. In this paper, the authors identify the source of those negative effects and propose improvements over the current construction to eliminate or limit their influence. The new construction concept is tested and compared with the current one. Possible ideas for further development are also proposed.

Supervised robotic platforms, able to perform a non-invasive therapy or minimal invasive surgery, represent one of the main achievements in recent years. Robotic-assisted medical procedures with medical doctor, patient and medical assistants interacting with a robotic platform can be seen as a paradigmatic example of the coexistence between system autonomy and human action in medicine. However, this can involve unpredicted and dangerous contacts between robotic structures and humans, contacts that have to be managed with appropriate safety strategies, often embedding specific sensitive components into the robot itself. In this paper, a smart sensorized polymeric skin based on textile multi-touch piezoresistive sensors, able to sense and safely manage pressure exerted during a collision with the surrounding environment (e.g., humans), has been designed, fabricated, integrated on a robotic manipulator and tested. The proposed system shows promising results in managing the pressure exerted during the collision, with a close correlation with the analytical analysis (difference lower than 5.6 kPa - error of 9%).

Minimally invasive Surgery (MIS) is one of the most challenging fields for robot designers due to the limited size of the access points, to the high miniaturization level and to the dexterity needed for performing surgical tasks. For this reason, the integration of actuators should proceed in parallel with the identification of the most effective transmission mechanisms and kinematics. Conversely, only a few microfabrication technologies are adequate for developing small size mechanisms with safe operation in the human body. In this paper a SMA actuated, miniaturized, origami-enabled, parallel structure is presented as a versatile module for novel robotic tool in MIS, the parallel structure has been combined with a twisting module and a gripper obtaining a 4-DOFs on board actuated end-effector.

Micro-technologies based on wirelessly powered and manoeuvred submillimeter device, i.e.,microrobots, are attracting growing attention. Their application in lab-on-a-chip systems, such as micromanipulation and in vitro cell sorting, is expected to steeply increase. However, the actuation, powering and control of microrobots are challenges that still need concrete solutions. Magnetic fields generally enable wireless navigation of microrobots, but proper control architectures and magnetic navigation systems are needed, depending on the specific task and on the level of interaction required to the user. Here we present a magnetic navigation platform intended for lab-on-a-chip applications and we address its usability with different levels of human involvement by using two control architectures: teleoperated and autonomous. We perform an experimental analysis to demonstrate that both architectures, enrolling different levels of interaction by the user, lead to reliable execution of the microrobotic task. First, we validate the open-loop response of the microrobotic system, and second, we evaluate the performance of the system by testing both control architectures with a standard mobility task. The results show that users can teleoperate the microrobot with 100% success rate, in 14.4±1.9s with a normalized spatial mean error of 0.60±0.13. Moreover, results show a fast decaying learning curve for the users involved in the study. Compared to this, when the navigation task is performed by the autonomous control, 100% success rate, a time of 8.0±0.5s and a normalized spatial mean error of 0.50±0.05 are obtained. Finally, we quantitatively demonstrate how both control methodologies enable very smooth movements of the microrobot, suggesting application for any task where repeatable and dexterous movements in liquid microenvironments are key requirements.

As a result of the rapid spreading of stereoscopy in the consumer market, three-dimensional (3D) vision systems are replacing two-dimensional devices. A fast growing technology in the 3D visualization systems market is multi-views autostereoscopic displays (ADs). However, these devices have not yet found a direct application in minimally invasive surgery (MIS), as it is really challenging to embed a high number of point-of-views in a device which has to pass through a MIS incision. The aim of this work is the development of a miniaturized vision acquisition system for MIS, which can be interfaced with multi-views ADs. The system is anchored by a magnetic link to the abdomen and freely moved by magnetic actuation to adjust the point of view and the horizon of the cameras. The laparoscope can embed up to 9 cameras, while matching typical MIS access incision size.

Wireless capsule endoscopy recently demonstrated its potential as leading technology for gastrointestinal tract examinations. Many research groups are focusing their efforts on the design of active locomotion methods to allow a complete maneuverability of the device along the gastrointestinal tract. A promising approach for locomotion is represented by master-slave magnetic coupling; however the typical large gradients of magnetic forces make device controllability very hard with important safety concerns: in this framework magnetic capsule localization and interaction force control become extremely relevant. In the present work, a preliminary on-line localization has been implemented obtaining a position feedback closed loop control of a magnetic driven capsule endoscope. Furthermore, interaction forces with the environment have been evaluated by exploiting a dedicated setup for magnetic dragging. Distributed charges-current and dipole-dipole magnetic models applied to capsule endoscopy have been investigated and results have been compared with experimentally measured magnetic forces. Advantages and limitations of employed models have been evaluated and their usability for Real-Time force calculation has been discussed.

This paper presents the concept design, the fabrication and the experimental characterization of a unit of a modular manipulator for minimal access surgery. Traditional surgical manipulators are usually based on metallic steerable needles, tendon driven mechanisms or articulated motorized links. In this work the main idea is to combine flexible fluidic actuators enabling omnidirectional bending and elongation capability and the granular jamming phenomenon to implement a selective stiffness changing. The proposed manipulator is based on a series of identical modules, each one consisting of a silicone tube with pneumatic chambers for allowing 3D motion and one central channel for the implementation of the granular jamming phenomenon for stiffening. The silicone is covered by a novel bellows-shaped braided structure maximizing the bending still limiting lateral expansion. In this paper one single module is tested in terms of bending range, elongation capability, generated forces and stiffness changing.

Magnetically driven wireless capsule endoscopy (WCE) represents one of the last achievements in the research of minimally invasive tools for gastrointestinal tract (GI) diagnosis. Recently, capsule localization methodologies have been employed to enable system autonomy maintaining a magnetic link with the device and managing interaction forces with GI tissues. To achieve these objectives, the locomotion platforms exploit automatic motion in some degrees of freedom and unsupervised contact with the external patient abdomen can occur. In this paper safety issues are faced; in particular a safety system, able to monitor pressure with patient abdomen, has been designed, characterized, and integrated with a magnetically driven WCE locomotion platform. New technologies, such as smart textiles, have been employed as sensible element. The proposed system showed promising results in controlling the pressure exerted on the abdomen respecting safety limits and increasing the efficiency and range of locomotion.

Exploitation of miniature robots and microrobots for endovascular therapeutics is a promising approach; besides chemical strategies (typically systemic), topical mechanical approaches exist for obstruction removal, which however produce harmful debris for blood circulation. Magnetic particles (MPs) are also studied for blood clot targeting. We investigated magnetic dragging of clots/debris by means of both electrostatic and antibody binding. We successfully produced magnetotactic blood clots in vitro and experimentally showed that they can be effectively dragged within a fluidic channel. We also exploited a magnetic force model in order to quantitatively analyze the experimental results, up to obtaining an estimate of the relative efficiency between electrostatic and antibody binding. Our study takes a first step towards more realistic in vivo investigations, in view of integration into microrobotic approaches to vascular obstructions removal.

The novel concept of Trans-abdominal Active Magnetic Linkage for laparoendoscopic single site surgery has the potential to enable the deployment of a bimanual robotic platform trough a single laparoscopic incision. The main advantage of this approach consists in shifting the actuators outside the body of the patient, while transmitting a controlled robotic motion by magnetic field across the abdomen without the need for dedicated incisions. An actuation mechanism based on this approach can be comprised of multiple anchoring and actuation units, mixed depending upon the specific needs. A static model providing anchoring and actuation forces and torques available at the internal side of the magnetic link was developed to provide a tool to navigate among the many possibilities of such an open ended design approach. The model was assessed through bench top experiments, showing a maximum relative error of 4% on force predictions. An example of a single degree of freedom manipulator actuated with the proposed concept and compatible with a 12-mm access port is able to provide an anchoring force of 3.82 N and an actuation force of 2.95 N.

This paper presents a novel master-slave teleoperated robotic platform designed for Single Port Laparoscopy. The SPRINT (Single-Port lapaRoscopy bimaNual roboT) is composed of two high-dexterity 6 Degrees of Freedom (DOFs) robotic arms, a stereoscopic camera and a dedicated console for the robot control by the surgeon. Along with a short summary of the hardware features of the system, this paper describes the real-time control architecture of the SPRINT. Particular attention was given to the kinematic coupling between the master and the slave manipulators, as well as to the inverse kinematics algorithm. Tests performed to validate the performance of the robot in terms of accuracy are satisfactory, thus positioning the SPRINT as a candidate for the next generation of robots for Single Port Laparoscopy.

In this work, the design and development of an integrated platform for the steering of swimming microrobot is reported. The system consists of: a near-spherical soft and buoyant magnetic microrobot (with a diameter of about 500 μm) conceived for operation in liquid; a wireless magnetic steering system, including a compact magnetic field generator based on two pairs of Helmholtz and Maxwell coils; an electronic system for their driving; a control software; a joypad physical user interface; and, the micro-arena as working environment. The platform design fulfills the requirements for the “Mobility Task” of the 2011 NIST Mobile Microrobotics Challenge. The results obtained from preliminary validation experiments confirm that the microrobots can move in a fully controlled way, successfully accomplishing an intricate eight-shape path, as required, in the water filled micro-arena. In particular we achieved a maximum average speed of 0.71 mm/s and an exceptionally smooth motion.

Wireless capsule endoscopy offers significant advantages compared with traditional endoscopic procedures, since it limits the invasiveness of gastrointestinal tract screening and diagnosis. Moreover, active locomotion devices would allow endoscopy to be performed in a totally controlled manner, avoiding failures in the correct visualization of pathologies. Previous works demonstrated that magnetic locomotion through a robotic-aided platform would allow us to reach this goal reliably. In this paper, the authors present a comparative evaluation of control methodologies and user interfaces for a robotic-aided magnetic platform for capsule endoscopy, controlled through human-robot cooperative and teleoperated control algorithms. A detailed statistical analysis of significant control parameters was performed: teleoperated control is the more reliable control approach, and a serial kinematic haptic device results as the most suitable control interface to perform effective robotic-aided endoscopic procedures.

A novel approach for the design of magnetically-propelled microrobots is proposed as an effective solution for swimming in a liquid medium. While intrinsic neutral buoyancy of a microrobot per se simplifies propulsion in the liquid environments, softness makes it compliant with delicate environments, such as the human body, thus guaranteeing a safe interaction with soft structures. With this aim, two groups of soft microrobots with paramagnetic and ferromagnetic behaviors were designed, fabricated and their features were experimentally analyzed. In agreement with the theoretical predictions, in the performed trials the ferromagnetic microrobots showed orientation capabilities in response to the magnetic field that could not be achieved by the paramagnetic one. Moreover, it was observed that the ferromagnetic microrobot could reach higher speed values (maximum value of 0.73 body length/s) than the paramagnetic prototype.

A wired miniature surgical camera robot with a novel Magnetic Levitation System (MLS) was modeled, designed and fabricated. A simple analysis and a theoretical model were developed in order to describe and predict basic behavior for different structural parameters of the system. The robot is composed of two main parts (head and tail) linked by a thin elastic flexible joint. The tail module embeds two magnets for anchoring and manual rough translation. The head module incorporates two motorized donut-shaped magnets and a miniaturized vision system at the tip. The MLS can exploit the external magnetic field to induce a smooth bending of the robotic head, guaranteeing a high span tilt motion of the point of view (0°-80°). The device is 100 mm long and 12.7 mm in diameter. Use of such a robot in single port or standard multiport laparoscopy could enable reduction of number/size of ancillary trocars, and/or increase the number of working devices that can be deployed, thus paving the way for multiple point of view laparoscopy.

A novel mechanism for actuating a miniature swimming robot is described, modeled, and experimentally validated. Underwater propulsion is obtained through the interaction of mobile internal permanent magnets that move a number of polymeric flaps arranged around the body of the robot. Due to the flexibility of the proposed swimming mechanism, a different range of performances can be obtained by varying the design features. A simple multiphysics dynamic model was developed in order to predict basic behavior in fluids for different structural parameters of the robot. In order to experimentally verify the proposed mechanism and to validate the model, a prototype of the swimming robot was fabricated. The device is 35 mm in length and 18 mm in width and thickness, and the forward motion is provided by four flaps with an active length of 20 mm. The model was able to correctly predict flap dynamics, thrust, and energy expenditure for magnetic dragging within a spindle-frequency range going from 2 to 5 Hz. Additionally, the model was used to infer robot-thrust variation related to different spindle frequencies and a 25% increase in flap active length. Concerning swimming performance, the proposed technical implementation of the concept was able to achieve 37 mm/s with 4.9% magnetic mechanism efficiency.

Polymeric ultra-thin films, also called nanosheets, show peculiar properties in terms of thickness, flexibility and chemical structure. For these reasons, they were proposed as nanoplasters for localized drug release or as a new solution for closing endoluminal surgical wounds. This paper presents the fabrication and characterization of free-standing nanosheets loaded with iron oxide nanoparticles, which can be manipulated in liquid environment by means of magnetic fields. A theoretical model of magnetic manipulation of the nanosheet is proposed and validated by dragging the film with a permanent magnet mounted on an industrial robotic arm. Controlling the magnetic sheet in liquid environment represents a first step towards the application of these nanostructures as free-standing carriers to be released and magnetically controlled in endoluminal surgery or as plasters with nanometric thickness to be delivered in situ on surgical incisions. Furthermore, these magnetic nanofilms can be adapted and used as micro and nanocomponents for the design of a novel generation of magnetic actuated polymeric microrobots.

In this work, we propose a new concept for locomotion of a miniature jellyfish-like robot based on the interaction of mobile permanent magnets. The robot is 35 mm in length and 15 mm in width, and it incorporates a rotary actuator, a magnetic rotor, several elastic magnetic tails and a polymeric body embedding a wireless microcontroller and power supply. The novel magnetic mechanism is very versatile for numerous applications and can be tailored and adapted on the basis of different specifications. An analytical model of the magnetic mechanism allows to shape the robot design based on the specific application. The working principle of the robot together with the design, prototyping and testing phases are illustrated in this paper.

In this paper, a reconfigurable modular robotic system is proposed to augment the dexterity of endoluminal interventions in the gastrointestinal tract. In the proposed system, miniaturized robotic modules are ingested and assembled in the stomach cavity. The assembled robot can change its configuration according to the target location, thus enabling complicated surgical tasks. The robotic assembly, the robotic configuration and the surgical tasks are controlled via wireless bidirectional communication. Based on this concept, early prototypes of the robotic modules were designed and fabricated. The developed module has 2DOF (±90° of bending and 360° of rotation), measures 15.4 mm in diameter and 36.5 mm in length. It weighs 5.6 g and contains a Li-Po battery, two brushless DC motors, and a custom-made control board capable of wireless communication. The performance of the bending and rotational motion was evaluated and the future work has been discussed.

An automated design generation algorithm for a serial kinematic chain is presented for the reconfigurable robot used in a novel endoluminal surgical procedure (European Union project ARES). The algorithm produces the possible topologies, given the design constraints, desired performance, and available modules, such that all constraints are satisfied for every point in the desired workspace. This is achieved through the use of interval analysis methods and branch-and-bound loop that searches through the end-effector pose and the design parameter spaces. The resulting algorithm is demonstrated through an example of a serial chain manipulator made of the reconfigurable modules of the surgical robot for the application. The results are presented and discussed.

As medical robotics gathers increasing attention, the ergonomics of the surgical-console design becomes an important issue. Motivated by the need of augmenting the surgeon mastery, we explore the capabilities of a near infrared brain-computer interface as a complementary input modality to enhance the human-robot interaction at the robotic console. A multistage analysis framework is proposed and evaluated by an exploratory off-line synchronous study. The three stages of the data processing flow, namely dimensionality reduction, solution to binary problems and aggregation into multi-class decision are examined to address key challenges during the pattern recognition step. Early experimental results endorse near infrared based brain-computer interface as a suitable additional communication modality between the surgeon and the robotic console.

We present design and experimental performance results for a novel mechanism for robotic legged locomotion at the mesoscale (from hundreds of microns to tens of centimeters). The new mechanism is compact and strikes a balance between conflicting design objectives, exhibiting high foot forces and low power consumption. It enables a small robot to traverse a compliant, slippery, tubular environment, even while climbing against gravity. This mechanism is useful for many mesoscale locomotion tasks, including endoscopic capsule robot locomotion in the gastrointestinal tract. It has enabled fabrication of the first legged endoscopic capsule robot whose mechanical components match the dimensions of commercial pill cameras (11 mm diameter by 25 mm long). A novel slot-follower mechanism driven via lead screw enables the mechanical components of the capsule robot to be as small while simultaneously generating 0.63 N average propulsive force at each leg tip. In this paper, we describe kinematic and static analyses of the lead screw and slot-follower mechanisms, optimization of design parameters, and experimental design and tuning of a gait suitable for locomotion. A series ofex vivoexperiments demonstrate capsule performance and ability to traverse the intestine in a manner suitable for inspection of the colon in a time period equivalent to standard colonoscopy.

In this paper a polymer sensorised microgripping tool for micromanipulation is presented. The gripper structure is made by moulding of polyurethane in silicon moulds by the technique of shape deposition manufacturing (SDM), in which the force sensing elements and part of the actuator (in this case, microstrain gauges and SMA (shape memory alloy) wire, respectively) are embedded into the microgripper in one process step. The actuation principle for the microgripper is an SMA wire. The advantages of the fabrication process are low cost and manufacture cycle time. This paper details the technique for fabrication of the microgripper to produce prototypes. These prototypes were then tested and characterised in terms of force output, hysteresis and repeatability. A further miniaturised unsensorised microgripper based on the same actuation principle and fabrication process (but less than half the size) was fabricated to demonstrate the possibility of further downscaling.

Many compelling future surgical applications will be enabled by a new kind of surgical tool, capable of entering the human body through natural orifices or very small incisions and then reconfiguring into complex kinematic structures at the site of intervention. We describe a first step toward this goal - the development of a microactuator designed for use in surgical robots that are composed of large quantities of reconfigurable micro-robotic modules. The miniaturizable design proposed harnesses the Bourdon effect to convert electrolytic pressure into mechanical motion obtaining more than 400% displacement variation while consuming less than 0.5 W at less than 5 V. We describe the design, construction, and experimental results with our prototype microactuator.

In this paper we present the design of a swallowable (11mm diameter by 25mm long), 12-legged endoscopic capsule for locomotion in the lower gastro intestinal tract (large bowel). A novel slot-follower mechanism driven via lead-screw allows the capsule to be as small as current commercial pill-cameras, while simultaneously generating 2/3 N of force at each leg tip. Kinematic and static analyses of the lead screw and slot-follower mechanisms allow optimization of design parameters so that the capsule satisfies experimental and clinical design requirements for legged locomotion in the GI tract.

Remote manipulation tasks in the small scale can often not be performed autonomously, due to the unstructured nature of the environments and the limited capabilities of sensor and localization technologies. For these tasks, teleoperated systems are used, in which the human operator is integral part of the control. In time-delayed teleoperation, the operator gradually adopts discrete control strategies, such as 'move-and-wait'. In this paper, we present and compare three different control strategies for driving a nanomanipulation system with direct vision feedback. Two strategies are based on a fixed step size to move the manipulator, while the third uses a variable step size. The strategies are compared on a 2D fine positioning task. Experimental results are in agreement with Fitts' law and show that the third strategy, besides allowing movements of size ranging across several orders of magnitude, also allows to complete the fine positioning task in less time. The control strategies can be used in general to control vision-guided teleoperation systems affected by time delay.

A biological paradigm of versatile locomotion and effective motion control is provided by the polychaete annelid worms, whose motion adapts to a large variety of unstructured environmental conditions (sand, mud, sediment, water, etc.), and could thus be of interest to replicate by robotic analogs. Their locomotion is characterized by the combination of a unique form of tail-to-head body undulations (opposite to snakes and eels), with the rowing-like action of numerous lateral appendages distributed along their long segmented body. Focusing on the former aspect of polychaete locomotion, computational models of crawling and swimming by such tail-to-head body undulations have been developed in this paper. These are based on the Lagrangian dynamics of the system and on resistive models of its interaction with the environment, and are used for simulation studies demonstrating the generation of undulatory gaits. Several biomimetic robotic prototypes have been developed, whose undulatory actuation achieves propulsion on sand and other granular unstructured environments. Extensive experimental studies demonstrate the feasibility of robot propulsion by tail-to-head body undulations in such environments, as well as the agreement of its qualitative and quantitative characteristics to the predictions of the corresponding computational models.

This paper focus on developing a flexible biomimetic sensor, which is embedded in a soft earthworm-like crawling mini-robot and mimics exteroceptive and proprioceptive functions of invertebrates, such as its biological counterpart-earthworm. A polyvinylidene fluoride (PVDF) film is selected as the sensing element because it is flexible, highly sensitive and easy to be integrated in different shapes. Thin and narrow PVDF strips are embedded with an innovative molding-embedding-remolding fabrication procedure in a segmented compliant silicone shell which serves as skin and passive actuation of a crawling earthworm-like mini-robot with the ability to elongate and contract. Several experiments were performed by using a purposely developed test-bench in order to test sensor behaviour. The results show that the biomimetic flexible PVDF-based sensor can detect both the external contact and the internal actions, thus imitating the exteroceptive and proprioceptive sensing capabilities of real earthworms. The developed biomimetic sensors are promising in order to achieve an useful sensor feedback for the earthworm-like minirobot motion control

This paper introduces the main objectives of the neurobotics project aimed at designing and developing innovative hybrid bionic systems (HBSs) by fusing neuroscience and robotics. Eight different HBSs have been jointly designed and are being developed. This paper presents in detail the telepresence platform. The neurobotics artificial lamprey model has been designed to validate a number of neuroscience models and to investigate new telepresence strategies

This paper describes the development of an active clamping mechanism to be integrated into a swallowable pill for the diagnosis of the gastrointestinal (GI) tract. The clamping system allows to stop the pill in desired sites of the GI tract for long monitoring purposes. After discussing the major technical constraints, the design of the clamping system, based on FEA (Finite Element Analysis), is illustrated as well as its fabrication process. The clamping unit is actuated exploiting Shape Memory Alloys (SMA), in wires and spring configuration, and it is driven by a dedicated electrical interface. A fine tuning has been performed in order to limit the power consumption. Then a working prototype is fabricated and preliminarily tested, pointing out a capability of the grasping system over 40 g.

Polychaete annelid worms provide a biological paradigm of versatile locomotion and effective motion control, adaptable to a large variety of unstructured environmental conditions (water, sand, mud, sediment, etc.). The undulatory locomotion of their segmented body is characterized by the combination of a unique form of tail-to-head body undulations, with the rowing-like action of numerous lateral appendages distributed along their body. Computational models of polychaete-like crawling and swimming have been developed, based on the Lagrangian dynamics of the system and on resistive models of its interaction with the environment, and used for simulation studies demonstrating the generation of undulatory gaits. Several lightweight robotic prototypes have been developed, whose undulatory actuation achieves propulsion on sand. Extensive experiments demonstrate that the propulsion of these robots is characterized by essential features of polychaete locomotion, in agreement with the corresponding simulations.

This paper presents the design and development of a microrobot which aims to replicate the locomotion principle of earthworms. The undulatory locomotion of living earthworms has been investigated deeply from the biological point of view, but attempts at replication of earthworm models in real size are limited. The authors have designed an artificial earthworm with four modules which can be driven independently according to defined undulatory patterns with a typical frequency of 0.5 Hz. Each module is actuated by one or more SMA springs whose configuration has been designed in order to limit wiring problems and optimize working frequency. The robot is covered by a shaped silicone material which can be used as a platform to insert tiny legs for obtaining differential friction conditions. Preliminary tests demonstrate that the earthworm prototypes can move with a speed of 0.22 mm/s, thus approximating the behavior of biological earthworms.

This paper illustrates the analysis of locomotion in the gastrointestinal tract obtainable by a legged capsule for diagnostic and therapeutic purposes. A preliminary simulation of the legged locomotion onto slippery and deformable substrates has been performed and -simultaneously - mechanisms for on board actuation of the legs have been developed and tested. Moreover, an engineering translation of medical needs in endoscopy is presented, with some ad hoc solutions for improving diagnostic capabilities.

This paper describes a microcontroller-based multichannel telemetry system, suitable for in vivo monitoring of physiological parameters. The device can digitalize and transmit up to three analog signals coming from different sensors. The telemetry transmission is obtained by using a carrier frequency of 433.92 MHz and an amplitude-shift keying modulation. The signal data rate is 13 kb/s per channel. The digital microcontroller provides good flexibility and interesting performance, such as the threshold monitoring, the transmission error detection, and a low power consumption, thanks to the implementation of a sleep mode. The small overall size (less than 1 cm3), the power density compatible with current regulations for the design of implantable devices, and the dedicated packaging make the system suitable for in vivo monitoring in humans. The design, fabrication, operation, packaging, and performance of the system are described in this paper. An in vivo pressure monitoring case study is described as well.

This paper presents the design, development and preliminary test of a new active microendoscope for neuroendoscopy and therapy of the spinal cord. Endoscopy of the spinal sub-arachnoid space is useful for some pathologies, but it is a very challenging task for several reasons: the navigation space is very narrow, there are many blood vessels and delicate structures which could be damaged by maneuvers and large forces and, finally, the CerebroSpinal Fluid (CSF) is a peculiar environment which must be preserved. An innovative method for active safe navigation in the sub-arachnoid space has been devised, based on hydrojets sustentation of the endoscope. The hydrojets, if appropriately tuned and oriented, allow the tip of the endoscope to avoid the delicate structures of the spinal cord and could also assist propulsion. A MATLAB simulation of the hydrojets is illustrated and a digital controller for the regulation of the hydrojets is demonstrated. The pressure ripple is about 5%, as tested experimentally on a 2D simulator. A prototype of steerable microendoscope whose tip is equipped with hydrojets has been fabricated and tested in an artificial path simulating the sub-arachnoid space. Performance are quite interesting.

Colonoscopy is an important medical procedure for the diagnosis of various diseases, such as cancers in the colon and rectum. However, it requires a lot of time for a doctor to acquire dexterous skills necessary to perform successful colonoscopy. Moreover, for many patients, conventional colonoscopy simply takes long time. Therefore, some studies on the development of autonomous and more convenient colonoscopes are carried out. In this paper, we propose a functional colonoscope robot system that has a locomotive function with a hollow body, a steering system, and other basic functions of typical conventional colonoscope systems. The concept and each component of the functional colonoscope system are described in this paper. In order to evaluate the functional performance of the colonoscope robot, we carried out in-vitro and in-vivo tests.

This paper is focused on a portable sensorized micro end-effector purposely designed for operating in biomedical test-benches. The gripper, previously designed and fabricated in various materials exploiting different technologies, has been devised to perform tasks of micromanipulation and characterization of biological tissues once integrated into the workstation developed in the authors' lab. The last model of the gripper prototype has been integrated in a "smart" mounting, with on board electronics for signal processing, and further improvements are planned in order to enhance the portability of the tool. Actually, for the development of novel tools and methodologies in the fields of biomedical engineering and computer assisted surgery (CAS), ever-growing importance have both in vitro and in vivo tests, aimed at validating methods and at optimizing innovative tools. The selected gripper, fabricated in stainless steel by laser machining, is equipped with commercial semiconductor strain gauges as force sensors.

In this survey paper, the authors analyze the general structure of robotic systems for computer-assisted surgery, present a classification of such systems based on the degree of "intelligence" of the tools, and discuss some examples of different classes of devices. Computer-assisted surgery accelerated progress is related, on the one hand, to the improvement of medical imaging techniques and, on the other hand, to the evolution of surgical instrumentation. The integration of these two factors has determined an extraordinary progress that is not just a "linear" temporal development, but it is a "discontinuity" as regards traditional surgical procedures. Specifically, the authors consider the following classes of robotic-derived surgical devices/systems: a) handheld tools augmenting the capabilities of the surgeon; b) teleoperated surgical tools; and c) autonomous surgical robots. The paper will focus essentially on the analysis of systems and components of robots and tools designed for minimally invasive surgery. Although different classification methods exist on the basis of the clinical needs and/or on the design approach, the devices which will be illustrated in this paper are classified on the basis of their scale, degrees of freedom, autonomy, embedded intelligence, and features of the interface between the surgeon and the patient.

This paper illustrates a mechanism specifically designed for locomotion in the wet, collapsible and tortuous human gastrointestinal (GI) tract (the colon in particular). Previous works performed in the authors' laboratory were devoted to the fabrication of semi-autonomous inchworm locomotion devices for navigation in the colon; in this paper a further analysis of limitations and problems of these devices has been performed. The main limitation consists of the poor efficiency of these devices to negotiate acute bends (due to what the authors termed as the "accordion effect") and, in general, to advance in the scarcely supported colon tissue. Thus a different approach to locomotion has been developed based on "sliding clampers". This locomotion principle has been implemented in a minirobot system and has demonstrated (both theoretically and experimentally) to be effective in reducing the "accordion effect".

As changing the eating habit to low fiber and high fat diet, the pathology in the colon is growing up annually. Colonoscopy is an important medical procedure for the diagnosis of various diseases like cancer in the colon and rectum. But it requires much time for doctors to acquire a dexterous skill to perform the operation of colonoscope and the procedure is painful and long to the patient in many cases. Therefore, some studies on the development of autonomous and more convenient colonoscope are carried out. In this paper, we propose a smart colonoscope system that has the locomotive function, active camera system, and human-friendly user interface besides the basic functions of the conventional colonoscope system. Doctors will be able to concentrate on the diagnosis itself with this system. The dexterity required to doctors and the pains imposed to patients will also be reduced with this system. The concept and each component of the smart colonoscope system are described in this paper. We carried out in-vitro test to evaluate its validity.

This paper describes a novel microgripper, fabricated in a superelastic alloy (Ni/sub 50.8/Ti/sub 49.2/) by wired micro Electro Discharge Machining (/spl mu/EDM). The main features of the new microgripper are the use of a superelastic alloy to improve flexure performance by lowering stresses induced and the /spl mu/EDM fabrication technique. The microgripper was sensorized with commercial semiconductor strain-gauges and implemented in a force-feedback micromanipulation workstation developed in the authors' laboratory. Both FEM simulations and the results of experimental characterization in position and force are presented.

In this paper the authors illustrate the development of a semi-autonomous robot for colonoscopy. In particular they focus on two problems: the generation of an effective and reliable advancement in the colon, and the possibility to steer the robot in order to overcome acute intestinal bends. Both problems are present also during traditional colonoscopy, but they can be solved with an external pushing action produced by the endoscopist. The main feature of this work is the attempt to replicate the effects of external forces (generated by the medical doctors) by using just internal actions (generated by the robotic devices). The robotic solutions and the mechanisms illustrated in this paper could be in principle integrated in an "all inside" device, with electrical wires and service tubes, but without structural cables or rigid tails which are currently used for the advancement and orientation of traditional colonoscopes.

Miniaturized and "smart" instruments capable of characterizing the mechanical properties of tiny biological tissues are needed for research in biology, physiology and biomechanics, and can find very important clinical applications for diagnostics and minimally invasive surgery (MIS). We are developing a set of robotic microinstruments designed to augment the performance of the surgeon during MIS. These microtools are intended to restore (or even enhance) the finger palpation capabilities that the surgeon exploits to characterize tissue hardness and to measure pulsating vessels in traditional surgery, but that are substantially reduced in MIS. The paper describes the main features and the performance of a prototype miniature robotic instrument consisting of a microfabricated microgripper, instrumented with semiconductor strain-gauges as force sensors. For the (in vitro) experiments reported in the paper, the microgripper is mounted on a workstation and teleoperated. A haptic interface provides force feedback to the operator. We have demonstrated that the system can discriminate tiny skin samples based on their different elastic properties, and feel microvessels based on pulsating fluid flowing through them.

This paper describes a novel 4-axis microgripping system consisting of two fingers, each driven by a 2-axis moving coil actuator taken from a CD-lens assembly. These electromagnetic actuators are small, very linear, virtually frictionless and low cost. We measured the electrical actuator parameters and characterized the actuator performance in terms of displacement vs. current, force vs. current and resonant frequency. Experimental results indicate that the proposed microgripping system can be an attractive solution to the problem of micromanipulating small objects for precision manufacturing and biotechnology with high accuracy in a relatively large workspace.

We first discuss some general aspects of micromanipulation and possible different approaches. Then, we present new results in the micromanipulation of mechanical and biological objects. The apparatus we use is a purposely developed workstation comprising macro- and micro-manipulators. The most innovative component of the workstation is a micro-gripper fabricated using LIGA technology and actuated by piezoelectric actuators. We describe the design, fabrication and performance of a few prototypes of LIGA micro-grippers. Results are presented which demonstrate the ability of the system to manipulate effectively both micro-mechanical and biological micro-objects.