The continuous monitoring of an individual's breathing can be an instrument for the assessment and enhancement of human wellness. Specific respiratory features are unique markers of the deterioration of a health condition, the onset of a disease, fatigue and stressful circumstances. The early and reliable prediction of high-risk situations can result in the implementation of appropriate intervention strategies that might be lifesaving. Hence, smart wearables for the monitoring of continuous breathing have recently been attracting the interest of many researchers and companies. However, most of the existing approaches do not provide comprehensive respiratory information. For this reason, a meta-learning algorithm based on LSTM neural networks for inferring the respiratory flow from a wearable system embedding FBG sensors and inertial units is herein proposed. Different conventional machine learning approaches were implemented as well to ultimately compare the results. The meta-learning algorithm turned out to be the most accurate in predicting respiratory flow when new subjects are considered. Furthermore, the LSTM model memory capability has been proven to be advantageous for capturing relevant aspects of the breathing pattern. The algorithms were tested under different conditions, both static and dynamic, and with more unobtrusive device configurations. The meta-learning results demonstrated that a short one-time calibration may provide subject-specific models which predict the respiratory flow with high accuracy, even when the number of sensors is reduced. Flow RMS errors on the test set ranged from 22.03 L/min, when the minimum number of sensors was considered, to 9.97 L/min for the complete setting (target flow range: 69.231 ± 21.477 L/min). The correlation coefficient r between the target and the predicted flow changed accordingly, being higher (r = 0.9) for the most comprehensive and heterogeneous wearable device configuration. Similar results were achieved even with simpler settings which included the thoracic sensors (r ranging from 0.84 to 0.88; test flow RMSE = 10.99 L/min, when exclusively using the thoracic FBGs). The further estimation of respiratory parameters, i.e., rate and volume, with low errors across different breathing behaviors and postures proved the potential of such approach. These findings lay the foundation for the implementation of reliable custom solutions and more sophisticated artificial intelligence-based algorithms for daily life health-related applications.

This paper presents the full experience of designing, developing and testing ASTROMOBILE, a system composed of an enhanced robotic platform integrated in an Ambient Intelligent (AmI) infrastructure that was conceived to provide favourable independent living, improved quality of life and efficiency of care for senior citizens. The design and implementation of ASTRO robot was sustained by a multidisciplinary team in which technology developers, designers and end-user representatives collaborated using a user-centred design approach. The key point of this work is to demonstrate the general feasibility and scientific/technical effectiveness of a mobile robotic platform integrated in a smart environment and conceived to provide useful services to humans and in particular to elderly people in domestic environments. The main aspects faced in this paper are related to the design of the ASTRO's appearance and functionalities by means of a substantial analysis of users' requirements, the improvement of the ASTRO's behaviour by means of a smart sensor network able to share information with the robot (Ubiquitous Robotics) and the development of advanced human robot interfaces based on natural language.

The field of wearable robotics is gaining momentum thanks to its potential application in rehabilitation engineering, assistive robotics, and power augmentation. These devices are designed to be used in direct contact with the user to aid with movement or increase the power of specific skeletal joints. The design of the so-called physical human-robot interface is critical, since it determines not only the efficacy of the robot but the kinematic compatibility of the device with the human skeleton and the degree of adaptation to different anthropometries as well. Failing to deal with these problems causes misalignments between the robot and the user joint. Axes misalignment leads to the impossibility of controlling the torque effectively transmitted to the user joint and causes undesired loading forces on articulations and soft tissues. In this paper, we propose a general analytical method for the design of exoskeletons able to assist human joints without being subjected to misalignment effects. This method is based on a kinetostatic analysis of a coupled mechanism (robot-human skeleton) and can be applied in the design of self-aligning mechanisms. The method is exemplified in the design of an assistive robotic chain for a two-degree-of-freedom (DOF) human articulation.

Estimation of the temporal derivatives of a noisy position signal is a ubiquitous problem in industrial and robotics engineering. Here, we propose a new approach to get velocity and acceleration estimates of cyclical/periodic signals near to steady-state regime, by using adaptive oscillators. Our method combines the advantages of introducing no delay, and filtering out the high-frequency noise. We expect this method to be useful in control applications requiring undelayed but smooth estimates of velocity and acceleration (e.g., velocity control and inverse dynamics) of quasi-periodic tasks (e.g., active vibration compensation, robot locomotion, and lower-limb movement assistance).

This paper presents the design and experimental testing of the robotic elbow exoskeleton NEUROBOTICS Elbow Exoskeleton (NEUROExos). The design of NEUROExos focused on three solutions that enable its use for poststroke physical rehabilitation. First, double-shelled links allow an ergonomic physical human-robot interface and, consequently, a comfortable interaction. Second, a four-degree-of-freedom passive mechanism, embedded in the link, allows the user's elbow and robot axes to be constantly aligned during movement. The robot axis can passively rotate on the frontal and horizontal planes 30° and 40°, respectively, and translate on the horizontal plane 30 mm. Finally, a variable impedance antagonistic actuation system allows NEUROExos to be controlled with two alternative strategies: independent control of the joint position and stiffness, for robot-in-charge rehabilitation mode, and near-zero impedance torque control, for patient-in-charge rehabilitation mode. In robot-in-charge mode, the passive joint stiffness can be changed in the range of 24-56 N·m/rad. In patient-in-charge mode, NEUROExos output impedance ranges from 1 N·m/rad, for 0.3 Hz motion, to 10 N·m/rad, for 3.2 Hz motion.

Inferring temporal derivatives (like velocity and acceleration) from a noisy position signal is a well-known challenge in control engineering, due to the intrinsic trade-off between noise filtering and estimation bandwidth. To tackle this problem, in this paper we propose a new approach specifically designed for periodic movements. This approach uses an adaptive oscillator as fundamental building block. It is a tool capable of synchronizing to a periodic input while learning its features (frequency, amplitude, ...) in dedicated state variables. Since the oscillator's input and output are perfectly synchronized during steady-state regime, a non-delayed estimate of the input temporal derivatives can be obtained simply by deriving the output analytical form. Pending a (quasi-)periodic input signal, these temporal derivatives are thus synchronized with the actual kinematics, while the signal bandwidth can be arbitrarily tuned by the intrinsic dynamics of the oscillator. We further validate this approach by developing an impedance-based strategy for assisting human walking in the LOPES lower-limb exoskeleton. Preliminary results with a single participant give rise to three main conclusions. First, our method indeed provides velocity and acceleration estimates of the participant's joint kinematics which are smoother and less delayed with respect to the actual kinematics than using a standard Kalman filter. Second, closing the human-robot loop with a high-gain impedance field depending on the acceleration is not possible with a Kalman filter approach, due to unstable dynamics. In contrast, our approach tolerates high gains (up to 70% of the nominal walking torque), showing its intrinsic stability. Finally, no clear benefit of the acceleration-dependent field with respect to a simpler position-dependent field is visible regarding the reduction of metabolic cost. This last result illustrates the challenge of designing sound assistive strategies for complex tasks like walking.

This paper introduces NEUROExos, an elbow powered exoskeleton for rehabilitation. The NEUROExos is provided with three novel characteristics which address the major problems arising in rehabilitation robotics. A double shell link structure allows for a comfortable human-robot interaction, while a 4-DOF passive mechanism gives a perfect kinematic compatibility with the user. Moreover, NEUROExos is powered by a variable impedance antagonistic actuator, which provides the exoskeleton with a software-controllable passive compliance. We present the main characteristics of the exoskeleton, with a focus on the actuation and control of the platform. Additionally, results on a healthy subject show the relevance of this design during a prototypical rehabilitation task.

A 2 × 2 array of four microelectromechanical system (MEMS) tactile microsensors is integrated with readout electronics in the distal phalanx of an anthropomorphic robotic finger. A total of 16 sensing elements are available in a 22.3-mm area (i.e., 72 units/cm ) of the artificial finger, thus achieving a density comparable with human Merkel mechanoreceptors. The MEMS array is covered by a polymeric packaging with biomimetic fingerprints enhancing the sensitivity in roughness encoding. This paper shows the ability of the sensor array to encode roughness for discrimination of surfaces, without requiring dedicated proprioceptive sensors for end-effector velocity. Three fine surfaces with 400-, 440-, and 480- μm spatial periods are quantitatively evaluated. Core experiments consisted in active-touch exploration of surfaces by the finger executing a stereotyped human-like movement. A time-frequency analysis on pairs of tactile array outputs shows a clustering of the fundamental frequency, thus yielding 97.6% worst-case discrimination accuracy with a k -nearest-neighbor (k-NN) classifier. Hence, surfaces differing down to 40 μm are identified in active-touch by both hardware and processing methods based on exteroceptive tactile information. Finally, active-touch results with five textiles (which differ in texture or orientation) are shown as a preliminary qualitative assessment of discrimination in a more realistic tactile-stimulation scenario.

This paper introduces a novel exoskeleton device (HANDEXOS) for the rehabilitation of the hand for post-stroke patients. The nature of the impaired hand can be summarized in a limited extension, abduction and adduction leaving the fingers in a flexed position, so the exoskeleton goal is to train a safe extension motion from the typical closed position of the impaired hand. The mechanical design of HANDEXOS offers the possibility to overcome the exoskeleton limits often related to the general high level of complexity of the structure, mechanism and actuation. We describe the mechanical design of the index finger module, the dynamic model and some preliminary experimental results.

This paper presents the mechatronic design of an anthropomorphic 16 degree of freedom, 4 degree of mobility prosthetic hand for use by transradial amputees. Underactuated fingers and differential mechanisms have been used in order to fit all the functional components (actuators, sensors and electronics) in the size of a human hand. Moreover innovative non-back-drivable mechanisms have been designed in order to overcome some of the actual drawbacks of the mechanisms commonly used in prosthetic hands. The new hand is provided with a comprehensive sensory system embedded in the structure of the fingers composed of 40 proprioceptive and exteroceptive sensors. The large employment of sensors, combined with an actuation architecture that allows for grasping and gestures, will permit this hand to be used in clinical experimentation in the near future.

An anthropomorphic underactuated prosthetic hand, endowed with position and force sensors and controlled by means of myoelectric commands, is used to perform experiments of hierarchical shared control. Three different hierarchical control strategies combined with a vibrotactile feedback system have been developed and tested by able-bodied subjects through grasping tasks used in activities of daily living (ADLs). The first goal is to find a good tradeoff between good grasping capabilities and low attention required by the user to complete grasping tasks, without addressing advanced algorithm for electromyographic processing. The second goal is to understand whether a vibrotactile feedback system is subjectively or objectively useful and how it changes users' performance. Experiments showed that users were able to successfully operate the device in the three control strategies, and that the grasp success increased with more interactive control. Practice has proven that when too much effort is required, subjects do not do their best, preferring, instead, a less-interactive control strategy. Moreover, the experiments showed that when grasping tasks are performed under visual control, the enhanced proprioception offered by a vibrotactile system is practically not exploited. Nevertheless, in subjective opinion, feedback seems to be quite important.

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.

This paper presents the development of new transmission components and position controller of the NEURARM hydraulic actuation unit as critical components of a novel robotic arm specifically designed to perform joint experiments between neuroscience and robotics. NEURARM replicates the main functions and characteristics of the human arm during the execution of planar movements like reaching and catching, and it was used to investigate human motion control theories, to develop and evaluate models of control, of learning and of sensory-motor interaction.

The paper presents a controller for a multi-fingered underactuated prosthetic hand based on tendon transmission. The control architecture is implemented in two subsequent and different phases. The first one is the pre-shaping of the hand, based on the grasp type is implemented by stand-alone motion controllers using PID position control algorithms. The desired force closure value is calculated according to the pre-shape measured tendons tension and to the grasping force. In the second phase, the involved fingers rapidly close around the object to perform a balanced distribution of the forces within the hand, as it happens in the human hand. The controller is thus able to perform successfully many stable grasps. An overview of the hardware architecture and the results in terms of grasping capabilities based on Cutkosky grasp taxonomy are also presented

Recent research in prosthetic hands aims at developing innovative cybernetic systems able to allow users to feel an artificial hand as part of their bodies by providing the tactile sensation of a natural hand. Such prostheses must be endowed with artificial proprioceptive and exteroceptive sensory systems as well as appropriate neural interfaces able to exchange sensory-motor signals between the body and the nervous system of an amputee. Based on consideration of available neurophysiological and behavioral data in humans and on the specific sensory needs to control a prototypical grasp-and-lift task, two kinds of sensors were developed: on-off contact sensor arrays and triaxial force sensors. Both sensor types were characterized and compared with their biological counterparts. Their ability to convey critical information during a lift task was evaluated with the sensors integrated in a biomechatronic cybernetic hand

Personal robots, which are expected to become popular in the future, are required to be active in joint work and community life with humans. Such robots must have no bad physical or psychical effect on humans. The psychical effect of a robot on humans has been subjectively measured using questionnaires. However, it has not been objectively measured yet. Human emotion and the consciousness direction can be measured by physiological parameters and body motion, respectively. Therefore, the bioinstrumentation system WB-1 was developed in order to objectively measure the psychical effect of a robot on a human. It can measure physiological parameters such as respiration, heart rate, perspiration and pulse wave, and arm motion. Analyzing human stress in the interaction with a robot from electrocardiogram, the robot could generate a motion for decreasing the stress

In recent years, thanks to the advancement of robotics and mechatronics, new and more effective devices for the restoration and replacement of sensory-motor function in disabled people have been developed. In all these systems, user acceptability is strictly connected to several issues such as the residual abilities of the subject, the mechatronic characteristics of the robot, and also the interface chosen to link them. It is possible to figure out different "human-interface-device" combinations [also defined as "hybrid bionic systems" (HBSs)] characterized by different properties in terms of level of hybridness, connection, and augmentation. In particular, in HBSs the interface has to be customized according to the characteristics of the robotic artefact to be controlled and to the desires and needs of the final users. In this paper, our attention has been focused on the problem of the replacement of hand function after amputation. Three HBSs characterized by different levels of complexity, dexterity, and sensorization are presented in order to show the possibility of developing acceptable and effective systems by choosing different levels of connection and hybridness (i.e., different interfaces) for different devices and applications. The following case studies are presented: 1) the use of invasive interfaces to the peripheral nervous system to control a dexterous and highly sensorized hand prosthesis; 2) the use of electromyographic signals recorded using surface electrodes to control a compliant adaptive prosthesis; and 3) the use of a foot interface to control a two-degrees-of-freedom prosthesis. The preliminary results achieved so far seem to confirm the idea that the correct choice of the proper interface while developing an HBS can increase effectiveness and usability

This paper presents recent results aimed at developing a functional prosthetic hand characterized by an EMG-control and by a simple and low cost fabrication technology. In order to overcome some limitations of current prosthetic hands mainly related to the poor functionality and controllability, the prosthetic hand has been designed following a biomechatronic approach based on biologically-inspired design solutions. The core of the project described in this paper is the fabrication of a compliant under-actuated prosthetic hand: the structure of the hand (both palm and fingers) is moulded as a soft polymeric single part with compliant joints and embedded tendon driven underactuated mechanism for providing adaptive grasp. In order to make user trials, the hand is equipped with simple but functional EMG-based control of the single motor incorporated in the hand, and is integrated with a prosthesis socket. The paper presents the biomechatronics design, the fabrication process, the integration of the prosthetic device and first experimental results.

In this paper, some recent results about the experimental trials we are performing on a functional prosthetic hand characterized by an EMG-control and by a simple and low cost fabrication technology are shown. The innovation described in this paper is the fabrication of a compliant under-actuated prosthetic hand. The structure of the hand (both palm and fingers) is moulded as a soft polymeric single part with compliant joints and embedded tendon driven under-actuated mechanism for providing adaptive grasp. The prosthetic hand has been designed following a biomechatronic approach based on biologically-inspired design solutions. We describe the second release of this prosthesis. The evaluating tests are related to the maximum force exerted during grasping and to the fatigue problems occurring with cables and joint.

This paper presents an experimental investigation on a novel interface for high level control of robotic hands, based on selected foot movements. A prototype has been developed that integrates 4 sensitive areas, battery, and electronics for data acquisition and wireless transmission into a wearable insole. The prototype foot interface has been experimentally validated in the control of a robotic hand prosthesis. Comparative experimental trials were conducted with 10 able-bodied subjects, with both the foot interface and an EMG-based control, which represents the most advanced interface currently available in clinical implants for amputees. The results confirmed the effectiveness of the foot interface in the control of the hand prosthesis and showed a significant decrease in required adaptation and learning from the user's side.

The authors have been developing humanoid robots in order to develop new mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. We considered that human hands play an important role in communication because human hands have grasping, sensing and emotional expression abilities. Then, we developed the emotion expression humanoid robot WE-4RII (Waseda Eye No.4 Refined II) by integrating the new humanoid robot hands RCH-1 (RoboCasa Hand No.1) into the emotion expression humanoid robot WE-4R. Furthermore, we confirmed that RCH-1 and WE-4RII had effective emotional expression ability because the correct recognition rate of WE-4RII's emotional expressions was higher than the WE-4R's one. In this paper, we describe the mechanical features of WE-4RII.

Among social infrastructure technologies, robot technology (RT) is expected to play an important role in solving the problems of both decrease of birth rate and increase of elderly people in the 21st century, specially but not only in Japan. In order to achieve this objective, the new generation of personal robots should be capable of a natural communication with humans by expressing human-like emotion. In this sense, human hands play a fundamental role in communication, because they have grasping, sensing and emotional expression ability. This paper presents the recent results of the collaboration between the Takanishi Lab of Waseda University, Tokyo, Japan, and the Arts Lab of Scuola Superiore Sant'Anna, Pisa, Italy, and ROBOCASA. In this paper, the development of a novel anthropomorphic hand for humanoid robotics RCH-1 (ROBOCASA Hand No.1) and its integration into a humanoid robotic platform, named WE-4RII (Waseda Eye No.4 Refined II) is presented.

This paper presents an underactuated artificial hand intended for functional replacement of the natural hand in upper limb amputees. The natural hand has three basic functionalities: grasping, manipulation and exploration. To accomplish the goal of restoring these capabilities by implanting an artificial hand, two fundamental steps are necessary: to develop an artificial hand equipped with artificial proprioceptive and exteroceptive sensors and to fabricate an appropriate interface able to exchange sensory-motor signals with the amputee's body and the central nervous system. In order to address these objectives, we have studied an underactuated hand according to a biomimetic approach, and we have exploited robotic and microengineering technologies to design and fabricate its building blocks. The architecture of the hand comprises the following modules: an actuator system embedded in the underactuated mechanical structure (artificial musculoskeletal system), a proprioceptive sensory system (position and force sensors), an exteroceptive sensory system (3D force sensors distributed on the cosmetic glove), an embedded control unit, and a human/machine interface. The first prototype of the artificial hand has been designed and fabricated. The hand is underactuated, and is equipped with opposable thumb and a proprioceptive sensory system. This paper presents the fabrication and experimental characterization of the hand, focusing on the mechanical structure, the actuator system and the proprioceptive sensory system.

The objective of the project described in this paper is the development of a cybernetic prosthesis, replicating as much as possible the sensory-motor capabilities of the natural hand. The human hand is not only an effective tool but also an ideal instrument to acquire information from the external environment. The development of a truly human-like artificial hand is probably the most widely known paradigm of "bionics". The Cyberhand Project aims to obtain a cybernetic prosthetic hand interfaced to the peripheral nervous system. In particular this paper is focused on the hand mechanisms design and it presents preliminary results in developing the three fingered anthropomorphic hand prototype and its sensory system.

Current prosthetic hands are basically simple grippers with one or two degrees of freedom, which barely restore the capability of the thumb-index pinch. Although most amputees consider this performance as acceptable for usual tasks, there is ample room for improvement by exploiting recent progresses in mechatronic design and technology. This paper focus on an innovative approach for the design and development of prosthetic hands based on underactuated mechanisms. Furthermore, it describes the development and a preliminary analysis of a first prototype of an underactuated prosthetic hand.

We describe the design and results achieved in the development of a semi-automatic mechatronic tool for computer-assisted endoscopy. The aim of our research is to reduce the risk of damage to delicate anatomical parts in minimally invasive surgical interventions. To this purpose, in a stand-alone configuration, the mechatronic tool is able to detect contact between the steerable tip and surrounding tissues. With the addition of a localizer and an external control unit, a collision-avoidance mechanism prevents contact with pre-selected danger regions of the anatomy. This paper is focused on the architectural and functional description and on the experimental evaluation of the collision-avoidance mechanism. The results demonstrate that the endoscope is suitable for clinical practice, both in terms of spatial accuracy and reaction speed.

The field of humanoids robotics is widely recognized as the current challenge for robotics research. Developing humanoids poses fascinating problems in the realization of manipulation capability, which is still one of most complex problem in robotics. The paper, starting from an overview of current activities in the development of humanoid robots, with special focus on manipulation, presents the authors' approach to the design and development of anthropomorphic sensorized hands and of anthropomorphic control and sensory-motor coordination schemes. Current achievements at the Scuola Superiore Sant'Anna and Centro INAIL RTR (Research Centre on Rehabilitation Bioengineering) in the development of a robotic human prosthesis are described, together with preliminary experimental results, as well as in the implementation of biologically-inspired schemes for control and sensory-motor co-ordination, derived from models of well-identified human brain areas.

This paper describes a novel mechatronic tool for arthroscopy, which is at the same time a smart tool for traditional arthroscopy and the main component of a system for computer-assisted arthroscopy. The mechatronic arthroscope has a cable-actuated servomotor-driven multi-joint mechanical structure, is equipped with a position sensor measuring the orientation of the tip and with a force sensor detecting possible contact with delicate tissues in the knee, and incorporates an embedded microcontroller for sensor signal processing, motor driving and interfacing with the surgeon and/or the system control unit. When used manually, the mechatronic arthroscope enhances the surgeon's capabilities by enabling him/her to easily control tip motion and to prevent undesired contacts. When the tool is integrated in a complete system for computer-assisted arthroscopy, the trajectory of the arthroscope is reconstructed in real time by an optical tracking system using infrared emitters located in the handle, providing advantages in terms of improved intervention accuracy. The computer-assisted arthroscopy system comprises an image processing module for segmentation and three-dimensional reconstruction of preoperative computer tomography or magnetic resonance images, a registration module for measuring the position of the knee joint, tracking the trajectory of the operating tools, and matching preoperative and intra-operative images, and a human-machine interface that displays the enhanced reality scenario and data from the mechatronic arthroscope in a friendly and intuitive manner. By integrating preoperative and intra-operative images and information provided by the mechatronic arthroscope, the system allows virtual navigation in the knee joint during the planning phase and computer guidance by augmented reality during the intervention. This paper describes in detail the characteristics of the mechatronic arthroscope and of the system for computer-assisted arthroscopy and discusses experimental results obtained with a preliminary version of the tool and of the system.

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.

Colonoscopy is an important procedure for the diagnosis of various pathologies, in particular cancer of the colon and of the rectum, the second most malignant tumor in industrialized countries. At present however, colonoscopy is a procedure often painful for the patient and complex for the doctor. This is mainly due to the characteristics of current colonoscopes, which are quite rigid and require the doctor to perform difficult maneuvers for insertion. In this paper we present the concept and describe the design and fabrication of a new system for colonoscopy based on a microrobot capable of being propelled semi-autonomously along the colon. The microrobot system comprises a mothership incorporating devices for clamping the colon wall and tools for diagnosis and intervention. The actuation system is based on purposely developed shape memory alloy (SMA) pneumatic microvalves. A human/machine interface allows the doctor to teleoperate or supervise the functioning of the microrobot and to receive visual and other information during endoscopy. Particular attention has been paid to investigating a reliable and safe method of locomotion and to develop an efficient clamping system for the microrobot. The resulting configuration of the microrobot is very simple and potentially suitable for real clinical application. A prototype microrobot system has been tested in vitro with promising results.

Arthroscopic techniques are very popular in orthopaedic surgery for intervention on articular joints, especially on the knee. From an engineering viewpoint, current arthroscopic techniques can be improved in two ways: a) by augmenting visual information for the surgeon; b) by improving existing instrumentation. In our laboratory we are addressing both problems by developing an integrated system for computer-assisted arthroscopy. In this paper the procedures and instrumentation currently adopted for arthroscopy, and the limitations of both, are described first. Then the main characteristics of the integrated system we are developing are presented. The design requirements for new and better instruments for arthroscopy are discussed in detail and the fabrication and testing of a prototype of shape memory alloy-based actuator developed for steering the distal part of an arthroscope are discussed. The prototype steerable end-effector can rotate of /spl plusmn/90/spl deg/ and exert a maximum force at the tip of about 1N.

This paper describes a teleoperated mobile microrobot incorporating a novel type of electromagnetic micromotor. The overall dimensions of the microrobot are 10 mm/spl times/10 mm/spl times/10 mm. Two micromotors are used to actuate the two wheels of the microrobot. The micromotor is based on variable reluctance working principle and moves step by step. The micromotor is driven by a sequence of current pulses and performs about 200 steps per revolution. The micromotor generates a torque of 350.10/sup -6/ Nm at each step and a maximum speed of about 180 rpm. The heart of the control circuitry is the PIC16C73 microcontroller, that implements the control algorithm which allows the microrobot to move forward, backward and turn left or right. The operator controls the microrobot by a remote joystick and flexible ultraminiature wires. The microrobot has a maximum speed of 10 cm/s and can climb a slope of 15 degrees. The paper describes the design, fabrication and performance of the microrobot and of its components.