M.C. Carrozza

BioMechatronic Design and Control of an Anthropomorphic Artificial Hand for Prosthetics and Robotic Applications

The paper proposes a biomechatronic approach to the design of an anthropomorphic artificial hand. The hand is conceived to be applied to prosthetics and biomedical robotics; hence, anthropomorphism is a fundamental requirement to be addressed both in the physical aspect and in the functional behavior. As regards the hand mechanics, a cable-driven underactuation is proposed in order to enlighten the structure, allow anthropomorphic self-adaptation to the object to be grasped, and simplify the control. Two simple PD control systems are formulated and evaluated in a common task of grasping a cylindrical object. The reference input for the control is derived from data on human subjects performing the same task and extracted by the literature. The paper reports simulation results about the comparison with the human case when both control systems are used to close the finger, so to derive specific indications for the improvement of the hand design

The development of a novel biomechatronic hand-ongoing research and preliminary results

An ideal upper limb prosthesis should be perceived as part of the natural body by the amputee and should replicate sensory-motor capabilities of the amputated limb. However, such an ideal cybernetic prosthesis is still far from reality: current prosthetic hands are simple grippers with one or two degrees of freedom, which barely restore the capability of the thumb-index pinch. The paper describes the design and fabrication of a prosthetic hand based on a biomechatronic and cybernetic approach. Our approach is aimed at providing natural sensory-motor coordination to the amputee, by integrating biomimetic mechanisms, sensors, actuators and control, and by interfacing the hand with the peripheral nervous system.

Upper limb rehabilitation and evaluation of stroke patients using robot-aided techniques

This work presents two robot devices for use in the rehabilitation of upper limb movements and reports the quantitative parameters obtained to characterize the rate of improvement thus allowing a precise monitoring of the patients recovery. Two groups of chronic post-stroke patients were enrolled in a 3-week rehabilitation program including standard physical therapy plus treatment by means of robot devices respectively for wrist and elbow-shoulder movements. Both groups were evaluated by means of standard clinical assessment scales and a new robot measured evaluation metrics. After treatment, both groups improved their motor deficit and disability. The new evaluation metrics proposed should allow the therapist to implement targeted rehabilitative strategies and, if necessary, prompt adjustment of the treatment.

Impedance microprobes for myocardial ischemia monitoring

Describes the development, packaging and characterization of a silicon-based impedance microprobe for myocardial ischemia monitoring during open-heart surgery. The microprobe consists of four planar Pt electrodes micromachined on an isolated silicon substrate. The microprobe has been assembled on a ceramic substrate, packaged with epoxy resin and wired to the external instrumentation. Mechanical characterization of the system and in vitro biocompatibility tests of the device have been performed. Measurement instrumentation for preliminary tests has also been developed.

Design and control of an underactuated cybernetic artificial hand

In this paper some research efforts towards the realization of a cybernetic hand prosthesis are presented with specific focus on the biomechatronic design and the preliminary electromyography-based control system. In particular, the analysis of the natural low level control mechanisms and of the cognitive feedback information has been used for designing the CYBERHAND prosthetic hand. An experimental setup of the CYBERHAND system including an electromyography-based control system, a preliminary low level control system and the first biomechatronic hand has been integrated and presented in this paper

Experimental Analysis of a Soft Compliant Tactile Microsensor to be Integrated in an Anthropomorphic Artificial Hand

This paper presents the experimental analysis of a high shear sensitive 1.4mm3 three-axis force microsensor embedded in a soft, compliant and flexible packaging with minimum thickness of 2mm. The study is aimed at investigating the response of the tactile microsensor when it is stimulated with a combination of normal and shear loads. Experimental analysis is focused on the transient phenomena when a change of static to dynamic friction occurs at the packaged microsensor surface during interaction with an external object. According to a bioinspired design approach that is based on the emulation of natural mechanoreceptors of the human skin for providing appropriate tactile event encoding, the transient behaviour quantitative analysis is fundamental for assessing if the sensor is applicable in an artificial hand for controlling grasping and manipulation of an object.Copyright

Biorobotics for longevity

The main aim of this paper is to illustrate the potentials that the use of robotic and mechatronic technologies (in combination with advanced biomechanical models) can offer to help elderly people identifying and slowing down the effects of the age-related modifications of the neuro-musculo-skeletal systems and therefore increasing their possibility of staying at home reducing the hospitalization time. In particular, a three phases approach is proposed in this paper: (i) the use of robotic and mechatronic systems to analyse the age-related modifications of the motor control strategies (in particular for falling risk) in clinics or research laboratories; (ii) the use of wearable systems to assess motor performance in a unstructured environment (e.g., the house of the people); (iii) the use of technological aids to help elderly people to live autonomously in their domestic environment. The results illustrated in this manuscript seems to confirm that this approach can provide interesting and useful tools to increase the quality of life of elderly people.

Micro instrumentation for non-invasive measurement of mechanical properties of tissues

This paper addresses the problem of the in-vivo measurement of mechanical properties of soft tissues, especially dermis. A new device based on the pneumatic suction of tissues and consequent deformation measurement is presented. Preliminary results on human skin characterisation are illustrated and interpreted on the basis of an appropriate visco-elastic model.

Multisensor silicon needle for cardiac applications

An integrated chemical sensor with multiple ion and temperature sensors, composed of two ISFETs (pH and K/sup +/), one platinum pseudo-reference electrode and temperature sensor based on a platinum resistor has been realised by using a CMOS-compatible technology and silicon micromachining. This paper describes a summary of the fabrication process and results of the device characterisation in vitro. The feasibility of the fabrication technology has been demonstrated and all devices have operated satisfactory, with a response showing good sensitivity and linearity. This multisensor will be used in the on-line early detection of myocardial ischemia during cardiac surgery while the heart is artificially arrested (extracorporeal circulation).

Theoretical analysis and experimental testing of a miniature piezoelectric pump

A number of micropumps have been proposed in the last few years based on different actuating principles and fabricated by different technologies, In most cases, however, those micropumps have been designed taking into account primarily available microfabrication technologies rather than appropriate fluidodynamic analysis, In fact, not many papers are available in the literature presenting theoretical models usable to describe the functioning and predict the performance of existing micropumps, In this paper we present a new theoretical model suitable for guiding the design and predicting the performance of a volumetric micropump actuated by a piezoelectric actuator. The model takes into account the influence of inlet and outlet parameters, fluid viscosity, pump geometry, and displacement of pumping element. Simulations have been performed and compared satisfactorily with results of experiments on a prototype micropump fabricated in our laboratory.