Nicola Pellegrini

Automatic and manual devices for cardiopulmonary resuscitation: A review:

Rate of survival without any neurological consequence after cardiac arrest is driven not only by early recognition but also by high-quality cardiopulmonary resuscitation. Because the effectiveness of the manual cardiopulmonary resuscitation is usually impaired by rescuers’ fatigue, devices have been devised to improve it by appliances or ergonomic solutions. However, some devices are thought to replace the manual resuscitation altogether, either mimicking its action or generating hemodynamic effects with working principles which are entirely different. This article reviews such devices, both manual and automatic. They are mainly classified by actuation method, applied force, working space, and positioning time. Most of the trials and meta-analyses have not demonstrated that chest compressions given with automatic devices are more effective than those given manually. However, advances in clinical research and technology, with an improved understanding of the organizational implications of their use, are constantly improving the effectiveness of such devices.

Machine Tools Thermostabilization Using Passive Control Strategies

The aim of this study is to investigate passive control strategies using Phase Change Materials in Machine Tools (MTs) thermostabilization. By considering the main issues related to the thermal stability, authors presented the application of novel multifunctional materials to Machine Tools structures. A set of advanced materials are considered: aluminium foams, corrugate-core sandwich panels and polymeric concrete beds. The adopted solutions have been infiltrated by phase change materials (PCMs) in order to maintain the thermal stability of MTs when the environmental temperature is perturbed. The paper shows the results of simulative and experimental tests.

Innovative Modular SMA Actuator

A modular design for a shape memory actuator is proposed. The actuator is able to perform linear movements, while the modularity allows force and/or stroke improvements. Experimental results show how the behavior of the proposed implementation is sufficient for a wide class of problems and can be improved with proper developments.

Precision Point Design of a Cam Indexing Mechanism

This work regards on the design of a cylindrical cam indexing mechanism with a motion law that passes through a positional precision point. A numerical algorithm is proposed to solve this problem and, particularly, a genetic algorithm. The algorithm and the encoding of the problem are described.

Real-Time Performance of Mechatronic PZT Module Using Active Vibration Feedback Control

This paper proposes an innovative mechatronic piezo-actuated module to control vibrations in modern machine tools. Vibrations represent one of the main issues that seriously compromise the quality of the workpiece. The active vibration control (AVC) device is composed of a host part integrated with sensors and actuators synchronized by a regulator; it is able to make a self-assessment and adjust to alterations in the environment. In particular, an innovative smart actuator has been designed and developed to satisfy machining requirements during active vibration control. This study presents the mechatronic model based on the kinematic and dynamic analysis of the AVC device. To ensure a real time performance, a H2-LQG controller has been developed and validated by simulations involving a machine tool, PZT actuator and controller models. The Hardware in the Loop (HIL) architecture is adopted to control and attenuate the vibrations. A set of experimental tests has been performed to validate the AVC module on a commercial machine tool. The feasibility of the real time vibration damping is demonstrated and the simulation accuracy is evaluated.

PKM Mechatronic Clamping Adaptive Device

This study proposes a novel adaptive fixturing device based on active clamping systems for smart micropositioning of thin-walled precision parts. The modular architecture and the structure flexibility make the system suitable for various industrial applications. The proposed device is realized as a Parallel Kinematic Machine (PKM), opportunely sensorized and controlled, able to perform automatic error-free workpiece clamping procedures, drastically reducing the overall fixturing set-up time. The paper describes the kinematics and dynamics of this mechatronic system. A first campaign of experimental trails has been carried out on the prototype, obtaining promising results.

Functional Design in Rehabilitation: Modular Mechanisms for Ankle Complex

This paper is aimed at presenting an innovative ankle rehabilitation device based on a parallel mechanism. A functional analysis and design are described to obtain a device able to guarantee ankle movement while patients body remains stationary. Human ankle is a challenging context where a series of joints are highly integrated. The proposed rehabilitation device permits a patient with walking defects to improve his or her gait. The research focuses on plantar-flexion-dorsiflexion movement. The robust design starts from an accurate modelling of ankle movements during walking, assessing motion data from healthy individuals and patients. The kinematics analysis and functional evaluations lead the study and development of the articulated system. In particular, results of simulations support the effectiveness of the current design. A 3D prototype is presented highlighting that the ankle motion is successfully demonstrated.

Vibration Damping Analysis of Lightweight Structures in Machine Tools

The dynamic behaviour of a machine tool (MT) directly influences the machining performance. The adoption of lightweight structures may reduce the effects of undesired vibrations and increase the workpiece quality. This paper aims to present and compare a set of hybrid materials that may be excellent candidates to fabricate the MT moving parts. The selected materials have high dynamic characteristics and capacity to dampen mechanical vibrations. In this way, starting from the kinematic model of a milling machine, this study evaluates a number of prototypes made of Al foam sandwiches (AFS), Al corrugated sandwiches (ACS) and composite materials reinforced by carbon fibres (CFRP). These prototypes represented the Z-axis ram of a commercial milling machine. The static and dynamical properties have been analysed by using both finite element (FE) simulations and experimental tests. The obtained results show that the proposed structures may be a valid alternative to the conventional materials of MT moving parts, increasing machining performance. In particular, the AFS prototype highlighted a damping ratio that is 20 times greater than a conventional ram (e.g., steel). Its application is particularly suitable to minimize unwanted oscillations during high-speed finishing operations. The results also show that the CFRP structure guarantees high stiffness with a weight reduced by 48.5%, suggesting effective applications in roughing operations, saving MT energy consumption. The ACS structure has a good trade-off between stiffness and damping and may represent a further alternative, if correctly evaluated.

A Thermo-Dynamical Constitutive Model Based on Kinetic Approach for Shape Memory Materials

The technological application of nickel–titanium shape memory alloys (SMA) requires a constitutive model that can be easily implemented into numerical methods. For these reasons, macroscopic constitutive models have gained ground in SMA designs. A new model is developed that encompasses all the characteristics of these materials over the whole range of transformation temperatures, several macro-mechanical properties and evolution of martensite fraction. A finite element scheme is proposed to solve a semi-inverse dynamic problem. For a prescribed temperature range and external stress-boundary conditions, the outcomes are the possibility to identify the required electrical current density.

Design and Experimental Validation of a Shape Memory Alloy Actuator for Linear Motors

This paper presents an innovative mechanical actuator using a shape memory alloy (SMA) with a cooling system based on combined thermoelectric effect and forced air cooling systems. The main advantages of using SMAs include the reduction of the system weight, the ease and reliability in application, and a simple control strategy. This study focuses on the development of the system highlighting the mathematical model of the actuator, and an experimental prototype was implemented. Several experiments are used to validate the model and to identify best SMA actuator configuration parameters. Experiments were used to evaluate the actuator closed-loop performance, stability, and robustness properties.