Gabriele Baronio

A Critical Analysis of a Hand Orthosis Reverse Engineering and 3D Printing Process.

The possibility to realize highly customized orthoses is receiving boost thanks to the widespread diffusion of low-cost 3D printing technologies. However, rapid prototyping (RP) with 3D printers is only the final stage of patient personalized orthotics processes. A reverse engineering (RE) process is in fact essential before RP, to digitize the 3D anatomy of interest and to process the obtained surface with suitable modeling software, in order to produce the virtual solid model of the orthosis to be printed. In this paper, we focus on the specific and demanding case of the customized production of hand orthosis. We design and test the essential steps of the entire production process with particular emphasis on the accurate acquisition of the forearm geometry and on the subsequent production of a printable model of the orthosis. The choice of the various hardware and software tools (3D scanner, modeling software, and FDM printer) is aimed at the mitigation of the design and production costs while guaranteeing suitable levels of data accuracy, process efficiency, and design versatility. Eventually, the proposed method is critically analyzed so that the residual issues and critical aspects are highlighted in order to discuss possible alternative approaches and to derive insightful observations that could guide future research activities.

Analysis of an electromechanical generator implanted in a human total knee prosthesis

This paper describes a miniaturized electromechanical generator, integrable in a human total knee prosthesis, in which the mechanical energy, related to the knee joint movement, is converted into electrical energy. This device has been conceived in order to power an autonomous sensor system, integrated into the prosthesis, able to monitor the loads on the articular surfaces and to transmit those outside the body.

Technical Drawing Learning Tool-Level 2: An interactive self-learning tool for teaching manufacturing dimensioning

This work presents an interactive self‐learning tool named Technical Drawing Learning Tool‐Level 2—TDLT‐L2—for teaching manufacturing dimensioning to engineering students. The tool was designed for the students enrolled in the first year of the Bachelor in Management and Mechanical Engineering of the Universities of Brescia and Udine. It consists of a simple interactive tool, based on video and drawing animations, aimed at demonstrating the connection between real and simple machining processes and workpiece dimensions on technical drawing. TDLT‐L2 is currently available in two versions: as a standalone application for Windows or Android based operating systems and as a set of interactive PDF documents. It was conceived as the first module of a package of tools that will be developed, based on the learning levels proposed in the Technical Drawing Evaluation Grid—TDEG. A preliminary evaluation of TDLT‐L2 effectiveness was done involving the Management and Mechanical engineering students of Udine in some dimensioning exercises. The statistically considerations done on the obtained results confirmed the validity of the tool as a self‐learning instrument with an average increase of marks of about 8.8%.

An energy harvesting converter to power sensorized total human knee prosthesis

Monitoring the internal loads acting in a total knee prosthesis (TKP) is fundamental aspect to improve their design. One of the main benefits of this improvement is the longer duration of the tibial inserts. In this work, an electromagnetic energy harvesting system, which is implantable in a TKP, is presented. This is conceived for powering a future implantable system that is able to monitor the loads (and, possibly, other parameters) that could influence the working conditions of a TKP in real-time. The energy harvesting system (EHS) is composed of two series of NdFeB magnets, positioned into each condyle, and a coil that is placed in a pin of the tibial insert and connected to an implantable power management circuit. The magnetic flux variation and the induced voltage are generated by the knees motion. A TKP prototype has been realized in order to reproduce the knee mechanics and to test the EHS performance. In the present work, the experimental results are obtained by adopting a resistive load of 2.2 kΩ, in order to simulate a real implanted autonomous system with a current consumption of 850 µA and voltage of 2 V. The tests showed that, after 7 to 30 s of walking with a gait cycle frequency of about 1.0 Hz, the EHS can generate an energy of about 70 μJ, guaranteeing a voltage between 2 and 1.4 V every 7.6 s. With this prototype we can verify that it is possible to power for 16 ms a circuit having a power consumption of 1.7 mW every 7.6 s. The proposed generator is a viable solution to power an implanted electronic system that is conceived for measuring and transmitting the TKP load parameters.

Design considerations of an electromechanical generator implanted in human total knee prosthesis

The energy generation inside the human body represents a crucial aspect for powering implantable measuring circuits. In this work, a system for the electromagnetic energy harvesting, implantable in a total knee prosthesis (TKP) and capable of generating electricity from the knee movement, is presented. The energy harvesting system (EHS) is composed of two series of NdFeB magnets, located on each condyle, and a coil placed in a pivot of the tibial tray. The operating principles, design considerations and performed simulations are shown. Simulation results demonstrate that it is possible to generate an alternating voltage of maximum 600 mV. The proposed generator eliminates the batteries inside the human body and the use of techniques for the inductive power supply. The structural changes with respect to commercial prosthesis are minimal. Furthermore, the proposed energy harvester allows to generate electricity without changing or hindering the patient natural movement.

3D scanning and geometry processing techniques for customised hand orthotics: an experimental assessment

ABSTRACT In the field of rehabilitation, the 3D scanning of body parts can be considered a crucial starting point for subsequent 3D model design of customised devices, especially when additive manufacturing techniques are involved in their production. This study experimentally evaluates and identifies appropriate procedures to acquire and process 3D anatomic images of the hand, including fingers, for the design of customised orthoses. Hand scanning is a complex activity and requires solutions capable of solving problematic aspects, such as the difficulty in maintaining the hand in a steady position and the presence of motion artefacts due to involuntary movements. We addressed such issues by considering the use of two different kinds of optical scanning device. The acquisition process has been initially defined based on healthy subjects and then extended to patients affected by pathologies that compromise upper limb functionality. Quality anatomical models were produced thanks to the application of advanced geometry processing technologies for the automated alignment of multiple scans and the removal of artefacts due to involuntary movements. As a result, with distinctive pros and cons, both the proposed combinations of scanning procedures and dedicated geometry processing evidenced their suitability in producing complete and accurate enough 3D models to be exploited for the subsequent design and production of customised hand orthoses in a typical reverse engineering pipeline.

Best practices in teaching technical drawing: experiences of collaboration in three Italian Universities

This work present some best practice cases in teaching technical drawing done by three Italian Universities: Brescia, Udine, and Cassino and Southern Lazio. The intention to innovate and improve the basic technical drawing courses offered by these three Universities started in 2014. The objective of this collaboration was the development of some tools to help the students in understanding the fundamental concepts of technical drawing. The first tool developed, in order of time, was the Technical Drawing Evaluation Grid – TDEG. Starting from this tool, other learning aids were developed for the undergraduate engineering students. Some of them are: an online test for students’ self-assessment of technical drawing knowledge; a questionnaire to collect students’ opinions on different technical drawing and engineering design topics; a method for the improvement of students’ motivation to study; and a self-learning tool for teaching manufacturing dimensioning. The preliminary results of these different practices are presented and discussed in the following, posing the basis of the definition of some best practice methods that can be used for the improvement of the teaching and learning of technical drawing basic concepts for engineering students.

Concept and Design of a 3D Printed Support to Assist Hand Scanning for the Realization of Customized Orthosis

In the rehabilitation field, the use of additive manufacturing techniques to realize customized orthoses is increasingly widespread. Obtaining a 3D model for the 3D printing phase can be done following different methodologies. We consider the creation of personalized upper limb orthoses, also including fingers, starting from the acquisition of the hand geometry through accurate 3D scanning. However, hand scanning procedure presents differences between healthy subjects and patients affected by pathologies that compromise upper limb functionality. In this work, we present the concept and design of a 3D printed support to assist hand scanning of such patients. The device, realized with FDM additive manufacturing techniques in ABS material, allows palmar acquisitions, and its design and test are motivated by the following needs: (1) immobilizing the hand of patients during the palmar scanning to reduce involuntary movements affecting the scanning quality and (2) keeping hands open and in a correct position, especially to contrast the high degree of hypertonicity of spastic subjects. The resulting device can be used indifferently for the right and the left hand; it is provided in four-dimensional sizes and may be also suitable as a palmar support for the acquisition of the dorsal side of the hand.

TDEG based framework and tools for innovation in teaching technical drawing: The example of LaMoo project

This work presents the development of an integrated framework and related tools for innovation and improvement in the teaching of Technical Drawing. This framework is based on the “Technical Drawing Evaluation Grid—TDEG.” This grid is currently used, by the authors, for the definition and the development of different kinds of tools for supporting both teaching and learning and for the evaluation of Technical Drawing and engineering graphics topics knowledge in general. In particular, this paper focuses on the problems related to knowledge evaluation and assessment of Technical Drawing using online tests. Then, the LaMoo project which is a tool under development for the structured construction of questions for online tests in Moodle environment is presented.

Gölem project: Concept and design of a trekking/hiking wheelchair

This work concerns the growing interest in accessible tourism and describes the early stages of development of Gölem project. In particular, it takes into account accompanying activities of disabled people in mountain areas. Although literature and market analysis highlight the presence of different technical solutions used for the movement of disabled persons on rough terrains, there are only a couple of solutions based on the help of guides: Joëlette© and TrailRider©. Even if the use of these devices is generally satisfactory, our analysis has highlighted the presence of some limitations such as the difficulty of maintaining the lateral balance of the devices (which involves a considerable physical effort for the guides) and their reduced comfort for the passenger. This article describes the activities developed within the Gölem project. Its main goals are to design and to test an improved model of trekking/hiking wheelchair taking into account passengers comfort and better functionality of the device. At this moment, the design and modeling phases with the definition of dynamic parameters and of the suspension system of the device have been completed. The prototype implementation phase is in progress. Future activities will provide validation and field testing of the new solution with users.