Pilar Lafont Morgado

Novel system for bite-force sensing and monitoring based on magnetic near field communication.

Intraoral devices for bite-force sensing have several applications in odontology and maxillofacial surgery, as bite-force measurements provide additional information to help understand the characteristics of bruxism disorders and can also be of help for the evaluation of post-surgical evolution and for comparison of alternative treatments. A new system for measuring human bite forces is proposed in this work. This system has future applications for the monitoring of bruxism events and as a complement for its conventional diagnosis. Bruxism is a pathology consisting of grinding or tight clenching of the upper and lower teeth, which leads to several problems such as lesions to the teeth, headaches, orofacial pain and important disorders of the temporomandibular joint. The prototype uses a magnetic field communication scheme similar to low-frequency radio frequency identification (RFID) technology (NFC). The reader generates a low-frequency magnetic field that is used as the information carrier and powers the sensor. The system is notable because it uses an intra-mouth passive sensor and an external interrogator, which remotely records and processes information regarding a patients dental activity. This permits a quantitative assessment of bite-force, without requiring intra-mouth batteries, and can provide supplementary information to polysomnographic recordings, current most adequate early diagnostic method, so as to initiate corrective actions before irreversible dental wear appears. In addition to describing the systems operational principles and the manufacture of personalized prototypes, this report will also demonstrate the feasibility of the system and results from the first in vitro and in vivo trials.

Development of Personalized Annuloplasty Rings: Combination of CT Images and CAD-CAM Tools

Although the use of personalized annuloplasty rings manufactured for each patient according to the size and morphology of their valve complex could be beneficial for the treatment of mitral insufficiency, this possibility has been limited for reasons of timelines and costs as well as for design and manufacturing difficulties, as has been the case with other personalized implant and prosthetic developments. However, the present quality of medical image capture equipment together with the benefits to be had from computer-aided design and manufacturing technologies (CAD-CAM) and the capabilities furnished by rapid prototyping technologies, present new opportunities for a personalized response to the development of implants and prostheses, the social impact of which could turn out to be highly positive. This paper sets out a personalized development of an annuloplasty ring based on the combined use of information from medical imaging, from CAD-CAM design programs and prototype manufacture using rapid prototyping technologies.

Enhancing Product Development through CT Images, Computer-Aided Design and Rapid Manufacturing: Present Capabilities, Main Applications and Challenges

1.1 Historical perspective of product development methodologies It is difficult to find the origins of what we call “systematic design”. To offer but one example, anyone studying the diagrams and sketches of Leonardo da Vinci can hardly fail to observe the depth of his analysis and how he systematically used variations to suggest possible solutions and be able to compare them (Taddei, Kaiser, Konig, 2006, Bautista, 2007). Up to the Industrial revolution, product design and development work was essentially linked to art and craft and only with the gradual mechanization of processes halfway through the 19th Century did a need begin to emerge to optimize the use of materials and perform detailed studies on strength, stiffness, wear, friction, assembly and maintenance (Reuleaux, 1875). However, it was not until the 20th Century that a systematic evaluation of these parameters was put forward as a way of gradually reaching an optimal solution. (Erkens, Worgebauer). Just before the Second World War a need was beginning to be noticed to rationalize product design processes but progress in this direction was hampered by the following factors: • An absence of effective methods for representing abstract ideas. • The widespread belief that design was an art and not a technical activity that could be carried out methodically and not just through creativity. A large-scale use of systematic design methodologies would have to wait for these limitations to be overcome and for the introduction of a more widespread use of automation and the appearance of more modern data processing procedures. Modern ideas on systematic development were given an enormous boost by relevant figures (Kesselring, 1951, 1954, Tschochner, 1954, Matousek, 1957 or Niemann, 1950, 1965, 1975), whose revolutionary ideas continue to suggest ways of solving and dealing with specific tasks related to machine and product design processes (Kaiser, Konig, 2006). During the 40s and the 50s Kesserling put forward a method based on successive approaches where each approach optimized different variables in line with technical and economic criteria. He also proposed several principles like “minimal production costs”, “minimal weight and

Analysis of different multiaxial fatigue criteria in the prediction of pitting failure in spur gears

The aim of this article is to study the appearance of pitting in spur gears by taking account of different multiaxial fatigue criteria. The stress levels undergone by the teeth are considered in order to be able to predict their life and compare the fatigue strength of gear materials. The process begins calculating the stress field inside the teeth flanks due to the pressure and shear stress in the contact along the mesh. Once the stresses are known, the appearance of failure is studied by using different multiaxial fatigue criteria: Dang Van, Crossland and Liu-Mahadevan criteria. The accuracy of each criterion to predict pitting in gears is analysed using experimental data.

Rapid Form Copying and Rapid Mould-Making Systems for Biodevices

Previous chapters have focused on different technologies for automated rapid prototyping of parts for validation trials and also final production parts, with two main approaches, in the one side high-speed CNC machining and in the other side “AMT” or “layer by layer” based.

Micro-manufacturing Technologies for Biodevices: Interacting at a Cellular Scale

Micro-manufacturing technologies started in the late 1950s mainly linked to the electronic industry, for producing circuits with improved performance, without a dramatic increase of final device size. Such beginning was very connected to the properties of silicon, which can be easily micromachined using chemical attacks through specially designed patterns or masks.

Computer-Aided Design (CAD) Technologies for Biodevices

Computer-aided design (CAD) consists of using computer systems to assist the creation, modification, analysis, and optimization of a design. Initial developments were carried out in the 1960s, linked to the aeronautic and automotive industries, although it was not until the 1980s that these tools started to be used in small and midsize companies, thus reducing the need of draftsmen. Initially designs attainable with CAD tools were mainly 2D, but nowadays the use of 3D modeling packages is widespread, due to its versatility.

Biomedical Microsystems for Disease Management

The modern and integrated study of biomechanical and biochemical issues in disease is usually carried out with the fundamental support of fluidic microdevices and of microfluidic diagnostic platforms, as fluids allow for the transport of nutrients, gases, debris, pathogens and drugs to and from cells, help to control the movement of microorganisms in vitro and make the application of controlled stresses in culture systems possible. In consequence, biomimetic responses are promoted and in many cases results obtained in vitro are more accurate than those obtained from animal models. In fact the field of microfluidic systems for diagnosis has experienced an explosive growth in the last two decades, promoted by the convergence of clinical diagnostic techniques, computer-aided modeling and mature micro- and nano-fabrication technologies capable of producing submillimeter-size fluidic channels, reservoirs and nanometric features in several materials, structures and devices. This chapter provides and introduction to the field of biomedical devices for disease study and management, with examples of systems devoted to purposes such as: in vitro drug screening, disease modeling and diagnosis, disease modeling and prediction, and modeling of tumors, among the most important and already well-established applications. The application of computer-aided design and rapid prototyping resources to the complete development of a capillary actuated microfluidic platform, as versatile framework for the potential point-of-care testing of different diseases and their eventual response to different antibiotics, is detailed as additional case of study.

General Considerations for the Development of Biomedical Devices

The development process of medical devices and of any products oriented to interacting with biological systems (biodevices) involves several special features deriving from the typical multidisciplinary characteristics of such devices and of their surrounding environment.

Brief Overview of Novel Technologies with Impact in the Biomedical Device Industry

The central objective of this handbook is to provide detailed information about different design and manufacturing technologies, most of them developed or greatly improved in the last two decades, with remarkable impact in the design and production of novel medical devices and biodevices.