Isa C. T. Santos

Medical device specificities: opportunities for a dedicated product development methodology.

The medical sector, similarly to other industries such as the aviation industry, has to comply with multiple regulations, guidelines and standards. In addition, there are multiple definitions for the expression ‘medical device’, and before entering the market, manufacturers must demonstrate their product’s safety and effectiveness. In such a complex and demanding environment, it is crucial to know the particularities surrounding the product being developed in order to minimize the chances of a commercial flop. Thus, in this paper, medical device specificities are identified, and the most relevant legislation is reviewed providing the foundations for a dedicated product development methodology.

Additional peculiarities of medical devices that should be considered in their development process.

Medical devices are peculiar products: their definition varies from country to country, they are used to treat diseases and they are different from pharmaceuticals. In 2012, the authors began to describe the complex and demanding environment of the medical device industry. In this article, the authors’ previous research is extended with additional peculiarities of medical devices such as recall, pricing and adoption factors.

Mechanical properties of stent–graft materials:

An aneurysm is a localized blood-filled dilatation of an artery whose consequences can be deadly. One of its current treatments is endovascular aneurysm repair, a minimally invasive procedure in which an endoprosthesis, called a stent–graft, is placed transluminally to prevent wall rupture. Early stent–grafts were custom designed for the patient through the assembling of off-the-shelf components by the operating surgeon. However, nowadays, stent–grafts have become a commercial product. The existing endoprostheses differ in several aspects, such as shape design and materials, but they have in common a metallic scaffold with a polymeric covering membrane. This article aims to gather relevant information for those who wish to understand the principles of stent–grafts and even to develop new devices. Hence, a stent–graft classification based on different characteristics is presented and the desired features for an ideal device are pointed out. Additionally, the materials currently in use to fabricate this type of endoprosthesis are reviewed and new materials are suggested.

Modeling of the medical device development process.

Models are abstract representations of reality that are built, analyzed and manipulated to augment the understanding of that reality. They can either be mental or codified but, in both cases, they contribute to good decision-making by ensuring that the right people use the right information at the right time. In order to reduce time to market, companies commonly adopt product development processes (PDP) and the medical device sector is no different. However, one can question which is the most adequate PDP model to follow or what information that model should contain, or even how the information should be represented. Here, the authors review the existing PDP models dedicated to medical devices. The model’s representation and usability are also debated in order to assist developers to select the most suitable model and adapt it to their needs and reality.

Acquisition and analysis of 3D mandibular movement using a device based on electromagnetic sensors and a neural network

In dental medicine, the study of mandibular movement has an important role in oral rehabilitation as it allows diagnosis of pathologies in the temporomandibular joint and the definition of adequate treatment plans. In this paper, a new device specially developed for the acquisition and analysis of 3D mandibular movement is presented. A facial arc is adopted as its main support structure and electromagnetic sensors are employed to acquire the mandibular movement. A neural network is used to transform the electrical signals output by the sensors into 3D Cartesian coordinates. A custom-made computer application is developed to display and analyse the movement acquired. The device is shown to be easy to use, comfortable for patients and capable of being produced at an affordable price.

Improving Post-EVAR Surveillance with a Smart Stent-Graft

Abdominal aortic aneurysms (AAA or triple A’s) are indolent and deadly diseases. Their treatment options involve either an invasive procedure or a minimally invasive one. When the minimally invasive procedure, endovascular aneurysm repair (EVAR), was introduced, it revolutionized the treatment of AAA’s due to advantages such as shortened hospital stays and reduced costs. As EVAR requires periodic imaging exams, questions are nowadays being raised regarding the procedure’s long-term cost-benefit relation. In order to reduce follow-up costs, new technological solutions are being pursued, namely EVAR stent-grafts with sensing capabilities. In this chapter, the suitability of aneurysm sac pressure measurement for EVAR surveillance is evaluated using an AAA computer model. In addition the design drivers underlying EVAR stent-grafts are reviewed and the development of a new flexible pressure sensor integrated into a stent-graft is described.

Diabetes Mellitus: a necessidade de um dispositivo de administração de insulina para crianças e adolescentes

O diabetes mellitus e uma doenca cronica em rapida expansao pelo mundo, afetando pessoas de qualquer idade ou sexo. E uma doenca que atinge o pâncreas prejudicando a producao de insulina, e em alguns casos o pâncreas para de produzir este hormonio. Apesar de nao haver cura, o tratamento da diabetes consiste em injecoes diarias de insulina; assim, as corretas administracoes de insulina sao indispensaveis para manter o controle glicemico e prevenir futuras complicacoes. A identificacao da oportunidade do desenvolvimento deste projeto e apresentada pela inexistencia de um dispositivo de administracao de insulina especifico para criancas. Este estudo visou a identificacao das necessidades para o desenvolvimento de um novo dispositivo de administracao de insulina para criancas diabeticas que permitisse aumentar a qualidade de vida das mesmas. Para tal, foi estudado o historico da doenca, identificados dispositivos existentes, levantadas novas tecnologias apara o tratamento da doenca e identificadas as necessidades do utilizador.

Evolution of the cost-effectiveness of Endovascular and Open Surgical Repair of Abdominal Aortic Aneurysms

A cost-effectiveness analysis refers to the economic study in which consequences of distinct interventions are evaluated using a single outcome. In healthcare, these analysis measure ‘natural’ units, such as life-years gained or deaths avoided, and are used to either compare alternative programs with a common health outcome or assess the consequences of expanding an existing program. Commonly, costeffectiveness results are used to support decisions regarding the adoption of medical devices, coverage of treatments or their reimbursement rate [1]. It is commonly accepted that, with time, experience increases as well as success rates and, on the other hand, costs decrease due to economies of scale or the maturation of technologies. However, there is uncertainty regarding the applicability of these assumptions to medical procedures involving medical devices. Here, we study the evolution of the cost-effectiveness of endovascular abdominal aortic aneurysm repair versus the conventional treatment, open surgery. Contrary to what was expected, the effectiveness decreases and costs increase along the time. If this behavior is similar in other procedures, one can question the applicability of cost-effectiveness analysis to support decisions involving medical devices.

CONCEPT SELECTION IN THE DEVELOPMENT OF MEDICAL DEVICES: THE CASE OF THE SMART STENT-GRAFT

During product development, ideas are narrowed down to a single one by the designers in order to satisfy the customers’ needs. This process is called concept selection and is crucial to the development of new products because, from this point onward, the design team is committed to a concept whose modification implies delays and additional costs. Decisions made during the concept selection phase are often difficult due to the uncertainty caused by the lack of objective data. However, it is possible to reduce this uncertainty assessing each concept’s expected costs and benefits. Medical devices, before entering the market, are scrutinized by several agencies around the world to assess their clinical- and cost-effectiveness. In order to reduce the uncertainty associated with concept selection, the parameters evaluated by the multiple agencies should be used to support the idea to pursue. However, as that data is not available yet, in this paper, several parameters are identified to evaluate each concept and, for each metric, the most adequate measurement technique is described. This paper also presents a specific implementation of the design process for a new stent-graft.