Design, Modeling, and Evaluation of the Eddy Current Sensor Deeply Implanted in the Human Body.

Joint replacement surgeries have enabled motion for millions of people suffering from arthritis or grave injuries. However, over 10% of these surgeries are revision surgeries. We have first analyzed the data from the worldwide orthopedic registers and concluded that the micromotion of orthopedic implants is the major reason for revisions. Then, we propose the use of inductive eddy current sensors for in vivo micromotion detection of the order of tens of μ m. To design and evaluate its characteristics, we have developed efficient strategies for the accurate numerical simulation of eddy current sensors implanted in the human body. We present the response of the eddy current sensor as a function of its frequency and position based on the robust curve fit analysis. Sensitivity and Sensitivity Range parameters are defined for the present context and are evaluated. The proposed sensors are fabricated and tested in the bovine leg

Recent Advances on Implantable Wireless Sensor Networks

Implantable electronic devices are undergoing a miniaturization age, becoming more efficient and yet more powerful as well. Biomedical sensors are used to monitor a multitude of physiological parameters, such as glucose levels, blood pressure and neural activity. A group of sensors working together in the human body is the main component of a body area network, which is a wireless sensor network applied to the human body. In this chapter, applications of wireless biomedical sensors are presented, along with state-of-the-art communication and powering mechanisms of these devices. Furthermore, recent integration methods that allow the sensors to become smaller and more suitable for implantation are summarized. For individual sensors to become a body area network (BAN), they must form a network and work together. Issues that must be addressed when developing these networks are detailed and, finally, mobility methods for implanted sensors are presented

Biomedical Engineering

Biomedical engineering is currently relatively wide scientific area which has been constantly bringing innovations with an objective to support and improve all areas of medicine such as therapy, diagnostics and rehabilitation. It holds a strong position also in natural and biological sciences. In the terms of application, biomedical engineering is present at almost all technical universities where some of them are targeted for the research and development in this area. The presented book brings chosen outputs and results of research and development tasks, often supported by important world or European framework programs or grant agencies. The knowledge and findings from the area of biomaterials, bioelectronics, bioinformatics, biomedical devices and tools or computer support in the processes of diagnostics and therapy are defined in a way that they bring both basic information to a reader and also specific outputs with a possible further use in research and development

Skin-Integrated wearable systems and implantable biosensors: a comprehensive review

Biosensors devices have attracted the attention of many researchers across the world. They have the capability to solve a large number of analytical problems and challenges. They are future ubiquitous devices for disease diagnosis, monitoring, treatment and health management. This review presents an overview of the biosensors field, highlighting the current research and development of bio-integrated and implanted biosensors. These devices are micro- and nano-fabricated, according to numerous techniques that are adapted in order to offer a suitable mechanical match of the biosensor to the surrounding tissue, and therefore decrease the body’s biological response. For this, most of the skin-integrated and implanted biosensors use a polymer layer as a versatile and flexible structural support, combined with a functional/active material, to generate, transmit and process the obtained signal. A few challenging issues of implantable biosensor devices, as well as strategies to overcome them, are also discussed in this review, including biological response, power supply, and data communication.This research was funded by FCT- FUNDAÇÃO PARA A CIÊNCIA E TECNOLOGIA, grant numbers: PTDC/EMD-EMD/31590/2017 and PTDC/BTM-ORG/28168/2017

Sensor capacitivo para a monitorização da interface osso-implante

Mestrado em Engenharia MecânicaOs implantes ósseos usados atualmente não são capazes de substituir integralmente a articulação onde são aplicadas. A redistribuição da carga no osso origina o efeito stress-shielding, o que pode provocar perda de massa óssea e migração do implante. O desgaste das componentes integrais do implante também causa alterações na interface ossoimplante. Os pacientes com estas complicações, podem ser submetidos a operações de revisão, onde o risco de insucesso e infeções é elevado. Para prevenir tais casos, recentemente foi proposto o conceito de Implante Instrumentado para dotar esta tecnologia com: sistemas de atuação (sobre a interface osso-implante), monitorização da integração osso-implante, sistemas de comunicação implante-exterior e sistemas de geração autónoma de energia. No entanto, uma revisão da literatura mostrou que os sistemas de monitorização propostos não são viáveis para serem incorporados em implantes instrumentados. Este é um estudo preliminar que visa propor um sistema de monitorização capacitivo com configuração em co-superfície listrado integrado num circuito ressonante RLC. Foi desenvolvido um aparato experimental para o teste do sistema in vitro usando estruturas de osso porcino. Observaram-se variações de 0,2 fF da capacitância por cada μm de deslocamento relativo entre a estrutura óssea e o sistema de monitorização. Embora preliminar, este estudo apresenta resultados promissores para a monitorização de diferentes interfaces osso-implante usando em sistemas capacitivos em co-superfície.The prostheses currently used, are not able to fully replace the joint where they are applied. The redistribution of the load in the bone causes stressshielding, which origins loss of bone mass, and migration of the implant. Also, the wear of the integral components of the prosthesis causes changes between the interface of the bone and the implant. Patients with these complications can be submitted to review surgeries, where the risk of failure and infection is high. To prevent such cases, instrumented prosthesis have been recently proposed, to enhance this technology with: actuation systems (over the bone-implant interface), osseointegration monitoring, communication systems between implant-exterior and systems capable of generating energy autonomously. However, a review over these technologies showed that the proposed monitoring systems are not feasible to be incorporated into instrumented implants. This is a preliminary study which aims to advocate a monitoring capacitive system with a cosurface stripe pattern integrated in a RLC resonant circuit. An experimental apparatus was developed to test the system in vitro using a porcine bone. Variations of 0,2 fF in the capacitance were observed, for each ìm of relative movement between the bone and the monitoring system. Although preliminary, this study presents promising result for monitoring different bone-implant interfaces using a cosurface capacitive system

Beyond Tissue replacement: The Emerging role of smart implants in healthcare

Smart implants are increasingly used to treat various diseases, track patient status, and restore tissue and organ function. These devices support internal organs, actively stimulate nerves, and monitor essential functions. With continuous monitoring or stimulation, patient observation quality and subsequent treatment can be improved. Additionally, using biodegradable and entirely excreted implant materials eliminates the need for surgical removal, providing a patient-friendly solution. In this review, we classify smart implants and discuss the latest prototypes, materials, and technologies employed in their creation. Our focus lies in exploring medical devices beyond replacing an organ or tissue and incorporating new functionality through sensors and electronic circuits. We also examine the advantages, opportunities, and challenges of creating implantable devices that preserve all critical functions. By presenting an in-depth overview of the current state-of-the-art smart implants, we shed light on persistent issues and limitations while discussing potential avenues for future advancements in materials used for these devices

Medical semiconductor sensors: a market perspective on state-of-the-art solutions and trends

The aim of this Master Thesis is to analyse the worldwide state-of-the art market solutions and trends in semiconductor sensors within medical applications; specially magnetic and pressure sensors, with the intention of developing a potential entry plan of Infineon Technologies AG into this market. For that purpose, a fit between a top-down and bottom-up qualitative and quantitative estimation of the medical semiconductor sensor’s market size has been made; with application units, sensor volumes and sensor revenues, with a horizontal scope of five years. Once understood the existing market, some insight into the competitive landscape is provided, where the key suppliers are analysed in terms of product portfolio and revenue share estimates, on an application basis. And also, a spotlight on innovation and trends at three levels – healthcare, medical devices and medical semiconductor sensors – is presented, to forecast a possible evolution of the fore-mentioned market. The research that has been conducted is based on three main sources of information; internal contacts (i.e. within Infineon), external contacts (most of them through internal references) and internet research. Access to market research company’s reports and interviews has been particularly helpful, to complement extensive internet research. Outcomes of this study indicate that the global medical semiconductor magnetic sensor market reveals low revenue potential; as most of the applications are yet innovation fields. Reed switch replacement in battery-powered medical devices can be an opportunity for magnetic switches. However, this project suggests that there is a key investment opportunity: magnetic beads for viral detection with spintronics sensors. The global medical semiconductor pressure sensor market seems a fairly mature market; the gross part of the revenue comes from blood pressure measurement. Blood pressure measurement might be an opportunity for existing automotive semiconductor pressure sensor products. Furthermore, this report suggests that the future of blood pressure measurement might tend towards implantable pressure sensors, with a non-significantly different technological basis. To conclude, this report unveils certain business opportunities for Infineon’s semiconductor magnetic and pressure sensor products; and puts special focus on the development of derivative products to pioneer the commercialization of innovative medical applications, with a forecasted huge revenue potential