Multi-purpose and Multi-source Energy Management System for Biomedical Implants

AbstractThis paper describes a multi-purpose energy management system that can harvest energy from a multitude of power sources. In order to suffice power needs of a smart hip prosthesis, a prototype was built considering the use of two types of power sources: energy harvesting micro-power generators for intermittent implant electronics powering; wireless energy, by means of an activation system, responsible for, when needed, continuously powering the implant electronics and also configuring its mode of operation. Intermittently or continuously, it is now possible to energize more power demanding systems as the ones that uses a RF transceiver. The smart hip prosthesis can now become a wireless body sensor network node using LR-WPAN protocols such as Bluetooth low energy as is intended in this work. Preliminary results proved that is possible to energize a Bluetooth low energy module, for over 100 s, solely using the stored energy produced by one of the micro-power generators

Experimental and numerical characterization of a gravitational electromagnetic energy harvester

In this paper, the dynamic experimental identification of an inductive energy harvester for the conversion of vibration energy into electric power is presented. Recent advances and requirements in structural monitoring and vehicle diagnostic allow defining Autonomous Internet of Things (AIoT) systems that combine wireless sensor nodes with energy harvester devices properly designed considering the specific duty cycle. The proposed generator was based on an asymmetrical magnetic suspension and was addressed to structural monitoring applications on vehicles. The design of the interfaces of the electric, magnetic, and structural coupled systems forming the harvester are described including dynamic modeling and simulation. Finally, the results of laboratory tests were compared with the harvester dynamic response calculated through numerical simulations, and a good correspondence was obtained

Estudo comparativo de geradores eletromagnéticos para prótese de anca

Mestrado em Engenharia MecânicaA necessidade de substituir os tradicionais métodos de alimentação de dispositivos médicos instrumentados implantáveis, baseados em baterias, por sistemas alternativos de durabilidade superior conduziu à crescente investigação nesta área. Após a verificação precedente desta dissertação do melhor desempenho da indução eletromagnética relativamente a outros sistemas de geração de energia, partindo do movimento humano, este trabalho descreve a conceção e avaliação comparativa de geradores eletromagnéticos, focado na implementação destes em próteses de anca em pacientes. Estes foram criados com o objetivo de operar sob movimento análogo ao da anca humana, tanto em regime de repetibilidade, recorrendo a um manipulador robótico, como em regime empírico, acoplando-o à zona da anca de um indivíduo. Uma análise comparativa foi efetuada entre diversas configurações de geradores com o intuito de, no futuro, uma otimização recorrente a modelos matemáticos não lineares seja validada e aplicada. Os resultados revelaram que a extrapolação dos dados obtidos pelos ensaios realizados no manipulador para o ciclo de marcha humano contínuo apresentou um grau considerável de discrepância para com o teste empírico. O melhor ensaio do manipulador, obtido ao longo de um período de marcha, quando multiplicado por ciclos perfaz um total de , enquanto o ensaio empírico gerou durante os mesmos ciclos de marcha. Considerando que o ensaio de marcha executado empiricamente apresenta movimento aproximadamente equivalente ao do interior de uma prótese de anca, verificou-se a geração de energia considerável para alimentar um implante inteligente, ainda que as dimensões do gerador testado sejam ainda relativamente elevadas.The need of replacing traditional methods of feeding implantable instrumented medical devices, based on batteries, by alternative systems of superior lifetime led to an increasing investigation in this area. After the verification, preceding this dissertation, of the electromagnetic induction better performance relatively to other energy harvesting systems using human motion, this work describes the conception and comparative evaluation of electromagnetic generators, focused on their implementation in hip prostheses on patients. A comparative analysis was performed between different generator configurations, with the goal of, in the future, validating and applying an optimization resorting to non linear mathematical models. These were created with the goal of operating under motion analogous to the human hip, in either a state of repeatability, resorting to a robotic manipulator, as in empiric state, attaching it to one’s hip. The results revealed that the extrapolation of the obtained data from the trials obtained from the manipulator into a continuous human gait cycle presented a considerable degree of discrepancy with the empiric test. The best manipulator trial, obtained from one gait cycle period, when multiplied by cycles totals a harvested energy of , whilst the empiric rehearsal generated over the same gait cycle periods. Considering that the walking rehearse tested empirically presents motion approximately equivalent to the interior of a hip prosthesis, considerable energy harvesting to feed an intelligent implant was verified, although the tested generator’s dimensions are still relatively large

Fast-waking and low-voltage thermoelectric and photovoltaic CMOS chargers for energy-harvesting wireless microsensors

The small size of wireless microsystems allows them to be deployed within larger systems to sense and monitor various indicators throughout many applications. However, their small size restricts the amount of energy that can be stored in the system. Current microscale battery technologies do not store enough energy to power the microsystems for more than a few months without recharging. Harvesting ambient energy to replenish the on-board battery extend the lifetime of the microsystem. Although light and thermal energy are more practical in some applications than other forms of ambient energy, they nevertheless suffer from long energy droughts. Additionally, due to the very limited space available in the microsystem, the system cannot store enough energy to continue operation throughout these energy droughts. Therefore, the microsystem must reliably wake from these energy droughts, even if the on-board battery has been depleted. The challenge here is waking a microsystem directly from an ambient source transducer whose voltage and power levels are limited due to their small size. Starter circuits must be used to ensure the system wakes regardless of the state of charge of the energy storage device. The purpose of the presented research is to develop, design, simulate, fabricate, test and evaluate CMOS integrated circuits that can reliably wake from no energy conditions and quickly recharge a depleted battery. Since the battery is depleted during startup, the system must use the low voltage produced by the energy harvesting transducer to transfer energy. The presented system has the fastest normalized wake time while reusing the inductor already present in the battery charger for startup, therefore, minimizing the overall footprint of the system.Ph.D

Advanced Energy Harvesting Technologies

Energy harvesting is the conversion of unused or wasted energy in the ambient environment into useful electrical energy. It can be used to power small electronic systems such as wireless sensors and is beginning to enable the widespread and maintenance-free deployment of Internet of Things (IoT) technology. This Special Issue is a collection of the latest developments in both fundamental research and system-level integration. This Special Issue features two review papers, covering two of the hottest research topics in the area of energy harvesting: 3D-printed energy harvesting and triboelectric nanogenerators (TENGs). These papers provide a comprehensive survey of their respective research area, highlight the advantages of the technologies and point out challenges in future development. They are must-read papers for those who are active in these areas. This Special Issue also includes ten research papers covering a wide range of energy-harvesting techniques, including electromagnetic and piezoelectric wideband vibration, wind, current-carrying conductors, thermoelectric and solar energy harvesting, etc. Not only are the foundations of these novel energy-harvesting techniques investigated, but the numerical models, power-conditioning circuitry and real-world applications of these novel energy harvesting techniques are also presented