Innovative Inductive Charger Powers Electronic Implants

A prototype noninvasive battery recharger system could allow a longer life for implantable devices such as pacemakers, defibrillators, and electric hearts.

The prototype was developed by António Abreu, a PhD Student under the MIT (Cambridge, MA, USA) Portugal Program, currently developing research work at Laboratório Nacional de Energia e Geologia (LNEG; Amadora, Portugal), and is based on the use of a high efficient transcutaneous power (TP) system. While a typical TP system, which uses electronic converters, can cause electromagnetic interferences (EMI) that can damage the implants and patients, the prototype device takes into account the energy efficiency of electric transmission systems without ferromagnetic cores, which optimizes the energy flow.


The device is composed of three essential components: a generator, a transmitter unit, and a receptor coil. The generator is destined to produce an energy signal with determined amplitude and frequency that is carried across through a coaxial cable to the transmitter unit. The emitted magnetic field is captured by the receptor coil implanted inside the human body, generating a voltage with the absence of the Gibbs phenomenon.

The patented prototype was initially designed for pacemakers, but using improved techniques, it has been adapted for high power and high voltage devices as well, such defibrillators, electric hearts, insulin pumps, or other type of implantable prosthesis. Moreover, the same principle that allows the supply of lower energy voltages can be applied to broadly improve high power electrical transmission and distribution systems such as the electrical grid, possibly reducing consumer electric consumption costs.

“The noninvasive battery also allows for a customize energy consumption of the cardiac implants, therefore the consumption of energy can be regulated to adapted to its function and patients’ pathology and activity,” said inventor António Abreu. “It guarantees the energetic supply of a communication channel between the exterior for diagnosis and/or implant reprogramming. In this case, there will be no demand of energy from the internal battery.”

The theoretical model behind the device lies in the Predictor-Corrector Abacus concept, a complex grid situation where a specific load is supplied by electrical energy to an active Power P, and a reactive Power Q. What characterizes the Abacus is the effect of the reactance and the resistance of longitudinal transmission lines, dependant on the position of the angles of segments lines. The best position of the segments lines defines the maximum of power transference without EMI.

Related Links:
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Laboratório Nacional de Energia e Geologia