| Implantable pacemaker was invented in 1958, technology and performances of it have also been increasingly perfect. However, most pacemakers now are still using chemical batteries to supply power, so its life is limited and it is unable to replenish energy. To solve this problem, the wireless energy transmission technology based on resonant magnetic coupling is proposed in this paper. Resonant magnetic coupling technology has the characteristics of high transmission efficiency, good stability, and no electromagnetic pollution. It is one of the effective ways to solve the problem of energy supply in implantable cardiac pacemakers.Based on earlier researches of wireless energy transmission technology of resonant magnetic coupling, a wireless energy transmission system for implantable cardiac pacemaker is mainly designed. And a wireless power transmission system, which is convenient to charge and power at any time and any place, has been developed. The following works were mainly completed in this paper:Firstly, the transfer model and operation mechanism of resonant magnetic coupling wireless energy transfer system for implantable cardiac pacemaker were been introduced. Through analysis of the transmission performance and application situation of the four kinds of loop compensation models, the optimum resonant compensation method was finally obtained. Based on the compensation method that selected, simulation of the system was carried out, and relationship between the energy transfer efficiency and parameters related were analyzed.Secondly, the primary emitting circuit and secondary receiving circuit of the system were been designed. The LC oscillation circuit used in primary circuit and rectifier, filter, voltage regulator circuit that used in secondary circuit were described. And the primary and secondary circuits, which used 5-12 V DC power to produce stable output voltage with adjustable frequency, were been designed.Thirdly, coils, resonant compensation capacitor, match load and etc. related to the system were been analyzed. By comparing coil winding and performance parameters of different types, the most appropriate coils were selected. Then the electromagnetic field that produced during the system working was analyzed through the finite element analysis software. Under the determined coil parameters condition, the compensation capacitors of the system were selected, and the influence of different compensation capacitance value on the transmission performance of the system were analyzed. the load was matched after.Finally, the system was built on the basis of earlier analysis. The PCB board of primary and secondary circuit was made and corresponding electronic components were welded. Then the system was tested. Through analysis of collected waveform and data, the transmission performances and electromagnetic interference, electromagnetic compatibility and so on were analyzed and the optimal working conditions were found. Based on the optimal working conditions, the whole system was encapsulated, and a wireless energy transmission device that was miniature and portable was manufactured. The experimental results showed that when the operating frequency, transmission distance and input voltage are stable, enough energy transfer efficiency was able to be obtained and stable output voltage for the cardiac pacemaker to use can be produced. |
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