Jow Uei-Ming, Ghovanloo Maysam
GT-Bionics lab, School of Electrical and Computer Engineering at the Georgia Institute of Technology, Atlanta, GA 30308, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:6387-90. doi: 10.1109/IEMBS.2009.5333876.
Printed spiral coils (PSC) are viable candidates for near field wireless power transmission to the next generation of prosthetic devices with extreme size constraints. Implantable devices need to be hermetically sealed in biocompatible materials and placed in conductive environment with high permittivity, which can affect the PSC characteristics. We have constructed a detailed model that includes the effects of surrounding environment on the PSC parasitic components and eventually on the power transfer efficiency. This model is combined with an iterative design method that starts with a set of realistic design constraints and ends with the optimal PSC geometries. This was applied to optimize the wireless link of a 1 cm(2) implantable device operating at 13.56 MHz. Measurement results showed that optimized PSC pairs, coated with 0.3 mm of silicone, achieved 72.2% and 30.8% efficiencies at a face to face relative distance of 10 mm in the air and muscle environment respectively. The PSC which was optimized for air could only bear 21.8% efficiency in muscle, showing that considering the PSC surrounding environment in the design process can result in nearly 10% improvement in the power transfer efficiency.
印刷螺旋线圈（PSC）是向尺寸极度受限的下一代假肢装置进行近场无线电力传输的可行候选方案。可植入装置需要用生物相容性材料进行气密密封，并放置在具有高介电常数的导电环境中，这会影响PSC的特性。我们构建了一个详细模型，该模型包括周围环境对PSC寄生元件的影响以及最终对功率传输效率的影响。该模型与一种迭代设计方法相结合，该方法从一组实际设计约束开始，以优化的PSC几何形状结束。这被用于优化一个工作在13.56 MHz的1平方厘米可植入装置的无线链路。测量结果表明，涂有0.3毫米硅胶的优化PSC对在空气中面对面相对距离为10毫米时效率达到72.2%，在肌肉环境中达到30.8%。在空气中优化的PSC在肌肉中只能承受21.8%的效率，这表明在设计过程中考虑PSC的周围环境可使功率传输效率提高近10%。
