中文摘要：

在经颅磁刺激中,尽管传统八字线圈的聚焦性要优于圆形线圈的聚焦性,但是八字线圈的两侧边缘产生的磁场与感应电场的峰值仍然较高.设计一种基于折叠变形的八字线圈,通过数值计算分析变形八字线圈空间磁场与感应电场的分布,并与传统八字线圈进行对比.结果表明,当变形八字线圈的折叠角度在45° ～60°范围内时,其中心位置产生的空间磁场和感应电场占传统八字线圈在中心位置的90％左右,而变形线圈两侧产生的空间磁场与感应电场占传统八字线圈两侧的30％左右.因此,在空间磁场和感应电场的聚焦度方面,折叠变形八字线圈均优于传统八字线圈.所提出的折叠变形八字线圈为设计新型经颅磁刺激线圈提供了新的思路.

英文摘要：

Although the focality of conventional figure-of-eight （fo8） coil is superior to that of round coil in transcranial magnetic stimulation, there still exists higher magnetic fields and induced electric fields near the outer rim of double wings of fo8 coil. In this paper, we presented a deformed figure-of-eight coil （Dfo8） by bending its two wings from the surface of the coil. The distribution of magnetic fields and the induced electric fields were calculated numerically, and the results were compared with those of conventional fo8. Results show that when the bending angle for Dfo8 was between 45 degree and 60 degree, the magnetic fields and the induced electric fields over the centre position of Dfo8 were about 90% of that of fo8, while the magnetic fields and the induced electric fields over the outer rim of Dfo8 were about 30% of that of fo8. It is indicated that the focality of the magnetic fields and the induced electric fields has been improved by Dfo8 coil, which provided a new method for designing the new transcranial magnetic stimulation coil.