Design and Optimization of an Ultra Wideband and Compact Microwave Antenna for Radiometric Monitoring of Brain Temperature
Design and Optimization of an Ultra Wideband and Compact Microwave Antenna for Radiometric Monitoring of Brain Temperature
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DOI：
10.1109/tbme.2014.2317484
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发表时间：
2014-07-01
影响因子：
4.6
通讯作者：
Stauffer, Paul R.
中科院分区：
文献类型：
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作者：
Rodrigues, Dario B.;Maccarini, Paolo F.;Stauffer, Paul R.
我们介绍了在天线设计和频率选择方面的建模工作，以使用非侵入性微波辐射测量在延长的手术期间监测大脑温度。选择锥形对数螺旋天线设计是因为它的宽带特性允许从大脑深处收集更高的功率。利用HFSS软件进行参数分析，对脑深部温度传感天线的性能进行了优化。辐射天线效率(ETA)是根据从大脑收集的功率与天线接收的总功率的比率来评估的。从几个成人计算机断层扫描中提取的解剖信息被用来建立用于构建准确的层状3-D组织模型的设计参数。这个头部模型包括分开的大脑和头皮区域，在一个完整的头骨的两侧，组织等量的液体在独立的温度下循环。优化后的频段为1.1~1.6 GHz，两圈对数螺旋天线的平均效率为50.3%。整个传感器包装包含在一个轻薄的、直径2.8厘米、高1.5厘米的组件中，可以使用电磁屏蔽粘合剂贴片将其固定在皮肤上。当大脑体模降低10摄氏度，然后在4.6小时的实验中恢复到原始温度(37摄氏度)时，计算出的辐射当量脑温度与测量的大脑体模温度相差0.4摄氏度。数值计算和实验结果表明，优化后的2.5 cm对数螺旋天线非常适合于脑深部温度的无创辐射传感。
We present the modeling efforts on antenna design and frequency selection to monitor brain temperature during prolonged surgery using noninvasive microwave radiometry. A tapered log-spiral antenna design is chosen for its wideband characteristics that allow higher power collection from deep brain. Parametric analysis with the software HFSS is used to optimize antenna performance for deep brain temperature sensing. Radiometric antenna efficiency (eta) is evaluated in terms of the ratio of power collected from brain to total power received by the antenna. Anatomical information extracted from several adult computed tomography scans is used to establish design parameters for constructing an accurate layered 3-D tissue phantom. This head phantom includes separate brain and scalp regions, with tissue equivalent liquids circulating at independent temperatures on either side of an intact skull. The optimized frequency band is 1.1-1.6 GHz producing an average antenna efficiency of 50.3% from a two turn log-spiral antenna. The entire sensor package is contained in a lightweight and low-profile 2.8 cm diameter by 1.5 cm high assembly that can be held in place over the skin with an electromagnetic interference shielding adhesive patch. The calculated radiometric equivalent brain temperature tracks within 0.4 degrees C of the measured brain phantom temperature when the brain phantom is lowered 10. C and then returned to the original temperature (37 degrees C) over a 4.6-h experiment. The numerical and experimental results demonstrate that the optimized 2.5-cm log-spiral antenna is well suited for the noninvasive radiometric sensing of deep brain temperature.