Key Lab of Medical Instrumentation and Pharmaceutical Technology of Fujian Province, Fuzhou University, Fuzhou, Fujian, China.
College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian, China.
Technol Health Care. 2021;29(6):1089-1098. doi: 10.3233/THC-181485.
Implantable medical sensors for monitoring and transmitting physiological signals like blood glucose, blood oxygen, electrocardiogram, and endoscopic video present a new way for health care and disease prevention. Nevertheless, the signals transmitted by implantable sensors undergo significant attenuation as they propagate through various biological tissue layers.
This paper mainly aims to investigate the power loss of an out-to-in body wireless radio frequency link at 2.45 GHz.
Two simulation models including the single-layer human tissue model and three-layer human tissue model were established, applying the finite element method (FEM). Two experiments using physiological saline and excised porcine tissue were conducted to measure the power loss of a wireless radio frequency link at 2.45 GHz. Various communication distances and implantation depths were investigated in our study.
The results from our measurements show that each 2 cm increase in implantation depth will result in an additional power loss of about 10 dB. The largest difference in values obtained from the measurements and the simulations is within 4 dB, which indicates that the experiments are in good agreement with the simulations.
These results are significant for the estimate of how electromagnetic energy changes after propagating through human tissues, which can be used as a reference for the link budget of transceivers or other implantable medical devices.
用于监测和传输生理信号（如血糖、血氧、心电图和内窥镜视频）的植入式医疗传感器为医疗保健和疾病预防提供了新的途径。然而，植入式传感器传输的信号在穿过各种生物组织层时会经历显著衰减。
本文主要旨在研究 2.45GHz 外到内体无线射频链路的功率损耗。
应用有限元法（FEM）建立了包括单层人体组织模型和三层人体组织模型在内的两种仿真模型。进行了两项使用生理盐水和离体猪组织的实验，以测量 2.45GHz 无线射频链路的功率损耗。本研究调查了各种通信距离和植入深度。
测量结果表明，植入深度每增加 2cm，功率损耗约增加 10dB。测量值和模拟值之间最大差异在 4dB 以内，这表明实验与模拟吻合良好。
这些结果对于估计电磁能在穿过人体组织后如何变化具有重要意义，可作为收发器或其他植入式医疗设备链路预算的参考。
