Institute of Electronics, Lodz University of Technology, Politechniki 10 Street, 93-590 Lodz, Poland.
Sensors (Basel). 2022 Mar 11;22(6):2200. doi: 10.3390/s22062200.
Wireless capsule endoscopes take and send photos of the human digestive tract, which are used for medical diagnosis. The capsule's location enables exact identification of the regions with lesions. This can be carried out by analyzing the parameters of the electromagnetic wave received from the capsule. Because the human body is a complex heterogeneous environment that impacts the propagation of wireless signals, determining the distance between the transmitter and the receiver based on the received power level is challenging. An enhanced approach of identifying the location of endoscope capsules using a wireless signal phase detection algorithm is presented in this paper. For each capsule position, this technique uses adaptive estimation of human body model permittivity. This approach was tested using computer simulations in Remcom XFdtd software using a numerical, heterogeneous human body model, as well as measurements with physical phantom. The type of transmitting antenna employed in the capsule also has a significant impact on the suggested localization method's accuracy. As a result, the helical antenna, which is smaller than the dipole, was chosen as the signal's source. For both the numerical and physical phantom studies, the proposed technique with adaptive body model enhances localization accuracy by roughly 30%.
无线胶囊内窥镜拍摄并发送人体消化道的照片，用于医学诊断。胶囊的位置能够精确定位有病变的区域。这可以通过分析从胶囊接收到的电磁波参数来实现。由于人体是一个复杂的非均匀环境，会影响无线信号的传播，因此根据接收功率电平确定发射器和接收器之间的距离具有挑战性。本文提出了一种使用无线信号相位检测算法来识别内窥镜胶囊位置的增强方法。对于每个胶囊位置，该技术都使用人体模型介电常数的自适应估计。该方法在 Remcom XFdtd 软件中使用数值异质人体模型进行了计算机模拟测试，并使用物理模型进行了测量。胶囊中使用的发射天线类型对所提出的定位方法的准确性也有重大影响。因此，选择螺旋天线作为信号源，其尺寸小于偶极子天线。对于数值和物理模型研究，具有自适应人体模型的建议技术将定位精度提高了约 30%。
