Design of Ultra-Wideband Phased Array Applicator for Breast Cancer Hyperthermia Therapy.

Focused microwave-hyperthermia therapy has recently emerged as a key technology in the treatment of breast cancer due to non-invasive treatment. An applicator of a three-ring phased array consisting of ultra-wideband (UWB) microstrip antennas was designed for breast cancer therapy and operates at 0.915 GHz and 2.45 GHz. The proposed antenna has an ultra-wideband from 0.7 GHz to 5.5 GHz with resonant frequencies of 0.915 GHz and 2.45 GHz and dimensions of 15 × 43.5 × 1.575 mm3. The number of each ring was chosen to be 12 based on the SAR distribution and the performance indicators of tumor off-center focusing results for four different numbers of single-ring arrays. The homogeneous breast model is applied to a three-ring phased array consisting of 36 elements for focused simulation, and 1 cm3 and 2 cm3 tumors are placed in three different locations in the breast. The simulation results show that the proposed phased array has good performance and the capability to raise the temperature of different volumes of breast cancer above 42.5 °C after choosing a suitable operating frequency. The proposed applicator allows for precise treatment of tumors by selecting the appropriate operating frequency based on the size of the malignant tumor.

Flexible pH sensor based on a conductive PANI membrane for pH monitoring.

pH is a critical parameter used to specify the acidity or alkalinity of an aqueous solution in chemistry, food processing, and medical care. In this study, a conductimetric-type micro pH sensor has been achieved using PANI membrane fabricated on a flexible substrate film aiming to monitor wound healing. The sensor is based on the incorporation of a polyaniline (PANI) membrane, interdigital electrode, and polyimide (PI) substrate. PANI was doped with dodecyl benzene sulfonic acid (DBSA) to obtain good conductivity. The electrodes were patterned on the PI film by etching. The contact area between the PANI and interdigital electrodes improves the responsiveness of the pH sensor. A sensitivity of 58.57 mV per pH over the entire pH range from 5.45 to 8.62 was obtained experimentally, along with a superior repeatability of 8% FS (full scale) and a temperature drift of 6.8% FS. This micro flexible pH sensor aims to monitor the pH value of wound healing, which also facilitates the realization of online monitoring of the pH for telemedicine, food safety, and home health care.