Computational study on focused microwave thermotherapy for knee pathological treatment

Abstract

This study is a computational study on focused microwave thermotherapy for knee pathological treatment using the time reversal (TR) principle in musculoskeletal disorders. The authors presented a modified TR algorithm with amplitude compensation for an accurate beam focusing of the knee tumour location in a lossy medium. Furthermore, they proposed a new approach called the truncated threshold method, which could be used to apply an effective beam focusing on a tumour location in the knee while the unwanted hot spots are controlled in the normal tissue region. Compared to the other existing methods, this new approach has the advantages of being implemented simply in the unwanted hot spot control and having a similar performance to the beam focusing on the target location. The application of the proposed algorithm and the new hot spot control method to knee pathological tissue achieved acceptable electromagnetic (EM) and thermal results. The anatomical based two‐dimensional (2D) knee model for the simulation analysis was implemented using a segmentation result of the Korean human body model obtained from magnetic resonance imaging. 2D finite‐difference time‐domain electromagnetic and thermal solvers were developed and applied to conduct the 915 MHz focused microwave thermotherapy for knee pathological treatment.

Numerical and experimental assessments of focused microwave thermotherapy system at 925 MHz

“…The method is also applicable to a 3D environment. In a previously reported study [6,9], we verified the proposed method in a 2D environment by comparing it with an existing method developed by Iero and others [20].…”

“…Therefore, the accuracy of the proposed TR algorithm is confirmed. The focal spot size of the phantom model, as shown in Figure 6, can be calculated using (9). As the permittivity of the phantom model is 55 based on (9), the theoretical focal size is calculated as 22 mm, corresponding to 0.5 λ g .…”

“…The focused microwave thermotherapy (FMT) technique can be useful for pain relief and the treatment of pathologies in numerous types of musculoskeletal diseases including arthritis, cancer, and inflammation. The thermal effects of such a technique on the ablation of cancer cells are currently being investigated by several groups [4][5][6][7][8][9][10][11][12][13][14][15].…”

“…In previous studies [6,9], we applied a noninvasive microwave thermotherapy method for the pathological treatment of a two-dimensional (2D) knee model using a modified time reversal (TR) algorithm. The results confirmed that a beam could be focused on a desired target position.…”

Focused microwave thermotherapy technique based on microwave tomographic imaging

“…Introduction: Focused microwave thermotherapy (FMT) is a noninvasive microwave hyperthermia to increase the temperature of the target location to above 43°C while maintaining a normal temperature in other areas [1]. It employs an antenna array around the human body and focuses a transmitting power to the target point, such as a tumour.…”