Volume 3, Issue 2

The mandible plays a crucial role in facial structure and function. Mandibular defects, often caused by tumor resection, trauma, or congenital conditions, severely impact patients' physiological functions and quality of life. Reconstruction methods for mandibular defects primarily include autologous bone grafting, computer-aided reconstruction, and distraction osteogenesis. Among these, autologous bone grafting remains the most widely used technique. As medical technologies advance, the integration of computer-aided design and 3D printing has provided new technical support for personalized mandibular reconstruction, improving both surgical precision and safety. Moreover, distraction osteogenesis has emerged as a promising alternative in recent years. This paper reviews research on fixation methods for V mandibular defect reconstruction to offer clinical guidance for effective mandibular repair.

With the rapid development of artificial intelligence, deep learning technology has been widely applied across various fields. In the medical field, deep learning models, by analyzing medical images and clinical data, can automatically detect features of different types of lesions, such as polyps, ulcers, and cancers, thereby assisting physicians in early diagnosis of disease. This review provides an overview of recent progress in applying deep learning for disease diagnosis in various parts of the gastrointestinal tract, including the esophagus, stomach, small intestine, and colon. It also discusses the challenges and potential future directions for deep learning in this field.

Radiofrequency ablation (RFA) is a widely used minimally invasive treatment for non-surgical hepatocellular carcinoma. This review synthesizes the technical principles, core components, and key modeling aspects of RFA. RFA induces tumor necrosis via Joule heating from ionic vibration. Electrode needle design critically impacts ablation efficacy and safety, with multipolar needles offering larger zones yet posing power and tissue risks. Crucially, biological tissue parameters exhibit dynamic spatial and thermal variations, necessitating nonlinear modeling for accurate temperature prediction. While the Pennes bioheat model remains mainstream for its simplicity, more advanced models (e.g., porous medium) enhance physiological realism. Thermal damage assessment commonly employs the Arrhenius model and isothermal thresholds, aided by real-time monitoring for intraoperative precision. Future research should prioritize the development of smart electrodes, creation of personalized tissue parameter databases, and exploration of multi-energy techniques to shift RFA from an "empirically oriented" approach to an "accurate prediction" paradigm, ultimately improving hepatocellular carcinoma patient survival and quality of life.

Objectives: The key to an ultrasound-guided system is to accurately determine the spatial position of the surgical instrument. The size and shape of the optical positioning target in the optical positioning device can restrict the doctor's hand movements. Additionally, the use of a binocular camera occupies valuable operating room space. To reduce both the space occupation and the impact on surgical procedures, this paper presents a device designed to provide enhanced navigation information to assist the surgeon. Methods: The proposed device is equipped with an angle sensor and a button. The angle sensor measures the relative angle between the puncture device and the ultrasound probe in real time. The button assists the surgeon in measuring the depth of the surgical target before performing the puncture. Furthermore, we propose a filtering algorithm to reduce noise in the angle sensor's output signal. The device's performance was evaluated using an ultrasound instrument and an experimental setup for data collection and testing. Results: The filtering algorithm effectively reduced noise in the angular data. After filtering, the Signal Smoothness decreased from 0.036989 to 0.0010376, the Coefficient of Variation decreased from 0.00046682 to 0.0004323, and the Count of Local Extrema decreased from 251 to 135. Additionally, we collected and compared the coordinates of the guide line endpoints at the tip of the puncture needle and found an average point-to-point error of 3.53 pixel. Conclusions: The developed guidance device and filtering algorithm provide valuable navigation data, supporting the surgeon's operations.

Objective: This study utilizes finite element modeling to investigate the coupled electric-thermal field distributions for three novel electrode designs, assessing their ability to induce electric breakdown in saline for plasma generation. Furthermore, the ablation effects of various electrode shapes were validated through ex vivo tissue ablation experiments, ensuring both the safety and feasibility of the electrodes. Methods: Three electrode structures were designed: the ring-needle electrode, the needle electrode, and the cylinder electrode. A COMSOL Multiphysics finite element model simulated their behavior in saline. This modeling approach enabled a detailed analysis of the spatial variations in both the electric and temperature fields. Furthermore, the electrodes were tested at four voltages (180 V, 220 V, 260 V, and 300 V) and a frequency of 100 kHz on porcine liver tissue to evaluate ablation performance. Results: Simulations showed temperatures of 25-70 °C at 0.3 mm above the three electrodes, with electric field strength exceeding 1 *10^6 V/m, which are sufficient to trigger electric breakdown and plasma formation. Ex vivo experiments confirmed ablation efficacy, with the ring-needle electrode exhibited the best performance at a voltage of 300 V, achieving a 2.3 mm ablation depth and 0.72 mm² thermal damage area. Conclusion: Finite element simulation and ex vivo experiments demonstrate the feasibility of the proposed electrodes, highlighting their potential as an innovative solution for plasma-based ablation technologies.

Objective: To design and validate a portable multi-degree-of-freedom electric needle holder to improve operational flexibility and precision in laparoscopic surgery, while reducing the operator's workload. The design optimizes the transmission system to enable precise control of surgical instruments, addressing the challenges of complex surgical environments. Methods: A multi-degree-of-freedom transmission structure, driven by steel wires, was designed. It integrates motors and angle sensors to achieve multi-directional rotation and force control for the grasping forceps. The experimental section includes tests for maximum gripping force, maximum extraction force, and a porcine suturing experiment. The performance of the electric needle holder was compared with traditional needle holders in simulated laparoscopic surgery to verify its effectiveness. Results: Experimental results show that the maximum gripping force of the electric needle holder at various angles reached 29.6 N, significantly higher than that of traditional needle holders. The maximum extraction force for needles of different sizes is approximately 12.9 N, effectively preventing needle slippage. Additionally, the porcine suturing experiment demonstrated that the electric needle holder significantly reduced operation time and improved suturing precision in complex surgical settings. Conclusion: The portable multi-degree-of-freedom electric needle holder enhances operational flexibility and safety in laparoscopic surgery by increasing the rotational degrees of freedom and precise motor control. Its superior gripping force and operational efficiency suggest strong clinical potential, offering significant improvements over traditional surgical instruments.

This paper presents an interpretation of the latest international technical report, IEC TR 62926-2019 (Medical electrical system – Guidelines for safe integration and operation of adaptive external beam radiotherapy systems) for real-time adaptive radiotherapy. It outlines the background for the development of this report, analyzes general safety guidelines for adaptive radiotherapy systems, and discusses the key design elements required for the integration of such systems. Additionally, the paper reviews and summarizes two typical reference models for adaptive external beam radiotherapy systems. The aim is to enhance the understanding and implementation of this technical report and to support its potential adaptation into a national standardized guidance document in China.