Volume 3, Issue 1

Objective: This study presents the design of an innovative lower limb exoskeleton featuring dynamic self-balancing capabilities. It employs Zero Moment Point and Model Predictive Control online gait algorithms to plan stable walking patterns, thereby facilitating precise gait training for individuals with lower limb motor impairments and enhancing the overall training effectiveness. Methods: The positive and negative kinematic solutions of the lower limb exoskeleton were determined using the Denavit-Hartenberg method and the geometric method, respectively. The geometric relationships of the exoskeleton’s linkage components were employed to derive workspace expres sions for various gait phases. By utilizing Zero Moment Point and Model Predictive Control online gait algorithms, simulation experiments were conducted to validate the dynamic self-balancing capability of the exoskeleton while walking on flat terrain. Results: In the evaluation of the online gait generation algorithm’s validity, the generated gait trajectory aligned with the planned trajectory. When examining dynamic self-balancing walking capability, the trajectories from initial simulation experiments on flat terrain closely matched the intended trajectories. Conclusion: The online gait generation algorithm presented in this study is capable of producing a stable walking pattern for continuous bipedal gait. This newly designed lower limb exoskeleton can achieve stable dynamic self-balancing walking.

Objective: To investigate electrode weight reduction through structural modifications, focusing on variations in the thickness of circular electrodes to meet mechanical requirements. Additionally, optimal welding parameters were identified via experimental methods. Methods: Three electrode thicknesses were designed: 0.2 mm (T1), 0.3 mm (T2), and 0.4 mm (T3). The finite element method was used to analyze the stress, strain, and thermal effects on the surrounding tissue. In vitro tissue experiments assessed the mechanical strength of the anastomosis by measuring tear force and rupture pressure. Results: Among the three designs, the T3 electrode exhibited the lowest strain (1.2%) and stress (122.26 MPa). Thermal simulations showed maximum tissue damage of 53.3% and minimum damage of 48.6%. The maximum tear force (9.87±0.83 N) and rupture pressure (222.88±13.48 mmHg) were achieved with a compression force of 20 N, welding power of 160 W, and welding time of 8 seconds. Conclusion: T3 electrode demonstrated superior mechanical performance in the finite element analysis and successfully completed in vitro welding while minimizing electrode weight. Optimal welding parameters were identified.

Radiation therapy is a complex and high-precision technique that requires strict performance criteria for linear accelerators. One of the key factors influencing the quality of radiotherapy is the positioning accuracy of each leaf of the multileaf collimator. This mini-review discusses three commonly used dosimetry-based methods for evaluating multileaf collimator positioning accuracy: the dose film method, the Matrixx ionization chamber array method, and the electronic portal imaging device method. The review highlights the differences between these methods, showing that both the electronic portal imaging device and Matrixx methods offer higher measurement repeatabil ity compared to the dose film method. However, the electronic portal imaging device method is more complex to implement than the Matrixx method.

Medical ultrasound imaging, as a non-invasive, safe, and reliable technology, plays an important role in clinical diagnosis and treatment. However, traditional ultrasound imaging techniques have limitations such as low resolution, poor penetration depth, and high noise levels. To address these issues, beamforming algorithms have become essential. This paper discusses the development and current research status of beamforming algorithms in the context of medical ultrasound systems, focusing on commonly used beamforming algorithms such as synthetic aperture imaging, adaptive beamforming (especially minimum variance distortionless response), and generalized sidelobe canceller technology. These algorithms optimize the emission and reception of ultrasound waves, overcoming the limitations of traditional techniques and improving image resolution, penetration depth, and noise suppression. They provide support for the advancement of medical ultrasound imaging technology and its clinical applications.

With the development of medical-engineering integration technology and the growing clinical rehabilitation demands, intelligent rehabilitation robots have emerged as a prominent area of research in stroke rehabilitation. The application of exoskeleton rehabilitation robots holds significant potential to alleviate the pressure on rehabilitation resources in China. These robots offer high-intensity, high-repetition rehabilitation training for stroke patients, helping to restore limb motor function, improve daily living independence, and contribute to neuroplasticity. As such, they are becoming an essential treatment modality for patients with motor function disorders. In this review, we first categorize ankle-foot rehabilitation robots based on the interaction methods between the robot and the user, detailing their structural characteristics and application scenarios. Additionally, we classify existing control strategies, including admittance control, impedance control, electromyography control, trajectory tracking control, and Proportional-Integral-Derivative control, based on the rehabilitation needs at various stages of recovery. Each control method is summarized, and their current research status is analyzed. Besides, current research status of key technologies in rehabilitation robots, both domestically and internationally are also summarized in this paper. Finally, the key challenges in the development of ankle-foot rehabilitation robots and future research directions are discussed, providing a reference for the research and design of these robots.

This paper presents a gait prediction method for lower limb exoskeleton robots using a real-time adaptive Kalman filtering algorithm. The exoskeleton robot targets two user groups: individuals with impaired lower limb motor function requiring rehabilitation training, where the device aids in muscle exercise during walking to facilitate recovery, and healthy individuals using it as a wearable assistive device. To enhance movement intention prediction and improve human-machine coordination, this study focuses on the gait prediction algorithm for walking assistance in healthy users and proposes a gait prediction control strategy based on normal gait orientation. The control system utilizes a microcontroller and Raspberry Pi as its core, enabling functional mode selection through multi-sensor data fusion and effective control of the robot via Bluetooth communication. By comparing the original model algorithm with the proposed real-time updating Kalman filter algorithm, the latter demonstrates feasibility, achieving a prediction error within 1°. This validates the model’s effectiveness in real-time gait prediction.

This review comprehensively examines current intestinal anastomosis techniques. Traditional manual suturing methods, including intermittent and continuous sutures, provide high flexibility but but vary in infection risk and operation time. Continuous suturing is particularly effective in reducing operative time and infection risk. Suture materials include non-absorbable sutures, absorbable sutures, and natural materials, with absorbable sutures the most preferred for intestinal anastomosis. Mechanical anastomosis has gained widespread adoption, featuring both linear and circular metal staplers. Linear staplers are simple to operate, while circular staplers better align with physiological structures. Materials used in staplers include non-degradable metals (e.g., titanium, titanium alloy) and biodegradable anastomosis (e.g., magnesium alloy). Metal nail anastomosis often results in fewer complications than manual suturing in specific surgeries. Magnetic pressure anastomosis, relying on magnet attraction, has been successfully applied in clinical scenarios following extensive research. The adhesive-based approach involves medical adhesives such as cyanoacrylate and fibrin glue, offering auxiliary support for anastomosis. Energy tissue welding encompasses laser and radio frequency energy tissue welding. While laser welding poses a risk of thermal damage, radio frequency welding offers significant advantages, including faster, seamless anastomosis with reduced complications. The support method for intestinal anastomosis is a novel concept, involving the addition of support materials to the original anastomosis. It can be divided into composite and simple support methods. The simple support method, as evidenced by the "degradable internal scaffold method for digestive tract anastomosis" developed by Cai et al. in China, has demonstrated promising results in animal experiments. In conclusion, selecting the appropriate intestinal anastomosis technique depends on clinical scenarios to optimize surgical outcomes and reduce complications. The diverse technological advancements reviewed here present valuable opportunities for enhancing the quality and safety of intestinal surgery.