Volume 1, Issue 2

Cardiovascular diseases are still the primary threats to people's health around the world. Automatic heart sound classification technology, as a fast and efficient means for diagnosis and treatment, is of great clinical significance. With the rapid development of artificial intelligence technology, deep learning algorithms are widely used in automatic heart sound classification. This paper reviewed the key technologies related to the automatic classification of heart sounds in recent years, including heart sound denoising, segmentation, feature extraction, and classification recognition. The classification and recognition technologies related to deep learning are presented in detail, with a focus on the application and development of convolutional neural network and recurrent neural network, as well as various combination models for heart sound classification in the past five years.

Bile duct stenosis is a common condition in gastroenterology and hepatobiliary surgery and can be divided into benign stenosis and malignant stenosis according to different etiologies. The implantation of a gall stent into the site of the stenosis or obstruction is currently an important means of treating the bile duct stenosis. Biliary stents encompass two main types: plastic stents and metal stents. In recent years, biodegradable biliary stents and drug-eluting stents have also emerged. The material and structure of biliary stents have an important influence on their performance. In this paper, the research progress on biliary stent implantation technology in the treatment of biliary stenosis is reviewed. Besides, the advantages and disadvantages of biliary stents made from different materials and structures, along with their respective indications are summarized, and the development trend of degradable biliary stents is prospected.

Minimally invasive surgeries are widely applied due to the advantages of small surgical wound, short postoperative recovery period, and low surgical infection rate. In minimally invasive surgery, vascular clips play a significant role in hemostasis and managing the direction of blood flow, ensuring the success of surgical procedures. The mechanical structure and manufacturing materials of vascular clips have an important influence on its clinical application effect. In this paper, we classify and summarize the mechanical structure and manufacturing materials of the currently available vascular clips worldwide, and then analyze the hemostatic coating materials of vascular clips. Besides, we also summarize the shortcomings of the existing vascular clips and propose a coat-absorbable vascular clip with future research potential.

In ultrasound imaging, the pleura is visualized as echo reflection formed by the echoes of the interface between the pleura and the lung surface. Three major signs of pleura determines whether the patient has pneumothorax. In this paper, we propose a method to identify pleural line for the diagnosis of pneumothorax. Firstly, the gray threshold of ultrasonic image is properly classified by pre-experiment. Secondly, possible pleural line regions are identified based on threshold classification. Thirdly, the region of pleural line is identified based on the known characteristics of pleural line. The last step is to consider whether it is necessary to modify the threshold to accurately identify the pleural line region. Moreover, we tested 890 ultrasound samples, which included three categories: lung sliding, lung point, and lung sliding disappearance. Each category of samples was divided into two subsets, typical and atypical. The average identification rate reached 90.45%. According to the test results, the advantages and disadvantages of the proposed method as well as the further improvement direction were analyzed. This method for identifying pleural line can serve as the groundwork for developing automatic algorithm for diagnosing pneumothorax.

Urinalysis is an essential diagnostic tool for urinary tract infections, kidney disease, diabetes, and other clinical conditions. Dipsticks, which allow for quick screening of urine specimens, are used in the clinic settings to identify the presence and concentration of labeled substances such as urine pH, urine protein, urine glucose, urine ketone, and urine nitrite. This paper reviews four urine dry chemical analysis methods, which are based on human eyes, integrating sphere, color sensors, and image sensors, respectively. The techniques of each method are also discussed.

Images taken under hazy weather conditions suffer from problems such as blurring, low contrast, and low saturation due to the scattering of atmospheric light by aerosol particles in the air, which affects the performance and judgment of image analysis equipment. With the rapid development of image processing technology and computer vision technology, researchers have proposed a large number of targeted haze removal algorithms to improve the quality of images taken under hazy weather conditions. According to the haze removal principle, mainstream haze removal algorithms can be classified into three categories: image enhancement-based, physics model-based, and neural network-based. This paper introduces and explores classic haze removal algorithms from the perspectives of principles, development, advantages, and disadvantages, and outlines the prospects for the future development and application direction of haze removal algorithms.

Electro-conductive hydrogel is a new composite hydrogel with high electrical conductivity, extraordinary mechanical properties, and controllability. It can be equipped with specific materials to obtain specific properties, which has attracted considerable research attention due to its wide range of application as a biomaterial in the biomedical engineering field. It can be used as a patch to promote healing and as a dressing for burns and pressure wounds. In pharmaceutical science, it is widely studied as a carrier of targeted and quantitative drug release. In surgery, it can serve as a cell scaffold for implantable therapy. Currently, increasing research is focusing on the development of sensors as simulated skin for robots, as well as in health monitors for human activity and well-being. In this review, we summarize the classification and selection of conductive mediums, natural polymer hydrogel matrices, and the application of electro-conductive hydrogels in the fields of bioengineering and biomedicine. We delve into the properties of different conductive mediums and the principle of combining different hydrogel matrices and discuss the advantages and disadvantages of emerging composite hydrogels. Our focus extends to the forefront of conductive hydrogel research in various fields, while also elucidating the current problems and challenges in terms of performance integration, preparation process and practical applications.

Radiofrequency ablation (RFA) represents a convenient, minimally invasive, and cost-effective approach for the treatment of small liver cancers measuring less than 3 cm in diameter. Nonetheless, the existing RFA techniques encounter challenges in precisely controlling the extent of ablation and the risk of overheating, which can lead to damage on the surrounding tissues. The ability to control the ablation area also plays a crucial role in the success of RFA procedures. To address these issues, we introduce a novel method that utilizes tumor boundary temperature monitoring to achieve precise control over the RFA process. Through the utilization of COMSOL Multiphysics simulation software, the proposed method was verified by comprehensive simulation and modeling and its efficacy in achieving regional control was testified. Subsequently, ex vivo experiments were conducted employing a custom-designed cooling RFA instrument. The experimental results demonstrated that the RFA controlled by boundary temperature yielded an ablation area with a diameter approaching 30 mm. In comparison to the standard spherical solidification zone (characterized by both the ellipticity and regularity indices of 1), the cooling RFA discoloration zone, under boundary temperature control, exhibited a maximum deviation of 7% in the ellipticity index and 17% in the regularity index. The average ellipticity index was determined to be 0.96, while the average regularity index was 0.86. Collectively, these findings underscore the capability of the proposed temperature-controlled cooling RFA method to attain precise control over the ablation area, contributing to comprehensive ablation of tumor tissue within the target region.