Objective To evaluate the effect of optimizing the management measures of cataract ambulatory surgery. Methods The patients who underwent cataract phacoemulsification combined with intraocular lens implantation in the Ambulatory Surgery Center of East District of Beijing Tongren Hospital affiliated to Capital Medical University were selected. Patients between January and December 2021 (after the optimization of ambulatory surgery process) were included, and patients between January and December 2020 (before the optimization of ambulatory surgery process) were included as control. The three factors of age, gender and surgical eye type were used as predictive variables for propensity score matching. The proportion of patients who completed the surgery according to the scheduled time, the proportion of eye drops used according to the doctor’s instructions and the number of hospital visits before and after the optimization of the ambulatory surgery process were compared with the patients who successfully matched. Results A total of 28306 patients were included, including 13284 before and 15022 after process optimization. There were 13467 males and 14839 females, with a median age of 70 (60, 78) years. There was no statistically significant difference in the age of patients before the process optimization (P>0.05), but there was statistically significant difference in gender and surgical eye (P<0.05). After the propensity score matching, a total of 12932 pairs of patients were matched successfully. After the propensity score matching, there was no statistically significant difference between the two groups in age, gender and surgical eye (P>0.05). After the process optimization, the proportion of patients who completed surgery on schedule (98.8% vs. 93.3%) and used eyedrops according to the doctor’s instructions (97.4% vs. 93.0%) were higher than that before the process optimization, and the proportion of patients who came to hospital more than 3 times (0.7% vs. 1.9%) was lower than that before the process optimization (P<0.05). Conclusion The optimized ambulatory surgery process can help patients complete the surgery according to the scheduled time and use eye medication according to the doctor’s instructions, and can reduce the number of patients coming to the hospital.
We used near-infrared spectroscopy technology to monitor and assess the treatment effect of dehydrating agent in injured rat brain in real time style. We employed the brain edema model in rats resulting from Feeney's freefall damage, then treated with different doses of mannitol, and collected reduced scattering coefficient (μ's) and intracranial pressure (ICP) values after the injury and during the treatment. The results showed that brain edema happened 1 h after the injury in rats' brain tissue, peaked around 72 h after injury, and then began to decrease gradually. The reduced scattering coefficient and ICP values of the treatment group injected with mannitol all decreased after administration. Compared with the effect of low-dose mannitol treatment, that of high-dose mannitol treatment was much better. The duration of the plateau was longer and most experiments results declined significantly. From this we conclude that the reduced scattering coefficient and ICP are consistent with the trend changes, and the reduced scattering coefficient could be used as an indicator for monitoring cerebral edema.
Hemolysis is one of the main complications associated with the use of ventricular assist devices. The primary factors influencing hemolysis include the shear stress and exposure time experienced by red blood cells. In addition, factors such as local negative pressure and temperature may also impact hemolysis. The different combinations of hemolysis prediction models and their empirical constants lead to significant variations in prediction results; compared to the power-law model, the OPO model better accounts for the complexity of turbulence. In terms of improving hemolytic performance, research has primarily focused on optimizing blood pump structures, such as adjustments to pump gaps, impellers, and guide vanes. A small number of scholars have studied hemolytic performance through control modes of blood pump speed and the selection of blood-compatible materials. This paper reviews the main factors influencing hemolysis, prediction methods, and improvement strategies for rotary blood pumps, which are currently the most widely used. It also discusses the limitations in current hemolysis research and provides an outlook on future research directions.
The goal of this paper is to solve the problems of large volume, slow dynamic response and poor intelligent controllability of traditional gait rehabilitation training equipment by using the characteristic that the shear yield strength of magnetorheological fluid changes with the applied magnetic field strength. Based on the extended Bingham model, the main structural parameters of the magnetorheological fluid damper and its output force were simulated and optimized by using scientific computing software, and the three-dimensional modeling of the damper was carried out after the size was determined. On this basis and according to the design and use requirements of the damper, the finite element analysis software was used for force analysis, strength check and topology optimization of the main force components. Finally, a micro magnetorheological fluid damper suitable for wearable rehabilitation training system was designed, which has reference value for the design of lightweight, portable and intelligent rehabilitation training equipment.
Colorectal cancer (CRC) is a common malignant tumor that seriously threatens human health. CRC presents a formidable challenge in terms of accurate identification due to its indistinct boundaries. With the widespread adoption of convolutional neural networks (CNNs) in image processing, leveraging CNNs for automatic classification and segmentation holds immense potential for enhancing the efficiency of colorectal cancer recognition and reducing treatment costs. This paper explores the imperative necessity for applying CNNs in clinical diagnosis of CRC. It provides an elaborate overview on research advancements pertaining to CNNs and their improved models in CRC classification and segmentation. Furthermore, this work summarizes the ideas and common methods for optimizing network performance and discusses the challenges faced by CNNs as well as future development trends in their application towards CRC classification and segmentation, thereby promoting their utilization within clinical diagnosis.
The nondestructive reconstruction of three-dimensional (3D) temperature field in biological tissue is always an important problem to be resolved in biomedical engineering field. This paper presents a novel method of nondestructive reconstruction of 3D temperature field in biological tissue based on multi-island genetic algorithm (MIGA). By this method, the resolving of inverse problem of bio-heat transfer is transformed to be a solving process of direct problem. An experiment and its corresponding simulation were carried out to verify the feasibility and reliability. In the experiment a high purity polypropylene material, whose thermophysical parameters were similar to the fat tissue being tested, were adopted so that it could avoid the negative results created by the other factors. We set the position P(x, y, z) as the point heat source in the biological tissue and its temperature t as optimization variable, got the experimental temperature values of the points in a module surface, subtracted them from the corresponding simulating temperature values in the same module surface, and then took the sum of absolute value. We took it as the objective function of successive iteration. It was found that the less the target value was, the more optimal the current variables, i.e. the heat source position and the temperature values, were. To improve the optimization efficiency, a novel establishment method of objective function was also provided. The simulating position and experimental position of heat source were very approximate to each other. When the optimum values are determined, the corresponding 3D temperature field is also confirmed, and the temperature distribution of arbitrary section can be acquired. The MIGA can be well applied in the reconstruction of 3D temperature field in biological tissue. Because of the differences between the MIGA and the traditional numerical methods, we do not have to acquire all the data of surface. It is convenient and fast, and shows a prosperous application future.
In order to improve the wearing comfort and bearing effectiveness of the exoskeleton, based on the prototype and working mechanism analysis of a relaxation wearable system for knee exoskeleton robot, the static optimization synthesis and its method are studied. Firstly, based on the construction of the virtual prototype model of the system, a comprehensive wearable comfort evaluation index considering the factors such as stress, deformation and the proportion of stress nodes was constructed. Secondly, based on the static simulation and evaluation index of system virtual prototype, multi-objective genetic optimization and local optimization synthesis of armor layer topology were carried out. Finally, the model reconstruction simulation data confirmed that the system had good wearing comfort. Our study provides a theoretical basis for the bearing performance and prototype construction of the subsequent wearable system.
Objective To explore the experience and needs of orthopedic inpatients for pre-hospital examinations led by nurses, provide a reference for optimizing the pre-hospital examination procedures and improve the pre-hospital examination experience of patient. Methods Using the method of phenomenology, semi-structured in-depth interviews were conducted on 35 patients who attended the Department of Orthopedics of the Second Affiliated Hospital of Army Medical University from July to August 2018 and had undergone pre-hospital examinations. Colaizzi’s seven-step method was used to encode, analyze, organize, summarize, and refine topics. Results Patients’ experience and needs for pre-hospital examinations led by nurses could be divided into three major sections: attitudes and emotions, individualized pre-rehabilitation needs and pre-hospital examination feelings. Attitudes and emotions included high treatment expectations, feelings of loss, and some patients’ understanding of pre-hospital examinations. Individualized pre-rehabilitation needs included pre-rehabilitation needs with cardiopulmonary diseases, pre-rehabilitation needs with sleep dysfunction, nutritional conditioning needs, and medication safety needs. Patients’ feelings during pre-hospital examinations mainly included complicated procedures and staff attitudes that need to be improved. Conclusion Some links in the pre-hospital inspection process urgently need to be optimized. In pre-hospital examinations, it is necessary to focus on patient expectation management and predictive communication, improve multidisciplinary cooperation, formulate personalized pre-rehabilitation plans, optimize examination procedures, strengthen humanistic care, and improve patient experience.
The stiffness of an ideal fracture internal fixation implant should have a time-varying performance, so that the fracture can generate reasonable mechanical stimulation at different healing stages, and biodegradable materials meet this performance. A topology optimization design method for composite structures of fracture internal fixation implants with time-varying stiffness is proposed, considering the time-dependent degradation process of materials. Using relative density and degradation residual rate to describe the distribution and degradation state of two materials with different degradation rates and elastic modulus, a coupled mathematical model of degradation simulation mechanical analysis was established. Biomaterial composite structures were designed based on variable density method to exhibit time-varying stiffness characteristics. Taking the bone plate used for the treatment of tibial fractures as an example, a composite structure bone plate with time-varying stiffness characteristics was designed using the proposed method. The optimization results showed that material 1 with high stiffness formed a columnar support structure, while material 2 with low stiffness was distributed at the degradation boundary and inside. Using a bone remodeling simulation model, the optimized bone plates were evaluated. After 11 months of remodeling, the average elastic modulus of callus using degradable time-varying stiffness plates, titanium alloy plates, and stainless steel plates were 8 634 MPa, 8 521 MPa, and 8 412 MPa, respectively, indicating that the use of degradable time-varying stiffness plates would result in better remodeling effects on the callus.