Objective To investigate effectiveness of applying the Bone Morphingbased image-free computer-assisted system for the ligament balancing managementin the total knee arthroplasty (TKA). Methods Between November 2002 and June 2003, twenty-one posterior stabilized total knee prostheses (Ceraver, France) were implanted in 21 patients using the Bone Morphing based image-free Ceravision system.This cohort included 5 men and 16 women with an average age of 72.4 years, two undergoing high tibial osteotomy and 1 undergoing distal femoral osteotomy before. The preoperative deviation was measured by the full-length AP X-rays. The knees were in varus deviation in 14 patients and in valgus deviation in 7 patients, with an average of 2.36°(varus 13°-valgus 13°). The frontal X-rays ofthe knee were assessed, the mean value of the varus force-stress test was 8.47°(varus 2°-varus 20°), and the mean value of the valgus forcestress test was 3.63°(varus 7°-valgus 12°). Results With the Ceravisionrecorded data, the intraoperative alignment was assessed, the mean lower limb axis was 3.33°(varus 12°-valgus 10°),and compared with the preoperative data, the difference was significant (Plt;0.05); the mean value of the varus force-stress test was 6.47°(varus 0°-varus 24°), the mean value of the valgus force-stress test was 4.32°(varus 8°- valgus 15°), and compared with the preoperative data, the difference was significant (Plt;0.05). The post-prosthetic alignment on Ceravision with a deviation of 0.175°(varus 2°- valgus 3°) was compared with the postoperative alignment by the full-length AP X-rays, with a deviation of 0.3°(varus 3.5°-valgus 1.5°), the difference wasn’t significant(Pgt;0.05).The clinical check-up performed 3 months after operation showed that the average range of movement (ROM) was 115°(105-130°), the mean frontal laxity was 0.27 mm(0.2-0.5 mm). The femoral and tibial components were implanted in the satisfactory 3 dimensional position without ligament imbalance in all the patients, andthere were no instability or patella complications.Conclusion Utilization of the Bone Morphing based image-free computer-assisted system can achieve an accurate component 3 dimensional alignment, optimal bone resection, optimal control of surgical decision in releasing the soft tissues, rotating the femoral component to gain an extension/flexion rectangular gap, and managing theligament balancing so as to achieve a satisfactory initial clinical outcome. This system can be routinely used in the TKA.
Integration of heterogeneous systems is the key to hospital information construction due to complexity of the healthcare environment. Currently, during the process of healthcare information system integration, people participating in integration project usually communicate by free-format document, which impairs the efficiency and adaptability of integration. A method utilizing business process model and notation (BPMN) to model integration requirement and automatically transforming it to executable integration configuration was proposed in this paper. Based on the method, a tool was developed to model integration requirement and transform it to integration configuration. In addition, an integration case in radiology scenario was used to verify the method.
Objective To evaluated the application effect of reverse digital modeling combined with three-dimensional (3D)-printed disease models in the standardized training of orthopedic residents focusing on pelvic tumors. Methods From August 2022 to August 2023, 60 orthopedic residents from West China Hospital, Sichuan University were randomly assigned to a trial group (n=30) and a control group (n=30). The trial group received instruction using reverse digital modeling and 3D-printed pelvic tumor models, while the control group underwent traditional teaching methods. Teaching outcomes were evaluated and compared between groups through knowledge tests, practical skill assessments, and satisfaction surveys. Results Before training, there was no statistically significant difference in knowledge tests or practical skill assessments between the two groups (P>0.05). After training, the trial group showed significantly better performance than the control group in knowledge tests (90.5±5.2 vs. 78.4±6.8, P<0.05), skill assessments (92.7±4.9 vs. 81.3±6.2, P<0.05), and satisfaction surveys (9.40±1.10 vs. 7.60±1.20, P<0.05). One month after training, the trial group still showed significantly better performance than the control group in knowledge tests (88.1±6.4 vs. 72.3±7.1, P<0.05) and skill assessments (90.3±5.8 vs. 75.6±6.9, P<0.05). Conclusions Reverse digital modeling combined with 3D printing offers an intuitive and effective teaching approach that improves comprehension of pelvic tumor anatomy and strengthens clinical and technical competencies. This method significantly enhances learning outcomes in standardized residency training and holds promise for broader integration into medical education.
A good cushion can not only provide the sitter with a high comfort, but also control the distribution of the hip pressure to reduce the incidence of diseases. The purpose of this study is to introduce a computer-aided design (CAD) modeling method of the buttocks-cushion using numerical finite element (FE) simulation to predict the pressure distribution on the buttocks-cushion interface. The buttock and the cushion model geometrics were acquired from a laser scanner, and the CAD software was used to create the solid model. The FE model of a true seated individual was developed using ANSYS software (ANSYS Inc, Canonsburg, PA). The model is divided into two parts, i.e. the cushion model made of foam and the buttock model represented by the pelvis covered with a soft tissue layer. Loading simulations consisted of imposing a vertical force of 520N on the pelvis, corresponding to the weight of the user upper extremity, and then solving iteratively the system.
Virtual clinical trials are clinical trials conducted through computer simulation technology, which breaks through the limitations of traditional clinical trials and has the advantages of saving time, reducing costs, and reducing the risk of human trials. With the application of new computer technologies such as population pharmacokinetics, physiologically-based pharmacokinetics, quantitative systems pharmacology, and artificial intelligence, the field of virtual clinical trials in healthcare has become an important development direction. This article will give a preliminary review of the connotation, methods and future development trends of virtual clinical trials, aiming to provide reference for the application of new technologies and methods in clinical trials.
During transfer tasks, the dual-arm nursing-care robot require a human-robot mechanics model to determine the balance region to support the patient safely and stably. Previous studies utilized human-robot two-dimensional static equilibrium models, ignoring the human body volume and muscle torques, which decreased model accuracy and confined the robot ability to adjust the patient’s posture in three-dimensional spatial. Therefore, this study proposes a three-dimensional spatial mechanics modeling method based on individualized human musculoskeletal multibody dynamics. Firstly, based on the mechanical features of dual-arm support, this study constructed a foundational three-dimensional human-robot mechanics model including body posture, contact position and body force. With the computed tomography data from subjects, a three-dimensional femur-pelvis-sacrum model was reconstructed, and the individualized musculoskeletal dynamics was analyzed using the ergonomics software, which derived the human joint forces and completed the mechanic model. Then, this study established a dual-arm robot transfer platform to conduct subject transfer experiments, showing that the constructed mechanics model possessed higher accuracy than previous methods. In summary, this study provides a three-dimensional human-robot mechanics model adapting to individual transfers, which has potential application in various scenarios such as nursing-care and rehabilitating robots.
Magnetic resonance imaging (MRI)-based electroencephalography (EEG) forward modeling method has become prevalent in the field of EEG. However, due to the inability to obtain clear images of an infant’s fontanel through MRI, the fontanelle information is often lacking in the EEG forward model, which affects accuracy of modeling in infants. To address this issue, we propose a novel method to achieve fontanel compensation for infant EEG forward modeling method. First, we employed imaging segmentation and meshing to the head MRIs, creating a fontanel-free model. Second, a projection-based surface reconstruction method was proposed, which utilized priori information on fontanel morphology and the fontanel-free head model to reconstruct the two-dimensional measured fontanel into a three-dimensional fontanel model to achieve fontanel-compensation modeling. Finally, we calculated a fontanel compensation-based EEG forward model for infants based on this model. Simulation results, based on a real head model, demonstrated that the compensation of fontanel had a potential to improve EEG forward modeling accuracy, particularly for the sources beneath the fontanel (relative difference measure larger than 0.05). Additional experimental results revealed that the uncertainty of the infant’s skull conductivity had the widest impact range on the neural sources, and the absence of fontanel had the strongest impact on the neural sources below the fontanel. Overall, the proposed fontanel-compensated method showcases the potential to improve the modeling accuracy of EEG forward problem without relying on computed tomography (CT) acquisition, which is more in line with the requirements of practical application scenarios.
In order to quantitatively analyze the morphology and period of pulse signals, a time-space analytical modeling and quantitative analysis method for pulse signals were proposed. Firstly, according to the production mechanism of the pulse signal, the pulse space-time analytical model was built after integrating the period and baseline of pulse signal into the analytical model, and the model mathematical expression and its 12 parameters were obtained for pulse wave quantification. Then, the model parameters estimation process based on the actual pulse signal was presented, and the optimization method, constraints and boundary conditions in parameter estimation were given. The spatial-temporal analytical modeling method was applied to the pulse waves of healthy subjects from the international standard physiological signal sub-database Fantasia of the PhysioNet in open-source, and we derived some changes in heartbeat rhythm and hemodynamic generated by aging and gender difference from the analytical models. The model parameters were employed as the input of some machine learning methods, e.g. random forest and probabilistic neural network, to classify the pulse waves by age and gender, and the results showed that random forest has the best classification performance with Kappa coefficients over 98%. Therefore, the space-time analytical modeling method proposed in this study can effectively quantify and analyze the pulse signal, which provides a theoretical basis and technical framework for some related applications based on pulse signals.
A method of ultrasonic simulation based on the FIELD II software platform for carotid artery plaque was proposed according to the analysis for geometrical shape, tissue characteristics and acoustic properties of carotid artery plaques in clinic, and then a simulation system was developed by using the MATLAB graphical user interface (GUI). In the simulation and development, a three-dimensional geometric model of blood vessel with plaques was set up by using the metaball implicit surface technique, and a tissue model was established based on the scatterers with spatial position of gamma random distribution. Comparison of the statistical and geometrical characteristics from simulated ultrasound B-mode images with those based on clinical ones and preset values, the results fully demonstrated the effectiveness of the simulation methods and system.
The prevalence of cardiovascular disease in our country is increasing, and it has been a big problem affecting the social and economic development. It has been demonstrated that early intervention of cardiovascular risk factors can effectively reduce cardiovascular disease-caused mortality. Therefore, extensive implementation of cardiovascular testing and risk factor screening in the general population is the key to the prevention and treatment of cardiovascular disease. However, the categories of devices available for quick cardiovascular testing are limited, and in particular, many existing devices suffer from various technical problems, such as complex operation, unclear working principle, or large inter-individual variability in measurement accuracy, which lead to an overall low popularity and reliability of cardiovascular testing. In this study, we introduce the non-invasive measurement mechanisms and relevant technical progresses for several typical cardiovascular indices (e.g., peripheral/central arterial blood pressure, and arterial stiffness), with emphasis on describing the applications of biomechanical modeling and simulation in mechanism verification, analysis of influential factors, and technical improvement/innovation.