Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine最新文献

Cervical cancer ranks as the fourth most prevalent cancer among women worldwide. Early diagnosis facilitates timely intervention and treatment. Traditional colposcopy is a widely employed technique for evaluating cervical lesions. Nevertheless, the growing number of patients with cervical cancer, and the rising workload of doctors may lead to misdiagnosis and underdiagnosis. Therefore, many researchers use deep learning to make paramedical diagnoses of cervical disease. However, the current neural network models for cervical image recognition lead to poor diagnostic results due to limitations in feature extraction. Consequently, this study proposes a novel model for classifying cervical images into normal, cervical intraepithelial neoplasia, and cancerous categories. The model proposes three new modules, namely a Feature Cognitive Screening Module, Multi-scale Feature Classification Module, and Overlapping Sampling Module (FSMO), which can realize the extraction of global features and local feature areas, multi-scale feature fusion classification and short-range interactions in the images, and enhance the edge capturing ability of the model and the proficiency of solving complex problems, thereby elevating prediction accuracy. The results showed that the recognition accuracy of FSMO in the self-constructed cervical image dataset was 91.88%, a precision of 92.91%, a recall of 91.92%, and an F1-Score of 91.99%; and the accuracy is 97.5% under the kaggle dataset. The performance surpasses other advanced models. Consequently, this model holds significant potential for rapid auxiliary diagnosis in cervical imaging, contributing to the early detection and treatment of cervical cancer.

Various strategies have been proposed to reduce operator-dependent variability in musculoskeletal ultrasound, including mechanical stabilization techniques. However, their effects on image reproducibility and transducer handling remain unclear in anatomically complex regions such as hand. This two-phase study aimed to (1) develop and validate a transducer guiding system for hand ultrasound and (2) evaluate its influence on image reproducibility and operational stability through image-based analyses. In Phase I, test-retest reliability of the guiding system was examined by repeatedly measuring soft-tissue thickness in 30 healthy participants. Intraclass Correlation Coefficients (ICC) ranged from 0.766 to 0.948, demonstrating good to excellent reliability. In Phase II, 16 ultrasound users acquired images under handheld and guiding-system-assisted conditions based on predefined reference images. Image reproducibility was evaluated using Normalized Cross-Correlation (NCC) and ICC, while operational stability was assessed via cosine similarity derived from M-mode segments during the pre-capture period, with group comparisons performed using the Wilcoxon signed-rank test. Novice users showed substantial ICC improvement when using the guiding system (0.487-0.681), approaching the consistency observed in experienced users. Both novice and experienced groups displayed higher NCC and cosine similarity values with the guiding system, indicating improved reproducibility and operational stability. Overall, the guiding system enhanced image outcomes by providing standardized positioning and mechanical stabilization. These findings highlight its potential to improve consistency in hand ultrasound assessments and serve as a supportive tool for novice ultrasound training. The results further demonstrate the feasibility of mechanical stabilization in reducing operator-related variability and enhancing image consistency in hand ultrasound examinations.

Dental implantation is the most reliable method for replacing missing teeth. Success rate of dental implants is influenced by osseointegration. Surface roughness of implants influences osseointegration by altering surface area and texture, providing stimulation to cells. Sandblasting and acid-etching are common methods for making implant surfaces rough. Main goal of this study was to investigate effects of sandblasting and acid-etching variables, that is, blasting-pressure and acid-temperature, on surface roughness of implants to find the controlled values of variables for a favorable surface roughness. An acceptable surface roughness was assumed to have an arithmetic average height (Sa) between 1 and 2 µm, and an area developed ratio (Sdr) over 50%. Seventy-two titanium-made analogs were sandblasted with three different pressures, that is, 4, 5, and 6 MPa, and three different durations, that is, 15, 30, and 45 s, and then were etched with two different etching temperature, that is, 60°C and 80°C, and two exposure-time, that is, 5 and 10 min (two repetition for each combination). Surface roughness parameters were then measured using a profilometer. Multi-factorial ANOVA was used as statistical analysis method. Results showed that 14 groups demonstrated favorable Sa (1-2 µm), among which just four groups had acceptable Sdr (Sdr > 50%). Among four parameters stated above, which affect sandblasting and acid-etching processes, it was found that blasting duration is the most effective variable on implants roughness. This work highlights the importance of sandblasting and acid-etching parameters for a controlled titanium dental implant surface, which can achieve surface roughness parameters that correspond to those previously reported in the literature as favorable ones for osseointegration.

The viscoelastic characteristics of the intervertebral disc (IVD) govern spinal response to applied dynamic loading which is important in understanding how the spine responds to loads experienced in everyday activity. The common method of reporting experimental load response data in terms of linear stiffnesses represents a significant oversimplification of this behaviour. This study presents a method yielding substantially increased accuracy for principal direction load-displacement response of porcine lumbar spine segments. It compares quality of fit to experimental data of nonlinear viscoelastic models and the typical linear stiffness method. Experimental load response data were recorded from six porcine lumbar spine segments tested under 6 DOF cyclic displacement control at low strain rates (0.1 Hz). Model spring and damper coefficients were determined using an optimisation procedure to minimise the differences between model and experimental load response vectors in each axis. Experimental hysteresis area cannot be reproduced using the linear method but was replicated to within 17% by nonlinear viscoelastic models. Fit quality was substantially improved by nonlinear models compared to the linear stiffness model, with RMSE reduced by 60%. Results indicate that three-element nonlinear viscoelastic models are well-suited for characterisation of principal direction load response to cyclic loading, replicating key features.

Knee injuries are prevalent in the sports world, particularly during single and double-leg landings. These injuries can affect various structures of the knee, including ligaments, menisci, condyles, the patellar tendon and others. While body posture at the time of ground impact plays a significant role in the occurrence of such injuries, extrinsic factors such as fall height, contact conditions and landing surface properties are also critical. Additionally, the stiffness-damping characteristics of the human joints may contribute to the risk of knee injury. This paper proposes a new dynamic model to investigate the influence of intrinsic and extrinsic parameters on knee joint forces and moments during a double-leg landing task. The model considers the mass, posture and movement of the body segments, the stiffness-damping of the joints, the ground reaction force and the landing surface conditions. The calibration of the model is based on ground reaction force behaviour reported in the literature. A sensitivity analysis using the Morris method is conducted to evaluate the influence of intrinsic and extrinsic parameters on knee joint forces. The results indicate that foot, shank and thigh posture, as well as the fall height, have the most significant influence on the knee joint forces and moments. This study provides valuable insights into the mechanisms of knee injuries and highlights the importance of considering both intrinsic and extrinsic factors in injury prevention strategies.

Early detection of Diabetic Neuropathy (DN) relies on quantifying Sweat Glands (SGs) function through non-invasive measures of sweat volume and pore activation. Gravimetry, the most common method, measures sweat mass but cannot assess pore activation and is limited by inter- and intra-patient variability. To address this, an optimized starch-iodine test with a stamper-like mechanism was developed to simultaneously quantify sweat volume and pore activation. An algorithm incorporating Structural Similarity Index Measure (SSIM) and its related correction on estimated volume was employed to enhance measurement accuracy. The study aimed to validate this optimized method against the conventional gravimetry test. Volunteers are recruited across four groups (Control, No DN, DN Stage1, DN Stage2). Both tests were conducted on all participants. DN patients showed significantly reduced sweat volume and pore activation compared to healthy individuals and diabetics without neuropathy. The optimized starch-iodine method demonstrated strong agreement with gravimetry (96.3% accuracy) and showed a significant positive correlation (Spearman's ρ = 0.846, p < 0.001). Microscopic analysis confirmed progressive structural changes in sweat pores among DN patients, supporting the physiological basis for reduced sweat production. Statistical analysis using one-way Analysis of Variance (ANOVA) revealed that forehead sweat volume (F = 59.53, p < 0.001), diabetes duration (F = 182.75, p < 0.001) showed significant differences across groups, indicating their potential utility as distinguishing parameters. Two-way ANOVA confirmed a strong interaction (F = 331.34, p < 0.001) between forehead sweat and starch-iodine outcomes across groups. By capturing nerve damage through SG activity, this approach enables early and accurate DN diagnosis.

A biodegradable ultrasonically welded device has for the first time been developed for in-body sutures that eliminates the need for surgical knotting. The device comprises two parts that fit together, with a suture inserted between them. Ultrasonic welding is then used to secure the suture by welding the two parts together. The device was manufactured from three biodegradable polymers: Poly(L-lactide-co-D,L-lactide) [PLDLA]; Poly(L-lactide-co-glycolide) [PLGA]; Poly(L-lactide) [PLLA]. All devices were degraded through immersion in phosphate buffer solution at a temperature of 37°C ± 2°C. Knotted sutures on their own were also subject to degradation testing. The devices and knotted sutures were mechanically tested at week zero and after 1, 3 and 6 weeks of degradation. Mechanically testing was undertaken to measure the pull-out strength of sutures from the device. PLGA is not suitable for the device, where a significant reduction in failure force was seen after 3 weeks of degradation. By week 6 the mean failure force (±SD) for PLGA was 74.9 ± 23.4 N, which was significantly less than the use of a suture knot on its own, with a mean failure force of 153.2 ± 37.2 N. PLDLA and PLLA were found to be promising materials, with only a small reduction in mean failure force after 6 weeks of degradation. At week 6 there was no significant difference between the mean failure force of PLDLA, PLLA or the suture knot, with mean failure forces of 152.6 ± 15.0, 128.8 ± 35.0 and 153.2 ± 37.2 N, respectively.

The structural performance of hinges in mechanical heart valves (MHVs) is essential for durability and reliability. This study evaluates the iValve, a novel bileaflet MHV, using advanced finite element method (FEM) simulations to assess its hinge design under physiological and supra-physiological conditions. The hinge design aims to minimize stress concentrations, reduce wear, and enhance durability compared to conventional valves. A detailed 3D FEM model, incorporating precise hinge geometry, was developed to analyze stress distribution, deformation, and potential failure zones. While our study uses a quasi-static finite element approach, and thus does not capture full dynamic or fluid-structure interactions, it evaluates peak physiological loading conditions representative of the cardiac cycle. The results show a lower and more uniform stress distribution in the iValve compared to conventional bileaflet MHVs, suggesting reduced stress concentrations and potentially improved fatigue life. The model was validated against experimental data from in vitro flow simulators, ensuring accurate representation of the hemodynamic forces during the cardiac cycle. Results show that the iValve's hinge design achieves superior stress distribution with significantly lower peak von Mises stresses than traditional designs. Optimized materials and geometric features reduce the risk of fatigue and wear, while high-cycle fatigue simulations confirmed minimal deformation, demonstrating suitability for extended use. This study highlights the role of FEM in advancing MHV design by balancing mechanical performance with physiological compatibility. The iValve addresses hinge failure and thrombus risks, offering a durable, anticoagulation-free solution.

Procedural-related musculoskeletal pain is common among orthopaedic surgeons, often caused by the repetitive use of high-force bone-cutting tools. Ultrasonic cutting devices, which can operate with lower force, may help reduce this physical burden. In this study, three practising orthopaedic surgeons each performed two cuts on three fresh cortical bone samples, harvested from excised femoral necks from three patients undergoing hip replacement surgery. The study was conducted using an ultrasonic cutting device in a controlled yet clinically reflective environment. A novel setup captured real-time data on surgeon-related parameters, including vertical cutting force and vertical and horizontal cutting speed. Consistent with previous research, we confirmed that ultrasonic devices enable low force cutting (average 1.91 N). However, our findings revealed significant variability in how each surgeon interacted with the device - including how much force each surgeon applied, and how the device was manoeuvred which can influence device performance, thermal effects, and overall clinical outcomes. Given the critical importance of surgeon-related factors, our results highlight the need to understand how each surgeon interacts with these devices differently. This insight can inform training and device optimisation strategies; help translate bench testing results into effective clinical use and ultimately improve surgical performance and patient outcomes. Additionally, our findings support the potential benefits of integrating ultrasonic devices with robotic platforms to maintain consistent cutting parameters. Future research should investigate optimal cutting parameters, evaluate different blade profiles, assess result generalisability and compare outcomes before and after training or system enhancements.

Ulnar shortening osteotomy (USO) is a commonly used technique for treating ulnar impaction syndrome (UIS), but nonunion remains a non-negligible complication. Currently, there is still no consensus on the best surgical protocol to prevent nonunion. There are limited studies on plate placement, which is a key factor influencing the mechanical environment at the osteotomy site. In this study, finite element analysis (FEA) was used to investigate the biomechanical differences between volar and dorsal plate fixation in USO. The results showed that the volar-side plate model demonstrated superior initial stability with significantly lower interfragmentary strain than the dorsal-side plate model, particularly under axial (48.6% reduction) and extension (38.3% reduction) loading. The von Mises stress analysis demonstrated the biomechanical superiority of the volar-side plate over dorsal-side plate in ulnar shortening osteotomy, as evidenced by lower stress values under four loadings, and more favorable stress distribution patterns, especially reduced stress concentrations at critical locations. These findings suggested that volar-side plate fixation would provide better initial stability for healing, providing insights into optimizing surgical strategies for USO.