Medical Engineering & Physics最新文献

{"title":"Physiology-based identifiable model-quantity subset selection for early prediction of intradialytic mean arterial pressure trajectories from sparse observations.","authors":"Penghui Li, Xiaobo Rao, Jun Zhang, Hongtao Zhang, Fengmin Shao","doi":"10.1088/1873-4030/ae8c1c","DOIUrl":"10.1088/1873-4030/ae8c1c","url":null,"abstract":"<p><p>Intradialytic hypotension (IDH) is a common and harmful complication of hemodialysis that is closely associated with changes in mean arterial pressure (MAP). However, mechanistic prediction of intradialytic MAP is hindered by sparse early-stage observations and model-quantity non-identifiability in physiology-based models. This study develops a dimensionality-reduced predictive framework following a screen-select-estimate workflow for early prediction of intradialytic MAP trajectories from sparse MAP observations. Among 35 candidate model quantities considered in the screening procedure, the initial blood volumeand post-capillary venous resistanceare selected for estimation, whereas the remaining candidate quantities and treatment inputs are kept fixed or prescribed. Sensitivity analysis and Fisher information matrix-based subset selection show that this two-quantity subset provides the best trade-off between physiological information content, identifiability, and numerical stability. Using MAP observations from the first 100 min of dialysis, the selected subset supports prediction of subsequent MAP trajectories across four representative patient types. At the end of the 240 min ultrafiltration period, corresponding to approximately 3.00 l prescribed ultrafiltration in the reference simulation, the model-derived terminal specific blood volume ranges from 66.48 to 69.19 ml kg^-1andranges from 88.74% to 91.83% across the four phenotypes. Prediction-phase root-mean-square error ranges from 1.09 to 5.78 mmHg, and the maximum error ranges from 1.71 to 8.51 mmHg. This patient-type-level framework enables interpretable MAP trajectory prediction and provides a methodological basis for future patient-level evaluation of IDH-related MAP decline.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148473853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ankle-worn accelerometers for gait analysis in people with Alzheimer's disease and mild cognitive impairment: reliability of a finite state machine approach.","authors":"Benjamin F Cornish, Karen Van Ooteghem, Frederico Pieruccini-Faria, Manuel Montero-Odasso, William E McIlroy","doi":"10.1088/1873-4030/ae8dd0","DOIUrl":"10.1088/1873-4030/ae8dd0","url":null,"abstract":"<p><p>Clinical gait analysis is essential for understanding motor and cognitive contributions to mobility impairment. Continued methodological advancement in gait analysis is needed to detect important and subtle changes in walking behaviour that will inform this understanding. This study evaluated the reliability of a finite state machine (FSM) algorithm for stride segmentation during preferred and dual-task walking (DTW) and examined changes to temporal and accelerometry kinematic outcomes between tasks. Participants diagnosed with Alzheimer's disease or mild cognitive impairment completed a gait assessment as part of the Ontario Neurodegenerative Disease Research Initiative foundational study. Ankle-worn accelerometers and a GAITRite walkway captured data during preferred walking and three DTW conditions (counting backwards by ones, animal naming, counting backwards by sevens). Acceleration data were processed using the FSM algorithm to extract temporal and accelerometry kinematic outcomes defined by the FSM intra-stride segments. Stride time demonstrated excellent reliability (ICC ⩾ 0.97). Gait speed was significantly associated with gait variability during animal naming and counting backwards by sevens (<i>p</i>< 0.05), but not during counting backwards by ones. The FSM approach showed changes to intra-stride phases and accelerometry derived kinematics not seen with conventional stride-based approaches. There was a reduction in flat-foot phase and an increase in push-off phase across all dual-task conditions compared with PREF (<i>p</i>< 0.05), where conventional stance-phase segmentation did not show consistent differences. Kinematic outcomes were also significantly lower during DTW conditions when compared to preferred walking trials (<i>p</i>< 0.05) for the mid-swing peak amplitude and the slope of the accelerometer push-off. Findings demonstrate differences in performance between preferred and DTW conditions, the influence of gait speed on gait variability, and unique accelerometry-derived kinematics. The FSM segmentation method advances gait assessment by providing precise stride characteristics using low-cost, clinically accessible tools.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148551197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polychromatic quantitative absorption tomography for multi-component samples with cross-contamination artifact correction.","authors":"Abdul Rafay Ibrahim, Tony Kirk, Paul Di Pasquale, Jake Rogers, Minh H Dao, Pierce Bowman, David Hoxley, Chanh Quoc Tran","doi":"10.1088/1873-4030/ae8f4b","DOIUrl":"10.1088/1873-4030/ae8f4b","url":null,"abstract":"<p><p>Beam-hardening and material cross-contamination remain significant challenges in quantitative computed tomography of multi-component samples acquired using polychromatic x-ray sources. In this work, a polychromatic quantitative absorption tomography (QAT) technique is extended to reconstruct component-specific density distribution maps in a two-component sample. The technique decomposes projection sinograms acquired under two distinct incident x-ray spectra into component-specific column density sinograms using a spectral forward model. Residual cross-contamination artifacts are addressed using a quantitative correction procedure based on spatial reference masks obtained by segmenting conventional linear attenuation reconstructions. Contaminated regions are identified from these masks and reinterpreted in the sinogram domain using the same polychromatic forward model prior to back-projection. Experimental validation was performed on an intertwined Al-Cu wire sample. The proposed correction improves material separation, reduces streak artifacts, and brings reconstructed densities within one standard deviation of independently measured average densities of the components. Together, the extended QAT technique and quantitative correction procedure provide a physically consistent methodology for improved quantitative densitometry in multi-component samples, with extensibility to samples containingcomponents.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148580905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental analysis of the effects of idealized surface groove amplitudes on post-stenotic pulsatile flow dynamics.","authors":"Donghyeon Jang, Taesik Go, Woorak Choi","doi":"10.1088/1873-4030/ae8f4c","DOIUrl":"10.1088/1873-4030/ae8f4c","url":null,"abstract":"<p><p>Surface irregularities can substantially modify local hemodynamics within coronary arteries. This study experimentally investigated the influence of controlled grooved surface geometries on pulsatile flow characteristics using idealized coronary-type stenosis models. Four transparent models were fabricated, consisting of a smooth control and three grooved surfaces with increasing groove amplitudes. Time-resolved particle image velocimetry was employed to quantify phase-averaged velocity fields, recirculation structures, and turbulent kinetic energy (TKE). The results showed that groove-induced surface irregularities enhanced jet deflection, near-wall recirculation, and in-plane cross-stream motion compared with the smooth stenosis model. As groove amplitude increased, downstream jet deflection became more pronounced, indicating a redistribution of velocity fluctuations in the post-stenotic region. In contrast, the smooth stenosis sustained a longer and more coherent jet structure. Increased groove amplitude also reduced the downstream extent and magnitude of measured planar TKE. These findings demonstrate that even small-scale surface features can significantly alter post-stenotic flow structures and the spatial development of turbulence under coronary-relevant pulsatile flow conditions.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148580918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deviating from mechanical alignment in total knee arthroplasty: are native kinematic and ligament strain restoration interchangeable targets?","authors":"Periklis Tzanetis, Nico Verdonschot","doi":"10.1088/1873-4030/ae8859","DOIUrl":"10.1088/1873-4030/ae8859","url":null,"abstract":"<p><p>The main proposed targets for implant alignment in total knee arthroplasty (TKA) include restoration of native knee kinematics and/or ligament strains. These two targets may be inherently interchangeable, yet the extent of their relationship remains to be determined. For a single osteoarthritic patient, we used a previously established workflow to generate a personalized musculoskeletal model of the native knee and, subsequently, an implanted model configuration according to mechanical alignment (MA) principles. In the mechanically aligned model, the rotational alignment of the components was systematically varied within ± 4° relative to MA position in 2° increments/decrements, resulting in a total of 5⁶(15,625) simulated positions. Of these, 1103 positions more closely reproduced native kinematics compared with MA, and 84% of these also resulted in ligament strains closer to the native state. About three-times more positions (3294) were favorable when considering ligament strains, but only 28% of these also resulted in improved kinematics. There was a moderate positive correlation between the two targets (Pearson's<i>r</i>= 0.607,<i>R</i>²= 0.369), suggesting they are related but not completely interchangeable. Although targeting restoration of native knee kinematics is generally expected to facilitate restoration of ligament strains, and vice versa, both objectives should be considered within a unified objective function to better achieve reconstruction of native biomechanical conditions after TKA.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148425926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rheology-directed design of multifunctional human-like skin materials for extrusion-based 3D bioprinting combining bioadhesion, bacteriostatic, and wound repair.","authors":"Bowen Li, Chuanzhen Huang, Zhen Wang, Zhenyu Shi, Longhua Xu, Shuiquan Huang, Meina Qu, Zhengkai Xu, Dijia Zhang, Baosu Guo, Tianye Jin, Xiaodan Wang, Hanlian Liu, Dun Liu, Peng Yao","doi":"10.1088/1873-4030/ae8858","DOIUrl":"10.1088/1873-4030/ae8858","url":null,"abstract":"<p><p>Severe skin injuries require printable biomaterials that combine tissue adhesion, infection-control potential, and wound-repair compatibility. In this study, a gelatin/tannic acid/hyaluronic acid/elastin hydrogel precursor was developed using a rheology-directed design strategy for extrusion-based 3D printing. Rheological tests showed that the precursor ink exhibited controllable shear-thinning behavior, thixotropic recovery, and yield-stress characteristics suitable for extrusion at 25 °C, which corresponds to the ambient printing environment rather than physiological temperature. EDC/NHS secondary crosslinking was introduced to improve post-printing structural stability; however, the rheological stability of the post-crosslinked network at physiological temperature, approximately 37 °C, requires further systematic evaluation. The optimized formulation showed tissue adhesion,<i>in vitro</i>bacteriostatic activity against<i>E. coli</i>and<i>S. aureus</i>, and preliminary wound-closure potential in a non-infected mouse wound model. These results suggest that rheology-directed formulation design may support the development of printable bioadhesive hydrogel dressings, while further studies are needed to validate post-crosslinked mechanical stability, post-printing cell viability, and infection-control efficacy in infected wound models.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148425912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Centre of rotation in total hip arthroplasty: a critical review with emphasis on three-dimensional planning.","authors":"Sara De Angelis, Johann Henckel, Alister Hart, Anna Di Laura","doi":"10.1088/1873-4030/ae8dcc","DOIUrl":"10.1088/1873-4030/ae8dcc","url":null,"abstract":"<p><p>Accurate restoration of the centre of rotation (CoR) is crucial for the long-term success of a total hip replacement (THR); however, cup positioning remains one of the major challenges of this procedure. The aim of this study was to critically review the existing literature documenting CoR planning in THR. Specifically: 1. The rationale behind component placement; 2. The benefits and limitations of the current techniques used; and 3. Future directions and their application to clinical practice. Traditional two-dimensional (2D) templating, although widely used, has limited accuracy due to magnification errors and variability in patient positioning. Three-dimensional computed tomography (3D-CT) preoperative planning allows for a more precise estimation of CoR. Integration with robotic systems enables intraoperative execution of the plan but comes with high costs and a steep learning curve. Patient-specific instrumentation (PSI) provides a cost-effective alternative. Meanwhile, surgeon experience and intraoperative judgement remain crucial, particularly in patients with abnormal anatomy or deformities. Restoration of CoR within approximately 5 mm of the planned medial and superior position has been associated with improved biomechanical performance and implant longevity. While 2D templating can achieve this in most routine cases, 3D planning, robotic-assisted surgery, and PSI allow for more accurate placement. This is particularly useful in complex cases, such as revisions or developmental dysplasia of the hip, where the risk of clinically significant deviations remains high and more targeted surgical strategies are needed.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148551276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of calibration approach on image quality and volumetric bone mineral density in low-dose chest computed tomography.","authors":"Bryn E Matheson, Matthias Walle, Steven K Boyd","doi":"10.1088/1873-4030/ae8dcd","DOIUrl":"10.1088/1873-4030/ae8dcd","url":null,"abstract":"<p><p>Opportunistic assessment of volumetric bone mineral density (vBMD) from computed tomography (CT) scans offers a strategy to identify individuals at risk of osteoporosis. However, accurate CT-based vBMD quantification depends on appropriate density calibration, and direct comparisons of synchronous, asynchronous, and tissue-based internal calibration in low-dose chest imaging are limited. This study had two objectives: (1) to assess the impact of calibration methods on image quality in low-dose chest CT, particularly whether the inclusion of a calibration phantom compromises image quality, and (2) to examine whether these variations influence agreement in vBMD measurements across calibration techniques. 51 participants underwent chest CT; 23 with a calibration phantom (synchronous) and 28 without (asynchronous). Trabecular vBMD was quantified at the fourth and eighth thoracic vertebrae (T4 and T8, respectively) and the first lumbar vertebra (L1). Image quality was assessed using stochastic noise and signal-to-noise ratio (SNR) in calibration phantom rods and tissue-based reference regions. Agreement in vBMD measurements was evaluated using Pearson's correlation coefficients, Bland-Altman analyses, and absolute deviations relative to internal calibration. Internal calibration tissues demonstrated stable image quality across synchronous and asynchronous acquisitions, whereas synchronously scanned calibration phantoms exhibited increased noise and reduced SNR. In vBMD measurements, asynchronous calibration demonstrated smaller deviations (19.15 ± 11.59 mg cm^-3vs. 10.19 ± 9.69 mg cm^-3) than synchronous across vertebral levels. These findings show that calibration strategy affects both image quality and vBMD agreement in low-dose chest CT. Asynchronous and tissue-based internal methods provided more consistent estimates than synchronous calibration, supporting their use for opportunistic osteoporosis assessment.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148551244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identifying potential optimal donor graft for talar osteochondral transplantation: a finite element analysis of different femoral condyle sites.","authors":"Jingtao Liao, Haoyu Song, Jianjing Lin, Jingtao Huang, Ying Shan, Xintao Zhang, Lu Bai","doi":"10.1088/1873-4030/ae8dcf","DOIUrl":"10.1088/1873-4030/ae8dcf","url":null,"abstract":"<p><p><i>Purpose.</i>To compare the biomechanical performance of different femoral condyle donor sites for autologous osteochondral transplantation (AOT) of the talus.<i>Methods.</i>Patient-specific finite element models were constructed based on postoperative computed tomography scans from 17 individuals with cystic osteochondral lesions of the talus. The femoral condyles were divided into six distinct donor sites: the medial superior (MS), medial central (MC), medial inferior, lateral superior , lateral central, and lateral inferior regions. Finite element analysis (FEA) was employed to simulate the biomechanical response under a simulated standing load, quantifying von Mises stress, displacement, and strain.<i>Results.</i>No significant differences were observed in mean stress or mean strain among graft from different femoral condyle sites (<i>P</i>> 0.05). The MS graft demonstrated significantly lower displacement compared to the MC graft (Kruskal-Wallis test,<i>H</i>= 14.710,<i>P</i>= 0.012; Dunn's post-hoc,<i>Z</i>= 3.527, adjusted<i>P</i>= 0.0063) and relative to the adjacent talar articular surface (<i>P</i>= 0.002, Bonferroni-corrected<i>α</i>* = 0.0028). No significant differences were observed in mean stress or strain among other femoral condyle graft sites (<i>P</i>> 0.0028 Bonferroni correction).<i>Conclusion.</i>In AOT using the femoral condyle as the donor site, stress distribution did not differ significantly across different donor regions; however, the MS region showed relatively small displacement.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148551212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical hand kinematics for machine learning-based screening of carpal tunnel syndrome.","authors":"Şerife Çelikbaş, Abdurrahim Akgündoğdu, Ayşegül Gündüz","doi":"10.1088/1873-4030/ae8dce","DOIUrl":"10.1088/1873-4030/ae8dce","url":null,"abstract":"<p><p>Carpal tunnel syndrome is usually assessed by clinical examination and electrodiagnostic testing, but these methods may not always be practical for rapid screening. In this work, it was explored whether hand motion recorded with a low-cost optical camera could add useful information to routine clinical data. Demographic variables, symptom-related findings obtained after the Phalen test, and five thumb-to-finger opposition tasks were collected. Hand landmarks were extracted with MediaPipe and used to derive kinematic descriptors, which were then analyzed together with clinical variables by machine-learning and hybrid deep-learning models. To reduce the risk of overly optimistic estimates, the main evaluation was carried out at hand level with leave-one-group-out cross-validation. In the primary leakage-safe comparison, the best Dataset 4 multimodal model yielded the strongest binary screening profile. Compared with the clinical Dataset 1 baseline, accuracy increased from 82.6% (95% CI 75.0%-90.2%) to 87.0% (79.3%-93.5%), sensitivity from 70.0% (54.4%-85.1%) to 80.0% (64.7%-93.4%), specificity from 88.7% (80.3%-95.6%) to 90.3% (83.1%-96.8%), and ROC-AUC from 0.845 (0.745-0.934) to 0.855 (0.752-0.945). In the same-architecture tests, the kinematic variables did not behave uniformly across model families. The clearest gain among the classical models was seen with light gradient boosting machine. Feature-level results were also consistent with the model findings, as selected thumb-opposition coordinates differed across stages and appeared to capture a functional component not represented by symptom scores. In the four-class severity task, the improvement was small: accuracy increased from 81.5% (72.8%-89.1%) to 82.6% (73.9%-90.2%), and macro-1 increased from 0.706 (0.544-0.823) to 0.748 (0.588-0.850). In this cohort, the optical hand-kinematic measures mainly strengthened the screening analysis. Their use for finer severity staging will need confirmation in larger external datasets and in participant-level analyses.</p>","PeriodicalId":49836,"journal":{"name":"Medical Engineering & Physics","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148551249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}