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Showing 1 - 99 of 99 Journals sorted alphabetically
AAPS PharmSciTech     Hybrid Journal   (Followers: 9)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 7)
Adipocyte     Open Access   (Followers: 1)
African Journal of Laboratory Medicine     Open Access   (Followers: 2)
American Journal of Experimental and Clinical Research     Open Access   (Followers: 4)
American Journal of Medical and Biological Research     Open Access   (Followers: 10)
Animal Models and Experimental Medicine     Open Access  
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Applied In Vitro Toxicology     Hybrid Journal   (Followers: 2)
Archives of Clinical and Experimental Medicine     Open Access  
Archives of Medical Research     Hybrid Journal   (Followers: 3)
Archives of Pathology & Laboratory Medicine     Full-text available via subscription   (Followers: 31)
Archives of Preventive Medicine     Open Access   (Followers: 3)
Biomedical Engineering     Hybrid Journal   (Followers: 3)
Bulletin of Experimental Biology and Medicine     Hybrid Journal  
Clinica Chimica Acta     Hybrid Journal   (Followers: 30)
Clinical & Experimental Metastasis     Hybrid Journal  
Clinical and Experimental Medical Journal     Full-text available via subscription   (Followers: 1)
Clinical and Experimental Medicine     Hybrid Journal   (Followers: 4)
Clinical Trials     Hybrid Journal   (Followers: 21)
Clinical Trials in Degenerative Diseases     Open Access  
Clinical Trials in Orthopedic Disorders     Open Access   (Followers: 1)
Current Medicine Research and Practice     Full-text available via subscription  
Current Research in Drug Discovery     Open Access   (Followers: 1)
Drug Design, Development and Therapy     Open Access   (Followers: 4)
Ecography     Hybrid Journal   (Followers: 28)
European Journal of Hospital Pharmacy : Science and Practice (EJHP)     Hybrid Journal   (Followers: 8)
European Journal of Medical Research     Open Access   (Followers: 1)
European Journal of Nanomedicine     Hybrid Journal   (Followers: 1)
Experimental & Molecular Medicine     Open Access   (Followers: 1)
Experimental Aging Research: An International Journal Devoted to the Scientific Study of the Aging Process     Hybrid Journal   (Followers: 3)
Experimental and Therapeutic Medicine     Full-text available via subscription   (Followers: 1)
Experimental Biology and Medicine     Hybrid Journal   (Followers: 3)
Expert Opinion on Drug Delivery     Hybrid Journal   (Followers: 20)
Frontiers in Laboratory Medicine     Open Access  
Frontiers in Medical Technology     Open Access   (Followers: 1)
IN VIVO     Full-text available via subscription   (Followers: 5)
International Archives of Biomedical and Clinical Research     Open Access  
International Journal of Experimental Pathology     Hybrid Journal   (Followers: 1)
International Journal of Health Research and Innovation     Open Access   (Followers: 1)
International Journal of Research in Medical Sciences     Open Access   (Followers: 5)
International Journal of Statistics in Medical Research     Hybrid Journal   (Followers: 5)
Journal of Cell Science & Therapy     Open Access   (Followers: 1)
Journal of Applied Biomaterials & Functional Materials     Hybrid Journal   (Followers: 1)
Journal of Biomedical and Clinical Research     Open Access  
Journal of Clinical Laboratory Analysis     Open Access   (Followers: 14)
Journal of Clinical Medicine and Research     Open Access  
Journal of Clinical Medicine Research     Open Access   (Followers: 4)
Journal of Clinical Trials     Open Access   (Followers: 6)
Journal of Current and Advance Medical Research     Open Access   (Followers: 1)
Journal of Current Medical Research and Practice     Open Access  
Journal of Current Research in Scientific Medicine     Open Access  
Journal of Current Researches on Health Sector     Open Access  
Journal of Drug Delivery and Therapeutics JDDT     Open Access   (Followers: 1)
Journal of Enzyme Inhibition and Medicinal Chemistry     Open Access   (Followers: 4)
Journal of Experimental & Clinical Medicine     Full-text available via subscription   (Followers: 1)
Journal of Experimental & Clinical Cancer Research     Open Access   (Followers: 2)
Journal of Experimental and Clinical Medicine     Open Access  
Journal of Experimental Medicine     Full-text available via subscription   (Followers: 45)
Journal of Experimental Pharmacology     Open Access   (Followers: 2)
Journal of Histotechnology     Hybrid Journal   (Followers: 2)
Journal of International Medical Research     Open Access   (Followers: 3)
Journal of Investigative Medicine High Impact Case Reports     Open Access  
Journal of Medicine and Biomedical Research     Open Access   (Followers: 1)
Journal of Muhammadiyah Medical Laboratory Technologist     Open Access  
Journal of Operating Department Practitioners     Full-text available via subscription   (Followers: 2)
Journal of the American Society of Cytopathology     Hybrid Journal   (Followers: 6)
Journal of Trace Elements in Medicine and Biology     Hybrid Journal   (Followers: 1)
Lab on a Chip     Full-text available via subscription   (Followers: 42)
Laboratory Investigation     Hybrid Journal   (Followers: 3)
Medical Devices & Sensors     Hybrid Journal  
Medical Image Analysis     Hybrid Journal   (Followers: 15)
Medical Instrumentation     Open Access  
Medical Laboratory Observer     Full-text available via subscription  
Medical Laboratory Technology Journal     Open Access  
Medicinal Chemistry Research     Hybrid Journal   (Followers: 12)
Medtech Insight     Full-text available via subscription   (Followers: 4)
Nanomedicine: Nanotechnology, Biology and Medicine     Hybrid Journal   (Followers: 7)
New Zealand Journal of Medical Laboratory Science     Full-text available via subscription   (Followers: 1)
Oriental Pharmacy and Experimental Medicine     Partially Free   (Followers: 3)
Pathology and Laboratory Medicine International     Open Access   (Followers: 7)
Physical Biology     Hybrid Journal   (Followers: 4)
Practical Laboratory Medicine     Open Access   (Followers: 2)
Proceedings of the Institution of Mechanical Engineers Part H: Journal of Engineering in Medicine     Hybrid Journal   (Followers: 3)
Prosthetics and Orthotics International     Hybrid Journal   (Followers: 9)
Pulse     Full-text available via subscription  
Qualitative Research in Medicine & Healthcare     Open Access  
Recent Advances in Biology and Medicine     Open Access  
Regulatory Toxicology and Pharmacology     Hybrid Journal   (Followers: 43)
Reproduction     Full-text available via subscription   (Followers: 7)
Revista Peruana de Medicina Experimental y Salud Pública     Open Access  
Revista Romana de Medicina de Laborator     Open Access  
RSC Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
SA Pharmacist's Assistant     Open Access  
Savannah Journal of Medical Research and Practice     Full-text available via subscription  
SLAS Technology     Hybrid Journal   (Followers: 2)
Statistics in Medicine     Hybrid Journal   (Followers: 190)
Trends in Molecular Medicine     Full-text available via subscription   (Followers: 14)
Turkish Journal of Clinics and Laboratory     Open Access   (Followers: 1)
Similar Journals
Journal Cover
Proceedings of the Institution of Mechanical Engineers Part H: Journal of Engineering in Medicine
Journal Prestige (SJR): 0.44
Citation Impact (citeScore): 1
Number of Followers: 3  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0954-4119 - ISSN (Online) 2041-3033
Published by Sage Publications Homepage  [1093 journals]
  • Exploring neurodegenerative disorders using a novel integrated model of
           cerebral transport: Initial results
    • Authors: John C Vardakis, Dean Chou, Liwei Guo, Yiannis Ventikos
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The neurovascular unit (NVU) underlines the complex and symbiotic relationship between brain cells and the cerebral vasculature, and dictates the need to consider both neurodegenerative and cerebrovascular diseases under the same mechanistic umbrella. Importantly, unlike peripheral organs, the brain was thought not to contain a dedicated lymphatics system. The glymphatic system concept (a portmanteau of glia and lymphatic) has further emphasized the importance of cerebrospinal fluid transport and emphasized its role as a mechanism for waste removal from the central nervous system. In this work, we outline a novel multiporoelastic solver which is embedded within a high precision, subject specific workflow that allows for the co-existence of a multitude of interconnected compartments with varying properties (multiple-network poroelastic theory, or MPET), that allow for the physiologically accurate representation of perfused brain tissue. This novel numerical template is based on a six-compartment MPET system (6-MPET) and is implemented through an in-house finite element code. The latter utilises the specificity of a high throughput imaging pipeline (which has been extended to incorporate the regional variation of mechanical properties) and blood flow variability model developed as part of the VPH-DARE@IT research platform. To exemplify the capability of this large-scale consolidated pipeline, a cognitively healthy subject is used to acquire novel, biomechanistically inspired biomarkers relating to primary and derivative variables of the 6-MPET system. These biomarkers are shown to capture the sophisticated nature of the NVU and the glymphatic system, paving the way for a potential route in deconvoluting the complexity associated with the likely interdependence of neurodegenerative and cerebrovascular diseases. The present study is the first, to the best of our knowledge, that casts and implements the 6-MPET equations in a 3D anatomically accurate brain geometry.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-10-20T09:30:56Z
      DOI: 10.1177/0954411920964630
       
  • Statistical ankle-shape and pressure analysis for design of elastic
           tubular bandage
    • Authors: Chunqiang Zhang, Xiaomin Ji, Yanmin Xue, Gang Hu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Ankles can benefit from the elastic tube bandage (ETB) by providing the ankle joint with compression, but partial high- or low-pressure leads to body discomfort. The aim of this paper is to propose a method for analyzing the ankle shape with the fabric compression which is basis on the comfortable pressure on human body. First, a standard model of ankle is established from the scanned data of 306 samples, and the mapping of the fabric shape curves on ankle were constructed by the U-direction convex curves of the model. The positions or areas of maximum and minimum pressure are then marked by extracting the curvatures of the fabric shape curves. According to the Laplace’s Law, the sizes of ETBs can be calculated given that the value of comfortable pressure on human body is the maximum one. The data of calculation is approximate to the relevant previous studies which has the same parameters of ETBs. Nine groups of the ankle shapes from the database are discussed, each group has a proportional coefficient to the standard model, and the result shows that six sizes of ETBs with comfort pressure match for the nine groups. These can be applied to the comfort design, and the method proposed can boost size customization of ETBs, as well as will inspire the research on other elastic compression garments.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-10-19T08:59:14Z
      DOI: 10.1177/0954411920965286
       
  • Biomechanical evaluation of the screw preload values used in the plate
           placement for bone fractures
    • Authors: Talip Çelik
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The purpose of this study is to examine the effects of screw preload values on the bone-plate system. The preload value was taken differently in the literature range from 50 N to 3000 N. These preload value were examined in this study. The finite element method was used to calculate the strain and stress on the models. The long bone, plate and screws were modeled as 3D using CAD software. The finite element models were created using Ansys Workbench software. The convergence and validation study were made for the correct results. The 400 N axial load was applied to the proximal end of bone. The distal end of the bone fixed for boundary condition. The preload values were applied to the screws differently. The results of the finite element analysis were compared and evaluated. The results showed that when the preload values increased, the von Mises stresses and strains on the bone and plate system increased. The critical preload value of the screw is the 500 N. The upper values of this critical value can be damaged bone and plate system. The critical region of the bone is the holes where the screw inserted. In conclusion, the preload values of the screw should not exceed the 500 N for the successful fixation.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-10-16T09:19:16Z
      DOI: 10.1177/0954411920964628
       
  • Does vacuum mixing affect diameter shrinkage of a PMMA cement mantle
           during in vitro cemented acetabulum implantation'
    • Authors: Alexander T Boote, Robert JA Bigsby, David J Deehan, Kenneth S Rankin, David C Swailes, Philip J Hyde
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Radiolucent lines on immediate postoperative cemented acetabular component radiographs between the PMMA bone cement mantle and bone are an indicator of an increased risk of early loosening. The cause of these lines has yet to be identified. Thermal and chemical necrosis, fluid interposition and cement shrinkage have all been suggested in the literature. The aim of the study reported here was to take an engineering approach – eliminating confounding variables present during surgery – to quantify the size of the interstice created by cement shrinkage when a 50 mm diameter flanged acetabular cup is implanted in a model acetabulum with a 52 mm hemispherical bore under controlled conditions using vacuum and non-vacuum mixed cement. Irrespective of the mixing method used, a significant interstice was created between the bone cement and the mock acetabulum. When the cement was mixed under vacuum the interstice created between the mock acetabulum and the cement mantle was 0.60 mm ± 0.09 mm; when the cement was mixed under non-vacuum conditions the interstice created was 0.39 mm ± 0.15 mm. Possible explanations for radiolucent lines are discussed.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-10-15T07:30:37Z
      DOI: 10.1177/0954411920964023
       
  • The relations between the stress in temporomandibular joints and the
           deviated distances for mandibular asymmetric patients
    • Authors: Jingheng Shu, Xin Xiong, Desmond YR Chong, Yang Liu, Zhan Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The study aimed to compare the difference of stress distributions in temporomandibular joints (TMJs) between the patients with mandibular asymmetry and asymptomatic subjects and find the relations between deviated distance and biomechanical stress using three-dimensional finite element method, to give guidance to dentists for correction of mandibular asymmetry. Ten facial symmetric subjects without symptoms of temporomandibular disorders (TMD) and 10 mandibular asymmetric patients were recruited and assigned as the Control and Case group respectively. The FE models of the mandible and maxilla were reconstructed from cone-beam computed tomography (CBCT) images. Muscle forces and boundary conditions were applied to the two groups corresponding to centric and anterior occlusions. The simulation manifested significant differences in stresses of the TMJs between the non-deviated and deviated sides in the Case group under the centric and anterior occlusions. The stresses in the Case group were significantly greater than those in the Control group, especially on the non-deviated side. Besides, there were weak and moderate correlations between the third principal stresses and deviated distances for the patients under centric and anterior occlusions. The excessive stresses in the TMJ of patients with mandibular asymmetry were associated with temporomandibular disorders.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-10-14T06:58:50Z
      DOI: 10.1177/0954411920962392
       
  • Physiological fluid mechanics research: A special Issue with a taster of
           forefront research
    • Authors: Ashraf W Khir, Patrick Segers
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.

      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-10-10T07:50:45Z
      DOI: 10.1177/0954411920959955
       
  • Contact patterns in the ankle joint after lateral ligamentous injury
           during internal rotation: A computational study
    • Authors: G Marta, C Quental, J Folgado, F Guerra-Pinto
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Lateral ankle instability, resulting from the inability of ankle ligaments to heal after injury, is believed to cause a change in the articular contact mechanics that may promote cartilage degeneration. Considering that lateral ligaments’ insufficiency has been related to rotational instability of the talus, and that few studies have addressed the contact mechanics under this condition, the aim of this work was to evaluate if a purely rotational ankle instability could cause non-physiological changes in contact pressures in the ankle joint cartilages using the finite element method. A finite element model of a healthy ankle joint, including bones, cartilages and nine ligaments, was developed. Pure internal talus rotations of 3.67°, 9.6° and 13.43°, measured experimentally for three ligamentous configurations, were applied. The ligamentous configurations consisted in a healthy condition, an injured condition in which the anterior talofibular ligament was cut, and an injured condition in which the anterior talofibular and calcaneofibular ligaments were cut. For all simulations, the contact areas and maximum contact pressures were evaluated for each cartilage. The results showed not only an increase of the maximum contact pressures in the ankle cartilages, but also novel contact regions at the anteromedial and posterolateral sections of the talar cartilage with increasing internal rotation. The anteromedial and posterolateral contact regions observed due to pathological internal rotations of the talus are a computational evidence that supports the link between a pure rotational instability and the pattern of pathological cartilaginous load seen in patients with long-term lateral chronic ankle instability.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-10-03T06:07:02Z
      DOI: 10.1177/0954411920960256
       
  • Impact of varying diastolic pressure fitting technique for the
           reservoir-wave model on wave intensity analysis
    • Authors: Nicola Pomella, Ernst R Rietzschel, Patrick Segers, Ashraf William Khir
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The reservoir-wave model assumes that the measured arterial pressure is made of two components: reservoir and excess. The effect of the reservoir volume should be excluded to quantify the effects of forward and backward traveling waves on blood pressure. Whilst the validity of the reservoir-wave concept is still debated, there is no consensus on the best fitting method for the calculation of the reservoir pressure waveform. Therefore, the aim of this parametric study is to examine the effects of varying the fitting technique on the calculation of reservoir and excess components of pressure and velocity waveforms. Common carotid pressure and flow velocity were measured using applanation tonometry and doppler ultrasound, respectively, in 1037 healthy humans collected randomly from the Asklepios population, aged 35 to 55 years old. Different fitting techniques to the diastolic decay of the measured arterial pressure were used to determine the asymptotic pressure decay, which in turn was used to determine the reservoir pressure waveform. The corresponding wave speed was determined using the PU-loop method, and wave intensity parameters were calculated and compared. Different fitting methods resulted in significant changes in the shape of the reservoir pressure waveform; however, its peak and time integral remained constant in this study. Although peak and integral of excess pressure, velocity components and wave intensity changed significantly with changing the diastolic decay fitting method, wave speed was not substantially modified. We conclude that wave speed, peak reservoir pressure and its time integral are independent of the diastolic pressure decay fitting techniques examined in this study. Therefore, these parameters are considered more reliable diagnostic indicators than excess pressure and velocity which are more sensitive to fitting techniques.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-30T09:23:31Z
      DOI: 10.1177/0954411920959957
       
  • Influence of outer geometry on primary stability for uncemented acetabular
           shells in developmental dysplasia of the hip
    • Authors: Kazuhiro Yoshida, Kensuke Fukushima, Rina Sakai, Katsufumi Uchiyama, Naonobu Takahira, Masanobu Ujihira
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Excellent primary stability of uncemented acetabular shells is essential to obtain successful clinical outcomes. However, in the case of developmental dysplasia of the hip (DDH), aseptic loosening may be induced by instability due to a decrease of the contact area between the acetabular shell and host bone. The aim of this study was to assess the primary stability of two commercially-available acetabular shells, hemispherical and hemielliptical, in normal and DDH models. Synthetic bone was reamed using appropriate surgical reamers for each reaming condition (normal acetabular model). The normal acetabular model was also cut diagonally at 40° to create a dysplasia model. Stability of the acetabular components was evaluated by the lever-out test. In the normal acetabular model conditions, the maximum primary stabilities of hemispherical and hemielliptical shells were observed in the 1-mm under- and 1-mm over-reamed conditions, respectively, and the resulting stabilities were comparable. The lateral defect in the dysplasia model had an adverse effect on the primary stabilities of the two designs. The lever-out moment of the hemielliptical acetabular shell was 1.4 times greater than that of the hemispherical acetabular shell in the dysplasia model. The hemispherical shell is useful for the normal acetabular condition, and the hemielliptical shell for the severe dysplasia condition, in the context of primary stability.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-30T09:23:08Z
      DOI: 10.1177/0954411920960000
       
  • Development of a smart-fit system for CPAP interface selection
    • Authors: Zhichao Ma, Philip Hyde, Michael Drinnan, Javier Munguia
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Continuous Positive Airway Pressure (CPAP) therapy is commonly prescribed for longstanding, acute cases of Obstructive Sleep Apnea (OSA) during which patients must wear a tight-fitting breathing mask overnight for the duration of the treatment. Because this condition frequently leads to the permanent use of CPAP masks, interface selection is a crucial factor influencing the treatment quality and effectiveness. Masks/interface selection is normally performed on a trial an error basis with clinicians informing their selection based on OSA-related factors with basic fitting feedback from patients. However, it is not uncommon for patients to abandon the treatment or request additional consultations due to ill-fitting CPAP mask with the main sources of discomfort being perceived air leakage and mask/strap overtightening leading to skin damage. This work introduces a novel system (Smart-Fit), for CPAP interface selection using advanced digital technologies, such as Reverse Engineering and Computational Modeling (Finite Element Analysis) which are paired to evaluate and determine the best fitting interface for each clinical case. The model simplifies the number of 3D facial landmarks to 12 and established that a 2 mm scan resolution is enough for accurate scans. The Von Mises stress map in ANSYS serves as an indicator of potential high-pressure areas, triggering the need for a chance of mask size. Current results indicate the Smart Fit System can enable a “best fit CPAP interface” to be selected considering individual’s physical characteristics and existing CPAP interface configurations. The development of the Smart Fit System is an evolution compared to traditional CPAP interface selection approach, which optimizes the CPAP interface selection process.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-29T05:22:26Z
      DOI: 10.1177/0954411920959879
       
  • Design and evaluation of a novel anti-reflux biliary stent with cone
           spiral valve
    • Authors: Yue Wang, Xiao-Fei Song, Yu-Shan Su, Xin-Sheng Xu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Endoscopic placement of biliary stent is a well-established palliative treatment for biliary obstruction. However, duodenobiliary reflux after stent placement has been a common problem which may lead to dreadful complications. This paper designed a novel anti-reflux biliary stent with a cone spiral valve. Fluid-Structure Interaction (FSI) simulations were established to evaluate the efficiency of the anti-reflux stent comparing with a clinically applied standard stent. According to the stress distribution of the valve, the fatigue performance in the stress concentration area was analyzed. The results show that when the antegrade flow through the valve, the cone spiral valve could stretch and open to realize adequate drainage under the normal physiological pressure of biliary tract; When the duodenal reflux through the valve, the valve would be compressed and close with a result of nearly zero at the outlet flow rate. Furthermore, the anti-reflux stent achieved improved radial mechanical performance with 2.7 times higher radial stiffness than standard stent. Finite element analysis (FEA) also indicates that compared with the standard stent, the addition of the anti-reflux valve had little negative effect on flexibility of the stent. Fatigue analysis results showed that the valve was reliable. This research provides the new stent with a cone spiral valve and proves that it is technically feasible and effective for preventing the duodenobiliary reflux while ensuring the antegrade bile flow without compromising the other biomechanical performances.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-29T05:22:06Z
      DOI: 10.1177/0954411920959986
       
  • Design and development of model eye for retina laser by using additive
           manufacturing
    • Authors: Arivazhagan Pugalendhi, Rajesh Ranganathan, Narendran Venkatapathy, Kalpana Narendran, Parag K Shah
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Surgical skill of the surgeon can be improved by surgical simulation. Especially in ophthalmology, it is impossible to use real human/non-human primate eyes for ophthalmology surgery practice. However, surgical practice is most important for ophthalmologist. The retina laser surgery is one of the ophthalmology surgeries and it requires more surgical practice for surgeons to use the laser beam precisely to coagulate and fuse small areas of tissue. Dealing with the prospect of vision reduction or vision loss presents a peculiar problem and that can be highly stressful and frustrating for both doctors and patients. In this regard, training for indirect ophthalmoscopy and retinal photocoagulation is undergone using model eyes instead of real eyes. Properties and functioning of an existing model eye are huge and they differ from real human eye such as casings are completely rigid and focusing of retinal fundus is not completely covered. Therefore, this research concentrates to develop a model eye that assimilates close to the human eye by focussing on the maximum viewing area that is not done at the moment. Finally, the design and development of re-engineered model eye for retina laser is fabricated by additive manufacturing. Compared to existing plastic model eye, viewing area and viewing angle of the re-engineered model eye is increased by 16.66% and 6.14%, respectively. Due to design modifications and elimination of the insert, it can be reduced by 18.99% and 13.95% of height and weight of the top casing respectively. Developed re-engineered model eye will improve the surgical and diagnostic skill of the surgeon and increase their confidence and proficiency. It also augments the effective use of essential ophthalmic instruments. Additionally, it can reduce the surgical error and meet the existing demand of actual eyes for surgical practices.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-29T05:20:41Z
      DOI: 10.1177/0954411920960548
       
  • Fabrication, characterization, and in vivo biocompatibility evaluation of
           titanium-niobium implants
    • Authors: Abdurrahman Yolun, Murat Şimşek, Mehmet Kaya, Ebru Elibol Annaç, Mustafa Köm, Ömer Çakmak
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      In this study, biocompatible titanium-niobium (Ti-Nb) alloys were fabricated by using powder metallurgy methods. Physical, morphological, thermal, and mechanical analyses were performed and their in vivo compatibility was evaluated. Besides α, β, and α″ martensitic phases, α+β Widmanstätten phase due to increasing sintering temperature was seen in the microstructure of the alloys. Phase transformation temperatures of the samples decreased as Nb content increased. The ratio of Nb in the samples affected their mechanical properties. No toxic effect was observed on implanted sites. This study shows that Ti-Nb alloys can be potentially used for orthopedic applications without any toxic effects.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-29T05:20:23Z
      DOI: 10.1177/0954411920960854
       
  • Multi-modal infusion pump real-time monitoring technique for improvement
           in safety of intravenous-administration patients
    • Authors: Young Jun Hwang, Gun Ho Kim, Eui Suk Sung, Kyoung Won Nam
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Intravenous (IV) medication administration processes have been considered as high-risk steps, because accidents during IV administration can lead to serious adverse effects, which can deteriorate the therapeutic effect or threaten the patient’s life. In this study, we propose a multi-modal infusion pump (IP) monitoring technique, which can detect mismatches between the IP setting and actual infusion state and between the IP setting and doctor’s prescription in real time using a thin membrane potentiometer and convolutional-neural-network-based deep learning technique. During performance evaluation, the percentage errors between the reference infusion rate (IR) and average estimated IR were in the range of 0.50–2.55%, while those between the average actual IR and average estimated IR were in the range of 0.22–2.90%. In addition, the training, validation, and test accuracies of the implemented deep learning model after training were 98.3%, 97.7%, and 98.5%, respectively. The training and validation losses were 0.33 and 0.36, respectively. According to these experimental results, the proposed technique could provide improved protection functions to IV-administration patients.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-25T08:01:36Z
      DOI: 10.1177/0954411920960260
       
  • An engineering perspective of vacuum assisted delivery devices in
           obstetrics: A review
    • Authors: Dushyant Goordyal, John Anderson, Ali Alazmani, Peter Culmer
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Complications during childbirth result in the need for clinicians to use ‘assisted delivery’ in over 12% of cases (UK). After more than 50 years in clinical practice, vacuum assisted delivery (VAD) devices remain a mainstay in physically assisting child delivery; sometimes preferred over forceps due to their ease of use and reduced maternal morbidity. Despite their popularity and enduring track-record, VAD devices have shown little evidence of innovation or design change since their inception. In addition, evidence on the safety and functionality of VAD devices remains limited but does present opportunities for improvements to reduce adverse clinical outcomes. Consequently in this review we examine the literature and patent landscape surrounding VAD biomechanics, design evolution and performance from an engineering perspective, aiming to collate the limited but valuable information from a disparate field and provide a series of recommendations to inform future research into improved, safer, VAD systems.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-15T07:23:53Z
      DOI: 10.1177/0954411920956467
       
  • Wearable sensing devices for upper limbs: A systematic review
    • Authors: Mingjie Dong, Bin Fang, Jianfeng Li, Fuchun Sun, Huaping Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Wearable sensing devices, which are smart electronic devices that can be worn on the body as implants or accessories, have attracted much research interest in recent years. They are rapidly advancing in terms of technology, functionality, size, and real-time applications along with the fast development of manufacturing technologies and sensor technologies. By covering some of the most important technologies and algorithms of wearable devices, this paper is intended to provide an overview of upper-limb wearable device research and to explore future research trends. The review of the state-of-the-art of upper-limb wearable technologies involving wearable design, sensor technologies, wearable computing algorithms and wearable applications is presented along with a summary of their advantages and disadvantages. Toward the end of this paper, we highlight areas of future research potential. It is our goal that this review will guide future researchers to develop better wearable sensing devices for upper limbs.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-04T09:13:12Z
      DOI: 10.1177/0954411920953031
       
  • Experimental study of the optimum puncture pattern of robot-assisted
           needle insertion into hyperelastic materials
    • Authors: Yao Wang, Zhuang Fu, Zhi-Feng Zhao, Yun Shen, Tie-Feng Zhang, Wei-Yi Shi, Jian Fei, Guang-Biao Chen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The robot-assisted insertion surgery plays a crucial role in biopsy and therapy. This study focuses on determining the optimum puncture pattern for robot-assisted insertion, aiming at the matching problem of needle insertion parameters, thereby to reduce the pain for patients and to improve the reachability to the lesion point. First, a 6-degrees of freedom (DOFs) Computed Tomography (CT)-guided surgical robotic system for minimally invasive percutaneous lung is developed and used to perform puncture experiments. The effects of four main insertion factors on the robotic puncture are verified by designing the orthogonal test, where the inserting object is the artificial skin-like specimen with high transparent property and a digital image processing method is used to analyze the needle tip deflection. Next, the various phases of puncture process are divided and analyzed in detail in view of the tissue deformation and puncture force. Then, short discussion on the comparison of puncture force with different effect factors for the same beveled needle is presented. The same pattern can be observed for all of the cases. Finally, based on the experimental data, the formulations of the puncture force and needle deflection which depends on Gauge size, insertion velocity, insertion angle, and insertion depth are developed using the multiple regression method, which can be used to get an optimum puncture pattern under the constrains of minimum peak force and minimum needle tip deflection. The developed models have the effectiveness and applicability on determining the optimum puncture pattern for one puncture event, and which can also provide insights useful for the setting of insertion parameters in clinical practice.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-09-02T07:20:26Z
      DOI: 10.1177/0954411920950904
       
  • Finite element modelling of hybrid stabilization systems for the human
           lumbar spine
    • Authors: Eylül Demir, Peter Eltes, Andre PG Castro, Damien Lacroix, İhsan Toktaş
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Intersomatic fusion is a very popular treatment for spinal diseases associated with intervertebral disc degeneration. The effects of three different hybrid stabilization systems on both range of motion and intradiscal pressure were investigated, as there is no consensus in the literature about the efficiency of these systems. Finite element simulations were designed to predict the variations of range of motion and intradiscal pressure from intact to implanted situations. After hybrid stabilization system implantation, L4-L5 level did not lose its motion completely, while L5-S1 had no mobility as a consequence of disc removal and fusion process. BalanC hybrid stabilization system represented higher mobility at the index level, reduced intradiscal pressure of adjacent level, but caused to increment in range of motion by 20% under axial rotation. Higher tendency by 93% to the failure was also detected under axial rotation. Dynesys hybrid stabilization system represented more restricted motion than BalanC, and negligible effects to the adjacent level. B-DYN hybrid stabilization system was the most rigid one among all three systems. It reduced intradiscal pressure and range of motion at the adjacent level except from motion under axial rotation being increased by 13%. Fracture risk of B-DYN and Dynesys Transition Optima components was low when compared with BalanC. Mobility of the adjacent level around axial direction should be taken into account in case of implantation with BalanC and B-DYN systems, as well as on the development of new designs. Having these findings in mind, it is clear that hybrid systems need to be further tested, both clinically and numerically, before being considered for common use.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-19T05:05:05Z
      DOI: 10.1177/0954411920946636
       
  • Comparison of femur strain under different loading scenarios: Experimental
           testing
    • Authors: Ievgen Levadnyi, Jan Awrejcewicz, Yan Zhang, Yaodong Gu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Bone fracture, formation and adaptation are related to mechanical strains in bone. Assessing bone stiffness and strain distribution under different loading conditions may help predict diseases and improve surgical results by determining the best conditions for long-term functioning of bone-implant systems. In this study, an experimentally wide range of loading conditions (56) was used to cover the directional range spanned by the hip joint force. Loads for different stance configurations were applied to composite femurs and assessed in a material testing machine. The experimental analysis provides a better understanding of the influence of the bone inclination angle in the frontal and sagittal planes on strain distribution and stiffness. The results show that the surface strain magnitude and stiffness vary significantly under different loading conditions. For the axial compression, maximal bending is observed at the mid-shaft, and bone stiffness is also maximal. The increased inclination leads to decreased stiffness and increased magnitude of maximum strain at the distal end of the femur. For comparative analysis of results, a three-dimensional, finite element model of the femur was used. To validate the finite element model, strain gauges and digital image correlation system were employed. During validation of the model, regression analysis indicated robust agreement between the measured and predicted strains, with high correlation coefficient and low root-mean-square error of the estimate. The results of stiffnesses obtained from multi-loading conditions experiments were qualitatively compared with results obtained from a finite element analysis of the validated model of femur with the same multi-loading conditions. When the obtained numerical results are qualitatively compared with experimental ones, similarities can be noted. The developed finite element model of femur may be used as a promising tool to estimate proximal femur strength and identify the best conditions for long-term functioning of the bone-implant system in future study.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-19T05:05:02Z
      DOI: 10.1177/0954411920951033
       
  • Concussion and the severity of head impacts in mixed martial arts
    • Authors: Stephen Tiernan, Aidan Meagher, David O’Sullivan, Eoin O’Keeffe, Eoin Kelly, Eugene Wallace, Colin P Doherty, Matthew Campbell, Yuzhe Liu, August G Domel
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Concern about the consequences of head impacts in US football has motivated researchers to investigate and develop instrumentation to measure the severity of these impacts. However, the severity of head impacts in unhelmeted sports is largely unknown as miniaturised sensor technology has only recently made it possible to measure these impacts in vivo. The objective of this study was to measure the linear and angular head accelerations in impacts in mixed martial arts, and correlate these with concussive injuries. Thirteen mixed martial arts fighters were fitted with the Stanford instrumented mouthguard (MiG2.0) participated in this study. The mouthguard recorded linear acceleration and angular velocity in 6 degrees of freedom. Angular acceleration was calculated by differentiation. All events were video recorded, time stamped and reported impacts confirmed. A total of 451 verified head impacts above 10g were recorded during 19 sparring events (n = 298) and 11 competitive events (n = 153). The average resultant linear acceleration was 38.0624.3g while the average resultant angular acceleration was 256761739 rad/s2. The competitive bouts resulted in five concussions being diagnosed by a medical doctor. The average resultant acceleration (of the impact with the highest angular acceleration) in these bouts was 86.7618.7g and 756163438 rad/s2. The average maximum Head Impact Power was 20.6kW in the case of concussion and 7.15kW for the uninjured athletes. In conclusion, the study recorded novel data for sub-concussive and concussive impacts. Events that resulted in a concussion had an average maximum angular acceleration that was 24.7% higher and an average maximum Head Impact Power that was 189% higher than events where there was no injury. The findings are significant in understanding the human tolerance to short-duration, high linear and angular accelerations.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-16T01:40:28Z
      DOI: 10.1177/0954411920947850
       
  • Design and control of a lower limb rehabilitation robot considering
           undesirable torques of the patient’s limb
    • Authors: Karam Almaghout, Bahram Tarvirdizadeh, Khalil Alipour, Alireza Hadi
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      This research introduces a new exoskeleton-type rehabilitation robot, which can be used in lower limb rehabilitation therapy for post-stroke patients. A novel design of a typical knee and ankle rehabilitation robot is proposed. The kinematic and dynamic models of the knee and ankle rehabilitation robot are derived. Furthermore, a super-twisting nonsingular terminal sliding mode control is developed to achieve the desired training missions and its results are compared with those of an adaptive sliding mode control. To reduce undesired interaction torques between knee and ankle rehabilitation robot and patient, an admittance control algorithm is added to the controller to guarantee a safe therapy session. The admittance super-twisting nonsingular terminal sliding mode control structure is considered as the novelty of this article. Taking into account the dynamic uncertainties, external disturbances, and the interaction torques, the validity of the admittance super-twisting nonsingular terminal sliding mode control controller is approved by various numerical simulations over the admittance adaptive sliding mode control.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-11T07:13:24Z
      DOI: 10.1177/0954411920947849
       
  • An in vitro assessment of atrial fibrillation flow types on cardiogenic
           emboli trajectory paths
    • Authors: Fiona Malone, Eugene McCarthy, Patrick Delassus, Jan-Hendrick Buhk, Jens Fiehler, Liam Morris
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Atrial fibrillation is the most significant contributor to thrombus formation within the heart and is responsible for 45% of all cardio embolic strokes, which account for approximately 15% of acute ischemic strokes cases worldwide. Atrial fibrillation can result in a reduction of normal cardiac output and cycle length of up to 30% and 40%, respectively. A total of 240 embolus analogues were released into a thin-walled, patient-specific aortic arch under normal (60 embolus analogues) and varying atrial fibrillation (180 embolus analogues) pulsatile flow conditions. Under healthy flow conditions (n = 60), the embolus analogues tended to follow the flow rate split through each outlet vessel. There was an increase in clot trajectories along the common carotid arteries under atrial fibrillation flow conditions. A shorter pulse period (0.3 s) displayed the highest percentage of clots travelling to the brain (24%), with a greater percentage of clots travelling through the left common carotid artery (17%). This study provides an experimental insight into the effect varying cardiac output and cycle length can have on the trajectory of a cardiac source blood clots travelling to the cerebral vasculature and possibly causing a stroke.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-05T12:18:04Z
      DOI: 10.1177/0954411920946873
       
  • Haemodynamic mechanism of formation and distribution of coronary
           atherosclerosis: A lesion-specific model
    • Authors: Jiling Feng, Nannan Wang, Yiliang Wang, Xiaoxian Tang, Jie Yuan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Coronary arterial disease, as the most devastated cardiovascular disease, is caused by the atherosclerosis in the coronary arteries, which blocks the blood flow to the heart, resulting in the deficient supply of oxygen and nutrition to the heart, and eventually leading to heart failure. To date, haemodynamic mechanisms for atherosclerosis development are not fully understood although it is believed that the haemodynamic disturbance at the region of the arterial bifurcation, particular, bifurcation angle, plays an important role in the atherosclerosis development. In this study, two types of computational fluid dynamics models, lesion-specific and idealized models, combined with the computer tomography imaging techniques, are used to explore the mechanism of formation and distribution of the atherosclerosis around the bifurcation of left coronary artery and its association with the bifurcation angle. The lesion-specific model is used to characterize the effect of personalized features on the haemodynamic performance, while the idealized model is focusing on the effect of single factor, bifurcation angle, on the haemodynamic performance. The simulated results from both types of the models, combined with the clinical observation, revealed that the three key areas around the bifurcations are prone to formation of the atherosclerosis. Unlike the idealized models, lesion-specific modelling results did not show the significant correlation between the wall shear stress and bifurcation angle, although the mean value of the wall shear stress in smaller bifurcation angles (less than 90°) is higher than that with larger bifurcation angles (greater than 90°). In conclusion, lesion-specific computational fluid dynamics modelling is an efficient and convenient way to predict the haemodynamic performance around the bifurcation region, allowing the comprehensive information for the clinicians to predict the atherosclerosis development. The idealized models, which only focus on single parameter, may not provide the sufficient and reliable information for the clinical application. A novel multi-parameters modelling technique, therefore, is suggested to be developed in future, allowing the effects of many parameters on the haemodynamic performance to be evaluated.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-04T09:14:15Z
      DOI: 10.1177/0954411920947972
       
  • Artificial intelligence approaches to predict coronary stenosis severity
           using non-invasive fractional flow reserve
    • Authors: Jason M Carson, Neeraj Kavan Chakshu, Igor Sazonov, Perumal Nithiarasu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Fractional flow reserve is the current reference standard in the assessment of the functional impact of a stenosis in coronary heart disease. In this study, three models of artificial intelligence of varying degrees of complexity were compared to fractional flow reserve measurements. The three models are the multivariate polynomial regression, which is a statistical method used primarily for correlation; the feed-forward neural network; and the long short-term memory, which is a type of recurrent neural network that is suited to modelling sequences. The models were initially trained using a virtual patient database that was generated from a validated one-dimensional physics-based model. The feed-forward neural network performed the best for all test cases considered, which were a single vessel case from a virtual patient database, a multi-vessel network from a virtual patient database, and 25 clinically invasive fractional flow reserve measurements from real patients. The feed-forward neural network model achieved around 99% diagnostic accuracy in both tests involving virtual patients, and a respectable 72% diagnostic accuracy when compared to the invasive fractional flow reserve measurements. The multivariate polynomial regression model performed well in the single vessel case, but struggled on network cases as the variation of input features was much larger. The long short-term memory performed well for the single vessel cases, but tended to have a bias towards a positive fractional flow reserve prediction for the virtual multi-vessel case, and for the patient cases. Overall, the feed-forward neural network shows promise in successfully predicting fractional flow reserve in real patients, and could be a viable option if trained using a large enough data set of real patients.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-03T08:36:03Z
      DOI: 10.1177/0954411920946526
       
  • Leveraging subject-specific musculoskeletal modeling to assess effect of
           anterior cruciate ligament retaining total knee arthroplasty during
           walking gait
    • Authors: Qida Zhang, Zhenxian Chen, Zhifeng Zhang, Zhongmin Jin, Orhun K Muratoglu, Kartik M Varadarajan
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Bi-cruciate retaining total knee arthroplasty has several potential advantages including improved anteroposterior knee stability compared to contemporary posterior cruciate-retaining total knee arthroplasty. However, few studies have explored whether there is significant differences of knee biomechanics following bi-cruciate retaining total knee arthroplasty compared to posterior cruciate-retaining total knee arthroplasty. In the present study, subject-specific lower extremity musculoskeletal multi-body dynamics models for bi-cruciate retaining, bi-cruciate retaining without anterior cruciate ligament, and posterior cruciate-retaining total knee arthroplasty were developed based on the musculoskeletal modeling framework using force-dependent kinematics method and validated against in vivo telemetric data. The experiment data of two subjects who underwent total knee arthroplasty were obtained for the SimTK “Grand Challenge Competition” repository, and integrated into the musculoskeletal model. Five walking gait trials for each subject were used as partial inputs for the model to predict the knee biomechanics for bi-cruciate retaining, bi-cruciate retaining without anterior cruciate ligament, and posterior cruciate-retaining total knee arthroplasty. The results revealed significantly greater range of anterior/posterior tibiofemoral translation, and significantly more posterior tibial location during the early phase of gait and more anterior tibial location during the late phase of gait were found in bi-cruciate retaining total knee arthroplasty without anterior cruciate ligament when compared to the bi-cruciate retaining total knee arthroplasty. No significant differences in tibiofemoral contact forces, rotations, translations, and ligament forces between bi-cruciate retaining and posterior cruciate-retaining total knee arthroplasty during normal walking gait, albeit slight differences in range of tibiofemoral internal/external rotation and anterior/posterior translation were observed. The present study revealed that anterior cruciate ligament retention has a positive effect on restoring normal knee kinematics in bi-cruciate retaining total knee arthroplasty. Preservation of anterior cruciate ligament in total knee arthroplasty and knee implant designs interplay each other and both contribute to restoring normal knee kinematics in different types of total knee arthroplasty. Further evaluation of more demanding activities and subject data from patients with bi-cruciate retaining and posterior cruciate-retaining total knee arthroplasty via musculoskeletal modeling may better highlight the role of the anterior cruciate ligament and its stabilizing influence.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-03T08:35:43Z
      DOI: 10.1177/0954411920947204
       
  • Predicting ground reaction and tibiotalar contact forces after total ankle
           arthroplasty during walking
    • Authors: Yanwei Zhang, Zhenxian Chen, Yinghu Peng, Hongmou Zhao, Xiaojun Liang, Zhongmin Jin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The motion capture and force plates data are essential inputs for musculoskeletal multibody dynamics models to predict in vivo tibiotalar contact forces. However, it could be almost impossible to obtain valid force plates data in old patients undergoing total ankle arthroplasty under some circumstances, such as smaller gait strides and inconsistent walking speeds during gait analysis. To remove the dependence of force plates, this study has established a patient-specific musculoskeletal multibody dynamics model with total ankle arthroplasty by combining a foot-ground contact model based on elastic contact elements. And the established model could predict ground reaction forces, ground reaction moments and tibiotalar contact forces simultaneously. Three patients’ motion capture and force plates data during their normal walking were used to establish the patient-specific musculoskeletal models and evaluate the predicted ground reaction forces and ground reaction moments. Reasonable accuracies were achieved for the predicted and measured ground reaction forces and ground reaction moments. The predicted tibiotalar contact forces for all patients using the foot-ground contact model had good consistency with those using force plates data. These findings suggested that the foot-ground contact model could take the place of the force plates data for predicting the tibiotalar contact forces in other total ankle arthroplasty patients, thus providing a simplified and valid platform for further study of the patient-specific prosthetic designs and clinical problems of total ankle arthroplasty in the absence of force plates data.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-08-03T08:35:13Z
      DOI: 10.1177/0954411920947208
       
  • Orthodontic force prediction model of T-loop closing spring based on
           dynamic resistance model
    • Authors: Jingang Jiang, Houjun Chen, Zhiyuan Huang, Xuefeng Ma, Yongde Zhang, Yi Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Malocclusion has been seriously endangering human oral function. The most effective and mature therapy is orthodontic treatment. But the relationship between the shape of the T-loop and the orthodontic force is unclear, and the precise mathematical model has not been established. In this article, the dynamic orthodontic force prediction model of the T-loop was established by analyzing the treatment process of the T-loop. The model was based on the dynamic resistance model of waxy dental jaw, the theory of beam deformation, and the deformation characteristics of the T-loop. In the experimental process, 11 kinds of orthodontic archwires were used as experimental samples, including 2 kinds of common archwire materials, 7 kinds of cross-sectional sizes, and 10 kinds of clearance distances. The T-loop was put into the extraction space and immersed in 75°C constant temperature water for 2 min. And the experimental data were measured and collected by the dynamic force measuring device. The experimental results show that the cross-sectional size and the clearance distance are positively correlated with the orthodontic force. The influence of the clearance distance on the orthodontic force is greater than that of the cross-section size. The deviation rates between the experimental values of orthodontic force and the theoretical values are between 1.10% and 9.09%, which verifies the accuracy of the dynamic orthodontic force prediction model. The model can predict the orthodontic force, improve the treatment effect, shorten the treatment cycle, and provide reference and guidance for orthodontists to carry out orthodontic treatment safely and effectively.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-30T11:42:01Z
      DOI: 10.1177/0954411920943433
       
  • Influence of patellar implantation on the patellofemoral joint of an
           anatomic customised total knee replacement implant: A case study
    • Authors: Linjie Wang, Chang Jiang Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Few studies have been conducted to investigate kinematics and kinetics of the patellofemoral joint under physiological muscle forces and ankle joint loads. In this study, a preliminary design of a customised total knee implant was proposed and created. To compare the influences of different patella treatment scenarios, a dynamic knee simulation model was created with patient-specific muscle forces and ankle joint loads that are calculated from an OpenSim musculoskeletal model. The goal is to improve patellar implant-bone connection and restore patellofemoral joint mobility. Identical dynamic boundary conditions were applied on an unresurfaced patella and three different dome-shaped patellar implants. It was found that the unresurfaced patella and patellar implants resulted in different motions of patellar internal rotation and medial tilt. The size of the dome-shaped patellar implant affected the motion and loading of the patellofemoral joint. When the exposed patella bone was not fully covered by the patellar implant, the patella bone then contacted the femoral component during knee flexion. This would most likely lead to anterior knee pain and subsequent revision.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-29T10:56:22Z
      DOI: 10.1177/0954411920941400
       
  • Structural and hemodynamic properties of murine pulmonary arterial
           networks under hypoxia-induced pulmonary hypertension
    • Authors: Megan J Chambers, Mitchel J Colebank, M Umar Qureshi, Rachel Clipp, Mette S Olufsen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Detection and monitoring of patients with pulmonary hypertension, defined as a mean blood pressure in the main pulmonary artery above 25 mmHg, requires a combination of imaging and hemodynamic measurements. This study demonstrates how to combine imaging data from microcomputed tomography images with hemodynamic pressure and flow waveforms from control and hypertensive mice. Specific attention is devoted to developing a tool that processes computed tomography images, generating subject-specific arterial networks in which one-dimensional fluid dynamics modeling is used to predict blood pressure and flow. Each arterial network is modeled as a directed graph representing vessels along the principal pathway to ensure perfusion of all lobes. The one-dimensional model couples these networks with structured tree boundary conditions representing the small arteries and arterioles. Fluid dynamics equations are solved in this network and compared to measurements of pressure in the main pulmonary artery. Analysis of microcomputed tomography images reveals that the branching ratio is the same in the control and hypertensive animals, but that the vessel length-to-radius ratio is significantly lower in the hypertensive animals. Fluid dynamics predictions show that in addition to changed network geometry, vessel stiffness is higher in the hypertensive animal models than in the control models.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-28T09:59:11Z
      DOI: 10.1177/0954411920944110
       
  • Rapid prototyping of custom radiocontrast agent markers for computed
           tomography–guided procedures
    • Authors: Rui Li, Austin J Taylor, Zion Tsz Ho Tse
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The objective of this study was to evaluate a method for printing a custom radiocontrast agent mixture to develop computed tomography markers of various shapes and sizes for assisting physicians in computed tomography–guided procedures. The radiocontrast agent mixture was designed to be bright in a computed tomography image, able to be extruded from a nozzle as a liquid and transition into a solid, and sufficiently viscous to be extruded through the tip of a needle in a controlled manner. A mixture printing method was developed using a syringe to house the mixture, a syringe pump to extrude the mixture, and a computer numeric control laser cutter to direct the nozzle in the desired path. To assess the efficacy of printing the radiocontrast agent mixture, we printed several designs, collected computed tomography images, and evaluated various physical properties of the printing method and the resulting computed tomography markers. The average line thickness was 1.56 mm (standard deviation of 0.19 mm, n = 30), the infill percentage was 99.9%, and the deviation in roundness was 0.23 mm (n = 30). These results demonstrated the ability of the proposed method to create various types of skin markers, such as dots, lines, and hollow or solid shapes. Additionally, flat printed patterns can be folded to form three-dimensional structures that can be used to guide and support needle insertions.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-28T09:59:07Z
      DOI: 10.1177/0954411920940840
       
  • Computational modeling of media flow through perfusion-based bioreactors
           for bone tissue engineering
    • Authors: Hanieh Nokhbatolfoghahaei, Mahboubeh Bohlouli, Kazem Adavi, Zahrasadat Paknejad, Maryam Rezai Rad, Mohammad Mehdi khani, Nasim Salehi-Nik, Arash Khojasteh
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Bioreactor system has been used in bone tissue engineering in order to simulate dynamic nature of bone tissue environments. Perfusion bioreactors have been reported as the most efficient types of shear-loading bioreactor. Also, combination of forces, such as rotation plus perfusion, has been reported to enhance cell growth and osteogenic differentiation. Mathematical modeling using sophisticated infrastructure processes could be helpful and streamline the development of functional grafts by estimating and defining an effective range of bioreactor settings for better augmentation of tissue engineering. This study is aimed to conduct computational modeling for newly designed bioreactors in order to alleviate the time and material consuming for evaluating bioreactor parameters and effect of fluid flow hydrodynamics (various amounts of shear stress) on osteogenesis. Also, biological assessments were performed in order to validate similar parameters under implementing the perfusion or rotating and perfusion fluid motions in bioreactors’ prototype. Finite element method was used to investigate the effect of hydrodynamic of fluid flow inside the bioreactors. The equations used in the simulation to calculate the velocity values and consequently the shear stress values include Navier–Stokes and Brinkman equations. It has been shown that rotational fluid motion in rotating and perfusion bioreactor produces more velocity and shear stress compared with perfusion bioreactor. Moreover, implementing the perfusion together with rotational force in rotating and perfusion bioreactors has been shown to have more cell proliferation and higher activity of alkaline phosphatase enzyme as well as formation of extra cellular matrix sheet, as an indicator of bone-like tissue formation.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-21T12:50:29Z
      DOI: 10.1177/0954411920944039
       
  • Simulating re-reflections of arterial pressure waves at the aortic valve
           using difference equations
    • Authors: Bernhard Hametner, Hannah Kastinger, Siegfried Wassertheurer
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Re-reflections of arterial pressure waves at the aortic valve and their influence on aortic wave shape are only poorly understood so far. Therefore, the aim of this work is to establish a model enabling the simulation of re-reflection and to test its properties. A mathematical difference equation model is used for the simulations. In this model, the aortic blood pressure is split into its forward and backward components which are calculated separately. The respective equations include reflection percentages representing reflections throughout the arterial system and a reflection coefficient at the aortic valve. While the distal reflections are fixed, different scenarios for the reflection coefficient at the valve are simulated. The results show that the model is capable to provide physiological pressure curves only if re-reflections are assumed to be present during the whole cardiac cycle. The sensitivity analysis on the reflection coefficient at the aortic valve shows various effects of re-reflections on the modelled blood pressure curve. Higher levels of the reflection coefficient lead to higher systolic and diastolic pressure values. The augmentation index is notably influenced by the systolic level of the reflection coefficient. This difference equation model gives an adequate possibility to simulate aortic pressure incorporating re-reflections at the site of the aortic valve. Since a strong dependence of the aortic pressure wave on the choice of the reflection coefficient have been found, this indicates that re-reflections should be incorporated into models of wave transmission. Furthermore, re-reflections may also be considered in methods of arterial pulse wave analysis.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-20T09:34:29Z
      DOI: 10.1177/0954411920942704
       
  • Hemodynamic performance of a compact centrifugal left ventricular assist
           device with fully magnetic levitation under pulsatile operation: An in
           vitro study
    • Authors: Tingting Wu, Hao Lin, Yuxin Zhu, Penghui Huang, Frank Lin, Chen Chen, Po-Lin Hsu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Long-term using continuous flow ventricular assist devices could trigger complications associated with diminished pulsatility, such as valve insufficiency and gastrointestinal bleeding. One feasible solution is to produce pulsatile flow assist with speed regulation in continuous flow ventricular assist devices. A third-generation blood pump with pulsatile operation control algorithm was first characterized alone under pulsatile mode at various speeds, amplitudes, and waveforms. The pump was then incorporated in a Mock circulation system to evaluate in vitro hemodynamic effects when using continuous and different pulsatile operations. Pulsatility was evaluated by surplus hemodynamic energy. Results showed that pulsatile operations provided sufficient hemodynamic assistance and increased pulsatility of the circulatory system (53% increment), the mean aortic pressure (65% increment), and cardiac output (27% increment). The pulsatility of the system under pulsatile operation support was increased 147% compared with continuous operation support. The hemodynamic performance of pulsatile operations is susceptible to phase shifts, which could be a tacking angle for physiological control optimization. This study found third-generation blood pumps using different pulsatile operations for ventricular assistance promising.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-11T06:14:30Z
      DOI: 10.1177/0954411920937919
       
  • Comparison of arterial wave intensity analysis by pressure–velocity and
           diameter–velocity methods in a virtual population of adult subjects
    • Authors: Ryan M Reavette, Spencer J Sherwin, Mengxing Tang, Peter D Weinberg
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Pressure–velocity-based analysis of arterial wave intensity gives clinically relevant information about the performance of the heart and vessels, but its utility is limited because accurate pressure measurements can only be obtained invasively. Diameter–velocity-based wave intensity can be obtained noninvasively using ultrasound; however, due to the nonlinear relationship between blood pressure and arterial diameter, the two wave intensities might give disparate clinical indications. To test the magnitude of the disagreement, we have generated an age-stratified virtual population to investigate how the two dominant nonlinearities ‘viscoelasticity and strain-stiffening’ cause the two formulations to differ. We found strong agreement between the pressure–velocity and diameter–velocity methods, particularly for the systolic wave energy, the ratio between systolic and diastolic wave heights, and older subjects. The results are promising regarding the introduction of noninvasive wave intensities in the clinic.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-11T06:13:50Z
      DOI: 10.1177/0954411920926094
       
  • Analysis of the surface topography of retrieved metal-on-polyethylene
           reverse shoulder prostheses
    • Authors: Israel Ramírez-Martínez, Susanna Stea, Thomas J. Joyce
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Despite the encouraging short- and medium-term clinical results and increased usage of reverse shoulder replacements, a higher revision rate is documented compared with other major joint arthroplasties. Adverse reaction to polyethylene wear debris is still an important factor which may influence the long-term survival of reverse shoulder arthroplasty. To date, only a small number of retrieval studies of reverse shoulder arthroplasty have reported the different damage modes on polyethylene components, but none have quantified the ex vivo surface roughness on both articulating surfaces. The main purpose of this study was to assess, for the first time, the surface roughness of 13 retrieved metal-on-polyethylene reverse shoulder replacements using a white light profilometre with nanometre resolution. Although no significant relationship was observed between the surface roughness values and patient variables, it was noted that half of the polyethylene components still showed their original machining marks, indicating little change in vivo and that the metallic humeral components in the reversed design configuration showed low values of surface roughness after their time in vivo.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-01T07:32:30Z
      DOI: 10.1177/0954411920935757
       
  • Arteriovenous fistula maturation and the influence of fluid dynamics
    • Authors: Eamonn Colley, Anne Simmons, Ramon Varcoe, Shannon Thomas, Tracie Barber
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Arteriovenous fistula creation is the preferred vascular access for haemodialysis therapy, but has a large failure rate in the maturation period. This period generally lasts 6 to 8 weeks after surgical creation, in which the vein and artery undergo extensive vascular remodelling. In this review, we outline proposed mechanisms for both arteriovenous fistula maturation and arteriovenous fistula failure. Clinical, animal and computational studies have not yet shown a definitive link between any metric and disease development, although a number of theories based on wall shear stress metrics have been suggested. Recent work allowing patient-based longitudinal studies may hold the key to understanding arteriovenous fistula maturation processes.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-06-27T10:26:11Z
      DOI: 10.1177/0954411920926077
       
  • Exploring wall shear stress spatiotemporal heterogeneity in coronary
           arteries combining correlation-based analysis and complex networks with
           computational hemodynamics
    • Authors: Karol Calò, Giuseppe De Nisco, Diego Gallo, Claudio Chiastra, Ayla Hoogendoorn, David A Steinman, Stefania Scarsoglio, Jolanda J Wentzel, Umberto Morbiducci
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Atherosclerosis at the early stage in coronary arteries has been associated with low cycle-average wall shear stress magnitude. However, parallel to the identification of an established active role for low wall shear stress in the onset/progression of the atherosclerotic disease, a weak association between lesions localization and low/oscillatory wall shear stress has been observed. In the attempt to fully identify the wall shear stress phenotype triggering early atherosclerosis in coronary arteries, this exploratory study aims at enriching the characterization of wall shear stress emerging features combining correlation-based analysis and complex networks theory with computational hemodynamics. The final goal is the characterization of the spatiotemporal and topological heterogeneity of wall shear stress waveforms along the cardiac cycle. In detail, here time-histories of wall shear stress magnitude and wall shear stress projection along the main flow direction and orthogonal to it (a measure of wall shear stress multidirectionality) are analyzed in a representative dataset of 10 left anterior descending pig coronary artery computational hemodynamics models. Among the main findings, we report that the proposed analysis quantitatively demonstrates that the model-specific inlet flow-rate shapes wall shear stress time-histories. Moreover, it emerges that a combined effect of low wall shear stress magnitude and of the shape of the wall shear stress–based descriptors time-histories could trigger atherosclerosis at its earliest stage. The findings of this work suggest for new experiments to provide a clearer determination of the wall shear stress phenotype which is at the basis of the so-called arterial hemodynamic risk hypothesis in coronary arteries.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-05-28T07:09:13Z
      DOI: 10.1177/0954411920923253
       
  • Minor impact of constraint from perivascular flow probes on wave intensity
           analysis
    • Authors: Jonathan P Mynard, Joseph J Smolich
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Perivascular flow probes are considered the gold-standard for measuring volumetric blood flow in animal studies. Although flow probes are generally placed non-constrictively around the vessel of interest, pressure-elevating interventions performed during an experiment may lead to vessel expansion and some probe-vessel impingement, particularly in highly compliant vessels such as adult sheep aorta or major pulmonary arteries in fetus lambs. This study assessed to what extent such mild flow probe constraint may impact on wave intensity analysis. We also investigated whether errors arising from flow probe constraint could explain apparent pressure reflection indices (Rp> 1) that have been observed in fetus lamb pulmonary arteries under some experimental conditions. These questions were investigated with one-dimensional models of an adult sheep aorta and fetus lamb pulmonary artery, with a virtual flow probe incorporated as a non-linear external constraint term in the vessel constitutive equation. Model-derived flow and pressure were subjected to standard analysis procedures that would be applied experimentally (correcting for apparent velocity lags and calculating wave speed via the PU-loop method). For the adult sheep model, simulations covering a wide range of haemodynamic conditions revealed a mostly minor effect ( 1. Mild flow probe constraint is likely to have little impact on wave intensity analysis.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-05-15T06:18:51Z
      DOI: 10.1177/0954411920917853
       
  • Mechanics of the dicrotic notch: An acceleration hypothesis
    • Authors: Mazen Abou Gamrah, Jing Xu, Amr El Sawy, Heba Aguib, Magdi Yacoub, Kim H Parker
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The dicrotic notch is a prominent and distinctive feature of the pressure waveform in the central arteries. It is universally used to demarcate the end of systole and the beginning of diastole in these arteries. Despite its importance clinically, no physical mechanism for the formation of the dicrotic notch has been demonstrated convincingly. We first explore a mechanism based on the reflection of a backward wavefront from the aortic valve at the time of closure. This hypothesis is rejected on the basis of experimental evidence from measurements made in dogs. A new hypothesis is presented involving the acceleration of the aortic valve apparatus at the time of valve closure. This hypothesis is supported by new calculations of the acceleration of the aortic valve apparatus during the cardiac cycle based on computed tomography scans in man.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-05-14T06:27:00Z
      DOI: 10.1177/0954411920921628
       
  • The modified arterial reservoir: An update with consideration of
           asymptotic pressure (P∞) and zero-flow pressure (Pzf)
    • Authors: Alun D Hughes, Kim H Parker
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      This article describes the modified arterial reservoir in detail. The modified arterial reservoir makes explicit the wave nature of both reservoir (Pres) and excess pressure (Pxs). The mathematical derivation and methods for estimating Pres in the absence of flow velocity data are described. There is also discussion of zero-flow pressure (Pzf), the pressure at which flow through the circulation ceases; its relationship to asymptotic pressure (P∞) estimated by the reservoir model; and the physiological interpretation of Pzf . A systematic review and meta-analysis provides evidence that Pzf differs from mean circulatory filling pressure.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-05-05T11:25:09Z
      DOI: 10.1177/0954411920917557
       
  • Design of an integrated model for diagnosis and classification of
           pediatric acute leukemia using machine learning
    • Authors: Ehsan Fathi, Mustafa Jahangoshai Rezaee, Reza Tavakkoli-Moghaddam, Azra Alizadeh, Aynaz Montazer
      First page: 1051
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Applying artificial intelligence techniques for diagnosing diseases in hospitals often provides advanced medical services to patients such as the diagnosis of leukemia. On the other hand, surgery and bone marrow sampling, especially in the diagnosis of childhood leukemia, are even more complex and difficult, resulting in increased human error and procedure time decreased patient satisfaction and increased costs. This study investigates the use of neuro-fuzzy and group method of data handling, for the diagnosis of acute leukemia in children based on the complete blood count test. Furthermore, a principal component analysis is applied to increase the accuracy of the diagnosis. The results show that distinguishing between patient and non-patient individuals can easily be done with adaptive neuro-fuzzy inference system, whereas for classifying between the types of diseases themselves, more pre-processing operations such as reduction of features may be needed. The proposed approach may help to distinguish between two types of leukemia including acute lymphoblastic leukemia and acute myeloid leukemia. Based on the sensitivity of the diagnosis, experts can use the proposed algorithm to help identify the disease earlier and lessen the cost.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-07T09:54:14Z
      DOI: 10.1177/0954411920938567
       
  • Design and validation of a foot–ankle dynamic simulator with a
           6-degree-of-freedom parallel mechanism
    • Authors: Dongmei Wang, Wei Wang, Qinyang Guo, Guanglin Shi, Genrui Zhu, Xu Wang, Anmin Liu
      First page: 1070
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      An in vitro simulation test using a designed well-targeted test rig has been regarded as an effective way to understand the kinematics and dynamics of the foot and ankle complex in the dynamic stance phase, and it also allows alterations in both internal and external control compared to in vivo tests. However, current simulators are limited by some assumptions. In this study, a novel foot and ankle bionic dynamic simulator was developed and validated. A movable 6-degree-of-freedom parallel mechanism, known as Steward platform, was used as the core structure to drive the tibia, with a tibial force actuator applied with different loads. Four major muscle groups were actuated by four sensored pulling cables connected to muscle tendons. Simulation processes were controlled using a software developed based on a proportional–integral–derivative control loop, with tension–compression sensors mounted on tendon pulling cables and used as real-time monitor signals. An iterative learning module for tibial force control was integrated into the control software. Six specimens of the cadaveric foot–ankle were used to validate the simulator. The stance phase was successfully simulated within 5 s, and the tibia loads were applied based on the body weight of the cadaveric specimen donors. Typical three-dimensional ground reaction forces were successfully reproduced. The coefficient of multiple correlation analysis demonstrated good repeatability of the dynamic simulator for the ground reaction force (coefficient of multiple correlation > 0.89) and the range of ankle motion (coefficient of multiple correlation > 0.87 with only one exception). The simulated ranges of the foot–ankle joint rotation in stance were consistent with in vivo measurements, indicating the success of the dynamic simulation process. The proposed dynamic simulator can enhance the understanding of the mechanism of the foot–ankle movement, related injury prevention, and surgical intervention.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-11T05:32:09Z
      DOI: 10.1177/0954411920938902
       
  • Comparing the capabilities of transfer learning models to detect skin
           lesion in humans
    • Authors: Aditi Singhal, Ramesht Shukla, Pavan Kumar Kankar, Saurabh Dubey, Sukhjeet Singh, Ram Bilas Pachori
      First page: 1083
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Effective diagnosis of skin tumours mainly relies on the analysis of the characteristics of the lesion. Automatic detection of malignant skin lesion has become a mandatory task to reduce the risk of human deaths and increase their survival. This article proposes a study of skin lesion classification using transfer learning approach. The transfer learning model uses four different state-of-the-art architectures, namely Inception v3, Residual Networks (ResNet 50), Dense Convolutional Networks (DenseNet 201) and Inception Residual Networks (Inception ResNet v2). These models are trained under the dataset comprising seven different classes of skin lesions. The skin lesion images are pre-processed using image quantization, grayscaling and the Wiener filter before final training step. These models are compared for performance evaluation on different metrics. The present study shows the efficacy of the methodology for automated classification of lesion images.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-09T12:01:33Z
      DOI: 10.1177/0954411920939829
       
  • Evaluation of spinal posture during gait with inertial measurement units
    • Authors: Elisa Digo, Giuseppina Pierro, Stefano Pastorelli, Laura Gastaldi
      First page: 1094
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The increasing number of postural disorders emphasizes the central role of the vertebral spine during gait. Indeed, clinicians need an accurate and non-invasive method to evaluate the effectiveness of a rehabilitation program on spinal kinematics. Accordingly, the aim of this work was the use of inertial sensors for the assessment of angles among vertebral segments during gait. The spine was partitioned into five segments and correspondingly five inertial measurement units were positioned. Articulations between two adjacent spine segments were modeled with spherical joints, and the tilt–twist method was adopted to evaluate flexion–extension, lateral bending and axial rotation. In total, 18 young healthy subjects (9 males and 9 females) walked barefoot in three different conditions. The spinal posture during gait was efficiently evaluated considering the patterns of planar angles of each spine segment. Some statistically significant differences highlighted the influence of gender, speed and imposed cadence. The proposed methodology proved the usability of inertial sensors for the assessment of spinal posture and it is expected to efficiently point out trunk compensatory pattern during gait in a clinical context.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-07T11:00:57Z
      DOI: 10.1177/0954411920940830
       
  • Tribological behavior of dental restorative composites in chewable tobacco
           environment
    • Authors: Abhijeet S Suryawanshi, Niranjana Behera
      First page: 1106
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      This study investigates the effect of smokeless tobacco on the tribological properties of two commercially used dental composite materials: Tetric N-Ceram and Z350 Dentin shade. It is to evaluate the effect of smokeless tobacco on the wear properties of two dental composite materials after some stipulated period. The wear test was conducted on pin-on-disk tribometer in the presence of artificial saliva under different loading conditions of 10, 15 and 20 N. The pins of the dental composite material were immersed in tobacco solution. The tribological behavior was studied after 2 days, 3.5 days, 6 days, 15 days and 1 month which represented the real conditions for the contact of 1 week, 2 weeks, 1 month, 2 months and 5 months, respectively, between the dental material and the tobacco solution. Under different loading conditions, Z350 Dentin material exhibited much less wear than the Tetric N-Ceram material in the presence of synthetic saliva for the specimen with or without tobacco immersion. The microstructure of the pin surface was inspected using scanning electron microscopy.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-09T12:00:33Z
      DOI: 10.1177/0954411920940829
       
  • A numerical investigation of the infrapatellar fat pad
    • Authors: Chiara Giulia Fontanella, Veronica Macchi, Andrea Porzionato, Alessandro Arduino, Joseph Vannel Fotso Fongang, Raffaele De Caro, Arturo Nicola Natali, Emanuele Luigi Carniel
      First page: 1113
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The infrapatellar fat pad is an adipose tissue in the knee that facilitates the distribution of synovial fluid and absorbs impulsive actions generated through the joint. The correlation between morphological configuration and mechanical properties is analyzed by a computational approach. The microscopic anatomy of the infrapatellar fat pad is studied aiming to measure the dimension of adipose lobules and the thickness of connective septa. Results from histomorphometric investigations show that the infrapatellar fat pad is an inhomogeneous tissue, constituted by large lobules in the superficial part and smaller lobules in the deepest one. Finite element models of the infrapatellar fat pad are developed. The first model considers the inhomogeneous conformation of the infrapatellar fat pad, composed of micro- and macro-chambers, while the second model considers a homogeneous distribution of adipose lobules with similar dimensions. Computational analyses are performed considering the static standing configuration and the passive flexion–extension movement. The computational results allow us to identify the different stress and strain fields within the tissue and to appreciate the variation of the mechanical performance of the overall system considering the distribution of adipose lobules. Results show that the distribution of adipose lobules in macro- and micro-chambers allows major deformation of the infrapatellar fat pad, decreasing the stress inside the tissues.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-11T06:15:30Z
      DOI: 10.1177/0954411920940839
       
  • Resistance of a novel ceramic acetabular cup to critical impact loads
    • Authors: Danielle de Villiers, Simon Collins
      First page: 1122
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      A novel thin-walled direct-to-bone fixation ceramic cup was tested under critical impact loads simulating lateral fall and car crash scenarios. Three sizes of BIOLOX delta ceramic cups (total hip replacement cup with bearing diameter of 32 mm and two hip resurfacing cups with bearing diameters of 40 and 64mm) were implanted into reamed Sawbones blocks representing acetabulae. Three cups of each size were fully supported by the block and three were implanted with 15° of the cup’s outer diameter unsupported by the block. All testing was conducted with the corresponding bearing diameter heads lateralised by approximately 1 mm to represent worst case subluxed hips and all then subjected to test, replicating a lateral fall impact followed by a car crash impact. All cups passed lateral fall conditions without visible damage, although some movement of the cups was measured and damage to the blocks was observed. Five out of six of each cup size survived the car crash impacts with one fracture per size. In all cases, this was in the fully supported condition representing the highest cup inclination angle. The car crash impact force was equivalent to that reported to fracture the acetabulum and in all simulated cases, the Sawbones block showed signs of damage. Survival of five cups per size suggests the pelvis is much more likely to fracture before the cup. The ability of the cups to withstand these critical impact forces indicates they are unlikely to fracture in normal clinical use and should meet the more challenging demands of active patients likely to receive this device.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-07T11:00:17Z
      DOI: 10.1177/0954411920941383
       
  • Fixation of distal tibia fracture through plating, nailing, and nailing
           with Poller screws: A comparative biomechanical-based experimental and
           numerical investigation
    • Authors: Amin Baseri, Mohammad Ali Bagheri, Gholamreza Rouhi, Mohammad Reza Aghighi, Nima Bagheri
      First page: 1129
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The goal of this study was to investigate two commonly used methods of fixation of distal metaphyseal tibia fractures, plating and nailing as well as the less frequently employed nailing with Poller screws, from a biomechanical perspective. Despite numerous studies, the best method to repair fractures of tibia the remains up for of debate. This study includes an in vitro experimental phase on human cadaveric tibias followed by a finite element analysis. In the experimental phase, under partial weight-bearing axial loading, the axial stiffness of the bone-implant construct and interfragmentary movements for each of the fixation methods, bone-plate, bone-nail, and bone-nail-Poller screw, were measured and compared with each other. Shear interfragmentary movement and stress distribution in the bone-implant construct for the three mentioned fixation methods were also determined from FE models and compared with each other. Results of in vitro experiments, i.e., the exertion of axial loading on the tibia-plate, tibia-nail, and tibia-nail-Poller screw, showed that utilization of tibia-nail and tibia-nail-Poller screw led to a stiffer bone-implant construct, and consequently, lower interfragmentary movement, compared to the tibia-plate construct (p values for tibia-nail and tibia-nail-Poller screw, and for both axial stiffness and interfragmentary movement, compared to those of tibia-plate construct, were less than 0.05). Numerical analyses showed that nailing produced less undesirable shear interfragmentary movement, compared to the plating, and application of a Poller screw decreased the shear movements, compared to tibia-nail. Furthermore, using the finite element analysis, maximum von Mises stress of adding a screw in tibia-nail, tibia-plate, and tibia-nail-Poller screw, was found to be: 51.5, 78.6, and 60.5 MPa, respectively. The results of this study suggested that from a biomechanical standpoint, nailing both with and without a Poller screw is superior to plating for the treatment of distal tibia fractures.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-11T06:15:50Z
      DOI: 10.1177/0954411920941664
       
  • Biomechanical comparison of implantation approaches for the treatment of
           mandibular total edentulism
    • Authors: Yunus Ziya Arslan, Derya Karabulut, Songul Kahya, Erol Cansiz
      First page: 1139
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Applying four anterior implants placed vertically or tilted in the mandible is considered to provide clinically reasonable results in the treatment of mandibular posterior edentulism. It is also reported that a combination of four anterior and two short posterior implants can be an alternative approach for the rehabilitation of severe atrophy cases. In this study, we aimed to evaluate the biomechanical responses of three different implant placement configurations, which represent the clinical options for the treatment of mandibular edentulism. Three-dimensional models of the mandible, prosthetic bar, dental implant, abutment, and screw were created. Finite element models of the three implant configurations (Protocol 1: Four anterior implants, Protocol 2: Four anterior and two short posterior implants, Protocol 3: Two anterior and two tilted posterior implants: All-on-4™ concept) were generated for 10 patients and analyzed under different loading conditions including chewing, biting, and impact forces. Protocol 2 led to the lowest stress concentrations over the mandible among the three protocols (p < 0.016). Protocol 2 resulted in significantly lower stresses than Protocol 3 and Protocol 1 over prosthetic bars under chewing forces (p < 0.016). None of the implant placement protocols consistently exhibited the lowest stress distribution over abutments. The lowest stresses over dental implants under the chewing, biting, and impact forces were obtained in Protocol 1, Protocol 2, and Protocol 3, respectively (p < 0.016). Protocol 3 was the best option to obtain the lowest stress values over the screws under all types of loading conditions (p < 0.016). In conclusion, Protocol 2 was biomechanically more ideal than Protocol 1 and Protocol 3 to manage the posterior edentulism.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-20T09:35:04Z
      DOI: 10.1177/0954411920943427
       
  • Stress response envelopes of intact tibiofemoral joint and knee
           osteoarthritis
    • Authors: Andi Haris, Vincent Beng Chye Tan
      First page: 1151
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The purpose of this study was to determine stress envelopes for an intact tibiofemoral joint and to study how they vary with knee loading, external–internal rotation, varus–valgus rotation and cartilage degradation (osteoarthritis) using the finite element method. The envelopes were presented in terms of knee flexion angle. The maximum von Mises stress for all tibiofemoral joint components increased with increasing the axial compressive force magnitude. Menisci exhibited the highest magnitude of maximum von Mises stress as compared to the femoral and tibial cartilages. In a range of flexion angles between 0° and 100°, the medial meniscus exhibited the highest maximum von Mises stress than the lateral meniscus and the stress in medial meniscus tended to increase with increasing the flexion angle. External–internal and varus–valgus rotations changed the stress distribution: higher stress on lateral compartment but lower stress on medial compartment, and conversely. The internal rotation provided more extreme effect than the external rotation. For the knee osteoarthritis, cartilage degradation (early stage) caused maximum von Mises stress to increase on the intact menisci revealing that knee osteoarthritis could also cause meniscal tear. The late osteoarthritis caused the maximum von Mises stress to increase on the calcified cartilage and subchondral bone.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-20T09:35:46Z
      DOI: 10.1177/0954411920944078
       
  • Effect of supporting implants inclination on stability of fixed partial
           denture: A finite element study
    • Authors: Amel Boukhlif, Ali Merdji, Sandipan Roy, Hashem Alkhaldi, Ibrahim Abu-Alshaikh, Nourddine Della, Corina Marilena Cristache, Rajshree Hillstrom
      First page: 1162
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      The aim of this finite element study was to analyze effect of supporting implants inclination on stress distribution in the bone for a four-unit fixed partial denture. A three-dimensional finite element model of mandibular molar section of the bone to receive implants was constructed. Three implant-supported fixed partial dentures, with null, moderate and wide tilting, of 0°, 15° and 30° implant inclinations, respectively, were modeled. A mechanical load of 10 MPa was applied in coronal–apical direction on bridge framework at the regions of crowns positions. The finite element analysis was performed, and von Mises stress levels were calculated. Peak stress concentration in the cortical bone was observed mostly around the implant necks, in inter-implants line. There was favorable stress distribution during loading, with peak stress being 90.04 MPa for 0°, which decreased to 54.33 MPa for 15° and 46.36 MPa for 30° inclination. The supporting implants inclination in fixed partial denture plays an important role in stress distribution and may be helpful in preventing bone loss and implant failure. This phenomenon is likely to be more pronounced in bones of poor quality. Within the limitation of this study, it seems that the inclination of implants in fixed partial denture has a favorable effect on stress distribution pattern values around the supporting implants.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-20T09:36:06Z
      DOI: 10.1177/0954411920944109
       
  • Development and surgical application of a custom implant that enables a
           vertical vector of mandibular distraction
    • Authors: Alba Gonzalez Alvarez, Lawrence Dovgalski, Peter Ll. Evans, Steven Key
      First page: 1172
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, Ahead of Print.
      Hemifacial microsomia is a congenital malformation that involves the underdevelopment of the mandible and the ear leading to facial asymmetry. Distraction osteogenesis is the gold standard surgical procedure for severe cases of hemifacial microsomia in which two sectioned bone parts are lengthened gradually to promote bony infill. The final shape of the bone depends on the position of the distractor and the vector of distraction. This article presents a complex clinical case of a 7-year-old patient with severe hemifacial microsomia that required distraction to correct mandibular asymmetry. Digital technology was applied to virtually plan the surgery pre-operatively. Optimal symmetrisation required a vertical vector of distraction that none of the ‘off-the-shelf’ distractors could provide. Consequently, a three-dimensional printed titanium implant was designed as a spacer to be attached to the inferior plate of a standard distractor, allowing the achievement of a vertical vector. By adding the spacer, the inferior footplate of the distractor was not directly fixed to bone and the vector of distraction was not dictated by the anatomical contour of the patient but by the shape of the spacer. Surgical guides were created to translate the virtual plan to the operating room. The guides prevented potential damage to tooth buds and the inferior alveolar nerve. This article describes the three-dimensional computer-aided design and additive manufacture of the custom devices that delivered the following: (1) symmetrisation of the mandible after distraction surgery without manipulation of the healthy side of the mandible; (2) a feasible and safer surgical solution; and (3) an innovative method that enables a wider range of vectors of distraction, bringing new prospects to the treatment of distraction osteogenesis in the future.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
      PubDate: 2020-07-15T12:13:05Z
      DOI: 10.1177/0954411920940848
       
 
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