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  Subjects -> MEDICAL SCIENCES (Total: 7328 journals)
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MEDICAL SCIENCES (1833 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 3562 Journals sorted alphabetically
16 de Abril     Open Access  
AADE in Practice     Hybrid Journal   (Followers: 4)
ABCS Health Sciences     Open Access   (Followers: 1)
Abia State University Medical Students' Association Journal     Full-text available via subscription  
ACIMED     Open Access   (Followers: 1)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 40)
Acta Bio Medica     Full-text available via subscription   (Followers: 2)
Acta Bioethica     Open Access   (Followers: 1)
Acta Bioquimica Clinica Latinoamericana     Open Access   (Followers: 1)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Informatica Medica     Open Access   (Followers: 1)
Acta Medica Bulgarica     Open Access  
Acta Medica Colombiana     Open Access   (Followers: 1)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Medica Indonesiana     Open Access  
Acta medica Lituanica     Open Access  
Acta Medica Marisiensis     Open Access  
Acta Medica Martiniana     Open Access  
Acta Medica Nagasakiensia     Open Access  
Acta Medica Peruana     Open Access   (Followers: 2)
Acta Médica Portuguesa     Open Access  
Acta Medica Saliniana     Open Access  
Acta Scientiarum. Health Sciences     Open Access  
Acupuncture & Electro-Therapeutics Research     Full-text available via subscription   (Followers: 2)
Addiction Science & Clinical Practice     Open Access   (Followers: 7)
Addictive Behaviors Reports     Open Access   (Followers: 7)
Advanced Health Care Technologies     Open Access   (Followers: 4)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advances in Bioscience and Clinical Medicine     Open Access   (Followers: 5)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 29)
Advances in Life Course Research     Hybrid Journal   (Followers: 8)
Advances in Lipobiology     Full-text available via subscription   (Followers: 2)
Advances in Medical Education and Practice     Open Access   (Followers: 26)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Medicine     Open Access   (Followers: 2)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 5)
Advances in Molecular Oncology     Open Access   (Followers: 2)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 9)
Advances in Parkinson's Disease     Open Access  
Advances in Phytomedicine     Full-text available via subscription  
Advances in Preventive Medicine     Open Access   (Followers: 6)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Therapy     Hybrid Journal   (Followers: 5)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 6)
Advances in Wound Care     Hybrid Journal   (Followers: 10)
African Health Sciences     Open Access   (Followers: 2)
African Journal of Biomedical Research     Open Access  
African Journal of Clinical and Experimental Microbiology     Open Access   (Followers: 1)
African Journal of Laboratory Medicine     Open Access   (Followers: 2)
African Journal of Medical and Health Sciences     Open Access   (Followers: 2)
African Journal of Trauma     Open Access  
Afrimedic Journal     Open Access   (Followers: 2)
Aggiornamenti CIO     Hybrid Journal   (Followers: 1)
AIDS Research and Human Retroviruses     Hybrid Journal   (Followers: 8)
AJOB Primary Research     Partially Free   (Followers: 3)
Aktuelle Ernährungsmedizin     Hybrid Journal   (Followers: 4)
Al-Azhar Assiut Medical Journal     Open Access  
Alexandria Journal of Medicine     Open Access   (Followers: 1)
Allgemeine Homöopathische Zeitung     Hybrid Journal   (Followers: 2)
Alpha Omegan     Full-text available via subscription  
ALTEX : Alternatives to Animal Experimentation     Open Access   (Followers: 3)
American Journal of Biomedical Engineering     Open Access   (Followers: 12)
American Journal of Biomedical Research     Open Access   (Followers: 2)
American Journal of Biomedicine     Full-text available via subscription   (Followers: 7)
American Journal of Chinese Medicine, The     Hybrid Journal   (Followers: 5)
American Journal of Clinical Medicine Research     Open Access   (Followers: 5)
American Journal of Family Therapy     Hybrid Journal   (Followers: 11)
American Journal of Law & Medicine     Full-text available via subscription   (Followers: 12)
American Journal of Lifestyle Medicine     Hybrid Journal   (Followers: 5)
American Journal of Managed Care     Full-text available via subscription   (Followers: 11)
American Journal of Medical Case Reports     Open Access   (Followers: 1)
American Journal of Medical Sciences and Medicine     Open Access   (Followers: 2)
American Journal of Medicine     Hybrid Journal   (Followers: 45)
American Journal of Medicine and Medical Sciences     Open Access   (Followers: 1)
American Journal of Medicine Studies     Open Access  
American Journal of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American Journal of the Medical Sciences     Hybrid Journal   (Followers: 12)
American Journal on Addictions     Hybrid Journal   (Followers: 10)
American medical news     Free   (Followers: 3)
American Medical Writers Association Journal     Full-text available via subscription   (Followers: 2)
Amyloid: The Journal of Protein Folding Disorders     Hybrid Journal   (Followers: 4)
Anales de la Facultad de Medicina     Open Access  
Anales de la Facultad de Medicina, Universidad de la República, Uruguay     Open Access  
Anales del Sistema Sanitario de Navarra     Open Access   (Followers: 1)
Analgesia & Resuscitation : Current Research     Hybrid Journal   (Followers: 3)
Anatomical Science International     Hybrid Journal   (Followers: 2)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1)
Anatomy Research International     Open Access   (Followers: 2)
Angewandte Schmerztherapie und Palliativmedizin     Hybrid Journal  
Angiogenesis     Hybrid Journal   (Followers: 3)
Annales de Pathologie     Full-text available via subscription  
Annales françaises d'Oto-rhino-laryngologie et de Pathologie Cervico-faciale     Full-text available via subscription   (Followers: 3)
Annals of African Medicine     Open Access   (Followers: 1)
Annals of Anatomy - Anatomischer Anzeiger     Hybrid Journal   (Followers: 2)
Annals of Bioanthropology     Open Access   (Followers: 4)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 18)
Annals of Biomedical Sciences     Full-text available via subscription   (Followers: 3)
Annals of Clinical Microbiology and Antimicrobials     Open Access   (Followers: 9)
Annals of Family Medicine     Open Access   (Followers: 12)
Annals of Fundeni Hospital     Open Access   (Followers: 1)
Annals of Ibadan Postgraduate Medicine     Open Access  
Annals of Medical and Health Sciences Research     Open Access   (Followers: 7)
Annals of Medicine     Hybrid Journal   (Followers: 12)
Annals of Medicine and Surgery     Open Access   (Followers: 7)
Annals of Microbiology     Hybrid Journal   (Followers: 10)
Annals of Nigerian Medicine     Open Access   (Followers: 1)
Annals of Saudi Medicine     Open Access  
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5)
Annals of The Royal College of Surgeons of England     Full-text available via subscription   (Followers: 3)
Annual Reports in Medicinal Chemistry     Full-text available via subscription   (Followers: 7)
Annual Reports on NMR Spectroscopy     Full-text available via subscription   (Followers: 4)
Annual Review of Medicine     Full-text available via subscription   (Followers: 17)
Anthropological Review     Open Access   (Followers: 24)
Anthropologie et santé     Open Access   (Followers: 5)
Antibiotics     Open Access   (Followers: 9)
Antibodies     Open Access   (Followers: 2)
Antibody Technology Journal     Open Access   (Followers: 1)
Anuradhapura Medical Journal     Open Access  
Anwer Khan Modern Medical College Journal     Open Access   (Followers: 2)
Apmis     Hybrid Journal   (Followers: 1)
Apparence(s)     Open Access   (Followers: 1)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Clinical Research, Clinical Trials and Regulatory Affairs     Hybrid Journal  
Applied Medical Informatics     Open Access   (Followers: 10)
Arab Journal of Nephrology and Transplantation     Open Access   (Followers: 1)
Arak Medical University Journal     Open Access  
Archive of Clinical Medicine     Open Access   (Followers: 1)
Archive of Community Health     Open Access  
Archives of Biomedical Sciences     Open Access   (Followers: 7)
Archives of Medical and Biomedical Research     Open Access   (Followers: 3)
Archives of Medical Laboratory Sciences     Open Access   (Followers: 1)
Archives of Medicine and Health Sciences     Open Access   (Followers: 3)
Archives of Trauma Research     Open Access   (Followers: 2)
Archivos de Medicina (Manizales)     Open Access  
ArgoSpine News & Journal     Hybrid Journal  
Arquivos Brasileiros de Oftalmologia     Open Access  
Arquivos de Ciências da Saúde     Open Access  
Arquivos de Medicina     Open Access  
Ars Medica : Revista de Ciencias Médicas     Open Access  
ARS Medica Tomitana     Open Access   (Followers: 1)
Art Therapy: Journal of the American Art Therapy Association     Full-text available via subscription   (Followers: 10)
Arterial Hypertension     Open Access  
Artificial Intelligence in Medicine     Hybrid Journal   (Followers: 12)
Artificial Organs     Hybrid Journal   (Followers: 1)
Asia Pacific Family Medicine     Open Access  
Asia Pacific Journal of Clinical Nutrition     Full-text available via subscription   (Followers: 9)
Asia Pacific Journal of Clinical Trials : Nervous System Diseases     Open Access  
Asian Bioethics Review     Full-text available via subscription   (Followers: 2)
Asian Journal of Cell Biology     Open Access   (Followers: 6)
Asian Journal of Health     Open Access   (Followers: 3)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 2)
Asian Journal of Medical and Pharmaceutical Researches     Open Access   (Followers: 1)
Asian Journal of Medical Sciences     Open Access   (Followers: 1)
Asian Journal of Scientific Research     Open Access   (Followers: 2)
Asian Journal of Transfusion Science     Open Access   (Followers: 2)
Asian Medicine     Hybrid Journal   (Followers: 4)
Asian Pacific Journal of Cancer Prevention     Open Access  
ASPIRATOR : Journal of Vector-borne Disease Studies     Open Access  
Astrocyte     Open Access  
Atención Familiar     Open Access  
Atención Primaria     Open Access   (Followers: 1)
Audiology - Communication Research     Open Access   (Followers: 8)
Auris Nasus Larynx     Full-text available via subscription  
Australian Coeliac     Full-text available via subscription   (Followers: 2)
Australian Family Physician     Full-text available via subscription   (Followers: 3)
Australian Journal of Medical Science     Full-text available via subscription   (Followers: 1)
Autopsy and Case Reports     Open Access  
Aviation, Space, and Environmental Medicine     Full-text available via subscription   (Followers: 10)
Avicenna     Open Access   (Followers: 2)
Avicenna Journal of Medicine     Open Access   (Followers: 1)
Bangabandhu Sheikh Mujib Medical University Journal     Open Access   (Followers: 1)
Bangladesh Journal of Anatomy     Open Access   (Followers: 1)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Medical Biochemistry     Open Access   (Followers: 3)
Bangladesh Journal of Medical Education     Open Access   (Followers: 2)
Bangladesh Journal of Medical Microbiology     Open Access   (Followers: 3)
Bangladesh Journal of Medical Physics     Open Access  
Bangladesh Journal of Medical Science     Open Access  
Bangladesh Journal of Medicine     Open Access   (Followers: 1)
Bangladesh Journal of Physiology and Pharmacology     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 2)
Bangladesh Medical Journal     Open Access  
Bangladesh Medical Journal Khulna     Open Access  
Basal Ganglia     Hybrid Journal  
Basic Sciences of Medicine     Open Access   (Followers: 2)
BBA Clinical     Open Access  
BC Medical Journal     Free  
Benha Medical Journal     Open Access  
Bijblijven     Hybrid Journal  
Bijzijn     Hybrid Journal   (Followers: 2)
Bijzijn XL     Hybrid Journal   (Followers: 1)
Bio-Algorithms and Med-Systems     Hybrid Journal   (Followers: 1)
BioDiscovery     Open Access   (Followers: 2)
Bioelectromagnetics     Hybrid Journal   (Followers: 1)
Bioengineering & Translational Medicine     Open Access  
Bioethics     Hybrid Journal   (Followers: 14)
Bioethics Research Notes     Full-text available via subscription   (Followers: 14)
Biologics in Therapy     Open Access  

        1 2 3 4 5 6 7 8 | Last

Journal Cover Annals of Biomedical Engineering
  [SJR: 1.182]   [H-I: 94]   [18 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1573-9686 - ISSN (Online) 0090-6964
   Published by Springer-Verlag Homepage  [2355 journals]
  • Biomechanical Characterisation of Bone-anchored Implant Systems for
           Amputation Limb Prostheses: A Systematic Review
    • Authors: Alexander Thesleff; Rickard Brånemark; Bo Håkansson; Max Ortiz-Catalan
      Pages: 377 - 391
      Abstract: Bone-anchored limb prostheses allow for the direct transfer of external loads from the prosthesis to the skeleton, eliminating the need for a socket and the associated problems of poor fit, discomfort, and limited range of movement. A percutaneous implant system for direct skeletal attachment of an external limb must provide a long-term, mechanically stable interface to the bone, along with an infection barrier to the external environment. In addition, the mechanical integrity of the implant system and bone must be preserved despite constant stresses induced by the limb prosthesis. Three different percutaneous implant systems for direct skeletal attachment of external limb prostheses are currently clinically available and a few others are under investigation in human subjects. These systems employ different strategies and have undergone design changes with a view to fulfilling the aforementioned requirements. This review summarises such strategies and design changes, providing an overview of the biomechanical characteristics of current percutaneous implant systems for direct skeletal attachment of amputation limb prostheses.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1976-4
      Issue No: Vol. 46, No. 3 (2018)
       
  • Cell Migration in 1D and 2D Nanofiber Microenvironments
    • Authors: Horacio M. Estabridis; Aniket Jana; Amrinder Nain; David J. Odde
      Pages: 392 - 403
      Abstract: Understanding how cells migrate in fibrous environments is important in wound healing, immune function, and cancer progression. A key question is how fiber orientation and network geometry influence cell movement. Here we describe a quantitative, modeling-based approach toward identifying the mechanisms by which cells migrate in fibrous geometries having well controlled orientation. Specifically, U251 glioblastoma cells were seeded onto non-electrospinning Spinneret based tunable engineering parameters fiber substrates that consist of networks of suspended 400 nm diameter nanofibers. Cells were classified based on the local fiber geometry and cell migration dynamics observed by light microscopy. Cells were found in three distinct geometries: adhering two a single fiber, adhering to two parallel fibers, and adhering to a network of orthogonal fibers. Cells adhering to a single fiber or two parallel fibers can only move in one dimension along the fiber axis, whereas cells on a network of orthogonal fibers can move in two dimensions. We found that cells move faster and more persistently in 1D geometries than in 2D, with cell migration being faster on parallel fibers than on single fibers. To explain these behaviors mechanistically, we simulated cell migration in the three different geometries using a motor-clutch based model for cell traction forces. Using nearly identical parameter sets for each of the three cases, we found that the simulated cells naturally replicated the reduced migration in 2D relative to 1D geometries. In addition, the modestly faster 1D migration on parallel fibers relative to single fibers was captured using a correspondingly modest increase in the number of clutches to reflect increased surface area of adhesion on parallel fibers. Overall, the integrated modeling and experimental analysis shows that cell migration in response to varying fibrous geometries can be explained by a simple mechanical readout of geometry via a motor-clutch mechanism.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1958-6
      Issue No: Vol. 46, No. 3 (2018)
       
  • The Advantages of Viscous Dissipation Rate over Simplified Power Loss as a
           Fontan Hemodynamic Metric
    • Authors: Zhenglun Alan Wei; Michael Tree; Phillip M. Trusty; Wenjun Wu; Shelly Singh-Gryzbon; Ajit Yoganathan
      Pages: 404 - 416
      Abstract: Flow efficiency through the Fontan connection is an important factor related to patient outcomes. It can be quantified using either a simplified power loss or a viscous dissipation rate metric. Though practically equivalent in simplified Fontan circulation models, these metrics are not identical. Investigation is needed to evaluate the advantages and disadvantages of these metrics for their use in in vivo or more physiologically-accurate Fontan modeling. Thus, simplified power loss and viscous dissipation rate are compared theoretically, computationally, and statistically in this study. Theoretical analysis was employed to assess the assumptions made for each metric and its clinical calculability. Computational simulations were then performed to obtain these two metrics. The results showed that apparent simplified power loss was always greater than the viscous dissipation rate for each patient. This discrepancy can be attributed to the assumptions derived in theoretical analysis. Their effects were also deliberately quantified in this study. Furthermore, statistical analysis was conducted to assess the correlation between the two metrics. Viscous dissipation rate and its indexed quantity show significant, strong, linear correlation to simplified power loss and its indexed quantity (p < 0.001, r > 0.99) under certain assumptions. In conclusion, viscous dissipation rate was found to be more advantageous than simplified power loss as a hemodynamic metric because of its lack of limiting assumptions and calculability in the clinic. Moreover, in addition to providing a time-averaged bulk measurement like simplified power loss, viscous dissipation rate has spatial distribution contours and time-resolved values that may provide additional clinical insight. Finally, viscous dissipation rate could maintain the relationship between Fontan connection flow efficiency and patient outcomes found in previous studies. Consequently, future Fontan hemodynamic studies should calculate both simplified power loss and viscous dissipation rate to maintain ties to previous studies, but also provide the most accurate measure of flow efficiency. Additional attention should be paid to the assumptions required for each metric.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1950-1
      Issue No: Vol. 46, No. 3 (2018)
       
  • Blood Pump Design Variations and Their Influence on Hydraulic Performance
           and Indicators of Hemocompatibility
    • Authors: L. Wiegmann; S. Boës; D. de Zélicourt; B. Thamsen; M. Schmid Daners; M. Meboldt; V. Kurtcuoglu
      Pages: 417 - 428
      Abstract: Patients with ventricular assist devices still suffer from high rates of adverse events. Since many of these complications are linked to the flow field within the pump, optimization of the device geometry is essential. To investigate design aspects that influence the flow field, we developed a centrifugal blood pump using industrial guidelines. We then systematically varied selected design parameters and investigated their effects on hemodynamics and hydraulic performance using computational fluid dynamics. We analysed the flow fields based on Eulerian and Lagrangian features, shear stress histograms and six indicators of hemocompatibility. Within the investigated range of clearance gaps (50–500 µm), number of impeller blades (4–7), and semi-open versus closed shroud design, we found association of potentially damaging shear stress conditions with larger gap size and more blades. The extent of stagnation and recirculation zones was reduced with lower numbers of blades and a semi-open impeller, but it was increased with smaller clearance. The Lagrangian hemolysis index, a metric commonly applied to estimate blood damage, showed a negative correlation with hydraulic efficiency and no correlation with the Eulerian threshold-based metric.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1951-0
      Issue No: Vol. 46, No. 3 (2018)
       
  • Mechanical Characterization and Material Modeling of Diabetic Aortas in a
           Rabbit Model
    • Authors: Jianhua Tong; F. Yang; X. Li; X. Xu; G. X. Wang
      Pages: 429 - 442
      Abstract: Diabetes has been recognized as a major risk factor to cause macrovascular diseases and plays a key role in aortic wall remodeling. However, the effects of diabetes on elastic properties of aortas remain largely unknown and quantitative mechanical data are lacking. Thirty adult rabbits (1.6–2.2 kg) were collected and the type 1 diabetic rabbit model was induced by injection of alloxan. A total of 15 control and 15 diabetic rabbit (abdominal) aortas were harvested. Uniaxial and biaxial tensile tests were performed to measure ultimate tensile strength and to characterize biaxial mechanical behaviors of the aortas. A material model was fitted to the biaxial experimental data to obtain constitutive parameters. Histological and mass fraction analyses were performed to investigate the underlying microstructure and dry weight percentages of elastin and collagen in the control and the diabetic aortas. No statistically significant difference was found in ultimate tensile strength between the control and the diabetic aortas. Regarding biaxial mechanical responses, the diabetic aortas exhibited significantly lower extensibility and significantly higher tissue stiffness than the control aortas. Notably, tissue stiffening occurred in both circumferential and axial directions for the diabetic aortas; however, mechanical anisotropy does not change significantly. The material model was able to fit biaxial experimental data very well. Histology showed that a number of isolated foam cells were embedded in the diabetic aortas and hyperplasia of collagen was identified. The dry weight percentages of collagen within the diabetic aortas increased significantly as compared to the control aortas, whereas no significant change was found for that of elastin. Our data suggest that the diabetes impairs elastic properties and alters microstructure of the aortas and consequently, these changes may further contribute to complex aortic wall remodeling.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1955-9
      Issue No: Vol. 46, No. 3 (2018)
       
  • Engineering Analysis of Tricuspid Annular Dynamics in the Beating Ovine
           Heart
    • Authors: Manuel K. Rausch; Marcin Malinowski; Penny Wilton; Asghar Khaghani; Tomasz A. Timek
      Pages: 443 - 451
      Abstract: Functional tricuspid regurgitation is a significant source of morbidity and mortality in the US. Furthermore, treatment of functional tricuspid regurgitation is suboptimal with significant recurrence rates, which may, at least in part, be due to our limited knowledge of the relationship between valvular shape and function. Here we study the dynamics of the healthy in vivo ovine tricuspid annulus to improve our understanding of normal annular deformations throughout the cardiac cycle. To this end, we determine both clinical as well as engineering metrics of in vivo annular dynamics based on sonomicrometry crystals surgically attached to the annulus. We confirm that the tricuspid annulus undergoes large dynamic changes in area, perimeter, height, and eccentricity throughout the cardiac cycle. This deformation may be described as asymmetric in-plane motion of the annulus with minor out-of-plane motion. In addition, we employ strain and curvature to provide mechanistic insight into the origin of this deformation. Specifically, we find that strain and curvature vary considerable across the annulus with highly localized minima and maxima resulting in aforementioned configurational changes throughout the cardiac cycle. It is our hope that these data provide valuable information for clinicians and engineers alike and ultimately help us improve treatment of functional tricuspid regurgitation.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1961-y
      Issue No: Vol. 46, No. 3 (2018)
       
  • AngleNav: MEMS Tracker to Facilitate CT-Guided Puncture
    • Authors: Rui Li; Sheng Xu; William F. Pritchard; John W. Karanian; Venkatesh P. Krishnasamy; Bradford J. Wood; Zion Tsz Ho Tse
      Pages: 452 - 463
      Abstract: As a low-cost needle navigation system, AngleNav may be used to improve the accuracy, speed, and ease of CT-guided needle punctures. The AngleNav hardware includes a wireless device with a microelectromechanical (MEMS) tracker that can be attached to any standard needle. The physician defines the target, desired needle path and skin entry point on a CT slice image. The accuracy of AngleNav was first tested in a 3D-printed calibration platform in a benchtop setting. An abdominal phantom study was then performed in a CT scanner to validate the accuracy of the device’s angular measurement. Finally, an in vivo swine study was performed to guide the needle towards liver targets (n = 8). CT scans of the targets were used to quantify the angular errors and needle tip-to-targeting distance errors between the planned needle path and the final needle position. The MEMS tracker showed a mean angular error of 0.01° with a standard deviation (SD) of 0.62° in the benchtop setting. The abdominal phantom test showed a mean angular error of 0.87° with an SD of 1.19° and a mean tip-to-target distance error of 4.89 mm with an SD of 1.57 mm. The animal experiment resulted in a mean angular error of 6.6° with an SD of 1.9° and a mean tip-to-target distance error of 8.7 mm with an SD of 3.1 mm. These results demonstrated the feasibility of AngleNav for CT-guided interventional workflow. The angular and distance errors were reduced by 64.4 and 54.8% respectively if using AngleNav instead of freehand insertion, with a limited number of operators. AngleNav assisted the physicians to deliver accurate needle insertion during CT-guided intervention. The device could potentially reduce the learning curve for physicians to perform CT-guided needle targeting.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1968-4
      Issue No: Vol. 46, No. 3 (2018)
       
  • A Robotic Flexible Drill and Its Navigation System for Total Hip
           Arthroplasty
    • Authors: Ahmad Nazmi Bin Ahmad Fuad; Hariprashanth Elangovan; Kamal Deep; Wei Yao
      Pages: 464 - 474
      Abstract: This paper presents a robotic flexible drill and its navigation system for total hip arthroplasty (THA). The new robotic system provides an unprecedented and unique capability to perform curved femoral milling under the guidance of a multimodality navigation system. The robotic system consists of three components. Firstly, a flexible drill manipulator comprises multiple rigid segments that act as a sheath to a flexible shaft with a drill/burr attached to the end. The second part of the robotic system is a hybrid tracking system that consists of an optical tracking system and a position tracking system. Optical tracking units are used to track the surgical objects and tools outside the drilling area, while a rotary encoder placed at each joint of the sheath is synchronized to provide the position information for the flexible manipulator with its virtual object. Finally, the flexible drill is integrated into a computer-aided navigation system. The navigation system provides real time guidance to a surgeon during the procedure. The flexible drill system is then able to implement THA by bone milling. The final section of this paper is an evaluation of the flexible and steerable drill and its navigation system for femoral bone milling in sawbones.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1959-5
      Issue No: Vol. 46, No. 3 (2018)
       
  • SpinoBot: An MRI-Guided Needle Positioning System for Spinal Cellular
           Therapeutics
    • Authors: Alexander Squires; John N. Oshinski; Nicholas M. Boulis; Zion Tsz Ho Tse
      Pages: 475 - 487
      Abstract: The neurodegenerative disease amyotrophic lateral sclerosis (ALS) results in the death of motor neurons in voluntary muscles. There are no cures for ALS and few available treatments. In studies with small animal models, injection of cellular therapeutics into the anterior horn of the spinal cord has been shown to inhibit the progression of ALS. It was hypothesized that spinal injection could be made faster and less invasive with the aid of a robot. The robotic system presented—SpinoBot—uses MRI guidance to position a needle for percutaneous injection into the spinal cord. With four degrees of freedom (DOF) provided by two translation stages and two rotational axes, SpinoBot proved capable of advanced targeting with a mean error of 1.12 mm and standard deviation of 0.97 mm in bench tests, and a mean error of 2.2 mm and standard deviation of 0.85 mm in swine cadaver tests. SpinoBot has shown less than 3% signal-to-noise ratio reduction in 3T MR imaging quality, demonstrating its compliance to the MRI environment. With the aid of SpinoBot, the length of the percutaneous injection procedure is reduced to less than 60 min with 10 min for each additional insertion. Although SpinoBot is designed for ALS treatment, it could potentially be used for other procedures that require precise access to the spine.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1960-z
      Issue No: Vol. 46, No. 3 (2018)
       
  • Trunk Reaction Time and Kinematic Changes Following Slip Perturbations in
           Subjects with Recurrent Low Back Pain
    • Authors: Paul S. Sung; Pamela Danial
      Pages: 488 - 497
      Abstract: Postural responses following slip perturbations are critical to fall prevention strategies. It is unclear how postural reactions with a handheld task can validly be transferred to treadmill-induced slip perturbations in subjects with recurrent low back pain (LBP). The purpose of this study was to investigate trunk reaction times and trunk flexion angle as well as velocity following the slips between subjects with and without LBP. There were 29 subjects with LBP and 40 control subjects who participated in the study. Three levels of consecutive treadmill-induced slip perturbations were introduced at level 1 (duration: 0.10 s, velocity: 0.24 m/s, displacement: 1.20 cm), level 2 (0.12 s, 0.72 m/s, 4.32 cm), and level 3 (0.12 s, 1.37 m/s, 8.22 cm). The trunk reaction time, swing/step times, and trunk flexion angle as well as velocity at heel strike/toe-off were compared between the groups. There were significantly longer trunk reaction times (t = − 2.03, p = 0.04), swing times (t = − 2.63, p = 0.01), and step times (t = − 2.53, p = 0.01) in the LBP group at the level 1 slip perturbation. The groups demonstrated a significant interaction between the levels and trunk flexion angles (F = 4.72, p = 0.03), but there was no interaction between the levels and trunk flexion velocities (F = 0.07, p = 0.79). The LBP group demonstrated longer reaction times at the level 1 perturbation due to a possible pain recurrence. However, this compensatory tolerance was limited at the level 3 perturbation due to increased trunk flexion angle at heel strike and toe-off in the LBP group. Clinicians may consider a compensatory strategy to improve reaction time and minimize trunk flexion following slip perturbations in patients with LBP.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1972-8
      Issue No: Vol. 46, No. 3 (2018)
       
  • Airflow Simulations in Infant, Child, and Adult Pulmonary Conducting
           Airways
    • Authors: Jessica M. Oakes; Steven C. Roth; Shawn C. Shadden
      Pages: 498 - 512
      Abstract: The airway structure continuously evolves from birth to adulthood, influencing airflow dynamics and respiratory mechanics. We currently know very little about how airflow patterns change throughout early life and its impact on airway resistance, namely because of experimental limitations. To uncover differences in respiratory dynamics between age groups, we performed subject-specific airflow simulations in an infant, child, and adult conducting airways. Airflow throughout the respiration cycle was calculated by coupling image-based models of the conducting airways to the global respiratory mechanics, where flow was driven by a pressure differential. Trachea diameter was 19, 9, and 4.5 mm for the adult (36 years, female), child (6 years, male), and infant (0.25 years, female), respectively. Mean Reynolds number within the trachea was nearly the same for each subject (1100) and Womersley number was above unity for all three subjects and largest for the adult, highlighting the significance of transient effects. In general, air speeds and airway resistances within the conducting airways were inversely correlated with age; the 3D pressure drop was highest in the infant model. These simulations provide new insight into age-dependent flow dynamics throughout the respiration cycle within subject-specific airways.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1971-9
      Issue No: Vol. 46, No. 3 (2018)
       
  • Using a Teaching Intervention and Calibrated Peer Review™ Diagnostics to
           Improve Visual Communication Skills
    • Authors: Ann Saterbak; Anoosha Moturu; Tracy Volz
      Pages: 513 - 524
      Abstract: Rice University’s bioengineering department incorporates written, oral, and visual communication instruction into its undergraduate curriculum to aid student learning and to prepare students to communicate their knowledge and discoveries precisely and persuasively. In a tissue culture lab course, we used a self- and peer-review tool called Calibrated Peer Review™ (CPR) to diagnose student learning gaps in visual communication skills on a poster assignment. We then designed an active learning intervention that required students to practice the visual communication skills that needed improvement and used CPR to measure the changes. After the intervention, we observed that students performed significantly better in their ability to develop high quality graphs and tables that represent experimental data. Based on these outcomes, we conclude that guided task practice, collaborative learning, and calibrated peer review can be used to improve engineering students’ visual communication skills.
      PubDate: 2018-03-01
      DOI: 10.1007/s10439-017-1946-x
      Issue No: Vol. 46, No. 3 (2018)
       
  • Electrical Conductivity Method to Determine Sexual Dimorphisms in Human
           Temporomandibular Disc Fixed Charge Density
    • Authors: Gregory J. Wright; Matthew C. Coombs; Yongren Wu; Brooke J. Damon; Thierry H. Bacro; Michael J. Kern; Xiaojing Chen; Hai Yao
      Pages: 310 - 317
      Abstract: To investigate potential mechanisms associated with the increased prevalence of temporomandibular joint (TMJ) disorders among women, the study objective was to determine sex-dependent and region-dependent differences in fixed charge density (FCD) using an electrical conductivity method. Seventeen TMJ discs were harvested from nine males (77 ± 4 years) and eight females (86 ± 4 years). Specimens were prepared from the anterior band, posterior band, intermediate zone, medial disc and lateral disc. FCD was determined using an electrical conductivity method, assessing differences among disc regions and between sexes. Statistical modeling showed significant effects for donor sex (p = 0.002), with cross-region FCD for male discs 0.051 ± 0.018 milliequivalent moles per gram (mEq/g) wet tissue and 0.043 ± 0.020 mEq/g wet tissue for female discs. FCD was significantly higher for male discs compared to female discs in the posterior band, with FCD 0.063 ± 0.015 mEq/g wet tissue for male discs and 0.032 ± 0.020 mEq/g wet tissue for female discs (p = 0.050). These results indicate FCD contributes approximately 20% towards TMJ disc compressive modulus, through osmotic swelling pressure regulation. Additionally, FCD regulates critical extracellular ionic/osmotic and nutrient environments. Sexual dimorphisms in TMJ disc FCD, and resulting differences in extracellular ionic/osmotic and nutrient environments, could result in altered mechano–electro-chemical environments between males and females and requires further study.
      PubDate: 2018-02-01
      DOI: 10.1007/s10439-017-1963-9
      Issue No: Vol. 46, No. 2 (2018)
       
  • The Turning Point for Morphomechanical Remodeling During Complete
           Intestinal Obstruction in Rats Occurs After 12–24 h
    • Authors: Daming Sun; Jingbo Zhao; Donghua Liao; Zhiyong Huang; Hans Gregersen
      Abstract: Intestinal obstruction prompts luminal dilation and wall remodeling proximal to the site of obstruction. Studies on temporal and spatial morphomechanical remodeling are needed for comprehending the pathophysiology of acute intestinal obstruction. The aim was to estimate the no-load and zero-stress morphomechanical properties in circumferential and longitudinal direction at 0, 6, 12, 24, 36, and 48 h after complete intestinal obstruction. Obstruction of the distal ileum was created surgically by placement of a polyethylene ring for up to 48 h in 30 rats. Sham and normal groups were also studied (n = 12). Five 6 cm-long intestinal segments proximal to the obstruction site were used for histological, morphometric and mechanical analysis at the designated times. Morphomechanical changes were huge but only subtle changes were observed between the 5 segments during the obstruction period. Due to dilation, the serosal length and mucosal length increased continuously from 6 to 48 h (p < 0.001). The wall area increased at 24 h and beyond (p < 0.001), demonstrating tissue growth. The opening and bending angle decreased to minimum values at 24 h where after the opening angle increased and the bending angle returned to pre-obstruction levels. For the residual stretch ratios and the position of the neutral axis the turning point was found after 24 h. Histologically, the thickness and area of most wall layers were quite stable for the first 12 h but with an increase at the 24 h time point that continued to the 48 h time point. The most pronounced change was found for the circumferential muscle layer (p < 0.05). Analysis of picrosirius red stained slides showed that submucosal type 3 collagen fraction increased significantly (p < 0.001), whereas the fraction of type 1 collagen decreased (p < 0.001). In conclusion, pronounced time-dependent morphomechanical remodeling was found. The obstructed intestine went from dilation remodeling to growth remodeling during the interval 12–24 h after creating the obstruction.
      PubDate: 2018-02-09
      DOI: 10.1007/s10439-018-1992-z
       
  • Collagen Damage Location in Articular Cartilage Differs if Damage is
           Caused by Excessive Loading Magnitude or Rate
    • Authors: Lorenza Henao-Murillo; Keita Ito; Corrinus C. van Donkelaar
      Abstract: Collagen damage in articular cartilage is considered nearly irreversible and may be an early indication of cartilage degeneration. Surface fibrillation and internal collagen damage may both develop after overloading. This study hypothesizes that damage develops at these different locations, because the distribution of excessive strains varies with loading rate as a consequence of time-dependent cartilage properties. The objective is to explore whether collagen damage could preferentially occur superficially or internally, depending on the magnitude and rate of overloading. Bovine osteochondral plugs were compressed with a 2 mm diameter indenter to 15, 25, 35 and 45 N, and at 5, 60 and 120 mm/min. Surface fibrillation and internal collagen damage were graded by four observers, based on histology and staining of collagen damage. Results show that loading magnitude affects the degree of collagen damage, while loading rate dominates the location of network damage: low rates predominantly damage superficial collagen, while at high rates, internal collagen damage occurs. The proposed explanation for the rate-dependent location is that internal fluid flows govern the time-dependent internal tissue deformation and therewith the location of overstained and damaged areas. This supports the hypothesis that collagen damage development is influenced by the time-dependent material behaviour of cartilage.
      PubDate: 2018-02-08
      DOI: 10.1007/s10439-018-1986-x
       
  • UROKIN: A Software to Enhance Our Understanding of Urogenital Motion
    • Authors: Catriona S. Czyrnyj; Michel R. Labrosse; Ryan B. Graham; Linda McLean
      Abstract: Transperineal ultrasound (TPUS) allows for objective quantification of mid-sagittal urogenital mechanics, yet current practice omits dynamic motion information in favor of analyzing only a rest and a peak motion frame. This work details the development of UROKIN, a semi-automated software which calculates kinematic curves of urogenital landmark motion. A proof of concept analysis, performed using UROKIN on TPUS video recorded from 20 women with and 10 women without stress urinary incontinence (SUI) performing maximum voluntary contraction of the pelvic floor muscles. The anorectal angle and bladder neck were tracked while the motion of the pubic symphysis was used to compensate for the error incurred by TPUS probe motion during imaging. Kinematic curves of landmark motion were generated for each video and curves were smoothed, time normalized, and averaged within groups. Kinematic data yielded by the UROKIN software showed statistically significant differences between women with and without SUI in terms of magnitude and timing characteristics of the kinematic curves depicting landmark motion. Results provide insight into the ways in which UROKIN may be useful to study differences in pelvic floor muscle contraction mechanics between women with and without SUI and other pelvic floor disorders. The UROKIN software improves on methods described in the literature and provides unique capacity to further our understanding of urogenital biomechanics.
      PubDate: 2018-02-07
      DOI: 10.1007/s10439-018-1989-7
       
  • Correction to: Mesenchymal Stem Cell Deformability and Implications for
           Microvascular Sequestration
    • Authors: Herbert H. Lipowsky; Daniel T. Bowers; Brittany L. Banik; Justin L. Brown
      Abstract: This article was updated to correct the spelling of author Brittany L. Banik’s name.
      PubDate: 2018-02-05
      DOI: 10.1007/s10439-018-1991-0
       
  • Human Brain Modeling with Its Anatomical Structure and Realistic Material
           Properties for Brain Injury Prediction
    • Authors: Noritoshi Atsumi; Yuko Nakahira; Eiichi Tanaka; Masami Iwamoto
      Abstract: Impairments of executive brain function after traumatic brain injury (TBI) due to head impacts in traffic accidents need to be obviated. Finite element (FE) analyses with a human brain model facilitate understanding of the TBI mechanisms. However, conventional brain FE models do not suitably describe the anatomical structure in the deep brain, which is a critical region for executive brain function, and the material properties of brain parenchyma. In this study, for better TBI prediction, a novel brain FE model with anatomical structure in the deep brain was developed. The developed model comprises a constitutive model of brain parenchyma considering anisotropy and strain rate dependency. Validation was performed against postmortem human subject test data associated with brain deformation during head impact. Brain injury analyses were performed using head acceleration curves obtained from reconstruction analysis of rear-end collision with a human whole-body FE model. The difference in structure was found to affect the regions of strain concentration, while the difference in material model contributed to the peak strain value. The injury prediction result by the proposed model was consistent with the characteristics in the neuroimaging data of TBI patients due to traffic accidents.
      PubDate: 2018-02-05
      DOI: 10.1007/s10439-018-1988-8
       
  • Eliminating Regurgitation Reduces Fibrotic Remodeling of Functional Mitral
           Regurgitation Conditioned Valves
    • Authors: Patrick S. Connell; Dragoslava P. Vekilov; Christine M. Diaz; Seulgi E. Kim; K. Jane Grande-Allen
      Abstract: Functional mitral regurgitation (FMR) is an insidious and poorly understood condition affecting patients with myocardial disease. While current treatments reduce regurgitation, their ability to reverse mitral valve pathology is unclear. We utilized a pseudo-physiological flow loop to study how repair impacted valve composition. Porcine mitral valves were cultured in control geometry (native papillary muscle position and annular area) or high-tension FMR geometry (5 mm apical and 5 mm lateral displacement of papillary muscles, 65% increased annular area) for 2 weeks. To mimic repair, a reversal condition was created by returning one-week FMR conditioned valves to a non-regurgitant geometry and culturing for 1 week. Valve composition and material properties were analyzed. After two-week culture, FMR conditioned tissues were stiffer and stronger than control and underwent extensive fibrotic remodeling, with increased prolyl-4-hydroxylase, lysyl oxidase, matrix metalloproteinase-1, and decorin. The reversal condition displayed a heterogeneous, leaflet- and orientation-dependent response. Reversal-conditioned anterior leaflets and circumferential tissue sections continued to have significant fibrotic remodeling compared to control, whereas reversal-conditioned posterior leaflets, chordae tendineae, and radial tissue sections had significantly decreased remodeling compared to FMR-conditioned tissues. These findings suggest current repairs only partially reverse pathology, underscoring the need for innovation in the treatment of FMR.
      PubDate: 2018-02-05
      DOI: 10.1007/s10439-018-1987-9
       
  • Correction to: Deformability of Human Mesenchymal Stem Cells Is Dependent
           on Vimentin Intermediate Filaments
    • Authors: Poonam Sharma; Zachary T. Bolten; Diane R. Wagner; Adam H. Hsieh
      Abstract: This erratum is to correct the following: (1) in the Western Blotting subsection under the Materials and Methods section, the concentration of protein from each sample loaded into Criterion Tris–HCl gels was incorrectly stated as 155 µg of protein. The correct value is 9.7 µg; (2) in Fig. 1b, the bar graph showed incorrect values for semi-quantitation of Western blots. Figure 1 has been updated with a corrected graph in Fig. 1b only.
      PubDate: 2018-01-02
      DOI: 10.1007/s10439-017-1975-5
       
 
 
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