5,020 results match your criteria Annals of biomedical engineering[Journal]


Effects of Level, Loading Rate, Injury and Repair on Biomechanical Response of Ovine Cervical Intervertebral Discs.

Ann Biomed Eng 2018 Jun 20. Epub 2018 Jun 20.

Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, Box 1188, New York, NY, 10029-6574, USA.

A need exists for pre-clinical large animal models of the spine to translate biomaterials capable of repairing intervertebral disc (IVD) defects. This study characterized the effects of cervical spinal level, loading rate, injury and repair with genipin-crosslinked fibrin (FibGen) on axial and torsional mechanics in an ovine cervical spine model. Cervical IVDs C2-C7 from nine animals were tested with cyclic tension-compression (- 240 to 100 N) and cyclic torsion (± 2° and ± 4°) tests at three rates (0. Read More

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Closed-Loop Active Compensation for Needle Deflection and Target Shift During Cooperatively Controlled Robotic Needle Insertion.

Ann Biomed Eng 2018 Jun 20. Epub 2018 Jun 20.

Robotics Engineering, Worcester Polytechnic Institute, 85 Prescott St., Worcester, MA, 10605, USA.

Intra-operative imaging is sometimes available to assist needle biopsy, but typical open-loop insertion does not account for unmodeled needle deflection or target shift. Closed-loop image-guided compensation for deviation from an initial straight-line trajectory through rotational control of an asymmetric tip can reduce targeting error. Incorporating robotic closed-loop control often reduces physician interaction with the patient, but by pairing closed-loop trajectory compensation with hands-on cooperatively controlled insertion, a physician's control of the procedure can be maintained while incorporating benefits of robotic accuracy. Read More

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In Vivo Inspection of the Olfactory Epithelium: Feasibility of Robotized Optical Biopsy.

Ann Biomed Eng 2018 Jun 19. Epub 2018 Jun 19.

AVR-ICube, CNRS, Université de Strasbourg, INSA Strasbourg, 1 Place de l'Hôpital, 67000, Strasbourg, France.

Inspecting the olfactory cleft can be of high interest, as it is an open access to neurons, and thus an opportunity to collect in situ related data in a non-invasive way. Also, recent studies show a strong link between olfactory deficiency and neurodegenerative diseases such as Alzheimer and Parkinson diseases. However, no inspection of this area is possible today, as it is very difficult to access. Read More

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MRI Robots for Needle-Based Interventions: Systems and Technology.

Ann Biomed Eng 2018 Jun 19. Epub 2018 Jun 19.

Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, 111 Michigan ave. NW, Washington, DC, 20010, USA.

Magnetic resonance imaging (MRI) provides high-quality soft-tissue images of anatomical structures and radiation free imaging. The research community has focused on establishing new workflows, developing new technology, and creating robotic devices to change an MRI room from a solely diagnostic room to an interventional suite, where diagnosis and intervention can both be done in the same room. Closed bore MRI scanners provide limited access for interventional procedures using intraoperative imaging. Read More

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Estimating Left Ventricular Elastance from Aortic Flow Waveform, Ventricular Ejection Fraction, and Brachial Pressure: An In Silico Study.

Ann Biomed Eng 2018 Jun 19. Epub 2018 Jun 19.

Laboratory of Hemodynamics and Cardiovascular Technology (LHTC), Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.

Although left ventricular end-systolic elastance (E) serves as a major index of cardiac contractility, a widely-accepted noninvasive estimation of E does not exist. To overcome this limitation, we developed a two-step inverse method that allows for its noninvasive estimation from measurements of aortic flow and brachial pressure using a previously validated one-dimensional model of the cardiovascular system. In a first step, aortic flow is set as the model input and the output brachial pressure is compared with the "real" values. Read More

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Toward Semi-autonomous Cryoablation of Kidney Tumors via Model-Independent Deformable Tissue Manipulation Technique.

Ann Biomed Eng 2018 Jun 19. Epub 2018 Jun 19.

Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD, USA, 21218.

We present a novel semi-autonomous clinician-in-the-loop strategy to perform the laparoscopic cryoablation of small kidney tumors. To this end, we introduce a model-independent bimanual tissue manipulation technique. In this method, instead of controlling the robot, which inserts and steers the needle in the deformable tissue (DT), the cryoprobe is introduced to the tissue after accurate manipulation of a target point on the DT to the desired predefined insertion location of the probe. Read More

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Construction of a Statistical Cervical Vertebrae Geometric Model for Children 3-10 Years Old.

Ann Biomed Eng 2018 Jun 19. Epub 2018 Jun 19.

HanDan Central Hospital, Handan, 056001, China.

Cervical spinal injuries of children in motor vehicle crashes have high morbidity and mortality rates. Cervical vertebrae change rapidly in both size and shape during growth. To accurately assess the risk of spinal injury for children of different ages, it is necessary to understand how the spatial geometric features of vertebrae change with the child's age and neck size. Read More

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Ultrarapid Inductive Rewarming of Vitrified Biomaterials with Thin Metal Forms.

Ann Biomed Eng 2018 Jun 19. Epub 2018 Jun 19.

Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN, 55455, USA.

Arteries with 1-mm thick walls can be successfully vitrified by loading cryoprotective agents (CPAs) such as VS55 (8.4 M) or less concentrated DP6 (6 M) and cooling at or beyond their critical cooling rates of 2.5 and 40 °C/min, respectively. Read More

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A Hydrogel Meniscal Replacement: Knee Joint Pressure and Distribution in an Ovine Model Compared to Native Tissue.

Ann Biomed Eng 2018 Jun 19. Epub 2018 Jun 19.

School of Biomedical Engineering, Colorado State University, Fort Collins, CO, 80523, USA.

Pressure distribution of the native ovine knee meniscus was compared to a medial meniscectomy and three treatment conditions including a suture reattachment of the native tissue, an allograft, and a novel thermoplastic elastomer hydrogel (TPE) construct. The objective of this study was to assess the efficacy of a novel TPE hydrogel construct at restoring joint pressure and distribution. Limbs were loaded in uniaxial compression at 45°, 60°, and 75° flexion and from 0 to 181 kg. Read More

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Learning-Based Cell Injection Control for Precise Drop-on-Demand Cell Printing.

Ann Biomed Eng 2018 Jun 5. Epub 2018 Jun 5.

Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 1197576, Singapore.

Drop-on-demand (DOD) printing is widely used in bioprinting for tissue engineering because of little damage to cell viability and cost-effectiveness. However, satellite droplets may be generated during printing, deviating cells from the desired position and affecting printing position accuracy. Current control on cell injection in DOD printing is primarily based on trial-and-error process, which is time-consuming and inflexible. Read More

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June 2018
3 Reads

Extracellular Matrix Expression and Production in Fibroblast-Collagen Gels: Towards an In Vitro Model for Ligament Wound Healing.

Ann Biomed Eng 2018 Jun 5. Epub 2018 Jun 5.

Department of Mechanical & Biomedical Engineering, Boise State University, 1910 University Drive, Boise, ID, 83725-2085, USA.

Ligament wound healing involves the proliferation of a dense and disorganized fibrous matrix that slowly remodels into scar tissue at the injury site. This remodeling process does not fully restore the highly aligned collagen network that exists in native tissue, and consequently repaired ligament has decreased strength and durability. In order to identify treatments that stimulate collagen alignment and strengthen ligament repair, there is a need to develop in vitro models to study fibroblast activation during ligament wound healing. Read More

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Material Processing and Design of Biodegradable Metal Matrix Composites for Biomedical Applications.

Ann Biomed Eng 2018 Jun 4. Epub 2018 Jun 4.

Beijing Engineering Research Center of Smart Mechanical Innovation Design Service, Beijing, People's Republic of China.

In recent years, biodegradable metallic materials have played an important role in biomedical applications. However, as typical for the metal materials, their structure, general properties, preparation technology and biocompatibility are hard to change. Furthermore, biodegradable metals are susceptible to excessive degradation and subsequent disruption of their mechanical integrity; this phenomenon limits the utility of these biomaterials. Read More

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Robotic Surgery Improves Technical Performance and Enhances Prefrontal Activation During High Temporal Demand.

Ann Biomed Eng 2018 Jun 4. Epub 2018 Jun 4.

Hamlyn Centre for Robotic Surgery, Imperial College London, London, UK.

Robotic surgery may improve technical performance and reduce mental demands compared to laparoscopic surgery. However, no studies have directly compared the impact of robotic and laparoscopic techniques on surgeons' brain function. This study aimed to assess the effect of the operative platform (robotic surgery or conventional laparoscopy) on prefrontal cortical activation during a suturing task performed under temporal demand. Read More

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June 2018
1 Read

Toward the Design of Personalized Continuum Surgical Robots.

Ann Biomed Eng 2018 May 31. Epub 2018 May 31.

Department of Mechanical Engineering, Stanford University, Stanford, CA, 94035, USA.

Robot-assisted minimally invasive surgical systems enable procedures with reduced pain, recovery time, and scarring compared to traditional surgery. While these improvements benefit a large number of patients, safe access to diseased sites is not always possible for specialized patient groups, including pediatric patients, due to their anatomical differences. We propose a patient-specific design paradigm that leverages the surgeon's expertise to design and fabricate robots based on preoperative medical images. Read More

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May 2018
1 Read

Toward a Flexible Variable Stiffness Endoport for Single-Site Partial Nephrectomy.

Ann Biomed Eng 2018 May 31. Epub 2018 May 31.

Laboratory for Continuum Robotics, Leibniz Universität Hannover, Appelstr. 11, 30167, Hanover, Germany.

Laparoscopic partial nephrectomy for localized renal tumors is an upcoming standard minimally invasive surgical procedure. However, a single-site laparoscopic approach would be even more preferable in terms of invasiveness. While the manual approach offers rigid curved tools, robotic single-site systems provide high degrees of freedom manipulators. Read More

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Automatic Robotic Steering of Flexible Needles from 3D Ultrasound Images in Phantoms and Ex Vivo Biological Tissue.

Ann Biomed Eng 2018 May 29. Epub 2018 May 29.

Université Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, 38000, Grenoble, France.

Robotic control of needle bending aims at increasing the precision of percutaneous procedures. Ultrasound feedback is preferable for its clinical ease of use, cost and compactness but raises needle detection issues. In this paper, we propose a complete system dedicated to robotized guidance of a flexible needle under 3D ultrasound imaging. Read More

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Triple-Layer Vascular Grafts Fabricated by Combined E-Jet 3D Printing and Electrospinning.

Ann Biomed Eng 2018 May 29. Epub 2018 May 29.

College of Biology, Hunan University, Changsha, 410082, Hunan, China.

Small-diameter tissue-engineered vascular grafts are urgently needed for clinic arterial substitute. To simulate the structures and functions of natural blood vessels, we designed a novel triple-layer poly(ε-caprolactone) (PCL) fibrous vascular graft by combining E-jet 3D printing and electrospinning techniques. The resultant vascular graft consisted of an interior layer comprising 3D-printed highly aligned strong fibers, a middle layer made by electrospun densely fibers, and an exterior structure composed of mixed fibers fabricated by co-electrospraying. Read More

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May 2018
2 Reads

Eye Movements Evoked by Pulsed Infrared Radiation of the Rat Vestibular System.

Ann Biomed Eng 2018 May 29. Epub 2018 May 29.

Department of Biomedical Engineering, University of Miami, 1251 Memorial Drive, MEA 204, Coral Gables, FL, 33146, USA.

Light at infrared wavelengths has been demonstrated to modulate the pattern of neural signals transmitted from the angular motion sensing semicircular canals of the vestibular system to the brain. In the present study, we have characterized physiological eye movements evoked by focused, pulsed infrared radiation (IR) stimuli directed at an individual semicircular canal in a mammalian model. Pulsed IR (1863 nm) trains were directed at the posterior semicircular canal in a rat using 200-400 µm optical fibers. Read More

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May 2018
2 Reads

In-Human Robot-Assisted Retinal Vein Cannulation, A World First.

Ann Biomed Eng 2018 May 24. Epub 2018 May 24.

Department of Mechanical Engineering, KU Leuven - University of Leuven, 3001, Heverlee, Belgium.

Retinal Vein Occlusion (RVO) is a blinding disease caused by one or more occluded retinal veins. Current treatment methods only focus on symptom mitigation rather than targeting a solution for the root cause of the disorder. Retinal vein cannulation is an experimental eye surgical procedure which could potentially cure RVO. Read More

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Mechanical Performance of Two Left Atrial Appendage Occlusion Systems: In Vitro Comparison of Tug Force, Radial Force, Sealing and Deformation.

Ann Biomed Eng 2018 May 24. Epub 2018 May 24.

Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.

The aim of this study was to establish in vitro bench-tests of left atrial appendage occlusion (LAAo) devices regarding tug force, radial force and sealing capacity. Two LAAo devices, namely the WATCHMAN™ and the Occlutech, of three different sizes underwent testing in novel dedicated in vitro setups. Radial force was assessed in a commercial radial force tester. Read More

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Fractal Dimension of Erythrocyte Membranes: A Highly Useful Precursor for Rapid Morphological Assay.

Ann Biomed Eng 2018 May 23. Epub 2018 May 23.

Department of Chemical Engineering, University of Calcutta, Kolkata, 700 009, India.

Morphology of erythrocyte membrane has been recognized as an alternative biomarker of several patho-physiological states. Numerous attempts have been made to upgrade the existing method of primitive manual counting, particularly exploring the light scattering properties of erythrocyte. All the techniques are at best semi-empirical and heavily rely on the effectiveness of the statistical correlations. Read More

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Augmented Reality Based Navigation for Computer Assisted Hip Resurfacing: A Proof of Concept Study.

Ann Biomed Eng 2018 May 23. Epub 2018 May 23.

Mechatronics in Medicine Laboratory, Imperial College, London, UK.

Implantation accuracy has a great impact on the outcomes of hip resurfacing such as recovery of hip function. Computer assisted orthopedic surgery has demonstrated clear advantages for the patients, with improved placement accuracy and fewer outliers, but the intrusiveness, cost, and added complexity have limited its widespread adoption. To provide seamless computer assistance with improved immersion and a more natural surgical workflow, we propose an augmented-reality (AR) based navigation system for hip resurfacing. Read More

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Motile Dendritic Cells Sense and Respond to Substrate Geometry.

Ann Biomed Eng 2018 May 22. Epub 2018 May 22.

Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA.

Dendritic cell (DC) migration is required for efficient presentation of antigen to T cells and the initiation of an adaptive immune response. In spite of its importance, many aspects of DC migration have not been characterized. DCs encounter a variety of environments with different stiffness and geometry, but the effect of these parameters on DC migration has not yet been determined. Read More

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The Biomechanics of the Inter-Lamellar Matrix and the Lamellae During Progression to Lumbar Disc Herniation: Which is the Weakest Structure?

Ann Biomed Eng 2018 May 21. Epub 2018 May 21.

Biomechanics and Implants Research Group, Medical Device Research Institute, College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia.

While microstructural observations have improved our understanding of possible pathways of herniation progression, no studies have measured the mechanical failure properties of the inter-lamellar matrix (ILM), nor of the adjacent lamellae during progression to herniation. The aim of this study was to employ multiscale, biomechanical and microstructural techniques to evaluate the effects of progressive induced herniation on the ILM and lamellae in control, pre-herniated and herniated discs (N = 7), using 2 year-old ovine spines. Pre-herniated and herniated (experimental) groups were subjected to macroscopic compression while held in flexion (13°), before micro-mechanical testing. Read More

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A Framework for Image-Based Modeling of Acute Myocardial Ischemia Using Intramurally Recorded Extracellular Potentials.

Ann Biomed Eng 2018 May 21. Epub 2018 May 21.

Department of Bioengineering, University of Utah, Salt Lake City, UT, USA.

The biophysical basis for electrocardiographic evaluation of myocardial ischemia stems from the notion that ischemic tissues develop, with relative uniformity, along the endocardial aspects of the heart. These injured regions of subendocardial tissue give rise to intramural currents that lead to ST segment deflections within electrocardiogram (ECG) recordings. The concept of subendocardial ischemic regions is often used in clinical practice, providing a simple and intuitive description of ischemic injury; however, such a model grossly oversimplifies the presentation of ischemic disease-inadvertently leading to errors in ECG-based diagnoses. Read More

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Stormram 4: An MR Safe Robotic System for Breast Biopsy.

Ann Biomed Eng 2018 May 21. Epub 2018 May 21.

Department of Robotics and Mechatronics, University of Twente, att. Vincent Groenhuis, Room CR-3.526, Postbus 217, 7500AE, Enschede, The Netherlands.

Suspicious lesions in the breast that are only visible on magnetic resonance imaging (MRI) need to be biopsied under MR guidance with high accuracy and efficiency for accurate diagnosis. The aim of this study is to present a novel robotic system, the Stormram 4, and to perform preclinical tests in an MRI environment. Excluding racks and needle, its dimensions are 72 × 51 × 40 mm. Read More

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Computational Fluid Dynamics Modeling of the Human Pulmonary Arteries with Experimental Validation.

Ann Biomed Eng 2018 May 21. Epub 2018 May 21.

UTSA/UTHSA Joint Graduate Program in Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA.

Pulmonary hypertension (PH) is a chronic progressive disease characterized by elevated pulmonary arterial pressure, caused by an increase in pulmonary arterial impedance. Computational fluid dynamics (CFD) can be used to identify metrics representative of the stage of PH disease. However, experimental validation of CFD models is often not pursued due to the geometric complexity of the model or uncertainties in the reproduction of the required flow conditions. Read More

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Towards Alternative Approaches for Coupling of a Soft Robotic Sleeve to the Heart.

Ann Biomed Eng 2018 May 15. Epub 2018 May 15.

Harvard-MIT Program in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA.

Efficient coupling of soft robotic cardiac assist devices to the external surface of the heart is crucial to augment cardiac function and represents a hurdle to translation of this technology. In this work, we compare various fixation strategies for local and global coupling of a direct cardiac compression sleeve to the heart. For basal fixation, we find that a sutured Velcro band adheres the strongest to the epicardium. Read More

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May 2018
2 Reads

Computational Pre-surgical Planning of Arterial Patch Reconstruction: Parametric Limits and In Vitro Validation.

Ann Biomed Eng 2018 May 14. Epub 2018 May 14.

Department of Mechanical Engineering, Koc University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey.

Surgical treatment of congenital heart disease (CHD) involves complex vascular reconstructions utilizing artificial and native surgical materials. A successful surgical reconstruction achieves an optimal hemodynamic profile through the graft in spite of the complex post-operative vessel growth pattern and the altered pressure loading. This paper proposes a new in silico patient-specific pre-surgical planning framework for patch reconstruction and investigates its computational feasibility. Read More

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Correction to: Predictive Simulations of Neuromuscular Coordination and Joint-Contact Loading in Human Gait.

Ann Biomed Eng 2018 May 14. Epub 2018 May 14.

Department of Mechanical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia.

In the "Materials and Methods" section, the link provided at the bottom of the second paragraph should be https://simtk.org/home/dcwithjtcontact/ . Read More

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Classification of Breast Masses Using a Computer-Aided Diagnosis Scheme of Contrast Enhanced Digital Mammograms.

Ann Biomed Eng 2018 May 10. Epub 2018 May 10.

School of Electrical and Computer Engineering, University of Oklahoma, 101 David L Boren Blvd, Norman, OK, 73019, USA.

Contrast-enhanced digital mammography (CEDM) is a promising imaging modality in breast cancer diagnosis. This study aims to investigate how to optimally develop a computer-aided diagnosis (CAD) scheme of CEDM images to classify breast masses. A CEDM dataset of 111 patients was assembled, which includes 33 benign and 78 malignant cases. Read More

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Feasibility Testing of Hydrophobic Carbon Electrodes for Acquisition of Underwater Surface Electromyography Data.

Ann Biomed Eng 2018 May 7. Epub 2018 May 7.

Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA.

Underwater surface electromyography (sEMG) signals are especially of interest for rehabilitation and sports medicine applications. Silver/silver chloride (Ag/AgCl) hydrogel electrodes, although the gold standard for sEMG data collection, require waterproofing for underwater applications. Having to apply waterproof tape over electrodes impedes the deployment of sEMG in immersed conditions. Read More

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May 2018
1 Read

Design, Modelling and Teleoperation of a 2 mm Diameter Compliant Instrument for the da Vinci Platform.

Ann Biomed Eng 2018 May 7. Epub 2018 May 7.

Centre for Image-Guided Innovation & Therapeutic Intervention, The Hospital for Sick Children, Toronto, Canada.

This work explores the feasibility of creating and accurately controlling an instrument for robotic surgery with a 2 mm diameter and a three degree-of-freedom (DoF) wrist which is compatible with the da Vinci platform. The instrument's wrist is composed of a two DoF bending notched-nitinol tube pattern, for which a kinematic model has been developed. A base mechanism for controlling the wrist is designed for integration with the da Vinci Research Kit. Read More

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Enhanced In Vivo Bone and Blood Vessel Formation by Iron Oxide and Silica Doped 3D Printed Tricalcium Phosphate Scaffolds.

Ann Biomed Eng 2018 May 4. Epub 2018 May 4.

Washington State University, Pullman, WA, 99164-2920, USA.

Calcium phosphate (CaP) ceramics show significant promise towards bone graft applications because of the compositional similarity to inorganic materials of bone. With 3D printing, it is possible to create ceramic implants that closely mimic the geometry of human bone and can be custom-designed for unusual injuries or anatomical sites. The objective of the study was to optimize the 3D-printing parameters for the fabrication of scaffolds, with complex geometry, made from synthesized tricalcium phosphate (TCP) powder. Read More

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Developments and Control of Biocompatible Conducting Polymer for Intracorporeal Continuum Robots.

Ann Biomed Eng 2018 Apr 30. Epub 2018 Apr 30.

FEMTO-ST Institute, Univ. Bourgogne Franche-Comté/CNRS, Besançon, France.

Dexterity of robots is highly required when it comes to integration for medical applications. Major efforts have been conducted to increase the dexterity at the distal parts of medical robots. This paper reports on developments toward integrating biocompatible conducting polymers (CP) into inherently dexterous concentric tube robot paradigm. Read More

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April 2018
3 Reads

Torso-Tank Validation of High-Resolution Electrogastrography (EGG): Forward Modelling, Methodology and Results.

Ann Biomed Eng 2018 Apr 27. Epub 2018 Apr 27.

Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.

Electrogastrography (EGG) is a non-invasive method for measuring gastric electrical activity. Recent simulation studies have attempted to extend the current clinical utility of the EGG, in particular by providing a theoretical framework for distinguishing specific gastric slow wave dysrhythmias. In this paper we implement an experimental setup called a 'torso-tank' with the aim of expanding and experimentally validating these previous simulations. Read More

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Immersive Virtual Reality to Improve Walking Abilities in Cerebral Palsy: A Pilot Study.

Ann Biomed Eng 2018 Apr 27. Epub 2018 Apr 27.

Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.

Immersive virtual reality (IVR) offers new possibilities to perform treatments in an ecological and interactive environment with multimodal online feedbacks. Sixteen school-aged children (mean age 11 ± 2.4 years) with Bilateral CP-diplegia, attending mainstream schools were recruited for a pilot study in a pre-post treatment experimental design. Read More

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The Effect of Heated CO Insufflation in Minimising Surgical Wound Contamination During Open Surgery.

Ann Biomed Eng 2018 Apr 27. Epub 2018 Apr 27.

Department of Engineering Science, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.

The primary source of infections in open surgeries has been found to be bacteria and viruses carried into the surgical wound on the surfaces of skin particles shed by patients and surgical staff. In open cardiac surgeries, insufflation of the wound with carbon dioxide is used to limit the quantity of air able to enter into the heart, avoiding air embolisms when the heart is restarted. This surgical technique has been evaluated as a method of limiting the number of skin particles able to enter into the wound, using computational fluid dynamics (CFD) simulations and experimental testing. Read More

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Tissue Identification in a Porcine Model by Differential Ion Mobility Spectrometry Analysis of Surgical Smoke.

Ann Biomed Eng 2018 Apr 24. Epub 2018 Apr 24.

Division of Vascular Surgery, Tampere University Hospital, Tampere, Finland.

Electrosurgery is widely used in various surgical operations. When tissue is cut with high-frequency current, the cell contents at the incision area evaporate and together with water and possible soot particles, form surgical smoke. The smoke contains cell metabolites, and therefore, possible biomarkers for cancer or bacterial infection. Read More

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April 2018
2 Reads

The Role of Circle of Willis Anatomy Variations in Cardio-embolic Stroke: A Patient-Specific Simulation Based Study.

Ann Biomed Eng 2018 Apr 24. Epub 2018 Apr 24.

Department of Mechanical Engineering, University of California, Berkeley, USA.

We describe a patient-specific simulation based investigation on the role of Circle of Willis anatomy in cardioembolic stroke. Our simulation framework consists of medical image-driven modeling of patient anatomy including the Circle, 3D blood flow simulation through patient vasculature, embolus transport modeling using a discrete particle dynamics technique, and a sampling based approach to incorporate parametric variations. A total of 24 (four patients and six Circle anatomies including the complete Circle) models were considered, with cardiogenic emboli of varying sizes and compositions released virtually and tracked to compute distribution to the brain. Read More

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April 2018
2 Reads

Mechanical and Clinical Evaluation of a Shape Memory Alloy and Conventional Struts in a Flexible Scoliotic Brace.

Ann Biomed Eng 2018 Apr 24. Epub 2018 Apr 24.

Centre for Orthopaedic Surgery, Central, Hong Kong SAR, China.

Smart materials have attracted considerable attention in the medical field. In particular, shape memory alloys (SMAs) are most commonly utilized for their superelasticity (SE) in orthopaedic treatment. In this study, the resin struts of a flexible brace for adolescent idiopathic scoliosis (AIS) are replaced with different conventional materials and an SMA. Read More

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April 2018
2 Reads

The Development of a Four-Electrode Bio-Impedance Sensor for Identification and Localization of Deep Pulmonary Nodules.

Ann Biomed Eng 2018 Apr 23. Epub 2018 Apr 23.

Department of Thoracic Surgery, Tracheal Diseases Research Center (TDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Identifying and localizing of deep pulmonary nodules are among the main challenges that thoracic surgeons face during operations, particularly in thoracoscopic procedures. To facilitate this, we have tried to introduce a non-invasive and safe method by measuring the lung electrical bio-impedance spectrum with a four-electrode array sensor. To study the feasibility of this method, since any change in the depth or diameter of the nodule in the lung tissue is not practical, we used the finite element modeling of the lung tissue and pulmonary nodule to allow changes in the depth and diameter of the nodule, as well as the distance in between the injection electrodes. Read More

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April 2018
2 Reads

A Skull-Mounted Robot with a Compact and Lightweight Parallel Mechanism for Positioning in Minimally Invasive Neurosurgery.

Ann Biomed Eng 2018 Apr 23. Epub 2018 Apr 23.

Department of Biomedical Engineering, National University of Singapore, EA-05-30, 9 Engineering Drive 1, Singapore, 117575, Singapore.

Robotic systems play an increasingly important role in improving feasibility and effectiveness of minimally invasive neurosurgery (MIN). However, large footprint, bulky size, and complex mechanisms limit the clinical application of existing robotic neurosurgery solutions. This paper proposes a novel skull-mounted robot with a compact and lightweight parallel mechanism for positioning of surgical tools in MIN. Read More

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April 2018
2 Reads

3D Reconstruction of Scoliotic Spines from Stereoradiography and Depth Imaging.

Ann Biomed Eng 2018 Apr 23. Epub 2018 Apr 23.

Department of Mechanical Engineering, Technion Israel Institute of Technology, 32000, Haifa, Israel.

Spine shape can be reconstructed from stereoradiography, but often requires specialized infrastructure or fails to account for subject posture. In this paper a protocol is presented for stereo reconstructions that integrates surface recordings with radiography and naturally accounts for variations in patient posture. Low cost depth cameras are added to an existing radiographic system to capture patient pose. Read More

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April 2018
1 Read

Computational Model for Hyperfibrinolytic Onset of Acute Traumatic Coagulopathy.

Ann Biomed Eng 2018 Apr 19. Epub 2018 Apr 19.

Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.

The onset of acute traumatic coagulopathy in trauma patients exacerbates hemorrhaging and dramatically increases mortality. The disease is characterized by increased localized bleeding, and the mechanism for its onset is not yet known. We propose that the fibrinolytic response, specifically the release of tissue-plasminogen activator (t-PA), within vessels of different sizes leads to a variable susceptibility to local coagulopathy through hyperfibrinolysis which can explain many of the clinical observations in the early stages from severely injured coagulopathic patients. Read More

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April 2018
1 Read

A New Venous Entry Detection Method Based on Electrical Bio-impedance Sensing.

Ann Biomed Eng 2018 Apr 19. Epub 2018 Apr 19.

Department of Advanced Robotics, Istituto Italiano di Tecnologia, 16163, Genoa, Italy.

Peripheral intravenous catheterization (PIVC) is frequently required for various medical treatments. Over 1 billion PIVC operations are performed per year in the United States alone. However, this operation is characterized by a very low success rate, especially amongst pediatric patients. Read More

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April 2018
8 Reads

Cell Mimicking Microparticles Influence the Organization, Growth, and Mechanophenotype of Stem Cell Spheroids.

Ann Biomed Eng 2018 Apr 18. Epub 2018 Apr 18.

Center for Biomedical Engineering, Brown University, 175 Meeting Street, Box G-B397, Providence, RI, 02912, USA.

Substrate stiffness is known to alter cell behavior and drive stem cell differentiation, though most research in this area has been restricted to traditional, two-dimensional culture systems rather than more physiologically relevant, three-dimensional (3D) platforms. In this study, we utilized polymer-based, cell mimicking microparticles (CMMPs) to deliver distinct, stable mechanical cues to human adipose derived stem cells in 3D spheroid culture to examine changes in adipogenic differentiation response and mechanophenotype. After 21 days of adipogenic induction, spheroids containing CMMPs (composite spheroids) stiffened in accordance with CMMP elasticity such that spheroids containing the stiffest, ~ 10 kPa, CMMPs were over 27% stiffer than those incorporating the most compliant, ~ 0. Read More

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April 2018
2 Reads

Novel Method for Superposing 3D Digital Models for Monitoring Orthodontic Tooth Movement.

Ann Biomed Eng 2018 Apr 18. Epub 2018 Apr 18.

Department of Orthodontics, Centre of Dentistry, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany.

Quantitative three-dimensional analysis of orthodontic tooth movement (OTM) is possible by superposition of digital jaw models made at different times during treatment. Conventional methods rely on surface alignment at palatal soft-tissue areas, which is applicable to the maxilla only. We introduce two novel numerical methods applicable to both maxilla and mandible. Read More

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April 2018
2 Reads

Predictive Simulations of Neuromuscular Coordination and Joint-Contact Loading in Human Gait.

Ann Biomed Eng 2018 Apr 18. Epub 2018 Apr 18.

Department of Mechanical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia.

We implemented direct collocation on a full-body neuromusculoskeletal model to calculate muscle forces, ground reaction forces and knee contact loading simultaneously for one cycle of human gait. A data-tracking collocation problem was solved for walking at the normal speed to establish the practicality of incorporating a 3D model of articular contact and a model of foot-ground interaction explicitly in a dynamic optimization simulation. The data-tracking solution then was used as an initial guess to solve predictive collocation problems, where novel patterns of movement were generated for walking at slow and fast speeds, independent of experimental data. Read More

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April 2018
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Finite Element Analysis of Tricuspid Valve Deformation from Multi-slice Computed Tomography Images.

Ann Biomed Eng 2018 Apr 16. Epub 2018 Apr 16.

The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.

Despite the growing clinical interest in the tricuspid valve (TV), there is an incomplete understanding of TV biomechanics which is important in normal TV function and successful TV repair techniques. Computational models with patient-specific human TV geometries can provide a quantitative understanding of TV biomechanic. Therefore, this study aimed to develop finite element (FE) models of human TVs from multi-slice computed tomography (MSCT) images to investigate chordal forces and leaflet stresses and strains. Read More

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April 2018
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