A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Heart Center Rostock, University Hospital of Rostock, Germany
Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the second electrode.
February 2012: This Month in JoVE
Here are some highlights from the February 2012 Issue of Journal of Visualized Experiments (JoVE).
Bronchial Thermoplasty: A Novel Therapeutic Approach to Severe Asthma
1Director of Pulmonary Special Procedures and the Lung Cancer Center, Virginia Hospital Center, 2Chief, Division of Pulmonary Critical Care and Sleep Medicine, Virginia Hospital Center
Bronchial thermoplasty is a non-drug procedure for severe persistent asthma that delivers thermal energy to the airway wall in a precisely controlled manner to reduce excessive airway smooth muscle. Reducing airway smooth muscle decreases the ability of the airways to constrict, thereby reducing the frequency of asthma attacks.
Ambulatory ECG Recording in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Telemetric ECG has emerged as an essential tool in evaluating animal models for cardiac arrhythmias and sudden cardiac death. Here, we present a stepwise guide to telemetric ECG recordings for application in long-term ambulatory ECG monitoring in mice.
Micro-drive Array for Chronic in vivo Recording: Drive Fabrication
1Picower Institute for Learning and Memory, MIT - Massachusetts Institute of Technology, 2Department of Brain and Cognitive Science, MIT - Massachusetts Institute of Technology
In this protocol we demonstrate how to fabricate a micro-drive array for chronic electrophysiological recordings in rats.
Fiber-optic Implantation for Chronic Optogenetic Stimulation of Brain Tissue
1Department of Molecular & Human Genetics, Baylor College of Medicine (BCM), 2Department of Neuroscience, Baylor College of Medicine (BCM), 3Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital
The development of optogenetics now provides the means to precisely stimulate genetically defined neurons and circuits, both in vitro and in vivo. Here we describe the assembly and implantation of a fiber optic for chronic photostimulation of brain tissue.
Phenotypic and Functional Characterization of Endothelial Colony Forming Cells Derived from Human Umbilical Cord Blood
Herman B Wells Center for Pediatric Research, Indiana University School of Medicine
Endothelial colony forming cells (ECFCs) are circulating endothelial cells with robust clonal proliferative potential that display intrinsic in vivo vessel forming ability. Phenotypic and functional characterization of outgrowth endothelial cells derived from CB are important to identify and isolate bona fide ECFCs for potential clinical application in repairing damaged tissues.
Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance
Department of Biomedical Physiology and Kinesiology, Simon Fraser University
We describe a "gold standard" for evaluating orthostatic tolerance (OT) using tilt testing with combined lower body negative pressure (LBNP). This can be combined with non-invasive evaluations of cardiovascular reflex control. Normal and abnormal responses are defined.
A Simple Guide Screw Method for Intracranial Xenograft Studies in Mice
1Monash Institute of Medical Research, 2MD Anderson Cancer Centre, University of Texas
In order to evaluate novel therapeutic paradigms for the treatment of glioma, physiological relevant models are essential. We utilize an implantable guide screw procedure for establishment of intracranial xenograft models that is more rapid and safer than stereotactic approaches.
September 2011: This Month in JoVE
Here are some highlights from the September 2011 Issue of Journal of Visualized Experiments (JoVE).
Engineering Biological-Based Vascular Grafts Using a Pulsatile Bioreactor
1Department of Biomedical Engineering, Yale University, 2Department of Anesthesiology, Yale University School of Medicine
Our group has developed a bioreactor culture system that mimics the physiological pulsatile stresses of the cardiovascular system to regenerate implantable small-diameter vascular grafts.
Behavioral Determination of Stimulus Pair Discrimination of Auditory Acoustic and Electrical Stimuli Using a Classical Conditioning and Heart-rate Approach
School of Psychological Science, La Trobe University
The application of a classical fear conditioning behavioral paradigm for auditory prosthetic research in rats is described. This paradigm provides a mechanism for identifying both detection of, and discrimination between, distinct acoustic and electrical stimuli using heart-rate as an outcome measure.
Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping
1Wadsworth Center, New York State Department of Health, 2Department of Neurology, Albany Medical College, 3Department of Neurosurgery, Albany Medical College, 4Department of Neurosurgery, Washington University, 5Department of Biomed. Eng., Rensselaer Polytechnic Institute, 6Department of Biomed. Sci., State University of New York at Albany, 7Department of Elec. and Comp. Eng., University of Texas at El Paso
We present a method for collecting electrocorticographic signals for research purposes from humans who are undergoing invasive epilepsy monitoring. We show how to use the BCI2000 software platform for data collection, signal processing and stimulus presentation. Specifically, we demonstrate SIGFRIED, a BCI2000-based tool for real-time functional brain mapping.
Hydrophobic Salt-modified Nafion for Enzyme Immobilization and Stabilization
Departments of Chemistry and Materials Science and Engineering, University of Utah
This article will describe the procedure for synthesizing a hydrophobically modified Nafion enzyme immobilization membrane and how to immobilize proteins and/or enzymes within the membrane and test their specific activity.
Design and Assembly of an Ultra-light Motorized Microdrive for Chronic Neural Recordings in Small Animals
1Center for Brain Science, Harvard University, 2Program in Neuroscience, Harvard University, 3Department of Organismic and Evolutionary Biology, Harvard University
The design, fabrication and assembly of an ultra-light motorized microdrive is described. The device provides a cost-effective and easy-to-use solution for chronic recordings of single units in small behaving animals.
Simultaneous Electroencephalography, Real-time Measurement of Lactate Concentration and Optogenetic Manipulation of Neuronal Activity in the Rodent Cerebral Cortex
A procedure is described for manipulating the activity of cerebral cortical pyramidal neurons optogenetically while the electroencephalogram, electromyogram, and cerebral lactate concentration are monitored. Experimental recordings are performed on cable-tethered mice while they undergo spontaneous sleep/wake cycles. Optogenetic equipment is assembled in our laboratory; recording equipment is commercially available.
Planar and Three-Dimensional Printing of Conductive Inks
1Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 2Center for Micro- and Nanotechnology, Lawrence Livermore National Laboratory, 3Presently at the Interdisciplinary Center for Wide Band-gap Semiconductors, University Of California Santa Barbara
Planar and three-dimensional printing of conductive metallic inks is described. Our approach provides new avenues for fabricating printed electronic, optoelectronic, and biomedical devices in unusual layouts at the microscale.
Procedure for Lung Engineering
1Department of Biomedical Engineering, Yale University, 2Department of Biomedical Engineering, School of Medicine, Duke University, 3Department of Anesthesia, Yale University
We have developed a decellularized lung extracellular matrix and novel biomimetic bioreactor that can be used to generate functional lung tissue. By seeding cells into the matrix and culturing in the bioreactor, we generate tissue that demonstrates effective gas exchange when transplanted in vivo for short periods of time.
Examining Local Network Processing using Multi-contact Laminar Electrode Recording
1Graduate School of Biomedical Science, Neuroscience Program, University of Texas, 2Department of Neurobiology and Anatomy, University of Texas
A fundamental issue in our understanding of cortical circuitry is how networks in different cortical layers encode sensory information. Here we describe electrophysiological techniques utilizing multi-contact laminar electrodes to record single-units and local field potentials and present analyses to identify cortical layers.
Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model
Institute of Human Physiology and Clinical Experimental Research, Semmelweis University
We demonstrate how to set up an in vitro ischemia/reperfusion model and how to evaluate the effect of stem cell therapy on postischemic cardiac cells.
Fabrication of Myogenic Engineered Tissue Constructs
1Department of Anesthesiology, Children's Hospital Boston and Harvard Medical School, 2Perioperative and Pain Medicine, Children's Hospital Boston and Harvard Medical School
Here, we demonstrate fabrication of collagen-based, tissue constructs containing skeletal myoblasts. These 3-D engineered constructs may be used to replace or repair tissues in vivo. For our purposes, we have designed these as an atrioventricular electrical conduit for the repair of complete heart block[1].
Measurement of Aggregate Cohesion by Tissue Surface Tensiometry
Department of Surgery, UMDNJ-Robert Wood Johnson Medical School
We describe a method of measuring binding energy, expressible as tissue surface tension, between cells within 3D tissue-like aggregates. Differences in tissue surface tension have been demonstrated to correlate with invasiveness of lung, muscle, and brain tumors, and are fundamental determinants of establishing spatial relationships between different cell types.
Large-scale Recording of Neurons by Movable Silicon Probes in Behaving Rodents
1Center for Molecular and Behavioral Neuroscience, University of New Jersey, 2Center for Interdisciplinary Research in Biology, Collège de France, 3Janelia Farm Research Campus, Howards Hughes Medical Institute, 4Deptartment of Psychology, University of Wisconsin at Milwaukee
We describe methods for large-scale recording of multiple single units and local field potential in behaving rodents with silicon probes. Drive fabrication, probe attachment to the drive and probe implantation processes are illustrated in sufficient details for easy replication.
Cell Co-culture Patterning Using Aqueous Two-phase Systems
1Department of Biomedical Engineering, University of Michigan, 2Department of Macromolecular Science and Engineering, University of Michigan
Aqueous two-phase systems were used to simultaneously pattern multiple populations of cells. This fast and easy method for cell patterning takes advantage of the phase separation of aqueous solutions of dextran and polyethylene glycol and the interfacial tension that exists between the two polymer solutions.
Silk Film Culture System for in vitro Analysis and Biomaterial Design
1Margaret M. Dyson Vision Research Institute, Weill Cornell Medical College, 2Department of Biomedical Engineering, Tufts University
Silk films are a novel class of biomaterials readily customizable for an array of biomedical applications. The presented silk film culture system is highly adaptable to a variety of in vitro analyses. This system represents a biomaterial design platform offering in vitro optimization before direct translation to in vivo models.
Implantation of Radiotelemetry Transmitters Yielding Data on ECG, Heart Rate, Core Body Temperature and Activity in Free-moving Laboratory Mice
1Division of Surgical Research, University Hospital Zurich, 2Institute of Laboratory Animal Science, University of Zurich
A surgical technique for implantation of commercially available telemetry transmitters used for continuous measurement of biopotential (one-lead ECG), heart rate, core body temperature and locomotor activity in freely moving mice is shown. Recommendations and protocols for post-operative care and pain relief, improving recovery, well being and survival rate are also presented.
Autologous Endothelial Progenitor Cell-Seeding Technology and Biocompatibility Testing For Cardiovascular Devices in Large Animal Model
1Department of Biomedical Engineering, Duke University, 2School of Medicine, Duke University, 3Department of Surgery, Duke University Medical Center, 4School of Medicine, University of Pennsylvania
A method for seeding titanium blood-contacting biomaterials with autologous cells and testing biocompatibility is described. This method uses endothelial progenitor cells and titanium tubes, seeded within minutes of surgical implantation into porcine venae cavae. This technique is adaptable to many other implantable biomedical devices.
Studying the Neural Basis of Adaptive Locomotor Behavior in Insects
Zoological Institute, University of Cologne
We describe a method to record motor activity, timed to the electrically recorded tarsal contact signal in a tethered insect, walking on a slippery surface. This is used to study the neural basis of adaptive behavior under reduced influence of mechanical interaction between legs through the substrate.
Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements
Department of Pharmacology and Toxicology, Michigan State University
Chronic catheterization of blood vessels in the rat is often required for administration of substances, obtain blood sample over a period of time or for direct conscious blood pressure measurements. Femoral arterial catheterization of the rat and corresponding measurements of blood pressure in the conscious animal will be demonstrated.
Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations
A methodology to estimate ventricular fiber orientations from in vivo images of patient heart geometries for personalized modeling is described. Validation of the methodology performed using normal and failing canine hearts demonstrate that that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level.
Remote Magnetic Navigation for Accurate, Real-time Catheter Positioning and Ablation in Cardiac Electrophysiology Procedures
1Cardiology, Robotic Cardiac Electrophysiology and Arrhythmia Unit, La Paz University Hospital, 2Magnetecs Corp., 3Cardiology, Geffen School of Medicine at UCLA Los Angeles
This report provides a detailed description of a new remote navigation system based on magnetic driven forces, which has been recently introduced as a new robotic tool for human cardiac electrophysiology procedures.
Bridging the Bio-Electronic Interface with Biofabrication
1Fischell Department of Bioengineering, University of Maryland, 2Institute for Bioscience and Biotechnology Research, University of Maryland, 3Department of Materials Science and Engineering, University of Maryland
This article describes a biofabrication approach: deposition of stimuli-responsive polysaccharides in the presence of biased electrodes to create biocompatible films which can be functionalized with cells or proteins. We demonstrate a bench-top strategy for the generation of the films as well as their basic uses for creating interactive biofunctionalized surfaces for lab-on-a-chip applications.
