Biomedical Engineering is inherently an interdisciplinary field. Innovative research involves synergistic collaborations of disciplines in science, engineering, and medicine. The objective of the GWIBE Interdisciplinary Research Fund is to provide impetus for biomedical researchers to seek collaborations across disciplines. We welcome researchers who are active in their own disciplines but have not had the opportunity to participate in biomedical engineering research. Prospective applicants may contact GWIBE for assistance in identifying potential collaborative partners. The ultimate objective of this initiative is to provide seed funds to develop successful externally-funded proposals in biomedical engineering.

Visit here for a list of past winners.

 

 

Volumetric datasets are used in many surgical applications. Displaying the 3D information contained in these datasets on 2D screens effectively is challenging, because of loss of information due to projection from 3D to 2D space. Problems such as opaque structures occluding each other and difficulty of perceiving depth of a given pixel complicates these kinds of volume visualizations. Application of effects like transparency and transfer functions to show certain anatomical structures makes the mental mapping between the visualization and the patient difficult. We have used the focus+context visualization paradigm to help with these problems. The users can explore the datasets by using different transfer functions in different parts of therendering. This way, internal structures can be displayed by exploring multiple co-registered datasets in a single coherent view. A novel rendering method using depth images minimizes the performance impact of this visualization approach.

An extension to this visualization idea is also developed by using volumetric brushes to perform volume editing tasks. This way, the users can perform accumulated selection of arbitrary shaped regions, and combine multiple datasets in a single visualization.

[More info and video] [ICG page]

Participants: Can Kirmizibayrak, James Hahn


  Traditional tactile interaction methods such as trackers or the mouse can cause problems when used in the operating room. Trackers can be expensive, difficult to setup and calibrate and prone to errors due to line-of-sight requirements or electromagnetic interference. The mouse is ubiquitous, but it is a 2D interface and might be difficult in 3D interaction tasks necessary for volume visualization. The common problem for all these interfaces is that they require sterilization, a process that is time consuming, costly, and possibly can cause complications.

The use of gestures can replace these interaction methods and eliminate these problems. Furthermore, intuitive methods like these can decrease the training time necessary for performing interaction tasks important for medical volume visualization. We are developing such methods for common tasks such as data exploration, editing and rotation. The user studies conducted showed that novice users can perform tasks such as matching rotations and finding internal structures in a volumetric dataset very effectively and quickly using a gesture-based interface compared to the mouse.

[More info and video] [ICG Page]

Participants: Can Kirmizibayrak, Nadezhda Radeva, James Hahn


  All swimming techniques in competitive swimming are primarily oriented towards two goals: maximizing thrust and minimizing drag. Two factors make these goals difficult to achieve:

1. The water flow past a swimmer, which ultimately determines the total force on the swimmer, is highly complex and turbulent, and little regarding the dynamics of this flow is currently understood.

2. The typical swimming stroke is generally quite complex and composed of a sequence of coordinated body motions. Variations are possible at every stage in the stroke making it difficult to determine which particular composition is optimal in terms of thrust production and drag reduction.

In the past, research in swimming techniques has been limited to relatively simple experiments, theoretical modeling and videographic analysis. However, with the recent advances in computer hardware and software, techniques such as computational fluid dynamics (CFD) and computer animation and visualization can now be brought to bear on this problem. We are working with USA Swimming to systematically addresses both of the above factors.
The near term objective of this research is to produce tangible results that can impact the performance of Team-USA in the 2008 Olympics. In the long term, this research is expected to generate research and development that will greatly improve our fundamental understanding of the fluid dynamics and biomechanics of swimming and produce tools that can be used for coaching, and assessing swimmers at all levels of performance.

Project Poster | High Resolution (3072x2034, TIFF file) | Low Resolution (1024x768, JPEG File)

Demo Video | (.AVI 51.8M) | (.WMV 21.3M)

Also visit:
Computer Animation and Visualization of Olympic Swimmers
Full Body Analysis of Swimming Techniques

 

 

In cancer medicine, the most common predictive factors and prognostic approach is the categorical system of TNM (Tumor, Lymph Node Status, and Metastasis) that defines the anatomic extent of disease at diagnosis. However, practice by medical professional specialties over many years has shown that TNM is useful but needs to be expanded to accommodate additional clinical, diagnostic, and therapeutic responsive predictive factors for higher accuracy in prediction. For example, by 1995, 76 predictive factors had been reported for breast cancer. However, not one of these factors has been incorporated into the TNM. The integration of new predictive factors into comprehensive systems with greater predictive power than the TNM will clearly benefit patients and physicians and is needed.

Currently we are working on novel clustering approaches that predict the outcome of cancer patients. These approaches aim at producing a prognostic system that provides descriptive statistics to ascertain which patients constitute a set of subgroups such that patients within each group are more similar in survival than patients from different groups. While our research focuses on cancer, we should emphasize that this research has general application. These are completely new approaches since it is the first time censored data has been taken into account within the framework of cluster analysis.

From a broader view, we primarily focus on development and application of machine learning techniques (e.g., support vector machines, the method of stochastic discrimination, etc.) including their feasibility and application to laboratory research and patient care. More specifically, we have five major research thrusts: 1) analysis of array data with application to cancer etiology, treatment, and personalized medicine, 2) evaluation and identification of risk factors for cancer and methods of evaluation, 3) clinical outcomes and survival prediction, 4) demographic and epidemiologic analysis, and 5) development and testing of novel computer based algorithms.

For more information, please contact Prof. Susan Cheng at cheng@gwu.edu

 
 
  Atherosclerosis is a major cause of death in the United States. Stroke, one consequence of this occlusive disease in a carotid artery, remains one of the leading contributors to major morbidity and mortality within the United States, in which approximately 700,000 new or recurrent cases are encountered annually (AHA 1999, Stroke & CVD 1992). Stroke also has become the leading cause of serious, long-term disability in the United States, accounting for more than half of all patients hospitalized for acute neurologic disease (AHA 1999). Clinicians rely heavily on the imaging modalities, such as Duplex US, in making judgements regarding the severity and need for intervention. Accurate correlation between post-stenotic flow characteristics and stenotic severity will aid immeasurably in making such critical decision-making more reliable. Profs. Guo, Mittal and Hahn will collaborate on the development of acoustic sensors that can provide accurate non-invasive assessment of peripheral vascular disease. Once a correlation between the stenotic severity and bruit frequency has been extracted from the simulations, we will develop a device that will employ this correlation to predict the severity of the arterial disease. The team expects to work closely with researchers from the GW School of Medicine in both the development and the eventual testing of this device.

In addition to this, the team also plans to work on analyzing the hemodynamic origins of "Korotkoff" sounds which form the basis for the indirect, auscultatory method of measuring blood pressure. Despite the availability of highly accurate invasive procedures, this method is still the cheapest and most convenient way of accurately measuring blood pressure. However, in addition to the 10% estimated inaccuracy of the auscultatory method, false measurements are common. The team proposes to use computer simulations to understand the hemodynamic mechanisms that cause these sounds and correlate more precisely the various stages in these sounds to the measured blood pressure. It is expected that such a study could eventually lead to devices ("smart" stethoscopes) that can improve the accuracy of the auscultatory method.

 
 
 
  Vocal cord paralysis and paresis are debilitating conditions leading to difficulty with voice production. Medialization laryngoplasty is a surgical procedure designed to restore the voice in patients by implanting a uniquely configured structural support lateral to the paretic vocal fold through a window cut in the thyroid cartilage of the larynx. Currently, the surgeon relies on experience and intuition to place the implant in the desired location, therefore it is subject to a significant level of uncertainty. Window placement errors of up to 5mm in the vertical dimension are common in patients admitted for revision surgery. The failure rate of this procedure is as high as 24% even for experienced surgeons. An intraoperative image-guided system will help the surgeon to accurately place the implant by superimposing the CT data from the patient with the actual larynx of the patient during surgery.
One of the fundamental challenges in our system is to accurately register the preoperative 3D CT data to the intraoperative 3D surfaces of the patient. Our proposed image guided system will use the anatomical and geometric landmarks and points to register intraoperative 3D surface of thyroid cartilage to the preoperative 3D radiological data. The proposed approach has three phases. First, the laryngeal cartilage surface is segmented out from the preoperative 3D CT data. Second, the surface of the exposed laryngeal cartilage during the surgery is reconstructed intraop-eratively using stereo vision and structured light based surface scanning. Third, the two geometries are registered using ICP based shape matching. The proposed ap-proach has several advantages over alternative approaches: the combination of stereo vision and structured light surface scanning is capable of tracking the fiducial markers, reconstructing the surface of laryngeal cartilage and matching the preoperative and postoperative surfaces for registration purposes. The computer vision based approach can be applied to delicate areas like laryngeal cartilage with no danger of causing physical damage.

   
 
  Since natural tissue is mainly nanometer in dimension and various cells directly interact with nanostructured extra-cellular matrices, the biomimetic features and excellent physiochemical properties of nanomaterials play a key role in guiding various tissue repair and regeneration. Our Nanomedicine and Tissue Engineering lab directed by Prof. Lijie Grace Zhang applies a range of interdisciplinary technologies and approaches in nanotechnology, tissue engineering, biomaterials, stem cells, drug delivery and biomechanics to create biologically inspired tissue scaffolds and investigate their efficacy for healing various tissues in vitro and in vivo. Specifically, there are three research directions in our lab:
- Biomimetic Nanomaterials for Bone & Cartilage Tissue Engineering and Orthopedic Applications
- Stem Cell Therapy for Tissue Regeneration
- Sustained Drug Delivery Systems for Biomedical Applications
More information can be found via http://home.gwu.edu/~lgzhang/
 
  (A) Fractured bone
(B) Endothelial cell growth on titanium with nanocoatings
(C) Biologically inspired DNA based rosette nanotube network
(D) The multipotential mesenchymal stem cell for bone and cartilage repair
 
 

Ventricular fibrillation (VF), a lethal cardiac arrhythmia, claims the life of almost one thousand Americans each day. A goal of GW's CERL is to understand the electrophysiologic events that cause VF and to investigate ways of preventing it. Computational models of cardiac tissue and innovative instrumentation developed at the CERL are currently used to study how the occlusion of a coronary artery may initiate VF, to improve electrical therapies for VF, and to understand how stem cell engraftment may improve the function of a diseased heart. The CERL is located at the GW Medical Center and is a multidisciplinary effort between the GW School of Engineering and Applied Science and the GW School of Medicine and Health Sciences.


 
 

Mechanism of a cardiac arrhythmia resulting from reperfusion after local ischemia.

Left: The time course of local ischemia was monitored as an increase in the epicardial fluorescence of NADH (lower panel) from a rat heart. No arrhythmia was detected before reperfusion (upper panel). Immediately upon reperfusion a tachyarrhythmia was generated and NADH fluorescence began to fall to pre-ischemia levels.

Right: Fluorescence images of transmembrane potential during reperfusion. Initially a fast ectopic (point) source motivated the arrhythmia and it later evolved into a transient reentrant source (rotor).

 

  We have started a new line of research associated with the use of medical informatics in a number of applications. In one of these applications, we are interested in creating a prototype system capable of detecting in real time, biologic, chemical, nuclear, and radiological terrorism attacks as well as routinely supporting the local public health community with information regarding natural outbreaks of contagious and traumatic diseases. This can be accomplished through syndromic surveillance of the Emergency Medical Dispatch (EMD) interrogatory data, collected by the computer aided dispatch (CAD) system at 911 Centers already in place. A set of tools will allow further analysis to determine possible causes (e.g. type of biological agents), the mechanism of transmission (for example, based on current atmospheric conditions and simulations of the dispersion of the plume), and possible actions (e.g. evacuation of a population center in danger). The system is intended to be used by local, regional, and national public health officials giving them advance information about possible man made or naturally occurring events, and helping them make decisions on possible actions to take.
  It's commonly known there are three states of matter: solid, liquid and gas, but there are actually four. And the last one would be plasma. It's wonderful substance, ionized gas that can be used as a source of the energy of various origins: thermal, electrical or light.
There are variety of different kinds of plasmas ranging from stars in universe to fluorescent lamps or plasma TVs. Recently it was breakthrough research in the area of cold atmospheric plasmas opened the gates to a world of technology straight out of science fiction.
A wide range of cold plasmas applications have been investigated including sterilization (food, medical equipment, contaminated civilian and military gear), the preparation of polymer materials for medical procedures, wound healing, tissue or cellular removal, surgery, treating skin disease and dental drills. Thus Dr. Michael Keidar and his group in collaboration with GW Medical Center are working in biomedical engineering area of studying various aspects of cold plasmas applications, particularly interaction of cold plasmas with living tissue at cellular and subcellular levels (cell adhesion, cell migration ect) and nanomedicine. Also plasma jet analysis (physical and chemical characterization, spectroscopy) and simulations are part of the ongoing work.

 
  The objective of this interdisciplinary research is to give the surgeon the tools to improve the outcome of the procedure and to reduce the revision rate. The research is composed of two interrelated components. The first component is a computer model for simulating vocal fold function during phonation. This will lead to a pre-operative planning system that will guide the surgeon in determining the optimal location and size/shape of the implant. This will be accomplished by developing a patient-specific model of the laryngeal cartilage and vocal folds (with implant included) and simulating the fluid dynamics and vocal fold vibration associated with voice production. The second component comprises an intra-operative image-guided system that will be developed to allow the surgeon to accurately place the implant at the desired location. Image guidance will be performed by registering a pre-operative 3D CT image with the 2D images of the patient during the operation. A novel graphical interface system will allow the surgeon to easily use the system without any major changes to current surgical practices.

The near-term goal of the proposal is to improve the clinical outcomes of the particular procedure. However, the long-term significance of the proposal is to solve fundamental scientific problems associated with the biomechanical modeling and simulation of voice production as well as the relatively unexplored problems associated with the use of intraoperative 2D imagery in image-guided surgical procedures.

 
  Medical simulations are used for a number of purposes. One of the most promising is the development of surgical simulators. The accepted paradigm for teaching in medicine has been "see one, do one, teach one". Although the methodology has served medicine well, there is a growing interest in the use of computer-based surgical simulators to teach complex surgical procedures. This has been prompted by the prevalence of "minimally-invasive" procedures. Minimally-invasive procedures involve the use of imaging techniques (MRI, CT, ultrasound, laparoscopes) to guide instruments through a small opening in the patient to perform certain surgical procedures. The benefit is the reduced amount of trauma to the patient. However, the procedures have become extremely complex making effective training critical. Personnel from SEAS and SMHS have been involved in a number of research projects that involve computer scientists, electrical engineers, mechanical engineers, and physicians to develop virtual reality simulators that allow physicians to see as well as feel the simulated procedure. This type of training, although of limited use currently, has a great deal of potential in revolutionizing medicine in much the same way that flight simulators have revolutionized pilot training. Similar technology can be used to guide physician to place an instrument (e.g. biopsy needle) at a precise location on the patient using imaging techniques along with computer guidance. We intend to leverage our current expertise in these areas to continue developing sophisticated simulators with the intention of expanding their use in training physicians as well as in the operating room.
 
 
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