Susan M. Blanchard

Biomedical information technology: medicine and health care in the digital future

Advancements in medicine and health care are being significantly influenced by the exploding information technology developments. The IEEE Transactions on Information Technology in Biomedicine will address the applications and the infrastructure innovations that would harness biomedical and health care programs in the 21st century.

Using an artificial neural network to detect activations during ventricular fibrillation

Ventricular fibrillation is a cardiac arrhythmia that can result in sudden death. Understanding and treatment of this disorder would be improved if patterns of electrical activation could be accurately identified and studied during fibrillation. A feedforward artificial neural network using backpropagation was trained with the Rule-Based Method and the Current Source Density Method to identify cardiac tissue activation during fibrillation. Another feedforward artificial neural network that used backpropagation was trained with data preprocessed by those methods and the Transmembrane Current Method. Staged training, a new method that uses different sets of training examples in different stages, was used to improve the ability of the artificial neural networks to detect activation. Both artificial neural networks were able to correctly classify more than 92% of new test examples. The performance of both artificial neural networks improved when staged training was used. Thus, artificial neural networks may beuseful for identifying activation during ventricular fibrillation.

The World Wide Web-a teaching tool for biomedical engineering

High quality images, movies, and sound are available through the World Wide Web (WWW). These can be used to supplement lectures and homework problems and as the basis for student projects. Students in a biomedical engineering applications course worked in teams to produce multimedia documents describing body systems (cardiovascular, muscular, and skeletal) and pre- and post-computer engineering solutions to health care problems (artificial limbs and cochlear implants). The students were required to write their documents in Hypertext Markup Language (HTML) and to link to relevant material on the WWW. These projects are now available for use by other students throughout the world at the following address (URL): http:/www2.bae.ncsu.edu/bae/courses/bae456/projects.html.

Biological and biomedical engineering teaching aids on the Internet

The amount of biological and biomedical information and the number of high quality images available on the Internet are expanding on a daily basis. These hypermedia materials provide colorful images, motion pictures, and sounds which can be used in engineering education to supplement printed textbooks and to form the basis for new electronic ones. A list of sources for biological and biomedical images and other information, including the address for a current version of the list of images, is provided. Problems may result from changes in Internet addresses, temporary inaccessibility of servers, the time required to download large image files, and copyright issues.

Detecting activations in unipolar epicardial electrograms recorded during ventricular fibrillation

Detecting activations (ACTs) from unipolar electrograms (UEGs) is difficult during ventricular fibrillation (VF) due to the superposition of distant activity from multiple wavefronts. Epicardial UEGs were recorded during the first 2 s of VF from an 11/spl times/11 array of Ag-AgCl electrodes spaced 280 /spl mu/m apart on the LV apex of 5 open-chest pigs. The Rule-Based Method (RBM) used maximum negative derivatives (DERs) located at least 56 ms apart to identify RBM-ACTs while the Transmembrane Current Method (TCM) used electrograms recorded from sites with 4 orthogonal neighbors to estimate I/sub m/ at the center site. Biphasic deflections of I/sub m/ that occurred at the same time as negative DERs were used to indicate TCM-ACTs. All RBM-ACTs with DER /spl les/-1.5 mV/ms (5119 of the 5650 investigated) were assumed to represent true activations. TCM-ACTs confirmed activation for 251 RBM-ACTs with -1.5<DER/spl les/-0.3 mV/ms and suggested electrotonic activity for 139 RBM-ACTs. Activation could not be confirmed or rejected for another 141 RBM-ACTs.

Capstone engineering design projects to aid disabled persons

Design projects to meet the assistive needs of identified disabled clients have provided the Capstone engineering design class in the Biological and Agricultural Engineering Department at North Carolina State University with a rich selection of opportunities for the Biomedical Concentration undergraduate students in the Biological Engineering degree program. Students who are enrolled in the two-semester senior-level engineering design class are required to select a design project from a prepared list unless they can propose a suitable topic based upon their own experience and interest. Each summer, an undergraduate student is employed to identify suitable projects and clients in consultation with various local agencies and individuals who provide assistance to disabled persons. The projects are funded by a grant from the National Science Foundation. Twelve projects have been completed and delivered to clients since 1997 and another 16 will be finished by May 2000. Designing, building, and delivering projects to aid disabled persons gives students interested in biomedical engineering an opportunity to hone their engineering skills while making a contribution to the community in which they live.

Multiple approaches to Internet-based instruction in biological engineering

Growing accessibility to the World Wide Web (WWW) and development of dynamic, graphically oriented browsers has vast potential for dissemination of curricular materials and instructional resources within engineering. This presentation examines three case-studies relating to the use of WWW pages in biological engineering education. Each case adapts an engineering based approach to teaching underlying system principles and extends interactive, demonstration examples within the respective applications areas of biological engineering. Together these cases serve as the beginning for a larger discussion of the utility of the WWW in (1) classroom and laboratory student learning; (2) educational outreach to off-site educators, and (3) academic productivity through the use of student constructed pages.

A neural network method for detecting unipolar activations during ventricular fibrillation

An artificial neural network was trained to detect local activations during the first 2 sec of an induced ventricular fibrillation performed on five pigs. A rule based method (RBM) and methodology based on the transmembrane current (TCM) were used to validate the data for training/testing the network. With appropriate pre- and post-processing, the neural network yielded encouraging results when trained and tested on a portion of the data. A stop training technique was implemented to avoid over-training the network.

Peer-reviewed literature - a resource for teaching mathematical modeling to undergraduates in biomedical engineering

The peer-reviewed literature provides a rich resource for mathematical models of human physiology that can be used in undergraduate education. Students in a human physiology for engineers course at North Carolina State University used SIMULINK/spl reg/ to reproduce published physiological models. Most teams were able to implement at least part of their selected model successfully. Some teams benefited by contacting the authors of the papers, an exercise that the teams recommended for future classes. All teams used differential equations to describe a physiological process, thus addressing one of the ABET program criteria for bioengineering.

Writing for the Web: student authors and authorities

Students in BAE 465: Biomedical Engineering Applications have been writing projects for the World Wide Web (WWW) since 1994. During that time, 170 students completed 47 projects. These projects have allowed students to learn technical material and develop Web skills, to produce permanent, professional examples of their scholarly work, and to write for a large and diverse audience. The students approached these projects with more enthusiasm and pride than normal term papers and valued their resultant products. With these projects, students have became both authors and authorities in an area of biomedical engineering.