By Topic

IEEE Engineering in Medicine and Biology Magazine

Issue 2 • Date June 1992

Filter Results

Displaying Results 1 - 8 of 8
  • Formation and anomalous properties of fractals

    Publication Year: 1992, Page(s):28 - 39
    Cited by:  Papers (10)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1132 KB)

    The basic mathematical concept of fractals is explained. A limited set of examples of fractals in nature, drawn mainly from condensed matter physics, is given. Current understanding of how fractals are formed in nature, as learned through computer simulation, is examined. Diffusion is used as an example to illustrate some of the anomalous physical properties of fractal systems.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fractal physiology

    Publication Year: 1992, Page(s):40 - 46
    Cited by:  Papers (6)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (871 KB)

    The nature of fractals and the use of fractals instead of classical scaling concepts to describe the irregular surfaces, structures, and processes exhibited by physiological systems are described. The mathematical development of fractals is reviewed, and examples of natural fractals are cited. Relationships among power laws, noise, and fractal time signals are examined.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fractal mechanisms in the electrophysiology of the heart

    Publication Year: 1992, Page(s):47 - 52
    Cited by:  Papers (58)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (631 KB)

    Fractals are defined, and the fractal-like anatomy of the heart is described. The concept of the healthy heartbeat as a temporal fractal is examined at two specific levels of cardiac function: ventricular depolarization and heart rate regulation. It is suggested that complex fluctuations in healthy heart rate may be due in part to deterministic chaos in the neuroautonomic control system. Furthermo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ion channel kinetics

    Publication Year: 1992, Page(s):53 - 56
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (435 KB)

    Proteins called ion channels, which are found in the lipid bilayer that forms the cell membrane, can have different shapes, called conformational states. Experimental evidence that the timing of switches between these states has fractal properties is examined. The physical interpretation of this phenomenon is discussed.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Four methods to estimate the fractal dimension from self-affine signals (medical application)

    Publication Year: 1992, Page(s):57 - 64
    Cited by:  Papers (16)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (775 KB)

    Four methods for estimating the fractal dimension, namely, relative dispersion, correlation, rescaled range, and Fourier (spectral) analysis, are described. Modifications of these methods for use on self-similar or self-affine signals are presented. It is found that correlation analysis and rescaled range analysis yield seriously biased results under many circumstances. Relative dispersion analysi... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fractal dimension in the analysis of medical images

    Publication Year: 1992, Page(s):65 - 71
    Cited by:  Papers (64)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (990 KB)

    The analysis of cardiac magnetic resonance (MR) images and X-rays of bone is considered. Each image type is approached using a different form of fractal parameterization. For the MR images, the goal of the study is segmentation, and to this end small regions of the image are assigned a local value of fractal dimension. For the bone X-rays, rather than segmentation, the large-scale structure is par... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Visualization and modeling of 3-D structures (medical imaging)

    Publication Year: 1992, Page(s):72 - 79
    Cited by:  Papers (9)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1605 KB)

    Two basic problems in defining and displaying 3-D structures are discussed. One is the development of segmentation methods and boundary description structures that are appropriate for data derived from real physical measurements. The other is assessing and guaranteeing the accuracy of the models that are created. Surface and volume rendering and reprojection techniques are examined.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Qualitative simulation of urea extraction during dialysis

    Publication Year: 1992, Page(s):80 - 84
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (425 KB)

    The methodologies of qualitative reasoning are applied to the urea extraction process. The information obtained by quantitative simulation is compared with that acquired by qualitative analysis. It is found that qualitative simulation can specify the response of the dialysis system, as it is usually described in the literature, with no substantial variations. The possibility of using a qualitative... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Engineering in Medicine and Biology Magazine contains articles on current technologies and methods used in biomedical and clinical engineering.

 

This Magazine ceased publication in 2010. The current retitled publication is IEEE Pulse.

Full Aims & Scope