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Noninvasive detection of ventricular wall motion by electromagnetic coupling

Part 2: Experimental: cardiokymography

  • Physiological Measurement
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Abstract

The cardiokymograph or displacement cardiograph (DCG) is a non-contacting device which senses movement of the heart throughout the cardiac cycle by the interaction of a radiofrequency (10–20 MHz) electromagnetic field, generated by a sensing coil, with the thorax. In the paper three different techniques of detecting this movement will be discussed: monitoring the changes in sensing resonant frequency (FM modulation), monitoring the changes in impedance of the coil at resonant frequency (AM modulation) and a new technique which monitors the changes in coil impedance at fixed frequency. The sensitivities of these three techniques will be compared. A simplified theory of the mode of coupling between the coil and the thorax will be studied in terms of a transformer model. Preliminary clinical measurements of anterior left and right ventricular motion will be given. The presence of higher-frequency features related to atrial motion and the opening and closing of the aortic and pulmonary values will also be described.

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References

  • Kwok, M. C. (1988) Detection of cardiac motion via electromagnetic coupling. Ph.D Thesis, University of Kent, Canterbury, UK, May 1988.

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Authors and Affiliations

  1. Electronic Engineering Laboratories, University of Kent at Canterbury, CT2 7NT, Canterbury, Kent, UK

    M. G. Pepper & M. C. Kwok

  2. Kent & Canterbury Hospital, CT1 3NG, Canterbury, Kent, UK

    M. G. Pepper & D. J. E. Taylor

Authors
  1. M. G. Pepper
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  2. D. J. E. Taylor
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  3. M. C. Kwok
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Pepper, M.G., Taylor, D.J.E. & Kwok, M.C. Noninvasive detection of ventricular wall motion by electromagnetic coupling. Med. Biol. Eng. Comput. 29, 141–148 (1991). https://doi.org/10.1007/BF02447099

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  • DOI: https://doi.org/10.1007/BF02447099

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