Fractal automatic control algorithm for an artificial heart system

T. Yambe, Y. Abe, K. Imachi, S. Nitta

Research output: Contribution to journalConference articlepeer-review


Until now, for the achievement of an automatic control algorithm for an artificial heart system, various control algorithms were developed and evaluated in all over the world. To evaluate the various control algorithms for an artificial heart, electrical circuit simulation and acute & chronic animal experiments were carried out in this study. Simple Windkesel model with an automatic control algorithm for an artificial heart had been evaluated with some kind of time delay. Acute & chronic animal experiments of the artificial heart with an automatic control algorithm were performed by the use of the adult goats. According to an alteration of the time delay of an automatic control algorithm, time series data of the electrical circuit simulation showed various interesting behaviors, limit cycle attractor, Bifurcation, torus and the strange attractor were observed. In the phase space constructed with hemodynamic parameters. This phenomenon was confirmed with animal experiments with an artificial heart automatic control. Artificial heart was controlled with optimal driving algorithm, left and right heart balances. On these basic control concepts, peripheral vascular resistances were calculated and driving rate were determined on the basis of the Baroreflex control of the hemodynamics. With time delay due to the calculation of the moving average of the hemodynamics, Fractal attractors with were observed in the hemodynamics, though limit cycle was observed in the hemodynamics with artificial heart fixed rate drive. These results suggest that we can make fractal time series with an automatic control algorithm for an artificial heart when we use an information of the hemodynamics for control algorithm. Several Investigators suggested that fractal behavior in hemodynamics showed Intelligent and flexible system. Thus, these results may be useful when we consider the flexible artificial heart control algorithm.

Original languageEnglish
Pages (from-to)162
Number of pages1
JournalASAIO Journal
Issue number2
Publication statusPublished - 2000
Event46th Annual Conference and Exposition of ASAIO - New York, NY, USA
Duration: 2000 Jun 282000 Jul 1

ASJC Scopus subject areas

  • Biophysics
  • Bioengineering
  • Biomaterials
  • Biomedical Engineering


Dive into the research topics of 'Fractal automatic control algorithm for an artificial heart system'. Together they form a unique fingerprint.

Cite this