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Electrohydraulic Pump-Driven Closed-Loop Blood Pressure Regulatory System

  • Ahn, Jae-Mok (Biomedical Engineering Lab., Department of Electronic Engineering, Hallym University)
  • 안재목 (한림대학교 전자공학과)
  • Published : 2007.08.30

Abstract

An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

Keywords

References

  1. Mattson, D. L., S. Lu, R. J. Roman, and A. W. Cowley, Jr., 'Relationship between renal perfusion pressure and blood flow in different regions of the kidney,' Am. J. Physiol, vol. 264 (Regulatory Integrative Compo Physiol. 33), pp. R578-R583, 1993
  2. Benno Nafz, Pontus B. Persson, Heimo Ehmke, Hartmut R. Kirchheimi., 'A servo-control system for open-and closed-loop blood pressure regulation,' Am. J. Physiol., vol. 262, pp. F320-F325, 1992
  3. Hester, R. L., J. P. Granger, J. Williams, J. E. Hall., 'A cute and chronic servo-control of renal perfusion pressure,' Am. J. Physiol., vol. 244 (Renal Fluid Electrolyte Physiol. 13), pp. F455-F460, 1983
  4. A. W. Cowley Jr., 'Role of the renal medulla in volume and arterial pressure regulation,' Am. J. Physiol., vol. 273 (Regulatory, Integrative and Comparative Physiology), pp. R1-R15, 1997
  5. Armin Just, Uwe Wittmann, Heimo Ehmke, Hartrnut R. Kirchheim., 'Autoregulation of renal blood flow in the conscious dog and the contribution of the tubuloglomerular feedback,' The J. of Physiol., vol. 506, pp. 275-290, 1998 https://doi.org/10.1111/j.1469-7793.1998.275bx.x
  6. W. A. Cupples, P. Novak, V. Novak, F. C. Salevsky., 'Spontaneous blood pressure fluctuations and renal blood flow dynamics,' Am. J. Physiol., vol. 270, pp. F82-F89, 1996
  7. Hengliang Wang, Kin Siu, Kihwan Ju, Leon C. Moore, Ki H. Chon., 'Identification of transient renal autoregulatory mechanisms using time-frequency spectral techniques,' IEEE Trans. on Biomedical Engineering, vol. 52(6), pp.1033-1039, 2005 https://doi.org/10.1109/TBME.2005.846720
  8. T. Wronski, E. Seeliger, P. B. Persson, C. Forner, C. Fichtner, J. Scheller, B. Flemming., 'The step response: a method to characterize mechanisms of renal blood flow autoregulation,' Am. J. Physiol., vol. 285 (Renal Physiol.), pp. F758-F764, 2003
  9. Morff, R. J., H. J. Granger., 'An inexpensive servo-control system for regulating microvascular perfusion pressures in small animals,' Microvasc. Res., vol. 22, pp. 367-371, 1978
  10. U. Pinsopon, T. Hwang, S Cetinkunt, R. Ingram, Q. Zhang, M. Cobo, D. Koehler, R. Ottman., 'Hydraulic actuator control with open-center electrohydraulic valve using a cerebeller model articulation controller neural network algorithm,' in Proc. Instn Mech Engrs, 1999, vol. 213, pp. 33-48
  11. Persson P.B., Ehmke H., Kirchheim H.R., Janssen B.,Baumann J.E., Just A., Nafz B., 'Autoregulation and non-homeostatic behavior of renal blood flow in conscious dogs,' J Physiology, vol. 462, pp. 261-273, 1993 https://doi.org/10.1113/jphysiol.1993.sp019554
  12. Volker Vallon, Timothy Traynor, Luciano Barajas, Yuning G. Huang, Josie P. Briggs, Jurgen Schnermann, 'Feedback control of glomerular vascular tone in neuronal nitric oxide synthase knockout mice,' J. Am. Soc. Nephrol., vol. 12, pp. 1599-1606, 2001