Development of expiratory CO2-concentration control system for regulation of autonomic nervous tone by the adaptive control method.

Research Project

Project/Area Number	61870006
Research Category	Grant-in-Aid for Developmental Scientific Research
Allocation Type	Single-year Grants
Research Field	General physiology
Research Institution	Nagoya University
Principal Investigator	KUMAZAWA Takao The Res. Inst. of Environ. Med., Nagoya Univ.,Professor, 環境医学研究所, 教授 (20022775)
Co-Investigator(Kenkyū-buntansha)	只木英子金城学院大学, 家政学部, 教授 (80079459) MIZUMURA Kazue The Res. Inst. of Environ. Med., Nagoya Univ., Associate Professor, 環境医学研究所, 助教授 (00109349) MIZUNO Naoki Dept. of Mech. Engineering, Nagoya Intst. of Technol, Associate Professo (, 機械工学科, 助教授 (30135404) FUJII Shouzou Fac. of Engineering, Nagoya Univ., professor (, 工学部, 教授 (20023038) TADAKI Eiko Dept. of Home Economics, Kinjo Gakuin Univ., Professor
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥3,600,000 (Direct Cost: ¥3,600,000) Fiscal Year 1987: ¥900,000 (Direct Cost: ¥900,000) Fiscal Year 1986: ¥2,700,000 (Direct Cost: ¥2,700,000)
Keywords	Adaptive control method / Expired gas conrol system / Pco_2 / Po_2 / Autonomic nervous activity / Po_2 / 【Pco_2】 / 【Po_2】
Research Abstract	Is is well known that CO^2 has a profound influences on many physiological func- tions. To regulate expiratory gas concentrations of animals under artificial ventilation, a new control system was developed. The regulation was performed by changing the opening periods of magnetic valves through which gases (CO_2 and O_2 were added to the inspired air using the discrete-time adaptive control method< Ther system was composed of a respiratory gas monitor (Respina 1H26, NEC- San-ei) a A/D converter (Analog-pro DMA, Canopus), a parallel input-output module (PIO 16/16T(987), Cotec), a valve controller (Tyokai-rika), a personal computer (PC-9801MM2, NEC) and a respirator. The control program is written in Basic, and controlled variables (O_2 and CO_2 concentrations)and manipulated variables (opening period of the valve) and output of the reference model were displayd on a CRT. By introducing a numerical co-processor (8087) computation time was shortened so that the ventilation rate up to 60/min could be employed. Even in circumstances that the inspired and expired gas concentrations were reversed during tracking a changed set point, correct controlled varbiables were dupplirf yo yhr vonytollrt by sampling from instantaneous gas concentrations at a fixed interval determined by previous respiratory cycles. In the anes- thetized, paralyzed and artificially ventrilated cats, this system could control expiratory CO_2 concentration within + 0.1% around a desired level in a steady state and provided fast and smooth tracking of a new set point. This system will provide a useful tool for studying autonomic functions by controlling one of many "background activities", the respiratory gas concentration.