Online computer for assessing respiratory and metabolic function during exercise

Miyamoto, Yuri; Sakakibara, Kazuhito; Takahashi, Masashige; Tamura, Tsutomu; Takahashi, Tsuneo; T, Hiura; Mikami, Tomohisa

doi:10.1007/bf02442555

Cited by 12 publications

(3 citation statements)

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“…Parameters indicating respiratory and metabolic functions were as follows: respiratory frequency (j), tidal volume (VT), minute expired ventilation (VE), oxygen uptake (Vo2), carbon dioxide output (Vco2), respiratory quotient (R), ventilation equivalents for oxygen and carbon dioxide (J/ J'02, J/ J02), and end-tidal carbon dioxide tension (PETCo2) at rest as well as during exercise. These variables were calculated breath by breath using an on-line computer system (MIYAMOTO et al, 1981a), to which expired air flow signals detected at the mouth by a hot wire type pneumotachograph (MINATO, model RF-2) and expired gas composition signals analyzed by a mass spectrometer (MEDSPECT, model MS-8) were fed.…”

Section: Methodsmentioning

confidence: 99%

Neurogenic factors affecting ventilatory and circulatory responses to static and dynamic exercise in man.

1987

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The possible influence of neurogenic factors on respiratory and circulatory responses to continuous static (CSE), rhythmic static (RSE), and dynamic (DE) exercises was studied in 15 healthy young men. Ventilation (VE), oxygen uptake (Vo 2), cardiac output (Q), and blood pressure (BP) were measured during the steady-state of the exercise. For a given V02, VE, and respiratory frequency (f) enhanced significantly with increasing frequency of RSE, and for the same frequency, the responses of these variables to RSE were significantly higher than those for DE. Although a similar trend was observed in heart rate (HR) and Q responses to exercises, it was not as strong as for ventilatory responses. These results lead to the conclusion that ventilation and circulation during exercise may be influenced by some neurogenic factors mediated either centrally or peripherally. Although the neuro-humoral concept of DEJOUxs (1964) is widely accepted as the origin of exercise hyperpnea, the contribution ratio of the two factors is not clear. We examined the possible role of peripheral neurogenic drives which might influence the cardiorespiratory responses during the steady-state of exercise. The total energy required for a muscular contraction may be given by the sum of the energy to produce force or tension in the muscles and the energy appearing as external work. Since static exercise lacks external work in its definition, one can expect that static exercise is energically cheaper than dynamic exercise for the same intensity of tension production. Conversely, for the same value of oxygen consumption, static exercise can expected to produce more tension than dynamic exercise. The achievements in neurophysiology during the last decade suggest that

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Section: Methodsmentioning

confidence: 99%

Neurogenic factors affecting ventilatory and circulatory responses to static and dynamic exercise in man.

1987

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“…A detailed description of this system has been published elsewhere (MIYAMOTO et al, 1981a(MIYAMOTO et al, , 1982. The impedance pneumograph used in the previous study (MIYAMOTO et al, 1982) was replaced by a hot-wire type pneumotachograph with a small dead space of 10 ml.…”

Section: Methodsmentioning

confidence: 99%

Cardiorespiratory dynamics in men in response to passive work.

Nakazono

Miyamoto

1985

Jpn.J.Physiol

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Dynamic characteristics of ventilation, cardiac output, and gas exchange in response to passive limb movements were studied in four healthy men in an upright position. Passive exercise was performed on a motor-driven bicycle ergometer, of which pedaling rate was varied from control (30 rpm) to stimulus (90 rpm) level in a stepwise fashion. Stroke volume (SV), heart rate (HR), and cardiac output (Q) were determined continuously during the exercise by using an automated impedance cardiograph. Minute ventilation (VE), respiratory frequency (f), tidal volume (VT), oxygen consumption (PO2), carbon dioxide output (VCO2), end-tidal pressure of oxygen and carbon dioxide (PETO2 and PETCO2), and the gas exchange ratio (R) were also determined at each breath. When the pedaling rate was increased, Q and VE rose in excess of metabolic need with a half response time of about 10 sec, and remained elevated for the duration of the stimulus.VO2 and VCO2 rose transiently, then recovered to the initial control level after a few min. PETCO2 remained at the control level for about one min, then decreased by 1 Torr.PETO2 and R rose transiently.These results suggest that hyperpnea during passive exercise is not induced by chemical stimuli to known chemoreceptors, but is due to reflexes mediated either by moving limbs or the right heart.

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“…We have recently developed a computer-based system in which impedance cardiography is incorporated, enabling us to measure cardiac output continuously (MIYAMOTO et al, 1981b). We also reported on another computer system for the assessment of respiratory function breath-by-breath (MIYAMOTO et al, 1981a). During the course of other investigations on the circulatory effects of tilting using these devices, we accidentally recorded the cardiopulmonary function during an attack of vasovagal reaction appearing in a normal subject.…”

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confidence: 99%