Damped-oscillator model of adaptive response and its consequences

Clinicians and experimentalists routinely estimate vagal-cardiac nerve traffic from respiratory sinus arrhythmia. However, evidence suggests that sympathetic mechanisms may also modulate respiratory sinus arrhythmia. Our study examined modulation of respiratory sinus arrhythmia by sympathetic outflow. We measured R-R interval spectral power in 10 volunteers that breathed sequentially at 13 frequencies, from 15 to 3 breaths/min, before and after β-adrenergic blockade. We fitted changes of respiratory frequency R-R interval spectral power with a damped oscillator model: frequency-dependent oscillations with a resonant frequency, generated by driving forces and modified by damping influences. β-Adrenergic blockade enhanced respiratory sinus arrhythmia at all frequencies (at some, fourfold). The damped oscillator model fit experimental data well (39 of 40 ramps; r = 0.86 ± 0.02). β-Adrenergic blockade increased respiratory sinus arrhythmia by amplifying respiration-related driving forces ( P < 0.05), without altering resonant frequency or damping influences. Both spectral power data and the damped oscillator model indicate that cardiac sympathetic outflow markedly reduces heart period oscillations at all frequencies. This challenges the notion that respiratory sinus arrhythmia is mediated simply by vagal-cardiac nerve activity. These results have important implications for clinical and experimental estimation of human vagal cardiac tone.

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Surface-like over-damped oscillator model to interpret impedance spectroscopy data

Journal of Electroanalytical Chemistry ◽

10.1016/j.jelechem.2016.08.012 ◽

2016 ◽

Vol 778 ◽

pp. 74-79 ◽

Cited By ~ 2

Author(s):

F.C.M. Freire ◽

T.M. Andrade

Keyword(s):

Impedance Spectroscopy ◽

Oscillator Model ◽

Spectroscopy Data ◽

Damped Oscillator

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A Damped Oscillator Model for Infrared Spectra of Formamide in the Liquid State

Bulletin of the Chemical Society of Japan ◽

10.1246/bcsj.81.248 ◽

2008 ◽

Vol 81 (2) ◽

pp. 248-253 ◽

Cited By ~ 4

Author(s):

Isao Kanesaka ◽

Eiji Mitsuhashi

Keyword(s):

Infrared Spectra ◽

Liquid State ◽

Oscillator Model ◽

Damped Oscillator

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A damped oscillator model of the 50-day oscillation in the length of the day

Chinese Astronomy and Astrophysics ◽

10.1016/0275-1062(88)90024-0 ◽

1988 ◽

Vol 12 (1) ◽

pp. 48-54 ◽

Cited By ~ 2

Author(s):

Zhi-an Li ◽

Clark R. Wilson

Keyword(s):

Oscillator Model ◽

Length Of The Day ◽

Damped Oscillator

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Research of Contact Response of an Elastic Sphere Impacting a Rigid Plate Based on the Mass-Spring-Damped Oscillator Model and Dimensionless Parameter \omega_\Omega

10.20855/ijav.2020.25.21523 ◽

2020 ◽

Vol 25 (2) ◽

pp. 141-152

Author(s):

Yang Yang ◽

Qingliang Zeng ◽

Lirong Wan ◽

Liang Wang ◽

Guangjun Yin

Keyword(s):

Contact Force ◽

Material Properties ◽

Dimensionless Parameter ◽

Contact Theory ◽

Oscillator Model ◽

Force Model ◽

Contact Response ◽

Mass Spring ◽

The Impact ◽

Damped Oscillator

The contact theory, such as the Hertz theory and Hunt-Crossley model can just solve the contact response when the sphere goes to the maximum compression but can't solve the contact process. In traditional research the impact process is considered as a single degree of freedom dynamical spring-damping system, however, the calculated contact force is much greater than the actual one. Based on the shortage of the conducted studies, a new dimensionless parameter Omega is proposed in this paper, the mass-spring-damped oscillator model (MSDOM) and the new contact theory with the consideration of the sphere mass and Omega are established. The correctness of the theoretical model is verified by 3D simulation, and the optimal contact force model is obtained. Furthermore, influence rules of material properties and contact parameters on contact response were studied. The results show that the contact deformation, velocity, piecewise nonlinear contact force and acceleration based on MSDOM and Omega are effective to calculate the contact response. The contact stiffness, damping, material properties of sphere and elastic modulus of the plate have different influence on the contact response while the Poisson's ratio nu_2 has little effect on it.

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