Transfer function analysis of respiratory sinus arrhythmia: A measure of autonomic function in diabetic neuropathy

1995 ◽  
Vol 18 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Roy Freeman ◽  
Richard J. Cohen ◽  
J. Philip Saul
Keyword(s):  
Transfer Function ◽  
Diabetic Neuropathy ◽  
Respiratory Sinus Arrhythmia ◽  
Autonomic Function ◽  
Function Analysis ◽  
Sinus Arrhythmia ◽  
Transfer Function Analysis

Transfer function analysis of autonomic regulation. II. Respiratory sinus arrhythmia

1989 ◽  
Vol 256 (1) ◽  
pp. H153-H161 ◽  
Author(s):  
J. P. Saul ◽  
R. D. Berger ◽  
M. H. Chen ◽  
R. J. Cohen
Keyword(s):  
Heart Rate ◽  
Transfer Function ◽  
Respiratory Sinus Arrhythmia ◽  
Respiratory Activity ◽  
Autonomic Regulation ◽  
Upright Posture ◽  
Sinus Arrhythmia ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Transfer Function Analysis

An efficient new technique was developed to investigate heart rate control at all physiologically relevant frequencies by using respiratory activity as a frequency probe of the autonomic nervous response. The transfer function from respiratory activity to heart rate was determined during 6-min periods in which the respiratory rate was voluntarily controlled in a predetermined but erratic fashion. Changes in posture were used to manipulate autonomic balance. Respiratory sinus arrhythmia was determined to be a frequency-dependent phenomenon with the magnitude and phase characteristics of a low-pass filter. In agreement with previous work, at typical respiratory frequencies (greater than 0.15 Hz) increases in heart rate occurred simultaneously with the onset of inspiratory activity; however, at frequencies less than 0.15 Hz the phase relationship was quite different, such that increases in heart rate preceded inspiration. Between 0.15 and 0.45 Hz, the transfer magnitude was consistently lower while the subjects were in the upright posture than when in the supine posture, but below 0.15 Hz, it was equal in both postures. A model for respiratory modulation of heart rate, based on the atrial rate response characteristics determined in the companion paper [Am. J. Physiol. 256 (Heart Circ. Physiol. 25): H142-H152, 1989], suggests that the magnitude and phase characteristics of the subjects in the supine and upright postures differ because of relatively increased sympathetic outflow in the upright posture. A precise and efficient characterization of respiratory sinus arrhythmia can yield considerable insight into the autonomic regulation of the heart.

Transfer function analysis of the circulation: unique insights into cardiovascular regulation

1991 ◽  
Vol 261 (4) ◽  
pp. H1231-H1245 ◽  
Author(s):  
J. P. Saul ◽  
R. D. Berger ◽  
P. Albrecht ◽  
S. P. Stein ◽  
M. H. Chen ◽  
...  
Keyword(s):  
Transfer Function ◽  
Arterial Pressure ◽  
Transfer Functions ◽  
Function Analysis ◽  
Pressure Fluctuations ◽  
Rate Of Change ◽  
Phase Delay ◽  
Sinus Arrhythmia ◽  
Mechanical Effects ◽  
Transfer Function Analysis

We have demonstrated previously that transfer function analysis can be used to precisely characterize the respiratory sinus arrhythmia (RSA) in normal humans. To further investigate the role of the autonomic nervous system in RSA and to understand the complex links between respiratory activity and arterial pressure, we determined the transfer functions between respiration, heart rate (HR), and phasic, systolic, diastolic, and pulse arterial pressures in 14 healthy subjects during 6-min periods in which the respiratory rate was controlled in a predetermined but erratic fashion. Pharmacological autonomic blockade with atropine, propranolol, and both, in combination with changes in posture, was used to characterize the sympathetic and vagal contributions to these relationships, as well as to dissect the direct mechanical links between respiration and arterial pressure from the effects of the RSA on arterial pressure. We found that 1) the pure sympathetic (standing + atropine) HR response is characterized by markedly reduced magnitude at frequencies greater than 0.1 Hz and a phase delay, whereas pure vagal (supine + propranolol) modulation of HR is characterized by higher magnitude at all frequencies and no phase delay; 2) both the mechanical links between respiration and arterial pressure and the RSA contribute significantly to the effects of respiration on arterial pressure; 3) the RSA contribution to arterial pressure fluctuations is significant for vagal but not for sympathetic modulation of HR; 4) the mechanical effects of respiration on arterial pressure are related to the negative rate of change of instantaneous lung volume; 5) the mechanical effects have a higher magnitude during systole than during diastole; and 6) the mechanical effects are larger in teh standing than the supine position. Most of these findings can be explained by a simple model of circulatory control based on previously published experimental transfer functions from our laboratory.

Transfer function analysis of heart rate variability in response to water intake: correlation with gastric myoelectrical activity

2004 ◽  
Vol 96 (6) ◽  
pp. 2226-2230 ◽  
Author(s):  
C. L. Chen ◽  
H. H. Lin ◽  
William C. Orr ◽  
Cheryl C. H. Yang ◽  
Terry B. J. Kuo
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Transfer Function ◽  
Water Intake ◽  
Function Analysis ◽  
Gastric Myoelectrical Activity ◽  
Myoelectrical Activity ◽  
Sinus Arrhythmia ◽  
Transfer Function Analysis ◽  
Before And After

We utilized transfer function analysis of heart rate variability (HRV) and respiration to investigate the effect of water intake on gastric myoelectrical activity and its relationship to vagal activity. The electrogastrography (EGG) and HRV were recorded simultaneously before and after drinking 500 ml of water in 10 healthy subjects. We observed good linearity between lung volumes and HRV signals at a ventilatory rate between 0.2 and 0.4 Hz before and after water intake. The EGG power of 3 cycles/min increased remarkably after the water intake. We found that there was a significant increase in the magnitude of the respiration-HRV transfer function after water intake ( P < 0.05). The EGG 3 cycles/min power was positively correlated with the transfer magnitude throughout the study ( r = 0.54, P = 0.01). These results confirm that transfer function analysis of HRV sensitively identifies subtle changes in the respiratory sinus arrhythmia that occurs with water intake. The present findings suggest that transfer function analysis of HRV and respiration after water intake can be used to evaluate vagal nervous activity in the human gut.

Individual differences in respiratory sinus arrhythmia

2004 ◽  
Vol 286 (6) ◽  
pp. H2305-H2312 ◽  
Author(s):  
Samia Ben Lamine ◽  
Pascale Calabrese ◽  
Hélène Perrault ◽  
Tuan Pham Dinh ◽  
André Eberhard ◽  
...  
Keyword(s):  
Heart Rate ◽  
Correlation Coefficient ◽  
Respiratory Sinus Arrhythmia ◽  
Spontaneous Breathing ◽  
Function Analysis ◽  
Sinus Arrhythmia ◽  
Interindividual Differences ◽  
Breathing Period ◽  
Transfer Function Analysis ◽  
Instantaneous Heart Rate

To investigate the interindividual differences in respiratory sinus arrhythmia (RSA), recordings of ventilation and electrocardiogram were obtained from 12 healthy subjects for five imposed breathing periods ( TTOT) surrounding each individual's spontaneous breathing period. In addition to the spectral analysis of the R-R interval signal at each breathing period, RSA characteristics were quantified by using a breath-by-breath analysis where a sinusoid was fitted to the changes in instantaneous heart rate in each breath. The amplitude and phase (or delay = phase × TTOT) of this sinusoid were taken as the RSA characteristics for each breath. It was found that for each subject the RSA amplitude- TTOT relationship was linear, whereas the delay- TTOT relationship was parabolic. However, the parameters of these relationships differed between individuals. Linear correlation between the slopes of RSA amplitude versus TTOT regression lines and 1) mean breathing period and 2) mean R-R interval during spontaneous breathing were calculated. Only the correlation coefficient with breathing period was significantly different from zero, indicating that the longer the spontaneous breathing period the lesser the increase in RSA amplitude with increasing breathing period. Similarly, only the correlation coefficient between the curvature of the RSA delay- TTOT parabola and mean breathing period was significantly different from zero; the longer the spontaneous breathing period the larger the curvature of RSA delay. These results suggest that the changes in RSA characteristics induced by changing the breathing period may be explained partly by the spontaneous breathing period of each individual. Furthermore, a transfer function analysis performed on these data suggested interindividual differences in the autonomic modulation of the heart rate.

scholarly journals Spatial Unmasking Effect on Speech Reception Threshold in the Median Plane

2020 ◽  
Vol 10 (15) ◽  
pp. 5257
Author(s):  
Nathan Berwick ◽  
Hyunkook Lee
Keyword(s):  
Transfer Function ◽  
Input Signal ◽  
Function Analysis ◽  
Median Plane ◽  
Speech Reception ◽  
Transfer Function Analysis ◽  
Spatial Unmasking ◽  
Head Related Transfer Function ◽  
Speech Reception Thresholds ◽  
Energy Weighting

This study examined whether the spatial unmasking effect operates on speech reception thresholds (SRTs) in the median plane. SRTs were measured using an adaptive staircase procedure, with target speech sentences and speech-shaped noise maskers presented via loudspeakers at −30°, 0°, 30°, 60° and 90°. Results indicated a significant median plane spatial unmasking effect, with the largest SRT gain obtained for the −30° elevation of the masker. Head-related transfer function analysis suggests that the result is associated with the energy weighting of the ear-input signal of the masker at upper-mid frequencies relative to the maskee.

Transfer Function Analysis and Broadband Scalable Model for On-Chip Spiral Inductors

2011 ◽  
Vol 59 (7) ◽  
pp. 1696-1708 ◽  
Author(s):  
Huang Wang ◽  
Lingling Sun ◽  
Jun Liu ◽  
Huanhuan Zou ◽  
Zhiping Yu ◽  
...  
Keyword(s):  
Transfer Function ◽  
Function Analysis ◽  
Transfer Function Analysis ◽  
Spiral Inductors ◽  
On Chip

scholarly journals A novel method for assessing cerebral autoregulation in preterm infants using transfer function analysis

2015 ◽  
Vol 79 (3) ◽  
pp. 453-459 ◽  
Author(s):  
Zachary A. Vesoulis ◽  
Steve M. Liao ◽  
Shamik B. Trivedi ◽  
Nathalie El Ters ◽  
Amit M. Mathur
Keyword(s):  
Transfer Function ◽  
Preterm Infants ◽  
Cerebral Autoregulation ◽  
Function Analysis ◽  
Transfer Function Analysis ◽  
Novel Method
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