Estimation of baroreflex sensitivity using transfer function analysis: normal values and theoretical considerations

1996 ◽  
Vol 6 (3) ◽  
pp. 157-161 ◽  
Author(s):  
D. Linden ◽  
R. R. Diehl
Keyword(s):  
Transfer Function ◽  
Baroreflex Sensitivity ◽  
Normal Values ◽  
Function Analysis ◽  
Transfer Function Analysis ◽  
Theoretical Considerations

scholarly journals Role of aortic arch vascular mechanics in cardiovagal baroreflex sensitivity

2016 ◽  
Vol 311 (1) ◽  
pp. R24-R32 ◽  
Author(s):  
Stephen A. Klassen ◽  
Daniele Chirico ◽  
Kylie S. Dempster ◽  
J. Kevin Shoemaker ◽  
Deborah D. O'Leary
Keyword(s):  
Sex Differences ◽  
Transfer Function ◽  
Aortic Arch ◽  
Baroreflex Sensitivity ◽  
Function Analysis ◽  
Low Frequency ◽  
Vascular Mechanics ◽  
Relative Contribution ◽  
Transfer Function Analysis

Cardiovagal baroreflex sensitivity (cvBRS) measures the efficiency of the cardiovagal baroreflex to modulate heart rate in response to increases or decreases in systolic blood pressure (SBP). Given that baroreceptors are located in the walls of the carotid sinuses (CS) and aortic arch (AA), the arterial mechanics of these sites are important contributors to cvBRS. However, the relative contribution of CS and AA mechanics to cvBRS remains unclear. This study employed sex differences as a model to test the hypothesis that differences in cvBRS between groups would be explained by the vascular mechanics of the AA but not the CS. Thirty-six young, healthy, normotensive individuals (18 females; 24 ± 2 yr) were recruited. cvBRS was measured using transfer function analysis of the low-frequency region (0.04–0.15 Hz). Ultrasonography was performed at the CS and AA to obtain arterial diameters for the measurement of distensibility. Local pulse pressure (PP) was taken at the CS using a hand-held tonometer, whereas AA PP was estimated using a transfer function of brachial PP. Both cvBRS (25 ± 11 vs. 19 ± 7 ms/mmHg, P = 0.04) and AA distensibility (16.5 ± 6.0 vs. 10.5 ± 3.8 mmHg−1 × 10−3, P = 0.02) were greater in females than males. Sex differences in cvBRS were eliminated after controlling for AA distensibility ( P = 0.19). There were no sex differences in CS distensibility (5.32 ± 2.3 vs. 4.63 ± 1.3 mmHg−1 × 10−3, P = 0.32). The present data demonstrate that AA mechanics are an important contributor to differences in cvBRS.

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

Midlife Aerobic Exercise and Dynamic Cerebral Autoregulation: Associations with Baroreflex Sensitivity and Central Arterial Stiffness

2021 ◽  
Author(s):  
Tsubasa Tomoto ◽  
Justin Repshas ◽  
Rong Zhang ◽  
Takashi Tarumi
Keyword(s):  
Arterial Stiffness ◽  
Aerobic Exercise ◽  
Cerebral Autoregulation ◽  
Baroreflex Sensitivity ◽  
Function Analysis ◽  
Middle Aged ◽  
Age Related ◽  
Transfer Function Analysis ◽  
Carotid Distensibility ◽  
Dynamic Cerebral Autoregulation

Midlife aerobic exercise may significantly impact age-related changes in the cerebro- and cardiovascular regulations. This study investigated the associations of midlife aerobic exercise with dynamic cerebral autoregulation (dCA), cardiovagal baroreflex sensitivity (BRS), and central arterial stiffness. Twenty middle-aged athletes (MA) who had aerobic training for >10 years were compared with 20 young (YS) and 20 middle-aged sedentary (MS) adults. Beat-to-beat cerebral blood flow velocity, blood pressure (BP), and heart rate were measured at rest and during forced BP oscillations induced by repeated sit-stand maneuvers at 0.05 Hz. Transfer function analysis was used to calculate dCA and BRS parameters. Carotid distensibility was measured by ultrasonography. MA had the highest peak oxygen uptake (VO2peak) among all groups. During forced BP oscillations, MS showed lower BRS gain than YS, but this age-related reduction was absent in MA. Conversely, dCA was similar among all groups. At rest, BRS and dCA gains at low frequency (~0.1 Hz) were higher in the MA compared with MS and YS groups. Carotid distensibility was similar between MA and YS groups, but it was lower in the MS. Across all subjects, VO2peak was positively associated with BRS gains at rest and during forced BP oscillations (r=0.257~0.382, p=0.003~0.050) and carotid distensibility (r=0.428~0.490, p=0.001). Furthermore, dCA gain at rest and carotid distensibility were positively correlated with BRS gain at rest in YS and MA groups (all p<0.05). These findings suggest that midlife aerobic exercise improves central arterial elasticity and BRS which may contribute to CBF regulation through dCA.

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