Related Experiment Video
Updated: Jun 1, 2026
11:54
Real-Time Proxy-Control of Re-Parameterized Peripheral Signals using a Close-Loop Interface
Published on: May 8, 2021
Quantification of cardiorespiratory interactions based on joint symbolic dynamics
Muammar M Kabir1, David A Saint, Eugene Nalivaiko
1Centre for Heart Rhythm Disorders, The University of Adelaide, Adelaide, SA 5005, Australia. muammar.kabir@adelaide.edu.au
Annals of Biomedical Engineering
|May 28, 2011
Summary
Joint symbolic dynamics effectively analyzes cardiorespiratory interactions, showing significant changes in R-R intervals and respiratory phases with body posture. This method is sensitive to orthostatic challenges.
Area of Science:
- Cardiovascular Physiology
- Respiratory Physiology
- Nonlinear Dynamics
Background:
- Cardiac and respiratory rhythms are complex, nonlinear, and nonstationary.
- Traditional time-domain methods struggle to analyze these dynamics.
- Understanding cardiorespiratory interactions is crucial for physiological assessment.
Purpose of the Study:
- Introduce a novel technique, joint symbolic dynamics, to analyze cardiorespiratory interactions.
- Investigate the relationship between R-R intervals and respiratory phases.
- Evaluate the technique's sensitivity to postural changes.
Main Methods:
- Recorded electrocardiograms (ECG) and respiratory signals.
- Extracted R-R time series and respiratory phases.
- Transformed data into ternary symbol vectors and analyzed word correspondences.
- Quantified cardiorespiratory interaction using joint symbolic dynamics.
Main Results:
- Joint symbolic dynamics revealed significantly reduced symbol sequence similarity in the upright position compared to supine (26.4 ± 4.7% vs. 20.5 ± 5.4%, p < 0.01).
- Respiratory sinus arrhythmia (RSA) also decreased in the upright posture, though less significantly (0.11 ± 0.02 s vs. 0.08 ± 0.01 s, p < 0.05).
- The technique demonstrated high sensitivity to orthostatic challenges.
Conclusions:
- Joint symbolic dynamics offers an efficient new method for analyzing cardiorespiratory interactions.
- This technique is highly sensitive to the physiological effects of orthostatic challenges.
- The findings highlight the utility of joint symbolic dynamics in understanding cardiorespiratory coupling.
Related Concept Videos
01:09Functional Classification of Joints
Functional Classification of Joints
The functional classification of joints is determined by the amount of mobility between the adjacent bones. Joints are functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, a freely moveable joint. Fibrous and cartilaginous joints can be functionally classified as either synarthroses or amphiarthroses, whereas all synovial joints are classified as diarthroses.
Synarthrosis
An immobile...
The functional classification of joints is determined by the amount of mobility between the adjacent bones. Joints are functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, a freely moveable joint. Fibrous and cartilaginous joints can be functionally classified as either synarthroses or amphiarthroses, whereas all synovial joints are classified as diarthroses.
Synarthrosis
An immobile...
01:29Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory Depth
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:
01:20Structural Classification of Joints
Joints, also known as articulations, are classified based on their structural characteristics, i.e., based on whether the articulating surfaces of the adjacent bones are directly connected by fibrous connective tissue or cartilage, or whether the articulating surfaces contact each other within a fluid-filled joint cavity. These differences serve to divide the joints of the body into three structural classifications.
A fibrous joint is where the adjacent bones are united by fibrous connective...
A fibrous joint is where the adjacent bones are united by fibrous connective...
01:23Physiological Control of Respiration
Introduction
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
01:30Quantitative Aspects of Drug-Receptor Interaction
The receptor occupancy theory connects a drug's response to the number of occupied receptors. With higher drug concentrations, more receptors are occupied, leading to increased responses. The formation of drug-receptor complexes involves association and dissociation rates, which reach equilibrium when the forward and backward reactions are equal. The equilibrium association constant (Ka) and its inverse, the equilibrium dissociation constant (Kd), indicate drug affinity. Higher Ka and lower Kd...
01:24Respiratory Capacities
Respiratory capacities are crucial indicators of lung function, representing the maximum amount of air an individual's respiratory system can handle during various breathing phases.
One key metric is the Inspiratory Capacity (IC), which represents the maximum amount of air that can be inhaled with full effort. IC is calculated by summing the tidal volume and inspiratory reserve volume, typically ranging from 2.4 to 3.6 liters.
The Functional Residual Capacity (FRC) represents the air in the...
One key metric is the Inspiratory Capacity (IC), which represents the maximum amount of air that can be inhaled with full effort. IC is calculated by summing the tidal volume and inspiratory reserve volume, typically ranging from 2.4 to 3.6 liters.
The Functional Residual Capacity (FRC) represents the air in the...