Related Experiment Video
Updated: Jul 17, 2026
11:26
Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression
Published on: December 10, 2014
Residual pulse morphology visualization and analysis in pressure signals
Tim Ellis1, James McNames, Brahm Goldstein
1Thrasher Research Fund. T. Ellis and J. McNames (director) are members of the Biomedical Signal Processing Laboratory, Electrical & Computer Engineering, Portland State University, Portland, Oregon, USA.
Summary
We developed a novel method to analyze intracranial pulse morphology, revealing changes independent of mean intracranial pressure. This finding highlights the need for further research into the underlying physiology of pulse waveform variations.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Physiology
Background:
- Intracranial pressure (ICP) monitoring is crucial in neurocritical care.
- Pulse morphology contains physiological information beyond mean ICP.
- Current methods may not fully capture morphology-dependent information.
Purpose of the Study:
- To introduce a new method for analyzing intracranial pulse morphology.
- To identify information in pulse morphology not explained by mean ICP.
- To provide an intuitive visualization of morphology changes.
Main Methods:
- Calculating the difference between actual and predicted pulse morphology.
- Using mean ICP as a primary predictor variable.
- Developing a display for intuitive recognition of unaccounted morphology changes.
Main Results:
- The method successfully visualizes deviations from expected pulse morphology.
- Exploratory analysis of ICP signals identified morphology changes independent of mean ICP.
- Demonstrated applicability to other physiological signals with consistent morphology.
Conclusions:
- The developed method offers a novel approach to analyzing physiological signals.
- Observed morphology changes independent of mean ICP suggest complex underlying physiology.
- Further investigation into the physiological basis of pulse morphology is warranted.
Related Concept Videos
01:17Pulse amplitude and quality
Pulse amplitude is a crucial indicator of cardiac health because it provides valuable insights into the strength of left ventricular contractions and the overall uniformity of blood circulation within the vasculature. The strength of the pulse is directly related to the force with which the heart contracts and the volume of blood being pumped.
A weak or absent pulse may indicate reduced cardiac output or poor left ventricular contraction, which can be signs of cardiovascular dysfunction or...
A weak or absent pulse may indicate reduced cardiac output or poor left ventricular contraction, which can be signs of cardiovascular dysfunction or...
01:13Special considerations while measuring pulse
Assessing a patient's pulse is a fundamental skill in healthcare, but certain situations require special attention:
01:16Pulse
When the heart pumps blood out, arterial elastic fibers play a crucial role in sustaining a high-pressure gradient. They expand to accommodate the received blood and then recoil - a process known as the pulse that can be either manually palpated or electronically quantified. Despite a reduction in its effect with increased distance from the heart, elements of the pulse's systolic and diastolic components persist, observable even at the arteriole level.
The pulse serves as a clinical indicator...
The pulse serves as a clinical indicator...
01:30Pulse rhythm
Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding.
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
01:19Rectangular and Triangular Pulse Function
The unit rectangular pulse function is mathematically represented by a rectangular function centered at the origin with a height of one unit. This function is defined by two parameters: T, which specifies the center location of the pulse along the time axis, and τ, which determines the pulse duration.
For example, consider a rectangular pulse with a 5V amplitude, a 3-second duration, and centered at t=2 seconds. This pulse can be expressed using the rectangular function, written as,
For example, consider a rectangular pulse with a 5V amplitude, a 3-second duration, and centered at t=2 seconds. This pulse can be expressed using the rectangular function, written as,
01:20Regulation of Pulse
Pulse regulation involves physiological mechanisms that ensure adequate blood flow throughout the body. The heartbeat, regulated by the autonomic nervous system, is influenced by hormonal balance, physical activity, and emotional state.