scholarly journals The effects of acute oxygen changes on heart rate in the freshwater crab Poppiana dentata (Randall, 1840)

2020 ◽  
Vol 48 (3) ◽  
pp. 480-487
Author(s):  
Delezia Shivani Singh ◽  
Mary Alkins-Koo ◽  
Luke Victor Rostant ◽  
Azad Mohammed
Keyword(s):  
Heart Rate ◽  
Invasive Technique ◽  
Cardiac Physiology ◽  
Low Oxygen ◽  
Heart Rates ◽  
Oxygen Levels ◽  
Non Invasive ◽  
Hypoxic Conditions ◽  
Cardiac Responses ◽  
Insight Into

Heart rate is a key physiological feature that can be used to assess the response of organisms to changing environmental conditions in aquatic habitats, such as acute fluctuations in oxygen levels and hypoxic conditions. This experiment, therefore, investigated cardiac responses in a freshwater brachyuran species, Poppiana dentata, exposed to low oxygen levels. Heart rate was derived from beats per minute (bpm) signals (n = 576) using an infrared, non-invasive technique over a 96 h period, under different dissolved oxygen (DO) conditions. These involved three regimes: normoxic (6.8 ± 0.1 mg L-1), decreasing DO to hypoxic levels (6.2 to 1.7 mg L-1), and recovery with normoxic levels (6.3 ± 0.1 mg L-1). Changes in heart rates among the three regimes were significant (P < 0.05); reflecting the shift in heart rate during different conditions of oxygen availability, normoxic (59 to 61 bpm), declining DO (54 to 62 bpm) and recovery DO (53 to 64 bpm). Additionally, the normal rhythmicity of heart rates under the normoxic condition was not maintained throughout most of the declining DO and recovery periods. P. dentata has demonstrated cardiac compensations in heart rate during low oxygen levels, providing insight into the species cardiac physiology.

scholarly journals Gyrocardiography: A Review of the Definition, History, Waveform Description, and Applications

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6675
Author(s):  
Szymon Sieciński ◽  
Paweł S. Kostka ◽  
Ewaryst J. Tkacz
Keyword(s):  
Heart Rate ◽  
Invasive Technique ◽  
Heart Rate Variability Analysis ◽  
Additional Insight ◽  
Microelectromechanical System ◽  
Non Invasive ◽  
Current State ◽  
Definition Of ◽  
Insight Into

Gyrocardiography (GCG) is a non-invasive technique of analyzing cardiac vibrations by a MEMS (microelectromechanical system) gyroscope placed on a chest wall. Although its history is short in comparison with seismocardiography (SCG) and electrocardiography (ECG), GCG becomes a technique which may provide additional insight into the mechanical aspects of the cardiac cycle. In this review, we describe the summary of the history, definition, measurements, waveform description and applications of gyrocardiography. The review was conducted on about 55 works analyzed between November 2016 and September 2020. The aim of this literature review was to summarize the current state of knowledge in gyrocardiography, especially the definition, waveform description, the physiological and physical sources of the signal and its applications. Based on the analyzed works, we present the definition of GCG as a technique for registration and analysis of rotational component of local cardiac vibrations, waveform annotation, several applications of the gyrocardiography, including, heart rate estimation, heart rate variability analysis, hemodynamics analysis, and classification of various cardiac diseases.

Fertilization state ofAscaris suumdetermined by electrorotation

2006 ◽  
Vol 80 (1) ◽  
pp. 25-31 ◽  
Author(s):  
C. Dalton ◽  
A.D. Goater ◽  
H.V. Smith
Keyword(s):  
Dielectric Properties ◽  
Physicochemical Properties ◽  
Parasitic Nematode ◽  
Invasive Technique ◽  
Non Invasive ◽  
Egg Morphology ◽  
Parasite Biology ◽  
Response Modelling ◽  
Non Destructive ◽  
Insight Into

AbstractElectrorotation is a non-invasive technique that is capable of detecting changes in the morphology and physicochemical properties of microorganisms. The first detailed electrorotation study of the egg (ovum) of a parasitic nematode, namelyAscaris suumis described to show that electrorotation can rapidly differentiate between fertilized and non-fertilized eggs. Support for this conclusion is by optical microscopy of egg morphology, and also from modelling of the electrorotational response. Modelling was used to determine differences in the dielectric properties of the unfertilized and fertilized eggs, and also to investigate specific differences in the spectra of fertilized eggs only, potentially reflecting embryogenesis. The potential of electrorotation as an investigative tool is shown, as undamaged eggs can be subjected to further non-destructive and destructive techniques, which could provide further insight into parasite biology and epidemiology.

The cardiac responses to shell opening and closure in the bivalve Arctica islandica (L.)

1976 ◽  
Vol 64 (3) ◽  
pp. 751-759
Author(s):  
A. C. Taylor
Keyword(s):  
Heart Rate ◽  
Oxygen Tension ◽  
Mantle Cavity ◽  
Initial Increase ◽  
Shell Closure ◽  
Low Oxygen ◽  
Arctica Islandica ◽  
Cardiac Responses ◽  
Lower Oxygen ◽  
Pumping Activity

Shell closure in Arctica islandica is followed by an exponential decrease in the oxygen tension of the mantle cavity water and is accompanied by an initial increase in heart rate which is followed at lower oxygen tensions by a bradycardia. Prior to shell opening there is a slight increase in heart rate before any movement of the shell valves can be detected. However, once the shell opens and pumping activity recommences there is a rapid increase in heart rate, often to levels above normal. Perfusion of the mantle cavity with water of high and low oxygen tension resulted in the cardiac responses normally associated with shell opening and closure. Recordings of the PO2 of the blood in the ventricle, made simultaneously with cardiac recordings, showed that the changes in heart rate were recorded only after the PO2 of the blood had changed. These experiments suggest that changes in the PO2 of the mantle cavity water may be primarily responsible for the cardiac responses to shell closure in Arctica.

scholarly journals Acquisition and Analysis System of the Ballistocardiogram Signal Based on Virtual Instruments

2011 ◽  
Vol 2-3 ◽  
pp. 595-598
Author(s):  
Fang Fang Jiang ◽  
Xu Wang ◽  
Dan Yang ◽  
Yu Hao
Keyword(s):  
Heart Rate ◽  
Cardiac Function ◽  
Real Time ◽  
High Efficiency ◽  
Virtual Instruments ◽  
Invasive Technique ◽  
Operational Environment ◽  
Respiration Frequency ◽  
Non Invasive ◽  
Analysis System

Ballistocardiogram signal (BCG) is a non-invasive technique for the assessment of the cardiac function. It consists mainly of heart movement and the movement of blood in aorta, arteries, and periphery, which can be used to real-time monitor the heart rate and respiration frequency at home. In our laboratory, a sitting BCG detection chair has been designed successfully, and the acquisition and analysis system based on virtual instruments is proposed in this paper. MATLAB7.0 and LabVIEW8.5 were used to simulate the operational environment, and the results show high efficiency and accuracy in displaying waveform and spectrum, extracting main characteristics of heart rate and respiratory frequency, and alerting when abnormal heart-rate occurs.

scholarly journals Real-Time Cardiac Beat Detection and Heart Rate Monitoring from Combined Seismocardiography and Gyrocardiography

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3472 ◽  
Author(s):  
D’Mello ◽  
Skoric ◽  
Xu ◽  
Roche ◽  
Lortie ◽  
...  
Keyword(s):  
Heart Rate ◽  
Real Time ◽  
Time Algorithm ◽  
Cardiac Monitoring ◽  
Computational Time ◽  
Heart Rate Monitoring ◽  
Heart Rates ◽  
Non Invasive ◽  
Beat Detection ◽  
Speed Accuracy

Cardiography is an indispensable element of health care. However, the accessibility of at-home cardiac monitoring is limited by device complexity, accuracy, and cost. We have developed a real-time algorithm for heart rate monitoring and beat detection implemented in a custom-built, affordable system. These measurements were processed from seismocardiography (SCG) and gyrocardiography (GCG) signals recorded at the sternum, with concurrent electrocardiography (ECG) used as a reference. Our system demonstrated the feasibility of non-invasive electro-mechanical cardiac monitoring on supine, stationary subjects at a cost of $100, and with the SCG–GCG and ECG algorithms decoupled as standalone measurements. Testing was performed on 25 subjects in the supine position when relaxed, and when recovering from physical exercise, to record 23,984 cardiac cycles at heart rates in the range of 36–140 bpm. The correlation between the two measurements had r2 coefficients of 0.9783 and 0.9982 for normal (averaged) and instantaneous (beat identification) heart rates, respectively. At a sampling frequency of 250 Hz, the average computational time required was 0.088 s per measurement cycle, indicating the maximum refresh rate. A combined SCG and GCG measurement was found to improve accuracy due to fundamentally different noise rejection criteria in the mutually orthogonal signals. The speed, accuracy, and simplicity of our system validated its potential as a real-time, non-invasive, and affordable solution for outpatient cardiac monitoring in situations with negligible motion artifact.

The Effect of Swimming Activity and Section of the Vagus Nerves on Heart Rate in Rainbow Trout

1974 ◽  
Vol 60 (2) ◽  
pp. 305-319 ◽  
Author(s):  
IMANTS G. PRIEDE
Keyword(s):  
Heart Rate ◽  
Maximum Rate ◽  
Critical Speed ◽  
Swimming Activity ◽  
Vagus Nerves ◽  
Maximum Heart Rate ◽  
Heart Rates ◽  
Cardiac Responses ◽  
Different Temperatures ◽  
Speed Up

1. Heart rates associated with swimming activity were measured in intact and vagotomized fish at 6.5 and 15 °C. 2. Low swimming speeds had no effect on heart rate but above a threshold speed it increased logarithmically with swimming speed up to the critical speed and maximum heart rate. 3. Times for recovery after exercise increased rapidly above the critical speed. 4. Bilaterally vagotomized fish at 6.5 °C showed high resting heart rates and erratic cardiac responses to exercise. 5. In bilaterally vagotomized fish at 15 °C heart rates were normal except for a low maximum rate. 6. It is concluded that the vagus nerve can function differently at different temperatures.

Use of Individualized Versus Standard Criteria to Identify Abnormal Levels of Heart Rate or Oxygen Saturation in Preterm Infants

2001 ◽  
Vol 9 (2) ◽  
pp. 181-200 ◽  
Author(s):  
Lynda Harrison ◽  
Michael L. Berbaum ◽  
John T. Stem ◽  
Katherine Peters
Keyword(s):  
Heart Rate ◽  
Oxygen Saturation ◽  
Preterm Infants ◽  
Neonatal Intensive Care ◽  
Physiological Responses ◽  
Clinical Effectiveness ◽  
Low Oxygen ◽  
Heart Rates ◽  
Developmental Care ◽  
Physiological Indicators

Preterm infants’ physiological indicators, such as heart rate, respiratory rate, and oxygen saturation levels, are routinely monitored by devices that can alert nurses to threatening changes in condition. Most Neonatal Intensive Care Units use standard criteria as alerting algorithms to determine when an alert should be issued, and these standard criteria have been adopted uncritically in studies of preterm infants. This article presents results from a study examining preterm infants’ physiological responses to a gentle human touch (GHT) intervention in which we compared the use of standard and individualized criteria to define the percentages of abnormally low and high heart rates (HRs) and abnormally low oxygen saturation (O2 sat) levels before, during, and after periods of GHT. Results indicated that there were no differences in the percentages of abnormal HRs or O2 sat values between periods using standard criteria. However, using individualized criteria, there were significantly greater percentages of abnormally low heart rates and O2 sat levels during and after GHT periods as compared to baseline periods. The findings suggest that standard criteria may not be sensitive enough to detect subtle physiological responses to environmental stimuli such as touch. Moreover, consistent with the recognition of the value of individualized developmental care, these results suggest that the clinical effectiveness of individualized criteria for setting monitor alert limits merits further investigation.

scholarly journals Normative values, reliability and sample size estimates in heart rate variability

2007 ◽  
Vol 113 (3) ◽  
pp. 129-130 ◽  
Author(s):  
Gavin Sandercock
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sample Size ◽  
Normative Values ◽  
Autonomic Modulation ◽  
Non Invasive ◽  
Physiological Processes ◽  
Test Retest Reliability ◽  
Size Estimates ◽  
Insight Into

HRV (heart rate variability) is a non-invasive maker of cardiac autonomic modulation utilized in many hundreds of scientific studies each year. The reliability of heart rate variability has been frequently investigated yet remains poorly quantified. Assessing the reliability of a measure that assesses dynamic physiological processes and shows large between- and within-subject variation is a complex task. In this issue of Clinical Science, Pinna and co-workers provide excellent insight into the test–retest reliability of commonly used HRV indices and put the values obtained into context by comparing them with levels of between-subject variation and by producing sample size estimates.

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