Poincare plot: A simple and powerful expression of physiological variability

Vasovagal reactions may occur occasionally during electrical stimulation using interferential current (IFC). The purpose of this study was to examine variations in autonomic activity during the application of IFC in asymptomatic participants by analysis of their heart rate variability (HRV). Seventy-three male volunteers were randomly assigned to a placebo group (n = 36; HRV was documented for 10 min, both at rest and during a placebo intervention) and an intervention group (n = 37; HRV was documented for 10 min in two conditions labelled as (1) rest and (2) application of IFC technique on the lumbar segment). The diameters of the Poincaré plot (SD1, SD2), stress score (SS), and the ratio between sympathetic and parasympathetic activity (S/PS) were measured. After interventions, differences amongst the placebo group and the IFC group were found in SD2 (p < 0.001), SS (p = 0.01) and S/PS ratio (p = 0.003). The IFC technique was associated with increased parasympathetic modulation, which could induce a vasovagal reaction. Monitorization of adverse reactions should be implemented during the application of IFC technique. HRV indicators might have a part in prevention of vasovagal reactions. Further studies in patients with lumbar pain are needed to explore possible differences in HRV responses due to the presence of chronic pain.

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Cardiac Parasympathetic Withdrawal and Sympathetic Activity: Effect of Heat Exposure on Heart Rate Variability

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18115934 ◽

2021 ◽

Vol 18 (11) ◽

pp. 5934

Author(s):

Oriol Abellán-Aynés ◽

Pedro Manonelles ◽

Fernando Alacid

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Environmental Conditions ◽

Sympathetic Activity ◽

Heat Exposure ◽

Repeated Measurements ◽

Control Group ◽

Poincaré Plot ◽

Activity Effect ◽

And Control

(1) Background: Research on heart rate variability has increased in recent years and the temperature has not been controlled in some studies assessing repeated measurements. This study aimed to analyze how heart rate variability may change based on environmental temperature during measurement depending on parasympathetic and sympathetic activity variations. (2) Methods: A total of 22 volunteers participated in this study divided into an experimental (n = 12) and control group (n = 10). Each participant was assessed randomly under two different environmental conditions for the experimental group (19 °C and 35 °C) and two identical environmental conditions for the control group (19 °C). During the procedure, heart rate variability measurements were carried out for 10 min. (3) Results: Significantly changes were observed for time and frequency domains as well as Poincaré plot variables after heat exposure (p < 0.05). These findings were not observed in the control group, whose conditions between measurements did not change. (4) Conclusions: The reduction of heart rate variability due to exposure to hot conditions appears to be produced mostly by a parasympathetic withdrawal rather than a sympathetic activation. Therefore, if consecutive measurements have to be carried out, these should always be done under the same temperature conditions.

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Merged Poincare plot based heart rate analysis

2020 17th Biennial Baltic Electronics Conference (BEC) ◽

10.1109/bec49624.2020.9277229 ◽

2020 ◽

Author(s):

Matti Huotari ◽

Kari Maatta ◽

Julia Roning

Keyword(s):

Heart Rate ◽

Poincaré Plot ◽

Rate Analysis ◽

Heart Rate Analysis

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Fault severity detection of a worm gearbox based on several feature extraction methods through a developed condition monitoring system

SN Applied Sciences ◽

10.1007/s42452-020-04131-w ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Berkan Hızarcı ◽

Rafet Can Ümütlü ◽

Zeki Kıral ◽

Hasan Öztürk

Keyword(s):

Fault Detection ◽

Condition Monitoring ◽

Extraction Methods ◽

Poincaré Plot ◽

Vibration Data ◽

Sliding Motion ◽

Fault Severity ◽

Fault Features ◽

Gearbox Vibration ◽

Condition Monitoring System

AbstractThis study presents the severity detection of pitting faults on worm gearbox through the assessment of fault features extracted from the gearbox vibration data. Fault severity assessment on worm gearbox is conducted by the developed condition monitoring instrument with observing not only traditional but also multidisciplinary features. It is well known that the sliding motion between the worm gear and wheel gear causes difficulties about fault detection on worm gearboxes. Therefore, continuous monitoring and observation of different types of fault features are very important, especially for worm gearboxes. Therefore, in this study, time-domain statistics, the features of evaluated vibration analysis method and Poincaré plot are examined for fault severity detection on worm gearbox. The most reliable features for fault detection on worm gearbox are determined via the parallel coordinate plot. The abnormality detection during worm gearbox operation with the developed system is performed successfully by means of a decision tree.

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Abstract WP281: Incorporating Biological Variability in Experimental Stroke to Better Mimic Human Stroke

Stroke ◽

10.1161/str.48.suppl_1.wp281 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Thomas A Kent ◽

Harriett C Rea ◽

William Dalmeida ◽

Roderic H Fabian ◽

Cenk Ayata ◽

...

Keyword(s):

Middle Surface ◽

Lower Surface ◽

Clinical Results ◽

Experimental Stroke ◽

Biological Variability ◽

Occlusion Time ◽

Physiological Variability ◽

Functional Measure ◽

Stroke Models ◽

Human Stroke

Introduction: Failures to translate pre-clinical results have been discouraging. We have contended that stroke is too heterogeneous with respect to factors influencing outcome to expect small studies to be balanced. It is not only difficult to control for biological and methodological variability but efforts to improve homogeneity, such as minimizing physiological variability, may render results less applicable to humans. Here, we report a predictive outcome model in experimental stroke which incorporates baseline variability and provides statistical thresholds a treatment must exceed to be efficacious in a broad population. Methods: We generated a mathematical model to predict outcome using transient MCA occlusion in 23 unfasted rats. To create baseline variability, we varied occlusion times from 90-120 min, altered baseline glucose with streptozotocin, and assessed neurological outcome 3 days later with a modified Bederson Score (BS; 0-6 functional measure, 7 death). Statistical surfaces in 3 dimensions were generated using Jacobian matrices flanking the model to provide a screening threshold (1 SD) for comparing new therapies against this model. Results: We successfully generated an outcome model from occlusion time, glucose and BS (Fig; R 2 =.49, p=.0003; middle surface is the model surrounded by ±SD surfaces). Outcome was sensitive to change in glucose and time, suggesting small imbalances in these factors between groups may influence outcome, and hence the perceived efficacy of a new therapeutic intervention. At normoglycemia and 90 mins, the lower surface overlapped with no deficit, indicating it would be difficult to reliably demonstrate benefit under those conditions. Conclusions: These results indicate it is feasible to incorporate biological variability to generate more clinically relevant conditions. The method will be tested with other stroke models and modifiers towards a generalized model to screen for therapies worthy of further study.

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Análisis de la Variabilidad de la Frecuencia Cardiaca durante Entrenamiento Físico de Distinta Intensidad a través de Índices de la Gráfica de Poincaré

10.24254/cnib.21.14 ◽

2021 ◽

Author(s):

◽

V. J. Martínez Hernández

Keyword(s):

Cardiovascular Health ◽

Autonomic Function ◽

Moderate Intensity ◽

Vagal Activity ◽

Cardiac Autonomic Function ◽

Test Protocol ◽

Poincaré Plot ◽

Control Stage ◽

Control Exercise

Exercise induces parasympathetic withdrawal and sympathetic activation. Heart rate variability (HRV) is a noninvasive tool for the assessment of cardiac autonomic function. Physical training can improve cardiovascular health through an increase in HRV. In this study, two physical trainings were conducted, one with moderate intensity (MT) and the second one with higher intensity (IT), for 10 weeks. A test protocol which consisted of 3 maneuvers: control, exercise, and recovery was performed each week of training to follow up the HRV changes in 18 sedentary volunteers aged 20.3±2 years. The RR intervals were analyzed by indexes of traditional Poincaré plot (SPP) and segmented Poincaré plot (SEPP). The results showed an increase in column 7 probabilities in week 10 with respect to week 4 during control stage for both trainings. Regarding, trainings differences, row 9 probability decreases in MT training suggesting a higher cardiac vagal activity in this training.

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