The kinocardiograph for assessment of fluid status in patients with acute decompensated heart failure.

Aims: To improve telemonitoring strategies in heart failure patients, there is a need for novel non-obtrusive sensors that monitor parameters closely related to intracardiac filling pressures. This proof-of-concept study aims to evaluate the responsiveness of cardiac kinetic energy (KE) measured with the Kinocardiograph (KCG), consisting of a seismocardiographic (SCG) sensor and a ballistocardiographic (BCG) sensor, during treatment of patients with acute decompensated heart failure.

Methods And Results: Eleven patients with acute decompensated heart failure who were hospitalized for treatment with intravenous diuretics received daily KCG measurements.

Cardiovascular deconditioning and impact of artificial gravity during 60-day head-down bed rest-Insights from 4D flow cardiac MRI.

Microgravity has deleterious effects on the cardiovascular system. We evaluated some parameters of blood flow and vascular stiffness during 60 days of simulated microgravity in head-down tilt (HDT) bed rest. We also tested the hypothesis that daily exposure to 30 min of artificial gravity (1 g) would mitigate these adaptations.

Closed-Loop Multiscale Computational Model of Human Blood Circulation. Applications to Ballistocardiography.

Cardiac mechanical activity leads to periodic changes in the distribution of blood throughout the body, which causes micro-oscillations of the body's center of mass and can be measured by ballistocardiography (BCG). However, many of the BCG findings are based on parameters whose origins are poorly understood. Here, we generate simulated multidimensional BCG signals based on a more exhaustive and accurate computational model of blood circulation than previous attempts.

The kinocardiograph for assessment of changes in haemodynamic load in patients with chronic heart failure with reduced ejection fraction.

Aims: The kinocardiograph (KCG) is an unobtrusive device, consisting of a chest sensor, which records local thoracic vibrations produced in result of cardiac contraction and ejection of blood into the great vessels [seismocardiography (SCG)], and a lower back sensor, which records micromovements of the body in reaction to blood flowing through the vasculature [ballistocardiography (BCG)]. SCG and BCG signals are translated to the integral of cardiac kinetic energy (iK) and cardiac maximum power (Pmax), which might be promising metrics for future telemonitoring purposes in heart failure (HF). As a first step of validation, this study aimed to determine whether iK and Pmax are responsive to exercise-induced changes in the haemodynamic load of the heart in HF patients.

Quantification of Cardiac Kinetic Energy and Its Changes During Transmural Myocardial Infarction Assessed by Multi-Dimensional Seismocardiography.

Seismocardiography (SCG) records cardiac and blood-induced motions transmitted to the chest surface as vibratory phenomena. Evidences demonstrate that acute myocardial ischemia (AMI) profoundly affects the SCG signals. Multidimensional SCG records cardiac vibrations in linear and rotational dimensions, and scalar parameters of kinetic energy can be computed.

Kinocardiography Derived from Ballistocardiography and Seismocardiography Shows High Repeatability in Healthy Subjects.

Recent years have witnessed an upsurge in the usage of ballistocardiography () and seismocardiography () to record myocardial function both in normal and pathological populations. Kinocardiography (KCG) combines these techniques by measuring 12 degrees-of-freedom of body motion produced by myocardial contraction and blood flow through the cardiac chambers and major vessels. The integral of kinetic energy () obtained from the linear and rotational / signals, and automatically computed over the cardiac cycle, is used as a marker of cardiac mechanical function.

Assessment of left ventricular twist by 3D ballistocardiography and seismocardiography compared with 2D STI echocardiography in a context of enhanced inotropism in healthy subjects.

Ballistocardiography (BCG) and Seismocardiography (SCG) assess the vibrations produced by cardiac contraction and blood flow, respectively, by means of micro-accelerometers and micro-gyroscopes. From the BCG and SCG signals, maximal velocities (V), integral of kinetic energy (iK), and maximal power (P) can be computed as scalar parameters, both in linear and rotational dimensions. Standard echocardiography and 2-dimensional speckle tracking imaging echocardiography were performed on 34 healthy volunteers who were infused with increasing doses of dobutamine (5-10-20 μg/kg/min).

Effects of acquisition device, sampling rate, and record length on kinocardiography during position-induced haemodynamic changes.

Background: Kinocardiography (KCG) is a promising new technique used to monitor cardiac mechanical function remotely. KCG is based on ballistocardiography (BCG) and seismocardiography (SCG), and measures 12 degrees-of-freedom (DOF) of body motion produced by myocardial contraction and blood flow through the cardiac chambers and major vessels.

Results: The integral of kinetic energy ([Formula: see text]) obtained from the linear and rotational SCG/BCG signals was computed over each dimension over the cardiac cycle, and used as a marker of cardiac mechanical function.

Cardiac adaptations to 60 day head-down-tilt bed rest deconditioning. Findings from the AGBRESA study.

Aims: Reduced physical activity increases the risk of heart failure; however, non-invasive methodologies detecting subclinical changes in myocardial function are not available. We hypothesized that myocardial, left ventricular, systolic strain measurements could capture subtle abnormalities in myocardial function secondary to physical inactivity.

Methods And Results: In the AGBRESA study, which assessed artificial gravity through centrifugation as potential countermeasure for space travel, 24 healthy persons (eight women) were submitted to 60 day strict -6° head-down-tilt bed rest.

Cardiovascular adaptation to simulated microgravity and countermeasure efficacy assessed by ballistocardiography and seismocardiography.

Head-down bed rest (HDBR) reproduces the cardiovascular effects of microgravity. We tested the hypothesis that regular high-intensity physical exercise (JUMP) could prevent this cardiovascular deconditioning, which could be detected using seismocardiography (SCG) and ballistocardiography (BCG). 23 healthy males were exposed to 60-day HDBR: 12 in a physical exercise group (JUMP), the others in a control group (CTRL).

Influence of sympathetic activation on myocardial contractility measured with ballistocardiography and seismocardiography during sustained end-expiratory apnea.

Ballistocardiography (BCG) and seismocardiography (SCG) assess vibrations produced by cardiac contraction and blood flow, respectively, through micro-accelerometers and micro-gyroscopes. BCG and SCG kinetic energies (KE) and their temporal integrals (K) during a single heartbeat are computed in linear and rotational dimensions. Our aim was to test the hypothesis that K from BCG and SCG are related to sympathetic activation during maximal voluntary end-expiratory apnea.

Ballistocardiography and seismocardiography detection of hemodynamic changes during simulated obstructive apnea.

Objective: To investigate if modern seismocardiography (SCG) and ballistocardiography (BCG) are useful in the detection of hemodynamic changes occurring during simulated obstructive apneic events.

Methods: Forty-seven healthy volunteers performed a voluntary maximum Mueller maneuver (MM) for 10 s, and SCG and BCG signals were simultaneously taken. The kinetic energy of a set of cardiac cycles before and during the apneic episode was automatically computed from the rotational and linear channels of the SCG and BCG waveforms and its temporal integral (i K) was derived (unit of measure: microjoules per second (µJ·s)).

Publisher Correction: Accurate Detection of Dobutamine-induced Haemodynamic Changes by Kino-Cardiography: A Randomised Double-Blind Placebo-Controlled Validation Study.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Modification of the mechanical cardiac performance during end-expiratory voluntary apnea recorded with ballistocardiography and seismocardiography.

Objective: To assess if micro-accelerometers and gyroscopes may provide useful information for the detection of breathing disturbances in further studies.

Approach: Forty-three healthy volunteers performed a 10 s end-expiratory breath-hold, while ballistocardiograph (BCG) and seismocardiograph (SCG) determined changes in kinetic energy and its integral over time (iK, J · s). BCG measures overall body accelerations in response to blood mass ejection into the main vasculature at each cardiac cycle, while SCG records local chest wall vibrations generated beat-by-beat by myocardial activity.

Accurate Detection of Dobutamine-induced Haemodynamic Changes by Kino-Cardiography: A Randomised Double-Blind Placebo-Controlled Validation Study.

Non-invasive remote detection of cardiac and blood displacements is an important topic in cardiac telemedicine. Here we propose kino-cardiography (KCG), a non-invasive technique based on measurement of body vibrations produced by myocardial contraction and blood flow through the cardiac chambers and major vessels. KCG is based on ballistocardiography and measures 12 degrees-of-freedom (DOF) of body motion.

The arterial baroreflex and inherent G tolerance.

Purpose: High G tolerance is based on the capacity to maintain a sufficient level of arterial pressure (AP) during G load; therefore, we hypothesized that subjects with high G tolerance (H group) would have stronger arterial baroreflex responses compared to subjects with low G tolerance (L group). The carotid baroreflex was evaluated using the neck pressure method (NP), which assesses open-loop responses.

Methods: The carotid baroreflex was tested in 16 subjects, n = 8 in the H and L group, respectively, in the supine and upright posture.

Dysfunctional vestibular system causes a blood pressure drop in astronauts returning from space.

It is a challenge for the human body to maintain stable blood pressure while standing. The body's failure to do so can lead to dizziness or even fainting. For decades it has been postulated that the vestibular organ can prevent a drop in pressure during a position change--supposedly mediated by reflexes to the cardiovascular system.

Ballistocardiography and seismocardiography: a review of recent advances.

In the past decade, there has been a resurgence in the field of unobtrusive cardiomechanical assessment, through advancing methods for measuring and interpreting ballistocardiogram (BCG) and seismocardiogram (SCG) signals. Novel instrumentation solutions have enabled BCG and SCG measurement outside of clinical settings, in the home, in the field, and even in microgravity. Customized signal processing algorithms have led to reduced measurement noise, clinically relevant feature extraction, and signal modeling.

Perception of verticality and cardiovascular responses during short-radius centrifugation.

Background: Artificial gravity using short-radius centrifugation has been proposed as an integrative countermeasure during spaceflight.

Objective: To determine the rotation parameters of a short-radius centrifuge so that subjects rotating in the dark would feel as if they were standing upright.

Methods: Twelve subjects were lying supine in a nacelle on a 2.

Comparing real-life and laboratory-induced stress reactivity on cardio-respiratory parameters: differentiation of a tonic and a phasic component.

To recreate stress in laboratory conditions, the nature of the elicited physiological reactions to the presentation of mental tasks has been extensively studied. However, whether this experimental response is equivalent to real-life stress reactivity is still under debate. We investigated cardio-respiratory reactivity to a sequential protocol of different mental tasks of varying difficulties, some of them involving emotional material, and repeated the measures in a baseline and in a real-life stress situation.

Respiratory sinus arrhythmia on the ESA-short-arm human centrifuge.

In this article, we investigated the hypothesis that the effects of hypergravity on respiratory sinus arrhythmia (RSA) can mimic the effects observed after spaceflight cardiovascular deconditioning. Artificial gravity along the head-to-feet axis on a short-arm centrifuge induces gravity gradients. This physiological condition of significantly higher g at the feet than at the heart level is specific and likely induces blood sequestration in the lower limbs.

A method for the analysis of respiratory sinus arrhythmia using continuous wavelet transforms.

A continuous wavelet transform-based method is presented to study the nonstationary strength and phase delay of the respiratory sinus arrhythmia (RSA). The RSA is the cyclic variation of instantaneous heart rate at the breathing frequency. In studies of cardio-respiratory interaction during sleep, paced breathing or postural changes, low respiratory frequencies, and fast changes can occur.