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Robotics technology promises an enhanced way of performing off-pump coronary artery bypass graft (CABG) surgery. In the robotic-assisted CABG surgery, surgeon performs the operation with intelligent robotic instruments controlled through teleoperation that replace conventional surgical tools. The robotic tools actively cancel the relative motion between the surgical instruments and the point-of-interest...
Nonlinear processes of the autonomic nervous system (ANS) can produce breath-to-breath variability in the pattern of breathing. In order to provide assess to these nonlinear processes, nonlinear statistical dependencies between heart rate variability and respiratory pattern variability are analyzed. In this way, auto-mutual information and cross-mutual information concepts are applied. This information...
In this paper is described the study leading to the implementation of two novel classes of textile piezoresistive sensors, for application in the field of post stroke rehabilitation and cardiovascular diseases monitoring. Two different approaches have been used, the first one leading to the realization of knitted transducer fabric to be integrated in bio-clothes for motion activity and respiration...
Cardiovascular signals such as arterial blood pressure (ABP), pulse oximetry (SpO2), and central venous pressure (CVP) contain useful information such as heart rate, respiratory rate, and pulse pressure variation (PPV). We present a statistical state-space model of cardiovascular signals that can be used with the extended Kalman filter or smoother to simultaneously estimate and track many cardiovascular...
Baroreflex sensitivity (BRS) is assessed in subjects with and without obstructive sleep apnea (OSA) using the time domain direct sequence technique, the spectral transfer function (TF) technique and the alpha index technique. All three measures showed a significantly depressed BRS value in subjects with severe apnea. The high frequency (HF) component of the spectral measures showed higher correlation...
The following topics are dealt: time-frequency analysis; functional magnetic resonance imaging; cancer drug delivery; glucose sensor and diabetics control; neural computing; EEG; biomechanics; biomedical information network; health care environment; optical coherence tomography; medical diagnostics device; image-guided surgery; radiation therapy; laparoscopy; circadian rhythms; rehabilitation techniques;...
Robotics technology promises an enhanced way of performing off-pump coronary artery bypass graft (CABG) surgery. In the robotic-assisted CABG surgery, surgeon performs the operation with intelligent robotic instruments controlled through teleoperation that replace conventional surgical tools. The robotic tools actively cancel the relative motion between the surgical instruments and the point-of-interest...
In this study, Ursino and Magosso model that includes respiration effect on cardiovascular system is implemented using Matlab. The simulations are performed to investigate the effects of respiration rate, tidal volume and expiration-inspiration time ratio on heart rate variability (HRV) signals. Power spectral density (PSD) of HRV signals that are obtained from model simulation was determined by periodogram...
Arousal from sleep is a normal physiologic event during normal sleep, which produces a tachycardia-bradycardia pattern on the heart rate variability (HRV) signal, which testifies the involvement of the autonomic nervous system related to a central nervous system event. Repetitive arousals may be associated to excessive sleep fragmentation (for example in respiratory pathologies such as obstructive...
This paper describes the design and development of a simple hardware setup for recording the blood volume pulse from the finger tip using transmission mode of photoplethysmography (PPG). PPG is known for its simple construction, ease of use and cost effectiveness and can provide information about the changes in the respiratory and cardiac activity and as well aid in earlier non-invasive diagnostics...
The maximum left ventricular elastance (Elvmax ) is a valuable index of ventricular contractility. However, conventional methods for its measurements are too invasive for routine use. We propose a non-invasive technique for tracking changes in Elvmax by mathematically determining the dynamic coupling between beat-to-beat fluctuations in instantaneous lung volume and arterial blood pressure measured...
The electrocardiogram (ECG) is a representative signal containing useful information about the condition of the heart. The shape and size of the P-QRS-T wave, the R-R interval etc. may help to identify the nature of disease afflicting the heart. However, human observer can not directly monitor these subtle details. Hence, the fusion of ECG, blood pressure, saturated oxygen content and respiratory...
A method to segment cardiovascular time series is proposed using ECG-derived metrics. Segmentation of cardiovascular time series into quasi-stationary and low noise segments is important for the construction of models (based around fixed operational points) and the evaluation of a variety of indices, including cardiovascular (such as HRV) and signal quality-based metrics. Noise and activity-related...
Obstructive sleep apnea (OSA) is a common sleep disorder which causes the reduction of the upper airways muscular tone collapsing the same. This disorder is associated with bad sleep quality leading to excessive daytime sleepiness and increased risk of cardiovascular diseases. The main therapies are the continuous positive airways pressure (CPAP) and auto-CPAP which are devices that force a positive...
The aim of this study was to evaluate the usefulness of complex demodulation (CDM) in assessing frequency components of heart rate variability (HRV) in the setting of dynamic amplitude variations. First, analysis of simulated data showed that the upper limit of rapid amplitude variations corresponded to a period of less than 16 s in order to allow a 95% reliable LF and HF estimation. Second, in terms...
Few authors have used spectral analysis of heart rate variability to characterize cardiovascular control mechanisms during isometric exercise. This technique requires stationary signals and long exercise protocols for different loads, using at least three minutes per load. In this work we explore the use of cardiovascular time-variant spectral indexes during a continuous incremental isometric exercise...
The ability to reliably measure phase between changes in heart rate and blood pressure is important when developing cardiovascular models. This study recorded 20 subjects breathing normally for periods of five minutes. RR intervals and systolic pressure (SP) levels were extracted from ECG and blood pressure signals. Phase was calculated using cross spectral analysis using four different windowing...
The objective of this study was to determine the effect of body characteristics on the electrical transfer function of the human thorax. Twenty patients undergoing electrophysiologic study were enrolled. Unipolar stimuli were applied in the right ventricular apical and posterioseptal areas. XYZ surface ECGs and unipolar intra-cardiac electrograms of the pacing impulses were recorded and signal-averaged...
The cardiovascular system may be investigated by observing fluctuations in the heart rate, blood pressure and rate of respiration. Its time evolution is governed by the baroreflex control mechanism, where the sympathetic and vagal nerves compete to increase and decrease the heart rate respectively. A nonlinear delay-differential equation model is constructed to describe this control mechanism and...
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