1,720,969 research outputs found
HRV Spectral and Fractal Analysis in Heart Failure Patients with Different Aetiologies
No full textHeart Rate Variability (HRV) has been widely studied both in healthy subjects and congestive heart failure (CHF) patients. Significant variations in the HRV patterns have been reported in cardiac patients and quantified both in time and spectral domain by various linear and nonlinear parameters which may be useful not only for the characterization of the autonomous nervous system but also for patients risk stratification. Nevertheless, the relationship between HRV measures
and CHF aetiologies has not been completelyinvestigated yet.
The purpose of this work was to evaluate the spectral and fractal properties of HRV in patients with CHF caused by either dilated cardiomyopathy or ischemic heart disease, and to compare the results with those coming from normal subjects. Results revealed that changes in some of the examined parameters may lead to a possible separation of the CHF aetiologies
Impact of intrapulmonary percussive ventilation settings on respiratory mechanics parameters
No full textIntrapulmonary percussive ventilation (IPV) is an
airway clearance technique recently introduced as an
alternative to conventional chest physiotherapy in chronic
obstructive pulmonary diseases (COPD). A new portable device
delivering IPV, called Impulsator® (Percussionaire
Corporation, Sandpoint, Idaho, USA), has been introduced for
IPV home therapy with the aim to foster COPD patients’
autonomy. Nevertheless, the lack of detailed information about
the exact functioning of the device restricts the possibility of
treatment optimization, possibly reducing the clinical usefulness
of the therapy. This work aims to obtain quantitative
information about the physical variables related to the use of the
Impulsator® (e.g. pulsatile flow and pressure magnitudes),
allowing treatment personalization
Characterization of the mechanical behavior of Intrapulmonary Percussive Ventilation
No full textA new device delivering intrapulmonary percussive ventilation (IPV), called Impulsator® (Percussionaire Corporation, Sandpoint, ID, USA), has recently been introduced in an effort to provide effective clearance and to promote homogeneity of ventilation in the lungs of patients with cystic fibrosis. In order to optimize the treatment based on its use, a better understanding of its functioning is still necessary. In fact, up to now, a complete characterization of this device has not been carried out, thus reducing its effective utilization in clinical practice. With the aim of overcoming this lack, in this study, data concerning flow and pressure delivered during in vitro IPV were acquired under different combinations of device settings and respiratory loads. Quantitative information was obtained about the physical variables administered by the device like percussive frequency, ratio of inspiratory to expiratory time, flow and pressure magnitudes and volume exchanged. The analysis of the data determined the relations among these variables and between them and the mechanical loads, laying the basis for an optimal clinical application of the device
Estimation of pressure drop in pediatric endotracheal tubes during HFPV
No full textHigh-frequency percussive ventilation (HFPV) is a
ventilation modality which has been proved useful as an
alternative to conventional mechanical ventilation. In
clinical practice the ventilator measures the pressure that
represents the sum of the pressure drop due to the
endotracheal tube (ΔPEET) and the pressure dissipated to
inflate lung. From the clinical point of view, it is of
paramount importance to estimate the real amount of ΔPEET.
This study aimed at identifying in vitro the most
adequate model and parameters for estimating ΔPEET of
pediatric endotracheal tube during HFPV, under different
working pressures, percussive frequencies and resistive and
elastic lung loads.
The results show that it is possible to estimate ΔPEET in
pediatric endotracheal tubes by using a simple Blasius’
model, considering the presence of inertance. The Blasius’
model presents the same estimation error as Rohrer’s model
and its coefficients result largely independent from
ventilator settings and lung loads
Comparison of methods for tracheal pressure estimation during HFPV
No full textIntubation and mechanical ventilation are frequently
used in case of impaired gas exchange. High-frequency
percussive ventilation (HFPV) is a nonconventional ventilation
modality, which has been proven highly useful in the treatment
of several different pathological pulmonary conditions. The
pressure measured by the ventilator represents the sum of the
tracheal pressure and of the pressure dissipated by endotracheal
tube. Given that HFPV is not an intuitive ventilatory modality,
the possibility to know the real value of tracheal pressure will be
very helpful to optimize the treatment. This study compares two
different methods for the estimation of the tracheal pressure in
order to ascertain the applicability and limitations of these
approaches in the clinical practice. The two models are based on
fluid dynamics and on genetic programing. The simple former
model for estimation of tracheal pressure showed to be effective
and easily applied in everyday clinical practice
Influence of Mother Tongue on Dynamic Handwriting Features in Primary School
Full text linkHandwriting is an essential fine motor skill in school-aged children and plays a crucial role for educational development and autonomy of everyday life. To analyze hand-writing movement an objective quantitative kinematic analysis can be performed by using digital tablets. Through this tech-nology it was possible to identify a lot of parameters useful to characterize the handwriting process.
In order to study the influence of mother tongue on the dy-namic of handwriting in primary school, we examined the writing response of 42 non-native speakers and compared their characteristics with those of 131 Italian mother tongue chil-dren. All children undertook one repetitive sequence of le and an Italian sentence written in two different ways: as accurately as and as fast as possible.
The results showed that the differences between native and non-native speakers were not significant in the repetitive se-quence while a clear influence of mother tongue was present only in the third grade for the sentence tasks
EEG Analysis in Resting State and during a Memorization Task in Mild Cognitive Impairment and Subjective Cognitive Impairment
No full textMild Cognitive Impairment (MCI) and Subjective Cognitive Impairment (SCI) are brain disorders with a high risk to progress to Alzheimer’s disease. This work investigates the possible EEG differences in MCI and SMC subjects, with respect to control subjects (CS), both during rest and cognitive stimulation. EEG data were analyzed by decomposing the power spectral density into frequency sub-bands and by calculating the power-law beta exponent parameter. Moreover, from a nonlinear point of view, also Higuchi’s fractal dimension and Poincaré plot indexes were estimated. Feature extraction was performed by using the Principal Component Analysis method, in an effort to distinguish CS, MCI and SCI patients. Results show that some parameters present statistically significant differences between SCI and control subjects, whereas MCI patients present intermediate values between the other two groups. The use of the principal component analysis allows a preliminary visual separation of CS and SCI, even if the difficulty in distinguishing MCI subjects persists
Estimation of Respiratory Mechanics Parameters during HFPV
No full textThe respiratory mechanics parameters (resistance and elastance) are important for adequate mechanical ventilation settings and for a correct clinical diagnosis. High-frequency percussive ventilation (HFPV) is a non-conventional ventilatory strategy characterized by inspiratory high frequency pulsatile flow, while the expiratory phase is passive. It associates the beneficial aspects of conventional mechanical ventilation with those of high-frequency ventilation.
This bench study, as preliminary to patients study, aimed to estimate respiratory mechanics parameters through a non-invasive method, during HFPV at different working pressures, frequencies and mechanical (resistive and elastic) loads. For such purpose, a multiple linear regression method to estimate parameters of the Dorkin high frequency pulmonary model was applied, starting from in vitro measured pressure and flow signals, considering inspiratory phase exclusively.
The results encourage further in vivo studies of this methodology, which has to be clinically assessed. The low rmse% values confirm validity of Dorkin three element model during HFPV
Impact of Device Settings and Spontaneous Breathing during IPV in CF Patients
No full textIntrapulmonary Percussive Ventilation (IPV) is a
ventilation technique that has been introduced for promoting
airway clearance and for recruiting areas of lung in patients
with restrictive and obstructive pulmonary diseases.
Recently, a new transportable device providing noninvasive
IPV has been proposed as an alternative to traditional chest
physiotherapy for patients with cystic fibrosis (CF). Nevertheless,
its clinical effectiveness has not been completely demonstrated
yet and further investigations have to be carried out.
The aim of this work was to investigate the functioning of
the new proposed IPV system, evaluating the tolerance to this
ventilation and assessing flow and pressure modulation when
spontaneous breathing was superimposed
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