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Ankle-Foot Orthoses (AFOs) are common non-surgical treatments used to support foot and ankle joint when their normal functioning is compromised. AFOs have relevant impact on gait biomechanics, while scientific literature about effects on static balance is less strong and confusing. This study aims to assess the effectiveness of a plastic semi-rigid AFO in improving static balance on foot drop patients. Results underline that no significant effects on static balance is obtained on the study population when the AFO is used on the impaired foot.

Foot drop is a deficit in foot dorsiflexion causing difficulties in walking. Passive ankle-foot orthoses are external devices used to support the drop foot improving gait functions. Foot drop deficits and therapeutic effects of AFO can be highlighted using gait analysis. This study reports values of the major spatiotemporal gait parameters assessed using wearable inertial sensors on a group of 25 subjects suffering from unilateral foot drop. Collected data were used to assess the test-retest reliability by means of Intraclass Correlation Coefficient and Minimum Detectable Change. Excellent test-retest reliability was found for all the parameters in all walking conditions. The analysis of Minimum Detectable Change identified the gait phases duration and the cadence as the most appropriate parameters to detect changes or improvements in subject gait after rehabilitation or specific treatment.

Among diagnostic techniques for foetal monitoring, phonocardiography is gaining more and more interest for its low cost, passive nature and capability to detect some cardiac diseases. In spite of these characteristics, its use in clinical routine is still limited due to different troubles; for example, signals recorded through maternal abdomen show generally a quite low signal-to-noise ratio, so that detection and analysis of foetal heart sounds result very difficult. In this scenario, the availability of artificial phonocardiographic signals, simulated with conditions resembling different foetal conditions, week of gestation and noise amount, to name someone, can be a very useful tool to train medical staff. In this paper a software for phonocardiography simulation, updated to take account also of the split is presented. The software is completed with a user interface which allow to modify in a simple way simulation parameters. It is worth highlighting that this software can be useful also for testing performances of other analysis software and mathematical tools for recognising of valves components in the heart sounds.

Obstructive sleep apnea syndrome (OSAS) is characterized by recurrent episodes of partial or complete upper-airway obstruction during sleep. Although cardiac autonomic impairment is involved in the development of cardiovascular disease in OSAS, the mechanism underlying this derangement is rather unknown. It can be assessed by a recently introduced analysis of the heart rate turbulence (HRT). The aim of the paper is to describe the effects of pathological respiratory pattern on HRT in OSAS. HRT has been assessed by turbulence onset (TO) and turbulence slope (TS) indexes in 20 polysomnographic recordings of severe OSAS patients, and separately calculated during both normal (NR) and obstructive apnea (OA) respiratory pattern. Results showed that, although there is an overall depressed HRT for both indexes, while the TO during OA phases is not significantly different from those of NR epochs, the TS during OA phases is very significantly higher than in NR phases. This novel finding shows a previously unknown paradoxical increase of TS during OA episodes, followed by a marked decrease during subsequent NR phases, where OSAS patient show higher sympathetic tone. Such deeper understanding of the integrated autonomic response in different OSAS pathophysiological conditions could be useful to address an overall cardiorespiratory assessment and treatment in sleep-related breathing disorders.

Heart failure (HF) is a cardiac disease associated with prominent alterations in the autonomic control of the cardiovascular system and high neurohormonal activation levels. Useful assessment tools may be heart rate variability (HRV) analysis and/or the study of norepinephrine (NPE) level. Nevertheless, traditional techniques of HRV analysis have proved not sufficient and the second is an invasive measurement. In this work the correlation between a parameter (kurtosis-K) computed by an emerging nonlinear technique, the symbolic dynamics analysis, and neurohormonal and functional parameters has been investigated. Results obtained show an interesting relationship between K and both ejection fraction and NPE. In particular, higher K values are associated to increasing NPE levels This finding could be useful for highlighting changes in HF patients otherwise detectable only with invasive examinations.

Foetal heart rate variability is one of the most important parameters to monitor foetal wellbeing. Linear parameters, widely employed to study foetal heart variability, have shown some limitations in highlight dynamics potentially relevant. During the last decades, therefore, nonlinear analysis methods have gained a growing interest to analyze the chaotic nature of cardiac activity. Parameters derived by techniques investigating nonlinear can be included in computerised systems of cardiotocographic monitoring. In this work, we described an application of symbolic dynamics to analyze foetal heart rate variability in healthy foetuses and a concise index, introduced for its classification in antepartum CTG monitoring. The introduced index demonstrated to be capable to highlight differences in heart rate variability and resulted correlated with the Apgar score at birth, in particular, higher variability indexes values are associated to early greater vitality at birth. These preliminary results confirm that SD can be a helpful tool in CTG monitoring, supporting medical decisions in order to assure the maximum well-being of newborns.

Obstructive sleep apnea syndrome (OSAS) is characterized by repeated upper-airway obstruction during sleep. It is diagnosed by polysomnographic studies, scoring OSAS severity by an apneas/hypopneas index associated to worse prognosis, mainly for an increased cardiovascular morbidity. Cardiac autonomic impairments involved in the development of cardiovascular disease in OSAS can be assessed by heart rate turbulence (HRT) analysis and aim of the paper is to show the increased medical decision support by HRT evaluation in OSAS patients. HRT has been assessed in 274 polysomnographic recordings of mild-to-severe OSAS patients and an overall cardiorespiratory risk scoring (CRRIS) index has been proposed on the base of both OSAS severity and HRT assessment. Results showed that, while the only polysomnografic analysis would have equally ranked OSAS patients within their mild-to-severe classification, CRRIS index allows to identify a 19% of severe-OSAS patients at very high risk of sudden cardiac death, a 13% of moderate-OSAS patients with a risk level comparable to those of severe, and a 17% of mild-OSAS patients with evidence of an autonomic impairment. CRRIS index, detecting patients at greater probability of worsening could give to the physician a very useful medical decision support in the follow up of this particular chronic disease.

Fetal heart rate variability is surely one of the most important parameters to monitor fetal wellbeing. Linear studies, widely employed to study fetal heart variability and its correlations with the development of the autonomous nervous system, have shown some limitations in highlight dynamics potentially relevant. During the last decades, therefore, nonlinear analysis methods have gained a growing interest to analyze the chaotic nature of cardiac activity. Techniques investigating nonlinear dynamics have been already successfully employed in adults, to analyze different physiological and pathological states. Concerning fetal monitoring, instead, a smaller number of papers is available in the literature; even if symbolic dynamics was recently employed to quantify fetal heart rate regularity, demonstrating that the use of this technique may lead to a better and more differentiated understanding of normal fetal physiological development. In this work, we applied the symbolic dynamics to analyze fetal heart rate variability in healthy fetuses at the end of a physiological pregnancy. Our results confirmed the potentiality of the technique to highlight differences between signals characterized by more or less variability.

The analysis of heart rate variability (HRV) is a powerful tool in the study of the autonomic control of the heart. While circadian HRV rhythms have widely been characterized by traditional spectral measures, ultradian oscillations are not commonly investigated. In this study the identification of HRV ultradian rhythms is assigned to a quantitative measure characterizing the fractal-like behavior of the time series: the fractal dimension (FD). In order to assess ultradian regulation in Chronic Obstructive Pulmonary Disease (COPD) 24-h Holter ECG recordings of 52 COPD and 10 normal (healthy) subjects were analyzed. The FD was calculated by Higuchi's algorithm both during daytime and nighttime to highlight possible wake-sleep states differences. All subjects showed a similar common rhythm (0.06mHz) that persists with generally higher amplitude during night-time. A further rhythm becomes predominant in normal subjects in the day-to-night transition (0.15mHz), probably under the influence of the REM/non-REM ultradian sleep cycle. A very large difference between night and day amplitudes of this rhythm and of the next one (at about 0.22mHz) characterize the HRV fractal dimension of the Normal in respect of COPD. In conclusion, the FD could be used as a marker of ultradian cardiac autonomic regulation providing new insights into autonomic physiology of normal and COPD patients.

Visually-impaired people can develop several unhealthy behaviors, including the lack of physical activity or sports, due to the incomplete maturity in the control of their body in the space. This research focuses on the creation of an "exergame" - a videogame especially designed to stimulate physical exercise - that, through voice commands, allows the visually impaired users to practice physical activity and train their abilities. This tool has been developed starting from an existing dance-game, by generating some appropriate interfaces that also involve the sensory channel of sight. Our research aims to study the effects related to this exergame on the motor control mechanism in a blind children's group, aged between 8 and 13 years: it focuses also on the joint use of movement analysis systems and of videogames in order to stimulate the physical activity in these subjects.

In this paper we describe an Italian experience of fetal home monitor, organized using a portable phonocardiography system (product by Pentavox, Hungary), and the method utilized to evaluate its effectiveness in providing quality services and patient satisfaction. Patient satisfaction is an important dimension in the evaluation of quality care delivery. We used phonocardiography technique in our experience of fetal home monitoring as it is non invasive and passive in nature, low-cost and easy to use. A lightweight portable phonocardiograph (Fetaphon-home) was assigned to six selected patients, without effective pregnancy risk to monitor fetal heartbeat, uterine contractions and fetal movements at home or wherever they need it. The selected patients were instructed by trained personnel in the use of the monitoring device. Patients were asked to perform the recording two times a week and to transmit 20-min signal to the reference centre. The home monitoring sessions were performed in addition to the routine surveillance at a gynecologist's office; thus, the home monitoring did not replace clinic visits. The women were requested to fill a satisfaction questionnaire in order to evaluate their quality of life and anxiety state. Preliminary results have shown that home fetal surveillance appreciably reduces the need of travel for patients and consequently their stress. Furthermore, our results suggest that, after a short training, pregnant women are able to record and transmit long traces without troubles. Use of telemedicine system was generally well accepted by pregnant women since it increased the possibility of fetal long-term home surveillance which in turn could increase the efficiency of the service offered to them.

Non-linear parameters obtained from heart rate variability (HRV) analysis has recently been recognized to provide valuable information for physiological interpretation of heart rate fluctuation. Among the numerous non-linear parameters related to the fractal behaviour of the HRV signal, two classes have gained wide interest in the last years: the beta exponent based on the 1/f-like relationship, starting from the spectral power, and that based on fractal dimension. In order to evaluate the relationship between lesion's severity and fractal behaviour, 20 first-ever stroke subjects and 10 healthy subjects were studied. Patients were divided in two groups according to single or multiple medium cerebral artery lesions. All subjects underwent 24-hour Holter recording analysed by fractal and 1/f-like techniques. Differently from methods usually used in literature to evaluate the fractal dimension (FD), in this work the FD was extracted by using the Higuchi's algorithm that permits to calculate the parameter directly from the HRV sequences in the time domain. Results show that fractal analysis contains relevant information related to different HRV dynamics that permits to separate normal subjects from stroke patients. FD is also able to distinguish between normal and stroke subjects with different lesion's severity.