Search

Beside other Clinical Engineering activities to reduce risks in hospitals, functional assessment of medical devices is becoming more and more extended. Once evaluated the common risk such those electric and mechanical, specific risk are connected to the device performance: functional assessment aims to verify the specific proper operations of a medical apparatus. In particular, neonatal incubators have the primary aim to maintain an adequate microclimate for the newborn, especially those premature and smaller, who may not be able to regulates body temperature. To prevent newborn heat loss, incubator mainly stabilizes the temperature of the baby compartment to a selected value, reducing the risk of hypothermia. As suggested by the Particular Standards for safety of baby incubators, temperature have to be measured in 5 specific points inside infant chamber: the difference between measured temperatures and that selected on incubator must be limited to fractions of °C. Also the time needed to reach a given temperature must be limited. Other tests should be performed to verify humidity, air velocity, noise level, CO2 concentration, etc.. A prototype device was developed to automatically perform functional assessment of neonatal incubators. A microcontroller continuously performs a 12-bit analog to digital conversion of voltage signals generated by 5 thermal probes and a humidity sensor and sends those data to a PC, where a software process received signal and provide tests. The HW device is of little dimensions, battery powered and capable to continuously transmit data wirelessly, the SW allows real-time signal display, average values, optic and acoustic alarms for limits exceeding, data storage, etc. The device can be easily used to perform periodical functional tests on neonatal incubators. Further analysis of recorded data can be used to evaluate more specific features such as modalities of temperature control, etc. [ABSTRACT FROM AUTHOR]

Whole Body Vibration training is more and more utilized in sport medicine to enhance athletic performance and training; recently, vibration treatment is being also used for therapy and rehabilitation for patients affected by different pathologies. It is also worth mention that excessive vibrations can be hazardous. The treatment is based on the hypothesis that under some circumstances vibration loads induce specific responses from the neuromuscular system; some clinical evidences suggest mechanical and metabolic reaction. Usually, vibrations are transmitted by means of a platform oscillating at different frequencies (10-80Hz) to patient body; mainly, limb muscles are involved. Many studies about the subject employ surface EMG recordings to evaluate muscle activity during vibration training. On electrodes, this condition generates large motion artifact at the vibration frequency. To get rid of such artifact an adaptive filter was designed: accelerometers placed onto platform or directly on muscles provide an error signal shape to be cancelled from the raw EMG. In particular, surface EMG have been recorded from leg quadriceps muscles of volunteers during whole body vibration therapy sessions at different oscillating frequency. [ABSTRACT FROM AUTHOR]

Cardiotocography is the most commonly used noninvasive diagnostic technique that provides physicians information about fetal development (in particular about development of autonomous nervous system - ANS) and wellbeing. It allows the simultaneous recording of Fetal Heart Rate (FHR), by means of a Doppler probe, and Uterine Contractions (UC), by means of an indirect pressure transducer. Currently, in cardiotocographic devices, Doppler methodology involves autocorrelation techniques to recognize heart beats, so evaluation of inter-beats time-interval is very improved. However, recorded FHR signals may contain artifacts, because of the possible degradation, or even less, of the Doppler signal due to relative motion between probe and fetal heart, maternal movements, muscle contractions and other causes. Moreover, fetal cardiac arrhythmias can have an effect on FHR signals. These arrhythmias do not represent an expression of the physiological behavior of the ANS. Both, artifacts and cardiac arrhythmias represent outliers of the FHR signals, so they affect both time domain and time frequency signal analysis. [ABSTRACT FROM AUTHOR]

Cardiotocography (CTG) is the most widely used diagnostic technique to monitor fetal health. Its usefulness is undoubted; however, several analysis methodologies were proposed in recent years to improve its reliability and objectivity. To this end, great interest was dedicated to the Variability of the Fetal Heart Rate (FHRV). In particular, Short Term Variability (STV), which reflects changes in consecutive beatto- beat intervals, in general reveals autonomic nervous system functioning. Many groups of researchers described time domain parameters for quantifying FHRV. However, there are marked differences in the methodologies used, making comparison difficult, while there is no many comprehensive studies of all the indices. This work aims to analyze technical characteristics and problems related to the CTG application and comparison of some STV indexes proposed in literature and/or used in clinical environment. 9 different STV indexes were programmed and then compared by means of simulated FHR signals. In particular, we analyzed their dependence on CTG sampling frequency and FHR mean. [ABSTRACT FROM AUTHOR]

Congenital nystagmus (CN) is a disturbance of the oculomotor centers which develops at birth or in the first months of life. Nystagmus consists essentially in involuntary, conjugated, horizontal rhythmic movements of the eye. Its pathogenesis is still unknown. Current therapies for CN aim to increase the patient's visual acuity by means of refraction defects correction, drug delivery and ocular muscle surgery. Eye movement recording supports for accurate diagnosis, for patient follow-up and for therapy evaluation. In general, CN patients show a considerable decrease of visual acuity (image fixation on the retina is obstructed by nystagmus continuous oscillations) and severe postural alterations such as the anomalous head position, searched by patient to obtain a better fixation of the target image onto the retina. Often CN presents ‘neutral zones' corresponding to particular gaze angles, in which nystagmus amplitude minimizes allowing a longer foveation time and a more stable repositioning of foveations, increasing visual acuity. Selected patients' eye movements were recorded by using EOG or infrared oculography devices. Visual stimulation was delivered by means of an arched LED bar covering a visual field of -30 +30 degrees with respect to the central position. Computation of CN concise parameters allows in-dept analysis of foveations and estimation of visual acuity at different gaze angles. Preliminary results show a maximum of visual acuity at a specific gaze angle; this angle is mostly located at the patient's right side for the analyzed group. [ABSTRACT FROM AUTHOR]

Continuous patient monitoring during daily life can provide valuable information to different medical specialties. Indeed, long recording of related cardiac signals such as ECG, respiration and also other information such as body motion can improve diagnosis and monitor the evolution of many widespread diseases. Key-issues for portable or even wearable biomedical devices are: power consumption, longterm sensors, comfortable wearing, easy and wireless connectivity. Within this scenario, is valuable to realize prototypes making use of novel electronic technologies and common available communication technologies to assess practical use of long-term personal monitoring and foster new ways to provide healthcare services. We realized a small, battery powered, portable monitor capable to record ECG and body three-axes acceleration and continuously wireless transmit to any Bluetooth device including PDA or cellular phone. The ECG front end offers ultra-high input impedance allowing use of dry, long-lasting electrodes such conductive rubbers or novel textile electrodes that can be embedded in clothes. A small size MEMS 3-axes accelerometer was also integrated. Patient monitor incorporate a microprocessor that controls 12-bit ADC of signals at programmable sampling frequencies (e.g. 100 Hz) and drives a Bluetooth module capable to reliable transmit real-time signals within 10 m range. All circuitry can be powered by a standard mobile phone like Ni-MH 3.6V battery that can sustain more than seven day continuous functioning utilizing the Bluetooth Sniff mode to reduce TX power. At the moment we are developing dedicated software to process data and to extract concise parameters valuable for medical studies. [ABSTRACT FROM AUTHOR]