Papers by Salvatore Sciuto
The open biomedical engineering journal, 2014
Instrumented gait analysis based on optoelectronic systems is an expensive technique used to obje... more Instrumented gait analysis based on optoelectronic systems is an expensive technique used to objectively measure the human movement features and it is generally considered as the gold standard. Opto-electronic plethysmography (OEP) is a particular motion analysis system able to: (i) determine chest wall kinematic via the evaluation of marker displacements placed on the thorax and (ii) compute respiratory volumes during breathing. The aim of this work is to describe the performances of a custom made, bio-inspired, mechatronic chest wall simulator (CWS), specifically designed to assess the metrological performances of the OEP system. The design of the simulator is based on the chest wall kinematic analysis of three healthy subjects previously determined. Two sets of experiments were carried out: (i) to investigate the CWS dynamic response using different target displacements (1 - 12 mm), and (ii) to assess the CWS accuracy and precision in simulating quite breathing, covering the phys...
Preliminary evaluation of a fiber-optic sensor for flow measurements in pulmonary ventilators
A novel optical fiber air flow sensor was developed for monitoring flow rates supplied by infant ... more A novel optical fiber air flow sensor was developed for monitoring flow rates supplied by infant ventilators. The device is based on a fiber optic sensing technique and overcomes some important shortcomings of biomedical applications, such as electromagnetic interference and possible electrical hazard. The sensing principle is based on measuring the displacement of an emitting optical fiber cantilever by means of a photodiode linear array: the detection of the illumination pattern makes the developed system less sensitive to light intensity source variations than intensity-based sensors. A preliminary evaluation of the relationship between displacement and flow rate is theoretically and experimentally conducted, as well as a measurement range up to 3.00•10 -4 m 3 /s (18.0 l/min) has been verified, in accordance to the flow range usual for tidal breathing of infants.
Strain
During usual data gathering, the statistical analysis eficiency strongly depends on the noise lev... more During usual data gathering, the statistical analysis eficiency strongly depends on the noise level superimposed on the signal. It has been found that some well known statistical tests, commonly utilised in data acquisition in order to detect the presence of drift, can fail under some conditions. Thus, a statistical procedure for the predictive reliability estimation of the utilised statistical method could be usefil in the design of experimental analysis. This paper reports the results of a simulation study carried out to evaluate the performance in drift detection of non-parametric tests suck as the Wald-Wolfowitz run test, in comparison with the Mann-Wkitney, reverse arrangement test. In order to detect the sensitivity of the tests to evaluate a monotonous drift, a simulation program was developed. In the program a Gaussian raw data sequence with a linear pattern of variable slope and with variable variance was simulated and given as the input to the tests. The capability to detect the presence of drift as a function of angular coeficient and variance of the noise superimposed on the signal was verified. The obtained data were synthesised in graphs so that the experimentalist could determine preliminarily the eflectiveness of each of the considered statistical methods in terms of percentage of success in detecting the presence of drift phenomena as a function of drift relevance and the noise amplitude. Finally, the graphs permitted the elucidation of the causes of contradictovy failing results observed in long term experimental analysis.
Preliminary characterization of an optical device for pulmonary ventilators testing
Manufacture recommended methods for the evaluation of performances of lung ventilators are often ... more Manufacture recommended methods for the evaluation of performances of lung ventilators are often considered inadequate, not comprehensive and limitative in terms of patient simulated load conditions. In order to reduce the above mentioned drawbacks, a novel fiber-optic measurement system for the evaluation of performances of infant pulmonary ventilators has been developed and is here described.
A preliminary study on a method for objective uniformity assessment in diagnostic ultrasound imaging
Ultrasound image uniformity is a parameter often used in medical ultrasound system testing, as an... more Ultrasound image uniformity is a parameter often used in medical ultrasound system testing, as an object can be displayed in different shapes and textures within the field of view, depending on instrumentation performances. Therefore Ultrasound Image Uniformity evaluation can be used for failures detection as well for quality assurance. In this paper a novel method is developed to measure B-mode image uniformity over the whole field of view or its part (Region Of Interest): it is based on the image gray level histogram weighted by a sigmoid function to detect non uniformities. Preliminary results are explained and discussed.
The open biomedical engineering journal, 2015
To check or to prevent failures in ultrasound medical systems, some tests should be scheduled for... more To check or to prevent failures in ultrasound medical systems, some tests should be scheduled for both clinical suitability and technical functionality evaluation: among them, image quality assurance tests performed by technicians through ultrasound phantoms are widespread today and their results depend on issues related to scanner settings as well as phantom features and operator experience. In the present study variations on some features of the B-mode image were measured when the ultrasound probe is handled by the technician in a routine image quality test: ultrasound phantom images from two array transducers are processed to evaluate measurement dispersion in distance accuracy, high contrast spatial resolution and penetration depth when probe is handled by the operator. All measurements are done by means of an in-house image analysis software that minimizes errors due to operator's visual acuity and subjective judgment while influences of ultrasound transducer position on qu...
A novel approach to a phantom based method for maximum depth of penetration measurement in diagnostic ultrasound: a preliminary study
2015 IEEE International Symposium on Medical Measurements and Applications (MeMeA) Proceedings, 2015
ABSTRACT In the present work a new approach for maximum depth of ultrasound signal visualization ... more ABSTRACT In the present work a new approach for maximum depth of ultrasound signal visualization has been proposed by means of a tissue mimicking phantoms: the novel method is based on a threshold on the tangent applied to the mean depth profile that is drawn by averaging adjacent columns in the diagnostic image. It has been implemented and preliminary tested on three different diagnostic systems equipped with linear array probes under similar settings: results have been compared with the mean judgment of 5 observer and with output from another method, based on a threshold of the mean depth profile above the noise level, as suggested in literature. Even though a not negligible difference among some results is observed, due likely to the high electronic noise level displayed in the ultrasound image, the tangent method seems to agree with observer judgment and be more sensitive to echo signal than the other one, even at higher noise levels. Nevertheless other test are going to be performed in the next future for a more detailed characterization of the method.
Preliminary study for a water-paraffin based phantom in MRI quality assurance test
2015 IEEE International Symposium on Medical Measurements and Applications (MeMeA) Proceedings, 2015
ABSTRACT Magnetic Resonance Imaging (MRI) scanners are widely used both for diagnostic purpose an... more ABSTRACT Magnetic Resonance Imaging (MRI) scanners are widely used both for diagnostic purpose and in studies on material properties. As a consequence they play an important role in diagnosis of diseases and in materials investigations. MRI Quality assurance tests are mandatory to obtain and maintain optimal images during time, some institutional organizations have proposed requirements on MRI image quality even if there are no worldwide standardization procedures .The purpose of this study is to design a novel MRI phantom useful to evaluate basic image quality requirements: our phantom is designed, realized and tested in order to define specific image assurance protocols and tests. Moreover the developed device is low cost, reusable and can be filled with different MRI-compatible materials. In our application the phantom is filled with water and paraffin to compare contrast resolution and signal-to-noise ratio measurements for a same scanner. Tests have been performed on a 3T scanner with 7 different scansion settings. First experimental results are encouraging and confirm a previous theoretical investigation on the employed material characteristics. Therefore other tests and data are going to be collected for the future development and performance improvement of the device.
Design and development of a rheometer for biological fluids of limited availability
The Review of scientific instruments, 2014
From studies on the dynamic characterization of human bones, it is noticed that reference data on... more From studies on the dynamic characterization of human bones, it is noticed that reference data on the viscous behavior of the bone marrow are quite poor. Dependently from marrow limited availability and its opacity, we have not been able to retrieve a tool of appropriate characteristics able to measure bone marrow viscosity. Therefore, principal techniques for the viscosity measurement have been preliminarily examined, and a device suitable for viscosity measurements of biological fluids has been realized. In particular, a rotational rheometer has been developed: it is a coaxial cylinders system, where the fluid flows dragged by the inner cylinder. The device is an absolute rheometer, that is, particularly useful as nowadays it is not known the classification of the bone as far as it concerns its viscous behavior. In this work a preliminary evaluation of the metrological characteristics of the measurement system has been carried out and its main metrological performances have been e...
An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique
The Review of scientific instruments, 2013
In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing techniq... more In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sen...
Fiber-Optic Flow Sensor for the Measurement of Inspiratory Efforts in Mechanical Neonatal Ventilation
Lecture Notes in Electrical Engineering, 2013
ABSTRACT A novel fiber-optic flow sensor has been developed for monitoring inspiratory efforts du... more ABSTRACT A novel fiber-optic flow sensor has been developed for monitoring inspiratory efforts during neonatal mechanical ventilation. The considered sensor is based on a fiber-optic sensing techniques, allowing the reduction of the effects due to electromagnetic interferences and a possible improvement of the electrical safety conditions. In the arrangement here described, the fiber-optic sensor is able to measure, with an accuracy of 5 percent, flow variations in the range between 0.5 l/min and 5 l/min, that are the typical flow variations due to infants’ inspiratory attempts and typical flow trigger levels set during assist-control ventilation (ACV). Moreover, a good agreement (r2=0.998) between experimental data and the parabolic theoretical model can be deduced. The metrological characteristics confirm that the novel proposed configuration for the optical fiber air flow sensor is suitable for monitoring flow variations due to infants’ inspiratory attempts.
Preliminary Evaluation of a Simple Optical Fiber Measurement System for Monitoring Respiratory Pressure in Mechanically Ventilated Infants
Biomedical Engineering / 765: Telehealth / 766: Assistive Technologies, 2012
ABSTRACT A novel fiber-optic pressure sensor is proposed for monitoring respiratory pressure in m... more ABSTRACT A novel fiber-optic pressure sensor is proposed for monitoring respiratory pressure in mechanically ventilated infants. The sensor principle is based on the measurement of the displacement of an emitting optical fiber cantilever due to the differential pressure applied on a capsule, performed by means of a photodiode array. The proposed fiber-optic sensing technique can reduce typical drawbacks affecting all biomedical fields, such as patient electrical safety and electromagnetic interference; moreover the device is not sensitive to optical power variations independent by pressure, because it is based on a detection of the illumination pattern of the emitting optical fiber. Two different arrangements of the fiber-optic pressure sensor have been examined: optimal configuration was found when the displacement of a capsule is amplified by means of an optical fiber cantilever, with a measurement range up to 15 cmH2O (i.e. the usual range of airway pressures encountered during tidal breathing of infants) and a high sensitivity (2.6 pixel/cmH2O) are obtained. The achieved metrological characteristics confirm that the proposed optical fiber pressure sensor is particularly suitable for monitoring respiratory pressure in mechanically ventilated infants and for detecting pressure drops due to infant’s inspiratory attempts. The proposed measurement system has been preliminarily verified through simple respiratory tests.
Experimental Characterization of a Novel Fiber-Optic Accelerometer for the Quantitative Assessment of Rest Tremor in Parkinsonian Patients
Biomedical Engineering / 765: Telehealth / 766: Assistive Technologies, 2012
ABSTRACT A novel fiber-optic accelerometer has been developed for the quantitative assessment of ... more ABSTRACT A novel fiber-optic accelerometer has been developed for the quantitative assessment of parkinsonian tremor at rest. The transducers is based on a fiber-optic sensing technique, that reduce some important drawbacks of biomedical applications, such as patient electrical safety and electromagnetic interference, and allows a non-invasive solution for monitoring of human movement, due to their limited mass. The sensing principle is based on the measurement of the transversal displacement of an emitting optical fiber cantilever due to the acceleration, conducted by means of a photodiode array: the detection of the light intensity profile makes the developed measurement system less sensitive to the light intensity variations independent from acceleration than intensity-based sensors. A dynamic calibration of the optical fiber accelerometer has been performed and a linear relationship between the lateral displacement of the fiber cantilever and acceleration has been experimentally evaluated. Moreover, a flat frequency response function between 3 Hz and 7 Hz (i.e. typical frequency range in which tremor at rest occurs in parkinsonian patients) and an high sensitivity in this frequency range (about 14 pixel/(m∙s-2) have been experimentally derived. These metrological features confirm that the proposed measurement system is particularly suitable for the quantitative assessment of parkinsonian tremor at rest.
Preliminary evaluation of a fiber-optic sensor for flow measurements in pulmonary ventilators
2011 IEEE International Symposium on Medical Measurements and Applications, 2011
A novel optical fiber air flow sensor was developed for monitoring flow rates supplied by infant ... more A novel optical fiber air flow sensor was developed for monitoring flow rates supplied by infant ventilators. The device is based on a fiber optic sensing technique and overcomes some important shortcomings of biomedical applications, such as electromagnetic interference and possible electrical hazard. The sensing principle is based on measuring the displacement of an emitting optical fiber cantilever by means of a photodiode linear array: the detection of the illumination pattern makes the developed system less sensitive to light intensity source variations than intensity-based sensors. A preliminary evaluation of the relationship between displacement and flow rate is theoretically and experimentally conducted, as well as a measurement range up to 3.00•10 -4 m 3 /s (18.0 l/min) has been verified, in accordance to the flow range usual for tidal breathing of infants.
Circuit compliance compensation in lung protective ventilation
2006 International Conference of the IEEE Engineering in Medicine and Biology Society, 2006
Lung protective ventilation utilizes low tidal volumes to ventilate patients with severe lung pat... more Lung protective ventilation utilizes low tidal volumes to ventilate patients with severe lung pathologies. The compensation of breathing circuit effects, i.e. those induced by compressible volume of the circuit, results particularly critical in the calculation of the actual tidal volume delivered to patient's respiratory system which in turns is responsible of the level of permissive hypercapnia. The present work analyzes the applicability of the equation for circuit compressible volume compensation in the case of pressure and volume controlled lung protective ventilation. Experimental tests conducted in-vitro show that the actual tidal volume can be reliably estimated if the compliance of the breathing circuit is measured with the same parameters and ventilation technique that will be utilized in lung protective ventilation. Differences between volume and pressure controlled ventilation are also quantitatively assessed showing that pressure controlled ventilation allows a more reliable compensation of breathing circuit compressible volume.
Review of Scientific Instruments, 2000
The Leakage Current Sentinel ͑LCS͒ has been designed and implemented for the detection of hazardo... more The Leakage Current Sentinel ͑LCS͒ has been designed and implemented for the detection of hazardous situations caused by dangerous earth leakage current values in intensive care units and operating theaters. The device, designed and manufactured with full compliance of the high risk environment requirements, is able to monitor online the earth leakage current and detect ground wire faults. Operation utilizes a microammeter with an overall sensitivity of 2.5ϫ10 4 V/A. In order to assure the reliability of the device in providing alarm signals, the simultaneous presence of absorbed power current is monitored by means of another ammeter with decreased sensitivity ͑3.0 V/A͒. The measured root mean square current values are compared with reference values in order to send signals to NAND and OR complementary metal-oxide-semiconductor gates to enable audible and visible alarms according to the possible hazardous cases examined in the article. The final LCS packaging was shaped as a wall socket adapter for common electromedical device power cord plugs, with particular attention to minimizing its dimensions and to provide analog voltage outputs for both measured leakage and power currents, in order to allow automatic data acquisition and computerized hazardous situation management. Finally, a personal computer based automatic measuring system has been configured to simultaneously monitor several LCSs installed in the same intensive care unit room and, as a consequence, to distinguish different hazardous scenarios and provide an adequate alert to the clinical personnel whose final decision is still required. The test results confirm the effectiveness and reliability of the LCS in giving an alert in case of leakage current anomalous values, either in case of a ground fault or in case of a dangerous leakage current.
Preliminary study on a remote system for diagnostic-therapeutic postural measurements
ABSTRACT The study refers to an experimental set up to achieve the remote control of a therapeuti... more ABSTRACT The study refers to an experimental set up to achieve the remote control of a therapeutic-diagnostic system composed of (a) a local host, connected with (b) a rotating platform, (c) a helmet instrumented with transducers, (d) an audio-video acquisition system and (e) a webcam with microphone. The whole system is able to collect acquired signals related to some diagnostic parameters of a patient submitted to a body rotation applied by in an integrated service of home care assistance. On the basis of available scientific literature, the requirements of measuring and control remote system are investigated and some methods for the optimal data transmission between client (diagnostic station at hospital) and server (measurement station in home care assistance) were implemented by means of a set of virtual tools on Labview and the performances are evaluated. Sinusoidal signals were used to test the proposed device during operative conditions. Frequency sweep test signals were applied to the file server and the comparison between transmitted and received signals was adopted to estimate the effective bandwidth of the whole system. Measurements are carried out in different experimental conditions within city areas. In particular various connection types were tested, such as analogue telephone line and an asymmetric digital subscriber line: results confirm that by an appropriate bandwidth limit can be reached in order to fulfill the diagnostic system requirements
Influence of transducer position on quality assurance measurements in B-mode Ultrasound: a case study
ABSTRACT Image quality assurance tests on medical ultrasound systems are often performed by techn... more ABSTRACT Image quality assurance tests on medical ultrasound systems are often performed by technicians using ultrasound phantoms and results depend on phantom features as well as scanner settings and operator experience. In the present study variations on some features of the B-mode image have been investigated when the ultrasound probe is handled by the technician during a routine quality test: ultrasound images of two different ultrasound phantom are acquired from two ultrasound transducer (convex and linear array) and processed by software to evaluate measurement dispersion in high contrast spatial resolution, penetration depth and accuracy in distance measurements. Measurement uncertainties depend strongly on probe model and parameter investigated: they ranges from 0.1 to 5.5 percent in distance measurements error, from 0.1 to 1.9 mm in high contrast resolution and from 2 to 10 mm in maximum depth of signal visualization. Although numerical results are limited to the two examined probes some general consideration can be done: (a) measurements depend on settings as well on phantoms features, probes and parameters investigated (b) Field of View settings seems to be more important for measurement repeatability than Dynamic Range, (c) accuracy in distance measurements seems to be less dependent on settings and transducer position. However use of support stands and clamps is highly recommended during routine quality assurance tests in order to reduce uncertainty in ultrasound system performances estimation.
Experimental investigation on dynamical performances of a novel fiber-optic pressure sensor for pulmonary ventilation
ABSTRACT A new optical fiber differential pressure sensor has been proposed for neonatal pulmonar... more ABSTRACT A new optical fiber differential pressure sensor has been proposed for neonatal pulmonary ventilation and an experimental investigation on its dynamical metrological performances is here reported. The proposed measurement system has been preliminarily tested by monitoring the mouth pressure during simple respiratory tests in healthy patients and during mechanical ventilation performed by means of a infant ventilator typically used in the neonatal intensive care units; results show that the output of the transducer is consistent with that measured by means of a reference sensor.
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Papers by Salvatore Sciuto