From intensive care to rehabilitation: survey on the satisfaction with care received during prolonged hospitalization for COVID-19 at a northern Italian university hospital.

OBJECTIVE: Investigating the experiences perceived by COVID-19 inpatients is a fundamental research area that is starting to be explored. For this reason, our objective was to provide the first Italian survey on COVID-19 inpatients' satisfaction, obtained through a self-completed questionnaire previously used in a reference study in a UK cohort of COVID-19 patients. SUBJECTS AND METHODS: Hospitalized COVID-19 patients (>20 days) admitted to Ferrara University Hospital who underwent rehabilitation during their hospital stay were invited to complete an anonymous questionnaire. The survey's questions explored the patients' satisfaction with the health services received, and their completion took place approximately one year after hospitalization. Information on sex, number of wards, ICU stays, and hospital discharge dates was collected. RESULTS: Sixty-two completed questionnaires were analyzed. The average overall satisfaction score obtained from the answers indicated by the participants in the tenth question was 4.7 out of 5.0. Very positive responses were observed for information about discharge plans, privacy, management of pain, sleep quality, and feeling of safety. The possibility of being consulted about medications and side effects received a very low satisfaction score. Considering overall satisfaction, no significant differences were noted for sex or ICU stay. The obtained results were almost superimposable to those reported in the cohort of COVID-19 patients of the reference study. CONCLUSIONS: This survey suggested that COVID-19 patients' healthcare satisfaction was high. Nevertheless, some areas must be improved, such as the communication and involvement of the patients in the decision-making of care and the discussion about medications or possible side effects.

Fatigue can influence the development of late-onset pain in post-COVID-19 syndrome: An observational study.

BACKGROUND: Late-onset pain is frequent following COVID-19, and many pathogenetic mechanisms have been proposed. Identifying the main features of patients may help in designing tailored rehabilitative interventions. METHODS: We enrolled post-COVID-19 patients with an increase in pain intensity of two points on the COVID-19 Yorkshire Rehabilitation Scale (C19-YRS) at 52 weeks compared to the pre-COVID-19 condition. All subjects were retrospectively monitored at 12, 26, and 52 weeks. A specific pain assessment was performed to determine the characteristics and mechanisms of pain. Catastrophizing, kinesiophobia, and other psychological symptoms were evaluated. The pressure pain threshold (PPT) and temporal summation (TS) were measured and compared in age- and sex-matched healthy controls to analyse pain characteristics. RESULTS: A total of 67 patients were recruited, with 20 of them presenting an increase in pain at 52 weeks. Subjects of the two subgroups were similar in demographic and clinical characteristics at baseline; significant differences in fatigue, anxiety, mobility, ability to perform daily activities, and general health perception were recorded at 26 weeks. Fatigue significantly predicted pain onset (ß = 0.54, p = 0.002). Sixteen different body regions were identified as painful, with a pain intensity of 6.0 ± 1.9. Most of the samples did not show neuropathic or nociplastic mechanisms. No differences in PPT and TS were recorded between patients and healthy controls. CONCLUSIONS: Almost one out of three patients hospitalized for COVID-19 developed pain 1 year later, and fatigue seems responsible for chronicity. An overlapping of conditions may explain late-onset post-COVID-19 pain, and a comprehensive approach must be considered for patient management. SIGNIFICANCE: Late-onset pain is frequent in post-COVID-19 syndrome and an overlapping of different mechanisms seems to be responsible for its development. Among many predisposing factors, fatigue in the months before seems to be one of the primary causes of pain one year following infection and its management may help to identify new strategies for prevention and treatment of late-onset pain.

Infodemiology of renal diseases: a novel opportunity to investigate public global interest.

OBJECTIVE: The aim of this study was to investigate the global community interest about renal diseases through relative search volumes (RSVs) of Google Trends (GT). MATERIALS AND METHODS: The online interest for the search terms hematuria (H), proteinuria (P), chronic kidney disease (CKD) and dialysis (D) was measured by evaluating RSVs from 2010 to 2019. All countries listed in GT were analysed and those presenting RSVs related to all search terms were considered following geographical position. RESULTS: Mean values of RSVs for D, CKD, H and P were 80±9%, 11±2%, 17±2% and 11±1%, respectively. D is the search term most frequently typed in English-speaking countries. On the other hand, in Latin Countries, the interest for P and H was higher than D. Searching for D, CKD and H are highly correlated whilst correlation coefficients between RSVs for D, CKD, and H with P are lower. Since 2010, the interest for renal diseases maintained stable. CONCLUSIONS: GT is a reliable tool in evaluating global interest for renal diseases in different geographical areas and temporal patterns. Although infodemiology represents a method for investigating the dissemination of information at a global level, our results suggest the need for increasing general population's interest for renal diseases especially, and move from simple interest to global awareness in the view of prevention strategies.

Infodemiology of solid organ transplantation: relationship to the Global Observatory on Donation and Transplantation data.

OBJECTIVE: Although transplantation medicine has been continuously improving, its impact on the general population needs to be evaluated. This study describes the global community interest in solid organ transplantation (SOT) using Google Trends, comparing relative search volumes (RSVs) and data from the World Health Organization (WHO) Global Observatory on Donation and Transplantation (GODT) regarding SOT activity all around the world. MATERIALS AND METHODS: The online interest for the search terms "kidney transplantation", "liver transplantation", "heart transplantation" and "lung transplantation" was measured, evaluating RSVs and the number of worldwide SOT recorded in the GODT website from 2008 to 2018. RESULTS: The mean values of RSVs were 51.7±16.8 for liver transplantation, 39.8±9.6 for kidney transplantation, 22.4±7.4 for heart transplantation and 15.4±5.2 for lung transplantation, and these values gradually reduced during the study period. Anglo Saxon countries had the highest interest for SOT, and the mean values of RSVs per year and annual numbers of SOT were inversely correlated. CONCLUSIONS: Despite the apparent interest and awareness, we found that public interest in SOT is decreasing. Access to information is crucial for improving understanding of transplantation and motivation to donate. Health care professionals could take advantage by using the internet, and evaluation of RSVs could represent valuable feedback.

Body mass index and metabolic syndrome impact differently on major clinical events in renal transplant patients.

OBJECTIVE: Kidney transplant recipients (KTRs) are bound to develop cardiovascular disease (CVD), and obesity represents a well-known risk factor for CVD. It has been reported that the metabolic syndrome (MetS) is a frequent finding in KTRs, and MetS could develop even if body mass index (BMI) is only mildly increased. We compared the impact of BMI and MetS on the development of major clinical events (MCEs) in a cohort of 107 KTRs during a follow-up of 63 ± 31 months. PATIENTS AND METHODS: Clinical characteristics were recorded at the time of enrollment and patients were classified on the basis of MCEs development. In a Cox model, MCEs were the dependent variable while age, sex, history of CVD, glomerular filtration rate, length of dialysis pre-transplantation, BMI classes and diagnosis of MetS were independent variables. Patients were classified into 3 groups: normal (BMI < 25 kg/m2), overweight (BMI of 25 to 30 kg/m2) and obese (BMI > 30 kg/m2). RESULTS: During follow-up, 55 MCEs were recorded: 16 patients died (15%), 19 (18%) had major cardiovascular events (CVEs), and 20 (19%) started dialysis due to graft failure. KTRs who had MCEs (n = 42) were older, had a lower renal function, longer dialysis vintage pre-transplantation, higher prevalence of history of CVD and higher BMI than those without MCEs. Cox regression analysis showed that length of dialysis pre-transplantation, renal function, previous CVD, and BMI classes (overweight and obesity) were related to MCEs. CONCLUSIONS: BMI, but not MetS, predicted MCEs in KTRs as well as non-traditional CVD risk factors such as length of dialysis pre-transplantation and graft function. Thus, a simple evaluation during clinic visits could identify KTRs at high risk for MCEs.

A Toe Flexion NIRS assisted Test for Rapid Assessment of Foot Perfusion in Peripheral Arterial Disease: Feasibility, Validity, and Diagnostic Accuracy.

OBJECTIVES: Feasibility, validity, and diagnostic accuracy of a non-invasive dynamic ambulatory test were assessed with near infrared spectroscopy (NIRS) evaluating foot perfusion in peripheral arterial disease (PAD). METHODS: This was a prospective observational study. Eighty PAD patients (63 males, 71 ± 9 years), including 41 patients with coexisting diabetes, participated. Thirteen healthy subjects (8 males, 26 ± 8 years) were also studied by echo colour Doppler providing 160 diseased and 26 non-diseased limbs. Under identical clinostatic conditions, participants performed a 10-repetition toe flexion tests with NIRS probes on the dorsum of each foot; the area under the curve of the oxygenated haemoglobin trace ("toflex area") was calculated and the ankle-brachial index (ABI) was measured. Time of execution, rate of wrong tests, and adverse reactions were recorded. Within session reliability was assessed by administering the test twice, with a 5 minute interval between tests. The validity was assessed determining whether the toflex area was (a) dependent on the oxygen delivery from the lower limb arteries simulating PAD conditions by a progressive blood flow restriction (40-120% of systolic pressure) in healthy subjects; (b) consistent with the degree of PAD ranked by ABI and correlated with ABI and ankle pressure values in PAD patients. The diagnostic accuracy in detecting PAD was compared with examination using echo colour Doppler ultrasound. RESULTS: All tests were rapidly, satisfactorily (<1% mistakes), and safely performed. Toflex area values, superimposable in the two sessions (intra-class correlation coefficient 0.92), were comparable to PAD values following blood flow restriction, consistent with PAD severity, correlated with dorsal pedis artery pressure (r = .21; p = .007) and ABI (r = .65; p < .001) in PAD, but not in the presence of diabetes. Toflex area was similar to echo colour Doppler for detecting PAD following receiver operating characteristic curve analysis (area = 0.987, p < .001; toflex area values ≤ -28 arbitrary units, sensitivity/specificity 95.6/100). CONCLUSION: The toe flexion test enables ambulatory assessment of foot perfusion and PAD detection, even in the presence of non-measurable ABI or diseases affecting the microcirculation.

An ultrasound technique for monitoring the alcoholic wine fermentation.

In this paper an ultrasonic technique, usually used in non-destructive-testing (NDT), is applied to the monitoring of alcoholic wine fermentation. This technique consists in placing a test tube, containing the analyzing fluid, between two matched ultrasonic piezoelectric transducers, one used as transmitter and the other as receiver. The transmitter generates an ultrasonic wave in the liquid sample which is received by the receiver; the attenuation and the delay of the received signal in respect to the transmitted one are used to characterize the testing fluid. As first experiments this technique was applied to some test solutions of saccharose in water, ethanol in water and of both solvents in water, in order to evaluate the method applicability and resolution. Best results are obtained by the propagation velocity measurement, with a resolution less than 2%. The method was then applied to monitor the wine fermentation: the propagation velocity in the must was measured every day and the results were related to chemical analyses. The obtained results show that the propagation velocity has the same behaviour of the saccharose concentration, putting in evidence the possibility of monitoring the process state by measuring the ultrasound propagation velocity.

Characterization of piezoceramic rectangular parallelepipeds by means of a two-dimensional model.

The characterization of piezoelectric resonators is a field of intense scientific work; moreover, clear and accepted IEEE and IEC Standards have been published, showing the concepts and routes to perform the complete characterization of piezoelectric resonators. All of the accepted procedures define some resonator geometries, each of them related with a set of parameters, that can be obtained following resonance measurements at the corresponding resonance frequencies. The basis of the standards is the existence, for each geometry, of well-defined modes that have been analytically solved. The development of multi-dimensional models of the waves' propagation in piezoceramic materials opens the possibility of characterizing piezoelectric resonators with geometries different from those recommended in the standards. In this paper, a two-dimensional model, which takes into account the mechanical and dielectric losses, has been used to characterize piezoceramics with the shape of a regular parallelepiped. A set of elastic, dielectric, and piezoelectric parameters, which are useful for piezoelectric transducer design, can be obtained. For a given sample, the measured input electrical impedance is used to obtain the parameters by means of a fitting process with the corresponding model output. The results obtained with low and high loss materials show that the parameters found have values similar to those obtained following the procedures and geometries recommended by the standards. This procedure permits the characterization of materials when the manufacturing procedure does not allow the fabrication of the shapes recommended by the standards, making it a useful tool for transducer manufacturers and material scientists.

A matrix model of the axle vibration of a piezoelectric motor

In this work, a matrix model of the axle vibration of a piezoelectric motor is proposed. The stator of this motor is composed of a thin piezoelectric membrane and a steel axle fitted at the center of the membrane. The rotor consists of a cylinder-shaped permanent magnet, pressed in contact with the other end of the axle by means of the magnetic forces. A travelling wave is excited in the membrane by using four electrodes and four, properly delayed, driving signals. The rotating flexural displacement of the membrane produces a wide precessional motion of the axle. In this way, a continuous slipping takes place between the axle and the rotor, and therefore, a torque is transmitted to the rotor. In this paper, the precessional motion of the axle is modeled as the composition of two transverse vibrations belonging to two perpendicular planes passing through the axle. The axle, vibrating in its transverse mode, is modeled as a two-port system: the input is the bending moment supplied by the membrane, and the output is the transverse force at the terminal end of the axle. With this model, we have computed the trasmission transfer function as a function of frequency, and the transversal displacement along the axle at its resonance frequency. The computed results are in reasonable agreement with experimental interferometric measurements carried out on a prototype.

Two-dimensional modelling of multifrequency piezocomposites.

The multifrequency composites of 2-2 connectivity modelled in this work are made with groups of piezoelectric elements of different lateral dimensions, periodically reproduced in the structure. These composites have potential to improve the performances of standard piezoelectric composites with the same materials and ceramic fraction, on account that they have different resonators coupled mechanically along the structure. A one-dimensional model was developed to study their performances in a first approximation. In order to obtain a design model, a two-dimensional model, previously used to describe multielement array transducers, has been extended to the case of 2-2 polymer-piezoceramic composites. Several composite samples, having piezoceramic strips with different width-to-thickness ratios, have been built, and their resonance behaviour compared with the model prediction. Finally, the model has been extended to the case of 2-2 multifrequency composites. For multifrequency composites having in the same composite structure two or three piezoceramic strips with different lateral dimensions, the comparison between experimental and predicted results shows good agreement. The model has been used to optimise a double composite in comparison with a standard one with the same volume fraction and constituents.

Analysis of the radial symmetrical modes of thin piezoceramic rings.

In this work, the radial symmetric vibration modes of thin piezoceramic rings have been analyzed by means of a previously proposed theoretical model. Both the resonance frequencies and the effective electromechanical coupling factor (k(eff)), as a function of the aspect ratio G between the inner and outer radii of the ring, were computed. The results have shown that the disk structure (G-->0) has only one radial symmetrical mode (with its harmonics), but, for the ring structure (G-->1), two different modes are clearly distinguished: the ring mode, which has no harmonics, and a width-like mode, with its harmonics. Moreover, the results show that the ring structure can be assumed to be definitely reached for G>0.6. An analysis of the material coupling factor in the ring geometry is reported as well.

A piezoelectric motor using flexural vibration of a thin piezoelectric membrane.

This paper describes a new implementation of a disk-type piezoelectric motor, whose stator is a commercial available piezomembrane composed of a nickel alloy disk to which a piezoceramic disk is bonded. The two disks are concentric, and the total thickness is very small. Ultrasonic motors are based on the concept of driving a rotor by mechanical vibration excited on a stator, via the piezoelectric effect. The rotor is in contact with the stator, and the driving force is the frictional force between rotor and stator. To transform the mechanical vibration of the stator in the rotor rotation, a traveling wave must be excited on the stator surface. The proposed motor can be regarded as a disk-type, single wavelength motor in which the traveling wave is due to the natural flexural vibration of the piezomembrane at low frequency. The behavior of the stator is analyzed both theoretically, by using the theory of isotropic and homogeneous vibrating plates, and by means of a commercial finite element computer code, finding a good agreement with the experimental results. The main features of the motor are very small thickness, appreciable torque, and high speed, obtained with low input power at low voltage; the intended application is to substitute the moving-coil in analogic instrumentation.

An approximated 3-D model of cylinder-shaped piezoceramic elements for transducer design.

In this paper an approximated 3-D model of cylinder shaped piezoceramics is described. In the hypothesis of axial symmetry, the element vibration in the extensional and radial directions is described by two coupled differential wave equations. The model is obtained choosing, as solution of these equations, two orthogonal wave functions, each depending only on one axis, corresponding to the propagation direction. The mechanical boundary conditions are applied imposing continuity between the stresses and the external forces on the surfaces of the element in an integral way, while, as far as the electrical boundary condition is concerned, two possibilities are explored: to neglect the piezoelectric constant in the transverse direction and to impose an integral condition also for the electric field. Comparisons with experimental results show this last approach to give better results. The model predicts with sufficient accuracy only the first radial and the first thickness modes of the cylinder-shaped piezoceramic element of arbitrary aspect ratio; but, for these modes, it is able to compute all the relations between the input applied voltage and the output forces and velocities on every external surface. Because only these two modes are of relevance in the practical applications of piezoceramic elements as ultrasonic transducers, the model can be used as a simple and useful tool in transducer design and optimization. Experimental validations of the model are also shown in the work.

A new approach for the design of ultrasono-therapy transducers.

In this paper we describe a new approach for the design of ultrasono-therapy transducers. Usually, in this kind of transducer, a lambda/2 front plate is inserted only in order to ensure a good mechanical protection of the active crystal from the surrounding medium. However, with an accurate design, the plate can also be used to match the piezoelectric element to the load both in terms of gain and bandwidth. To this end we apply the technique normally used in acoustical imaging and nondestructive testing, and, by means of a distributed matrix model, we optimize the thickness and impedance of the plate in order to obtain a strong response and a large bandwidth at the working frequency. Using a front plate of thickness about lambda/3, the model predicts better performances than the ones obtained with the classical design, also in terms of efficiency. An experimental comparison between a transducer realized according to the proposed design and a commercial half wave transducer shows better performances the former and therefore validates the new design criterion.