Input-output characterization of an ultrasonic testing system by digital signal analysis

The input/output characteristics of an ultrasonic testing system used for stress wave factor measurements were studied. The fundamentals of digital signal processing are summarized. The inputs and outputs are digitized and processed in a microcomputer using digital signal processing techniques. The entire ultrasonic test system, including transducers and all electronic components, is modeled as a discrete-time linear shift-invariant system. Then the impulse response and frequency response of the continuous time ultrasonic test system are estimated by interpolating the defining points in the unit sample response and frequency response of the discrete time system. It is found that the ultrasonic test system behaves as a linear phase bandpass filter. Good results were obtained for rectangular pulse inputs of various amplitudes and durations and for tone burst inputs whose center frequencies are within the passband of the test system and for single cycle inputs of various amplitudes. The input/output limits on the linearity of the system are determined

A 10-day course of SPA therapy is beneficial for people with severe knee osteoarthritis

The objective of this study was to test if spa therapy can play a role in the management of severe knee osteoarthritis (OA). Twenty patients with radiologically and clinically severe knee OA were randomly assigned into spa and drug therapy groups. Spa group (n=10) traveled to a spa town and stayed at a hotel for a 10-day spa therapy course. They followed a balneotherapy regimen including thermal pool baths at 37 degrees C for 20 min two times daily. Drug therapy group (n=10) stayed at home and followed their individually prescribed drug therapy (NSAIDs and paracetamol). Patients were assessed at baseline (week 0), after spa therapy at 2 weeks (week 2) and during follow-up period at 12 (week 12) and 24 (week 24) weeks by a blinded investigator. Patients assessed with Lequesne algofunctional index (LAFI), pain (visual analogue scale, VAS), patient's and investigator's global evaluation (VAS), ten-stairs stepping up and down time, 15 m walking time and three times squatting up and down time. Significant improvement in pain and LAFI scores were found at week 2, week 12 and week 24 in the spa therapy group compared to baseline. Comparing the two group differences, spa therapy was superior to drug therapy in pain reduction and in physician's global assessment at all time points. This superiority was also found in LAFI scores and patients' global assessments at week 12 and week 24. A 10-day course of spa therapy may be beneficial in short- and medium-term up to 24 weeks by reducing pain and improving functional status and overall well-being in patients with severe knee OA and may be considered as an effective therapeutic tool for such patients in countries like Turkey where it is widely available and (at least partly) reimbursed

The efficacy of peloidotherapy on the patients with chronic low back pain

Objective: This study was designed to evaluate the efficacy of mudpack therapy in 31 patients with chronic low back pain for more than 3 months. Material and Methods: In this study, that included 16 females and 15 males, the mean age was 49.23 (35-66) years. Mudpack therapy was applied at 45 degrees C for 30 minutes once a day for 12 days. All patients were evaluated using Visual Anlogue Scale (VAS), Beck Depression Inventory (BDI), Modified Schober Test (MST) and Short Form-36 (SF-36) scores. Results: All instruments were administered three times (before therapy, at the end of week 3 and at the end of the 3rd month). VAS, BDI, MST and SF-36 scores improved significantly (p< 0.001). Conclusion: We conclude that mudpack therapy gives satisfatory results in the early period for patients with chronic low back pain and improves quality of life and that it can be safely applied for these patients

Simulation and experimental analysis of active vibration control of smart beams under harmonic excitation

In the present study, active control of a smart beam under forced vibration is analyzed. The aluminum smart beam is composed of two piezoelectric patches and strain gauge. One of the piezoelectric patches is used as controlling actuator while the other piezoelectric patch is used as vibration generating shaker. The smart beam is harmonically excited by the piezoelectric shaker at its fundamental frequency. The strain gauge is utilized to sense the vibration level. Active vibration reduction under harmonic excitation is achieved using both strain and displacement feedback control. Control actions, the finite element (FE) modeling and analyses are directly carried Out by using ANSYS parametric design language (APDL). Experimental applications are performed with LabVIEW. Dynamic behavior at the tip of the beam is evaluated for the uncontrolled and controlled responses. The simulation and experimental results are compared. Good agreement is observed between simulation and experimental results under harmonic excitation

Oxidative stress, hemoglobin content, superoxide dismutase and catalase activity influenced by sulphur baths and mud packs in patients with osteoarthritis

Background/Aim. It is weel-known that sulphur baths and mud paks demonstrate beneficial effects on patients suffering from degenerative knee and hip osteoarthritis (OA) through the increased activity of protective antioxidant enzymes. The aim of this study was to assess lipid peroxidation level, i.e. malondialdehyde concetration, in individuals with knee and/or hip osteoarthritis (OA), as well as to determine the influence of sulphur baths and mud packs application on the activity of superoxide dismutase (SOD) and catalase (CAT) in order to minimize or eliminate excessive free radical species production (oxidative stress). Methods. Thirty one patiens with knee and/or hip OA of both sexes were included in the study. All OA patients received mud pack and sulphur bath for 20 minutes a day, for 6 consecutive days a week, over 3 weeks. Blood lipid peroxidation, ie malondialdehyde concentration, superoxide dismutase and catalase activity were measured spectrophotometrically, before, on day 5 during the treatment and at the end of spa cure. Healthy volunteers (n = 31) were the controls. Results. The sulphur baths and mud packs treatment of OA patients caused a significant decrease in plasma malondialdehyde concentration compared to the controls (p < 0.001). The mean SOD activity before the terapy was 1 836.24 U/gHb, on day 5 it rose to 1 942.15 U/gHb and after the spa cure dropped to 1 745.98 U/gHb. Catalase activity before the therapy was 20.56 kU/gHb and at the end of the terapy decreased to 16.16 kU/gHb. The difference in catalase activity before and after the therapy was significant (p < 0.001), and also significant as compared to control (p < 0.001). At the end of the treatment significant increase of hemoglobin level and significant decrease of pain intensity were noticed. Conclusion. A combined 3-week treatment by sulphur bath and mud packs led to a significant decrease of lipid peroxidation in plasma, as well as pain intensity in the patients with OA. These changes were associated with changes in plasma activity of SOD and CAT and a significant increase of hemoglobin level suggesting their role in beneficial effect of spa therapy in the patients with OA