PD Signals Research Articles

Clinical and diagnostic imaging characteristics of lateral digital flexor tendinitis within the tarsal sheath in four horses.

Lateral digital flexor tendonitis is a rarely reported cause of hind limb lameness in performance horses. The purpose of this retrospective study was to describe clinical and diagnostic imaging findings for a group of horses with lateral digital flexor tendinitis within the tarsal sheath. Equine cases with a diagnosis of lateral digital flexor tendonitis and magnetic resonance imaging (MRI) studies of the affected region were retrieved from North Carolina University’s medical record database. Recorded data for included horses were signalment; findings from history, physical examination, lameness examination, and all diagnostic imaging studies; treatment administered; and outcome. Four horses met inclusion criteria. Lameness was mild/moderate in severity and insidious in onset in all patients. Responses to flexion tests were variable. All horses showed positive improvement(70–90%) in lameness after tarsal sheath analgesia. Radiographic, scintigraphic, and ultrasonographic findings were inconclusive. For all horses, MRI characteristics included increased T2, PD, and STIR signal intensity within the lateral digital flexor tendon in the area of the tarsal sheath. Tarsal sheath effusion was slight in three horses, and mild/moderate in one horse. With medical treatment, two horses were sound at 6-month follow up, one horse was sound at 1-year followup, and one horse had a slight persistent lameness (grade 1/5) at 9-month followup. Findings supported the use of MRI for diagnosing lateral digital flexor tendonitis within the tarsal sheath in horses. Affected horses may have a good prognosis for return to athletic performance following appropriate medical treatment.

Reassigned Time Frequency Analysis for PD Signals in GIS

Partial discharge signal in GIS is a kind of typical non-stationary signal, using the time or frequency domain simply is not enough to describe the time-varying information of PD. Based on the reason above, this paper introduces a joint time-frequency analysis method according to the reassignment theory for analyzing the PD of GIS. After the processing of the PD signals simulated and on field, we conclude that this method provides a higher concentration in the time-frequency plane and reduces the most influence of the cross-interference terms.

Study of the Ultrasonic Characteristics of Typical Partial Discharge on GIS

This Paper studied the typical PD in GIS by ultrasonic method. A GIS PD simulating and testing system is established, including a PD simulating system, an ultrasonic detecting system and a conventional pulse current method measurement system. The thesis focuses on four typical kinds of PD signals in GIS, including metal particles, bad contacts on high and grounding potential conductor, the protrusion on the high potential conductor. The statistics characteristics are obtained which include N-Φ spectrogram (relationship between discharge frequency and discharge phase Spectrogram) and Umax-Φ spectrogram (relationship between discharge amplitude and discharge phase Spectrogram). Experimental results show that low-frequency ultrasonic sensors can detect this four PD signals， signal spectra analysis shows that ultrasonic signals of different statistical model are with different characteristics. The results provide test data for the pattern recognition of Partial Discharge in GIS.

OP0172 The Presence and Intensity of Power Doppler Signal are not Modified by Time of Assessment: Data form Patients with Rheumatoid Arthritis

BackgroundPower Doppler (PD) ultrasound is a sensitive and reliable method for the assessment of inflammatory activity in rheumatoid arthritis (RA). Many variables, however, were described to modulate the intensity of...

SAT0497 The Influence of Age, Gender, Tobacco and Manual Tasks in the Presence of Power Doppler Signal in Subjects with Non Inflammatory Arthritides

BackgroundPower Doppler (PD) ultrasound is a sensitive and reliable method for the assessment of inflammatory activity in rheumatoid arthritis (RA). Many variables, however, were described to modulate the presence of...

SAT0284 In Early PSA, the Ultrasonography of Hands and Wrists Synovitis and Digital soft Tissue Involvement Is More Sensitive Than Traditional Clinical Examination

BackgroundClinical measures are widely used in established psoriatic arthritis (PsA) but in early phase of disease, often fail to identify the joint and tendons involvement.ObjectivesTo investigate the ultrasonography (US) abnormalities...

OP0269 Detection of Synovitis in Clinically Inactive Juvenile Idiopathic Arthritis Patients by Ultrasonography with Power Doppler

BackgroundJuvenile idiopathic arthritis (JIA) is a heterogeneous group of arthritides that all present with chronic joint inflammation that can lead to structural damage. The advances in therapeutic effectiveness have created...

THU0448 The Profile of Musculoskeletal Ultrasonography in Patients with Adult Onset Still Disease.

BackgroundAdult onset Still disease (AoSD) is a systemic inflammatory disease and characterized by daily spiking high fevers accompanied by a rash, arthritis, and systemic manifestations. The clinical course of AoSD...

AB0510 Monitoring disease activity and response through power doppler ultrasonography in rheumatoid arthritis patients treated with rituximab – correlations with antibodies pannel

BackgroundRituximab is a a chimeric anti-CD20 monoclonal antibody approved to reduce the signs and symptoms of moderately to severely active rheumatoid arthritis (RA) in patients with inadequate response to first...

SAT0400 Ultrasound assessment of the enthesopaty in patients with ankylosing spondylitis without history of entheseal involvement

BackgroundEnthesitis is one of the most common and specific manifestations of spondyloarthropathy (SpA). Ultrasonography has demonstrated to be a highly sensitive tool in the evaluation of entheses in patients with...

SAT0499 Power Doppler Ulrasonographic Monitoring of Response to Treatment in Gout Patients

BackgroundThe accepted outcome measures for gout are seric urate, recurrent outbreaks, tophi regression and joint damage image. The Power Doppler ultrasound (PDUS) has demonstrated validity in the monitoring of treatment...

FRI0503 Can ultrasonographic findings predict response to tumor necrosis factor-a inhibitor treatment in rheumatoid arthritis?

BackgroundTumor necrosis factor-α inhibitors (TNFi) are highly effective in patients with rheumatoid arthritis (RA), while not effective in all, with predictors of response being necessary. Although genetic, inflammatory and serologic...

SAT0514 Associations between Functional Status and Ultrasound – Detected Synovitis and Joint Damage in Rheumatoid Arthritis during Tocilizumab Treatment

BackgroundPhysical function is one of the major outcomes in rheumatoid arthritis (RA) which can predict work disability, quality of life and mortality. It has been shown that multiple factors are...

SAT0089 Non-Steroidal Anti-Inflammatory Drugs Have an Independent Effect on Synovial Vascularity Assessed by Musculoskeletal Ultrasound in Rheumatoid Arthritis

BackgroundMusculoskeletal ultrasound (MSUS) is useful in monitoring rheumatoid arthritis (RA) and is emphasized its high sensitivity for detecting synovitis and good correlation with clinical disease activity indices, such as Disease...

FRI0508 Correlation of power doppler ultrasonographic findings with site-matched histopathology of the synovial tissue

BackgroundUltrasonography (US) has been recently established as an imaging modality to evaluate inflamed joints of patients with rheumatoid arthritis (RA). It is reported that power doppler ultrasonography (PDUS) is capable...

OP0315 Ultrasound Features of Inflammation in the Knee Joint and its Relationship to Pain and Radiographic Osteoarthritis

BackgroundUltrasound (US) is a useful imaging modality that allows the evaluation of features suggestive of inflammation in osteoarthritis (OA). US features are more common in those with painful knee OA...

THU0155 Sensitivity to Change of the Ultrasound Disease Activity Score

BackgroundWe have investigated construct validity and reliability of the Ultrasound Disease Activity Score (USDAS) compared with DAS28 in assessing joint inflammation and in prediction of structural damage in patients with...

THU0445 High ultrasonographic scores persist among patients with rheumatoid arthritis in clinical remission with normal serum MMP-3 values

BackgroundSerum matrix metalloproteinase-3 (MMP-3) levels are useful conventional markers of synovitis associated with rheumatoid arthritis (RA). Ultrasonography (US) has recently become more popular as a method of evaluating joint synovitis.ObjectivesTo...

Research on Method for Obtaining Time Difference of Localization of Transformer PD Source

Ultrasonic positioning accuracy of transformer partial discharge is not high. The main reason is that it is difficult to obtain accurate time difference of the ultrasonic signals reaching two different sensors, especially when the signal-to-noise ratio is not high enough. To solve this problem, Hilbert-Huang transform (HHT) is applied in signal processing to extract the precise moment, and in this way the precise time difference is easily obtained. The signal-to-noise ratio (SNR) of received signal is low, and even worse PD signal is drowned in the strong interference signal. For this, the method named fast independent component analysis (FastICA) is applied in ultrasonic signal denoising before obtaining the time difference. FastICA is not effective in separating the ultrasonic signal from the separated components and in order to solve the problem, envelope identification method is proposed in this paper. In the method, the upper envelope of the signal waveform is sampled and the average of the sampling points is calculated to extract the ultrasonic signal. The numerical result confirmed the practicality of all the mentioned methods.

Portable Acoustic-Electric Combined System for Partial Discharge Detection in GIS

A portable acoustic-electric detection system for GIS partial discharge is developed. This system integrates both high and low-speed data acquisition devices, and is capable of multichannel joint detection of ultra-high-frequency and high-frequency current as well as ultrasonic signal generated during the GIS partial discharge process. The software of this system is developed based on LabVIEW. It can successively capture, acquire and store the pulse waveform of partial discharge, calculate the phase of discharge pulse and realize time-frequency analysis and amplitude-phase distribution analysis of PD signals at the same time. By calculating the time difference of multi-channel ultra-high-frequency (UHF) signals and of PD ultrasonic signals or the time difference between the two, the system is able to locate the PD source. This system has been applied to on-site partial discharge detection of 220kV and 500kV GIS substations, and the test results have verified the performance of the system.