scholarly journals The Influence of Filters on EEG-ERP Testing: Analysis of Motor Cortex in Healthy Subjects

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7711
Author(s):  
Ilona Karpiel ◽  
Zofia Kurasz ◽  
Rafał Kurasz ◽  
Klaudia Duch
Keyword(s):  
Gold Standard ◽  
Healthy Subjects ◽  
Data Interpretation ◽  
Eeg Signal ◽  
Sensorimotor Area ◽  
Eeg Data ◽  
Reduction Methods ◽  
Characteristic Values ◽  
No Gold Standard ◽  
Correct Data

The raw EEG signal is always contaminated with many different artifacts, such as muscle movements (electromyographic artifacts), eye blinking (electrooculographic artifacts) or power line disturbances. All artifacts must be removed for correct data interpretation. However, various noise reduction methods significantly influence the final shape of the EEG signal and thus its characteristic values, latency and amplitude. There are several types of filters to eliminate noise early in the processing of EEG data. However, there is no gold standard for their use. This article aims to verify and compare the influence of four various filters (FIR, IIR, FFT, NOTCH) on the latency and amplitude of the EEG signal. By presenting a comparison of selected filters, the authors intend to raise awareness among researchers as regards the effects of known filters on latency and amplitude in a selected area—the sensorimotor area.

scholarly journals Predicted sensory consequences of voluntary actions modulate amplitude and temporal dynamics of preceding readiness potentials

2017 ◽  
Author(s):  
Daniel Reznik ◽  
Shiri Simon ◽  
Roy Mukamel
Keyword(s):  
Motor Activity ◽  
Early Phase ◽  
Healthy Subjects ◽  
Temporal Dynamics ◽  
Readiness Potential ◽  
Button Press ◽  
Eeg Signal ◽  
Eeg Data ◽  
Readiness Potentials ◽  
Neural Signature

AbstractSelf-generated, voluntary actions, are preceded by a slow negativity in the scalp electroencephalography (EEG) signal recorded from frontal regions (termed ‘readiness potential’; RP). This signal, and its lateralized subcomponent (LRP), is mainly regarded as preparatory motor activity associated with the forthcoming motor act. However, it is not clear whether this neural signature is associated with preparatory motor activity, expectation of its associated sensory consequences, or both. Here we recorded EEG data from 12 healthy subjects while they performed self-paced button presses with their right index and middle fingers. In one condition (motor+sound) these button-presses triggered a sound while in another (motor-only) they did not. Additionally, subjects passively listened to sounds delivered in expected timings (sound-only). We found that the RP amplitude (locked to time of button press) was significantly more negative in the motor+sound compared with motor-only conditions starting ~1.4 seconds prior to button press. Importantly, no signal negativity was observed prior to expected sound delivery in the sound-only condition. Thus, the differences in RP amplitude between motor+sound and motor-only conditions are beyond differences in mere expectation of a forthcoming auditory sound. No significant differences between the two conditions were obtained in the LRP component. Our results suggest that expected auditory consequences are encoded in the early phase of the RP preceding the voluntary actions that generate them.

On the robustness of latent class models for diagnostic testing with no gold standard

2021 ◽  
Author(s):  
Matthew R. Schofield ◽  
Michael J. Maze ◽  
John A. Crump ◽  
Matthew P. Rubach ◽  
Renee Galloway ◽  
...  
Keyword(s):  
Gold Standard ◽  
Latent Class ◽  
Diagnostic Testing ◽  
Latent Class Models ◽  
No Gold Standard ◽  
Class Models

scholarly journals The holding temperature of blood during a delay to processing can affect serum and plasma protein measurements

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Milton Ashworth ◽  
Benjamin Small ◽  
Lucy Oldfield ◽  
Anthony Evans ◽  
William Greenhalf ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Room Temperature ◽  
Serum Levels ◽  
Data Interpretation ◽  
Blood Samples ◽  
Specific Manner ◽  
Associated Proteins ◽  
Holding Temperature ◽  
Pai 1 ◽  
Meaningful Data

AbstractAccurate blood-borne biomarkers are sought for diagnosis, prognosis and treatment stratification. Consistent handling of blood is essential for meaningful data interpretation, however, delays during processing are occasionally unavoidable. We investigated the effects of immediately placing blood samples on ice versus room temperature for 1 h (reference protocol), and holding samples on ice versus room temperature during a 3 h delay to processing. Using Luminex multi-plex assays to assess cytokines (n = 29) and diabetes-associated proteins (n = 15) in healthy subjects, we observed that placing blood samples immediately on ice decreased the serum levels of several cytokines, including PAI-1, MIP1-β, IL-9, RANTES and IL-8. During a delay to processing, some analytes, e.g. leptin and insulin, showed little change in serum or plasma values. However, for approximately half of the analytes studied, a delay, regardless of the holding temperature, altered the measured levels compared to the reference protocol. Effects differed between serum and plasma and for some analytes the direction of change in level varied across individuals. The optimal holding temperature for samples during a delay was analyte-specific. In conclusion, deviations from protocol can lead to significant changes in blood analyte levels. Where possible, protocols for blood handling should be pre-determined in an analyte-specific manner.

SIMULATION AND MODELING OF EVOKED RESPONSE ELECTROENCEPHALOGRAPH SIGNAL

1999 ◽  
Vol 10 (04) ◽  
pp. 759-776
Author(s):  
D. R. KULKARNI ◽  
J. C. PARIKH ◽  
R. PRATAP
Keyword(s):  
Small Range ◽  
Eeg Signal ◽  
Simulation And Modeling ◽  
State Space Reconstruction ◽  
Eyes Closed ◽  
Normal Individuals ◽  
Eeg Data ◽  
Closed Data ◽  
Simulation Results ◽  
Low Dimensional

Electroencephalograph (EEG) data for normal individuals with eyes-closed and under stimuli is analyzed. The stimuli consisted of photo, audio, motor and mental activity. We use several measures from nonlinear dynamics to analyze and characterize the data. We find that the dynamics of the EEG signal is deterministic and chaotic but it is not a low dimensional chaotic system. The evoked responses lead to a redistribution of strengths relative to eyes-closed data. Basically, strength in α waves decreases whereas that in β wave increases. We also carried out simulations separately and in combination for δ, θ, α and β waves to understand the data. From the simulation results, it appears that the characteristics of EEG data are consequences of filtering the data with a relatively small range of frequency (0.5–32 Hz). In view of this, we believe that calculation of known nonlinear measures is not likely to be very useful for studying the dynamics of EEG data. We have also successfully modeled the EEG time series using the concept of state space reconstruction in the framework of artificial neural network. It gives us confidence that one would be able to understand, in a more basic way, how collectivity in EEG signal arises.

Rejoinder to “On the robustness of latent class models for diagnostic testing with no gold standard”

2021 ◽  
Vol 40 (22) ◽  
pp. 4770-4771
Author(s):  
Matthew R. Schofield ◽  
Michael J. Maze ◽  
John A. Crump ◽  
Matthew P. Rubach ◽  
Renee L. Galloway ◽  
...  
Keyword(s):  
Gold Standard ◽  
Latent Class ◽  
Diagnostic Testing ◽  
Latent Class Models ◽  
No Gold Standard ◽  
Class Models

scholarly journals LVNC – A review

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Lisa Brandon ◽  
◽  
Brian Kerr ◽  
Ken McDonald ◽  
◽  
...  
Keyword(s):  
Heart Failure ◽  
Congenital Heart Disease ◽  
Heart Disease ◽  
Gold Standard ◽  
Congenital Heart ◽  
Imaging Techniques ◽  
Disease Modifying Therapies ◽  
Increased Risk ◽  
Disease Modifying ◽  
No Gold Standard

LVNC is a relatively new clinical entity, with a significant increase in awareness and diagnosis in recent years. Currently the aetiology and pathogenesis of LVNC remains uncertain, alongside prevalence, however the diagnosis of LVNC appears to be increasing with improving imaging techniques. For educational purposes involving a rare clinical condition, we present the case of a 52 year old gentleman who was diagnosed with LV non compaction via ECHO and CMR. Interestingly it was noted two of his children had congenital heart disease, one daughter had Tetralogy of Fallot, and a second daughter had both an ASD and VSD. Challenges facing LVNC involve difficulty of diagnosis with no gold standard yet available, uncertainty of benefit with standard disease modifying therapies for HF-REF, and apparent increased risk of arrhythmias suggesting early ICD placement may be warranted for patients. Keywords: Hr-Ref; heart failure; lv non compaction; arrhythmias; lcd Risk.

scholarly journals Therapeutic difficulties in vesicorectal fistula treatment using several techniques in one center

2021 ◽  
Author(s):  
Maciej Przudzik ◽  
Maria Derkaczew ◽  
Robert Hofman ◽  
Marek Roslan
Keyword(s):  
Radical Cystectomy ◽  
Gold Standard ◽  
Ileal Conduit ◽  
Surgical Techniques ◽  
Anterior Rectal Resection ◽  
Surgical Methods ◽  
The Mean ◽  
Fistula Treatment ◽  
No Gold Standard ◽  
Radiotherapy Treatment

Introduction: Vesicorectal fistula (VRF) is a rare but devastating condition that may develop after surgery or radiotherapy. Many surgical methods to treat VRF have been described, but there is still no gold standard of VRF treatment. Aim: The aim of the study is to present our experience in the treatment of VRFs and analyze different surgical techniques applied in our center retrospectively. Material and methods: From June 2016 to June 2020, 7 patients (5 males and 2 females) aged 59–73 years (average 67.3 years) were treated for VRF in our center. The primary causes of VRFs were complications after laparoscopic radical prostatectomy (LRP), sigmoidectomy, laparotomy with removal of the tumour of the vaginal stump and anterior rectal resection and colostomy, Hartmann’s operation due to rectosigmoid carcinoma, radiotherapy, treatment of cervical cancer and transurethral resection of bladder tumor (TURBT). The patients were treated with one of the following methods: transvesical laparoscopic single-site surgery (T-LESS), transanal minimally invasive surgery (TAMIS), transurethral fulguration and radical cystectomy with the Bricker’s ileal conduit. Results and discussion: Five patients underwent T-LESS, 2 TAMIS, 1 transurethral fulguration and 1 radical cystectomy with the Bricker’s ileal conduit. The mean postoperative hospital stay was 4 days (range 2–8 days). The mean operative time was 139 minutes (range 100–285 minutes). Only 1 patient had a recurrence of a fistula. Conclusions: Surgical management of VRFs is obligatory to prevent possible complications. Currently, there is no gold standard for treatment of VRFs. Therefore, this condition requires further investigation.

The Role of Average Health Status

2016 ◽  
pp. 884-899
Author(s):  
Jordan Panayotov
Keyword(s):  
Health Status ◽  
Population Health ◽  
Gold Standard ◽  
Health Impact ◽  
Local Context ◽  
Policy Options ◽  
The Matrix ◽  
The Right ◽  
No Gold Standard ◽  
Average Health

Economic, social and environmental policies, programs and projects have impact on health. Health in All Policies (HiAP) aims to improve population health by taking into account these impacts. HiAP needs appropriate tools for assessing impacts on population health. When making choices between policy options, decision-makers rely on predictions from Health Impact Assessment. Currently there is no gold standard for establishing and assessing validity of predictions. This paper distinguishes between two levels of causal pathways regarding health impacts – specific and conditional, and proposes the Average Health Status – Health Inequalities Matrix as gold standard. The Matrix facilitates making the right choices at any level and local context, thus is useful for researchers, policy-makers and practitioners for designing, analysing and evaluating all kinds of policies. By allowing quick, reliable and inexpensive appraisal of different policy options the matrix makes feasible taking into account the impacts on population health and paves the way for institutionalizing of HiAP.

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