scholarly journals Kalman Filter Implementation of Subglottal Impedance-Based Inverse Filtering to Estimate Glottal Airflow during Phonation

2021 ◽  
Author(s):  
Juan P. Cortés ◽  
Gabriel A. Alzamendi ◽  
Alejandro J. Weinstein ◽  
Juan I. Yuz ◽  
Víctor M. Espinoza ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Reference Signal ◽  
Ambulatory Monitoring ◽  
Ground Truth ◽  
Inverse Filtering ◽  
Vocal Function ◽  
Non Invasive ◽  
Model Mismatch ◽  
Amplitude Estimation

Subglottal Impedance-Based Inverse Filtering (IBIF) allows for the continuous, non-invasive estimation of glottal airflow from a surface accelerometer placed over the anterior neck skin below the larynx, which has been shown to be advantageous for the ambulatory monitoring of vocal function. However, during long-term ambulatory recordings over several days, conditions may drift from the laboratory environment where the IBIF parameters were initially estimated due to sensor positioning, skin attachment, and temperature, among other factors. Observation uncertainties and model mismatch may result in significant deviations in the glottal airflow estimates, but are very difficult to quantify in ambulatory conditions due to a lack of a reference signal. To address this issue, we propose a Kalman filter implementation of the IBIF filter, which allows for both estimating the model uncertainty and adapting the airflow estimates to correct for signal deviations. One-way ANOVA results from laboratory experiments using the Rainbow Passage indicate a an improvement on amplitude-based measures for PVH subjects compared to IBIF which shows a statistically difference with respect to the reference oral airflow (p=0.02,F=4.1). MFDR from PVH subjects is slightly different to the oral airflow when compared to IBIF (p=0.04, F=3.3). Other measures did not have significant differences with either Kalman or IBIF, with the exception of H1H2, whose performance deteriorates for both methods. Overall, both methods show similar flottal airflow measures, with the advantage of Kalman by improving amplitude estimation. Moreover, Kalman filter deviations from the IBIF output airflow might suggest a better representation of some fine details in the ground-truth glottal airflow signal. Other applications may take more advantage from the adaptation offered by the Kalman filter implementation.

scholarly journals Kalman Filter Implementation of Subglottal Impedance-Based Inverse Filtering to Estimate Glottal Airflow during Phonation

2021 ◽  
Vol 12 (1) ◽  
pp. 401
Author(s):  
Juan P. Cortés ◽  
Gabriel A. Alzamendi ◽  
Alejandro J. Weinstein ◽  
Juan I. Yuz ◽  
Víctor M. Espinoza ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Reference Signal ◽  
Ambulatory Monitoring ◽  
Maximum Flow ◽  
Ground Truth ◽  
P Value ◽  
Inverse Filtering ◽  
Velocity Signal ◽  
Modified Kalman Filter

Subglottal Impedance-Based Inverse Filtering (IBIF) allows for the continuous, non-invasive estimation of glottal airflow from a surface accelerometer placed over the anterior neck skin below the larynx. It has been shown to be advantageous for the ambulatory monitoring of vocal function, specifically in the use of high-order statistics to understand long-term vocal behavior. However, during long-term ambulatory recordings over several days, conditions may drift from the laboratory environment where the IBIF parameters were initially estimated due to sensor positioning, skin attachment, or temperature, among other factors. Observation uncertainties and model mismatch may result in significant deviations in the glottal airflow estimates; unfortunately, they are very difficult to quantify in ambulatory conditions due to a lack of a reference signal. To address this issue, we propose a Kalman filter implementation of the IBIF filter, which allows for both estimating the model uncertainty and adapting the airflow estimates to correct for signal deviations. One-way analysis of variance (ANOVA) results from laboratory experiments using the Rainbow Passage indicate an improvement using the modified Kalman filter on amplitude-based measures for phonotraumatic vocal hyperfunction (PVH) subjects compared to the standard IBIF; the latter showing a statistically difference (p-value =0.02, F=4.1) with respect to a reference glottal volume velocity signal estimated from a single notch filter used here as ground-truth in this work. In contrast, maximum flow declination rates from subjects with vocal phonotrauma exhibit a small but statistically difference between the ground-truth signal and the modified Kalman filter when using one-way ANOVA (p-value =0.04, F=3.3). Other measures did not have significant differences with either the modified Kalman filter or IBIF compared to ground-truth, with the exception of H1-H2, whose performance deteriorates for both methods. Overall, both methods (modified Kalman filter and IBIF) show similar glottal airflow measures, with the advantage of the modified Kalman filter to improve amplitude estimation. Moreover, Kalman filter deviations from the IBIF output airflow might suggest a better representation of some fine details in the ground-truth glottal airflow signal. Other applications may take more advantage from the adaptation offered by the modified Kalman filter implementation.

Ambulatory Monitoring of Daily Voice Use

2011 ◽  
Vol 21 (2) ◽  
pp. 56-61 ◽  
Author(s):  
Robert E. Hillman ◽  
Daryush D. Mehta
Keyword(s):  
State Of The Art ◽  
Ambulatory Monitoring ◽  
Vocal Behavior ◽  
Future Directions ◽  
Vocal Function ◽  
Current State ◽  
Voice Use ◽  
Insight Into

Many common voice disorders are chronic or recurring conditions likely to result from faulty and/or abusive patterns of vocal behavior. Such behaviorally based disorders can be difficult to assess accurately in the clinical setting and potentially could be much better characterized by long-term ambulatory monitoring of vocal function as individuals engage in their typical daily activities. Ambulatory monitoring also could provide new insight into the actual role of voice use in common disorders and missing quantitative data on what constitutes normal levels of daily voice use for different groups of individuals, activities, and occupations. This report describes the motivation, previous development efforts, current state-of-the-art technology, and future directions in ambulatory monitoring of voice use.

scholarly journals Glottal Aerodynamics Estimated From Neck-Surface Vibration in Women With Phonotraumatic and Nonphonotraumatic Vocal Hyperfunction

2020 ◽  
Vol 63 (9) ◽  
pp. 2861-2869
Author(s):  
Víctor M. Espinoza ◽  
Daryush D. Mehta ◽  
Jarrad H. Van Stan ◽  
Robert E. Hillman ◽  
Matías Zañartu
Keyword(s):  
Muscle Tension ◽  
Ambulatory Monitoring ◽  
Maximum Flow ◽  
Air Pressure ◽  
Control Group ◽  
Inverse Filtering ◽  
Linear Regression Models ◽  
Vocal Function ◽  
Surface Vibration ◽  
Vocal Hyperfunction

Purpose The purpose of this study was to determine whether estimates of glottal aerodynamic measures based on neck-surface vibration are comparable to those previously obtained using oral airflow and air pressure signals (Espinoza et al., 2017) in terms of discriminating patients with phonotraumatic and nonphonotraumatic vocal hyperfunction (PVH and NPVH) from vocally healthy controls. Method Consecutive /pae/ syllables at comfortable and loud level were produced by 16 women with PVH (organic vocal fold lesions), 16 women with NPVH (primary muscle tension dysphonia), and 32 vocally healthy women who were each matched to a patient according to age and occupation. Subglottal impedance-based inverse filtering of the anterior neck-surface accelerometer (ACC) signal yielded estimates of peak-to-peak glottal airflow, open quotient, and maximum flow declination rate. Average subglottal pressure and microphone-based sound pressure level (SPL) were also estimated from the ACC signal using subject-specific linear regression models. The ACC-based measures of glottal aerodynamics were normalized for SPL and statistically compared between each patient and matched-control group. Results Patients with PVH and NPVH exhibited lower SPL-normalized glottal aerodynamics values than their respective control subjects ( p values ranging from < .01 to .07) with very large effect sizes (1.04–2.16), regardless of loudness condition or measurement method (i.e., ACC-based values maintained discriminatory power). Conclusions The results of this study demonstrate that ACC-based estimates of most glottal aerodynamic measures are comparable to those previously obtained from oral airflow and air pressure (Espinoza et al., 2017) in terms of differentiating between hyperfunctional (PVH and NPVH) and normal vocal function. ACC-based estimates of glottal aerodynamic measures may be used to assess vocal function during continuous speech and enables this assessment of daily voice use during ambulatory monitoring to provide better insight into the pathophysiological mechanisms associated with vocal hyperfunction.

Comparison of different SLAM approaches for a driverless race car

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nick Le Large ◽  
Frank Bieder ◽  
Martin Lauer
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Ground Truth ◽  
Time Constraints ◽  
Differential Gps ◽  
Real World Data ◽  
Race Car ◽  
Localization And Mapping ◽  
Slam Algorithm ◽  
Computational Resources

Abstract For the application of an automated, driverless race car, we aim to assure high map and localization quality for successful driving on previously unknown, narrow race tracks. To achieve this goal, it is essential to choose an algorithm that fulfills the requirements in terms of accuracy, computational resources and run time. We propose both a filter-based and a smoothing-based Simultaneous Localization and Mapping (SLAM) algorithm and evaluate them using real-world data collected by a Formula Student Driverless race car. The accuracy is measured by comparing the SLAM-generated map to a ground truth map which was acquired using high-precision Differential GPS (DGPS) measurements. The results of the evaluation show that both algorithms meet required time constraints thanks to a parallelized architecture, with GraphSLAM draining the computational resources much faster than Extended Kalman Filter (EKF) SLAM. However, the analysis of the maps generated by the algorithms shows that GraphSLAM outperforms EKF SLAM in terms of accuracy.

scholarly journals Taxonomic signatures of cause-specific mortality risk in human gut microbiome

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aaro Salosensaari ◽  
Ville Laitinen ◽  
Aki S. Havulinna ◽  
Guillaume Meric ◽  
Susan Cheng ◽  
...  
Keyword(s):  
Mortality Risk ◽  
Gut Microbiome ◽  
Human Gut ◽  
Cross Sectional ◽  
Microbiome Composition ◽  
Human Gut Microbiome ◽  
Non Invasive ◽  
Sequencing Technologies

AbstractThe collection of fecal material and developments in sequencing technologies have enabled standardised and non-invasive gut microbiome profiling. Microbiome composition from several large cohorts have been cross-sectionally linked to various lifestyle factors and diseases. In spite of these advances, prospective associations between microbiome composition and health have remained uncharacterised due to the lack of sufficiently large and representative population cohorts with comprehensive follow-up data. Here, we analyse the long-term association between gut microbiome variation and mortality in a well-phenotyped and representative population cohort from Finland (n = 7211). We report robust taxonomic and functional microbiome signatures related to the Enterobacteriaceae family that are associated with mortality risk during a 15-year follow-up. Our results extend previous cross-sectional studies, and help to establish the basis for examining long-term associations between human gut microbiome composition, incident outcomes, and general health status.

scholarly journals Serum Anti-Collagen IV IgM and IgG Antibodies as Indicators of Low Vascular Turnover of Collagen IV in Patients with Long-Term Complications of Type 2 Diabetes

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 900
Author(s):  
Krasimir Kostov ◽  
Alexander Blazhev
Keyword(s):  
Type 2 Diabetes ◽  
Serum Levels ◽  
Vascular Wall ◽  
Collagen Iv ◽  
Collagen Type Iv ◽  
Non Invasive ◽  
Type Iv ◽  
Antibody Levels

Thickening of the vascular basement membrane (BM) is a fundamental structural change in the small blood vessels in diabetes. Collagen type IV (CIV) is a major component of the BMs, and monitoring the turnover of this protein in type 2 diabetes (T2D) can provide important information about the mechanisms of vascular damage. The aim of the study was through the use of non-invasive biomarkers of CIV (autoantibodies, derivative peptides, and immune complexes) to investigate vascular turnover of CIV in patients with long-term complications of T2D. We measured serum levels of these biomarkers in 59 T2D patients with micro- and/or macrovascular complications and 20 healthy controls using an ELISA. Matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) were also tested. In the T2D group, significantly lower levels of CIV markers and significantly higher levels of MMP-2 and MMP-9 were found compared to controls. A significant positive correlation was found between IgM antibody levels against CIV and MMP-2. These findings suggest that vascular metabolism of CIV is decreased in T2D with long-term complications and show that a positive linear relationship exists between MMP-2 levels and CIV turnover in the vascular wall.

A NOVEL EXTENSIVE EX-VIVO OCT DATABASE FROM MURINE MODELS OF COLORECTAL CANCER

2021 ◽  
Vol 108 (Supplement_3) ◽  
Author(s):  
J Bote ◽  
J F Ortega-Morán ◽  
C L Saratxaga ◽  
B Pagador ◽  
A Picón ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Machine Learning ◽  
Structural Information ◽  
Ex Vivo ◽  
Ground Truth ◽  
Colon Polyps ◽  
Learning Methods ◽  
Non Invasive ◽  
Machine Learning Methods ◽  
In Situ Methods

Abstract INTRODUCTION New non-invasive technologies for improving early diagnosis of colorectal cancer (CRC) are demanded by clinicians. Optical Coherence Tomography (OCT) provides sub-surface structural information and offers diagnosis capabilities of colon polyps, further improved by machine learning methods. Databases of OCT images are necessary to facilitate algorithms development and testing. MATERIALS AND METHODS A database has been acquired from rat colonic samples with a Thorlabs OCT system with 930nm centre wavelength that provides 1.2KHz A-scan rate, 7μm axial resolution in air, 4μm lateral resolution, 1.7mm imaging depth in air, 6mm x 6mm FOV, and 107dB sensitivity. The colon from anaesthetised animals has been excised and samples have been extracted and preserved for ex-vivo analysis with the OCT equipment. RESULTS This database consists of OCT 3D volumes (C-scans) and 2D images (B-scans) of murine samples from: 1) healthy tissue, for ground-truth comparison (18 samples; 66 C-scans; 17,478 B-scans); 2) hyperplastic polyps, obtained from an induced colorectal hyperplastic murine model (47 samples; 153 C-scans; 42,450 B-scans); 3) neoplastic polyps (adenomatous and adenocarcinomatous), obtained from clinically validated Pirc F344/NTac-Apcam1137 rat model (232 samples; 564 C-scans; 158,557 B-scans); and 4) unknown tissue (polyp adjacent, presumably healthy) (98 samples; 157 C-scans; 42,070 B-scans). CONCLUSIONS A novel extensive ex-vivo OCT database of murine CRC model has been obtained and will be openly published for the research community. It can be used for classification/segmentation machine learning methods, for correlation between OCT features and histopathological structures, and for developing new non-invasive in-situ methods of diagnosis of colorectal cancer.

scholarly journals A comparative two-cohort study of pediatric patients with long term stay in ICUs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julia García Mancebo ◽  
Sara de la Mata Navazo ◽  
Estíbaliz López-Herce Arteta ◽  
Rosario Montero Mateo ◽  
Isabel María López Esteban ◽  
...  
Keyword(s):  
Healthcare Resources ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Number Of Patients ◽  
Single Center Study ◽  
High Flow Oxygen ◽  
Hospital Acquired ◽  
Complications And Mortality ◽  
Second Period

AbstractDuring the last decades, the number of patients with long stay admissions (LSA) in PICU has increased. The purpose of this study was to identify factors associated with PICU LSA, assessing healthcare resources use and changes in the profile of these patients. A retrospective, observational, single-center study was carried out. Characteristics of LSA were compared between two periods (2006–2010 and 2011–2015). During the earlier period there were 2,118 admissions (3.9% of them LSA), whereas during the second period, there were 1,763 (5.4% of them LSA) (p = 0.025). LSA accounted for 33.7% PICU stay days during the first period and 46.7% during the second (p < 0.001). Higher use of non-invasive ventilation (80.2% vs. 37.8%, p = 0.001) and high-flow oxygen therapy (68.8% vs. 37.8%, p = 0.005) was observed in the 2011–2015 cohort, whereas the use of arterial catheter (77.1% vs. 92.6%, p = 0.005), continuous infusion of adrenaline (55.2% vs. 75.9%, p = 0.004), and hemoderivative transfusion (74% vs. 89.2%, p = 0.010) was less frequent. In the 2006–2010 cohort, hospital-acquired infections were more common (95.2% vs. 68.8%, p < 0.001) and mortality was higher (26.8% vs. 13.8%, p = 0.026). The number of long-stay PICU admissions have increased entailing an intensive use of healthcare resources. These patients have a high risk for complications and mortality.

scholarly journals Serum sCD25 Protein as a Predictor of Lack of Long-Term Benefits from Immunotherapy in Non-Small Cell Lung Cancer: A Pilot Study

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3702
Author(s):  
Anna Siemiątkowska ◽  
Maciej Bryl ◽  
Katarzyna Kosicka-Noworzyń ◽  
Jakub Tvrdoň ◽  
Iwona Gołda-Gocka ◽  
...  
Keyword(s):  
Treatment Cycle ◽  
Small Cell Lung Carcinoma ◽  
Interleukin 2 ◽  
Serum Levels ◽  
Small Cell ◽  
Soluble Form ◽  
Small Cell Lung ◽  
Cell Lung Carcinoma ◽  
Non Invasive

Prognosis of advanced non-small cell lung carcinoma (NSCLC) is poor. Even though it can improve with anti-PD-1/PD-L1 agents, most patients do not respond to treatment. We hypothesized that the serum soluble form of the unit α of the interleukin-2 receptor (sCD25) could be used as a biomarker of successful immunotherapy in NSCLC. We recruited patients dosed with atezolizumab (n = 42) or pembrolizumab (n = 20) and collected samples at baseline and during the treatment. Levels of sCD25 were quantified with the ELISA kits. Patients with a high sCD25 at baseline (sCD25.0 ≥ 5.99 ng/mL) or/and at the end of the fourth treatment cycle (sCD25.4 ≥ 7.73 ng/mL) progressed faster and lived shorter without the disease progression and serious toxicity. None of the patients with high sCD25 at both time points continued therapy longer than 9.3 months, while almost 40% of patients with low sCD25 were treated for ≥12.3 months. There was a 6.3-times higher incidence of treatment failure (HR = 6.33, 95% CI: 2.10–19.06, p = 0.001) and a 6.5-times higher incidence of progression (HR = 6.50, 95% CI: 2.04–20.73, p = 0.002) in patients with high compared with low sCD25.0 and sCD25.4. Serum levels of sCD25 may serve as a non-invasive biomarker of long-term benefits from the anti-PD-1/PD-L1s in NSCLC.

scholarly journals Framework for patient-ventilator asynchrony during long-term non-invasive ventilation

Thorax ◽  
2019 ◽  
Vol 74 (7) ◽  
pp. 715-717 ◽  
Author(s):  
Jesus Gonzalez-Bermejo ◽  
Jean-Paul Janssens ◽  
Claudio Rabec ◽  
Christophe Perrin ◽  
Frédéric Lofaso ◽  
...  
Keyword(s):  
Present Report ◽  
Time Windows ◽  
Clinical Impact ◽  
Positive Pressure ◽  
Systematic Analysis ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Polygraphic Recordings ◽  
Bench Testing

Episodes of patient-ventilator asynchrony (PVA) occur during acute and chronic non-invasive positive pressure ventilation (NIV). In long-term NIV, description and quantification of PVA is not standardised, thus limiting assessment of its clinical impact. The present report provides a framework for a systematic analysis of polygraphic recordings of patients under NIV for the detection and classification of PVA validated by bench testing. The algorithm described uses two different time windows: rate asynchrony and intracycle asynchrony. This approach should facilitate further studies on prevalence and clinical impact of PVA in long-term NIV.

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