A5049359099- Non-Invasive Vital Sign Monitoring
- Heart Rate Variability and Autonomic Control
- Balance, Gait, and Falls Prevention
- Neurological disorders and treatments
- Neuroscience and Neural Engineering
- Hemodynamic Monitoring and Therapy
- Parkinson's Disease Mechanisms and Treatments
- EEG and Brain-Computer Interfaces
- Traumatic Brain Injury and Neurovascular Disturbances
- ECG Monitoring and Analysis
- Cerebral Palsy and Movement Disorders
- Blind Source Separation Techniques
- Genetic Neurodegenerative Diseases
- Industrial Vision Systems and Defect Detection
- Neural dynamics and brain function
- Neural Networks and Applications
- Advanced Statistical Process Monitoring
- Fault Detection and Control Systems
- Target Tracking and Data Fusion in Sensor Networks
- Cerebrospinal fluid and hydrocephalus
- Speech and Audio Processing
- Time Series Analysis and Forecasting
- Indoor and Outdoor Localization Technologies
- Inertial Sensor and Navigation
- Integrated Circuits and Semiconductor Failure Analysis
Portland State University
2015-2025
Motion Control (United States)
2023
Oregon Health & Science University
2003-2018
Signal Processing (United States)
2003-2017
Xunta de Galicia
2006
Universidade de Vigo
2006
Society of Critical Care Medicine
2003
Doernbecher Children's Hospital
2003
Northeastern University
2003
University of Pittsburgh Medical Center
2003
Wearable inertial systems have recently been used to track human movement in and outside of the laboratory. Continuous monitoring can provide valuable information relevant individuals' level physical activity functional ability. Traditionally, orientation has calculated by integrating angular velocity from gyroscopes. However, a small drift measured leads increasing integration error over time. To compensate that drift, complementary data accelerometers are normally fused into tracking using...
Difficulty with turning is a major contributor to mobility disability and falls in people movement disorders, such as Parkinson’s disease (PD). Turning often results freezing and/or falling patients PD. However, asking patient execute turn the clinic does not reveal their impairments. Continuous monitoring of wearable sensors during spontaneous daily activities may help clinicians determine who at risk could benefit from preventative interventions. In this study, we show that continuous...
Beat detection algorithms have many clinical applications including pulse oximetry, cardiac arrhythmia detection, and output monitoring. Most of these been developed by medical device companies are proprietary. Thus, researchers who wish to investigate contour analysis must rely on manual annotations or develop their own algorithms. We designed an automatic algorithm for pressure signals that locates the first peak following each heart beat. This is called percussion in intracranial (ICP)...
Difficulty turning during gait is a major contributor to mobility disability, falls and reduced quality of life in patients with Parkinson's disease (PD). Unfortunately, the assessment clinic may not adequately reflect typical function or its variability daily life. We hypothesized that mobility, rather than overall quantity activity, would be impaired people PD over seven days continuous recording.Thirteen subjects 8 healthy control similar age wore three Opal inertial sensors (on their...
Traditionally, human movement has been captured primarily by motion capture systems. These systems are costly, require fixed cameras in a controlled environment, and suffer from occlusion. Recently, the availability of low-cost wearable inertial sensors containing accelerometers, gyroscopes, magnetometers have provided an alternative means to overcome limitations Wearable can be used anywhere, cannot occluded, low cost. Several groups described algorithms for tracking joint angles. We...
Quantitative assessment of severity ataxia-specific gait impairments from wearable technology could provide sensitive performance outcome measures with high face validity to power clinical trials.The aim this study was identify a set body-worn inertial sensors that best discriminate between people prodromal or manifest spinocerebellar ataxia (SCA) and age-matched, healthy control subjects (HC) determine how these relate disease severity.One hundred sixty-three SCA (subtypes 1, 2, 3, 6), 42...
A new fast nearest-neighbor algorithm is described that uses principal component analysis to build an efficient search tree. At each node in the tree, data set partitioned along direction of maximum variance. The efficiently a depth-first and elimination criterion. was compared 16 other algorithms on three types common benchmark sets including problems from time series prediction image vector quantization. This comparative study illustrates strengths weaknesses all leading algorithms....
We studied changes in intracranial pressure (ICP) complexity, estimated by the approximate entropy (ApEn) of ICP signal, as subjects progressed from a state normal (<20--25 mmHg) to acutely elevated (an "spike" defined >25 mmHg for /spl les/ 5 min). hypothesized that measures complexity and irregularity would decrease during acute elevations ICP. To test this hypothesis we spikes pediatric with severe traumatic brain injury (TBI). conclude decreased coincides episodes hypertension (ICH) TBI....
Currently, no reliable method exists to predict the onset of paroxysmal atrial fibrillation (PAF). We propose a predictor that includes an analysis R-R time series. The uses three criteria: number premature complexes (PAC) not followed by regular interval, runs bigeminy and trigeminy, length any short run tachycardia. An increase in activity detected these criteria is indication imminent episode PAF. Using Physionet database Computers Cardiology 2001 Challenge, achieved sensitivity 89%...
<strong>Background:</strong> Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge their limitations and data analysis. purpose this review is to provide practical overview example software using portable in the quantification tremor. <strong>Methods:</strong> Medline was searched via PubMed.gov December 2015 Boolean expression ‘‘tremor AND (accelerometer OR accelerometry gyroscope inertial...
Recent findings suggest that a gait assessment at discrete moment in clinic or laboratory setting may not reflect functional, everyday mobility. As step towards better understanding during daily life neurological populations, we compared measures best discriminated people with multiple sclerosis (MS) and Parkinson's Disease (PD) from their respective, age-matched, healthy control subjects (MS-Ctl, PD-Ctl) tests versus week of monitoring.
Identifying digital biomarkers of mobility is important for clinical trials in Parkinson's disease (PD).To determine which outcome measures discriminate people with PD from healthy control (HC) subjects over a week continuous monitoring.We recruited 29 PD, and 27 age-matched HC subjects. Subjects were asked to wear three inertial sensors (Opal by APDM) attached both feet the lumbar region, subset also wore two wrist sensors, monitoring. We derived 43 grouped into five domains. An Area Under...
Synchronous averaging is difficult to use with epicyclic gear systems because the dominant frequencies are slightly skewed and asymmetrical. This Tech Brief uses Fourier series analysis add new insight this phenomenon. The results illustrated on vibration data recorded from a Cobra AH-1S helicopter gearbox.
The subject of this paper is variance reduction and nearest neighbor residual estimates for I/sub DDQ/ other continuous-valued test measurements. key, new concept introduced data-driven neighborhood identification about a die to reduce the good faulty distributions. Using LSI Logic production data, selection techniques are demonstrated. main contribution by systematic use location wafer- or lot-level patterns improved outliers data such as DDQ/.
Abstract Background Maintaining balance is crucial for independence and quality of life. Loss a hallmark spinocerebellar ataxia (SCA). Objective The aim this study was to identify which standing conditions digital measures body sway were most discriminative, reliable, valid quantifying in SCA. Methods Fifty‐three people with SCA (13 SCA1, 13 SCA2, 14 SCA3, SCA6) Scale Assessment Rating Ataxia (SARA) scores 9.28 ± 4.36 31 healthy controls recruited. Subjects stood six test (natural stance,...
Gait assessments in a clinical setting may not accurately reflect mobility everyday life. To better understand gait during daily life, we compared measures that discriminated Friedreich ataxia (FRDA) from healthy control (HC) subjects prescribed clinic tests and free, daily-life monitoring. We recruited 9 people with FRDA (median age: 20, IQR [12, 48] years). A comparative subject cohort of was sampled using propensity matching on age 18 [13, 22] Subjects wore 3 inertial sensors (one each...
Healthy physiological systems exhibit marked signal variability and complexity, whereas diseased generally show a loss of variability, decreased complexity ("decomplexification"), increased regularity. The goal this study was to evaluate the uncoupling recoupling phenomenon in children with septic shock by observing serial changes heart rate metrics. Data were collected from 7 using computer system Complex Systems Laboratory at Oregon Health Sciences University. Heart time series constructed...
Describes the findings of an exploratory study effect obstructive sleep apnea (OSA) on electrocardiogram (ECG) signal. Episodes are characterized by periodic cycles breathing cessation find restoration. The authors' analysis was guided hypothesis that these synchronously alter ECG. They discovered several characteristic indicators in ECG Their focused data sets provided for Computers Cardiology (CINC) 2000 classification competition. After careful QRS detection, artifact removal, and...
Heart rate variability (HRV) measures have been used to assess autonomic cardiac regulation. The standard lengths in HRV analyses are 5 minutes and 24 hours. In this paper we investigated the accuracy of three for ultra-short record length, 10 seconds, which is length electrocardiograms. chosen were: Standard Deviation Normal-Normal (SDNN), Root Mean Square Successive Differences (RMSSD), frequency peak high-frequency (HF) spectra derived using a non-parametric spectrum method. Our indicated...