A5006622916- Heart Rate Variability and Autonomic Control
- Neurological disorders and treatments
- Muscle activation and electromyography studies
- Non-Invasive Vital Sign Monitoring
- Electrical and Bioimpedance Tomography
- Parkinson's Disease Mechanisms and Treatments
- EEG and Brain-Computer Interfaces
- Neural dynamics and brain function
- Balance, Gait, and Falls Prevention
- Advanced MRI Techniques and Applications
- Osteoarthritis Treatment and Mechanisms
- Lower Extremity Biomechanics and Pathologies
- ECG Monitoring and Analysis
- Functional Brain Connectivity Studies
- Control Systems and Identification
- Geophysical and Geoelectrical Methods
- Cardiac electrophysiology and arrhythmias
- Flow Measurement and Analysis
- Fault Detection and Control Systems
- Blind Source Separation Techniques
- Neuroscience and Neural Engineering
- Advanced Chemical Sensor Technologies
- Cardiovascular and exercise physiology
- Medical Imaging Techniques and Applications
- Winter Sports Injuries and Performance
University of Eastern Finland
2016-2025
Finland University
2012-2024
Satakunta Central Hospital
2023
University of Oulu
1997-2013
Northern Ostrobothnia Hospital District
2012
Kuopio University Hospital
1974-2008
An advanced, simple to use, detrending method be used before heart rate variability analysis (HRV) is presented. The based on smoothness priors approach and operates like a time-varying finite-impulse response high-pass filter. effect of the time- frequency-domain HRV studied.
The solution of impedance distribution in electrical tomography is a nonlinear inverse problem that requires the use regularization method. generalized Tikhonov methods have been popular many problems. matrices are usually used with method more or less ad hoc and implicit prior assumptions are, thus, cases inappropriate. In this paper, we propose an approach to construction matrix conforms on distribution. based approximating subspace for expected distributions. It shown by simulations...
In electrical impedance tomography (EIT), an estimate for the cross-sectional distribution is obtained from body by using current and voltage measurements made boundary. All well-known reconstruction algorithms use a full set of independent patterns each reconstruction. some applications, changes may be so fast that information on time evolution either lost or severely blurred. this paper, we propose algorithm EIT able to track in distribution. The method based formulation as...
In electrical impedance tomography (EIT), difference imaging is often preferred over static imaging. This because of the many unknowns in forward modelling which make it difficult to obtain reliable absolute resistivity estimates. However, and values are needed some potential applications EIT. this paper we demonstrate by simulation effects different error components that included reconstruction EIT images. All simulations carried out two dimensions with so-called complete electrode model....
An adaptive spectrum estimation method for nonstationary electroencephalogram by means of time-varying autoregressive moving average modeling is presented. The parameter problem solved Kalman filtering along with a fixed-interval smoothing procedure. filter an optimal in the mean square sense and it generalization other filters such as recursive least squares or square. Furthermore, using smoother unavoidable tracking lag can be avoided. Due to properties benefits time-frequency resolution...
In this study perceived mental stress during occupational work was compared to heart rate variability (HRV) using a traditional questionnaire and novel wristop monitor with related software. The aim find HRV parameters useful for detection. We found the highest correlation between differences values of triangular interpolation rhythm-to-rhythm (RR) interval histogram (TINN) root mean square successive RR intervals (RMSSD) obtained in morning workday (r=-.73 r=-.60, respectively). analysis...
Fatigue is a prevalent problem in the workplace and common symptom of many diseases. However, its relationship with autonomic nervous system, specifically sympathetic arousal, needs clarification. The objective this study was to determine association between fatigue heart rate variability (HRV). HRV regarded as an indicator regulation activity rate, parasympathetic activity. Spectral changes low-frequency (LF; 0.04–0.15 Hz) high-frequency (HF; 0.15–0.4 components have been reported be...
In this paper, we consider the impedance tomography problem of estimating conductivity distribution within body from static current/voltage measurements on body's surface. We present a new method implementing prior information conductivities in optimization algorithm. The is based approximation covariance matrix by simulated samples feasible conductivities. reduction dimensionality performed principal component analysis (PCA).
A method for single-trial dynamical estimation of event-related potentials (ERPs) is presented. The based on recursive Bayesian mean square and the estimators are obtained with a Kalman filtering procedure. We especially focus case that previous trials contain prior information relevance to trial being analyzed. estimated sequentially using estimates as information. performance evaluated simulations real P300 responses measured auditory stimuli. Our approach shown have excellent capability...
The purpose of the study was to evaluate linear and nonlinear tremor characteristics hand in patients with Parkinson's disease (PD) compare results those healthy old young control subjects. Furthermore, aim correlation between clinical signs. A variety (sample entropy, cross-sample recurrence rate, determinism dimension) (amplitude, spectral peak frequency total power, coherence) parameters were computed from acceleration measurements for PD (n = 30, 68.3 ± 7.8 years), 20, 64.2 7.0 years)...
Joint tissue mechanics (e.g., stress and strain) are believed to have a major involvement in the onset progression of musculoskeletal disorders, e.g., knee osteoarthritis (KOA). Accordingly, considerable efforts been made develop finite element (MS-FE) models estimate highly detailed that predict cartilage degeneration. However, creating such is time-consuming requires advanced expertise. This limits these complex, yet promising, MS-FE research applications with few participants makes...
Heart rate variability (HRV) provides reliable tools to assess the integrity and reactivity of autonomic nervous function. Our aim was examine HRV in resting condition during different mental loads acute psychosis compared healthy controls. measured 17 first-episode drug-naive patients with 21 controls oddball tasks while performing Wisconsin Card Sorting Test. A discrete event series constructed by an adaptive QRS detector algorithm power spectrum estimation carried out. The RMSSD...
A time-varying parametric spectrum estimation method for analysing non-stationary heart rate variability signals is presented. As a case study, the dynamics of during an orthostatic test examined. In this method, signal first modelled with autoregressive model and parameters are estimated recursively Kalman smoother algorithm. The benefit using that lag error present in filter, as well all other adaptive filters, can be avoided. estimates each time instant then obtained from parameters....
A novel approach is presented for the analysis of surface electromyogram (EMG) morphology in Parkinson's disease (PD). The method based on histogram and crossing rate (CR) EMG signal. In method, histograms CR values are used as high-dimensional feature vectors. dimensionality them then reduced using Karhunen-Loève transform (KLT). Finally, discriminant vectors performed low-dimensional eigenspace. Histograms were chosen analysis, because Parkinsonian signals typically involve patterns...
Abstract Navigated transcranial magnetic stimulation (TMS) can be used to stimulate functional cortical areas at precise anatomical location induce measurable responses. The has commonly been focused on anatomically predefined motor areas: TMS of that area elicits a muscle response, the evoked potential. In clinical pathologies, however, well‐known homunculus somatotopy theory may not straightforward, and representation is fixed. Traditionally, locations stimulations have reported group...