A5009617849- Non-Invasive Vital Sign Monitoring
- Cardiovascular Health and Disease Prevention
- Heart Rate Variability and Autonomic Control
- Hemodynamic Monitoring and Therapy
- ECG Monitoring and Analysis
- Dialysis and Renal Disease Management
- Blood Pressure and Hypertension Studies
- Acute Kidney Injury Research
- Optical Imaging and Spectroscopy Techniques
- Context-Aware Activity Recognition Systems
- Electrochemical sensors and biosensors
- Cardiac electrophysiology and arrhythmias
- Cardiovascular Function and Risk Factors
- Diabetic Foot Ulcer Assessment and Management
- Analytical Chemistry and Sensors
- Renal function and acid-base balance
- Body Composition Measurement Techniques
- Central Venous Catheters and Hemodialysis
- Physical Activity and Health
- Healthcare Systems and Public Health
- Neurological and metabolic disorders
- Sensor Technology and Measurement Systems
- Bipolar Disorder and Treatment
- Cardiovascular and exercise physiology
- Microbial Inactivation Methods
Tallinn University of Technology
2015-2024
University of Electro-Communications
2005
The ability to identify premature arterial stiffening is of considerable value in the prevention cardiovascular diseases. “ageing index” ( AGI ), which calculated from second derivative photoplethysmographic (SDPPG) waveform, has been used as one method for stiffness estimation and evaluation ageing. In this study, new SDPPG analysis algorithm proposed with optimal filtering signal normalization time. filter parameters were optimized order achieve minimal standard deviation , gives more...
The aim of this research was to assess the validity photoplethysmographic (PPG) waveform index PPGAI for estimation increased arterial stiffness. For purpose, PPG signals were recorded from 24 healthy subjects and 20 type II diabetes patients. processed with analysis algorithm developed similar augmentation (AIx) calculated. As a reference, aortic AIx assessed normalized heart rate 75 bpm (AIx@75) by SphygmoCor device. A strong correlation (r = 0.85) between AIx@75 positive both indices age...
In this study, we assume that microwave radiation affects hydrogen bonding between dipolar water molecules and through diffusion in at constant temperature. The experimental study was performed on the setup of two identical reservoirs filled with pure 0.9% NaCl solution connected by a thin tube. Alterations concentration reservoir initially were measured using resistance as an indicator. applied 450 MHz continuous-wave field had maximal specific absorption rate 0.4 W/kg connecting standard...
Tryptophan is an essential dietary amino acid that originates uremic toxins contribute to end-stage kidney disease (ESKD) patient outcomes. We evaluated serum levels and removal during haemodialysis haemodiafiltration of tryptophan tryptophan-derived toxins, indoxyl sulfate (IS) indole acetic (IAA), in ESKD patients different dialysis treatment settings. This prospective multicentre study four European centres enrolled 78 with ESKD. Blood spent dialysate samples obtained were analysed...
This study analyses the photoplethysmographic (PPG) signal waveform rising front in order to discriminate subjects with premature increase arterial ageing.As a reference measure for evaluation of system, aortic augmentation index (AIx@75) was calculated using SphygmoCor device.The carried out on 24 healthy and 20 diabetes patients.Negative correlation relationships (r = -0.68 r -0.77)were found between age slopes PPG signal.Significant differences were controls patients.The highest...
Current work is a part of long term research, which aim to study the possibilities diagnose atherosclerosis in early stadium by using pulse wave velocity and its waveform analysis. The mobile experimental measurement complex built technically tested for hospital. Measurement consists ten physiological signal recording channels reference devices: Sphygmocor, Arteriograph, Finapres. measurements with this are planned carry out during six month on patients different severity coronary disease diabetes.
Associations found between pulse wave velocity (PWV) and cardiovascular risk factors (CVrF) are diverse. We aimed to evaluate whether differences in PWV its associations with CVrF a high population exist genders the whole (WHgr) groups of apparently healthy (AHgr) those hypertensive, obese or diabetics (Rgr).Pulse measured by Arteriograph was investigated 805 adults aged 20-65, randomly selected from Tallinn Population Register.Pulse highest Rgr no were same group. In women WHgr AHgr age SBP...
Pulse transit time, which correlates with blood pressure, is measured between the electrocardiogram R-wave peak and 50% raising front level of a photoplethysmographic (PPG) signal.Registered PPG signal bandwidth may be shared by noise therefore undetectable.Electrocardiogram reference adaptive sum comb filter was used to extract harmonic components suppress noises them.Averaging effect on studied adjustments were made.The influence filtered measurement pulse time analysed.
The aim of this study was to develop an optimized physical activity classifier for real-time wearable systems with the focus on reducing requirements device power consumption and memory buffer. Classification parameters evaluated in were sampling frequency acceleration signal, window length classification fragment, number features, found different feature selection methods. For parameter evaluation, a decision tree created based signals recorded during tests, where 25 healthy test subjects...
For applications where PPG signal AC component needs to be measured without disturbances in its shape and recorded digitally with high digitalization accuracy, the step- by-step DC eliminator is developed. This paper describes step-by-step eliminator, which utilized analogue comparator operational amplifier. It allows record 24-hours monitoring system. The experiments have been carried out.
The study was carried out in order to analyse the changes photoplethysmographic (PPG) signal waveform, which are caused by cold and warm stimulation. on 7 subjects. right hand immersed water up wrist during experiment. PPG registered from index finger. As a reference, temperatures of finger pulse transit time (PTT) values were measured. A correlation r=-0.70 found between normalised slope subject's age. increased noticeably due decreased It opposite expected results with PTTs behaviour has...
The aim of this study was to evaluate how the physical activity classification window length, accelerometer sampling frequency and number correlating features affect classifier performance. It is important effect these elements in order reduce computational power memory buffers needed for wearable systems, where done real-time. Three different lengths (5 s, 3 1s), frequencies (50 Hz, 25 13 Hz) two feature sets (110 43 features) were tested evaluated study. As a result, it found that...
This paper proposes a novel method for physical fatigue assessment that can be applied in wearable systems, by utilizing set of real-time measurable cardiovascular parameters. Daylength measurements, including morning test set, exercise during the day, and an afternoon were conducted on 16 healthy subjects (8 female 8 male). To analyze parameters assessment, electrocardiography, pulse wave blood pressure measured sets. The questionnaire score, reaction time, countermovement jump height hand...
Optical online methods are used to monitor the haemodialysis treatment efficiency of end stage kidney disease (ESKD) patients. The aim this study was analyse effect administration UV-absorbing drugs, such as paracetamol (Par), on accuracy optical monitoring removal uremic toxins uric acid (UA) and indoxyl sulfate (IS) during standard (HD) haemodiafiltration (HDF) treatments. Nine patients received Par in daily dosages 1–4 g for 30 sessions. For 137 sessions, 36 total dosage drugs less than...
Measured PPG signals can be often affected by noises and motion artefacts. The usual band-pass filter does not remove noises, which are sharing the same frequency band as signal. signal AC component fundamental harmonic all other multiples of extracted comb filter. adaptive has been proposed, uses ECG reference. Comparative experiments have carried out.
The aim of the study was to determine whether different sleep stages, especially REM sleep, affect QT interval duration and variability in male patients without obstructive apnea (OSA). Polysomnographic recordings 30 were analyzed. Beat-to-beat calculated using QTV index (QTVI) formula. For QTc calculation, addition Bazett’s formula, linear parabolic heart rate correction formulas with two separate α values used. QTVI as means 2 awake, 3 NREM, episodes; each episode 300 sec. Mean not...