A. Vehkaoja - Academia.edu (original) (raw)

Papers by A. Vehkaoja

Research paper thumbnail of Auto-regression-driven, reallocative particle filtering approaches in PPG-based respiration rate estimation

IFMBE Proceedings, 2017

Interest towards respiratory state assessment with non-obtrusive instrumentation has led to the d... more Interest towards respiratory state assessment with non-obtrusive instrumentation has led to the design of novel algorithmic solutions. Notably, respiratory behavior has been observed to cause modulative changes in two discreetly measurable physiological signals, PPG and ECG. The potential to integrate respiratory rate measurements in widely used instrumentation with no additional cost has made the research of suitable signal processing methods attractive. We have studied and compared auto-regressive (AR) model order optimization and coefficient extraction methods combined with a reallocative particle filtering approach for respiration rate estimation from finger PPG signal. The evaluated coefficient extraction methods were Yule-Walker, Burg, and Least-square. Considered model order optimization methods were Akaike's information criteria (AIC) and Minimum description length. Methods were evaluated with a publicly available dataset comprised of approximately 10-minute measurements from 39 healthy subjects at rest. From the evaluated AR model parameter extraction methods, Burg's method combined AIC performed the best. We obtained the mean absolute error of 2.7 and bias of-0.4 respirations per minute with this combination.

Research paper thumbnail of Arterial pulse waves measured with EMFi and PPG sensors and comparison of the pulse waveform spectral and decomposition analysis in healthy young and elderly subjects

Modelling in Medicine and Biology X, 2013

The purpose of this study is to show the time domain and frequency domain analysis of signals rec... more The purpose of this study is to show the time domain and frequency domain analysis of signals recorded with electromechanical film (EMFi) and photoplethysmographic (PPG) sensors in arterial elasticity estimation via pulse wave decomposition and spectral components obtained from left forefinger, left wrist, and left second toe arteries. ECG and pulse waves from the subjects were recorded firstly from 20 voluntaries by PPG sensors and from 7 persons (30-60 y) by parallel EMFi and PPG sensors in supine position. Decomposition of the pulse waves produces five components: percussion wave, tidal wave, dicrotic wave, and 1st and 2nd presystolic waves. Pulse wave decomposition parameters between EMFi and PPG are compared to find out information on a person's arterial elasticity. Results show that elastic information in the form of pulse wave decomposition from PPG waves is obtainable and shows clear shortening between percussion wave and tidal wave time with age. The spectral information obtained with frequency domain analysis could also be valuable in assessing the arterial elasticity.

Research paper thumbnail of Optical and mechanical measurement of the arterial elasticity

Artery Research, 2012

There was no statistically significant correlation between raPWV and arm musculature. 3)Left hand... more There was no statistically significant correlation between raPWV and arm musculature. 3)Left handed individuals had higher raPWV than right handers, figure below. (unpaired t-test; both limbs PWV p<0.0001, dominant only p<0.015, non-dominant p<0.001). Summary and Conclusions: Results failed to support hypotheses 1 and 2, although differences in muscularity between the two arms were small. Intriguingly, for reasons unknown, left handers had stiffer arms than right handers. In future we will measure PWV at other sites and include racquet sport players with greater muscular disparity between each arm.

Research paper thumbnail of Arterial pulse wave analysis based on PPG and EMFi measurements

2012 13th Biennial Baltic Electronics Conference, 2012

ABSTRACT Photoplethysmography (PPG) is an optical measurement technique either in reflective or t... more ABSTRACT Photoplethysmography (PPG) is an optical measurement technique either in reflective or transmission mode over the skin. PPG amplitudes depend on light wavelength which is typically in near infrared region. Eletromechanical film (EMFi) is an excellent sensor material for low-current long-term applications, e.g., arterial pulse wave recordings. EMFi measures extremely very small movements of the arterial wall and the tissue around the artery on the skin whereas PPG measures very low light absorption, transmission, and scattering caused by oxihemoglobin. Both PPG and EMFi sense elastic wave recoil, impact, and reflection caused by left ventricular contraction. Each type of pulse waves can be analysed in different ways, but they are extensively synergetic. Analysis type (PSD, PDF, NPWD, SDPPG, SDEMFi) shows different information.

Research paper thumbnail of Photoplethysmography and its detailed pulse waveform analysis for arterial stiffness

rmseura.tkk.fi

Summary. Arterial stiffness index is one of the biomechanical indices of vascular healthiness. Th... more Summary. Arterial stiffness index is one of the biomechanical indices of vascular healthiness. These indexes are based on detailed pulse waveform analysis which is presented here. After photoplethysmographyic (PPG) pulse wave measurement, we ...

Research paper thumbnail of System for ECG and heart rate monitoring during group training

2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008

Research paper thumbnail of Utilization of wireless sensor network for health monitoring in home environment

Proceedings - 2009 IEEE International Symposium on Industrial Embedded Systems, SIES 2009, 2009

The health care costs in developed countries are increasing fast due to the aging of the populati... more The health care costs in developed countries are increasing fast due to the aging of the population. In-home monitoring of health is becoming more and more attractive both because of expected cost-savings and technical development of suitable measurement devices and wireless sensor networks. In this paper, we present on-going work about embedding health monitoring devices into ordinary homes. The developed

Research paper thumbnail of Auto-regression-driven, reallocative particle filtering approaches in PPG-based respiration rate estimation

IFMBE Proceedings, 2017

Interest towards respiratory state assessment with non-obtrusive instrumentation has led to the d... more Interest towards respiratory state assessment with non-obtrusive instrumentation has led to the design of novel algorithmic solutions. Notably, respiratory behavior has been observed to cause modulative changes in two discreetly measurable physiological signals, PPG and ECG. The potential to integrate respiratory rate measurements in widely used instrumentation with no additional cost has made the research of suitable signal processing methods attractive. We have studied and compared auto-regressive (AR) model order optimization and coefficient extraction methods combined with a reallocative particle filtering approach for respiration rate estimation from finger PPG signal. The evaluated coefficient extraction methods were Yule-Walker, Burg, and Least-square. Considered model order optimization methods were Akaike's information criteria (AIC) and Minimum description length. Methods were evaluated with a publicly available dataset comprised of approximately 10-minute measurements from 39 healthy subjects at rest. From the evaluated AR model parameter extraction methods, Burg's method combined AIC performed the best. We obtained the mean absolute error of 2.7 and bias of-0.4 respirations per minute with this combination.

Research paper thumbnail of Arterial pulse waves measured with EMFi and PPG sensors and comparison of the pulse waveform spectral and decomposition analysis in healthy young and elderly subjects

Modelling in Medicine and Biology X, 2013

The purpose of this study is to show the time domain and frequency domain analysis of signals rec... more The purpose of this study is to show the time domain and frequency domain analysis of signals recorded with electromechanical film (EMFi) and photoplethysmographic (PPG) sensors in arterial elasticity estimation via pulse wave decomposition and spectral components obtained from left forefinger, left wrist, and left second toe arteries. ECG and pulse waves from the subjects were recorded firstly from 20 voluntaries by PPG sensors and from 7 persons (30-60 y) by parallel EMFi and PPG sensors in supine position. Decomposition of the pulse waves produces five components: percussion wave, tidal wave, dicrotic wave, and 1st and 2nd presystolic waves. Pulse wave decomposition parameters between EMFi and PPG are compared to find out information on a person's arterial elasticity. Results show that elastic information in the form of pulse wave decomposition from PPG waves is obtainable and shows clear shortening between percussion wave and tidal wave time with age. The spectral information obtained with frequency domain analysis could also be valuable in assessing the arterial elasticity.

Research paper thumbnail of Optical and mechanical measurement of the arterial elasticity

Artery Research, 2012

There was no statistically significant correlation between raPWV and arm musculature. 3)Left hand... more There was no statistically significant correlation between raPWV and arm musculature. 3)Left handed individuals had higher raPWV than right handers, figure below. (unpaired t-test; both limbs PWV p<0.0001, dominant only p<0.015, non-dominant p<0.001). Summary and Conclusions: Results failed to support hypotheses 1 and 2, although differences in muscularity between the two arms were small. Intriguingly, for reasons unknown, left handers had stiffer arms than right handers. In future we will measure PWV at other sites and include racquet sport players with greater muscular disparity between each arm.

Research paper thumbnail of Arterial pulse wave analysis based on PPG and EMFi measurements

2012 13th Biennial Baltic Electronics Conference, 2012

ABSTRACT Photoplethysmography (PPG) is an optical measurement technique either in reflective or t... more ABSTRACT Photoplethysmography (PPG) is an optical measurement technique either in reflective or transmission mode over the skin. PPG amplitudes depend on light wavelength which is typically in near infrared region. Eletromechanical film (EMFi) is an excellent sensor material for low-current long-term applications, e.g., arterial pulse wave recordings. EMFi measures extremely very small movements of the arterial wall and the tissue around the artery on the skin whereas PPG measures very low light absorption, transmission, and scattering caused by oxihemoglobin. Both PPG and EMFi sense elastic wave recoil, impact, and reflection caused by left ventricular contraction. Each type of pulse waves can be analysed in different ways, but they are extensively synergetic. Analysis type (PSD, PDF, NPWD, SDPPG, SDEMFi) shows different information.

Research paper thumbnail of Photoplethysmography and its detailed pulse waveform analysis for arterial stiffness

rmseura.tkk.fi

Summary. Arterial stiffness index is one of the biomechanical indices of vascular healthiness. Th... more Summary. Arterial stiffness index is one of the biomechanical indices of vascular healthiness. These indexes are based on detailed pulse waveform analysis which is presented here. After photoplethysmographyic (PPG) pulse wave measurement, we ...

Research paper thumbnail of System for ECG and heart rate monitoring during group training

2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008

Research paper thumbnail of Utilization of wireless sensor network for health monitoring in home environment

Proceedings - 2009 IEEE International Symposium on Industrial Embedded Systems, SIES 2009, 2009

The health care costs in developed countries are increasing fast due to the aging of the populati... more The health care costs in developed countries are increasing fast due to the aging of the population. In-home monitoring of health is becoming more and more attractive both because of expected cost-savings and technical development of suitable measurement devices and wireless sensor networks. In this paper, we present on-going work about embedding health monitoring devices into ordinary homes. The developed