This paper gives an overview of a research, which is focused on the development of the convenient device for continuous non-invasive monitoring of arterial blood pressure. The blood pressure estimation method is based on a presumption that there is a singular relationship between the pulse wave propagation time in arterial system and blood pressure. The parameter used in this study is pulse wave transit time (PWTT). The measurement of PWTT involves the registration of two time markers, one of which is based on ECG R peak detection and another on the detection of pulse wave in peripheral arteries. The reliability of beat to beat systolic blood pressure calculation during physical exercise was the main focus for the current paper. Sixty-one subjects (healthy and hypertensive) were studied with the bicycle exercise test. As a result of current study it is shown that with the correct personal calibration it is possible to estimate the beat to beat systolic arterial blood pressure during the exercise with comparable accuracy to conventional noninvasive methods.

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In Tallinn women population, electrocardiographic parameters reflecting ventricular repolarization are associated with systolic blood pressure, pulse pressure, blood pressure value grade, heart rate and left ventricular hypertrophy.

The aim of this study was to determine the association of left ventricular (LV) geometry with sex, age, arterial hypertension and obesity in Tallinn. In a framework of a population study for cardiovascular risk factors, echocardiography was carried out in 325 men and 398 women (69.3% of all 1043 participants aged 35-59) in 1999-2001. Left ventricular hypertrophy was defined if left ventricular mass (LVM), LVM/height and LVM/body surface area were 294 g, 163 g/m and 150 g/m2 in men, and 198 g, 121 g/m and 120 g/m2 in women, respectively. LV geometry was analysed according to four types generally recognized (with regard to relative wall thickness > 0.45). The prevalence of concentric hypertrophy was similar in men and women: 7.7% and 9.1%. The prevalence of eccentric hypertrophy was significantly higher in women than in men (33.3% vs 4.9%). Concentric remodelling was also found in women more often than in men (9.5 vs 5.5%; p < 0.05). Regardless of sex and age, concentric hypertrophy was never found in participants with blood pressure < 140/90. In hypertensives, there was a tendency for age-related increase of concentric hypertrophy prevalence: the latter was higher in women than in men: 39.1% vs 25.5%; p < 0.05. In examinees with BMI < 30, this type of LV geometry was seldom found: in 3.1% of men and 5.0% of women; p < 0.05. In obese persons, it increased with age, reaching 26.5% in men and 21.2% in women (p < 0.05). The prevalence of eccentric hypertrophy in men increased with age, and with hypertension and obesity. The prevalence of concentric remodelling in men was not related to BMI; it was significantly more often found in older age groups and in hypertensives. In women, the prevalence of eccentric hypertrophy and concentric remodelling was not related to age, hypertension or obesity.

Abstract. 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 and therefore the signal raising front is undetectable. Electrocardiogram reference adaptive sum comb filter was used to extract the harmonic components of the PPG signal and suppress the noises between them. Averaging effect of the filter on the PPG signal was studied and adjustments were made. The influence of the comb filtered PPG signal on the measurement of pulse transit time was analysed.