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Energooszczędny system zarządzania urządzeniami IoT inteligentnego domu

Nowakowska Katarzyna, Sieczkowski Krzysztof

Elektronika : konstrukcje, technologie, zastosowania

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2023

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Vol. 64, Nr 9

15--20

PL

W artykule przedstawiono projekt innowacyjnego, energooszczęd nego systemu zarządzania urządzeniami IoT inteligentnego domu. W opracowanym systemie położono szczególny nacisk na niski pobór prądu co bezpośrednio przekłada się na redukcję kosztów związanych z eksploatacją urządzenia. Zaprojektowany system pozwala również na zasilanie z wykorzystaniem ogniw akumulato rowych, bez konieczności zasilania komponentów systemu z sieci energetycznej. Komunikacja pomiędzy komponentami systemu odbywa się za pomocą technologii Bluetooth Low Energy (BLE), a dane pomiarowe pozyskane z podłączonych do systemu czujni ków są wyświetlane na energooszczędnym ekranie typu e-papier. Dzięki zastosowaniu przedstawianego rozwiązania możliwe jest zarządzanie w sposób ekonomiczny urządzeniami takimi jak np. systemy ogrzewania, rolety okienne, urządzenia RTV/AGD, a nawet pompa ciepła.

EN

Article presents innovation project of energy efficient, IoT de vices smart home management system. Main goal in deve lopment was low power consumption which reduces running costs. The designed system can be used also with recharge able battery pack. That implies IoT system could operating without electrical grid. Communication between components of the system was realized via Bluetooth Low Energy (BLE), probed data by sensors included in the system are displayed at e-paper screen. This solution provides cost-effective mana gement of IoT smart home system which can consist various appliances e.g., window shutters, consumer devices, heating system and also heat pump.

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Validation of a new device for photoplethysmographic measurement of multi-site arterial pulse wave velocity

Sondej Tadeusz, Jannasz Iwona, Sieczkowski Krzysztof, Dobrowolski Andrzej, Obiała Karolina, Targowski Tomasz, Olszewski Robert

Biocybernetics and Biomedical Engineering

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2021

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Vol. 41, no. 4

1664--1684

EN

Pulse wave velocity (PWV) is commonly used for assessing arterial stiffness and it is a useful and accurate cardiovascular mortality predictor. Currently, many techniques and devices for PWV measurement are known, but they are usually expensive and require operator experience. One possible solution for PWV measurement is photoplethysmography (PPG), which is convenient, inexpensive and provides continuous PWV results. The aim of this paper is validation of a new device for PPG sensor-based measurement of multisite arterial PWV using a SphygmoCor XCEL (as the reference device) according to the recommendations of the Artery Society Guidelines (ASG). In this study, 108 subjects (56 men and 52 women, 20–91 years in 3 required age groups) were enrolled. The multi-site PWV was simultaneous measured by 7 PPG sensors commonly used in pulse oximetry in clinical settings. These sensors were placed on the forehead, and right and left earlobes, fingers and toes. Pulse transit time (PTT) was measured offline as the difference of time delay between two onsets of the pulse wave determined by the intersecting tangent method. The PWV was calculated by dividing the distance between PPG sensors by PTT. During PPG signals measurement, reference carotid to femoral PWV (cfPWV) was performed with a SphygmoCor XCEL system. The Pearson correlation coefficient (r) between the obtained PWV results was calculated. The Bland-Altman method was used to establish the level of agreement between the two devices. Mean difference (md) and standard deviation (SD) were also calculated. The multi-site PWV was highly correlated with accuracy at the ASG-defined level of ‘‘Acceptable” (md < 1.0 m/s and SD ≤ 1.5 m/s) with cfPWV: forehead - right toe (r = 0.75, md = 0.20, SD = 0.97), forehead - left toe (r = 0.79, md = 0.18, SD = 0.91), right ear - right toe (r = 0.79, md = 0.11, SD = 0.96), left ear - left toe (r = 0.75, md = 0.43, SD = 0.99), right ear - left toe (r = 0.78, md = 0.40, SD = 0.93), left ear - right toe (r = 0.78, md = 0.11, SD = 0.96), right finger - right toe (r = 0.66, md = 0.95, SD = 1.29), left finger - lefttoe (r = 0.67, md = 0.68, SD = 1.35). This study showed that PWV measured with the multisite PPG system, in relation to the obtained numerical values, correlated very well with that measured using the commonly known applanation tonometry method. However, it should be noted, that the measured PWV concerns the central and muscular part of the arterial tree while the cfPWV is only for the central one. The best results were obtained when the proximal PPG sensor was placed on the head (ear or forehead) and the distal PPG sensor on the toe. PPG sensors can be placed in many sites at the same time, which provides greater freedom of their configuration. Multi-site photoplethysmography is an alternative method for PWV measurement and creates new possibilities for the diagnostics of cardiovascular diseases.

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Wyznaczanie czasu propagacji Fali tętna w oparciu o sygnały EKG i PPG

Sieczkowski Krzysztof, Dobrowolski Andrzej P., Sondej Tadeusz, Olszewski Robert

Przegląd Elektrotechniczny

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2019

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R. 95, nr 11

101--104

PL

W artykule przedstawiono nowatorską metodę pozwalającą na wyznaczanie czasów propagacji fali tętna, która bazuje na jednoczesnym pomiarze sygnałów EKG i PPG. Kluczowa dla proponowanego algorytmu dokładność wyznaczenia początkowego i końcowego punktu pomiarowego danego sygnału, silnie zależy od procedur wstępnego przetwarzania. Proponowane rozwiązanie opiera się na rozwijanej przez autorów metodzie korelacji aktualizowanego na bieżąco wzorca sygnału z aktualnie analizowanym fragmentem sygnału.

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In this article was presented a novel method for determining a pulse transit time, which is based on simultaneous measurement of ECG and PPG signals. The key to the proposed algorithm, the accuracy of determining the starting and ending measuring point of a given signal, strongly depends on the pre-processing procedures. The proposed solution is based on the method of correlation of the currently updated signal pattern with the currently analyzed fragment of signal, developed by the authors.

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Simultaneous multi-site measurement system for the assessment of pulse wave delays

Sondej Tadeusz, Sieczkowski Krzysztof, Olszewski Robert, Dobrowolski Andrzej

Biocybernetics and Biomedical Engineering

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2019

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Vol. 39, no. 2

488--502

EN

A precise, multi-track system for the simultaneous, real-time measurement of electrocardiographic (ECG) and many photopletysmographic (PPG) signals is described. This system allows the calculation of pulse wave delay parameters such as pulse arrival time (PAT) and pulse transit time (PTT). The measurement system was built on a custom, real-time embedded system with multiple specific analogue-front-end devices. Signals were recorded on-line and data were processed off-line in the Matlab software. Testing of human subjects was carried out on a group of 16 volunteers. The system was capable of taking a measurement of one 24-bit ECG and eight 22-bit PPG tracks with high precision (input-referred noise 1.4 mV for ECG and about 20 pA for PPG). All signals are sampled simultaneously (phase shift between ECG and PPG is only 1.5 ms for 250 Hz frequency sampling). Significant differences in pulse wave delays were found for the 16 subjects studied (e.g. about 100 ms for PAT on a right toe, 40 ms for differential PAT on left-right toes and about 100 ms for PTT calculated for forehead-right toe pulse wave). The proposed system provides a simultaneous and continuous evaluation of pulse wave delays for the entire arterial bed. The proposed measurement methods are comfortable and can be used for a long time. Simultaneous measurements of pulse wave delays at various sites increase the reliability of measurement and create new possibilities for medical diagnosis.