Seismocardiography (SCG) measures the precordial micro-vibration produced at every heartbeat by the cardiac contraction, valves opening and closing and by blood ejection into the vascular tree. Underwater activities put a significant strain on the cardiovascular system and diving is increasingly practiced by sedentary subjects along with an aging population. Thus, there is an increased need to provide technological solutions that could allow the diver to self-monitor their cardiovascular health in underwater conditions and get a feedback on their fitness to dive. The aim of this study was then to evaluate and quantify the mechano-electrical cadiac activity and its spontaneous adaptation to the underwater environment in controlled conditions and determine normality ranges for future comparisons. Data were collected in an indoor swimming pool from 23 experienced divers using the Movisens EcgMove4 device worn under a drysuit. The protocol consisted in 10 minutes long recordings for each of the four phases: outside the pool to determine a baseline, at two and five meters depth and again outside the pool. SCG heartbeats were located using the ECG as a reference and isovolumetric contraction (IVC) and aortic valve opening (AO) identified. For each beat temporal and morphological biomarkers were then computed and inter-phases changes assessed (Wilcoxon Signed Rank test, p < 0.05). The results showed a significant change in general, particularly between baseline and five meters depth; however, the restriction exerted by the dry suit must be taken into account when interpreting results closely related to myocardial mechanical activity. The study suggests that the SCG signal can effectively detect myocardial mechanical activity typical of human physiological adaptation to the underwater environment, associated to the ECG for electrical activity. Such combined information, easily collectible using a wearable device, open new opportunities for future developments in this field.
La sismocardiografia (SCG) misura le microvibrazioni precordiali prodotte ad ogni battito cardiaco dalla contrazione cardiaca, dall’apertura e chiusura delle valvole e dalla espulsione del sangue. Le attività subacquee sottopongono il sistema cardiovascolare a uno sforzo significativo e l’immersione è sempre più praticata da sedentari e da una popolazione di età avanzata. Pertanto, c’è una crescente necessità di fornire soluzioni tecnologiche che possano consentire al subacqueo di auto-monitorare la propria salute cardiovascolare in condizioni subacquee e di ottenere un riscontro sulla loro idoneità all’immersione. Lo scopo di questo studio è stato quindi quello di valutare e quantificare l’attività cardiaca meccano-elettrica e il suo adattamento spontaneo all’ambiente subacqueo in condizioni controllate e determinare gli intervalli di normalità per futuri confronti. I dati sono stati raccolti in una piscina coperta su 23 subacquei esperti utilizzando il dispositivo Movisens EcgMove4 indossato sotto una muta stagna. Il protocollo consisteva in registrazioni della durata di 10 minuti per ciascuna delle quattro fasi: fuori dalla piscina per determinare un riferimento, a due e cinque metri di profondità e fuori dalla piscina. I battiti cardiaci SCG sono stati localizzati utilizzando l’ECG come riferimento e sono stati identificati la contrazione isovolumetrica (IVC) e l’apertura della valvola aortica (AO). Per ogni battito sono stati calcolati biomarcatori temporali e morfologici e sono stati valutati i cambiamenti tra le fasi (Wilcoxon Signed Rank test, p < 0,05). I risultati hanno mostrato un cambiamento significativo in generale, in particolare tra riferimento e cinque metri di profondità; tuttavia, la restrizione esercitata dalla muta stagna deve essere presa in considerazione quando si interpretano i risultati strettamente correlati all’attività meccanica miocardica. Lo studio suggerisce che il segnale SCG può efficacemente rilevare l’attività meccanica miocardica tipica dell’adattamento fisiologico dell’uomo all’ambiente subacqueo, associata all’ECG per l’attività elettrica. Queste informazioni combinate, facilmente raccoglibili con un dispositivo indossabile, aprono nuove opportunità per futuri sviluppi.
Monitoring of mechano-electrical cardiac activity underwater
Di TURSI, GIUSEPPE
2022/2023
Abstract
Seismocardiography (SCG) measures the precordial micro-vibration produced at every heartbeat by the cardiac contraction, valves opening and closing and by blood ejection into the vascular tree. Underwater activities put a significant strain on the cardiovascular system and diving is increasingly practiced by sedentary subjects along with an aging population. Thus, there is an increased need to provide technological solutions that could allow the diver to self-monitor their cardiovascular health in underwater conditions and get a feedback on their fitness to dive. The aim of this study was then to evaluate and quantify the mechano-electrical cadiac activity and its spontaneous adaptation to the underwater environment in controlled conditions and determine normality ranges for future comparisons. Data were collected in an indoor swimming pool from 23 experienced divers using the Movisens EcgMove4 device worn under a drysuit. The protocol consisted in 10 minutes long recordings for each of the four phases: outside the pool to determine a baseline, at two and five meters depth and again outside the pool. SCG heartbeats were located using the ECG as a reference and isovolumetric contraction (IVC) and aortic valve opening (AO) identified. For each beat temporal and morphological biomarkers were then computed and inter-phases changes assessed (Wilcoxon Signed Rank test, p < 0.05). The results showed a significant change in general, particularly between baseline and five meters depth; however, the restriction exerted by the dry suit must be taken into account when interpreting results closely related to myocardial mechanical activity. The study suggests that the SCG signal can effectively detect myocardial mechanical activity typical of human physiological adaptation to the underwater environment, associated to the ECG for electrical activity. Such combined information, easily collectible using a wearable device, open new opportunities for future developments in this field.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/214401