Effect of chest morphology on vibrational cardiography waveforms using multi-sensor analysis
Notice bibliographique
Résumé
Vibrational waves generated by cardiac events can be detected by an accelerometer or a gyroscope placed on the surface of the chest. These waves are generally in the infrasonic range and contain information about cardiac mechanics. Recent advances in sensor technology have paved the way to portable, and non-invasive sensors. Wearable devices developed with these sensors can be used to monitor cardiac vibrations continuously, providing early detection of cardiovascular diseases. These are especially important in rural areas or even for astronauts in the space, that is, in places where proper clinical support is often unavailable. However, these vibrations are extremely sensitive to sensor placement. Hence a better understanding of the waves in connection the human body is necessary to take this system from the lab to a hospital setting, and our households. This thesis studies cardiac vibrations through acceleration recorded on seven locations on the chest. Previous studies have attempted to investigate chest vibrations through physical testing, analytical solution, and simulation. However, any connection between morphological changes in the chest and vibrational cardiography (VCG) signal quality is yet to be established. In this study, we propose a novel method to connect the vibrations to the changes in body composition level by testing in the lab, and by building simple numerical models of the human chest containing individual material properties for the organs within. A multi-sensor based simultaneous VCG recording system was developed in the lab and detailed in this thesis. A pilot test was performed on three subjects at McGill University, during the restrictions placed by the Covid-19 pandemic. One participant underwent a weight loss and strength training program and testing revealed that the signal-to-noise ratio of cardiac vibrations improved during that period. Amplitude modulation due to different sensor positioning was observed and it helped to identify the best locations on the chest for VCG recording. All sensor positions were able to pick up cardiac valvular activity. The systolic and the diastolic peak of the vibrational waves were studied simultaneously in time and frequency domain and revealed similar frequency contents in the signal during both events. A detailed study on a larger population must be completed to validate the findings
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Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».