Di Rienzo Marco, Meriggi Paolo, Rizzo Francesco, Vaini Emanuele, Faini Andrea, Merati Giampiero, Parati Gianfranco, Castiglioni Paolo
Biomedical Technology Department, Fondazione Don Carlo Gnocchi, Milano, Italy.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:4263-6. doi: 10.1109/IEMBS.2011.6091058.
Seismocardiogram (SCG) is the recording of the minute body accelerations induced by the heart activity, and reflects mechanical aspects of heart contraction and blood ejection. So far, most of the available systems for the SCG assessment are designed to be used in a laboratory or in controlled behavioral and environmental conditions. In this paper we propose a modified version of a textile-based wearable device for the unobtrusive recording of ECG, respiration and accelerometric data (the MagIC system), to assess the 3d sternal SCG in daily life. SCG is characterized by an extremely low magnitude of the accelerations (in the order of g × 10(-3)), and is masked by major body accelerations induced by locomotion. Thus in daily life recordings, SCG can be measured whenever the subject is still. We observed that about 30 seconds of motionless behavior are sufficient for a stable estimate of the average SCG waveform, independently from the subject's posture. Since it is likely that during spontaneous behavior the subject may stay still for at least 30 seconds several times in a day, it is expected that the SCG could be repeatedly estimated and tracked over time through a prolonged data recording. These observations represent the first testing of the system in the assessment of SCG out of a laboratory environment, and open the possibility to perform SCG studies in a wide range of everyday conditions without interfering with the subject's activity tasks.
心震图（SCG）是对心脏活动引起的微小身体加速度的记录，反映了心脏收缩和血液喷射的力学方面。到目前为止，大多数现有的用于SCG评估的系统设计用于实验室或可控的行为和环境条件下。在本文中，我们提出了一种基于纺织品的可穿戴设备的改进版本，用于无创记录心电图、呼吸和加速度计数据（MagIC系统），以评估日常生活中的三维胸骨SCG。SCG的特点是加速度幅度极低（约为g×10⁻³），并被运动引起的主要身体加速度所掩盖。因此在日常生活记录中，只要受试者静止，就可以测量SCG。我们观察到，大约30秒的静止行为足以稳定估计平均SCG波形，与受试者的姿势无关。由于在自发行为中，受试者一天中可能会多次静止至少30秒，因此预计通过长时间的数据记录，可以随时间反复估计和跟踪SCG。这些观察结果代表了该系统在实验室环境之外评估SCG的首次测试，并为在各种日常条件下进行SCG研究开辟了可能性，而不会干扰受试者的活动任务。
