No abstract

The paper presents a new textile-based wearable system for the unobtrusive recording of cardiorespiratory and motion signals during spontaneous behavior along with the first results concerning the application of this device in daily life and in a clinical environment. The system, called MagIC (Maglietta Interattiva Computerizzata), is composed of a vest, including textile sensors for detecting ECG and respiratory activity, and a portable electronic board for motion detection, signal preprocessing and wireless data transmission to a remote monitoring station. The MagIC system has been tested in freely moving subjects at work, at home, while driving and cycling and in microgravity condition during a parabolic flight. Applicability of the system in cardiac in-patients is now under evaluation. Preliminary data derived from recordings performed on patients in bed and during physical exercise showed 1) good signal quality over most of the monitoring periods, 2) a correct identification of arrhythmic events, and 3) a correct estimation of the average beat-by-beat heart rate. These positive results supports further developments of the MagIC system, aimed at tuning this approach for a routine use in clinical practice and in daily life.

No abstract

This paper illustrates two extensive applications of a smart garment we previously developed for the monitoring of ECG, respiration, and movement. In the first application, the device, named Maglietta Interattiva Computerizzata (MagIC), was used for the home monitoring of cardiac patients. The used platform included MagIC for signals collection, a touchscreen computer with a dedicated software for data handling, and a universal mobile telecommunications system (UMTS) dongle for data transmission, via email, to three cardiologists. Three patients daily-performed 3-min telemonitoring sessions for 30 days by using the platform. The whole system behaved correctly in 85 out of 90 sessions. In five instances, a second session was required due to UMTS traffic congestion. Only in three sessions, cardiologists asked the patient to repeat the acquisition because of poor signal quality. In the second application, MagIC was used to evaluate the effects of high-altitude hypoxia on sleep and 24 h daily life in 30 healthy subjects at 3500 and 5400 m above sea level on Mount Everest slopes. The use of MagIC garment was reported to be simple and requiring short instrumentation time even in the demanding expedition environment. The signal quality was adequate in 111 out of 115 recordings and 90% of the subjects found the vest comfortable.

No abstract

This article presents a new wearable platform, SeisMote, for the monitoring of cardiovascular function in controlled conditions and daily life. It consists of a wireless network of sensorized nodes providing simultaneous multiple measures of electrocardiogram (ECG), acceleration, rotational velocity, and photoplethysmogram (PPG) from different body areas. A custom low-power transmission protocol was developed to allow the concomitant real-time monitoring of 32 signals (16 bit @200 Hz) from up to 12 nodes with a jitter in the among-node time synchronization lower than 0.2 ms. The BluetoothLE protocol may be used when only a single node is needed. Data can also be collected in the off-line mode. Seismocardiogram and pulse transit times can be derived from the collected data to obtain additional information on cardiac mechanics and vascular characteristics. The employment of the system in the field showed recordings without data gaps caused by transmission errors, and the duration of each battery charge exceeded 16 h. The system is currently used to investigate strategies of hemodynamic regulation in different vascular districts (through a multisite assessment of ECG and PPG) and to study the propagation of precordial vibrations along the thorax. The single-node version is presently exploited to monitor cardiac patients during telerehabilitation.

Sternal seismocardiogram (SCG) is the assessment of microvibrations produced by the beating heart as detected by an accelerometer positioned on the sternum. This signal reflects mechanical events of the heart contraction, including the opening and closure of mitral and aortic valves and maximal blood flow acceleration. Traditionally, SCG has been detected in a laboratory setting with the subject lying at rest in supine position. Aims of this study were 1) to investigate the feasibility of a SCG monitoring over the 24 hours in ambulant subjects, and 2) to calculate number and time distribution of the SCG estimates obtainable over the 24 hours. In 5 healthy subjects ECG, respiration, body accelerations and sternal SCG were recorded for 24 hours in a workday by a smart garment recently developed in our laboratory, the MagIC-SCG system. Each recording was split into a series of contiguous 5-s data segments and SCG was estimated in each segment where the magnitude of the acceleration vector was < 4 milli-g (this condition indicates that the subject was not moving).All the 24-h recordings were found of good quality and could be entirely analyzed. A large number of SCG estimates could be obtained over the 24 hours. In particular, more than 100 estimates per hour were available during the day; at night this rate was three times higher.Thus our study indicates that not only the 24h SCG monitoring in daily life is feasible but also that possible changes over time in SCG and its derived parameters may be tracked with an extreme temporal detail.

This study indicates that in static condition MagIC has a capability of monitoring cardiac rhythm and arrhythmic events which is comparable with what obtainable by a traditional one-lead ECG recorder. During movement MagIC provides an ECG signal of better quality.