Wearable device for continuous monitoring of the respiratory rate
Data di pubblicazione
Data di priorità
International PCT patent application
Politecnico di Milano
Department of Electronics, Information and Bioengineering
Andrea Aliverti, Ambra Cesareo
The invention consists in a non-invasive wearable device aimed at monitoring the respiratory rate (RR) over the long period even in dynamic conditions. The device is based on 9-DoF inertial sensors (accelerometers, gyroscopes and magnetometers) that allow patients’ respiratory checking at home and during daily activities. The system works as a “holter” for the respiration function. The main novelty is the modular solution of the system, which includes three units. Two of the three units are placed on the thorax and the abdomen respectively, while the third unit works as a reference unit, and must be placed on a part of the trunk that is not involved in the respiratory movements (e.g. coccyx, 7th cervical vertebra, anterior Superior Iliac spine). The data recorded from the thorax and the abdomen units are then referred to the reference unit, through an ad hoc implemented algorithm, to consider only movement information linked to the breaths. This is particularly important in semi-static (e.g. wheel-chair bound patients) and dynamic conditions (e.g. during walking).
Data collected with the units are sent via wireless to a PC, a smartphone or a tablet that manage the acquisition process (start/stop acquisition, selection of the acquisition mode, etc.), save and visualize data.
Campo di applicazione
This device can be of interest for companies in the biomedical field, dealing with the monitoring of vital parameters or tele-monitoring.
The proposed system overcomes the limitations of the devices that estimate the respiratory rate by using a single accelerometer or more complex systems (IMU and MARG systems), that are not suitable for dynamic conditions due to motion artifacts, and are therefore unable to ensure a continuous monitoring of the RR. The reference unit introduced by this new configuration and placed on a body area integral with the trunk but non-subjected to respiratory movements solves the problem linked to the use of the device during movement. Moreover, the use of two units on the trunk that records respiratory movements linked to both chest and abdomen activity, takes account of the properties of the chest-wall motion, based on two-degree of-freedom model.
Stadio di sviluppo
Working prototype tested in static and dynamic conditions on healthy subjects.