@misc{10481/75809,
year = {2022},
month = {5},
url = {http://hdl.handle.net/10481/75809},
abstract = {In this work, we present a ballistocardiographic (BCG) system for the determination
of heart and breath rates and activity of a user lying in bed. Our primary goal was to simplify
the analog and digital processing usually required in these kinds of systems while retaining high
performance. A novel sensing approach is proposed consisting of a white LED facing a digital light
detector. This detector provides precise measurements of the variations of the light intensity of
the incident light due to the vibrations of the bed produced by the subject’s breathing, heartbeat,
or activity. Four small springs, acting as a bandpass filter, connect the boards where the LED and
the detector are mounted. Owing to the mechanical bandpass filtering caused by the compressed
springs, the proposed system generates a BCG signal that reflects the main frequencies of the
heartbeat, breathing, and movement of the lying subject. Without requiring any analog signal
processing, this device continuously transmits the measurements to a microcontroller through a twowire
communication protocol, where they are processed to provide an estimation of the parameters of
interest in configurable time intervals. The final information of interest is wirelessly sent to the user’s
smartphone by means of a Bluetooth connection. For evaluation purposes, the proposed system
has been compared with typical BCG systems showing excellent performance for different subject
positions. Moreover, applied postprocessing methods have shown good behavior for information
separation from a single-channel signal. Therefore, the determination of the heart rate, breathing rate,
and activity of the patient is achieved through a highly simplified signal processing without any need
for analog signal conditioning.},
organization = {Junta de Andalucia
European Commission	PYC20-RE-040 UGR	
MCIN/AEI/10.13039/501100011033/with	
PID2019-103938RB-I00},
organization = {European Commission},
publisher = {MDPI},
keywords = {Ballistocardiogram},
keywords = {Digital detector},
keywords = {Instrumentation},
keywords = {Android application},
title = {Digital Optical Ballistocardiographic System for Activity, Heart Rate, and Breath Rate Determination during Sleep},
doi = {10.3390/s22114112},
author = {López Ruiz, Nuria and Escobedo Araque, Pablo and Ruiz García, Isidoro and Carvajal Rodríguez, Miguel Ángel and Palma López, Alberto José and Martínez Olmos, Antonio},
}