Physiological Impact of Vibration and Noise in an Open-Air Magnetic Resonance Imager: Analysis of a PPG Signal of an Examined Person

Abstract

The paper represents a preliminary analysis of the physiological and psychological impact of vibration and acoustic noise on a person examined by a low-field magnetic resonance imaging (MRI) tomograph. First, a methodology for the measurement of different signals of a tested person was found. The main investigation consists of a parallel heart rate and blood pressure measurement using a photoplethysmographic (PPG) optical sensor and standard portable blood pressure monitors. The recorded PPG signal is filtered and processed to obtain a clean waveform used to determine an instantaneous heart rate. Different types of portable blood pressure monitors are tested and compared to choose the best one for further experiments.

First-Step PPG Signal Analysis for Evaluation of Stress Induced during Scanning in the Open-Air MRI Device

“…The current article is practically an extension of our previous work [ 25 ], where our first experiments with sensing and analyzing of a PPG signal have been described. The choice of the optical sensor HRM-2511E working in transmission mode together with the analog interface Easy Pulse was motivated by its successful application in the measurement that was already published in [ 25 ]. Prior to it, we had also tested several PPG sensors based on a reflection principle, but the obtained results were unsatisfactory owing to not very good PPG signal purity and stability.…”

“…The choice of the optical sensor HRM-2511E working in the transmission mode together with the analog interface Easy Pulse was made for its successful application in the measurement that was already presented in [ 25 ]. Prior to this, we had also tested several PPG sensors based on a reflection principle, but the obtained results were unsatisfactory owing to not very good PPG signal purity and stability.…”

Comparison of Three Prototypes of PPG Sensors for Continual Real-Time Measurement in Weak Magnetic Field

“…Here, the stress-evoked vocal cord tension has an influence on the recorded speech signal [ 8 ] by modifying its supra-segmental and spectral features; therefore, it can bring about errors and inaccuracy in calculation of 3D models of the human vocal tract [ 9 ]. Analysis, mapping, detection, and evaluation of this negative effect were the basis of our previous [ 10 , 11 ] as well as present [ 12 ] research investigation. For this reason, three prototypes of PPG sensors with real-time Bluetooth (BT) transmission were subsequently developed.…”

Wearable PPG Sensor with Bluetooth Data Transmission for Continual Measurement in Low Magnetic Field Environment

“…The mental stress can effectively be identified by the photoplethysmography (PPG) signal [3]. We have already used the PPG measurement of the HR to monitor the physiological impact of the noise on a person examined inside the MRI scanning device [4]. In this measurement, the PPG sensors, the control units, and the storage devices were interconnected by cables leading from the shielding cage of the MRI device.…”