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

Jiří Přibil,Ivan Frollo,Anna Přibilová

doi:10.3390/s20123532

Abstract

The paper describes first-step experiments with parallel measurement of cardiovascular parameters using a photoplethysmographic optical sensor and standard portable blood pressure monitors in different situations of body relaxation and stimulation. Changes in the human cardiovascular system are mainly manifested by differences in the Oliva–Roztocil index, the instantaneous heart rate, and variations in blood pressure. In the auxiliary experiments, different physiological and psychological stimuli were applied to test whether relaxation and activation phases produce different measured parameters suitable for further statistical analysis and processing. The principal investigation is aimed at analysis of vibration and acoustic noise impact on a physiological and psychological state of a person lying inside the low-field open-air magnetic resonance imager (MRI). The obtained results will be used to analyze, quantify, and suppress a possible stress factor that has an impact on the speech signal recorded during scanning in the MRI device in the research aimed at 3D modeling of the human vocal tract.

Highlights

At present, non-invasive, fast, and precise methods for investigation of a human body are increasingly used in clinical practice
This may be the case of the magnetic resonance imaging (MRI) approach where the negative effect is caused by exposition of a patient to vibration and acoustic noise produced by the gradient system of this type of a scan device
The heart rate variability affected by the stress has been examined by other authors, the use of the Oliva–Roztocil index (ORi) feature from the measured fingertip PPG was not found in the scientific literature of the current period, so it can be treated as a new approach

Summary

Introduction

Non-invasive, fast, and precise methods for investigation of a human body are increasingly used in clinical practice. Application of other methods and devices working on different physical principles brings unwanted negative physiological and psychological effects on examined persons, for example, exposition to noise and vibration can pose a health risk to humans [2]. This may be the case of the magnetic resonance imaging (MRI) approach where the negative effect is caused by exposition of a patient to vibration and acoustic noise produced by the gradient system of this type of a scan device. The whole-body MRI device may have a negative influence

Results

Discussion

Conclusion