Objective Assessment of Covid-19 Severity Affecting the Vocal and Respiratory System Using a Wearable, Autonomous Sound Collar

Introduction

Since the outbreak began in January 2020, Covid-19 has affected more than 161 million people worldwide and resulted in about 3.3 million deaths. Despite efforts to detect human infection with the virus as early as possible, the confirmatory test still requires the analysis of sputum or blood with estimated results available within approximately 30 minutes; this may potentially be followed by clinical referral if the patient shows signs of aggravated pneumonia. This work aims to implement a soft collar as a sound device dedicated to the objective evaluation of the pathophysiological state resulting from dysphonia of laryngeal origin or respiratory failure of inflammatory origin, in particular caused by Covid-19.

Methods

In this study, we exploit the vibrations of waves generated by the vocal and respiratory system of 30 people. A biocompatible acoustic sensor embedded in a soft collar around the neck collects these waves. The collar is also equipped with thermal sensors and a cross-data analysis module in both the temporal and frequency domains (STFT). The optimal coupling conditions and the electrical and dimensional characteristics of the sensors were defined based on a mathematical approach using a matrix formalism.

Results

The characteristics of the signals in the time domain combined with the quantities obtained from the STFT offer multidimensional information and a decision support tool for determining a pathophysiological state representative of the symptoms explored. The device, tested on 30 people, was able to differentiate patients with mild symptoms from those who had developed acute signs of respiratory failure on a severity scale of 1 to 10.

Conclusion

With the health constraints imposed by the effects of Covid-19, the heavy organization to be implemented resulting from the flow of diagnostics, tests and clinical management, it was urgent to develop innovative and safe biomedical technologies. This passive listening technique will contribute to the non-invasive assessment and dynamic observation of lesions. Moreover, it merits further examination to provide support for medical operators to improve clinical management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-021-00712-w.

Acoustic concept based on an autonomous capsule and a wideband concentric ring resonator for pathophysiological prevention

BACKGROUND

Research on the performance of elements constituting our modern environment is constantly evolving, both on a daily basis and on technological basis. But to date, the response of the system to the expectations of the population remains too modest.

AIM

To elaborate an ultrasonic technique to scan and evaluate in-vivo physiological properties by coupling sensors and multilayer biological tissues model.

METHODS

A low-frequency ultrasonic method (around a frequency of 32 KHz) based on the use of an innovative autonomous ultrasonic capsule as a miniaturized elementary spherical sensor (1 cm of diameter) and micro-rings resonators were examined.

RESULTS

Other their functions as passive listeners for the prevention and diagnosis in physiopathology of the respiratory and laryngeal apparatus, these micro-resonators coupled to the ultrasonic capsule through biological tissues (the body) are capable of evaluating the effects of aggression of the environment on human metabolism.

CONCLUSION

This would allow consequently the detection of some potential diseases at an early stage, even in people who still represent no symptoms, which would permit an early treatment and a higher chance of cure.

Global transmission and reflection coefficients of the ultrasonic component in porous media: a new approach

The purpose of this paper is to propose a new approach to determining the global ultrasonic transmission and reflection coefficients in a random porous medium. Boundary conditions at the interface of the medium were used to determine local transmission and reflection coefficients. A study of the behavior of different waves inside the medium was carried out to derive a new global formulation that takes interior phenomena into consideration. All the results were obtained independently of the geometrical and physical characteristics of the medium so that the method can be applied to any two-phase porous medium. This study is based on normal incidence ultrasonic wave propagation.

Ultrasonic measurement of bulk and shear moduli variations in porous alumina media

In this paper we studied some acoustical parameters of a porous medium based on the Biot's theory. The basic idea was to find, using an inversion method, variations in the bulk modulus K(b) and the shear modulus G(b) in the frequency domain. This was achieved by comparing the theoretical and experimental results obtained on a selection of porous alumina samples with different physical characteristics. Then, using the transmission coefficient, a numerical process was applied to a virtual porous alumina medium in order to find K(b) and G(b) values at low frequency under static conditions. Using a frequency range of 50kHz to 600kHz, fast and slow waves were considered and both were included in the transmission coefficient.