Observation of Aerosol Generation by Human Subjects During Cardiopulmonary Exercise Testing Using a High-Powered Laser Technique: A Pilot Project

Abstract

Purpose Human respiratory aerosols may have important implications for transmission of pathogens. The study of aerosol production during vigorous breathing activities such as exercise is limited. In particular, data on aerosol production during cardiopulmonary exercise testing (CPET) are lacking. Methods In this pilot project, we used a high-powered, pulsed Nd:YAG laser to illuminate a region of interest in front of two healthy adult subjects during CPET. Subjects exercised to the point of respiratory compensation. Images were captured with a high-speed, high-resolution camera to determine net exhaled particle (NEP) counts at different phases of CPET, including resting breathing, submaximal exercise, peak exercise, and active recovery. Experiments were performed with the room ventilation activated. Results Net exhaled particle counts remained relatively constant until late/peak exercise when they decreased prior to rebounding into recovery. NEP counts at resting breathing were higher than those reported using other methods of measurement. Exhaled particles were in the submicron size range. Conclusion Our method of aerosol particle quantification enables measurement of significant quantities of ultrafine particles and dynamic assessment of aerosol production during CPET. The unique pattern of aerosol production observed during submaximal and peak exercise suggests that extension of results from resting breathing to CPET may not be appropriate.

Cardiorespiratory fitness as a vital sign of CVD risk in the COVID-19 era

“… 47 Despite the transition towards endemic status, there remains a level of uncertainty regarding the ability to safely undertake CPET procedures given concerns around patients and staff safety due primarily to human respiratory aerosols that are important in the transmission of viral pathogens. 48 Several papers have established responses to the challenges around delivering CPETs 47 , 49 and other lung function assessments 50 alongside the guidelines produced by a number of governing bodies and associations. 51 Despite the highlighted risks that remain prevalent due to sustained transmission and the threat of emerging variants, CPET remains an integral investigative tool in clinical practice and consideration for how these can be restored in the post-COVID-19 phase is crucial, particularly given the value of CPET in the new long COVID patient population.…”

Aerosol Generation During High Intensity Exercise—Implications for COVID-19 Transmission

“…It requires sophisticated, expensive, high fidelity aerosol measurement equipment with operator expertise; a low background particle count to detect small increases in aerosol concentration; comparison between interventions such as face masks and circumferential distance from the participant; and accurate measures of minute ventilation and work rate. To date, the available data for aerosol generation during HIE has limitations [ [22] , [23] , [24] ].…”