A Physiologic Research to Assess the Effect of an Inline Filter During Cardiopulmonary Exercise Testing (CPET): A Healthy Volunteer Study
Phase: NA
Conditions: Transmission, Patient-Professional
Sponsor: Rush University Medical Center

A Physiologic Research to Assess the Effect of an Inline Filter during Cardiopulmonary 
Exercise Testing (CPET): A Healthy Volunteer Study 
Jie Li1; Ellen M Moran1; Renee D Kiourkas1; Ryndell V Magbalon1; David Vines1; Sara Mirza1; 
Mark A Yoder1. 
1 Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University 
Medical Center, Chicago, IL. 
2 Department of pulmonary and critical care medicine, Rush University Medical Center, 
Chicago, IL.
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020

Objectives
1. Assess the Effects of an In-Line Filter on the Physiologic Responses during 
CardioPulmonary Exercise Testing (CPET) and the Aerosol Particle Size Distribution 
in the Environment.
2. Hypothesis:  An in-line filter will have minimal effects (< 5% effect) on minute 
ventilation (V̇E), oxygen uptake (V̇O2), carbon dioxide output (V̇CO2), and heart rate 
(HR) during CPET. The placement of filter will significantly reduce the particle 
concentrations generated by subjects during CPET.
Background
The arrival of the COVID-19 pandemic (SARS-CoV-2) has dramatically changed 
the landscape of healthcare, including clinical care and research trials (Zhu, Zhang et al. 
2020).  The initial response of health care systems and research institutions was to cease 
all activity and turn all efforts towards the pandemic response (Christian, Sprung et al. 
2014).  However, as levels of infection in the local community begin to recede, 
institutions are considering ways to restore normal clinical care and research trials 
(Faghy, Sylvester et al. 2020).
Physiologic testing (Pulmonary Function Testing - PFT) and (Cardiopulmonary 
Exercise Testing – CPET) is an important component of clinical care (Wasserman, 
Hansen et al. 2012), however both are aerosol generating procedures (AGPs) 
(https://www.advocatehealth.com/covid-19-info/_assets/documents/aerosol-generating-procedures.pdf), 
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020

and thus may pose a risk to patients, and clinical staff (Tran, Cimon et al. 2012).  PFT 
AGPs are mitigated by using an inline filter during breathing trials, however, this is not 
standard practice with CPET. For example, European respiratory society (ERS) does not 
recommend the utilization of HEPA filter during CPET, due to the concerns of creating 
the resistance for breathing. 
Therefore, the issue that requires investigation is the effect of the in-line filter on 
the gas exchange measurements, as these are the ultimate ‘product’ of the CPET testing.  
If these values are severely affected (> 5%) by an inline filter, then other mitigation 
strategies may need to be considered.  
Further, we need to establish the effects of the in-line filter on several of the 
common CPET hardware/software platforms in use throughout the world (e.g Medical 
Graphics Corporation, Vyair Vmax, Cosmed, etc), specifically on the important measured 
variables (V̇E, V̇O2, V̇CO2 and HR). We also want to evaluate the effects of the filter on 
reducing particle concentrations that are generated by subjects during CPET, as well as 
the time that is required to clean the room air. 
Acquiring this data and publishing it in the near future would be important to 
safely return to practice and also to support our CPET colleagues throughout the world.
Methods
1. Inclusion and Exclusion Criteria 
Inclusions:

Ages 18-65, Male or Female
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020


Normal exercise tolerance without dyspnea or clinically important limitation of 
exercise tolerance.
Exclusions:

Complicated heart or lung disease

Pregnancy

Complex arrhythmias

Severe Anemia

Uncontrolled Diabetes, hypertension, or untreated thyroid disease

Has any of the following symptoms in the last 21 days: sore throat, cough, chills, 
body aches for unknown reasons, shortness of breath for unknown reasons, loss of 
smell, loss of taste, fever at or greater than 100 degrees Fahrenheit.

COVID-19 test positive within 21 days.  

Any Disease that the PI feels will markedly increase the risk of CPET testing
2. Sample size: 10 subjects
3. Subject recruitment: 
Advertisement will be posted in the public area at Rush University Medical Center, 
including fitness center, healthy subjects including employee or patients/family in Rush 
University Medical Center will be recruited. 
4. Study Timelines

The duration of an individual subject’s participation in the study.
This requires two visits over two days for an hour or less on each visit. Two 
increment work rate CPET studies with one performed on each day taking no 
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020

more than 45 minutes.  With a one-hour break for cleaning and room air 
exchange between subjects.

The duration anticipated to enroll all study subjects.
3 weeks ( to prescreen and set up testing schedule)

The estimated date for the investigators to complete this study (complete 
primary analyses)
August 2020
5. Study outcome

Primary:  Determine the effect of the in-line filter (< 5% effect or > 5% effect) on 
minute ventilation (V̇E), oxygen uptake (V̇O2), carbon dioxide output (V̇CO2), and 
heart rate (HR) during CPET. Effect of in line filter on oxygen pulse, ventilatory 
equivalents, end tidal O2 and CO2.  Sensation of dyspnea by the subject (Borg 
Score).

Secondary:  Effect of in line filter on aerosol particle concentrations inside the test 
room during CPET testing to determine if wait time between patients can be 
calculated
6. Termination criteria: 
Standard termination criteria for CPET during testing are BP > 240/120, serious arrhythmias, 
chest pain, oxygen desaturation and severe dyspnea.
7. Procedures Involved*

study design.
    The subject will spend two visits one hour each day (~ 1 hour) in the PFT lab 
and will have two separate CPET (Vyair Vmax, Vyaire medical, Mettawa, IL) 
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020

tests performed by registered pulmonary function technologists. One day the test 
will be performed with the inline filter during CPET, and the second day the 
CPET will be performed without a filter. During the test, electrocardiogram 
(ECG) electrodes will be attached to participants as well as a mask, and their heart 
rate will be measured for 10 minutes at rest, and then they will ride bicycle for 20 
minutes at different levels of intensity. The work rate increment will be the same 
for both tests. All gas exchange and aerosol particle concentrations measures will 
be compared with Bland Altman analysis and paired t-testing.

Provide a description of all research procedures being performed and when they are 
performed, including procedures being performed to monitor subjects for safety or 
minimize risks.
The standard CPET (Wasserman 2012) includes real time monitoring of the 12 lead 
EKG, pulse oximetry, gas exchange variables, physician assessment, and symptom query.

Procedures performed to lessen the probability or magnitude of risks.

All drugs and devices used in the research and the purpose of their 
use, and their regulatory approval status.
No drugs.  The device is an inline filter (MicroGard™ II PFT Filter).
MicroGard™ II PFT Filter
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020

Proposed filter to be used (current standard of care with PFTs)
MicroGard™ II PFT Filter in line with Mouthpiece and Flow Sensor
** Picture shows the Pitot flow sensor, and adapter, the Microgard 
Filter, and a standard mouthpiece.

The relevant characteristics of this filter are:
Inspiratory Resistance: 0.45 cm/H2O/L/S 
Expiratory Resistance: 0.45 cm/H2O/L/S 
Filter Efficiency: Bacteria>99.98% 
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020

Virus filtering efficiency > 99.92% 
Dead Space = 53ml 
The filter is for single patient and single occasion use only.
8. Data Management* and Confidentiality

Describe the data analysis plan, including any statistical procedures.
Data from each subject will be compared with a Bland Altman Analysis 
(https://www.jstor.org/stable/2987937?seq=1) and paired T-Testing using the non-filter 
data for minute ventilation (V̇E), oxygen uptake (V̇O2), carbon dioxide output (V̇CO2), 
and heart rate (HR) during a work rate increment CPET, comparison of the non-filter to 
the filter data will be analyzed.  Mean and standard deviation of the measurements will be 
presented.  Statistical importance will be assigned at P ≤ 0.05.

Describe the steps that will be taken secure the data (e.g., training, authorization of 
access, password protection, encryption, physical controls, certificates of 
confidentiality, and separation of identifiers and data) during storage, use, and 
transmission.
No identification will be collected. The electronic data will be stored on the Redcap, 
which is a secure network with appropriate institutional security, and password 
protection.
ORA: 20070810-IRB01   Date IRB Approved: 8/17/2020