vmax and innocor presentation aug 1
TRANSCRIPT
Vmax and InnocorA comparison of two metabolic carts during rest and exercise
Zach Blain
Methods• The volume of oxygen consumed and utilized by working muscle per
minute during rest or exercise.
• Defined by Fick:• VO2 = Q × a-vO2 difference
• Q = SV × HR• Q= Cardiac output; SV= Stroke volume; HR= Heart rate
• Calculated as: • VO2 = [VE × (FEN2 / FIN2) × FIO2] – [VE × FEO2]
• VE= Ventilation, volume/min; FEN2= Fraction of expired nitrogen; FIN2= Fraction of inspired nitrogen; FIO2= Fraction of inspired oxygen; FEO2= Fraction of expired oxygen
• To measure Q • Pulmonary artery catheter (PAC)
• To measure a-vO2 Diff• Arterial venous catheter• blood sampling
How they work
Innocor
• Flowmeter
• Gas Analyzer
• Oxygen sensor
Vmax
• Flow/Volume
• O2 Analyzer
• CO2 Analyzer
• Flash Multi-Gas
Innocor Vmax
Purpose
The aim of this study is to compare the metabolic
measurements between Vmax and Innocor simultaneously
during rest and exercise.
HypothesisIt is hypothesized that there will be no difference between Vmax
and Innocor during rest and exercise.
Design and Protocol• Simultaneous measurements
• Baseline• 50 W• 100 W• 150 W• 200 W• 250 W• 300 W• Staged steady state
exercise - 2 minutes
Demographics
Patient DemographicsParticipants (male/female) 7 (4/3)Age (years) 24 ± 3Height (cm) 171 ± 8Weight (kg) 73 ± 20BMI (kg/m²) 25 ± 6
Absolute VO2/ VCO2 vs. Workloads
0 50 100 150 200 250 3000
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Vmax
Innocor
Workload (Watts)
VO₂ (
L/m
in)
*
* Significant Difference P< 0.05
0 50 100 150 200 250 3000
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Vmax
Innocor
Workload (Watts)VC
O₂ (
L/m
in)
*
Figure 2: Absolute VO2 (L/min) vs Workload (Watts) Figure 3: Absolute VCO2 (L/min) vs Workload (Watts)
Ventilation
0 50 100 150 200 250 3000
0.5
1
1.5
2
2.5
3
3.5
VmaxInnocor
Workload (Watts)
Vt (l
iter
s per
bre
ath)
0 50 100 150 200 250 3000
10
20
30
40
50
Vmax
Innocor
Workload (Watts)
RR (b
reat
hs p
er m
in)
Figure 4: Respiration rate (breaths per min) vs. Workload (Watts)
Figure 5: Tidal volume (liters per breath) vs. Workload (Watts)
Discussion
• No significant change in results for low workloads• After 200W there becomes a deviation in the results
• No significant difference in the respiration, at any workload
• VO2 and VCO2 at high workloads (300W)• Account for gas analysis• FIO2 and FEO2
Features
FeaturesSafe Yes YesStart up cost 160,000 60,000Mobility Minimal MaximalSkill required Maximal MinimalRange Rest- Maximal? Rest-Maximal?Issues
TechnicianMouthpiece discomfort
Vmax Innocor
Conclusion
Both Vmax and Innocor can attain similar
results for lower workloads, but begin to drift
during higher workloads.
Acknowledgments
• Brad Byers• Desi Fuhr• Karishma Kapoor• Linn Moore• Melissa Bouwsema• Michael Stickland• Vince Tedjasaputra
References
• Allen et al. (2013). ACSM’s Guidelines for exercise testing and prescription. Baltimore, MD. Wolters Kluwer, Lippincott Williams &Wilkins
• Beekley et al. (2004). Cross-Validation of the YMCA Submaximal Cycle Ergometer Test to Predict VO2max. Research Quarterly for Exercise and Sport. 75:3, 337-342.
• CareFusion Corporation. (2014). Vmax Encore Metabolic Cart. Retrieved from www.carefusion.com
• Innovision ApS. (2014). Innocor. Retrieved from www.innovision.dk• Stringer, W. Hansen, J. Wasserman, K. (1997). Cardiac output estimated
noninvasively from oxygen uptake during exercise. J Appl Physiol 82:908-912.
• Welch, HG. Pedersen, PK. (1981). Measurement of metabolic rate in hyperoxia. J Appll Physiol Respir Environ Exerc Physiol. Sep; 51(3): 725-31.
50 100 150 200 250 30015
20
25
30
35
40
45
50
55
VmaxInnocorPredicted VO2
Workload (Watts)
VO2
(ml/
kg/m
in)
Figure 6: Relative VO2 (ml/kg/min) vs. Workloads (Watts)
VO2 = (Watts (Watts)/ Bodyweight (kg) × 10.8) + 7ml/kg/min