REE (Resting Energy Expenditure) / BMR (Basal Metabolic Rate)
Vista Slim Lab provides a low cost REE measurement system using either disposable or reusable masks. There is no cost per test.
Since it does not have a CO2 sensor, an RQ (RER) of 0.85 (or any other you may choose) is assumed. Diet LAB II has both O2 and CO2 sensors.
An optional canopy module is available.
Vista MX/REE is a research quality system utilizing either mask and canopy.
It replaces (and is superior) to the DeltaTrac system montioned below.
The REE Calibrator simulates a known VO2 and VCO2 with an accuracy of 1%.
It may be used with REE systems from any manufacturer; it is included as standard equipment with the MX-REE.
Special Requirements for Canopy REE Measurements
For past 20 years or so, the DeltaTrac (Datex, Finland)
was the instrument of choice for Canopy measurements.
It had been specifically designed for that purpose.
That instrument was discontinued in 2007.
It was not perfect, most questionable was its method of calibration.
For example: Calibration consisted of performing a Methanol burn,
the instrument was then adjusted (fudged!) to provide the expected results.
The customer then performed the methanol burn again,
and the instrument was considered calibrated if results could be repeated.
In other words, if you recreate the same questionable procedure
with all its inherent weaknesses, you could claim victory.
In addition, flow was not measured; instead a suction blower
sucked mixed exhaled gases through a fixed orifice.
VacuMed has a better system.
Model MX-REE is based on our reliable Vista platform,
in use for about 20 years, but carefully modified to
provide the highest accuracy of any system on the market.
MX-REE runs on our TurboFit software, which has been
refined over this 20-year period.
Much more information click on catalog number 17585 above.
Our MX-REE has been specifically modified, fine-tuned and optimized
for canopy measurements, resulting in independently verifiable accuracy of ±2%.
How can we make such a statement? We include a "VO2 Standard".
If you wanted to know the accuracy of a scale, for example,
you would place a known weight on it; say a 1 kg verified standard.
If the scale now reads exactly 1 kg, you would surely trust its accuracy.
So it is with our VO2 Standard.
It delivers a gas mixture of precisely set mass flow to produce
a known VO2 and VCO2 of .400 ml at an RQ of 1,
or any other preset or requested value.
The VO2 (and VCO2) Standard is our model 17055 Canopy Calibrator,
which also checks overall system accuracy, including software,
to verify the accuracy of any Canopy metabolic measurement!
In addition, our system does not depend on fixed orifices to set canopy flow,
as did DeltaTrac; we actually measure the flow with a precision turbine sensor.
Furthermore, our software allows minor "tweaking", if needed,
to match the software calculated VO2 and VCO2 exactly to the delivered mass flow.
In normal VO2 measurements the difference between
inspired and expired gases is typically about 4%.
In the canopy mode the exhaled gases are diluted,
so that the difference is only about 1%.
Therefore, any instability, drift or errors are amplified by a factor of 4.
Here are key features of the MX-REE instrument:
- A more expensive ($3000 paramagnetic vs. $175 fuel cell)
O2 sensor is used, it has better long-term stability.
- The CO2 sensor is modified and optimized for the range
of 0.5% to 1.5%.
- A different circuit board is used that has 16-bit resolution.
- A VO2 standard as described above is included.
- An active mixing circuit assures homogenized mixed expired
- It may be used with a canopy (hood) or face mask.
- It accurately MEASURES gas flow with a special low-flow sensor
instead of relying on "calibrated" orifices.
- It offers continuously variable airflow to assure optimal dilution ratio.
- Automatic "Fi" re-calibration:
Since ambient FiO2 and FiCO2 may change during the test,
and may affect measurement accuracy, you can set a periodic "Fi Re-Calibration
interval" that will measure the Fi and automatically
insert the new values into the VO2 and VCO2 computation.
- Optional 2-gas calibration: Traditionally,
ambient air is used for one calibration gas;
a calibration gas cylinder provides a second gas mixture.
In our system, you can substitute a second calibration gas bottle
or produce a "Zero CO2" calibration by drawing ambient air through a CO2 absorber.
- Barometric pressure compensated gas sensors remain stable
as barometric pressure changes with the weather.
Since the delivered mass flow accuracy is better than 1%,
we can confidently promise overall VO2 and VCO2 accuracy of ±2%.
One of the benefits of the VO2 Standard is that you can deliver the
gas flow of the VO2 Standard during the first minute or so of
any test in order to keep an irrefutable record of correct calibration,
thus test data accuracy.
DeltaTrac is a trademark of Viasys Corporation
Last update: 28 February 2012