G E M N u t r i t i o n  L t d.

GEM - Product Information

 

 

                              

                              

The GEM is an open circuit indirect calorimeter designed for nutritionists needing to measure energy balance and substrate turnover.  The compact bedside unit measures gas exchange volumes, respiratory quotient and energy expenditure.

 

The GEM determines a persons energy expenditure by alternatively measuring O2 and CO2  concentrations of inspired and expired air.  Flow rate is continually measured to determine the dilution factor.

 

Gas collection is via a comfortable ventilated hood placed over the patients head.  Air flow through the hood is completely variable between 20 and 80 litres/min to give optimum conditions for patient comfort.

Lightweight flexible tubing connects the hood to the calorimeter, allowing the unit to be some distance away from the hood.  A standard disposable heat and moisture exchange filter in the air line removes particulates and prevents cross contamination.

Automated Calibration

 

Calibration uses two cylinders of reference gas which may be mounted on a portable trolley.  The calibration procedure is completely automated and software controlled.

 

HIGH accuracy

 

The latest transducers for O2 and CO2 and flow rate measurement, combined with stae-of-the-art data acquisition and control electronics, ensure highly accurate measurements.  Great care has been taken in sample conditioning prior to anlaysis, to ensure all gases enter the analysers under the same conditions.  In particular, NafionR tubing is used to avoid measurement errors created by water vapour in breath.

 

Intuitive Software Controlled

 

 

 The whole system is controlled by custom designed Windows style software on a standard PC.  The software is intuitive, easy to use and offers increased flexibility for more demanding users.

 

  • Variable air flow rate from 20 to 80 l/min for measurement across a range of patients.
  • Highly automated operation
  • Latest transducers for accurate measurement of flow, O2 and CO2
  • PC based Windows software designed for ease of use
  • Real time graphical or tabular displays of VO2, VCO2, RQ and EE

 

SPECIFICATION

 

Measurement Technique

Open circuit flow through indirect calorimeter for measurement of spontaneously breathing patients.

 

Oxygen Measurement

High performance paramagnetic oxygen analyser.

Range: 0-100%

Linearity:+0.1%

Repeatability: +0.01% abs

 

Carbon Dioxide Measurement

Infra red carbon dioxide analyser

Range: 0-2.5% (other ranges available)

Linearity: +1%

Repeatability: +0.02% abs

 

Flow measurement

Thermal mass flow meter, gives flow rate at standard temperature and pressure.

Range: 0-100 litres/min

Accuracy: +1% including linearity

Repeatability: +0.2% abs

 

Sample rate

Approximately 120ml/min

 

Warm up time

At least 30 minutes

 

Power

100/120/220/240 V+10%, 50-60Hz, spike-free, single phase, 240W

 

Dimensions

Instrument: 495 mm wide, 430mm deep, 250mm high

Hood: 340mm wide, 530mm deep, 270mm high

 

Weight

26Kg

 

Environment

15-30o relative humidity <80%

 

Calibration

Requires span and zero gas

  1. 1% CO2 , 21% O2 , balance N2
  2. 99.998 N2