Oxygen AnalyzersOxygen Analyzers

What does it do? How What does it do? How does it work?does it work?

Measures the OMeasures the O22

It is important to know how much oxygen the It is important to know how much oxygen the patient is receivingpatient is receiving

– Optimal OOptimal O22

– Decrease the risk of ODecrease the risk of O22 toxicity toxicity

– Titrate OTitrate O22 for patient’s needs for patient’s needs

Monitor ABG’s and perform calculationsMonitor ABG’s and perform calculations Monitor vital signsMonitor vital signs Monitor SpOMonitor SpO22

Chemical AnalyzerChemical Analyzer measure Omeasure O22 percent percent

AdvantagesAdvantages– Very preciseVery precise

DisadvantagesDisadvantages– Not safe in ORNot safe in OR– Cumbersome to useCumbersome to use

Electrochemical OElectrochemical O22 AnalyzersAnalyzers

Galvanic Fuel CellGalvanic Fuel Cell Polarographic (Clark Polarographic (Clark Electrode)Electrode)

Galvanic Fuel CellGalvanic Fuel Cell(Chemical Reaction)(Chemical Reaction)

Two electrodes are contained in a potassium Two electrodes are contained in a potassium hydroxide bathhydroxide bath

OO22 enters a Teflon semi permeable membrane and enters a Teflon semi permeable membrane and picks up electrons from the (–) gold cathode, picks up electrons from the (–) gold cathode, combines with Hcombines with H22O, and travels to the (+) lead O, and travels to the (+) lead anodeanode

The flow of electrons is proportional to the PP of The flow of electrons is proportional to the PP of OO22

Polarographic Analyzer (Clark)Polarographic Analyzer (Clark)

Similar to the Galvanic Fuel CellSimilar to the Galvanic Fuel Cellbut uses a 9-volt battery but uses a 9-volt battery

A chemical reaction takes placeA chemical reaction takes place– OO22 enters through the teflon membrane and into a enters through the teflon membrane and into a

KCL bathKCL bath– OO22 takes electrons from the (-) platinum cathode, takes electrons from the (-) platinum cathode,

combines with Hcombines with H22O and travels to the (+) silver O and travels to the (+) silver anode anode

– The flow of electrons is proportional to the PP of The flow of electrons is proportional to the PP of OO22

Galvanic vs. PolarographicGalvanic vs. Polarographic

Galvanic Fuel CellGalvanic Fuel CellAdvantagesAdvantages

– No batteriesNo batteries– Safe in ORSafe in OR– Makes own currentMakes own current

Polarographic ElectrodePolarographic ElectrodeAdvantagesAdvantages

– Faster response timeFaster response time

DisadvantagesDisadvantages– Consumes O2Consumes O2– Accuracy affected by temp – Accuracy affected by temp –

increasesincreases

pressure – increasespressure – increases

humidity –decreaseshumidity –decreases

altitude- decreases altitude- decreases

DisadvantagesDisadvantages– Consumes O2 fasterConsumes O2 faster– Accuracy affected byAccuracy affected by– temp – increasestemp – increases

pressure – increasespressure – increases

humidity –decreaseshumidity –decreases

altitude- decreasesaltitude- decreases

Analyzer CalibrationAnalyzer Calibration

3 point calibration3 point calibration– Expose analyzer to known FiO2Expose analyzer to known FiO2– 100% 21% 100% 100% 21% 100%

2 point calibration2 point calibration15% 24%15% 24%

3 point vs 2 point3 point vs 2 point

3 point calibration for wide range of FiO23 point calibration for wide range of FiO2– Typically 21%-100% applications in healthcareTypically 21%-100% applications in healthcare

2 point calibration2 point calibration– Narrower range of FiO2 encountered, (exercise Narrower range of FiO2 encountered, (exercise

testing)testing)

Mass SpectroscopyMass Spectroscopy

Gas molecules are Gas molecules are ionized and separated ionized and separated via an electronic beam via an electronic beam and are collected on and are collected on plates according to the plates according to the charge to mass ratiocharge to mass ratio

Bulky & costly but Bulky & costly but accurateaccurate