Pressure Measurement

Hg or H20 Barometer
Measures Pressure
Hg – read at the of meniscus
H2O – Read at the of meniscus
Mercury Spill – Wipe up ASAP and dispose of in sealed contained
If air is not evacuated from barometer it will read .

Inductive Plethysmography
Bands containing coated wire or sensitive semiconductors are wrapped around /
Used to monitor chest motion and Vt in

Aneroid Manometer
Used to measure / and

Pressure Transducers
Used to convert one of to another
Most common gauge transducer
Used in monitoring to convert to digital.

BP manometer
Best Method – catheter w/pressure transducer
Measures: , , arterial pressure

Gas Delivery Systems
Blenders: to deliver O2
Equalizes pressure of air and o2
Precision metering device – valve
Low alarm
Can be used with a nonrebreather mask to deliver precise O2

Flowmeters
Controls gas flow to patient
Flow indicated by
Different gases will cause readings

– Process in which flow is divided into very small intervals. Flow is volume/time – end result is volume.

- Device that provides reverse of integration. Flow is obtained from volume signals

Data Backup- Temporary Storage, permanent patient files, database storage

Interface – Allows for both access to data and control of equipment during testing
12 bit converters – used most for volume and flow measurements

Converter speed – important for tests that require signal changes like FVC

Software – contains stored in memory of computer. Most software contains interpretation programs that utilize algorithims

Mass Storage Devices – Hard Drives, stores lots of info
CPU – Performs most functions in software

- Smallest change that can be measure by computer. Calculated via: Volume range (liters), Signal range (volts), A/D converter (bits