Fysisk institutt - Rikshospitalet1 FYS 4250. Fysisk institutt - Rikshospitalet2 FYS 4250 Table 1 Content of air Volume %, equal to kPa if the barometric

Fysisk institutt - Rikshospitalet 1FYS 4250


Table 1 Content of air Volume %, equal to kPa if the barometric pressure is 100 kPa.

drysaturated

37oC

nitrogen 78.1 73.4

oxygen 20.9 19.6

argon 0.9 0.8

carbon dioxide 0.04 0.04

water vapor 0 6.3


Figure 1 Airways with

larynx, trachea, bronchi and

alveoles


Figure 2

Lung volume parameters

Equation 1 Compliance C = ΔV / ΔP [L/Pa, L/cmH2O]


Equation 2 Poiseuille4

8

r

LR

πη

= [Pa/m3/s = pressure / flow rate]


Figure 4 Flow lines with local hindrance

and a back eddy (non-laminar zone)

turbulence


Figure 5 PV-diagram

for a closed volume

PV=nRT


Gas properties

Tc [oC] Pc [bar] Tb [oC]

Helium (He) -268 2,4 -269

Nitrogen (N2) -147 33,6 -196

Argon (Ar) -122 49 -186

Oxygen (O2) -119 50,3 -183

Carbon dioxide (CO2) 31 73 *

Nitrous oxide (N2O) 36,5 72 *

Water (H2O) 374 218 100


Figure 6

Laplace cylinder model

P=T/r


Figure 7 Left: dry gas mixture, right: after insertion of a water filled dish


gas/blood [L/L]

gas/oil [L/L]

Nitrous oxide 0.5 1.4

Halotane 2.3 224

Enflurane 1.8 96

Isoflurane 1.4 91

Desflurane 0.4 19

Sevoflurane 0.6 53

Ether 12 65

Oxygen 0.02

Carbon dioxide 0.8

Nitrogen 0.015

Table 3 Solubility of gases in blood and oil

at 37 oC


Figure 8 Laryngoscope

and tube insertion.


Figure 9 One-way

small portable resuscitation

system


Figure 10

Rebreathing circle

with one-directional valves 1 and 2


Figure 11

Sidestream sampling

to a multigas analyzer


Figure 12

Mainstream sampling


Table 4 Three measuring

principles

Measuring principlemedium variables time

constcomments

1a Spectrophotometric gas CO2, H2O,

agent vapors

0.1s capnography included

1b Spectrophotometric puls oximetry

blood O2 1-10s also in-vitro cuvette-oximetry and in blood gas analyzers

2a Paramagnetic, contin. gas O2 10s sample gas unchanged

2b Paramagnetisk, pulsed

gas O2 0.2s sample gas changed

3a El.chem. fuel cell, membrane covered

gas or liquid

O2 30s limited lifetime, drifts and frequent calibration, single use

3b El.chem. polarographic membrane covered (Clark)

gas or liquid

O2 0.1-20s

membrane & el.lyte change and reuse, used in blood gas machine

3c El.chem. membrane covered (Severinghaus)

gas or liquid

CO2 30s used in blood gas machine

3d El.chem. pH and ion-selective electrodes

liquid pHNa, K etc

10s used in blood gas machine


Figure 13 IR absorption spectra for some anaesthetic agent vapours.

Datex Ohmeda Division, Instrumentarium Corporation


Figure 14 Multigas spectrophotometric gas analyzer

with rotating filter wheel


Table 5 Magnetic molar susceptibility m of respiratory gases. SI unit: [m3/mol], but according to customary practice,

cgs units are used and given here as m/10-6cm3mol-1 (CRC Handbook of Chemistry and Physics).

gasm m relative

oxygen O2 +3449 +100

nitrogen N2 -12 -0.35

nitric oxide NO +1461 +42

nitrous oxide N2O -18.9 -0.55

nitrogen dioxide NO2 +150 +4.3

water vapour H2O -13.1 -0.38

carbon dioxide CO2 -21 -0,61

argon -19.3 -0.56


Figure 15Paramagnetic

oxygen analyzer. The construction is enclosed

in a tight box with inlet and outlet

for the gas to be examined, the reference gas

is enclosed in the two spheres.


Figure 16 Paramagnetic oxygen analyzer

using pulsed magnetic field. Gray lines are tubes.


Figure 17 Closed variable volume


Figure 18 Pressure sensors. Left: piezoelectric transducer with an optional dome to be

positioned so as to form a closed volume above the membrane. Right: optical transducer


Rotameter, gas flow sensor


Figure 19 Hot wire flow meter with two termistors,

cross section shown to the right


Figure 20 Vane flow sensor in a tube,



Figure 21 Pitot flow sensor in a tube,



Figure 22 Poiseuille gas flow sensor

(pneumotachometer)


Figure 23 Servocontrolled ventilator

shown in the inspiration cycle


FYS4250 Fysisk institutt - Rikshospitalet 31

Figure 24 Compression loss model


FYS4250 Fysisk institutt - Rikshospitalet 32

Figure 25Anaesthesia

machine


Figure 26 Spirometer, watersealed


Spirometer, electronic

4

8

r

LR

πη

=


Figure 27 Whole body

plethysmograph


Figure 28 Hyperbar chambers


Fig.29Venturi

suction system


Figure 30 Vacuum pressure

as a function of static suction flow


Equation Bernoulli

Ps + ½ v2 + gh = constant

Ps = static (v=0) pressure [Pa]. = density [kg/m3]. v = velocity [m/s]. g = acceleration due to gravity [m/s2]. h = height difference [m].

Validity range: Laminar flow, any geometry, valid at any point along a line of flow, gases or liquids, no frictional (viscous) losses.

Actually the Bernoulli equation is about the conservation of energy along a flow line, but it is usually given as here in terms not of energy, but pressure.


Figure 31 Equivalent electrical circuit for a dynamic suction system


Figure 32Cryo principle

according to a Joule-Thomson

capillary model.


Figure 33 Principle components of cryo equipment according to Joule-Thomson


Figure 34 CO2 phase diagram

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Fysisk institutt - Rikshospitalet1 FYS 4250. Fysisk institutt - Rikshospitalet2 FYS 4250 Table 1 Content of air Volume %, equal to kPa if the barometric