1. MEDICAL INSTRUMENTATION II MEASUREMENTS OF THE RESPIRATORY SYSTEM
CHAPTER 9.
MEASUREMENTS OF THE RESPIRATORY SYSTEM
BIOMEDICAL ENGINEERING
TAE_EUI, KIM

2. Respiratory Observation
PFT (Pulmonary Functional Tests) -
Patient monitoring

3. Architecture

4. Physiological Function
O2 Transport into blood stream
CO2 removal from blood stream
Homeostasis of PO2, PCO2

5. Equivalent Model Respiration – Ventilatory mechanics
=> RC equivalent model
- Gas transport
=> Mass balance equivalent
( Diffusion process )

6. Pressure Measurement - Differential Pressure Transducer
Diaphragm P1 P2
Diaphragm
Strain gage

7. Pressure Measurement - Balloon Sensor
+5V
Metal Switch
Pressure
Sensor
Hole
Gas Vi
Pressure
Control
A switch should not be stable state
Should be attached and detached
so that able to measure change of external Pressure P.

8. Pressure Measurement - Balloon Sensor

9. Pressure Measurement - N2 Washout Technique
- Patient at FRC
Prepare spirometer with O2, Vsp
Patient breath to the spirometer
Measure into concentration into the expirotory gas

10. Gas Concentration Measurement
Mass spectroscophy
Gas chromatography
Infrared spectroscophy
Ramen spectroscophy
Emission spectroscophy
Paramagnetic O2 Analyzer

11. Gas Transport Measurement - Gas distribution Test

12. Gas Transport Measurement - Diffusion Test
CO Diffusion Capacity
The more FCO reduce compared to FHe,
the more diffusion.