II Report 9 2005200427 Medical Instrumentation II Chap

생체계측 II Report #9 2005200427 송성진 Medical Instrumentation II

Chap 8. Part I. Flow and Volume of Blood <Topics Covered in Chapter 8> • Cardiac Output Method Fick Technique Indicator Dilution Thermodilution • Electromagnetic Flowmeter (Not good) • Ultrasound Flowmeters • Plethysmography Medical Instrumentation II

1. Indicator Dilution Method • Fick Method • Indicator Dilution using rapid injection • Thermodilution Medical Instrumentation II

(Infusion rate) -> We Known (Mass balance equation) Conclusion : Medical Instrumentation II

Fick Method Substitution of Equation! (O₂ Consumption, L/min) measure By Spirometer (O₂ density of Artery Blood) (O₂ density of Vein Blood) Medical Instrumentation II

Indicator Dilution using rapid injection Dye Dilution Method Indocyanine green (cardiogreen) Indictor dilution curve Recirculation Bolus injection Extrapolation Medical Instrumentation II

Find Area! Conclusion : Medical Instrumentation II

Weak Point : Once dye get an injection, it remains in our body. The dye should be excreted in the urine. In order to remeasure the blood flow, you should wait for a long time. Medical Instrumentation II

Thermodiltion (standard) Using 4 lumen catheter (Swan-Ganz catheter) Bolus injection Weak Point : We unknown temperature of Right artium. Medical Instrumentation II

Conclusion : (Heat content of injectate) (Blood density) (Specific heat of blood) Medical Instrumentation II

2. Ultra Sound -> pressure element, approvaled by 1 MHz frequency. Ex) Primary Echo skin No reflection Medical Instrumentation II

Near field Far field Medical Instrumentation II

Transit Time Flowmeter Velocity of ultrasound. Velocity of RBC, WRC, and plate. Medical Instrumentation II

i ) Down stream ( = Blood flow direction) ii ) Up stream ( = Blood flow reverse direction) Conclusion : Because… C >> ucosφ Medical Instrumentation II

Continuous Doppler Flowmeter Doppler frequency shift Ex) aviation, ship, submarine… Medical Instrumentation II

Pulsed Doppler Flowmeter Flow profile measurement Medical Instrumentation II

Thermal Convection Flowmeter Thermister i ) Bias current -> Thermister heating ii ) T₂Thermister is cooled by thermal convection Weak Point : Invasive and Probe position is difficult. Medical Instrumentation II

3. Plethysmography -> Volume, blood flow measurement ` Howland Current Source V Artery open Vein close C uf f Medical Instrumentation II

Volume Normal Slope = flow Venous Thrombosis Arterial Cuff On Cuff Out Medical Instrumentation II

Part II. Pulmonary Function Test Patient monitoring (Respiration monitoring) 1. Architecture Trachea Area Bronchus Alveoli Because… O₂ & CO₂ diffusion at alveoli Medical Instrumentation II

2. Physiological Functions • O₂ transport into blood stream • CO₂ removal from blood stream • Homeostasis of p. H, Po₂, Pco₂ Medical Instrumentation II

3. Respiration • Ventilatory mechamis - RC equivalent circuit model • Gas transport - Mass balance equation(Diffusion process) Medical Instrumentation II

4. Pressure measurement Differential pressure transducer i) Diaphragm ii ) Diaphragm Medical Instrumentation II

iii ) Differential pressure sensor Mouth Flow Mesh screen Conclusion : Medical Instrumentation II

Ballon sensor Ballon Hole Pressure sensor Gas Switch On -> Switch Off -> Metal switch MP Air pump Control Medical Instrumentation II Pressure

5. Flow measurement • • Rotating Vane Ultrasound Flowmeter Thermal Convection Flowmeter Pneumotachometer (standard) Medical Instrumentation II

6. Volume measurement -> Plethysmography IC TLC FRC RV VC TV (Tidal Volume) ERC Weak Point : It is Relative value, not absolute value. Medical Instrumentation II

Water Spirometer Rotating Paper Air Water Pen Mouth CO₂ absorber Medical Instrumentation II

Dry Spirometer Mouth Valve Air (gas) Inspiratory gas Expiratory gas Piston Gas is Separated by two section Medical Instrumentation II

7. FRC measurement He dilution technique - patient at FRC - prepare a spirometer of volume VSP and initial He, concentration of f. IHE - patient breaths tooth spirometer - find He concentration of expiration F Medical Instrumentation II

N₂ washout technique - patient at FRC - prepare a spirometer of O₂, VSP - patient breaths to the spirometer - Measure N₂ concentration in (FFN₂) the expiratory. Medical Instrumentation II

8. Gas concentration measurement • • • Mass spetroscophy Gas chromatography Infrared spectrography Raman spectrography Emission spectrography Paremagnetic O₂ analyzer Medical Instrumentation II

9. Gas transport measurement Gas distribution test (Single breath N₂ wachout) - RC -> TLC O₂ inspiration - Pause (hold breath) - Expiration and measure f. N 2 Medical Instrumentation II

Diffusion test (CO diffusion capacity) - Inspire ω, He in air - f. ICO, f. IHe - Hold breath for 10 sec - Expire to measure FFCO, FFHe Medical Instrumentation II