생체계측 II Report # 송성진 Medical Instrumentation II

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

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

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

Fick Method Medical Instrumentation II Substitution of Equation! (O ₂ density of Artery Blood) (O ₂ density of Vein Blood) (O ₂ Consumption, L/min) measure By Spirometer

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

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.

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

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

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

Medical Instrumentation II Near field Far field

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

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

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

Medical Instrumentation II Pulsed Doppler Flowmeter Flow profile measurement

Thermal Convection Flowmeter Medical Instrumentation II Thermister i ) Bias current -> Thermister heating ii ) T ₂ Thermister is cooled by thermal convection Weak Point : Invasive and Probe position is difficult.

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

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

Patient monitoring (Respiration monitoring) Part II. Pulmonary Function Test Medical Instrumentation II 1. Architecture Trachea Bronchus Alveoli Area Because… O ₂ & CO ₂ diffusion at alveoli

Medical Instrumentation II 2. Physiological Functions O ₂ transport into blood stream CO ₂ removal from blood stream Homeostasis of pH, Po ₂, Pco ₂

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 Diaphragm i ) ii ) Diaphragm

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

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

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

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

Medical Instrumentation II Water Spirometer Water Air Pen Rotating Paper Mouth CO ₂ absorber

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

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

Medical Instrumentation II N ₂ washout technique - patient at FRC - prepare a spirometer of O ₂, V SP - patient breaths to the spirometer - Measure N ₂ concentration in (F FN ₂ ) the expiratory.

Medical Instrumentation II 8. Gas concentration measurement Mass spetroscophy Gas chromatography Infrared spectrography Raman spectrography Emission spectrography Paremagnetic O ₂ analyzer

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

Medical Instrumentation II Diffusion test (CO diffusion capacity) - Inspire ω, He in air - f I CO, f I He - Hold breath for 10sec - Expire to measure F F CO, F F He