생체계측 II Report #7 2005200427 송성진

1. 생체계측 II Report #72005200427 송성진 Medical Instrumentation II

2. Multi physics. ref. <Electric Circuit> V o l t a g e C u r r e n t C h a r g e <Fluid Mechanics> P r e s s u r e F l o w V o l u m e ρ is density L is length η is viscosity C is compliance ρ is resistivity Medical Instrumentation II

3. Catheter Model. We must measure pressure, Pi ! Diaphragm + Strain gage Pi -> Vi - Cable Blood vessel Po -> Vo Sensor Medical Instrumentation II

4. Equivalent Circuit Model. 1) 2) Medical Instrumentation II

5. 3) Second order Ordinary Differential Equation(ODE) 4) Laplace equivalent transform Medical Instrumentation II

6. Damping Ratio Natural Frequency (or undamped Frequency) Medical Instrumentation II

7. Frequency transfer function Medical Instrumentation II

8. Medical Instrumentation II

9. ІHІ 1/2ζ ∞ → 0 ω Wn We know that Wn is 1/root(LcCd) almost 80Hz ~ 90Hz Medical Instrumentation II

10. Flat (response) ІHІ 1. If ζ = 0.5 , 1/2ζ = 1 ω Wn Critical damping But, Wn isincreasing, not flat So ІHІ is decreasing Medical Instrumentation II

11. ІHІ 2. If ζ = 1 , 1 1/2ζ = 0.5 ω Wn Over damped It is that high frequency decreasing Medical Instrumentation II

12. Іvi(ј ω)І Ex) Wn is going to be more 30Hz so that amplified same magnitude. ω 30Hz If Іvi(ј ω)І Medical Instrumentation II

13. ІHІ • If ζ = 0.25 , Ex) 1/2ζ = 2 1 ω Wn Under damped Medical Instrumentation II

14. Phaser transfer graph Wn <H → ∞ ω We must regulate phase & magnitude response appropriate -π/2 -π ζ increasing -> G -> B -> R Medical Instrumentation II

15. Question) Why change D by jω? 1. D operation GeneralRLCCircuit d/dt Δ= D (operater) Operational transfer function Medical Instrumentation II

16. 2. Fourier transform Medical Instrumentation II

17. 0 Medical Instrumentation II