University of Limerick - Optical Metrology presentation - EFPI presentation

1. Miniature Low-Cost Extrinsic Fabry-Perot
Interferometer for Low-Pressure Detection
[Optical Metrology, 2013]
Sven Poeggel, Daniele Tosi, Gabriel Leen, Elfed Lewis
University of Limerick, Ireland
Optical Fibre Sensors Research Centre (OFSRC)

2. Problem
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
In-vivo pressure measurement
High accuracy (1 mmHg or below)
Minimum invasiveness (size, weight)
Low-cost disposable probe
Immunity to EMI
FIBER-OPTIC

3. Extrinsic FP
Interferometer
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
EFPI: Fiber-optic Fabry-Perot interferometric sensor based on all-
silica glass structure: (1) launch fiber, (2) diaphragm, (3) capillary +
FBG
Capillary
Launch SM
fiber
Diaphragm
MM fiber
AIR-GAP
dL
Fiber
Bragg
Grating
(FBG)

4. EFPI/FBG spectrum
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
FBG
λB = (Tλ 0) + 10.2 pm/°C ・ TΔ
EFPI
L = -SΔ p P -1.6 nm/°CΔ ・ TΔ

5. Air-gap length L
FP Spectrum ~ S0 + k cos[4πL/ ]λ
d
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
EFPI principle
L

6. Pressure
Air-gap length L = L0 - Sp PΔ
FP Spectrum ~ S0 + k cos[4π(L - Sp PΔ )/ ]λ
Temperature: L = L0 - Sp P + SΔ T TΔ ⇒ FBG
L0 - Sp PΔ
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
EFPI principle
L

7. FBG detectionFBG detection
EFPI/FBG system
ASE sourceASE source
SpectrometerSpectrometer
1530-1600 nm
1520-1596 nm CouplerCoupler
3 dB
1x4 switch
ServerServer
EFPI
EFPI
EFPI
EFPI+FBG
DAQDAQ
(LabVIEW)(LabVIEW) Pressure
Temperature}
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
EFPI detectionEFPI detection
ProbeProbe
calibrationcalibration

8. Performance chart
UL EFPI/FBG
St. Jude
PressureWire
Opsens OPP-M
Technology
Fiber optic,
EFPI/FBG
Guidewire Fiber optic, EFPI
Diameter 0.2 mm 0.35 mm 0.55 mm
Accuracy 0.2 mmHg 2 mmHg 2 mmHg
Speed 100 Hz 25 Hz 20/250 Hz
Stability 0.6 mmHg/hr >5 mmHg/hr 4.0 mmHg/hr
Temperature
Compens.
0.5°C
None None
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

9. Burette test
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
RMSE = 2.29 mmH2O
RMSE = 1.30 mmH2O

10. Burette test
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
RMSE = 2.29 mmH2O =
= 0.21 mmHg

11. Long-term stability
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
0.63 mmHg
2.76 mmHg
Typical fiber optic drift ~ 5 mmHg/hr

12. Heart simulator
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
Heart simulator
Interrogator/processing
Heart pumping
Sensor positioning
(short access)
EFPI spectrum
Pressure meas.
Spectrometer
ASE source
Heart pumping
inletFiber inlet

13. Heart simulator
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
Time (s)
Pressure (mmHg)

14. Ventricular assist
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
Polymer Core,
Cleveland Clinic, US
Mar 2013FPI positioning
Ventricular assist
Reference (fluidic)
Pressure readout

15. Ventricular assist
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

16. Ventricular assist
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick
Pressure (mmHg)
Polymer Core,
Cleveland Clinic, US
Mar 2013

17. Daniele Tosi - Optical Fibre Sensors Research Centre - project portfolio - UL2013
Urodynamics
InterrogatorInterrogator
Differential pressure measurement
Bladder outlet obstruction (BOO) diagnostic

18. Acknowledgments
‣ Cleveland Clinic and Pointec Medical
‣ FP7 Marie Curie (299985-PROBESENSE)
‣ Science Foundation Ireland (RFP/ECE2898)
‣ Enterprise Ireland (IP-2012-0166-Y)
‣ University of Limerick, MSSI and CES depts.
Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick