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, IrelandOptical Fibre Sensors Research Centre (OFSRC)

Problem

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

In-vivo pressure measurementHigh accuracy (1 mmHg or below)Minimum invasiveness (size, weight)Low-cost disposable probeImmunity to EMI

FIBER-OPTIC

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

FiberBragg

Grating(FBG)

EFPI/FBG spectrum

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

FBGλB = λ(T0) + 10.2 pm/°C ・ ΔT

EFPIΔL = -Sp ΔP -1.6 nm/°C ・ ΔT

Air-gap length LFP Spectrum ~ S0 + k cos[4πL/λ]

d Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

EFPI principle

L

Pressure

Air-gap length L = L0 - Sp ΔPFP Spectrum ~ S0 + k cos[4π(L - Sp

ΔP)/λ]Temperature: L = L0 - Sp ΔP + ST ΔT ⇒ FBG

L0 - Sp ΔP

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

EFPI principle

L

FBG FBG detectiondetection

EFPI/FBG system

ASE sourceASE source

SpectrometeSpectrometerr

1530-1600 nm

1520-1596 nm

CouplerCoupler

3 dB1x4 switch

ServerServer

EFPI

EFPI

EFPI

EFPI+FBG

DAQ DAQ (LabVIEW)(LabVIEW) Pressure

Temperature

} Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

EFPI EFPI detectiondetection

Probe Probe calibrationcalibration

Performance chartUL EFPI/FBG

St. JudePressureWire

Opsens OPP-M

TechnologyFiber optic, EFPI/FBG

GuidewireFiber 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

TemperatureCompens.

0.5°CNone None

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

Burette test

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

RMSE = 2.29 mmH2O

RMSE = 1.30 mmH2O

Burette test

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

RMSE = 2.29 mmH2O = = 0.21 mmHg

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

Heart simulator

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

Heart simulator

Interrogator/processing

Heart pumping

Sensor positioning

(short access)

EFPI spectrumPressure meas.

Spectrometer

ASE source

Heart pumping inle

tFiber inlet

Heart simulator

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

Time (s)

Pressure (mmHg)

Ventricular assist

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

Polymer Core,Cleveland Clinic, US

Mar 2013FPI positioningVentricular

assist

Reference (fluidic)

Pressure readout

Ventricular assist

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

Ventricular assist

Daniele Tosi - Optical Fibre Sensors Research Centre (OFSRC) - University of Limerick

Pressure (mmHg)

Polymer Core,Cleveland Clinic, US

Mar 2013

Daniele Tosi - Optical Fibre Sensors Research Centre - project portfolio - UL2013

Urodynamics

InterrogatorInterrogator

Differential pressure measurement

Bladder outlet obstruction (BOO) diagnostic

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