Nu talk

Optical ﬁber sensors for biomedical applications

!
[Nazarbayev University Seminar - Feb 2015]
DanieleTosi

!
Nazarbayev University

School of Engineering, EEE Department

daniele.tosi@nu.edu.kz

!

DanieleTosi - Optical Fiber Sensors for Biomedical Application - NU 2015

Overview
‣ Optical ﬁbers and sensors

‣Technology highlights

‣ Our biomedical sensors

‣ Projects, applications, and results

‣ Future development

Amongst all known
mediums to
transport waves,
optical ﬁbers have
the smallest
attenuation

Optical fibers
cladding
core
Optical fiber: cylindrical guiding structure for light

Light travels by means of total internal refraction (TIR) on the borders
Standard fibers are made on silica (glass): $0.08/m
80-250μm
Telecom

(devices)
Sensors

OFS identity
Size: down to 80μm
EMI/MRI-immune
Chemically inert
Top performance

Principles
Target-based
Macro-bending

Principles
Fiber Bragg grating (FBG) Fabry-Perot interferometry (FPI)
Surface plasmon resonance (SPR)
Interferometry

Hollow-core fibers

Photonic crystal fibers

Evanescent-field

…

Distribution
Punctual
Distributed
Arrayed
Integrated
1544 1546 1548 1550 1552 1554
0
1
2
3
4
5
x 10
4
Wavelength (nm)
Intensity(a.u.)
0s
45s
84s

Goal
‣ Pressure sensor with
<1 mmHg accuracy

!
‣ Integrate with
temperature sensor

!
‣ Expand temperature
distribution

Air-gap length L

FP Spectrum ~
d L

Pressure
Air-gap length
FP Spectrum ~
Temperature:
L0 - Sp ΔP
L

fs laser inscription
Femtosecond laser pattern

fs laser inscription
Inscription performed at Cyprus Institute ofTechnology

Biocompatible

Spectra
Temperature
Pressure

Calibration

Competitor’s sensor

Our sensor

System

Comparison
Our sensors Opsens St Jude
Technology Fiber optic Fiber optic Guidewire
Diameter 0.2 mm 0.2-0.5 mm 0.35 mm
Accuracy 0.05 mmHg 1 mmHg 2 mmHg
Speed 100 Hz 20-250 Hz 25 Hz
Stability 0.2 mmHg/hr 0.2 mmHg/hr >5 mmHg/hr
Temperature Compens. 1.6 mmHg/˚C 3 mmHg/˚C
Biocompatible Yes Not really Yes

Application areas
‣Thermal ablation of tumors

‣ Urodynamics

‣ Fractional ﬂow reserve

Thermal ablation:
generate a “sphere”
of heat that kills
tumor cells

RFTA
10 mm
Monitoring available
only on surface, or ex
vivo. Sensors can
perform monitoring at
the point of treatment
in vivo!
Percutaneous

(outpatient)

Smart-RFTA
10 mm
RF source
Ablator
TissueImaging
RF ablation
Sensors
Smart
Power
Frequency
Shape/position

Setup
Temperature
Pressure

Pressure
0 0.2 0.4 0.6 0.8 1
−15
10
35
60
85
110
135
160
Pressure(kPa)
0 0.2 0.4 0.6 0.8 1
20
45
70
95
120
145
170
Temperature(o
C)
Exp.1 (1mm)
Exp.2 (5mm)
Exp.3 (8mm)
Normalized time
The only prior experiment was performed at 3 cm
distance from ablation point!

Temperature
8 radii with Luna
OBR4600
Fusion: spatial distribution

Comparison
0 0.2 0.4 0.6 0.8 1 1.2
0
20
40
60
80
100
120
140
Normalized time
Temperature(°C)
DTS, 0mm
DTS, 20mm
FBG, 0mm
FBG, 20mm
LCFBG, 0mm
LCFBG, 10mm

Pre
Post
Bladder outlet obstruction

Urodynamic analysis
Optical ﬁber
Reference
Differential
Fill/voidV

Pressure differential
F
M
M
F
Pressure differential vs
pressure level, recorded
in vivo for ﬁrst time in M
and F patients with
suspected bladder
conditions.
Correlation with
volume of solution
infused

Improving FFR
Current FFR: the clinician acquires
2 non-simultaneous pressure
values moving guide wire
Improved FFR: the clinician
acquires 2+ simultaneous
pressure values, without
moving cable (long term)

LVAD measurement
FPI positioning
Ventricular assist
Reference (ﬂuidic)
Pressure readout
March 2013, Cleveland

Heart simulator
Heart simulator
Interrogator/processing
Heart pumping
EFPI spectrum
Pressure meas.
Spectrometer

ASE source
Heart pumping
inletFiber inlet
Sensor positioning

(short access)

Femoral artery
Mid-term (8hrs) monitoring of
femoral artery: 2x pressure

TATour 2015
Politecnico diTorino

Integration of laser ablator
and sensors on same ﬁber
Biomedical Campus Rome

Pressure measurem. in laser
ablation of pancreas tumours
Universita’ di Pavia

Multi-pressure measurement

3D temperature measur.

Ongoing
Come up with the best positioning of a multi-sensors
probe that has max chances to record an obstruction
Development of first-ever working
algorithm for distributed detection
of a chirped grating
Integrate a high-power fiber laser
with fiber-optic sensors on same
fiber
Polarization beam steering
Help wanted!

Acknowledgments
Funding agencies:
‣ FP7 - Marie Curie Actions

‣ Enterprise Ireland

‣ Science Foundation Ireland

‣ FP7 - COST network

‣ CMT Foundation

Acknowledgments
Partners:
‣ University of Limerick (Ireland)

‣ Federico II University (Italy)

‣ Universita’ di Pavia (Italy)

‣ Politecnico di Milano (Italy)

‣ Politecnico diTorino (Italy)

‣ Cyprus Institute of Technology (Cyprus)

‣ FBGS International (Belgium)

‣ Endophys (US)

‣ Cleveland Clinic (US)

Nu talk

Recommended

Recommended

More Related Content

What's hot

What's hot (17)

Similar to Nu talk

Similar to Nu talk (20)

More from Daniele Tosi

More from Daniele Tosi (13)

Recently uploaded

Recently uploaded (20)

Nu talk