CAMPUS GROSSHADERN
LIFE-ZENTRUM – LASER-FORSCHUNGSLABOR (LFL)
In-vitro investigations on fluorescence behavior
of urinary and kidney calculi
Stephan Ströbl, Max Eisel, Thomas Pongratz, Stefan Stöberl,
Frank Strittmatter, Ronald Sroka
30.05.2017
Oulu Summer School 2017 – Stephan Ströbl
Laser lithotripsy – Investigations
Propulsive movement during
treatment leads to stone chasing
Dependency of Fragmentation
process on laser parameter
Remaining fragments can hardly be
distinguished from surrounding tissue
KLINIKUM DER UNIVERSITÄT MÜNCHEN®
2
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Propulsion Measurement – Materials & Methods (1)
Laser system:
AURIGA QI
StarMedTec
Ho:YAG (2.1 µm)
Stone phantom:
mixture:
edge length:
mass:
BEGO powder
15:4
5 mm
(0.2243 ± 0.0061) g
Application fibre:
365µm bare fibre
Containment:
Acrylic glass tube
Camera System:
Sony RX100V
1000 fps
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3
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Movement in y-direction
Movement in y-direction [a.u.]
Propulsion Measurement – Materials & Methods (2)
Detection of stone phantom via colour threshold (red value)
1st derivative of rising flanks displays mean velocity of stone
𝒗=
𝝏𝝏
𝝏𝝏
Recording of around 70 rising flanks per video (at repetition rate of e.g. 10 Hz)
Mean of 70 velocity values per video
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4
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Propulsion Measurement – Reproducibility
Day 1
Day 2
P = 0.012
Comparison of propulsive movement
triggered by two laser settings on two
consecutive days.
P = 0.004
Laser parameter:
Power:
10 W
Energy per Pulse:
1 J/Pulse
Repetition rate:
10 Hz
Pulse duration:
0.3 and 1.0 ms
P = 0.285
P = 0.435
n = 5 per setting
Standard error (±7.5%)
Variation in pulse duration leads to significant different velocity values
Day to Day variability does not differ significantly
Highly reproducible
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5
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Propulsion Measurement – Discussion
Pendulum
Video Tracking
Weakness
Strength
Weakness
Only first laser pulse
Multiple pulses
Cubic stone phantom
Hardly reproducible
High sample size possible
Neglecting fluid dynamics
High Standard deviation
Hands-free measurement
Acceleration process not
resolvable
Reproducible measurement
conditions
Sroka, R. et al, Laser Med Sci (2012) 27:637-643
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6
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Practical Phase – Overview – Stephan Ströbl
Fragmentation in ureter model
Laser parameters:
Laser system:
repetition rate:
energy per pulse:
pulse duration:
AURIGA QI Ho:YAG
10Hz
0.5J/pulse and 1.0J/pulse
0.25ms - 1.6ms
Stone phantom:
Bore hole 2.3 mm
BEGO powder
mixture:
edge length:
mass:
15:4
5 mm
(0.2243 ± 0.0061) g
Application fibre:
365µm bare fibre
Vessel:
Acrylic Glass tube;
Mesh size 2.3 mm
Stone phantoms
dust
fragments
2.3 mm - 1 mm
˂ 1 mm
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7
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Practical Phase – Overview – Stephan Ströbl
Fragmentation in ureter model
Experimental procedure:
•
weighing of the stone (Satorius, RC210P)
•
fragmenting (≤ 2.3 mm)
Total application time
ttot
Time until stone breaks
tuntil break
Time after break
tafter break
•
sieving (mesh grid: 1 mm)
•
drying (ca. 24h)
•
weighing of the fragments
Mass of dust:
𝑚𝑑𝑑𝑑𝑑 = 𝑚𝑑𝑑𝑠𝑠𝑠 − 𝑚𝑓𝑓𝑓𝑓𝑚𝑠𝑠𝑑𝑑
Dusting part:
D=
Fragment part:
F=
Fragments
𝑚𝑑𝑑𝑑𝑑
𝑚𝑑𝑑𝑠𝑠𝑠
𝑚𝑓𝑓𝑓𝑓𝑚𝑠𝑠𝑑𝑑
𝑚𝑑𝑑𝑠𝑠𝑠
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8
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Fragmentation - Results
1.0J 10Hz: toptical
0.25ms
tbreak
tmean: 318.0 s
1.0ms
Dust
D
Frag
F
60.8%
39.2%
69.3%
30.7%
67.5%
32.5%
72.9%
27.1%
71.7%
28.3%
61.2%
38.3%
67.2%
32.8%
66.9%
33.1%
tmean: 206.4 s
burst 1.6ms
tmean: 257.0 s
1.2ms
tmean: 240.8 s
0.5J 10Hz: toptical
tmean: 361.4 s
0.84ms
0.25ms
tmean: 785.0 s
1.3ms
tmean: 447.6 s
burst 1.6ms
tmean: 616.0 s
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800
time [s]
Variation in pulse duration or energy per pulse leads to different fragmentation times
and dusting ratios
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9
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Fluorescence Microscopy – Materials & Methods
Camera
Microscope:
Leica DM IRBE Lens 10x – 20x
Light source:
Osram HBO 103
Mercury Arc Lamp
Filter:
Excitation Bandpass
400nm, 450nm und 550nm
Emission Longpass
470nm, 520nm und 590nm
Camera:
Leica DFC 300 FX
1.4 MPixel Resolution
Spectrometer:
Ocean Opitcs USB 2000+
via 1mm multimode wave guide
Measurement Object
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10
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Fluorescence Microscopy
70000
60000
60000
50000
50000
40000
30000
60000
50000
40000
30000
20000
20000
10000
10000
0
70000
Intensity [a.u.]
70000
Intensity [a.u.]
Intensity [a.u.]
λext = 550 nm
λdet > 590 nm
λext = 450 nm
λdet > 520 nm
λext = 400 nm
λdet > 470 nm
500
Wavelength (nm)
600
700
30000
20000
10000
0
400
40000
400
500
600
700
0
400
500
Wavelength (nm)
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11
30.05.2017
600
Wavelength (nm)
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
700
Oulu Summer School 2017 – Stephan Ströbl
Fluorescence Endoscopy – Materials & Methods
Light-source:
D-Light, STORZ,
20133220
Endoscope:
STORZ, 0°, HOPKINS II
Long pass filter:
λdet < 610 nm
Fiber:
1000 μm, 0.39 NA
Spectrometer:
Ocean Optics, USB
Camera:
STORZ, telecam PDD
20212037
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12
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
2000+
Oulu Summer School 2017 – Stephan Ströbl
Fluorescence Endoscopy – In vivo images
High Intensity
Intensity [a.u.]
Fluorescence Spectra
Low Intensity
Wavelength [nm]
•
•
λexc = 500 nm - 570 nm
λdet < 610 nm
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30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Summary
Propulsion
Fragmentation
Method
developed
established
Evaluation
Mean velocity
Fragmentation times and
dusting ratio
Handling
No influence of experimentator
Small influence of
experimentator
Reproducibility
proven
proven
Two setups for investigations on dependency of laser lithotripsy on laser parameters
Deriving of optimal laser parameters
Fluorescence
stones show fluorescence
fluorescence spectra depend on λexc
Distinguish stones from tissue looks promising
Potential use for in-situ stone composition determination
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14
30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)
Oulu Summer School 2017 – Stephan Ströbl
Thank you for your attention.
Kiitos huomiostanne.
Stephan Ströbl, B.Sc.
Klinikum der Universität München
LIFE-Zentrum
Laser-Forschungslabor
Phone: 089 / 4400-74883
E-mail: [email protected]
Website: www.klinikum.uni-muenchen.de
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30.05.2017
LIFE-ZENTRUM
LASER-FORSCHUNGSLABOR (LFL)