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Fluoroscopic kinematography: Technical background and potential applications Peter Böttcher Prof. Dr. med. vet., Dipl. ECVS www.fluokin.de
Fluoroscopic kinematography: Technical background and
potential applications
Peter Böttcher Prof. Dr. med. vet., Dipl. ECVS
www.fluokin.de
FluoKin.de
Kinematics vs. kinetics
• Kinematics = motion
• Kinetics = forces
FluoKin.de
Common approaches in-vivo
• Force plate
Tepic 2007
FluoKin.de
Common approaches in-vivo
• Kinematography
Clements et al. 2005
FluoKin.de
Video based 3D-gait analysis
Dogs in Motion, Martin S. Fischer & Karin E.Lilje
FluoKin.de
Skin movement
Dogs in Motion, Martin S. Fischer & Karin E.Lilje
FluoKin.de
Skin movement
FluoKin.de
Skin Movement
FluoKin.de
Non-invasive estimation of kinematics in-vivo
• Video-analysisa c
“The large soft-tissue artefacts when using clustered skin markers, irrespective of the fixation method, question the usefulness of parameters found with external movement registration and clinical interpretation of stair data in small patient groups”.
Garling et al. Journal of Biomechanics (2007)
FluoKin.de
Why do we need more detail?• Pathologies with low range of motion
• Contact Analysis– Restoration of normal contact mechanics?
FluoKin.de
Prof. Martin S. Fischer, Institut für Spezielle Zoologie und Evolutionsbiologie, Jena, Germany
FluoKin.de
Complex Skeletal Animation
Dogs in Motion, Martin S. Fischer & Karin E.Lilje
FluoKin.de
Musculo-Skeletal Animation
Dogs in Motion, Martin S. Fischer & Karin E.Lilje
FluoKin.de
Uniplanar Fluoroscopy
• 1.5 y, Rottweiler• Lameness left hind leg, knee stable on palpation
FluoKin.de
C-Arm + Videocamera
FluoKin.de
Uni-planar, C-Arm
FluoKin.de
Fluoroscopic kinematography
= Shadow theatre
FluoKin.de
Image Undistortion
FluoKin.de
Image Calibration
FluoKin.de
www.xromm.org
FluoKin.de
3D Animation
With markers• Tantalum beads
0.5-1.0 mm Ø• Precision: 0.064 mm*
Without markers• 2D to 3D image registration• Tracking of anatomical
features (bone shape)• Precision: 0.77 mm#
Invasive Non invasive
*Tashman et al. 2003 *Rey et al. 2009
FluoKin.de
3D-2D-image registration
Fluoroscopic video sequence
Digital reconstructed radiograph (DRR)
FluoKin.de
Optimisation
Intelligent form of trial & error
FluoKin.de
Find the optimal match
FluoKin.de
Automatic tracking
FluoKin.de
Final 3D Animation
FluoKin.de
Scientific Rotoscoping
Xromm.org
FluoKin.de
Free Software
• XROMM (Brown University)
– Marker-based– Rotoscoping– AutoScoper
• JointTrack(Florida)
FluoKin.de
Accuracy with uni-planar• Left tibia• Known translation• CT-Data (0.5 mm slice thickness)• Fluo: 576x768 (0.54mm2)
• Focal distance 90 cm
Iopollo et al. Journal of Biome-chanics (2007)
FluoKin.de
Results
• Cranio-caudal translation
• Mean error: 0.31 mm
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Fluo
DRR
FluoKin.de
Results
• Medio-lateral translation (in-plane)
• Mean error: 4.58 mm
6065707580859095
100105110115120125130 2
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810
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Fluo
DRR
FluoKin.de
Stereo = 3D = High accuracy
FluoKin.de
Bi-planar, high-powered X-ray
FluoKin.de
Final 3D-Animation
Xromm.org
FluoKin.de
Bone embedded coordinate system
FluoKin.de
Contact Analysis
FluoKin.de
Current Projects
• Stifle
• Elbow
• Shoulder
FluoKin.de
Other applications
FluoKin.de
Other applications
FluoKin.de
Other applications
Brown University
FluoKin.de
Other applications
Source unknown
FluoKin.de
www.fluokin.de
