SpineRepair Hybrid CMOS‐polymer neural interfaces for restoration of sensorimotor functions after spinal cord injury PI: Stéphanie P. Lacour (EPFL) coPIs: Grégoire Courtine, Silvestro Micera (EPFL) Janos Vöros, Andreas Hierlemann (ETHZ) Jean Luc Nagel (CSEM)
Introduction Context Problematic: -
2.5 million people live with a chronic spinal cord injury (SCI). Half of them do not recover the ability to stand or walk with current therapeutic interventions.
Approach: -
Robotic training & functional electric stimulation facilitate motor control and functional recovery after SCI.
Missing technological solution: -
Autonomous spinal neuroprosthesis High density conformal electrodes Adaptive stimulation strategies (closed loop)
R. Van Den Brand, in Science, 2012
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Spine Repair Consortium Prof. Micera EPFL
Prof. Courtine EPFL
Jean Luc Nagel CSEM Wireless, SoC
Prof. Hielemann ETHZ Electrophysiology IC
Stimulation Pattern model
Prof. Lacour EPFL SMEA & Integration
Prof. Vörös ETHZ SMEA
Wireless Communication
Prof. Courtine EPFL In vivo evaluation Mechanistic framework
Prof. Micera EPFL
Real Time Monitoring
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Mechanistic framework Prof. Micera EPFL
Prof. Courtine EPFL
Jean Luc Nagel CSEM Wireless, SoC
Prof. Hielemann ETHZ Electrophysiology IC
Stimulation Pattern model
Prof. Lacour EPFL SMEA & Integration
Prof. Vörös ETHZ SMEA
Wireless Communication
Prof. Courtine EPFL In vivo evaluation Mechanistic framework
Prof. Micera EPFL
Real Time Monitoring
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SPINAL CIRCUIT DYNAMICS
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SPINAL S P I N ACIRCUIT L C I R CDYNAMICS UIT DYNAMICS
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O P T I M A L ELECTRODE E L E C T R O D E C O N F I G U R AT I O N OPTIMAL CONFIGURATION
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TARGETED ACTIVATION PROFILES
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Mechanistic framework Prof. Micera EPFL
Prof. Courtine EPFL
Jean Luc Nagel CSEM Wireless, SoC
Prof. Hielemann ETHZ Electrophysiology IC
Stimulation Pattern model
Prof. Lacour EPFL SMEA & Integration
Prof. Vörös ETHZ SMEA
Wireless Communication
Prof. Courtine EPFL In vivo evaluation Mechanistic framework
Prof. Micera EPFL
Real Time Monitoring
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Soft MEA design E-dura
I. MINEV
A. HIRSCH
P. MUSIENKO
MINEV*, MUSIENKO* ET AL. | SCIENCE | 2015 5/29/2015
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N. WENGER 9
Soft MEA design Biomechanical matching INSERTION OF IMPLANT control
e‐dura
MECHANICAL MODEL
polyimide
I. MINEV
ELASTICITY
A. HIRSCH
P. MUSIENKO
MINEV*, MUSIENKO* ET AL. | SCIENCE | 2015 5/29/2015
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N. WENGER 10
Soft MEA design Chronic Biointegration e-dura I. MINEV
3mm
3mm
Q. BARRAUD
A. HIRSCH
Iba1
GFAP
Iba1
GFAP
P. MUSIENKO
1mm
1mm
MINEV*, MUSIENKO* ET AL. | SCIENCE | 2015 5/29/2015
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Soft MEA design Nanowire eletride
15v% porous Ag‐ PDMS
F.STAUFFER 20 µm
- Patterning silver nanowires (AgNW) networks using photolithography Toothpick
AgNW tracks (200µm pitch) 5/29/2015
- Characterization of electromechanical performance of high aspect ratio AgNW Tracks
T.KLAS
- Introducing porosity for decreasing electrode impedance Nano Tera Meeting ‐ Spine Repair
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Mechanistic framework Prof. Micera EPFL
Prof. Courtine EPFL
Jean Luc Nagel CSEM Wireless, SoC
Prof. Hielemann ETHZ Electrophysiology IC
Stimulation Pattern model
Prof. Lacour EPFL SMEA & Integration
Prof. Vörös ETHZ SMEA
Wireless Communication
Prof. Courtine EPFL In vivo evaluation Mechanistic framework
Prof. Micera EPFL
Real Time Monitoring
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Stimulator ASIC Layout & Die Photo
Monopolar & biphasic
Bipolar & monophasic
Y.Tao Layout View
Bipolar & monophasic
Die Photo
Bipolar & asymmetrically biphasic
‐ Chip size: 3.3mm x 2.8mm ‐ 15‐channel stimulator
TA O e t a l . | I E E E T B C S | s u b m i t t e d
Stimulator ASIC Initial in-vivo test
Reference Electrode A
+6V
Reference Electrode B 0 V
+12V
(earth ground)
i(t)
To EMG Amplifier
Stimulator Stimulation Electrode A
EMG Electrode B
0 V Rat under Test
Test setup
Produced voltage waveform
Performance equivalent to that of desktop equipment.
Y.Tao
Mechanistic framework Prof. Micera EPFL
Prof. Courtine EPFL
Jean Luc Nagel CSEM Wireless, SoC
Prof. Hielemann ETHZ Electrophysiology IC
Stimulation Pattern model
Prof. Lacour EPFL SMEA & Integration
Prof. Vörös ETHZ SMEA
Wireless Communication
Prof. Courtine EPFL In vivo evaluation Mechanistic framework
Prof. Micera EPFL
Real Time Monitoring
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Telemetry & power management
Customised Stimulator
1.8 V (internal icycom VPROG)
icycom receiver
J.L. NAGEL
3 V (main supply)
6V
Antenna & inductive recharge
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12 V
Step-up (COTS)
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Mechanistic framework Prof. Micera EPFL
Prof. Courtine EPFL
Jean Luc Nagel CSEM Wireless, SoC
Prof. Hielemann ETHZ Electrophysiology IC
Stimulation Pattern model
Prof. Lacour EPFL SMEA & Integration
Prof. Vörös ETHZ SMEA
Wireless Communication
Prof. Courtine EPFL In vivo evaluation Mechanistic framework
Prof. Micera EPFL
Real Time Monitoring
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Software Design WENGER ET AL. | SCIENCE TRANS. MED. | 2014
REAL-TIME MONITORING Kinematics (200Hz) EMG (2KHz) GRF (2KHz)
Crest Hip
Interpolate Automatic labeling Online filtering
Knee
RECONSTRUCT BIOMECHANICAL STATE E. MARTIN
Right MG (mV)
8
Right TA (mV)
8
Ground Forces (N) Right foot height (cm)
Extract key features
3
FOOT HEIGHT J. GANDAR
6
X coord
FEEDBACK FORWARD MODEL proprotional integral controller
Z coord Detections
Angle
Event1 Event2
X coord
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REFERENCE BAND Trigger EVENT
DETECT GAIT EVENTS
PROCESSING UNIT STIMULUS ISOLATOR
CONTROL POLICIES
Z coordinate
PI Time
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Height
N. WENGER
Freq
+ 19
STIMULATION ADAPTATION
Next steps
selective stimulation of the roots
20µm
Stimulator gen 2 with integrated potential recording and impedance Miniaturisation
Spatio-temporal development
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Communications
• 5 Journal publications (+ 2 submitted) – IEEE Trans. on Circuits and Systems II, 2015 in press – Science, 2015 347(6218): 159‐163 – Science Translational Medicine, 2014 Sep 24;6(255):255ra133 – Journal of Neuroscience 2013 Dec 4;33(49):19326‐40
• > 15 international conference contributions – Materials Research Society – Society for Neuroscience
• 3 patent applications (pending) 5/29/2015
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Thanks from the SpineRepair Team Questions & Answers
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