Neural interfaces for Implantable Neuroprosthetics & Neuromodulation
Daryl R. Kipke, Ph.D. ([email protected]) Professor, Biomedical Engineering University of Michigan, Ann Arbor, Michigan USA Neural Engineering Laboratory nelab.engin.umich.edu
Center for Neural Communication Technology (CNCT) cnct.engin.umich.edu
NIH/NIBIB Biotechnology Resource Center; P41-EB002030
May 2009 D. Kipke, Center for Neural Communication Technology (http://cnct.engin.umich.edu) Disclosure: D. Kipke has a financial and leadership interest in NeuroNexus Technologies, Inc. Microscale Neural Interfaces
1 mm 2 mm
~60,000 neurons 1.4x109 synapses Breakthrough neurotechnology (clinical, scientific) – Permanent, high-fidelity, high-bandwidth neural interface – Multi-modal interfaces Electrical AND chemical sensing/actuation – Integrated microsystems for “smart” neural interface Interplay between neuroscience, technology & clinical applications
Science drivers: Increased Technology drivers: Increased understanding of normal, diseased, and neural interface selectivity, injury mechanisms in brain sensitivity, fidelity, bandwidth
Science pull
Technology push Advanced, Microfabricated Electrode Arrays • Conventional microelectrodes: glass or metal, single tip site • Microfabricated electrode – 64 recording and/or stimulation on same sized or smaller carrier than a conventional single channel microelectrode • Attributes – Multiple channels – Batch fabricated – High reproducibility – Any 2-D shape – Precise dimensions – Biocompatible materials Manufacturing of Planar Microfabricated Electrode Arrays Sites Leads (Neural interface) (Signal transfer) Iridium Polysilicon Gold Gold Platinum Platinum TiN
Substrate Dielectrics (Structural support) (Lead insulation, Silicon structural support)
Ceramic SiO2 Polyimide Si3N4 Parylene SiC PDMS Polyimide Parylene PDMS PTFE Survey of Microelectrode Array Technology
7 Technology Base
Site coatings 3D array assembly
Wise, et al. IEEE Trans. Biomed. Eng., 1970. Buried fluidic channels
Silicon ribbon cables Site formation process
Boron doped substrate NIH contract to Michigan 1st microfabricated array
1960 1970 1980 1990 2000 2010 Technology Base
Site coatings Najafi, et al., IEEE Trans. Elec. Dev., 1985. 3D array assembly
Buried fluidic channels
Silicon ribbon cables Site formation process
Boron doped substrate
NIH contract to Michigan 1st microfabricated array
1960 1970 1980 1990 2000 2010 Technology Base Application Space Site coatings
3D array assembly
Buried fluidic channels
Silicon ribbon cables Spinal cord stim Chronic recording Auditory mapping Cardiac tissue Site formation process Brain response to Si
Insect antennal lobe Boron doped substrate CNCT I began NIH contract to Michigan 1st CSD application paper 1st microfabricated array
1960 1970 1980 1990 2000 2010 1st probe shipped to external user, 1st detailed analysis of recording capability Implantable Michigan Probes Basic probe assembly for chronic studies in animals
Vetter, Kipke, et al. (2004) IEEE Trans Biomed Eng Kipke et al. (2003). IEEE Trans Neural Systems and Rehab. Engin. Multi-site Neural Recordings: Spikes & Local Field Potentials
Buzsaki 2003
A. Schwartz A
CNCT II began
CNCT I ended, NeuroNexus Technology Base launched Application Space Site coatings
3D array assembly
Buried fluidic channels
Silicon ribbon cables Spinal cord stim Chronic recording Auditory mapping Site formation process Cardiac tissue Brain response to Si
Insect antennalclinical device development lobe Boron doped substrate CNCT I began Long-term neural interface and NIH contract to Michigan 1st CSD application paper 1st microfabricated array
1960 1970 1980 1990 2000 2010 1st probe shipped to external user, 1st detailed analysis of recording capability Center for Neural Communication Technology Biotechnology Resource Center supported by the NIH NIBIB
Mission: Develop microscale neural probe technologies to enable chronic, high-fidelity neural interfaces to the CNS Objectives: ! Develop implantable neural probes for multichannel chronic electrical and chemical interfaces ! Characterize and control long-term device biocompatibility ! Provide service and training to facilitate technology development with collaborators and users ! Disseminate research and technology outcomes to broad neuroscience, neurology, and bioengineering communities Conductive Polymer (PEDOT) Electrode Site Coatings for Improved Recording Characteristics
Ludwig et al, J Neural Engin., 2006
Abidian et al, IEEE Conf. on Neural Engineering, 2007
15 Ultra-small edge electrodes for neural recording
Seymour & Kipke, Biomaterials, 2007 Parylene-based Edge Electrodes
80 !m2 footprint
Sub-cellular parylene edge 5 !m thick
Edge electrode has site area ~100 um2
Seymour & Kipke, In preparation (2008) Biomaterials 2007 Parylene-based Edge Electrodes Summary of Recordings
Example Recordings
Seymour & Kipke, In preparation (2008) Interplay between neuroscience, technology & clinical applications
Science drivers: Increased Technology drivers: Increased understanding of normal, diseased, and neural interface selectivity, injury mechanisms in brain sensitivity, fidelity, bandwidth
Clinical drivers: Meeting specific and significant clinical needs Standard and customized Global marketing and sales to neural interface products neuroscience researchers Clinical translation: Innovative Deep-Brain Mapping Array to improve surgical targeting Partnership with FHC, Inc. Clinical translation: Innovative implantable DBS system to improve DBS therapy
Press Release (Nov 2008) “NeuroNexus Technologies and Philips partner to research next-generation deep brain stimulation devices for the treatment of central nervous system disorders”
• Multi-directional stimulation • Miniaturized, cranial chamber • Wireless and rechargeable • MR-safe • Segmented thin-film electrodes • (outpatient) Neural recording 23