Intracortical Visual Prosthesis: The Clinical Trial The ICVP Project
Microprobes is honored to be one of the seven team members of the IntraCortical Visual Prosthesis (ICVP) project which received NIH funding to proceed with the first human clinical trial of the implantation of miniature wireless 16-channel stimulation modules into the occipital lobe for the purpose of providing visual perception to people with blindness.
WFMA PHYSICAL FEATURES
Left WFMA from the Intracortical Visual Prosthesis System (ICVP) using 1.5mm electrodes and longer guide pins. Center Internal structure of the WFMA. Right Typical Iridium electrode exposed by laser.
IIT Intracortical Visual Prosthesis Module
Design of the Intracortical wireless stimulator module. The position of 16 AIROF electrodes, plus Pt-Ir counter and reference electrodes, are maintained within the ceramic substrate superstructure. The electrode shafts are insulated with Parylene-C and the tips of the Ir electrodes are exposed with a solid state laser.
The transcutaneous-link coil is fabricated from 25-micron heat-fusible polyimide Au wire, and is used to provide power and bi-directional telemetry. The ASIC chip contains all needed circuitry with no external components. Packaging of the module is accomplished by vacuum molding of the plasma-cleaned assembly using a strongly adherent addition-cure PDMS.. Final module is 5mm diameter, and ~0.5-mm thick.
Activated Iridium Oxide Electrode design
- Parylene-C insulated iridium shaft with AIROF tip.
- 2000 sq. micron laser-exposed surface area.
- Activation of iridium performed over the wireless link.
- “Goldilocks” blunt-tip electrode displaces blood vessels upon insertion.
CAD drawing of the ASIC for the wireless module
- Each of the 16 electrodes is driven by a dedicated compliance-supply-limited constant-current driver.
- Power Link Frequency: 4.8MHz; FSK modulation – 1.2Mbits/sec.
- Power Supply: 5V; 2.5nF on-chip capacitance.
- Electrode Drivers: 16 independent drivers; constant current cathodic-first with subsequent recharge and biasing of the electrodes.
- Stimulus Pulse amplitude: 64 uA maximum in 0.5 uA steps.
- Pulsewidth: 750 usec maximum in 50 usec steps.
- Arbitrary Waveshape possible.
- Outward Telemetry: 150kHz carrier; Pulse duration modulation; power supply and electrode voltage monitoring.
- Intrinsic Capability for Activation of AIROF Electrodes over Wireless Link.
- Fabrication Technology: Xfab CX08.
Insertion Tool Technology
Array Collet System
* The ICVP project is supported by the National Institute Of Neurological Disorders And Stroke of the National Institutes of Health under Award Number UG3NS09555. The content here is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
For more information about the ICVP project please call: (312) 567-5304.