A Miniature, Implantable Wireless Neural Stimulation System
Scott K. Arfin
2006

This stimulator is tailored for zebra finches- small avians/birds weighing 12-15g. This design uses an onboard battery, but wirelessly receives stimulation data. Four addressable electrodes-- so this isn't going to be the super-data-downloader from the Matrix.

Runs at 25 kbps with the possibility of 1 Mbps. The lithium-manganese rechargeable battery lasts for 3 days on a full charge.

Interestingly, the zebra finch can carry a maximum of 2 g on the cranium, making this a very specific mass and size restrained project. 

transcranial wireless link

Wavelength of 22 m, so for 5 to 15 cm from the implant, data can be received.

transcutaneous inductive link
voltage swing
carrier frequency
resonant amplifier circuits
transmixer
Colpitts oscillator-transmitter

-- Model neural tissue when testing electrodes as a 0.9% NaCL electrolye (physiological saline) ??

ref: 9, 14, -- a more detailed treatment of electrodes as they apply to neural stimulation

[9] S. K. Kelly. A System for Efficient Neural Stimulation with Energy Recovery.
    Ph.D. Thesis, Massachusetts Institute of Technology, Department of Electrical
    Engineering and Computer Science, October 2003.

[14] K. L. Roach. Electro chemical Mo dels for Electro de Behavior in Retinal Pros-
     theses. M. Eng. Thesis, Massachusetts Institute of Technology, Department of
     Electrical Engineering and Computer Science, May 2003.


Gouy-Chapman capacitance model
Helmholtz model
Randles model
Warburg impedance
Faradaic current
potentiostat (this document includes a schematic of a potentiostat)
cyclic voltammetry (CV)
electrode impedance spectroscopy
biphasic amperometry
pulse width demodulator (PWD) (including a schematic of a PWD)

-- Need to design a standby system to reduce power consumption during idletime


- Cites Sandquist's "Design of a wireless power and data link for a cranially-implanted neural prosthesis" (2004), which I also have in my neuro/ directory.